Core files. This patch includes core kevent files: * userspace controlling * kernelspace interfaces * initialization * notification state machines
Some bits of documentation can be found on project's homepage (and links from there): http://tservice.net.ru/~s0mbre/old/?section=projects&item=kevent Signed-off-by: Evgeniy Polyakov <[EMAIL PROTECTED]> diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S index 7e639f7..fa8075b 100644 --- a/arch/i386/kernel/syscall_table.S +++ b/arch/i386/kernel/syscall_table.S @@ -318,3 +318,7 @@ ENTRY(sys_call_table) .long sys_vmsplice .long sys_move_pages .long sys_getcpu + .long sys_kevent_get_events + .long sys_kevent_ctl /* 320 */ + .long sys_kevent_wait + .long sys_kevent_ring_init diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S index b4aa875..95fb252 100644 --- a/arch/x86_64/ia32/ia32entry.S +++ b/arch/x86_64/ia32/ia32entry.S @@ -714,8 +714,12 @@ #endif .quad compat_sys_get_robust_list .quad sys_splice .quad sys_sync_file_range - .quad sys_tee + .quad sys_tee /* 315 */ .quad compat_sys_vmsplice .quad compat_sys_move_pages .quad sys_getcpu + .quad sys_kevent_get_events + .quad sys_kevent_ctl /* 320 */ + .quad sys_kevent_wait + .quad sys_kevent_ring_init ia32_syscall_end: diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h index bd99870..2161ef2 100644 --- a/include/asm-i386/unistd.h +++ b/include/asm-i386/unistd.h @@ -324,10 +324,14 @@ #define __NR_tee 315 #define __NR_vmsplice 316 #define __NR_move_pages 317 #define __NR_getcpu 318 +#define __NR_kevent_get_events 319 +#define __NR_kevent_ctl 320 +#define __NR_kevent_wait 321 +#define __NR_kevent_ring_init 322 #ifdef __KERNEL__ -#define NR_syscalls 319 +#define NR_syscalls 323 #include <linux/err.h> /* diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h index 6137146..3669c0f 100644 --- a/include/asm-x86_64/unistd.h +++ b/include/asm-x86_64/unistd.h @@ -619,10 +619,18 @@ #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) +#define __NR_kevent_wait 282 +__SYSCALL(__NR_kevent_wait, sys_kevent_wait) +#define __NR_kevent_ring_init 283 +__SYSCALL(__NR_kevent_ring_init, sys_kevent_ring_init) #ifdef __KERNEL__ -#define __NR_syscall_max __NR_move_pages +#define __NR_syscall_max __NR_kevent_ring_init #include <linux/err.h> #ifndef __NO_STUBS diff --git a/include/linux/kevent.h b/include/linux/kevent.h new file mode 100644 index 0000000..f7cbf6b --- /dev/null +++ b/include/linux/kevent.h @@ -0,0 +1,223 @@ +/* + * 2006 Copyright (c) Evgeniy Polyakov <[EMAIL PROTECTED]> + * 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 <linux/types.h> +#include <linux/list.h> +#include <linux/rbtree.h> +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/wait.h> +#include <linux/net.h> +#include <linux/rcupdate.h> +#include <linux/fs.h> +#include <linux/kevent_storage.h> +#include <linux/ukevent.h> + +#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 tree. */ + struct rb_node kevent_node; + /* 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; +}; + +struct kevent_user +{ + struct rb_root kevent_root; + 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; + + /* Mutex protecting userspace ring buffer. */ + struct mutex ring_lock; + /* Kernel index and size of the userspace ring buffer. */ + unsigned int kidx, ring_size; + /* Pointer to userspace ring buffer. */ + struct kevent_ring __user *pring; + +#ifdef CONFIG_KEVENT_USER_STAT + unsigned long im_num; + unsigned long wait_num, ring_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(const struct kevent_callbacks *cb, int pos); + +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) +{ + printk(KERN_INFO "%s: u: %p, wait: %lu, ring: %lu, immediately: %lu, total: %lu.