If lots of threads do lots of malloc/free and they overflow
per-pthread DenseSlabAlloc cache, it causes lots of contention:
31.97% race.old race.old [.] __sanitizer::StaticSpinMutex::LockSlow
17.61% race.old race.old [.] __tsan_read4
10.77% race.old race.old [.] __tsan::SlotLock
Optimize DenseSlabAlloc to use a lock-free stack of batches of nodes.
This way we don't take any locks in steady state at all and do only
1 push/pop per Refill/Drain.
Effect on the added benchmark:
$ TIME="%e %U %S %M" time ./test.old 36 5 2000000
34.51 978.22 175.67 5833592
32.53 891.73 167.03 5790036
36.17 1005.54 201.24 5802828
36.94 1004.76 226.58 5803188
$ TIME="%e %U %S %M" time ./test.new 36 5 2000000
26.44 720.99 13.45 5750704
25.92 721.98 13.58 5767764
26.33 725.15 13.41 5777936
25.93 713.49 13.41 5791796
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D130002
We already link libunwind explicitly so avoid trying to link toolchain's
default libunwind which may be missing. This matches what we already do
for libcxx and libcxxabi.
Differential Revision: https://reviews.llvm.org/D129472
Callers of TraceSwitchPart expect that TraceAcquire will always succeed
after the call. It's possible that TryTraceFunc/TraceMutexLock in TraceSwitchPart
that restore the current stack/mutexset filled the trace part exactly up
to the TracePart::kAlignment gap and the next TraceAcquire won't succeed.
Skip the alignment gap after writing initial stack/mutexset to avoid that.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D129777
This is a follow up to D118200 which applies a similar cleanup to
headers when using in-tree libc++ to avoid accidentally picking up
the system headers.
Differential Revision: https://reviews.llvm.org/D128035
This is a follow up to D118200 which applies a similar cleanup to
headers when using in-tree libc++ to avoid accidentally picking up
the system headers.
Differential Revision: https://reviews.llvm.org/D128035
While investigating another issue, I noticed that `MaybeReexec()` never
actually "re-executes via `execv()`" anymore. `DyldNeedsEnvVariable()`
only returned true on macOS 10.10 and below.
Usually, I try to avoid "unnecessary" cleanups (it's hard to be certain
that there truly is no fallout), but I decided to do this one because:
* I initially tricked myself into thinking that `MaybeReexec()` was
relevant to my original investigation (instead of being dead code).
* The deleted code itself is quite complicated.
* Over time a few other things were mushed into `MaybeReexec()`:
initializing `MonotonicNanoTime()`, verifying interceptors are
working, and stripping the `DYLD_INSERT_LIBRARIES` env var to avoid
problems when forking.
* This platform-specific thing leaked into `sanitizer_common.h`.
* The `ReexecDisabled()` config nob relies on the "strong overrides weak
pattern", which is now problematic and can be completely removed.
* `ReexecDisabled()` actually hid another issue with interceptors not
working in unit tests. I added an explicit `verify_interceptors`
(defaults to `true`) option instead.
Differential Revision: https://reviews.llvm.org/D129157
Many tests for the `UBSan-Standalone-iossim-x86_64` fail with this.
Reverting so I can investigate.
This reverts commit 0a9667b0f56b1b450abd02f74c6175bea54f832e.
While investigating another issue, I noticed that `MaybeReexec()` never
actually "re-executes via `execv()`" anymore. `DyldNeedsEnvVariable()`
only returned true on macOS 10.10 and below.
Usually, I try to avoid "unnecessary" cleanups (it's hard to be certain
that there truly is no fallout), but I decided to do this one because:
* I initially tricked myself into thinking that `MaybeReexec()` was
relevant to my original investigation (instead of being dead code).
* The deleted code itself is quite complicated.
* Over time a few other things were mushed into `MaybeReexec()`:
initializing `MonotonicNanoTime()`, verifying interceptors are
working, and stripping the `DYLD_INSERT_LIBRARIES` env var to avoid
problems when forking.
* This platform-specific thing leaked into `sanitizer_common.h`.
* The `ReexecDisabled()` config nob relies on the "strong overrides weak
pattern", which is now problematic and can be completely removed.
* `ReexecDisabled()` actually hid another issue with interceptors not
working in unit tests. I added an explicit `verify_interceptors`
(defaults to `true`) option instead.
Differential Revision: https://reviews.llvm.org/D129157
Add a missing "#if !SANITIZER_GO" guard for a call to DumpProcessMap
in the Finalize hook (needed to build an updated Go race detector syso
image).
