freebsd-dev/lib/libthr/thread/thr_create.c
Konstantin Belousov 8495e8b1e9 Fix known issues which blow up the process after dlopen("libthr.so")
(or loading a dso linked to libthr.so into process which was not
linked against threading library).

- Remove libthr interposers of the libc functions, including
  __error(). Instead, functions calls are indirected through the
  interposing table, similar to how pthread stubs in libc are already
  done.  Libc by default points either to syscall trampolines or to
  existing libc implementations.  On libthr load, libthr rewrites the
  pointers to the cancellable implementations already in libthr.  The
  interposition table is separate from pthreads stubs indirection
  table to not pull pthreads stubs into static binaries.

- Postpone the malloc(3) internal mutexes initialization until libthr
  is loaded.  This avoids recursion between calloc(3) and static
  pthread_mutex_t initialization.

- Reinstall signal handlers with wrapper on libthr load.  The
  _rtld_is_dlopened(3) is used to avoid useless calls to sigaction(2)
  when libthr is statically referenced from the main binary.

In the process, fix openat(2), swapcontext(2) and setcontext(2)
interposing.  The libc symbols were exported at different versions
than libthr interposers.  Export both libc and libthr versions from
libc now, with default set to the higher version from libthr.

Remove unused and disconnected swapcontext(3) userspace implementation
from libc/gen.

No objections from:	deischen
Tested by:	pho, antoine (exp-run) (previous versions)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-01-03 18:38:46 +00:00

