[mirror_ubuntu-bionic-kernel.git] / fs / signalfd.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  fs/signalfd.c
 *
 *  Copyright (C) 2003  Linus Torvalds
 *
 *  Mon Mar 5, 2007: Davide Libenzi <davidel@xmailserver.org>
 *      Changed ->read() to return a siginfo strcture instead of signal number.
 *      Fixed locking in ->poll().
 *      Added sighand-detach notification.
 *      Added fd re-use in sys_signalfd() syscall.
 *      Now using anonymous inode source.
 *      Thanks to Oleg Nesterov for useful code review and suggestions.
 *      More comments and suggestions from Arnd Bergmann.
 *  Sat May 19, 2007: Davi E. M. Arnaut <davi@haxent.com.br>
 *      Retrieve multiple signals with one read() call
 *  Sun Jul 15, 2007: Davide Libenzi <davidel@xmailserver.org>
 *      Attach to the sighand only during read() and poll().
 */

#include <linux/file.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/list.h>
#include <linux/anon_inodes.h>
#include <linux/signalfd.h>
#include <linux/syscalls.h>
#include <linux/proc_fs.h>
#include <linux/compat.h>

void signalfd_cleanup(struct sighand_struct *sighand)
{
	wait_queue_head_t *wqh = &sighand->signalfd_wqh;
	/*
	 * The lockless check can race with remove_wait_queue() in progress,
	 * but in this case its caller should run under rcu_read_lock() and
	 * sighand_cachep is SLAB_TYPESAFE_BY_RCU, we can safely return.
	 */
	if (likely(!waitqueue_active(wqh)))
		return;

	/* wait_queue_entry_t->func(POLLFREE) should do remove_wait_queue() */
	wake_up_poll(wqh, POLLHUP | POLLFREE);
}

struct signalfd_ctx {
	sigset_t sigmask;
};

static int signalfd_release(struct inode *inode, struct file *file)
{
	kfree(file->private_data);
	return 0;
}

static unsigned int signalfd_poll(struct file *file, poll_table *wait)
{
	struct signalfd_ctx *ctx = file->private_data;
	unsigned int events = 0;

	poll_wait(file, &current->sighand->signalfd_wqh, wait);

	spin_lock_irq(&current->sighand->siglock);
	if (next_signal(&current->pending, &ctx->sigmask) ||
	    next_signal(&current->signal->shared_pending,
			&ctx->sigmask))
		events |= POLLIN;
	spin_unlock_irq(&current->sighand->siglock);

	return events;
}

/*
 * Copied from copy_siginfo_to_user() in kernel/signal.c
 */
static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
			     siginfo_t const *kinfo)
{
	long err;

	BUILD_BUG_ON(sizeof(struct signalfd_siginfo) != 128);

	/*
	 * Unused members should be zero ...
	 */
	err = __clear_user(uinfo, sizeof(*uinfo));

