tree 6158fc809ee4854c22f5ad83e744a04fe7eea983
parent c54d307ffdca290f7931ad04a5acbf873a9ee849
author Mitch Phillips <mitchp@google.com> 1724262188 +0200
committer Florian Mayer <fmayer@google.com> 1728925239 -0700

Implement deterministic MTE globals for dlext RELRO sharing

This patch makes MTE globals deterministic for dlext loading that uses
either ANDROID_DLEXT_WRITE_RELRO or ANDROID_DLEXT_USE_RELRO. Without
this patch, every load of a dynamic library ends up with completely
random tags. This of course, kills the page sharing 15/16-th of the
time.

So, instead, for this specific RELRO loading, we use deterministic
global tags. This provides a small amount of protection without
killing the sharing and eating up more ram.

As a nice side effect, this fixes up one of the dlext tests that ensures
that the RELRO pages do get shared.

Bug: 315182011
Test: On both an MTE-enabled and non-MTE-enabled device:
Test: atest libprocinfo_test bionic-unit-tests bionic-unit-tests-static
CtsGwpAsanTestCases gwp_asan_unittest debuggerd_test

Change-Id: Ifbb55372346734d0a68e20c34cb0ae5be895021b