Commit Graph

3123 Commits

Author SHA1 Message Date
KP Singh
fb2b0e2901 libbpf: Update light skeleton for signing
* The metadata map is created with as an exclusive map (with an
excl_prog_hash) This restricts map access exclusively to the signed
loader program, preventing tampering by other processes.

* The map is then frozen, making it read-only from userspace.

* BPF_OBJ_GET_INFO_BY_ID instructs the kernel to compute the hash of the
  metadata map (H') and store it in bpf_map->sha.

* The loader is then loaded with the signature which is then verified by
  the kernel.

loading signed programs prebuilt into the kernel are not currently
supported. These can supported by enabling BPF_OBJ_GET_INFO_BY_ID to be
called from the kernel.

Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250921160120.9711-3-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-09-22 19:17:25 -07:00
KP Singh
3492715683 bpf: Implement signature verification for BPF programs
This patch extends the BPF_PROG_LOAD command by adding three new fields
to `union bpf_attr` in the user-space API:

  - signature: A pointer to the signature blob.
  - signature_size: The size of the signature blob.
  - keyring_id: The serial number of a loaded kernel keyring (e.g.,
    the user or session keyring) containing the trusted public keys.

When a BPF program is loaded with a signature, the kernel:

1.  Retrieves the trusted keyring using the provided `keyring_id`.
2.  Verifies the supplied signature against the BPF program's
    instruction buffer.
3.  If the signature is valid and was generated by a key in the trusted
    keyring, the program load proceeds.
4.  If no signature is provided, the load proceeds as before, allowing
    for backward compatibility. LSMs can chose to restrict unsigned
    programs and implement a security policy.
5.  If signature verification fails for any reason,
    the program is not loaded.

Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250921160120.9711-2-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-09-22 18:58:03 -07:00
Arnaldo Carvalho de Melo
72c181399b Merge remote-tracking branch 'torvalds/master' into perf-tools-next
To pick up the latest perf-tools batch sent by Namhyung Kim for
v6.17-rc7.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-09-19 12:38:16 -03:00
KP Singh
567010a547 libbpf: Support exclusive map creation
Implement setters and getters that allow map to be registered as
exclusive to the specified program. The registration should be done
before the exclusive program is loaded.

Signed-off-by: KP Singh <kpsingh@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-5-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-09-18 19:11:42 -07:00
KP Singh
c297fe3e9f libbpf: Implement SHA256 internal helper
Use AF_ALG sockets to not have libbpf depend on OpenSSL. The helper is
used for the loader generation code to embed the metadata hash in the
loader program and also by the bpf_map__make_exclusive API to calculate
the hash of the program the map is exclusive to.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-4-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-09-18 19:11:42 -07:00
hupu
a5edf3550f perf subcmd: avoid crash in exclude_cmds when excludes is empty
When cross-compiling the perf tool for ARM64, `perf help` may crash
with the following assertion failure:

  help.c:122: exclude_cmds: Assertion `cmds->names[ci] == NULL' failed.

This happens when the perf binary is not named exactly "perf" or when
multiple "perf-*" binaries exist in the same directory. In such cases,
the `excludes` command list can be empty, which leads to the final
assertion in exclude_cmds() being triggered.

Add a simple guard at the beginning of exclude_cmds() to return early
if excludes->cnt is zero, preventing the crash.

Signed-off-by: hupu <hupu.gm@gmail.com>
Reported-by: Guilherme Amadio <amadio@gentoo.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250909094953.106706-1-amadio@gentoo.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-09-12 17:51:35 -07:00
Jiawei Zhao
b338cf849e libbpf: Remove unused args in parse_usdt_note
Remove unused 'elf' and 'path' parameters from parse_usdt_note function
signature. These parameters are not referenced within the function body
and only add unnecessary complexity.

The function only requires the note header, data buffer, offsets, and
output structure to perform USDT note parsing.

Update function declaration, definition, and the single call site in
collect_usdt_targets() to match the simplified signature.

This is a safe internal cleanup as parse_usdt_note is a static function.

Signed-off-by: Jiawei Zhao <phoenix500526@163.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250904030525.1932293-1-phoenix500526@163.com
2025-09-04 11:35:44 -07:00
Ian Rogers
b39c915a4f libperf event: Ensure tracing data is multiple of 8 sized
Perf's synthetic-events.c will ensure 8-byte alignment of tracing
data, writing it after a perf_record_header_tracing_data event.

Add padding to struct perf_record_header_tracing_data to make it 16-byte
rather than 12-byte sized.

Fixes: 055c67ed39 ("perf tools: Move event synthesizing routines to separate .c file")
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: Collin Funk <collin.funk1@gmail.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Polensky <japo@linux.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Nam Cao <namcao@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20250821163820.1132977-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-09-03 12:34:54 -03:00
Jiawei Zhao
758acb9ccf libbpf: Fix USDT SIB argument handling causing unrecognized register error
On x86-64, USDT arguments can be specified using Scale-Index-Base (SIB)
addressing, e.g. "1@-96(%rbp,%rax,8)". The current USDT implementation
in libbpf cannot parse this format, causing `bpf_program__attach_usdt()`
to fail with -ENOENT (unrecognized register).

This patch fixes this by implementing the necessary changes:
- add correct handling for SIB-addressed arguments in `bpf_usdt_arg`.
- add adaptive support to `__bpf_usdt_arg_type` and
  `__bpf_usdt_arg_spec` to represent SIB addressing parameters.

Signed-off-by: Jiawei Zhao <phoenix500526@163.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250827053128.1301287-2-phoenix500526@163.com
2025-08-27 15:44:25 -07:00
Cryolitia PukNgae
78e097fbca libbpf: Add documentation to version and error API functions
Add documentation for the following API functions:

- libbpf_major_version()
- libbpf_minor_version()
- libbpf_version_string()
- libbpf_strerror()

Signed-off-by: Cryolitia PukNgae <cryolitia@uniontech.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250820-libbpf-doc-1-v1-1-13841f25a134@uniontech.com
2025-08-20 13:33:02 -07:00
Mykyta Yatsenko
2693227c11 libbpf: Export bpf_object__prepare symbol
Add missing LIBBPF_API macro for bpf_object__prepare function to enable
its export. libbpf.map had bpf_object__prepare already listed.

Fixes: 1315c28ed8 ("libbpf: Split bpf object load into prepare/load")
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20250819215119.37795-1-mykyta.yatsenko5@gmail.com
2025-08-20 14:59:57 +02:00
Yureka Lilian
6c6b4146de libbpf: Fix reuse of DEVMAP
Previously, re-using pinned DEVMAP maps would always fail, because
get_map_info on a DEVMAP always returns flags with BPF_F_RDONLY_PROG set,
but BPF_F_RDONLY_PROG being set on a map during creation is invalid.

Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from
get_map_info when checking for compatibility with an existing DEVMAP.

The same problem is handled in a third-party ebpf library:
- https://github.com/cilium/ebpf/issues/925
- https://github.com/cilium/ebpf/pull/930

Fixes: 0cdbb4b09a ("devmap: Allow map lookups from eBPF")
Signed-off-by: Yureka Lilian <yuka@yuka.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250814180113.1245565-3-yuka@yuka.dev
2025-08-15 16:52:50 -07:00
Ilya Leoshkevich
9474e27a24 libbpf: Add the ability to suppress perf event enablement
Automatically enabling a perf event after attaching a BPF prog to it is
not always desirable.

Add a new "dont_enable" field to struct bpf_perf_event_opts. While
introducing "enable" instead would be nicer in that it would avoid
a double negation in the implementation, it would make
DECLARE_LIBBPF_OPTS() less efficient.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Suggested-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Co-developed-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20250806162417.19666-2-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-08-07 09:01:41 -07:00
Linus Torvalds
a6923c06a3 bpf-fixes
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Alexei Starovoitov:

 - Fix kCFI failures in JITed BPF code on arm64 (Sami Tolvanen, Puranjay
   Mohan, Mark Rutland, Maxwell Bland)

 - Disallow tail calls between BPF programs that use different cgroup
   local storage maps to prevent out-of-bounds access (Daniel Borkmann)

 - Fix unaligned access in flow_dissector and netfilter BPF programs
   (Paul Chaignon)

 - Avoid possible use of uninitialized mod_len in libbpf (Achill
   Gilgenast)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Test for unaligned flow_dissector ctx access
  bpf: Improve ctx access verifier error message
  bpf: Check netfilter ctx accesses are aligned
  bpf: Check flow_dissector ctx accesses are aligned
  arm64/cfi,bpf: Support kCFI + BPF on arm64
  cfi: Move BPF CFI types and helpers to generic code
  cfi: add C CFI type macro
  libbpf: Avoid possible use of uninitialized mod_len
  bpf: Fix oob access in cgroup local storage
  bpf: Move cgroup iterator helpers to bpf.h
  bpf: Move bpf map owner out of common struct
  bpf: Add cookie object to bpf maps
2025-08-01 17:13:26 -07:00
Linus Torvalds
f4f346c346 [GIT PULL] perf tools changes for v6.17
Build-ID processing goodies
 ---------------------------
 Build-IDs are content based hashes to link regions of memory to ELF files
 in post processing. They have been available in distros for quite a while:
 
     $ file /bin/bash
     /bin/bash: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV),
     dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2,
     BuildID[sha1]=707a1c670cd72f8e55ffedfbe94ea98901b7ce3a,
     for GNU/Linux 3.2.0, stripped
 
 It is possible to ask the kernel to get it from mmap executable backing
 storage at time they are being put in place and send it as metadata at
 that moment to have in perf.data.
 
 Prefer that across the board to speed up 'record' time - it post processes
 the samples to find binaries touched by any samples and to save them with
 build-ID.  It can skip reading build-ID in userspace if it comes from the
 kernel.
 
 perf record
 -----------
 * Make --buildid-mmap default.  The kernel can generate MMAP2 events
   with a build-ID from ELF header.  Use that by default instead of using
   inode and device ID to identify binaries.  It also can be disabled
   with --no-buildid-mmap.
 
 * Use BPF for -u/--uid option to sample processes belong to a user.
   BPF can track user processes more accurately and the existing logic
   often fails to get the list of processes due to race with reading the
   /proc filesystem.
 
 * Generate PERF_RECORD_BPF_METADATA when it profiles BPF programs and
   they have variables starting with "bpf_metadata_".  This will help to
   identify BPF objects used in the profile.  This has been supported in
   bpftool for some time and allows the recording of metadata such as
   commit hashes, versions, etc, that now gets recorded in perf.data as
   well.
 
 * Collect list of DSOs touched in the sample callchains as well as in
   the sample itself.  This would increase the processing time at the end
   of record, but can improve the data quality.
 
 perf stat
 ---------
 * Add a new 'drm' pseudo-PMU support like in 'hwmon'.  It can collect
   DRM usage stats using fdinfo in /proc.
 
   On my Intel laptop, it shows like below:
 
     $ perf list drm
     ...
 
     drm:
       drm-active-stolen-system0
            [Total memory active in one or more engines. Unit: drm_i915]
       drm-active-system0
            [Total memory active in one or more engines. Unit: drm_i915]
       drm-engine-capacity-video
            [Engine capacity. Unit: drm_i915]
       drm-engine-copy
            [Utilization in ns. Unit: drm_i915]
       drm-engine-render
            [Utilization in ns. Unit: drm_i915]
       drm-engine-video
            [Utilization in ns. Unit: drm_i915]
       ...
 
     $ sudo perf stat -a -e drm-engine-render,drm-engine-video,drm-engine-capacity-video sleep 1
 
      Performance counter stats for 'system wide':
 
     48,137,316,988,873 ns       drm-engine-render
         34,452,696,746 ns       drm-engine-video
                     20 capacity drm-engine-capacity-video
 
            1.002086194 seconds time elapsed
 
 perf list
 ---------
 * Add description for software events.  The description is in JSON format
   and the event parser now can handle the software events like others
   (for example, it's case-insensitive and subject to wildcard matching).
 
     $ perf list software
 
     List of pre-defined events (to be used in -e or -M):
 
     software:
       alignment-faults
            [Number of kernel handled memory alignment faults. Unit: software]
       bpf-output
            [An event used by BPF programs to write to the perf ring buffer. Unit: software]
       cgroup-switches
            [Number of context switches to a task in a different cgroup. Unit: software]
       context-switches
            [Number of context switches [This event is an alias of cs]. Unit: software]
       cpu-clock
            [Per-CPU high-resolution timer based event. Unit: software]
       cpu-migrations
            [Number of times a process has migrated to a new CPU [This event is an alias of migrations]. Unit: software]
       cs
            [Number of context switches [This event is an alias of context-switches]. Unit: software]
       dummy
            [A placeholder event that doesn't count anything. Unit: software]
       emulation-faults
            [Number of kernel handled unimplemented instruction faults handled through emulation. Unit: software]
       faults
            [Number of page faults [This event is an alias of page-faults]. Unit: software]
       major-faults
            [Number of major page faults. Major faults require I/O to handle. Unit: software]
       migrations
            [Number of times a process has migrated to a new CPU [This event is an alias of cpu-migrations]. Unit: software]
       minor-faults
            [Number of minor page faults. Minor faults don't require I/O to handle. Unit: software]
       page-faults
            [Number of page faults [This event is an alias of faults]. Unit: software]
       task-clock
            [Per-task high-resolution timer based event. Unit: software]
 
 perf ftrace
 -----------
 * Add -e/--events option to perf ftrace latency to measure latency
   between the two events instead of a function.
 
     $ sudo perf ftrace latency -ab -e i915_request_wait_begin,i915_request_wait_end --hide-empty -- sleep 1
     #   DURATION     |      COUNT | GRAPH                                |
        256 -  512 us |          4 | ######                               |
          2 -    4 ms |          2 | ###                                  |
          4 -    8 ms |         12 | ###################                  |
          8 -   16 ms |         10 | ################                     |
 
     # statistics  (in usec)
       total time:               194915
         avg time:                 6961
         max time:                12855
         min time:                  373
            count:                   28
 
 * Add new function graph tracer options (--graph-opts) to display more
   info like arguments and return value.  They will be passed to the
   kernel ftrace directly.
 
     $ sudo perf ftrace -G vfs_write --graph-opts retval,retaddr
     # tracer: function_graph
     #
     # CPU  DURATION                  FUNCTION CALLS
     # |     |   |                     |   |   |   |
     ...
     5)               |  mutex_unlock() { /* <-rb_simple_write+0xda/0x150 */
     5)   0.188 us    |    local_clock(); /* <-lock_release+0x2ad/0x440 ret=0x3bf2a3cf90e */
     5)               |    rt_mutex_slowunlock() { /* <-rb_simple_write+0xda/0x150 */
     5)               |      _raw_spin_lock_irqsave() { /* <-rt_mutex_slowunlock+0x4f/0x200 */
     5)   0.123 us    |        preempt_count_add(); /* <-_raw_spin_lock_irqsave+0x23/0x90 ret=0x0 */
     5)   0.128 us    |        local_clock(); /* <-__lock_acquire.isra.0+0x17a/0x740 ret=0x3bf2a3cfc8b */
     5)   0.086 us    |        do_raw_spin_trylock(); /* <-_raw_spin_lock_irqsave+0x4a/0x90 ret=0x1 */
     5)   0.845 us    |      } /* _raw_spin_lock_irqsave ret=0x292 */
     ...
 
 misc
 ----
 * Add perf archive --exclude-buildids <FILE> option to skip some binaries.
   The format of the FILE should be same as an output of perf buildid-list.
 
 * Get rid of dependency of libcrypto.  It was just to get SHA-1 hash so
   implement it directly like in the kernel.  A side effect is that it
   needs -fno-strict-aliasing compiler option (again, like in the kernel).
 
 * Convert all shell script tests to use bash.
 
 Reviewed-by: Arnaldo Carvalho de Melo <acme@kernel.org>
 Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-for-v6.17-2025-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Namhyung Kim:
 "Build-ID processing goodies:

     Build-IDs are content based hashes to link regions of memory to ELF
     files in post processing. They have been available in distros for
     quite a while:

       $ file /bin/bash
       /bin/bash: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV),
       dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2,
       BuildID[sha1]=707a1c670cd72f8e55ffedfbe94ea98901b7ce3a,
       for GNU/Linux 3.2.0, stripped

     It is possible to ask the kernel to get it from mmap executable
     backing storage at time they are being put in place and send it as
     metadata at that moment to have in perf.data.

     Prefer that across the board to speed up 'record' time - it post
     processes the samples to find binaries touched by any samples and
     to save them with build-ID. It can skip reading build-ID in
     userspace if it comes from the kernel.

  perf record:

   * Make --buildid-mmap default.  The kernel can generate MMAP2 events
     with a build-ID from ELF header.  Use that by default instead of using
     inode and device ID to identify binaries.  It also can be disabled
     with --no-buildid-mmap.

   * Use BPF for -u/--uid option to sample processes belong to a user.
     BPF can track user processes more accurately and the existing logic
     often fails to get the list of processes due to race with reading the
     /proc filesystem.

   * Generate PERF_RECORD_BPF_METADATA when it profiles BPF programs and
     they have variables starting with "bpf_metadata_".  This will help to
     identify BPF objects used in the profile.  This has been supported in
     bpftool for some time and allows the recording of metadata such as
     commit hashes, versions, etc, that now gets recorded in perf.data as
     well.

   * Collect list of DSOs touched in the sample callchains as well as in
     the sample itself.  This would increase the processing time at the end
     of record, but can improve the data quality.

  perf stat:

   * Add a new 'drm' pseudo-PMU support like in 'hwmon'.  It can collect
     DRM usage stats using fdinfo in /proc.

     On my Intel laptop, it shows like below:

       $ perf list drm
       ...

       drm:
         drm-active-stolen-system0
              [Total memory active in one or more engines. Unit: drm_i915]
         drm-active-system0
              [Total memory active in one or more engines. Unit: drm_i915]
         drm-engine-capacity-video
              [Engine capacity. Unit: drm_i915]
         drm-engine-copy
              [Utilization in ns. Unit: drm_i915]
         drm-engine-render
              [Utilization in ns. Unit: drm_i915]
         drm-engine-video
              [Utilization in ns. Unit: drm_i915]
         ...

       $ sudo perf stat -a -e drm-engine-render,drm-engine-video,drm-engine-capacity-video sleep 1

        Performance counter stats for 'system wide':

       48,137,316,988,873 ns       drm-engine-render
           34,452,696,746 ns       drm-engine-video
                       20 capacity drm-engine-capacity-video

              1.002086194 seconds time elapsed

  perf list

   * Add description for software events.  The description is in JSON format
     and the event parser now can handle the software events like others
     (for example, it's case-insensitive and subject to wildcard matching).

       $ perf list software

       List of pre-defined events (to be used in -e or -M):

       software:
         alignment-faults
              [Number of kernel handled memory alignment faults. Unit: software]
         bpf-output
              [An event used by BPF programs to write to the perf ring buffer. Unit: software]
         cgroup-switches
              [Number of context switches to a task in a different cgroup. Unit: software]
         context-switches
              [Number of context switches [This event is an alias of cs]. Unit: software]
         cpu-clock
              [Per-CPU high-resolution timer based event. Unit: software]
         cpu-migrations
              [Number of times a process has migrated to a new CPU [This event is an alias of migrations]. Unit: software]
         cs
              [Number of context switches [This event is an alias of context-switches]. Unit: software]
         dummy
              [A placeholder event that doesn't count anything. Unit: software]
         emulation-faults
              [Number of kernel handled unimplemented instruction faults handled through emulation. Unit: software]
         faults
              [Number of page faults [This event is an alias of page-faults]. Unit: software]
         major-faults
              [Number of major page faults. Major faults require I/O to handle. Unit: software]
         migrations
              [Number of times a process has migrated to a new CPU [This event is an alias of cpu-migrations]. Unit: software]
         minor-faults
              [Number of minor page faults. Minor faults don't require I/O to handle. Unit: software]
         page-faults
              [Number of page faults [This event is an alias of faults]. Unit: software]
         task-clock
              [Per-task high-resolution timer based event. Unit: software]

  perf ftrace:

   * Add -e/--events option to perf ftrace latency to measure latency
     between the two events instead of a function.

       $ sudo perf ftrace latency -ab -e i915_request_wait_begin,i915_request_wait_end --hide-empty -- sleep 1
       #   DURATION     |      COUNT | GRAPH                                |
          256 -  512 us |          4 | ######                               |
            2 -    4 ms |          2 | ###                                  |
            4 -    8 ms |         12 | ###################                  |
            8 -   16 ms |         10 | ################                     |

       # statistics  (in usec)
         total time:               194915
           avg time:                 6961
           max time:                12855
           min time:                  373
              count:                   28

   * Add new function graph tracer options (--graph-opts) to display more
     info like arguments and return value.  They will be passed to the
     kernel ftrace directly.

       $ sudo perf ftrace -G vfs_write --graph-opts retval,retaddr
       # tracer: function_graph
       #
       # CPU  DURATION                  FUNCTION CALLS
       # |     |   |                     |   |   |   |
       ...
       5)               |  mutex_unlock() { /* <-rb_simple_write+0xda/0x150 */
       5)   0.188 us    |    local_clock(); /* <-lock_release+0x2ad/0x440 ret=0x3bf2a3cf90e */
       5)               |    rt_mutex_slowunlock() { /* <-rb_simple_write+0xda/0x150 */
       5)               |      _raw_spin_lock_irqsave() { /* <-rt_mutex_slowunlock+0x4f/0x200 */
       5)   0.123 us    |        preempt_count_add(); /* <-_raw_spin_lock_irqsave+0x23/0x90 ret=0x0 */
       5)   0.128 us    |        local_clock(); /* <-__lock_acquire.isra.0+0x17a/0x740 ret=0x3bf2a3cfc8b */
       5)   0.086 us    |        do_raw_spin_trylock(); /* <-_raw_spin_lock_irqsave+0x4a/0x90 ret=0x1 */
       5)   0.845 us    |      } /* _raw_spin_lock_irqsave ret=0x292 */
       ...

  Misc:

   * Add perf archive --exclude-buildids <FILE> option to skip some binaries.
     The format of the FILE should be same as an output of perf buildid-list.

   * Get rid of dependency of libcrypto.  It was just to get SHA-1 hash so
     implement it directly like in the kernel.  A side effect is that it
     needs -fno-strict-aliasing compiler option (again, like in the kernel).

   * Convert all shell script tests to use bash"

* tag 'perf-tools-for-v6.17-2025-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (179 commits)
  perf record: Cache build-ID of hit DSOs only
  perf test: Ensure lock contention using pipe mode
  perf python: Stop using deprecated PyUnicode_AsString()
  perf list: Skip ABI PMUs when printing pmu values
  perf list: Remove tracepoint printing code
  perf tp_pmu: Add event APIs
  perf tp_pmu: Factor existing tracepoint logic to new file
  perf parse-events: Remove non-json software events
  perf jevents: Add common software event json
  perf tools: Remove libtraceevent in .gitignore
  perf test: Fix comment ordering
  perf sort: Use perf_env to set arch sort keys and header
  perf test: Move PERF_SAMPLE_WEIGHT_STRUCT parsing to common test
  perf sample: Remove arch notion of sample parsing
  perf env: Remove global perf_env
  perf trace: Avoid global perf_env with evsel__env
  perf auxtrace: Pass perf_env from session through to mmap read
  perf machine: Explicitly pass in host perf_env
  perf bench synthesize: Avoid use of global perf_env
  perf top: Make perf_env locally scoped
  ...
2025-08-01 16:55:47 -07:00
Achill Gilgenast
13cb75730b libbpf: Avoid possible use of uninitialized mod_len
Though mod_len is only read when mod_name != NULL and both are initialized
together, gcc15 produces a warning with -Werror=maybe-uninitialized:

libbpf.c: In function 'find_kernel_btf_id.constprop':
libbpf.c:10100:33: error: 'mod_len' may be used uninitialized [-Werror=maybe-uninitialized]
10100 |                 if (mod_name && strncmp(mod->name, mod_name, mod_len) != 0)
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
libbpf.c:10070:21: note: 'mod_len' was declared here
10070 |         int ret, i, mod_len;
      |                     ^~~~~~~

Silence the false positive.

Signed-off-by: Achill Gilgenast <fossdd@pwned.life>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250729094611.2065713-1-fossdd@pwned.life
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-31 11:39:46 -07:00
Ian Rogers
811082e4b6 perf parse-events: Support user CPUs mixed with threads/processes
Counting events system-wide with a specified CPU prior to this change
worked:
```
$ perf stat -e 'msr/tsc/,msr/tsc,cpu=cpu_core/,msr/tsc,cpu=cpu_atom/' -a sleep 1

  Performance counter stats for 'system wide':

     59,393,419,099      msr/tsc/
     33,927,965,927      msr/tsc,cpu=cpu_core/
     25,465,608,044      msr/tsc,cpu=cpu_atom/
```

However, when counting with process the counts became system wide:
```
$ perf stat -e 'msr/tsc/,msr/tsc,cpu=cpu_core/,msr/tsc,cpu=cpu_atom/' perf test -F 10
 10.1: Basic parsing test                                            : Ok
 10.2: Parsing without PMU name                                      : Ok
 10.3: Parsing with PMU name                                         : Ok

 Performance counter stats for 'perf test -F 10':

        59,233,549      msr/tsc/
        59,227,556      msr/tsc,cpu=cpu_core/
        59,224,053      msr/tsc,cpu=cpu_atom/
```

Make the handling of CPU maps with event parsing clearer. When an
event is parsed creating an evsel the cpus should be either the PMU's
cpumask or user specified CPUs.

Update perf_evlist__propagate_maps so that it doesn't clobber the user
specified CPUs. Try to make the behavior clearer, firstly fix up
missing cpumasks. Next, perform sanity checks and adjustments from the
global evlist CPU requests and for the PMU including simplifying to
the "any CPU"(-1) value. Finally remove the event if the cpumask is
empty.

So that events are opened with a CPU and a thread change stat's
create_perf_stat_counter to give both.

With the change things are fixed:
```
$ perf stat --no-scale -e 'msr/tsc/,msr/tsc,cpu=cpu_core/,msr/tsc,cpu=cpu_atom/' perf test -F 10
 10.1: Basic parsing test                                            : Ok
 10.2: Parsing without PMU name                                      : Ok
 10.3: Parsing with PMU name                                         : Ok

 Performance counter stats for 'perf test -F 10':

        63,704,975      msr/tsc/
        47,060,704      msr/tsc,cpu=cpu_core/                        (4.62%)
        16,640,591      msr/tsc,cpu=cpu_atom/                        (2.18%)
```

However, note the "--no-scale" option is used. This is necessary as
the running time for the event on the counter isn't the same as the
enabled time because the thread doesn't necessarily run on the CPUs
specified for the counter. All counter values are scaled with:

  scaled_value = value * time_enabled / time_running

and so without --no-scale the scaled_value becomes very large. This
problem already exists on hybrid systems for the same reason. Here are
2 runs of the same code with an instructions event that counts the
same on both types of core, there is no real multiplexing happening on
the event:

```
$ perf stat -e instructions perf test -F 10
...
 Performance counter stats for 'perf test -F 10':

        87,896,447      cpu_atom/instructions/                       (14.37%)
        98,171,964      cpu_core/instructions/                       (85.63%)
...
$ perf stat --no-scale -e instructions perf test -F 10
...
 Performance counter stats for 'perf test -F 10':

        13,069,890      cpu_atom/instructions/                       (19.32%)
        83,460,274      cpu_core/instructions/                       (80.68%)
...
```
The scaling has inflated per-PMU instruction counts and the overall
count by 2x.

To fix this the kernel needs changing when a task+CPU event (or just
task event on hybrid) is scheduled out. A fix could be that the state
isn't inactive but off for such events, so that time_enabled counts
don't accumulate on them.

Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250719030517.1990983-13-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-24 13:41:35 -07:00
Ian Rogers
9a711ef3bd libperf evsel: Factor perf_evsel__exit out of perf_evsel__delete
This allows the perf_evsel__exit to be called when the struct
perf_evsel is embedded inside another struct, such as struct evsel in
perf.

Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250719030517.1990983-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-24 13:41:35 -07:00
Ian Rogers
6d765f5f7e libperf evsel: Rename own_cpus to pmu_cpus
own_cpus is generally the cpumask from the PMU. Rename to pmu_cpus to
try to make this clearer. Variable rename with no other changes.

Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250719030517.1990983-7-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-24 13:41:35 -07:00
Ian Rogers
478272d1cd tools subcmd: Tighten the filename size in check_if_command_finished
FILENAME_MAX is often PATH_MAX (4kb), far more than needed for the
/proc path. Make the buffer size sufficient for the maximum integer
plus "/proc/" and "/status" with a '\0' terminator.

Fixes: 5ce42b5de4 ("tools subcmd: Add non-waitpid check_if_command_finished()")
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250717150855.1032526-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-22 18:17:53 -07:00
Eduard Zingerman
42be23e8f2 libbpf: Verify that arena map exists when adding arena relocations
Fuzzer reported a memory access error in bpf_program__record_reloc()
that happens when:
- ".addr_space.1" section exists
- there is a relocation referencing this section
- there are no arena maps defined in BTF.

Sanity checks for maps existence are already present in
bpf_program__record_reloc(), hence this commit adds another one.

[1] https://github.com/libbpf/libbpf/actions/runs/16375110681/job/46272998064

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250718222059.281526-1-eddyz87@gmail.com
2025-07-18 17:12:50 -07:00
Alexei Starovoitov
beb1097ec8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after rc6
Cross-merge BPF and other fixes after downstream PR.

No conflicts.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-18 12:15:59 -07:00
Matteo Croce
0ee30d937c libbpf: Fix warning in calloc() usage
When compiling libbpf with some compilers, this warning is triggered:

libbpf.c: In function ‘bpf_object__gen_loader’:
libbpf.c:9209:28: error: ‘calloc’ sizes specified with ‘sizeof’ in the earlier argument and not in the later argument [-Werror=calloc-transposed-args]
 9209 |         gen = calloc(sizeof(*gen), 1);
      |                            ^
libbpf.c:9209:28: note: earlier argument should specify number of elements, later size of each element

Fix this by inverting the calloc() arguments.

Signed-off-by: Matteo Croce <teknoraver@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250717200337.49168-1-technoboy85@gmail.com
2025-07-18 08:29:50 -07:00
Andrii Nakryiko
0238c45fbb libbpf: Fix handling of BPF arena relocations
Initial __arena global variable support implementation in libbpf
contains a bug: it remembers struct bpf_map pointer for arena, which is
used later on to process relocations. Recording this pointer is
problematic because map pointers are not stable during ELF relocation
collection phase, as an array of struct bpf_map's can be reallocated,
invalidating all the pointers. Libbpf is dealing with similar issues by
using a stable internal map index, though for BPF arena map specifically
this approach wasn't used due to an oversight.

The resulting behavior is non-deterministic issue which depends on exact
layout of ELF object file, number of actual maps, etc. We didn't hit
this until very recently, when this bug started triggering crash in BPF
CI when validating one of sched-ext BPF programs.

The fix is rather straightforward: we just follow an established pattern
of remembering map index (just like obj->kconfig_map_idx, for example)
instead of `struct bpf_map *`, and resolving index to a pointer at the
point where map information is necessary.

While at it also add debug-level message for arena-related relocation
resolution information, which we already have for all other kinds of
maps.

Fixes: 2e7ba4f8fd ("libbpf: Recognize __arena global variables.")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250718001009.610955-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-17 19:17:46 -07:00
Andrii Nakryiko
8080500cba libbpf: start v1.7 dev cycle
With libbpf 1.6.0 released, adjust libbpf.map and libbpf_version.h to
start v1.7 development cycles.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250716175936.2343013-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-16 18:37:27 -07:00
Eduard Zingerman
aaa0e57e69 libbpf: __arg_untrusted in bpf_helpers.h
Make btf_decl_tag("arg:untrusted") available for libbpf users via
macro. Makes the following usage possible:

  void foo(struct bar *p __arg_untrusted) { ... }
  void bar(struct foo *p __arg_trusted) {
    ...
    foo(p->buz->bar); // buz derefrence looses __trusted
    ...
  }

Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250704230354.1323244-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-07 08:25:07 -07:00
Kumar Kartikeya Dwivedi
3bbc1ba9cc libbpf: Introduce bpf_prog_stream_read() API
Introduce a libbpf API so that users can read data from a given BPF
stream for a BPF prog fd. For now, only the low-level syscall wrapper
is provided, we can add a bpf_program__* accessor as a follow up if
needed.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-11-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-03 19:30:07 -07:00
Kumar Kartikeya Dwivedi
21a3afc76a libbpf: Add bpf_stream_printk() macro
Add a convenience macro to print data to the BPF streams. BPF_STDOUT and
BPF_STDERR stream IDs in the vmlinux.h can be passed to the macro to
print to the respective streams.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-10-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-03 19:30:07 -07:00
Namhyung Kim
1fdf938168 perf tools: Fix use-after-free in help_unknown_cmd()
Currently perf aborts when it finds an invalid command.  I guess it
depends on the environment as I have some custom commands in the path.

  $ perf bad-command
  perf: 'bad-command' is not a perf-command. See 'perf --help'.
  Aborted (core dumped)

It's because the exclude_cmds() in libsubcmd has a use-after-free when
it removes some entries.  After copying one to another entry, it keeps
the pointer in the both position.  And the next copy operation will free
the later one but it's the same entry in the previous one.

For example, let's say cmds = { A, B, C, D, E } and excludes = { B, E }.

  ci  cj  ei   cmds-name  excludes
  -----------+--------------------
   0   0   0 |     A         B       :    cmp < 0, ci == cj
   1   1   0 |     B         B       :    cmp == 0
   2   1   1 |     C         E       :    cmp < 0, ci != cj

At this point, it frees cmds->names[1] and cmds->names[1] is assigned to
cmds->names[2].

   3   2   1 |     D         E       :    cmp < 0, ci != cj

Now it frees cmds->names[2] but it's the same as cmds->names[1].  So
accessing cmds->names[1] will be invalid.

This makes the subcmd tests succeed.

  $ perf test subcmd
   69: libsubcmd help tests                                            :
   69.1: Load subcmd names                                             : Ok
   69.2: Uniquify subcmd names                                         : Ok
   69.3: Exclude duplicate subcmd names                                : Ok

Fixes: 4b96679170 ("libsubcmd: Avoid SEGV/use-after-free when commands aren't excluded")
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250701201027.1171561-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-02 18:58:50 -07:00
Alexei Starovoitov
886178a33a Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after rc3
Cross-merge BPF, perf and other fixes after downstream PRs.
It restores BPF CI to green after critical fix
commit bc4394e5e7 ("perf: Fix the throttle error of some clock events")

No conflicts.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-06-26 09:49:39 -07:00
Adin Scannell
fa6f092cc0 libbpf: Fix possible use-after-free for externs
The `name` field in `obj->externs` points into the BTF data at initial
open time. However, some functions may invalidate this after opening and
before loading (e.g. `bpf_map__set_value_size`), which results in
pointers into freed memory and undefined behavior.

The simplest solution is to simply `strdup` these strings, similar to
the `essent_name`, and free them at the same time.

In order to test this path, the `global_map_resize` BPF selftest is
modified slightly to ensure the presence of an extern, which causes this
test to fail prior to the fix. Given there isn't an obvious API or error
to test against, I opted to add this to the existing test as an aspect
of the resizing feature rather than duplicate the test.

