[Bug sanitizer/100439] stack overflow running ubsan

["florin.iucha at amd dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100439

--- Comment #2 from Florin Iucha <florin.iucha at amd dot com> ---
This is for regular x86-64; we're using a cross-compiler sysroot to avoid
dependency on system libraries and be able to run the binary on different Linux
distributions.

I can't reproduce the problem on a "hello, world" C++ program, but I was able
to reproduce it on a minimal Google test:

   --8< --8< --8< --8< --8< --8< --8< --8< --8< --8< --8< --8< 

   #include <gtest/gtest.h>

   #include <string>

   TEST(Hello, World)
   {
       ASSERT_EQ(43, std::stoi("42"));
   }

   --8< --8< --8< --8< --8< --8< --8< --8< --8< --8< --8< --8< 

Built using:

/opt/tng-gcc11-glibc-linux5.4/bin/x86_64-tng-linux-gnu-g++ -m64 -g -std=c++20
-fsanitize=undefined -fno-omit-frame-pointer -o hello.o -c hello.cpp
/opt/tng-gcc11-glibc-linux5.4/bin/x86_64-tng-linux-gnu-g++ -o hello -Wl,-rpath
-Wl,/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib
-Wl,-dynamic-linker
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/ld-linux-x86-64.so.2
-fsanitize=undefined hello.o
/opt/tng-gcc11-glibc-linux5.4/bin/x86_64-tng-linux-gnu-g++ -m64 -g -std=c++20
-fsanitize=undefined -fno-omit-frame-pointer -o test_hello.o
-I/home/fiucha/.conan/data/gtest/20201109/amd/tng/package/150f650d359c1c443c3bb8ac2ffee0bdec61d239/include
-c test_hello.cpp

/opt/tng-gcc11-glibc-linux5.4/bin/x86_64-tng-linux-gnu-g++ -o test_hello
-Wl,-rpath -Wl,/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib
-Wl,-dynamic-linker
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/ld-linux-x86-64.so.2
-fsanitize=undefined test_hello.o
/home/fiucha/.conan/data/gtest/20201109/amd/tng/package/150f650d359c1c443c3bb8ac2ffee0bdec61d239/lib/libgmock_maind.a
/home/fiucha/.conan/data/gtest/20201109/amd/tng/package/150f650d359c1c443c3bb8ac2ffee0bdec61d239/lib/libgmockd.a
/home/fiucha/.conan/data/gtest/20201109/amd/tng/package/150f650d359c1c443c3bb8ac2ffee0bdec61d239/lib/libgtestd.a
-lpthread

 ./test_hello
zsh: segmentation fault (core dumped)  ./test_hello

Running under gdb:

(gdb) b __dynamic_cast
Breakpoint 1 at 0x40a620
(gdb) run
Breakpoint 1, 0x00007ffff7ea92fd in __dynamic_cast () from
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/libstdc++.so.6
(gdb) bt
#0  0x00007ffff7ea92fd in __dynamic_cast () from
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/libstdc++.so.6
#1  0x00007ffff7eef6ff in bool std::has_facet<std::ctype<char> >(std::locale
const&) ()
   from
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/libstdc++.so.6
#2  0x00007ffff7ee6977 in std::basic_ios<char, std::char_traits<char>
>::_M_cache_locale(std::locale const&) ()
   from
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/libstdc++.so.6
#3  0x00007ffff7ee6c01 in std::basic_ios<char, std::char_traits<char>
>::init(std::basic_streambuf<char, std::char_traits<char> >*) ()
   from
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/libstdc++.so.6
#4  0x00007ffff7ef6c6d in std::basic_ostream<char, std::char_traits<char>
>::basic_ostream(std::basic_streambuf<char, std::char_traits<char> >*) ()
   from
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/libstdc++.so.6
#5  0x00007ffff7eb335b in std::ios_base::Init::Init() () from
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/libstdc++.so.6
#6  0x000000000040af7b in __static_initialization_and_destruction_0
(__initialize_p=1, __priority=65535)
    at
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/include/c++/11.1.1/iostream:74
#7  0x000000000040b1d3 in _GLOBAL__sub_I__ZN16Hello_World_Test10test_info_E ()
at test_hello.cpp:8
#8  0x000000000053c5f5 in __libc_csu_init (argc=argc@entry=1,
argv=argv@entry=0x7fffffffe8b8, envp=0x7fffffffe8c8) at elf-init.c:89
#9  0x00007ffff71aa76d in __libc_start_main (main=0x40f8b9 <main(int, char**)>,
argc=1, argv=0x7fffffffe8b8, init=0x53c5b0 <__libc_csu_init>,
    fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe8a8)
at ../csu/libc-start.c:279
#10 0x000000000040ac4a in _start () at ../sysdeps/x86_64/start.S:120
(gdb) ignore 1 9999999
Will ignore next 9999999 crossings of breakpoint 1.
(gdb) c
Continuing.

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff736ae75 in ?? () from
/opt/tng-gcc11-glibc-linux5.4/x86_64-tng-linux-gnu/sysroot/lib/libubsan.so.1
(gdb) info breakpoints
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x00007ffff7ea92fd <__dynamic_cast>
        breakpoint already hit 7488 times
        ignore next 9992512 hits