https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103978
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note trunk gives:
=================================================================
==1==ERROR: AddressSanitizer: stack-buffer-underflow on address 0x7f2aac7fedf0
at pc 0x7f2aae9b28e1 bp 0x7f2aac7fedb0 sp 0x7f2aac7fe560
WRITE of size 24 at 0x7f2aac7fedf0 thread T-1
#0 0x7f2aae9b28e0
(/opt/compiler-explorer/gcc-snapshot/lib64/libasan.so.8+0x628e0)
#1 0x7f2aaea2916d
(/opt/compiler-explorer/gcc-snapshot/lib64/libasan.so.8+0xd916d)
#2 0x7f2aaea18e64
(/opt/compiler-explorer/gcc-snapshot/lib64/libasan.so.8+0xc8e64)
#3 0x7f2aae5a95a0 in __nptl_deallocate_tsd.part.0
(/lib/x86_64-linux-gnu/libpthread.so.0+0x85a0)
#4 0x7f2aae5aa629 in start_thread
(/lib/x86_64-linux-gnu/libpthread.so.0+0x9629)
#5 0x7f2aae4cf292 in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x122292)
Address 0x7f2aac7fedf0 is a wild pointer inside of access range of size
0x000000000018.
SUMMARY: AddressSanitizer: stack-buffer-underflow
(/opt/compiler-explorer/gcc-snapshot/lib64/libasan.so.8+0x628e0)
Shadow bytes around the buggy address:
0x0fe5d58f7d60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe5d58f7d70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe5d58f7d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe5d58f7d90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe5d58f7da0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0fe5d58f7db0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[f1]f1
0x0fe5d58f7dc0: f1 f1 00 00 f3 f3 00 00 00 00 00 00 00 00 00 00
0x0fe5d58f7dd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe5d58f7de0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe5d58f7df0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0fe5d58f7e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==1==ABORTING
