Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751827AbWHUJ51 (ORCPT ); Mon, 21 Aug 2006 05:57:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751826AbWHUJ50 (ORCPT ); Mon, 21 Aug 2006 05:57:26 -0400 Received: from dea.vocord.ru ([217.67.177.50]:33245 "EHLO uganda.factory.vocord.ru") by vger.kernel.org with ESMTP id S1751824AbWHUJ5F convert rfc822-to-8bit (ORCPT ); Mon, 21 Aug 2006 05:57:05 -0400 Cc: David Miller , Ulrich Drepper , Andrew Morton , Evgeniy Polyakov , netdev , Zach Brown , Christoph Hellwig Subject: [take12 1/3] kevent: Core files. In-Reply-To: <11561555871530@2ka.mipt.ru> X-Mailer: gregkh_patchbomb Date: Mon, 21 Aug 2006 14:19:49 +0400 Message-Id: <115615558935@2ka.mipt.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Reply-To: Evgeniy Polyakov To: lkml Content-Transfer-Encoding: 7BIT From: Evgeniy Polyakov Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 45479 Lines: 1748 Core files. This patch includes core kevent files: - userspace controlling - kernelspace interfaces - initialization - notification state machines Signed-off-by: Evgeniy Polyakov diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S index dd63d47..091ff42 100644 --- a/arch/i386/kernel/syscall_table.S +++ b/arch/i386/kernel/syscall_table.S @@ -317,3 +317,5 @@ ENTRY(sys_call_table) .long sys_tee /* 315 */ .long sys_vmsplice .long sys_move_pages + .long sys_kevent_get_events + .long sys_kevent_ctl diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S index 5d4a7d1..b2af4a8 100644 --- a/arch/x86_64/ia32/ia32entry.S +++ b/arch/x86_64/ia32/ia32entry.S @@ -713,4 +713,6 @@ #endif .quad sys_tee .quad compat_sys_vmsplice .quad compat_sys_move_pages + .quad sys_kevent_get_events + .quad sys_kevent_ctl ia32_syscall_end: diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h index fc1c8dd..c9dde13 100644 --- a/include/asm-i386/unistd.h +++ b/include/asm-i386/unistd.h @@ -323,10 +323,12 @@ #define __NR_sync_file_range 314 #define __NR_tee 315 #define __NR_vmsplice 316 #define __NR_move_pages 317 +#define __NR_kevent_get_events 318 +#define __NR_kevent_ctl 319 #ifdef __KERNEL__ -#define NR_syscalls 318 +#define NR_syscalls 320 /* * user-visible error numbers are in the range -1 - -128: see diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h index 94387c9..61363e0 100644 --- a/include/asm-x86_64/unistd.h +++ b/include/asm-x86_64/unistd.h @@ -619,10 +619,14 @@ #define __NR_vmsplice 278 __SYSCALL(__NR_vmsplice, sys_vmsplice) #define __NR_move_pages 279 __SYSCALL(__NR_move_pages, sys_move_pages) +#define __NR_kevent_get_events 280 +__SYSCALL(__NR_kevent_get_events, sys_kevent_get_events) +#define __NR_kevent_ctl 281 +__SYSCALL(__NR_kevent_ctl, sys_kevent_ctl) #ifdef __KERNEL__ -#define __NR_syscall_max __NR_move_pages +#define __NR_syscall_max __NR_kevent_ctl #ifndef __NO_STUBS diff --git a/include/linux/kevent.h b/include/linux/kevent.h new file mode 100644 index 0000000..eef9709 --- /dev/null +++ b/include/linux/kevent.h @@ -0,0 +1,174 @@ +/* + * 2006 Copyright (c) Evgeniy Polyakov + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef __KEVENT_H +#define __KEVENT_H +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define KEVENT_MAX_EVENTS 4096 +#define KEVENT_MIN_BUFFS_ALLOC 3 + +struct kevent; +struct kevent_storage; +typedef int (* kevent_callback_t)(struct kevent *); + +/* @callback is called each time new event has been caught. */ +/* @enqueue is called each time new event is queued. */ +/* @dequeue is called each time event is dequeued. */ + +struct kevent_callbacks { + kevent_callback_t callback, enqueue, dequeue; +}; + +#define KEVENT_READY 0x1 +#define KEVENT_STORAGE 0x2 +#define KEVENT_USER 0x4 + +struct kevent +{ + /* Used for kevent freeing.*/ + struct rcu_head rcu_head; + struct ukevent event; + /* This lock protects ukevent manipulations, e.g. ret_flags changes. */ + spinlock_t ulock; + + /* Entry of user's queue. */ + struct list_head kevent_entry; + /* Entry of origin's queue. */ + struct list_head storage_entry; + /* Entry of user's ready. */ + struct list_head ready_entry; + + u32 flags; + + /* User who requested this kevent. */ + struct kevent_user *user; + /* Kevent container. */ + struct kevent_storage *st; + + struct kevent_callbacks callbacks; + + /* Private data for different storages. + * poll()/select storage has a list of wait_queue_t containers + * for each ->poll() { poll_wait()' } here. + */ + void *priv; +}; + +#define KEVENT_HASH_MASK 0xff + +struct kevent_user +{ + struct list_head kevent_list[KEVENT_HASH_MASK+1]; + spinlock_t kevent_lock; + /* Number of queued kevents. */ + unsigned int kevent_num; + + /* List of ready kevents. */ + struct list_head ready_list; + /* Number of ready kevents. */ + unsigned int ready_num; + /* Protects all manipulations with ready queue. */ + spinlock_t ready_lock; + + /* Protects against simultaneous kevent_user control manipulations. */ + struct mutex ctl_mutex; + /* Wait until some events are ready. */ + wait_queue_head_t wait; + + /* Reference counter, increased for each new kevent. */ + atomic_t refcnt; + + unsigned int pages_in_use; + /* Array of pages forming mapped ring buffer */ + unsigned long *pring; + +#ifdef CONFIG_KEVENT_USER_STAT + unsigned long im_num; + unsigned long wait_num; + unsigned long total; +#endif +}; + +int kevent_enqueue(struct kevent *k); +int kevent_dequeue(struct kevent *k); +int kevent_init(struct kevent *k); +void kevent_requeue(struct kevent *k); +int kevent_break(struct kevent *k); + +int kevent_add_callbacks(struct kevent_callbacks *cb, int pos); + +void kevent_user_ring_add_event(struct kevent *k); + +void kevent_storage_ready(struct kevent_storage *st, + kevent_callback_t ready_callback, u32 event); +int kevent_storage_init(void *origin, struct kevent_storage *st); +void kevent_storage_fini(struct kevent_storage *st); +int kevent_storage_enqueue(struct kevent_storage *st, struct kevent *k); +void kevent_storage_dequeue(struct kevent_storage *st, struct kevent *k); + +int kevent_user_add_ukevent(struct ukevent *uk, struct kevent_user *u); + +#ifdef CONFIG_KEVENT_POLL +void kevent_poll_reinit(struct file *file); +#else +static inline void kevent_poll_reinit(struct file *file) +{ +} +#endif + +#ifdef CONFIG_KEVENT_USER_STAT +static inline void kevent_stat_init(struct kevent_user *u) +{ + u->wait_num = u->im_num = u->total = 0; +} +static inline void kevent_stat_print(struct kevent_user *u) +{ + pr_debug("%s: u=%p, wait=%lu, immediately=%lu, total=%lu.\n", + __func__, u, u->wait_num, u->im_num, u->total); +} +static inline void kevent_stat_im(struct kevent_user *u) +{ + u->im_num++; +} +static inline void kevent_stat_wait(struct kevent_user *u) +{ + u->wait_num++; +} +static inline void kevent_stat_total(struct kevent_user *u) +{ + u->total++; +} +#else +#define kevent_stat_print(u) ({ (void) u;}) +#define kevent_stat_init(u) ({ (void) u;}) +#define kevent_stat_im(u) ({ (void) u;}) +#define kevent_stat_wait(u) ({ (void) u;}) +#define kevent_stat_total(u) ({ (void) u;}) +#endif + +#endif /* __KEVENT_H */ diff --git a/include/linux/kevent_storage.h b/include/linux/kevent_storage.h new file mode 100644 index 0000000..a38575d --- /dev/null +++ b/include/linux/kevent_storage.h @@ -0,0 +1,11 @@ +#ifndef __KEVENT_STORAGE_H +#define __KEVENT_STORAGE_H + +struct kevent_storage +{ + void *origin; /* Originator's pointer, e.g. struct sock or struct file. Can be NULL. */ + struct list_head list; /* List of queued kevents. */ + spinlock_t lock; /* Protects users queue. */ +}; + +#endif /* __KEVENT_STORAGE_H */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 008f04c..8609910 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -597,4 +597,7 @@ asmlinkage long sys_get_robust_list(int asmlinkage long sys_set_robust_list(struct robust_list_head __user *head, size_t len); +asmlinkage long sys_kevent_get_events(int ctl_fd, unsigned int min, unsigned int max, + unsigned int timeout, void __user *buf, unsigned flags); +asmlinkage long sys_kevent_ctl(int ctl_fd, unsigned int cmd, unsigned int num, void __user *buf); #endif diff --git a/include/linux/ukevent.h b/include/linux/ukevent.h new file mode 100644 index 0000000..4282793 --- /dev/null +++ b/include/linux/ukevent.h @@ -0,0 +1,136 @@ +/* + * 2006 Copyright (c) Evgeniy Polyakov + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef __UKEVENT_H +#define __UKEVENT_H + +/* + * Kevent request flags. + */ + +/* Process this event only once and then dequeue. */ +#define KEVENT_REQ_ONESHOT 0x1 + +/* + * Kevent return flags. + */ +/* Kevent is broken. */ +#define KEVENT_RET_BROKEN 0x1 +/* Kevent processing was finished successfully. */ +#define KEVENT_RET_DONE 0x2 + +/* + * Kevent type set. + */ +#define KEVENT_SOCKET 0 +#define KEVENT_INODE 1 +#define KEVENT_TIMER 2 +#define KEVENT_POLL 3 +#define KEVENT_NAIO 4 +#define KEVENT_AIO 5 +#define KEVENT_MAX 6 + +/* + * Per-type event sets. + * Number of per-event sets should be exactly as number of kevent types. + */ + +/* + * Timer events. + */ +#define KEVENT_TIMER_FIRED 0x1 + +/* + * Socket/network asynchronous IO events. + */ +#define KEVENT_SOCKET_RECV 0x1 +#define KEVENT_SOCKET_ACCEPT 0x2 +#define KEVENT_SOCKET_SEND 0x4 + +/* + * Inode events. + */ +#define KEVENT_INODE_CREATE 0x1 +#define KEVENT_INODE_REMOVE 0x2 + +/* + * Poll events. + */ +#define KEVENT_POLL_POLLIN 0x0001 +#define KEVENT_POLL_POLLPRI 0x0002 +#define KEVENT_POLL_POLLOUT 0x0004 +#define KEVENT_POLL_POLLERR 0x0008 +#define KEVENT_POLL_POLLHUP 0x0010 +#define KEVENT_POLL_POLLNVAL 0x0020 + +#define KEVENT_POLL_POLLRDNORM 0x0040 +#define KEVENT_POLL_POLLRDBAND 0x0080 +#define KEVENT_POLL_POLLWRNORM 0x0100 +#define KEVENT_POLL_POLLWRBAND 0x0200 +#define KEVENT_POLL_POLLMSG 0x0400 +#define KEVENT_POLL_POLLREMOVE 0x1000 + +/* + * Asynchronous IO events. + */ +#define KEVENT_AIO_BIO 0x1 + +#define KEVENT_MASK_ALL 0xffffffff +/* Mask of all possible event values. */ +#define KEVENT_MASK_EMPTY 0x0 +/* Empty mask of ready events. */ + +struct kevent_id +{ + __u32 raw[2]; +}; + +struct ukevent +{ + /* Id of this request, e.g. socket number, file descriptor and so on... */ + struct kevent_id id; + /* Event type, e.g. KEVENT_SOCK, KEVENT_INODE, KEVENT_TIMER and so on... */ + __u32 type; + /* Event itself, e.g. SOCK_ACCEPT, INODE_CREATED, TIMER_FIRED... */ + __u32 event; + /* Per-event request flags */ + __u32 req_flags; + /* Per-event return flags */ + __u32 ret_flags; + /* Event