On 20/03/2025 14:31, Alfie Richards wrote: > Hello, > > This is a cherry pick of 20385cb92cbd4a1934661ab97a162c1e25935836 which > didn't apply cleanly > so needed a very minor edit to for it to apply for GCC 12 and 13. > > Regtested and bootstrapped for gcc-13 on aarch64-linux-gnu. > > This applies cleanly to gcc-12 but there is a regression for > `c-c++-common/hwasan/large-aligned-1.c`. > > The output of execution was > > ``` > ==2242916==ERROR: HWAddressSanitizer: tag-mismatch on address 0xfffffffff680 > at pc 0xfffff780e08c > READ of size 4 at 0xfffffffff680 tags: 02/01(00) (ptr/mem) in thread T0 > #0 0xfffff780e08c in SigTrap<2> > ../../../../src/libsanitizer/hwasan/hwasan_checks.h:28 > ``` > > and has changed to > > ``` > ==2242927==ERROR: HWAddressSanitizer: tag-mismatch on address 0xfffffffff690 > at pc 0xfffff780e08c > READ of size 4 at 0xfffffffff690 tags: 02/00 (ptr/mem) in thread T0 > #0 0xfffff780e08c in SigTrap<2> > ../../../../src/libsanitizer/hwasan/hwasan_checks.h:28 > ``` > > Note the difference in the tags. > > Does anyone with experience of HWAddressSanitizer know what caused this and > if it's an issue?
Yeah, I ran into this too in the past when testing GCC 12 backports. I think those hwasan tests are flaky due to the dg-output checks being overly strict. Martin Liska pushed a fix to GCC 13 to relax them (r13-100-g3771486daa1e904ceae6f3e135b28e58af33849). I think that patch needs backporting to the GCC 12 branch, which I requested here: https://gcc.gnu.org/pipermail/gcc-patches/2024-February/645278.html but that backport request was never ACKed. I still think we should backport it. Alex > > Kind regards, > Alfie Richards > > > Andrew Carlotti (1): > aarch64: Use PAUTH instead of V8_3A in some places > > gcc/config/aarch64/aarch64.cc | 6 +++--- > gcc/config/aarch64/aarch64.md | 8 ++++---- > 2 files changed, 7 insertions(+), 7 deletions(-) > > -- > 2.34.1 >
