[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/capability.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 <linux/signal.h>
#include <linux/rcupdate.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;
	struct fdtable *fdt;
	spin_lock(&files->file_lock);
	fdt = files_fdtable(files);
	if (flag)
		FD_SET(fd, fdt->close_on_exec);
	else
		FD_CLR(fd, fdt->close_on_exec);
	spin_unlock(&files->file_lock);
}

static int get_close_on_exec(unsigned int fd)
{
	struct files_struct *files = current->files;
	struct fdtable *fdt;
	int res;
	rcu_read_lock();
	fdt = files_fdtable(files);
	res = FD_ISSET(fd, fdt->close_on_exec);
	rcu_read_unlock();
	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;
	struct fdtable *fdt;

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

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

	newfd = start;
	if (start < fdt->max_fds)
		newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
					   fdt->max_fds, 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;

	/*
	 * We reacquired files_lock, so we are safe as long as
	 * we reacquire the fdtable pointer and use it while holding
	 * the lock, no one can free it during that time.
	 */
	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;
	struct fdtable *fdt;
	int fd;

	spin_lock(&files->file_lock);
	fd = locate_fd(files, file, start);
	if (fd >= 0) {
		/* locate_fd() may have expanded fdtable, load the ptr */
		fdt = files_fdtable(files);
		FD_SET(fd, fdt->open_fds);
		FD_CLR(fd, fdt->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;
	struct fdtable *fdt;

	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;
	fdt = files_fdtable(files);
	tofree = fdt->fd[newfd];
	if (!tofree && FD_ISSET(newfd, fdt->open_fds))
		goto out_fput;

	rcu_assign_pointer(fdt->fd[newfd], file);
	FD_SET(newfd, fdt->open_fds);
	FD_CLR(newfd, fdt->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_path.dentry->d_inode;
	int error = 0;

	/*
	 * O_APPEND cannot be cleared if the file is marked as append-only
	 * and the file is open for write.
	 */
	if (((arg ^ filp->f_flags) & 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 (!is_owner_or_cap(inode))
			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, struct pid *pid, enum pid_type type,
                     uid_t uid, uid_t euid, int force)
{
	write_lock_irq(&filp->f_owner.lock);
	if (force || !filp->f_owner.pid) {
		put_pid(filp->f_owner.pid);
		filp->f_owner.pid = get_pid(pid);
		filp->f_owner.pid_type = type;
		filp->f_owner.uid = uid;
		filp->f_owner.euid = euid;
	}
	write_unlock_irq(&filp->f_owner.lock);
}

int __f_setown(struct file *filp, struct pid *pid, enum pid_type type,
		int force)
{
	int err;
	
	err = security_file_set_fowner(filp);
	if (err)
		return err;

	f_modown(filp, pid, type, current->uid, current->euid, force);
	return 0;
}
EXPORT_SYMBOL(__f_setown);

int f_setown(struct file *filp, unsigned long arg, int force)
{
	enum pid_type type;
	struct pid *pid;
	int who = arg;
	int result;
	type = PIDTYPE_PID;
	if (who < 0) {
		type = PIDTYPE_PGID;
		who = -who;
	}
	rcu_read_lock();
	pid = find_pid(who);
	result = __f_setown(filp, pid, type, force);
	rcu_read_unlock();
	return result;
}
EXPORT_SYMBOL(f_setown);

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

pid_t f_getown(struct file *filp)
{
	pid_t pid;
	read_lock(&filp->f_owner.lock);
	pid = pid_nr(filp->f_owner.pid);
	if (filp->f_owner.pid_type == PIDTYPE_PGID)
		pid = -pid;
	read_unlock(&filp->f_owner.lock);
	return pid;
}

