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author | David S. Miller <davem@davemloft.net> | 2009-12-12 01:12:17 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2009-12-12 01:12:17 (GMT) |
commit | 501706565b2d4d2d40d0d301d5411ede099b8a6f (patch) | |
tree | 142a18bf1f1e74a09dbfa27540b893ade0fd797d /drivers/char/tty_io.c | |
parent | e93737b0f0159a61772894943199fd3b6f315641 (diff) | |
parent | 2fe77b81c77eed92c4c0439f74c8148a295b4a86 (diff) | |
download | linux-501706565b2d4d2d40d0d301d5411ede099b8a6f.tar.xz |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
include/net/tcp.h
Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r-- | drivers/char/tty_io.c | 151 |
1 files changed, 86 insertions, 65 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 59499ee..684f0e0 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -142,7 +142,6 @@ ssize_t redirected_tty_write(struct file *, const char __user *, size_t, loff_t *); static unsigned int tty_poll(struct file *, poll_table *); static int tty_open(struct inode *, struct file *); -static int tty_release(struct inode *, struct file *); long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); #ifdef CONFIG_COMPAT static long tty_compat_ioctl(struct file *file, unsigned int cmd, @@ -506,8 +505,6 @@ static void do_tty_hangup(struct work_struct *work) if (!tty) return; - /* inuse_filps is protected by the single kernel lock */ - lock_kernel(); spin_lock(&redirect_lock); if (redirect && redirect->private_data == tty) { @@ -516,7 +513,11 @@ static void do_tty_hangup(struct work_struct *work) } spin_unlock(&redirect_lock); + /* inuse_filps is protected by the single kernel lock */ + lock_kernel(); check_tty_count(tty, "do_tty_hangup"); + unlock_kernel(); + file_list_lock(); /* This breaks for file handles being sent over AF_UNIX sockets ? */ list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) { @@ -530,6 +531,7 @@ static void do_tty_hangup(struct work_struct *work) } file_list_unlock(); + lock_kernel(); tty_ldisc_hangup(tty); read_lock(&tasklist_lock); @@ -708,6 +710,8 @@ void disassociate_ctty(int on_exit) struct tty_struct *tty; struct pid *tty_pgrp = NULL; + if (!current->signal->leader) + return; tty = get_current_tty(); if (tty) { @@ -773,8 +777,7 @@ void no_tty(void) { struct task_struct *tsk = current; lock_kernel(); - if (tsk->signal->leader) - disassociate_ctty(0); + disassociate_ctty(0); unlock_kernel(); proc_clear_tty(tsk); } @@ -1017,14 +1020,16 @@ out: void tty_write_message(struct tty_struct *tty, char *msg) { - lock_kernel(); if (tty) { mutex_lock(&tty->atomic_write_lock); - if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) + lock_kernel(); + if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { + unlock_kernel(); tty->ops->write(tty, msg, strlen(msg)); + } else + unlock_kernel(); tty_write_unlock(tty); } - unlock_kernel(); return; } @@ -1202,14 +1207,21 @@ static int tty_driver_install_tty(struct tty_driver *driver, struct tty_struct *tty) { int idx = tty->index; + int ret; - if (driver->ops->install) - return driver->ops->install(driver, tty); + if (driver->ops->install) { + lock_kernel(); + ret = driver->ops->install(driver, tty); + unlock_kernel(); + return ret; + } if (tty_init_termios(tty) == 0) { + lock_kernel(); tty_driver_kref_get(driver); tty->count++; driver->ttys[idx] = tty; + unlock_kernel(); return 0; } return -ENOMEM; @@ -1302,10 +1314,14 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, struct tty_struct *tty; int retval; + lock_kernel(); /* Check if pty master is being opened multiple times */ if (driver->subtype == PTY_TYPE_MASTER && - (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) + (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { + unlock_kernel(); return ERR_PTR(-EIO); + } + unlock_kernel(); /* * First time open is complex, especially for PTY devices. @@ -1335,7 +1351,6 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, * If we fail here just call release_tty to clean up. No need * to decrement the use counts, as release_tty doesn't care. */ - retval = tty_ldisc_setup(tty, tty->link); if (retval) goto release_mem_out; @@ -1350,7 +1365,9 @@ release_mem_out: if (printk_ratelimit()) printk(KERN_INFO "tty_init_dev: ldisc open failed, " "clearing slot %d\n", idx); + lock_kernel(); release_tty(tty, idx); + unlock_kernel(); return ERR_PTR(retval); } @@ -1464,7 +1481,17 @@ static void release_tty(struct tty_struct *tty, int idx) tty_kref_put(tty); } -/* +/** + * tty_release - vfs callback for close + * @inode: inode of tty + * @filp: file pointer for handle to tty + * + * Called the last time each file handle is closed that references + * this tty. There may however be several such references. + * + * Locking: + * Takes bkl. See tty_release_dev + * * Even releasing the tty structures is a tricky business.. We have * to be very careful that the structures are all released at the * same time, as interrupts might otherwise get the wrong pointers. @@ -1472,20 +1499,20 @@ static void release_tty(struct tty_struct *tty, int idx) * WSH 09/09/97: rewritten to avoid some nasty race conditions that could * lead to double frees or releasing memory still in use. */ -void tty_release_dev(struct file *filp) + +int tty_release(struct inode *inode, struct file *filp) { struct tty_struct *tty, *o_tty; int pty_master, tty_closing, o_tty_closing, do_sleep; int devpts; int idx; char buf[64]; - struct inode *inode; - inode = filp->f_path.dentry->d_inode; tty = (struct tty_struct *)filp->private_data; if (tty_paranoia_check(tty, inode, "tty_release_dev")) - return; + return 0; + lock_kernel(); check_tty_count(tty, "tty_release_dev"); tty_fasync(-1, filp, 0); @@ -1500,19 +1527,22 @@ void tty_release_dev(struct file *filp) if (idx < 0 || idx >= tty->driver->num) { printk(KERN_DEBUG "tty_release_dev: bad idx when trying to " "free (%s)\n", tty->name); - return; + unlock_kernel(); + return 0; } if (!devpts) { if (tty != tty->driver->ttys[idx]) { + unlock_kernel(); printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty " "for (%s)\n", idx, tty->name); - return; + return 0; } if (tty->termios != tty->driver->termios[idx]) { + unlock_kernel(); printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios " "for (%s)\n", idx, tty->name); - return; + return 0; } } #endif @@ -1526,26 +1556,30 @@ void tty_release_dev(struct file *filp) if (tty->driver->other && !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { if (o_tty != tty->driver->other->ttys[idx]) { + unlock_kernel(); printk(KERN_DEBUG "tty_release_dev: other->table[%d] " "not o_tty for (%s)\n", idx, tty->name); - return; + return 0 ; } if (o_tty->termios != tty->driver->other->termios[idx]) { + unlock_kernel(); printk(KERN_DEBUG "tty_release_dev: other->termios[%d] " "not o_termios for (%s)\n", idx, tty->name); - return; + return 0; } if (o_tty->link != tty) { + unlock_kernel(); printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n"); - return; + return 0; } } #endif if (tty->ops->close) tty->ops->close(tty, filp); + unlock_kernel(); /* * Sanity check: if tty->count is going to zero, there shouldn't be * any waiters on tty->read_wait or tty->write_wait. We test the @@ -1568,6 +1602,7 @@ void tty_release_dev(struct file *filp) opens on /dev/tty */ mutex_lock(&tty_mutex); + lock_kernel(); tty_closing = tty->count <= 1; o_tty_closing = o_tty && (o_tty->count <= (pty_master ? 