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authorAlexei Starovoitov <ast@kernel.org>2023-03-17 13:19:19 -0700
committerAndrii Nakryiko <andrii@kernel.org>2023-03-17 15:46:00 -0700
commit5cbd3fe3a91df46ea201cc5d8ab4e390332ec26e (patch)
tree0731f47023f2105efcca7be36cbacffaf5269d36 /tools/lib
parent5fc13ad59b60708e52932188854d4d5bf2b0e10e (diff)
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
Diffstat (limited to 'tools/lib')
-rw-r--r--tools/lib/bpf/bpf_helpers.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 7d12d3e620cc..e7e1a8acc299 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