Fixes: 9d0a23313b ("libbpf: Add capability for resizing datasec maps")
Signed-off-by: Adin Scannell <amscanne@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250625050215.2777374-1-amscanne@meta.com
2025-06-25 12:28:58 -07:00
Ian Rogers
be59dba332 libperf evsel: Add missed puts and asserts
A missed evsel__close before evsel__delete was the source of leaking
perf events due to a hybrid test. Add asserts in debug builds so that
this shouldn't happen in the future. Add puts missing on the cpu map
and thread maps.

Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250617223356.2752099-4-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-06-24 10:27:51 -07:00
Yuan Chen
aa485e8789 libbpf: Fix null pointer dereference in btf_dump__free on allocation failure
When btf_dump__new() fails to allocate memory for the internal hashmap
(btf_dump->type_names), it returns an error code. However, the cleanup
function btf_dump__free() does not check if btf_dump->type_names is NULL
before attempting to free it. This leads to a null pointer dereference
when btf_dump__free() is called on a btf_dump object.

Fixes: 351131b51c ("libbpf: add btf_dump API for BTF-to-C conversion")
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250618011933.11423-1-chenyuan_fl@163.com
2025-06-23 11:13:40 -07:00
Namhyung Kim
c833e8cc4d Linux 6.16-rc3
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Merge tag 'v6.16-rc3' into perf-tools-next

To get the fixes in libbpf and perf tools.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-06-22 21:54:03 -07:00
Blake Jones
ab38e84ba9 perf record: collect BPF metadata from existing BPF programs
Look for .rodata maps, find ones with 'bpf_metadata_' variables, extract
their values as strings, and create a new PERF_RECORD_BPF_METADATA
synthetic event using that data. The code gets invoked from the existing
routine perf_event__synthesize_one_bpf_prog().

For example, a BPF program with the following variables:

    const char bpf_metadata_version[] SEC(".rodata") = "3.14159";
    int bpf_metadata_value[] SEC(".rodata") = 42;

would generate a PERF_RECORD_BPF_METADATA record with:

    .prog_name        = <BPF program name, e.g. "bpf_prog_a1b2c3_foo">
    .nr_entries       = 2
    .entries[0].key   = "version"
    .entries[0].value = "3.14159"
    .entries[1].key   = "value"
    .entries[1].value = "42"

Each of the BPF programs and subprograms that share those variables would
get a distinct PERF_RECORD_BPF_METADATA record, with the ".prog_name"
showing the name of each program or subprogram. The prog_name is
deliberately the same as the ".name" field in the corresponding
PERF_RECORD_KSYMBOL record.

This code only gets invoked if support for displaying BTF char arrays
as strings is detected.

Signed-off-by: Blake Jones <blakejones@google.com>
Link: https://lore.kernel.org/r/20250612194939.162730-3-blakejones@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-06-20 14:48:35 -07:00
Yonghong Song
1d6711667c libbpf: Support link-based cgroup attach with options
Currently libbpf supports bpf_program__attach_cgroup() with signature:
  LIBBPF_API struct bpf_link *
  bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);

To support mprog style attachment, additionsl fields like flags,
relative_{fd,id} and expected_revision are needed.

Add a new API:
  LIBBPF_API struct bpf_link *
  bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd,
                                  const struct bpf_cgroup_opts *opts);
where bpf_cgroup_opts contains all above needed fields.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250606163146.2429212-1-yonghong.song@linux.dev
2025-06-09 16:28:30 -07:00
Andrii Nakryiko
02670deede libbpf: Handle unsupported mmap-based /sys/kernel/btf/vmlinux correctly
libbpf_err_ptr() helpers are meant to return NULL and set errno, if
there is an error. But btf_parse_raw_mmap() is meant to be used
internally and is expected to return ERR_PTR() values. Because of this
mismatch, when libbpf tries to mmap /sys/kernel/btf/vmlinux, we don't
detect the error correctly with IS_ERR() check, and never fallback to
old non-mmap-based way of loading vmlinux BTF.

Fix this by using proper ERR_PTR() returns internally.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fixes: 3c0421c93c ("libbpf: Use mmap to parse vmlinux BTF from sysfs")
Cc: Lorenz Bauer <lmb@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250606202134.2738910-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-06-06 14:07:07 -07:00
Blake Jones
87c9c79a02 libbpf: Add support for printing BTF character arrays as strings
The BTF dumper code currently displays arrays of characters as just that -
arrays, with each character formatted individually. Sometimes this is what
makes sense, but it's nice to be able to treat that array as a string.

This change adds a special case to the btf_dump functionality to allow
0-terminated arrays of single-byte integer values to be printed as
character strings. Characters for which isprint() returns false are
printed as hex-escaped values. This is enabled when the new ".emit_strings"
is set to 1 in the btf_dump_type_data_opts structure.

As an example, here's what it looks like to dump the string "hello" using
a few different field values for btf_dump_type_data_opts (.compact = 1):

- .emit_strings = 0, .skip_names = 0:  (char[6])['h','e','l','l','o',]
- .emit_strings = 0, .skip_names = 1:  ['h','e','l','l','o',]
- .emit_strings = 1, .skip_names = 0:  (char[6])"hello"
- .emit_strings = 1, .skip_names = 1:  "hello"

Here's the string "h\xff", dumped with .compact = 1 and .skip_names = 1:

- .emit_strings = 0:  ['h',-1,]
- .emit_strings = 1:  "h\xff"

Signed-off-by: Blake Jones <blakejones@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250603203701.520541-1-blakejones@google.com
2025-06-05 13:45:16 -07:00
Jiawei Zhao
919319b4ed libbpf: Correct some typos and syntax issues in usdt doc
Fix some incorrect words, such as "and" -> "an", "it's" -> "its".  Fix
some grammar issues, such as removing redundant "will", "would
complicated" -> "would complicate".

Signed-off-by: Jiawei Zhao <Phoenix500526@163.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250531095111.57824-1-Phoenix500526@163.com
2025-06-05 11:45:48 -07:00
Linus Torvalds
0939bd2fcf perf tools improvements and fixes for Linux v6.16:
perf report/top/annotate TUI:
 
 - Accept the left arrow key as a Zoom out if done on the first column.
 
 - Show if source code toggle status in title, to help spotting bugs with
   the various disassemblers (capstone, llvm, objdump).
 
 - Provide feedback on unhandled hotkeys.
 
 Build:
 
 - Better inform when certain features are not available with warnings in the
   build process and in 'perf version --build-options' or 'perf -vv'.
 
 perf record:
 
 - Improve the --off-cpu code by synthesizing events for switch-out -> switch-in
   intervals using a BPF program. This can be fine tuned using a --off-cpu-thresh
   knob.
 
 perf report:
 
 - Add 'tgid' sort key.
 
 perf mem/c2c:
 
 - Add 'op', 'cache', 'snoop', 'dtlb' output fields.
 
 - Add support for 'ldlat' on AMD IBS (Instruction Based Sampling).
 
 perf ftrace:
 
 - Use process/session specific trace settings instead of messing with
   the global ftrace knobs.
 
 perf trace:
 
 - Implement syscall summary in BPF.
 
 - Support --summary-mode=cgroup.
 
 - Always print return value for syscalls returning a pid.
 
 - The rseq and set_robust_list don't return a pid, just -errno.
 
 perf lock contention:
 
 -  Symbolize zone->lock using BTF.
 
 - Add -J/--inject-delay option to estimate impact on application performance by
   optimization of kernel locking behavior.
 
 perf stat:
 
 - Improve hybrid support for the NMI watchdog warning.
 
 Symbol resolution:
 
 - Handle 'u' and 'l' symbols in /proc/kallsyms, resolving some Rust symbols.
 
 - Improve Rust demangler.
 
 Hardware tracing:
 
 Intel PT:
 
 - Fix PEBS-via-PT data_src.
 
 - Do not default to recording all switch events.
 
 - Fix pattern matching with python3 on the SQL viewer script.
 
 arm64:
 
 - Fixups for the hip08 hha PMU.
 
 Vendor events:
 
 - Update Intel events/metrics files for alderlake, alderlaken, arrowlake,
   bonnell, broadwell, broadwellde, broadwellx, cascadelakex, clearwaterforest,
   elkhartlake, emeraldrapids, grandridge, graniterapids, haswell, haswellx,
   icelake, icelakex, ivybridge, ivytown, jaketown, lunarlake, meteorlake,
   nehalemep, nehalemex, rocketlake, sandybridge, sapphirerapids, sierraforest,
   skylake, skylakex, snowridgex, tigerlake, westmereep-dp, westmereep-sp,
   westmereep-sx.
 
 python support:
 
 - Add support for event counts in the python binding, add a counting.py example.
 
 perf list:
 
 - Display the PMU name associated with a perf metric in JSON.
 
 perf test:
 
 - Hybrid improvements for metric value validation test.
 
 - Fix LBR test by ignoring idle task.
 
 - Add AMD IBS sw filter ana d'ldlat' tests.
 
 - Add 'perf trace --summary-mode=cgroup' test.
 
 - Add tests for the various language symbol demanglers.
 
 Miscellaneous.
 
 - Allow specifying the cpu an event will be tied using '-e event/cpu=N/'.
 
 - Sync various headers with the kernel sources.
 
 - Add annotations to use clang's -Wthread-safety and fix some problems
   it detected.
 
 - Make dump_stack() use perf's symbol resolution to provide better backtraces.
 
 - Intel TPEBS support cleanups and fixes. TPEBS stands for Timed PEBS
   (Precision Event-Based Sampling), that adds timing info, the retirement
   latency of instructions.
 
 - Various memory allocation (some detected by ASAN) and reference counting
   fixes.
 
 - Add a 8-byte aligned PERF_RECORD_COMPRESSED2 to replace PERF_RECORD_COMPRESSED.
 
 - Skip unsupported event types in perf.data files, don't stop when finding one.
 
 - Improve lookups using hashmaps and binary searches.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-tools-for-v6.16-1-2025-06-03' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Arnaldo Carvalho de Melo:
 "perf report/top/annotate TUI:

   - Accept the left arrow key as a Zoom out if done on the first column

   - Show if source code toggle status in title, to help spotting bugs
     with the various disassemblers (capstone, llvm, objdump)

   - Provide feedback on unhandled hotkeys

  Build:

   - Better inform when certain features are not available with warnings
     in the build process and in 'perf version --build-options' or 'perf -vv'

  perf record:

   - Improve the --off-cpu code by synthesizing events for switch-out ->
     switch-in intervals using a BPF program. This can be fine tuned
     using a --off-cpu-thresh knob

  perf report:

   - Add 'tgid' sort key

  perf mem/c2c:

   - Add 'op', 'cache', 'snoop', 'dtlb' output fields

   - Add support for 'ldlat' on AMD IBS (Instruction Based Sampling)

  perf ftrace:

   - Use process/session specific trace settings instead of messing with
     the global ftrace knobs

  perf trace:

   - Implement syscall summary in BPF

   - Support --summary-mode=cgroup

   - Always print return value for syscalls returning a pid

   - The rseq and set_robust_list don't return a pid, just -errno

  perf lock contention:

   - Symbolize zone->lock using BTF

   - Add -J/--inject-delay option to estimate impact on application
     performance by optimization of kernel locking behavior

  perf stat:

   - Improve hybrid support for the NMI watchdog warning

  Symbol resolution:

   - Handle 'u' and 'l' symbols in /proc/kallsyms, resolving some Rust
     symbols

   - Improve Rust demangler

  Hardware tracing:

  Intel PT:

   - Fix PEBS-via-PT data_src

   - Do not default to recording all switch events

   - Fix pattern matching with python3 on the SQL viewer script

  arm64:

   - Fixups for the hip08 hha PMU

  Vendor events:

   - Update Intel events/metrics files for alderlake, alderlaken,
     arrowlake, bonnell, broadwell, broadwellde, broadwellx,
     cascadelakex, clearwaterforest, elkhartlake, emeraldrapids,
     grandridge, graniterapids, haswell, haswellx, icelake, icelakex,
     ivybridge, ivytown, jaketown, lunarlake, meteorlake, nehalemep,
     nehalemex, rocketlake, sandybridge, sapphirerapids, sierraforest,
     skylake, skylakex, snowridgex, tigerlake, westmereep-dp,
     westmereep-sp, westmereep-sx

  python support:

   - Add support for event counts in the python binding, add a
     counting.py example

  perf list:

   - Display the PMU name associated with a perf metric in JSON

  perf test:

   - Hybrid improvements for metric value validation test

   - Fix LBR test by ignoring idle task

   - Add AMD IBS sw filter ana d'ldlat' tests

   - Add 'perf trace --summary-mode=cgroup' test

   - Add tests for the various language symbol demanglers

  Miscellaneous:

   - Allow specifying the cpu an event will be tied using '-e
     event/cpu=N/'

   - Sync various headers with the kernel sources

   - Add annotations to use clang's -Wthread-safety and fix some
     problems it detected

   - Make dump_stack() use perf's symbol resolution to provide better
     backtraces

   - Intel TPEBS support cleanups and fixes. TPEBS stands for Timed PEBS
     (Precision Event-Based Sampling), that adds timing info, the
     retirement latency of instructions

   - Various memory allocation (some detected by ASAN) and reference
     counting fixes

   - Add a 8-byte aligned PERF_RECORD_COMPRESSED2 to replace
     PERF_RECORD_COMPRESSED

   - Skip unsupported event types in perf.data files, don't stop when
     finding one

   - Improve lookups using hashmaps and binary searches"

* tag 'perf-tools-for-v6.16-1-2025-06-03' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (206 commits)
  perf callchain: Always populate the addr_location map when adding IP
  perf lock contention: Reject more than 10ms delays for safety
  perf trace: Set errpid to false for rseq and set_robust_list
  perf symbol: Move demangling code out of symbol-elf.c
  perf trace: Always print return value for syscalls returning a pid
  perf script: Print PERF_AUX_FLAG_COLLISION flag
  perf mem: Show absolute percent in mem_stat output
  perf mem: Display sort order only if it's available
  perf mem: Describe overhead calculation in brief
  perf record: Fix incorrect --user-regs comments
  Revert "perf thread: Ensure comm_lock held for comm_list"
  perf test trace_summary: Skip --bpf-summary tests if no libbpf
  perf test intel-pt: Skip jitdump test if no libelf
  perf intel-tpebs: Avoid race when evlist is being deleted
  perf test demangle-java: Don't segv if demangling fails
  perf symbol: Fix use-after-free in filename__read_build_id
  perf pmu: Avoid segv for missing name/alias_name in wildcarding
  perf machine: Factor creating a "live" machine out of dwarf-unwind
  perf test: Add AMD IBS sw filter test
  perf mem: Count L2 HITM for c2c statistic
  ...
2025-06-03 15:11:44 -07:00
Linus Torvalds
90b83efa67 bpf-next-6.16
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Merge tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Fix and improve BTF deduplication of identical BTF types (Alan
   Maguire and Andrii Nakryiko)

 - Support up to 12 arguments in BPF trampoline on arm64 (Xu Kuohai and
   Alexis Lothoré)

 - Support load-acquire and store-release instructions in BPF JIT on
   riscv64 (Andrea Parri)

 - Fix uninitialized values in BPF_{CORE,PROBE}_READ macros (Anton
   Protopopov)

 - Streamline allowed helpers across program types (Feng Yang)

 - Support atomic update for hashtab of BPF maps (Hou Tao)

 - Implement json output for BPF helpers (Ihor Solodrai)

 - Several s390 JIT fixes (Ilya Leoshkevich)

 - Various sockmap fixes (Jiayuan Chen)

 - Support mmap of vmlinux BTF data (Lorenz Bauer)

 - Support BPF rbtree traversal and list peeking (Martin KaFai Lau)

 - Tests for sockmap/sockhash redirection (Michal Luczaj)

 - Introduce kfuncs for memory reads into dynptrs (Mykyta Yatsenko)

 - Add support for dma-buf iterators in BPF (T.J. Mercier)

 - The verifier support for __bpf_trap() (Yonghong Song)

* tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (135 commits)
  bpf, arm64: Remove unused-but-set function and variable.
  selftests/bpf: Add tests with stack ptr register in conditional jmp
  bpf: Do not include stack ptr register in precision backtracking bookkeeping
  selftests/bpf: enable many-args tests for arm64
  bpf, arm64: Support up to 12 function arguments
  bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem()
  bpf: Avoid __bpf_prog_ret0_warn when jit fails
  bpftool: Add support for custom BTF path in prog load/loadall
  selftests/bpf: Add unit tests with __bpf_trap() kfunc
  bpf: Warn with __bpf_trap() kfunc maybe due to uninitialized variable
  bpf: Remove special_kfunc_set from verifier
  selftests/bpf: Add test for open coded dmabuf_iter
  selftests/bpf: Add test for dmabuf_iter
  bpf: Add open coded dmabuf iterator
  bpf: Add dmabuf iterator
  dma-buf: Rename debugfs symbols
  bpf: Fix error return value in bpf_copy_from_user_dynptr
  libbpf: Use mmap to parse vmlinux BTF from sysfs
  selftests: bpf: Add a test for mmapable vmlinux BTF
  btf: Allow mmap of vmlinux btf
  ...
2025-05-28 15:52:42 -07:00
Lorenz Bauer
3c0421c93c libbpf: Use mmap to parse vmlinux BTF from sysfs
Teach libbpf to use mmap when parsing vmlinux BTF from /sys. We don't
apply this to fall-back paths on the regular file system because there
is no way to ensure that modifications underlying the MAP_PRIVATE
mapping are not visible to the process.

Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250520-vmlinux-mmap-v5-3-e8c941acc414@isovalent.com
2025-05-23 10:06:28 -07:00
Ian Rogers
3ee2255c4f libperf threadmap: Add perf_thread_map__idx()
Allow computation of thread map index from a PID.

Note, with a 'struct perf_cpu_map' the sorted nature allows for a binary
search to compute the index which isn't currently possible with a
'struct perf_thread_map' as they aren't guaranteed sorted.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250519195148.1708988-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-05-21 15:07:13 -03:00
Ian Rogers
eead8a0114 libperf threadmap: Don't segv for index 0 for the NULL 'struct perf_thread_map' pointer
perf_thread_map__nr() returns length 1 if the perf_thread_map is NULL,
meaning index 0 is valid.

When perf_thread_map__pid() of index 0 is read then return the expected
"any" -1 value.

Assert this is only done for index 0.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250519195148.1708988-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-05-21 15:07:13 -03:00
Alan Maguire
4e29128a9a libbpf/btf: Fix string handling to support multi-split BTF
libbpf handling of split BTF has been written largely with the
assumption that multiple splits are possible, i.e. split BTF on top of
split BTF on top of base BTF.  One area where this does not quite work
is string handling in split BTF; the start string offset should be the
base BTF string section length + the base BTF string offset.  This
worked in the past because for a single split BTF with base the start
string offset was always 0.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250519165935.261614-2-alan.maguire@oracle.com
2025-05-20 16:22:30 -07:00
Chun-Tse Shao
208c0e1683 perf record: Add 8-byte aligned event type PERF_RECORD_COMPRESSED2
The original PERF_RECORD_COMPRESS is not 8-byte aligned, which can cause
asan runtime error:

  # Build with asan
  $ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame-pointer -fsanitize=undefined"
  # Test success with many asan runtime errors:
  $ /tmp/perf/perf test "Zstd perf.data compression/decompression" -vv
   83: Zstd perf.data compression/decompression:
  ...
  util/session.c:1959:13: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 13 byte alignment
  0x7f69e3f99653: note: pointer points here
   d0  3a 50 69 44 00 00 00 00  00 08 00 bb 07 00 00 00  00 00 00 44 00 00 00 00  00 00 00 ff 07 00 00
                ^
  util/session.c:2163:22: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 8 byte alignment
  0x7f69e3f99653: note: pointer points here
   d0  3a 50 69 44 00 00 00 00  00 08 00 bb 07 00 00 00  00 00 00 44 00 00 00 00  00 00 00 ff 07 00 00
                ^
  ...

Since there is no way to align compressed data in zstd compression, this
patch add a new event type `PERF_RECORD_COMPRESSED2`, which adds a field
`data_size` to specify the actual compressed data size.

The `header.size` contains the total record size, including the padding
at the end to make it 8-byte aligned.

Tested with `Zstd perf.data compression/decompression`

Signed-off-by: Chun-Tse Shao <ctshao@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250303183646.327510-1-ctshao@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-05-16 17:31:40 -03:00
Mykyta Yatsenko
d0445d7dd3 libbpf: Check bpf_map_skeleton link for NULL
Avoid dereferencing bpf_map_skeleton's link field if it's NULL.
If BPF map skeleton is created with the size, that indicates containing
link field, but the field was not actually initialized with valid
bpf_link pointer, libbpf crashes. This may happen when using libbpf-rs
skeleton.
Skeleton loading may still progress, but user needs to attach struct_ops
map separately.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250514113220.219095-1-mykyta.yatsenko5@gmail.com
2025-05-14 09:30:06 -07:00
Anton Protopopov
fd5fd538a1 libbpf: Use proper errno value in nlattr
Return value of the validate_nla() function can be propagated all the
way up to users of libbpf API. In case of error this libbpf version
of validate_nla returns -1 which will be seen as -EPERM from user's
point of view. Instead, return a more reasonable -EINVAL.

Fixes: bbf48c18ee ("libbpf: add error reporting in XDP")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250510182011.2246631-1-a.s.protopopov@gmail.com
2025-05-12 15:22:54 -07:00
Ian Rogers
2e7a2f7f3c libperf cpumap: Add ability to create CPU from a single CPU number
Add perf_cpu_map__new_int() so that a CPU map can be created from a
single integer.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20250403194337.40202-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-05-12 14:18:16 -03:00
Jakub Kicinski
6b02fd7799 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.15-rc6).

No conflicts.

Adjacent changes:

net/core/dev.c:
  08e9f2d584 ("net: Lock netdevices during dev_shutdown")
  a82dc19db1 ("net: avoid potential race between netdev_get_by_index_lock() and netns switch")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-08 08:59:02 -07:00
Andrii Nakryiko
62e23f1838 libbpf: Improve BTF dedup handling of "identical" BTF types
BTF dedup has a strong assumption that compiler with deduplicate identical
types within any given compilation unit (i.e., .c file). This property
is used when establishing equilvalence of two subgraphs of types.

Unfortunately, this property doesn't always holds in practice. We've
seen cases of having truly identical structs, unions, array definitions,
and, most recently, even pointers to the same type being duplicated
within CU.

Previously, we mitigated this on a case-by-case basis, adding a few
simple heuristics for validating that two BTF types (having two
different type IDs) are structurally the same. But this approach scales
poorly, and we can have more weird cases come up in the future.

So let's take a half-step back, and implement a bit more generic
structural equivalence check, recursively. We still limit it to
reasonable depth to avoid long reference loops. Depth-wise limiting of
potentially cyclical graph isn't great, but as I mentioned below doesn't
seem to be detrimental performance-wise. We can always improve this in
the future with per-type visited markers, if necessary.

Performance-wise this doesn't seem too affect vmlinux BTF dedup, which
makes sense because this logic kicks in not so frequently and only if we
already established a canonical candidate type match, but suddenly find
a different (but probably identical) type.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/r/20250501235231.1339822-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-05-05 14:51:47 -07:00
Anton Protopopov
41d4ce6df3 bpf: Fix uninitialized values in BPF_{CORE,PROBE}_READ
With the latest LLVM bpf selftests build will fail with
the following error message:

    progs/profiler.inc.h:710:31: error: default initialization of an object of type 'typeof ((parent_task)->real_cred->uid.val)' (aka 'const unsigned int') leaves the object uninitialized and is incompatible with C++ [-Werror,-Wdefault-const-init-unsafe]
      710 |         proc_exec_data->parent_uid = BPF_CORE_READ(parent_task, real_cred, uid.val);
          |                                      ^
    tools/testing/selftests/bpf/tools/include/bpf/bpf_core_read.h:520:35: note: expanded from macro 'BPF_CORE_READ'
      520 |         ___type((src), a, ##__VA_ARGS__) __r;                               \
          |                                          ^

This happens because BPF_CORE_READ (and other macro) declare the
variable __r using the ___type macro which can inherit const modifier
from intermediate types.

Fix this by using __typeof_unqual__, when supported. (And when it
is not supported, the problem shouldn't appear, as older compilers
haven't complained.)

Fixes: 792001f4f7 ("libbpf: Add user-space variants of BPF_CORE_READ() family of macros")
Fixes: a4b09a9ef9 ("libbpf: Add non-CO-RE variants of BPF_CORE_READ() macro family")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250502193031.3522715-1-a.s.protopopov@gmail.com
2025-05-05 14:20:28 -07:00
Anton Protopopov
358b1c0f56 libbpf: Use proper errno value in linker
Return values of the linker_append_sec_data() and the
linker_append_elf_relos() functions are propagated all the
way up to users of libbpf API. In some error cases these
functions return -1 which will be seen as -EPERM from user's
point of view. Instead, return a more reasonable -EINVAL.

Fixes: faf6ed321c ("libbpf: Add BPF static linker APIs")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250430120820.2262053-1-a.s.protopopov@gmail.com
2025-04-30 09:04:20 -07:00
James Clark
8988c4b919 perf tools: Fix in-source libperf build
When libperf is built alone in-source, $(OUTPUT) isn't set. This causes
the generated uapi path to resolve to '/../arch' which results in a
permissions error:

  mkdir: cannot create directory '/../arch': Permission denied

Fix it by removing the preceding '/..' which means that it gets
generated either in the tools/lib/perf part of the tree or the OUTPUT
folder. Some other rules that rely on OUTPUT further refine this
conditionally depending on whether it's an in-source or out-of-source
build, but I don't think we need the extra complexity here. And this
rule is slightly different to others because the header is needed by
both libperf and Perf. This is further complicated by the fact that Perf
always passes O=... to libperf even for in source builds, meaning that
OUTPUT isn't set consistently between projects.

Because we're no longer going one level up to try to generate the file
in the tools/ folder, Perf's include rule needs to descend into libperf.
Also fix the clean rule while we're here.

Reported-by: Thorsten Leemhuis <linux@leemhuis.info>
Closes: https://lore.kernel.org/linux-perf-users/7703f88e-ccb7-4c98-9da4-8aad224e780f@leemhuis.info/
Fixes: bfb713ea53 ("perf tools: Fix arm64 build by generating unistd_64.h")
Signed-off-by: James Clark <james.clark@linaro.org>
Tested-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/20250429-james-perf-fix-libperf-in-source-build-v1-1-a1a827ac15e5@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-04-29 12:32:31 -07:00
Alan Maguire
8e64c387c9 libbpf: Add identical pointer detection to btf_dedup_is_equiv()
Recently as a side-effect of

commit ac053946f5 ("compiler.h: introduce TYPEOF_UNQUAL() macro")

issues were observed in deduplication between modules and kernel BTF
such that a large number of kernel types were not deduplicated so
were found in module BTF (task_struct, bpf_prog etc).  The root cause
appeared to be a failure to dedup struct types, specifically those
with members that were pointers with __percpu annotations.

The issue in dedup is at the point that we are deduplicating structures,
we have not yet deduplicated reference types like pointers.  If multiple
copies of a pointer point at the same (deduplicated) integer as in this
case, we do not see them as identical.  Special handling already exists
to deal with structures and arrays, so add pointer handling here too.

Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250429161042.2069678-1-alan.maguire@oracle.com
2025-04-29 10:16:23 -07:00
Jonathan Wiepert
91dbac4076 Use thread-safe function pointer in libbpf_print
This patch fixes a thread safety bug where libbpf_print uses the
global variable storing the print function pointer rather than the local
variable that had the print function set via __atomic_load_n.

Fixes: f1cb927cdb ("libbpf: Ensure print callback usage is thread-safe")
Signed-off-by: Jonathan Wiepert <jonathan.wiepert@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Mykyta Yatsenko <mykyta.yatsenko5@gmail.com>
Link: https://lore.kernel.org/bpf/20250424221457.793068-1-jonathan.wiepert@gmail.com
2025-04-25 09:27:17 -07:00
Tao Chen
64821d25f0 libbpf: Remove sample_period init in perf_buffer
It seems that sample_period is not used in perf buffer. Actually, only
wakeup_events are meaningful to enable events aggregation for wakeup notification.
Remove sample_period setting code to avoid confusion.

Fixes: fb84b82246 ("libbpf: add perf buffer API")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/bpf/20250423163901.2983689-1-chen.dylane@linux.dev
2025-04-25 09:24:47 -07:00
James Clark
bfb713ea53 perf tools: Fix arm64 build by generating unistd_64.h
Since pulling in the kernel changes in commit 22f72088ff ("tools
headers: Update the syscall table with the kernel sources"), arm64 is
no longer using a generic syscall header and generates one from the
syscall table. Therefore we must also generate the syscall header for
arm64 before building Perf.

Add it as a dependency to libperf which uses one syscall number. Perf
uses more, but as libperf is a dependency of Perf it will be generated
for both.

Future platforms that need this will have to add their own syscall-y
targets in libperf manually. Unfortunately the arch specific files that
do this (e.g. arch/arm64/include/asm/Kbuild) can't easily be imported
into the Perf build. But Perf only needs a subset of the generated files
anyway, so redefining them is probably the correct thing to do.

Fixes: 22f72088ff ("tools headers: Update the syscall table with the kernel sources")
Signed-off-by: James Clark <james.clark@linaro.org>
Tested-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20250417-james-perf-fix-gen-syscall-v1-1-1d268c923901@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-04-23 08:57:12 -07:00
Feng Yang
4dde20b1aa libbpf: Fix event name too long error
When the binary path is excessively long, the generated probe_name in libbpf
exceeds the kernel's MAX_EVENT_NAME_LEN limit (64 bytes).
This causes legacy uprobe event attachment to fail with error code -22.

The fix reorders the fields to place the unique ID before the name.
This ensures that even if truncation occurs via snprintf, the unique ID
remains intact, preserving event name uniqueness. Additionally, explicit
checks with MAX_EVENT_NAME_LEN are added to enforce length constraints.

Before Fix:
	./test_progs -t attach_probe/kprobe-long_name
	......
	libbpf: failed to add legacy kprobe event for 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0': -EINVAL
	libbpf: prog 'handle_kprobe': failed to create kprobe 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0' perf event: -EINVAL
	test_attach_kprobe_long_event_name:FAIL:attach_kprobe_long_event_name unexpected error: -22
	test_attach_probe:PASS:uprobe_ref_ctr_cleanup 0 nsec
	#13/11   attach_probe/kprobe-long_name:FAIL
	#13      attach_probe:FAIL

	./test_progs -t attach_probe/uprobe-long_name
	......
	libbpf: failed to add legacy uprobe event for /root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9: -EINVAL
	libbpf: prog 'handle_uprobe': failed to create uprobe '/root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9' perf event: -EINVAL
	test_attach_uprobe_long_event_name:FAIL:attach_uprobe_long_event_name unexpected error: -22
	#13/10   attach_probe/uprobe-long_name:FAIL
	#13      attach_probe:FAIL
After Fix:
	./test_progs -t attach_probe/uprobe-long_name
	#13/10   attach_probe/uprobe-long_name:OK
	#13      attach_probe:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

	./test_progs -t attach_probe/kprobe-long_name
	#13/11   attach_probe/kprobe-long_name:OK
	#13      attach_probe:OK
	Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Fixes: 46ed5fc33d ("libbpf: Refactor and simplify legacy kprobe code")
Fixes: cc10623c68 ("libbpf: Add legacy uprobe attaching support")
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250417014848.59321-2-yangfeng59949@163.com
2025-04-22 17:13:37 -07:00
Amery Hung
4b15121da7 libbpf: Support creating and destroying qdisc
Extend struct bpf_tc_hook with handle, qdisc name and a new attach type,
BPF_TC_QDISC, to allow users to add or remove any qdisc specified in
addition to clsact.

Signed-off-by: Amery Hung <amery.hung@bytedance.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409214606.2000194-8-ameryhung@gmail.com
2025-04-17 10:54:41 -07:00
Ihor Solodrai
8582d9ab3e libbpf: Verify section type in btf_find_elf_sections
A valid ELF file may contain a SHT_NOBITS .BTF section. This case is
not handled correctly in btf_parse_elf, which leads to a segfault.

Before attempting to load BTF section data, check that the section
type is SHT_PROGBITS, which is the expected type for BTF data.  Fail
with an error if the type is different.

Bug report: https://github.com/libbpf/libbpf/issues/894
v1: https://lore.kernel.org/bpf/20250408184104.3962949-1-ihor.solodrai@linux.dev/

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250410182823.1591681-1-ihor.solodrai@linux.dev
2025-04-15 15:18:55 -07:00
Viktor Malik
ee684de5c1 libbpf: Fix buffer overflow in bpf_object__init_prog
As shown in [1], it is possible to corrupt a BPF ELF file such that
arbitrary BPF instructions are loaded by libbpf. This can be done by
setting a symbol (BPF program) section offset to a large (unsigned)
number such that <section start + symbol offset> overflows and points
before the section data in the memory.

Consider the situation below where:
- prog_start = sec_start + symbol_offset    <-- size_t overflow here
- prog_end   = prog_start + prog_size

    prog_start        sec_start        prog_end        sec_end
        |                |                 |              |
        v                v                 v              v
    .....................|################################|............

The report in [1] also provides a corrupted BPF ELF which can be used as
a reproducer:

    $ readelf -S crash
    Section Headers:
      [Nr] Name              Type             Address           Offset
           Size              EntSize          Flags  Link  Info  Align
    ...
      [ 2] uretprobe.mu[...] PROGBITS         0000000000000000  00000040
           0000000000000068  0000000000000000  AX       0     0     8

    $ readelf -s crash
    Symbol table '.symtab' contains 8 entries:
       Num:    Value          Size Type    Bind   Vis      Ndx Name
    ...
         6: ffffffffffffffb8   104 FUNC    GLOBAL DEFAULT    2 handle_tp

Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will
point before the actual memory where section 2 is allocated.

This is also reported by AddressSanitizer:

    =================================================================
    ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490
    READ of size 104 at 0x7c7302fe0000 thread T0
        #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76)
        #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856
        #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928
        #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930
        #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067
        #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090
        #6 0x000000400c16 in main /poc/poc.c:8
        #7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4)
        #8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667)
        #9 0x000000400b34 in _start (/poc/poc+0x400b34)

    0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8)
    allocated by thread T0 here:
        #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b)
        #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600)
        #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018)
        #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740

The problem here is that currently, libbpf only checks that the program
end is within the section bounds. There used to be a check
`while (sec_off < sec_sz)` in bpf_object__add_programs, however, it was
removed by commit 6245947c1b ("libbpf: Allow gaps in BPF program
sections to support overriden weak functions").

Add a check for detecting the overflow of `sec_off + prog_sz` to
bpf_object__init_prog to fix this issue.

[1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md

Fixes: 6245947c1b ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
Reported-by: lmarch2 <2524158037@qq.com>
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md
Link: https://lore.kernel.org/bpf/20250415155014.397603-1-vmalik@redhat.com
2025-04-15 15:17:01 -07:00
Mykyta Yatsenko
243d720e2e libbpf: Add getters for BTF.ext func and line info
Introducing new libbpf API getters for BTF.ext func and line info,
namely:
  bpf_program__func_info
  bpf_program__func_info_cnt
  bpf_program__line_info
  bpf_program__line_info_cnt

This change enables scenarios, when user needs to load bpf_program
directly using `bpf_prog_load`, instead of higher-level
`bpf_object__load`. Line and func info are required for checking BTF
info in verifier; verification may fail without these fields if, for
example, program calls `bpf_obj_new`.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250408234417.452565-2-mykyta.yatsenko5@gmail.com
2025-04-09 16:16:56 -07:00
Anton Protopopov
dafae1ae2a libbpf: Add likely/unlikely macros and use them in selftests
A few selftests and, more importantly, consequent changes to the
bpf_helpers.h file, use likely/unlikely macros, so define them here
and remove duplicate definitions from existing selftests.

Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250331203618.1973691-3-a.s.protopopov@gmail.com
2025-04-04 08:53:24 -07:00
Carlos Llamas
75011ad69b libbpf: Fix implicit memfd_create() for bionic
Since memfd_create() is not consistently available across different
bionic libc implementations, using memfd_create() directly can break
some Android builds:

  tools/lib/bpf/linker.c:576:7: error: implicit declaration of function 'memfd_create' [-Werror,-Wimplicit-function-declaration]
    576 |         fd = memfd_create(filename, 0);
        |              ^

To fix this, relocate and inline the sys_memfd_create() helper so that
it can be used in "linker.c". Similar issues were previously fixed by
commit 9fa5e1a180 ("libbpf: Call memfd_create() syscall directly").

Fixes: 6d5e5e5d7c ("libbpf: Extend linker API to support in-memory ELF files")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250330211325.530677-1-cmllamas@google.com
2025-04-04 08:52:37 -07:00
Linus Torvalds
d6b02199cd - The 7 patch series "powerpc/crash: use generic crashkernel
reservation" from Sourabh Jain changes powerpc's kexec code to use more
   of the generic layers.
 
 - The 2 patch series "get_maintainer: report subsystem status
   separately" from Vlastimil Babka makes some long-requested improvements
   to the get_maintainer output.
 
 - The 4 patch series "ucount: Simplify refcounting with rcuref_t" from
   Sebastian Siewior cleans up and optimizing the refcounting in the ucount
   code.
 
 - The 12 patch series "reboot: support runtime configuration of
   emergency hw_protection action" from Ahmad Fatoum improves the ability
   for a driver to perform an emergency system shutdown or reboot.
 
 - The 16 patch series "Converge on using secs_to_jiffies() part two"
   from Easwar Hariharan performs further migrations from
   msecs_to_jiffies() to secs_to_jiffies().
 
 - The 7 patch series "lib/interval_tree: add some test cases and
   cleanup" from Wei Yang permits more userspace testing of kernel library
   code, adds some more tests and performs some cleanups.
 
 - The 2 patch series "hung_task: Dump the blocking task stacktrace" from
   Masami Hiramatsu arranges for the hung_task detector to dump the stack
   of the blocking task and not just that of the blocked task.
 
 - The 4 patch series "resource: Split and use DEFINE_RES*() macros" from
   Andy Shevchenko provides some cleanups to the resource definition
   macros.
 
 - Plus the usual shower of singleton patches - please see the individual
   changelogs for details.
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Merge tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - The series "powerpc/crash: use generic crashkernel reservation" from
   Sourabh Jain changes powerpc's kexec code to use more of the generic
   layers.

 - The series "get_maintainer: report subsystem status separately" from
   Vlastimil Babka makes some long-requested improvements to the
   get_maintainer output.

 - The series "ucount: Simplify refcounting with rcuref_t" from
   Sebastian Siewior cleans up and optimizing the refcounting in the
   ucount code.

 - The series "reboot: support runtime configuration of emergency
   hw_protection action" from Ahmad Fatoum improves the ability for a
   driver to perform an emergency system shutdown or reboot.

 - The series "Converge on using secs_to_jiffies() part two" from Easwar
   Hariharan performs further migrations from msecs_to_jiffies() to
   secs_to_jiffies().

 - The series "lib/interval_tree: add some test cases and cleanup" from
   Wei Yang permits more userspace testing of kernel library code, adds
   some more tests and performs some cleanups.

 - The series "hung_task: Dump the blocking task stacktrace" from Masami
   Hiramatsu arranges for the hung_task detector to dump the stack of
   the blocking task and not just that of the blocked task.

 - The series "resource: Split and use DEFINE_RES*() macros" from Andy
   Shevchenko provides some cleanups to the resource definition macros.

 - Plus the usual shower of singleton patches - please see the
   individual changelogs for details.

* tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
  mailmap: consolidate email addresses of Alexander Sverdlin
  fs/procfs: fix the comment above proc_pid_wchan()
  relay: use kasprintf() instead of fixed buffer formatting
  resource: replace open coded variant of DEFINE_RES()
  resource: replace open coded variants of DEFINE_RES_*_NAMED()
  resource: replace open coded variant of DEFINE_RES_NAMED_DESC()
  resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED()
  samples: add hung_task detector mutex blocking sample
  hung_task: show the blocker task if the task is hung on mutex
  kexec_core: accept unaccepted kexec segments' destination addresses
  watchdog/perf: optimize bytes copied and remove manual NUL-termination
  lib/interval_tree: fix the comment of interval_tree_span_iter_next_gap()
  lib/interval_tree: skip the check before go to the right subtree
  lib/interval_tree: add test case for span iteration
  lib/interval_tree: add test case for interval_tree_iter_xxx() helpers
  lib/rbtree: add random seed
  lib/rbtree: split tests
  lib/rbtree: enable userland test suite for rbtree related data structure
  checkpatch: describe --min-conf-desc-length
  scripts/gdb/symbols: determine KASLR offset on s390
  ...
2025-04-01 10:06:52 -07:00
Linus Torvalds
802f0d58d5 perf tools changes for v6.15
perf record
 -----------
 * Introduce latency profiling using scheduler information.  The latency
   profiling is to show impacts on wall-time rather than cpu-time.  By
   tracking context switches, it can weight samples and find which part
   of the code contributed more to the execution latency.
 
   The value (period) of the sample is weighted by dividing it by the
   number of parallel execution at the moment.  The parallelism is
   tracked in perf report with sched-switch records.  This will reduce
   the portion that are run in parallel and in turn increase the portion
   of serial executions.
 
   For now, it's limited to profile processes, IOW system-wide profiling
   is not supported.  You can add --latency option to enable this.
 
     $ perf record --latency -- make -C tools/perf
 
   I've run the above command for perf build which adds -j option to
   make with the number of CPUs in the system internally.  Normally
   it'd show something like below:
 
     $ perf report -F overhead,comm
     ...
     #
     # Overhead  Command
     # ........  ...............
     #
         78.97%  cc1
          6.54%  python3
          4.21%  shellcheck
          3.28%  ld
          1.80%  as
          1.37%  cc1plus
          0.80%  sh
          0.62%  clang
          0.56%  gcc
          0.44%  perl
          0.39%  make
 	 ...
 
   The cc1 takes around 80% of the overhead as it's the actual compiler.
   However it runs in parallel so its contribution to latency may be less
   than that.  Now, perf report will show both overhead and latency (if
   --latency was given at record time) like below:
 
     $ perf report -s comm
     ...
     #
     # Overhead   Latency  Command
     # ........  ........  ...............
     #
         78.97%    48.66%  cc1
          6.54%    25.68%  python3
          4.21%     0.39%  shellcheck
          3.28%    13.70%  ld
          1.80%     2.56%  as
          1.37%     3.08%  cc1plus
          0.80%     0.98%  sh
          0.62%     0.61%  clang
          0.56%     0.33%  gcc
          0.44%     1.71%  perl
          0.39%     0.83%  make
 	 ...
 
   You can see latency of cc1 goes down to around 50% and python3 and ld
   contribute a lot more than their overhead.  You can use --latency
   option in perf report to get the same result but ordered by latency.
 
     $ perf report --latency -s comm
 
 perf report
 -----------
 * As a side effect of the latency profiling work, it adds a new output
   field 'latency' and a sort key 'parallelism'.  The below is a result
   from my system with 64 CPUs.  The build was well-parallelized but
   contained some serial portions.
 
     $ perf report -s parallelism
     ...
     #
     # Overhead   Latency  Parallelism
     # ........  ........  ...........
     #
         16.95%     1.54%           62
         13.38%     1.24%           61
         12.50%    70.47%            1
         11.81%     1.06%           63
          7.59%     0.71%           60
          4.33%    12.20%            2
          3.41%     0.33%           59
          2.05%     0.18%           64
          1.75%     1.09%            9
          1.64%     1.85%            5
          ...
 
 * Support Feodra mini-debuginfo which is a LZMA compressed symbol table
   inside ".gnu_debugdata" ELF section.
 
 perf annotate
 -------------
 * Add --code-with-type option to enable data-type profiling with the
   usual annotate output.  Instead of focusing on data structure, it
   shows code annotation together with data type it accesses in case the
   instruction refers to a memory location (and it was able to resolve
   the target data type).  Currently it only works with --stdio.
 
     $ perf annotate --stdio --code-with-type
     ...
      Percent |      Source code & Disassembly of vmlinux for cpu/mem-loads,ldlat=30/pp (18 samples, percent: local period)
     ----------------------------------------------------------------------------------------------------------------------
              : 0                0xffffffff81050610 <__fdget>:
         0.00 :   ffffffff81050610:        callq   0xffffffff81c01b80 <__fentry__>           # data-type: (stack operation)
         0.00 :   ffffffff81050615:        pushq   %rbp              # data-type: (stack operation)
         0.00 :   ffffffff81050616:        movq    %rsp, %rbp
         0.00 :   ffffffff81050619:        pushq   %r15              # data-type: (stack operation)
         0.00 :   ffffffff8105061b:        pushq   %r14              # data-type: (stack operation)
         0.00 :   ffffffff8105061d:        pushq   %rbx              # data-type: (stack operation)
         0.00 :   ffffffff8105061e:        subq    $0x10, %rsp
         0.00 :   ffffffff81050622:        movl    %edi, %ebx
         0.00 :   ffffffff81050624:        movq    %gs:0x7efc4814(%rip), %rax  # 0x14e40 <current_task>              # data-type: struct task_struct* +0
         0.00 :   ffffffff8105062c:        movq    0x8d0(%rax), %r14         # data-type: struct task_struct +0x8d0 (files)
         0.00 :   ffffffff81050633:        movl    (%r14), %eax              # data-type: struct files_struct +0 (count.counter)
         0.00 :   ffffffff81050636:        cmpl    $0x1, %eax
         0.00 :   ffffffff81050639:        je      0xffffffff810506a9 <__fdget+0x99>
         0.00 :   ffffffff8105063b:        movq    0x20(%r14), %rcx          # data-type: struct files_struct +0x20 (fdt)
         0.00 :   ffffffff8105063f:        movl    (%rcx), %eax              # data-type: struct fdtable +0 (max_fds)
         0.00 :   ffffffff81050641:        cmpl    %ebx, %eax
         0.00 :   ffffffff81050643:        jbe     0xffffffff810506ef <__fdget+0xdf>
         0.00 :   ffffffff81050649:        movl    %ebx, %r15d
         5.56 :   ffffffff8105064c:        movq    0x8(%rcx), %rdx           # data-type: struct fdtable +0x8 (fd)
 	...
 
   The "# data-type:" part was added with this change.  The first few
   entries are not very interesting.  But later you can it accesses
   a couple of fields in the task_struct, files_struct and fdtable.
 
 perf trace
 ----------
 * Support syscall tracing for different ABI.  For example it can trace
   system calls for 32-bit applications on 64-bit kernel transparently.
 
 * Add --summary-mode=total option to show global syscall summary.  The
   default is 'thread' to show per-thread syscall summary.
 
 Python support
 --------------
 * Add more interfaces to 'perf' module to parse events, and config,
   enable or disable the event list properly so that it can implement
   basic functionalities purely in Python.  There is an example code
   for these new interfaces in python/tracepoint.py.
 
 * Add mypy and pylint support to enable build time checking.  Fix
   some code based on the findings from these tools.
 
 Internals
 ---------
 * Introduce io_dir__readdir() API to make directory traveral (usually
   for proc or sysfs) efficient with less memory footprint.
 
 JSON vendor events
 ------------------
 * Add events and metrics for ARM Neoverse N3 and V3
 * Update events and metrics on various Intel CPUs
 * Add/update events for a number of SiFive processors
 
 Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-for-v6.15-2025-03-27' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Namhyung Kim:
 "perf record:

   - Introduce latency profiling using scheduler information.

     The latency profiling is to show impacts on wall-time rather than
     cpu-time. By tracking context switches, it can weight samples and
     find which part of the code contributed more to the execution
     latency.

     The value (period) of the sample is weighted by dividing it by the
     number of parallel execution at the moment. The parallelism is
     tracked in perf report with sched-switch records. This will reduce
     the portion that are run in parallel and in turn increase the
     portion of serial executions.

     For now, it's limited to profile processes, IOW system-wide
     profiling is not supported. You can add --latency option to enable
     this.

       $ perf record --latency -- make -C tools/perf

     I've run the above command for perf build which adds -j option to
     make with the number of CPUs in the system internally. Normally
     it'd show something like below:

       $ perf report -F overhead,comm
       ...
       #
       # Overhead  Command
       # ........  ...............
       #
           78.97%  cc1
            6.54%  python3
            4.21%  shellcheck
            3.28%  ld
            1.80%  as
            1.37%  cc1plus
            0.80%  sh
            0.62%  clang
            0.56%  gcc
            0.44%  perl
            0.39%  make
  	 ...

     The cc1 takes around 80% of the overhead as it's the actual
     compiler. However it runs in parallel so its contribution to
     latency may be less than that. Now, perf report will show both
     overhead and latency (if --latency was given at record time) like
     below:

       $ perf report -s comm
       ...
       #
       # Overhead   Latency  Command
       # ........  ........  ...............
       #
           78.97%    48.66%  cc1
            6.54%    25.68%  python3
            4.21%     0.39%  shellcheck
            3.28%    13.70%  ld
            1.80%     2.56%  as
            1.37%     3.08%  cc1plus
            0.80%     0.98%  sh
            0.62%     0.61%  clang
            0.56%     0.33%  gcc
            0.44%     1.71%  perl
            0.39%     0.83%  make
  	 ...

     You can see latency of cc1 goes down to around 50% and python3 and
     ld contribute a lot more than their overhead. You can use --latency
     option in perf report to get the same result but ordered by
     latency.

       $ perf report --latency -s comm

  perf report:

   - As a side effect of the latency profiling work, it adds a new
     output field 'latency' and a sort key 'parallelism'. The below is a
     result from my system with 64 CPUs. The build was well-parallelized
     but contained some serial portions.

       $ perf report -s parallelism
       ...
       #
       # Overhead   Latency  Parallelism
       # ........  ........  ...........
       #
           16.95%     1.54%           62
           13.38%     1.24%           61
           12.50%    70.47%            1
           11.81%     1.06%           63
            7.59%     0.71%           60
            4.33%    12.20%            2
            3.41%     0.33%           59
            2.05%     0.18%           64
            1.75%     1.09%            9
            1.64%     1.85%            5
            ...

   - Support Feodra mini-debuginfo which is a LZMA compressed symbol
     table inside ".gnu_debugdata" ELF section.

  perf annotate:

   - Add --code-with-type option to enable data-type profiling with the
     usual annotate output.

     Instead of focusing on data structure, it shows code annotation
     together with data type it accesses in case the instruction refers
     to a memory location (and it was able to resolve the target data
     type). Currently it only works with --stdio.

       $ perf annotate --stdio --code-with-type
       ...
        Percent |      Source code & Disassembly of vmlinux for cpu/mem-loads,ldlat=30/pp (18 samples, percent: local period)
       ----------------------------------------------------------------------------------------------------------------------
                : 0                0xffffffff81050610 <__fdget>:
           0.00 :   ffffffff81050610:        callq   0xffffffff81c01b80 <__fentry__>           # data-type: (stack operation)
           0.00 :   ffffffff81050615:        pushq   %rbp              # data-type: (stack operation)
           0.00 :   ffffffff81050616:        movq    %rsp, %rbp
           0.00 :   ffffffff81050619:        pushq   %r15              # data-type: (stack operation)
           0.00 :   ffffffff8105061b:        pushq   %r14              # data-type: (stack operation)
           0.00 :   ffffffff8105061d:        pushq   %rbx              # data-type: (stack operation)
           0.00 :   ffffffff8105061e:        subq    $0x10, %rsp
           0.00 :   ffffffff81050622:        movl    %edi, %ebx
           0.00 :   ffffffff81050624:        movq    %gs:0x7efc4814(%rip), %rax  # 0x14e40 <current_task>              # data-type: struct task_struct* +0
           0.00 :   ffffffff8105062c:        movq    0x8d0(%rax), %r14         # data-type: struct task_struct +0x8d0 (files)
           0.00 :   ffffffff81050633:        movl    (%r14), %eax              # data-type: struct files_struct +0 (count.counter)
           0.00 :   ffffffff81050636:        cmpl    $0x1, %eax
           0.00 :   ffffffff81050639:        je      0xffffffff810506a9 <__fdget+0x99>
           0.00 :   ffffffff8105063b:        movq    0x20(%r14), %rcx          # data-type: struct files_struct +0x20 (fdt)
           0.00 :   ffffffff8105063f:        movl    (%rcx), %eax              # data-type: struct fdtable +0 (max_fds)
           0.00 :   ffffffff81050641:        cmpl    %ebx, %eax
           0.00 :   ffffffff81050643:        jbe     0xffffffff810506ef <__fdget+0xdf>
           0.00 :   ffffffff81050649:        movl    %ebx, %r15d
           5.56 :   ffffffff8105064c:        movq    0x8(%rcx), %rdx           # data-type: struct fdtable +0x8 (fd)
  	...

     The "# data-type:" part was added with this change. The first few
     entries are not very interesting. But later you can it accesses a
     couple of fields in the task_struct, files_struct and fdtable.

  perf trace:

   - Support syscall tracing for different ABI. For example it can trace
     system calls for 32-bit applications on 64-bit kernel
     transparently.

   - Add --summary-mode=total option to show global syscall summary. The
     default is 'thread' to show per-thread syscall summary.

  Python support:

   - Add more interfaces to 'perf' module to parse events, and config,
     enable or disable the event list properly so that it can implement
     basic functionalities purely in Python. There is an example code
     for these new interfaces in python/tracepoint.py.

   - Add mypy and pylint support to enable build time checking. Fix some
     code based on the findings from these tools.

  Internals:

   - Introduce io_dir__readdir() API to make directory traveral (usually
     for proc or sysfs) efficient with less memory footprint.

  JSON vendor events:

   - Add events and metrics for ARM Neoverse N3 and V3

   - Update events and metrics on various Intel CPUs

   - Add/update events for a number of SiFive processors"

* tag 'perf-tools-for-v6.15-2025-03-27' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (229 commits)
  perf bpf-filter: Fix a parsing error with comma
  perf report: Fix a memory leak for perf_env on AMD
  perf trace: Fix wrong size to bpf_map__update_elem call
  perf tools: annotate asm_pure_loop.S
  perf python: Fix setup.py mypy errors
  perf test: Address attr.py mypy error
  perf build: Add pylint build tests
  perf build: Add mypy build tests
  perf build: Rename TEST_LOGS to SHELL_TEST_LOGS
  tools/build: Don't pass test log files to linker
  perf bench sched pipe: fix enforced blocking reads in worker_thread
  perf tools: Fix is_compat_mode build break in ppc64
  perf build: filter all combinations of -flto for libperl
  perf vendor events arm64 AmpereOneX: Fix frontend_bound calculation
  perf vendor events arm64: AmpereOne/AmpereOneX: Mark LD_RETIRED impacted by errata
  perf trace: Fix evlist memory leak
  perf trace: Fix BTF memory leak
  perf trace: Make syscall table stable
  perf syscalltbl: Mask off ABI type for MIPS system calls
  perf build: Remove Makefile.syscalls
  ...
2025-03-31 08:52:33 -07:00
Linus Torvalds
fa593d0f96 bpf-next-6.15
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Merge tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:
 "For this merge window we're splitting BPF pull request into three for
  higher visibility: main changes, res_spin_lock, try_alloc_pages.

  These are the main BPF changes:

   - Add DFA-based live registers analysis to improve verification of
     programs with loops (Eduard Zingerman)

   - Introduce load_acquire and store_release BPF instructions and add
     x86, arm64 JIT support (Peilin Ye)

   - Fix loop detection logic in the verifier (Eduard Zingerman)

   - Drop unnecesary lock in bpf_map_inc_not_zero() (Eric Dumazet)

   - Add kfunc for populating cpumask bits (Emil Tsalapatis)

   - Convert various shell based tests to selftests/bpf/test_progs
     format (Bastien Curutchet)

   - Allow passing referenced kptrs into struct_ops callbacks (Amery
     Hung)

   - Add a flag to LSM bpf hook to facilitate bpf program signing
     (Blaise Boscaccy)

   - Track arena arguments in kfuncs (Ihor Solodrai)

   - Add copy_remote_vm_str() helper for reading strings from remote VM
     and bpf_copy_from_user_task_str() kfunc (Jordan Rome)

   - Add support for timed may_goto instruction (Kumar Kartikeya
     Dwivedi)

   - Allow bpf_get_netns_cookie() int cgroup_skb programs (Mahe Tardy)

   - Reduce bpf_cgrp_storage_busy false positives when accessing cgroup
     local storage (Martin KaFai Lau)

   - Introduce bpf_dynptr_copy() kfunc (Mykyta Yatsenko)

   - Allow retrieving BTF data with BTF token (Mykyta Yatsenko)

   - Add BPF kfuncs to set and get xattrs with 'security.bpf.' prefix
     (Song Liu)

   - Reject attaching programs to noreturn functions (Yafang Shao)

   - Introduce pre-order traversal of cgroup bpf programs (Yonghong
     Song)"

* tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (186 commits)
  selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
  bpf: Fix out-of-bounds read in check_atomic_load/store()
  libbpf: Add namespace for errstr making it libbpf_errstr
  bpf: Add struct_ops context information to struct bpf_prog_aux
  selftests/bpf: Sanitize pointer prior fclose()
  selftests/bpf: Migrate test_xdp_vlan.sh into test_progs
  selftests/bpf: test_xdp_vlan: Rename BPF sections
  bpf: clarify a misleading verifier error message
  selftests/bpf: Add selftest for attaching fexit to __noreturn functions
  bpf: Reject attaching fexit/fmod_ret to __noreturn functions
  bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates storage
  bpf: Make perf_event_read_output accessible in all program types.
  bpftool: Using the right format specifiers
  bpftool: Add -Wformat-signedness flag to detect format errors
  selftests/bpf: Test freplace from user namespace
  libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID
  bpf: Return prog btf_id without capable check
  bpf: BPF token support for BPF_BTF_GET_FD_BY_ID
  bpf, x86: Fix objtool warning for timed may_goto
  bpf: Check map->record at the beginning of check_and_free_fields()
  ...
2025-03-30 12:43:03 -07:00
Ian Rogers
307ef667e9 libbpf: Add namespace for errstr making it libbpf_errstr
When statically linking symbols can be replaced with those from other
statically linked libraries depending on the link order and the hoped
for "multiple definition" error may not appear. To avoid conflicts it
is good practice to namespace symbols, this change renames errstr to
libbpf_errstr. To avoid churn a #define is used to turn use of
errstr(err) to libbpf_errstr(err).

Fixes: 1633a83bf9 ("libbpf: Introduce errstr() for stringifying errno")
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250320222439.1350187-1-irogers@google.com
2025-03-21 13:44:54 -07:00
James Clark
f5b07010c1 libperf: Don't remove -g when EXTRA_CFLAGS are used
When using EXTRA_CFLAGS, for example "EXTRA_CFLAGS=-DREFCNT_CHECKING=1",
this construct stops setting -g which you'd expect would not be affected
by adding extra flags. Additionally, EXTRA_CFLAGS should be the last
thing to be appended so that it can be used to undo any defaults. And no
condition is required, just += appends to any existing CFLAGS and also
appends or doesn't append EXTRA_CFLAGS if they are or aren't set.

It's not clear why DEBUG=1 is required for -g in Perf when in libperf
it's always on, but I don't think we need to change that behavior now
because someone may be depending on it.

Signed-off-by: James Clark <james.clark@linaro.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250319114009.417865-1-james.clark@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-03-19 17:00:39 -07:00
Mykyta Yatsenko
974ef9f0d2 libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID
Pass BPF token from bpf_program__set_attach_target to
BPF_BTF_GET_FD_BY_ID bpf command.
When freplace program attaches to target program, it needs to look up
for BTF of the target, this may require BPF token, if, for example,
running from user namespace.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250317174039.161275-4-mykyta.yatsenko5@gmail.com
2025-03-17 13:45:12 -07:00
Wei Yang
82114e4513 lib/interval_tree: add test case for interval_tree_iter_xxx() helpers
Verify interval_tree_iter_xxx() helpers could find intersection ranges
as expected.

[sfr@canb.auug.org.au: some of tools/ uses -Wno-unused-parameter]
  Link: https://lkml.kernel.org/r/20250312113612.31ac808e@canb.auug.org.au
Link: https://lkml.kernel.org/r/20250310074938.26756-5-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 12:17:00 -07:00
Wei Yang
4164e1525d lib/rbtree: enable userland test suite for rbtree related data structure
Patch series "lib/interval_tree: add some test cases and cleanup", v2.

Since rbtree/augmented tree/interval tree share similar data structure,
besides new cases for interval tree, this patch set also does cleanup for
others.


This patch (of 7):

Currently we have some tests for rbtree related data structure, e.g. 
rbtree, augmented rbtree, interval tree, in lib/ as kernel module.

To facilitate the test and debug for those fundamental data structure,
this patch enable those tests in userland.

Link: https://lkml.kernel.org/r/20250310074938.26756-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20250310074938.26756-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 12:17:00 -07:00
Mykyta Yatsenko
1315c28ed8 libbpf: Split bpf object load into prepare/load
Introduce bpf_object__prepare API: additional intermediate preparation
step that performs ELF processing, relocations, prepares final state of
BPF program instructions (accessible with bpf_program__insns()), creates
and (potentially) pins maps, and stops short of loading BPF programs.

We anticipate few use cases for this API, such as:
* Use prepare to initialize bpf_token, without loading freplace
programs, unlocking possibility to lookup BTF of other programs.
* Execute prepare to obtain finalized BPF program instructions without
loading programs, enabling tools like veristat to process one program at
a time, without incurring cost of ELF parsing and processing.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250303135752.158343-4-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-15 11:48:28 -07:00
Mykyta Yatsenko
9a9e347835 libbpf: Introduce more granular state for bpf_object
We are going to split bpf_object loading into 2 stages: preparation and
loading. This will increase flexibility when working with bpf_object
and unlock some optimizations and use cases.
This patch substitutes a boolean flag (loaded) by more finely-grained
state for bpf_object.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250303135752.158343-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-15 11:48:28 -07:00
Mykyta Yatsenko
6ef78c4191 libbpf: Use map_is_created helper in map setters
Refactoring: use map_is_created helper in map setters that need to check
the state of the map. This helps to reduce the number of the places that
depend explicitly on the loaded flag, simplifying refactoring in the
next patch of this set.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250303135752.158343-2-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-15 11:48:27 -07:00
Arnaldo Carvalho de Melo
0c9f3a8597 libapi: Add missing header with NAME_MAX define to io_dir.h
Most systems get this indirectly, but some odd cases (some musl libc
systems) can't find it, so just add the header where NAME_MAX is defined
to avoid that.

Fixes: d118b08f7e ("tools lib api: Add io_dir an allocation free readdir alternative")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20250310194534.265487-2-acme@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-03-13 00:29:36 -07:00
Ian Rogers
c760174401 perf cpumap: Reduce cpu size from int to int16_t
Fewer than 32k logical CPUs are currently supported by perf. A cpumap
is indexed by an integer (see perf_cpu_map__cpu) yielding a perf_cpu
that wraps a 4-byte int for the logical CPU - the wrapping is done
deliberately to avoid confusing a logical CPU with an index into a
cpumap. Using a 4-byte int within the perf_cpu is larger than required
so this patch reduces it to the 2-byte int16_t. For a cpumap
containing 16 entries this will reduce the array size from 64 to 32
bytes. For very large servers with lots of logical CPUs the size
savings will be greater.

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250210191231.156294-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-02-27 08:47:25 -08:00
Ihor Solodrai
b62dff1440 libbpf: Implement bpf_usdt_arg_size BPF function
Information about USDT argument size is implicitly stored in
__bpf_usdt_arg_spec, but currently it's not accessbile to BPF programs
that use USDT.

Implement bpf_sdt_arg_size() that returns the size of an USDT argument
in bytes.

v1->v2:
  * do not add __bpf_usdt_arg_spec() helper

v1: https://lore.kernel.org/bpf/20250220215904.3362709-1-ihor.solodrai@linux.dev/

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250224235756.2612606-1-ihor.solodrai@linux.dev
2025-02-26 08:59:44 -08:00
Linus Torvalds
9f5270d758 perf tools fixes for v6.14: 2nd batch
- Fix tools/ quiet build Makefile infrastructure that was broken when
   working on tools/perf/ without testing on other tools/ living
   utilities.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix tools/ quiet build Makefile infrastructure that was broken when
   working on tools/perf/ without testing on other tools/ living
   utilities.

* tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  tools: Remove redundant quiet setup
  tools: Unify top-level quiet infrastructure
2025-02-25 13:32:32 -08:00
Ian Rogers
d118b08f7e tools lib api: Add io_dir an allocation free readdir alternative
glibc's opendir allocates a minimum of 32kb, when called recursively
for a directory tree the memory consumption can add up - nearly 300kb
during perf start-up when processing modules. Add a stack allocated
variant of readdir sized a little more than 1kb.

As getdents64 may be missing from libc, add support using syscall. As
the system call number maybe missing, add #defines for those.

Note, an earlier version of this patch had a feature test for
getdents64 but there were problems on certains distros where
getdents64 would be #define renamed to getdents breaking the code. The
syscall use was made uncondtional to work around this. There is
context in:
https://lore.kernel.org/lkml/20231207050433.1426834-1-irogers@google.com/

Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250222061015.303622-2-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-02-24 15:46:33 -08:00
Nandakumar Edamana
236d391011 libbpf: Fix out-of-bound read
In `set_kcfg_value_str`, an untrusted string is accessed with the assumption
that it will be at least two characters long due to the presence of checks for
opening and closing quotes. But the check for the closing quote
(value[len - 1] != '"') misses the fact that it could be checking the opening
quote itself in case of an invalid input that consists of just the opening
quote.

This commit adds an explicit check to make sure the string is at least two
characters long.

Signed-off-by: Nandakumar Edamana <nandakumar@nandakumar.co.in>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250221210110.3182084-1-nandakumar@nandakumar.co.in
2025-02-24 13:58:41 -08:00
Andrii Nakryiko
e0525cd72b libbpf: Fix hypothetical STT_SECTION extern NULL deref case
Fix theoretical NULL dereference in linker when resolving *extern*
STT_SECTION symbol against not-yet-existing ELF section. Not sure if
it's possible in practice for valid ELF object files (this would require
embedded assembly manipulations, at which point BTF will be missing),
but fix the s/dst_sym/dst_sec/ typo guarding this condition anyways.

Fixes: faf6ed321c ("libbpf: Add BPF static linker APIs")
Fixes: a46349227c ("libbpf: Add linker extern resolution support for functions and global variables")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250220002821.834400-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-02-20 18:42:16 -08:00
Tao Chen
e8af068239 libbpf: Wrap libbpf API direct err with libbpf_err
Just wrap the direct err with libbpf_err, keep consistency
with other APIs.

Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20250219153711.29651-1-chen.dylane@linux.dev
2025-02-19 14:56:30 -08:00
Charlie Jenkins
42367eca76 tools: Remove redundant quiet setup
Q is exported from Makefile.include so it is not necessary to manually
set it.

Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Benjamin Tissoires <bentiss@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Mykola Lysenko <mykolal@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20250213-quiet_tools-v3-2-07de4482a581@rivosinc.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-02-18 16:27:43 -03:00
Andrii Nakryiko
06096d19ee libbpf: fix LDX/STX/ST CO-RE relocation size adjustment logic
Libbpf has a somewhat obscure feature of automatically adjusting the
"size" of LDX/STX/ST instruction (memory store and load instructions),
based on originally recorded access size (u8, u16, u32, or u64) and the
actual size of the field on target kernel. This is meant to facilitate
using BPF CO-RE on 32-bit architectures (pointers are always 64-bit in
BPF, but host kernel's BTF will have it as 32-bit type), as well as
generally supporting safe type changes (unsigned integer type changes
can be transparently "relocated").

One issue that surfaced only now, 5 years after this logic was
implemented, is how this all works when dealing with fields that are
arrays. This isn't all that easy and straightforward to hit (see
selftests that reproduce this condition), but one of sched_ext BPF
programs did hit it with innocent looking loop.

Long story short, libbpf used to calculate entire array size, instead of
making sure to only calculate array's element size. But it's the element
that is loaded by LDX/STX/ST instructions (1, 2, 4, or 8 bytes), so
that's what libbpf should check. This patch adjusts the logic for
arrays and fixed the issue.

Reported-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250207014809.1573841-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-02-14 19:58:05 -08:00
Ihor Solodrai
2019c58318 libbpf: Check the kflag of type tags in btf_dump
If the kflag is set for a BTF type tag, then the tag represents an
arbitrary __attribute__. Change btf_dump accordingly.

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250130201239.1429648-4-ihor.solodrai@linux.dev
2025-02-05 16:17:59 -08:00
Ihor Solodrai
51d1b1d428 libbpf: Introduce kflag for type_tags and decl_tags in BTF
Add the following functions to libbpf API:
  * btf__add_type_attr()
  * btf__add_decl_attr()

These functions allow to add to BTF the type tags and decl tags with
info->kflag set to 1. The kflag indicates that the tag directly
encodes an __attribute__ and not a normal tag.

See Documentation/bpf/btf.rst changes in the subsequent patch for
details on the semantics.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250130201239.1429648-2-ihor.solodrai@linux.dev
2025-02-05 16:17:59 -08:00
Tony Ambardar
0a7c2a8435 libbpf: Fix accessing BTF.ext core_relo header
Update btf_ext_parse_info() to ensure the core_relo header is present
before reading its fields. This avoids a potential buffer read overflow
reported by the OSS Fuzz project.

Fixes: cf579164e9 ("libbpf: Support BTF.ext loading and output in either endianness")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://issues.oss-fuzz.com/issues/388905046
Link: https://lore.kernel.org/bpf/20250125065236.2603346-1-itugrok@yahoo.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-02-03 03:33:51 -08:00
Linus Torvalds
7685b334d1 perf-tools changes for v6.14
There are a lot of changes in the perf tools in this cycle.
 
 build
 -----
 * Use generic syscall table to generate syscall numbers on supported archs.
 * This also enables to get rid of libaudit which was used for syscall numbers.
 * Remove python2 support as it's deprecated for years.
 * Fix issues on static build with libzstd.
 
 perf record
 -----------
 * Intel-PT supports "aux-action" config term to pause or resume tracing in
   the aux-buffer.  Users can start the intel_pt event as "started-paused" and
   configure other events to control the Intel-PT tracing.
 
     # perf record --kcore -e intel_pt/aux-action=start-paused/   \
         -e syscalls:sys_enter_newuname/aux-action=resume/        \
         -e syscalls:sys_exit_newuname/aux-action=pause/ -- uname
 
   This requires the kernel support (which was added in v6.13).
 
 perf lock
 ---------
 * 'perf lock contention' command has an ability to symbolize locks in
   dynamically allocated objects using slab cache name when it runs with BPF.
   Those dynamic locks would have "&" prefix in the name to distinguish them
   from ordinary (static) locks.
 
