[Bug libgcc/109712] Segmentation fault in linear_search_fdes

["carlosgalvezp at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109712

--- Comment #10 from Carlos Galvez <carlosgalvezp at gmail dot com> ---
Hi!

I've continued to look into this and am having a slightly different but
essentially same error with yet another Nvidia library, but this time is with a
pure shared library, "libnvinfer.so", which was compiled against GCC 7. Most
likely the library is statically linked against libcudart_static.a. The issue
is not solved using bfd or lld linker.

My program simply links against that library, which internally throws an
exception. I get a very similar backtrace:

#0  linear_search_fdes (ob=0x7fffffffd350, this_fde=0x0, pc=0x7fffdf4b6a69) at
../../../gcc/libgcc/unwind-dw2-fde.c:973
#1  0x00007fffdde1cde1 in find_fde_tail (dbase=2424076, bases=0x7fffffffd5a8,
hdr=0x7ffff690ca70, pc=140736939649641) at
../../../gcc/libgcc/unwind-dw2-fde-dip.c:519
#2  _Unwind_Find_FDE (pc=<optimized out>, bases=bases@entry=0x7fffffffd5a8) at
../../../gcc/libgcc/unwind-dw2-fde-dip.c:573
#3  0x00007fffdde1847a in uw_frame_state_for (context=0x7fffffffd500,
fs=0x7fffffffd5f0) at ../../../gcc/libgcc/unwind-dw2.c:1005
#4  0x00007fffdde19ecd in _Unwind_RaiseException (exc=0x904320) at
../../../gcc/libgcc/unwind.inc:104
#5  0x00007fffde2b7e6a in __cxa_throw () from /path/to/usr/lib64/libstdc++.so.6
#6  0x00007fffdf4b6a6a in ?? () from /path/to/nvinfer/lib/libnvinfer.so.8
#7  0x00007fffdf4c21b5 in ?? () from /path/to/nvinfer/lib/libnvinfer.so.8
#8  0x00007fffdfbddf02 in ?? () from /path/to/nvinfer/lib/libnvinfer.so.8
#9  0x00007fffdf42a118 in createInferBuilder_INTERNAL () from
/path/to/nvinfer/lib/libnvinfer.so.8
#10 0x0000000000401163 in nvinfer1::(anonymous namespace)::createInferBuilder
(logger=...) at nvinfer/include/NvInfer.h:9093
#11 0x0000000000401182 in main () at main.cpp:13


So the library was compiled with GCC 7 and has a dependency on libstdc++.so.6.
Via LD_LIBRARY_PATH, I run my executable using GCC trunk (14)'s libstdc++.so.6.

Now, I try to see if "libnvinfer_static.a" uses any symbol from "libgcc_eh.a",
by doing:

- Run "nm libgcc_eh.a" and store a list of all "T" or "t" symbols.
- Run "nm libnvinfer_static.a" and store a list of all "U" symbols.
- Compute the intersection between those two lists.

This results in that "libnvinfer_static.a" only uses 1 symbol from libgcc_eh.a:
_Unwind_Resume.

Is the above test procedure correct to determine the symbols used from
libgcc_eh.a?

How come linking a pure shared library such as libnvinfer.so would lead to
mixing types from different versions of libgcc_eh.a, i.e. how could those
internal changes leak outside the shared library boundaries? 

After all this comes from __cxa_throw() from libstdc++.so.6, which is a
versioned symbol. Shouldn't that function get a new symbol version if there's
an ABI incompatible change?

Thank you for your time and help, really appreciated!