Re: [PATCH] bpf: add __printf() to for printf fmt strings

[Ben Dooks]

On 22/11/2023 16:44, Alan Maguire wrote:
> On 22/11/2023 13:36, Ben Dooks wrote:
> > The btf_seq_show() and btf_snprintf_show() take a printk format
> > string so add a __printf() to these two functions. This fixes the
> > following extended warnings:
> >
> > kernel/bpf/btf.c:7094:29: error: function ‘btf_seq_show’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format]
> > kernel/bpf/btf.c:7131:9: error: function ‘btf_snprintf_show’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format]
> >
> > Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
>
> Looks good to me, thanks for fixing! Could also add a
>
> Fixes: eb411377aed9 ("bpf: Add bpf_seq_printf_btf helper")
>
> Reviewed-by: Alan Maguire <alan.maguire@xxxxxxxxxx>


Thanks, looks like the test robot found some issues so will
go back and look at those as soon as I can.

> > ---
> >   kernel/bpf/btf.c | 6 +++---
> >   1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> > index 15d71d2986d3..46c2e87c383d 100644
> > --- a/kernel/bpf/btf.c
> > +++ b/kernel/bpf/btf.c
> > @@ -7088,8 +7088,8 @@ 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)
> > +static __printf(2,0) void btf_seq_show(struct btf_show *show, const char *fmt,
> > +				       va_list args)
> >   {
> >   	seq_vprintf((struct seq_file *)show->target, fmt, args);
> >   }
> > @@ -7122,7 +7122,7 @@ struct btf_show_snprintf {
> >   	int len;		/* length we would have written */
> >   };
> >   
> > -static void btf_snprintf_show(struct btf_show *show, const char *fmt,
> > +static __printf(2,0) void btf_snprintf_show(struct btf_show *show, const char *fmt,
> >   			      va_list args)
> >   {
> >   	struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;

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Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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