Re: [PATCH 00/12] Clang -Wformat warning fixes

From: Jan Engelhardt
Date: Thu Jun 09 2022 - 19:03:58 EST



On Friday 2022-06-10 00:49, Bill Wendling wrote:
>On Thu, Jun 9, 2022 at 3:25 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>> On Thu, 9 Jun 2022 22:16:19 +0000 Bill Wendling <morbo@xxxxxxxxxx> wrote:
>>
>> > This patch set fixes some clang warnings when -Wformat is enabled.
>>
>> tldr:
>>
>> - printk(msg);
>> + printk("%s", msg);
>>
>> Otherwise these changes are a
>> useless consumer of runtime resources.
>
>Calling a "printf" style function is already insanely expensive.
>[...]
>The "printk" and similar functions all have the "__printf" attribute.
>I don't know of a modification to that attribute which can turn off
>this type of check.

Perhaps you can split vprintk_store in the middle (after the call to
vsnprintf), and offer the second half as a function of its own (e.g.
"puts"). Then the tldr could be

- printk(msg);
+ puts(msg);