[llvm] 866ee23 - [KernelAddressSanitizer] Make globals constructors compatible with kernel
Marco Elver via llvm-commits
llvm-commits at lists.llvm.org
Fri Jun 5 11:26:59 PDT 2020
Author: Marco Elver
Date: 2020-06-05T20:20:46+02:00
New Revision: 866ee2353f7d0224644799d0d1faed53c7f3a06d
URL: https://github.com/llvm/llvm-project/commit/866ee2353f7d0224644799d0d1faed53c7f3a06d
DIFF: https://github.com/llvm/llvm-project/commit/866ee2353f7d0224644799d0d1faed53c7f3a06d.diff
LOG: [KernelAddressSanitizer] Make globals constructors compatible with kernel
Summary:
This makes -fsanitize=kernel-address emit the correct globals
constructors for the kernel. We had to do the following:
- Disable generation of constructors that rely on linker features such
as dead-global elimination.
- Only emit constructors for globals *not* in explicit sections. The
kernel uses sections for special globals, which we should not touch.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203493
Tested:
1. With 'clang/test/CodeGen/asan-globals.cpp'.
2. With test_kasan.ko, we can see:
BUG: KASAN: global-out-of-bounds in kasan_global_oob+0xb3/0xba [test_kasan]
Reviewers: glider, andreyknvl
Reviewed By: glider
Subscribers: cfe-commits, nickdesaulniers, hiraditya, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D80805
Added:
Modified:
clang/test/CodeGen/asan-globals.cpp
llvm/include/llvm/Transforms/Utils/ModuleUtils.h
llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
llvm/lib/Transforms/Utils/ModuleUtils.cpp
Removed:
################################################################################
diff --git a/clang/test/CodeGen/asan-globals.cpp b/clang/test/CodeGen/asan-globals.cpp
index 93abb0023cfa..2feb305ebecd 100644
--- a/clang/test/CodeGen/asan-globals.cpp
+++ b/clang/test/CodeGen/asan-globals.cpp
@@ -1,40 +1,59 @@
// RUN: echo "int extra_global;" > %t.extra-source.cpp
// RUN: echo "global:*blacklisted_global*" > %t.blacklist
-// RUN: %clang_cc1 -include %t.extra-source.cpp -fsanitize=address -fsanitize-blacklist=%t.blacklist -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -include %t.extra-source.cpp -fsanitize=address -fsanitize-blacklist=%t.blacklist -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK,ASAN
+// RUN: %clang_cc1 -include %t.extra-source.cpp -fsanitize=kernel-address -fsanitize-blacklist=%t.blacklist -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK,KASAN
// The blacklist file uses regexps, so Windows path backslashes.
// RUN: echo "src:%s" | sed -e 's/\\/\\\\/g' > %t.blacklist-src
// RUN: %clang_cc1 -include %t.extra-source.cpp -fsanitize=address -fsanitize-blacklist=%t.blacklist-src -emit-llvm -o - %s | FileCheck %s --check-prefix=BLACKLIST-SRC
+// RUN: %clang_cc1 -include %t.extra-source.cpp -fsanitize=kernel-address -fsanitize-blacklist=%t.blacklist-src -emit-llvm -o - %s | FileCheck %s --check-prefix=BLACKLIST-SRC
int global;
int dyn_init_global = global;
int __attribute__((no_sanitize("address"))) attributed_global;
int blacklisted_global;
+int __attribute__((section(".foo.bar"))) sectioned_global;
void func() {
static int static_var = 0;
const char *literal = "Hello, world!";
}
-// CHECK: !llvm.asan.globals = !{![[EXTRA_GLOBAL:[0-9]+]], ![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[ATTR_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]}
+// 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(i64 ptrtoint ({{.*}}, i64 6)
+// KASAN-NEXT: call void @__asan_register_globals(i64 ptrtoint ({{.*}}, i64 5)
+// 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: ![[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}
-// CHECK: ![[GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 8, i32 5}
+// CHECK: ![[GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 10, i32 5}
// CHECK: ![[DYN_INIT_GLOBAL]] = !{{{.*}} ![[DYN_INIT_LOC:[0-9]+]], !"dyn_init_global", i1 true, i1 false}
-// CHECK: ![[DYN_INIT_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 9, i32 5}
+// CHECK: ![[DYN_INIT_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 11, i32 5}
// CHECK: ![[ATTR_GLOBAL]] = !{{{.*}}, null, null, i1 false, i1 true}
// 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 42}
// CHECK: ![[STATIC_VAR]] = !{{{.*}} ![[STATIC_LOC:[0-9]+]], !"static_var", i1 false, i1 false}