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(fd, 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 = f_getown(filp);
		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 (!valid_signal(arg)) {
			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(fd, 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 const 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.  */
			BUG_ON((reason & __SI_MASK) != __SI_POLL);
			if (reason - POLL_IN >= NSIGPOLL)
				si.si_band  = ~0L;
			else
				si.si_band = band_table[reason - POLL_IN];
			si.si_fd    = fd;
			if (!group_send_sig_info(fown->signum, &si, p))
				break;
		/* fall-through: fall back on the old plain SIGIO signal */
		case 0:
			group_send_sig_info(SIGIO, SEND_SIG_PRIV, p);
	}
}

void send_sigio(struct fown_struct *fown, int fd, int band)
{
	struct task_struct *p;
	enum pid_type type;
	struct pid *pid;
	
	read_lock(&fown->lock);
	type = fown->pid_type;
	pid = fown->pid;
	if (!pid)
		goto out_unlock_fown;
	
	read_lock(&tasklist_lock);
	do_each_pid_task(pid, type, p) {
		send_sigio_to_task(p, fown, fd, band);
	} while_each_pid_task(pid, type, 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))
		group_send_sig_info(SIGURG, SEND_SIG_PRIV, p);
}

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

	ret = 1;
	
	read_lock(&tasklist_lock);
	do_each_pid_task(pid, type, p) {
		send_sigurg_to_task(p, fown);
	} while_each_pid_task(pid, type, p);
	read_unlock(&tasklist_lock);
 out_unlock_fown:
	read_unlock(&fown->lock);
	return ret;
}

static DEFINE_RWLOCK(fasync_lock);
static struct kmem_cache *fasync_cache __read_mostly;