	/*
	 * If you change siginfo_t structure, please be sure
	 * this code is fixed accordingly.
	 */
	err |= __put_user(kinfo->si_signo, &uinfo->ssi_signo);
	err |= __put_user(kinfo->si_errno, &uinfo->ssi_errno);
	err |= __put_user(kinfo->si_code, &uinfo->ssi_code);
	switch (siginfo_layout(kinfo->si_signo, kinfo->si_code)) {
	case SIL_KILL:
		err |= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
		err |= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
		break;
	case SIL_TIMER:
		 err |= __put_user(kinfo->si_tid, &uinfo->ssi_tid);
		 err |= __put_user(kinfo->si_overrun, &uinfo->ssi_overrun);
		 err |= __put_user((long) kinfo->si_ptr, &uinfo->ssi_ptr);
		 err |= __put_user(kinfo->si_int, &uinfo->ssi_int);
		break;
	case SIL_POLL:
		err |= __put_user(kinfo->si_band, &uinfo->ssi_band);
		err |= __put_user(kinfo->si_fd, &uinfo->ssi_fd);
		break;
	case SIL_FAULT:
		err |= __put_user((long) kinfo->si_addr, &uinfo->ssi_addr);
#ifdef __ARCH_SI_TRAPNO
		err |= __put_user(kinfo->si_trapno, &uinfo->ssi_trapno);
#endif
#ifdef BUS_MCEERR_AO
		/* 
		 * Other callers might not initialize the si_lsb field,
		 * so check explicitly for the right codes here.
		 */
		if (kinfo->si_signo == SIGBUS &&
		    (kinfo->si_code == BUS_MCEERR_AR ||
		     kinfo->si_code == BUS_MCEERR_AO))
			err |= __put_user((short) kinfo->si_addr_lsb,
					  &uinfo->ssi_addr_lsb);
#endif
		break;
	case SIL_CHLD:
		err |= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
		err |= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
		err |= __put_user(kinfo->si_status, &uinfo->ssi_status);
		err |= __put_user(kinfo->si_utime, &uinfo->ssi_utime);
		err |= __put_user(kinfo->si_stime, &uinfo->ssi_stime);
		break;
	case SIL_RT:
	default:
		/*
		 * This case catches also the signals queued by sigqueue().
		 */
		err |= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
		err |= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
		err |= __put_user((long) kinfo->si_ptr, &uinfo->ssi_ptr);
		err |= __put_user(kinfo->si_int, &uinfo->ssi_int);
		break;
	}

	return err ? -EFAULT: sizeof(*uinfo);
}

static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, siginfo_t *info,
				int nonblock)
{
	ssize_t ret;
	DECLARE_WAITQUEUE(wait, current);

	spin_lock_irq(&current->sighand->siglock);
	ret = dequeue_signal(current, &ctx->sigmask, info);
	switch (ret) {
	case 0:
		if (!nonblock)
			break;
		ret = -EAGAIN;
	default:
		spin_unlock_irq(&current->sighand->siglock);
		return ret;
	}

	add_wait_queue(&current->sighand->signalfd_wqh, &wait);
	for (;;) {
		set_current_state(TASK_INTERRUPTIBLE);
		ret = dequeue_signal(current, &ctx->sigmask, info);
		if (ret != 0)
			break;
		if (signal_pending(current)) {
			ret = -ERESTARTSYS;
			break;
		}
		spin_unlock_irq(&current->sighand->siglock);
		schedule();
		spin_lock_irq(&current->sighand->siglock);
	}
	spin_unlock_irq(&current->sighand->siglock);

	remove_wait_queue(&current->sighand->signalfd_wqh, &wait);
	__set_current_state(TASK_RUNNING);

	return ret;
}

/*
 * Returns a multiple of the size of a "struct signalfd_siginfo", or a negative
 * error code. The "count" parameter must be at least the size of a
 * "struct signalfd_siginfo".
 */
static ssize_t signalfd_read(struct file *file, char __user *buf, size_t count,
			     loff_t *ppos)
{
	struct signalfd_ctx *ctx = file->private_data;
	struct signalfd_siginfo __user *siginfo;
	int nonblock = file->f_flags & O_NONBLOCK;
	ssize_t ret, total = 0;
	siginfo_t info;

	count /= sizeof(struct signalfd_siginfo);
	if (!count)
		return -EINVAL;

	siginfo = (struct signalfd_siginfo __user *) buf;
	do {
		ret = signalfd_dequeue(ctx, &info, nonblock);
		if (unlikely(ret <= 0))
			break;
		ret = signalfd_copyinfo(siginfo, &info);
		if (ret < 0)
			break;
		siginfo++;
		total += ret;
		nonblock = 1;
	} while (--count);

	return total ? total: ret;
}

#ifdef CONFIG_PROC_FS
static void signalfd_show_fdinfo(struct seq_file *m, struct file *f)
{
	struct signalfd_ctx *ctx = f->private_data;
	sigset_t sigmask;

	sigmask = ctx->sigmask;
	signotset(&sigmask);
	render_sigset_t(m, "sigmask:\t", &sigmask);
}
#endif

static const struct file_operations signalfd_fops = {
#ifdef CONFIG_PROC_FS
	.show_fdinfo	= signalfd_show_fdinfo,
#endif
	.release	= signalfd_release,
	.poll		= signalfd_poll,
	.read		= signalfd_read,
	.llseek		= noop_llseek,
};

