[all-commits] [llvm/llvm-project] 2d5fb2: [ubsan] Support static linking with standalone run...

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2d5fb27db71b57f299793160181ef28fea5573e7
      https://github.com/llvm/llvm-project/commit/2d5fb27db71b57f299793160181ef28fea5573e7
  Author: Fangrui Song <i at maskray.me>
  Date:   2024-02-14 (Wed, 14 Feb 2024)

  Changed paths:
    M compiler-rt/lib/ubsan/ubsan_signals_standalone.cpp
    M compiler-rt/test/ubsan/TestCases/Misc/Linux/static-link.cpp

  Log Message:
  -----------
  [ubsan] Support static linking with standalone runtime (#80943)

The standalone runtime (not
-fsanitize-minimal-runtime/-fsanitize-trap=undefined) installs some
signal handlers using `real_sigaction`. With static linking
(-static/-static-pie), the called `REAL(sigaction)` is null, leading to
an immediate segfault, which is confusing (#51538).

Fix #51538 by bailing out.

`// REQUIRES: librt_has_multf3` from https://reviews.llvm.org/D109709
actually disabled the test because `librt_has_*` features are only for
`compiler-rt/test/builtins`. The test does not reproduce for me:
libclang_rt.builtins.a or libgcc. Revert the REQUIRES.