return data. Event originator fills it with anything it likes. */ + __u32 ret_data[2]; + /* User's data. It is not used, just copied to/from user. */ + union { + __u32 user[2]; + void *ptr; + }; +}; + +struct mukevent +{ + struct kevent_id id; + __u32 ret_flags; +}; + +#define KEVENT_CTL_ADD 0 +#define KEVENT_CTL_REMOVE 1 +#define KEVENT_CTL_MODIFY 2 +#define KEVENT_CTL_INIT 3 + +#endif /* __UKEVENT_H */ diff --git a/init/Kconfig b/init/Kconfig index a099fc6..c550fcc 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -218,6 +218,8 @@ config AUDITSYSCALL such as SELinux. To use audit's filesystem watch feature, please ensure that INOTIFY is configured. +source "kernel/kevent/Kconfig" + config IKCONFIG bool "Kernel .config support" ---help--- diff --git a/kernel/Makefile b/kernel/Makefile index d62ec66..2d7a6dd 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -47,6 +47,7 @@ obj-$(CONFIG_DETECT_SOFTLOCKUP) += softl obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ obj-$(CONFIG_SECCOMP) += seccomp.o obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o +obj-$(CONFIG_KEVENT) += kevent/ obj-$(CONFIG_RELAY) += relay.o obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o diff --git a/kernel/kevent/Kconfig b/kernel/kevent/Kconfig new file mode 100644 index 0000000..a756e85 --- /dev/null +++ b/kernel/kevent/Kconfig @@ -0,0 +1,31 @@ +config KEVENT + bool "Kernel event notification mechanism" + help + This option enables event queue mechanism. + It can be used as replacement for poll()/select(), AIO callback + invocations, advanced timer notifications and other kernel + object status changes. + +config KEVENT_USER_STAT + bool "Kevent user statistic" + depends on KEVENT + default N + help + This option will turn kevent_user statistic collection on. + Statistic data includes total number of kevent, number of kevents + which are ready immediately at insertion time and number of kevents + which were removed through readiness completion. + It will be printed each time control kevent descriptor is closed. + +config KEVENT_TIMER + bool "Kernel event notifications for timers" + depends on KEVENT + help + This option allows to use timers through KEVENT subsystem. + +config KEVENT_POLL + bool "Kernel event notifications for poll()/select()" + depends on KEVENT + help + This option allows to use kevent subsystem for poll()/select() + notifications. diff --git a/kernel/kevent/Makefile b/kernel/kevent/Makefile new file mode 100644 index 0000000..ab6bca0 --- /dev/null +++ b/kernel/kevent/Makefile @@ -0,0 +1,3 @@ +obj-y := kevent.o kevent_user.o +obj-$(CONFIG_KEVENT_TIMER) += kevent_timer.o +obj-$(CONFIG_KEVENT_POLL) += kevent_poll.o diff --git a/kernel/kevent/kevent.c b/kernel/kevent/kevent.c new file mode 100644 index 0000000..2872aa2 --- /dev/null +++ b/kernel/kevent/kevent.c @@ -0,0 +1,238 @@ +/* + * kevent.c + * + * 2006 Copyright (c) Evgeniy Polyakov + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Attempts to add an event into appropriate origin's queue. + * Returns positive value if this event is ready immediately, + * negative value in case of error and zero if event has been queued. + * ->enqueue() callback must increase origin's reference counter. + */ +int kevent_enqueue(struct kevent *k) +{ + if (k->event.type >= KEVENT_MAX) + return -EINVAL; + + if (!k->callbacks.enqueue) { + kevent_break(k); + return -EINVAL; + } + + return k->callbacks.enqueue(k); +} + +/* + * Remove event from the appropriate queue. + * ->dequeue() callback must decrease origin's reference counter. + */ +int kevent_dequeue(struct kevent *k) +{ + if (k->event.type >= KEVENT_MAX) + return -EINVAL; + + if (!k->callbacks.dequeue) { + kevent_break(k); + return -EINVAL; + } + + return k->callbacks.dequeue(k); +} + +/* + * Mark kevent as broken. + */ +int kevent_break(struct kevent *k) +{ + unsigned long flags; + + spin_lock_irqsave(&k->ulock, flags); + k->event.ret_flags |= KEVENT_RET_BROKEN; + spin_unlock_irqrestore(&k->ulock, flags); + return 0; +} + +static struct kevent_callbacks kevent_registered_callbacks[KEVENT_MAX]; + +int kevent_add_callbacks(struct kevent_callbacks *cb, int pos) +{ + if (pos >= KEVENT_MAX) + return -EINVAL; + kevent_registered_callbacks[pos] = *cb; + printk(KERN_INFO "KEVENT: Added callbacks for type %d.\n", pos); + return 0; +} + +/* + * Must be called before event is going to be added into some origin's queue. + * Initializes ->enqueue(), ->dequeue() and ->callback() callbacks. + * If failed, kevent should not be used or kevent_enqueue() will fail to add + * this kevent into origin's queue with setting + * KEVENT_RET_BROKEN flag in kevent->event.ret_flags. + */ +int kevent_init(struct kevent *k) +{ + spin_lock_init(&k->ulock); + k->flags = 0; + + if (k->event.type >= KEVENT_MAX) + return -EINVAL; + + k->callbacks = kevent_registered_callbacks[k->event.type]; + if (!k->callbacks.callback) { + kevent_break(k); + return -EINVAL; + } + + return 0; +} + +/* + * Called from ->enqueue() callback when reference counter for given + * origin (socket, inode...) has been increased. + */ +int kevent_storage_enqueue(struct kevent_storage *st, struct kevent *k) +{ + unsigned long flags; + + k->st = st; + spin_lock_irqsave(&st->lock, flags); + list_add_tail_rcu(&k->storage_entry, &st->list); + k->flags |= KEVENT_STORAGE; + spin_unlock_irqrestore(&st->lock, flags); + return 0; +} + +/* + * Dequeue kevent from origin's queue. + * It does not decrease origin's reference counter in any way + * and must be called before it, so storage itself must be valid. + * It is called from ->dequeue() callback. + */ +void kevent_storage_dequeue(struct kevent_storage *st, struct kevent *k) +{ + unsigned long flags; + + spin_lock_irqsave(&st->lock, flags); + if (k->flags & KEVENT_STORAGE) { + list_del_rcu(&k->storage_entry); + k->flags &= ~KEVENT_STORAGE; + } + spin_unlock_irqrestore(&st->lock, flags); +} + +/* + * Call kevent ready callback and queue it into ready queue if needed. + * If kevent is marked as one-shot, then remove it from storage queue. + */ +static void __kevent_requeue(struct kevent *k, u32 event) +{ + int ret, rem; + unsigned long flags; + + ret = k->callbacks.callback(k); + + spin_lock_irqsave(&k->ulock, flags); + if (ret > 0) + k->event.ret_flags |= KEVENT_RET_DONE; + else if (ret < 0) + k->event.ret_flags |= (KEVENT_RET_BROKEN | KEVENT_RET_DONE); + else + ret = (k->event.ret_flags & (KEVENT_RET_BROKEN|KEVENT_RET_DONE)); + rem = (k->event.req_flags & KEVENT_REQ_ONESHOT); + spin_unlock_irqrestore(&k->ulock, flags); + + if (ret) { + if ((rem || ret < 0) && (k->flags & KEVENT_STORAGE)) { + list_del_rcu(&k->storage_entry); + k->flags &= ~KEVENT_STORAGE; + } + + spin_lock_irqsave(&k->user->ready_lock, flags); + if (!(k->flags & KEVENT_READY)) { + kevent_user_ring_add_event(k); + list_add_tail(&k->ready_entry, &k->user->ready_list); + k->flags |= KEVENT_READY; + k->user->ready_num++; + } + spin_unlock_irqrestore(&k->user->ready_lock, flags); + wake_up(&k->user->wait); + } +} + +/* + * Check if kevent is ready (by invoking it's callback) and requeue/remove + * if needed. + */ +void kevent_requeue(struct kevent *k) +{ + unsigned long flags; + + spin_lock_irqsave(&k->st->lock, flags); + __kevent_requeue(k, 0); + spin_unlock_irqrestore(&k->st->lock, flags); +} + +/* + * Called each time some activity in origin (socket, inode...) is noticed. + */ +void kevent_storage_ready(struct kevent_storage *st, + kevent_callback_t ready_callback, u32 event) +{ + struct kevent *k; + + rcu_read_lock(); + if (ready_callback) + list_for_each_entry_rcu(k, &st->list, storage_entry) + (*ready_callback)(k); + + list_for_each_entry_rcu(k, &st->list, storage_entry) + if (event & k->event.event) + __kevent_requeue(k, event); + rcu_read_unlock(); +} + +int kevent_storage_init(void *origin, struct kevent_storage *st) +{ + spin_lock_init(&st->lock); + st->origin = origin; + INIT_LIST_HEAD(&st->list); + return 0; +} + +/* + * Mark all events as broken, that will remove them from storage, + * so storage origin (inode, sockt and so on) can be safely removed. + * No new entries are allowed to be added into the storage at this point. + * (Socket is removed from file table at this point for example). + */ +void kevent_storage_fini(struct kevent_storage *st) +{ + kevent_storage_ready(st, kevent_break, KEVENT_MASK_ALL); +} diff --git a/kernel/kevent/kevent_user.c b/kernel/kevent/kevent_user.c new file mode 100644 index 0000000..6e1bf3a --- /dev/null +++ b/kernel/kevent/kevent_user.c @@ -0,0 +1,986 @@ +/* + * 2006 Copyright (c) Evgeniy Polyakov + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static char kevent_name[] = "kevent"; +static kmem_cache_t *kevent_cache; + +static int kevent_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data, struct vfsmount *mnt) +{ + /* So original magic... */ + return get_sb_pseudo(fs_type, kevent_name, NULL, 0xbcdbcdul, mnt); +} + +static struct file_system_type kevent_fs_type = { + .name = kevent_name, + .get_sb = kevent_get_sb, + .kill_sb = kill_anon_super, +}; + +static struct vfsmount *kevent_mnt; + +/* + * kevents are pollable, return POLLIN and POLLRDNORM + * when there is at least one ready kevent. + */ +static unsigned int kevent_user_poll(struct file *file, struct poll_table_struct *wait) +{ + struct kevent_user *u = file->private_data; + unsigned int mask; + + poll_wait(file, &u->wait, wait); + mask = 0; + + if (u->ready_num) + mask |= POLLIN | POLLRDNORM; + + return mask; +} + +/* + * Note that kevents does not exactly fill the page (each mukevent is 40 bytes), + * so we reuse 4 bytes at the begining of the first page to store index. + * Take that into account if you want to change size of struct ukevent. + */ +#define KEVENTS_ON_PAGE ((PAGE_SIZE-sizeof(unsigned int))/sizeof(struct mukevent)) +struct kevent_mring +{ + unsigned int index; + struct mukevent event[KEVENTS_ON_PAGE]; +}; + +static inline void kevent_user_ring_set(struct kevent_user *u, unsigned int num) +{ + struct kevent_mring *ring; + + ring = (struct kevent_mring *)u->pring[0]; + ring->index = num; +} + +static inline void kevent_user_ring_inc(struct kevent_user *u) +{ + struct kevent_mring *ring; + + ring = (struct kevent_mring *)u->pring[0]; + ring->index++; +} + +static int kevent_user_ring_grow(struct kevent_user *u) +{ + struct kevent_mring *ring; + unsigned int idx; + + ring = (struct kevent_mring *)u->pring[0]; + + idx = (ring->index + 1) / KEVENTS_ON_PAGE; + if (idx >= u->pages_in_use) { + u->pring[idx] = __get_free_page(GFP_KERNEL); + if (!u->pring[idx]) + return -ENOMEM; + u->pages_in_use++; + } + return 0; +} + +/* + * Called under kevent_user->ready_lock, so updates are always protected. + */ +void kevent_user_ring_add_event(struct kevent *k) +{ + unsigned int pidx, off; + struct kevent_mring *ring, *copy_ring; + + ring = (struct kevent_mring *)k->user->pring[0]; + + pidx = ring->index/KEVENTS_ON_PAGE; + off = ring->index%KEVENTS_ON_PAGE; + + copy_ring = (struct kevent_mring *)k->user->pring[pidx]; + + copy_ring->event[off].id.raw[0] = k->event.id.raw[0]; + copy_ring->event[off].id.raw[1] = k->event.id.raw[1]; + copy_ring->event[off].ret_flags = k->event.ret_flags; + + if (++ring->index >= KEVENT_MAX_EVENTS) + ring->index = 0; +} + +/* + * Initialize mmap ring buffer. + * It will store ready kevents, so userspace could get them directly instead + * of using syscall. Esentially syscall becomes just a waiting point. + */ +static int kevent_user_ring_init(struct kevent_user *u) +{ + int pnum; + + pnum = ALIGN(KEVENT_MAX_EVENTS*sizeof(struct mukevent) + sizeof(unsigned int), PAGE_SIZE)/PAGE_SIZE; + + u->pring = kmalloc(pnum * sizeof(unsigned long), GFP_KERNEL); + if (!u->pring) + return -ENOMEM; + + u->pring[0] = __get_free_page(GFP_KERNEL); + if (!u->pring[0]) + goto err_out_free; + + u->pages_in_use = 1; + kevent_user_ring_set(u, 0); + + return 0; + +err_out_free: + kfree(u->pring); + + return -ENOMEM; +} + +static void kevent_user_ring_fini(struct kevent_user *u) +{ + int i; + + for (i = 0; i < u->pages_in_use; ++i) + free_page(u->pring[i]); + + kfree(u->pring); +} + + +/* + * Allocate new kevent userspace control entry. + */ +static struct kevent_user *kevent_user_alloc(void) +{ + struct kevent_user *u; + int i; + + u = kzalloc(sizeof(struct kevent_user), GFP_KERNEL); + if (!u) + return NULL; + + INIT_LIST_HEAD(&u->ready_list); + spin_lock_init(&u->ready_lock); + kevent_stat_init(u); + spin_lock_init(&u->kevent_lock); + for (i = 0; i < ARRAY_SIZE(u->kevent_list); ++i) + INIT_LIST_HEAD(&u->kevent_list[i]); + + mutex_init(&u->ctl_mutex); + init_waitqueue_head(&u->wait); + + atomic_set(&u->refcnt, 1); + + if (kevent_user_ring_init(u)) { + kfree(u); + u = NULL; + } + + return u; +} + +static int kevent_user_open(struct inode *inode, struct file *file) +{ + struct kevent_user *u = kevent_user_alloc(); + + if (!u) + return -ENOMEM; + + file->private_data = u; + + return 0; +} + + +/* + * Kevent userspace control block reference counting. + * Set to 1 at creation time, when appropriate kevent file descriptor + * is closed, that reference counter is decreased. + * When counter hits zero block is freed. + */ +static inline void kevent_user_get(struct kevent_user *u) +{ + atomic_inc(&u->refcnt); +} + +static inline void kevent_user_put(struct kevent_user *u) +{ + if (atomic_dec_and_test(&u->refcnt)) { + kevent_stat_print(u); + kevent_user_ring_fini(u); + kfree(u); + } +} + +static struct page *kevent_user_nopage(struct vm_area_struct *vma, unsigned long addr, int *type) +{ + struct kevent_user *u = vma->vm_file->private_data; + unsigned long off = (addr - vma->vm_start)/PAGE_SIZE; + + if (type) + *type = VM_FAULT_MINOR; + + if (off >= u->pages_in_use) + goto err_out_sigbus; + + return virt_to_page(u->pring[off]); + +err_out_sigbus: + return NOPAGE_SIGBUS; +} + +static struct vm_operations_struct kevent_user_vm_ops = { + .nopage = &kevent_user_nopage, +}; + +/* + * Mmap implementation for ring buffer, which is created as array + * of pages, so vm_pgoff is an offset (in pages, not in bytes) of + * the first page to be mapped. + */ +static int kevent_user_mmap(struct file *file, struct vm_area_struct *vma) +{ + unsigned long start = vma->vm_start; + struct kevent_user *u = file->private_data; + + if (vma->vm_flags & VM_WRITE) + return -EPERM; + + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + vma->vm_ops = &kevent_user_vm_ops; + vma->vm_flags |= VM_RESERVED; + vma->vm_file = file; + + if (vm_insert_page(vma, start, virt_to_page((void *)u->pring[0]))) + return -EFAULT; + + return 0; +} + +static inline unsigned int kevent_user_hash(struct ukevent *uk) +{ + return jhash_1word(uk->id.raw[0], 0) & KEVENT_HASH_MASK; +} + +/* + * RCU protects storage list (kevent->storage_entry). + * Free entry in RCU callback, it is dequeued from all lists at + * this point. + */ + +static void kevent_free_rcu(struct rcu_head *rcu) +{ + struct kevent *kevent = container_of(rcu, struct kevent, rcu_head); + kmem_cache_free(kevent_cache, kevent); +} + +/* + * Complete kevent removing - it dequeues kevent from storage list + * if it is requested, removes kevent from ready list, drops userspace + * control block reference counter and schedules kevent freeing through RCU. + */ +static void kevent_finish_user_complete(struct kevent *k, int deq) +{ + struct kevent_user *u = k->user; + unsigned long flags; + + if (deq) + kevent_dequeue(k); + + spin_lock_irqsave(&u->ready_lock, flags); + if (k->flags & KEVENT_READY) { + list_del(&k->ready_entry); + k->flags &= ~KEVENT_READY; + u->ready_num--; + } + spin_unlock_irqrestore(&u->ready_lock, flags); + + kevent_user_put(u); + call_rcu(&k->rcu_head, kevent_free_rcu); +} + +/* + * Remove