[llvm] r240723 - [asan] Do not instrument special purpose LLVM sections.

[Anna Zaks]

Author: zaks
Date: Thu Jun 25 18:35:48 2015
New Revision: 240723

URL: http://llvm.org/viewvc/llvm-project?rev=240723&view=rev
Log:
[asan] Do not instrument special purpose LLVM sections.

Do not instrument globals that are placed in sections containing "__llvm"
in their name.

This fixes a bug in ASan / PGO interoperability. ASan interferes with LLVM's
PGO, which places its globals into a special section, which is memcpy-ed by
the linker as a whole. When those goals are instrumented, ASan's memcpy wrapper
reports an issue.

http://reviews.llvm.org/D10541

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
    llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll
    llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=240723&r1=240722&r2=240723&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Thu Jun 25 18:35:48 2015
@@ -1144,6 +1144,8 @@ bool AddressSanitizerModule::ShouldInstr
 
     // Globals from llvm.metadata aren't emitted, do not instrument them.
     if (Section == "llvm.metadata") return false;
+    // Do not instrument globals from special LLVM sections.
+    if (Section.find("__llvm") != StringRef::npos) return false;
 
     // Callbacks put into the CRT initializer/terminator sections
     // should not be instrumented.

Modified: llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll?rev=240723&r1=240722&r2=240723&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll (original)
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll Thu Jun 25 18:35:48 2015
@@ -1,12 +1,15 @@
-; This test checks that we are not instrumenting globals in llvm.metadata.
+; This test checks that we are not instrumenting globals in llvm.metadata
+; and other llvm internal globals.
 ; RUN: opt < %s -asan -asan-module -S | FileCheck %s
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.10.0"
 
 @.str_noinst = private unnamed_addr constant [4 x i8] c"aaa\00", section "llvm.metadata"
+ at .str_noinst_prof = private unnamed_addr constant [4 x i8] c"aaa\00", section "__DATA,__llvm_covmap"
 @.str_inst = private unnamed_addr constant [4 x i8] c"aaa\00"
 
 ; CHECK-NOT: {{asan_gen.*str_noinst}}
+; CHECK-NOT: {{asan_gen.*str_noinst_prof}}
 ; CHECK: {{asan_gen.*str_inst}}
 ; CHECK: @asan.module_ctor

Modified: llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll?rev=240723&r1=240722&r2=240723&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll (original)
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll Thu Jun 25 18:35:48 2015
@@ -1,12 +1,15 @@
-; This test checks that we are not instrumenting globals in llvm.metadata.
+; This test checks that we are not instrumenting globals in llvm.metadata
+; and other llvm internal globals.
 ; RUN: opt < %s -asan -asan-module -S | FileCheck %s
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 @.str_noinst = private unnamed_addr constant [4 x i8] c"aaa\00", section "llvm.metadata"
+ at .str_noinst_prof = private unnamed_addr constant [4 x i8] c"aaa\00", section "__llvm_prf_data"
 @.str_inst = private unnamed_addr constant [4 x i8] c"aaa\00"
 
 ; CHECK-NOT: {{asan_gen.*str_noinst}}
+; CHECK-NOT: {{asan_gen.*str_noinst_prof}}
 ; CHECK: {{asan_gen.*str_inst}}
 ; CHECK: @asan.module_ctor