#
05f9cdd5 |
|
23-Jan-2024 |
Andrii Nakryiko <andrii@kernel.org> |
libbpf: Move feature detection code into its own file It's quite a lot of well isolated code, so it seems like a good candidate to move it out of libbpf.c to reduce its size. 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/20240124022127.2379740-24-andrii@kernel.org
|
#
d17aff80 |
|
19-Dec-2023 |
Andrii Nakryiko <andrii@kernel.org> |
Revert BPF token-related functionality This patch includes the following revert (one conflicting BPF FS patch and three token patch sets, represented by merge commits): - revert 0f5d5454c723 "Merge branch 'bpf-fs-mount-options-parsing-follow-ups'"; - revert 750e785796bb "bpf: Support uid and gid when mounting bpffs"; - revert 733763285acf "Merge branch 'bpf-token-support-in-libbpf-s-bpf-object'"; - revert c35919dcce28 "Merge branch 'bpf-token-and-bpf-fs-based-delegation'". Link: https://lore.kernel.org/bpf/CAHk-=wg7JuFYwGy=GOMbRCtOL+jwSQsdUaBsRWkDVYbxipbM5A@mail.gmail.com Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
|
#
ab8fc393 |
|
13-Dec-2023 |
Andrii Nakryiko <andrii@kernel.org> |
libbpf: move feature detection code into its own file It's quite a lot of well isolated code, so it seems like a good candidate to move it out of libbpf.c to reduce its size. Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231213190842.3844987-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
48f0dfd8 |
|
25-Nov-2023 |
Jiri Olsa <jolsa@kernel.org> |
libbpf: Add st_type argument to elf_resolve_syms_offsets function We need to get offsets for static variables in following changes, so making elf_resolve_syms_offsets to take st_type value as argument and passing it to elf_sym_iter_new. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/bpf/20231125193130.834322-2-jolsa@kernel.org
|
#
137df118 |
|
16-Oct-2023 |
Andrii Nakryiko <andrii@kernel.org> |
libbpf: Don't assume SHT_GNU_verdef presence for SHT_GNU_versym section Fix too eager assumption that SHT_GNU_verdef ELF section is going to be present whenever binary has SHT_GNU_versym section. It seems like either SHT_GNU_verdef or SHT_GNU_verneed can be used, so failing on missing SHT_GNU_verdef actually breaks use cases in production. One specific reported issue, which was used to manually test this fix, was trying to attach to `readline` function in BASH binary. Fixes: bb7fa09399b9 ("libbpf: Support symbol versioning for uprobe") Reported-by: Liam Wisehart <liamwisehart@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Manu Bretelle <chantr4@gmail.com> Reviewed-by: Fangrui Song <maskray@google.com> Acked-by: Hengqi Chen <hengqi.chen@gmail.com> Link: https://lore.kernel.org/bpf/20231016182840.4033346-1-andrii@kernel.org
|
#
bb7fa093 |
|
17-Sep-2023 |
Hengqi Chen <hengqi.chen@gmail.com> |
libbpf: Support symbol versioning for uprobe In current implementation, we assume that symbol found in .dynsym section would have a version suffix and use it to compare with symbol user supplied. According to the spec ([0]), this assumption is incorrect, the version info of dynamic symbols are stored in .gnu.version and .gnu.version_d sections of ELF objects. For example: $ nm -D /lib/x86_64-linux-gnu/libc.so.6 | grep rwlock_wrlock 000000000009b1a0 T __pthread_rwlock_wrlock@GLIBC_2.2.5 000000000009b1a0 T pthread_rwlock_wrlock@@GLIBC_2.34 000000000009b1a0 T pthread_rwlock_wrlock@GLIBC_2.2.5 $ readelf -W --dyn-syms /lib/x86_64-linux-gnu/libc.so.6 | grep rwlock_wrlock 706: 000000000009b1a0 878 FUNC GLOBAL DEFAULT 15 __pthread_rwlock_wrlock@GLIBC_2.2.5 2568: 000000000009b1a0 878 FUNC GLOBAL DEFAULT 15 pthread_rwlock_wrlock@@GLIBC_2.34 2571: 000000000009b1a0 878 FUNC GLOBAL DEFAULT 15 pthread_rwlock_wrlock@GLIBC_2.2.5 In this case, specify pthread_rwlock_wrlock@@GLIBC_2.34 or pthread_rwlock_wrlock@GLIBC_2.2.5 in bpf_uprobe_opts::func_name won't work. Because the qualified name does NOT match `pthread_rwlock_wrlock` (without version suffix) in .dynsym sections. This commit implements the symbol versioning for dynsym and allows user to specify symbol in the following forms: - func - func@LIB_VERSION - func@@LIB_VERSION In case of symbol conflicts, error out and users should resolve it by specifying a qualified name. [0]: https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/symversion.html Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20230918024813.237475-3-hengqi.chen@gmail.com
