freebsd-dev/lib/libc/gen/_pthread_stubs.c
Konstantin Belousov 2a339d9e3d Add implementation of robust mutexes, hopefully close enough to the
intention of the POSIX IEEE Std 1003.1TM-2008/Cor 1-2013.

A robust mutex is guaranteed to be cleared by the system upon either
thread or process owner termination while the mutex is held.  The next
mutex locker is then notified about inconsistent mutex state and can
execute (or abandon) corrective actions.

The patch mostly consists of small changes here and there, adding
neccessary checks for the inconsistent and abandoned conditions into
existing paths.  Additionally, the thread exit handler was extended to
iterate over the userspace-maintained list of owned robust mutexes,
unlocking and marking as terminated each of them.

The list of owned robust mutexes cannot be maintained atomically
synchronous with the mutex lock state (it is possible in kernel, but
is too expensive).  Instead, for the duration of lock or unlock
operation, the current mutex is remembered in a special slot that is
also checked by the kernel at thread termination.

Kernel must be aware about the per-thread location of the heads of
robust mutex lists and the current active mutex slot.  When a thread
touches a robust mutex for the first time, a new umtx op syscall is
issued which informs about location of lists heads.

The umtx sleep queues for PP and PI mutexes are split between
non-robust and robust.

Somewhat unrelated changes in the patch:
1. Style.
2. The fix for proper tdfind() call use in umtxq_sleep_pi() for shared
   pi mutexes.
3. Removal of the userspace struct pthread_mutex m_owner field.
4. The sysctl kern.ipc.umtx_vnode_persistent is added, which controls
   the lifetime of the shared mutex associated with a vnode' page.

Reviewed by:	jilles (previous version, supposedly the objection was fixed)
Discussed with:	brooks, Martin Simmons <martin@lispworks.com> (some aspects)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2016-05-17 09:56:22 +00:00