Reviewed By: dvyukov
Differential Revision: https://reviews.llvm.org/D128641
We no longer support the use of LLVM_ENABLE_PROJECTS for libcxx and
libcxxabi. We don't use paths to libcxx and libcxxabi in compiler-rt.
Differential Revision: https://reviews.llvm.org/D126905
We no longer support the use of LLVM_ENABLE_PROJECTS for libcxx and
libcxxabi. We don't use paths to libcxx and libcxxabi in compiler-rt.
Differential Revision: https://reviews.llvm.org/D126905
The stack pointer is stored in the second slot in the jump buffer on
AArch64. Use the correct slot value to read this rather than the
following register.
Reviewed by: melver
Differential Revision: https://reviews.llvm.org/D125762
This is a follow up to [Sanitizers][Darwin] Rename Apple macro SANITIZER_MAC -> SANITIZER_APPLE (D125816)
Performed a global search/replace as in title against LLVM sources
Differential Revision: https://reviews.llvm.org/D126263
Fixes:
tsan/tsan_shadow.h:93:32: warning: enumerated and non-enumerated type in conditional expression [-Wextra]
tsan/tsan_shadow.h:94:44: warning: enumerated and non-enumerated type in conditional expression [-Wextra]
Differential Revision: https://reviews.llvm.org/D124828
After cd0a5889d71, unittest would run in shard mode where many tests
share a single process. Need to clear some global state to make the test
results stable.
Reviewed By: thetruestblue, rsundahl
Differential Revision: https://reviews.llvm.org/D124591
An application can use the mere fact of epoll_wait returning an fd
as synchronization with the write on the fd that triggered the notification.
This pattern come up in an internal networking server (b/229276331).
If an fd is added to epoll, setup a link from the fd to the epoll fd
and use it for synchronization as well.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D124518
from compiler-rt/lib/tsan
[NFC] As part of using inclusive language within the llvm project, this
patch rewords comments to remove sanity check and sanity test.
Reviewed By: dvyukov
Differential Revision: https://reviews.llvm.org/D124390
Currently, we only print how threads involved in data race are created from their parent threads.
Add a runtime flag 'print_full_thread_history' to print thread creation stacks for the threads involved in the data race and their ancestors up to the main thread.
Reviewed By: dvyukov
Differential Revision: https://reviews.llvm.org/D122131
For errno spoiling reports we only print the stack
where the signal handler is invoked. And the top
frame is the signal handler function, which is supposed
to give the info for debugging.
But in same cases the top frame can be some common thunk,
which does not give much info. E.g. for Go/cgo it's always
runtime.cgoSigtramp.
Print the signal number.
This is what we can easily gather and it may give at least
some hints regarding the issue.
Reviewed By: melver, vitalybuka
Differential Revision: https://reviews.llvm.org/D121979
The false positive fixed by commit f831d6fc80
("tsan: fix false positive during fd close") still happens episodically
on the added more stressful test which does just open/close.
I don't have a coherent explanation as to what exactly happens
but the fix fixes the false positive on this test as well.
The issue may be related to lost writes during asynchronous MADV_DONTNEED.
I've debugged similar unexplainable false positive related to freed and
reused memory and at the time the only possible explanation I found is that
an asynchronous MADV_DONTNEED may lead to lost writes. That's why commit
302ec7b9bc ("tsan: add memory_limit_mb flag") added StopTheWorld around
the memory flush, but unfortunately the commit does not capture these findings.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D121363
FdClose is a subjet to the same atomicity problem as MemoryRangeFreed
(memory state is not "monotoic" wrt race detection).
So we need to lock the thread slot in FdClose the same way we do
in MemoryRangeFreed.
This fixes the modified stress.cpp test.
Reviewed By: vitalybuka, melver
Differential Revision: https://reviews.llvm.org/D121143
The upstream project ships CMake rules for building vanilla gtest/gmock which conflict with the names chosen by LLVM. Since LLVM's build rules here are quite specific to LLVM, prefixing them to avoid collision is the right thing (i.e. there does not appear to be a path to letting someone *replace* LLVM's googletest with one they bring, so co-existence should be the goal).
This allows LLVM to be included with testing enabled within projects that themselves have a dependency on an official gtest release.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D120789
There should be 1-bit unused field between tid field and is_atomic field of Shadow.
Reviewed By: dvyukov, vitalybuka
Differential Revision: https://reviews.llvm.org/D119417
There should be 1-bit unused field between tid field and is_atomic field of Shadow.