     # perf lock con -abl -E 5 sleep 1
        contended   total wait     max wait     avg wait            address   symbol
 
                2      1.95 us      1.77 us       975 ns   ffff9d5e852d3498   &task_struct (mutex)
                1      1.18 us      1.18 us      1.18 us   ffff9d5e852d3538   &task_struct (mutex)
                4      1.12 us       354 ns       279 ns   ffff9d5e841ca800   &kmalloc-cg-512 (mutex)
                2       859 ns       617 ns       429 ns   ffffffffa41c3620   delayed_uprobe_lock (mutex)
                3       691 ns       388 ns       230 ns   ffffffffa41c0940   pack_mutex (mutex)
 
   This also requires the kernel/BPF support (which was added in v6.13).
 
 perf ftrace
 -----------
 * 'perf ftrace latency' command gets a couple of options to support linear
   buckets instead of exponential.  Also it's possible to specify max and
   min latency for the linear buckets.
 
     # perf ftrace latency -abn -T switch_mm_irqs_off --bucket-range=100   \
         --min-latency=200 --max-latency=800 -- sleep 1
     #   DURATION     |      COUNT | GRAPH                                  |
          0 -  200 ns |        186 | ###                                    |
        200 -  300 ns |        256 | #####                                  |
        300 -  400 ns |        364 | #######                                |
        400 -  500 ns |        223 | ####                                   |
        500 -  600 ns |        111 | ##                                     |
        600 -  700 ns |         41 |                                        |
        700 -  800 ns |        141 | ##                                     |
        800 -  ... ns |        169 | ###                                    |
 
     # statistics  (in nsec)
       total time:              2162212
         avg time:                  967
         max time:                16817
         min time:                  132
            count:                 2236
 
 * As you can see in the above example, it nows shows the statistics at the
   end so that users can see the avg/max/min latencies easily.
 
 * 'perf ftrace profile' command has --graph-opts option like 'perf ftrace
   trace' so that it can control the tracing behaviors in the same way.
   For example, it can limit the function call depth or threshold.
 
 perf script
 -----------
 * Improve physical memory resolution in 'mem-phys-addr' script by parsing
   /proc/iomem file.
 
     # perf script mem-phys-addr -- find /
     ...
     Event: mem_inst_retired.all_loads:P
     Memory type                                    count  percentage
     ----------------------------------------  ----------  ----------
     100000000-85f7fffff : System RAM                8929        69.7
       547600000-54785d23f : Kernel data             1240         9.7
       546a00000-5474bdfff : Kernel rodata            490         3.8
       5480ce000-5485fffff : Kernel bss               121         0.9
     0-fff : Reserved                                3860        30.1
     100000-89c01fff : System RAM                      18         0.1
     8a22c000-8df6efff : System RAM                     5         0.0
 
 Others
 ------
 * 'perf test' gets --runs-per-test option to run the test cases repeatedly.
   This would be helpful to see if it's flaky.
 
 * Add 'parse_events' method to Python perf extension module, so that users
   can use the same event parsing logic in the python code.  One more step
   towards implementing perf tools in Python. :)
 
 * Support opening tracepoint events without libtraceevent.  This will be
   helpful if it won't use the tracing data like in 'perf stat'.
 
 * Update ARM Neoverse N2/V2 JSON events and metrics
 
 Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-for-v6.14-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf-tools updates from Namhyung Kim:
 "There are a lot of changes in the perf tools in this cycle.

  build:

   - Use generic syscall table to generate syscall numbers on supported
     archs

   - This also enables to get rid of libaudit which was used for syscall
     numbers

   - Remove python2 support as it's deprecated for years

   - Fix issues on static build with libzstd

  perf record:

   - Intel-PT supports "aux-action" config term to pause or resume
     tracing in the aux-buffer. Users can start the intel_pt event as
     "started-paused" and configure other events to control the Intel-PT
     tracing:

         # perf record --kcore -e intel_pt/aux-action=start-paused/   \
             -e syscalls:sys_enter_newuname/aux-action=resume/        \
             -e syscalls:sys_exit_newuname/aux-action=pause/ -- uname

     This requires kernel support (which was added in v6.13)

  perf lock:

   - 'perf lock contention' command has an ability to symbolize locks in
     dynamically allocated objects using slab cache name when it runs
     with BPF. Those dynamic locks would have "&" prefix in the name to
     distinguish them from ordinary (static) locks

        # perf lock con -abl -E 5 sleep 1
           contended   total wait     max wait     avg wait            address   symbol

                   2      1.95 us      1.77 us       975 ns   ffff9d5e852d3498   &task_struct (mutex)
                   1      1.18 us      1.18 us      1.18 us   ffff9d5e852d3538   &task_struct (mutex)
                   4      1.12 us       354 ns       279 ns   ffff9d5e841ca800   &kmalloc-cg-512 (mutex)
                   2       859 ns       617 ns       429 ns   ffffffffa41c3620   delayed_uprobe_lock (mutex)
                   3       691 ns       388 ns       230 ns   ffffffffa41c0940   pack_mutex (mutex)

     This also requires kernel/BPF support (which was added in v6.13)

  perf ftrace:

   - 'perf ftrace latency' command gets a couple of options to support
     linear buckets instead of exponential. Also it's possible to
     specify max and min latency for the linear buckets:

        # perf ftrace latency -abn -T switch_mm_irqs_off --bucket-range=100   \
            --min-latency=200 --max-latency=800 -- sleep 1
        #   DURATION     |      COUNT | GRAPH                                  |
             0 -  200 ns |        186 | ###                                    |
           200 -  300 ns |        256 | #####                                  |
           300 -  400 ns |        364 | #######                                |
           400 -  500 ns |        223 | ####                                   |
           500 -  600 ns |        111 | ##                                     |
           600 -  700 ns |         41 |                                        |
           700 -  800 ns |        141 | ##                                     |
           800 -  ... ns |        169 | ###                                    |

        # statistics  (in nsec)
          total time:              2162212
            avg time:                  967
            max time:                16817
            min time:                  132
               count:                 2236

   - As you can see in the above example, it nows shows the statistics
     at the end so that users can see the avg/max/min latencies easily

   - 'perf ftrace profile' command has --graph-opts option like 'perf
     ftrace trace' so that it can control the tracing behaviors in the
     same way. For example, it can limit the function call depth or
     threshold

  perf script:

   - Improve physical memory resolution in 'mem-phys-addr' script by
     parsing /proc/iomem file

        # perf script mem-phys-addr -- find /
        ...
        Event: mem_inst_retired.all_loads:P
        Memory type                                    count  percentage
        ----------------------------------------  ----------  ----------
        100000000-85f7fffff : System RAM                8929        69.7
          547600000-54785d23f : Kernel data             1240         9.7
          546a00000-5474bdfff : Kernel rodata            490         3.8
          5480ce000-5485fffff : Kernel bss               121         0.9
        0-fff : Reserved                                3860        30.1
        100000-89c01fff : System RAM                      18         0.1
        8a22c000-8df6efff : System RAM                     5         0.0

  Others:

   - 'perf test' gets --runs-per-test option to run the test cases
     repeatedly. This would be helpful to see if it's flaky

   - Add 'parse_events' method to Python perf extension module, so that
     users can use the same event parsing logic in the python code. One
     more step towards implementing perf tools in Python. :)

   - Support opening tracepoint events without libtraceevent. This will
     be helpful if it won't use the tracing data like in 'perf stat'

   - Update ARM Neoverse N2/V2 JSON events and metrics"

* tag 'perf-tools-for-v6.14-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (176 commits)
  perf test: Update event_groups test to use instructions
  perf bench: Fix undefined behavior in cmpworker()
  perf annotate: Prefer passing evsel to evsel->core.idx
  perf lock: Rename fields in lock_type_table
  perf lock: Add percpu-rwsem for type filter
  perf lock: Fix parse_lock_type which only retrieve one lock flag
  perf lock: Fix return code for functions in __cmd_contention
  perf hist: Fix width calculation in hpp__fmt()
  perf hist: Fix bogus profiles when filters are enabled
  perf hist: Deduplicate cmp/sort/collapse code
  perf test: Improve verbose documentation
  perf test: Add a runs-per-test flag
  perf test: Fix parallel/sequential option documentation
  perf test: Send list output to stdout rather than stderr
  perf test: Rename functions and variables for better clarity
  perf tools: Expose quiet/verbose variables in Makefile.perf
  perf config: Add a function to set one variable in .perfconfig
  perf test perftool_testsuite: Return correct value for skipping
  perf test perftool_testsuite: Add missing description
  perf test record+probe_libc_inet_pton: Make test resilient
  ...
2025-01-24 05:45:40 -08:00
Andrii Nakryiko
f8a05692de libbpf: Work around kernel inconsistently stripping '.llvm.' suffix
Some versions of kernel were stripping out '.llvm.<hash>' suffix from
kerne symbols (produced by Clang LTO compilation) from function names
reported in available_filter_functions, while kallsyms reported full
original name. This confuses libbpf's multi-kprobe logic of finding all
matching kernel functions for specified user glob pattern by joining
available_filter_functions and kallsyms contents, because joining by
full symbol name won't work for symbols containing '.llvm.<hash>' suffix.

This was eventually fixed by [0] in the kernel, but we'd like to not
regress multi-kprobe experience and add a work around for this bug on
libbpf side, stripping kallsym's name if it matches user pattern and
contains '.llvm.' suffix.

  [0] fb6a421fb6 ("kallsyms: Match symbols exactly with CONFIG_LTO_CLANG")

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250117003957.179331-1-andrii@kernel.org
2025-01-17 15:16:56 +01:00
Pu Lehui
5ca681a86e libbpf: Fix incorrect traversal end type ID when marking BTF_IS_EMBEDDED
When redirecting the split BTF to the vmlinux base BTF, we need to mark
the distilled base struct/union members of split BTF structs/unions in
id_map with BTF_IS_EMBEDDED. This indicates that these types must match
both name and size later. Therefore, we need to traverse the entire
split BTF, which involves traversing type IDs from nr_dist_base_types to
nr_types. However, the current implementation uses an incorrect
traversal end type ID, so let's correct it.

Fixes: 19e00c897d ("libbpf: Split BTF relocation")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250115100241.4171581-3-pulehui@huaweicloud.com
2025-01-16 15:34:18 -08:00
Pu Lehui
5436a54332 libbpf: Fix return zero when elf_begin failed
The error number of elf_begin is omitted when encapsulating the
btf_find_elf_sections function.

Fixes: c86f180ffc ("libbpf: Make btf_parse_elf process .BTF.base transparently")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250115100241.4171581-2-pulehui@huaweicloud.com
2025-01-16 15:34:18 -08:00
Yonghong Song
e2b0bda62d libbpf: Add unique_match option for multi kprobe
Jordan reported an issue in Meta production environment where func
try_to_wake_up() is renamed to try_to_wake_up.llvm.<hash>() by clang
compiler at lto mode. The original 'kprobe/try_to_wake_up' does not
work any more since try_to_wake_up() does not match the actual func
name in /proc/kallsyms.

There are a couple of ways to resolve this issue. For example, in
attach_kprobe(), we could do lookup in /proc/kallsyms so try_to_wake_up()
can be replaced by try_to_wake_up.llvm.<hach>(). Or we can force users
to use bpf_program__attach_kprobe() where they need to lookup
/proc/kallsyms to find out try_to_wake_up.llvm.<hach>(). But these two
approaches requires extra work by either libbpf or user.

Luckily, suggested by Andrii, multi kprobe already supports wildcard ('*')
for symbol matching. In the above example, 'try_to_wake_up*' can match
to try_to_wake_up() or try_to_wake_up.llvm.<hash>() and this allows
bpf prog works for different kernels as some kernels may have
try_to_wake_up() and some others may have try_to_wake_up.llvm.<hash>().

The original intention is to kprobe try_to_wake_up() only, so an optional
field unique_match is added to struct bpf_kprobe_multi_opts. If the
field is set to true, the number of matched functions must be one.
Otherwise, the attachment will fail. In the above case, multi kprobe
with 'try_to_wake_up*' and unique_match preserves user functionality.

Reported-by: Jordan Rome <linux@jordanrome.com>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250109174023.3368432-1-yonghong.song@linux.dev
2025-01-10 13:11:42 -08:00
Daniel Xu
1846dd8e3a libbpf: Set MFD_NOEXEC_SEAL when creating memfd
Starting from 105ff5339f ("mm/memfd: add MFD_NOEXEC_SEAL and
MFD_EXEC") and until 1717449b44 ("memfd: drop warning for missing
exec-related flags"), the kernel would print a warning if neither
MFD_NOEXEC_SEAL nor MFD_EXEC is set in memfd_create().

If libbpf runs on on a kernel between these two commits (eg. on an
improperly backported system), it'll trigger this warning.

To avoid this warning (and also be more secure), explicitly set
MFD_NOEXEC_SEAL. But since libbpf can be run on potentially very old
kernels, leave a fallback for kernels without MFD_NOEXEC_SEAL support.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/6e62c2421ad7eb1da49cbf16da95aaaa7f94d394.1735594195.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-30 14:48:15 -08:00
Alexei Starovoitov
06103dccbb Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

No conflicts.

Adjacent changes in:
Auto-merging include/linux/bpf.h
Auto-merging include/linux/bpf_verifier.h
Auto-merging kernel/bpf/btf.c
Auto-merging kernel/bpf/verifier.c
Auto-merging kernel/trace/bpf_trace.c
Auto-merging tools/testing/selftests/bpf/progs/test_tp_btf_nullable.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-16 08:53:59 -08:00
Anton Protopopov
f9933acda3 libbpf: prog load: Allow to use fd_array_cnt
Add new fd_array_cnt field to bpf_prog_load_opts
and pass it in bpf_attr, if set.

Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241213130934.1087929-6-aspsk@isovalent.com
2024-12-13 14:48:39 -08:00
Arnaldo Carvalho de Melo
aec95d7ce1 Merge remote-tracking branch 'torvalds/master' into perf-tools-next
To get the fixes that went thru perf-tools for v6.13.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-13 11:53:27 -03:00
Alastair Robertson
6d5e5e5d7c libbpf: Extend linker API to support in-memory ELF files
The new_fd and add_fd functions correspond to the original new and
add_file functions, but accept an FD instead of a file name. This
gives API consumers the option of using anonymous files/memfds to
avoid writing ELFs to disk.

This new API will be useful for performing linking as part of
bpftrace's JIT compilation.

The add_buf function is a convenience wrapper that does the work of
creating a memfd for the caller.

Signed-off-by: Alastair Robertson <ajor@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241211164030.573042-3-ajor@meta.com
2024-12-12 15:16:53 -08:00
Alastair Robertson
b641712925 libbpf: Pull file-opening logic up to top-level functions
Move the filename arguments and file-descriptor handling from
init_output_elf() and linker_load_obj_file() and instead handle them
at the top-level in bpf_linker__new() and bpf_linker__add_file().

This will allow the inner functions to be shared with a new,
non-filename-based, API in the next commit.

Signed-off-by: Alastair Robertson <ajor@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241211164030.573042-2-ajor@meta.com
2024-12-12 15:09:21 -08:00
James Clark
f7e36d02d7 libperf: evlist: Fix --cpu argument on hybrid platform
Since the linked fixes: commit, specifying a CPU on hybrid platforms
results in an error because Perf tries to open an extended type event
on "any" CPU which isn't valid. Extended type events can only be opened
on CPUs that match the type.

Before (working):

  $ perf record --cpu 1 -- true
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 2.385 MB perf.data (7 samples) ]

After (not working):

  $ perf record -C 1 -- true
  WARNING: A requested CPU in '1' is not supported by PMU 'cpu_atom' (CPUs 16-27) for event 'cycles:P'
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cpu_atom/cycles:P/).
  /bin/dmesg | grep -i perf may provide additional information.

(Ignore the warning message, that's expected and not particularly
relevant to this issue).

This is because perf_cpu_map__intersect() of the user specified CPU (1)
and one of the PMU's CPUs (16-27) correctly results in an empty (NULL)
CPU map. However for the purposes of opening an event, libperf converts
empty CPU maps into an any CPU (-1) which the kernel rejects.

Fix it by deleting evsels with empty CPU maps in the specific case where
user requested CPU maps are evaluated.

Fixes: 251aa04024 ("perf parse-events: Wildcard most "numeric" events")
Reviewed-by: Ian Rogers <irogers@google.com>
Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20241114160450.295844-2-james.clark@linaro.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2024-12-11 09:19:44 -08:00
Ian Rogers
05be17eed7 tool api fs: Correctly encode errno for read/write open failures
Switch from returning -1 to -errno so that callers can determine types
of failure.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Paran Lee <p4ranlee@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Yang Jihong <yangjihong@bytedance.com>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Cc: Ze Gao <zegao2021@gmail.com>
Cc: Zixian Cai <fzczx123@gmail.com>
Cc: zhaimingbing <zhaimingbing@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20241118225345.889810-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-09 17:52:42 -03:00
Ian Rogers
bfb9467535 libperf cpumap: Grow array of read CPUs in smaller increments
Instead of growing the array by 2048, grow by the larger of the current
range or 16.

As ranges are typical for things like the online CPUs this will mean a
single allocation happens.

While uncore CPU maps will grow 16 at a time which is a value that is
generous except say on large servers.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kyle Meyer <kyle.meyer@hpe.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241206044035.1062032-9-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-09 17:52:41 -03:00
Ian Rogers
e9ca57d711 libperf cpumap: Remove perf_cpu_map__read()
Function is no longer used and duplicates the parsing logic from
perf_cpu_map__new().

Remove to allow simplification.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kyle Meyer <kyle.meyer@hpe.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241206044035.1062032-8-irogers@google.com
[ Applied manually to cope with "libperf cpumap: Refactor perf_cpu_map__merge()" ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-09 17:52:41 -03:00
Ian Rogers
9d9a83c51a libperf cpumap: Remove use of perf_cpu_map__read()
Remove use of a FILE and switch to reading a string that is then
passed to perf_cpu_map__new().

Being able to remove perf_cpu_map__read() avoids duplicated parsing
logic.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kyle Meyer <kyle.meyer@hpe.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241206044035.1062032-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-09 17:52:41 -03:00
Ian Rogers
5d2fd516bb libperf cpumap: Be tolerant of newline at the end of a cpumask
File cpumasks often have a newline that shouldn't trigger the invalid
parsing case in perf_cpu_map__new().

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kyle Meyer <kyle.meyer@hpe.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241206044035.1062032-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-09 17:52:41 -03:00
Ian Rogers
e8399d34d5 libperf cpumap: Hide/reduce scope of MAX_NR_CPUS
Avoid redefinition of MAX_NR_CPUS as a global constant, the original
definition is tools/perf/perf.h.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kyle Meyer <kyle.meyer@hpe.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241206044035.1062032-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-09 17:52:41 -03:00
Kyle Meyer
9a1e106550 perf: Increase MAX_NR_CPUS to 4096
Systems have surpassed 2048 CPUs. Increase MAX_NR_CPUS to 4096.

Bitmaps declared with MAX_NR_CPUS bits will increase from 256B to 512B,
cpus_runtime will increase from 81960B to 163880B, and max_entries will
increase from 8192B to 16384B.

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241206044035.1062032-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-09 17:52:41 -03:00
Leo Yan
a9d2217556 libperf cpumap: Refactor perf_cpu_map__merge()
The perf_cpu_map__merge() function has two arguments, 'orig' and
'other'.  The function definition might cause confusion as it could give
the impression that the CPU maps in the two arguments are copied into a
new allocated structure, which is then returned as the result.

The purpose of the function is to merge the CPU map 'other' into the CPU
map 'orig'.  This commit changes the 'orig' argument to a pointer to
pointer, so the new result will be updated into 'orig'.

The return value is changed to an int type, as an error number or 0 for
success.

Update callers and tests for the new function definition.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241107125308.41226-2-leo.yan@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-12-09 17:52:41 -03:00
Quentin Monnet
e10500b69c libbpf: Fix segfault due to libelf functions not setting errno
Libelf functions do not set errno on failure. Instead, it relies on its
internal _elf_errno value, that can be retrieved via elf_errno (or the
corresponding message via elf_errmsg()). From "man libelf":

    If a libelf function encounters an error it will set an internal
    error code that can be retrieved with elf_errno. Each thread
    maintains its own separate error code. The meaning of each error
    code can be determined with elf_errmsg, which returns a string
    describing the error.

As a consequence, libbpf should not return -errno when a function from
libelf fails, because an empty value will not be interpreted as an error
and won't prevent the program to stop. This is visible in
bpf_linker__add_file(), for example, where we call a succession of
functions that rely on libelf:

    err = err ?: linker_load_obj_file(linker, filename, opts, &obj);
    err = err ?: linker_append_sec_data(linker, &obj);
    err = err ?: linker_append_elf_syms(linker, &obj);
    err = err ?: linker_append_elf_relos(linker, &obj);
    err = err ?: linker_append_btf(linker, &obj);
    err = err ?: linker_append_btf_ext(linker, &obj);

If the object file that we try to process is not, in fact, a correct
object file, linker_load_obj_file() may fail with errno not being set,
and return 0. In this case we attempt to run linker_append_elf_sysms()
and may segfault.

This can happen (and was discovered) with bpftool:

    $ bpftool gen object output.o sample_ret0.bpf.c
    libbpf: failed to get ELF header for sample_ret0.bpf.c: invalid `Elf' handle
    zsh: segmentation fault (core dumped)  bpftool gen object output.o sample_ret0.bpf.c

Fix the issue by returning a non-null error code (-EINVAL) when libelf
functions fail.

Fixes: faf6ed321c ("libbpf: Add BPF static linker APIs")
Signed-off-by: Quentin Monnet <qmo@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241205135942.65262-1-qmo@kernel.org
2024-12-05 15:19:00 -08:00
Ben Olson
9a17db586d libbpf: Improve debug message when the base BTF cannot be found
When running `bpftool` on a kernel module installed in `/lib/modules...`,
this error is encountered if the user does not specify `--base-btf` to
point to a valid base BTF (e.g. usually in `/sys/kernel/btf/vmlinux`).
However, looking at the debug output to determine the cause of the error
simply says `Invalid BTF string section`, which does not point to the
actual source of the error. This just improves that debug message to tell
users what happened.

Signed-off-by: Ben Olson <matthew.olson@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/Z0YqzQ5lNz7obQG7@bolson-desk
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-02 08:41:51 -08:00
Andrii Nakryiko
98ebe5ef6f libbpf: don't adjust USDT semaphore address if .stapsdt.base addr is missing
USDT ELF note optionally can record an offset of .stapsdt.base, which is
used to make adjustments to USDT target attach address. Currently,
libbpf will do this address adjustment unconditionally if it finds
.stapsdt.base ELF section in target binary. But there is a corner case
where .stapsdt.base ELF section is present, but specific USDT note
doesn't reference it. In such case, libbpf will basically just add base
address and end up with absolutely incorrect USDT target address.

This adjustment has to be done only if both .stapsdt.sema section is
present and USDT note is recording a reference to it.

Fixes: 74cc6311ce ("libbpf: Add USDT notes parsing and resolution logic")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20241121224558.796110-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-02 08:41:17 -08:00
Linus Torvalds
b50ecc5aca perf tools changes for v6.13
perf record
 -----------
 * Enable leader sampling for inherited task events.  It was supported
   only for system-wide events but the kernel started to support such a
   setup since v6.12.
 
   This is to reduce the number of PMU interrupts.  The samples of the
   leader event will contain counts of other events and no samples will
   be generated for the other member events.
 
     $ perf record -e '{cycles,instructions}:S'  ${MYPROG}
 
 perf report
 -----------
 * Fix --branch-history option to display more branch-related information
   like prediction, abort and cycles which is available on Intel machines.
 
     $ perf record -bg -- perf test -w brstack
 
     $ perf report --branch-history
     ...
     #
     # Overhead  Source:Line               Symbol          Shared Object         Predicted  Abort  Cycles  IPC   [IPC Coverage]
     # ........  ........................  ..............  ....................  .........  .....  ......  ....................
     #
          8.17%  copy_page_64.S:19         [k] copy_page   [kernel.kallsyms]     50.0%      0      5       -      -
                 |
                 ---xas_load xarray.h:171
                    |
                    |--5.68%--xas_load xarray.c:245 (cycles:1)
                    |          xas_load xarray.c:242
                    |          xas_load xarray.h:1260 (cycles:1)
                    |          xas_descend xarray.c:146
                    |          xas_load xarray.c:244 (cycles:2)
                    |          xas_load xarray.c:245
                    |          xas_descend xarray.c:218 (cycles:10)
     ...
 
 perf stat
 ---------
 * Add HWMON PMU support.  The HWMON provides various system information
   like CPU/GPU temperature, fan speed and so on.  Expose them as PMU
   events so that users can see the values using perf stat commands.
 
     $ perf stat -e temp_cpu,fan1 true
 
      Performance counter stats for 'true':
 
                  60.00 'C   temp_cpu
                      0 rpm  fan1
 
            0.000745382 seconds time elapsed
 
            0.000883000 seconds user
            0.000000000 seconds sys
 
 * Display metric threshold in JSON output.  Some metrics define
   thresholds to classify value ranges.  It used to be in a different
   color but it won't work for JSON.  Add "metric-threshold" field to
   the JSON that can be one of "good", "less good", "nearly bad" and
   "bad".
 
     # perf stat -a -M TopdownL1 -j true
     {"counter-value" : "18693525.000000", "unit" : "", "event" : "TOPDOWN.SLOTS", "event-runtime" : 5552708, "pcnt-running" : 100.00, "metric-value" : "43.226002", "metric-unit" : "%  tma_backend_bound", "metric-threshold" : "bad"}
     {"metric-value" : "29.212267", "metric-unit" : "%  tma_frontend_bound", "metric-threshold" : "bad"}
     {"metric-value" : "7.138972", "metric-unit" : "%  tma_bad_speculation", "metric-threshold" : "good"}
     {"metric-value" : "20.422759", "metric-unit" : "%  tma_retiring", "metric-threshold" : "good"}
     {"counter-value" : "3817732.000000", "unit" : "", "event" : "topdown-retiring", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
     {"counter-value" : "5472824.000000", "unit" : "", "event" : "topdown-fe-bound", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
     {"counter-value" : "7984780.000000", "unit" : "", "event" : "topdown-be-bound", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
     {"counter-value" : "1418181.000000", "unit" : "", "event" : "topdown-bad-spec", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
     ...
 
 perf sched
 ----------
 * Add -P/--pre-migrations option for 'timehist' sub-command to track
   time a task waited on a run-queue before migrating to a different CPU.
 
     $ perf sched timehist -P
                time    cpu  task name                       wait time  sch delay   run time  pre-mig time
                             [tid/pid]                          (msec)     (msec)     (msec)     (msec)
     --------------- ------  ------------------------------  ---------  ---------  ---------  ---------
       585940.535527 [0000]  perf[584885]                        0.000      0.000      0.000      0.000
       585940.535535 [0000]  migration/0[20]                     0.000      0.002      0.008      0.000
       585940.535559 [0001]  perf[584885]                        0.000      0.000      0.000      0.000
       585940.535563 [0001]  migration/1[25]                     0.000      0.001      0.004      0.000
       585940.535678 [0002]  perf[584885]                        0.000      0.000      0.000      0.000
       585940.535686 [0002]  migration/2[31]                     0.000      0.002      0.008      0.000
       585940.535905 [0001]  <idle>                              0.000      0.000      0.342      0.000
       585940.535938 [0003]  perf[584885]                        0.000      0.000      0.000      0.000
       585940.537048 [0001]  sleep[584886]                       0.000      0.019      1.142      0.001
       585940.537749 [0002]  <idle>                              0.000      0.000      2.062      0.000
     ...
 
 Build
 -----
 * Make libunwind opt-in (LIBUNWIND=1) rather than opt-out.  The perf
   tools are generally built with libelf and libdw which has unwinder
   functionality.  The libunwind support predates it and no need to
   have duplicate unwinders by default.
 
 * Rename NO_DWARF=1 build option to NO_LIBDW=1 in order to clarify it's
   using libdw for handling DWARF information.
 
 Internals
 ---------
 * Do not set exclude_guest bit in the perf_event_attr by default.  This
   was causing a trouble in AMD IBS PMU as it doesn't support the bit.
   The bit will be set when it's needed later by the fallback logic.
   Also update the missing feature detection logic to make sure not clear
   supported bits unnecessarily.
 
 * Run perf test in parallel by default and mark flaky tests "exclusive"
   to run them serially at the end.  Some test numbers are changed but
   the test can complete in less than half the time.
 
 JSON vendor events
 ------------------
 * Add AMD Zen 5 events and metrics.
 
 * Add i.MX91 and i.MX95 DDR metrics
 
 * Fix HiSilicon HIP08 Topdown metric name.
 
 * Support compat events on PowerPC.
 
 Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-for-v6.13-2024-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Namhyung Kim:
 "perf record:

   - Enable leader sampling for inherited task events. It was supported
     only for system-wide events but the kernel started to support such
     a setup since v6.12.

     This is to reduce the number of PMU interrupts. The samples of the
     leader event will contain counts of other events and no samples
     will be generated for the other member events.

       $ perf record -e '{cycles,instructions}:S'  ${MYPROG}

  perf report:

   - Fix --branch-history option to display more branch-related
     information like prediction, abort and cycles which is available
     on Intel machines.

       $ perf record -bg -- perf test -w brstack

       $ perf report --branch-history
       ...
       #
       # Overhead  Source:Line               Symbol          Shared Object         Predicted  Abort  Cycles  IPC   [IPC Coverage]
       # ........  ........................  ..............  ....................  .........  .....  ......  ....................
       #
            8.17%  copy_page_64.S:19         [k] copy_page   [kernel.kallsyms]     50.0%      0      5       -      -
                   |
                   ---xas_load xarray.h:171
                      |
                      |--5.68%--xas_load xarray.c:245 (cycles:1)
                      |          xas_load xarray.c:242
                      |          xas_load xarray.h:1260 (cycles:1)
                      |          xas_descend xarray.c:146
                      |          xas_load xarray.c:244 (cycles:2)
                      |          xas_load xarray.c:245
                      |          xas_descend xarray.c:218 (cycles:10)
       ...

  perf stat:

   - Add HWMON PMU support.

     The HWMON provides various system information like CPU/GPU
     temperature, fan speed and so on. Expose them as PMU events so that
     users can see the values using perf stat commands.

       $ perf stat -e temp_cpu,fan1 true

        Performance counter stats for 'true':

                    60.00 'C   temp_cpu
                        0 rpm  fan1

              0.000745382 seconds time elapsed

              0.000883000 seconds user
              0.000000000 seconds sys

   - Display metric threshold in JSON output.

     Some metrics define thresholds to classify value ranges. It used to
     be in a different color but it won't work for JSON.

     Add "metric-threshold" field to the JSON that can be one of "good",
     "less good", "nearly bad" and "bad".

       # perf stat -a -M TopdownL1 -j true
       {"counter-value" : "18693525.000000", "unit" : "", "event" : "TOPDOWN.SLOTS", "event-runtime" : 5552708, "pcnt-running" : 100.00, "metric-value" : "43.226002", "metric-unit" : "%  tma_backend_bound", "metric-threshold" : "bad"}
       {"metric-value" : "29.212267", "metric-unit" : "%  tma_frontend_bound", "metric-threshold" : "bad"}
       {"metric-value" : "7.138972", "metric-unit" : "%  tma_bad_speculation", "metric-threshold" : "good"}
       {"metric-value" : "20.422759", "metric-unit" : "%  tma_retiring", "metric-threshold" : "good"}
       {"counter-value" : "3817732.000000", "unit" : "", "event" : "topdown-retiring", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
       {"counter-value" : "5472824.000000", "unit" : "", "event" : "topdown-fe-bound", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
       {"counter-value" : "7984780.000000", "unit" : "", "event" : "topdown-be-bound", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
       {"counter-value" : "1418181.000000", "unit" : "", "event" : "topdown-bad-spec", "event-runtime" : 5552708, "pcnt-running" : 100.00, }
       ...

  perf sched:

   - Add -P/--pre-migrations option for 'timehist' sub-command to track
     time a task waited on a run-queue before migrating to a different
     CPU.

       $ perf sched timehist -P
                  time    cpu  task name                       wait time  sch delay   run time  pre-mig time
                               [tid/pid]                          (msec)     (msec)     (msec)     (msec)
       --------------- ------  ------------------------------  ---------  ---------  ---------  ---------
         585940.535527 [0000]  perf[584885]                        0.000      0.000      0.000      0.000
         585940.535535 [0000]  migration/0[20]                     0.000      0.002      0.008      0.000
         585940.535559 [0001]  perf[584885]                        0.000      0.000      0.000      0.000
         585940.535563 [0001]  migration/1[25]                     0.000      0.001      0.004      0.000
         585940.535678 [0002]  perf[584885]                        0.000      0.000      0.000      0.000
         585940.535686 [0002]  migration/2[31]                     0.000      0.002      0.008      0.000
         585940.535905 [0001]  <idle>                              0.000      0.000      0.342      0.000
         585940.535938 [0003]  perf[584885]                        0.000      0.000      0.000      0.000
         585940.537048 [0001]  sleep[584886]                       0.000      0.019      1.142      0.001
         585940.537749 [0002]  <idle>                              0.000      0.000      2.062      0.000
       ...

  Build:

   - Make libunwind opt-in (LIBUNWIND=1) rather than opt-out.

     The perf tools are generally built with libelf and libdw which has
     unwinder functionality. The libunwind support predates it and no
     need to have duplicate unwinders by default.

   - Rename NO_DWARF=1 build option to NO_LIBDW=1 in order to clarify
     it's using libdw for handling DWARF information.

  Internals:

   - Do not set exclude_guest bit in the perf_event_attr by default.

     This was causing a trouble in AMD IBS PMU as it doesn't support the
     bit. The bit will be set when it's needed later by the fallback
     logic. Also update the missing feature detection logic to make sure
     not clear supported bits unnecessarily.

   - Run perf test in parallel by default and mark flaky tests
     "exclusive" to run them serially at the end. Some test numbers are
     changed but the test can complete in less than half the time.

  JSON vendor events:

   - Add AMD Zen 5 events and metrics.

   - Add i.MX91 and i.MX95 DDR metrics

   - Fix HiSilicon HIP08 Topdown metric name.

   - Support compat events on PowerPC"

* tag 'perf-tools-for-v6.13-2024-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (232 commits)
  perf tests: Fix hwmon parsing with PMU name test
  perf hwmon_pmu: Ensure hwmon key union is zeroed before use
  perf tests hwmon_pmu: Remove double evlist__delete()
  perf/test: fix perf ftrace test on s390
  perf bpf-filter: Return -ENOMEM directly when pfi allocation fails
  perf test: Correct hwmon test PMU detection
  perf: Remove unused del_perf_probe_events()
  perf pmu: Move pmu_metrics_table__find and remove ARM override
  perf jevents: Add map_for_cpu()
  perf header: Pass a perf_cpu rather than a PMU to get_cpuid_str
  perf header: Avoid transitive PMU includes
  perf arm64 header: Use cpu argument in get_cpuid
  perf header: Refactor get_cpuid to take a CPU for ARM
  perf header: Move is_cpu_online to numa bench
  perf jevents: fix breakage when do perf stat on system metric
  perf test: Add missing __exit calls in tool/hwmon tests
  perf tests: Make leader sampling test work without branch event
  perf util: Remove kernel version deadcode
  perf test shell trace_exit_race: Use --no-comm to avoid cases where COMM isn't resolved
  perf test shell trace_exit_race: Show what went wrong in verbose mode
  ...
2024-11-26 14:54:00 -08:00
Linus Torvalds
f5f4745a7f - The series "resource: A couple of cleanups" from Andy Shevchenko
performs some cleanups in the resource management code.
 
