[net-next-2.6.git] / fs / fcntl.c

/*
 *  linux/fs/fcntl.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/syscalls.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/dnotify.h>
#include <linux/smp_lock.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/security.h>
#include <linux/ptrace.h>

#include <asm/poll.h>
#include <asm/siginfo.h>
#include <asm/uaccess.h>

void fastcall set_close_on_exec(unsigned int fd, int flag)
{
	struct files_struct *files = current->files;
	spin_lock(&files->file_lock);
	if (flag)
		FD_SET(fd, files->close_on_exec);
	else
		FD_CLR(fd, files->close_on_exec);
	spin_unlock(&files->file_lock);
}

static inline int get_close_on_exec(unsigned int fd)
{
	struct files_struct *files = current->files;
	int res;
	spin_lock(&files->file_lock);
	res = FD_ISSET(fd, files->close_on_exec);
	spin_unlock(&files->file_lock);
	return res;
}

/*
 * locate_fd finds a free file descriptor in the open_fds fdset,
 * expanding the fd arrays if necessary.  Must be called with the
 * file_lock held for write.
 */

static int locate_fd(struct files_struct *files, 
			    struct file *file, unsigned int orig_start)
{
	unsigned int newfd;
	unsigned int start;
	int error;

	error = -EINVAL;
	if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
		goto out;

repeat:
	/*
	 * Someone might have closed fd's in the range
	 * orig_start..files->next_fd
	 */
	start = orig_start;
	if (start < files->next_fd)
		start = files->next_fd;

	newfd = start;
	if (start < files->max_fdset) {
		newfd = find_next_zero_bit(files->open_fds->fds_bits,
			files->max_fdset, start);
	}
	
	error = -EMFILE;
	if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
		goto out;

	error = expand_files(files, newfd);
	if (error < 0)
		goto out;

	/*
	 * If we needed to expand the fs array we
	 * might have blocked - try again.
	 */
	if (error)
		goto repeat;

	if (start <= files->next_fd)
		files->next_fd = newfd + 1;
	
	error = newfd;
	
out:
	return error;
}

static int dupfd(struct file *file, unsigned int start)
{
	struct files_struct * files = current->files;
	int fd;

	spin_lock(&files->file_lock);
	fd = locate_fd(files, file, start);
	if (fd >= 0) {
		FD_SET(fd, files->open_fds);
		FD_CLR(fd, files->close_on_exec);
		spin_unlock(&files->file_lock);
		fd_install(fd, file);
	} else {
		spin_unlock(&files->file_lock);
		fput(file);
	}

	return fd;
}

asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
{
	int err = -EBADF;
	struct file * file, *tofree;
	struct files_struct * files = current->files;

	spin_lock(&files->file_lock);
	if (!(file = fcheck(oldfd)))
		goto out_unlock;
	err = newfd;
	if (newfd == oldfd)
		goto out_unlock;
	err = -EBADF;
	if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
		goto out_unlock;
	get_file(file);			/* We are now finished with oldfd */

	err = expand_files(files, newfd);
	if (err < 0)
		goto out_fput;

	/* To avoid races with open() and dup(), we will mark the fd as
	 * in-use in the open-file bitmap throughout the entire dup2()
	 * process.  This is quite safe: do_close() uses the fd array
	 * entry, not the bitmap, to decide what work needs to be
	 * done.  --sct */
	/* Doesn't work. open() might be there first. --AV */

	/* Yes. It's a race. In user space. Nothing sane to do */
	err = -EBUSY;
	tofree = files->fd[newfd];
	if (!tofree && FD_ISSET(newfd, files->open_fds))
		goto out_fput;

	files->fd[newfd] = file;
	FD_SET(newfd, files->open_fds);
	FD_CLR(newfd, files->close_on_exec);
	spin_unlock(&files->file_lock);

	if (tofree)
		filp_close(tofree, files);
	err = newfd;
out:
	return err;
out_unlock:
	spin_unlock(&files->file_lock);
	goto out;

out_fput:
	spin_unlock(&files->file_lock);
	fput(file);
	goto out;
}

asmlinkage long sys_dup(unsigned int fildes)
{
	int ret = -EBADF;
	struct file * file = fget(fildes);

	if (file)
		ret = dupfd(file, 0);
	return ret;
}

#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC | O_DIRECT | O_NOATIME)

static int setfl(int fd, struct file * filp, unsigned long arg)
{
	struct inode * inode = filp->f_dentry->d_inode;
	int error = 0;

