[all-commits] [llvm/llvm-project] cddc53: libunwind: Don't attempt to authenticate a null re...

[pcc via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cddc53ef088b68586094c9841a76b41bee3994a4
      https://github.com/llvm/llvm-project/commit/cddc53ef088b68586094c9841a76b41bee3994a4
  Author: Peter Collingbourne <peter at pcc.me.uk>
  Date:   2021-02-16 (Tue, 16 Feb 2021)

  Changed paths:
    M libunwind/src/DwarfInstructions.hpp

  Log Message:
  -----------
  libunwind: Don't attempt to authenticate a null return address.

Null return addresses can appear at the bottom of the stack (i.e. the
frame corresponding to the entry point). Authenticating these addresses
will set the error code in the address, which will lead to a segfault
in the sigreturn trampoline detection code. Fix this problem by not
authenticating null addresses.

Differential Revision: https://reviews.llvm.org/D96560