D28596 added SANITIZER_INTERFACE_WEAK_DEF which can guarantee `*_default_options` are always defined.
The weak attributes on the `__{asan,lsan,msan,ubsan}_default_options` declarations can thus be removed.
`MaybeCall*DefaultOptions` no longer need nullptr checks, so their call sites can just be replaced by `__*_default_options`.
Reviewed By: #sanitizers, vitalybuka
Differential Revision: https://reviews.llvm.org/D87175
The interceptor for the block variants of the API references the
function versions (via `REAL(name##_f)`). On Linux, this accesses the
underlying "real pointer", defined by the interceptor macro. So we need
to declare interceptors in the right order to avoid undefined symbol
compiler error:
```
error: no member named 'real_dispatch_async_and_wait_f' in namespace '__tsan::__interception'
```
rdar://68181542
Handle NULL address argument in the `mach_vm_[de]allocate()`
interceptors and fix test: `Assignment 2` is not valid if we weren't
able to re-allocate memory.
rdar://67680613
`dispatch_async_and_wait()` was introduced in macOS 10.14, which is
greater than our minimal deployment target. We need to forward declare
it as a "weak import" to ensure we generate a weak reference so the TSan
dylib continues to work on older systems. We cannot simply `#include
<dispatch.h>` or use the Darwin availability macros since this file is
multi-platform.
In addition, we want to prevent building these interceptors at all when
building with older SDKs because linking always fails.
Before:
```
➤ dyldinfo -bind ./lib/clang/12.0.0/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib | grep dispatch_async_and_wait
__DATA __interpose 0x000F5E68 pointer 0 libSystem _dispatch_async_and_wait_f
```
After:
```
➤ dyldinfo -bind ./lib/clang/12.0.0/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib | grep dispatch_async_and_wait
__DATA __got 0x000EC0A8 pointer 0 libSystem _dispatch_async_and_wait (weak import)
__DATA __interpose 0x000F5E78 pointer 0 libSystem _dispatch_async_and_wait (weak import)
```
This is a follow-up to D85854 and should fix:
https://reviews.llvm.org/D85854#2221529
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D86103
The linker errors caused by this revision have been addressed.
Add interceptors for `dispatch_async_and_wait[_f]()` which was added in
macOS 10.14. This pair of functions is similar to `dispatch_sync()`,
but does not force a context switch of the queue onto the caller thread
when the queue is active (and hence is more efficient). For TSan, we
can apply the same semantics as for `dispatch_sync()`.
From the header docs:
> Differences with dispatch_sync()
>
> When the runtime has brought up a thread to invoke the asynchronous
> workitems already submitted to the specified queue, that servicing
> thread will also be used to execute synchronous work submitted to the
> queue with dispatch_async_and_wait().
>
> However, if the runtime has not brought up a thread to service the
> specified queue (because it has no workitems enqueued, or only
> synchronous workitems), then dispatch_async_and_wait() will invoke the
> workitem on the calling thread, similar to the behaviour of functions
> in the dispatch_sync family.
Additional context:
> The guidance is to use `dispatch_async_and_wait()` instead of
> `dispatch_sync()` when it is necessary to mix async and sync calls on
> the same queue. `dispatch_async_and_wait()` does not guarantee
> execution on the caller thread which allows to reduce context switches
> when the target queue is active.
> https://gist.github.com/tclementdev/6af616354912b0347cdf6db159c37057
rdar://35757961
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D85854
Add interceptors for `dispatch_async_and_wait[_f]()` which was added in
macOS 10.14. This pair of functions is similar to `dispatch_sync()`,
but does not force a context switch of the queue onto the caller thread
when the queue is active (and hence is more efficient). For TSan, we
can apply the same semantics as for `dispatch_sync()`.
From the header docs:
> Differences with dispatch_sync()
>
> When the runtime has brought up a thread to invoke the asynchronous
> workitems already submitted to the specified queue, that servicing
> thread will also be used to execute synchronous work submitted to the
> queue with dispatch_async_and_wait().
>
> However, if the runtime has not brought up a thread to service the
> specified queue (because it has no workitems enqueued, or only
> synchronous workitems), then dispatch_async_and_wait() will invoke the
> workitem on the calling thread, similar to the behaviour of functions
> in the dispatch_sync family.
Additional context:
> The guidance is to use `dispatch_async_and_wait()` instead of
> `dispatch_sync()` when it is necessary to mix async and sync calls on
> the same queue. `dispatch_async_and_wait()` does not guarantee
> execution on the caller thread which allows to reduce context switches
> when the target queue is active.
> https://gist.github.com/tclementdev/6af616354912b0347cdf6db159c37057
rdar://35757961
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D85854
Disable huge pages in the TSan shadow regions when no_huge_pages_for_shadow == true (default).
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D85841
Not matching the (real) variadic declaration makes the interceptor take garbage inputs on Darwin/AArch64.
Differential Revision: https://reviews.llvm.org/D84570
This patch splits the handling of racy address and racy stack into separate
functions. If a race was already reported for the address, we can avoid the
cost for collecting the involved stacks.
