On Thu, Jul 20, 2017 at 09:24:21AM +0200, Arnd Bergmann wrote: > On Wed, Jul 19, 2017 at 11:50 PM, <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > ------------------------------------------------------ > > From: Arnd Bergmann <arnd@xxxxxxxx> > > Subject: kbuild: disable -Wformat-truncation warnings by default > > > > With x86 allmodconfig, we currently get 233 -Wformat-truncation warnings, > > which makes the entire warnings rather useless. > > > > This turns off the warning by default, unless we specify W=1 or higher > > > > Link: http://lkml.kernel.org/r/20170714120720.906842-2-arnd@xxxxxxxx > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > --- > > > > scripts/Makefile.extrawarn | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff -puN scripts/Makefile.extrawarn~kbuild-disable-wformat-truncation-warnings-by-default scripts/Makefile.extrawarn > > --- a/scripts/Makefile.extrawarn~kbuild-disable-wformat-truncation-warnings-by-default > > +++ a/scripts/Makefile.extrawarn > > @@ -67,5 +67,8 @@ KBUILD_CFLAGS += $(call cc-disable-warni > > KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare) > > KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length) > > KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized) > > +else > > +# noisy gcc-7 warnings > > +KBUILD_CFLAGS += $(call cc-option,-Wformat-truncation=0) > > endif > > endif > > Hi Andrew, Linus, Greg, > > I noticed that Linus has made a similar patch in 4.13-rc1, commit bd664f6b3e37 > ("disable new gcc-7.1.1 warnings for now"), and it completely disables three > warnings (format-truncation, format-overflow and int-in-bool-context). > > Obviously there is no point in having both, so let's talk about what we > want for 4.13, stable-backports and for future kernels, I'll then send those > patches. Here is my first suggestion: > > - enable all three warnings with "make W=1" in 4.13, but leave them > disabled by default. > - backport Linus' patch, plus the follow-up for W=1 to stable kernels, > to allow stable kernels to build cleanly I don't care which of these, I'll take whatever is in Linus's tree. And I'll go backport that patch now as I'm getting annoyed by the warnings at the moment... > - backport the patches that address any other gcc-7 warnings, as > well as those that are not obvious false-positives to stable kernels I'll do that as well, as I notice them go by. > - In 4.14+, use my version above and address all int-in-bool-context > and format-overflow warnings, but only use -Wformat-truncation > with make W=1. I don't really care about this, as long as we are not forced to do "silly things" like some of the patches seemed to do :) thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