Reviewed By: dvyukov, vitalybuka
Differential Revision: https://reviews.llvm.org/D119417
This is a follow up to 4f3f4d672254
("sanitizer_common: fix __sanitizer_get_module_and_offset_for_pc signature mismatch")
which fixes a similar problem for msan build.
I am getting the following error compiling a unit test for code that
uses sanitizer_common headers and googletest transitively includes
sanitizer interface headers:
In file included from third_party/gwp_sanitizers/singlestep_test.cpp:3:
In file included from sanitizer_common/sanitizer_common.h:19:
sanitizer_interface_internal.h:41:5: error: typedef redefinition with different types
('struct __sanitizer_sandbox_arguments' vs 'struct __sanitizer_sandbox_arguments')
} __sanitizer_sandbox_arguments;
common_interface_defs.h:39:3: note: previous definition is here
} __sanitizer_sandbox_arguments;
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D119546
Similar to 60cc1d3218fc for NetBSD, add aliases and interceptors for the
following pthread related functions:
- pthread_cond_init(3)
- pthread_cond_destroy(3)
- pthread_cond_signal(3)
- pthread_cond_broadcast(3)
- pthread_cond_wait(3)
- pthread_mutex_init(3)
- pthread_mutex_destroy(3)
- pthread_mutex_lock(3)
- pthread_mutex_trylock(3)
- pthread_mutex_unlock(3)
- pthread_rwlock_init(3)
- pthread_rwlock_destroy(3)
- pthread_rwlock_rdlock(3)
- pthread_rwlock_tryrdlock(3)
- pthread_rwlock_wrlock(3)
- pthread_rwlock_trywrlock(3)
- pthread_rwlock_unlock(3)
- pthread_once(3)
- pthread_sigmask(3)
In FreeBSD's libc, a number of internal aliases of the pthread functions
are invoked, typically with an additional prefixed underscore, e.g.
_pthread_cond_init() and so on.
ThreadSanitizer needs to intercept these aliases too, otherwise some
false positive reports about data races might be produced.
Reviewed By: dvyukov
Differential Revision: https://reviews.llvm.org/D119034
In glibc before 2.33, include/sys/stat.h defines fstat/fstat64 to
`__fxstat/__fxstat64` and provides `__fxstat/__fxstat64` in libc_nonshared.a.
The symbols are glibc specific and not needed on other systems.
Reviewed By: vitalybuka, #sanitizers
Differential Revision: https://reviews.llvm.org/D118423
When using the in-tree libc++, we should be using the full path to
ensure that we're using the right library and not accidentally pick up
the system library.
Differential Revision: https://reviews.llvm.org/D118200
`_vfork` moved from libsystem_kernel.dylib to libsystem_c.dylib as part
of the below changes. The iOS simulator does not actually have
libsystem_kernel.dylib of its own, it only has the host Mac's. The
umbrella-nature of Libsystem makes this movement transparent to
everyone; except the simulator! So when we "back deploy", i.e., use the
current version of TSan with an older simulator runtime then this symbol
is now missing, when we run on the latest OS (but an older simulator
runtime).
Note we use `SANITIZER_IOS` because usage of vfork is forbidden on iOS
and the API is completely unavailable on watchOS and tvOS, even if this
problem is specific to the iOS simulator.
Caused by:
rdar://74818691 (Shim vfork() to fork syscall on iOS)
rdar://76762076 (Shim vfork() to fork syscall on macOS)
Radar-Id: rdar://8634734
These tests are now green:
```
Trace.MultiPart
Trace.RestoreAccess
Trace.RestoreMutexLock
TraceAlloc.FinishedThreadReuse
TraceAlloc.FinishedThreadReuse2
TraceAlloc.SingleThread
```
rdar://82107856
Currently we use very common names for macros like ACQUIRE/RELEASE,
which cause conflicts with system headers.
Prefix all macros with SANITIZER_ to avoid conflicts.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D116652
This reverts commit 859ebca744e634dcc89a2294ffa41574f947bd62.
The change contained many unrelated changes and e.g. restored
unit test failes for the old lld port.
This reverts commit 640beb38e7710b939b3cfb3f4c54accc694b1d30.
That commit caused performance degradtion in Quicksilver test QS:sGPU and a functional test failure in (rocPRIM rocprim.device_segmented_radix_sort).
Reverting until we have a better solution to s_cselect_b64 codegen cleanup
Change-Id: Ibf8e397df94001f248fba609f072088a46abae08
Reviewed By: kzhuravl
Differential Revision: https://reviews.llvm.org/D115960
Change-Id: Id169459ce4dfffa857d5645a0af50b0063ce1105
