[Sanitizers] Secondary allocator respects allocator_may_return_null=1.

Summary:
Context: https://github.com/google/sanitizers/issues/740.

Making secondary allocator to respect allocator_may_return_null=1 flag
and return nullptr when "out of memory" happens.

More changes in primary allocator and operator new will follow.

Reviewers: eugenis

Subscribers: kubamracek, llvm-commits

Differential Revision: https://reviews.llvm.org/D34243

llvm-svn: 305569

1 files changed, 5 insertions, 2 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_secondary.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_secondary.h
index 2e98e591b43..2c69f47ec4e 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_secondary.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_secondary.h
@@ -36,9 +36,12 @@ class LargeMmapAllocator {
     if (alignment > page_size_)
       map_size += alignment;
     // Overflow.
-    if (map_size < size) return ReturnNullOrDieOnBadRequest();
+    if (map_size < size)
+      return ReturnNullOrDieOnBadRequest();
     uptr map_beg = reinterpret_cast<uptr>(
-        MmapOrDie(map_size, "LargeMmapAllocator"));
+        MmapOrDieOnFatalError(map_size, "LargeMmapAllocator"));
+    if (!map_beg)
+      return ReturnNullOrDieOnOOM();
     CHECK(IsAligned(map_beg, page_size_));
     MapUnmapCallback().OnMap(map_beg, map_size);
     uptr map_end = map_beg + map_size;