Commit Graph

127 Commits

Author SHA1 Message Date
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Arnaud A. de Grandmaison 86a5e43656 [compiler-rt][TSan] Add TSan runtime support for Go on linux-aarch64.
Summary:
This patch adds TSan runtime support for Go on linux-aarch64
platforms. This enables people working on golang to implement their
platform/language part of the TSan support.

Basic testing is done with lib/tsan/go/buildgo.sh. Additional testing will be
done as part of the work done in the Go project.

It is intended to support other VMA sizes, except 39 which does not
have enough bits to support the Go heap requirements.

Patch by Fangming Fang <Fangming.Fang@arm.com>.

Reviewers: kubamracek, dvyukov, javed.absar

Subscribers: mcrosier, dberris, mgorny, kristof.beyls, delcypher, #sanitizers, llvm-commits

Differential Revision: https://reviews.llvm.org/D52167

llvm-svn: 342541
2018-09-19 11:56:20 +00:00
Vitaly Buka 2a20955169 [sanitizer] Replace InternalScopedBuffer with InternalMmapVector
llvm-svn: 331618
2018-05-07 05:56:36 +00:00
Vitaly Buka 20f49662f6 [sanitizer] Make InternalScopedBuffer::size() behavior similar to vector.
llvm-svn: 331612
2018-05-07 01:08:13 +00:00
Dmitry Vyukov 4132b849e5 tsan: fix compiler warnings
vmaSize is uptr, so we need to print it with %zd.

llvm-svn: 330312
2018-04-19 07:42:08 +00:00
Dmitry Vyukov 3a99c76e3d tsan: add support for linux/powerpc64 in buildgo.sh
The current implementation of the Go sanitizer only works on x86_64.
Added some modifications to the buildgo.sh script and the Tsan code
to make it work on powerpc64/linux.

Author: cseo (Carlos Eduardo Seo)
Reviewed in: https://reviews.llvm.org/D43025

llvm-svn: 330122
2018-04-16 11:43:00 +00:00
Bill Seurer 785294d497 [PowerPC][tsan] Update tsan to handle changed memory layouts in newer kernels
In more recent Linux kernels with 47 bit VMAs the layout of virtual memory
for powerpc64 changed causing the thread sanitizer to not work properly. This
patch adds support for 47 bit VMA kernels for powerpc64.

(second part)

Tested on several 4.x and 3.x kernel releases.

llvm-svn: 319180
2017-11-28 16:28:54 +00:00
Kamil Rytarowski 9c1eeaca80 Add NetBSD improvements in sanitizers
Summary:
Changes:

 * Add initial msan stub support.
 * Handle NetBSD specific pthread_setname_np(3).
 * NetBSD supports __attribute__((tls_model("initial-exec"))),
   define it in SANITIZER_TLS_INITIAL_EXEC_ATTRIBUTE.
 * Add ReExec() specific bits for NetBSD.
 * Simplify code and add syscall64 and syscall_ptr for !NetBSD.
 * Correct bunch of syscall wrappers for NetBSD.
 * Disable test/tsan/map32bit on NetBSD as not applicable.
 * Port test/tsan/strerror_r to a POSIX-compliant OSes.
 * Disable __libc_stack_end on NetBSD.
 * Disable ReadNullSepFileToArray() on NetBSD.
 * Define struct_ElfW_Phdr_sz, detected missing symbol by msan.
 * Change type of __sanitizer_FILE from void to char. This helps
   to reuse this type as an array. Long term it will be properly
   implemented along with SANITIZER_HAS_STRUCT_FILE setting to 1.
 * Add initial NetBSD support in lib/tsan/go/buildgo.sh.
 * Correct referencing stdout and stderr in tsan_interceptors.cc
   on NetBSD.
 * Document NetBSD x86_64 specific virtual memory layout in
   tsan_platform.h.
 * Port tests/rtl/tsan_test_util_posix.cc to NetBSD.
 * Enable NetBSD tests in test/msan/lit.cfg.
 * Enable NetBSD tests in test/tsan/lit.cfg.

