[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240723 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index ff4368198be2f419fd9f8ec0ace81e4b5806c6be..92b13c49ede829760d0fff2232556feb39f424c5 100644 (file)
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1144,6 +1144,8 @@ bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
 
     // 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.

diff --git a/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll b/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll
index 7617dbde0b7e34b1e7b59b56917ef83e3880b23c..f67155a29c2a8c95509a41a53ddcc342a5edd391 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll
+++ b/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata-darwin.ll
@@ -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"
+@.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

diff --git a/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll b/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll
index d02f12aec98d06d4460603ec3d3a58a42ce95169..93eca5bfd824b363cc89ba1a7db4c61343fcffa0 100644 (file)
--- a/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll
+++ b/test/Instrumentation/AddressSanitizer/do-not-instrument-llvm-metadata.ll
@@ -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"
+@.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