	/* O_APPEND cannot be cleared if the file is marked as append-only */
	if (!(arg & O_APPEND) && IS_APPEND(inode))
		return -EPERM;

	/* O_NOATIME can only be set by the owner or superuser */
	if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
		if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
			return -EPERM;

	/* required for strict SunOS emulation */
	if (O_NONBLOCK != O_NDELAY)
	       if (arg & O_NDELAY)
		   arg |= O_NONBLOCK;

	if (arg & O_DIRECT) {
		if (!filp->f_mapping || !filp->f_mapping->a_ops ||
			!filp->f_mapping->a_ops->direct_IO)
				return -EINVAL;
	}

	if (filp->f_op && filp->f_op->check_flags)
		error = filp->f_op->check_flags(arg);
	if (error)
		return error;

	lock_kernel();
	if ((arg ^ filp->f_flags) & FASYNC) {
		if (filp->f_op && filp->f_op->fasync) {
			error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
			if (error < 0)
				goto out;
		}
	}

	filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
 out:
	unlock_kernel();
	return error;
}

static void f_modown(struct file *filp, unsigned long pid,
                     uid_t uid, uid_t euid, int force)
{
	write_lock_irq(&filp->f_owner.lock);
	if (force || !filp->f_owner.pid) {
		filp->f_owner.pid = pid;
		filp->f_owner.uid = uid;
		filp->f_owner.euid = euid;
	}
	write_unlock_irq(&filp->f_owner.lock);
}

int f_setown(struct file *filp, unsigned long arg, int force)
{
	int err;
	
	err = security_file_set_fowner(filp);
	if (err)
		return err;

	f_modown(filp, arg, current->uid, current->euid, force);
	return 0;
}

EXPORT_SYMBOL(f_setown);

void f_delown(struct file *filp)
{
	f_modown(filp, 0, 0, 0, 1);
}

static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
		struct file *filp)
{
	long err = -EINVAL;

	switch (cmd) {
	case F_DUPFD:
		get_file(filp);
		err = dupfd(filp, arg);
		break;
	case F_GETFD:
		err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
		break;
	case F_SETFD:
		err = 0;
		set_close_on_exec(fd, arg & FD_CLOEXEC);
		break;
	case F_GETFL:
		err = filp->f_flags;
		break;
	case F_SETFL:
		err = setfl(fd, filp, arg);
		break;
	case F_GETLK:
		err = fcntl_getlk(filp, (struct flock __user *) arg);
		break;
	case F_SETLK:
	case F_SETLKW:
		err = fcntl_setlk(filp, cmd, (struct flock __user *) arg);
		break;
	case F_GETOWN:
		/*
		 * XXX If f_owner is a process group, the
		 * negative return value will get converted
		 * into an error.  Oops.  If we keep the
		 * current syscall conventions, the only way
		 * to fix this will be in libc.
		 */
		err = filp->f_owner.pid;
		force_successful_syscall_return();
		break;
	case F_SETOWN:
		err = f_setown(filp, arg, 1);
		break;
	case F_GETSIG:
		err = filp->f_owner.signum;
		break;
	case F_SETSIG:
		/* arg == 0 restores default behaviour. */
		if (arg < 0 || arg > _NSIG) {
			break;
		}
		err = 0;
		filp->f_owner.signum = arg;
		break;
	case F_GETLEASE:
		err = fcntl_getlease(filp);
		break;
	case F_SETLEASE:
		err = fcntl_setlease(fd, filp, arg);
		break;
	case F_NOTIFY:
		err = fcntl_dirnotify(fd, filp, arg);
		break;
	default:
		break;
	}
	return err;
}

asmlinkage long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)
{	
	struct file *filp;
	long err = -EBADF;

	filp = fget(fd);
	if (!filp)
		goto out;

	err = security_file_fcntl(filp, cmd, arg);
	if (err) {
		fput(filp);
		return err;
	}

	err = do_fcntl(fd, cmd, arg, filp);