Sponsored by <The NetBSD Foundation>

Reviewers: joerg, vitalybuka, eugenis, kcc, dvyukov

Reviewed By: dvyukov

Subscribers: #sanitizers, llvm-commits, kubamracek

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D39124

llvm-svn: 316591
2017-10-25 17:09:05 +00:00
Kostya Serebryany c56d444b75 Fix sanitizer build against latest glibc
Summary:
libsanitizer doesn't build against latest glibc anymore, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81066 for details.
One of the changes is that stack_t changed from typedef struct sigaltstack { ... } stack_t; to typedef struct { ... } stack_t; for conformance reasons.
And the other change is that the glibc internal __need_res_state macro is now ignored, so when doing
```
#define __need_res_state
#include <resolv.h>
```
the effect is now the same as just
```
#include <resolv.h>
```
and thus one doesn't get just the
```
struct __res_state { ... };
```
definition, but newly also the
```
extern struct __res_state *__res_state(void) __attribute__ ((__const__));
```
prototype.  So __res_state is no longer a type, but a function.

Reviewers: kcc, ygribov

Reviewed By: kcc

Subscribers: kubamracek

Differential Revision: https://reviews.llvm.org/D35246

llvm-svn: 307969
2017-07-13 21:59:01 +00:00
Francis Ricci f6a4329b7d Refactor MemoryMappingLayout::Next to use a single struct instead of output parameters. NFC.
Summary:
This is the first in a series of patches to refactor sanitizer_procmaps
to allow MachO section information to be exposed on darwin.

In addition, grouping all segment information in a single struct is
cleaner than passing it through a large set of output parameters, and
avoids the need for annotations of NULL parameters for unneeded
information.

The filename string is optional and must be managed and supplied by the
calling function. This is to allow the MemoryMappedSegment struct to be
stored on the stack without causing overly large stack sizes.

Reviewers: alekseyshl, kubamracek, glider

Subscribers: emaste, llvm-commits

Differential Revision: https://reviews.llvm.org/D35135

llvm-svn: 307688
2017-07-11 18:54:00 +00:00
Alex Shlyapnikov 35adb43950 [Sanitizers] Consolidate internal errno definitions.
Move internal errno definitions to common to be shared by all sanitizers
and to be used by allocators.

llvm-svn: 307233
2017-07-06 00:50:57 +00:00
Francis Ricci 75ca300f2b Don't require ThreadState to be contained within tls on all platforms
The existing implementation ran CHECKs to assert that the thread state
was stored inside the tls. However, the mac implementation of tsan doesn't
store the thread state in tls, so these checks fail once darwin tls support
is added to the sanitizers. Only run these checks on platforms where
the thread state is expected to be contained in the tls.

llvm-svn: 303886
2017-05-25 17:41:10 +00:00
Kostya Kortchinsky 7fc481e561 [compiler-rt] move tsan's Android __get_tls() to sanitizer_common
Summary:
TSan's Android `__get_tls()` and `TLS_SLOT_TSAN` can be used by other sanitizers as well (see D32649), this change moves them to sanitizer_common.
I picked sanitizer_linux.h as their new home.
In the process, add the 32-bit versions for ARM, i386 & MIPS.

Can the address of `__get_tls()[TLS_SLOT_TSAN]` change in between the calls?
I am not sure if there is a need to repeat the construct as opposed to using a variable. So I left things as they were.

Testing on my side was restricted to a successful cross-compilation.

Reviewers: dvyukov, kubamracek

Reviewed By: dvyukov

Subscribers: aemerson, rengolin, srhines, dberris, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D32705

llvm-svn: 301926
2017-05-02 15:13:36 +00:00
Evgeniy Stepanov e109ef854a Release memory to OS only when the requested range covers the entire page
Summary:
The current code was sometimes attempting to release huge chunks of
memory due to undesired RoundUp/RoundDown interaction when the requested
range is fully contained within one memory page.

Reviewers: eugenis

Subscribers: kubabrecka, llvm-commits

Patch by Aleksey Shlyapnikov.

Differential Revision: https://reviews.llvm.org/D27228

llvm-svn: 288271
2016-11-30 20:41:59 +00:00
Dmitry Vyukov 5dc443619e tsan: always define SANITIZER_GO
Currently we either define SANITIZER_GO for Go or don't define it at all for C++.
This works fine with preprocessor (ifdef/ifndef/defined), but does not work
for C++ if statements (e.g. if (SANITIZER_GO) {...}). Also this is different
from majority of SANITIZER_FOO macros which are always defined to either 0 or 1.

