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authorKostya Serebryany <kcc@google.com>2013-09-10 13:16:56 +0000
committerKostya Serebryany <kcc@google.com>2013-09-10 13:16:56 +0000
commitf3d4b35f24f4e54b2cb99e06f47a958e5557d01e (patch)
treeba0938e41826d476c0aa23dd6ba0533d46bf2f99 /lib/Transforms
parent4c708e586eecb039811fdd54a8846002324936b2 (diff)
downloadexternal_llvm-f3d4b35f24f4e54b2cb99e06f47a958e5557d01e.zip
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[asan] refactor the use-after-return API so that the size class is computed at compile time instead of at run-time. llvm part
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190407 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
-rw-r--r--lib/Transforms/Instrumentation/AddressSanitizer.cpp42
1 files changed, 32 insertions, 10 deletions
diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 2ee3e01..98794e1 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -59,6 +59,7 @@ static const uint64_t kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G.
static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa8000;
+static const size_t kMinStackMallocSize = 1 << 6; // 64B
static const size_t kMaxStackMallocSize = 1 << 16; // 64K
static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
@@ -78,8 +79,9 @@ static const char *const kAsanInitName = "__asan_init_v3";
static const char *const kAsanHandleNoReturnName = "__asan_handle_no_return";
static const char *const kAsanMappingOffsetName = "__asan_mapping_offset";
static const char *const kAsanMappingScaleName = "__asan_mapping_scale";
-static const char *const kAsanStackMallocName = "__asan_stack_malloc";
-static const char *const kAsanStackFreeName = "__asan_stack_free";
+static const int kMaxAsanStackMallocSizeClass = 10;
+static const char *const kAsanStackMallocNameTemplate = "__asan_stack_malloc_";
+static const char *const kAsanStackFreeNameTemplate = "__asan_stack_free_";
static const char *const kAsanGenPrefix = "__asan_gen_";
static const char *const kAsanPoisonStackMemoryName =
"__asan_poison_stack_memory";
@@ -396,7 +398,8 @@ struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
uint64_t TotalStackSize;
unsigned StackAlignment;
- Function *AsanStackMallocFunc, *AsanStackFreeFunc;
+ Function *AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
+ *AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
// Stores a place and arguments of poisoning/unpoisoning call for alloca.
@@ -1271,11 +1274,15 @@ bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
void FunctionStackPoisoner::initializeCallbacks(Module &M) {
IRBuilder<> IRB(*C);
- AsanStackMallocFunc = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanStackMallocName, IntptrTy, IntptrTy, IntptrTy, NULL));
- AsanStackFreeFunc = checkInterfaceFunction(M.getOrInsertFunction(
- kAsanStackFreeName, IRB.getVoidTy(),
- IntptrTy, IntptrTy, IntptrTy, NULL));
+ for (int i = 0; i <= kMaxAsanStackMallocSizeClass; i++) {
+ std::string Suffix = itostr(i);
+ AsanStackMallocFunc[i] = checkInterfaceFunction(
+ M.getOrInsertFunction(kAsanStackMallocNameTemplate + Suffix, IntptrTy,
+ IntptrTy, IntptrTy, NULL));
+ AsanStackFreeFunc[i] = checkInterfaceFunction(M.getOrInsertFunction(
+ kAsanStackFreeNameTemplate + Suffix, IRB.getVoidTy(), IntptrTy,
+ IntptrTy, IntptrTy, NULL));
+ }
AsanPoisonStackMemoryFunc = checkInterfaceFunction(M.getOrInsertFunction(
kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
AsanUnpoisonStackMemoryFunc = checkInterfaceFunction(M.getOrInsertFunction(
@@ -1344,12 +1351,24 @@ void FunctionStackPoisoner::poisonRedZones(
}
}
+// Fake stack allocator (asan_fake_stack.h) has 11 size classes
+// for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
+static int StackMallocSizeClass(uint64_t LocalStackSize) {
+ assert(LocalStackSize <= kMaxStackMallocSize);
+ uint64_t MaxSize = kMinStackMallocSize;
+ for (int i = 0; ; i++, MaxSize *= 2)
+ if (LocalStackSize <= MaxSize)
+ return i;
+ llvm_unreachable("impossible LocalStackSize");
+}
+
void FunctionStackPoisoner::poisonStack() {
uint64_t LocalStackSize = TotalStackSize +
(AllocaVec.size() + 1) * RedzoneSize();
bool DoStackMalloc = ASan.CheckUseAfterReturn
&& LocalStackSize <= kMaxStackMallocSize;
+ int StackMallocIdx = -1;
assert(AllocaVec.size() > 0);
Instruction *InsBefore = AllocaVec[0];
@@ -1367,7 +1386,9 @@ void FunctionStackPoisoner::poisonStack() {
Value *LocalStackBase = OrigStackBase;
if (DoStackMalloc) {
- LocalStackBase = IRB.CreateCall2(AsanStackMallocFunc,
+ StackMallocIdx = StackMallocSizeClass(LocalStackSize);
+ assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
+ LocalStackBase = IRB.CreateCall2(AsanStackMallocFunc[StackMallocIdx],
ConstantInt::get(IntptrTy, LocalStackSize), OrigStackBase);
}
@@ -1442,8 +1463,9 @@ void FunctionStackPoisoner::poisonStack() {
// Unpoison the stack.
poisonRedZones(AllocaVec, IRBRet, ShadowBase, false);
if (DoStackMalloc) {
+ assert(StackMallocIdx >= 0);
// In use-after-return mode, mark the whole stack frame unaddressable.
- IRBRet.CreateCall3(AsanStackFreeFunc, LocalStackBase,
+ IRBRet.CreateCall3(AsanStackFreeFunc[StackMallocIdx], LocalStackBase,
ConstantInt::get(IntptrTy, LocalStackSize),
OrigStackBase);
} else if (HavePoisonedAllocas) {