 	fput(filp);
out:
	return err;
}

#if BITS_PER_LONG == 32
asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
{	
	struct file * filp;
	long err;

	err = -EBADF;
	filp = fget(fd);
	if (!filp)
		goto out;

	err = security_file_fcntl(filp, cmd, arg);
	if (err) {
		fput(filp);
		return err;
	}
	err = -EBADF;
	
	switch (cmd) {
		case F_GETLK64:
			err = fcntl_getlk64(filp, (struct flock64 __user *) arg);
			break;
		case F_SETLK64:
		case F_SETLKW64:
			err = fcntl_setlk64(filp, cmd, (struct flock64 __user *) arg);
			break;
		default:
			err = do_fcntl(fd, cmd, arg, filp);
			break;
	}
	fput(filp);
out:
	return err;
}
#endif

/* Table to convert sigio signal codes into poll band bitmaps */

static long band_table[NSIGPOLL] = {
	POLLIN | POLLRDNORM,			/* POLL_IN */
	POLLOUT | POLLWRNORM | POLLWRBAND,	/* POLL_OUT */
	POLLIN | POLLRDNORM | POLLMSG,		/* POLL_MSG */
	POLLERR,				/* POLL_ERR */
	POLLPRI | POLLRDBAND,			/* POLL_PRI */
	POLLHUP | POLLERR			/* POLL_HUP */
};

static inline int sigio_perm(struct task_struct *p,
                             struct fown_struct *fown, int sig)
{
	return (((fown->euid == 0) ||
		 (fown->euid == p->suid) || (fown->euid == p->uid) ||
		 (fown->uid == p->suid) || (fown->uid == p->uid)) &&
		!security_file_send_sigiotask(p, fown, sig));
}

static void send_sigio_to_task(struct task_struct *p,
			       struct fown_struct *fown, 
			       int fd,
			       int reason)
{
	if (!sigio_perm(p, fown, fown->signum))
		return;

	switch (fown->signum) {
		siginfo_t si;
		default:
			/* Queue a rt signal with the appropriate fd as its
			   value.  We use SI_SIGIO as the source, not 
			   SI_KERNEL, since kernel signals always get 
			   delivered even if we can't queue.  Failure to
			   queue in this case _should_ be reported; we fall
			   back to SIGIO in that case. --sct */
			si.si_signo = fown->signum;
			si.si_errno = 0;
		        si.si_code  = reason;
			/* Make sure we are called with one of the POLL_*
			   reasons, otherwise we could leak kernel stack into
			   userspace.  */
			if ((reason & __SI_MASK) != __SI_POLL)
				BUG();
			if (reason - POLL_IN >= NSIGPOLL)
				si.si_band  = ~0L;
			else
				si.si_band = band_table[reason - POLL_IN];
			si.si_fd    = fd;
			if (!send_sig_info(fown->signum, &si, p))
				break;
		/* fall-through: fall back on the old plain SIGIO signal */
		case 0:
			send_group_sig_info(SIGIO, SEND_SIG_PRIV, p);
	}
}

void send_sigio(struct fown_struct *fown, int fd, int band)
{
	struct task_struct *p;
	int pid;
	
	read_lock(&fown->lock);
	pid = fown->pid;
	if (!pid)
		goto out_unlock_fown;
	
	read_lock(&tasklist_lock);
	if (pid > 0) {
		p = find_task_by_pid(pid);
		if (p) {
			send_sigio_to_task(p, fown, fd, band);
		}
	} else {
		do_each_task_pid(-pid, PIDTYPE_PGID, p) {
			send_sigio_to_task(p, fown, fd, band);
		} while_each_task_pid(-pid, PIDTYPE_PGID, p);
	}
	read_unlock(&tasklist_lock);
 out_unlock_fown:
	read_unlock(&fown->lock);
}

static void send_sigurg_to_task(struct task_struct *p,
                                struct fown_struct *fown)
{
	if (sigio_perm(p, fown, SIGURG))
		send_group_sig_info(SIGURG, SEND_SIG_PRIV, p);
}

int send_sigurg(struct fown_struct *fown)
{
	struct task_struct *p;
	int pid, ret = 0;
	
	read_lock(&fown->lock);
	pid = fown->pid;
	if (!pid)
		goto out_unlock_fown;

	ret = 1;
	
	read_lock(&tasklist_lock);
	if (pid > 0) {
		p = find_task_by_pid(pid);
		if (p) {
			send_sigurg_to_task(p, fown);
		}
	} else {
		do_each_task_pid(-pid, PIDTYPE_PGID, p) {
			send_sigurg_to_task(p, fown);
		} while_each_task_pid(-pid, PIDTYPE_PGID, p);
	}
	read_unlock(&tasklist_lock);
 out_unlock_fown:
	read_unlock(&fown->lock);
	return ret;
}

static DEFINE_RWLOCK(fasync_lock);
static kmem_cache_t *fasync_cache;