 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of task_struct.comm[].
 
 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest.
 
 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code.
 
 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification.
 
 - The series "add detect count for hung tasks" from Lance Yang adds more
   userspace visibility into the hung-task detector's activity.
 
 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details.
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Merge tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...
2024-11-25 16:09:48 -08:00
Linus Torvalds
6e95ef0258 bpf-next-bpf-next-6.13
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Merge tag 'bpf-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Add BPF uprobe session support (Jiri Olsa)

 - Optimize uprobe performance (Andrii Nakryiko)

 - Add bpf_fastcall support to helpers and kfuncs (Eduard Zingerman)

 - Avoid calling free_htab_elem() under hash map bucket lock (Hou Tao)

 - Prevent tailcall infinite loop caused by freplace (Leon Hwang)

 - Mark raw_tracepoint arguments as nullable (Kumar Kartikeya Dwivedi)

 - Introduce uptr support in the task local storage map (Martin KaFai
   Lau)

 - Stringify errno log messages in libbpf (Mykyta Yatsenko)

 - Add kmem_cache BPF iterator for perf's lock profiling (Namhyung Kim)

 - Support BPF objects of either endianness in libbpf (Tony Ambardar)

 - Add ksym to struct_ops trampoline to fix stack trace (Xu Kuohai)

 - Introduce private stack for eligible BPF programs (Yonghong Song)

 - Migrate samples/bpf tests to selftests/bpf test_progs (Daniel T. Lee)

 - Migrate test_sock to selftests/bpf test_progs (Jordan Rife)

* tag 'bpf-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (152 commits)
  libbpf: Change hash_combine parameters from long to unsigned long
  selftests/bpf: Fix build error with llvm 19
  libbpf: Fix memory leak in bpf_program__attach_uprobe_multi
  bpf: use common instruction history across all states
  bpf: Add necessary migrate_disable to range_tree.
  bpf: Do not alloc arena on unsupported arches
  selftests/bpf: Set test path for token/obj_priv_implicit_token_envvar
  selftests/bpf: Add a test for arena range tree algorithm
  bpf: Introduce range_tree data structure and use it in bpf arena
  samples/bpf: Remove unused variable in xdp2skb_meta_kern.c
  samples/bpf: Remove unused variables in tc_l2_redirect_kern.c
  bpftool: Cast variable `var` to long long
  bpf, x86: Propagate tailcall info only for subprogs
  bpf: Add kernel symbol for struct_ops trampoline
  bpf: Use function pointers count as struct_ops links count
  bpf: Remove unused member rcu from bpf_struct_ops_map
  selftests/bpf: Add struct_ops prog private stack tests
  bpf: Support private stack for struct_ops progs
  selftests/bpf: Add tracing prog private stack tests
  bpf, x86: Support private stack in jit
  ...
2024-11-21 08:11:04 -08:00
Sidong Yang
2c8b09ac25 libbpf: Change hash_combine parameters from long to unsigned long
The hash_combine() could be trapped when compiled with sanitizer like "zig cc"
or clang with signed-integer-overflow option. This patch parameters and return
type to unsigned long to remove the potential overflow.

Signed-off-by: Sidong Yang <sidong.yang@furiosa.ai>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241116081054.65195-1-sidong.yang@furiosa.ai
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-16 11:01:38 -08:00
Jiri Olsa
fab974e648 libbpf: Fix memory leak in bpf_program__attach_uprobe_multi
Andrii reported memory leak detected by Coverity on error path
in bpf_program__attach_uprobe_multi. Fixing that by moving
the check earlier before the offsets allocations.

Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241115115843.694337-1-jolsa@kernel.org
2024-11-15 11:29:12 -08:00
Alexei Starovoitov
8714381703 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

In particular to bring the fix in
commit aa30eb3260 ("bpf: Force checkpoint when jmp history is too long").
The follow up verifier work depends on it.
And the fix in
commit 6801cf7890 ("selftests/bpf: Use -4095 as the bad address for bits iterator").
It's fixing instability of BPF CI on s390 arch.

No conflicts.

Adjacent changes in:
Auto-merging arch/Kconfig
Auto-merging kernel/bpf/helpers.c
Auto-merging kernel/bpf/memalloc.c
Auto-merging kernel/bpf/verifier.c
Auto-merging mm/slab_common.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-13 12:52:51 -08:00
Luo Yifan
31bedc1fb1 libsubcmd: Move va_end() before exit
This patch makes a minor adjustment by moving the va_end call before
exit. Since the exit() function terminates the program, any code
after exit(128) (i.e., va_end(params)) is unreachable and thus not
executed. Placing va_end before exit ensures that the va_list is
properly cleaned up.

Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20241111091701.275496-1-luoyifan@cmss.chinamobile.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-11-13 16:27:35 -03:00
Mykyta Yatsenko
4ce16ddd71 libbpf: Stringify errno in log messages in the remaining code
Convert numeric error codes into the string representations in log
messages in the rest of libbpf source files.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241111212919.368971-5-mykyta.yatsenko5@gmail.com
2024-11-11 20:29:45 -08:00
Mykyta Yatsenko
af8380d519 libbpf: Stringify errno in log messages in btf*.c
Convert numeric error codes into the string representations in log
messages in btf.c and btf_dump.c.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241111212919.368971-4-mykyta.yatsenko5@gmail.com
2024-11-11 20:29:45 -08:00
Mykyta Yatsenko
271abf041c libbpf: Stringify errno in log messages in libbpf.c
Convert numeric error codes into the string representations in log
messages in libbpf.c.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241111212919.368971-3-mykyta.yatsenko5@gmail.com
2024-11-11 20:29:45 -08:00
Mykyta Yatsenko
1633a83bf9 libbpf: Introduce errstr() for stringifying errno
Add function errstr(int err) that allows converting numeric error codes
into string representations.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241111212919.368971-2-mykyta.yatsenko5@gmail.com
2024-11-11 20:29:20 -08:00
Jiri Olsa
022367ec92 libbpf: Add support for uprobe multi session attach
Adding support to attach program in uprobe session mode
with bpf_program__attach_uprobe_multi function.

Adding session bool to bpf_uprobe_multi_opts struct that allows
to load and attach the bpf program via uprobe session.
the attachment to create uprobe multi session.

Also adding new program loader section that allows:
  SEC("uprobe.session/bpf_fentry_test*")

and loads/attaches uprobe program as uprobe session.

Adding sleepable hook (uprobe.session.s) as well.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241108134544.480660-6-jolsa@kernel.org
2024-11-11 08:18:06 -08:00
Jiri Olsa
d920179b3d bpf: Add support for uprobe multi session attach
Adding support to attach BPF program for entry and return probe
of the same function. This is common use case which at the moment
requires to create two uprobe multi links.

Adding new BPF_TRACE_UPROBE_SESSION attach type that instructs
kernel to attach single link program to both entry and exit probe.

It's possible to control execution of the BPF program on return
probe simply by returning zero or non zero from the entry BPF
program execution to execute or not the BPF program on return
probe respectively.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241108134544.480660-4-jolsa@kernel.org
2024-11-11 08:18:03 -08:00
Rafael J. Wysocki
c285b11e28 Merge back thermal control material for 6.13 2024-11-11 15:20:44 +01:00
Ian Rogers
f4db95b68a tools api io: Ensure line_len_out is always initialized
Ensure initialization to avoid compiler warnings about potential use
of uninitialized variables.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Yoshihiro Furudera <fj5100bi@fujitsu.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ze Gao <zegao2021@gmail.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Junhao He <hejunhao3@huawei.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20241109003759.473460-2-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2024-11-08 22:46:44 -08:00
Kuan-Wei Chiu
ff1a39c3f8 tools/lib/list_sort: remove unnecessary header includes
Since lib/list_sort.c no longer requires ARRAY_SIZE() and memset(), the
includes for kernel.h, bug.h, and string.h have been removed.  Similarly,
tools/lib/list_sort.c also does not need to include these headers, so they
have been removed as well.

Link: https://lkml.kernel.org/r/20241012042828.471614-3-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 17:12:33 -08:00
zhang jiao
c5426dcc5a tools/lib/thermal: Remove the thermal.h soft link when doing make clean
Run "make -C tools thermal" can create a soft link for thermal.h in
tools/include/uapi/linux.  Just rm it when make clean.

Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20240912045031.18426-1-zhangjiao2@cmss.chinamobile.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-04 15:38:29 +01:00
Emil Dahl Juhl
fcd54cf480 tools/lib/thermal: Fix sampling handler context ptr
The sampling handler, provided by the user alongside a void* context,
was invoked with an internal structure instead of the user context.

Correct the invocation of the sampling handler to pass the user context
pointer instead.

Note that the approach taken is similar to that in events.c, and will
reduce the chances of this mistake happening if additional sampling
callbacks are added.

Fixes: 47c4b0de08 ("tools/lib/thermal: Add a thermal library")
Signed-off-by: Emil Dahl Juhl <emdj@bang-olufsen.dk>
Link: https://lore.kernel.org/r/20241015171826.170154-1-emdj@bang-olufsen.dk
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-11-04 15:38:29 +01:00
Andrii Nakryiko
74975e1303 libbpf: start v1.6 development cycle
With libbpf v1.5.0 release out, start v1.6 dev cycle.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241029184045.581537-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-29 13:42:52 -07:00
Ian Rogers
5ce42b5de4 tools subcmd: Add non-waitpid check_if_command_finished()
Using waitpid can cause stdout/stderr of the child process to be
lost. Use Linux's /prod/<pid>/status file to determine if the process
has reached the zombie state. Use the 'status' file rather than 'stat'
to avoid issues around skipping the process name.

Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Veronika Molnarova <vmolnaro@redhat.com>
Link: https://lore.kernel.org/r/20241025192109.132482-2-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2024-10-28 09:32:57 -07:00
Kui-Feng Lee
7aa12b8d9f libbpf: define __uptr.
Make __uptr available to BPF programs to enable them to define uptrs.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20241023234759.860539-8-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24 10:25:59 -07:00
Daniel Lezcano
7569406e95 thermal/lib: Fix memory leak on error in thermal_genl_auto()
The function thermal_genl_auto() does not free the allocated message
in the error path. Fix that by putting a out label and jump to it
which will free the message instead of directly returning an error.

Fixes: 47c4b0de08 ("tools/lib/thermal: Add a thermal library")
Reported-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20241024105938.1095358-1-daniel.lezcano@linaro.org
[ rjw: Fixed up the !msg error path, added Fixes tag ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-10-24 15:58:57 +02:00
Daniel Lezcano
a262672486 tools/lib/thermal: Add the threshold netlink ABI
The thermal framework supports the thresholds and allows the userspace
to create, delete, flush, get the list of the thresholds as well as
getting the list of the thresholds set for a specific thermal zone.

Add the netlink abstraction in the thermal library to take full
advantage of thresholds for the userspace program.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20241022155147.463475-5-daniel.lezcano@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-10-24 14:54:01 +02:00
Daniel Lezcano
24b216b2d1 tools/lib/thermal: Make more generic the command encoding function
The thermal netlink has been extended with more commands which require
an encoding with more information. The generic encoding function puts
the thermal zone id with the command name. It is the unique
parameters.

The next changes will provide more parameters to the command. Set the
scene for those new parameters by making the encoding function more
generic.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20241022155147.463475-4-daniel.lezcano@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-10-24 14:54:01 +02:00
Andrii Nakryiko
137978f422 libbpf: move global data mmap()'ing into bpf_object__load()
Since BPF skeleton inception libbpf has been doing mmap()'ing of global
data ARRAY maps in bpf_object__load_skeleton() API, which is used by
code generated .skel.h files (i.e., by BPF skeletons only).

This is wrong because if BPF object is loaded through generic
bpf_object__load() API, global data maps won't be re-mmap()'ed after
load step, and memory pointers returned from bpf_map__initial_value()
would be wrong and won't reflect the actual memory shared between BPF
program and user space.

bpf_map__initial_value() return result is rarely used after load, so
this went unnoticed for a really long time, until bpftrace project
attempted to load BPF object through generic bpf_object__load() API and
then used BPF subskeleton instantiated from such bpf_object. It turned
out that .data/.rodata/.bss data updates through such subskeleton was
"blackholed", all because libbpf wouldn't re-mmap() those maps during
bpf_object__load() phase.

Long story short, this step should be done by libbpf regardless of BPF
skeleton usage, right after BPF map is created in the kernel. This patch
moves this functionality into bpf_object__populate_internal_map() to
achieve this. And bpf_object__load_skeleton() is now simple and almost
trivial, only propagating these mmap()'ed pointers into user-supplied
skeleton structs.

We also do trivial adjustments to error reporting inside
bpf_object__populate_internal_map() for consistency with the rest of
libbpf's map-handling code.

Reported-by: Alastair Robertson <ajor@meta.com>
Reported-by: Jonathan Wiepert <jwiepert@meta.com>
Fixes: d66562fba1 ("libbpf: Add BPF object skeleton support")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241023043908.3834423-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-23 22:15:09 -07:00
Eder Zulian
7a4ffec9fd libsubcmd: Silence compiler warning
Initialize the pointer 'o' in options__order to NULL to prevent a
compiler warning/error which is observed when compiling with the '-Og'
option, but is not emitted by the compiler with the current default
compilation options.

For example, when compiling libsubcmd with

 $ make "EXTRA_CFLAGS=-Og" -C tools/lib/subcmd/ clean all

Clang version 17.0.6 and GCC 13.3.1 fail to compile parse-options.c due
to following error:

  parse-options.c: In function ‘options__order’:
  parse-options.c:832:9: error: ‘o’ may be used uninitialized [-Werror=maybe-uninitialized]
    832 |         memcpy(&ordered[nr_opts], o, sizeof(*o));
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  parse-options.c:810:30: note: ‘o’ was declared here
    810 |         const struct option *o, *p = opts;
        |                              ^
  cc1: all warnings being treated as errors

Signed-off-by: Eder Zulian <ezulian@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20241022172329.3871958-4-ezulian@redhat.com
2024-10-23 14:38:34 -07:00
Eder Zulian
7f4ec77f3f libbpf: Prevent compiler warnings/errors
Initialize 'new_off' and 'pad_bits' to 0 and 'pad_type' to  NULL in
btf_dump_emit_bit_padding to prevent compiler warnings/errors which are
observed when compiling with 'EXTRA_CFLAGS=-g -Og' options, but do not
happen when compiling with current default options.

For example, when compiling libbpf with

  $ make "EXTRA_CFLAGS=-g -Og" -C tools/lib/bpf/ clean all

Clang version 17.0.6 and GCC 13.3.1 fail to compile btf_dump.c due to
following errors:

  btf_dump.c: In function ‘btf_dump_emit_bit_padding’:
  btf_dump.c:903:42: error: ‘new_off’ may be used uninitialized [-Werror=maybe-uninitialized]
    903 |         if (new_off > cur_off && new_off <= next_off) {
        |                                  ~~~~~~~~^~~~~~~~~~~
  btf_dump.c:870:13: note: ‘new_off’ was declared here
    870 |         int new_off, pad_bits, bits, i;
        |             ^~~~~~~
  btf_dump.c:917:25: error: ‘pad_type’ may be used uninitialized [-Werror=maybe-uninitialized]
    917 |                         btf_dump_printf(d, "\n%s%s: %d;", pfx(lvl), pad_type,
        |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    918 |                                         in_bitfield ? new_off - cur_off : 0);
        |                                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  btf_dump.c:871:21: note: ‘pad_type’ was declared here
    871 |         const char *pad_type;
        |                     ^~~~~~~~
  btf_dump.c:930:20: error: ‘pad_bits’ may be used uninitialized [-Werror=maybe-uninitialized]
    930 |                 if (bits == pad_bits) {
        |                    ^
  btf_dump.c:870:22: note: ‘pad_bits’ was declared here
    870 |         int new_off, pad_bits, bits, i;
        |                      ^~~~~~~~
  cc1: all warnings being treated as errors

Signed-off-by: Eder Zulian <ezulian@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20241022172329.3871958-3-ezulian@redhat.com
2024-10-23 14:38:31 -07:00
Namhyung Kim
77b679453d Linux 6.12-rc3
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Merge tag 'v6.12-rc3' into perf-tools-next

To get the fixes in the current perf-tools tree.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2024-10-14 10:45:28 -07:00
Namhyung Kim
989a29cfed libbpf: Fix possible compiler warnings in hashmap
The hashmap__for_each_entry[_safe] is accessing 'map' as a pointer.
But it does without parentheses so passing a static hash map with an
ampersand (like '&slab_hash') will cause compiler warnings due
to unmatched types as '->' operator has a higher precedence.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241011170021.1490836-1-namhyung@kernel.org
2024-10-11 12:36:59 -07:00
Andrii Nakryiko
db089c9158 libbpf: never interpret subprogs in .text as entry programs
Libbpf pre-1.0 had a legacy logic of allowing singular non-annotated
(i.e., not having explicit SEC() annotation) function to be treated as
sole entry BPF program (unless there were other explicit entry
programs).

This behavior was dropped during libbpf 1.0 transition period (unless
LIBBPF_STRICT_SEC_NAME flag was unset in libbpf_mode). When 1.0 was
released and all the legacy behavior was removed, the bug slipped
through leaving this legacy behavior around.

Fix this for good, as it actually causes very confusing behavior if BPF
object file only has subprograms, but no entry programs.

Fixes: bd054102a8 ("libbpf: enforce strict libbpf 1.0 behaviors")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241010211731.4121837-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-11 11:15:45 -07:00
Andrii Nakryiko
4073213488 libbpf: fix sym_is_subprog() logic for weak global subprogs
sym_is_subprog() is incorrectly rejecting relocations against *weak*
global subprogs. Fix that by realizing that STB_WEAK is also a global
function.

While it seems like verifier doesn't support taking an address of
non-static subprog right now, it's still best to fix support for it on
libbpf side, otherwise users will get a very confusing error during BPF
skeleton generation or static linking due to misinterpreted relocation:

  libbpf: prog 'handle_tp': bad map relo against 'foo' in section '.text'
  Error: failed to open BPF object file: Relocation failed

It's clearly not a map relocation, but is treated and reported as such
without this fix.

Fixes: 53eddb5e04 ("libbpf: Support subprog address relocation")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241009011554.880168-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-09 18:24:11 -07:00
Eric Long
4b146e95da libbpf: Do not resolve size on duplicate FUNCs
FUNCs do not have sizes, thus currently btf__resolve_size will fail
with -EINVAL. Add conditions so that we only update size when the BTF
object is not function or function prototype.

Signed-off-by: Eric Long <i@hack3r.moe>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241002-libbpf-dup-extern-funcs-v4-1-560eb460ff90@hack3r.moe
2024-10-07 20:28:53 -07:00
Björn Töpel
710fbca820 libbpf: Add missing per-arch include path
libbpf does not include the per-arch tools include path, e.g.
tools/arch/riscv/include. Some architectures depend those files to
build properly.

Include tools/arch/$(SUBARCH)/include in the libbpf build.

Fixes: 6d74d178fe ("tools: Add riscv barrier implementation")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240927131355.350918-1-bjorn@kernel.org
2024-10-07 20:20:55 -07:00
Tony Ambardar
8ca3323dce libbpf: Support creating light skeleton of either endianness
Track target endianness in 'struct bpf_gen' and process in-memory data in
native byte-order, but on finalization convert the embedded loader BPF
insns to target endianness.

The light skeleton also includes a target-accessed data blob which is
heterogeneous and thus difficult to convert to target byte-order on
finalization. Add support functions to convert data to target endianness
as it is added to the blob.

Also add additional debug logging for data blob structure details and
skeleton loading.

Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/569562e1d5bf1cce80a1f1a3882461ee2da1ffd5.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:36 -07:00
Tony Ambardar
0aed726cf6 libbpf: Support linking bpf objects of either endianness
Allow static linking object files of either endianness, checking that input
files have consistent byte-order, and setting output endianness from input.

Linking requires in-memory processing of programs, relocations, sections,
etc. in native endianness, and output conversion to target byte-order. This
is enabled by built-in ELF translation and recent BTF/BTF.ext endianness
functions. Further add local functions for swapping byte-order of sections
containing BPF insns.

Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/b47ca686d02664843fc99b96262fe3259650bc43.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:36 -07:00
Tony Ambardar
bcc60abd67 libbpf: Support opening bpf objects of either endianness
Allow bpf_object__open() to access files of either endianness, and convert
included BPF programs to native byte-order in-memory for introspection.
Loading BPF objects of non-native byte-order is still disallowed however.

Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/26353c1a1887a54400e1acd6c138fa90c99cdd40.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:36 -07:00
Tony Ambardar
cf579164e9 libbpf: Support BTF.ext loading and output in either endianness
Support for handling BTF data of either endianness was added in [1], but
did not include BTF.ext data for lack of use cases. Later, support for
static linking [2] provided a use case, but this feature and later ones
were restricted to native-endian usage.

Add support for BTF.ext handling in either endianness. Convert BTF.ext data
to native endianness when read into memory for further processing, and
support raw data access that restores the original byte-order for output.
Add internal header functions for byte-swapping func, line, and core info
records.

Add new API functions btf_ext__endianness() and btf_ext__set_endianness()
for query and setting byte-order, as already exist for BTF data.

[1] 3289959b97 ("libbpf: Support BTF loading and raw data output in both endianness")
[2] 8fd27bf69b ("libbpf: Add BPF static linker BTF and BTF.ext support")

Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/133407ab20e0dd5c07cab2a6fa7879dee1ffa4bc.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:36 -07:00
Tony Ambardar
f896b4a539 libbpf: Fix output .symtab byte-order during linking
Object linking output data uses the default ELF_T_BYTE type for '.symtab'
section data, which disables any libelf-based translation. Explicitly set
the ELF_T_SYM type for output to restore libelf's byte-order conversion,
noting that input '.symtab' data is already correctly translated.

Fixes: faf6ed321c ("libbpf: Add BPF static linker APIs")
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/87868bfeccf3f51aec61260073f8778e9077050a.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:36 -07:00
Tony Ambardar
769ad3a61e libbpf: Fix header comment typos for BTF.ext
Mention struct btf_ext_info_sec rather than non-existent btf_sec_func_info
in BTF.ext struct documentation.

Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/cde65e01a5f2945c578485fab265ef711e2daeb6.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:36 -07:00
Tony Ambardar
e8957c0dde libbpf: Improve log message formatting
Fix missing newlines and extraneous terminal spaces in messages.

Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/086884b7cbf87e524d584f9bf87f7a580e378b2b.1726475448.git.tony.ambardar@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:36 -07:00
Chen Ni
90d0f736bd libbpf: Remove unneeded semicolon
Remove unneeded semicolon in zip_archive_open().

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240926023823.3632993-1-nichen@iscas.ac.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:35 -07:00
Tao Chen
a400d08b30 libbpf: Fix expected_attach_type set handling in program load callback
Referenced commit broke the logic of resetting expected_attach_type to
zero for allowed program types if kernel doesn't yet support such field.
We do need to overwrite and preserve expected_attach_type for
multi-uprobe though, but that can be done explicitly in
libbpf_prepare_prog_load().

Fixes: 5902da6d8a ("libbpf: Add uprobe multi link support to bpf_program__attach_usdt")
Suggested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Tao Chen <chen.dylane@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240925153012.212866-1-chen.dylane@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:35 -07:00
Ihor Solodrai
8b334d9183 libbpf: Change log level of BTF loading error message
Reduce log level of BTF loading error to INFO if BTF is not required.

Andrii says:

  Nowadays the expectation is that the BPF program will have a valid
  .BTF section, so even though .BTF is "optional", I think it's fine
  to emit a warning for that case (any reasonably recent Clang will
  produce valid BTF).

  Ihor's patch is fixing the situation with an outdated host kernel
  that doesn't understand BTF. libbpf will try to "upload" the
  program's BTF, but if that fails and the BPF object doesn't use
  any features that require having BTF uploaded, then it's just an
  information message to the user, but otherwise can be ignored.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-03 17:47:35 -07:00
Ben Gainey
80c281fca2 tools/perf: Correctly calculate sample period for inherited SAMPLE_READ values
Sample period calculation in deliver_sample_value is updated to
calculate the per-thread period delta for events that are inherit +
PERF_SAMPLE_READ. When the sampling event has this configuration, the
read_format.id is used with the tid from the sample to lookup the
storage of the previously accumulated counter total before calculating
the delta. All existing valid configurations where read_format.value
represents some global value continue to use just the read_format.id to
locate the storage of the previously accumulated total.

perf_sample_id is modified to support tracking per-thread
values, along with the existing global per-id values. In the
per-thread case, values are stored in a hash by tid within the
perf_sample_id, and are dynamically allocated as the number is not known
ahead of time.

Signed-off-by: Ben Gainey <ben.gainey@arm.com>
Cc: james.clark@arm.com
Link: https://lore.kernel.org/r/20241001121505.1009685-2-ben.gainey@arm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2024-10-02 14:58:03 -07:00
Akihiko Odaki
6490dda55d libperf: Explicitly specify install-html dependencies
install_doc of tools/lib/perf/Makefile invokes install-man,
install-html, and install-examples of
tools/lib/perf/Documentation/Makefile at once. This invocation succeeds
when make runs in serial but can fail when make runs in parallel because
while install-man of tools/lib/perf/Documentation/Makefile depends on
all, install-html depends on nothing and can run ahead of all.

Explicitly specify the dependencies of install-html to ensure that
they are resolved before install-html.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Link: https://lore.kernel.org/r/20240915-perf-v1-1-cbfd9cd1d482@daynix.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2024-09-26 15:45:48 -07:00
Linus Torvalds
aa486552a1 memblock: updates for 6.12-rc1
* new memblock_estimated_nr_free_pages() helper to replace totalram_pages()
   which is less accurate when CONFIG_DEFERRED_STRUCT_PAGE_INIT is set
 * fixes for memblock tests
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Merge tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock updates from Mike Rapoport:

 - new memblock_estimated_nr_free_pages() helper to replace
   totalram_pages() which is less accurate when
   CONFIG_DEFERRED_STRUCT_PAGE_INIT is set

 - fixes for memblock tests

* tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  s390/mm: get estimated free pages by memblock api
  kernel/fork.c: get estimated free pages by memblock api
  mm/memblock: introduce a new helper memblock_estimated_nr_free_pages()
  memblock test: fix implicit declaration of function 'strscpy'
  memblock test: fix implicit declaration of function 'isspace'
  memblock test: fix implicit declaration of function 'memparse'
  memblock test: add the definition of __setup()
  memblock test: fix implicit declaration of function 'virt_to_phys'
  tools/testing: abstract two init.h into common include directory
  memblock tests: include export.h in linkage.h as kernel dose
  memblock tests: include memory_hotplug.h in mmzone.h as kernel dose
2024-09-25 11:35:19 -07:00
Linus Torvalds
891e8abed5 perf tools improvements and fixes for v6.12:
- Use BPF + BTF to collect and pretty print syscall and tracepoint arguments in
   'perf trace', done as an GSoC activity.
 
 - Data-type profiling improvements:
 
   - Cache debuginfo to speed up data type resolution.
 
   - Add the 'typecln' sort order, to show which cacheline in a target is hot or
     cold. The following shows members in the cfs_rq's first cache line:
 
       $ perf report -s type,typecln,typeoff -H
       ...
       -    2.67%        struct cfs_rq
          +    1.23%        struct cfs_rq: cache-line 2
          +    0.57%        struct cfs_rq: cache-line 4
          +    0.46%        struct cfs_rq: cache-line 6
          -    0.41%        struct cfs_rq: cache-line 0
                  0.39%        struct cfs_rq +0x14 (h_nr_running)
                  0.02%        struct cfs_rq +0x38 (tasks_timeline.rb_leftmost)
 
   - When a typedef resolves to a unnamed struct, use the typedef name.
 
   - When a struct has just one basic type field (int, etc), resolve the type
     sort order to the name of the struct, not the type of the field.
 
   - Support type folding/unfolding in the data-type annotation TUI.
 
   - Fix bitfields offsets and sizes.
 
   - Initial support for PowerPC, using libcapstone and the usual objdump
     disassembly parsing routines.
 
 - Add support for disassembling and addr2line using the LLVM libraries,
   speeding up those operations.
 
 - Support --addr2line option in 'perf script' as with other tools.
 
 - Intel branch counters (LBR event logging) support, only available in recent
   Intel processors, for instance, the new "brcntr" field can be asked from
   'perf script' to print the information collected from this feature:
 
   $ perf script -F +brstackinsn,+brcntr
 
   # Branch counter abbr list:
   # branch-instructions:ppp = A
   # branch-misses = B
   # '-' No event occurs
   # '+' Event occurrences may be lost due to branch counter saturated
       tchain_edit  332203 3366329.405674:  53030 branch-instructions:ppp:    401781 f3+0x2c (home/sdp/test/tchain_edit)
          f3+31:
       0000000000401774   insn: eb 04                  br_cntr: AA  # PRED 5 cycles [5]
       000000000040177a   insn: 81 7d fc 0f 27 00 00
       0000000000401781   insn: 7e e3                  br_cntr: A   # PRED 1 cycles [6] 2.00 IPC
       0000000000401766   insn: 8b 45 fc
       0000000000401769   insn: 83 e0 01
       000000000040176c   insn: 85 c0
       000000000040176e   insn: 74 06                  br_cntr: A   # PRED 1 cycles [7] 4.00 IPC
       0000000000401776   insn: 83 45 fc 01
       000000000040177a   insn: 81 7d fc 0f 27 00 00
       0000000000401781   insn: 7e e3                  br_cntr: A   # PRED 7 cycles [14] 0.43 IPC
 
 - Support Timed PEBS (Precise Event-Based Sampling), a recent hardware feature
   in Intel processors.
 
 - Add 'perf ftrace profile' subcommand, using ftrace's function-graph tracer so
   that users can see the total, average, max execution time as well as the
   number of invocations easily, for instance:
 
   $ sudo perf ftrace profile -G __x64_sys_perf_event_open -- \
     perf stat -e cycles -C1 true 2> /dev/null | head
   # Total (us)  Avg (us)  Max (us)  Count  Function
         65.611    65.611    65.611      1  __x64_sys_perf_event_open
         30.527    30.527    30.527      1  anon_inode_getfile
         30.260    30.260    30.260      1  __anon_inode_getfile
         29.700    29.700    29.700      1  alloc_file_pseudo
         17.578    17.578    17.578      1  d_alloc_pseudo
         17.382    17.382    17.382      1  __d_alloc
         16.738    16.738    16.738      1  kmem_cache_alloc_lru
         15.686    15.686    15.686      1  perf_event_alloc
         14.012     7.006    11.264      2  obj_cgroup_charge
   #
 
 - 'perf sched timehist' improvements, including the addition of priority
   showing/filtering command line options.
 
 - Varios improvements to the 'perf probe', including 'perf test' regression
   testings.
 
 - Introduce the 'perf check', initially to check if some feature is in place,
   using it in 'perf test'.
 
 - Various fixes for 32-bit systems.
 
 - Address more leak sanitizer failures.
 
 - Fix memory leaks (LBR, disasm lock ops, etc).
 
 - More reference counting fixes (branch_info, etc).
 
 - Constify 'struct perf_tool' parameters to improve code generation and reduce
   the chances of having its internals changed, which isn't expected.
 
 - More constifications in various other places.
 
 - Add more build tests, including for JEVENTS.
 
 - Add more 'perf test' entries ('perf record LBR', pipe/inject, --setup-filter,
   'perf ftrace', 'cgroup sampling', etc).
 
 - Inject build ids for all entries in a call chain in 'perf inject', not just
   for the main sample.
 
 - Improve the BPF based sample filter, allowing root to setup filters in bpffs
   that then can be used by non-root users.
 
 - Allow filtering by cgroups with the BPF based sample filter.
 
 - Allow a more compact way for 'perf mem report' using the -T/--type-profile and
   also provide a --sort option similar to the one in 'perf report', 'perf top',
   to setup the sort order manually.
 
 - Fix --group behavior in 'perf annotate' when leader has no samples, where it
   was not showing anything even when other events in the group had samples.
 
 - Fix spinlock and rwlock accounting in 'perf lock contention'
 
 - Fix libsubcmd fixdep Makefile dependencies.
 
 - Improve 'perf ftrace' error message when ftrace isn't available.
 
 - Update various Intel JSON vendor event files.
 
 - ARM64 CoreSight hardware tracing infrastructure improvements, mostly not
   visible to users.
 