/*
 * 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, GFP_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>
16f7e0fe	12	#include <linux/capability.h>
1da177e4 LT	13	#include <linux/dnotify.h>
	14	#include <linux/smp_lock.h>
	15	#include <linux/slab.h>
	16	#include <linux/module.h>
	17	#include <linux/security.h>
	18	#include <linux/ptrace.h>
7ed20e1a	19	#include <linux/signal.h>
ab2af1f5	20	#include <linux/rcupdate.h>
1da177e4 LT	21
	22	#include <asm/poll.h>
	23	#include <asm/siginfo.h>
	24	#include <asm/uaccess.h>
	25
	26	void fastcall set_close_on_exec(unsigned int fd, int flag)
	27	{
	28	struct files_struct *files = current->files;
badf1662	29	struct fdtable *fdt;
1da177e4	30	spin_lock(&files->file_lock);
badf1662	31	fdt = files_fdtable(files);
1da177e4	32	if (flag)
badf1662	33	FD_SET(fd, fdt->close_on_exec);
1da177e4	34	else
badf1662	35	FD_CLR(fd, fdt->close_on_exec);
1da177e4 LT	36	spin_unlock(&files->file_lock);
	37	}
	38
858119e1	39	static int get_close_on_exec(unsigned int fd)
1da177e4 LT	40	{
1da177e4 LT	41	struct files_struct *files = current->files;
badf1662	42	struct fdtable *fdt;
1da177e4	43	int res;
b835996f	44	rcu_read_lock();
badf1662 DS	45	fdt = files_fdtable(files);
badf1662 DS	46	res = FD_ISSET(fd, fdt->close_on_exec);
b835996f	47	rcu_read_unlock();
1da177e4 LT	48	return res;
	49	}
	50
	51	/*
	52	* locate_fd finds a free file descriptor in the open_fds fdset,
	53	* expanding the fd arrays if necessary. Must be called with the
	54	* file_lock held for write.
	55	*/
	56
	57	static int locate_fd(struct files_struct *files,
	58	struct file *file, unsigned int orig_start)
	59	{
	60	unsigned int newfd;
	61	unsigned int start;
	62	int error;
badf1662	63	struct fdtable *fdt;
1da177e4 LT	64
	65	error = -EINVAL;
	66	if (orig_start >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
	67	goto out;
	68
	69	repeat:
ab2af1f5	70	fdt = files_fdtable(files);
1da177e4 LT	71	/*
1da177e4 LT	72	* Someone might have closed fd's in the range
badf1662	73	* orig_start..fdt->next_fd
1da177e4 LT	74	*/
1da177e4 LT	75	start = orig_start;
0c9e63fd ED	76	if (start < files->next_fd)
0c9e63fd ED	77	start = files->next_fd;
1da177e4 LT	78
1da177e4 LT	79	newfd = start;
bbea9f69	80	if (start < fdt->max_fds)
badf1662	81	newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
bbea9f69	82	fdt->max_fds, start);
1da177e4 LT	83
	84	error = -EMFILE;
	85	if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
	86	goto out;
	87
	88	error = expand_files(files, newfd);
	89	if (error < 0)
	90	goto out;
	91
	92	/*
	93	* If we needed to expand the fs array we
	94	* might have blocked - try again.
	95	*/
	96	if (error)
	97	goto repeat;
	98
ab2af1f5 DS	99	/*
	100	* We reacquired files_lock, so we are safe as long as
	101	* we reacquire the fdtable pointer and use it while holding
	102	* the lock, no one can free it during that time.
	103	*/
0c9e63fd ED	104	if (start <= files->next_fd)
0c9e63fd ED	105	files->next_fd = newfd + 1;
ab2af1f5	106
1da177e4 LT	107	error = newfd;
	108
	109	out:
	110	return error;
	111	}
	112
	113	static int dupfd(struct file *file, unsigned int start)
	114	{
	115	struct files_struct * files = current->files;
badf1662	116	struct fdtable *fdt;
1da177e4 LT	117	int fd;
	118
	119	spin_lock(&files->file_lock);
	120	fd = locate_fd(files, file, start);
	121	if (fd >= 0) {
badf1662 DS	122	/* locate_fd() may have expanded fdtable, load the ptr */
	123	fdt = files_fdtable(files);
	124	FD_SET(fd, fdt->open_fds);
	125	FD_CLR(fd, fdt->close_on_exec);
1da177e4 LT	126	spin_unlock(&files->file_lock);
