diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/tty/amiserial.c | 14 | ||||
-rw-r--r-- | drivers/tty/cyclades.c | 2 | ||||
-rw-r--r-- | drivers/tty/n_r3964.c | 10 | ||||
-rw-r--r-- | drivers/tty/pty.c | 25 | ||||
-rw-r--r-- | drivers/tty/serial/crisv10.c | 8 | ||||
-rw-r--r-- | drivers/tty/synclink.c | 4 | ||||
-rw-r--r-- | drivers/tty/synclink_gt.c | 4 | ||||
-rw-r--r-- | drivers/tty/synclinkmp.c | 4 | ||||
-rw-r--r-- | drivers/tty/tty_io.c | 66 | ||||
-rw-r--r-- | drivers/tty/tty_ldisc.c | 69 | ||||
-rw-r--r-- | drivers/tty/tty_mutex.c | 71 | ||||
-rw-r--r-- | drivers/tty/tty_port.c | 6 |
12 files changed, 174 insertions, 109 deletions
diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c index 0e8441e..998731f 100644 --- a/drivers/tty/amiserial.c +++ b/drivers/tty/amiserial.c @@ -1033,7 +1033,7 @@ static int get_serial_info(struct tty_struct *tty, struct serial_state *state, if (!retinfo) return -EFAULT; memset(&tmp, 0, sizeof(tmp)); - tty_lock(); + tty_lock(tty); tmp.line = tty->index; tmp.port = state->port; tmp.flags = state->tport.flags; @@ -1042,7 +1042,7 @@ static int get_serial_info(struct tty_struct *tty, struct serial_state *state, tmp.close_delay = state->tport.close_delay; tmp.closing_wait = state->tport.closing_wait; tmp.custom_divisor = state->custom_divisor; - tty_unlock(); + tty_unlock(tty); if (copy_to_user(retinfo,&tmp,sizeof(*retinfo))) return -EFAULT; return 0; @@ -1059,12 +1059,12 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state, if (copy_from_user(&new_serial,new_info,sizeof(new_serial))) return -EFAULT; - tty_lock(); + tty_lock(tty); change_spd = ((new_serial.flags ^ port->flags) & ASYNC_SPD_MASK) || new_serial.custom_divisor != state->custom_divisor; if (new_serial.irq || new_serial.port != state->port || new_serial.xmit_fifo_size != state->xmit_fifo_size) { - tty_unlock(); + tty_unlock(tty); return -EINVAL; } @@ -1074,7 +1074,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state, (new_serial.xmit_fifo_size != state->xmit_fifo_size) || ((new_serial.flags & ~ASYNC_USR_MASK) != (port->flags & ~ASYNC_USR_MASK))) { - tty_unlock(); + tty_unlock(tty); return -EPERM; } port->flags = ((port->flags & ~ASYNC_USR_MASK) | @@ -1084,7 +1084,7 @@ static int set_serial_info(struct tty_struct *tty, struct serial_state *state, } if (new_serial.baud_base < 9600) { - tty_unlock(); + tty_unlock(tty); return -EINVAL; } @@ -1116,7 +1116,7 @@ check_and_exit: } } else retval = startup(tty, state); - tty_unlock(); + tty_unlock(tty); return retval; } diff --git a/drivers/tty/cyclades.c b/drivers/tty/cyclades.c index e77db71..c8850ea 100644 --- a/drivers/tty/cyclades.c +++ b/drivers/tty/cyclades.c @@ -1599,7 +1599,7 @@ static int cy_open(struct tty_struct *tty, struct file *filp) * If the port is the middle of closing, bail out now */ if (tty_hung_up_p(filp) || (info->port.flags & ASYNC_CLOSING)) { - wait_event_interruptible_tty(info->port.close_wait, + wait_event_interruptible_tty(tty, info->port.close_wait, !(info->port.flags & ASYNC_CLOSING)); return (info->port.flags & ASYNC_HUP_NOTIFY) ? -EAGAIN: -ERESTARTSYS; } diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c index 5c6c314..1e64050 100644 --- a/drivers/tty/n_r3964.c +++ b/drivers/tty/n_r3964.c @@ -1065,7 +1065,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, TRACE_L("read()"); - tty_lock(); + tty_lock(tty); pClient = findClient(pInfo, task_pid(current)); if (pClient) { @@ -1077,7 +1077,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, goto unlock; } /* block until there is a message: */ - wait_event_interruptible_tty(pInfo->read_wait, + wait_event_interruptible_tty(tty, pInfo->read_wait, (pMsg = remove_msg(pInfo, pClient))); } @@ -1107,7 +1107,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, } ret = -EPERM; unlock: - tty_unlock(); + tty_unlock(tty); return ret; } @@ -1156,7 +1156,7 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file, pHeader->locks = 0; pHeader->owner = NULL; - tty_lock(); + tty_lock(tty); pClient = findClient(pInfo, task_pid(current)); if (pClient) { @@ -1175,7 +1175,7 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file, add_tx_queue(pInfo, pHeader); trigger_transmit(pInfo); - tty_unlock(); + tty_unlock(tty); return 0; } diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index d6579a9..4399f1d 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -47,6 +47,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp) wake_up_interruptible(&tty->read_wait); wake_up_interruptible(&tty->write_wait); tty->packet = 0; + /* Review - krefs on tty_link ?? */ if (!tty->link) return; tty->link->packet = 0; @@ -62,9 +63,9 @@ static void pty_close(struct tty_struct *tty, struct file *filp) mutex_unlock(&devpts_mutex); } #endif - tty_unlock(); + tty_unlock(tty); tty_vhangup(tty->link); - tty_lock(); + tty_lock(tty); } } @@ -617,26 +618,27 @@ static int ptmx_open(struct inode *inode, struct file *filp) return retval; /* find a device that is not in use. */ - tty_lock(); + mutex_lock(&devpts_mutex); index = devpts_new_index(inode); - tty_unlock(); if (index < 0) { retval = index; goto err_file; } + mutex_unlock(&devpts_mutex); + mutex_lock(&tty_mutex); - mutex_lock(&devpts_mutex); tty = tty_init_dev(ptm_driver, index); - mutex_unlock(&devpts_mutex); - tty_lock(); - mutex_unlock(&tty_mutex); if (IS_ERR(tty)) { retval = PTR_ERR(tty); goto out; } + /* The tty returned here is locked so we can safely + drop the mutex */ + mutex_unlock(&tty_mutex); + set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ tty_add_file(tty, filp); @@ -649,16 +651,17 @@ static int ptmx_open(struct inode *inode, struct file *filp) if (retval) goto err_release; - tty_unlock(); + tty_unlock(tty); return 0; err_release: - tty_unlock(); + tty_unlock(tty); tty_release(inode, filp); return retval; out: + mutex_unlock(&tty_mutex); devpts_kill_index(inode, index); - tty_unlock(); err_file: + mutex_unlock(&devpts_mutex); tty_free_file(filp); return retval; } diff --git a/drivers/tty/serial/crisv10.c b/drivers/tty/serial/crisv10.c index 6b705b2..a770b10 100644 --- a/drivers/tty/serial/crisv10.c +++ b/drivers/tty/serial/crisv10.c @@ -3976,7 +3976,7 @@ block_til_ready(struct tty_struct *tty, struct file * filp, */ if (tty_hung_up_p(filp) || (info->flags & ASYNC_CLOSING)) { - wait_event_interruptible_tty(info->close_wait, + wait_event_interruptible_tty(tty, info->close_wait, !(info->flags & ASYNC_CLOSING)); #ifdef SERIAL_DO_RESTART if (info->flags & ASYNC_HUP_NOTIFY) @@ -4052,9 +4052,9 @@ block_til_ready(struct tty_struct *tty, struct file * filp, printk("block_til_ready blocking: ttyS%d, count = %d\n", info->line, info->count); #endif - tty_unlock(); + tty_unlock(tty); schedule(); - tty_lock(); + tty_lock(tty); } set_current_state(TASK_RUNNING); remove_wait_queue(&info->open_wait, &wait); @@ -4115,7 +4115,7 @@ rs_open(struct tty_struct *tty, struct file * filp) */ if (tty_hung_up_p(filp) || (info->flags & ASYNC_CLOSING)) { - wait_event_interruptible_tty(info->close_wait, + wait_event_interruptible_tty(tty, info->close_wait, !