 - Update power10 JSON events.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-tools-for-v6.12-1-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Arnaldo Carvalho de Melo:

 - Use BPF + BTF to collect and pretty print syscall and tracepoint
   arguments in 'perf trace', done as an GSoC activity

 - Data-type profiling improvements:

     - Cache debuginfo to speed up data type resolution

     - Add the 'typecln' sort order, to show which cacheline in a target
       is hot or cold. The following shows members in the cfs_rq's first
       cache line:

         $ perf report -s type,typecln,typeoff -H
         ...
         -    2.67%        struct cfs_rq
            +    1.23%        struct cfs_rq: cache-line 2
            +    0.57%        struct cfs_rq: cache-line 4
            +    0.46%        struct cfs_rq: cache-line 6
            -    0.41%        struct cfs_rq: cache-line 0
                    0.39%        struct cfs_rq +0x14 (h_nr_running)
                    0.02%        struct cfs_rq +0x38 (tasks_timeline.rb_leftmost)

     - When a typedef resolves to a unnamed struct, use the typedef name

     - When a struct has just one basic type field (int, etc), resolve
       the type sort order to the name of the struct, not the type of
       the field

     - Support type folding/unfolding in the data-type annotation TUI

     - Fix bitfields offsets and sizes

     - Initial support for PowerPC, using libcapstone and the usual
       objdump disassembly parsing routines

 - Add support for disassembling and addr2line using the LLVM libraries,
   speeding up those operations

 - Support --addr2line option in 'perf script' as with other tools

 - Intel branch counters (LBR event logging) support, only available in
   recent Intel processors, for instance, the new "brcntr" field can be
   asked from 'perf script' to print the information collected from this
   feature:

     $ perf script -F +brstackinsn,+brcntr

     # Branch counter abbr list:
     # branch-instructions:ppp = A
     # branch-misses = B
     # '-' No event occurs
     # '+' Event occurrences may be lost due to branch counter saturated
         tchain_edit  332203 3366329.405674:  53030 branch-instructions:ppp:    401781 f3+0x2c (home/sdp/test/tchain_edit)
            f3+31:
         0000000000401774   insn: eb 04                  br_cntr: AA  # PRED 5 cycles [5]
         000000000040177a   insn: 81 7d fc 0f 27 00 00
         0000000000401781   insn: 7e e3                  br_cntr: A   # PRED 1 cycles [6] 2.00 IPC
         0000000000401766   insn: 8b 45 fc
         0000000000401769   insn: 83 e0 01
         000000000040176c   insn: 85 c0
         000000000040176e   insn: 74 06                  br_cntr: A   # PRED 1 cycles [7] 4.00 IPC
         0000000000401776   insn: 83 45 fc 01
         000000000040177a   insn: 81 7d fc 0f 27 00 00
         0000000000401781   insn: 7e e3                  br_cntr: A   # PRED 7 cycles [14] 0.43 IPC

 - Support Timed PEBS (Precise Event-Based Sampling), a recent hardware
   feature in Intel processors

 - Add 'perf ftrace profile' subcommand, using ftrace's function-graph
   tracer so that users can see the total, average, max execution time
   as well as the number of invocations easily, for instance:

     $ sudo perf ftrace profile -G __x64_sys_perf_event_open -- \
       perf stat -e cycles -C1 true 2> /dev/null | head
     # Total (us)  Avg (us)  Max (us)  Count  Function
           65.611    65.611    65.611      1  __x64_sys_perf_event_open
           30.527    30.527    30.527      1  anon_inode_getfile
           30.260    30.260    30.260      1  __anon_inode_getfile
           29.700    29.700    29.700      1  alloc_file_pseudo
           17.578    17.578    17.578      1  d_alloc_pseudo
           17.382    17.382    17.382      1  __d_alloc
           16.738    16.738    16.738      1  kmem_cache_alloc_lru
           15.686    15.686    15.686      1  perf_event_alloc
           14.012     7.006    11.264      2  obj_cgroup_charge

 - 'perf sched timehist' improvements, including the addition of
   priority showing/filtering command line options

 - Varios improvements to the 'perf probe', including 'perf test'
   regression testings

 - Introduce the 'perf check', initially to check if some feature is
   in place, using it in 'perf test'

 - Various fixes for 32-bit systems

 - Address more leak sanitizer failures

 - Fix memory leaks (LBR, disasm lock ops, etc)

 - More reference counting fixes (branch_info, etc)

 - Constify 'struct perf_tool' parameters to improve code generation
   and reduce the chances of having its internals changed, which isn't
   expected

 - More constifications in various other places

 - Add more build tests, including for JEVENTS

 - Add more 'perf test' entries ('perf record LBR', pipe/inject,
   --setup-filter, 'perf ftrace', 'cgroup sampling', etc)

 - Inject build ids for all entries in a call chain in 'perf inject',
   not just for the main sample

 - Improve the BPF based sample filter, allowing root to setup filters
   in bpffs that then can be used by non-root users

 - Allow filtering by cgroups with the BPF based sample filter

 - Allow a more compact way for 'perf mem report' using the
   -T/--type-profile and also provide a --sort option similar to the one
   in 'perf report', 'perf top', to setup the sort order manually

 - Fix --group behavior in 'perf annotate' when leader has no samples,
   where it was not showing anything even when other events in the group
   had samples

 - Fix spinlock and rwlock accounting in 'perf lock contention'

 - Fix libsubcmd fixdep Makefile dependencies

 - Improve 'perf ftrace' error message when ftrace isn't available

 - Update various Intel JSON vendor event files

 - ARM64 CoreSight hardware tracing infrastructure improvements, mostly
   not visible to users

 - Update power10 JSON events

* tag 'perf-tools-for-v6.12-1-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (310 commits)
  perf trace: Mark the 'head' arg in the set_robust_list syscall as coming from user space
  perf trace: Mark the 'rseq' arg in the rseq syscall as coming from user space
  perf env: Find correct branch counter info on hybrid
  perf evlist: Print hint for group
  tools: Drop nonsensical -O6
  perf pmu: To info add event_type_desc
  perf evsel: Add accessor for tool_event
  perf pmus: Fake PMU clean up
  perf list: Avoid potential out of bounds memory read
  perf help: Fix a typo ("bellow")
  perf ftrace: Detect whether ftrace is enabled on system
  perf test shell probe_vfs_getname: Remove extraneous '=' from probe line number regex
  perf build: Require at least clang 16.0.6 to build BPF skeletons
  perf trace: If a syscall arg is marked as 'const', assume it is coming _from_ userspace
  perf parse-events: Remove duplicated include in parse-events.c
  perf callchain: Allow symbols to be optional when resolving a callchain
  perf inject: Lazy build-id mmap2 event insertion
  perf inject: Add new mmap2-buildid-all option
  perf inject: Fix build ID injection
  perf annotate-data: Add pr_debug_scope()
  ...
2024-09-22 09:11:14 -07:00
Ihor Solodrai
ea02a94687 libbpf: Add bpf_object__token_fd accessor
Add a LIBBPF_API function to retrieve the token_fd from a bpf_object.

Without this accessor, if user needs a token FD they have to get it
manually via bpf_token_create, even though a token might have been
already created by bpf_object__load.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240913001858.3345583-1-ihor.solodrai@pm.me
2024-09-12 19:07:13 -07:00
Sam James
eb9b9a6f5a tools: Drop nonsensical -O6
-O6 is very much not-a-thing. Really, this should've been dropped
entirely in 49b3cd306e ("tools: Set the maximum optimization level
according to the compiler being used") instead of just passing it for
not-Clang.

Just collapse it down to -O3, instead of "-O6 unless Clang, in which case
-O3".

GCC interprets > -O3 as -O3. It doesn't even interpret > -O3 as -Ofast,
which is a good thing, given -Ofast has specific (non-)requirements for
code built using it. So, this does nothing except look a bit daft.

Remove the silliness and also save a few lines in the Makefiles accordingly.

Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Jesper Juhl <jesperjuhl76@gmail.com>
Signed-off-by: Sam James <sam@gentoo.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/4f01524fa4ea91c7146a41e26ceaf9dae4c127e4.1725821201.git.sam@gentoo.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-09-11 13:08:36 -03:00
Jiri Olsa
8c8b475974 libbpf: Fix uretprobe.multi.s programs auto attachment
As reported by Andrii we don't currently recognize uretprobe.multi.s
programs as return probes due to using (wrong) strcmp function.

Using str_has_pfx() instead to match uretprobe.multi prefix.

Tests are passing, because the return program was executed
as entry program and all counts were incremented properly.

Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240910125336.3056271-1-jolsa@kernel.org
2024-09-10 11:35:13 -07:00
Yusheng Zheng
41d0c4677f libbpf: Fix some typos in comments
Fix some spelling errors in the code comments of libbpf:

betwen -> between
paremeters -> parameters
knowning -> knowing
definiton -> definition
compatiblity -> compatibility
overriden -> overridden
occured -> occurred
proccess -> process
managment -> management
nessary -> necessary

Signed-off-by: Yusheng Zheng <yunwei356@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240909225952.30324-1-yunwei356@gmail.com
2024-09-09 16:05:40 -07:00
Shuyi Cheng
12707b9159 libbpf: Fixed getting wrong return address on arm64 architecture
ARM64 has a separate lr register to store the return address, so here
you only need to read the lr register to get the return address, no need
to dereference it again.

Signed-off-by: Shuyi Cheng <chengshuyi@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1725787433-77262-1-git-send-email-chengshuyi@linux.alibaba.com
2024-09-09 15:56:22 -07:00
Sam James
8a3f14bb1e libbpf: Workaround (another) -Wmaybe-uninitialized false positive
We get this with GCC 15 -O3 (at least):
```
libbpf.c: In function ‘bpf_map__init_kern_struct_ops’:
libbpf.c:1109:18: error: ‘mod_btf’ may be used uninitialized [-Werror=maybe-uninitialized]
 1109 |         kern_btf = mod_btf ? mod_btf->btf : obj->btf_vmlinux;
      |         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
libbpf.c:1094:28: note: ‘mod_btf’ was declared here
 1094 |         struct module_btf *mod_btf;
      |                            ^~~~~~~
In function ‘find_struct_ops_kern_types’,
    inlined from ‘bpf_map__init_kern_struct_ops’ at libbpf.c:1102:8:
libbpf.c:982:21: error: ‘btf’ may be used uninitialized [-Werror=maybe-uninitialized]
  982 |         kern_type = btf__type_by_id(btf, kern_type_id);
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
libbpf.c: In function ‘bpf_map__init_kern_struct_ops’:
libbpf.c:967:21: note: ‘btf’ was declared here
  967 |         struct btf *btf;
      |                     ^~~
```

This is similar to the other libbpf fix from a few weeks ago for
the same modelling-errno issue (fab45b9627).

Signed-off-by: Sam James <sam@gentoo.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://bugs.gentoo.org/939106
Link: https://lore.kernel.org/bpf/f6962729197ae7cdf4f6d1512625bd92f2322d31.1725630494.git.sam@gentoo.org
2024-09-06 14:09:24 -07:00
Lin Yikai
bd4d67f8ae libbpf: fix some typos in libbpf
Hi, fix some spelling errors in libbpf, the details are as follows:

-in the code comments:
	termintaing->terminating
	architecutre->architecture
	requring->requiring
	recored->recoded
	sanitise->sanities
	allowd->allowed
	abover->above
	see bpf_udst_arg()->see bpf_usdt_arg()

Signed-off-by: Lin Yikai <yikai.lin@vivo.com>
Link: https://lore.kernel.org/r/20240905110354.3274546-3-yikai.lin@vivo.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-09-05 13:07:47 -07:00
Pu Lehui
9985742233 libbpf: Fix accessing first syscall argument on RV64
On RV64, as Ilya mentioned before [0], the first syscall parameter should be
accessed through orig_a0 (see arch/riscv64/include/asm/syscall.h),
otherwise it will cause selftests like bpf_syscall_macro, vmlinux,
test_lsm, etc. to fail on RV64. Let's fix it by using the struct pt_regs
style CO-RE direct access.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-1-iii@linux.ibm.com [0]
Link: https://lore.kernel.org/bpf/20240831041934.1629216-5-pulehui@huaweicloud.com
2024-09-04 17:06:39 -07:00
Pu Lehui
9ab94078e8 libbpf: Access first syscall argument with CO-RE direct read on arm64
Currently PT_REGS_PARM1 SYSCALL(x) is consistent with PT_REGS_PARM1_CORE
SYSCALL(x), which will introduce the overhead of BPF_CORE_READ(), taking
into account the read pt_regs comes directly from the context, let's use
CO-RE direct read to access the first system call argument.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/bpf/20240831041934.1629216-3-pulehui@huaweicloud.com
2024-09-04 17:06:06 -07:00
Pu Lehui
e4db2a821b libbpf: Access first syscall argument with CO-RE direct read on s390
Currently PT_REGS_PARM1 SYSCALL(x) is consistent with PT_REGS_PARM1_CORE
SYSCALL(x), which will introduce the overhead of BPF_CORE_READ(), taking
into account the read pt_regs comes directly from the context, let's use
CO-RE direct read to access the first system call argument.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240831041934.1629216-2-pulehui@huaweicloud.com
2024-09-04 17:05:30 -07:00
Aditya Gupta
1a5efc9e13 libsubcmd: Don't free the usage string
Currently, commands which depend on 'parse_options_subcommand()' don't
show the usage string, and instead show '(null)'

    $ ./perf sched
	Usage: (null)

    -D, --dump-raw-trace  dump raw trace in ASCII
    -f, --force           don't complain, do it
    -i, --input <file>    input file name
    -v, --verbose         be more verbose (show symbol address, etc)

'parse_options_subcommand()' is generally expected to initialise the usage
string, with information in the passed 'subcommands[]' array

This behaviour was changed in:

  230a7a71f9 ("libsubcmd: Fix parse-options memory leak")

Where the generated usage string is deallocated, and usage[0] string is
reassigned as NULL.

As discussed in [1], free the allocated usage string in the main
function itself, and don't reset usage string to NULL in
parse_options_subcommand

With this change, the behaviour is restored.

    $ ./perf sched
        Usage: perf sched [<options>] {record|latency|map|replay|script|timehist}

           -D, --dump-raw-trace  dump raw trace in ASCII
           -f, --force           don't complain, do it
           -i, --input <file>    input file name
           -v, --verbose         be more verbose (show symbol address, etc)

[1]: https://lore.kernel.org/linux-perf-users/htq5vhx6piet4nuq2mmhk7fs2bhfykv52dbppwxmo3s7du2odf@styd27tioc6e/

Fixes: 230a7a71f9 ("libsubcmd: Fix parse-options memory leak")
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240904061836.55873-2-adityag@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-09-04 09:54:24 -03:00
Tony Ambardar
da18bfa59d libbpf: Ensure new BTF objects inherit input endianness
New split BTF needs to preserve base's endianness. Similarly, when
creating a distilled BTF, we need to preserve original endianness.

Fix by updating libbpf's btf__distill_base() and btf_new_empty() to retain
the byte order of any source BTF objects when creating new ones.

Fixes: ba451366bf ("libbpf: Implement basic split BTF support")
Fixes: 58e185a0dc ("libbpf: Add btf__distill_base() creating split BTF with distilled base BTF")
Reported-by: Song Liu <song@kernel.org>
Reported-by: Eduard Zingerman <eddyz87@gmail.com>
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/6358db36c5f68b07873a0a5be2d062b1af5ea5f8.camel@gmail.com/
Link: https://lore.kernel.org/bpf/20240830095150.278881-1-tony.ambardar@gmail.com
2024-08-30 10:41:01 -07:00
Andrii Nakryiko
c634d6f4e1 libbpf: Fix bpf_object__open_skeleton()'s mishandling of options
We do an ugly copying of options in bpf_object__open_skeleton() just to
be able to set object name from skeleton's recorded name (while still
allowing user to override it through opts->object_name).

This is not just ugly, but it also is broken due to memcpy() that
doesn't take into account potential skel_opts' and user-provided opts'
sizes differences due to backward and forward compatibility. This leads
to copying over extra bytes and then failing to validate options
properly. It could, technically, lead also to SIGSEGV, if we are unlucky.

So just get rid of that memory copy completely and instead pass
default object name into bpf_object_open() directly, simplifying all
this significantly. The rule now is that obj_name should be non-NULL for
bpf_object_open() when called with in-memory buffer, so validate that
explicitly as well.

We adopt bpf_object__open_mem() to this as well and generate default
name (based on buffer memory address and size) outside of bpf_object_open().

Fixes: d66562fba1 ("libbpf: Add BPF object skeleton support")
Reported-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Daniel Müller <deso@posteo.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240827203721.1145494-1-andrii@kernel.org
2024-08-29 17:47:27 +02:00
Alexei Starovoitov
50c374c6d1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR including
important fixes (from bpf-next point of view):
commit 41c24102af ("selftests/bpf: Filter out _GNU_SOURCE when compiling test_cpp")
commit fdad456cbc ("bpf: Fix updating attached freplace prog in prog_array map")

No conflicts.

Adjacent changes in:
include/linux/bpf_verifier.h
kernel/bpf/verifier.c
tools/testing/selftests/bpf/Makefile

Link: https://lore.kernel.org/bpf/20240813234307.82773-1-alexei.starovoitov@gmail.com/
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-08-22 09:48:44 -07:00
Sam James
fab45b9627 libbpf: Workaround -Wmaybe-uninitialized false positive
In `elf_close`, we get this with GCC 15 -O3 (at least):
```
In function ‘elf_close’,
    inlined from ‘elf_close’ at elf.c:53:6,
    inlined from ‘elf_find_func_offset_from_file’ at elf.c:384:2:
elf.c:57:9: warning: ‘elf_fd.elf’ may be used uninitialized [-Wmaybe-uninitialized]
   57 |         elf_end(elf_fd->elf);
      |         ^~~~~~~~~~~~~~~~~~~~
elf.c: In function ‘elf_find_func_offset_from_file’:
elf.c:377:23: note: ‘elf_fd.elf’ was declared here
  377 |         struct elf_fd elf_fd;
      |                       ^~~~~~
In function ‘elf_close’,
    inlined from ‘elf_close’ at elf.c:53:6,
    inlined from ‘elf_find_func_offset_from_file’ at elf.c:384:2:
elf.c:58:9: warning: ‘elf_fd.fd’ may be used uninitialized [-Wmaybe-uninitialized]
   58 |         close(elf_fd->fd);
      |         ^~~~~~~~~~~~~~~~~
elf.c: In function ‘elf_find_func_offset_from_file’:
elf.c:377:23: note: ‘elf_fd.fd’ was declared here
  377 |         struct elf_fd elf_fd;
      |                       ^~~~~~
```

In reality, our use is fine, it's just that GCC doesn't model errno
here (see linked GCC bug). Suppress -Wmaybe-uninitialized accordingly
by initializing elf_fd.fd to -1 and elf_fd.elf to NULL.

I've done this in two other functions as well given it could easily
occur there too (same access/use pattern).

Signed-off-by: Sam James <sam@gentoo.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://gcc.gnu.org/PR114952
Link: https://lore.kernel.org/bpf/14ec488a1cac02794c2fa2b83ae0cef1bce2cb36.1723578546.git.sam@gentoo.org
2024-08-15 15:56:40 -07:00
Alan Maguire
4a4c013d33 libbpf: Fix license for btf_relocate.c
License should be

// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)

...as with other libbpf files.

Fixes: 19e00c897d ("libbpf: Split BTF relocation")
Reported-by: Neill Kapron <nkapron@google.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240810093504.2111134-1-alan.maguire@oracle.com
2024-08-12 13:18:25 -07:00
Wei Yang
a88cde5769 memblock test: fix implicit declaration of function 'memparse'
Commit 1e4c64b71c ("mm/memblock: Add "reserve_mem" to reserved named
memory at boot up") introduce the usage of memparse(), which is not
defined in memblock test.

Add the definition and link it to fix the build.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Link: https://lore.kernel.org/r/20240806010319.29194-3-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2024-08-06 08:21:25 +03:00
Brian Norris
dbb2a7a986 tools build: Correct bpf fixdep dependencies
The dependencies in tools/lib/bpf/Makefile are incorrect. Before we
recurse to build $(BPF_IN_STATIC), we need to build its 'fixdep'
executable.

I can't use the usual shortcut from Makefile.include:

  <target>: <sources> fixdep

because its 'fixdep' target relies on $(OUTPUT), and $(OUTPUT) differs
in the parent 'make' versus the child 'make' -- so I imitate it via
open-coding.

I tweak a few $(MAKE) invocations while I'm at it, because
1. I'm adding a new recursive make; and
2. these recursive 'make's print spurious lines about files that are "up
   to date" (which isn't normally a feature in Kbuild subtargets) or
   "jobserver not available" (see [1])

I also need to tweak the assignment of the OUTPUT variable, so that
relative path builds work. For example, for 'make tools/lib/bpf', OUTPUT
is unset, and is usually treated as "cwd" -- but recursive make will
change cwd and so OUTPUT has a new meaning. For consistency, I ensure
OUTPUT is always an absolute path.

And $(Q) gets a backup definition in tools/build/Makefile.include,
because Makefile.include is sometimes included without
tools/build/Makefile, so the "quiet command" stuff doesn't actually work
consistently without it.

After this change, top-level builds result in an empty grep result from:

  $ grep 'cannot find fixdep' $(find tools/ -name '*.cmd')

[1] https://www.gnu.org/software/make/manual/html_node/MAKE-Variable.html
If we're not using $(MAKE) directly, then we need to use more '+'.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20240715203325.3832977-4-briannorris@chromium.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-08-05 12:19:48 -03:00
Brian Norris
96f30c8f0a tools build: Correct libsubcmd fixdep dependencies
All built targets need fixdep to be built first, before handling object
dependencies [1]. We're missing one such dependency before the libsubcmd
target.

This resolves .cmd file generation issues such that the following
sequence produces many fewer results:

  $ git clean -xfd tools/
  $ make tools/objtool
  $ grep "cannot find fixdep" $(find tools/objtool -name '*.cmd')

In particular, only a buggy tools/objtool/libsubcmd/.fixdep.o.cmd
remains, due to circular dependencies of fixdep on itself.

Such incomplete .cmd files don't usually cause a direct problem, since
they're designed to fail "open", but they can cause some subtle problems
that would otherwise be handled by proper fixdep'd dependency files. [2]

[1] This problem is better described in commit abb26210a3 ("perf
tools: Force fixdep compilation at the start of the build"). I don't
apply its solution here, because additional recursive make can be a bit
of overkill.

[2] Example failure case:

  cp -arl linux-src linux-src2
  cd linux-src2
  make O=/path/to/out
  cd ../linux-src
  rm -rf ../linux-src2
  make O=/path/to/out

Previously, we'd see errors like:

  make[6]: *** No rule to make target
  '/path/to/linux-src2/tools/include/linux/compiler.h', needed by
  '/path/to/out/tools/bpf/resolve_btfids/libsubcmd/exec-cmd.o'.  Stop.

Now, the properly-fixdep'd .cmd files will ignore a missing
/path/to/linux-src2/...

Signed-off-by: Brian Norris <briannorris@chromium.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/all/ZGVi9HbI43R5trN8@bhelgaas/
Link: https://lore.kernel.org/all/Zk-C5Eg84yt6_nml@google.com/
Link: https://lore.kernel.org/r/20240715203325.3832977-2-briannorris@chromium.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-08-05 12:08:29 -03:00
Tiezhu Yang
b48543c451 perf list: Give clues if failed to open tracing events directory
When executing the command "perf list", I met "Error: failed to open
tracing events directory" twice, the first reason is that there is no
"/sys/kernel/tracing/events" directory due to it does not enable the
kernel tracing infrastructure with CONFIG_FTRACE, the second reason
is that there is no root privileges.

Add the error string to tell the users what happened and what should
to do, and also call put_tracing_file() to free events_path a little
later to avoid messy code in the error message.

At the same time, just remove the redundant "/" of the file path in
the function get_tracing_file(), otherwise it shows something like
"/sys/kernel/tracing//events".

Before:

  $ ./perf list
  Error: failed to open tracing events directory

After:

(1) Without CONFIG_FTRACE

  $ ./perf list
  Error: failed to open tracing events directory
  /sys/kernel/tracing/events: No such file or directory

(2) With CONFIG_FTRACE but no root privileges

  $ ./perf list
  Error: failed to open tracing events directory
  /sys/kernel/tracing/events: Permission denied

Committer testing:

Redirect stdout to null to quickly test the patch:

Before:

  $ perf list > /dev/null
  Error: failed to open tracing events directory
  $

After:

  $ perf list > /dev/null
  Error: failed to open tracing events directory
  /sys/kernel/tracing/events: Permission denied
  $

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/20240730062301.23244-3-yangtiezhu@loongson.cn
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-08-01 12:11:33 -03:00
Charlie Jenkins
d261f9ebcf libperf: Add gitignore
Ignore files that are generated by libperf and libperf tests.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/20240729-libperf_gitignore-v1-1-1c70dd98edf9@rivosinc.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-08-01 12:11:33 -03:00
Athira Rajeev
06dd4c5a56 perf annotate: Add disasm_line__parse() to parse raw instruction for powerpc
Currently, the perf tool infrastructure uses the disasm_line__parse
function to parse disassembled line.

Example snippet from objdump:

  objdump  --start-address=<address> --stop-address=<address>  -d --no-show-raw-insn -C <vmlinux>

  c0000000010224b4:	lwz     r10,0(r9)

This line "lwz r10,0(r9)" is parsed to extract instruction name,
registers names and offset.

In powerpc, the approach for data type profiling uses raw instruction
instead of result from objdump to identify the instruction category and
extract the source/target registers.

Example: 38 01 81 e8     ld      r4,312(r1)

Here "38 01 81 e8" is the raw instruction representation. Add function
"disasm_line__parse_powerpc" to handle parsing of raw instruction.
Also update "struct disasm_line" to save the binary code/
With the change, function captures:

line -> "38 01 81 e8     ld      r4,312(r1)"
raw instruction "38 01 81 e8"

Raw instruction is used later to extract the reg/offset fields. Macros
are added to extract opcode and register fields. "struct disasm_line"
is updated to carry union of "bytes" and "raw_insn" of 32 bit to carry raw
code (raw).

Function "disasm_line__parse_powerpc fills the raw instruction hex value
and can use macros to get opcode. There is no changes in existing code
paths, which parses the disassembled code.  The size of raw instruction
depends on architecture.

In case of powerpc, the parsing the disasm line needs to handle cases
for reading binary code directly from DSO as well as parsing the objdump
result. Hence adding the logic into separate function instead of
updating "disasm_line__parse".  The architecture using the instruction
name and present approach is not altered. Since this approach targets
powerpc, the macro implementation is added for powerpc as of now.

Since the disasm_line__parse is used in other cases (perf annotate) and
not only data tye profiling, the powerpc callback includes changes to
work with binary code as well as mnemonic representation.

Also in case if the DSO read fails and libcapstone is not supported, the
approach fallback to use objdump as option. Hence as option, patch has
changes to ensure objdump option also works well.

Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Kajol Jain <kjain@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Akanksha J N <akanksha@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Link: https://lore.kernel.org/lkml/20240718084358.72242-5-atrajeev@linux.vnet.ibm.com
[ Add check for strndup() result ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-07-31 16:12:59 -03:00
David Vernet
04a94133f1 libbpf: Don't take direct pointers into BTF data from st_ops
In struct bpf_struct_ops, we have take a pointer to a BTF type name, and
a struct btf_type. This was presumably done for convenience, but can
actually result in subtle and confusing bugs given that BTF data can be
invalidated before a program is loaded. For example, in sched_ext, we
may sometimes resize a data section after a skeleton has been opened,
but before the struct_ops scheduler map has been loaded. This may cause
the BTF data to be realloc'd, which can then cause a UAF when loading
the program because the struct_ops map has pointers directly into the
BTF data.

We're already storing the BTF type_id in struct bpf_struct_ops. Because
type_id is stable, we can therefore just update the places where we were
looking at those pointers to instead do the lookups we need from the
type_id.

Fixes: 590a008882 ("bpf: libbpf: Add STRUCT_OPS support")
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240724171459.281234-1-void@manifault.com
2024-07-29 15:05:09 -07:00
Linus Torvalds
51c4767503 bitmap-6.11-rc1
Random fixes for v6.11.
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Merge tag 'bitmap-6.11-rc1' of https://github.com:/norov/linux

Pull bitmap updates from Yury Norov:
 "Random fixes"

* tag 'bitmap-6.11-rc1' of https://github.com:/norov/linux:
  riscv: Remove unnecessary int cast in variable_fls()
  radix tree test suite: put definition of bitmap_clear() into lib/bitmap.c
  bitops: Add a comment explaining the double underscore macros
  lib: bitmap: add missing MODULE_DESCRIPTION() macros
  cpumask: introduce assign_cpu() macro
2024-07-26 09:50:36 -07:00
Linus Torvalds
1722389b0d A lot of networking people were at a conference last week, busy
catching COVID, so relatively short PR. Including fixes from bpf
 and netfilter.
 
 Current release - regressions:
 
  - tcp: process the 3rd ACK with sk_socket for TFO and MPTCP
 
 Current release - new code bugs:
 
  - l2tp: protect session IDR and tunnel session list with one lock,
    make sure the state is coherent to avoid a warning
 
  - eth: bnxt_en: update xdp_rxq_info in queue restart logic
 
  - eth: airoha: fix location of the MBI_RX_AGE_SEL_MASK field
 
 Previous releases - regressions:
 
  - xsk: require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len,
    the field reuses previously un-validated pad
 
 Previous releases - always broken:
 
  - tap/tun: drop short frames to prevent crashes later in the stack
 
  - eth: ice: add a per-VF limit on number of FDIR filters
 
  - af_unix: disable MSG_OOB handling for sockets in sockmap/sockhash
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf and netfilter.

  A lot of networking people were at a conference last week, busy
  catching COVID, so relatively short PR.

  Current release - regressions:

   - tcp: process the 3rd ACK with sk_socket for TFO and MPTCP

  Current release - new code bugs:

   - l2tp: protect session IDR and tunnel session list with one lock,
     make sure the state is coherent to avoid a warning

   - eth: bnxt_en: update xdp_rxq_info in queue restart logic

   - eth: airoha: fix location of the MBI_RX_AGE_SEL_MASK field

  Previous releases - regressions:

   - xsk: require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len,
     the field reuses previously un-validated pad

  Previous releases - always broken:

   - tap/tun: drop short frames to prevent crashes later in the stack

   - eth: ice: add a per-VF limit on number of FDIR filters

   - af_unix: disable MSG_OOB handling for sockets in sockmap/sockhash"

* tag 'net-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (34 commits)
  tun: add missing verification for short frame
  tap: add missing verification for short frame
  mISDN: Fix a use after free in hfcmulti_tx()
  gve: Fix an edge case for TSO skb validity check
  bnxt_en: update xdp_rxq_info in queue restart logic
  tcp: process the 3rd ACK with sk_socket for TFO/MPTCP
  selftests/bpf: Add XDP_UMEM_TX_METADATA_LEN to XSK TX metadata test
  xsk: Require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len
  bpf: Fix a segment issue when downgrading gso_size
  net: mediatek: Fix potential NULL pointer dereference in dummy net_device handling
  MAINTAINERS: make Breno the netconsole maintainer
  MAINTAINERS: Update bonding entry
  net: nexthop: Initialize all fields in dumped nexthops
  net: stmmac: Correct byte order of perfect_match
  selftests: forwarding: skip if kernel not support setting bridge fdb learning limit
  tipc: Return non-zero value from tipc_udp_addr2str() on error
  netfilter: nft_set_pipapo_avx2: disable softinterrupts
  ice: Fix recipe read procedure
  ice: Add a per-VF limit on number of FDIR filters
  net: bonding: correctly annotate RCU in bond_should_notify_peers()
  ...
2024-07-25 13:32:25 -07:00
Jakub Kicinski
f7578df913 bpf-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2024-07-25

We've added 14 non-merge commits during the last 8 day(s) which contain
a total of 19 files changed, 177 insertions(+), 70 deletions(-).

The main changes are:

1) Fix af_unix to disable MSG_OOB handling for sockets in BPF sockmap and
   BPF sockhash. Also add test coverage for this case, from Michal Luczaj.

2) Fix a segmentation issue when downgrading gso_size in the BPF helper
   bpf_skb_adjust_room(), from Fred Li.

3) Fix a compiler warning in resolve_btfids due to a missing type cast,
   from Liwei Song.

4) Fix stack allocation for arm64 to align the stack pointer at a 16 byte
   boundary in the fexit_sleep BPF selftest, from Puranjay Mohan.

5) Fix a xsk regression to require a flag when actuating tx_metadata_len,
   from Stanislav Fomichev.

6) Fix function prototype BTF dumping in libbpf for prototypes that have
   no input arguments, from Andrii Nakryiko.

7) Fix stacktrace symbol resolution in perf script for BPF programs
   containing subprograms, from Hou Tao.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Add XDP_UMEM_TX_METADATA_LEN to XSK TX metadata test
  xsk: Require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len
  bpf: Fix a segment issue when downgrading gso_size
  tools/resolve_btfids: Fix comparison of distinct pointer types warning in resolve_btfids
  bpf, events: Use prog to emit ksymbol event for main program
  selftests/bpf: Test sockmap redirect for AF_UNIX MSG_OOB
  selftests/bpf: Parametrize AF_UNIX redir functions to accept send() flags
  selftests/bpf: Support SOCK_STREAM in unix_inet_redir_to_connected()
  af_unix: Disable MSG_OOB handling for sockets in sockmap/sockhash
  bpftool: Fix typo in usage help
  libbpf: Fix no-args func prototype BTF dumping syntax
  MAINTAINERS: Update powerpc BPF JIT maintainers
  MAINTAINERS: Update email address of Naveen
  selftests/bpf: fexit_sleep: Fix stack allocation for arm64
====================

Link: https://patch.msgid.link/20240725114312.32197-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-25 07:40:25 -07:00
Linus Torvalds
527eff227d - In the series "treewide: Refactor heap related implementation",
Kuan-Wei Chiu has significantly reworked the min_heap library code and
   has taught bcachefs to use the new more generic implementation.
 
 - Yury Norov's series "Cleanup cpumask.h inclusion in core headers"
   reworks the cpumask and nodemask headers to make things generally more
   rational.
 
 - Kuan-Wei Chiu has sent along some maintenance work against our sorting
   library code in the series "lib/sort: Optimizations and cleanups".
 
 - More library maintainance work from Christophe Jaillet in the series
   "Remove usage of the deprecated ida_simple_xx() API".
 
 - Ryusuke Konishi continues with the nilfs2 fixes and clanups in the
   series "nilfs2: eliminate the call to inode_attach_wb()".
 
 - Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix GDB
   command error".
 
 - Plus the usual shower of singleton patches all over the place.  Please
   see the relevant changelogs for details.
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Merge tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - In the series "treewide: Refactor heap related implementation",
   Kuan-Wei Chiu has significantly reworked the min_heap library code
   and has taught bcachefs to use the new more generic implementation.

 - Yury Norov's series "Cleanup cpumask.h inclusion in core headers"
   reworks the cpumask and nodemask headers to make things generally
   more rational.

 - Kuan-Wei Chiu has sent along some maintenance work against our
   sorting library code in the series "lib/sort: Optimizations and
   cleanups".

 - More library maintainance work from Christophe Jaillet in the series
   "Remove usage of the deprecated ida_simple_xx() API".

 - Ryusuke Konishi continues with the nilfs2 fixes and clanups in the
   series "nilfs2: eliminate the call to inode_attach_wb()".

 - Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix
   GDB command error".

 - Plus the usual shower of singleton patches all over the place. Please
   see the relevant changelogs for details.

* tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (98 commits)
  ia64: scrub ia64 from poison.h
  watchdog/perf: properly initialize the turbo mode timestamp and rearm counter
  tsacct: replace strncpy() with strscpy()
  lib/bch.c: use swap() to improve code
  test_bpf: convert comma to semicolon
  init/modpost: conditionally check section mismatch to __meminit*
  init: remove unused __MEMINIT* macros
  nilfs2: Constify struct kobj_type
  nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro
  math: rational: add missing MODULE_DESCRIPTION() macro
  lib/zlib: add missing MODULE_DESCRIPTION() macro
  fs: ufs: add MODULE_DESCRIPTION()
  lib/rbtree.c: fix the example typo
  ocfs2: add bounds checking to ocfs2_check_dir_entry()
  fs: add kernel-doc comments to ocfs2_prepare_orphan_dir()
  coredump: simplify zap_process()
  selftests/fpu: add missing MODULE_DESCRIPTION() macro
  compiler.h: simplify data_race() macro
  build-id: require program headers to be right after ELF header
  resource: add missing MODULE_DESCRIPTION()
  ...
2024-07-21 17:56:22 -07:00
Linus Torvalds
68b5973045 perf tools changes for v6.11
Build
 -----
 * Build each directory as a library so that depedency check for the
   python extension module can be automatic.  But it also introduces
   some trivial merge conflicts with other trees that touched perf tools
   codes.  Basically it changes perf-y to perf-util-y or similar and you
   can find the resolution in the perf-next tree here.
 
   - https://lore.kernel.org/r/Zn8HeRRX3JV2IcxQ@sirena.org.uk
   - https://lore.kernel.org/r/20240709100536.238f4d12@canb.auug.org.au
 
 * Use pkg-config to check libtraceevent and libtracefs.
 
 perf sched
 ----------
 * Add --task-name and --fuzzy-name options for `perf sched map`.  It's
   to focus on selected tasks only by removing unrelated tasks in the
   output.  It matches the task comm with the given string and the
   --fuzzy-name option allows the partial matching.
 
