linux-stable.git/tools/lib/bpf, branch v6.14

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

2025-02-25T21:32:32+00:00

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

tools: Remove redundant quiet setup

2025-02-18T19:27:43+00:00

Q is exported from Makefile.include so it is not necessary to manually
set it.

Reviewed-by: Jiri Olsa 
Signed-off-by: Charlie Jenkins 
Acked-by: Andrii Nakryiko 
Acked-by: Quentin Monnet 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Benjamin Tissoires 
Cc: Daniel Borkmann 
Cc: Daniel Lezcano 
Cc: Eduard Zingerman 
Cc: Hao Luo 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Kosina 
Cc: John Fastabend 
Cc: Josh Poimboeuf 
Cc: KP Singh 
Cc: Lukasz Luba 
Cc: Mark Rutland 
Cc: Martin KaFai Lau 
Cc: Mykola Lysenko 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Rafael J. Wysocki 
Cc: Shuah Khan 
Cc: Song Liu 
Cc: Stanislav Fomichev 
Cc: Steven Rostedt (VMware) 
Cc: Yonghong Song 
Cc: Zhang Rui 
Link: https://lore.kernel.org/r/20250213-quiet_tools-v3-2-07de4482a581@rivosinc.com
Signed-off-by: Arnaldo Carvalho de Melo

libbpf: Work around kernel inconsistently stripping '.llvm.' suffix

2025-01-17T14:16:56+00:00

Some versions of kernel were stripping out '.llvm.' 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.' 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] fb6a421fb615 ("kallsyms: Match symbols exactly with CONFIG_LTO_CLANG")

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20250117003957.179331-1-andrii@kernel.org

libbpf: Fix incorrect traversal end type ID when marking BTF_IS_EMBEDDED

2025-01-16T23:34:18+00:00

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: 19e00c897d50 ("libbpf: Split BTF relocation")
Signed-off-by: Pu Lehui 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20250115100241.4171581-3-pulehui@huaweicloud.com

libbpf: Fix return zero when elf_begin failed

2025-01-16T23:34:18+00:00

The error number of elf_begin is omitted when encapsulating the
btf_find_elf_sections function.

Fixes: c86f180ffc99 ("libbpf: Make btf_parse_elf process .BTF.base transparently")
Signed-off-by: Pu Lehui 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20250115100241.4171581-2-pulehui@huaweicloud.com

libbpf: Add unique_match option for multi kprobe

2025-01-10T21:11:42+00:00

Jordan reported an issue in Meta production environment where func
try_to_wake_up() is renamed to try_to_wake_up.llvm.() 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.(). 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.(). 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.() 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.().

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 
Suggested-by: Andrii Nakryiko 
Signed-off-by: Yonghong Song 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20250109174023.3368432-1-yonghong.song@linux.dev

libbpf: Set MFD_NOEXEC_SEAL when creating memfd

2024-12-30T22:48:15+00:00

Starting from 105ff5339f49 ("mm/memfd: add MFD_NOEXEC_SEAL and
MFD_EXEC") and until 1717449b4417 ("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 
Link: https://lore.kernel.org/r/6e62c2421ad7eb1da49cbf16da95aaaa7f94d394.1735594195.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov

libbpf: prog load: Allow to use fd_array_cnt

2024-12-13T22:48:39+00:00

Add new fd_array_cnt field to bpf_prog_load_opts
and pass it in bpf_attr, if set.

Signed-off-by: Anton Protopopov 
Signed-off-by: Andrii Nakryiko 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20241213130934.1087929-6-aspsk@isovalent.com

libbpf: Extend linker API to support in-memory ELF files

2024-12-12T23:16:53+00:00

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 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20241211164030.573042-3-ajor@meta.com

libbpf: Pull file-opening logic up to top-level functions

2024-12-12T23:09:21+00:00

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 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20241211164030.573042-2-ajor@meta.com