[Bug 1894166] Re: libasan missing debug symbols break debugging

Mon Nov 30 12:33:34 UTC 2020

This bug was fixed in the package gcc-10 - 10.2.0-19ubuntu3

---------------
gcc-10 (10.2.0-19ubuntu3) hirsute; urgency=medium

  * Update to git 20201129 from the gcc-10 branch.
    - Fix PR target/97528 (ARM), PR debug/97599, PR c/97958, PR fortran/85796,
      PR libstdc++/98001, PR libstdc++/97935, PR target/97939 (SPARC),
      PR target/96607 (SPARC).
  * Don't strip the sanitizer libraries, these are only used for debugging.
    LP: #1894166.
  * Don't run the libgphobos-link test on powerpc architectures.
  * Install libstdc++6 gdb pretty printer files in /usr/share/gcc (unversioned).
  * Re-enable the lto build on arm64.

gcc-10 (10.2.0-19ubuntu2) hirsute; urgency=medium

  * Disable the lto build on arm64 for now, builds still not
    succeeding on the buildds.

gcc-10 (10.2.0-19ubuntu1) hirsute; urgency=medium

  * Merge with Debian; remaining changes:
    - Build from upstream sources.
  * Don't run the testsuite on armhf and arm64, better chances for
    a succeeding build on the buildds.

gcc-10 (10.2.0-19) unstable; urgency=medium

  * Update to git 20201125 from the gcc-10 branch.
    - Fix PR target/97730 (AArch64), PR target/97887 (x86), PR d/97889,
      PR d/97843, PR d/97842, PR libstdc++/92546, PR libstdc++/97876,
      PR libstdc++/95989, PR libstdc++/97869, PR c++/97918, PR debug/97060,
      PR target/97534 (ARM), PR c++/96805, PR c++/96199.
  * Configure again with --enable-checking=release.
  * Enable again pgo and lto builds for 64bit architectures.

gcc-10 (10.2.0-18ubuntu1) hirsute; urgency=medium

  * Merge with Debian; remaining changes:
    - Build from upstream sources.

gcc-10 (10.2.0-18) unstable; urgency=medium

  * Update to git 20201118 from the gcc-10 branch.
    - Fix PR target/97535 (AArch64), PR target/97682 (RISCV), PR c/97748,
      PR c++/97790, PR c/97748, PR c++/67453, PR c++/97663, PR fortran/97782,
      PR fortran/95847, PR fortran/97768, PR libstdc++/97828,
      PR libstdc++/93456, PR libstdc++/97798, PR libstdc++/96042,
      PR libstdc++/96042, PR libstdc++/96042.
  * Update VCS attributes.
  * Add an autopkg test for linking libphobos.
  * Build the gcn offload compiler using LLVM 11, and work around the
    broken as in LLVM 11. See also LLVM Bug 48201 for this issue and
    https://reviews.llvm.org/D73999 for the patch causing the issue.
  * Fix PR target/97528, proposed patch. Closes: #972665.

 -- Matthias Klose <doko at ubuntu.com>  Sun, 29 Nov 2020 09:50:30 +0100

** Changed in: gcc-10 (Ubuntu)
       Status: New => Fix Released

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to gcc-10 in Ubuntu.
https://bugs.launchpad.net/bugs/1894166

Title:
  libasan missing debug symbols break debugging

Status in gcc-10 package in Ubuntu:
  Fix Released
Status in gcc-9 package in Ubuntu:
  New

Bug description:
  By default, all symbols are missing from libasan binary that is
  installed with this package. This, among other things, effectively
  breaks debugging with gdb (and LLDB , but that doesn't matter).

  To be able to catch ASAN errors in GDB , one would break on
  "__sanitizer::Die" and go from there, but without symbols, this won't
  work. Other tools rely on symbol lookups to determine instrumentation
  presence , which would fail in this case as well.

  For example, without libasan5-dbgsym  installed:

  (gdb) break __sanitizer::Die
  Function "__sanitizer::Die" not defined.
  Make breakpoint pending on future shared library load? (y or [n]) y
  Breakpoint 1 (__sanitizer::Die) pending.
  (gdb) r
  ...
  ASAN REPORT
  ...
  ==1802381==ABORTING
  [Inferior 1 (process 1802381) exited with code 01]

  However, with libasan5-dbgsym installed:

  (gdb) break __sanitizer::Die
  Breakpoint 1 at 0x7ffff76bc200: file ../../../../src/libsanitizer/sanitizer_common/sanitizer_termination.cc, line 49.
  (gdb) r
  ...
  ASAN REPORT
  ...
  ==1805058==ABORTING

  Breakpoint 1, __sanitizer::Die () at ../../../../src/libsanitizer/sanitizer_common/sanitizer_termination.cc:49
  49      ../../../../src/libsanitizer/sanitizer_common/sanitizer_termination.cc: No such file or directory.
  (gdb) bt
  #0  __sanitizer::Die () at ../../../../src/libsanitizer/sanitizer_common/sanitizer_termination.cc:49
  #1  0x00007ffff769d8ec in __asan::ScopedInErrorReport::~ScopedInErrorReport (this=0x7fffffffd156, __in_chrg=<optimized out>)
      at ../../../../src/libsanitizer/asan/asan_report.cc:185
  #2  0x00007ffff769d363 in __asan::ReportGenericError (pc=93824992236075, bp=bp at entry=140737488346576, sp=sp at entry=140737488346560, addr=106034152603909,
      is_write=is_write at entry=false, access_size=access_size at entry=1, exp=0, fatal=true) at ../../../../src/libsanitizer/asan/asan_report.cc:192
  #3  0x00007ffff769de4b in __asan::__asan_report_load1 (addr=<optimized out>) at ../../../../src/libsanitizer/asan/asan_rtl.cc:116
  #4  0x000055555555522b in main ()
  (gdb)

  In this example, it's fairly obvious that missing symbols will prevent one to put a breakpoint on __sanitizer::Die , but as I mentioned, checks in other tools would fail silently and the issue isn't immediately traceable back to missing symbols. 

  Since AddressSanitizer is primarily used for debugging anyway, would
  it make sense to have libasan with symbols by default?

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/gcc-10/+bug/1894166/+subscriptions