On Fri, Jan 26, 2024, at 22:22, Linus Torvalds wrote: > On Mon, 22 Jan 2024 at 07:29, Gustavo A. R. Silva <gustavo...@kernel.org> > wrote: >> >> Enable -Wstringop-overflow globally > > I suspect I'll have to revert this. > > On arm64, I get a "writing 16 bytes into a region of size 0" in the Xe driver > > drivers/gpu/drm/xe/xe_gt_pagefault.c:340 > > but I haven't looked into it much yet. > > It's not some gcc-11 issue, though, this is with gcc version 13.2.1 > > It looks like the kernel test robot reported this too (for s390), at > > https://lore.kernel.org/all/202401161031.hjgjhmij-...@intel.com/T/ > > and in that case it was gcc-13.2.0. > > So I don't think the issue is about gcc-11 at all, but about other > random details.
I did a creduce pass on this warning when it first showed up and opened a gcc bug report as well as a driver workaround: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113214 https://lore.kernel.org/lkml/20240103114819.2913937-1-a...@kernel.org/#r The reply in bugzilla is that sanitizers are expected to randomly produce false-positive warnings like this one. In this case it's -fsanitize=thread (KCSAN) that triggers it. There are other warnings that have similar problems, so I guess we could work around it by having certain warnings moved back to W=1 when any sanitizers are enabled. Arnd