328 lines
14 KiB
C

/*
* Copyright (c) 2001 Daniel Eischen <deischen@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, 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 DANIEL EISCHEN 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 AUTHOR 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <signal.h>
#include <pthread.h>
#include <stdlib.h>
#include <errno.h>
#include "libc_private.h"
/*
* Weak symbols: All libc internal usage of these functions should
* use the weak symbol versions (_pthread_XXX). If libpthread is
* linked, it will override these functions with (non-weak) routines.
* The _pthread_XXX functions are provided solely for internal libc
* usage to avoid unwanted cancellation points and to differentiate
* between application locks and libc locks (threads holding the
* latter can't be allowed to exit/terminate).
*/
/* Define a null pthread structure just to satisfy _pthread_self. */
struct pthread {
};
static struct pthread main_thread;
static int stub_main(void);
static void *stub_null(void);
static struct pthread *stub_self(void);
static int stub_zero(void);
static int stub_fail(void);
static int stub_true(void);
static void stub_exit(void);
#define PJT_DUAL_ENTRY(entry) \
(pthread_func_t)entry, (pthread_func_t)entry
pthread_func_entry_t __thr_jtable[PJT_MAX] = {
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATFORK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_DESTROY */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_GETDETACHSTATE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_GETGUARDSIZE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_GETINHERITSCHED */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_GETSCHEDPARAM */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_GETSCHEDPOLICY */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_GETSCOPE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_GETSTACKADDR */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_GETSTACKSIZE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_INIT */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_SETDETACHSTATE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_SETGUARDSIZE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_SETINHERITSCHED */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_SETSCHEDPARAM */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_SETSCHEDPOLICY */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_SETSCOPE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_SETSTACKADDR */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_ATTR_SETSTACKSIZE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CANCEL */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CLEANUP_POP */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CLEANUP_PUSH */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_COND_BROADCAST */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_COND_DESTROY */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_COND_INIT */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_COND_SIGNAL */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_COND_TIMEDWAIT */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_COND_WAIT */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_DETACH */
{PJT_DUAL_ENTRY(stub_true)}, /* PJT_EQUAL */
{PJT_DUAL_ENTRY(stub_exit)}, /* PJT_EXIT */
{PJT_DUAL_ENTRY(stub_null)}, /* PJT_GETSPECIFIC */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_JOIN */
{PJT_DUAL_ENTRY(stub_fail)}, /* PJT_KEY_CREATE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_KEY_DELETE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_KILL */
{PJT_DUAL_ENTRY(stub_main)}, /* PJT_MAIN_NP */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEXATTR_DESTROY */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEXATTR_INIT */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEXATTR_SETTYPE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEX_DESTROY */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEX_INIT */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEX_LOCK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEX_TRYLOCK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEX_UNLOCK */