\n", + __func__, u, u->wait_num, u->ring_num, u->im_num, u->total); +} +static inline void kevent_stat_im(struct kevent_user *u) +{ + u->im_num++; +} +static inline void kevent_stat_ring(struct kevent_user *u) +{ + u->ring_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_ring(u) ({ (void) u;}) +#define kevent_stat_total(u) ({ (void) u;}) +#endif + +#ifdef CONFIG_LOCKDEP +void kevent_socket_reinit(struct socket *sock); +void kevent_sk_reinit(struct sock *sk); +#else +static inline void kevent_socket_reinit(struct socket *sock) +{ +} +static inline void kevent_sk_reinit(struct sock *sk) +{ +} +#endif +#ifdef CONFIG_KEVENT_SOCKET +void kevent_socket_notify(struct sock *sock, u32 event); +int kevent_socket_dequeue(struct kevent *k); +int kevent_socket_enqueue(struct kevent *k); +#define sock_async(__sk) sock_flag(__sk, SOCK_ASYNC) +#else +static inline void kevent_socket_notify(struct sock *sock, u32 event) +{ +} +#define sock_async(__sk) ({ (void)__sk; 0; }) +#endif + +#ifdef CONFIG_KEVENT_POLL +static inline void kevent_init_file(struct file *file) +{ + kevent_storage_init(file, &file->st); +} + +static inline void kevent_cleanup_file(struct file *file) +{ + kevent_storage_fini(&file->st); +} +#else +static inline void kevent_init_file(struct file *file) {} +static inline void kevent_cleanup_file(struct file *file) {} +#endif + +#ifdef CONFIG_KEVENT_PIPE +extern void kevent_pipe_notify(struct inode *inode, u32 events); +#else +static inline void kevent_pipe_notify(struct inode *inode, u32 events) {} +#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 2d1c3d5..471a685 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -54,6 +54,8 @@ struct compat_stat; struct compat_timeval; struct robust_list_head; struct getcpu_cache; +struct ukevent; +struct kevent_ring; #include <linux/types.h> #include <linux/aio_abi.h> @@ -599,4 +601,9 @@ asmlinkage long sys_set_robust_list(stru size_t len); asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, struct getcpu_cache __user *cache); +asmlinkage long sys_kevent_get_events(int ctl_fd, unsigned int min, unsigned int max, + __u64 timeout, struct ukevent __user *buf, unsigned flags); +asmlinkage long sys_kevent_ctl(int ctl_fd, unsigned int cmd, unsigned int num, struct ukevent __user *buf); +asmlinkage long sys_kevent_wait(int ctl_fd, unsigned int num, __u64 timeout); +asmlinkage long sys_kevent_ring_init(int ctl_fd, struct kevent_ring __user *ring, unsigned int num); #endif diff --git a/include/linux/ukevent.h b/include/linux/ukevent.h new file mode 100644 index 0000000..b14e14e --- /dev/null +++ b/include/linux/ukevent.h @@ -0,0 +1,165 @@ +/* + * 2006 Copyright (c) Evgeniy Polyakov <[EMAIL PROTECTED]> + * 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 remove it. */ +#define KEVENT_REQ_ONESHOT 0x1 +/* Wake up only when event exclusively belongs to this thread, + * for example when several threads are waiting for new client + * connection so they could perform accept() it is a good idea + * to set this flag, so only one thread of all with this flag set + * will be awakened. + * If there are events without this flags, appropriate threads will + * be awakened too. */ +#define KEVENT_REQ_WAKEUP_ONE 0x2 +/* Edge Triggered behaviour. */ +#define KEVENT_REQ_ET 0x4 +/* Perform the last check on kevent (call appropriate callback) when + * kevent is marked as ready and has been removed from ready queue. + * If it will be confirmed that kevent is ready + * (k->callbacks.callback(k) returns true) then kevent will be copied + * to userspace, otherwise it will be requeued back to storage. + * Second (checking) call is performed with this bit _cleared_ so + * callback can detect when it was called from + * kevent_storage_ready() - bit is set, or + * kevent_dequeue_ready() - bit is cleared. + * If kevent will be requeued, bit will be set again. */ +#define KEVENT_REQ_LAST_CHECK 0x8 + +/* + * Kevent return flags. + */ +/* Kevent is broken. */ +#define KEVENT_RET_BROKEN 0x1 +/* Kevent processing was finished successfully. */ +#define KEVENT_RET_DONE 0x2 +/* Kevent was not