Date: Thu, 9 Mar 2017 18:33:40 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r314970 - in head/sys: compat/linuxkpi/common/include/linux compat/linuxkpi/common/src conf modules/linuxkpi Message-ID: <201703091833.v29IXedF092439@repo.freebsd.org>
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Author: hselasky Date: Thu Mar 9 18:33:40 2017 New Revision: 314970 URL: https://svnweb.freebsd.org/changeset/base/314970 Log: Implement support for mutexes with deadlock avoidance in the LinuxKPI. When locking a mutex and deadlock is detected the first mutex lock call that sees the deadlock will return -EDEADLK . MFC after: 1 week Sponsored by: Mellanox Technologies Added: head/sys/compat/linuxkpi/common/include/linux/ww_mutex.h (contents, props changed) head/sys/compat/linuxkpi/common/src/linux_lock.c (contents, props changed) Modified: head/sys/conf/files head/sys/modules/linuxkpi/Makefile Added: head/sys/compat/linuxkpi/common/include/linux/ww_mutex.h ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/compat/linuxkpi/common/include/linux/ww_mutex.h Thu Mar 9 18:33:40 2017 (r314970) @@ -0,0 +1,142 @@ +/*- + * Copyright (c) 2017 Mellanox Technologies, Ltd. + * 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. + * + * $FreeBSD$ + */ +#ifndef _LINUX_WW_MUTEX_H_ +#define _LINUX_WW_MUTEX_H_ + +#include <sys/param.h> +#include <sys/proc.h> +#include <sys/condvar.h> +#include <sys/kernel.h> + +#include <linux/mutex.h> + +struct ww_class { + const char *mutex_name; +}; + +struct ww_acquire_ctx { +}; + +struct ww_mutex { + struct mutex base; + struct cv condvar; +}; + +#define DEFINE_WW_CLASS(name) \ + struct ww_class name = { \ + .mutex_name = mutex_name(#name "_mutex") \ + } + +#define DEFINE_WW_MUTEX(name, ww_class) \ + struct ww_mutex name; \ + static void name##_init(void *arg) \ + { \ + ww_mutex_init(&name, &ww_class); \ + } \ + SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_init, NULL) + +#define ww_mutex_is_locked(_m) \ + sx_xlocked(&(_m)->base.sx) + +#define ww_mutex_lock_slow(_m, _x) \ + ww_mutex_lock(_m, _x) + +#define ww_mutex_lock_slow_interruptible(_m, _x) \ + ww_mutex_lock_interruptible(_m, _x) + +static inline int __must_check +ww_mutex_trylock(struct ww_mutex *lock) +{ + return (mutex_trylock(&lock->base)); +} + +extern int linux_ww_mutex_lock_sub(struct ww_mutex *, int catch_signal); + +static inline int +ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + if (MUTEX_SKIP()) + return (0); + else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread) + return (-EALREADY); + else + return (linux_ww_mutex_lock_sub(lock, 0)); +} + +static inline int +ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) +{ + if (MUTEX_SKIP()) + return (0); + else if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == curthread) + return (-EALREADY); + else + return (linux_ww_mutex_lock_sub(lock, 1)); +} + +extern void linux_ww_mutex_unlock_sub(struct ww_mutex *); + +static inline void +ww_mutex_unlock(struct ww_mutex *lock) +{ + if (MUTEX_SKIP()) + return; + else + linux_ww_mutex_unlock_sub(lock); +} + +static inline void +ww_mutex_destroy(struct ww_mutex *lock) +{ + cv_destroy(&lock->condvar); + mutex_destroy(&lock->base); +} + +static inline void +ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class) +{ +} + +static inline void +ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class) +{ + linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS); + cv_init(&lock->condvar, "lkpi-ww"); +} + +static inline void +ww_acquire_fini(struct ww_acquire_ctx *ctx) +{ +} + +static inline void +ww_acquire_done(struct ww_acquire_ctx *ctx) +{ +} + +#endif /* _LINUX_WW_MUTEX_H_ */ Added: head/sys/compat/linuxkpi/common/src/linux_lock.