linux.git/include/linux/btf_ids.h, branch v6.12.80 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git bpf: Include linux/types.h for u32 2024-04-29T23:28:07+00:00 Dmitrii Bundin dmitrii.bundin.a@gmail.com 2024-04-20T04:24:57+00:00 cfd3bfe9507b4aa39f7e86772e60b50b799e490e Inclusion of the header linux/btf_ids.h relies on indirect inclusion of the header linux/types.h. Including it directly on the top level helps to avoid potential problems if linux/types.h hasn't been included before. The main motivation to introduce this it is to avoid similar problems that have shown up in the bpftool where GNU libc indirectly pulls linux/types.h causing compile error of the form: error: unknown type name 'u32' u32 cnt; ^~~ The bpftool compile error was fixed in 62248b22d01e ("tools/resolve_btfids: fix build with musl libc"). Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240420042457.3198883-1-dmitrii.bundin.a@gmail.com 
Inclusion of the header linux/btf_ids.h relies on indirect inclusion of
the header linux/types.h. Including it directly on the top level helps
to avoid potential problems if linux/types.h hasn't been included
before.

The main motivation to introduce this it is to avoid similar problems that
have shown up in the bpftool where GNU libc indirectly pulls
linux/types.h causing compile error of the form:

   error: unknown type name 'u32'
                             u32 cnt;
                             ^~~

The bpftool compile error was fixed in
62248b22d01e ("tools/resolve_btfids: fix build with musl libc").

Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240420042457.3198883-1-dmitrii.bundin.a@gmail.com
bpf: btf: Add BTF_KFUNCS_START/END macro pair 2024-02-01T04:40:52+00:00 Daniel Xu dxu@dxuuu.xyz 2024-01-29T01:24:07+00:00 a05e90427ef6706f59188b379ad6366b9d298bc5 This macro pair is functionally equivalent to BTF_SET8_START/END, except with BTF_SET8_KFUNCS flag set in the btf_id_set8 flags field. The next commit will codemod all kfunc set8s to this new variant such that all kfuncs are tagged as such in .BTF_ids section. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/d536c57c7c2af428686853cc7396b7a44faa53b7.1706491398.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
This macro pair is functionally equivalent to BTF_SET8_START/END, except
with BTF_SET8_KFUNCS flag set in the btf_id_set8 flags field. The next
commit will codemod all kfunc set8s to this new variant such that all
kfuncs are tagged as such in .BTF_ids section.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/d536c57c7c2af428686853cc7396b7a44faa53b7.1706491398.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: btf: Support flags for BTF_SET8 sets 2024-01-31T20:05:24+00:00 Daniel Xu dxu@dxuuu.xyz 2024-01-29T01:24:06+00:00 79b47344bbc5a693a92ed6b2b09dac59254bfac8 This commit adds support for flags on BTF_SET8s. struct btf_id_set8 already supported 32 bits worth of flags, but was only used for alignment purposes before. We now use these bits to encode flags. The first use case is tagging kfunc sets with a flag so that pahole can recognize which BTF_ID_FLAGS(func, ..) are actual kfuncs. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/7bb152ec76d6c2c930daec88e995bf18484a5ebb.1706491398.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
This commit adds support for flags on BTF_SET8s. struct btf_id_set8
already supported 32 bits worth of flags, but was only used for
alignment purposes before.