(info->flags & ASYNC_CLOSING)); #ifdef SERIAL_DO_RESTART return ((info->flags & ASYNC_HUP_NOTIFY) ? diff --git a/drivers/tty/synclink.c b/drivers/tty/synclink.c index bdeeb31..991bae8 100644 --- a/drivers/tty/synclink.c +++ b/drivers/tty/synclink.c @@ -3338,9 +3338,9 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp, printk("%s(%d):block_til_ready blocking on %s count=%d\n", __FILE__,__LINE__, tty->driver->name, port->count ); - tty_unlock(); + tty_unlock(tty); schedule(); - tty_lock(); + tty_lock(tty); } set_current_state(TASK_RUNNING); diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c index f02d18a..9130253 100644 --- a/drivers/tty/synclink_gt.c +++ b/drivers/tty/synclink_gt.c @@ -3336,9 +3336,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, } DBGINFO(("%s block_til_ready wait\n", tty->driver->name)); - tty_unlock(); + tty_unlock(tty); schedule(); - tty_lock(); + tty_lock(tty); } set_current_state(TASK_RUNNING); diff --git a/drivers/tty/synclinkmp.c b/drivers/tty/synclinkmp.c index ae75a3c..95fd4e2 100644 --- a/drivers/tty/synclinkmp.c +++ b/drivers/tty/synclinkmp.c @@ -3357,9 +3357,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, printk("%s(%d):%s block_til_ready() count=%d\n", __FILE__,__LINE__, tty->driver->name, port->count ); - tty_unlock(); + tty_unlock(tty); schedule(); - tty_lock(); + tty_lock(tty); } set_current_state(TASK_RUNNING); diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 6784aae..6902244 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -187,6 +187,7 @@ void free_tty_struct(struct tty_struct *tty) put_device(tty->dev); kfree(tty->write_buf); tty_buffer_free_all(tty); + tty->magic = 0xDEADDEAD; kfree(tty); } @@ -575,7 +576,7 @@ void __tty_hangup(struct tty_struct *tty) } spin_unlock(&redirect_lock); - tty_lock(); + tty_lock(tty); /* some functions below drop BTM, so we need this bit */ set_bit(TTY_HUPPING, &tty->flags); @@ -668,7 +669,7 @@ void __tty_hangup(struct tty_struct *tty) clear_bit(TTY_HUPPING, &tty->flags); tty_ldisc_enable(tty); - tty_unlock(); + tty_unlock(tty); if (f) fput(f); @@ -1105,12 +1106,12 @@ void tty_write_message(struct tty_struct *tty, char *msg) { if (tty) { mutex_lock(&tty->atomic_write_lock); - tty_lock(); + tty_lock(tty); if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { - tty_unlock(); + tty_unlock(tty); tty->ops->write(tty, msg, strlen(msg)); } else - tty_unlock(); + tty_unlock(tty); tty_write_unlock(tty); } return; @@ -1403,6 +1404,7 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) } initialize_tty_struct(tty, driver, idx); + tty_lock(tty); retval = tty_driver_install_tty(driver, tty); if (retval < 0) goto err_deinit_tty; @@ -1418,9 +1420,11 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) retval = tty_ldisc_setup(tty, tty->link); if (retval) goto err_release_tty; + /* Return the tty locked so that it cannot vanish under the caller */ return tty; err_deinit_tty: + tty_unlock(tty); deinitialize_tty_struct(tty); free_tty_struct(tty); err_module_put: @@ -1429,6 +1433,7 @@ err_module_put: /* call the tty release_tty routine to clean out this slot */ err_release_tty: + tty_unlock(tty); printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " "clearing slot %d\n", idx); release_tty(tty, idx); @@ -1622,7 +1627,7 @@ int tty_release(struct inode *inode, struct file *filp) if (tty_paranoia_check(tty, inode, __func__)) return 0; - tty_lock(); + tty_lock(tty); check_tty_count(tty, __func__); __tty_fasync(-1, filp, 0); @@ -1631,10 +1636,11 @@ int tty_release(struct inode *inode, struct file *filp) pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER); devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; + /* Review: parallel close */ o_tty = tty->link; if (tty_release_checks(tty, o_tty, idx)) { - tty_unlock(); + tty_unlock(tty); return 0; } @@ -1646,7 +1652,7 @@ int tty_release(struct inode *inode, struct file *filp) if (tty->ops->close) tty->ops->close(tty, filp); - tty_unlock(); + tty_unlock(tty); /* * 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 @@ -1669,7 +1675,7 @@ int tty_release(struct inode *inode, struct file *filp) opens on /dev/tty */ mutex_lock(&tty_mutex); - tty_lock(); + tty_lock_pair(tty, o_tty); tty_closing = tty->count <= 1; o_tty_closing = o_tty && (o_tty->count <= (pty_master ? 