[Sanitizer] Linux explicitally migrate shadow mapping to Transparent Huge Page

in madvise mode, the shadow pages will be migrated only via madvise explicit calls.

Reviewers: vitalybuka

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D65775

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@368090 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 5 deletions

diff --git a/lib/sanitizer_common/sanitizer_posix_libcdep.cpp b/lib/sanitizer_common/sanitizer_posix_libcdep.cpp
index ad8a1ec99..24c42f3c9 100644
--- a/lib/sanitizer_common/sanitizer_posix_libcdep.cpp
+++ b/lib/sanitizer_common/sanitizer_posix_libcdep.cpp
@@ -68,13 +68,12 @@ void ReleaseMemoryPagesToOS(uptr beg, uptr end) {
             SANITIZER_MADVISE_DONTNEED);
 }
 
-bool SetShadowRegionHugePageMode(uptr addr, uptr size) {
+void SetShadowRegionHugePageMode(uptr addr, uptr size) {
 #ifdef MADV_NOHUGEPAGE  // May not be defined on old systems.
   if (common_flags()->no_huge_pages_for_shadow)
-    return madvise((char *)addr, size, MADV_NOHUGEPAGE) == 0;
-  return true;
-#else
-  return true;
+    madvise((char *)addr, size, MADV_NOHUGEPAGE);
+  else
+    madvise((char *)addr, size, MADV_HUGEPAGE) == 0;
 #endif  // MADV_NOHUGEPAGE
 }