We now use these bits to encode flags. The first use case is tagging
kfunc sets with a flag so that pahole can recognize which
BTF_ID_FLAGS(func, ..) are actual kfuncs.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/7bb152ec76d6c2c930daec88e995bf18484a5ebb.1706491398.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: Fix BTF_ID symbol generation collision 2023-09-15T19:08:27+00:00 Jiri Olsa jolsa@kernel.org 2023-09-15T17:34:27+00:00 8f908db77782630c45ba29dac35c434b5ce0b730 Marcus and Satya reported an issue where BTF_ID macro generates same symbol in separate objects and that breaks final vmlinux link. ld.lld: error: ld-temp.o <inline asm>:14577:1: symbol '__BTF_ID__struct__cgroup__624' is already defined This can be triggered under specific configs when __COUNTER__ happens to be the same for the same symbol in two different translation units, which is already quite unlikely to happen. Add __LINE__ number suffix to make BTF_ID symbol more unique, which is not a complete fix, but it would help for now and meanwhile we can work on better solution as suggested by Andrii. Cc: stable@vger.kernel.org Reported-by: Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com> Reported-by: Marcus Seyfarth <m.seyfarth@gmail.com> Closes: https://github.com/ClangBuiltLinux/linux/issues/1913 Debugged-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/bpf/CAEf4Bzb5KQ2_LmhN769ifMeSJaWfebccUasQOfQKaOd0nQ51tw@mail.gmail.com/ Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20230915-bpf_collision-v3-1-263fc519c21f@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Marcus and Satya reported an issue where BTF_ID macro generates same
symbol in separate objects and that breaks final vmlinux link.

ld.lld: error: ld-temp.o <inline asm>:14577:1: symbol
'__BTF_ID__struct__cgroup__624' is already defined

This can be triggered under specific configs when __COUNTER__ happens to
be the same for the same symbol in two different translation units,
which is already quite unlikely to happen.

Add __LINE__ number suffix to make BTF_ID symbol more unique, which is
not a complete fix, but it would help for now and meanwhile we can work
on better solution as suggested by Andrii.

Cc: stable@vger.kernel.org
Reported-by: Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com>
Reported-by: Marcus Seyfarth <m.seyfarth@gmail.com>
Closes: https://github.com/ClangBuiltLinux/linux/issues/1913
Debugged-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/bpf/CAEf4Bzb5KQ2_LmhN769ifMeSJaWfebccUasQOfQKaOd0nQ51tw@mail.gmail.com/
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230915-bpf_collision-v3-1-263fc519c21f@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: consider CONST_PTR_TO_MAP as trusted pointer to struct bpf_map 2023-07-19T16:48:52+00:00 Anton Protopopov aspsk@isovalent.com 2023-07-19T09:29:50+00:00 5ba190c29cf92f157bd63c9909c7050d6dc43df7 Add the BTF id of struct bpf_map to the reg2btf_ids array. This makes the values of the CONST_PTR_TO_MAP type to be considered as trusted by kfuncs. This, in turn, allows users to execute trusted kfuncs which accept `struct bpf_map *` arguments from non-tracing programs. While exporting the btf_bpf_map_id variable, save some bytes by defining it as BTF_ID_LIST_GLOBAL_SINGLE (which is u32[1]) and not as BTF_ID_LIST (which is u32[64]). Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Link: https://lore.kernel.org/r/20230719092952.41202-3-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Add the BTF id of struct bpf_map to the reg2btf_ids array. This makes the
values of the CONST_PTR_TO_MAP type to be considered as trusted by kfuncs.
This, in turn, allows users to execute trusted kfuncs which accept `struct
bpf_map *` arguments from non-tracing programs.

While exporting the btf_bpf_map_id variable, save some bytes by defining
it as BTF_ID_LIST_GLOBAL_SINGLE (which is u32[1]) and not as BTF_ID_LIST
(which is u32[64]).

Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Link: https://lore.kernel.org/r/20230719092952.41202-3-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: Increase size of BTF_ID_LIST without CONFIG_DEBUG_INFO_BTF again 2023-03-07T15:49:28+00:00 Nathan Chancellor nathan@kernel.org 2023-03-07T15:14:06+00:00 2d5bcdcda8799cf21f9ab84598c946dd320207a2 After commit 66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr"), clang builds without CONFIG_DEBUG_INFO_BTF warn: kernel/bpf/verifier.c:10298:24: warning: array index 16 is past the end of the array (that has type 'u32[16]' (aka 'unsigned int[16]')) [-Warray-bounds] meta.func_id == special_kfunc_list[KF_bpf_dynptr_slice_rdwr]) { ^ ~~~~~~~~~~~~~~~~~~~~~~~~ kernel/bpf/verifier.c:9150:1: note: array 'special_kfunc_list' declared here BTF_ID_LIST(special_kfunc_list) ^ include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST' #define BTF_ID_LIST(name) static u32 __maybe_unused name[16]; ^ 1 warning generated. A warning of this nature was previously addressed by commit beb3d47d1d3d ("bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set") but there have been new kfuncs added since then. Quadruple the size of the CONFIG_DEBUG_INFO_BTF=n definition so that this problem is unlikely to show up for some time. Link: https://github.com/ClangBuiltLinux/linux/issues/1810 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Tom Rix <trix@redhat.com> Link: https://lore.kernel.org/r/20230307-bpf-kfuncs-warray-bounds-v1-1-00ad3191f3a6@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
After commit 66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr"),
clang builds without CONFIG_DEBUG_INFO_BTF warn:

