Commit Graph

3063 Commits

Author SHA1 Message Date
Magnus Karlsson
d2e5414949 selftests/xsk: do not change XDP program when not necessary
Do not change the XDP program for the Tx thread when not needed. It
was erroneously compared to the XDP program for the Rx thread, which
is always going to be different, which meant that the code made
unnecessary switches to the same program it had before. This did not
affect functionality, just performance.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-2-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Jiri Olsa
65eb006d85 bpf: Move kernel test kfuncs to bpf_testmod
Moving kernel test kfuncs into bpf_testmod kernel module, and adding
necessary init calls and BTF IDs records.

We need to keep following structs in kernel:
  struct prog_test_ref_kfunc
  struct prog_test_member (embedded in prog_test_ref_kfunc)

The reason is because they need to be marked as rcu safe (check test
prog mark_ref_as_untrusted_or_null) and such objects are being required
to be defined only in kernel at the moment (see rcu_safe_kptr check
in kernel).

We need to keep also dtor functions for both objects in kernel:
  bpf_kfunc_call_test_release
  bpf_kfunc_call_memb_release

We also keep the copy of these struct in bpf_testmod_kfunc.h, because
other test functions use them. This is unfortunate, but this is just
temporary solution until we are able to these structs them to bpf_testmod
completely.

As suggested by David adding bpf_testmod.ko make dependency for
bpf programs, so they are rebuilt if we change the bpf_testmod.ko
module.

Also adding missing __bpf_kfunc to bpf_kfunc_call_test4 functions.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230515133756.1658301-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:24 -07:00
Jiri Olsa
6e2b50fa81 selftests/bpf: Remove extern from kfuncs declarations
There's no need to keep the extern in kfuncs declarations.

Suggested-by: David Vernet <void@manifault.com>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-10-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
f26ebdd3e4 selftests/bpf: Allow to use kfunc from testmod.ko in test_verifier
Currently the test_verifier allows test to specify kfunc symbol
and search for it in the kernel BTF.

Adding the possibility to search for kfunc also in bpf_testmod
module when it's not found in kernel BTF.

To find bpf_testmod btf we need to get back SYS_ADMIN cap.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-9-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
b23b385fa1 selftests/bpf: Load bpf_testmod for verifier test
Loading bpf_testmod kernel module for verifier test. We will
move all the tests kfuncs into bpf_testmod in following change.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-8-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
11642eb92b selftests/bpf: Use un/load_bpf_testmod functions in tests
Now that we have un/load_bpf_testmod helpers in testing_helpers.h,
we can use it in other tests and save some lines.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-7-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
b58f3f0e6f selftests/bpf: Do not unload bpf_testmod in load_bpf_testmod
Do not unload bpf_testmod in load_bpf_testmod, instead call
unload_bpf_testmod separatelly.

This way we will be able use un/load_bpf_testmod functions
in other tests that un/load bpf_testmod module.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-6-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
d18decca69 selftests/bpf: Use only stdout in un/load_bpf_testmod functions
We are about to use un/load_bpf_testmod functions in couple tests
and it's better  to print output to stdout,  so it's aligned with
tests ASSERT macros output, which use stdout as well.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
45db310984 selftests/bpf: Move test_progs helpers to testing_helpers object
Moving test_progs helpers to testing_helpers object so they can be
used from test_verifier in following changes.

Also adding missing ifndef header guard to testing_helpers.h header.

Using stderr instead of env.stderr because un/load_bpf_testmod helpers
will be used outside test_progs. Also at the point of calling them
in test_progs the std files are not hijacked yet and stderr is the
same as env.stderr.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-4-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
8e9af82171 selftests/bpf: Move kfunc exports to bpf_testmod/bpf_testmod_kfunc.h
Move all kfunc exports into separate bpf_testmod_kfunc.h header file
and include it in tests that need it.

We will move all test kfuncs into bpf_testmod in following change,
so it's convenient to have declarations in single place.

The bpf_testmod_kfunc.h is included by both bpf_testmod and bpf
programs that use test kfuncs.

