tree af86aa4f16a5f26abaa40dd40f63e6be98cc3cc7
parent c1b3c8ef2629eac2a73aa4a95bf43a66edf4cd0f
author Christopher Ferris <cferris@google.com> 1489097083 -0800
committer Christopher Ferris <cferris@google.com> 1489169628 -0800

Restore errno in signal handlers.

There was a problem where errno could be set in a signal handler
and cause bugs if other system calls were interrupted.

There isn't strong evidence this is causing any issues, but add this
proactively.

Bug: 31448909

Test: Ran the backtrace unit tests, backtraces few random processes,
Test: forced the ANR path for some zygote based processes.
Test: Ran the art ThreadStress test a few times.
Change-Id: I5abc9e330a5e86cea7015e2362f66044c6bc37d0