[compiler-rt] r192687 - [msan] Implement allocator_may_return_null=1 in MemorySanitizer.
Evgeniy Stepanov
eugeni.stepanov at gmail.com
Tue Oct 15 04:33:48 PDT 2013
Author: eugenis
Date: Tue Oct 15 06:33:48 2013
New Revision: 192687
URL: http://llvm.org/viewvc/llvm-project?rev=192687&view=rev
Log:
[msan] Implement allocator_may_return_null=1 in MemorySanitizer.
Added:
compiler-rt/trunk/lib/msan/lit_tests/allocator_returns_null.cc (with props)
Modified:
compiler-rt/trunk/lib/msan/msan_allocator.cc
Added: compiler-rt/trunk/lib/msan/lit_tests/allocator_returns_null.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/msan/lit_tests/allocator_returns_null.cc?rev=192687&view=auto
==============================================================================
--- compiler-rt/trunk/lib/msan/lit_tests/allocator_returns_null.cc (added)
+++ compiler-rt/trunk/lib/msan/lit_tests/allocator_returns_null.cc Tue Oct 15 06:33:48 2013
@@ -0,0 +1,81 @@
+// Test the behavior of malloc/calloc/realloc when the allocation size is huge.
+// By default (allocator_may_return_null=0) the process should crash.
+// With allocator_may_return_null=1 the allocator should return 0.
+//
+// RUN: %clangxx_msan -O0 %s -o %t
+// RUN: not %t malloc 2>&1 | FileCheck %s --check-prefix=CHECK-mCRASH
+// RUN: MSAN_OPTIONS=allocator_may_return_null=0 not %t malloc 2>&1 | FileCheck %s --check-prefix=CHECK-mCRASH
+// RUN: MSAN_OPTIONS=allocator_may_return_null=1 %t malloc 2>&1 | FileCheck %s --check-prefix=CHECK-mNULL
+// RUN: MSAN_OPTIONS=allocator_may_return_null=0 not %t calloc 2>&1 | FileCheck %s --check-prefix=CHECK-cCRASH
+// RUN: MSAN_OPTIONS=allocator_may_return_null=1 %t calloc 2>&1 | FileCheck %s --check-prefix=CHECK-cNULL
+// RUN: MSAN_OPTIONS=allocator_may_return_null=0 not %t calloc-overflow 2>&1 | FileCheck %s --check-prefix=CHECK-coCRASH
+// RUN: MSAN_OPTIONS=allocator_may_return_null=1 %t calloc-overflow 2>&1 | FileCheck %s --check-prefix=CHECK-coNULL
+// RUN: MSAN_OPTIONS=allocator_may_return_null=0 not %t realloc 2>&1 | FileCheck %s --check-prefix=CHECK-rCRASH
+// RUN: MSAN_OPTIONS=allocator_may_return_null=1 %t realloc 2>&1 | FileCheck %s --check-prefix=CHECK-rNULL
+// RUN: MSAN_OPTIONS=allocator_may_return_null=0 not %t realloc-after-malloc 2>&1 | FileCheck %s --check-prefix=CHECK-mrCRASH
+// RUN: MSAN_OPTIONS=allocator_may_return_null=1 %t realloc-after-malloc 2>&1 | FileCheck %s --check-prefix=CHECK-mrNULL
+
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+#include <limits>
+int main(int argc, char **argv) {
+ volatile size_t size = std::numeric_limits<size_t>::max() - 10000;
+ assert(argc == 2);
+ char *x = 0;
+ if (!strcmp(argv[1], "malloc")) {
+ fprintf(stderr, "malloc:\n");
+ x = (char*)malloc(size);
+ }
+ if (!strcmp(argv[1], "calloc")) {
+ fprintf(stderr, "calloc:\n");
+ x = (char*)calloc(size / 4, 4);
+ }
+
+ if (!strcmp(argv[1], "calloc-overflow")) {
+ fprintf(stderr, "calloc-overflow:\n");
+ volatile size_t kMaxSizeT = std::numeric_limits<size_t>::max();
+ size_t kArraySize = 4096;
+ volatile size_t kArraySize2 = kMaxSizeT / kArraySize + 10;
+ x = (char*)calloc(kArraySize, kArraySize2);
+ }
+
+ if (!strcmp(argv[1], "realloc")) {
+ fprintf(stderr, "realloc:\n");
+ x = (char*)realloc(0, size);
+ }
+ if (!strcmp(argv[1], "realloc-after-malloc")) {
+ fprintf(stderr, "realloc-after-malloc:\n");
+ char *t = (char*)malloc(100);
+ *t = 42;
+ x = (char*)realloc(t, size);
+ assert(*t == 42);
+ }
+ // The NULL pointer is printed differently on different systems, while (long)0
+ // is always the same.