Always define SANITIZER_GO to either 0 or 1.
This allows to use SANITIZER_GO in expressions and in flag default values.

Also remove kGoMode and kCppMode, which were meant to be used in expressions,
but they are not defined in sanitizer_common code, so SANITIZER_GO become prevalent.

Also convert some preprocessor checks to C++ if's or ternary expressions.

Majority of this change is done mechanically with:
sed "s#ifdef SANITIZER_GO#if SANITIZER_GO#g"
sed "s#ifndef SANITIZER_GO#if \!SANITIZER_GO#g"
sed "s#defined(SANITIZER_GO)#SANITIZER_GO#g"

llvm-svn: 285443
2016-10-28 20:14:18 +00:00
Kostya Serebryany b72479b84a [asan] first attempt at releasing free-d memory back to the system using madvise. Requires quite some tuning.
llvm-svn: 279887
2016-08-26 23:58:42 +00:00
Adhemerval Zanella daa3ebce28 tsan: Remove __pointer_chk_guard@GLIBC_PRIVATE requirement for AArch64
Current AArch64 {sig}{set,long}jmp interposing requires accessing glibc
private __pointer_chk_guard to get process xor mask to demangled the
internal {sig}jmp_buf function pointers.

It causes some packing issues, as described in gcc PR#71042 [1], and is
is not a godd practice to rely on a private glibc namespace (since ABI is
not meant to be stable).

This patch fixes it by changing how libtsan obtains the guarded pointer
value: at initialization a specific routine issues a setjmp call and
using the mangled function pointer and the original value derive the
random guarded pointer.

Checked on aarch64 39-bit VMA.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71042

llvm-svn: 278292
2016-08-10 21:39:28 +00:00
Adhemerval Zanella 4f9de1e7bf tsan: Enable 48-bit VMA support on aarch64
This patch adds 48-bits VMA support for tsan on aarch64.  As current
mappings for aarch64, 48-bit VMA also supports PIE executable.  This
limits the mapping mechanism because the PIE address bits
(usually 0aaaaXXXXXXXX) makes it harder to create a mask/xor value
to include all memory regions.  I think it is possible to create a
large application VAM range by either dropping PIE support or tune
current range.

It also changes slight the way addresses are packed in SyncVar structure:
previously it assumes x86_64 as the maximum VMA range.  Since ID is 14 bits
wide, shifting 48 bits should be ok.

Tested on x86_64, ppc64le and aarch64 (39 and 48 bits VMA).

llvm-svn: 277137
2016-07-29 12:45:35 +00:00
Dmitry Vyukov 0f7e949a42 tsan: rely on AnnotateRWLockCreateStatic to detect linker-initialized mutexes
The new annotation was added a while ago, but was not actually used.
Use the annotation to detect linker-initialized mutexes instead
of the broken IsGlobalVar which has both false positives and false
negatives. Remove IsGlobalVar mess.

llvm-svn: 271663
2016-06-03 11:48:27 +00:00
Marcin Koscielnicki 0a91cf8a84 Revert "[sanitizer] [SystemZ] Abort if the kernel might be vulnerable to CVE-2016-2143."
This reverts commit r266297.

llvm-svn: 266470
2016-04-15 20:00:12 +00:00
Marcin Koscielnicki c8dda336bb [sanitizer] [SystemZ] Abort if the kernel might be vulnerable to CVE-2016-2143.
In short, CVE-2016-2143 will crash the machine if a process uses both >4TB
virtual addresses and fork().  ASan, TSan, and MSan will, by necessity, map
a sizable chunk of virtual address space, which is much larger than 4TB.
Even worse, sanitizers will always use fork() for llvm-symbolizer when a bug
is detected.  Disable all three by aborting on process initialization if
the running kernel version is not known to contain a fix.

Unfortunately, there's no reliable way to detect the fix without crashing
the kernel.  So, we rely on whitelisting - I've included a list of upstream
kernel versions that will work.  In case someone uses a distribution kernel
or applied the fix themselves, an override switch is also included.

