https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91256
Bug ID: 91256
Summary: openmp crash in shutdown
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgomp
Assignee: unassigned at gcc dot gnu.org
Reporter: Danack at basereality dot com
CC: jakub at gcc dot gnu.org
Target Milestone: ---
Hi,
I maintain Imagick the PHP extension that allows people to use the ImageMagick
library from PHP code.
It seems that under certain scenarios, there is a segfault when the program is
terminating if ImageMagick has been compiled with OpenMP support, and has used
more than one thread. The segfault backtrace is very not helpful:
#0 0x00007fffef9ebb56 in ?? () from /lib64/libgomp.so.1
#1 0x00007fffef9e9448 in ?? () from /lib64/libgomp.so.1
#2 0x00007ffff727e58e in start_thread () from /lib64/libpthread.so.0
#3 0x00007ffff73b0713 in clone () from /lib64/libc.so.6
That's almost certainly not enough info to fix the bug.
Please could someone direct me as to how I can get more useful information from
either gdb or any other tool.
In case it helps, I've created a docker box at
https://github.com/Imagick/imagick/issues/295 where this issue was reported
that allows reproducing the issue easily.
The crash doesn't always happen - so it's presumably a race condition of some
sort.
