forked from OSchip/llvm-project
858eb8fc11
We would like to use TLS to store the ThreadState object (or at least a reference ot it), but on Darwin accessing TLS via __thread or manually by using pthread_key_* is problematic, because there are several places where interceptors are called when TLS is not accessible (early process startup, thread cleanup, ...). Previously, we used a "poor man's TLS" implementation, where we use the shadow memory of the pointer returned by pthread_self() to store a pointer to the ThreadState object. The problem with that was that certain operations can populate shadow bytes unbeknownst to TSan, and we later interpret these non-zero bytes as the pointer to our ThreadState object and crash on when dereferencing the pointer. This patch changes the storage location of our reference to the ThreadState object to "real" TLS. We make this work by artificially keeping this reference alive in the pthread_key destructor by resetting the key value with pthread_setspecific(). This change also fixes the issue were the ThreadState object is re-allocated after DestroyThreadState() because intercepted functions can still get called on the terminating thread after the THREAD_TERMINATE event. Radar-Id: rdar://problem/72010355 Reviewed By: dvyukov Differential Revision: https://reviews.llvm.org/D110236 |
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| .. | ||
| benchmarks | ||
| dd | ||
| go | ||
| rtl | ||
| tests | ||
| .clang-format | ||
| CMakeLists.txt | ||
| analyze_libtsan.sh | ||
| check_analyze.sh | ||
| check_cmake.sh | ||