Differential Revision: http://reviews.llvm.org/D18915

llvm-svn: 266297
2016-04-14 12:56:24 +00:00
Yabin Cui c7db569cc1 [tsan] Fix freebsd build.
Summary:
Freebsd doesn't have <sys/personality.h>, so call personality() only in
SANITIZER_LINUX.

Reviewers: llvm-commits, dvyukov, zatrazz, rengolin, beanz

Subscribers: beanz, emaste

Differential Revision: http://reviews.llvm.org/D18785

llvm-svn: 265378
2016-04-05 05:37:48 +00:00
Yabin Cui e3f558ba14 [tsan] Disable randomized address space on aarch64 linux.
Summary:
After patch https://lkml.org/lkml/2015/12/21/340 is introduced in
linux kernel, the random gap between stack and heap is increased
from 128M to 36G on 39-bit aarch64. And it is almost impossible
to cover this big range. So we need to disable randomized virtual
space on aarch64 linux.

Reviewers: llvm-commits, zatrazz, dvyukov, rengolin

Subscribers: aemerson, rengolin, tberghammer, danalbert, srhines

Differential Revision: http://reviews.llvm.org/D18526

llvm-svn: 265366
2016-04-04 23:48:25 +00:00
Renato Golin c8622e8cde Revert "[tsan] Disable randomized address space on linux aarch64."
This reverts commits r264068 and r264079, and they were breaking the build and
weren't reverted in time, nor they exhibited expected behaviour from the
reviewers. There is more to discuss than just a test fix.

llvm-svn: 264150
2016-03-23 11:24:30 +00:00
Yabin Cui 28f367d7b3 [tsan] Fix check-tsan build by using CHECK_NE.
Reviewers: llvm-commits, srhines, dvyukov

Subscribers: srhines

Differential Revision: http://reviews.llvm.org/D18361

llvm-svn: 264079
2016-03-22 18:12:18 +00:00
Yabin Cui 909e600abd [tsan] Disable randomized address space on linux aarch64.
Summary:
After patch https://lkml.org/lkml/2015/12/21/340 is introduced in
linux kernel, the random gap between stack and heap is increased
from 128M to 36G on 39-bit aarch64. And it is almost impossible
to cover this big range. So I think we need to disable randomized
virtual space on aarch64 linux.

Reviewers: kcc, llvm-commits, eugenis, zatrazz, dvyukov, rengolin

Subscribers: rengolin, aemerson, tberghammer, danalbert, srhines, enh

Differential Revision: http://reviews.llvm.org/D18003

llvm-svn: 264068
2016-03-22 17:16:26 +00:00
Yabin Cui 19e8c0e2f7 [tsan] Fix some tiny errors.
Summary:
1. Fix spell error for sigaction.
2. Make line_length <= 80.

Reviewers: llvm-commits, eugenis, kcc, dvyukov

Subscribers: tberghammer, danalbert, srhines

Differential Revision: http://reviews.llvm.org/D16210

llvm-svn: 257872
2016-01-15 06:21:46 +00:00
Yabin Cui bd3a772e9f [tsan] Store the pointer to ThreadState in TLS slot on Android.
Summary:
1. Android doesn't support __thread keyword. So allocate ThreadState
dynamically and store its pointer in one TLS slot provided by Android.
2. On Android, intercepted functions can be called before ThreadState
is initialized. So add test of thr_->is_inited in some places.
3. On Android, intercepted functions can be called after ThreadState
is destroyed. So add a fake dead_thread_state to represent all
destroyed ThreadStates. And that is also why we don't store the pointer
to ThreadState in shadow memory of pthread_self().

