Commit Graph

171 Commits

Author SHA1 Message Date
Jiri Olsa
da3a4c3ec7 libbpf: Add path_fd to struct bpf_link_create_opts
Adding the path_fd field to struct bpf_link_create_opts and passing it
through kernel attr interface.

Assisted-by: Codex:GPT-5.4
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260611114230.950379-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-14 17:24:25 -07:00
Jiri Olsa
630e85a9f0 libbpf: Add bpf_link_create support for tracing_multi link
Adding bpf_link_create support for tracing_multi link with
new tracing_multi record in struct bpf_link_create_opts.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-19-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-07 10:03:02 -07:00
Tiezhu Yang
a4a5d4ee06 libbpf: Add __NR_bpf definition for LoongArch
LoongArch uses the generic syscall table, where __NR_bpf is defined
as 280 in include/uapi/asm-generic/unistd.h.

To align with other architectures, add the __NR_bpf definition for
LoongArch to avoid a potential compilation failure: "error __NR_bpf
not defined. libbpf does not support your arch."

This is a follow up patch of:

  commit b0c47807d3 ("bpf: Add sparc support to tools and samples.")
  commit bad1926dd2 ("bpf, s390: fix build for libbpf and selftest suite")
  commit ca31ca8247 ("tools/bpf: fix perf build error with uClibc (seen on ARC)")
  commit e32cb12ff5 ("bpf, mips: Fix build errors about __NR_bpf undeclared")

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260526063936.16769-1-yangtiezhu@loongson.cn
2026-05-28 14:38:15 -07:00
Leon Hwang
b4844cb6d1 libbpf: Add OPTS_VALID() for log_opts in bpf_map_create
There should be an OPTS_VALID() check for log_opts before extracting its
fields.

If no such OPTS_VALID() check and an application compiled against a future
libbpf header passes a log_opts with new, non-zero fields to libbpf.so,
those fields will be ignored silently.

Fixes: 702259006f ("libbpf: Add syscall common attributes support for map_create")
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260518145446.6794-4-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-05-18 18:51:32 -07:00
Leon Hwang
702259006f libbpf: Add syscall common attributes support for map_create
With the previous commit adding common attribute support for
BPF_MAP_CREATE, users can now retrieve detailed error messages when map
creation fails via the log_buf field.

Introduce struct bpf_log_opts with the following fields:
log_buf, log_size, log_level, and log_true_size.

Extend bpf_map_create_opts with a new field log_opts, allowing users to
capture and inspect log messages on map creation failures.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260512153157.28382-8-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-05-12 12:44:46 -07:00
Leon Hwang
b1bff40809 libbpf: Add support for extended BPF syscall
To support the extended BPF syscall introduced in the previous commit,
introduce the following internal APIs:

* 'sys_bpf_ext()'
* 'sys_bpf_ext_fd()'
  They wrap the raw 'syscall()' interface to support passing extended
  attributes.
* 'probe_sys_bpf_ext()'
  Check whether current kernel supports the BPF syscall common attributes.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260512153157.28382-3-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-05-12 12:44:39 -07:00
Menglong Dong
257c43688b libbpf: add fsession support
Add BPF_TRACE_FSESSION to libbpf.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20260124062008.8657-9-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-01-24 18:49:36 -08:00
Amery Hung
87cd177b14 libbpf: Add support for associating BPF program with struct_ops
Add low-level wrapper and libbpf API for BPF_PROG_ASSOC_STRUCT_OPS
command in the bpf() syscall.

Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20251203233748.668365-4-ameryhung@gmail.com
2025-12-05 16:17:57 -08:00
Jianyun Gao
54c134f379 libbpf: Fix the incorrect reference to the memlock_rlim variable in the comment.
The variable "memlock_rlim_max" referenced in the comment does not exist.
I think that the author probably meant the variable "memlock_rlim". So,
correct it.

Signed-off-by: Jianyun Gao <jianyungao89@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20251027032008.738944-1-jianyungao89@gmail.com
2025-10-28 10:28:53 -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
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
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
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
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
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
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
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
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
36ffb2023e libbpf: add support for BPF cookie for raw_tp/tp_btf programs
Wire up BPF cookie passing or raw_tp and tp_btf programs, both in
low-level and high-level APIs.

Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-5-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19 23:05:34 -07:00
Andrii Nakryiko
f3dcee938f libbpf: Wire up token_fd into feature probing logic
Adjust feature probing callbacks to take into account optional token_fd.
In unprivileged contexts, some feature detectors would fail to detect
kernel support just because BPF program, BPF map, or BTF object can't be
loaded due to privileged nature of those operations. So when BPF object
is loaded with BPF token, this token should be used for feature probing.

This patch is setting support for this scenario, but we don't yet pass
non-zero token FD. This will be added in the next patch.

We also switched BPF cookie detector from using kprobe program to
tracepoint one, as tracepoint is somewhat less dangerous BPF program
type and has higher likelihood of being allowed through BPF token in the
future. This change has no effect on detection behavior.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-25-andrii@kernel.org
2024-01-24 16:21:02 -08:00
Andrii Nakryiko
d6dd1d4936 libbpf: Further decouple feature checking logic from bpf_object
Add feat_supported() helper that accepts feature cache instead of
bpf_object. This allows low-level code in bpf.c to not know or care
about higher-level concept of bpf_object, yet it will be able to utilize
custom feature checking in cases where BPF token might influence the
outcome.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-23-andrii@kernel.org
2024-01-24 16:21:02 -08:00
Andrii Nakryiko
404cbc149c libbpf: Add BPF token support to bpf_prog_load() API
Wire through token_fd into bpf_prog_load().

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-16-andrii@kernel.org
2024-01-24 16:21:02 -08:00
Andrii Nakryiko
a3d63e8525 libbpf: Add BPF token support to bpf_btf_load() API
Allow user to specify token_fd for bpf_btf_load() API that wraps
kernel's BPF_BTF_LOAD command. This allows loading BTF from unprivileged
process as long as it has BPF token allowing BPF_BTF_LOAD command, which
can be created and delegated by privileged process.

Wire through new btf_flags as well, so that user can provide
BPF_F_TOKEN_FD flag, if necessary.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-15-andrii@kernel.org
2024-01-24 16:21:02 -08:00
Andrii Nakryiko
364f848375 libbpf: Add BPF token support to bpf_map_create() API
Add ability to provide token_fd for BPF_MAP_CREATE command through
bpf_map_create() API.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-14-andrii@kernel.org
2024-01-24 16:21:01 -08:00
Andrii Nakryiko
639ecd7d62 libbpf: Add bpf_token_create() API
Add low-level wrapper API for BPF_TOKEN_CREATE command in bpf() syscall.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-13-andrii@kernel.org
2024-01-24 16:21:01 -08:00
Martin KaFai Lau
c9f1155645 libbpf: Ensure undefined bpf_attr field stays 0
The commit 9e926acda0 ("libbpf: Find correct module BTFs for struct_ops maps and progs.")
sets a newly added field (value_type_btf_obj_fd) to -1 in libbpf when
the caller of the libbpf's bpf_map_create did not define this field by
passing a NULL "opts" or passing in a "opts" that does not cover this
new field. OPT_HAS(opts, field) is used to decide if the field is
defined or not:

	((opts) && opts->sz >= offsetofend(typeof(*(opts)), field))

Once OPTS_HAS decided the field is not defined, that field should
be set to 0. For this particular new field (value_type_btf_obj_fd),
its corresponding map_flags "BPF_F_VTYPE_BTF_OBJ_FD" is not set.
Thus, the kernel does not treat it as an fd field.

Fixes: 9e926acda0 ("libbpf: Find correct module BTFs for struct_ops maps and progs.")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240124224418.2905133-1-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-24 16:19:39 -08:00
Kui-Feng Lee
9e926acda0 libbpf: Find correct module BTFs for struct_ops maps and progs.
Locate the module BTFs for struct_ops maps and progs and pass them to the
kernel. This ensures that the kernel correctly resolves type IDs from the
appropriate module BTFs.

For the map of a struct_ops object, the FD of the module BTF is set to
bpf_map to keep a reference to the module BTF. The FD is passed to the
kernel as value_type_btf_obj_fd when the struct_ops object is loaded.