This patch also removes the race condition in storing the racy address / racy
stack. This race condition allowed all threads to report the race.
This patch changes the transitive suppression of reports. Previously
suppression could transitively chain memory location and racy stacks.
Now racy memory and racy stack are separate suppressions.
Commit again, now with fixed tests.
Reviewed by: dvyukov
Differential Revision: https://reviews.llvm.org/D83625
This patch splits the handling of racy address and racy stack into separate
functions. If a race was already reported for the address, we can avoid the
cost for collecting the involved stacks.
This patch also removes the race condition in storing the racy address / racy
stack. This race condition allowed all threads to report the race.
This patch changes the transitive suppression of reports. Previously
suppression could transitively chain memory location and racy stacks.
Now racy memory and racy stack are separate suppressions.
Reviewed by: dvyukov
Differential Revision: https://reviews.llvm.org/D83625
This flag suppresses TSan FPs on Darwin. I removed this flag
prematurely and have been dealing with the fallout ever since.
This commit puts back the flag, reverting 7d1085cb [1].
[1] https://reviews.llvm.org/D55075
Use a struct to represent numerical versions instead of encoding release
names in an enumeration. This avoids the need to extend the enumeration
every time there is a new release.
Rename `GetMacosVersion() -> GetMacosAlignedVersion()` to better reflect
how this is used on non-MacOS platforms.
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D79970
Add ThreadClock:: global_acquire_ which is the last time another thread
has done a global acquire of this thread's clock.
It helps to avoid problem described in:
https://github.com/golang/go/issues/39186
See test/tsan/java_finalizer2.cpp for a regression test.
Note the failuire is _extremely_ hard to hit, so if you are trying
to reproduce it, you may want to run something like:
$ go get golang.org/x/tools/cmd/stress
$ stress -p=64 ./a.out
The crux of the problem is roughly as follows.
A number of O(1) optimizations in the clocks algorithm assume proper
transitive cumulative propagation of clock values. The AcquireGlobal
operation may produce an inconsistent non-linearazable view of
thread clocks. Namely, it may acquire a later value from a thread
with a higher ID, but fail to acquire an earlier value from a thread
with a lower ID. If a thread that executed AcquireGlobal then releases
to a sync clock, it will spoil the sync clock with the inconsistent
values. If another thread later releases to the sync clock, the optimized
algorithm may break.
The exact sequence of events that leads to the failure.
- thread 1 executes AcquireGlobal
- thread 1 acquires value 1 for thread 2
- thread 2 increments clock to 2
- thread 2 releases to sync object 1
- thread 3 at time 1
- thread 3 acquires from sync object 1
- thread 1 acquires value 1 for thread 3
- thread 1 releases to sync object 2
- sync object 2 clock has 1 for thread 2 and 1 for thread 3
- thread 3 releases to sync object 2
- thread 3 sees value 1 in the clock for itself
and decides that it has already released to the clock
and did not acquire anything from other threads after that
(the last_acquire_ check in release operation)
- thread 3 does not update the value for thread 2 in the clock from 1 to 2
- thread 4 acquires from sync object 2
- thread 4 detects a false race with thread 2
as it should have been synchronized with thread 2 up to time 2,
but because of the broken clock it is now synchronized only up to time 1
The global_acquire_ value helps to prevent this scenario.
Namely, thread 3 will not trust any own clock values up to global_acquire_
for the purposes of the last_acquire_ optimization.
Reviewed-in: https://reviews.llvm.org/D80474
Reported-by: nvanbenschoten (Nathan VanBenschoten)
Create a sanitizer_ptrauth.h header that #includes <ptrauth> when
available and defines just the required macros as "no ops" otherwise.
This should avoid the need for excessive #ifdef'ing.
Follow-up to and discussed in: https://reviews.llvm.org/D79132
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D79540
Fixes:
1. Setting the number of entries in a thread's clock to max between
the thread and the SyncClock the thread is acquiring from
2. Setting last_acquire_
Unit- and stress-test for releaseStoreAcquire added to
tests/unit/tsan_clock_test.cpp
When creating and destroying fibers in tsan a thread state is created and destroyed. Currently, a memory mapping is leaked with each fiber (in __tsan_destroy_fiber). This causes applications with many short running fibers to crash or hang because of linux vm.max_map_count.
The root of this is that ThreadState holds a pointer to ThreadSignalContext for handling signals. The initialization and destruction of it is tied to platform specific events in tsan_interceptors_posix and missed when destroying a fiber (specifically, SigCtx is used to lazily create the ThreadSignalContext in tsan_interceptors_posix). This patch cleans up the memory by makinh the ThreadState create and destroy the ThreadSignalContext.
The relevant code causing the leak with fibers is the fiber destruction:
void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber) {
FiberSwitchImpl(thr, fiber);
ThreadFinish(fiber);
FiberSwitchImpl(fiber, thr);
internal_free(fiber);
}
Author: Florian
Reviewed-in: https://reviews.llvm.org/D76073
Temporarily revert "tsan: fix leak of ThreadSignalContext for fibers"
because it breaks the LLDB bot on GreenDragon.