Reviewers: kcc, eugenis, dvyukov

Subscribers: kubabrecka, llvm-commits, tberghammer, danalbert, srhines

Differential Revision: http://reviews.llvm.org/D15301

llvm-svn: 257866
2016-01-15 03:39:04 +00:00
Bill Schmidt e193989c17 [TSAN, PPC64] Fix obvious typo of supported virtual memory sizes
llvm-svn: 255507
2015-12-14 16:26:00 +00:00
Yabin Cui 903ab8a2a3 [tsan] Disable interceptors not supported in Android.
Reviewers: kcc, eugenis, dvyukov

Subscribers: llvm-commits, tberghammer, danalbert, srhines

Differential Revision: http://reviews.llvm.org/D15295

llvm-svn: 255164
2015-12-09 22:23:47 +00:00
Alexey Samsonov 9c54984d43 [TSan] Try harder to avoid compiler-generated memset calls.
check_memcpy test added in r254959 fails on some configurations due to
memset() calls inserted by Clang. Try harder to avoid them:
* Explicitly use internal_memset() instead of empty braced-initializer.
* Replace "new T()" with "new T", as the former generates zero-initialization
  for structs in C++11.

llvm-svn: 255136
2015-12-09 18:48:10 +00:00
Bill Schmidt 2979162732 [PPC64, TSAN] LLVM basic enablement of thread sanitizer for PPC64 (BE and LE)
This patch is by Simone Atzeni with portions by Adhemerval Zanella.

This contains the LLVM patches to enable the thread sanitizer for
PPC64, both big- and little-endian.  Two different virtual memory
sizes are supported:  Old kernels use a 44-bit address space, while
newer kernels require a 46-bit address space.

There are two companion patches that will be added shortly.  There is
a Clang patch to actually turn on the use of the thread sanitizer for
PPC64.  There is also a patch that I wrote to provide interceptor
support for setjmp/longjmp on PPC64.

Patch discussion at reviews.llvm.org/D12841.

llvm-svn: 255057
2015-12-08 21:54:39 +00:00
Adhemerval Zanella 066c5f0f92 [compiler-rt] [tsan] Unify aarch64 mapping
This patch unify the 39 and 42-bit support for AArch64 by using an external
memory read to check the runtime detected VMA and select the better mapping
and transformation.  Although slower, this leads to same instrumented binary
to be independent of the kernel.

Along with this change this patch also fix some 42-bit failures with
ALSR disable by increasing the upper high app memory threshold and also
the 42-bit madvise value for non large page set.

llvm-svn: 254151
2015-11-26 13:10:47 +00:00
Kuba Brecka 40ad607be6 [tsan] Use malloc zone interceptors on OS X, part 2
TSan needs to use a custom malloc zone on OS X, which is already implemented in ASan.  This patch uses the sanitizer_common implementation in `sanitizer_malloc_mac.inc` for TSan as well.

Reviewed at http://reviews.llvm.org/D14330

llvm-svn: 252155
2015-11-05 10:31:21 +00:00
Kuba Brecka 88bccf0344 [tsan] Shadow memory setup for OS X
Updating the shadow memory initialization in `tsan_platform_mac.cc` to also initialize the meta shadow and to mprotect the memory ranges that need to be avoided.

Differential Revision: http://reviews.llvm.org/D14324

llvm-svn: 252044
2015-11-04 11:39:40 +00:00
Adhemerval Zanella d7984710ae [tsan] Enable tsan for aarch64
This patch enabled TSAN for aarch64 with 39-bit VMA layout.  As defined by
tsan_platform.h the layout used is:

0000 4000 00 - 0200 0000 00: main binary
2000 0000 00 - 4000 0000 00: shadow memory
4000 0000 00 - 5000 0000 00: metainfo
5000 0000 00 - 6000 0000 00: -
6000 0000 00 - 6200 0000 00: traces
6200 0000 00 - 7d00 0000 00: -
7d00 0000 00 - 7e00 0000 00: heap
7e00 0000 00 - 7fff ffff ff: modules and main thread stack

Which gives it about 8GB for main binary, 4GB for heap and 8GB for
modules and main thread stack.

Most of tests are passing, with the exception of:

 * ignore_lib0, ignore_lib1, ignore_lib3 due a kernel limitation for
   no support to make mmap page non-executable.

 * longjmp tests due missing specialized assembly routines.

These tests are xfail for now.