As suggested by David, the bpf_testmod_kfunc.h includes vmlinux.h
and bpf/bpf_helpers.h for bpf programs build, so the declarations
have proper __ksym attribute and we can resolve all the structs.

Note in kfunc_call_test_subprog.c we can no longer use the sk_state
define from bpf_tcp_helpers.h (because it clashed with vmlinux.h)
and we need to address __sk_common.skc_state field directly.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Yonghong Song
de58ef414d selftests/bpf: Fix s390 sock_field test failure
llvm patch [1] enabled cross-function optimization for func arguments
(ArgumentPromotion) at -O2 level. And this caused s390 sock_fields
test failure ([2]). The failure is gone right now as patch [1] was
reverted in [3]. But it is possible that patch [3] will be reverted
again and then the test failure in [2] will show up again. So it is
desirable to fix the failure regardless.

The following is an analysis why sock_field test fails with
llvm patch [1].

The main problem is in
  static __noinline bool sk_dst_port__load_word(struct bpf_sock *sk)
  {
        __u32 *word = (__u32 *)&sk->dst_port;
        return word[0] == bpf_htons(0xcafe);
  }
  static __noinline bool sk_dst_port__load_half(struct bpf_sock *sk)
  {
        __u16 *half = (__u16 *)&sk->dst_port;
        return half[0] == bpf_htons(0xcafe);
  }
  ...
  int read_sk_dst_port(struct __sk_buff *skb)
  {
	...
        sk = skb->sk;
	...
        if (!sk_dst_port__load_word(sk))
                RET_LOG();
        if (!sk_dst_port__load_half(sk))
                RET_LOG();
	...
  }

Through some cross-function optimization by ArgumentPromotion
optimization, the compiler does:
  static __noinline bool sk_dst_port__load_word(__u32 word_val)
  {
        return word_val == bpf_htons(0xcafe);
  }
  static __noinline bool sk_dst_port__load_half(__u16 half_val)
  {
        return half_val == bpf_htons(0xcafe);
  }
  ...
  int read_sk_dst_port(struct __sk_buff *skb)
  {
        ...
        sk = skb->sk;
        ...
        __u32 *word = (__u32 *)&sk->dst_port;
        __u32 word_val = word[0];
        ...
        if (!sk_dst_port__load_word(word_val))
                RET_LOG();

        __u16 half_val = word_val >> 16;
        if (!sk_dst_port__load_half(half_val))
                RET_LOG();
        ...
  }

In current uapi bpf.h, we have
  struct bpf_sock {
	...
        __be16 dst_port;        /* network byte order */
        __u16 :16;              /* zero padding */
	...
  };
But the old kernel (e.g., 5.6) we have
  struct bpf_sock {
	...
	__u32 dst_port;         /* network byte order */
	...
  };

So for backward compatability reason, 4-byte load of
dst_port is converted to 2-byte load internally.
Specifically, 'word_val = word[0]' is replaced by 2-byte load
by the verifier and this caused the trouble for later
sk_dst_port__load_half() where half_val becomes 0.

Typical usr program won't have such a code pattern tiggering
the above bug, so let us fix the test failure with source
code change. Adding an empty asm volatile statement seems
enough to prevent undesired transformation.

  [1] https://reviews.llvm.org/D148269
  [2] https://lore.kernel.org/bpf/e7f2c5e8-a50c-198d-8f95-388165f1e4fd@meta.com/
  [3] https://reviews.llvm.org/rG141be5c062ecf22bd287afffd310e8ac4711444a

Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230516214945.1013578-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 20:57:16 -07:00
Andrii Nakryiko
24a86d833b selftests/bpf: improve netcnt test robustness
Change netcnt to demand at least 10K packets, as we frequently see some
stray packet arriving during the test in BPF CI. It seems more important
to make sure we haven't lost any packet than enforcing exact number of
packets.