from all lists and free kevent. + * Must be called under kevent_user->kevent_lock to protect + * kevent->kevent_entry removing. + */ +static void __kevent_finish_user(struct kevent *k, int deq) +{ + struct kevent_user *u = k->user; + + list_del(&k->kevent_entry); + k->flags &= ~KEVENT_USER; + u->kevent_num--; + kevent_finish_user_complete(k, deq); +} + +/* + * Remove kevent from user's list of all events, + * dequeue it from storage and decrease user's reference counter, + * since this kevent does not exist anymore. That is why it is freed here. + */ +static void kevent_finish_user(struct kevent *k, int deq) +{ + struct kevent_user *u = k->user; + unsigned long flags; + + spin_lock_irqsave(&u->kevent_lock, flags); + list_del(&k->kevent_entry); + k->flags &= ~KEVENT_USER; + u->kevent_num--; + spin_unlock_irqrestore(&u->kevent_lock, flags); + kevent_finish_user_complete(k, deq); +} + +/* + * Dequeue one entry from user's ready queue. + */ +static struct kevent *kqueue_dequeue_ready(struct kevent_user *u) +{ + unsigned long flags; + struct kevent *k = NULL; + + spin_lock_irqsave(&u->ready_lock, flags); + if (u->ready_num && !list_empty(&u->ready_list)) { + k = list_entry(u->ready_list.next, struct kevent, ready_entry); + list_del(&k->ready_entry); + k->flags &= ~KEVENT_READY; + u->ready_num--; + } + spin_unlock_irqrestore(&u->ready_lock, flags); + + return k; +} + +/* + * Search a kevent inside hash bucket for given ukevent. + */ +static struct kevent *__kevent_search(struct list_head *head, struct ukevent *uk, + struct kevent_user *u) +{ + struct kevent *k, *ret = NULL; + + list_for_each_entry(k, head, kevent_entry) { + spin_lock(&k->ulock); + if (k->event.user[0] == uk->user[0] && k->event.user[1] == uk->user[1] && + k->event.id.raw[0] == uk->id.raw[0] && + k->event.id.raw[1] == uk->id.raw[1]) { + ret = k; + spin_unlock(&k->ulock); + break; + } + spin_unlock(&k->ulock); + } + + return ret; +} + +/* + * Search and modify kevent according to provided ukevent. + */ +static int kevent_modify(struct ukevent *uk, struct kevent_user *u) +{ + struct kevent *k; + unsigned int hash = kevent_user_hash(uk); + int err = -ENODEV; + unsigned long flags; + + spin_lock_irqsave(&u->kevent_lock, flags); + k = __kevent_search(&u->kevent_list[hash], uk, u); + if (k) { + spin_lock(&k->ulock); + k->event.event = uk->event; + k->event.req_flags = uk->req_flags; + k->event.ret_flags = 0; + spin_unlock(&k->ulock); + kevent_requeue(k); + err = 0; + } + spin_unlock_irqrestore(&u->kevent_lock, flags); + + return err; +} + +/* + * Remove kevent which matches provided ukevent. + */ +static int kevent_remove(struct ukevent *uk, struct kevent_user *u) +{ + int err = -ENODEV; + struct kevent *k; + unsigned int hash = kevent_user_hash(uk); + unsigned long flags; + + spin_lock_irqsave(&u->kevent_lock, flags); + k = __kevent_search(&u->kevent_list[hash], uk, u); + if (k) { + __kevent_finish_user(k, 1); + err = 0; + } + spin_unlock_irqrestore(&u->kevent_lock, flags); + + return err; +} + +/* + * Detaches userspace control block from file descriptor + * and decrease it's reference counter. + * No new kevents can be added or removed from any list at this point. + */ +static int kevent_user_release(struct inode *inode, struct file *file) +{ + struct kevent_user *u = file->private_data; + struct kevent *k, *n; + int i; + + for (i = 0; i < ARRAY_SIZE(u->kevent_list); ++i) { + list_for_each_entry_safe(k, n, &u->kevent_list[i], kevent_entry) + kevent_finish_user(k, 1); + } + + kevent_user_put(u); + file->private_data = NULL; + + return 0; +} + +/* + * Read requested number of ukevents in one shot. + */ +static struct ukevent *kevent_get_user(unsigned int num, void __user *arg) +{ + struct ukevent *ukev; + + ukev = kmalloc(sizeof(struct ukevent) * num, GFP_KERNEL); + if (!ukev) + return NULL; + + if (copy_from_user(ukev, arg, sizeof(struct ukevent) * num)) { + kfree(ukev); + return NULL; + } + + return ukev; +} + +/* + * Read from userspace all ukevents and modify appropriate kevents. + * If provided number of ukevents is more that threshold, it is faster + * to allocate a room for them and copy in one shot instead of copy + * one-by-one and then process them. + */ +static int kevent_user_ctl_modify(struct kevent_user *u, unsigned int num, void __user *arg) +{ + int err = 0, i; + struct ukevent uk; + + mutex_lock(&u->ctl_mutex); + + if (num > u->kevent_num) { + err = -EINVAL; + goto out; + } + + if (num > KEVENT_MIN_BUFFS_ALLOC) { + struct ukevent *ukev; + + ukev = kevent_get_user(num, arg); + if (ukev) { + for (i = 0; i < num; ++i) { + if (kevent_modify(&ukev[i], u)) + ukev[i].ret_flags |= KEVENT_RET_BROKEN; + ukev[i].ret_flags |= KEVENT_RET_DONE; + } + if (copy_to_user(arg, ukev, num*sizeof(struct ukevent))) + err = -EFAULT; + kfree(ukev); + goto out; + } + } + + for (i = 0; i < num; ++i) { + if (copy_from_user(&uk, arg, sizeof(struct ukevent))) { + err = -EFAULT; + break; + } + + if (kevent_modify(&uk, u)) + uk.ret_flags |= KEVENT_RET_BROKEN; + uk.ret_flags |= KEVENT_RET_DONE; + + if (copy_to_user(arg, &uk, sizeof(struct ukevent))) { + err = -EFAULT; + break; + } + + arg += sizeof(struct ukevent); + } +out: + mutex_unlock(&u->ctl_mutex); + + return err; +} + +/* + * Read from userspace all ukevents and remove appropriate kevents. + * If provided number of ukevents is more that threshold, it is faster + * to allocate a room for them and copy in one shot instead of copy + * one-by-one and then process them. + */ +static int kevent_user_ctl_remove(struct kevent_user *u, unsigned int num, void __user *arg) +{ + int err = 0, i; + struct ukevent uk; + + mutex_lock(&u->ctl_mutex); + + if (num > u->kevent_num) { + err = -EINVAL; + goto out; + } + + if (num > KEVENT_MIN_BUFFS_ALLOC) { + struct ukevent *ukev; + + ukev = kevent_get_user(num, arg); + if (ukev) { + for (i = 0; i < num; ++i) { + if (kevent_remove(&ukev[i], u)) + ukev[i].ret_flags |= KEVENT_RET_BROKEN; + ukev[i].ret_flags |= KEVENT_RET_DONE; + } + if (copy_to_user(arg, ukev, num*sizeof(struct ukevent))) + err = -EFAULT; + kfree(ukev); + goto out; + } + } + + for (i = 0; i < num; ++i) { + if (copy_from_user(&uk, arg, sizeof(struct ukevent))) { + err = -EFAULT; + break; + } + + if (kevent_remove(&uk, u)) + uk.ret_flags |= KEVENT_RET_BROKEN; + + uk.ret_flags |= KEVENT_RET_DONE; + + if (copy_to_user(arg, &uk, sizeof(struct ukevent))) { + err = -EFAULT; + break; + } + + arg += sizeof(struct ukevent); + } +out: + mutex_unlock(&u->ctl_mutex); + + return err; +} + +/* + * Queue kevent into userspace control block and increase + * it's reference counter. + */ +static void kevent_user_enqueue(struct kevent_user *u, struct kevent *k) +{ + unsigned long flags; + unsigned int hash = kevent_user_hash(&k->event); + + spin_lock_irqsave(&u->kevent_lock, flags); + list_add_tail(&k->kevent_entry, &u->kevent_list[hash]); + k->flags |= KEVENT_USER; + u->kevent_num++; + kevent_user_get(u); + spin_unlock_irqrestore(&u->kevent_lock, flags); +} + +/* + * Add kevent from both kernel and userspace users. + * This function allocates and queues kevent, returns negative value + * on error, positive if kevent is ready immediately and zero + * if kevent has been queued. + */ +int kevent_user_add_ukevent(struct ukevent *uk, struct kevent_user *u) +{ + struct kevent *k; + int err; + + if (kevent_user_ring_grow(u)) { + err = -ENOMEM; + goto err_out_exit; + } + + k = kmem_cache_alloc(kevent_cache, GFP_KERNEL); + if (!k) { + err = -ENOMEM; + goto err_out_exit; + } + + memcpy(&k->event, uk, sizeof(struct ukevent)); + INIT_RCU_HEAD(&k->rcu_head); + + k->event.ret_flags = 0; + + err = kevent_init(k); + if (err) { + kmem_cache_free(kevent_cache, k); + goto err_out_exit; + } + k->user = u; + kevent_stat_total(u); + kevent_user_enqueue(u, k); + + err = kevent_enqueue(k); + if (err) { + memcpy(uk, &k->event, sizeof(struct ukevent)); + kevent_finish_user(k, 0); + goto err_out_exit; + } + + kevent_user_ring_inc(u); + return 0; + +err_out_exit: + if (err < 0) { + uk->ret_flags |= KEVENT_RET_BROKEN | KEVENT_RET_DONE; + uk->ret_data[1] = err; + } else if (err > 0) + uk->ret_flags |= KEVENT_RET_DONE; + return err; +} + +/* + * Copy all ukevents from userspace, allocate kevent for each one + * and add them into appropriate kevent_storages, + * e.g. sockets, inodes and so on... + * Ready events will replace ones provided by used and number + * of ready events is returned. + * User must check ret_flags field of each ukevent structure + * to determine if it is fired or failed event. + */ +static int kevent_user_ctl_add(struct kevent_user *u, unsigned int num, void __user *arg) +{ + int err, cerr = 0, knum = 0, rnum = 0, i; + void __user *orig = arg; + struct ukevent uk; + + mutex_lock(&u->ctl_mutex); + + err = -EINVAL; + if (u->kevent_num + num >= KEVENT_MAX_EVENTS) + goto out_remove; + + if (num > KEVENT_MIN_BUFFS_ALLOC) { + struct ukevent *ukev; + + ukev = kevent_get_user(num, arg); + if (ukev) { + for (i = 0; i < num; ++i) { + err = kevent_user_add_ukevent(&ukev[i], u); + if (err) { + kevent_stat_im(u); + if (i != rnum) + memcpy(&ukev[rnum], &ukev[i], sizeof(struct ukevent)); + rnum++; + } else + knum++; + } + if (copy_to_user(orig, ukev, rnum*sizeof(struct ukevent))) + cerr = -EFAULT; + kfree(ukev); + goto out_setup; + } + } + + for (i = 0; i < num; ++i) { + if (copy_from_user(&uk, arg, sizeof(struct ukevent))) { + cerr = -EFAULT; + break; + } + arg += sizeof(struct ukevent); + + err = kevent_user_add_ukevent(&uk, u); + if (err) { + kevent_stat_im(u); + if (copy_to_user(orig, &uk, sizeof(struct ukevent))) { + cerr = -EFAULT; + break; + } + orig += sizeof(struct ukevent); + rnum++; + } else + knum++; + } + +out_setup: + if (cerr < 0) { + err = cerr; + goto out_remove; + } + + err = rnum; +out_remove: + mutex_unlock(&u->ctl_mutex); + + return err; +} + +/* + * In nonblocking mode it returns as many events as possible, but not more than @max_nr. + * In blocking mode it waits until timeout or if at least @min_nr events are ready. + */ +static int kevent_user_wait(struct file *file, struct kevent_user *u, + unsigned int min_nr, unsigned int max_nr, unsigned int timeout, + void __user *buf) +{ + struct kevent *k; + int num = 0; + + if (!