From 4b4a8824289c48c823cd38bc63289d121aae3d67 Mon Sep 17 00:00:00 2001 From: Elliott Hughes Date: Tue, 12 Feb 2013 17:15:59 -0800 Subject: [PATCH] Clean up pthread_create. Bug: 3461078 Change-Id: I082122a86d7692cd58f4145539241be026258ee0 --- libc/Android.mk | 3 + libc/bionic/pthread.c | 232 --------------------------------- libc/bionic/pthread_create.cpp | 232 +++++++++++++++++++++++++++++++++ 3 files changed, 235 insertions(+), 232 deletions(-) create mode 100644 libc/bionic/pthread_create.cpp diff --git a/libc/Android.mk b/libc/Android.mk index bf4ca7b1e..9e6f4ddbe 100644 --- a/libc/Android.mk +++ b/libc/Android.mk @@ -409,6 +409,7 @@ libc_common_src_files += \ libc_static_common_src_files += \ bionic/pthread.c.arm \ + bionic/pthread_create.cpp.arm \ bionic/pthread_key.cpp.arm \ # these are used by the static and dynamic versions of the libc @@ -450,6 +451,7 @@ libc_common_src_files += \ libc_static_common_src_files += \ bionic/pthread.c \ + bionic/pthread_create.cpp \ bionic/pthread_key.cpp \ libc_arch_static_src_files := \ @@ -497,6 +499,7 @@ libc_common_src_files += \ libc_static_common_src_files += \ bionic/pthread.c \ + bionic/pthread_create.cpp \ bionic/pthread_key.cpp \ libc_arch_static_src_files := \ diff --git a/libc/bionic/pthread.c b/libc/bionic/pthread.c index 3564c7321..d5f818744 100644 --- a/libc/bionic/pthread.c +++ b/libc/bionic/pthread.c @@ -31,7 +31,6 @@ #include #include #include -#include #include #include "bionic_atomic_inline.h" @@ -39,14 +38,12 @@ #include "bionic_pthread.h" #include "bionic_ssp.h" #include "bionic_tls.h" -#include "debug_format.h" #include "pthread_internal.h" #include "thread_private.h" extern void pthread_debug_mutex_lock_check(pthread_mutex_t *mutex); extern void pthread_debug_mutex_unlock_check(pthread_mutex_t *mutex); -extern int __pthread_clone(int (*fn)(void*), void *child_stack, int flags, void *arg); extern void _exit_with_stack_teardown(void * stackBase, int stackSize, int retCode); extern void _exit_thread(int retCode); @@ -63,21 +60,8 @@ int __futex_wait_ex(volatile void *ftx, int pshared, int val, const struct time #define __likely(cond) __builtin_expect(!!(cond), 1) #define __unlikely(cond) __builtin_expect(!!(cond), 0) -#ifdef __i386__ -#define ATTRIBUTES __attribute__((noinline)) __attribute__((fastcall)) -#else -#define ATTRIBUTES __attribute__((noinline)) -#endif - -void ATTRIBUTES _thread_created_hook(pid_t thread_id); - -static const int kPthreadInitFailed = 1; - -static pthread_mutex_t mmap_lock = PTHREAD_MUTEX_INITIALIZER; - __LIBC_HIDDEN__ pthread_internal_t* gThreadList = NULL; __LIBC_HIDDEN__ pthread_mutex_t gThreadListLock = PTHREAD_MUTEX_INITIALIZER; -static pthread_mutex_t gDebuggerNotificationLock = PTHREAD_MUTEX_INITIALIZER; static void _pthread_internal_remove_locked(pthread_internal_t* thread) { if (thread->next != NULL) { @@ -135,222 +119,6 @@ __get_stack_base(int *p_stack_size) } -void __init_tls(void** tls, void* thread) { - ((pthread_internal_t*) thread)->tls = tls; - - // Zero-initialize all the slots. - for (size_t i = 0; i < BIONIC_TLS_SLOTS; ++i) { - tls[i] = NULL; - } - - // Slot 0 must point to itself. The x86 Linux kernel reads the TLS from %fs:0. - tls[TLS_SLOT_SELF] = tls; - tls[TLS_SLOT_THREAD_ID] = thread; - // GCC looks in the TLS for the stack guard on x86, so copy it there from our global. - tls[TLS_SLOT_STACK_GUARD] = (void*) __stack_chk_guard; - - __set_tls((void*) tls); -} - - -/* - * This trampoline is called from the assembly _pthread_clone() function. - */ -void __thread_entry(int (*func)(void*), void *arg, void **tls) -{ - // Wait for our creating thread to release us. This lets it have time to - // notify gdb about this thread before we start doing anything. - // - // This also provides the memory barrier needed to ensure that all memory - // accesses previously made by the creating thread are visible to us. - pthread_mutex_t* start_mutex = (pthread_mutex_t*) &tls[TLS_SLOT_SELF]; - pthread_mutex_lock(start_mutex); - pthread_mutex_destroy(start_mutex); - - pthread_internal_t* thread = (pthread_internal_t*) tls[TLS_SLOT_THREAD_ID]; - __init_tls(tls, thread); - - if ((thread->internal_flags & kPthreadInitFailed) != 0) { - pthread_exit(NULL); - } - - int result = func(arg); - pthread_exit((void*) result); -} - -#include - -__LIBC_ABI_PRIVATE__ -int _init_thread(pthread_internal_t* thread, pid_t kernel_id, bool add_to_thread_list) { - int error = 0; - - thread->kernel_id = kernel_id; - - // Set the scheduling policy/priority of the thread. - if (thread->attr.sched_policy != SCHED_NORMAL) { - struct sched_param param; - param.sched_priority = thread->attr.sched_priority; - if (sched_setscheduler(kernel_id, thread->attr.sched_policy, ¶m) == -1) { - // For backwards compatibility reasons, we just warn about failures here. - // error = errno; - const char* msg = "pthread_create sched_setscheduler call failed: %s\n"; - __libc_format_log(ANDROID_LOG_WARN, "libc", msg, strerror(errno)); - } - } - - pthread_cond_init(&thread->join_cond, NULL); - thread->join_count = 0; - thread->cleanup_stack = NULL; - - if (add_to_thread_list) { - _pthread_internal_add(thread); - } - - return error; -} - -static void *mkstack(size_t size, size_t guard_size) -{ - pthread_mutex_lock(&mmap_lock); - - int prot = PROT_READ | PROT_WRITE; - int flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE; - void* stack = mmap(NULL, size, prot, flags, -1, 0); - if (stack == MAP_FAILED) { - stack = NULL; - goto done; - } - - if (mprotect(stack, guard_size, PROT_NONE) == -1) { - munmap(stack, size); - stack = NULL; - goto done; - } - -done: - pthread_mutex_unlock(&mmap_lock); - return stack; -} - -/* - * Create a new thread. The thread's stack is laid out like so: - * - * +---------------------------+ - * | pthread_internal_t | - * +---------------------------+ - * | | - * | TLS area | - * | | - * +---------------------------+ - * | | - * . . - * . stack area . - * . . - * | | - * +---------------------------+ - * | guard page | - * +---------------------------+ - * - * note that TLS[0] must be a pointer to itself, this is required - * by the thread-local storage implementation of the x86 Linux - * kernel, where the TLS pointer is read by reading fs:[0] - */ -int pthread_create(pthread_t *thread_out, pthread_attr_t const * attr, - void *(*start_routine)(void *), void * arg) -{ - int old_errno = errno; - - /* this will inform the rest of the C library that at least one thread - * was created. this will enforce certain functions to acquire/release - * locks (e.g. atexit()) to protect shared global structures. - * - * this works because pthread_create() is not called by the C library - * initialization routine that sets up the main thread's data structures. - */ - __isthreaded = 1; - - pthread_internal_t* thread = calloc(sizeof(*thread), 1); - if (thread == NULL) { - return EAGAIN; - } - thread->allocated_on_heap = true; - - if (attr == NULL) { - pthread_attr_init(&thread->attr); - } else { - thread->attr = *attr; - attr = NULL; // Prevent misuse below. - } - - // Make sure the stack size is PAGE_SIZE aligned. - size_t stack_size = (thread->attr.stack_size + (PAGE_SIZE-1)) & ~(PAGE_SIZE-1); - - if (thread->attr.stack_base == NULL) { - // The caller didn't provide a stack, so allocate one. - thread->attr.stack_base = mkstack(stack_size, thread->attr.guard_size); - if (thread->attr.stack_base == NULL) { - free(thread); - return EAGAIN; - } - } else { - // The caller did provide a stack, so remember we're not supposed to free it. - thread->attr.flags |= PTHREAD_ATTR_FLAG_USER_STACK; - } - - // Make room for TLS. - void** tls = (void**)((uint8_t*)(thread->attr.stack_base) + stack_size - BIONIC_TLS_SLOTS * sizeof(void*)); - - // Create a mutex for the thread in TLS_SLOT_SELF to wait on once it starts so we can keep - // it from doing anything until after we notify the debugger about it - // - // This also provides the memory barrier we need to ensure that all - // memory accesses previously performed by this thread are visible to - // the new thread. - pthread_mutex_t* start_mutex = (pthread_mutex_t*) &tls[TLS_SLOT_SELF]; - pthread_mutex_init(start_mutex, NULL); - pthread_mutex_lock(start_mutex); - - tls[TLS_SLOT_THREAD_ID] = thread; - - int