Re: [PATCH 1/2] tracing: work around -Wmissing-format-attribute warning

[Andy Shevchenko]

On Tue, Jun 02, 2026 at 10:32:04PM +0200, Arnd Bergmann wrote:
> On Tue, Jun 2, 2026, at 20:59, Andy Shevchenko wrote:
> > On Tue, Jun 02, 2026 at 05:07:05PM +0200, Arnd Bergmann wrote:

...

> > Why the __printf() annotation is in the C file and not here?
> > Is this all about headers as the second paragraph in the commit message 
> > explains?
> > I would add a comment to explain it here, otherwise we might see false 
> > patches to "make things consistent" in a wrong way.
> 
> I've tried to come up with a kerneldoc comment now, similar to
> the one for the vsnprintf() function, and added a separate prototype
> in the header. Does this address your concern?

Yes, see one nit, though.

> -int __printf(3, 0) __vsnprintf(char *buf, size_t size, const char *fmt_str, va_list args)
> +/**
> + * __vsnprintf - vsnprintf() wrapper without __printf() attribute
> + * @buf: The buffer to place the result into
> + * @size: The size of the buffer, including the trailing null space
> + * @fmt_str: The format string to use
> + * @args: Arguments for the format string
> + *
> + * This has the exact same behavior as vsnprintf() but can be used in call
> + * sites that are missing a __printf() annotation, e.g. because they
> + * get a 'va_format' argument instead of format and varargs.
> + *
> + * For this to work, the attribute is added to the declaration here but
> + * not in the header.

+ *
+ * Return: ...

> + */
> +int __printf(3, 0) __vsnprintf(char *buf, size_t size, const char *fmt_str, va_list args);

> +
> +int __vsnprintf(char *buf, size_t size, const char *fmt_str, va_list args)

Something slipped here...

-- 
With Best Regards,
Andy Shevchenko