On Fri, Jun 23, 2023, at 17:38, Christian Lamparter wrote: > On 6/23/23 17:23, Arnd Bergmann wrote: > > Wait! I want to point out this funny thing is happening in ath too! > > https://lore.kernel.org/linux-wireless/TYAP286MB03154F9AAFD4C35BEEDE4A99BC4CA@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/T/#mf1b8919a000fe661803c17073f48b3c410888541 > > And that patch got NACK by Jiri Slaby because like me he suspects that > this is a compiler bug. FWIW, that is one I don't see with clang-17 or gcc-13. The one I'm addressing here is the only thing I see in ath wireless with the default set of warning options, though this driver does have a couple of others that are unrelated, when you enable the source data check in memcpy() by building with W=1. In file included from drivers/net/wireless/ath/ath9k/xmit.c:17: In file included from include/linux/dma-mapping.h:7: In file included from include/linux/string.h:254: /home/arnd/arm-soc/include/linux/fortify-string.h:592:4: error: call to '__read_overflow2_field' declared with 'warning' attribute: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] __read_overflow2_field(q_size_field, size); ^ include/linux/fortify-string.h:592:4: error: call to '__read_overflow2_field' declared with 'warning' attribute: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] 2 errors generated. /home/arnd/arm-soc/include/linux/fortify-string.h:592:4: error: call to '__read_overflow2_field' declared with 'warning' attribute: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] __read_overflow2_field(q_size_field, size); > so, what's going wrong with fortified there? Kees might have a better answer to that, my best guess is that the one I'm addressing stems from the confusion between different union members. Doing the randconfig builds with the latest compilers, carl9170 is the only one I see with fortified-string warnings, and there are a few dozen other drivers that I see with W=1, including one that affects all wireless drivers. Arnd