Cc: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230515204833.2832000-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 20:57:16 -07:00
Florent Revest
90564f1e3d bpf, arm64: Support struct arguments in the BPF trampoline
This extends the BPF trampoline JIT to support attachment to functions
that take small structures (up to 128bit) as argument. This is trivially
achieved by saving/restoring a number of "argument registers" rather
than a number of arguments.

The AAPCS64 section 6.8.2 describes the parameter passing ABI.
"Composite types" (like C structs) below 16 bytes (as enforced by the
BPF verifier) are provided as part of the 8 argument registers as
explained in the section C.12.

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/bpf/20230511140507.514888-1-revest@chromium.org
2023-05-15 21:17:22 +02:00
Stanislav Fomichev
e01b4a72f1 selftests/bpf: Correctly handle optlen > 4096
Even though it's not relevant in selftests, the people
might still copy-paste from them. So let's take care
of optlen > 4096 cases explicitly.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230511170456.1759459-4-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-13 16:55:46 -07:00
Stanislav Fomichev
989a4a7dbf selftests/bpf: Update EFAULT {g,s}etsockopt selftests
Instead of assuming EFAULT, let's assume the BPF program's
output is ignored.

Remove "getsockopt: deny arbitrary ctx->retval" because it
was actually testing optlen. We have separate set of tests
for retval.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230511170456.1759459-3-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-13 16:55:44 -07:00
Daniel Rosenberg
798e48fc28 selftests/bpf: Accept mem from dynptr in helper funcs
This ensures that buffers retrieved from dynptr_data are allowed to be
passed in to helpers that take mem, like bpf_strncmp

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-6-drosen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-06 16:42:58 -07:00
Daniel Rosenberg
3881fdfed2 selftests/bpf: Check overflow in optional buffer
This ensures we still reject invalid memory accesses in buffers that are
marked optional.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-4-drosen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-06 16:42:57 -07:00
Daniel Rosenberg
1ce33b6c84 selftests/bpf: Test allowing NULL buffer in dynptr slice
bpf_dynptr_slice(_rw) no longer requires a buffer for verification. If the
buffer is needed, but not present, the function will return NULL.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-3-drosen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-06 16:42:57 -07:00
Feng Zhou
49e0263ab4 selftests/bpf: Add testcase for bpf_task_under_cgroup
test_progs:
Tests new kfunc bpf_task_under_cgroup().

The bpf program saves the new task's pid within a given cgroup to
the remote_pid, which is convenient for the user-mode program to
verify the test correctness.

The user-mode program creates its own mount namespace, and mounts the
cgroupsv2 hierarchy in there, call the fork syscall, then check if
remote_pid and local_pid are unequal.

Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230506031545.35991-3-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-06 13:56:38 -07:00
Andrii Nakryiko
c91ab90cea selftests/bpf: revert iter test subprog precision workaround
Now that precision propagation is supported fully in the presence of
subprogs, there is no need to work around iter test. Revert original
workaround.

This reverts be7dbd275d ("selftests/bpf: avoid mark_all_scalars_precise() trigger in one of iter tests").

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-11-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00
Andrii Nakryiko
3ef3d2177b selftests/bpf: add precision propagation tests in the presence of subprogs
Add a bunch of tests validating verifier's precision backpropagation
logic in the presence of subprog calls and/or callback-calling
helpers/kfuncs.