The only tsan issue still showing is:

  rtl/TsanRtlTest/Posix.ThreadLocalAccesses

Which still required further investigation.  The test is disable for
aarch64 for now.

llvm-svn: 244055
2015-08-05 15:17:59 +00:00
Dmitry Vyukov 70dd0e2087 tsan: mark meta shadow as NOHUGEPAGE
Meta shadow is compressing and we don't flush it,
so it makes sense to mark it as NOHUGEPAGE to not over-allocate memory.
On one program it reduces memory consumption from 5GB to 2.5GB.

llvm-svn: 240028
2015-06-18 16:57:37 +00:00
Evgeniy Stepanov 8e9c70be7f Add descriptive names to sanitizer entries in /proc/self/maps. Helps debugging.
This is done by creating a named shared memory region, unlinking it
and setting up a private (i.e. copy-on-write) mapping of that instead
of a regular anonymous mapping. I've experimented with regular
(sparse) files, but they can not be scaled to the size of MSan shadow
mapping, at least on Linux/X86_64 and ext3 fs.

Controlled by a common flag, decorate_proc_maps, disabled by default.

This patch has a few shortcomings:
* not all mappings are annotated, especially in TSan.
* our handling of memset() of shadow via mmap() puts small anonymous
  mappings inside larger named mappings, which looks ugly and can, in
  theory, hit the mapping number limit.

llvm-svn: 238621
2015-05-29 22:31:28 +00:00
Timur Iskhodzhanov ea1f332b79 Split Mprotect into MmapNoAccess and MprotectNoAccess to be more portable
On Windows, we have to know if a memory to be protected is mapped or not.
On POSIX, Mprotect was semantically different from mprotect most people know.

llvm-svn: 234602
2015-04-10 15:02:19 +00:00
Timur Iskhodzhanov 3745303c5b Move some POSIX-specific functions from sanitizer_libc.h to a new sanitizer_posix.h
llvm-svn: 234418
2015-04-08 17:08:24 +00:00
Dmitry Vyukov 8e39c404a0 tsan: handle async signals while blocked in pthread_cond_wait
Fixes https://code.google.com/p/thread-sanitizer/issues/detail?id=91

llvm-svn: 234394
2015-04-08 07:48:52 +00:00
Mohit K. Bhakkad a46d5a7438 [TSan][MIPS] Adding support for MIPS64
Patch by Sagar Thakur

Reviewers: dvyukov, samsonov, petarj, kcc, dsanders.

Subscribers:  mohit.bhakkad, Anand.Takale, llvm-commits.

Differential Revision: http://reviews.llvm.org/D6291

llvm-svn: 229972
2015-02-20 06:42:41 +00:00
Yury Gribov 8f848ff5ed [ASan] Add use_madv_dontdump flag.
Differential Revision: http://reviews.llvm.org/D7294

llvm-svn: 227959
2015-02-03 10:15:15 +00:00
Kostya Serebryany c6338ac943 [asan] use MADV_NOHUGEPAGE for shadow to reduce the actual memory usage
llvm-svn: 226636
2015-01-21 02:05:31 +00:00
Kostya Serebryany 83ed889bbd [tsan] remove TSAN_GO in favor of SANITIZER_GO
llvm-svn: 223732
2014-12-09 01:31:14 +00:00
Kostya Serebryany 6c54a6b5dd [asan] move GetRSS from tsan to sanitizer_common
llvm-svn: 223730
2014-12-09 01:22:59 +00:00
Dmitry Vyukov bf253a3d3f tsan: protect trace memory range on startup
so that user does not map something there ahead of us

llvm-svn: 223456
2014-12-05 10:06:06 +00:00
Viktor Kutuzov adf81dbcc6 [Tsan] Fix references to renamed variables in DPrintf()
Differential Revision: http://reviews.llvm.org/D5993

llvm-svn: 220674
2014-10-27 11:22:24 +00:00
Viktor Kutuzov a58fed9ab7 [Tsan] Fix guessing data range on FreeBSD
Differential Revision: http://reviews.llvm.org/D5990

llvm-svn: 220672
2014-10-27 11:14:24 +00:00
Dmitry Vyukov e9a5f03716 tsan: support mmap(MAP_32BIT)
Allow user memory in the first TB of address space.
This also enabled non-pie binaries and freebsd.
Fixes issue:
https://code.google.com/p/thread-sanitizer/issues/detail?id=5

llvm-svn: 220571
2014-10-24 17:07:29 +00:00