copied into ring buffer due to some error conditions. */ +#define KEVENT_RET_COPY_FAILED 0x4 + +/* + * 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_PIPE 6 +#define KEVENT_MAX 7 + +/* + * 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 +{ + union { + __u32 raw[2]; + __u64 raw_u64 __attribute__((aligned(8))); + }; +}; + +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. + * The whole structure is aligned to 8 bytes already, so the last union + * is aligned properly. + */ + union { + __u32 user[2]; + void *ptr; + }; +}; + +struct kevent_ring +{ + unsigned int ring_kidx; + struct ukevent event[0]; +}; + +#define KEVENT_CTL_ADD 0 +#define KEVENT_CTL_REMOVE 1 +#define KEVENT_CTL_MODIFY 2 + +#endif /* __UKEVENT_H */ diff --git a/init/Kconfig b/init/Kconfig index d2eb7a8..c7d8250 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -201,6 +201,8 @@ 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..267fc53 --- /dev/null +++ b/kernel/kevent/Kconfig @@ -0,0 +1,45 @@ +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 + 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. + +config KEVENT_SOCKET + bool "Kernel event notifications for sockets" + depends on NET && KEVENT + help + This option enables notifications through KEVENT subsystem of + sockets operations, like new packet receiving conditions, + ready for accept conditions and so on. + +config KEVENT_PIPE + bool "Kernel event notifications for pipes" + depends on KEVENT + help + This option enables notifications through KEVENT subsystem of + pipe read/write operations. diff --git a/kernel/kevent/Makefile b/kernel/kevent/Makefile new file mode 100644 index 0000000..d4d6b68 --- /dev/null +++ b/kernel/kevent/Makefile @@ -0,0 +1,5 @@ +obj-y := kevent.o kevent_user.o +obj-$(CONFIG_KEVENT_TIMER) += kevent_timer.o +obj-$(CONFIG_KEVENT_POLL) += kevent_poll.o +obj-$(CONFIG_KEVENT_SOCKET) += kevent_socket.o +obj-$(CONFIG_KEVENT_PIPE) += kevent_pipe.o diff --git a/kernel/kevent/kevent.c b/kernel/kevent/kevent.c new file mode 100644 index 0000000..24ee44a --- /dev/null +++ b/kernel/kevent/kevent.c @@ -0,0 +1,232 @@ +/* + * 2006 Copyright (c) Evgeniy Polyakov <[EMAIL PROTECTED]> + * 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 <linux/kernel.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/mempool.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/kevent.h> + +/* + * 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) +{ + 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) +{ + 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 -EINVAL; +} + +static struct kevent_callbacks kevent_registered_callbacks[KEVENT_MAX] __read_mostly; + +int kevent_add_callbacks(const struct kevent_callbacks *cb, int pos) +{ + struct kevent_callbacks *p; + + if (pos >= KEVENT_MAX) + return -EINVAL; + + p = &kevent_registered_callbacks[pos]; + + p->enqueue = (cb->enqueue) ? cb->enqueue : kevent_break; + p->dequeue = (cb->dequeue) ? cb->dequeue : kevent_break; + p->callback = (cb->callback) ? cb->callback : kevent_break; + + 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 (unlikely(k->event.type >= KEVENT_MAX || + !kevent_registered_callbacks[k->event.type].callback)) + return kevent_break(k); + + k->callbacks = kevent_registered_callbacks[k->event.type]; + if (unlikely(k->callbacks.callback == kevent_break)) + return kevent_break(k); + + 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 int __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)) { + 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); + } + + return ret; +} + +/* + * 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; + int wake_num = 0; + + 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) + if (!