[Libunwind-devel] SIGSEGV Segmentation Fault in access_mem

[Ali Nakipoglu]

Hi,

Hope everyone very well.

Im working on a memory tracking tool that gets linked at run-time via 
LD_PRELOAD. It's using libunwind to get stack trace information. With 
most of the test applications its working fine but, there is one that 
libunwind always crashes with the stack trace:

#0  0x00007ffff7bbfe74 in access_mem () from /build-debug/Intercept.so
#1  0x00007ffff7bbf724 in _Ux86_64_step () from /build-debug/Intercept.so
#2  0x00007ffff7bbc2b8 in Intercept::trace() () at 
/src/Intercept/Intercept.cpp:185
#3  0x00007ffff7bbc4c3 in calloc () at src/Intercept/Intercept.cpp:252
#4  0x00007fffe35f1b33 in ?? () from /usr/lib64/nvidia/libGL.so.1
#5  0x00007fffcb50302e in ?? () from 
/usr/lib64/nvidia/libnvidia-glcore.so.375.39
#6  0x00007fffcb50c11b in ?? () from 
/usr/lib64/nvidia/libnvidia-glcore.so.375.39
#7  0x00007fffcb50d1b8 in ?? () from 
/usr/lib64/nvidia/libnvidia-glcore.so.375.39
#8  0x00007fffcb510c63 in ?? () from 
/usr/lib64/nvidia/libnvidia-glcore.so.375.39
#9  0x00007fffcb6686f3 in ?? () from 
/usr/lib64/nvidia/libnvidia-glcore.so.375.39
#10 0x00007fffcb63be54 in ?? () from 
/usr/lib64/nvidia/libnvidia-glcore.so.375.39
#11 0x00007fffcb63d647 in ?? () from 
/usr/lib64/nvidia/libnvidia-glcore.so.375.39
#12 0x00007fffcb655f24 in ?? () from 
/usr/lib64/nvidia/libnvidia-glcore.so.375.39

Libunwind 1.2.1.

Is there a way to bypass it or its is a bug? Can CONSERVATIVE_CHECKS 
(https://github.com/pathscale/libunwind/blob/1fcbfc649837d2a28e1901986437ca6bf9c4f4d4/src/x86_64/Gstep.c#L61) 
build flag solve this?

Many thanks,

Ali