AddressSanitizer with LTO does not show file name and line number in backtrace

[Abhay Sachan]

Using ASan/UBSan with LTO leads to printing of only hex offsets in the stacktraces. The issue seems to be fixed in gcc-9 on Eoan, but it doesnt work with bionic gcc-8.

There is a GCC bug for this, which was fixed an year ago, but it is not there in bionic gcc-8.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78063

I have attached a simple test program to demonstrate the problem, which is compiled with following options:

$ gcc -flto -g -fsanitize=address -o leak leak.c

With bionic, gcc-8 gives:

Direct leak of 4 byte(s) in 1 object(s) allocated from:
    #0 0x7f35f6106f00 in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:86
    #1 0x56193a9fb7f6 in leak (/home/asachan/leak+0x7f6)
    #2 0x56193a9fb812 in main (/home/asachan/leak+0x812)
    #3 0x7f35f5c49b96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)

With Eoan, gcc-9 gives:

Direct leak of 4 byte(s) in 1 object(s) allocated from:
    #0 0x7fb3baa7eae8 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dae8)
    #1 0x55c775c2e16a in leak /home/asachan/kachra/leak.c:7
    #2 0x55c775c2e186 in main /home/asachan/kachra/leak.c:13
    #3 0x7fb3ba7a71e2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x271e2)

The fix seems to be in libbacktrace, which gets picked up in libsanitizer as well:

https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=268663

In case you are trying to reproduce this issue in Eoan with gcc-8, it wont be visible because libasan is same for gcc-8 and gcc-9, and libasan
for gcc-9 has the fix which works for gcc-8 as well.

[Abhay Sachan (asachan)]

Eoan gcc-v output:

 gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/9/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:hsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 9.2.1-9ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-9/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,gm2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-9 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none,hsa --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 9.2.1 20191008 (Ubuntu 9.2.1-9ubuntu2)

Bionic, gcc -v output:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 8.3.0-6ubuntu1~18.04.1' --with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-8 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 8.3.0 (Ubuntu 8.3.0-6ubuntu1~18.04.1)