[asan] Prevent folding of globals with redzones

Summary:
ICF prevented by removing unnamed_addr and local_unnamed_addr for all sanitized
globals.
Also in general unnamed_addr is not valid here as address now is important for
ODR violation detector and redzone poisoning.

Before the patch ICF on globals caused:
1. false ODR reports when we register global on the same address more than once
2. globals buffer overflow if we fold variables of smaller type inside of large
type. Then the smaller one will poison redzone which overlaps with the larger one.

Reviewers: eugenis, pcc

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55857

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349706 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 2ede46774b24ebff28080fefea5e8d0581710326..0c7aec4ac69df51d22b9c9f4376fcf05d518055d 100644 (file)
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -2150,6 +2150,10 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool
     NewGlobal->copyAttributesFrom(G);
     NewGlobal->setComdat(G->getComdat());
     NewGlobal->setAlignment(MinRZ);
+    // 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+    // is no longer valid for it to be marked unnamed_addr.
+    NewGlobal->setUnnamedAddr(GlobalValue::UnnamedAddr::None);
 
     // Move null-terminated C strings to "__asan_cstring" section on Darwin.
     if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&

diff --git a/test/Instrumentation/AddressSanitizer/global_cstring_darwin.ll b/test/Instrumentation/AddressSanitizer/global_cstring_darwin.ll
index eb31c15b34488f05384823a57a3b616a345eed1b..0fc3205ba492c519b43131547d05f3344d2f9c3c 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/global_cstring_darwin.ll
+++ b/test/Instrumentation/AddressSanitizer/global_cstring_darwin.ll
@@ -8,14 +8,14 @@ target triple = "x86_64-apple-macosx10.10.0"
 @.str.1 = private unnamed_addr constant [13 x i8] c"Hello world.\00", align 1
 @.str.2 = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
 
-; CHECK: @.str.1 = internal unnamed_addr constant { [13 x i8], [51 x i8] } { [13 x i8] c"Hello world.\00", [51 x i8] zeroinitializer }, section "__TEXT,__asan_cstring,regular", align 32
-; CHECK: @.str.2 = internal unnamed_addr constant { [4 x i8], [60 x i8] } { [4 x i8] c"%s\0A\00", [60 x i8] zeroinitializer }, section "__TEXT,__asan_cstring,regular", align 32
+; CHECK: @.str.1 = internal constant { [13 x i8], [51 x i8] } { [13 x i8] c"Hello world.\00", [51 x i8] zeroinitializer }, section "__TEXT,__asan_cstring,regular", align 32
+; CHECK: @.str.2 = internal constant { [4 x i8], [60 x i8] } { [4 x i8] c"%s\0A\00", [60 x i8] zeroinitializer }, section "__TEXT,__asan_cstring,regular", align 32
 
 ; Shouldn't be put into special section:
 @.str.3 = private unnamed_addr constant [4 x i8] c"\00\01\02\03", align 1
 @.str.4 = private unnamed_addr global [7 x i8] c"Hello.\00", align 1
 @.str.5 = private unnamed_addr constant [8 x i8] c"Hello.\00\00", align 1
 
-; CHECK: @.str.3 = internal unnamed_addr constant { [4 x i8], [60 x i8] } { [4 x i8] c"\00\01\02\03", [60 x i8] zeroinitializer }, align 32
-; CHECK: @.str.4 = private unnamed_addr global { [7 x i8], [57 x i8] } { [7 x i8] c"Hello.\00", [57 x i8] zeroinitializer }, align 32
-; CHECK: @.str.5 = internal unnamed_addr constant { [8 x i8], [56 x i8] } { [8 x i8] c"Hello.\00\00", [56 x i8] zeroinitializer }, align 32
+; CHECK: @.str.3 = internal constant { [4 x i8], [60 x i8] } { [4 x i8] c"\00\01\02\03", [60 x i8] zeroinitializer }, align 32
+; CHECK: @.str.4 = private global { [7 x i8], [57 x i8] } { [7 x i8] c"Hello.\00", [57 x i8] zeroinitializer }, align 32
+; CHECK: @.str.5 = internal constant { [8 x i8], [56 x i8] } { [8 x i8] c"Hello.\00\00", [56 x i8] zeroinitializer }, align 32

diff --git a/test/Instrumentation/AddressSanitizer/global_metadata.ll b/test/Instrumentation/AddressSanitizer/global_metadata.ll
index ee42f1cef97af1568b15adef91267fae6b4531f9..ecee77209667e268aeb8c44d634e1b17516a11d4 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/global_metadata.ll
+++ b/test/Instrumentation/AddressSanitizer/global_metadata.ll
@@ -15,7 +15,7 @@ target triple = "x86_64-unknown-linux-gnu"
 ; Check that globals were instrumented:
 
