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

[Ben Dooks <ben.dooks@codethink.co.uk>]

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@codethink.co.uk>
> 
> 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@oracle.com>


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;
> 

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

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