| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include "pthread_internal.h" |
| |
| #include <errno.h> |
| #include <semaphore.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/mman.h> |
| |
| #include <async_safe/log.h> |
| #include <bionic/reserved_signals.h> |
| |
| #include "private/ErrnoRestorer.h" |
| #include "private/ScopedRWLock.h" |
| #include "private/bionic_futex.h" |
| #include "private/bionic_tls.h" |
| |
| static pthread_internal_t* g_thread_list = nullptr; |
| static pthread_rwlock_t g_thread_list_lock = PTHREAD_RWLOCK_INITIALIZER; |
| |
| pthread_t __pthread_internal_add(pthread_internal_t* thread) { |
| ScopedWriteLock locker(&g_thread_list_lock); |
| |
| // We insert at the head. |
| thread->next = g_thread_list; |
| thread->prev = nullptr; |
| if (thread->next != nullptr) { |
| thread->next->prev = thread; |
| } |
| g_thread_list = thread; |
| return reinterpret_cast<pthread_t>(thread); |
| } |
| |
| void __pthread_internal_remove(pthread_internal_t* thread) { |
| ScopedWriteLock locker(&g_thread_list_lock); |
| |
| if (thread->next != nullptr) { |
| thread->next->prev = thread->prev; |
| } |
| if (thread->prev != nullptr) { |
| thread->prev->next = thread->next; |
| } else { |
| g_thread_list = thread->next; |
| } |
| } |
| |
| static void __pthread_internal_free(pthread_internal_t* thread) { |
| if (thread->mmap_size != 0) { |
| // Free mapped space, including thread stack and pthread_internal_t. |
| munmap(thread->mmap_base, thread->mmap_size); |
| } |
| } |
| |
| void __pthread_internal_remove_and_free(pthread_internal_t* thread) { |
| __pthread_internal_remove(thread); |
| __pthread_internal_free(thread); |
| } |
| |
| pid_t __pthread_internal_gettid(pthread_t thread_id, const char* caller) { |
| pthread_internal_t* thread = __pthread_internal_find(thread_id, caller); |
| return thread ? thread->tid : -1; |
| } |
| |
| pthread_internal_t* __pthread_internal_find(pthread_t thread_id, const char* caller) { |
| pthread_internal_t* thread = reinterpret_cast<pthread_internal_t*>(thread_id); |
| |
| // Check if we're looking for ourselves before acquiring the lock. |
| if (thread == __get_thread()) return thread; |
| |
| { |
| // Make sure to release the lock before the abort below. Otherwise, |
| // some apps might deadlock in their own crash handlers (see b/6565627). |
| ScopedReadLock locker(&g_thread_list_lock); |
| for (pthread_internal_t* t = g_thread_list; t != nullptr; t = t->next) { |
| if (t == thread) return thread; |
| } |
| } |
| |
| // Historically we'd return null, but from API level 26 we catch this error. |
| if (android_get_application_target_sdk_version() >= 26) { |
| if (thread == nullptr) { |
| // This seems to be a common mistake, and it's relatively harmless because |
| // there will never be a valid thread at address 0, whereas other invalid |
| // addresses might sometimes contain threads or things that look enough like |
| // threads for us to do some real damage by continuing. |
| // TODO: try getting rid of this when Treble lets us keep vendor blobs on an old API level. |
| async_safe_format_log(ANDROID_LOG_WARN, "libc", "invalid pthread_t (0) passed to %s", caller); |
| } else { |
| async_safe_fatal("invalid pthread_t %p passed to %s", thread, caller); |
| } |
| } |
| return nullptr; |
| } |
| |
| bool android_run_on_all_threads(bool (*func)(void*), void* arg) { |
| // Take the locks in this order to avoid inversion (pthread_create -> |
| // __pthread_internal_add). |
| ScopedWriteLock creation_locker(&g_thread_creation_lock); |
| ScopedReadLock list_locker(&g_thread_list_lock); |
| |
| // Call the function directly for the current thread so that we don't need to worry about |
| // the consequences of synchronizing with ourselves. |
| if (!func(arg)) { |
| return false; |
| } |
| |
| static sem_t g_sem; |
| if (sem_init(&g_sem, 0, 0) != 0) { |
| return false; |
| } |
| |
| static bool (*g_func)(void*); |
| static void *g_arg; |
| g_func = func; |
| g_arg = arg; |
| |
| static _Atomic(bool) g_retval; |
| atomic_init(&g_retval, true); |
| |
| auto handler = [](int, siginfo_t*, void*) { |
| ErrnoRestorer restorer; |
| if (!g_func(g_arg)) { |
| atomic_store(&g_retval, false); |
| } |
| sem_post(&g_sem); |
| }; |
| |
| struct sigaction act = {}, oldact; |
| act.sa_flags = SA_SIGINFO; |
| act.sa_sigaction = handler; |
| sigfillset(&act.sa_mask); |
| if (sigaction(BIONIC_SIGNAL_RUN_ON_ALL_THREADS, &act, &oldact) != 0) { |
| sem_destroy(&g_sem); |
| return false; |
| } |
| |
| pid_t my_pid = getpid(); |
| size_t num_tids = 0; |
| for (pthread_internal_t* t = g_thread_list; t != nullptr; t = t->next) { |
| // The function is called directly for the current thread above, so no need to send a signal to |
| // ourselves to call it here. |
| if (t == __get_thread()) continue; |
| |
| // If a thread is terminating (has blocked signals) or has already terminated, our signal will |
| // never be received, so we need to check for that condition and skip the thread if it is the |
| // case. |
| if (atomic_load(&t->terminating)) continue; |
| |
| if (tgkill(my_pid, t->tid, BIONIC_SIGNAL_RUN_ON_ALL_THREADS) == 0) { |
| ++num_tids; |
| } else { |
| atomic_store(&g_retval, false); |
| } |
| } |
| |
| for (size_t i = 0; i != num_tids; ++i) { |
| if (TEMP_FAILURE_RETRY(sem_wait(&g_sem)) != 0) { |
| atomic_store(&g_retval, false); |
| break; |
| } |
| } |
| |
| sigaction(BIONIC_SIGNAL_RUN_ON_ALL_THREADS, &oldact, 0); |
| sem_destroy(&g_sem); |
| return atomic_load(&g_retval); |
| } |