Hi, On 7/11/24 20:23, Alan Maguire wrote: > -Werror=suggest-attribute=format warns about two functions > in kernel/bpf/btf.c [1]; add __printf() annotations to silence > these warnings since for CONFIG_WERROR=y they will trigger > build failures. > > [1] https://lore.kernel.org/bpf/a8b20c72-6631-4404-9e1f-0410642d7d20@xxxxxxxxx/ > > Fixes: 31d0bc81637d ("bpf: Move to generic BTF show support, apply it to seq files/strings") > Reported-by: Mirsad Todorovac <mtodorovac69@xxxxxxxxx> > Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx> > --- > kernel/bpf/btf.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > index 4ff11779699e..d5019c4454d6 100644 > --- a/kernel/bpf/btf.c > +++ b/kernel/bpf/btf.c > @@ -7538,8 +7538,8 @@ static void btf_type_show(const struct btf *btf, u32 type_id, void *obj, > btf_type_ops(t)->show(btf, t, type_id, obj, 0, show); > } > > -static void btf_seq_show(struct btf_show *show, const char *fmt, > - va_list args) > +__printf(2, 0) static void btf_seq_show(struct btf_show *show, const char *fmt, > + va_list args) > { > seq_vprintf((struct seq_file *)show->target, fmt, args); > } > @@ -7572,8 +7572,8 @@ struct btf_show_snprintf { > int len; /* length we would have written */ > }; > > -static void btf_snprintf_show(struct btf_show *show, const char *fmt, > - va_list args) > +__printf(2, 0) static void btf_snprintf_show(struct btf_show *show, const char *fmt, > + va_list args) > { > struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show; > int len; The error returned from your patch is here: ./kernel/bpf/btf.c: In function ‘btf_type_seq_show_flags’: ./kernel/bpf/btf.c:7553:21: error: assignment left-hand side might be a candidate for a format attribute [-Werror=suggest-attribute=format] 7553 | sseq.showfn = btf_seq_show; | ^ ./kernel/bpf/btf.c: In function ‘btf_type_snprintf_show’: ./kernel/bpf/btf.c:7604:31: error: assignment left-hand side might be a candidate for a format attribute [-Werror=suggest-attribute=format] 7604 | ssnprintf.show.showfn = btf_snprintf_show; | ^ The patch is quite straightforward: -----------------------><------------------------------- diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 4ff11779699e..9711ee6a31e5 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -415,7 +415,7 @@ 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 { -- Life long and prosper! Best regards, Mirsad Todorovac