	127	fd_install(fd, file);
	128	} else {
	129	spin_unlock(&files->file_lock);
	130	fput(file);
	131	}
	132
	133	return fd;
	134	}
	135
	136	asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
	137	{
	138	int err = -EBADF;
	139	struct file * file, *tofree;
	140	struct files_struct * files = current->files;
badf1662	141	struct fdtable *fdt;
1da177e4 LT	142
	143	spin_lock(&files->file_lock);
	144	if (!(file = fcheck(oldfd)))
	145	goto out_unlock;
	146	err = newfd;
	147	if (newfd == oldfd)
	148	goto out_unlock;
	149	err = -EBADF;
	150	if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
	151	goto out_unlock;
	152	get_file(file); /* We are now finished with oldfd */
	153
	154	err = expand_files(files, newfd);
	155	if (err < 0)
	156	goto out_fput;
	157
	158	/* To avoid races with open() and dup(), we will mark the fd as
	159	* in-use in the open-file bitmap throughout the entire dup2()
	160	* process. This is quite safe: do_close() uses the fd array
	161	* entry, not the bitmap, to decide what work needs to be
	162	* done. --sct */
	163	/* Doesn't work. open() might be there first. --AV */
	164
	165	/* Yes. It's a race. In user space. Nothing sane to do */
	166	err = -EBUSY;
badf1662 DS	167	fdt = files_fdtable(files);
	168	tofree = fdt->fd[newfd];
	169	if (!tofree && FD_ISSET(newfd, fdt->open_fds))
1da177e4 LT	170	goto out_fput;
1da177e4 LT	171
ab2af1f5	172	rcu_assign_pointer(fdt->fd[newfd], file);
badf1662 DS	173	FD_SET(newfd, fdt->open_fds);
badf1662 DS	174	FD_CLR(newfd, fdt->close_on_exec);
1da177e4 LT	175	spin_unlock(&files->file_lock);
	176
	177	if (tofree)
	178	filp_close(tofree, files);
	179	err = newfd;
	180	out:
	181	return err;
	182	out_unlock:
	183	spin_unlock(&files->file_lock);
	184	goto out;
	185
	186	out_fput:
	187	spin_unlock(&files->file_lock);
	188	fput(file);
	189	goto out;
	190	}
	191
	192	asmlinkage long sys_dup(unsigned int fildes)
	193	{
	194	int ret = -EBADF;
	195	struct file * file = fget(fildes);
	196
	197	if (file)
	198	ret = dupfd(file, 0);
	199	return ret;
	200	}
	201
	202	#define SETFL_MASK (O_APPEND \| O_NONBLOCK \| O_NDELAY \| FASYNC \| O_DIRECT \| O_NOATIME)
	203
	204	static int setfl(int fd, struct file * filp, unsigned long arg)
	205	{
0f7fc9e4	206	struct inode * inode = filp->f_path.dentry->d_inode;
1da177e4 LT	207	int error = 0;
1da177e4 LT	208
7d95c8f2	209	/*
	210	* O_APPEND cannot be cleared if the file is marked as append-only
	211	* and the file is open for write.
	212	*/
	213	if (((arg ^ filp->f_flags) & O_APPEND) && IS_APPEND(inode))
1da177e4 LT	214	return -EPERM;
	215
	216	/* O_NOATIME can only be set by the owner or superuser */
	217	if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))
3bd858ab	218	if (!is_owner_or_cap(inode))
1da177e4 LT	219	return -EPERM;
	220
	221	/* required for strict SunOS emulation */
	222	if (O_NONBLOCK != O_NDELAY)
	223	if (arg & O_NDELAY)
	224	arg \|= O_NONBLOCK;
	225
	226	if (arg & O_DIRECT) {
	227	if (!filp->f_mapping \|\| !filp->f_mapping->a_ops \|\|
	228	!filp->f_mapping->a_ops->direct_IO)
	229	return -EINVAL;
	230	}
	231
	232	if (filp->f_op && filp->f_op->check_flags)
	233	error = filp->f_op->check_flags(arg);
	234	if (error)
	235	return error;
	236
	237	lock_kernel();
	238	if ((arg ^ filp->f_flags) & FASYNC) {
	239	if (filp->f_op && filp->f_op->fasync) {
	240	error = filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
	241	if (error < 0)
	242	goto out;
	243	}
	244	}
	245
	246	filp->f_flags = (arg & SETFL_MASK) \| (filp->f_flags & ~SETFL_MASK);
	247	out:
	248	unlock_kernel();