-// CHECK: ![[STATIC_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 14, i32 14}
+// CHECK: ![[STATIC_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 17, i32 14}
// CHECK: ![[LITERAL]] = !{{{.*}} ![[LITERAL_LOC:[0-9]+]], !"<string literal>", i1 false, i1 false}
-// CHECK: ![[LITERAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 15, i32 25}
+// CHECK: ![[LITERAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 18, 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]+]], ![[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]+]], ![[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}
// BLACKLIST-SRC: ![[DYN_INIT_GLOBAL]] = !{{{.*}} null, null, i1 true, i1 true}
// 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: ![[STATIC_VAR]] = !{{{.*}} null, null, i1 false, i1 true}
// BLACKLIST-SRC: ![[LITERAL]] = !{{{.*}} null, null, i1 false, i1 true}
diff --git a/llvm/include/llvm/Transforms/Utils/ModuleUtils.h b/llvm/include/llvm/Transforms/Utils/ModuleUtils.h
index 07fbb5b55678..65added8b7e1 100644
--- a/llvm/include/llvm/Transforms/Utils/ModuleUtils.h
+++ b/llvm/include/llvm/Transforms/Utils/ModuleUtils.h
@@ -42,6 +42,10 @@ void appendToGlobalDtors(Module &M, Function *F, int Priority,
FunctionCallee declareSanitizerInitFunction(Module &M, StringRef InitName,
ArrayRef<Type *> InitArgTypes);
+/// Creates sanitizer constructor function.
+/// \return Returns pointer to constructor.
+Function *createSanitizerCtor(Module &M, StringRef CtorName);
+
/// Creates sanitizer constructor function, and calls sanitizer's init
/// function from it.
/// \return Returns pair of pointers to constructor, and init functions
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 9c039f0cfcc7..666b3961eeb0 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -589,11 +589,10 @@ struct AddressSanitizer {
AddressSanitizer(Module &M, const GlobalsMetadata *GlobalsMD,
bool CompileKernel = false, bool Recover = false,
bool UseAfterScope = false)
- : UseAfterScope(UseAfterScope || ClUseAfterScope), GlobalsMD(*GlobalsMD) {
- this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
- this->CompileKernel =
- ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan : CompileKernel;
-
+ : CompileKernel(ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan
+ : CompileKernel),
+ Recover(ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover),
+ UseAfterScope(UseAfterScope || ClUseAfterScope), GlobalsMD(*GlobalsMD) {
C = &(M.getContext());
LongSize = M.getDataLayout().getPointerSizeInBits();
IntptrTy = Type::getIntNTy(*C, LongSize);
@@ -742,7 +741,11 @@ class ModuleAddressSanitizer {
ModuleAddressSanitizer(Module &M, const GlobalsMetadata *GlobalsMD,
bool CompileKernel = false, bool Recover = false,
bool UseGlobalsGC = true, bool UseOdrIndicator = false)
- : GlobalsMD(*GlobalsMD), UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC),
+ : GlobalsMD(*GlobalsMD),
+ CompileKernel(ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan
+ : CompileKernel),
+ Recover(ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover),
+ UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC && !this->CompileKernel),
// Enable aliases as they should have no downside with ODR indicators.
UsePrivateAlias(UseOdrIndicator || ClUsePrivateAlias),
UseOdrIndicator(UseOdrIndicator || ClUseOdrIndicator),
@@ -753,11 +756,7 @@ class ModuleAddressSanitizer {
// argument is designed as workaround. Therefore, disable both
// ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
// do globals-gc.
- UseCtorComdat(UseGlobalsGC && ClWithComdat) {
- this->Recover = ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover;
- this->CompileKernel =
- ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan : CompileKernel;
-
+ UseCtorComdat(UseGlobalsGC && ClWithComdat && !this->CompileKernel) {
C = &(M.getContext());
int LongSize = M.getDataLayout().getPointerSizeInBits();
IntptrTy = Type::getIntNTy(*C, LongSize);
@@ -1838,6 +1837,12 @@ bool ModuleAddressSanitizer::ShouldInstrumentGlobal(GlobalVariable *G) {
}
if (G->hasSection()) {
+ // The kernel uses explicit sections for mostly special global variables
+ // that we should not instrument. E.g. the kernel may rely on their layout
+ // without redzones, or remove them at link time ("discard.*"), etc.