We validate the following conditions:
  - subprog_result_precise: static subprog r0 result precision handling;
  - global_subprog_result_precise: global subprog r0 precision
    shortcutting, similar to BPF helper handling;
  - callback_result_precise: similarly r0 marking precise for
    callback-calling helpers;
  - parent_callee_saved_reg_precise, parent_callee_saved_reg_precise_global:
    propagation of precision for callee-saved registers bypassing
    static/global subprogs;
  - parent_callee_saved_reg_precise_with_callback: same as above, but in
    the presence of callback-calling helper;
  - parent_stack_slot_precise, parent_stack_slot_precise_global:
    similar to above, but instead propagating precision of stack slot
    (spilled SCALAR reg);
  - parent_stack_slot_precise_with_callback: same as above, but in the
    presence of callback-calling helper;
  - subprog_arg_precise: propagation of precision of static subprog's
    input argument back to caller;
  - subprog_spill_into_parent_stack_slot_precise: negative test
    validating that verifier currently can't support backtracking of stack
    access with non-r10 register, we validate that we fallback to
    forcing precision for all SCALARs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00
Andrii Nakryiko
c50c0b57a5 bpf: fix mark_all_scalars_precise use in mark_chain_precision
When precision backtracking bails out due to some unsupported sequence
of instructions (e.g., stack access through register other than r10), we
need to mark all SCALAR registers as precise to be safe. Currently,
though, we mark SCALARs precise only starting from the state we detected
unsupported condition, which could be one of the parent states of the
actual current state. This will leave some registers potentially not
marked as precise, even though they should. So make sure we start
marking scalars as precise from current state (env->cur_state).

Further, we don't currently detect a situation when we end up with some
stack slots marked as needing precision, but we ran out of available
states to find the instructions that populate those stack slots. This is
akin the `i >= func->allocated_stack / BPF_REG_SIZE` check and should be
handled similarly by falling back to marking all SCALARs precise. Add
this check when we run out of states.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00
Andrii Nakryiko
1ef22b6865 bpf: maintain bitmasks across all active frames in __mark_chain_precision
Teach __mark_chain_precision logic to maintain register/stack masks
across all active frames when going from child state to parent state.
Currently this should be mostly no-op, as precision backtracking usually
bails out when encountering subprog entry/exit.

It's not very apparent from the diff due to increased indentation, but
the logic remains the same, except everything is done on specific `fr`
frame index. Calls to bt_clear_reg() and bt_clear_slot() are replaced
with frame-specific bt_clear_frame_reg() and bt_clear_frame_slot(),
where frame index is passed explicitly, instead of using current frame
number.

We also adjust logging to emit affected frame number. And we also add
better logging of human-readable register and stack slot masks, similar
to previous patch.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00
Andrii Nakryiko
d9439c21a9 bpf: improve precision backtrack logging
Add helper to format register and stack masks in more human-readable
format. Adjust logging a bit during backtrack propagation and especially
during forcing precision fallback logic to make it clearer what's going
on (with log_level=2, of course), and also start reporting affected
frame depth. This is in preparation for having more than one active
frame later when precision propagation between subprog calls is added.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00
Andrii Nakryiko
5956f30116 veristat: add -t flag for adding BPF_F_TEST_STATE_FREQ program flag
Sometimes during debugging it's important that BPF program is loaded
with BPF_F_TEST_STATE_FREQ flag set to force verifier to do frequent
state checkpointing. Teach veristat to do this when -t ("test state")
flag is specified.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:34 -07:00
Stephen Veiss
64276f01dc selftests/bpf: Test_progs can read test lists from file
Improve test selection logic when using -a/-b/-d/-t options.
The list of tests to include or exclude can now be read from a file,
specified as @<filename>.

The file contains one name (or wildcard pattern) per line, and
comments beginning with # are ignored.

These options can be passed multiple times to read more than one file.

Signed-off-by: Stephen Veiss <sveiss@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20230427225333.3506052-3-sveiss@meta.com
2023-05-01 15:30:02 -07:00
Stephen Veiss
0a5c0de8b6 selftests/bpf: Extract insert_test from parse_test_list
Split the logic to insert new tests into test filter sets out from
parse_test_list.

Fix the subtest insertion logic to reuse an existing top-level test
filter, which prevents the creation of duplicate top-level test filters
each with a single subtest.

Signed-off-by: Stephen Veiss <sveiss@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20230427225333.3506052-2-sveiss@meta.com
2023-05-01 15:30:02 -07:00
Martin KaFai Lau
31f4f810d5 selftests/bpf: Add fexit_sleep to DENYLIST.aarch64
It is reported that the fexit_sleep never returns in aarch64.
The remaining tests cannot start. Put this test into DENYLIST.aarch64
for now so that other tests can continue to run in the CI.