	249	return error;
	250	}
	251
609d7fa9	252	static void f_modown(struct file filp, struct pid pid, enum pid_type type,
1da177e4 LT	253	uid_t uid, uid_t euid, int force)
	254	{
	255	write_lock_irq(&filp->f_owner.lock);
	256	if (force \|\| !filp->f_owner.pid) {
609d7fa9 EB	257	put_pid(filp->f_owner.pid);
	258	filp->f_owner.pid = get_pid(pid);
	259	filp->f_owner.pid_type = type;
1da177e4 LT	260	filp->f_owner.uid = uid;
	261	filp->f_owner.euid = euid;
	262	}
	263	write_unlock_irq(&filp->f_owner.lock);
	264	}
	265
609d7fa9 EB	266	int __f_setown(struct file filp, struct pid pid, enum pid_type type,
609d7fa9 EB	267	int force)
1da177e4 LT	268	{
	269	int err;
	270
	271	err = security_file_set_fowner(filp);
	272	if (err)
	273	return err;
	274
609d7fa9	275	f_modown(filp, pid, type, current->uid, current->euid, force);
1da177e4 LT	276	return 0;
1da177e4 LT	277	}
609d7fa9	278	EXPORT_SYMBOL(__f_setown);
1da177e4	279
609d7fa9 EB	280	int f_setown(struct file *filp, unsigned long arg, int force)
	281	{
	282	enum pid_type type;
	283	struct pid *pid;
	284	int who = arg;
	285	int result;
	286	type = PIDTYPE_PID;
	287	if (who < 0) {
	288	type = PIDTYPE_PGID;
	289	who = -who;
	290	}
	291	rcu_read_lock();
	292	pid = find_pid(who);
	293	result = __f_setown(filp, pid, type, force);
	294	rcu_read_unlock();
	295	return result;
	296	}
1da177e4 LT	297	EXPORT_SYMBOL(f_setown);
	298
	299	void f_delown(struct file *filp)
	300	{
609d7fa9 EB	301	f_modown(filp, NULL, PIDTYPE_PID, 0, 0, 1);
	302	}
	303
	304	pid_t f_getown(struct file *filp)
	305	{
	306	pid_t pid;
43fa1adb	307	read_lock(&filp->f_owner.lock);
609d7fa9 EB	308	pid = pid_nr(filp->f_owner.pid);
	309	if (filp->f_owner.pid_type == PIDTYPE_PGID)
	310	pid = -pid;
43fa1adb	311	read_unlock(&filp->f_owner.lock);
609d7fa9	312	return pid;
1da177e4 LT	313	}
	314
	315	static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
	316	struct file *filp)
	317	{
	318	long err = -EINVAL;
	319
	320	switch (cmd) {
	321	case F_DUPFD:
	322	get_file(filp);
	323	err = dupfd(filp, arg);
	324	break;
	325	case F_GETFD:
	326	err = get_close_on_exec(fd) ? FD_CLOEXEC : 0;
	327	break;
	328	case F_SETFD:
	329	err = 0;
	330	set_close_on_exec(fd, arg & FD_CLOEXEC);
	331	break;
	332	case F_GETFL:
	333	err = filp->f_flags;
	334	break;
	335	case F_SETFL:
	336	err = setfl(fd, filp, arg);
	337	break;
	338	case F_GETLK:
	339	err = fcntl_getlk(filp, (struct flock __user *) arg);
	340	break;
	341	case F_SETLK:
	342	case F_SETLKW:
c293621b	343	err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg);
1da177e4 LT	344	break;
	345	case F_GETOWN:
	346	/*
	347	* XXX If f_owner is a process group, the
	348	* negative return value will get converted
	349	* into an error. Oops. If we keep the
	350	* current syscall conventions, the only way
	351	* to fix this will be in libc.
	352	*/
609d7fa9	353	err = f_getown(filp);
1da177e4 LT	354	force_successful_syscall_return();
	355	break;
	356	case F_SETOWN:
	357	err = f_setown(filp, arg, 1);
	358	break;
	359	case F_GETSIG:
	360	err = filp->f_owner.signum;
	361	break;
	362	case F_SETSIG:
	363	/* arg == 0 restores default behaviour. */
7ed20e1a	364	if (!valid_signal(arg)) {
1da177e4 LT	365	break;
	366	}
	367	err = 0;
	368	filp->f_owner.signum = arg;
	369	break;
	370	case F_GETLEASE:
	371	err = fcntl_getlease(filp);
	372	break;
	373	case F_SETLEASE:
	374	err = fcntl_setlease(fd, filp, arg);
	375	break;
	376	case F_NOTIFY:
	377	err = fcntl_dirnotify(fd, filp, arg);
	378	break;
	379	default:
	380	break;
	381	}
	382	return err;
	383	}
	384