293 lines
8.1 KiB
C

/*
* Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
* Copyright (c) 2005, David Xu <davidxu@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. 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 AUTHOR ``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 AUTHOR 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.
*
* $FreeBSD$
*/
#include "namespace.h"
#include <sys/types.h>
#include <sys/rtprio.h>
#include <sys/signalvar.h>
#include <errno.h>
#include <link.h>
#include <stdlib.h>
#include <string.h>
#include <stddef.h>
#include <pthread.h>
#include <pthread_np.h>
#include "un-namespace.h"
#include "libc_private.h"
#include "thr_private.h"
static int create_stack(struct pthread_attr *pattr);
static void thread_start(struct pthread *curthread);
__weak_reference(_pthread_create, pthread_create);
int
_pthread_create(pthread_t * thread, const pthread_attr_t * attr,
void *(*start_routine) (void *), void *arg)
{
struct pthread *curthread, *new_thread;
struct thr_param param;
struct sched_param sched_param;
struct rtprio rtp;
int ret = 0, locked, create_suspended;
sigset_t set, oset;
cpuset_t *cpusetp = NULL;
int cpusetsize = 0;
int old_stack_prot;
_thr_check_init();
/*
* Tell libc and others now they need lock to protect their data.
*/
if (_thr_isthreaded() == 0) {
_malloc_first_thread();
if (_thr_setthreaded(1))
return (EAGAIN);
}
curthread = _get_curthread();
if ((new_thread = _thr_alloc(curthread)) == NULL)
return (EAGAIN);
memset(&param, 0, sizeof(param));
if (attr == NULL || *attr == NULL)
/* Use the default thread attributes: */
new_thread->attr = _pthread_attr_default;
else {
new_thread->attr = *(*attr);
cpusetp = new_thread->attr.cpuset;
cpusetsize = new_thread->attr.cpusetsize;
new_thread->attr.cpuset = NULL;
new_thread->attr.cpusetsize = 0;
}
if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
/* inherit scheduling contention scope */
if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
else
new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
new_thread->attr.prio = curthread->attr.prio;
new_thread->attr.sched_policy = curthread->attr.sched_policy;
}
new_thread->tid = TID_TERMINATED;
old_stack_prot = _rtld_get_stack_prot();
if (create_stack(&new_thread->attr) != 0) {
/* Insufficient memory to create a stack: */
_thr_free(curthread, new_thread);
return (EAGAIN);
}
/*
* Write a magic value to the thread structure
* to help identify valid ones:
*/
new_thread->magic = THR_MAGIC;
new_thread->start_routine = start_routine;
new_thread->arg = arg;
new_thread->cancel_enable = 1;
new_thread->cancel_async = 0;
/* Initialize the mutex queue: */
TAILQ_INIT(&new_thread->mutexq);
TAILQ_INIT(&new_thread->pp_mutexq);
/* Initialise hooks in the thread structure: */
if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
new_thread->flags = THR_FLAGS_NEED_SUSPEND;
create_suspended = 1;
} else {
create_suspended = 0;
}
new_thread->state = PS_RUNNING;
if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
new_thread->flags |= THR_FLAGS_DETACHED;
/* Add the new thread. */
new_thread->refcount = 1;
_thr_link(curthread, new_thread);
/*
* Handle the race between __pthread_map_stacks_exec and
* thread linkage.
*/
if (old_stack_prot != _rtld_get_stack_prot())
_thr_stack_fix_protection(new_thread);
/* Return thread pointer eariler so that new thread can use it. */
(*thread) = new_thread;
if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
THR_THREAD_LOCK(curthread, new_thread);
locked = 1;
} else
locked = 0;
param.start_func = (void (*)(void *)) thread_start;
param.arg = new_thread;
param.stack_base = new_thread->attr.stackaddr_attr;
param.stack_size = new_thread->attr.stacksize_attr;
param.tls_base = (char *)new_thread->tcb;
param.tls_size = sizeof(struct tcb);
param.child_tid = &new_thread->tid;
param.parent_tid = &new_thread->tid;
param.flags = 0;
if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
param.flags |= THR_SYSTEM_SCOPE;
if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
param.rtp = NULL;
else {
sched_param.sched_priority = new_thread->attr.prio;
_schedparam_to_rtp(new_thread->attr.sched_policy,
&sched_param, &rtp);
param.rtp = &rtp;
}
/* Schedule the new thread. */
if (create_suspended) {
SIGFILLSET(set);
SIGDELSET(set, SIGTRAP);
__sys_sigprocmask(SIG_SETMASK, &set, &oset);
new_thread->sigmask = oset;
SIGDELSET(new_thread->sigmask, SIGCANCEL);
}
ret = thr_new(&param, sizeof(param));
if (ret != 0) {
ret = errno;
/*
* Translate EPROCLIM into well-known POSIX code EAGAIN.
*/
if (ret == EPROCLIM)
ret = EAGAIN;
}
if (create_suspended)
__sys_sigprocmask(SIG_SETMASK, &oset, NULL);
if (ret != 0) {
if (!locked)
THR_THREAD_LOCK(curthread, new_thread);
new_thread->state = PS_DEAD;
new_thread->tid = TID_TERMINATED;
new_thread->flags |= THR_FLAGS_DETACHED;
new_thread->refcount--;
if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
new_thread->cycle++;
_thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
}
_thr_try_gc(curthread, new_thread); /* thread lock released */
atomic_add_int(&_thread_active_threads, -1);
} else if (locked) {
if (cpusetp != NULL) {
if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
TID(new_thread), cpusetsize, cpusetp)) {
ret = errno;
/* kill the new thread */
new_thread->force_exit = 1;
new_thread->flags |= THR_FLAGS_DETACHED;
_thr_try_gc(curthread, new_thread);
/* thread lock released */
goto out;
}
}
_thr_report_creation(curthread, new_thread);
THR_THREAD_UNLOCK(curthread, new_thread);
}
out:
if (ret)
(*thread) = 0;
return (ret);
}
static int
create_stack(struct pthread_attr *pattr)
{
int ret;
/* Check if a stack was specified in the thread attributes: */
if ((pattr->stackaddr_attr) != NULL) {
pattr->guardsize_attr = 0;
pattr->flags |= THR_STACK_USER;
ret = 0;
}
else
ret = _thr_stack_alloc(pattr);
return (ret);
}
static void
thread_start(struct pthread *curthread)
{
sigset_t set;
if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
set = curthread->sigmask;
/*
* This is used as a serialization point to allow parent
* to report 'new thread' event to debugger or tweak new thread's
* attributes before the new thread does real-world work.
*/
THR_LOCK(curthread);
THR_UNLOCK(curthread);
if (curthread->force_exit)
_pthread_exit(PTHREAD_CANCELED);
if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
#if 0
/* Done in THR_UNLOCK() */
_thr_ast(curthread);
#endif
/*
* Parent thread have stored signal mask for us,
* we should restore it now.
*/
__sys_sigprocmask(SIG_SETMASK, &set, NULL);
}
#ifdef _PTHREAD_FORCED_UNWIND
curthread->unwind_stackend = (char *)curthread->attr.stackaddr_attr +
curthread->attr.stacksize_attr;
#endif
/* Run the current thread's start routine with argument: */
_pthread_exit(curthread->start_routine(curthread->arg));
/* This point should never be reached. */
PANIC("Thread has resumed after exit");
}