[compiler-rt] r179007 - [sanitizer] Fix boundary condition in LargeMmapAllocator::GetBlockBegin. Patch by Sergey Matveev

[Kostya Serebryany]

Author: kcc
Date: Mon Apr  8 03:43:22 2013
New Revision: 179007

URL: http://llvm.org/viewvc/llvm-project?rev=179007&view=rev
Log:
[sanitizer] Fix boundary condition in LargeMmapAllocator::GetBlockBegin. Patch by Sergey Matveev

Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h
    compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_test.cc

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h?rev=179007&r1=179006&r2=179007&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator.h Mon Apr  8 03:43:22 2013
@@ -1014,7 +1014,7 @@ class LargeMmapAllocator {
     CHECK_GE(nearest_chunk, h->map_beg);
     CHECK_LT(nearest_chunk, h->map_beg + h->map_size);
     CHECK_LE(nearest_chunk, p);
-    if (h->map_beg + h->map_size < p)
+    if (h->map_beg + h->map_size <= p)
       return 0;
     return GetUser(h);
   }

Modified: compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_test.cc?rev=179007&r1=179006&r2=179007&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_test.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_test.cc Mon Apr  8 03:43:22 2013
@@ -337,6 +337,14 @@ TEST(SanitizerCommon, LargeMmapAllocator
       a.Deallocate(&stats, allocated[i]);
     }
   }
+
+  // Regression test for boundary condition in GetBlockBegin().
+  uptr page_size = GetPageSizeCached();
+  char *p = (char *)a.Allocate(&stats, page_size, 1);
+  CHECK_EQ(p, a.GetBlockBegin(p));
+  CHECK_EQ(p, (char *)a.GetBlockBegin(p + page_size - 1));
+  CHECK_NE(p, (char *)a.GetBlockBegin(p + page_size));
+  a.Deallocate(&stats, p);
 }
 
 template
@@ -629,7 +637,6 @@ TEST(SanitizerCommon, SizeClassAllocator
   TestSizeClassAllocatorIteration<Allocator32Compact>();
 }
 
-
 TEST(SanitizerCommon, LargeMmapAllocatorIteration) {
   LargeMmapAllocator<> a;
   a.Init();