1 : 0)); @@ -1598,6 +1633,7 @@ void tty_release_dev(struct file *filp) printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue " "active!\n", tty_name(tty, buf)); + unlock_kernel(); mutex_unlock(&tty_mutex); schedule(); } @@ -1661,8 +1697,10 @@ void tty_release_dev(struct file *filp) mutex_unlock(&tty_mutex); /* check whether both sides are closing ... */ - if (!tty_closing || (o_tty && !o_tty_closing)) - return; + if (!tty_closing || (o_tty && !o_tty_closing)) { + unlock_kernel(); + return 0; + } #ifdef TTY_DEBUG_HANGUP printk(KERN_DEBUG "freeing tty structure..."); @@ -1680,10 +1718,12 @@ void tty_release_dev(struct file *filp) /* Make this pty number available for reallocation */ if (devpts) devpts_kill_index(inode, idx); + unlock_kernel(); + return 0; } /** - * __tty_open - open a tty device + * tty_open - open a tty device * @inode: inode of device file * @filp: file pointer to tty * @@ -1703,7 +1743,7 @@ void tty_release_dev(struct file *filp) * ->siglock protects ->signal/->sighand */ -static int __tty_open(struct inode *inode, struct file *filp) +static int tty_open(struct inode *inode, struct file *filp) { struct tty_struct *tty = NULL; int noctty, retval; @@ -1720,10 +1760,12 @@ retry_open: retval = 0; mutex_lock(&tty_mutex); + lock_kernel(); if (device == MKDEV(TTYAUX_MAJOR, 0)) { tty = get_current_tty(); if (!tty) { + unlock_kernel(); mutex_unlock(&tty_mutex); return -ENXIO; } @@ -1755,12 +1797,14 @@ retry_open: goto got_driver; } } + unlock_kernel(); mutex_unlock(&tty_mutex); return -ENODEV; } driver = get_tty_driver(device, &index); if (!driver) { + unlock_kernel(); mutex_unlock(&tty_mutex); return -ENODEV; } @@ -1770,6 +1814,7 @@ got_driver: tty = tty_driver_lookup_tty(driver, inode, index); if (IS_ERR(tty)) { + unlock_kernel(); mutex_unlock(&tty_mutex); return PTR_ERR(tty); } @@ -1784,8 +1829,10 @@ got_driver: mutex_unlock(&tty_mutex); tty_driver_kref_put(driver); - if (IS_ERR(tty)) + if (IS_ERR(tty)) { + unlock_kernel(); return PTR_ERR(tty); + } filp->private_data = tty; file_move(filp, &tty->tty_files); @@ -1813,11 +1860,15 @@ got_driver: printk(KERN_DEBUG "error %d in opening %s...", retval, tty->name); #endif - tty_release_dev(filp); - if (retval != -ERESTARTSYS) + tty_release(inode, filp); + if (retval != -ERESTARTSYS) { + unlock_kernel(); return retval; - if (signal_pending(current)) + } + if (signal_pending(current)) { + unlock_kernel(); return retval; + } schedule(); /* * Need to reset f_op in case a hangup happened. @@ -1826,8 +1877,11 @@ got_driver: filp->f_op = &tty_fops; goto retry_open; } + unlock_kernel(); + mutex_lock(&tty_mutex); + lock_kernel(); spin_lock_irq(¤t->sighand->siglock); if (!noctty && current->signal->leader && @@ -1835,43 +1889,12 @@ got_driver: tty->session == NULL) __proc_set_tty(current, tty); spin_unlock_irq(¤t->sighand->siglock); + unlock_kernel(); mutex_unlock(&tty_mutex); return 0; } -/* BKL pushdown: scary code avoidance wrapper */ -static int tty_open(struct inode *inode, struct file *filp) -{ - int ret; - - lock_kernel(); - ret = __tty_open(inode, filp); - unlock_kernel(); - return ret; -} - - - - -/** - * tty_release - vfs callback for close - * @inode: inode of tty - * @filp: file pointer for handle to tty - * - * Called the last time each file handle is closed that references - * this tty. There may however be several such references. - * - * Locking: - * Takes bkl. See tty_release_dev - */ -static int tty_release(struct inode *inode, struct file *filp) -{ - lock_kernel(); - tty_release_dev(filp); - unlock_kernel(); - return 0; -} /** * tty_poll - check tty status @@ -2317,9 +2340,7 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) if (get_user(ldisc, p)) return -EFAULT; - lock_kernel(); ret = tty_set_ldisc(tty, ldisc); - unlock_kernel(); return ret; } |