melver updated this revision to Diff 269078.
melver added a comment.
Add 0-size array to test to check redzone calculation does not divide by 0.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D81346/new/
https://reviews.llvm.org/D81346
Files:
clang/test/CodeGen/asan-globals.cpp
llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
Index: llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -796,9 +796,10 @@
StringRef getGlobalMetadataSection() const;
void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
- size_t MinRedzoneSizeForGlobal() const {
+ uint64_t getMinRedzoneSizeForGlobal() const {
return RedzoneSizeForScale(Mapping.Scale);
}
+ uint64_t getRedzoneSizeForGlobal(uint64_t SizeInBytes) const;
int GetAsanVersion(const Module &M) const;
const GlobalsMetadata &GlobalsMD;
@@ -1807,7 +1808,7 @@
// - Need to poison all copies, not just the main thread's one.
if (G->isThreadLocal()) return false;
// For now, just ignore this Global if the alignment is large.
- if (G->getAlignment() > MinRedzoneSizeForGlobal()) return false;
+ if (G->getAlignment() > getMinRedzoneSizeForGlobal()) return false;
// For non-COFF targets, only instrument globals known to be defined by this
// TU.
@@ -2276,7 +2277,6 @@
M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
for (size_t i = 0; i < n; i++) {
- static const uint64_t kMaxGlobalRedzone = 1 << 18;
GlobalVariable *G = GlobalsToChange[i];
// FIXME: Metadata should be attched directly to the global directly instead
@@ -2290,16 +2290,8 @@
/*AllowMerging*/ true, kAsanGenPrefix);
Type *Ty = G->getValueType();
- uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
- uint64_t MinRZ = MinRedzoneSizeForGlobal();
- // MinRZ <= RZ <= kMaxGlobalRedzone
- // and trying to make RZ to be ~ 1/4 of SizeInBytes.
- uint64_t RZ = std::max(
- MinRZ, std::min(kMaxGlobalRedzone, (SizeInBytes / MinRZ / 4) * MinRZ));
- uint64_t RightRedzoneSize = RZ;
- // Round up to MinRZ
- if (SizeInBytes % MinRZ) RightRedzoneSize += MinRZ - (SizeInBytes % MinRZ);
- assert(((RightRedzoneSize + SizeInBytes) % MinRZ) == 0);
+ const uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
+ const uint64_t RightRedzoneSize = getRedzoneSizeForGlobal(SizeInBytes);
Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
@@ -2315,7 +2307,7 @@
"", G, G->getThreadLocalMode());
NewGlobal->copyAttributesFrom(G);
NewGlobal->setComdat(G->getComdat());
- NewGlobal->setAlignment(MaybeAlign(MinRZ));
+ NewGlobal->setAlignment(MaybeAlign(getMinRedzoneSizeForGlobal()));
// Don't fold globals with redzones. ODR violation detector and redzone
// poisoning implicitly creates a dependence on the global's address, so it
// is no longer valid for it to be marked unnamed_addr.
@@ -2437,6 +2429,39 @@
return true;
}
+uint64_t
+ModuleAddressSanitizer::getRedzoneSizeForGlobal(uint64_t SizeInBytes) const {
+ const uint64_t MinRZ = getMinRedzoneSizeForGlobal();
+ // Limit redzone size when compiling the kernel.
+ const uint64_t MaxRZ = CompileKernel ? MinRZ * 2 : 1 << 18;
+
+ // Calculate RZ, where MinRZ <= RZ <= MaxRZ, and RZ ~ 1/4 * SizeInBytes.
+ uint64_t RZ =
+ std::max(MinRZ, std::min(MaxRZ, (SizeInBytes / MinRZ / 4) * MinRZ));
+
+ // Round up to multiple of MinRZ.
+ if (SizeInBytes % MinRZ)
+ RZ += MinRZ - (SizeInBytes % MinRZ);
+ assert((RZ + SizeInBytes) % MinRZ == 0);
+
+ if (CompileKernel && SizeInBytes && RZ % SizeInBytes) {
+ // When compiling the Linux kernel, ensure that the size of global+redzone
+ // has the same divisors as before. For certain arrays, the kernel expects
+ // that the global's size remains a multiple of the type's size.
+ //
+ // For example, in kernel modules certain arrays of structs shared with
+ // userspace are checked to be a multiple of sizeof(shared struct). These
+ // checks happen on the final binary.
+ //
+ // We can ensure the checks do not fail by ensuring that the array's size
+ // remains a multiple of the original size.
+ RZ += SizeInBytes - (RZ % SizeInBytes);
+ assert((RZ + SizeInBytes) % SizeInBytes == 0);
+ }
+
+ return RZ;
+}
+
int ModuleAddressSanitizer::GetAsanVersion(const Module &M) const {
int LongSize = M.getDataLayout().getPointerSizeInBits();
bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
Index: clang/test/CodeGen/asan-globals.cpp
===================================================================
--- clang/test/CodeGen/asan-globals.cpp
+++ clang/test/CodeGen/asan-globals.cpp
@@ -12,26 +12,31 @@
int __attribute__((no_sanitize("address"))) attributed_global;
int blacklisted_global;
int __attribute__ ((section("__DATA, __common"))) sectioned_global;
+char large_array[100];
+char zero_size[0]; // Ensure the redzone size calculation can deal with size==0.