/*
 * fasync_helper() is used by some character device drivers (mainly mice)
 * to set up the fasync queue. It returns negative on error, 0 if it did
 * no changes and positive if it added/deleted the entry.
 */
int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp)
{
	struct fasync_struct *fa, **fp;
	struct fasync_struct *new = NULL;
	int result = 0;

	if (on) {
		new = kmem_cache_alloc(fasync_cache, SLAB_KERNEL);
		if (!new)
			return -ENOMEM;
	}
	write_lock_irq(&fasync_lock);
	for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
		if (fa->fa_file == filp) {
			if(on) {
				fa->fa_fd = fd;
				kmem_cache_free(fasync_cache, new);
			} else {
				*fp = fa->fa_next;
				kmem_cache_free(fasync_cache, fa);
				result = 1;
			}
			goto out;
		}
	}

	if (on) {
		new->magic = FASYNC_MAGIC;
		new->fa_file = filp;
		new->fa_fd = fd;
		new->fa_next = *fapp;
		*fapp = new;
		result = 1;
	}
out:
	write_unlock_irq(&fasync_lock);
	return result;
}

EXPORT_SYMBOL(fasync_helper);

void __kill_fasync(struct fasync_struct *fa, int sig, int band)
{
	while (fa) {
		struct fown_struct * fown;
		if (fa->magic != FASYNC_MAGIC) {
			printk(KERN_ERR "kill_fasync: bad magic number in "
			       "fasync_struct!\n");
			return;
		}
		fown = &fa->fa_file->f_owner;
		/* Don't send SIGURG to processes which have not set a
		   queued signum: SIGURG has its own default signalling
		   mechanism. */
		if (!(sig == SIGURG && fown->signum == 0))
			send_sigio(fown, fa->fa_fd, band);
		fa = fa->fa_next;
	}
}

EXPORT_SYMBOL(__kill_fasync);

void kill_fasync(struct fasync_struct **fp, int sig, int band)
{
	/* First a quick test without locking: usually
	 * the list is empty.
	 */
	if (*fp) {
		read_lock(&fasync_lock);
		/* reread *fp after obtaining the lock */
		__kill_fasync(*fp, sig, band);
		read_unlock(&fasync_lock);
	}
}
EXPORT_SYMBOL(kill_fasync);

static int __init fasync_init(void)
{
	fasync_cache = kmem_cache_create("fasync_cache",
		sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL, NULL);
	return 0;
}