SYSCALL_DEFINE4(signalfd4, int, ufd, sigset_t __user *, user_mask,
		size_t, sizemask, int, flags)
{
	sigset_t sigmask;
	struct signalfd_ctx *ctx;

	/* Check the SFD_* constants for consistency.  */
	BUILD_BUG_ON(SFD_CLOEXEC != O_CLOEXEC);
	BUILD_BUG_ON(SFD_NONBLOCK != O_NONBLOCK);

	if (flags & ~(SFD_CLOEXEC | SFD_NONBLOCK))
		return -EINVAL;

	if (sizemask != sizeof(sigset_t) ||
	    copy_from_user(&sigmask, user_mask, sizeof(sigmask)))
		return -EINVAL;
	sigdelsetmask(&sigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
	signotset(&sigmask);

	if (ufd == -1) {
		ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
		if (!ctx)
			return -ENOMEM;

		ctx->sigmask = sigmask;

		/*
		 * When we call this, the initialization must be complete, since
		 * anon_inode_getfd() will install the fd.
		 */
		ufd = anon_inode_getfd("[signalfd]", &signalfd_fops, ctx,
				       O_RDWR | (flags & (O_CLOEXEC | O_NONBLOCK)));
		if (ufd < 0)
			kfree(ctx);
	} else {
		struct fd f = fdget(ufd);
		if (!f.file)
			return -EBADF;
		ctx = f.file->private_data;
		if (f.file->f_op != &signalfd_fops) {
			fdput(f);
			return -EINVAL;
		}
		spin_lock_irq(&current->sighand->siglock);
		ctx->sigmask = sigmask;
		spin_unlock_irq(&current->sighand->siglock);

		wake_up(&current->sighand->signalfd_wqh);
		fdput(f);
	}

	return ufd;
}

SYSCALL_DEFINE3(signalfd, int, ufd, sigset_t __user *, user_mask,
		size_t, sizemask)
{
	return sys_signalfd4(ufd, user_mask, sizemask, 0);
}

#ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE4(signalfd4, int, ufd,
		     const compat_sigset_t __user *,sigmask,
		     compat_size_t, sigsetsize,
		     int, flags)
{
	sigset_t tmp;
	sigset_t __user *ksigmask;

	if (sigsetsize != sizeof(compat_sigset_t))
		return -EINVAL;
	if (get_compat_sigset(&tmp, sigmask))
		return -EFAULT;
	ksigmask = compat_alloc_user_space(sizeof(sigset_t));
	if (copy_to_user(ksigmask, &tmp, sizeof(sigset_t)))
		return -EFAULT;

