tree 2c6409eab9862d492f762757a47910beacfe4caa
parent 6853a187e37b541fb536154cc6a6057dae1e916a
author Christopher Ferris <cferris@google.com> 1539799073 -0700
committer Christopher Ferris <cferris@google.com> 1539811390 -0700

Fix which maps to search for globals.

If multiple threads are unwinding at the same time, new maps that contain
the global variables for dex files and jit information are created. This
leads to threads creating more new maps that then get searched, then
more maps, then more searching until virtual address space exhaustion.

Fix this so that we only search maps that have a corresponding rw map that
could contain the global memory.

Small refactor to combine the code to search for global variables into
one class that both classes inherit from.

Modify unit tests for the new pattern checking.

Bug: 117761427

Test: Ran unit tests for libunwindstack/libbacktrace/simpleperf.
Test: Ran art 004-ThreadStress that used to fail.
Change-Id: I837ca6b9d0383100079de090bc7d019598e0cdfe