(k->event.req_flags & KEVENT_REQ_WAKEUP_ONE) || wake_num == 0) + if (__kevent_requeue(k, event)) + wake_num++; + } + 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..00d942a --- /dev/null +++ b/kernel/kevent/kevent_user.c @@ -0,0 +1,936 @@ +/* + * 2006 Copyright (c) Evgeniy Polyakov <[EMAIL PROTECTED]> + * 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 <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/mount.h> +#include <linux/device.h> +#include <linux/poll.h> +#include <linux/kevent.h> +#include <linux/miscdevice.h> +#include <asm/io.h> + +static const char kevent_name[] = "kevent"; +static kmem_cache_t *kevent_cache __read_mostly; + +/* + * 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; +} + +/* + * Copies kevent into userspace ring buffer if it was initialized. + * Returns + * 0 on success, + * -EAGAIN if there were no place for that kevent (impossible) + * -EFAULT if copy_to_user() failed. + * + * Must be called under kevent_user->ring_lock locked. + */ +static int kevent_copy_ring_buffer(struct kevent *k) +{ + struct kevent_ring __user *ring; + struct kevent_user *u = k->user; + unsigned long flags; + int err; + + ring = u->pring; + if (!ring) + return 0; + + if (copy_to_user(&ring->event[u->kidx], &k->event, sizeof(struct ukevent))) { + err = -EFAULT; + goto err_out_exit; + } + + if (put_user(u->kidx, &ring->ring_kidx)) { + err = -EFAULT; + goto err_out_exit; + } + + if (++u->kidx >= u->ring_size) + u->kidx = 0; + + return 0; + +err_out_exit: + spin_lock_irqsave(&k->ulock, flags); + k->event.ret_flags |= KEVENT_RET_COPY_FAILED; + spin_unlock_irqrestore(&k->ulock, flags); + return err; +} + +static int kevent_user_open(struct inode *inode, struct file *file) +{ + struct kevent_user *u; + + u = kzalloc(sizeof(struct kevent_user), GFP_KERNEL); + if (!u) + return -ENOMEM; + + INIT_LIST_HEAD(&u->ready_list); + spin_lock_init(&u->ready_lock); + kevent_stat_init(u); + spin_lock_init(&u->kevent_lock); + u->kevent_root = RB_ROOT; + + mutex_init(&u->ctl_mutex); + init_waitqueue_head(&u->wait); + + atomic_set(&u->refcnt, 1); + + mutex_init(&u->ring_lock); + u->kidx = u->ring_size = 0; + u->pring = NULL; + + 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); + kfree(u); + } +} + +static inline int kevent_compare_id(struct kevent_id *left, struct kevent_id *right) +{ + if (left->raw_u64 > right->raw_u64) + return -1; + + if (right->raw_u64 > left->raw_u64) + return 1; + + return 0; +} + +/* + * 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); +} + +/* + * Must be called under u->ready_lock. + * This function unlinks kevent from ready queue. + */ +static inline void kevent_unlink_ready(struct kevent *k) +{ + list_del(&k->ready_entry); + k->flags &= ~KEVENT_READY; + k->user->ready_num--; +} + +static void kevent_remove_ready(struct kevent *k) +{ + struct kevent_user *u = k->user; + unsigned long flags; + + spin_lock_irqsave(&u->ready_lock, flags); + if (k->flags & KEVENT_READY) + kevent_unlink_ready(k); + spin_unlock_irqrestore(&u->ready_lock, flags); +} + +/* + * 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) +{ + if (deq) + kevent_dequeue(k); + + kevent_remove_ready(k); + + kevent_user_put(k->user); + 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; + + rb_erase(&k->kevent_node, &u->kevent_root); + 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); + rb_erase(&k->kevent_node, &u->kevent_root); + 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 *kevent_dequeue_ready(struct kevent_user *u) +{ + unsigned long flags; + struct kevent *k = NULL; + + mutex_lock(&u->ring_lock); + while (u->ready_num && !k) { + 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); + kevent_unlink_ready(k); + } + spin_unlock_irqrestore(&u->ready_lock, flags); + + if (k && (k->event.req_flags & KEVENT_REQ_LAST_CHECK)) { + unsigned long flags; + + spin_lock_irqsave(&k->ulock, flags); + k->event.req_flags &= ~KEVENT_REQ_LAST_CHECK; + spin_unlock_irqrestore(&k->ulock, flags); + + if (!k->callbacks.callback(k)) { + spin_lock_irqsave(&k->ulock, flags); + k->event.req_flags |= KEVENT_REQ_LAST_CHECK; + k->event.ret_flags = 0; + k->event.ret_data[0] = k->event.ret_data[1] = 0; + spin_unlock_irqrestore(&k->ulock, flags); + k = NULL; + } + } else + break; + } + + if (k) + kevent_copy_ring_buffer(k); + mutex_unlock(&u->ring_lock); + + return k; +} + +static void kevent_complete_ready(struct kevent *k) +{ + if (k->event.req_flags & KEVENT_REQ_ONESHOT) + /* + * If it is one-shot kevent, it has been removed already from + * origin's queue, so we can easily free it here. + */ + kevent_finish_user(k, 1); + else if (k->event.req_flags & KEVENT_REQ_ET) { + unsigned long flags; + + /* + * Edge-triggered behaviour: mark event as clear new one. + */ + + spin_lock_irqsave(&k->ulock, flags); + k->event.ret_flags = 0; + k->event.ret_data[0] = k->event.ret_data[1] = 0; + spin_unlock_irqrestore(&k->ulock, flags); + } +} + +/* + * Search a kevent inside kevent tree for given ukevent. + */ +static struct kevent *__kevent_search(struct kevent_id *id, struct kevent_user *u) +{ + struct kevent *k, *ret = NULL; + struct rb_node *n = u->kevent_root.rb_node; + int cmp; + + while (n) { + k = rb_entry(n, struct kevent, kevent_node); + cmp = kevent_compare_id(&k->event.id, id); + + if (cmp > 0) + n = n->rb_right; + else if (cmp < 0) + n = n->rb_left; + else { + ret = k; + break; + } + } + + return ret; +} + +/* + * Search and modify kevent according to provided ukevent. + */ +static int kevent_modify(struct ukevent *uk, struct kevent_user *u) +{ + struct kevent *k; + int err = -ENODEV; + unsigned long flags; + + spin_lock_irqsave(&u->kevent_lock, flags); + k = __kevent_search(&uk->id, 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 long flags; + + spin_lock_irqsave(&u->kevent_lock, flags); + k = __kevent_search(&uk->id, 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; + struct rb_node *n; + + for (n = rb_first(&u->kevent_root); n; n = rb_next(n)) { + k = rb_entry(n, struct kevent, kevent_node); + 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 int kevent_user_enqueue(struct kevent_user *u, struct kevent *new) +{ + unsigned long flags; + struct rb_node **p = &u->kevent_root.rb_node, *parent = NULL; + struct kevent *k; + int err = 0, cmp; + + spin_lock_irqsave(&u->kevent_lock, flags); + while (*p) { + parent = *p; + k = rb_entry(parent, struct kevent, kevent_node); + + cmp = kevent_compare_id(&k->event.id, &new->event.id); + if (cmp > 0) + p = &parent->rb_right; + else if (cmp < 0) + p = &parent->rb_left; + else { + err = -EEXIST; + break; + } + } + if (likely(!err)) { + rb_link_node(&new->kevent_node, parent, p); + rb_insert_color(&new->kevent_node, &u->kevent_root); + new->flags |= KEVENT_USER; + u->kevent_num++; + kevent_user_get(u); + } + spin_unlock_irqrestore(&u->kevent_lock, flags); + + return err; +} + +/* + * 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; + + 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); + err = kevent_user_enqueue(u, k); + if (err) { + kmem_cache_free(kevent_cache, k); + goto err_out_exit; + } + + err = kevent_enqueue(k); + if (err) { + memcpy(uk, &k->event, sizeof(struct ukevent)); + kevent_finish_user(k, 0); + goto err_out_exit; + } + + 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, rnum = 0, i; + void __user *orig = arg; + struct ukevent uk; + + mutex_lock(&u->ctl_mutex); + + err = -EINVAL; + 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++; + } + } + 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++; + } + } + +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, __u64 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, + clock_t_to_jiffies(nsec_to_clock_t(timeout))); + } + + while (num < max_nr && ((k = kevent_dequeue_ready(u)) != NULL)) { + if (copy_to_user(buf + num*sizeof(struct ukevent), + &k->event, sizeof(struct ukevent))) { + if (num == 0) + num = -EFAULT; + break; + } + kevent_complete_ready(k); + ++num; + kevent_stat_wait(u); + } + + return num; +} + +static struct file_operations kevent_user_fops = { + .