Re: [Libunwind-devel] SIGSEGV Segmentation Fault in access_mem

[Ali Nakipoglu]

Hi Milian,

Apologies for the huge delay in my response,

Yes, precisely! I was building a very similar tool because I totally 
missed Heaptrack.

Thank you so much for mentioning it. It's a very useful tool.

Next year I would love to get a bit more familiar with the project  and 
see if I can contribute anything.


Many thanks,

Ali.



On 21/06/17 09:25, Milian Wolff wrote:
> On Dienstag, 20. Juni 2017 16:15:14 CEST Ali Nakipoglu wrote:
> > Hi,
> >
> > Hope everyone very well.
> >
> > Im working on a memory tracking tool that gets linked at run-time via
> > LD_PRELOAD.
> I can't help you with the actual bug as I haven't encountered it myself. But
> the above sounds very much like my heaptrack tool:
>
> https://github.com/KDE/heaptrack
>
> May I invite you to collaborate?
>
> Cheers
>
> > 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/1fcbfc649837d2a28e1901986437ca6
> > bf9c4f4d4/src/x86_64/Gstep.c#L61) build flag solve this?
> >
> > Many thanks,
> >
> > Ali
> >
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