	385	asmlinkage long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)
	386	{
	387	struct file *filp;
	388	long err = -EBADF;
	389
	390	filp = fget(fd);
	391	if (!filp)
	392	goto out;
	393
	394	err = security_file_fcntl(filp, cmd, arg);
	395	if (err) {
	396	fput(filp);
	397	return err;
	398	}
	399
	400	err = do_fcntl(fd, cmd, arg, filp);
	401
	402	fput(filp);
	403	out:
	404	return err;
	405	}
	406
	407	#if BITS_PER_LONG == 32
	408	asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
	409	{
	410	struct file * filp;
	411	long err;
	412
	413	err = -EBADF;
	414	filp = fget(fd);
	415	if (!filp)
	416	goto out;
	417
	418	err = security_file_fcntl(filp, cmd, arg);
	419	if (err) {
	420	fput(filp);
	421	return err;
	422	}
	423	err = -EBADF;
	424
	425	switch (cmd) {
	426	case F_GETLK64:
	427	err = fcntl_getlk64(filp, (struct flock64 __user *) arg);
	428	break;
429	case F_SETLK64:
430	case F_SETLKW64:
c293621b PS	431	err = fcntl_setlk64(fd, filp, cmd,
c293621b PS	432	(struct flock64 __user *) arg);
1da177e4 LT	433	break;
	434	default:
	435	err = do_fcntl(fd, cmd, arg, filp);
	436	break;
	437	}
	438	fput(filp);
	439	out:
	440	return err;
	441	}
	442	#endif
	443
	444	/* Table to convert sigio signal codes into poll band bitmaps */
	445
fa3536cc	446	static const long band_table[NSIGPOLL] = {
1da177e4 LT	447	POLLIN \| POLLRDNORM, /* POLL_IN */
	448	POLLOUT \| POLLWRNORM \| POLLWRBAND, /* POLL_OUT */
	449	POLLIN \| POLLRDNORM \| POLLMSG, /* POLL_MSG */
	450	POLLERR, /* POLL_ERR */
	451	POLLPRI \| POLLRDBAND, /* POLL_PRI */
	452	POLLHUP \| POLLERR /* POLL_HUP */
	453	};
	454
	455	static inline int sigio_perm(struct task_struct *p,
	456	struct fown_struct *fown, int sig)
	457	{
	458	return (((fown->euid == 0) \|\|
	459	(fown->euid == p->suid) \|\| (fown->euid == p->uid) \|\|
	460	(fown->uid == p->suid) \|\| (fown->uid == p->uid)) &&
	461	!security_file_send_sigiotask(p, fown, sig));
	462	}
	463
	464	static void send_sigio_to_task(struct task_struct *p,
	465	struct fown_struct *fown,
	466	int fd,
	467	int reason)
	468	{
	469	if (!sigio_perm(p, fown, fown->signum))
	470	return;
	471
	472	switch (fown->signum) {
	473	siginfo_t si;
	474	default:
	475	/* Queue a rt signal with the appropriate fd as its
	476	value. We use SI_SIGIO as the source, not
	477	SI_KERNEL, since kernel signals always get
	478	delivered even if we can't queue. Failure to
	479	queue in this case _should_ be reported; we fall
	480	back to SIGIO in that case. --sct */
	481	si.si_signo = fown->signum;
	482	si.si_errno = 0;
	483	si.si_code = reason;
	484	/* Make sure we are called with one of the POLL_*
	485	reasons, otherwise we could leak kernel stack into
	486	userspace. */
f6298aab	487	BUG_ON((reason & __SI_MASK) != __SI_POLL);
1da177e4 LT	488	if (reason - POLL_IN >= NSIGPOLL)
	489	si.si_band = ~0L;
	490	else
	491	si.si_band = band_table[reason - POLL_IN];
	492	si.si_fd = fd;
850d6fbe	493	if (!group_send_sig_info(fown->signum, &si, p))
1da177e4 LT	494	break;
	495	/* fall-through: fall back on the old plain SIGIO signal */
	496	case 0:
850d6fbe	497	group_send_sig_info(SIGIO, SEND_SIG_PRIV, p);
1da177e4 LT	498	}
	499	}
	500
	501	void send_sigio(struct fown_struct *fown, int fd, int band)
	502	{
	503	struct task_struct *p;
609d7fa9 EB	504	enum pid_type type;
609d7fa9 EB	505	struct pid *pid;
1da177e4 LT	506
1da177e4 LT	507	read_lock(&fown->lock);
609d7fa9	508	type = fown->pid_type;
1da177e4 LT	509	pid = fown->pid;
	510	if (!pid)
	511	goto out_unlock_fown;
	512
	513	read_lock(&tasklist_lock);
609d7fa9 EB	514	do_each_pid_task(pid, type, p) {
