On Tue, Feb 03, 2026 at 05:45:29PM +0100, Arnd Bergmann wrote: > The sunrpc change to use trace_printk() for debugging caused > a new warning for every instance of dprintk() in some configurations, > when -Wformat-security is enabled: > > fs/nfs/getroot.c: In function 'nfs_get_root': > fs/nfs/getroot.c:90:17: error: format not a string literal and no format > arguments [-Werror=format-security] > 90 | nfs_errorf(fc, "NFS: Couldn't getattr on root"); > > I've been slowly chipping away at those warnings over time with the > intention of enabling them by default in the future. While I could not > figure out why this only happens for this one instance, I see that the > __trace_bprintk() function is always called with a local variable as > the format string, rather than a literal. > > Move the __printf(2,3) annotation on this function from the declaration > to the caller. As this is can only be validated for literals, the > attribute on the declaration causes the warnings every time, but > removing it entirely introduces a new warning on the __ftrace_vbprintk() > definition. > > The format strings still get checked because the underlying literal keeps > getting passed into __trace_printk() in the "else" branch, which is not > taken but still evaluated for compile-time warnings.
Acked-by: Andy Shevchenko <[email protected]> -- With Best Regards, Andy Shevchenko