{PJT_DUAL_ENTRY(stub_fail)}, /* PJT_ONCE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_RWLOCK_DESTROY */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_RWLOCK_INIT */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_RWLOCK_RDLOCK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_RWLOCK_TRYRDLOCK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_RWLOCK_TRYWRLOCK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_RWLOCK_UNLOCK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_RWLOCK_WRLOCK */
{PJT_DUAL_ENTRY(stub_self)}, /* PJT_SELF */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_SETCANCELSTATE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_SETCANCELTYPE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_SETSPECIFIC */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_SIGMASK */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_TESTCANCEL */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CLEANUP_POP_IMP */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CLEANUP_PUSH_IMP */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CANCEL_ENTER */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_CANCEL_LEAVE */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEX_CONSISTENT */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEXATTR_GETROBUST */
{PJT_DUAL_ENTRY(stub_zero)}, /* PJT_MUTEXATTR_SETROBUST */
};
/*
* Weak aliases for exported (pthread_*) and internal (_pthread_*) routines.
*/
#define WEAK_REF(sym, alias) __weak_reference(sym, alias)
#define FUNC_TYPE(name) __CONCAT(name, _func_t)
#define FUNC_INT(name) __CONCAT(name, _int)
#define FUNC_EXP(name) __CONCAT(name, _exp)
#define STUB_FUNC(name, idx, ret) \
static ret FUNC_EXP(name)(void) __used; \
static ret FUNC_INT(name)(void) __used; \
WEAK_REF(FUNC_EXP(name), name); \
WEAK_REF(FUNC_INT(name), __CONCAT(_, name)); \
typedef ret (*FUNC_TYPE(name))(void); \
static ret FUNC_EXP(name)(void) \
{ \
FUNC_TYPE(name) func; \
func = (FUNC_TYPE(name))__thr_jtable[idx][0]; \
return (func()); \
} \
static ret FUNC_INT(name)(void) \
{ \
FUNC_TYPE(name) func; \
func = (FUNC_TYPE(name))__thr_jtable[idx][1]; \
return (func()); \
}
#define STUB_FUNC1(name, idx, ret, p0_type) \
static ret FUNC_EXP(name)(p0_type) __used; \
static ret FUNC_INT(name)(p0_type) __used; \
WEAK_REF(FUNC_EXP(name), name); \
WEAK_REF(FUNC_INT(name), __CONCAT(_, name)); \
typedef ret (*FUNC_TYPE(name))(p0_type); \
static ret FUNC_EXP(name)(p0_type p0) \
{ \
FUNC_TYPE(name) func; \
func = (FUNC_TYPE(name))__thr_jtable[idx][0]; \
return (func(p0)); \
} \
static ret FUNC_INT(name)(p0_type p0) \
{ \
FUNC_TYPE(name) func; \
func = (FUNC_TYPE(name))__thr_jtable[idx][1]; \
return (func(p0)); \
}
#define STUB_FUNC2(name, idx, ret, p0_type, p1_type) \
static ret FUNC_EXP(name)(p0_type, p1_type) __used; \
static ret FUNC_INT(name)(p0_type, p1_type) __used; \
WEAK_REF(FUNC_EXP(name), name); \
WEAK_REF(FUNC_INT(name), __CONCAT(_, name)); \
typedef ret (*FUNC_TYPE(name))(p0_type, p1_type); \
static ret FUNC_EXP(name)(p0_type p0, p1_type p1) \
{ \
FUNC_TYPE(name) func; \
func = (FUNC_TYPE(name))__thr_jtable[idx][0]; \
return (func(p0, p1)); \
} \
static ret FUNC_INT(name)(p0_type p0, p1_type p1) \
{ \
FUNC_TYPE(name) func; \
func = (FUNC_TYPE(name))__thr_jtable[idx][1]; \
return (func(p0, p1)); \
}
#define STUB_FUNC3(name, idx, ret, p0_type, p1_type, p2_type) \
static ret FUNC_EXP(name)(p0_type, p1_type, p2_type) __used; \
static ret FUNC_INT(name)(p0_type, p1_type, p2_type) __used; \
WEAK_REF(FUNC_EXP(name), name); \
WEAK_REF(FUNC_INT(name), __CONCAT(_, name)); \
typedef ret (*FUNC_TYPE(name))(p0_type, p1_type, p2_type); \
static ret FUNC_EXP(name)(p0_type p0, p1_type p1, p2_type p2) \
{ \
FUNC_TYPE(name) func; \
func = (FUNC_TYPE(name))__thr_jtable[idx][0]; \
return (func(p0, p1, p2)); \
} \
static ret FUNC_INT(name)(p0_type p0, p1_type p1, p2_type p2) \
{ \
FUNC_TYPE(name) func; \
func = (FUNC_TYPE(name))__thr_jtable[idx][1]; \
return (func(p0, p1, p2)); \
}
STUB_FUNC1(pthread_cond_broadcast, PJT_COND_BROADCAST, int, void *)
STUB_FUNC1(pthread_cond_destroy, PJT_COND_DESTROY, int, void *)
STUB_FUNC2(pthread_cond_init, PJT_COND_INIT, int, void *, void *)
STUB_FUNC1(pthread_cond_signal, PJT_COND_SIGNAL, int, void *)
STUB_FUNC2(pthread_cond_wait, PJT_COND_WAIT, int, void *, void *)
STUB_FUNC1(pthread_getspecific, PJT_GETSPECIFIC, void *, pthread_key_t)
STUB_FUNC2(pthread_key_create, PJT_KEY_CREATE, int, void *, void *)
STUB_FUNC1(pthread_key_delete, PJT_KEY_DELETE, int, pthread_key_t)
STUB_FUNC(pthread_main_np, PJT_MAIN_NP, int)
