tree 560f4f455f264e8d3eb2e4d58783d415e61b9655
parent 96344a516c78f1b12c1827f2b9fa4256ebd3329e
author Peter Collingbourne <peter@pcc.me.uk> 1613089011 -0800
committer Copybara-Service <copybara-worker@google.com> 1613725745 -0800

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

GitOrigin-RevId: cddc53ef088b68586094c9841a76b41bee3994a4