	515	send_sigio_to_task(p, fown, fd, band);
	516	} while_each_pid_task(pid, type, p);
1da177e4 LT	517	read_unlock(&tasklist_lock);
	518	out_unlock_fown:
	519	read_unlock(&fown->lock);
	520	}
	521
	522	static void send_sigurg_to_task(struct task_struct *p,
	523	struct fown_struct *fown)
	524	{
	525	if (sigio_perm(p, fown, SIGURG))
850d6fbe	526	group_send_sig_info(SIGURG, SEND_SIG_PRIV, p);
1da177e4 LT	527	}
	528
	529	int send_sigurg(struct fown_struct *fown)
	530	{
	531	struct task_struct *p;
609d7fa9 EB	532	enum pid_type type;
	533	struct pid *pid;
	534	int ret = 0;
1da177e4 LT	535
1da177e4 LT	536	read_lock(&fown->lock);
609d7fa9	537	type = fown->pid_type;
1da177e4 LT	538	pid = fown->pid;
	539	if (!pid)
	540	goto out_unlock_fown;
	541
	542	ret = 1;
	543
	544	read_lock(&tasklist_lock);
609d7fa9 EB	545	do_each_pid_task(pid, type, p) {
	546	send_sigurg_to_task(p, fown);
	547	} while_each_pid_task(pid, type, p);
1da177e4 LT	548	read_unlock(&tasklist_lock);
	549	out_unlock_fown:
	550	read_unlock(&fown->lock);
	551	return ret;
	552	}
	553
	554	static DEFINE_RWLOCK(fasync_lock);
e18b890b	555	static struct kmem_cache *fasync_cache __read_mostly;
1da177e4 LT	556
	557	/*
	558	* fasync_helper() is used by some character device drivers (mainly mice)
	559	* to set up the fasync queue. It returns negative on error, 0 if it did
	560	* no changes and positive if it added/deleted the entry.
	561	*/
	562	int fasync_helper(int fd, struct file * filp, int on, struct fasync_struct **fapp)
	563	{
	564	struct fasync_struct fa, *fp;
	565	struct fasync_struct *new = NULL;
	566	int result = 0;
	567
	568	if (on) {
e94b1766	569	new = kmem_cache_alloc(fasync_cache, GFP_KERNEL);
1da177e4 LT	570	if (!new)
	571	return -ENOMEM;
	572	}
	573	write_lock_irq(&fasync_lock);
	574	for (fp = fapp; (fa = *fp) != NULL; fp = &fa->fa_next) {
	575	if (fa->fa_file == filp) {
	576	if(on) {
	577	fa->fa_fd = fd;
	578	kmem_cache_free(fasync_cache, new);
	579	} else {
	580	*fp = fa->fa_next;
	581	kmem_cache_free(fasync_cache, fa);
	582	result = 1;
	583	}
	584	goto out;
	585	}
	586	}
	587
	588	if (on) {
	589	new->magic = FASYNC_MAGIC;
	590	new->fa_file = filp;
	591	new->fa_fd = fd;
	592	new->fa_next = *fapp;
	593	*fapp = new;
	594	result = 1;
	595	}
	596	out:
	597	write_unlock_irq(&fasync_lock);
	598	return result;
	599	}
	600
	601	EXPORT_SYMBOL(fasync_helper);
	602
	603	void __kill_fasync(struct fasync_struct *fa, int sig, int band)
	604	{
	605	while (fa) {
	606	struct fown_struct * fown;
	607	if (fa->magic != FASYNC_MAGIC) {
	608	printk(KERN_ERR "kill_fasync: bad magic number in "
	609	"fasync_struct!\n");
	610	return;
	611	}
	612	fown = &fa->fa_file->f_owner;
	613	/* Don't send SIGURG to processes which have not set a
	614	queued signum: SIGURG has its own default signalling
	615	mechanism. */
	616	if (!(sig == SIGURG && fown->signum == 0))
	617	send_sigio(fown, fa->fa_fd, band);
	618	fa = fa->fa_next;
	619	}
	620	}
	621
	622	EXPORT_SYMBOL(__kill_fasync);
	623
	624	void kill_fasync(struct fasync_struct **fp, int sig, int band)
	625	{
	626	/* First a quick test without locking: usually
	627	* the list is empty.
	628	*/
	629	if (*fp) {
	630	read_lock(&fasync_lock);
	631	/* reread fp after obtaining the lock /
	632	__kill_fasync(*fp, sig, band);
	633	read_unlock(&fasync_lock);
634	}
635	}
636	EXPORT_SYMBOL(kill_fasync);
637
638	static int __init fasync_init(void)
639	{
640	fasync_cache = kmem_cache_create("fasync_cache",
641	sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL, NULL);
642	return 0;
643	}
644
645	module_init(fasync_init)