1//===-- scudo_tsd_exclusive.cpp ---------------------------------*- C++ -*-===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8/// 9/// Scudo exclusive TSD implementation. 10/// 11//===----------------------------------------------------------------------===// 12 13#include "scudo_tsd.h" 14 15#if SCUDO_TSD_EXCLUSIVE 16 17namespace __scudo { 18 19static pthread_once_t GlobalInitialized = PTHREAD_ONCE_INIT; 20static pthread_key_t PThreadKey; 21 22__attribute__((tls_model("initial-exec"))) 23THREADLOCAL ThreadState ScudoThreadState = ThreadNotInitialized; 24__attribute__((tls_model("initial-exec"))) 25THREADLOCAL ScudoTSD TSD; 26 27// Fallback TSD for when the thread isn't initialized yet or is torn down. It 28// can be shared between multiple threads and as such must be locked. 29ScudoTSD FallbackTSD; 30 31static void teardownThread(void *Ptr) { 32 uptr I = reinterpret_cast<uptr>(Ptr); 33 // The glibc POSIX thread-local-storage deallocation routine calls user 34 // provided destructors in a loop of PTHREAD_DESTRUCTOR_ITERATIONS. 35 // We want to be called last since other destructors might call free and the 36 // like, so we wait until PTHREAD_DESTRUCTOR_ITERATIONS before draining the 37 // quarantine and swallowing the cache. 38 if (I > 1) { 39 // If pthread_setspecific fails, we will go ahead with the teardown. 40 if (LIKELY(pthread_setspecific(PThreadKey, 41 reinterpret_cast<void *>(I - 1)) == 0)) 42 return; 43 } 44 TSD.commitBack(); 45 ScudoThreadState = ThreadTornDown; 46} 47 48 49static void initOnce() { 50 CHECK_EQ(pthread_key_create(&PThreadKey, teardownThread), 0); 51 initScudo(); 52 FallbackTSD.init(); 53} 54 55void initThread(bool MinimalInit) { 56 CHECK_EQ(pthread_once(&GlobalInitialized, initOnce), 0); 57 if (UNLIKELY(MinimalInit)) 58 return; 59 CHECK_EQ(pthread_setspecific(PThreadKey, reinterpret_cast<void *>( 60 GetPthreadDestructorIterations())), 0); 61 TSD.init(); 62 ScudoThreadState = ThreadInitialized; 63} 64 65} // namespace __scudo 66 67#endif // SCUDO_TSD_EXCLUSIVE 68