module_init(fasync_init)
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/fcntl.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	*/
	6
	7	#include <linux/syscalls.h>
	8	#include <linux/init.h>
	9	#include <linux/mm.h>
	10	#include <linux/fs.h>
	11	#include <linux/file.h>
	12	#include <linux/dnotify.h>
	13	#include <linux/smp_lock.h>
	14	#include <linux/slab.h>
	15	#include <linux/module.h>
	16	#include <linux/security.h>
	17	#include <linux/ptrace.h>
	18
	19	#include <asm/poll.h>
	20	#include <asm/siginfo.h>
	21	#include <asm/uaccess.h>
	22
	23	void fastcall set_close_on_exec(unsigned int fd, int flag)
	24	{
	25	struct files_struct *files = current->files;
	26	spin_lock(&files->file_lock);
	27	if (flag)
	28	FD_SET(fd, files->close_on_exec);
	29	else
	30	FD_CLR(fd, files->close_on_exec);
	31	spin_unlock(&files->file_lock);
	32	}
	33
	34	static inline int get_close_on_exec(unsigned int fd)
	35	{
	36	struct files_struct *files = current->files;
	37	int res;
	38	spin_lock(&files->file_lock);
	39	res = FD_ISSET(fd, files->close_on_exec);
	40	spin_unlock(&files->file_lock);
	41	return res;
	42	}
	43
	44	/*
	45	* locate_fd finds a free file descriptor in the open_fds fdset,
	46	* expanding the fd arrays if necessary. Must be called with the
	47	* file_lock held for write.
	48	*/
	49
	50	static int locate_fd(struct files_struct *files,
	51	struct file *file, unsigned int orig_start)
	52	{
	53	unsigned int newfd;
	54	unsigned int start;
	55	int error;
	56
	57	error = -EINVAL;
	58	if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
	59	goto out;
	60
	61	repeat:
	62	/*
	63	* Someone might have closed fd's in the range
	64	* orig_start..files->next_fd
65	*/
66	start = orig_start;
67	if (start < files->next_fd)
68	start = files->next_fd;
69
70	newfd = start;
71	if (start < files->max_fdset) {
72	newfd = find_next_zero_bit(files->open_fds->fds_bits,
73	files->max_fdset, start);
74	}
75
76	error = -EMFILE;
77	if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
78	goto out;
79
80	error = expand_files(files, newfd);
81	if (error < 0)
82	goto out;
83
84	/*
85	* If we needed to expand the fs array we
86	* might have blocked - try again.
87	*/
88	if (error)
89	goto repeat;
90
91	if (start <= files->next_fd)
92	files->next_fd = newfd + 1;
93
94	error = newfd;
95
96	out:
97	return error;
98	}
99
100	static int dupfd(struct file *file, unsigned int start)
101	{
102	struct files_struct * files = current->files;
103	int fd;
104
105	spin_lock(&files->file_lock);
106	fd = locate_fd(files, file, start);
107	if (fd >= 0) {
108	FD_SET(fd, files->open_fds);
109	FD_CLR(fd, files->close_on_exec);
110	spin_unlock(&files->file_lock);
111	fd_install(fd, file);
112	} else {
113	spin_unlock(&files->file_lock);
114	fput(file);
115	}
116
117	return fd;
118	}
119
120	asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
121	{
122	int err = -EBADF;
123	struct file * file, *tofree;
124	struct files_struct * files = current->files;
125
126	spin_lock(&files->file_lock);
127	if (!(file = fcheck(oldfd)))
128	goto out_unlock;
129	err = newfd;
130	if (newfd == oldfd)
131	goto out_unlock;
132	err = -EBADF;
133	if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
134	goto out_unlock;
135	get_file(file); /* We are now finished with oldfd */
136
137	err = expand_files(files, newfd);
138	if (err < 0)
139	goto out_fput;
140
141	/* To avoid races with open() and dup(), we will mark the fd as
142	* in-use in the open-file bitmap throughout the entire dup2()
143	* process. This is quite safe: do_close() uses the fd array
144	* entry, not the bitmap, to decide what work needs to be
145	* done. --sct */
146	/* Doesn't work. open() might be there first. --AV */