void func() {
static int static_var = 0;
const char *literal = "Hello, world!";
}
+// ASAN-CHECK: @large_array = global { [100 x i8], [60 x i8] }
+// KASAN-CHECK: @large_array = global { [100 x i8], [100 x i8] }
+
// CHECK-LABEL: define internal void @asan.module_ctor
// ASAN-NEXT: call void @__asan_init
// ASAN-NEXT: call void @__asan_version_mismatch_check
// KASAN-NOT: call void @__asan_init
// KASAN-NOT: call void @__asan_version_mismatch_check
-// ASAN-NEXT: call void @__asan_register_globals({{.*}}, i{{32|64}} 6)
-// KASAN-NEXT: call void @__asan_register_globals({{.*}}, i{{32|64}} 5)
+// ASAN-NEXT: call void @__asan_register_globals({{.*}}, i{{32|64}} 8)
+// KASAN-NEXT: call void @__asan_register_globals({{.*}}, i{{32|64}} 7)
// CHECK-NEXT: ret void
// CHECK-LABEL: define internal void @asan.module_dtor
// CHECK-NEXT: call void @__asan_unregister_globals
// CHECK-NEXT: ret void
-// CHECK: !llvm.asan.globals = !{![[EXTRA_GLOBAL:[0-9]+]], ![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[ATTR_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[SECTIONED_GLOBAL:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]}
+// CHECK: !llvm.asan.globals = !{![[EXTRA_GLOBAL:[0-9]+]], ![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[ATTR_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[SECTIONED_GLOBAL:[0-9]+]], ![[LARGE_ARRAY:[0-9]+]], ![[ZERO_SIZE:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]}
// CHECK: ![[EXTRA_GLOBAL]] = !{{{.*}} ![[EXTRA_GLOBAL_LOC:[0-9]+]], !"extra_global", i1 false, i1 false}
// CHECK: ![[EXTRA_GLOBAL_LOC]] = !{!"{{.*}}extra-source.cpp", i32 1, i32 5}
// CHECK: ![[GLOBAL]] = !{{{.*}} ![[GLOBAL_LOC:[0-9]+]], !"global", i1 false, i1 false}
@@ -42,12 +47,16 @@
// CHECK: ![[BLACKLISTED_GLOBAL]] = !{{{.*}}, null, null, i1 false, i1 true}
// CHECK: ![[SECTIONED_GLOBAL]] = !{{{.*}} ![[SECTIONED_GLOBAL_LOC:[0-9]+]], !"sectioned_global", i1 false, i1 false}
// CHECK: ![[SECTIONED_GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 14, i32 51}
+// CHECK: ![[LARGE_ARRAY]] = !{{{.*}} ![[LARGE_ARRAY_LOC:[0-9]+]], !"large_array", i1 false, i1 false}
+// CHECK: ![[LARGE_ARRAY_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 15, i32 6}
+// CHECK: ![[ZERO_SIZE]] = !{{{.*}} ![[ZERO_SIZE_LOC:[0-9]+]], !"zero_size", i1 false, i1 false}
+// CHECK: ![[ZERO_SIZE_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 16, i32 6}
// CHECK: ![[STATIC_VAR]] = !{{{.*}} ![[STATIC_LOC:[0-9]+]], !"static_var", i1 false, i1 false}
-// CHECK: ![[STATIC_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 17, i32 14}
+// CHECK: ![[STATIC_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 19, i32 14}
// CHECK: ![[LITERAL]] = !{{{.*}} ![[LITERAL_LOC:[0-9]+]], !"<string literal>", i1 false, i1 false}
-// CHECK: ![[LITERAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 18, i32 25}
+// CHECK: ![[LITERAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 20, i32 25}
-// BLACKLIST-SRC: !llvm.asan.globals = !{![[EXTRA_GLOBAL:[0-9]+]], ![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[ATTR_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[SECTIONED_GLOBAL:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]}
+// BLACKLIST-SRC: !llvm.asan.globals = !{![[EXTRA_GLOBAL:[0-9]+]], ![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[ATTR_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[SECTIONED_GLOBAL:[0-9]+]], ![[LARGE_ARRAY:[0-9]+]], ![[ZERO_SIZE:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]}
// BLACKLIST-SRC: ![[EXTRA_GLOBAL]] = !{{{.*}} ![[EXTRA_GLOBAL_LOC:[0-9]+]], !"extra_global", i1 false, i1 false}
// BLACKLIST-SRC: ![[EXTRA_GLOBAL_LOC]] = !{!"{{.*}}extra-source.cpp", i32 1, i32 5}
// BLACKLIST-SRC: ![[GLOBAL]] = !{{{.*}} null, null, i1 false, i1 true}
@@ -55,5 +64,7 @@
// BLACKLIST-SRC: ![[ATTR_GLOBAL]] = !{{{.*}}, null, null, i1 false, i1 true}
// BLACKLIST-SRC: ![[BLACKLISTED_GLOBAL]] = !{{{.*}}, null, null, i1 false, i1 true}
// BLACKLIST-SRC: ![[SECTIONED_GLOBAL]] = !{{{.*}} null, null, i1 false, i1 true}
+// BLACKLIST-SRC: ![[LARGE_ARRAY]] = !{{{.*}} null, null, i1 false, i1 true}
+// BLACKLIST-SRC: ![[ZERO_SIZE]] = !{{{.*}} null, null, i1 false, i1 true}
// BLACKLIST-SRC: ![[STATIC_VAR]] = !{{{.*}} null, null, i1 false, i1 true}
// BLACKLIST-SRC: ![[LITERAL]] = !{{{.*}} null, null, i1 false, i1 true}
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