Author: Marco Elver
Date: 2020-12-11T12:20:40+01:00
New Revision: c28b18af19621e6b5cca257ef7139ba93833df0c
URL:
https://github.com/llvm/llvm-project/commit/c28b18af19621e6b5cca257ef7139ba93833df0c
DIFF:
https://github.com/llvm/llvm-project/commit/c28b18af19621e6b5cca257ef7139ba93833df0c.diff
LOG: [KernelAddressSanitizer] Fix globals exclusion for indirect aliases
GlobalAlias::getAliasee() may not always point directly to a
GlobalVariable. In such cases, try to find the canonical GlobalVariable
that the alias refers to.
Link: https://github.com/ClangBuiltLinux/linux/issues/1208
Reviewed By: dvyukov, nickdesaulniers
Differential Revision: https://reviews.llvm.org/D92846
Added:
Modified:
clang/test/CodeGen/asan-globals-alias.cpp
llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
Removed:
diff --git a/clang/test/CodeGen/asan-globals-alias.cpp
b/clang/test/CodeGen/asan-globals-alias.cpp
index faf160ac79c9..c859d2f2b44a 100644
--- a/clang/test/CodeGen/asan-globals-alias.cpp
+++ b/clang/test/CodeGen/asan-globals-alias.cpp
@@ -1,17 +1,42 @@
// 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 the aliases exist:
+// CHECK: @__global_alias = alias
+// CHECK: @global_alias_2 = alias
+// CHECK: @__global_alias_2_alias = alias
+// CHECK: @__mod_joydev_ids_device_table = alias
// 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
index 7990bea90dc2..36d3942ffe14 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -792,7 +792,7 @@ class ModuleAddressSanitizer {
StringRef InternalSuffix);
Instruction *CreateAsanModuleDtor(Module &M);
- bool canInstrumentAliasedGlobal(const GlobalAlias &GA) const;
+ const GlobalVariable *getExcludedAliasedGlobal(const GlobalAlias &GA) const;
bool shouldInstrumentGlobal(GlobalVariable *G) const;
bool ShouldUseMachOGlobalsSection() const;
StringRef getGlobalMetadataSection() const;
@@ -1787,20 +1787,22 @@ void
ModuleAddressSanitizer::createInitializerPoisonCalls(
}
}
-bool ModuleAddressSanitizer::canInstrumentAliasedGlobal(
-const GlobalAlias &GA) const {
+const GlobalVariable *
+ModuleAddressSanitizer::getExcludedAliasedGlobal(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(CompileKern
