On Sat, May 21, 2022 at 09:58:28AM +0300, Kalle Valo wrote: > + arnd, kees, lkml > > Jakub Kicinski <kuba@xxxxxxxxxx> writes: > > > GCC 12 says: > > > > drivers/net/wireless/ath/ath9k/mac.c: In function ‘ath9k_hw_resettxqueue’: > > drivers/net/wireless/ath/ath9k/mac.c:373:22: warning: array subscript > > 32 is above array bounds of ‘struct ath9k_tx_queue_info[10]’ > > [-Warray-bounds] > > 373 | qi = &ah->txq[q]; > > | ~~~~~~~^~~ > > > > I don't know where it got the 32 from, relegate the warning to W=1+. > > > > Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> > > --- > > CC: toke@xxxxxxx > > CC: kvalo@xxxxxxxxxx > > CC: linux-wireless@xxxxxxxxxxxxxxx > > --- > > drivers/net/wireless/ath/ath9k/Makefile | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/net/wireless/ath/ath9k/Makefile b/drivers/net/wireless/ath/ath9k/Makefile > > index eff94bcd1f0a..9bdfcee2f448 100644 > > --- a/drivers/net/wireless/ath/ath9k/Makefile > > +++ b/drivers/net/wireless/ath/ath9k/Makefile > > @@ -45,6 +45,11 @@ ath9k_hw-y:= \ > > ar9003_eeprom.o \ > > ar9003_paprd.o > > > > +# FIXME: temporarily silence -Warray-bounds on non W=1+ builds > > +ifndef KBUILD_EXTRA_WARN > > +CFLAGS_mac.o += -Wno-array-bounds > > +endif > > There are now four wireless drivers which need this hack. Wouldn't it be > easier to add -Wno-array-bounds for GCC 12 globally instead of adding > the same hack to multiple drivers? I finally tracked this down to a GCC 12 bug related to -fsanitize=shift: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105679 Basically all the "32" stuff comes from the index being used in a shift, and the resulting internal GCC logic blowing up. I was going to do a before/after build with and without -fsanitize=shift to see how many of these false positives originate from that bug... -- Kees Cook
