platform_bionic/libc/bionic/pthread_internal.cpp
Elliott Hughes 95c6cd753f Stop using the __ANDROID_API_x__ constants.
Historically we've made a few mistakes where they haven't matched the
right number. And most non-Googlers are much more familiar with the
numbers, so it seems to make sense to rely more on them. Especially in
header files, which we actually expect real people to have to read from
time to time.

Test: treehugger
Change-Id: I0d4a97454ee108de1d32f21df285315c5488d886
2019-12-20 13:26:14 -08:00

117 lines
4.3 KiB
C++

/*
* 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 <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <async_safe/log.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;
}