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| author | Ihor Solodrai <ihor.solodrai@linux.dev> | 2026-03-27 23:32:40 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-03-29 19:56:06 +0300 |
| commit | d457072576a6a60ba853b1d815f123da57b48021 (patch) | |
| tree | bf4d2a5031e1cbb47d345d7dd56135ffd1ffc917 /include | |
| parent | 5e961eebef3011697cfc0f0b7d8c4f31c5563c74 (diff) | |
| download | linux-d457072576a6a60ba853b1d815f123da57b48021.tar.xz | |
bpf: Support struct btf_struct_meta via KF_IMPLICIT_ARGS
The following kfuncs currently accept void *meta__ign argument:
* bpf_obj_new_impl
* bpf_obj_drop_impl
* bpf_percpu_obj_new_impl
* bpf_percpu_obj_drop_impl
* bpf_refcount_acquire_impl
* bpf_list_push_back_impl
* bpf_list_push_front_impl
* bpf_rbtree_add_impl
The __ign suffix is an indicator for the verifier to skip the argument
in check_kfunc_args(). Then, in fixup_kfunc_call() the verifier may
set the value of this argument to struct btf_struct_meta *
kptr_struct_meta from insn_aux_data.
BPF programs must pass a dummy NULL value when calling these kfuncs.
Additionally, the list and rbtree _impl kfuncs also accept an implicit
u64 argument, which doesn't require __ign suffix because it's a
scalar, and BPF programs explicitly pass 0.
Add new kfuncs with KF_IMPLICIT_ARGS [1], that correspond to each
_impl kfunc accepting meta__ign. The existing _impl kfuncs remain
unchanged for backwards compatibility.
To support this, add "btf_struct_meta" to the list of recognized
implicit argument types in resolve_btfids.
Implement is_kfunc_arg_implicit() in the verifier, that determines
implicit args by inspecting both a non-_impl BTF prototype of the
kfunc.
Update the special_kfunc_list in the verifier and relevant checks to
support both the old _impl and the new KF_IMPLICIT_ARGS variants of
btf_struct_meta users.
[1] https://lore.kernel.org/bpf/20260120222638.3976562-1-ihor.solodrai@linux.dev/
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260327203241.3365046-1-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/btf_ids.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h index 139bdececdcf..af011db39ab3 100644 --- a/include/linux/btf_ids.h +++ b/include/linux/btf_ids.h @@ -217,7 +217,7 @@ BTF_SET8_END(name) #else -#define BTF_ID_LIST(name) static u32 __maybe_unused name[64]; +#define BTF_ID_LIST(name) static u32 __maybe_unused name[128]; #define BTF_ID(prefix, name) #define BTF_ID_FLAGS(prefix, name, ...) #define BTF_ID_UNUSED |