[compiler-rt] r322429 - [hwasan] An LLVM flag to disable stack tag randomization.

[Evgeniy Stepanov via llvm-commits]

Author: eugenis
Date: Fri Jan 12 17:32:15 2018
New Revision: 322429

URL: http://llvm.org/viewvc/llvm-project?rev=322429&view=rev
Log:
[hwasan] An LLVM flag to disable stack tag randomization.

Summary: Necessary to achieve consistent test results.

Reviewers: kcc, alekseyshl

Subscribers: kubamracek, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D42023

Modified:
    compiler-rt/trunk/lib/hwasan/hwasan.cc
    compiler-rt/trunk/lib/hwasan/hwasan_interface_internal.h
    compiler-rt/trunk/test/hwasan/lit.cfg

Modified: compiler-rt/trunk/lib/hwasan/hwasan.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/hwasan/hwasan.cc?rev=322429&r1=322428&r2=322429&view=diff
==============================================================================
--- compiler-rt/trunk/lib/hwasan/hwasan.cc (original)
+++ compiler-rt/trunk/lib/hwasan/hwasan.cc Fri Jan 12 17:32:15 2018
@@ -363,6 +363,14 @@ void __hwasan_tag_memory(uptr p, u8 tag,
   TagMemoryAligned(p, sz, tag);
 }
 
+static const u8 kFallbackTag = 0xBB;
+
+u8 __hwasan_generate_tag() {
+  HwasanThread *t = GetCurrentThread();
+  if (!t) return kFallbackTag;
+  return t->GenerateRandomTag();
+}
+
 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 extern "C" {
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE

Modified: compiler-rt/trunk/lib/hwasan/hwasan_interface_internal.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/hwasan/hwasan_interface_internal.h?rev=322429&r1=322428&r2=322429&view=diff
==============================================================================
--- compiler-rt/trunk/lib/hwasan/hwasan_interface_internal.h (original)
+++ compiler-rt/trunk/lib/hwasan/hwasan_interface_internal.h Fri Jan 12 17:32:15 2018
@@ -86,6 +86,9 @@ void __hwasan_store16_noabort(uptr);
 SANITIZER_INTERFACE_ATTRIBUTE
 void __hwasan_tag_memory(uptr p, u8 tag, uptr sz);
 
+SANITIZER_INTERFACE_ATTRIBUTE
+u8 __hwasan_generate_tag();
+
 // Returns the offset of the first tag mismatch or -1 if the whole range is
 // good.
 SANITIZER_INTERFACE_ATTRIBUTE

Modified: compiler-rt/trunk/test/hwasan/lit.cfg
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/hwasan/lit.cfg?rev=322429&r1=322428&r2=322429&view=diff
==============================================================================
--- compiler-rt/trunk/test/hwasan/lit.cfg (original)
+++ compiler-rt/trunk/test/hwasan/lit.cfg Fri Jan 12 17:32:15 2018
@@ -9,7 +9,7 @@ config.name = 'HWAddressSanitizer' + get
 config.test_source_root = os.path.dirname(__file__)
 
 # Setup default compiler flags used with -fsanitize=memory option.
-clang_hwasan_cflags = ["-fsanitize=hwaddress", config.target_cflags] + config.debug_info_flags
+clang_hwasan_cflags = ["-fsanitize=hwaddress", "-mllvm", "-hwasan-generate-tags-with-calls", config.target_cflags] + config.debug_info_flags
 clang_hwasan_cxxflags = config.cxx_mode_flags + clang_hwasan_cflags
 
 def build_invocation(compile_flags):