svn commit: r314970 - in head/sys: compat/linuxkpi/common/include/linux compat/linuxkpi/common/src conf modules/linuxkpi
Hans Petter Selasky
hselasky at FreeBSD.org
Thu Mar 9 18:33:41 UTC 2017
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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