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| author | Alexei Starovoitov <ast@kernel.org> | 2023-03-17 13:19:19 -0700 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2023-03-17 15:46:00 -0700 |
| commit | 5cbd3fe3a91df46ea201cc5d8ab4e390332ec26e (patch) | |
| tree | 0731f47023f2105efcca7be36cbacffaf5269d36 | |
| parent | 5fc13ad59b60708e52932188854d4d5bf2b0e10e (diff) | |
| download | bpf-5cbd3fe3a91df46ea201cc5d8ab4e390332ec26e.tar.gz | |
libbpf: Introduce bpf_ksym_exists() macro.
Introduce bpf_ksym_exists() macro that can be used by BPF programs
to detect at load time whether particular ksym (either variable or kfunc)
is present in the kernel.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230317201920.62030-4-alexei.starovoitov@gmail.com
| -rw-r--r-- | tools/lib/bpf/bpf_helpers.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h index 7d12d3e620cc8d..e7e1a8acc29970 100644 --- a/tools/lib/bpf/bpf_helpers.h +++ b/tools/lib/bpf/bpf_helpers.h @@ -177,6 +177,11 @@ enum libbpf_tristate { #define __kptr_untrusted __attribute__((btf_type_tag("kptr_untrusted"))) #define __kptr __attribute__((btf_type_tag("kptr"))) +#define bpf_ksym_exists(sym) ({ \ + _Static_assert(!__builtin_constant_p(!!sym), #sym " should be marked as __weak"); \ + !!sym; \ +}) + #ifndef ___bpf_concat #define ___bpf_concat(a, b) a ## b #endif |