147
148	/* Yes. It's a race. In user space. Nothing sane to do */
149	err = -EBUSY;
150	tofree = files->fd[newfd];
151	if (!tofree && FD_ISSET(newfd, files->open_fds))
152	goto out_fput;
153
154	files->fd[newfd] = file;
155	FD_SET(newfd, files->open_fds);
156	FD_CLR(newfd, files->close_on_exec);
157	spin_unlock(&files->file_lock);
158
159	if (tofree)
160	filp_close(tofree, files);
161	err = newfd;
162	out:
163	return err;
164	out_unlock:
165	spin_unlock(&files->file_lock);
166	goto out;
167
168	out_fput:
169	spin_unlock(&files->file_lock);
170	fput(file);
171	goto out;
172	}
173
174	asmlinkage long sys_dup(unsigned int fildes)
175	{
176	int ret = -EBADF;
177	struct file * file = fget(fildes);
178
179	if (file)
180	ret = dupfd(file, 0);
181	return ret;
182	}
183
184	#define SETFL_MASK (O_APPEND \| O_NONBLOCK \| O_NDELAY \| FASYNC \| O_DIRECT \| O_NOATIME)
185
186	static int setfl(int fd, struct file * filp, unsigned long arg)
187	{
188	struct inode * inode = filp->f_dentry->d_inode;
189	int error = 0;
190
191	/* O_APPEND cannot be cleared if the file is marked as append-only */
192	if (!(arg & O_APPEND) && IS_APPEND(inode))
193	return -EPERM;
194
195	/* O_NOATIME can only be set by the owner or superuser */
196	if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
197	if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
198	return -EPERM;
199
200	/* required for strict SunOS emulation */
201	if (O_NONBLOCK != O_NDELAY)
202	if (arg & O_NDELAY)
203	arg \|= O_NONBLOCK;
204
205	if (arg & O_DIRECT) {
206	if (!filp->f_mapping \|\| !filp->f_mapping->a_ops \|\|
207	!filp->f_mapping->a_ops->direct_IO)
208	return -EINVAL;
209	}
210
211	if (filp->f_op && filp->f_op->check_flags)
212	error = filp->f_op->check_flags(arg);
213	if (error)
214	return error;
215
216	lock_kernel();
217	if ((arg ^ filp->f_flags) & FASYNC) {
218	if (filp->f_op && filp->f_op->fasync) {
219	error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
220	if (error < 0)
221	goto out;
222	}
223	}
224
225	filp->f_flags = (arg & SETFL_MASK) \| (filp->f_flags & ~SETFL_MASK);
226	out:
227	unlock_kernel();
228	return error;
229	}
230
231	static void f_modown(struct file *filp, unsigned long pid,
232	uid_t uid, uid_t euid, int force)
233	{
234	write_lock_irq(&filp->f_owner.lock);
235	if (force \|\| !filp->f_owner.pid) {
236	filp->f_owner.pid = pid;
237	filp->f_owner.uid = uid;
238	filp->f_owner.euid = euid;
239	}
240	write_unlock_irq(&filp->f_owner.lock);
241	}
242
243	int f_setown(struct file *filp, unsigned long arg, int force)
244	{
245	int err;
246
247	err = security_file_set_fowner(filp);
248	if (err)
249	return err;
250
251	f_modown(filp, arg, current->uid, current->euid, force);
252	return 0;
253	}
254
255	EXPORT_SYMBOL(f_setown);
256
257	void f_delown(struct file *filp)
258	{
259	f_modown(filp, 0, 0, 0, 1);
260	}
261
262	static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
263	struct file *filp)
264	{
265	long err = -EINVAL;
266
267	switch (cmd) {
268	case F_DUPFD:
269	get_file(filp);
270	err = dupfd(filp, arg);
271	break;
272	case F_GETFD:
273	err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
274	break;
275	case F_SETFD:
276	err = 0;
277	set_close_on_exec(fd, arg & FD_CLOEXEC);
278	break;
279	case F_GETFL:
280	err = filp->f_flags;
281	break;
282	case F_SETFL:
283	err = setfl(fd, filp, arg);
284	break;
285	case F_GETLK:
286	err = fcntl_getlk(filp, (struct flock __user *) arg);
287	break;
288	case F_SETLK:
289	case F_SETLKW:
290	err = fcntl_setlk(filp, cmd, (struct flock __user *) arg);
291	break;
292	case F_GETOWN:
293	/*
294	* XXX If f_owner is a process group, the
295	* negative return value will get converted
296	* into an error. Oops. If we keep the
