linux-toradex.git/tools/lib/bpf, branch v5.17-rc7

libbpf: Add documentation for bpf_map batch operations

2022-01-06T23:12:42+00:00

This adds documention for:

- bpf_map_delete_batch()
- bpf_map_lookup_batch()
- bpf_map_lookup_and_delete_batch()
- bpf_map_update_batch()

This also updates the public API for the `keys` parameter
of `bpf_map_delete_batch()`, and both the
`keys` and `values` parameters of `bpf_map_update_batch()`
to be constants.

Signed-off-by: Grant Seltzer 
Signed-off-by: Andrii Nakryiko 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20220106201304.112675-1-grantseltzer@gmail.com

libbpf 1.0: Deprecate bpf_object__find_map_by_offset() API

2022-01-06T00:11:32+00:00

API created with simplistic assumptions about BPF map definitions.
It hasn’t worked for a while, deprecate it in preparation for
libbpf 1.0.

  [0] Closes: https://github.com/libbpf/libbpf/issues/302

Signed-off-by: Christy Lee 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20220105003120.2222673-1-christylee@fb.com

libbpf 1.0: Deprecate bpf_map__is_offload_neutral()

2022-01-06T00:09:06+00:00

Deprecate bpf_map__is_offload_neutral(). It’s most probably broken
already. PERF_EVENT_ARRAY isn’t the only map that’s not suitable
for hardware offloading. Applications can directly check map type
instead.

  [0] Closes: https://github.com/libbpf/libbpf/issues/306

Signed-off-by: Christy Lee 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20220105000601.2090044-1-christylee@fb.com

libbpf: Support repeated legacy kprobes on same function

2022-01-05T23:38:21+00:00

If repeated legacy kprobes on same function in one process,
libbpf will register using the same probe name and got -EBUSY
error. So append index to the probe name format to fix this
problem.

Co-developed-by: Chengming Zhou 
Signed-off-by: Qiang Wang 
Signed-off-by: Chengming Zhou 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20211227130713.66933-2-wangqiang.wq.frank@bytedance.com

libbpf: Use probe_name for legacy kprobe

2022-01-05T23:38:21+00:00

Fix a bug in commit 46ed5fc33db9, which wrongly used the
func_name instead of probe_name to register legacy kprobe.

Fixes: 46ed5fc33db9 ("libbpf: Refactor and simplify legacy kprobe code")
Co-developed-by: Chengming Zhou 
Signed-off-by: Qiang Wang 
Signed-off-by: Chengming Zhou 
Signed-off-by: Andrii Nakryiko 
Tested-by: Hengqi Chen 
Reviewed-by: Hengqi Chen 
Link: https://lore.kernel.org/bpf/20211227130713.66933-1-wangqiang.wq.frank@bytedance.com

libbpf: Deprecate bpf_perf_event_read_simple() API

2022-01-05T23:27:43+00:00

With perf_buffer__poll() and perf_buffer__consume() APIs available,
there is no reason to expose bpf_perf_event_read_simple() API to
users. If users need custom perf buffer, they could re-implement
the function.

Mark bpf_perf_event_read_simple() and move the logic to a new
static function so it can still be called by other functions in the
same file.

  [0] Closes: https://github.com/libbpf/libbpf/issues/310

Signed-off-by: Christy Lee 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20211229204156.13569-1-christylee@fb.com

libbpf: Improve LINUX_VERSION_CODE detection

2021-12-29T03:20:31+00:00

Ubuntu reports incorrect kernel version through uname(), which on older
kernels leads to kprobe BPF programs failing to load due to the version
check mismatch.

Accommodate Ubuntu's quirks with LINUX_VERSION_CODE by using
Ubuntu-specific /proc/version_code to fetch major/minor/patch versions
to form LINUX_VERSION_CODE.

While at it, consolide libbpf's kernel version detection code between
libbpf.c and libbpf_probes.c.

  [0] Closes: https://github.com/libbpf/libbpf/issues/421

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20211222231003.2334940-1-andrii@kernel.org

libbpf: Use 100-character limit to make bpf_tracing.h easier to read

2021-12-29T03:14:45+00:00

Improve bpf_tracing.h's macro definition readability by keeping them
single-line and better aligned. This makes it easier to follow all those
variadic patterns.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20211222213924.1869758-2-andrii@kernel.org

libbpf: Normalize PT_REGS_xxx() macro definitions

2021-12-29T03:14:44+00:00

Refactor PT_REGS macros definitions in  bpf_tracing.h to avoid excessive
duplication. We currently have classic PT_REGS_xxx() and CO-RE-enabled
PT_REGS_xxx_CORE(). We are about to add also _SYSCALL variants, which
would require excessive copying of all the per-architecture definitions.

Instead, separate architecture-specific field/register names from the
final macro that utilize them. That way for upcoming _SYSCALL variants
we'll be able to just define x86_64 exception and otherwise have one
common set of _SYSCALL macro definitions common for all architectures.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Tested-by: Ilya Leoshkevich 
Acked-by: Yonghong Song 
Acked-by: Ilya Leoshkevich 
Link: https://lore.kernel.org/bpf/20211222213924.1869758-1-andrii@kernel.org

libbpf: Do not use btf_dump__new() macro in C++ mode

2021-12-23T18:23:16+00:00

As reported in here [0], C++ compilers don't support
__builtin_types_compatible_p(), so at least don't screw up compilation
for them and let C++ users pick btf_dump__new vs
btf_dump__new_deprecated explicitly.

  [0] https://github.com/libbpf/libbpf/issues/283#issuecomment-986100727

Fixes: 6084f5dc928f ("libbpf: Ensure btf_dump__new() and btf_dump_opts are future-proof")
Signed-off-by: Jiri Olsa 
Signed-off-by: Andrii Nakryiko 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20211223131736.483956-1-jolsa@kernel.org