  kernel/bpf/verifier.c:10298:24: warning: array index 16 is past the end of the array (that has type 'u32[16]' (aka 'unsigned int[16]')) [-Warray-bounds]
                                     meta.func_id == special_kfunc_list[KF_bpf_dynptr_slice_rdwr]) {
                                                     ^                  ~~~~~~~~~~~~~~~~~~~~~~~~
  kernel/bpf/verifier.c:9150:1: note: array 'special_kfunc_list' declared here
  BTF_ID_LIST(special_kfunc_list)
  ^
  include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
  #define BTF_ID_LIST(name) static u32 __maybe_unused name[16];
                            ^
  1 warning generated.

A warning of this nature was previously addressed by
commit beb3d47d1d3d ("bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set")
but there have been new kfuncs added since then.

Quadruple the size of the CONFIG_DEBUG_INFO_BTF=n definition so that
this problem is unlikely to show up for some time.

Link: https://github.com/ClangBuiltLinux/linux/issues/1810
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230307-bpf-kfuncs-warray-bounds-v1-1-00ad3191f3a6@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: Fix a compilation failure with clang lto build 2022-12-01T01:13:25+00:00 Yonghong Song yhs@fb.com 2022-11-30T05:21:47+00:00 3144bfa5078e0df7507a4de72061501e6a0e56be When building the kernel with clang lto (CONFIG_LTO_CLANG_FULL=y), the following compilation error will appear: $ make LLVM=1 LLVM_IAS=1 -j ... ld.lld: error: ld-temp.o <inline asm>:26889:1: symbol 'cgroup_storage_map_btf_ids' is already defined cgroup_storage_map_btf_ids:; ^ make[1]: *** [/.../bpf-next/scripts/Makefile.vmlinux_o:61: vmlinux.o] Error 1 In local_storage.c, we have BTF_ID_LIST_SINGLE(cgroup_storage_map_btf_ids, struct, bpf_local_storage_map) Commit c4bcfb38a95e ("bpf: Implement cgroup storage available to non-cgroup-attached bpf progs") added the above identical BTF_ID_LIST_SINGLE definition in bpf_cgrp_storage.c. With duplicated definitions, llvm linker complains with lto build. Also, extracting btf_id of 'struct bpf_local_storage_map' is defined four times for sk, inode, task and cgrp local storages. Let us define a single global one with a different name than cgroup_storage_map_btf_ids, which also fixed the lto compilation error. Fixes: c4bcfb38a95e ("bpf: Implement cgroup storage available to non-cgroup-attached bpf progs") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221130052147.1591625-1-yhs@fb.com 
When building the kernel with clang lto (CONFIG_LTO_CLANG_FULL=y), the
following compilation error will appear:

  $ make LLVM=1 LLVM_IAS=1 -j
  ...
  ld.lld: error: ld-temp.o <inline asm>:26889:1: symbol 'cgroup_storage_map_btf_ids' is already defined
  cgroup_storage_map_btf_ids:;
  ^
  make[1]: *** [/.../bpf-next/scripts/Makefile.vmlinux_o:61: vmlinux.o] Error 1

In local_storage.c, we have
  BTF_ID_LIST_SINGLE(cgroup_storage_map_btf_ids, struct, bpf_local_storage_map)
Commit c4bcfb38a95e ("bpf: Implement cgroup storage available to
non-cgroup-attached bpf progs") added the above identical BTF_ID_LIST_SINGLE
definition in bpf_cgrp_storage.c. With duplicated definitions, llvm linker
complains with lto build.