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/compat/linuxkpi/common/src/linux_lock.c Thu Mar 9 18:33:40 2017 (r314970) @@ -0,0 +1,136 @@ +/*- + * Copyright (c) 2017 Mellanox Technologies, Ltd. + * 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 <sys/queue.h> + +#include <linux/ww_mutex.h> + +struct ww_mutex_thread { + TAILQ_ENTRY(ww_mutex_thread) entry; + struct thread *thread; + struct ww_mutex *lock; +}; + +static TAILQ_HEAD(, ww_mutex_thread) ww_mutex_head; +static struct mtx ww_mutex_global; + +static void +linux_ww_init(void *arg) +{ + TAILQ_INIT(&ww_mutex_head); + mtx_init(&ww_mutex_global, "lkpi-ww-mtx", NULL, MTX_DEF); +} + +SYSINIT(ww_init, SI_SUB_LOCK, SI_ORDER_SECOND, linux_ww_init, NULL); + +static void +linux_ww_uninit(void *arg) +{ + mtx_destroy(&ww_mutex_global); +} + +SYSUNINIT(ww_uninit, SI_SUB_LOCK, SI_ORDER_SECOND, linux_ww_uninit, NULL); + +static inline void +linux_ww_lock(void) +{ + mtx_lock(&ww_mutex_global); +} + +static inline void +linux_ww_unlock(void) +{ + mtx_unlock(&ww_mutex_global); +} + +/* lock a mutex with deadlock avoidance */ +int +linux_ww_mutex_lock_sub(struct ww_mutex *lock, int catch_signal) +{ + struct ww_mutex_thread entry; + struct ww_mutex_thread *other; + int retval = 0; + + linux_ww_lock(); + if (unlikely(sx_try_xlock(&lock->base.sx) == 0)) { + entry.thread = curthread; + entry.lock = lock; + TAILQ_INSERT_TAIL(&ww_mutex_head, &entry, entry); + + do { + struct thread *owner = (struct thread *) + SX_OWNER(lock->base.sx.sx_lock); + + /* scan for deadlock */ + TAILQ_FOREACH(other, &ww_mutex_head, entry) { + /* skip own thread */ + if (other == &entry) + continue; + /* + * If another thread is owning our + * lock and is at the same time trying + * to acquire a lock this thread owns, + * that means deadlock. + */ + if (other->thread == owner && + (struct thread *)SX_OWNER( + other->lock->base.sx.sx_lock) == curthread) { + retval = -EDEADLK; + goto done; + } + } + if (catch_signal) { + if (cv_wait_sig(&lock->condvar, &ww_mutex_global) != 0) { + retval = -EINTR; + goto done; + } + } else { + cv_wait(&lock->condvar, &ww_mutex_global); + } + } while (sx_try_xlock(&lock->base.sx) == 0); +done: + TAILQ_REMOVE(&ww_mutex_head, &entry, entry); + + /* if the lock is free, wakeup next lock waiter, if any */ + if ((struct thread *)SX_OWNER(lock->base.sx.sx_lock) == NULL) + cv_signal(&lock->condvar); + } + linux_ww_unlock(); + return (retval); +} + +void +linux_ww_mutex_unlock_sub(struct ww_mutex *lock) +{ + /* protect ww_mutex ownership change */ + linux_ww_lock(); + sx_xunlock(&lock->base.sx); + /* wakeup a lock waiter, if any */ + cv_signal(&lock->condvar); + linux_ww_unlock(); +} Modified: head/sys/conf/files ============================================================================== --- head/sys/conf/files Thu Mar 9 18:06:48 2017 (r314969) +++ head/sys/conf/files Thu Mar 9 18:33:40 2017 (r314970) @@ -4284,6 +4284,8 @@ compat/linuxkpi/common/src/linux_current compile-with "${LINUXKPI_C}" compat/linuxkpi/common/src/linux_kthread.c optional compat_linuxkpi \ compile-with "${LINUXKPI_C}" +compat/linuxkpi/common/src/linux_lock.c optional compat_linuxkpi \ + compile-with "${LINUXKPI_C}" compat/linuxkpi/common/src/linux_page.c optional compat_linuxkpi \ compile-with "${LINUXKPI_C}" compat/linuxkpi/common/src/linux_pci.c optional compat_linuxkpi pci \ Modified: head/sys/modules/linuxkpi/Makefile ============================================================================== --- head/sys/modules/linuxkpi/Makefile Thu Mar 9 18:06:48 2017 (r314969) +++ head/sys/modules/linuxkpi/Makefile Thu Mar 9 18:33:40 2017 (r314970) @@ -6,6 +6,7 @@ SRCS= linux_kmod.c \ linux_compat.c \ linux_current.c \ linux_kthread.c \ + linux_lock.c \ linux_page.c \ linux_pci.c \ linux_radix.c \
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