	return sys_signalfd4(ufd, ksigmask, sizeof(sigset_t), flags);
}

COMPAT_SYSCALL_DEFINE3(signalfd, int, ufd,
		     const compat_sigset_t __user *,sigmask,
		     compat_size_t, sigsetsize)
{
	return compat_sys_signalfd4(ufd, sigmask, sigsetsize, 0);
}
#endif
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
fba2afaa DL	2	/*
	3	* fs/signalfd.c
	4	*
	5	* Copyright (C) 2003 Linus Torvalds
	6	*
	7	* Mon Mar 5, 2007: Davide Libenzi <davidel@xmailserver.org>
	8	* Changed ->read() to return a siginfo strcture instead of signal number.
	9	* Fixed locking in ->poll().
	10	* Added sighand-detach notification.
	11	* Added fd re-use in sys_signalfd() syscall.
	12	* Now using anonymous inode source.
	13	* Thanks to Oleg Nesterov for useful code review and suggestions.
	14	* More comments and suggestions from Arnd Bergmann.
b8fceee1	15	* Sat May 19, 2007: Davi E. M. Arnaut <davi@haxent.com.br>
b3762bfc	16	* Retrieve multiple signals with one read() call
b8fceee1 DL	17	* Sun Jul 15, 2007: Davide Libenzi <davidel@xmailserver.org>
b8fceee1 DL	18	* Attach to the sighand only during read() and poll().
fba2afaa DL	19	*/
	20
	21	#include <linux/file.h>
	22	#include <linux/poll.h>
	23	#include <linux/init.h>
	24	#include <linux/fs.h>
	25	#include <linux/sched.h>
5a0e3ad6	26	#include <linux/slab.h>
fba2afaa DL	27	#include <linux/kernel.h>
	28	#include <linux/signal.h>
	29	#include <linux/list.h>
	30	#include <linux/anon_inodes.h>
	31	#include <linux/signalfd.h>
7ec37dfd	32	#include <linux/syscalls.h>
138d22b5	33	#include <linux/proc_fs.h>
7d197ed4	34	#include <linux/compat.h>
fba2afaa	35
d80e731e ON	36	void signalfd_cleanup(struct sighand_struct *sighand)
	37	{
	38	wait_queue_head_t *wqh = &sighand->signalfd_wqh;
971316f0 ON	39	/*
	40	* The lockless check can race with remove_wait_queue() in progress,
	41	* but in this case its caller should run under rcu_read_lock() and
5f0d5a3a	42	* sighand_cachep is SLAB_TYPESAFE_BY_RCU, we can safely return.
971316f0	43	*/
d80e731e ON	44	if (likely(!waitqueue_active(wqh)))
	45	return;
	46
ac6424b9	47	/* wait_queue_entry_t->func(POLLFREE) should do remove_wait_queue() */
d80e731e ON	48	wake_up_poll(wqh, POLLHUP \| POLLFREE);
	49	}
	50
fba2afaa	51	struct signalfd_ctx {
fba2afaa	52	sigset_t sigmask;
fba2afaa DL	53	};
fba2afaa DL	54
fba2afaa DL	55	static int signalfd_release(struct inode inode, struct file file)
fba2afaa DL	56	{
b8fceee1	57	kfree(file->private_data);
fba2afaa DL	58	return 0;
	59	}
	60
	61	static unsigned int signalfd_poll(struct file file, poll_table wait)
	62	{
	63	struct signalfd_ctx *ctx = file->private_data;
	64	unsigned int events = 0;
fba2afaa	65
b8fceee1	66	poll_wait(file, &current->sighand->signalfd_wqh, wait);
fba2afaa	67
b8fceee1 DL	68	spin_lock_irq(&current->sighand->siglock);
	69	if (next_signal(&current->pending, &ctx->sigmask) \|\|
	70	next_signal(&current->signal->shared_pending,
	71	&ctx->sigmask))
fba2afaa	72	events \|= POLLIN;
b8fceee1	73	spin_unlock_irq(&current->sighand->siglock);