flags = CLONE_FILES | CLONE_FS | CLONE_VM | CLONE_SIGHAND | - CLONE_THREAD | CLONE_SYSVSEM | CLONE_DETACHED; - int tid = __pthread_clone((int(*)(void*))start_routine, tls, flags, arg); - - if (tid < 0) { - int clone_errno = errno; - pthread_mutex_unlock(start_mutex); - if ((thread->attr.flags & PTHREAD_ATTR_FLAG_USER_STACK) == 0) { - munmap(thread->attr.stack_base, stack_size); - } - free(thread); - errno = old_errno; - return clone_errno; - } - - int init_errno = _init_thread(thread, tid, true); - if (init_errno != 0) { - // Mark the thread detached and let its __thread_entry run to - // completion. (It'll just exit immediately, cleaning up its resources.) - thread->internal_flags |= kPthreadInitFailed; - thread->attr.flags |= PTHREAD_ATTR_FLAG_DETACHED; - pthread_mutex_unlock(start_mutex); - errno = old_errno; - return init_errno; - } - - // Notify any debuggers about the new thread. - pthread_mutex_lock(&gDebuggerNotificationLock); - _thread_created_hook(tid); - pthread_mutex_unlock(&gDebuggerNotificationLock); - - // Publish the pthread_t and let the thread run. - *thread_out = (pthread_t) thread; - pthread_mutex_unlock(start_mutex); - - return 0; -} - - /* CAVEAT: our implementation of pthread_cleanup_push/pop doesn't support C++ exceptions * and thread cancelation */ diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp new file mode 100644 index 000000000..6e4fe4576 --- /dev/null +++ b/libc/bionic/pthread_create.cpp @@ -0,0 +1,232 @@ +/* + * 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 + +#include +#include + +#include "pthread_internal.h" + +#include "private/bionic_ssp.h" +#include "private/bionic_tls.h" +#include "private/debug_format.h" +#include "private/logd.h" +#include "private/thread_private.h" +#include "private/ErrnoRestorer.h" +#include "private/ScopedPthreadMutexLocker.h" + +extern "C" int __pthread_clone(int (*fn)(void*), void* child_stack, int flags, void* arg); + +#ifdef __i386__ +#define ATTRIBUTES __attribute__((noinline)) __attribute__((fastcall)) +#else +#define ATTRIBUTES __attribute__((noinline)) +#endif + +extern "C" void ATTRIBUTES _thread_created_hook(pid_t thread_id); + +static const int kPthreadInitFailed = 1; + +static pthread_mutex_t gPthreadStackCreationLock = PTHREAD_MUTEX_INITIALIZER; + +static pthread_mutex_t gDebuggerNotificationLock = PTHREAD_MUTEX_INITIALIZER; + +void __init_tls(void** tls, void* thread) { + ((pthread_internal_t*) thread)->tls = tls; + + // Zero-initialize all the slots. + for (size_t i = 0; i < BIONIC_TLS_SLOTS; ++i) { + tls[i] = NULL; + } + + // Slot 0 must point to itself. The x86 Linux kernel reads the TLS from %fs:0. + tls[TLS_SLOT_SELF] = tls; + tls[TLS_SLOT_THREAD_ID] = thread; + // GCC looks in the TLS for the stack guard on x86, so copy it there from our global. + tls[TLS_SLOT_STACK_GUARD] = (void*) __stack_chk_guard; + + __set_tls((void*) tls); +} + +// This trampoline is called from the assembly _pthread_clone() function. +extern "C" void __thread_entry(int (*func)(void*), void *arg, void **tls) { + // Wait for our creating thread to release us. This lets it have time to + // notify gdb about this thread before we start doing anything. + // This also provides the memory barrier needed to ensure that all memory + // accesses previously made by the creating thread are visible to us. + pthread_mutex_t* start_mutex = (pthread_mutex_t*) &tls[TLS_SLOT_SELF]; + pthread_mutex_lock(start_mutex); + pthread_mutex_destroy(start_mutex); + + pthread_internal_t* thread = (pthread_internal_t*) tls[TLS_SLOT_THREAD_ID]; + __init_tls(tls, thread); + + if ((thread->internal_flags & kPthreadInitFailed) != 0) { + pthread_exit(NULL); + } + + int result = func(arg); + pthread_exit((void*) result); +} + +__LIBC_ABI_PRIVATE__ +int _init_thread(pthread_internal_t* thread, pid_t kernel_id, bool add_to_thread_list) { + int error = 0; + + thread->kernel_id = kernel_id; + + // Set the scheduling policy/priority of the thread. + if (thread->attr.sched_policy != SCHED_NORMAL) { + struct sched_param param; + param.sched_priority = thread->attr.sched_priority; + if (sched_setscheduler(kernel_id, thread->attr.sched_policy, ¶m) == -1) { + // For backwards compatibility reasons, we just warn about failures here. + // error = errno; + const char* msg = "pthread_create sched_setscheduler call failed: %s\n"; + __libc_format_log(ANDROID_LOG_WARN, "libc", msg, strerror(errno)); + } + } + + pthread_cond_init(&thread->join_cond, NULL); + thread->join_count = 0; + thread->cleanup_stack = NULL; + + if (add_to_thread_list) { + _pthread_internal_add(thread); + } + + return error; +} + +static void* __create_thread_stack(size_t stack_size, size_t guard_size) { + ScopedPthreadMutexLocker lock(&gPthreadStackCreationLock); + + // Create a new private anonymous map. + int prot = PROT_READ | PROT_WRITE; + int flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE; + void* stack = mmap(NULL, stack_size, prot, flags, -1, 0); + if (stack == MAP_FAILED) { + return NULL; + } + + // Set the guard region at the end of the stack to PROT_NONE. + if (mprotect(stack, guard_size, PROT_NONE) == -1) { + munmap(stack, stack_size); + return NULL; + } + + return stack; +} + +int pthread_create(pthread_t* thread_out, pthread_attr_t const* attr, + void* (*start_routine)(void*), void* arg) { + ErrnoRestorer errno_restorer; + + // Inform the rest of the C library that at least one thread + // was created. This will enforce certain functions to acquire/release + // locks (e.g. atexit()) to protect shared global structures. + // This works because pthread_create() is not called by the C library + // initialization routine that sets up the main thread's data structures. + __isthreaded = 1; + + pthread_internal_t* thread = reinterpret_cast(calloc(sizeof(*thread), 1)); + if (thread == NULL) { + return EAGAIN; + } + thread->allocated_on_heap = true; + + if (attr == NULL) { + pthread_attr_init(&thread->attr); + } else { + thread->attr = *attr; + attr = NULL; // Prevent misuse below. + } + + // Make sure the stack size is PAGE_SIZE aligned. + size_t stack_size = (thread->attr.stack_size + (PAGE_SIZE-1)) & ~(PAGE_SIZE-1); + + if (thread->attr.stack_base == NULL) { + // The caller didn't provide a stack, so allocate one. + thread->attr.stack_base = __create_thread_stack(stack_size, thread->attr.guard_size); + if (thread->attr.stack_base == NULL) { + free(thread); + return EAGAIN; + } + } else { + // The caller did provide a stack, so remember we're not supposed to free it. + thread->attr.flags |= PTHREAD_ATTR_FLAG_USER_STACK; + } + + // Make room for TLS. + void** tls = (void**)((uint8_t*)(thread->attr.stack_base) + stack_size - BIONIC_TLS_SLOTS * sizeof(void*)); + + // Create a mutex for the thread in TLS_SLOT_SELF to wait on once it starts so we can keep + // it from doing anything until after we notify the debugger about it + // + // This also provides the memory barrier we need to ensure that all + // memory accesses previously performed by this thread are visible to + // the new thread. + pthread_mutex_t* start_mutex = (pthread_mutex_t*) &tls[TLS_SLOT_SELF]; + pthread_mutex_init(start_mutex, NULL); + ScopedPthreadMutexLocker start_locker(start_mutex); + + tls[TLS_SLOT_THREAD_ID] = thread; + + int flags = CLONE_FILES | CLONE_FS | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD | CLONE_SYSVSEM | CLONE_DETACHED; + int tid = __pthread_clone((int(*)(void*))start_routine, tls, flags, arg); + + if (tid < 0) { + int clone_errno = errno; + if ((thread->attr.flags & PTHREAD_ATTR_FLAG_USER_STACK) == 0) { + munmap(thread->attr.stack_base, stack_size); + } + free(thread); + return clone_errno; + } + + int init_errno = _init_thread(thread, tid, true); + if (init_errno != 0) { + // Mark the thread detached and let its __thread_entry run to + // completion. (It'll just exit immediately, cleaning up its resources.) + thread->internal_flags |= kPthreadInitFailed; + thread->attr.flags |= PTHREAD_ATTR_FLAG_DETACHED; + return init_errno; + } + + // Notify any debuggers about the new thread. + { + ScopedPthreadMutexLocker debugger_locker(&gDebuggerNotificationLock); + _thread_created_hook(tid); + } + + // Publish the pthread_t and let the thread run. + *thread_out = (pthread_t) thread; + + return 0; +}