This reverts commit 93f7743851.
This reverts commit d8a0f76de7.
When creating and destroying fibers in tsan a thread state
is created and destroyed. Currently, a memory mapping is
leaked with each fiber (in __tsan_destroy_fiber).
This causes applications with many short running fibers
to crash or hang because of linux vm.max_map_count.
The root of this is that ThreadState holds a pointer to
ThreadSignalContext for handling signals. The initialization
and destruction of it is tied to platform specific events
in tsan_interceptors_posix and missed when destroying a fiber
(specifically, SigCtx is used to lazily create the
ThreadSignalContext in tsan_interceptors_posix). This patch
cleans up the memory by inverting the control from the
platform specific code calling the generic ThreadFinish to
ThreadFinish calling a platform specific clean-up routine
after finishing a thread.
The relevant code causing the leak with fibers is the fiber destruction:
void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber) {
FiberSwitchImpl(thr, fiber);
ThreadFinish(fiber);
FiberSwitchImpl(fiber, thr);
internal_free(fiber);
}
I would appreciate feedback if this way of fixing the leak is ok.
Also, I think it would be worthwhile to more closely look at the
lifecycle of ThreadState (i.e. it uses no constructor/destructor,
thus requiring manual callbacks for cleanup) and how OS-Threads/user
level fibers are differentiated in the codebase. I would be happy to
contribute more if someone could point me at the right place to
discuss this issue.
Reviewed-in: https://reviews.llvm.org/D76073
Author: Florian (Florian)
realeaseAcquire() is a new function added to TSan in support of the Go data-race detector.
It's semantics is:
void ThreadClock::releaseAcquire(SyncClock *sc) const {
for (int i = 0; i < kMaxThreads; i++) {
tmp = clock[i];
clock[i] = max(clock[i], sc->clock[i]);
sc->clock[i] = tmp;
}
}
For context see: https://go-review.googlesource.com/c/go/+/220419
Reviewed-in: https://reviews.llvm.org/D76322
Author: dfava (Daniel Fava)
arm64e adds support for pointer authentication, which was adopted by
libplatform to harden setjmp/longjmp and friends. We need to teach
the TSan interceptors for those functions about this.
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D76257
Generally we ignore interceptors coming from called_from_lib-suppressed libraries.
However, we must not ignore critical interceptors like e.g. pthread_create,
otherwise runtime will lost track of threads.
pthread_detach is one of these interceptors we should not ignore as it affects
thread states and behavior of pthread_join which we don't ignore as well.
Currently we can produce very obscure false positives. For more context see:
https://groups.google.com/forum/#!topic/thread-sanitizer/ecH2P0QUqPs
The added test captures this pattern.
While we are here rename ThreadTid to ThreadConsumeTid to make it clear that
it's not just a "getter", it resets user_id to 0. This lead to confusion recently.
Reviewed in https://reviews.llvm.org/D74828
The removed loop clears reused for entries at the tail of a SyncClock.
The loop is redundant since those entries were already cleared by the
immediately preceding loop, which iterates over all entries in the
SyncClock (including the tail entries).
This skips calling `pthread_self` when `main_thread_identity` hasn't
been initialized yet. `main_thread_identity` is only ever assigned in
`__tsan::InitializePlatform`. This change should be relatively safe; we
are not changing behavior other than skipping the call to `pthread_self`
when `main_thread_identity == 0`.
rdar://57822138
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D71559
Summary:
The flag allows the user to specify a maximum allocation size that the
sanitizers will honor. Any larger allocations will return nullptr or
crash depending on allocator_may_return_null.
Reviewers: kcc, eugenis
Reviewed By: kcc, eugenis
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D69576
This #define is in the non-Go ppc64le build but not in the Go build.
Reviewed-in: https://reviews.llvm.org/D68046
Author: randall77 (Keith Randall)
llvm-svn: 374868
Summary:
It's needed to use __GLIBC_PREREQ from <features.h>
tsan didn't let us to include <features.h> by using --sysroot=. to disable system includes on
anything that is not named as "tsan*posix*", "tsan*mac*", "tsan*linux*".
See compiler-rt/lib/tsan/CMakeLists.txt
Reviewers: eugenis, dvyukov, kcc
Reviewed By: kcc
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D68176
llvm-svn: 373282
Adding annotation function variants __tsan_write_range_pc and
__tsan_read_range_pc to annotate ranged access to memory while providing a
program counter for the access.
Differential Revision: https://reviews.llvm.org/D66885
llvm-svn: 372730
I verified that the test is red without the interceptors.
rdar://40334350
Reviewed By: kubamracek, vitalybuka
Differential Revision: https://reviews.llvm.org/D66616
llvm-svn: 371439
Rename file `tsan_libdispatch.cpp -> tsan_libdispatch_interceptors.cpp`
to make it clear that it's main purpose is defining interceptors.
llvm-svn: 369289
Fangrui Song