(file->f_flags & O_NONBLOCK)) { + wait_event_interruptible_timeout(u->wait, + u->ready_num >= min_nr, msecs_to_jiffies(timeout)); + } + + while (num < max_nr && ((k = kqueue_dequeue_ready(u)) != NULL)) { + if (copy_to_user(buf + num*sizeof(struct ukevent), + &k->event, sizeof(struct ukevent))) + break; + + /* + * If it is one-shot kevent, it has been removed already from + * origin's queue, so we can easily free it here. + */ + if (k->event.req_flags & KEVENT_REQ_ONESHOT) + kevent_finish_user(k, 1); + ++num; + kevent_stat_wait(u); + } + + return num; +} + +static struct file_operations kevent_user_fops = { + .mmap = kevent_user_mmap, + .open = kevent_user_open, + .release = kevent_user_release, + .poll = kevent_user_poll, + .owner = THIS_MODULE, +}; + +static struct miscdevice kevent_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = kevent_name, + .fops = &kevent_user_fops, +}; + + +/* + * Userspace control block creation and initialization. + */ +static int kevent_ctl_init(void) +{ + struct kevent_user *u; + struct file *file; + int fd, ret; + + fd = get_unused_fd(); + if (fd < 0) + return fd; + + file = get_empty_filp(); + if (!file) { + ret = -ENFILE; + goto out_put_fd; + } + + u = kevent_user_alloc(); + if (unlikely(!u)) { + ret = -ENOMEM; + goto out_put_file; + } + + file->f_op = &kevent_user_fops; + file->f_vfsmnt = mntget(kevent_mnt); + file->f_dentry = dget(kevent_mnt->mnt_root); + file->f_mapping = file->f_dentry->d_inode->i_mapping; + file->f_mode = FMODE_READ; + file->f_flags = O_RDONLY; + file->private_data = u; + + fd_install(fd, file); + + return fd; + +out_put_file: + put_filp(file); +out_put_fd: + put_unused_fd(fd); + return ret; +} + +static int kevent_ctl_process(struct file *file, unsigned int cmd, unsigned int num, void __user *arg) +{ + int err; + struct kevent_user *u = file->private_data; + + if (!u || num > KEVENT_MAX_EVENTS) + return -EINVAL; + + switch (cmd) { + case KEVENT_CTL_ADD: + err = kevent_user_ctl_add(u, num, arg); + break; + case KEVENT_CTL_REMOVE: + err = kevent_user_ctl_remove(u, num, arg); + break; + case KEVENT_CTL_MODIFY: + err = kevent_user_ctl_modify(u, num, arg); + break; + default: + err = -EINVAL; + break; + } + + return err; +} + +/* + * Used to get ready kevents from queue. + * @ctl_fd - kevent control descriptor which must be obtained through kevent_ctl(KEVENT_CTL_INIT). + * @min_nr - minimum number of ready kevents. + * @max_nr - maximum number of ready kevents. + * @timeout - timeout in milliseconds to wait until some events are ready. + * @buf - buffer to place ready events. + * @flags - ununsed for now (will be used for mmap implementation). + */ +asmlinkage long sys_kevent_get_events(int ctl_fd, unsigned int min_nr, unsigned int max_nr, + unsigned int timeout, void __user *buf, unsigned flags) +{ + int err = -EINVAL; + struct file *file; + struct kevent_user *u; + + file = fget(ctl_fd); + if (!file) + return -ENODEV; + + if (file->f_op != &kevent_user_fops) + goto out_fput; + u = file->private_data; + + err = kevent_user_wait(file, u, min_nr, max_nr, timeout, buf); +out_fput: + fput(file); + return err; +} + +/* + * This syscall is used to perform various control operations + * on given kevent queue, which is obtained through kevent file descriptor @fd. + * @cmd - type of operation. + * @num - number of kevents to be processed. + * @arg - pointer to array of struct ukevent. + */ +asmlinkage long sys_kevent_ctl(int fd, unsigned int cmd, unsigned int num, void __user *arg) +{ + int err = -EINVAL; + struct file *file; + + if (cmd == KEVENT_CTL_INIT) + return kevent_ctl_init(); + + file = fget(fd); + if (!file) + return -ENODEV; + + if (file->f_op != &kevent_user_fops) + goto out_fput; + + err = kevent_ctl_process(file, cmd, num, arg); + +out_fput: + fput(file); + return err; +} + +/* + * Kevent subsystem initialization - create kevent cache and register + * filesystem to get control file descriptors from. + */ +static int __devinit kevent_user_init(void) +{ + int err = 0; + + kevent_cache = kmem_cache_create("kevent_cache", + sizeof(struct kevent), 0, SLAB_PANIC, NULL, NULL); + + err = register_filesystem(&kevent_fs_type); + if (err) + panic("%s: failed to register filesystem: err=%d.\n", + kevent_name, err); + + kevent_mnt = kern_mount(&kevent_fs_type); + if (IS_ERR(kevent_mnt)) + panic("%s: failed to mount silesystem: err=%ld.\n", + kevent_name, PTR_ERR(kevent_mnt)); + + err = misc_register(&kevent_miscdev); + if (err) { + printk(KERN_ERR "Failed to register kevent miscdev: err=%d.\n", err); + goto err_out_exit; + } + + printk("KEVENT subsystem has been successfully registered.\n"); + + return 0; + +err_out_exit: + mntput(kevent_mnt); + unregister_filesystem(&kevent_fs_type); + + return err; +} + +static void __devexit kevent_user_fini(void) +{ + misc_deregister(&kevent_miscdev); + mntput(kevent_mnt); + unregister_filesystem(&kevent_fs_type); +} + +module_init(kevent_user_init); +module_exit(kevent_user_fini); diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 6991bec..8d3769b 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -122,6 +122,9 @@ cond_syscall(ppc_rtas); cond_syscall(sys_spu_run); cond_syscall(sys_spu_create); +cond_syscall(sys_kevent_get_events); +cond_syscall(sys_kevent_ctl); + /* mmu depending weak syscall entries */ cond_syscall(sys_mprotect); cond_syscall(sys_msync); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/