Acked-by: Manu Bretelle <chantr4@gmail.com>
Reported-by: Manu Bretelle <chantra@meta.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-04-27 22:11:16 -07:00
Yonghong Song
f1f5553d91 selftests/bpf: Fix selftest test_global_funcs/global_func1 failure with latest clang
The selftest test_global_funcs/global_func1 failed with the latest clang17.
The reason is due to upstream ArgumentPromotionPass ([1]),
which may manipulate static function parameters and cause inlining
although the funciton is marked as noinline.

The original code:
  static __attribute__ ((noinline))
  int f0(int var, struct __sk_buff *skb)
  {
        return skb->len;
  }

  __attribute__ ((noinline))
  int f1(struct __sk_buff *skb)
  {
	...
        return f0(0, skb) + skb->len;
  }

  ...

  SEC("tc")
  __failure __msg("combined stack size of 4 calls is 544")
  int global_func1(struct __sk_buff *skb)
  {
        return f0(1, skb) + f1(skb) + f2(2, skb) + f3(3, skb, 4);
  }

After ArgumentPromotionPass, the code is translated to
  static __attribute__ ((noinline))
  int f0(int var, int skb_len)
  {
        return skb_len;
  }

  __attribute__ ((noinline))
  int f1(struct __sk_buff *skb)
  {
	...
        return f0(0, skb->len) + skb->len;
  }

  ...

  SEC("tc")
  __failure __msg("combined stack size of 4 calls is 544")
  int global_func1(struct __sk_buff *skb)
  {
        return f0(1, skb->len) + f1(skb) + f2(2, skb) + f3(3, skb, 4);
  }

And later llvm InstCombine phase recognized that f0()
simplify returns the value of the second argument and removed f0()
completely and the final code looks like:
  __attribute__ ((noinline))
  int f1(struct __sk_buff *skb)
  {
	...
        return skb->len + skb->len;
  }

  ...

  SEC("tc")
  __failure __msg("combined stack size of 4 calls is 544")
  int global_func1(struct __sk_buff *skb)
  {
        return skb->len + f1(skb) + f2(2, skb) + f3(3, skb, 4);
  }

If f0() is not inlined, the verification will fail with stack size
544 for a particular callchain. With f0() inlined, the maximum
stack size is 512 which is in the limit.

Let us add a `asm volatile ("")` in f0() to prevent ArgumentPromotionPass
from hoisting the code to its caller, and this fixed the test failure.

  [1] https://reviews.llvm.org/D148269

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230425174744.1758515-1-yhs@fb.com
2023-04-27 14:47:16 -07:00
Florent Revest
a464411920 selftests/bpf: Update the aarch64 tests deny list
Now that ftrace supports direct call on arm64, BPF tracing programs work
on that architecture. This fixes the vast majority of BPF selftests
except for:

- multi_kprobe programs which require fprobe, not available on arm64 yet
- tracing_struct which requires trampoline support to access struct args

This patch updates the list of BPF selftests which are known to fail so
the BPF CI can validate the tests which pass now.

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230427143207.635263-1-revest@chromium.org
2023-04-27 22:06:41 +02:00
Jesper Dangaard Brouer
bb32347876 selftests/bpf: xdp_hw_metadata track more timestamps
To correlate the hardware RX timestamp with something, add tracking of
two software timestamps both clock source CLOCK_TAI (see description in
man clock_gettime(2)).

XDP metadata is extended with xdp_timestamp for capturing when XDP
received the packet. Populated with BPF helper bpf_ktime_get_tai_ns(). I
could not find a BPF helper for getting CLOCK_REALTIME, which would have
been preferred. In userspace when AF_XDP sees the packet another
software timestamp is recorded via clock_gettime() also clock source
CLOCK_TAI.