fba2afaa DL	74
	75	return events;
	76	}
	77
	78	/*
	79	* Copied from copy_siginfo_to_user() in kernel/signal.c
	80	*/
	81	static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
	82	siginfo_t const *kinfo)
	83	{
	84	long err;
	85
	86	BUILD_BUG_ON(sizeof(struct signalfd_siginfo) != 128);
	87
	88	/*
14e4a0f2	89	* Unused members should be zero ...
fba2afaa DL	90	*/
	91	err = __clear_user(uinfo, sizeof(*uinfo));
	92
	93	/*
	94	* If you change siginfo_t structure, please be sure
	95	* this code is fixed accordingly.
	96	*/
96358de6 DL	97	err \|= __put_user(kinfo->si_signo, &uinfo->ssi_signo);
96358de6 DL	98	err \|= __put_user(kinfo->si_errno, &uinfo->ssi_errno);
cc731525 EB	99	err \|= __put_user(kinfo->si_code, &uinfo->ssi_code);
	100	switch (siginfo_layout(kinfo->si_signo, kinfo->si_code)) {
	101	case SIL_KILL:
96358de6 DL	102	err \|= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
96358de6 DL	103	err \|= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
fba2afaa	104	break;
cc731525	105	case SIL_TIMER:
96358de6 DL	106	err \|= __put_user(kinfo->si_tid, &uinfo->ssi_tid);
	107	err \|= __put_user(kinfo->si_overrun, &uinfo->ssi_overrun);
	108	err \|= __put_user((long) kinfo->si_ptr, &uinfo->ssi_ptr);
a2a20c41	109	err \|= __put_user(kinfo->si_int, &uinfo->ssi_int);
fba2afaa	110	break;
cc731525	111	case SIL_POLL:
96358de6 DL	112	err \|= __put_user(kinfo->si_band, &uinfo->ssi_band);
96358de6 DL	113	err \|= __put_user(kinfo->si_fd, &uinfo->ssi_fd);
fba2afaa	114	break;
cc731525	115	case SIL_FAULT:
96358de6	116	err \|= __put_user((long) kinfo->si_addr, &uinfo->ssi_addr);
fba2afaa	117	#ifdef __ARCH_SI_TRAPNO
96358de6	118	err \|= __put_user(kinfo->si_trapno, &uinfo->ssi_trapno);
b8aeec34 HS	119	#endif
	120	#ifdef BUS_MCEERR_AO
	121	/*
	122	* Other callers might not initialize the si_lsb field,
	123	* so check explicitly for the right codes here.
	124	*/
3ead7c52 AA	125	if (kinfo->si_signo == SIGBUS &&
	126	(kinfo->si_code == BUS_MCEERR_AR \|\|
	127	kinfo->si_code == BUS_MCEERR_AO))
b8aeec34 HS	128	err \|= __put_user((short) kinfo->si_addr_lsb,
b8aeec34 HS	129	&uinfo->ssi_addr_lsb);
fba2afaa DL	130	#endif
fba2afaa DL	131	break;
cc731525	132	case SIL_CHLD:
96358de6 DL	133	err \|= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
	134	err \|= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
	135	err \|= __put_user(kinfo->si_status, &uinfo->ssi_status);
	136	err \|= __put_user(kinfo->si_utime, &uinfo->ssi_utime);
	137	err \|= __put_user(kinfo->si_stime, &uinfo->ssi_stime);
fba2afaa	138	break;
cc731525	139	case SIL_RT:
0859ab59 DL	140	default:
	141	/*
	142	* This case catches also the signals queued by sigqueue().
	143	*/
96358de6 DL	144	err \|= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
96358de6 DL	145	err \|= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
0859ab59 DL	146	err \|= __put_user((long) kinfo->si_ptr, &uinfo->ssi_ptr);
0859ab59 DL	147	err \|= __put_user(kinfo->si_int, &uinfo->ssi_int);
fba2afaa DL	148	break;