STUB_FUNC1(pthread_mutex_destroy, PJT_MUTEX_DESTROY, int, void *)
STUB_FUNC2(pthread_mutex_init, PJT_MUTEX_INIT, int, void *, void *)
STUB_FUNC1(pthread_mutex_lock, PJT_MUTEX_LOCK, int, void *)
STUB_FUNC1(pthread_mutex_trylock, PJT_MUTEX_TRYLOCK, int, void *)
STUB_FUNC1(pthread_mutex_unlock, PJT_MUTEX_UNLOCK, int, void *)
STUB_FUNC1(pthread_mutex_consistent, PJT_MUTEX_CONSISTENT, int, void *)
STUB_FUNC1(pthread_mutexattr_destroy, PJT_MUTEXATTR_DESTROY, int, void *)
STUB_FUNC1(pthread_mutexattr_init, PJT_MUTEXATTR_INIT, int, void *)
STUB_FUNC2(pthread_mutexattr_settype, PJT_MUTEXATTR_SETTYPE, int, void *, int)
STUB_FUNC2(pthread_mutexattr_getrobust, PJT_MUTEXATTR_GETROBUST, int, void *,
int *)
STUB_FUNC2(pthread_mutexattr_setrobust, PJT_MUTEXATTR_SETROBUST, int, void *,
int)
STUB_FUNC2(pthread_once, PJT_ONCE, int, void *, void *)
STUB_FUNC1(pthread_rwlock_destroy, PJT_RWLOCK_DESTROY, int, void *)
STUB_FUNC2(pthread_rwlock_init, PJT_RWLOCK_INIT, int, void *, void *)
STUB_FUNC1(pthread_rwlock_rdlock, PJT_RWLOCK_RDLOCK, int, void *)
STUB_FUNC1(pthread_rwlock_tryrdlock, PJT_RWLOCK_TRYRDLOCK, int, void *)
STUB_FUNC1(pthread_rwlock_trywrlock, PJT_RWLOCK_TRYWRLOCK, int, void *)
STUB_FUNC1(pthread_rwlock_unlock, PJT_RWLOCK_UNLOCK, int, void *)
STUB_FUNC1(pthread_rwlock_wrlock, PJT_RWLOCK_WRLOCK, int, void *)
STUB_FUNC(pthread_self, PJT_SELF, pthread_t)
STUB_FUNC2(pthread_setspecific, PJT_SETSPECIFIC, int, pthread_key_t, void *)
STUB_FUNC3(pthread_sigmask, PJT_SIGMASK, int, int, void *, void *)
STUB_FUNC3(pthread_atfork, PJT_ATFORK, int, void *, void *, void*)
STUB_FUNC1(pthread_attr_destroy, PJT_ATTR_DESTROY, int, void *);
STUB_FUNC2(pthread_attr_getdetachstate, PJT_ATTR_GETDETACHSTATE, int, void *, void *)
STUB_FUNC2(pthread_attr_getguardsize, PJT_ATTR_GETGUARDSIZE, int, void *, void *)
STUB_FUNC2(pthread_attr_getstackaddr, PJT_ATTR_GETSTACKADDR, int, void *, void *)
STUB_FUNC2(pthread_attr_getstacksize, PJT_ATTR_GETSTACKSIZE, int, void *, void *)
STUB_FUNC2(pthread_attr_getinheritsched, PJT_ATTR_GETINHERITSCHED, int, void *, void *)
STUB_FUNC2(pthread_attr_getschedparam, PJT_ATTR_GETSCHEDPARAM, int, void *, void *)
STUB_FUNC2(pthread_attr_getschedpolicy, PJT_ATTR_GETSCHEDPOLICY, int, void *, void *)
STUB_FUNC2(pthread_attr_getscope, PJT_ATTR_GETSCOPE, int, void *, void *)
STUB_FUNC1(pthread_attr_init, PJT_ATTR_INIT, int, void *)
STUB_FUNC2(pthread_attr_setdetachstate, PJT_ATTR_SETDETACHSTATE, int, void *, int)
STUB_FUNC2(pthread_attr_setguardsize, PJT_ATTR_SETGUARDSIZE, int, void *, size_t)
STUB_FUNC2(pthread_attr_setstackaddr, PJT_ATTR_SETSTACKADDR, int, void *, void *)
STUB_FUNC2(pthread_attr_setstacksize, PJT_ATTR_SETSTACKSIZE, int, void *, size_t)
STUB_FUNC2(pthread_attr_setinheritsched, PJT_ATTR_SETINHERITSCHED, int, void *, int)
STUB_FUNC2(pthread_attr_setschedparam, PJT_ATTR_SETSCHEDPARAM, int, void *, void *)
STUB_FUNC2(pthread_attr_setschedpolicy, PJT_ATTR_SETSCHEDPOLICY, int, void *, int)
STUB_FUNC2(pthread_attr_setscope, PJT_ATTR_SETSCOPE, int, void *, int)
STUB_FUNC1(pthread_cancel, PJT_CANCEL, int, void *)
STUB_FUNC1(pthread_cleanup_pop, PJT_CLEANUP_POP, int, int)
STUB_FUNC2(pthread_cleanup_push, PJT_CLEANUP_PUSH, void, void *, void *)
STUB_FUNC3(pthread_cond_timedwait, PJT_COND_TIMEDWAIT, int, void *, void *, void *)
STUB_FUNC1(pthread_detach, PJT_DETACH, int, void *)
STUB_FUNC2(pthread_equal, PJT_EQUAL, int, void *, void *)
STUB_FUNC1(pthread_exit, PJT_EXIT, void, void *)
STUB_FUNC2(pthread_join, PJT_JOIN, int, void *, void *)
STUB_FUNC2(pthread_kill, PJT_KILL, int, void *, int)
STUB_FUNC2(pthread_setcancelstate, PJT_SETCANCELSTATE, int, int, void *)
STUB_FUNC2(pthread_setcanceltype, PJT_SETCANCELTYPE, int, int, void *)
STUB_FUNC(pthread_testcancel, PJT_TESTCANCEL, void)
STUB_FUNC1(__pthread_cleanup_pop_imp, PJT_CLEANUP_POP_IMP, int, int)
STUB_FUNC2(__pthread_cleanup_push_imp, PJT_CLEANUP_PUSH_IMP, void, void*, void *);
STUB_FUNC1(_pthread_cancel_enter, PJT_CANCEL_ENTER, int, int)
STUB_FUNC1(_pthread_cancel_leave, PJT_CANCEL_LEAVE, int, int)
static int
stub_zero(void)
{
return (0);
}
static void *
stub_null(void)
{
return (NULL);
}
static struct pthread *
stub_self(void)
{
return (&main_thread);
}
static int
stub_fail(void)
{
return (ENOSYS);
}
static int
stub_main(void)
{
return (-1);
}
static int
stub_true(void)
{
return (1);
}
static void
stub_exit(void)
{
exit(0);
}