On Thu, Aug 27, 2020 at 10:34 AM Linus Torvalds
<torva...@linux-foundation.org> wrote:
>
> How are you guys testing? I have UBSAN and GCOV on, and don't see
> crazy frames on either i386 or x86-64.
Oh, never mind. I also have COMPILE_TEST on, so it ends up disabling
GCOV_PROFILE_ALL and UBSAN_SANITIZE_ALL.
And yeah, this seems to be a gcc bug. It generates a ton of stack
slots for temporaries. It's -fsanitize=object-size that seems to do
it.
And "-fstack-reuse=all" doesn't seem to make any difference.
So I think
(a) our stack size check is good to catch this
(b) gcc and -fsanitize=object-size is basically an unusable combination
and it's not a bug in the kernel.
Linus