 ; CHECK: @global = global { i32, [60 x i8] } zeroinitializer, comdat, align 32
-; CHECK: @.str = internal unnamed_addr constant { [14 x i8], [50 x i8] } { [14 x i8] c"Hello, world!\00", [50 x i8] zeroinitializer }, comdat($".str${{[01-9a-f]+}}"), align 32
+; CHECK: @.str = internal constant { [14 x i8], [50 x i8] } { [14 x i8] c"Hello, world!\00", [50 x i8] zeroinitializer }, comdat($".str${{[01-9a-f]+}}"), align 32
 
 ; Check emitted location descriptions:
 ; CHECK: [[VARNAME:@___asan_gen_.[0-9]+]] = private unnamed_addr constant [7 x i8] c"global\00", align 1

diff --git a/test/Instrumentation/AddressSanitizer/global_metadata_array.ll b/test/Instrumentation/AddressSanitizer/global_metadata_array.ll
index 76f73778f0f169ac8cf6bb876b6baf2f0bb8e1ef..fbe0016140bafd530e42921792d41be9f5cc6cb4 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/global_metadata_array.ll
+++ b/test/Instrumentation/AddressSanitizer/global_metadata_array.ll
@@ -15,7 +15,7 @@ target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
 ; Check that globals were instrumented:
 ; CHECK: @global = global { i32, [60 x i8] } zeroinitializer, align 32
-; CHECK: @.str = internal unnamed_addr constant { [14 x i8], [50 x i8] } { [14 x i8] c"Hello, world!\00", [50 x i8] zeroinitializer }{{.*}}, align 32
+; CHECK: @.str = internal constant { [14 x i8], [50 x i8] } { [14 x i8] c"Hello, world!\00", [50 x i8] zeroinitializer }{{.*}}, align 32
 
 ; Check emitted location descriptions:
 ; CHECK: [[VARNAME:@___asan_gen_.[0-9]+]] = private unnamed_addr constant [7 x i8] c"global\00", align 1

diff --git a/test/Instrumentation/AddressSanitizer/global_metadata_windows.ll b/test/Instrumentation/AddressSanitizer/global_metadata_windows.ll
index eeac65e1847301d716abbe711eb1eb73df14cd01..5602cb26e0049e520939716d1c88183c65eb9cc8 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/global_metadata_windows.ll
+++ b/test/Instrumentation/AddressSanitizer/global_metadata_windows.ll
@@ -14,8 +14,8 @@ $mystr = comdat any
 ; CHECK: $dead_global = comdat noduplicates
 ; CHECK: $private_str = comdat noduplicates
 
-; CHECK: @dead_global = local_unnamed_addr global { i32, [60 x i8] } { i32 42, [60 x i8] zeroinitializer }, comdat, align 32
-; CHECK: @private_str = internal unnamed_addr constant { [8 x i8], [56 x i8] } { [8 x i8] c"private\00", [56 x i8] zeroinitializer }, comdat, align 32
+; CHECK: @dead_global = global { i32, [60 x i8] } { i32 42, [60 x i8] zeroinitializer }, comdat, align 32
+; CHECK: @private_str = internal constant { [8 x i8], [56 x i8] } { [8 x i8] c"private\00", [56 x i8] zeroinitializer }, comdat, align 32
 
 ; CHECK: @__asan_global_dead_global = private global { {{.*}} }, section ".ASAN$GL", comdat($dead_global), align 64
 ; CHECK: @__asan_global_private_str = private global { {{.*}} }, section ".ASAN$GL", comdat($private_str), align 64

diff --git a/test/Instrumentation/AddressSanitizer/win-string-literal.ll b/test/Instrumentation/AddressSanitizer/win-string-literal.ll
index a86581c1e8e52b68f80b4aa228c3623082cc34ef..05d96d123cdccc5ce7f130126e520ddb3fb04473 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/win-string-literal.ll
+++ b/test/Instrumentation/AddressSanitizer/win-string-literal.ll
@@ -7,7 +7,7 @@
 ; CHECK: $"??_C@_04JIHMPGLA@asdf?$AA@" = comdat any
 
 ; CHECK: @"??_C@_04JIHMPGLA@asdf?$AA@" =
-; CHECK-SAME: linkonce_odr dso_local unnamed_addr constant { [5 x i8], [59 x i8] }
+; CHECK-SAME: linkonce_odr dso_local constant { [5 x i8], [59 x i8] }
 ; CHECK-SAME: { [5 x i8] c"asdf\00", [59 x i8] zeroinitializer }, comdat, align 32
 
 ; CHECK: @"__asan_global_??_C@_04JIHMPGLA@asdf?$AA@" =