     $ sudo perf sched record -a sleep 1
 
     $ sudo perf sched map --task-name kworker --fuzzy-name
        .   .   .   .   -  *A0  .   .    481065.315131 secs A0 => kworker/5:2-i91:438521
        .   .   .   .   -  *-   .   .    481065.315160 secs
       *B0  .   .   .   -   .   .   .    481065.316435 secs B0 => kworker/0:0-i91:437860
       *-   .   .   .   .   .   .   .    481065.316441 secs
        .   .   .   .   .  *A0  .   .    481065.318703 secs
        .   .   .   .   .  *-   .   .    481065.318717 secs
        .   .  *C0  .   .   .   .   .    481065.320544 secs C0 => kworker/u16:30-:430186
        .   .  *-   .   .   .   .   .    481065.320555 secs
        .   .  *D0  .   .   .   .   .    481065.328524 secs D0 => kworker/2:0-kdm:429654
       *B0  .   D0  .   -   .   .   .    481065.328527 secs
       *-   .   D0  .   -   .   .   .    481065.328535 secs
        .   .  *-   .   .   .   .   .    481065.328535 secs
 
 * Fix -r/--repeat option of perf sched replay.  The documentation said
   -1 will work as infinity but it didn't accept the value.  Update the
   code and document to use 0 instead.
 
 * Fix perf sched timehist to account the delay time for preempted tasks.
 
 Perf event filtering
 --------------------
 * perf top gained filtering support on regular events using BPF like
   perf record.  Previously it was able to use it for tracepoints only.
 
 * The BPF filter now supports filtering by UID/GID.  This should be
   preferred than -u <UID> option as it's racy to scan /proc to check
   tasks for the user and fails to open an event for the task if it's
   already gone.
 
     $ sudo perf top -e cycles --filter "uid == $(id -u)"
 
 perf report
 -----------
 * Skip dummy events in the group output by default.  The --skip-empty
   option controls display of empty events without samples.  But perf
   report can force display all events in a group.  In this case, auto-
   added a dummy event (for a system-wide record) ends up in the output.
   Now it can skip those empty events even in the group display mode.
   To preserve the old behavior, run this:
 
     $ perf report --group --no-skip-empty
 
 perf stat
 ---------
 * Choose the most disaggregate option when multiple aggregation options
   are given.  It used to pick the last option in the command line but
   it can be confusing and not consistent.  Now it'll choose the smallest
   unit.
 
   For example, it'd aggregate the result per-core when the user gave
   both --per-socket and --per-core options at the same time.
 
 Internals
 ---------
 * Fix `perf bench` when some CPUs are offline.
 
 * Fix handling of JIT symbol mappings to accept "/tmp/perf-${PID}.map
   patterns only so that it can not be confused by other /tmp/perf-*
   files.
 
 * Many improvements and fixes for `perf test`.
 
 Others
 ------
 * Support some new instructions for Intel-PT.
 * Fix syscall ID mapping in perf trace.
 * Document AMD IBS PMU usages.
 * Change `perf lock info` to show map and thread info by default.
 
 Vendor JSON events
 ------------------
 * Update Intel events and metrics
 * Add i.MX9[35] DDR metrics
 
 Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-for-v6.11-2024-07-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Namhyung Kim:
 "Build:

   - Build each directory as a library so that depedency check for the
     python extension module can be automatic

   - Use pkg-config to check libtraceevent and libtracefs

  perf sched:

   - Add --task-name and --fuzzy-name options for `perf sched map`

     It focuses on selected tasks only by removing unrelated tasks in
     the output. It matches the task comm with the given string and the
     --fuzzy-name option allows the partial matching:

       $ sudo perf sched record -a sleep 1

       $ sudo perf sched map --task-name kworker --fuzzy-name
          .   .   .   .   -  *A0  .   .    481065.315131 secs A0 => kworker/5:2-i91:438521
          .   .   .   .   -  *-   .   .    481065.315160 secs
         *B0  .   .   .   -   .   .   .    481065.316435 secs B0 => kworker/0:0-i91:437860
         *-   .   .   .   .   .   .   .    481065.316441 secs
          .   .   .   .   .  *A0  .   .    481065.318703 secs
          .   .   .   .   .  *-   .   .    481065.318717 secs
          .   .  *C0  .   .   .   .   .    481065.320544 secs C0 => kworker/u16:30-:430186
          .   .  *-   .   .   .   .   .    481065.320555 secs
          .   .  *D0  .   .   .   .   .    481065.328524 secs D0 => kworker/2:0-kdm:429654
         *B0  .   D0  .   -   .   .   .    481065.328527 secs
         *-   .   D0  .   -   .   .   .    481065.328535 secs
          .   .  *-   .   .   .   .   .    481065.328535 secs

   - Fix -r/--repeat option of perf sched replay

     The documentation said -1 will work as infinity but it didn't
     accept the value. Update the code and document to use 0 instead

   - Fix perf sched timehist to account the delay time for preempted
     tasks

  Perf event filtering:

   - perf top gained filtering support on regular events using BPF like
     perf record. Previously it was able to use it for tracepoints only

   - The BPF filter now supports filtering by UID/GID. This should be
     preferred than -u <UID> option as it's racy to scan /proc to check
     tasks for the user and fails to open an event for the task if it's
     already gone

       $ sudo perf top -e cycles --filter "uid == $(id -u)"

  perf report:

   - Skip dummy events in the group output by default. The --skip-empty
     option controls display of empty events without samples. But perf
     report can force display all events in a group

     In this case, auto-added a dummy event (for a system-wide record)
     ends up in the output. Now it can skip those empty events even in
     the group display mode

     To preserve the old behavior, run this:

       $ perf report --group --no-skip-empty

  perf stat:

   - Choose the most disaggregate option when multiple aggregation
     options are given. It used to pick the last option in the command
     line but it can be confusing and not consistent. Now it'll choose
     the smallest unit

     For example, it'd aggregate the result per-core when the user gave
     both --per-socket and --per-core options at the same time

  Internals:

   - Fix `perf bench` when some CPUs are offline

   - Fix handling of JIT symbol mappings to accept "/tmp/perf-${PID}.map
     patterns only so that it can not be confused by other /tmp/perf-*
     files

   - Many improvements and fixes for `perf test`

  Others:

   - Support some new instructions for Intel-PT

   - Fix syscall ID mapping in perf trace

   - Document AMD IBS PMU usages

   - Change `perf lock info` to show map and thread info by default

  Vendor JSON events:

   - Update Intel events and metrics

   - Add i.MX9[35] DDR metrics"

* tag 'perf-tools-for-v6.11-2024-07-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (125 commits)
  perf trace: Fix iteration of syscall ids in syscalltbl->entries
  perf dso: Fix address sanitizer build
  perf mem: Warn if memory events are not supported on all CPUs
  perf arm-spe: Support multiple Arm SPE PMUs
  perf build x86: Fix SC2034 error in syscalltbl.sh
  perf record: Fix memset out-of-range error
  perf sched map: Add --fuzzy-name option for fuzzy matching in task names
  perf sched map: Add support for multiple task names using CSV
  perf sched map: Add task-name option to filter the output map
  perf build: Conditionally add feature check flags for libtrace{event,fs}
  perf install: Don't propagate subdir to Documentation submake
  perf vendor events arm64:: Add i.MX95 DDR Performance Monitor metrics
  perf vendor events arm64:: Add i.MX93 DDR Performance Monitor metrics
  perf dsos: When adding a dso into sorted dsos maintain the sort order
  perf comm str: Avoid sort during insert
  perf report: Calling available function for stats printing
  perf intel-pt: Fix exclude_guest setting
  perf intel-pt: Fix aux_watermark calculation for 64-bit size
  perf sched replay: Fix -r/--repeat command line option for infinity
  perf: pmus: Remove unneeded semicolon
  ...
2024-07-18 14:16:35 -07:00
Andrii Nakryiko
189f1a976e libbpf: Fix no-args func prototype BTF dumping syntax
For all these years libbpf's BTF dumper has been emitting not strictly
valid syntax for function prototypes that have no input arguments.

Instead of `int (*blah)()` we should emit `int (*blah)(void)`.

This is not normally a problem, but it manifests when we get kfuncs in
vmlinux.h that have no input arguments. Due to compiler internal
specifics, we get no BTF information for such kfuncs, if they are not
declared with proper `(void)`.

The fix is trivial. We also need to adjust a few ancient tests that
happily assumed `()` is correct.

Fixes: 351131b51c ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://lore.kernel.org/bpf/20240712224442.282823-1-andrii@kernel.org
2024-07-17 22:42:47 +02:00
Wei Yang
692a68ee9c radix tree test suite: put definition of bitmap_clear() into lib/bitmap.c
In tools/ directory, function bitmap_clear() is currently only used in
object file tools/testing/radix-tree/xarray.o.

But instead of keeping a bitmap.c with only bitmap_clear() definition in
radix-tree's own directory, it would be more proper to put it in common
directory lib/.

Sync the kernel definition and link some related libs, no functional
change is expected.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Matthew Wilcox <willy@infradead.org>
CC: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
2024-07-10 14:24:27 -07:00
Andrii Nakryiko
a459f4bb27 libbpf: improve old BPF skeleton handling for map auto-attach
Improve how we handle old BPF skeletons when it comes to BPF map
auto-attachment. Emit one warn-level message per each struct_ops map
that could have been auto-attached, if user provided recent enough BPF
skeleton version. Don't spam log if there are no relevant struct_ops
maps, though.

This should help users realize that they probably need to regenerate BPF
skeleton header with more recent bpftool/libbpf-cargo (or whatever other
means of BPF skeleton generation).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240708204540.4188946-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-09 19:03:36 -07:00
Andrii Nakryiko
99fb953188 libbpf: fix BPF skeleton forward/backward compat handling
BPF skeleton was designed from day one to be extensible. Generated BPF
skeleton code specifies actual sizes of map/prog/variable skeletons for
that reason and libbpf is supposed to work with newer/older versions
correctly.

Unfortunately, it was missed that we implicitly embed hard-coded most
up-to-date (according to libbpf's version of libbpf.h header used to
compile BPF skeleton header) sizes of those structs, which can differ
from the actual sizes at runtime when libbpf is used as a shared
library.

We have a few places were we just index array of maps/progs/vars, which
implicitly uses these potentially invalid sizes of structs.

This patch aims to fix this problem going forward. Once this lands,
we'll backport these changes in Github repo to create patched releases
for older libbpfs.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Fixes: d66562fba1 ("libbpf: Add BPF object skeleton support")
Fixes: 430025e5dc ("libbpf: Add subskeleton scaffolding")
Fixes: 08ac454e25 ("libbpf: Auto-attach struct_ops BPF maps in BPF skeleton")
Co-developed-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240708204540.4188946-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-07-09 19:03:24 -07:00
Andreas Ziegler
cedc12c5b5 libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
In the current state, an erroneous call to
bpf_object__find_map_by_name(NULL, ...) leads to a segmentation
fault through the following call chain:

  bpf_object__find_map_by_name(obj = NULL, ...)
  -> bpf_object__for_each_map(pos, obj = NULL)
  -> bpf_object__next_map((obj = NULL), NULL)
  -> return (obj = NULL)->maps

While calling bpf_object__find_map_by_name with obj = NULL is
obviously incorrect, this should not lead to a segmentation
fault but rather be handled gracefully.

As __bpf_map__iter already handles this situation correctly, we
can delegate the check for the regular case there and only add
a check in case the prev or next parameter is NULL.

Signed-off-by: Andreas Ziegler <ziegler.andreas@siemens.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240703083436.505124-1-ziegler.andreas@siemens.com
2024-07-08 18:13:07 +02:00
Namhyung Kim
74ad3cb08b Merge remote-tracking branch 'perf-tools' into perf-tools-next
Merge fixes and updates in v6.10 into perf-tools-next to resolve changes
in synthesizing the LOST_SAMPLES records and build fixes.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2024-07-02 11:51:32 -07:00
Alan Maguire
5b747c23f1 libbpf: Fix error handling in btf__distill_base()
Coverity points out that after calling btf__new_empty_split() the wrong
value is checked for error.

Fixes: 58e185a0dc ("libbpf: Add btf__distill_base() creating split BTF with distilled base BTF")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240629100058.2866763-1-alan.maguire@oracle.com
2024-07-01 17:05:08 +02:00
Alan Maguire
0f31c2c61f libbpf: Fix clang compilation error in btf_relocate.c
When building with clang for ARCH=i386, the following errors are
observed:

  CC      kernel/bpf/btf_relocate.o
./tools/lib/bpf/btf_relocate.c:206:23: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
  206 |                 info[id].needs_size = true;
      |                                     ^ ~
./tools/lib/bpf/btf_relocate.c:256:25: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion]
  256 |                         base_info.needs_size = true;
      |                                              ^ ~
2 errors generated.

The problem is we use 1-bit, 31-bit bitfields in a signed int.
Changing to

	bool needs_size: 1;
	unsigned int size:31;

...resolves the error and pahole reports that 4 bytes are used
for the underlying representation:

$ pahole btf_name_info tools/lib/bpf/btf_relocate.o
struct btf_name_info {
	const char  *              name;                 /*     0     8 */
	unsigned int               needs_size:1;         /*     8: 0  4 */
	unsigned int               size:31;              /*     8: 1  4 */
	__u32                      id;                   /*    12     4 */

	/* size: 16, cachelines: 1, members: 4 */
	/* last cacheline: 16 bytes */
};

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240624192903.854261-1-alan.maguire@oracle.com
2024-06-26 16:38:59 -07:00
Kuan-Wei Chiu
6d74e1e371 tools/lib/list_sort: remove redundant code for cond_resched handling
Since cond_resched() is not called in userspace, remove the redundant code
in userspace's list_sort() implementation.  This change eliminates the
unused 'count' variable and the associated logic for invoking cmp()
periodically, which was intended to trigger cond_resched() in kernel
space.

The removed code includes:
- Declaration and increment of the 'count' variable.
- Conditional invocation of cmp() based on 'count'.

This cleanup simplifies merge_final(), avoids unnecessary overhead, and
has no impact on the functionality of list_sort() in userspace.

Link: https://lkml.kernel.org/r/20240525230206.1077536-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24 22:25:04 -07:00
Antoine Tenart
c73a9683cb libbpf: Skip base btf sanity checks
When upgrading to libbpf 1.3 we noticed a big performance hit while
loading programs using CORE on non base-BTF symbols. This was tracked
down to the new BTF sanity check logic. The issue is the base BTF
definitions are checked first for the base BTF and then again for every
module BTF.

Loading 5 dummy programs (using libbpf-rs) that are using CORE on a
non-base BTF symbol on my system:
- Before this fix: 3s.
- With this fix: 0.1s.

Fix this by only checking the types starting at the BTF start id. This
should ensure the base BTF is still checked as expected but only once
(btf->start_id == 1 when creating the base BTF), and then only
additional types are checked for each module BTF.

Fixes: 3903802bb9 ("libbpf: Add basic BTF sanity validation")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20240624090908.171231-1-atenart@kernel.org
2024-06-24 09:19:42 -07:00
Alan Maguire
8646db2389 libbpf,bpf: Share BTF relocate-related code with kernel
Share relocation implementation with the kernel.  As part of this,
we also need the type/string iteration functions so also share
btf_iter.c file. Relocation code in kernel and userspace is identical
save for the impementation of the reparenting of split BTF to the
relocated base BTF and retrieval of the BTF header from "struct btf";
these small functions need separate user-space and kernel implementations
for the separate "struct btf"s they operate upon.

One other wrinkle on the kernel side is we have to map .BTF.ids in
modules as they were generated with the type ids used at BTF encoding
time. btf_relocate() optionally returns an array mapping from old BTF
ids to relocated ids, so we use that to fix up these references where
needed for kfuncs.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240620091733.1967885-5-alan.maguire@oracle.com
2024-06-21 14:45:07 -07:00
Alan Maguire
e7ac331b30 libbpf: Split field iter code into its own file kernel
This will allow it to be shared with the kernel.  No functional change.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240620091733.1967885-4-alan.maguire@oracle.com
2024-06-21 14:45:07 -07:00
Alan Maguire
d1cf840854 libbpf: BTF relocation followup fixing naming, loop logic
Use less verbose names in BTF relocation code and fix off-by-one error
and typo in btf_relocate.c.  Simplify loop over matching distilled
types, moving from assigning a _next value in loop body to moving
match check conditions into the guard.

Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240620091733.1967885-2-alan.maguire@oracle.com
2024-06-21 14:45:07 -07:00
Donglin Peng
cc5083d1f3 libbpf: Checking the btf_type kind when fixing variable offsets
I encountered an issue when building the test_progs from the repository [1]:

  $ pwd
  /work/Qemu/x86_64/linux-6.10-rc2/tools/testing/selftests/bpf/

  $ make test_progs V=1
  [...]
  ./tools/sbin/bpftool gen object ./ip_check_defrag.bpf.linked2.o ./ip_check_defrag.bpf.linked1.o
  libbpf: failed to find symbol for variable 'bpf_dynptr_slice' in section '.ksyms'
  Error: failed to link './ip_check_defrag.bpf.linked1.o': No such file or directory (2)
  [...]

Upon investigation, I discovered that the btf_types referenced in the '.ksyms'
section had a kind of BTF_KIND_FUNC instead of BTF_KIND_VAR:

  $ bpftool btf dump file ./ip_check_defrag.bpf.linked1.o
  [...]
  [2] DATASEC '.ksyms' size=0 vlen=2
        type_id=16 offset=0 size=0 (FUNC 'bpf_dynptr_from_skb')
        type_id=17 offset=0 size=0 (FUNC 'bpf_dynptr_slice')
  [...]
  [16] FUNC 'bpf_dynptr_from_skb' type_id=82 linkage=extern
  [17] FUNC 'bpf_dynptr_slice' type_id=85 linkage=extern
  [...]

For a detailed analysis, please refer to [2]. We can add a kind checking to
fix the issue.

  [1] https://github.com/eddyz87/bpf/tree/binsort-btf-dedup
  [2] https://lore.kernel.org/all/0c0ef20c-c05e-4db9-bad7-2cbc0d6dfae7@oracle.com/

Fixes: 8fd27bf69b ("libbpf: Add BPF static linker BTF and BTF.ext support")
Signed-off-by: Donglin Peng <dolinux.peng@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240619122355.426405-1-dolinux.peng@gmail.com
2024-06-21 20:00:17 +02:00
Eduard Zingerman
c86f180ffc libbpf: Make btf_parse_elf process .BTF.base transparently
Update btf_parse_elf() to check if .BTF.base section is present.
The logic is as follows:

  if .BTF.base section exists:
     distilled_base := btf_new(.BTF.base)
  if distilled_base:
     btf := btf_new(.BTF, .base_btf=distilled_base)
     if base_btf:
        btf_relocate(btf, base_btf)
  else:
     btf := btf_new(.BTF)
  return btf

In other words:
- if .BTF.base section exists, load BTF from it and use it as a base
  for .BTF load;
- if base_btf is specified and .BTF.base section exist, relocate newly
  loaded .BTF against base_btf.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240613095014.357981-6-alan.maguire@oracle.com
2024-06-17 14:38:31 -07:00
Alan Maguire
19e00c897d libbpf: Split BTF relocation
Map distilled base BTF type ids referenced in split BTF and their
references to the base BTF passed in, and if the mapping succeeds,
reparent the split BTF to the base BTF.

Relocation is done by first verifying that distilled base BTF
only consists of named INT, FLOAT, ENUM, FWD, STRUCT and
UNION kinds; then we sort these to speed lookups.  Once sorted,
the base BTF is iterated, and for each relevant kind we check
for an equivalent in distilled base BTF.  When found, the
mapping from distilled -> base BTF id and string offset is recorded.
In establishing mappings, we need to ensure we check STRUCT/UNION
size when the STRUCT/UNION is embedded in a split BTF STRUCT/UNION,
and when duplicate names exist for the same STRUCT/UNION.  Otherwise
size is ignored in matching STRUCT/UNIONs.

Once all mappings are established, we can update type ids
and string offsets in split BTF and reparent it to the new base.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240613095014.357981-4-alan.maguire@oracle.com
2024-06-17 14:38:31 -07:00
Alan Maguire
58e185a0dc libbpf: Add btf__distill_base() creating split BTF with distilled base BTF
To support more robust split BTF, adding supplemental context for the
base BTF type ids that split BTF refers to is required.  Without such
references, a simple shuffling of base BTF type ids (without any other
significant change) invalidates the split BTF.  Here the attempt is made
to store additional context to make split BTF more robust.

This context comes in the form of distilled base BTF providing minimal
information (name and - in some cases - size) for base INTs, FLOATs,
STRUCTs, UNIONs, ENUMs and ENUM64s along with modified split BTF that
points at that base and contains any additional types needed (such as
TYPEDEF, PTR and anonymous STRUCT/UNION declarations).  This
information constitutes the minimal BTF representation needed to
disambiguate or remove split BTF references to base BTF.  The rules
are as follows:

- INT, FLOAT, FWD are recorded in full.
- if a named base BTF STRUCT or UNION is referred to from split BTF, it
  will be encoded as a zero-member sized STRUCT/UNION (preserving
  size for later relocation checks).  Only base BTF STRUCT/UNIONs
  that are either embedded in split BTF STRUCT/UNIONs or that have
  multiple STRUCT/UNION instances of the same name will _need_ size
  checks at relocation time, but as it is possible a different set of
  types will be duplicates in the later to-be-resolved base BTF,
  we preserve size information for all named STRUCT/UNIONs.
- if an ENUM[64] is named, a ENUM forward representation (an ENUM
  with no values) of the same size is used.
- in all other cases, the type is added to the new split BTF.

Avoiding struct/union/enum/enum64 expansion is important to keep the
distilled base BTF representation to a minimum size.

When successful, new representations of the distilled base BTF and new
split BTF that refers to it are returned.  Both need to be freed by the
caller.

So to take a simple example, with split BTF with a type referring
to "struct sk_buff", we will generate distilled base BTF with a
0-member STRUCT sk_buff of the appropriate size, and the split BTF
will refer to it instead.

Tools like pahole can utilize such split BTF to populate the .BTF
section (split BTF) and an additional .BTF.base section.  Then
when the split BTF is loaded, the distilled base BTF can be used
to relocate split BTF to reference the current (and possibly changed)
base BTF.

So for example if "struct sk_buff" was id 502 when the split BTF was
originally generated,  we can use the distilled base BTF to see that
id 502 refers to a "struct sk_buff" and replace instances of id 502
with the current (relocated) base BTF sk_buff type id.

Distilled base BTF is small; when building a kernel with all modules
using distilled base BTF as a test, overall module size grew by only
5.3Mb total across ~2700 modules.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240613095014.357981-2-alan.maguire@oracle.com
2024-06-17 14:38:31 -07:00
Ian Rogers
6c1785cd75 perf record: Ensure space for lost samples
Previous allocation didn't account for sample ID written after the
lost samples event. Switch from malloc/free to a stack allocation.

Reported-by: Milian Wolff <milian.wolff@kdab.com>
Closes: https://lore.kernel.org/linux-perf-users/23879991.0LEYPuXRzz@milian-workstation/
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240611050626.1223155-1-irogers@google.com
2024-06-13 20:45:31 -07:00
Jakub Kicinski
b1156532bc bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-06-06

We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 50 files changed, 1887 insertions(+), 527 deletions(-).

The main changes are:

1) Add a user space notification mechanism via epoll when a struct_ops
   object is getting detached/unregistered, from Kui-Feng Lee.

2) Big batch of BPF selftest refactoring for sockmap and BPF congctl
   tests, from Geliang Tang.

3) Add BTF field (type and string fields, right now) iterator support
   to libbpf instead of using existing callback-based approaches,
   from Andrii Nakryiko.

4) Extend BPF selftests for the latter with a new btf_field_iter
   selftest, from Alan Maguire.

5) Add new kfuncs for a generic, open-coded bits iterator,
   from Yafang Shao.

6) Fix BPF selftests' kallsyms_find() helper under kernels configured
   with CONFIG_LTO_CLANG_THIN, from Yonghong Song.

7) Remove a bunch of unused structs in BPF selftests,
   from David Alan Gilbert.

8) Convert test_sockmap section names into names understood by libbpf
   so it can deduce program type and attach type, from Jakub Sitnicki.

9) Extend libbpf with the ability to configure log verbosity
   via LIBBPF_LOG_LEVEL environment variable, from Mykyta Yatsenko.

10) Fix BPF selftests with regards to bpf_cookie and find_vma flakiness
    in nested VMs, from Song Liu.

11) Extend riscv32/64 JITs to introduce shift/add helpers to generate Zba
    optimization, from Xiao Wang.

12) Enable BPF programs to declare arrays and struct fields with kptr,
    bpf_rb_root, and bpf_list_head, from Kui-Feng Lee.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
  selftests/bpf: Drop useless arguments of do_test in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp_fallback in bpf_tcp_ca
  selftests/bpf: Add start_test helper in bpf_tcp_ca
  selftests/bpf: Use connect_to_fd_opts in do_test in bpf_tcp_ca
  libbpf: Auto-attach struct_ops BPF maps in BPF skeleton
  selftests/bpf: Add btf_field_iter selftests
  selftests/bpf: Fix send_signal test with nested CONFIG_PARAVIRT
  libbpf: Remove callback-based type/string BTF field visitor helpers
  bpftool: Use BTF field iterator in btfgen
  libbpf: Make use of BTF field iterator in BTF handling code
  libbpf: Make use of BTF field iterator in BPF linker code
  libbpf: Add BTF field iterator
  selftests/bpf: Ignore .llvm.<hash> suffix in kallsyms_find()
  selftests/bpf: Fix bpf_cookie and find_vma in nested VM
  selftests/bpf: Test global bpf_list_head arrays.
  selftests/bpf: Test global bpf_rb_root arrays and fields in nested struct types.
  selftests/bpf: Test kptr arrays and kptrs in nested struct fields.
  bpf: limit the number of levels of a nested struct type.
  bpf: look into the types of the fields of a struct type recursively.
  ...
====================

Link: https://lore.kernel.org/r/20240606223146.23020-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-10 18:02:14 -07:00
Mykyta Yatsenko
08ac454e25 libbpf: Auto-attach struct_ops BPF maps in BPF skeleton
Similarly to `bpf_program`, support `bpf_map` automatic attachment in
`bpf_object__attach_skeleton`. Currently only struct_ops maps could be
attached.

On bpftool side, code-generate links in skeleton struct for struct_ops maps.
Similarly to `bpf_program_skeleton`, set links in `bpf_map_skeleton`.

On libbpf side, extend `bpf_map` with new `autoattach` field to support
enabling or disabling autoattach functionality, introducing
getter/setter for this field.

`bpf_object__(attach|detach)_skeleton` is extended with
attaching/detaching struct_ops maps logic.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240605175135.117127-1-yatsenko@meta.com
2024-06-06 10:06:05 -07:00
Andrii Nakryiko
0720887044 libbpf: Remove callback-based type/string BTF field visitor helpers
Now that all libbpf/bpftool code switched to btf_field_iter, remove
btf_type_visit_type_ids() and btf_type_visit_str_offs() callback-based
helpers as not needed anymore.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240605001629.4061937-6-andrii@kernel.org
2024-06-05 16:54:45 +02:00
Andrii Nakryiko
c264112369 libbpf: Make use of BTF field iterator in BTF handling code
Use new BTF field iterator logic to replace all the callback-based
visitor calls. There is still a .BTF.ext callback-based visitor APIs
that should be converted, which will happens as a follow up.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240605001629.4061937-4-andrii@kernel.org
2024-06-05 16:54:37 +02:00
Andrii Nakryiko
2bce2c1cb2 libbpf: Make use of BTF field iterator in BPF linker code
Switch all BPF linker code dealing with iterating BTF type ID and string
offset fields to new btf_field_iter facilities.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240605001629.4061937-3-andrii@kernel.org
2024-06-05 16:54:32 +02:00
Andrii Nakryiko
68153bb2ff libbpf: Add BTF field iterator
Implement iterator-based type ID and string offset BTF field iterator.
This is used extensively in BTF-handling code and BPF linker code for
various sanity checks, rewriting IDs/offsets, etc. Currently this is
implemented as visitor pattern calling custom callbacks, which makes the
logic (especially in simple cases) unnecessarily obscure and harder to
follow.

Having equivalent functionality using iterator pattern makes for simpler
to understand and maintain code. As we add more code for BTF processing
logic in libbpf, it's best to switch to iterator pattern before adding
more callback-based code.

The idea for iterator-based implementation is to record offsets of
necessary fields within fixed btf_type parts (which should be iterated
just once), and, for kinds that have multiple members (based on vlen
field), record where in each member necessary fields are located.

Generic iteration code then just keeps track of last offset that was
returned and handles N members correctly. Return type is just u32
pointer, where NULL is returned when all relevant fields were already
iterated.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240605001629.4061937-2-andrii@kernel.org
2024-06-05 16:54:26 +02:00
Andrii Nakryiko
531876c800 libbpf: keep FD_CLOEXEC flag when dup()'ing FD
Make sure to preserve and/or enforce FD_CLOEXEC flag on duped FDs.
Use dup3() with O_CLOEXEC flag for that.

Without this fix libbpf effectively clears FD_CLOEXEC flag on each of BPF
map/prog FD, which is definitely not the right or expected behavior.

Reported-by: Lennart Poettering <lennart@poettering.net>
Fixes: bc308d011a ("libbpf: call dup2() syscall directly")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240529223239.504241-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-31 20:35:55 -07:00
Andrii Nakryiko
7d0b3953f6 libbpf: don't close(-1) in multi-uprobe feature detector
Guard close(link_fd) with extra link_fd >= 0 check to prevent close(-1).

Detected by Coverity static analysis.

Fixes: 04d939a2ab ("libbpf: detect broken PID filtering logic for multi-uprobe")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240529231212.768828-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-31 14:56:51 -07:00
Ian Rogers
d163d60258 tools api io: Move filling the io buffer to its own function
In general a read fills 4kb so filling the buffer is a 1 in 4096
operation, move it out of the io__get_char function to avoid some
checking overhead and to better hint the function is good to inline.

For perf's IO intensive internal (non-rigorous) benchmarks there's a
small improvement to kallsyms-parsing with a default build.

Before:
```
$ perf bench internals all
Computing performance of single threaded perf event synthesis by
synthesizing events on the perf process itself:
  Average synthesis took: 146.322 usec (+- 0.305 usec)
  Average num. events: 61.000 (+- 0.000)
  Average time per event 2.399 usec
  Average data synthesis took: 145.056 usec (+- 0.155 usec)
  Average num. events: 329.000 (+- 0.000)
  Average time per event 0.441 usec

  Average kallsyms__parse took: 162.313 ms (+- 0.599 ms)
...
Computing performance of sysfs PMU event scan for 100 times
  Average core PMU scanning took: 53.720 usec (+- 7.823 usec)
  Average PMU scanning took: 375.145 usec (+- 23.974 usec)
```
After:
```
$ perf bench internals all
Computing performance of single threaded perf event synthesis by
synthesizing events on the perf process itself:
  Average synthesis took: 127.829 usec (+- 0.079 usec)
  Average num. events: 61.000 (+- 0.000)
  Average time per event 2.096 usec
  Average data synthesis took: 133.652 usec (+- 0.101 usec)
  Average num. events: 327.000 (+- 0.000)
  Average time per event 0.409 usec

  Average kallsyms__parse took: 150.415 ms (+- 0.313 ms)
...
Computing performance of sysfs PMU event scan for 100 times
  Average core PMU scanning took: 47.790 usec (+- 1.178 usec)
  Average PMU scanning took: 376.945 usec (+- 23.683 usec)
```

Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240519181716.4088459-1-irogers@google.com
2024-05-30 10:05:34 -07:00
Mykyta Yatsenko
eb4e772627 libbpf: Configure log verbosity with env variable
Configure logging verbosity by setting LIBBPF_LOG_LEVEL environment
variable, which is applied only to default logger. Once user set their
custom logging callback, it is up to them to handle filtering.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240524131840.114289-1-yatsenko@meta.com
2024-05-28 16:25:06 -07:00
Jakub Kicinski
2786ae339e bpf-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2024-05-27

We've added 15 non-merge commits during the last 7 day(s) which contain
a total of 18 files changed, 583 insertions(+), 55 deletions(-).

The main changes are:

1) Fix broken BPF multi-uprobe PID filtering logic which filtered by thread
   while the promise was to filter by process, from Andrii Nakryiko.

2) Fix the recent influx of syzkaller reports to sockmap which triggered
   a locking rule violation by performing a map_delete, from Jakub Sitnicki.

3) Fixes to netkit driver in particular on skb->pkt_type override upon pass
   verdict, from Daniel Borkmann.

4) Fix an integer overflow in resolve_btfids which can wrongly trigger build
   failures, from Friedrich Vock.

5) Follow-up fixes for ARC JIT reported by static analyzers,
   from Shahab Vahedi.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Cover verifier checks for mutating sockmap/sockhash
  Revert "bpf, sockmap: Prevent lock inversion deadlock in map delete elem"
  bpf: Allow delete from sockmap/sockhash only if update is allowed
  selftests/bpf: Add netkit test for pkt_type
  selftests/bpf: Add netkit tests for mac address
  netkit: Fix pkt_type override upon netkit pass verdict
  netkit: Fix setting mac address in l2 mode
  ARC, bpf: Fix issues reported by the static analyzers
  selftests/bpf: extend multi-uprobe tests with USDTs
  selftests/bpf: extend multi-uprobe tests with child thread case
  libbpf: detect broken PID filtering logic for multi-uprobe
  bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic
  bpf: fix multi-uprobe PID filtering logic
  bpf: Fix potential integer overflow in resolve_btfids
  MAINTAINERS: Add myself as reviewer of ARM64 BPF JIT
====================

Link: https://lore.kernel.org/r/20240527203551.29712-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-27 16:26:30 -07:00
Andrii Nakryiko
04d939a2ab libbpf: detect broken PID filtering logic for multi-uprobe
Libbpf is automatically (and transparently to user) detecting
multi-uprobe support in the kernel, and, if supported, uses
multi-uprobes to improve USDT attachment speed.

USDTs can be attached system-wide or for the specific process by PID. In
the latter case, we rely on correct kernel logic of not triggering USDT
for unrelated processes.

As such, on older kernels that do support multi-uprobes, but still have
broken PID filtering logic, we need to fall back to singular uprobes.

Unfortunately, whether user is using PID filtering or not is known at
the attachment time, which happens after relevant BPF programs were
loaded into the kernel. Also unfortunately, we need to make a call
whether to use multi-uprobes or singular uprobe for SEC("usdt") programs
during BPF object load time, at which point we have no information about
possible PID filtering.

The distinction between single and multi-uprobes is small, but important
for the kernel. Multi-uprobes get BPF_TRACE_UPROBE_MULTI attach type,
and kernel internally substitiute different implementation of some of
BPF helpers (e.g., bpf_get_attach_cookie()) depending on whether uprobe
is multi or singular. So, multi-uprobes and singular uprobes cannot be
intermixed.

All the above implies that we have to make an early and conservative
call about the use of multi-uprobes. And so this patch modifies libbpf's
existing feature detector for multi-uprobe support to also check correct
PID filtering. If PID filtering is not yet fixed, we fall back to
singular uprobes for USDTs.

This extension to feature detection is simple thanks to kernel's -EINVAL
addition for pid < 0.

Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-25 10:46:02 -07:00
Linus Torvalds
29c73fc794 perf tools fixes and improvements for v6.10:
- Add Kan Liang to MAINTAINERS as a perf tools reviewer.
 
 - Add support for using the 'capstone' disassembler library in various tools,
   such as 'perf script' and 'perf annotate'. This is an alternative for the
   use of the 'xed' and 'objdump' disassemblers.
 