|
#
7257cee6 |
|
17-Sep-2023 |
Hengqi Chen <hengqi.chen@gmail.com> |
libbpf: Resolve symbol conflicts at the same offset for uprobe Dynamic symbols in shared library may have the same name, for example: $ nm -D /lib/x86_64-linux-gnu/libc.so.6 | grep rwlock_wrlock 000000000009b1a0 T __pthread_rwlock_wrlock@GLIBC_2.2.5 000000000009b1a0 T pthread_rwlock_wrlock@@GLIBC_2.34 000000000009b1a0 T pthread_rwlock_wrlock@GLIBC_2.2.5 $ readelf -W --dyn-syms /lib/x86_64-linux-gnu/libc.so.6 | grep rwlock_wrlock 706: 000000000009b1a0 878 FUNC GLOBAL DEFAULT 15 __pthread_rwlock_wrlock@GLIBC_2.2.5 2568: 000000000009b1a0 878 FUNC GLOBAL DEFAULT 15 pthread_rwlock_wrlock@@GLIBC_2.34 2571: 000000000009b1a0 878 FUNC GLOBAL DEFAULT 15 pthread_rwlock_wrlock@GLIBC_2.2.5 Currently, users can't attach a uprobe to pthread_rwlock_wrlock because there are two symbols named pthread_rwlock_wrlock and both are global bind. And libbpf considers it as a conflict. Since both of them are at the same offset we could accept one of them harmlessly. Note that we already does this in elf_resolve_syms_offsets. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20230918024813.237475-2-hengqi.chen@gmail.com
|
#
e613d1d0 |
|
09-Aug-2023 |
Jiri Olsa <jolsa@kernel.org> |
libbpf: Add elf_resolve_pattern_offsets function Adding elf_resolve_pattern_offsets function that looks up offsets for symbols specified by pattern argument. The 'pattern' argument allows wildcards (*?' supported). Offsets are returned in allocated array together with its size and needs to be released by the caller. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230809083440.3209381-13-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
7ace84c6 |
|
09-Aug-2023 |
Jiri Olsa <jolsa@kernel.org> |
libbpf: Add elf_resolve_syms_offsets function Adding elf_resolve_syms_offsets function that looks up offsets for symbols specified in syms array argument. Offsets are returned in allocated array with the 'cnt' size, that needs to be released by the caller. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230809083440.3209381-12-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
3774705d |
|
09-Aug-2023 |
Jiri Olsa <jolsa@kernel.org> |
libbpf: Add elf symbol iterator Adding elf symbol iterator object (and some functions) that follow open-coded iterator pattern and some functions to ease up iterating elf object symbols. The idea is to iterate single symbol section with: struct elf_sym_iter iter; struct elf_sym *sym; if (elf_sym_iter_new(&iter, elf, binary_path, SHT_DYNSYM)) goto error; while ((sym = elf_sym_iter_next(&iter))) { ... } I considered opening the elf inside the iterator and iterate all symbol sections, but then it gets more complicated wrt user checks for when the next section is processed. Plus side is the we don't need 'exit' function, because caller/user is in charge of that. The returned iterated symbol object from elf_sym_iter_next function is placed inside the struct elf_sym_iter, so no extra allocation or argument is needed. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230809083440.3209381-11-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
f90eb70d |
|
09-Aug-2023 |
Jiri Olsa <jolsa@kernel.org> |
libbpf: Add elf_open/elf_close functions Adding elf_open/elf_close functions and using it in elf_find_func_offset_from_file function. It will be used in following changes to save some common code. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230809083440.3209381-10-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
#
5c742725 |
|
09-Aug-2023 |
Jiri Olsa <jolsa@kernel.org> |
libbpf: Move elf_find_func_offset* functions to elf object Adding new elf object that will contain elf related functions. There's no functional change. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230809083440.3209381-9-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|