Also, extracting btf_id of 'struct bpf_local_storage_map' is defined four times
for sk, inode, task and cgrp local storages. Let us define a single global one
with a different name than cgroup_storage_map_btf_ids, which also fixed
the lto compilation error.

Fixes: c4bcfb38a95e ("bpf: Implement cgroup storage available to non-cgroup-attached bpf progs")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221130052147.1591625-1-yhs@fb.com
bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set 2022-11-23T21:20:33+00:00 Yonghong Song yhs@fb.com 2022-11-23T15:57:59+00:00 beb3d47d1d3d7185bb401af628ad32ee204a9526 With CONFIG_DEBUG_INFO_BTF not set, we hit the following compilation error, /.../kernel/bpf/verifier.c:8196:23: error: array index 6 is past the end of the array (that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds] if (meta->func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx]) ^ ~~~~~~~~~~~~~~~~~~~~~~~ /.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here BTF_ID_LIST(special_kfunc_list) ^ /.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST' #define BTF_ID_LIST(name) static u32 __maybe_unused name[5]; ^ /.../kernel/bpf/verifier.c:8443:19: error: array index 5 is past the end of the array (that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds] btf_id == special_kfunc_list[KF_bpf_list_pop_back]; ^ ~~~~~~~~~~~~~~~~~~~~ /.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here BTF_ID_LIST(special_kfunc_list) ^ /.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST' #define BTF_ID_LIST(name) static u32 __maybe_unused name[5]; ... Fix the problem by increase the size of BTF_ID_LIST to 16 to avoid compilation error and also prevent potentially unintended issue due to out-of-bound access. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20221123155759.2669749-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
With CONFIG_DEBUG_INFO_BTF not set, we hit the following compilation error,
  /.../kernel/bpf/verifier.c:8196:23: error: array index 6 is past the end of the array
  (that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds]
        if (meta->func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx])
                             ^                  ~~~~~~~~~~~~~~~~~~~~~~~
  /.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here
  BTF_ID_LIST(special_kfunc_list)
  ^
  /.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
  #define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
                            ^
  /.../kernel/bpf/verifier.c:8443:19: error: array index 5 is past the end of the array
  (that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds]
                 btf_id == special_kfunc_list[KF_bpf_list_pop_back];
                           ^                  ~~~~~~~~~~~~~~~~~~~~
  /.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here
  BTF_ID_LIST(special_kfunc_list)
  ^
  /.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
  #define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
  ...

Fix the problem by increase the size of BTF_ID_LIST to 16 to avoid compilation error
and also prevent potentially unintended issue due to out-of-bound access.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221123155759.2669749-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: Make struct cgroup btf id global 2022-10-26T06:19:19+00:00 Yonghong Song yhs@fb.com 2022-10-26T04:28:40+00:00 5e67b8ef125bb6e83bf0f0442ad7ffc09e7956f9 Make struct cgroup btf id global so later patch can reuse the same btf id. Acked-by: David Vernet <void@manifault.com> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20221026042840.672602-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Make struct cgroup btf id global so later patch can reuse
the same btf id.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221026042840.672602-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf: Fix build error in case of !CONFIG_DEBUG_INFO_BTF 2022-07-22T16:07:07+00:00 Kumar Kartikeya Dwivedi memxor@gmail.com 2022-07-22T11:36:05+00:00 e423414375866a399ebbe55ed044acb39846e8bf BTF_ID_FLAGS macro needs to be able to take 0 or 1 args, so make it a variable argument. BTF_SET8_END is incorrect, it should just be empty. Reported-by: kernel test robot <lkp@intel.com> Fixes: ab21d6063c01 ("bpf: Introduce 8-byte BTF set") Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220722113605.6513-1-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
BTF_ID_FLAGS macro needs to be able to take 0 or 1 args, so make it a
variable argument. BTF_SET8_END is incorrect, it should just be empty.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: ab21d6063c01 ("bpf: Introduce 8-byte BTF set")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220722113605.6513-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>