	149	}
	150
	151	return err ? -EFAULT: sizeof(*uinfo);
	152	}
	153
b3762bfc DA	154	static ssize_t signalfd_dequeue(struct signalfd_ctx ctx, siginfo_t info,
	155	int nonblock)
	156	{
	157	ssize_t ret;
b3762bfc DA	158	DECLARE_WAITQUEUE(wait, current);
b3762bfc DA	159
b8fceee1 DL	160	spin_lock_irq(&current->sighand->siglock);
b8fceee1 DL	161	ret = dequeue_signal(current, &ctx->sigmask, info);
b3762bfc DA	162	switch (ret) {
	163	case 0:
	164	if (!nonblock)
	165	break;
	166	ret = -EAGAIN;
	167	default:
b8fceee1	168	spin_unlock_irq(&current->sighand->siglock);
b3762bfc DA	169	return ret;
	170	}
	171
b8fceee1	172	add_wait_queue(&current->sighand->signalfd_wqh, &wait);
b3762bfc DA	173	for (;;) {
b3762bfc DA	174	set_current_state(TASK_INTERRUPTIBLE);
b8fceee1	175	ret = dequeue_signal(current, &ctx->sigmask, info);
b3762bfc DA	176	if (ret != 0)
	177	break;
	178	if (signal_pending(current)) {
	179	ret = -ERESTARTSYS;
	180	break;
	181	}
b8fceee1	182	spin_unlock_irq(&current->sighand->siglock);
b3762bfc	183	schedule();
b8fceee1	184	spin_lock_irq(&current->sighand->siglock);
b3762bfc	185	}
b8fceee1	186	spin_unlock_irq(&current->sighand->siglock);
b3762bfc	187
b8fceee1	188	remove_wait_queue(&current->sighand->signalfd_wqh, &wait);
b3762bfc DA	189	__set_current_state(TASK_RUNNING);
	190
	191	return ret;
	192	}
	193
fba2afaa	194	/*
b8fceee1 DL	195	* Returns a multiple of the size of a "struct signalfd_siginfo", or a negative
	196	* error code. The "count" parameter must be at least the size of a
	197	* "struct signalfd_siginfo".
fba2afaa DL	198	*/
	199	static ssize_t signalfd_read(struct file file, char __user buf, size_t count,
	200	loff_t *ppos)
	201	{
	202	struct signalfd_ctx *ctx = file->private_data;
b3762bfc DA	203	struct signalfd_siginfo __user *siginfo;
	204	int nonblock = file->f_flags & O_NONBLOCK;
	205	ssize_t ret, total = 0;
fba2afaa	206	siginfo_t info;
fba2afaa	207
b3762bfc DA	208	count /= sizeof(struct signalfd_siginfo);
b3762bfc DA	209	if (!count)
fba2afaa	210	return -EINVAL;
fba2afaa	211
b3762bfc	212	siginfo = (struct signalfd_siginfo __user *) buf;
b3762bfc DA	213	do {
	214	ret = signalfd_dequeue(ctx, &info, nonblock);
	215	if (unlikely(ret <= 0))
	216	break;
	217	ret = signalfd_copyinfo(siginfo, &info);
	218	if (ret < 0)
	219	break;
	220	siginfo++;
	221	total += ret;
	222	nonblock = 1;
	223	} while (--count);
	224
b8fceee1	225	return total ? total: ret;
fba2afaa DL	226	}
fba2afaa DL	227
138d22b5	228	#ifdef CONFIG_PROC_FS
a3816ab0	229	static void signalfd_show_fdinfo(struct seq_file m, struct file f)
138d22b5 CG	230	{
	231	struct signalfd_ctx *ctx = f->private_data;
	232	sigset_t sigmask;
	233
	234	sigmask = ctx->sigmask;
	235	signotset(&sigmask);
	236	render_sigset_t(m, "sigmask:\t", &sigmask);
138d22b5 CG	237	}
	238	#endif
	239
fba2afaa	240	static const struct file_operations signalfd_fops = {
138d22b5 CG	241	#ifdef CONFIG_PROC_FS
	242	.show_fdinfo = signalfd_show_fdinfo,
	243	#endif
fba2afaa DL	244	.release = signalfd_release,