1 : 0)); @@ -1700,7 +1706,7 @@ int tty_release(struct inode *inode, struct file *filp) printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", __func__, tty_name(tty, buf)); - tty_unlock(); + tty_unlock_pair(tty, o_tty); mutex_unlock(&tty_mutex); schedule(); } @@ -1763,7 +1769,7 @@ int tty_release(struct inode *inode, struct file *filp) } mutex_unlock(&tty_mutex); - tty_unlock(); + tty_unlock_pair(tty, o_tty); /* At this point the TTY_CLOSING flag should ensure a dead tty cannot be re-opened by a racing opener */ @@ -1780,7 +1786,9 @@ int tty_release(struct inode *inode, struct file *filp) tty_ldisc_release(tty, o_tty); /* * The release_tty function takes care of the details of clearing - * the slots and preserving the termios structure. + * the slots and preserving the termios structure. The tty_unlock_pair + * should be safe as we keep a kref while the tty is locked (so the + * unlock never unlocks a freed tty). */ mutex_lock(&tty_mutex); release_tty(tty, idx); @@ -1789,7 +1797,6 @@ int tty_release(struct inode *inode, struct file *filp) /* Make this pty number available for reallocation */ if (devpts) devpts_kill_index(inode, idx); - return 0; } @@ -1893,6 +1900,9 @@ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. * tty->count should protect the rest. * ->siglock protects ->signal/->sighand + * + * Note: the tty_unlock/lock cases without a ref are only safe due to + * tty_mutex */ static int tty_open(struct inode *inode, struct file *filp) @@ -1916,8 +1926,7 @@ retry_open: retval = 0; mutex_lock(&tty_mutex); - tty_lock(); - + /* This is protected by the tty_mutex */ tty = tty_open_current_tty(device, filp); if (IS_ERR(tty)) { retval = PTR_ERR(tty); @@ -1938,17 +1947,19 @@ retry_open: } if (tty) { + tty_lock(tty); retval = tty_reopen(tty); - if (retval) + if (retval < 0) { + tty_unlock(tty); tty = ERR_PTR(retval); - } else + } + } else /* Returns with the tty_lock held for now */ tty = tty_init_dev(driver, index); mutex_unlock(&tty_mutex); if (driver) tty_driver_kref_put(driver); if (IS_ERR(tty)) { - tty_unlock(); retval = PTR_ERR(tty); goto err_file; } @@ -1977,7 +1988,7 @@ retry_open: printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, retval, tty->name); #endif - tty_unlock(); /* need to call tty_release without BTM */ + tty_unlock(tty); /* need to call tty_release without BTM */ tty_release(inode, filp); if (retval != -ERESTARTSYS) return retval; @@ -1989,17 +2000,15 @@ retry_open: /* * Need to reset f_op in case a hangup happened. */ - tty_lock(); if (filp->f_op == &hung_up_tty_fops) filp->f_op = &tty_fops; - tty_unlock(); goto retry_open; } - tty_unlock(); + tty_unlock(tty); mutex_lock(&tty_mutex); - tty_lock(); + tty_lock(tty); spin_lock_irq(¤t->sighand->siglock); if (!noctty && current->signal->leader && @@ -2007,11 +2016,10 @@ retry_open: tty->session == NULL) __proc_set_tty(current, tty); spin_unlock_irq(¤t->sighand->siglock); - tty_unlock(); + tty_unlock(tty); mutex_unlock(&tty_mutex); return 0; err_unlock: - tty_unlock(); mutex_unlock(&tty_mutex); /* after locks to avoid deadlock */ if (!IS_ERR_OR_NULL(driver)) @@ -2094,10 +2102,13 @@ out: static int tty_fasync(int fd, struct file *filp, int on) { + struct tty_struct *tty = file_tty(filp); int retval; - tty_lock(); + + tty_lock(tty); retval = __tty_fasync(fd, filp, on); - tty_unlock(); + tty_unlock(tty); + return retval; } @@ -2934,6 +2945,7 @@ void initialize_tty_struct(struct tty_struct *tty, tty->pgrp = NULL; tty->overrun_time = jiffies; tty_buffer_init(tty); + mutex_init(&tty->legacy_mutex); mutex_init(&tty->termios_mutex); mutex_init(&tty->ldisc_mutex); init_waitqueue_head(&tty->write_wait); diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index 3d06871..4d7b562 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -568,7 +568,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) if (IS_ERR(new_ldisc)) return PTR_ERR(new_ldisc); - tty_lock(); + tty_lock(tty); /* * We need to look at the tty locking here for pty/tty pairs * when both sides try to change in parallel. @@ -582,12 +582,12 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) */ if (tty->ldisc->ops->num == ldisc) { - tty_unlock(); + tty_unlock(tty); tty_ldisc_put(new_ldisc); return 0; } - tty_unlock(); + tty_unlock(tty); /* * Problem: What do we do if this blocks ? * We could deadlock here @@ -595,7 +595,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) tty_wait_until_sent(tty, 0); - tty_lock(); + tty_lock(tty); mutex_lock(&tty->ldisc_mutex); /* @@ -605,10 +605,10 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) while (test_bit(TTY_LDISC_CHANGING, &tty->flags)) { mutex_unlock(&tty->ldisc_mutex); - tty_unlock(); + tty_unlock(tty); wait_event(tty_ldisc_wait, test_bit(TTY_LDISC_CHANGING, &tty->flags) == 0); - tty_lock(); + tty_lock(tty); mutex_lock(&tty->ldisc_mutex); } @@ -623,7 +623,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) o_ldisc = tty->ldisc; - tty_unlock(); + tty_unlock(tty); /* * Make sure we don't change while someone holds a * reference to the line discipline. The TTY_LDISC bit @@ -650,7 +650,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) retval = tty_ldisc_wait_idle(tty, 5 * HZ); - tty_lock(); + tty_lock(tty); mutex_lock(&tty->ldisc_mutex); /* handle wait idle failure locked */ @@ -665,7 +665,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) clear_bit(TTY_LDISC_CHANGING, &tty->flags); mutex_unlock(&tty->ldisc_mutex); tty_ldisc_put(new_ldisc); - tty_unlock(); + tty_unlock(tty); return -EIO; } @@ -708,7 +708,7 @@ enable: if (o_work) schedule_work(&o_tty->buf.work); mutex_unlock(&tty->ldisc_mutex); - tty_unlock(); + tty_unlock(tty); return retval; } @@ -816,11 +816,11 @@ void tty_ldisc_hangup(struct tty_struct *tty) * need to wait for another function taking the BTM */ clear_bit(TTY_LDISC, &tty->flags); - tty_unlock(); + tty_unlock(tty); cancel_work_sync(&tty->buf.work); mutex_unlock(&tty->ldisc_mutex); retry: - tty_lock(); + tty_lock(tty); mutex_lock(&tty->ldisc_mutex); /* At this point we have a closed ldisc and we want to @@ -831,7 +831,7 @@ retry: if (atomic_read(&tty->ldisc->users) != 1) { char cur_n[TASK_COMM_LEN], tty_n[64]; long timeout = 3 * HZ; - tty_unlock(); + tty_unlock(tty); while (tty_ldisc_wait_idle(tty, timeout) == -EBUSY) { timeout = MAX_SCHEDULE_TIMEOUT; @@ -894,6 +894,23 @@ int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty) tty_ldisc_enable(tty); return 0; } + +static void tty_ldisc_kill(struct tty_struct *tty) +{ + mutex_lock(&tty->ldisc_mutex); + /* + * Now kill off the ldisc + */ + tty_ldisc_close(tty, tty->ldisc); + tty_ldisc_put(tty->ldisc); + /* Force an oops if we mess this up */ + tty->ldisc = NULL; + + /* Ensure the next open requests the N_TTY ldisc */ + tty_set_termios_ldisc(tty, N_TTY); + mutex_unlock(&tty->ldisc_mutex); +} + /** * tty_ldisc_release - release line discipline * @tty: tty being shut down @@ -912,29 +929,21 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty) * race