For a bpf_struct_ops prog, attach_btf_obj_fd of bpf_prog is the FD of a
module BTF in the kernel.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240119225005.668602-13-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-01-23 17:12:52 -08:00
Daniel Borkmann
05c31b4ab2 libbpf: Add link-based API for netkit
This adds bpf_program__attach_netkit() API to libbpf. Overall it is very
similar to tcx. The API looks as following:

  LIBBPF_API struct bpf_link *
  bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
                             const struct bpf_netkit_opts *opts);

The struct bpf_netkit_opts is done in similar way as struct bpf_tcx_opts
for supporting bpf_mprog control parameters. The attach location for the
primary and peer device is derived from the program section "netkit/primary"
and "netkit/peer", respectively.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20231024214904.29825-4-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-10-24 16:06:58 -07:00
Jiri Olsa
5054a303f8 libbpf: Add bpf_link_create support for multi uprobes
Adding new uprobe_multi struct to bpf_link_create_opts object
to pass multiple uprobe data to link_create attr uapi.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-14-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Daniel Borkmann
55cc376847 libbpf: Add link-based API for tcx
Implement tcx BPF link support for libbpf.

The bpf_program__attach_fd() API has been refactored slightly in order to pass
bpf_link_create_opts pointer as input.

A new bpf_program__attach_tcx() has been added on top of this which allows for
passing all relevant data via extensible struct bpf_tcx_opts.

The program sections tcx/ingress and tcx/egress correspond to the hook locations
for tc ingress and egress, respectively.

For concrete usage examples, see the extensive selftests that have been
developed as part of this series.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230719140858.13224-5-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-19 10:07:28 -07:00
Daniel Borkmann
fe20ce3a51 libbpf: Add opts-based attach/detach/query API for tcx
Extend libbpf attach opts and add a new detach opts API so this can be used
to add/remove fd-based tcx BPF programs. The old-style bpf_prog_detach() and
bpf_prog_detach2() APIs are refactored to reuse the new bpf_prog_detach_opts()
internally.

The bpf_prog_query_opts() API got extended to be able to handle the new
link_ids, link_attach_flags and revision fields.

For concrete usage examples, see the extensive selftests that have been
developed as part of this series.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230719140858.13224-4-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-19 10:07:28 -07:00
Florian Westphal
52364abb10 libbpf: Add netfilter link attach helper
Add new api function: bpf_program__attach_netfilter.

It takes a bpf program (netfilter type), and a pointer to a option struct
that contains the desired attachment (protocol family, priority, hook
location, ...).

It returns a pointer to a 'bpf_link' structure or NULL on error.

Next patch adds new netfilter_basic test that uses this function to
attach a program to a few pf/hook/priority combinations.

v2: change name and use bpf_link_create.

Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/bpf/CAEf4BzZrmUv27AJp0dDxBDMY_B8e55-wLs8DUKK69vCWsCG_pQ@mail.gmail.com/
Link: https://lore.kernel.org/bpf/CAEf4BzZ69YgrQW7DHCJUT_X+GqMq_ZQQPBwopaJJVGFD5=d5Vg@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20230628152738.22765-2-fw@strlen.de
2023-06-30 12:34:31 -07:00
Andrii Nakryiko
f1674dc79f libbpf: Add opts-based bpf_obj_pin() API and add support for path_fd
Add path_fd support for bpf_obj_pin() and bpf_obj_get() operations
(through their opts-based variants). This allows to take advantage of
new kernel-side support for O_PATH-based pin/get location specification.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230523170013.728457-4-andrii@kernel.org
2023-05-23 23:41:01 +02:00
Andrii Nakryiko
097d8002b7 libbpf: Wire through log_true_size for bpf_btf_load() API
Similar to what we did for bpf_prog_load() in previous patch, wire
returning of log_true_size value from kernel back to the user through
OPTS out field.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230406234205.323208-17-andrii@kernel.org
2023-04-11 18:05:44 +02:00
Andrii Nakryiko
94e55c0fda libbpf: Wire through log_true_size returned from kernel for BPF_PROG_LOAD
Add output-only log_true_size field to bpf_prog_load_opts to return
bpf_attr->log_true_size value back from bpf() syscall.

