5.10-stable review patch. If anyone has any objections, please let me know.
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From: Alan Maguire alan.maguire@oracle.com
[ Upstream commit 2454075f8e2915cebbe52a1195631bc7efe2b7e1 ]
As reported by Mirsad [1] we still see format warnings in kernel/bpf/btf.o at W=1 warning level:
CC kernel/bpf/btf.o ./kernel/bpf/btf.c: In function ‘btf_type_seq_show_flags’: ./kernel/bpf/btf.c:7553:21: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format] 7553 | sseq.showfn = btf_seq_show; | ^ ./kernel/bpf/btf.c: In function ‘btf_type_snprintf_show’: ./kernel/bpf/btf.c:7604:31: warning: assignment left-hand side might be a candidate for a format attribute [-Wsuggest-attribute=format] 7604 | ssnprintf.show.showfn = btf_snprintf_show; | ^
Combined with CONFIG_WERROR=y these can halt the build.
The fix (annotating the structure field with __printf()) suggested by Mirsad resolves these. Apologies I missed this last time. No other W=1 warnings were observed in kernel/bpf after this fix.
[1] https://lore.kernel.org/bpf/92c9d047-f058-400c-9c7d-81d4dc1ef71b@gmail.com/
Fixes: b3470da314fd ("bpf: annotate BTF show functions with __printf") Reported-by: Mirsad Todorovac mtodorovac69@gmail.com Suggested-by: Mirsad Todorovac mtodorovac69@gmail.com Signed-off-by: Alan Maguire alan.maguire@oracle.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Link: https://lore.kernel.org/bpf/20240712092859.1390960-1-alan.maguire@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 326feb2301700..cfbb038d150c4 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -340,7 +340,7 @@ static const char *btf_type_str(const struct btf_type *t) struct btf_show { u64 flags; void *target; /* target of show operation (seq file, buffer) */ - void (*showfn)(struct btf_show *show, const char *fmt, va_list args); + __printf(2, 0) void (*showfn)(struct btf_show *show, const char *fmt, va_list args); const struct btf *btf; /* below are used during iteration */ struct {