with the set_ldisc code path. */ + tty_lock_pair(tty, o_tty); tty_ldisc_halt(tty); tty_ldisc_flush_works(tty); - tty_lock(); - - mutex_lock(&tty->ldisc_mutex); - /* - * Now kill off the ldisc - */ - tty_ldisc_close(tty, tty->ldisc); - tty_ldisc_put(tty->ldisc); - /* Force an oops if we mess this up */ - tty->ldisc = NULL; - - /* Ensure the next open requests the N_TTY ldisc */ - tty_set_termios_ldisc(tty, N_TTY); - mutex_unlock(&tty->ldisc_mutex); - - tty_unlock(); + if (o_tty) { + tty_ldisc_halt(o_tty); + tty_ldisc_flush_works(o_tty); + } /* This will need doing differently if we need to lock */ + tty_ldisc_kill(tty); + if (o_tty) - tty_ldisc_release(o_tty, NULL); + tty_ldisc_kill(o_tty); + tty_unlock_pair(tty, o_tty); /* And the memory resources remaining (buffers, termios) will be disposed of when the kref hits zero */ } diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c index 9ff986c..67feac9 100644 --- a/drivers/tty/tty_mutex.c +++ b/drivers/tty/tty_mutex.c @@ -4,29 +4,70 @@ #include <linux/semaphore.h> #include <linux/sched.h> -/* - * The 'big tty mutex' - * - * This mutex is taken and released by tty_lock() and tty_unlock(), - * replacing the older big kernel lock. - * It can no longer be taken recursively, and does not get - * released implicitly while sleeping. - * - * Don't use in new code. - */ -static DEFINE_MUTEX(big_tty_mutex); +/* Legacy tty mutex glue */ + +enum { + TTY_MUTEX_NORMAL, + TTY_MUTEX_NESTED, +}; /* * Getting the big tty mutex. */ -void __lockfunc tty_lock(void) + +static void __lockfunc tty_lock_nested(struct tty_struct *tty, + unsigned int subclass) { - mutex_lock(&big_tty_mutex); + if (tty->magic != TTY_MAGIC) { + printk(KERN_ERR "L Bad %p\n", tty); + WARN_ON(1); + return; + } + tty_kref_get(tty); + mutex_lock_nested(&tty->legacy_mutex, subclass); +} + +void __lockfunc tty_lock(struct tty_struct *tty) +{ + return tty_lock_nested(tty, TTY_MUTEX_NORMAL); } EXPORT_SYMBOL(tty_lock); -void __lockfunc tty_unlock(void) +void __lockfunc tty_unlock(struct tty_struct *tty) { - mutex_unlock(&big_tty_mutex); + if (tty->magic != TTY_MAGIC) { + printk(KERN_ERR "U Bad %p\n", tty); + WARN_ON(1); + return; + } + mutex_unlock(&tty->legacy_mutex); + tty_kref_put(tty); } EXPORT_SYMBOL(tty_unlock); + +/* + * Getting the big tty mutex for a pair of ttys with lock ordering + * On a non pty/tty pair tty2 can be NULL which is just fine. + */ +void __lockfunc tty_lock_pair(struct tty_struct *tty, + struct tty_struct *tty2) +{ + if (tty < tty2) { + tty_lock(tty); + tty_lock_nested(tty2, TTY_MUTEX_NESTED); + } else { + if (tty2 && tty2 != tty) + tty_lock(tty2); + tty_lock_nested(tty, TTY_MUTEX_NESTED); + } +} +EXPORT_SYMBOL(tty_lock_pair); + +void __lockfunc tty_unlock_pair(struct tty_struct *tty, + struct tty_struct *tty2) +{ + tty_unlock(tty); + if (tty2 && tty2 != tty) + tty_unlock(tty2); +} +EXPORT_SYMBOL(tty_unlock_pair); diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c index edcb827..5246763 100644 --- a/drivers/tty/tty_port.c +++ b/drivers/tty/tty_port.c @@ -239,7 +239,7 @@ int tty_port_block_til_ready(struct tty_port *port, /* block if port is in the process of being closed */ if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) { - wait_event_interruptible_tty(port->close_wait, + wait_event_interruptible_tty(tty, port->close_wait, !(port->flags & ASYNC_CLOSING)); if (port->flags & ASYNC_HUP_NOTIFY) return -EAGAIN; @@ -305,9 +305,9 @@ int tty_port_block_til_ready(struct tty_port *port, retval = -ERESTARTSYS; break; } - tty_unlock(); + tty_unlock(tty); schedule(); - tty_lock(); + tty_lock(tty); } finish_wait(&port->open_wait, &wait); |