+ if (CompileKernel)
+ return false;
+
StringRef Section = G->getSection();
// Globals from llvm.metadata aren't emitted, do not instrument them.
@@ -2445,20 +2450,23 @@ int ModuleAddressSanitizer::GetAsanVersion(const Module &M) const {
bool ModuleAddressSanitizer::instrumentModule(Module &M) {
initializeCallbacks(M);
- if (CompileKernel)
- return false;
-
// Create a module constructor. A destructor is created lazily because not all
// platforms, and not all modules need it.
- std::string AsanVersion = std::to_string(GetAsanVersion(M));
- std::string VersionCheckName =
- ClInsertVersionCheck ? (kAsanVersionCheckNamePrefix + AsanVersion) : "";
- std::tie(AsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
- M, kAsanModuleCtorName, kAsanInitName, /*InitArgTypes=*/{},
- /*InitArgs=*/{}, VersionCheckName);
+ if (CompileKernel) {
+ // The kernel always builds with its own runtime, and therefore does not
+ // need the init and version check calls.
+ AsanCtorFunction = createSanitizerCtor(M, kAsanModuleCtorName);
+ } else {
+ std::string AsanVersion = std::to_string(GetAsanVersion(M));
+ std::string VersionCheckName =
+ ClInsertVersionCheck ? (kAsanVersionCheckNamePrefix + AsanVersion) : "";
+ std::tie(AsanCtorFunction, std::ignore) =
+ createSanitizerCtorAndInitFunctions(M, kAsanModuleCtorName,
+ kAsanInitName, /*InitArgTypes=*/{},
+ /*InitArgs=*/{}, VersionCheckName);
+ }
bool CtorComdat = true;
- // TODO(glider): temporarily disabled globals instrumentation for KASan.
if (ClGlobals) {
IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
InstrumentGlobals(IRB, M, &CtorComdat);
diff --git a/llvm/lib/Transforms/Utils/ModuleUtils.cpp b/llvm/lib/Transforms/Utils/ModuleUtils.cpp
index b2e6d981a622..ef9f18a2289e 100644
--- a/llvm/lib/Transforms/Utils/ModuleUtils.cpp
+++ b/llvm/lib/Transforms/Utils/ModuleUtils.cpp
@@ -119,6 +119,15 @@ llvm::declareSanitizerInitFunction(Module &M, StringRef InitName,
AttributeList());
}
+Function *llvm::createSanitizerCtor(Module &M, StringRef CtorName) {
+ Function *Ctor = Function::Create(
+ FunctionType::get(Type::getVoidTy(M.getContext()), false),
+ GlobalValue::InternalLinkage, CtorName, &M);
+ BasicBlock *CtorBB = BasicBlock::Create(M.getContext(), "", Ctor);
+ ReturnInst::Create(M.getContext(), CtorBB);
+ return Ctor;
+}
+
std::pair<Function *, FunctionCallee> llvm::createSanitizerCtorAndInitFunctions(
Module &M, StringRef CtorName, StringRef InitName,
ArrayRef<Type *> InitArgTypes, ArrayRef<Value *> InitArgs,
@@ -128,11 +137,8 @@ std::pair<Function *, FunctionCallee> llvm::createSanitizerCtorAndInitFunctions(
"Sanitizer's init function expects
diff erent number of arguments");
FunctionCallee InitFunction =
declareSanitizerInitFunction(M, InitName, InitArgTypes);
- Function *Ctor = Function::Create(
- FunctionType::get(Type::getVoidTy(M.getContext()), false),
- GlobalValue::InternalLinkage, CtorName, &M);
- BasicBlock *CtorBB = BasicBlock::Create(M.getContext(), "", Ctor);
- IRBuilder<> IRB(ReturnInst::Create(M.getContext(), CtorBB));
+ Function *Ctor = createSanitizerCtor(M, CtorName);
+ IRBuilder<> IRB(Ctor->getEntryBlock().getTerminator());
IRB.CreateCall(InitFunction, InitArgs);
if (!VersionCheckName.empty()) {
FunctionCallee VersionCheckFunction = M.getOrInsertFunction(
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