Example output shortly after loading igc driver:

  poll: 1 (0) skip=1 fail=0 redir=2
  xsk_ring_cons__peek: 1
  0x12557a8: rx_desc[1]->addr=100000000009000 addr=9100 comp_addr=9000
  rx_hash: 0x82A96531 with RSS type:0x1
  rx_timestamp:  1681740540304898909 (sec:1681740540.3049)
  XDP RX-time:   1681740577304958316 (sec:1681740577.3050) delta sec:37.0001 (37000059.407 usec)
  AF_XDP time:   1681740577305051315 (sec:1681740577.3051) delta sec:0.0001 (92.999 usec)
  0x12557a8: complete idx=9 addr=9000

The first observation is that the 37 sec difference between RX HW vs XDP
timestamps, which indicate hardware is likely clock source
CLOCK_REALTIME, because (as of this writing) CLOCK_TAI is initialised
with a 37 sec offset.

The 93 usec (microsec) difference between XDP vs AF_XDP userspace is the
userspace wakeup time. On this hardware it was caused by CPU idle sleep
states, which can be reduced by tuning /dev/cpu_dma_latency.

View current requested/allowed latency bound via:
  hexdump --format '"%d\n"' /dev/cpu_dma_latency

More explanation of the output and how this can be used to identify
clock drift for the HW clock can be seen here[1]:

[1] https://github.com/xdp-project/xdp-project/blob/master/areas/hints/xdp_hints_kfuncs02_driver_igc.org

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Yoong Siang <yoong.siang.song@intel.com>
Link: https://lore.kernel.org/bpf/168182466298.616355.2544377890818617459.stgit@firesoul
2023-04-27 18:42:30 +02:00
Daniel Borkmann
b3e8701dd1 selftests/bpf: Add test case to assert precise scalar path pruning
Add a test case to check for precision marking of safe paths. Ensure
that the verifier will not prematurely prune scalars contributing to
registers needing precision.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2023-04-27 10:48:23 +02:00
Joanne Koong
d911ba7cea selftests/bpf: Add tests for dynptr convenience helpers
Add various tests for the added dynptr convenience helpers.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230420071414.570108-6-joannelkoong@gmail.com
2023-04-27 10:40:52 +02:00
Andrii Nakryiko
be7dbd275d selftests/bpf: avoid mark_all_scalars_precise() trigger in one of iter tests
iter_pass_iter_ptr_to_subprog subtest is relying on actual array size
being passed as subprog parameter. This combined with recent fixes to
precision tracking in conditional jumps ([0]) is now causing verifier to
backtrack all the way to the point where sum() and fill() subprogs are
called, at which point precision backtrack bails out and forces all the
states to have precise SCALAR registers. This in turn causes each
possible value of i within fill() and sum() subprogs to cause
a different non-equivalent state, preventing iterator code to converge.

For now, change the test to assume fixed size of passed in array. Once
BPF verifier supports precision tracking across subprogram calls, these
changes will be reverted as unnecessary.

  [0] 71b547f561 ("bpf: Fix incorrect verifier pruning due to missing register precision taints")

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230424235128.1941726-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-24 17:46:44 -07:00
Dave Marchevsky
7deca5eae8 bpf: Disable bpf_refcount_acquire kfunc calls until race conditions are fixed
As reported by Kumar in [0], the shared ownership implementation for BPF
programs has some race conditions which need to be addressed before it
can safely be used. This patch does so in a minimal way instead of
ripping out shared ownership entirely, as proper fixes for the issues
raised will follow ASAP, at which point this patch's commit can be
reverted to re-enable shared ownership.

The patch removes the ability to call bpf_refcount_acquire_impl from BPF
programs. Programs can only bump refcount and obtain a new owning
reference using this kfunc, so removing the ability to call it
effectively disables shared ownership.

Instead of changing success / failure expectations for
bpf_refcount-related selftests, this patch just disables them from
running for now.

  [0]: https://lore.kernel.org/bpf/d7hyspcow5wtjcmw4fugdgyp3fwhljwuscp3xyut5qnwivyeru@ysdq543otzv2/

Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230424204321.2680232-1-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-24 14:02:11 -07:00
Eduard Zingerman
35150203e3 selftests/bpf: verifier/prevent_map_lookup converted to inline assembly
Test verifier/prevent_map_lookup automatically converted to use inline assembly.