 - Data-type profiling improvements:
 
   Resolve types for a->b->c by backtracking the assignments until it finds
   DWARF info for one of those members
 
   Support for global variables, keeping a cache to speed up lookups.
 
   Handle the 'call' instruction, dealing with effects on registers and handling
   its return when tracking register data types.
 
   Handle x86's segment based addressing like %gs:0x28, to support things like
   per CPU variables, the stack canary, etc.
 
   Data-type profiling got big speedups when using capstone for disassembling.
   The objdump outoput parsing method is left as a fallback when capstone fails or
   isn't available. There are patches posted for 6.11 that to use a LLVM
   disassembler.
 
   Support event group display in the TUI when annotating types with --data-type,
   for instance to show memory load and store events for the data type fields.
 
   Optimize the 'perf annotate' data structures, reducing memory usage.
 
   Add a initial 'perf test' for 'perf annotate', checking that a target symbol
   appears on the output, specifying objdump via the command line, etc.
 
 - Integrate the shellcheck utility with the build of perf to allow catching
   shell problems early in areas such as 'perf test', 'perf trace' scrape
   scripts, etc.
 
 - Add 'uretprobe' variant in the 'perf bench uprobe' tool.
 
 - Add script to run instances of 'perf script' in parallel.
 
 - Allow parsing tracepoint names that start with digits, such as
   9p/9p_client_req, etc. Make sure 'perf test' tests it even on systems
   where those tracepoints aren't available.
 
 Vendor Events:
 
 - Update Intel JSON files for Cascade Lake X, Emerald Rapids, Grand Ridge, Ice
   Lake X, Lunar Lake, Meteor Lake, Sapphire Rapids, Sierra Forest, Sky Lake X,
   Sky Lake and Snow Ridge X.  Remove info metrics erroneously in TopdownL1.
 
 - Add AMD's Zen 5 core and uncore events and metrics. Those come from the
   "Performance Monitor Counters for AMD Family 1Ah Model 00h- 0Fh Processors"
   document, with events that capture information on op dispatch, execution and
   retirement, branch prediction, L1 and L2 cache activity, TLB activity, etc.
 
 - Mark L1D_CACHE_INVAL impacted by errata for ARM64's AmpereOne/AmpereOneX.
 
 Miscellaneous:
 
 - Sync header copies with the kernel sources.
 
 - Move some header copies used only for generating translation string tables
   for ioctl cmds and other syscall integer arguments to a new directory under
   tools/perf/beauty/, to separate from copies in tools/include/ that are used
   to build the tools.
 
 - Introduce scrape script for several syscall 'flags'/'mask' arguments.
 
 - Improve cpumap utilization, fixing up pairing of refcounts, using the right
   iterators (perf_cpu_map__for_each_cpu), etc.
 
 - Give more details about raw event encodings in 'perf list', show tracepoint
   encoding in the detailed output.
 
 - Refactor the DSOs handling code, reducing memory usage.
 
 - Document the BPF event modifier and add a 'perf test' for it.
 
 - Improve the event parser, better error messages and add further 'perf test's
   for it.
 
 - Add reference count checking to 'struct comm_str' and 'struct mem_info'.
 
 - Make ARM64's 'perf test' entries for the Neoverse N1 more robust.
 
 - Tweak the ARM64's Coresight 'perf test's.
 
 - Improve ARM64's CoreSight ETM version detection and error reporting.
 
 - Fix handling of symbols when using kcore.
 
 - Fix PAI (Processor Activity Instrumentation) counter names for s390 virtual
   machines in 'perf report'.
 
 - Fix -g/--call-graph option failure in 'perf sched timehist'.
 
 - Add LIBTRACEEVENT_DIR build option to allow building with libtraceevent
   installed in non-standard directories, such as when doing cross builds.
 
 - Various 'perf test' and 'perf bench' fixes.
 
 - Improve 'perf probe' error message for long C++ probe names.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-tools-for-v6.10-1-2024-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Arnaldo Carvalho de Melo:
 "General:

   - Integrate the shellcheck utility with the build of perf to allow
     catching shell problems early in areas such as 'perf test', 'perf
     trace' scrape scripts, etc

   - Add 'uretprobe' variant in the 'perf bench uprobe' tool

   - Add script to run instances of 'perf script' in parallel

   - Allow parsing tracepoint names that start with digits, such as
     9p/9p_client_req, etc. Make sure 'perf test' tests it even on
     systems where those tracepoints aren't available

   - Add Kan Liang to MAINTAINERS as a perf tools reviewer

   - Add support for using the 'capstone' disassembler library in
     various tools, such as 'perf script' and 'perf annotate'. This is
     an alternative for the use of the 'xed' and 'objdump' disassemblers

  Data-type profiling improvements:

   - Resolve types for a->b->c by backtracking the assignments until it
     finds DWARF info for one of those members

   - Support for global variables, keeping a cache to speed up lookups

   - Handle the 'call' instruction, dealing with effects on registers
     and handling its return when tracking register data types

   - Handle x86's segment based addressing like %gs:0x28, to support
     things like per CPU variables, the stack canary, etc

   - Data-type profiling got big speedups when using capstone for
     disassembling. The objdump outoput parsing method is left as a
     fallback when capstone fails or isn't available. There are patches
     posted for 6.11 that to use a LLVM disassembler

   - Support event group display in the TUI when annotating types with
     --data-type, for instance to show memory load and store events for
     the data type fields

   - Optimize the 'perf annotate' data structures, reducing memory usage

   - Add a initial 'perf test' for 'perf annotate', checking that a
     target symbol appears on the output, specifying objdump via the
     command line, etc

  Vendor Events:

   - Update Intel JSON files for Cascade Lake X, Emerald Rapids, Grand
     Ridge, Ice Lake X, Lunar Lake, Meteor Lake, Sapphire Rapids, Sierra
     Forest, Sky Lake X, Sky Lake and Snow Ridge X. Remove info metrics
     erroneously in TopdownL1

   - Add AMD's Zen 5 core and uncore events and metrics. Those come from
     the "Performance Monitor Counters for AMD Family 1Ah Model 00h- 0Fh
     Processors" document, with events that capture information on op
     dispatch, execution and retirement, branch prediction, L1 and L2
     cache activity, TLB activity, etc

   - Mark L1D_CACHE_INVAL impacted by errata for ARM64's AmpereOne/
     AmpereOneX

  Miscellaneous:

   - Sync header copies with the kernel sources

   - Move some header copies used only for generating translation string
     tables for ioctl cmds and other syscall integer arguments to a new
     directory under tools/perf/beauty/, to separate from copies in
     tools/include/ that are used to build the tools

   - Introduce scrape script for several syscall 'flags'/'mask'
     arguments

   - Improve cpumap utilization, fixing up pairing of refcounts, using
     the right iterators (perf_cpu_map__for_each_cpu), etc

   - Give more details about raw event encodings in 'perf list', show
     tracepoint encoding in the detailed output

   - Refactor the DSOs handling code, reducing memory usage

   - Document the BPF event modifier and add a 'perf test' for it

   - Improve the event parser, better error messages and add further
     'perf test's for it

   - Add reference count checking to 'struct comm_str' and 'struct
     mem_info'

   - Make ARM64's 'perf test' entries for the Neoverse N1 more robust

   - Tweak the ARM64's Coresight 'perf test's

   - Improve ARM64's CoreSight ETM version detection and error reporting

   - Fix handling of symbols when using kcore

   - Fix PAI (Processor Activity Instrumentation) counter names for s390
     virtual machines in 'perf report'

   - Fix -g/--call-graph option failure in 'perf sched timehist'

   - Add LIBTRACEEVENT_DIR build option to allow building with
     libtraceevent installed in non-standard directories, such as when
     doing cross builds

   - Various 'perf test' and 'perf bench' fixes

   - Improve 'perf probe' error message for long C++ probe names"

* tag 'perf-tools-for-v6.10-1-2024-05-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (260 commits)
  tools lib subcmd: Show parent options in help
  perf pmu: Count sys and cpuid JSON events separately
  perf stat: Don't display metric header for non-leader uncore events
  perf annotate-data: Ensure the number of type histograms
  perf annotate: Fix segfault on sample histogram
  perf daemon: Fix file leak in daemon_session__control
  libsubcmd: Fix parse-options memory leak
  perf lock: Avoid memory leaks from strdup()
  perf sched: Rename 'switches' column header to 'count' and add usage description, options for latency
  perf tools: Ignore deleted cgroups
  perf parse: Allow tracepoint names to start with digits
  perf parse-events: Add new 'fake_tp' parameter for tests
  perf parse-events: pass parse_state to add_tracepoint
  perf symbols: Fix ownership of string in dso__load_vmlinux()
  perf symbols: Update kcore map before merging in remaining symbols
  perf maps: Re-use __maps__free_maps_by_name()
  perf symbols: Remove map from list before updating addresses
  perf tracepoint: Don't scan all tracepoints to test if one exists
  perf dwarf-aux: Fix build with HAVE_DWARF_CFI_SUPPORT
  perf thread: Fixes to thread__new() related to initializing comm
  ...
2024-05-21 15:45:14 -07:00
Linus Torvalds
eb6a9339ef Mainly singleton patches, documented in their respective changelogs.
Notable series include:
 
 - Some maintenance and performance work for ocfs2 in Heming Zhao's
   series "improve write IO performance when fragmentation is high".
 
 - Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
   exposed by fstests".
 
 - kfifo header rework from Andy Shevchenko in the series "kfifo: Clean
   up kfifo.h".
 
 - GDB script fixes from Florian Rommel in the series "scripts/gdb: Fixes
   for $lx_current and $lx_per_cpu".
 
 - After much discussion, a coding-style update from Barry Song
   explaining one reason why inline functions are preferred over macros.
   The series is "codingstyle: avoid unused parameters for a function-like
   macro".
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Merge tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-mm updates from Andrew Morton:
 "Mainly singleton patches, documented in their respective changelogs.
  Notable series include:

   - Some maintenance and performance work for ocfs2 in Heming Zhao's
     series "improve write IO performance when fragmentation is high".

   - Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
     exposed by fstests".

   - kfifo header rework from Andy Shevchenko in the series "kfifo:
     Clean up kfifo.h".

   - GDB script fixes from Florian Rommel in the series "scripts/gdb:
     Fixes for $lx_current and $lx_per_cpu".

   - After much discussion, a coding-style update from Barry Song
     explaining one reason why inline functions are preferred over
     macros. The series is "codingstyle: avoid unused parameters for a
     function-like macro""

* tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (62 commits)
  fs/proc: fix softlockup in __read_vmcore
  nilfs2: convert BUG_ON() in nilfs_finish_roll_forward() to WARN_ON()
  scripts: checkpatch: check unused parameters for function-like macro
  Documentation: coding-style: ask function-like macros to evaluate parameters
  nilfs2: use __field_struct() for a bitwise field
  selftests/kcmp: remove unused open mode
  nilfs2: remove calls to folio_set_error() and folio_clear_error()
  kernel/watchdog_perf.c: tidy up kerneldoc
  watchdog: allow nmi watchdog to use raw perf event
  watchdog: handle comma separated nmi_watchdog command line
  nilfs2: make superblock data array index computation sparse friendly
  squashfs: remove calls to set the folio error flag
  squashfs: convert squashfs_symlink_read_folio to use folio APIs
  scripts/gdb: fix detection of current CPU in KGDB
  scripts/gdb: make get_thread_info accept pointers
  scripts/gdb: fix parameter handling in $lx_per_cpu
  scripts/gdb: fix failing KGDB detection during probe
  kfifo: don't use "proxy" headers
  media: stih-cec: add missing io.h
  media: rc: add missing io.h
  ...
2024-05-19 14:02:03 -07:00
Andrii Nakryiko
1de27bba6d libbpf: fix feature detectors when using token_fd
Adjust `union bpf_attr` size passed to kernel in two feature-detecting
functions to take into account prog_token_fd field.

Libbpf is avoiding memset()'ing entire `union bpf_attr` by only using
minimal set of bpf_attr's fields. Two places have been missed when
wiring BPF token support in libbpf's feature detection logic.

Fix them trivially.

Fixes: f3dcee938f ("libbpf: Wire up token_fd into feature probing logic")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240513180804.403775-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-15 09:34:53 -07:00
Namhyung Kim
ea558c8624 tools lib subcmd: Show parent options in help
I've just realized that help message in a subcommand didn't show one
in the parent command.  Since the option parser understands the parent,
display code should do the same.  For example, `perf ftrace latency -h`
should show options in the `perf ftrace` command too.

Before:

  $ perf ftrace latency -h

   Usage: perf ftrace [<options>] [<command>]
      or: perf ftrace [<options>] -- [<command>] [<options>]
      or: perf ftrace {trace|latency} [<options>] [<command>]
      or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]

      -b, --use-bpf         Use BPF to measure function latency
      -n, --use-nsec        Use nano-second histogram
      -T, --trace-funcs <func>
                            Show latency of given function

After:

  $ perf ftrace latency -h

   Usage: perf ftrace [<options>] [<command>]
      or: perf ftrace [<options>] -- [<command>] [<options>]
      or: perf ftrace {trace|latency} [<options>] [<command>]
      or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>]

      -a, --all-cpus        System-wide collection from all CPUs
      -b, --use-bpf         Use BPF to measure function latency
      -C, --cpu <cpu>       List of cpus to monitor
      -n, --use-nsec        Use nano-second histogram
      -p, --pid <pid>       Trace on existing process id
      -T, --trace-funcs <func>
                            Show latency of given function
      -v, --verbose         Be more verbose
          --tid <tid>       Trace on existing thread id (exclusive to --pid)

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240429233707.1511175-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-05-12 21:09:52 -03:00
Ian Rogers
230a7a71f9 libsubcmd: Fix parse-options memory leak
If a usage string is built in parse_options_subcommand, also free it.

Fixes: 901421a5bd ("perf tools: Remove subcmd dependencies on strbuf")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240509052015.1914670-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-05-10 11:16:48 -03:00
Jose E. Marchesi
009367099e bpf: Avoid uninitialized value in BPF_CORE_READ_BITFIELD
[Changes from V1:
 - Use a default branch in the switch statement to initialize `val'.]

GCC warns that `val' may be used uninitialized in the
BPF_CRE_READ_BITFIELD macro, defined in bpf_core_read.h as:

	[...]
	unsigned long long val;						      \
	[...]								      \
	switch (__CORE_RELO(s, field, BYTE_SIZE)) {			      \
	case 1: val = *(const unsigned char *)p; break;			      \
	case 2: val = *(const unsigned short *)p; break;		      \
	case 4: val = *(const unsigned int *)p; break;			      \
	case 8: val = *(const unsigned long long *)p; break;		      \
        }       							      \
	[...]
	val;								      \
	}								      \

This patch adds a default entry in the switch statement that sets
`val' to zero in order to avoid the warning, and random values to be
used in case __builtin_preserve_field_info returns unexpected values
for BPF_FIELD_BYTE_SIZE.

Tested in bpf-next master.
No regressions.

Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240508101313.16662-1-jose.marchesi@oracle.com
2024-05-08 15:00:55 -07:00
Arnaldo Carvalho de Melo
bbed8b9ffe tools lib rbtree: pick some improvements from the kernel rbtree code
The tools/lib/rbtree.c code came from the kernel.  Remove the
EXPORT_SYMBOL() that make sense only there.  Unfortunately it is not being
checked with tools/perf/check_headers.sh.  Will try to remedy this.  Until
then pick the improvements from:

  b0687c1119 ("lib/rbtree: use '+' instead of '|' for setting color.")

That I noticed by doing:

  diff -u tools/lib/rbtree.c lib/rbtree.c
  diff -u tools/include/linux/rbtree_augmented.h include/linux/rbtree_augmented.h

There is one other cases, but lets pick it in separate patches.

Link: https://lkml.kernel.org/r/ZigZzeFoukzRKG1Q@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Noah Goldstein <goldstein.w.n@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-08 08:41:27 -07:00
Andrii Nakryiko
c78420bafe libbpf: improve early detection of doomed-to-fail BPF program loading
Extend libbpf's pre-load checks for BPF programs, detecting more typical
conditions that are destinated to cause BPF program failure. This is an
opportunity to provide more helpful and actionable error message to
users, instead of potentially very confusing BPF verifier log and/or
error.

In this case, we detect struct_ops BPF program that was not referenced
anywhere, but still attempted to be loaded (according to libbpf logic).
Suggest that the program might need to be used in some struct_ops
variable. User will get a message of the following kind:

  libbpf: prog 'test_1_forgotten': SEC("struct_ops") program isn't referenced anywhere, did you forget to use it?

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240507001335.1445325-6-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-07 16:21:59 -07:00
Andrii Nakryiko
548c2ede0d libbpf: fix libbpf_strerror_r() handling unknown errors
strerror_r(), used from libbpf-specific libbpf_strerror_r() wrapper is
documented to return error in two different ways, depending on glibc
version. Take that into account when handling strerror_r()'s own errors,
which happens when we pass some non-standard (internal) kernel error to
it. Before this patch we'd have "ERROR: strerror_r(524)=22", which is
quite confusing. Now for the same situation we'll see a bit less
visually scary "unknown error (-524)".

At least we won't confuse user with irrelevant EINVAL (22).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240507001335.1445325-5-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-07 16:21:59 -07:00
Andrii Nakryiko
e18e2e70db libbpf: handle yet another corner case of nulling out struct_ops program
There is yet another corner case where user can set STRUCT_OPS program
reference in STRUCT_OPS map to NULL, but libbpf will fail to disable
autoload for such BPF program. This time it's the case of "new" kernel
which has type information about callback field, but user explicitly
nulled-out program reference from user-space after opening BPF object.

Fix, hopefully, the last remaining unhandled case.

Fixes: 0737df6de9 ("libbpf: better fix for handling nulled-out struct_ops program")
Fixes: f973fccd43 ("libbpf: handle nulled-out program in struct_ops correctly")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240507001335.1445325-3-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-07 16:21:59 -07:00
Andrii Nakryiko
8374b56b1d libbpf: remove unnecessary struct_ops prog validity check
libbpf ensures that BPF program references set in map->st_ops->progs[i]
during open phase are always valid STRUCT_OPS programs. This is done in
bpf_object__collect_st_ops_relos(). So there is no need to double-check
that in bpf_map__init_kern_struct_ops().

Simplify the code by removing unnecessary check. Also, we avoid using
local prog variable to keep code similar to the upcoming fix, which adds
similar logic in another part of bpf_map__init_kern_struct_ops().

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240507001335.1445325-2-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-07 16:21:59 -07:00
Jose E. Marchesi
a9e7715ce8 libbpf: Avoid casts from pointers to enums in bpf_tracing.h
[Differences from V1:
  - Do not introduce a global typedef, as this is a public header.
  - Keep the void* casts in BPF_KPROBE_READ_RET_IP and
    BPF_KRETPROBE_READ_RET_IP, as these are necessary
    for converting to a const void* argument of
    bpf_probe_read_kernel.]

The BPF_PROG, BPF_KPROBE and BPF_KSYSCALL macros defined in
tools/lib/bpf/bpf_tracing.h use a clever hack in order to provide a
convenient way to define entry points for BPF programs as if they were
normal C functions that get typed actual arguments, instead of as
elements in a single "context" array argument.

For example, PPF_PROGS allows writing:

  SEC("struct_ops/cwnd_event")
  void BPF_PROG(cwnd_event, struct sock *sk, enum tcp_ca_event event)
  {
        bbr_cwnd_event(sk, event);
        dctcp_cwnd_event(sk, event);
        cubictcp_cwnd_event(sk, event);
  }

That expands into a pair of functions:

  void ____cwnd_event (unsigned long long *ctx, struct sock *sk, enum tcp_ca_event event)
  {
        bbr_cwnd_event(sk, event);
        dctcp_cwnd_event(sk, event);
        cubictcp_cwnd_event(sk, event);
  }

  void cwnd_event (unsigned long long *ctx)
  {
        _Pragma("GCC diagnostic push")
        _Pragma("GCC diagnostic ignored \"-Wint-conversion\"")
        return ____cwnd_event(ctx, (void*)ctx[0], (void*)ctx[1]);
        _Pragma("GCC diagnostic pop")
  }

Note how the 64-bit unsigned integers in the incoming CTX get casted
to a void pointer, and then implicitly converted to whatever type of
the actual argument in the wrapped function.  In this case:

  Arg1: unsigned long long -> void * -> struct sock *
  Arg2: unsigned long long -> void * -> enum tcp_ca_event

The behavior of GCC and clang when facing such conversions differ:

  pointer -> pointer

    Allowed by the C standard.
    GCC: no warning nor error.
    clang: no warning nor error.

  pointer -> integer type

    [C standard says the result of this conversion is implementation
     defined, and it may lead to unaligned pointer etc.]

    GCC: error: integer from pointer without a cast [-Wint-conversion]
    clang: error: incompatible pointer to integer conversion [-Wint-conversion]

  pointer -> enumerated type

    GCC: error: incompatible types in assigment (*)
    clang: error: incompatible pointer to integer conversion [-Wint-conversion]

These macros work because converting pointers to pointers is allowed,
and converting pointers to integers also works provided a suitable
integer type even if it is implementation defined, much like casting a
pointer to uintptr_t is guaranteed to work by the C standard.  The
conversion errors emitted by both compilers by default are silenced by
the pragmas.

However, the GCC error marked with (*) above when assigning a pointer
to an enumerated value is not associated with the -Wint-conversion
warning, and it is not possible to turn it off.

This is preventing building the BPF kernel selftests with GCC.

This patch fixes this by avoiding intermediate casts to void*,
replaced with casts to `unsigned long long', which is an integer type
capable of safely store a BPF pointer, much like the standard
uintptr_t.

Testing performed in bpf-next master:
  - vmtest.sh -- ./test_verifier
  - vmtest.sh -- ./test_progs
  - make M=samples/bpf
No regressions.

Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240502170925.3194-1-jose.marchesi@oracle.com
2024-05-02 22:58:58 -07:00
Jose E. Marchesi
cf9bea94f6 libbpf: Fix bpf_ksym_exists() in GCC
The macro bpf_ksym_exists is defined in bpf_helpers.h as:

  #define bpf_ksym_exists(sym) ({								\
  	_Static_assert(!__builtin_constant_p(!!sym), #sym " should be marked as __weak");	\
  	!!sym;											\
  })

The purpose of the macro is to determine whether a given symbol has
been defined, given the address of the object associated with the
symbol.  It also has a compile-time check to make sure the object
whose address is passed to the macro has been declared as weak, which
makes the check on `sym' meaningful.

As it happens, the check for weak doesn't work in GCC in all cases,
because __builtin_constant_p not always folds at parse time when
optimizing.  This is because optimizations that happen later in the
compilation process, like inlining, may make a previously non-constant
expression a constant.  This results in errors like the following when
building the selftests with GCC:

  bpf_helpers.h:190:24: error: expression in static assertion is not constant
  190 |         _Static_assert(!__builtin_constant_p(!!sym), #sym " should be marked as __weak");       \
      |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fortunately recent versions of GCC support a __builtin_has_attribute
that can be used to directly check for the __weak__ attribute.  This
patch changes bpf_helpers.h to use that builtin when building with a
recent enough GCC, and to omit the check if GCC is too old to support
the builtin.

The macro used for GCC becomes:

  #define bpf_ksym_exists(sym) ({									\
	_Static_assert(__builtin_has_attribute (*sym, __weak__), #sym " should be marked as __weak");	\
	!!sym;												\
  })

Note that since bpf_ksym_exists is designed to get the address of the
object associated with symbol SYM, we pass *sym to
__builtin_has_attribute instead of sym.  When an expression is passed
to __builtin_has_attribute then it is the type of the passed
expression that is checked for the specified attribute.  The
expression itself is not evaluated.  This accommodates well with the
existing usages of the macro:

- For function objects:

  struct task_struct *bpf_task_acquire(struct task_struct *p) __ksym __weak;
  [...]
  bpf_ksym_exists(bpf_task_acquire)

- For variable objects:

  extern const struct rq runqueues __ksym __weak; /* typed */
  [...]
  bpf_ksym_exists(&runqueues)

Note also that BPF support was added in GCC 10 and support for
__builtin_has_attribute in GCC 9.

Locally tested in bpf-next master branch.
No regressions.

Signed-of-by: Jose E. Marchesi <jose.marchesi@oracle.com>

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240428112559.10518-1-jose.marchesi@oracle.com
2024-05-02 22:47:22 -07:00
Andrii Nakryiko
087d757fb4 libbpf: fix ring_buffer__consume_n() return result logic
Add INT_MAX check to ring_buffer__consume_n(). We do the similar check
to handle int return result of all these ring buffer APIs in other APIs
and ring_buffer__consume_n() is missing one. This patch fixes this
omission.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240430201952.888293-2-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-02 16:41:03 -07:00
Andrii Nakryiko
00f0e08f23 libbpf: fix potential overflow in ring__consume_n()
ringbuf_process_ring() return int64_t, while ring__consume_n() assigns
it to int. It's highly unlikely, but possible for ringbuf_process_ring()
to return value larger than INT_MAX, so use int64_t. ring__consume_n()
does check INT_MAX before returning int result to the user.

Fixes: 4d22ea94ea ("libbpf: Add ring__consume_n / ring_buffer__consume_n")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240430201952.888293-1-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-02 16:41:02 -07:00
Jiri Olsa
7c13ef16e8 libbpf: Fix error message in attach_kprobe_multi
We just failed to retrieve pattern, so we need to print spec instead.

Fixes: ddc6b04989 ("libbpf: Add bpf_program__attach_kprobe_multi_opts function")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240502075541.1425761-2-jolsa@kernel.org
2024-05-02 08:56:24 -07:00
Jiri Olsa
5a3941f84b libbpf: Fix error message in attach_kprobe_session
We just failed to retrieve pattern, so we need to print spec instead.

Fixes: 2ca178f02b ("libbpf: Add support for kprobe session attach")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240502075541.1425761-1-jolsa@kernel.org
2024-05-02 08:56:23 -07:00
Andrii Nakryiko
0737df6de9 libbpf: better fix for handling nulled-out struct_ops program
Previous attempt to fix the handling of nulled-out (from skeleton)
struct_ops program is working well only if struct_ops program is defined
as non-autoloaded by default (i.e., has SEC("?struct_ops") annotation,
with question mark).

Unfortunately, that fix is incomplete due to how
bpf_object_adjust_struct_ops_autoload() is marking referenced or
non-referenced struct_ops program as autoloaded (or not). Because
bpf_object_adjust_struct_ops_autoload() is run after
bpf_map__init_kern_struct_ops() step, which sets program slot to NULL,
such programs won't be considered "referenced", and so its autoload
property won't be changed.

This all sounds convoluted and it is, but the desire is to have as
natural behavior (as far as struct_ops usage is concerned) as possible.

This fix is redoing the original fix but makes it work for
autoloaded-by-default struct_ops programs as well. We achieve this by
forcing prog->autoload to false if prog was declaratively set for some
struct_ops map, but then nulled-out from skeleton (programmatically).
This achieves desired effect of not autoloading it. If such program is
still referenced somewhere else (different struct_ops map or different
callback field), it will get its autoload property adjusted by
bpf_object_adjust_struct_ops_autoload() later.

We also fix selftest, which accidentally used SEC("?struct_ops")
annotation. It was meant to use autoload-by-default program from the
very beginning.

Fixes: f973fccd43 ("libbpf: handle nulled-out program in struct_ops correctly")
Cc: Kui-Feng Lee <thinker.li@gmail.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240501041706.3712608-1-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-01 10:17:24 -07:00
Viktor Malik
8f8a024272 libbpf: support "module: Function" syntax for tracing programs
In some situations, it is useful to explicitly specify a kernel module
to search for a tracing program target (e.g. when a function of the same
name exists in multiple modules or in vmlinux).

This patch enables that by allowing the "module:function" syntax for the
find_kernel_btf_id function. Thanks to this, the syntax can be used both
from a SEC macro (i.e. `SEC(fentry/module:function)`) and via the
bpf_program__set_attach_target API call.

Signed-off-by: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/9085a8cb9a552de98e554deb22ff7e977d025440.1714469650.git.vmalik@redhat.com
2024-05-01 09:53:47 -07:00
Jiri Olsa
7b94965429 libbpf: Add kprobe session attach type name to attach_type_name
Adding kprobe session attach type name to attach_type_name,
so libbpf_bpf_attach_type_str returns proper string name for
BPF_TRACE_KPROBE_SESSION attach type.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-6-jolsa@kernel.org
2024-04-30 09:45:53 -07:00
Jiri Olsa
2ca178f02b libbpf: Add support for kprobe session attach
Adding support to attach program in kprobe session mode
with bpf_program__attach_kprobe_multi_opts function.

Adding session bool to bpf_kprobe_multi_opts struct that allows
to load and attach the bpf program via kprobe session.
the attachment to create kprobe multi session.

Also adding new program loader section that allows:
 SEC("kprobe.session/bpf_fentry_test*")

and loads/attaches kprobe program as kprobe session.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-5-jolsa@kernel.org
2024-04-30 09:45:53 -07:00
Andrii Nakryiko
f973fccd43 libbpf: handle nulled-out program in struct_ops correctly
If struct_ops has one of program callbacks set declaratively and host
kernel is old and doesn't support this callback, libbpf will allow to
load such struct_ops as long as that callback was explicitly nulled-out
(presumably through skeleton). This is all working correctly, except we
won't reset corresponding program slot to NULL before bailing out, which
will lead to libbpf not detecting that BPF program has to be not
auto-loaded. Fix this by unconditionally resetting corresponding program
slot to NULL.

Fixes: c911fc61a7 ("libbpf: Skip zeroed or null fields if not found in the kernel type.")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240428030954.3918764-1-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-29 16:46:06 -07:00
Howard Chu
7cc72090fb perf record: Fix comment misspellings
Fix comment misspellings

Signed-off-by: Howard Chu <howardchu95@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240425060427.1800663-1-howardchu95@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-04-26 22:13:10 -03:00
Arnaldo Carvalho de Melo
cd88c11c6d tools lib rbtree: Pick some improvements from the kernel rbtree code
The tools/lib/rbtree.c code came from the kernel, removing the
EXPORT_SYMBOL() that make sense only there, unfortunately it is not
being checked with tools/perf/check_headers.sh, will try to remedy this,
till then pick the improvements from:

  b0687c1119 ("lib/rbtree: use '+' instead of '|' for setting color.")

That I noticed by doing:

  diff -u tools/lib/rbtree.c lib/rbtree.c
  diff -u tools/include/linux/rbtree_augmented.h include/linux/rbtree_augmented.h

There is one other cases, but lets pick it in separate patches.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Noah Goldstein <goldstein.w.n@gmail.com>
Link: https://lore.kernel.org/lkml/ZigZzeFoukzRKG1Q@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-04-26 22:07:19 -03:00
Jose E. Marchesi
6e25bcf06a bpf_helpers.h: Define bpf_tail_call_static when building with GCC
The definition of bpf_tail_call_static in tools/lib/bpf/bpf_helpers.h
is guarded by a preprocessor check to assure that clang is recent
enough to support it.  This patch updates the guard so the function is
compiled when using GCC 13 or later as well.

Tested in bpf-next master. No regressions.

Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240426145158.14409-1-jose.marchesi@oracle.com
2024-04-26 17:10:04 +02:00
Arnaldo Carvalho de Melo
173b0b5b0e Merge remote-tracking branch 'torvalds/master' into perf-tools-next
To pick up fixes sent via perf-tools, by Namhyung Kim.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-04-22 13:35:18 -03:00
Quentin Deslandes
e739e01d8d libbpf: Fix dump of subsequent char arrays
When dumping a character array, libbpf will watch for a '\0' and set
is_array_terminated=true if found. This prevents libbpf from printing
the remaining characters of the array, treating it as a nul-terminated
string.

However, once this flag is set, it's never reset, leading to subsequent
characters array not being printed properly:

.str_multi = (__u8[2][16])[
    [
        'H',
        'e',
        'l',
    ],
],

This patch saves the is_array_terminated flag and restores its
default (false) value before looping over the elements of an array,
then restores it afterward. This way, libbpf's behavior is unchanged
when dumping the characters of an array, but subsequent arrays are
printed properly:

.str_multi = (__u8[2][16])[
    [
        'H',
        'e',
        'l',
    ],
    [
        'l',
        'o',
    ],
],

Signed-off-by: Quentin Deslandes <qde@naccy.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240413211258.134421-3-qde@naccy.de
2024-04-17 15:24:02 +02:00
Quentin Deslandes
9213e52970 libbpf: Fix misaligned array closing bracket
In btf_dump_array_data(), libbpf will call btf_dump_dump_type_data() for
each element. For an array of characters, each element will be
processed the following way:

- btf_dump_dump_type_data() is called to print the character
- btf_dump_data_pfx() prefixes the current line with the proper number
  of indentations
- btf_dump_int_data() is called to print the character
- After the last character is printed, btf_dump_dump_type_data() calls
  btf_dump_data_pfx() before writing the closing bracket

However, for an array containing characters, btf_dump_int_data() won't
print any '\0' and subsequent characters. This leads to situations where
the line prefix is written, no character is added, then the prefix is
written again before adding the closing bracket:

(struct sk_metadata){
    .str_array = (__u8[14])[
        'H',
        'e',
        'l',
        'l',
        'o',
                ],

This change solves this issue by printing the '\0' character, which
has two benefits:

- The bracket closing the array is properly aligned
- It's clear from a user point of view that libbpf uses '\0' as a
  terminator for arrays of characters.

Signed-off-by: Quentin Deslandes <qde@naccy.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240413211258.134421-2-qde@naccy.de
2024-04-17 15:23:44 +02:00
Yonghong Song
849989af61 libbpf: Add bpf_link support for BPF_PROG_TYPE_SOCKMAP
Introduce a libbpf API function bpf_program__attach_sockmap()
which allow user to get a bpf_link for their corresponding programs.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240410043532.3737722-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-10 19:52:25 -07:00
Ian Rogers
705c09bb3c tools subcmd: Add check_if_command_finished()
Add non-blocking function to check if a 'struct child_process' has
completed. If the process has completed the exit code is stored in the
'struct child_process' so that finish_command() returns it.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240405070931.1231245-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-04-08 17:43:20 -03:00
Andrea Righi
4d22ea94ea libbpf: Add ring__consume_n / ring_buffer__consume_n
Introduce a new API to consume items from a ring buffer, limited to a
specified amount, and return to the caller the actual number of items
consumed.

Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/lkml/20240310154726.734289-1-andrea.righi@canonical.com/T
Link: https://lore.kernel.org/bpf/20240406092005.92399-4-andrea.righi@canonical.com
2024-04-06 09:11:55 -07:00
Andrea Righi
13e8125a22 libbpf: ringbuf: Allow to consume up to a certain amount of items
In some cases, instead of always consuming all items from ring buffers
in a greedy way, we may want to consume up to a certain amount of items,
for example when we need to copy items from the BPF ring buffer to a
limited user buffer.

This change allows to set an upper limit to the amount of items consumed
from one or more ring buffers.

Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240406092005.92399-3-andrea.righi@canonical.com
2024-04-06 09:11:54 -07:00
Andrea Righi
5bd2ed6582 libbpf: Start v1.5 development cycle
Bump libbpf.map to v1.5.0 to start a new libbpf version cycle.

Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240406092005.92399-2-andrea.righi@canonical.com
2024-04-06 09:11:10 -07:00