sym_is_subprog() is incorrectly rejecting relocations against *weak*
global subprogs. Fix that by realizing that STB_WEAK is also a global
function.
While it seems like verifier doesn't support taking an address of
non-static subprog right now, it's still best to fix support for it on
libbpf side, otherwise users will get a very confusing error during BPF
skeleton generation or static linking due to misinterpreted relocation:
libbpf: prog 'handle_tp': bad map relo against 'foo' in section '.text'
Error: failed to open BPF object file: Relocation failed
It's clearly not a map relocation, but is treated and reported as such
without this fix.
Fixes: 53eddb5e04ac ("libbpf: Support subprog address relocation")
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
tools/lib/bpf/libbpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 712b95e8891b..05ad264ff09b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -4013,7 +4013,7 @@ static bool sym_is_subprog(const Elf64_Sym *sym, int text_shndx)
return true;
/* global function */
- return bind == STB_GLOBAL && type == STT_FUNC;
+ return (bind == STB_GLOBAL || bind == STB_WEAK) && type == STT_FUNC;
}
static int find_extern_btf_id(const struct btf *btf, const char *ext_name)
--
2.43.5