Note, that we have to drop const modifier from opts in bpf_prog_load().
This could potentially cause compilation error for some users. But
the usual practice is to define bpf_prog_load_ops
as a local variable next to bpf_prog_load() call and pass pointer to it,
so const vs non-const makes no difference and won't even come up in most
(if not all) cases.

There are no runtime and ABI backwards/forward compatibility issues at all.
If user provides old struct bpf_prog_load_opts, libbpf won't set new
fields. If old libbpf is provided new bpf_prog_load_opts, nothing will
happen either as old libbpf doesn't yet know about this new field.

Adding a new variant of bpf_prog_load() just for this seems like a big
and unnecessary overkill. As a corroborating evidence is the fact that
entire selftests/bpf code base required not adjustment whatsoever.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230406234205.323208-16-andrii@kernel.org
2023-04-11 18:05:44 +02:00
Andrii Nakryiko
e0aee1facc libbpf: Don't enforce unnecessary verifier log restrictions on libbpf side
This basically prevents any forward compatibility. And we either way
just return -EINVAL, which would otherwise be returned from bpf()
syscall anyways.

Similarly, drop enforcement of non-NULL log_buf when log_level > 0. This
won't be true anymore soon.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-5-andrii@kernel.org
2023-04-11 18:05:43 +02:00
Kui-Feng Lee
912dd4b0c2 libbpf: Update a bpf_link with another struct_ops.
Introduce bpf_link__update_map(), which allows to atomically update
underlying struct_ops implementation for given struct_ops BPF link.

Also add old_map_fd to struct bpf_link_update_opts to handle
BPF_F_REPLACE feature.

Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
Link: https://lore.kernel.org/r/20230323032405.3735486-7-kuifeng@meta.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-22 22:53:02 -07:00
Ilya Leoshkevich
55a9ed0e16 libbpf: Introduce bpf_{btf,link,map,prog}_get_info_by_fd()
These are type-safe wrappers around bpf_obj_get_info_by_fd(). They
found one problem in selftests, and are also useful for adding
Memory Sanitizer annotations.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230214231221.249277-2-iii@linux.ibm.com
2023-02-16 15:32:36 -08:00
Roberto Sassu
97c8f9dd5d libbpf: Introduce bpf_link_get_fd_by_id_opts()
Introduce bpf_link_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_link_get_fd_by_id(), and call bpf_link_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.

Currently, the kernel does not support non-zero open_flags for
bpf_link_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-6-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Roberto Sassu
2ce7cbf2ba libbpf: Introduce bpf_btf_get_fd_by_id_opts()
Introduce bpf_btf_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_btf_get_fd_by_id(), and call bpf_btf_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.

Currently, the kernel does not support non-zero open_flags for
bpf_btf_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-5-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Roberto Sassu
8f13f168ea libbpf: Introduce bpf_prog_get_fd_by_id_opts()
Introduce bpf_prog_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_prog_get_fd_by_id(), and call bpf_prog_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.

Currently, the kernel does not support non-zero open_flags for
bpf_prog_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-4-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Roberto Sassu
243e300563 libbpf: Introduce bpf_get_fd_by_id_opts and bpf_map_get_fd_by_id_opts()
Define a new data structure called bpf_get_fd_by_id_opts, with the member
open_flags, to be used by callers of the _opts variants of
bpf_*_get_fd_by_id() to specify the permissions needed for the file
descriptor to be obtained.

Also, introduce bpf_map_get_fd_by_id_opts(), to let the caller pass a
bpf_get_fd_by_id_opts structure.

Finally, keep the existing bpf_map_get_fd_by_id(), and call
bpf_map_get_fd_by_id_opts() with NULL as opts argument, to request
read-write permissions (current behavior).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-3-roberto.sassu@huaweicloud.com
2022-10-10 16:49:20 -07:00
Andrii Nakryiko
abf84b64e3 libbpf: Clean up deprecated and legacy aliases
Remove three missed deprecated APIs that were aliased to new APIs:
bpf_object__unload, bpf_prog_attach_xattr and btf__load.

