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[msan] Implement allocator_may_return_null=1 in MemorySanitizer. 

llvm-svn: 192687
This commit is contained in:
Evgeniy Stepanov 2013-10-15 11:33:48 +00:00
parent 59c850de6d
commit 113c646c56
2 changed files with 90 additions and 2 deletions
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81
compiler-rt/lib/msan/lit_tests/allocator_returns_null.cc Normal file
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@ -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

11
compiler-rt/lib/msan/msan_allocator.cc
View File

@ -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, void *old_p, uptr new_size,
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;
}