[sanitizer] fix an allocator bug where the allocated memory may overlap with the free array (kudos to Kostya Korcthinsky). Also make sure that the allocator does not mmap more than requested. Test both.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@281103 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 1 deletions

diff --git a/lib/sanitizer_common/tests/sanitizer_allocator_test.cc b/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
index 30e4aa5db..4b5362ae4 100644
--- a/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
+++ b/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
@@ -931,16 +931,33 @@ TEST(SanitizerCommon, SizeClassAllocator64PopulateFreeListOOM) {
 
   // ...one man is on a mission to overflow a region with a series of
   // successive allocations.
+
   const uptr kClassID = 107;
-  const uptr kAllocationSize = DefaultSizeClassMap::Size(kClassID);
+  const uptr kAllocationSize = SpecialSizeClassMap::Size(kClassID);
   ASSERT_LT(2 * kAllocationSize, kRegionSize);
   ASSERT_GT(3 * kAllocationSize, kRegionSize);
   cache.Allocate(a, kClassID);
   EXPECT_DEATH(cache.Allocate(a, kClassID) && cache.Allocate(a, kClassID),
                "The process has exhausted");
+
+  const uptr Class2 = 100;
+  const uptr Size2 = SpecialSizeClassMap::Size(Class2);
+  ASSERT_EQ(Size2 * 8, kRegionSize);
+  char *p[7];
+  for (int i = 0; i < 7; i++) {
+    p[i] = (char*)cache.Allocate(a, Class2);
+    fprintf(stderr, "p[%d] %p s = %lx\n", i, (void*)p[i], Size2);
+    p[i][Size2 - 1] = 42;
+    if (i) ASSERT_LT(p[i - 1], p[i]);
+  }
+  EXPECT_DEATH(cache.Allocate(a, Class2), "The process has exhausted");
+  cache.Deallocate(a, Class2, p[0]);
+  cache.Drain(a);
+  ASSERT_EQ(p[6][Size2 - 1], 42);
   a->TestOnlyUnmap();
   delete a;
 }
+
 #endif
 
 TEST(SanitizerCommon, TwoLevelByteMap) {