+ fprintf(stderr, "x: %lx\n", (long)x);
+ return x != 0;
+}
+// CHECK-mCRASH: malloc:
+// CHECK-mCRASH: MemorySanitizer's allocator is terminating the process
+// CHECK-cCRASH: calloc:
+// CHECK-cCRASH: MemorySanitizer's allocator is terminating the process
+// CHECK-coCRASH: calloc-overflow:
+// CHECK-coCRASH: MemorySanitizer's allocator is terminating the process
+// CHECK-rCRASH: realloc:
+// CHECK-rCRASH: MemorySanitizer's allocator is terminating the process
+// CHECK-mrCRASH: realloc-after-malloc:
+// CHECK-mrCRASH: MemorySanitizer's allocator is terminating the process
+
+// CHECK-mNULL: malloc:
+// CHECK-mNULL: x: 0
+// CHECK-cNULL: calloc:
+// CHECK-cNULL: x: 0
+// CHECK-coNULL: calloc-overflow:
+// CHECK-coNULL: x: 0
+// CHECK-rNULL: realloc:
+// CHECK-rNULL: x: 0
+// CHECK-mrNULL: realloc-after-malloc:
+// CHECK-mrNULL: x: 0
Propchange: compiler-rt/trunk/lib/msan/lit_tests/allocator_returns_null.cc
------------------------------------------------------------------------------
svn:eol-style = LF
Modified: compiler-rt/trunk/lib/msan/msan_allocator.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/msan/msan_allocator.cc?rev=192687&r1=192686&r2=192687&view=diff
==============================================================================
--- compiler-rt/trunk/lib/msan/msan_allocator.cc (original)
+++ compiler-rt/trunk/lib/msan/msan_allocator.cc Tue Oct 15 06:33:48 2013
@@ -25,6 +25,7 @@ struct Metadata {
static const uptr kAllocatorSpace = 0x600000000000ULL;
static const uptr kAllocatorSize = 0x80000000000; // 8T.
static const uptr kMetadataSize = sizeof(Metadata);
+static const uptr kMaxAllowedMallocSize = 8UL << 30;
typedef SizeClassAllocator64<kAllocatorSpace, kAllocatorSize, kMetadataSize,
DefaultSizeClassMap> PrimaryAllocator;
@@ -48,6 +49,11 @@ static inline void Init() {
static void *MsanAllocate(StackTrace *stack, uptr size,
uptr alignment, bool zeroise) {
Init();
+ if (size > kMaxAllowedMallocSize) {
+ Report("WARNING: MemorySanitizer failed to allocate %p bytes\n",
+ (void *)size);
+ return AllocatorReturnNull();
+ }
void *res = allocator.Allocate(&cache, size, alignment, false);
Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(res));
meta->requested_size = size;
@@ -110,9 +116,10 @@ void *MsanReallocate(StackTrace *stack,
uptr memcpy_size = Min(new_size, old_size);
void *new_p = MsanAllocate(stack, new_size, alignment, zeroise);
// Printf("realloc: old_size %zd new_size %zd\n", old_size, new_size);
- if (new_p)
+ if (new_p) {
__msan_memcpy(new_p, old_p, memcpy_size);
- MsanDeallocate(stack, old_p);
+ MsanDeallocate(stack, old_p);
+ }
return new_p;
}
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