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, +}; + +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; + + 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 nanoseconds 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, + __u64 timeout, struct ukevent __user *buf, unsigned flags) +{ + int err = -EINVAL; + struct file *file; + struct kevent_user *u; + + file = fget(ctl_fd); + if (!file) + return -EBADF; + + 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; +} + +asmlinkage long sys_kevent_ring_init(int ctl_fd, struct kevent_ring __user *ring, unsigned int num) +{ + int err = -EINVAL; + struct file *file; + struct kevent_user *u; + + file = fget(ctl_fd); + if (!file) + return -EBADF; + + if (file->f_op != &kevent_user_fops) + goto out_fput; + u = file->private_data; + + mutex_lock(&u->ring_lock); + if (u->pring) { + err = -EINVAL; + goto err_out_exit; + } + u->pring = ring; + u->ring_size = num; + mutex_unlock(&u->ring_lock); + + fput(file); + + return 0; + +err_out_exit: + mutex_unlock(&u->ring_lock); +out_fput: + fput(file); + return err; +} + +/* + * This syscall is used to perform waiting until there is free space in kevent queue + * and removes/requeues requested number of events (commits them). Function returns + * number of actually committed events. + * + * @ctl_fd - kevent file descriptor. + * @num - number of kevents to process. + * @timeout - this timeout specifies number of nanoseconds to wait until there is + * free space in kevent queue. + * + * When we need to commit @num events, it means we should just remove first @num + * kevents from ready queue and copy them into the buffer. + * Kevents will be copied into ring buffer in order they were placed into ready queue. + */ +asmlinkage long sys_kevent_wait(int ctl_fd, unsigned int num, __u64 timeout) +{ + int err = -EINVAL, committed = 0; + struct file *file; + struct kevent_user *u; + struct kevent *k; + struct kevent_ring __user *ring; + unsigned int i; + + file = fget(ctl_fd); + if (!file) + return -EBADF; + + if (file->f_op != &kevent_user_fops) + goto out_fput; + u = file->private_data; + + ring = u->pring; + if (!ring || num >= u->ring_size) + goto out_fput; + + if (!(file->f_flags & O_NONBLOCK)) { + wait_event_interruptible_timeout(u->wait, + u->ready_num >= 1, + clock_t_to_jiffies(nsec_to_clock_t(timeout))); + } + + for (i=0; i<num; ++i) { + k = kevent_dequeue_ready(u); + if (!k) + break; + kevent_complete_ready(k); + kevent_stat_ring(u); + committed++; + } + + fput(file); + + return committed; +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, struct ukevent __user *arg) +{ + int err = -EINVAL; + struct file *file; + + file = fget(fd); + if (!file) + return -EBADF; + + 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 __init kevent_user_init(void) +{ + int err = 0; + + kevent_cache = kmem_cache_create("kevent_cache", + sizeof(struct kevent), 0, SLAB_PANIC, NULL, NULL); + + err = misc_register(&kevent_miscdev); + if (err) { + printk(KERN_ERR "Failed to register kevent miscdev: err=%d.\n", err); + goto err_out_exit; + } + + printk(KERN_INFO "KEVENT subsystem has been successfully registered.\n"); + + return 0; + +err_out_exit: + kmem_cache_destroy(kevent_cache); + return err; +} + +module_init(kevent_user_init); diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 7a3b2e7..5200583 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -122,6 +122,11 @@ cond_syscall(ppc_rtas); cond_syscall(sys_spu_run); cond_syscall(sys_spu_create); +cond_syscall(sys_kevent_get_events); +cond_syscall(sys_kevent_wait); +cond_syscall(sys_kevent_ctl); +cond_syscall(sys_kevent_ring_init); + /* mmu depending weak syscall entries */ cond_syscall(sys_mprotect); cond_syscall(sys_msync); - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