This was a part of a series [1] but could not be applied becuase
another patch from a series had to be witheld.

[1] https://lore.kernel.org/bpf/20230421174234.2391278-1-eddyz87@gmail.com/

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421204514.2450907-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-22 08:26:58 -07:00
Eduard Zingerman
4db10a8243 selftests/bpf: verifier/value_ptr_arith converted to inline assembly
Test verifier/value_ptr_arith automatically converted to use inline assembly.

Test cases "sanitation: alu with different scalars 2" and
"sanitation: alu with different scalars 3" are updated to
avoid -ENOENT as return value, as __retval() annotation
only supports numeric literals.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-25-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:27:19 -07:00
Eduard Zingerman
efe25a330b selftests/bpf: verifier/value_illegal_alu converted to inline assembly
Test verifier/value_illegal_alu automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-24-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:27:07 -07:00
Eduard Zingerman
82887c2568 selftests/bpf: verifier/unpriv converted to inline assembly
Test verifier/unpriv semi-automatically converted to use inline assembly.

The verifier/unpriv.c had to be split in two parts:
- the bulk of the tests is in the progs/verifier_unpriv.c;
- the single test that needs `struct bpf_perf_event_data`
  definition is in the progs/verifier_unpriv_perf.c.

The tests above can't be in a single file because:
- first requires inclusion of the filter.h header
  (to get access to BPF_ST_MEM macro, inline assembler does
   not support this isntruction);
- the second requires vmlinux.h, which contains definitions
  conflicting with filter.h.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-23-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:26:52 -07:00
Eduard Zingerman
81d1d6dd40 selftests/bpf: verifier/subreg converted to inline assembly
Test verifier/subreg automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-22-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:25:45 -07:00
Eduard Zingerman
f323a81806 selftests/bpf: verifier/spin_lock converted to inline assembly
Test verifier/spin_lock automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-21-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:25:31 -07:00
Eduard Zingerman
426fc0e3fc selftests/bpf: verifier/sock converted to inline assembly
Test verifier/sock automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-20-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:25:19 -07:00
Eduard Zingerman
034d9ad25d selftests/bpf: verifier/search_pruning converted to inline assembly
Test verifier/search_pruning automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-19-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:25:07 -07:00
Eduard Zingerman
65222842ca selftests/bpf: verifier/runtime_jit converted to inline assembly
Test verifier/runtime_jit automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-18-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:24:41 -07:00
Eduard Zingerman
16a42573c2 selftests/bpf: verifier/regalloc converted to inline assembly
Test verifier/regalloc automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-17-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:23:40 -07:00
Eduard Zingerman
8be6327959 selftests/bpf: verifier/ref_tracking converted to inline assembly
Test verifier/ref_tracking automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-16-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:23:13 -07:00
Eduard Zingerman
aee1779f0d selftests/bpf: verifier/map_ptr_mixing converted to inline assembly
Test verifier/map_ptr_mixing automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-13-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:20:38 -07:00
Eduard Zingerman
4a400ef9ba selftests/bpf: verifier/map_in_map converted to inline assembly
Test verifier/map_in_map automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-12-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:20:26 -07:00
Eduard Zingerman
b427ca576f selftests/bpf: verifier/lwt converted to inline assembly
Test verifier/lwt automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-11-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:19:20 -07:00
Eduard Zingerman
a6fc14dc5e selftests/bpf: verifier/loops1 converted to inline assembly
Test verifier/loops1 automatically converted to use inline assembly.

There are a few modifications for the converted tests.
"tracepoint" programs do not support test execution, change program
type to "xdp" (which supports test execution) for the following tests
that have __retval tags:
- bounded loop, count to 4
- bonded loop containing forward jump

Also, remove the __retval tag for test:
- bounded loop, count from positive unknown to 4

As it's return value is a random number.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230421174234.2391278-10-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-21 12:19:07 -07:00