diff --git a/clang/test/CodeGen/asan-globals-alias.cpp b/clang/test/CodeGen/asan-globals-alias.cpp --- a/clang/test/CodeGen/asan-globals-alias.cpp +++ b/clang/test/CodeGen/asan-globals-alias.cpp @@ -1,17 +1,36 @@ // RUN: %clang_cc1 -triple x86_64-linux -fsanitize=address -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK,ASAN +// RUN: %clang_cc1 -triple x86_64-linux -O2 -fsanitize=address -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK,ASAN // RUN: %clang_cc1 -triple x86_64-linux -fsanitize=kernel-address -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK,KASAN +// RUN: %clang_cc1 -triple x86_64-linux -O2 -fsanitize=kernel-address -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK,KASAN // // Not all platforms support aliases - test for Linux only. -int global; // to generate ctor for at least 1 global -int aliased_global; // KASAN - ignore globals prefixed by aliases with __-prefix (below) -extern int __attribute__((alias("aliased_global"))) __global_alias; // KASAN - aliased_global ignored +int global; // generate ctor for at least 1 global +int aliased_global; // KASAN ignored +extern int __attribute__((alias("aliased_global"))) __global_alias; + +// Recursive alias: +int aliased_global_2; // KASAN ignored +extern int __attribute__((alias("aliased_global_2"))) global_alias_2; +extern int __attribute__((alias("global_alias_2"))) __global_alias_2_alias; + +// Potential indirect alias: +struct input_device_id { + unsigned long keybit[24]; + unsigned long driver_info; +}; +struct input_device_id joydev_ids[] = { { {1}, 1234 } }; // KASAN ignored +extern struct input_device_id __attribute__((alias("joydev_ids"))) __mod_joydev_ids_device_table; // ASAN: @aliased_global{{.*}} global { i32, [60 x i8] }{{.*}}, align 32 +// ASAN: @aliased_global_2{{.*}} global { i32, [60 x i8] }{{.*}}, align 32 +// ASAN: @joydev_ids{{.*}} global { {{.*}}[56 x i8] zeroinitializer }, align 32 // KASAN: @aliased_global{{.*}} global i32 +// KASAN: @aliased_global_2{{.*}} global i32 +// KASAN: @joydev_ids{{.*}} global [1 x {{.*}}i64 1234 }], align 16 // CHECK-LABEL: define internal void @asan.module_ctor -// ASAN: call void @__asan_register_globals({{.*}}, i{{32|64}} 2) +// ASAN: call void @__asan_register_globals({{.*}}, i{{32|64}} 4) // KASAN: call void @__asan_register_globals({{.*}}, i{{32|64}} 1) // CHECK-NEXT: ret void diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp --- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -792,7 +792,8 @@ StringRef InternalSuffix); Instruction *CreateAsanModuleDtor(Module &M); - bool canInstrumentAliasedGlobal(const GlobalAlias &GA) const; + const GlobalVariable *getExcludedAliasedGlobal(const GlobalAlias &GA, + bool Rec = false) const; bool shouldInstrumentGlobal(GlobalVariable *G) const; bool ShouldUseMachOGlobalsSection() const; StringRef getGlobalMetadataSection() const; @@ -1787,20 +1788,39 @@ } } -bool ModuleAddressSanitizer::canInstrumentAliasedGlobal( - const GlobalAlias &GA) const { - // In case this function should be expanded to include rules that do not just - // apply when CompileKernel is true, either guard all existing rules with an - // 'if (CompileKernel) { ... }' or be absolutely sure that all these rules - // should also apply to user space. - assert(CompileKernel && "Only expecting to be called when compiling kernel"); - - // When compiling the kernel, globals that are aliased by symbols prefixed - // by "__" are special and cannot be padded with a redzone. - if (GA.getName().startswith("__")) - return false; +const GlobalVariable * +ModuleAddressSanitizer::getExcludedAliasedGlobal(const GlobalAlias &GA, + bool Rec) const { + if (!Rec) { // Non-recursive case. + // In case this function should be expanded to include rules that do not + // just apply when CompileKernel is true, either guard all existing rules + // with an 'if (CompileKernel) { ... }' or be absolutely sure that all these + // rules should also apply to user space. + assert(CompileKernel && + "Only expecting to be called when compiling kernel"); + + // When compiling the kernel, globals that are aliased by symbols prefixed + // by "__" are special and cannot be padded with a redzone. + if (!GA.getName().startswith("__")) + return nullptr; + } + + if (const auto *GV = dyn_cast(GA.getAliasee())) { + // Find GlobalVariable from aliasee. + return GV; + } else if (const auto *CE = dyn_cast(GA.getAliasee())) { + // Pointer expression into GlobalVariable; find it from one of the operands. + for (const Use &U : CE->operands()) { + if (const auto *GV = dyn_cast(U)) + return GV; + } + } else if (const auto *GAA = dyn_cast(GA.getAliasee())) { + // Recursive GlobalAlias + return getExcludedAliasedGlobal(*GAA, true); + } - return true; + // Not a GlobalVariable alias, ignore. + return nullptr; } bool ModuleAddressSanitizer::shouldInstrumentGlobal(GlobalVariable *G) const { @@ -2252,14 +2272,12 @@ *CtorComdat = false; // Build set of globals that are aliased by some GA, where - // canInstrumentAliasedGlobal(GA) returns false. + // getExcludedAliasedGlobal(GA) returns the relevant GlobalVariable. SmallPtrSet AliasedGlobalExclusions; if (CompileKernel) { for (auto &GA : M.aliases()) { - if (const auto *GV = dyn_cast(GA.getAliasee())) { - if (!canInstrumentAliasedGlobal(GA)) - AliasedGlobalExclusions.insert(GV); - } + if (const GlobalVariable *GV = getExcludedAliasedGlobal(GA)) + AliasedGlobalExclusions.insert(GV); } }