Also move legacy API libbpf_find_kernel_btf (aliased to
btf__load_vmlinux_btf) into libbpf_legacy.h.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20220816001929.369487-4-andrii@kernel.org
2022-08-17 22:42:56 +02:00
Andrii Nakryiko
813847a314 libbpf: Streamline bpf_attr and perf_event_attr initialization
Make sure that entire libbpf code base is initializing bpf_attr and
perf_event_attr with memset(0). Also for bpf_attr make sure we
clear and pass to kernel only relevant parts of bpf_attr. bpf_attr is
a huge union of independent sub-command attributes, so there is no need
to clear and pass entire union bpf_attr, which over time grows quite
a lot and for most commands this growth is completely irrelevant.

Few cases where we were relying on compiler initialization of BPF UAPI
structs (like bpf_prog_info, bpf_map_info, etc) with `= {};` were
switched to memset(0) pattern for future-proofing.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20220816001929.369487-3-andrii@kernel.org
2022-08-17 22:42:10 +02:00
Hangbin Liu
1f235777c3 libbpf: Making bpf_prog_load() ignore name if kernel doesn't support
Similar with commit 10b62d6a38 ("libbpf: Add names for auxiliary maps"),
let's make bpf_prog_load() also ignore name if kernel doesn't support
program name.

To achieve this, we need to call sys_bpf_prog_load() directly in
probe_kern_prog_name() to avoid circular dependency. sys_bpf_prog_load()
also need to be exported in the libbpf_internal.h file.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220813000936.6464-1-liuhangbin@gmail.com
2022-08-15 14:58:20 -07:00
Hangbin Liu
10b62d6a38 libbpf: Add names for auxiliary maps
The bpftool self-created maps can appear in final map show output due to
deferred removal in kernel. These maps don't have a name, which would make
users confused about where it comes from.

With a libbpf_ prefix name, users could know who created these maps.
It also could make some tests (like test_offload.py, which skip base maps
without names as a workaround) filter them out.

Kernel adds bpf prog/map name support in the same merge
commit fadad670a8 ("Merge branch 'bpf-extend-info'"). So we can also use
kernel_supports(NULL, FEAT_PROG_NAME) to check if kernel supports map name.

As discussed [1], Let's make bpf_map_create accept non-null
name string, and silently ignore the name if kernel doesn't support.

  [1] https://lore.kernel.org/bpf/CAEf4BzYL1TQwo1231s83pjTdFPk9XWWhfZC5=KzkU-VO0k=0Ug@mail.gmail.com/

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220811034020.529685-1-liuhangbin@gmail.com
2022-08-11 15:12:38 -07:00
Joe Burton
395fc4fa33 libbpf: Add bpf_obj_get_opts()
Add an extensible variant of bpf_obj_get() capable of setting the
`file_flags` parameter.

This parameter is needed to enable unprivileged access to BPF maps.
Without a method like this, users must manually make the syscall.

Signed-off-by: Joe Burton <jevburton@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220729202727.3311806-1-jevburton.kernel@gmail.com
2022-07-29 15:30:06 -07:00
Stanislav Fomichev
a4b2f3cf69 libbpf: implement bpf_prog_query_opts
Implement bpf_prog_query_opts as a more expendable version of
bpf_prog_query. Expose new prog_attach_flags and attach_btf_func_id as
well:

* prog_attach_flags is a per-program attach_type; relevant only for
  lsm cgroup program which might have different attach_flags
  per attach_btf_id
* attach_btf_func_id is a new field expose for prog_query which
  specifies real btf function id for lsm cgroup attachments

Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220628174314.1216643-10-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29 13:21:52 -07:00
Andrii Nakryiko
bd054102a8 libbpf: enforce strict libbpf 1.0 behaviors
Remove support for legacy features and behaviors that previously had to
be disabled by calling libbpf_set_strict_mode():
  - legacy BPF map definitions are not supported now;
  - RLIMIT_MEMLOCK auto-setting, if necessary, is always on (but see
    libbpf_set_memlock_rlim());
  - program name is used for program pinning (instead of section name);
  - cleaned up error returning logic;
  - entry BPF programs should have SEC() always.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220627211527.2245459-15-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28 13:13:33 -07:00
Andrii Nakryiko
765a34130e libbpf: remove deprecated low-level APIs
Drop low-level APIs as well as high-level (and very confusingly named)
BPF object loading bpf_prog_load_xattr() and bpf_prog_load_deprecated()
APIs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220627211527.2245459-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28 13:13:32 -07:00