[asan] Use dynamic shadow on 32-bit Android, try 2.

Summary:
This change reverts r318575 and changes FindDynamicShadowStart() to
keep the memory range it found mapped PROT_NONE to make sure it is
not reused. We also skip MemoryRangeIsAvailable() check, because it
is (a) unnecessary, and (b) would fail anyway.

Reviewers: pcc, vitalybuka, kcc

Subscribers: srhines, kubamracek, mgorny, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D40203

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@318666 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_fuchsia.cc b/lib/sanitizer_common/sanitizer_fuchsia.cc
index 554bc458c..c130c10c2 100644
--- a/lib/sanitizer_common/sanitizer_fuchsia.cc
+++ b/lib/sanitizer_common/sanitizer_fuchsia.cc
@@ -191,6 +191,10 @@ uptr GetMaxUserVirtualAddress() {
   return ShadowBounds.memory_limit - 1;
 }
 
+uptr GetMaxVirtualAddress() {
+  return GetMaxUserVirtualAddress();
+}
+
 static void *DoAnonymousMmapOrDie(uptr size, const char *mem_type,
                                   bool raw_report, bool die_for_nomem) {
   size = RoundUpTo(size, PAGE_SIZE);