297	* current syscall conventions, the only way
298	* to fix this will be in libc.
299	*/
300	err = filp->f_owner.pid;
301	force_successful_syscall_return();
302	break;
303	case F_SETOWN:
304	err = f_setown(filp, arg, 1);
305	break;
306	case F_GETSIG:
307	err = filp->f_owner.signum;
308	break;
309	case F_SETSIG:
310	/* arg == 0 restores default behaviour. */
311	if (arg < 0 \|\| arg > _NSIG) {
312	break;
313	}
314	err = 0;
315	filp->f_owner.signum = arg;
316	break;
317	case F_GETLEASE:
318	err = fcntl_getlease(filp);
319	break;
320	case F_SETLEASE:
321	err = fcntl_setlease(fd, filp, arg);
322	break;
323	case F_NOTIFY:
324	err = fcntl_dirnotify(fd, filp, arg);
325	break;
326	default:
327	break;
328	}
329	return err;
330	}
331
332	asmlinkage long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)
333	{
334	struct file *filp;
335	long err = -EBADF;
336
337	filp = fget(fd);
338	if (!filp)
339	goto out;
340
341	err = security_file_fcntl(filp, cmd, arg);
342	if (err) {
343	fput(filp);
344	return err;
345	}
346
347	err = do_fcntl(fd, cmd, arg, filp);
348
349	fput(filp);
350	out:
351	return err;
352	}
353
354	#if BITS_PER_LONG == 32
355	asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
356	{
357	struct file * filp;
358	long err;
359
360	err = -EBADF;
361	filp = fget(fd);
362	if (!filp)
363	goto out;
364
365	err = security_file_fcntl(filp, cmd, arg);
366	if (err) {
367	fput(filp);
368	return err;
369	}
370	err = -EBADF;
371
372	switch (cmd) {
373	case F_GETLK64:
374	err = fcntl_getlk64(filp, (struct flock64 __user *) arg);
375	break;
376	case F_SETLK64:
377	case F_SETLKW64:
378	err = fcntl_setlk64(filp, cmd, (struct flock64 __user *) arg);
379	break;
380	default:
381	err = do_fcntl(fd, cmd, arg, filp);
382	break;
383	}
384	fput(filp);
385	out:
386	return err;
387	}
388	#endif
389
390	/* Table to convert sigio signal codes into poll band bitmaps */
391
392	static long band_table[NSIGPOLL] = {
393	POLLIN \| POLLRDNORM, /* POLL_IN */
394	POLLOUT \| POLLWRNORM \| POLLWRBAND, /* POLL_OUT */
395	POLLIN \| POLLRDNORM \| POLLMSG, /* POLL_MSG */
396	POLLERR, /* POLL_ERR */
397	POLLPRI \| POLLRDBAND, /* POLL_PRI */
398	POLLHUP \| POLLERR /* POLL_HUP */
399	};
400
401	static inline int sigio_perm(struct task_struct *p,
402	struct fown_struct *fown, int sig)
403	{
404	return (((fown->euid == 0) \|\|
405	(fown->euid == p->suid) \|\| (fown->euid == p->uid) \|\|
406	(fown->uid == p->suid) \|\| (fown->uid == p->uid)) &&
407	!security_file_send_sigiotask(p, fown, sig));
408	}
409
410	static void send_sigio_to_task(struct task_struct *p,
411	struct fown_struct *fown,
412	int fd,
413	int reason)
414	{
415	if (!sigio_perm(p, fown, fown->signum))
416	return;
417
418	switch (fown->signum) {
419	siginfo_t si;
420	default:
421	/* Queue a rt signal with the appropriate fd as its
422	value. We use SI_SIGIO as the source, not
423	SI_KERNEL, since kernel signals always get
424	delivered even if we can't queue. Failure to
425	queue in this case _should_ be reported; we fall
426	back to SIGIO in that case. --sct */
427	si.si_signo = fown->signum;
428	si.si_errno = 0;
429	si.si_code = reason;
430	/* Make sure we are called with one of the POLL_*
431	reasons, otherwise we could leak kernel stack into
432	userspace. */
433	if ((reason & __SI_MASK) != __SI_POLL)
434	BUG();
435	if (reason - POLL_IN >= NSIGPOLL)
436	si.si_band = ~0L;
437	else
438	si.si_band = band_table[reason - POLL_IN];
439	si.si_fd = fd;
440	if (!send_sig_info(fown->signum, &si, p))
441	break;
442	/* fall-through: fall back on the old plain SIGIO signal */
443	case 0:
444	send_group_sig_info(SIGIO, SEND_SIG_PRIV, p);
445	}
446	}
447
448	void send_sigio(struct fown_struct *fown, int fd, int band)