	245	.poll = signalfd_poll,
	246	.read = signalfd_read,
6038f373	247	.llseek = noop_llseek,
fba2afaa DL	248	};
fba2afaa DL	249
836f92ad HC	250	SYSCALL_DEFINE4(signalfd4, int, ufd, sigset_t __user *, user_mask,
836f92ad HC	251	size_t, sizemask, int, flags)
fba2afaa	252	{
fba2afaa DL	253	sigset_t sigmask;
fba2afaa DL	254	struct signalfd_ctx *ctx;
fba2afaa	255
e38b36f3 UD	256	/* Check the SFD_* constants for consistency. */
	257	BUILD_BUG_ON(SFD_CLOEXEC != O_CLOEXEC);
	258	BUILD_BUG_ON(SFD_NONBLOCK != O_NONBLOCK);
	259
5fb5e049	260	if (flags & ~(SFD_CLOEXEC \| SFD_NONBLOCK))
9deb27ba UD	261	return -EINVAL;
9deb27ba UD	262
fba2afaa DL	263	if (sizemask != sizeof(sigset_t) \|\|
fba2afaa DL	264	copy_from_user(&sigmask, user_mask, sizeof(sigmask)))
f50cadaa	265	return -EINVAL;
fba2afaa DL	266	sigdelsetmask(&sigmask, sigmask(SIGKILL) \| sigmask(SIGSTOP));
	267	signotset(&sigmask);
	268
	269	if (ufd == -1) {
	270	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
	271	if (!ctx)
	272	return -ENOMEM;
	273
fba2afaa	274	ctx->sigmask = sigmask;
fba2afaa DL	275
	276	/*
	277	* When we call this, the initialization must be complete, since
	278	* anon_inode_getfd() will install the fd.
	279	*/
7d9dbca3	280	ufd = anon_inode_getfd("[signalfd]", &signalfd_fops, ctx,
628ff7c1	281	O_RDWR \| (flags & (O_CLOEXEC \| O_NONBLOCK)));
2030a42c AV	282	if (ufd < 0)
2030a42c AV	283	kfree(ctx);
fba2afaa	284	} else {
2903ff01 AV	285	struct fd f = fdget(ufd);
2903ff01 AV	286	if (!f.file)
fba2afaa	287	return -EBADF;
2903ff01 AV	288	ctx = f.file->private_data;
	289	if (f.file->f_op != &signalfd_fops) {
	290	fdput(f);
fba2afaa DL	291	return -EINVAL;
fba2afaa DL	292	}
b8fceee1 DL	293	spin_lock_irq(&current->sighand->siglock);
	294	ctx->sigmask = sigmask;
	295	spin_unlock_irq(&current->sighand->siglock);
	296
	297	wake_up(&current->sighand->signalfd_wqh);
2903ff01	298	fdput(f);
fba2afaa DL	299	}
	300
	301	return ufd;
fba2afaa	302	}
9deb27ba	303
836f92ad HC	304	SYSCALL_DEFINE3(signalfd, int, ufd, sigset_t __user *, user_mask,
836f92ad HC	305	size_t, sizemask)
9deb27ba UD	306	{
	307	return sys_signalfd4(ufd, user_mask, sizemask, 0);
	308	}
7d197ed4 AV	309
	310	#ifdef CONFIG_COMPAT
	311	COMPAT_SYSCALL_DEFINE4(signalfd4, int, ufd,
	312	const compat_sigset_t __user *,sigmask,
	313	compat_size_t, sigsetsize,
	314	int, flags)
	315	{
7d197ed4 AV	316	sigset_t tmp;
	317	sigset_t __user *ksigmask;
	318
	319	if (sigsetsize != sizeof(compat_sigset_t))
	320	return -EINVAL;
3968cf62	321	if (get_compat_sigset(&tmp, sigmask))
7d197ed4	322	return -EFAULT;
7d197ed4 AV	323	ksigmask = compat_alloc_user_space(sizeof(sigset_t));
	324	if (copy_to_user(ksigmask, &tmp, sizeof(sigset_t)))
	325	return -EFAULT;
	326
	327	return sys_signalfd4(ufd, ksigmask, sizeof(sigset_t), flags);
	328	}
	329
	330	COMPAT_SYSCALL_DEFINE3(signalfd, int, ufd,
	331	const compat_sigset_t __user *,sigmask,
	332	compat_size_t, sigsetsize)
	333	{
	334	return compat_sys_signalfd4(ufd, sigmask, sigsetsize, 0);
	335	}
	336	#endif