449	{
450	struct task_struct *p;
451	int pid;
452
453	read_lock(&fown->lock);
454	pid = fown->pid;
455	if (!pid)
456	goto out_unlock_fown;
457
458	read_lock(&tasklist_lock);
459	if (pid > 0) {
460	p = find_task_by_pid(pid);
461	if (p) {
462	send_sigio_to_task(p, fown, fd, band);
463	}
464	} else {
465	do_each_task_pid(-pid, PIDTYPE_PGID, p) {
466	send_sigio_to_task(p, fown, fd, band);
467	} while_each_task_pid(-pid, PIDTYPE_PGID, p);
468	}
469	read_unlock(&tasklist_lock);
470	out_unlock_fown:
471	read_unlock(&fown->lock);
472	}
473
474	static void send_sigurg_to_task(struct task_struct *p,
475	struct fown_struct *fown)
476	{
477	if (sigio_perm(p, fown, SIGURG))
478	send_group_sig_info(SIGURG, SEND_SIG_PRIV, p);
479	}
480
481	int send_sigurg(struct fown_struct *fown)
482	{
483	struct task_struct *p;
484	int pid, ret = 0;
485
486	read_lock(&fown->lock);
487	pid = fown->pid;
488	if (!pid)
489	goto out_unlock_fown;
490
491	ret = 1;
492
493	read_lock(&tasklist_lock);
494	if (pid > 0) {
495	p = find_task_by_pid(pid);
496	if (p) {
497	send_sigurg_to_task(p, fown);
498	}
499	} else {
500	do_each_task_pid(-pid, PIDTYPE_PGID, p) {
501	send_sigurg_to_task(p, fown);
502	} while_each_task_pid(-pid, PIDTYPE_PGID, p);
503	}
504	read_unlock(&tasklist_lock);
505	out_unlock_fown:
506	read_unlock(&fown->lock);
507	return ret;
508	}
509
510	static DEFINE_RWLOCK(fasync_lock);
511	static kmem_cache_t *fasync_cache;
512
513	/*
514	* fasync_helper() is used by some character device drivers (mainly mice)
515	* to set up the fasync queue. It returns negative on error, 0 if it did
516	* no changes and positive if it added/deleted the entry.
517	*/
518	int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp)
519	{
520	struct fasync_struct fa, *fp;
521	struct fasync_struct *new = NULL;
522	int result = 0;
523
524	if (on) {
525	new = kmem_cache_alloc(fasync_cache, SLAB_KERNEL);
526	if (!new)
527	return -ENOMEM;
528	}
529	write_lock_irq(&fasync_lock);
530	for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
531	if (fa->fa_file == filp) {
532	if(on) {
533	fa->fa_fd = fd;
534	kmem_cache_free(fasync_cache, new);
535	} else {
536	*fp = fa->fa_next;
537	kmem_cache_free(fasync_cache, fa);
538	result = 1;
539	}
540	goto out;
541	}
542	}
543
544	if (on) {
545	new->magic = FASYNC_MAGIC;
546	new->fa_file = filp;
547	new->fa_fd = fd;
548	new->fa_next = *fapp;
549	*fapp = new;
550	result = 1;
551	}
552	out:
553	write_unlock_irq(&fasync_lock);
554	return result;
555	}
556
557	EXPORT_SYMBOL(fasync_helper);
558
559	void __kill_fasync(struct fasync_struct *fa, int sig, int band)
560	{
561	while (fa) {
562	struct fown_struct * fown;
563	if (fa->magic != FASYNC_MAGIC) {
564	printk(KERN_ERR "kill_fasync: bad magic number in "
565	"fasync_struct!\n");
566	return;
567	}
568	fown = &fa->fa_file->f_owner;
569	/* Don't send SIGURG to processes which have not set a
570	queued signum: SIGURG has its own default signalling
571	mechanism. */
572	if (!(sig == SIGURG && fown->signum == 0))
573	send_sigio(fown, fa->fa_fd, band);
574	fa = fa->fa_next;
575	}
576	}
577
578	EXPORT_SYMBOL(__kill_fasync);
579
580	void kill_fasync(struct fasync_struct **fp, int sig, int band)
581	{
582	/* First a quick test without locking: usually
583	* the list is empty.
584	*/
585	if (*fp) {
586	read_lock(&fasync_lock);
587	/* reread fp after obtaining the lock /
588	__kill_fasync(*fp, sig, band);
589	read_unlock(&fasync_lock);
590	}
591	}
592	EXPORT_SYMBOL(kill_fasync);
593
594	static int __init fasync_init(void)
595	{
596	fasync_cache = kmem_cache_create("fasync_cache",
597	sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL, NULL);
598	return 0;
599	}
600
601	module_init(fasync_init)