From 04f378b198da233ca0aca341b113dc6579d46123 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 30 Apr 2008 00:53:29 -0700 Subject: [PATCH] tty: BKL pushdown - Push the BKL down into the line disciplines - Switch the tty layer to unlocked_ioctl - Introduce a new ctrl_lock spin lock for the control bits - Eliminate much of the lock_kernel use in n_tty - Prepare to (but don't yet) call the drivers with the lock dropped on the paths that historically held the lock BKL now primarily protects open/close/ldisc change in the tty layer [jirislaby@gmail.com: a couple of fixes] Signed-off-by: Alan Cox Signed-off-by: Jiri Slaby Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/n_hdlc.c | 24 ++++++--- drivers/char/n_r3964.c | 16 +++++- drivers/char/n_tty.c | 32 +++++++++--- drivers/char/pty.c | 3 ++ drivers/char/tty_io.c | 107 +++++++++++++++++++++++++++------------ drivers/char/tty_ioctl.c | 6 +++ drivers/char/vt.c | 8 ++- fs/compat_ioctl.c | 2 +- include/linux/tty.h | 4 +- 9 files changed, 149 insertions(+), 53 deletions(-) diff --git a/drivers/char/n_hdlc.c b/drivers/char/n_hdlc.c index 06803ed5568c..a07c0af4819e 100644 --- a/drivers/char/n_hdlc.c +++ b/drivers/char/n_hdlc.c @@ -578,26 +578,36 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file, return -EFAULT; } + lock_kernel(); + for (;;) { - if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) + if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { + unlock_kernel(); return -EIO; + } n_hdlc = tty2n_hdlc (tty); if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC || - tty != n_hdlc->tty) + tty != n_hdlc->tty) { + unlock_kernel(); return 0; + } rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list); if (rbuf) break; /* no data */ - if (file->f_flags & O_NONBLOCK) + if (file->f_flags & O_NONBLOCK) { + unlock_kernel(); return -EAGAIN; + } interruptible_sleep_on (&tty->read_wait); - if (signal_pending(current)) + if (signal_pending(current)) { + unlock_kernel(); return -EINTR; + } } if (rbuf->count > nr) @@ -618,7 +628,7 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file, kfree(rbuf); else n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,rbuf); - + unlock_kernel(); return ret; } /* end of n_hdlc_tty_read() */ @@ -661,6 +671,8 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file, count = maxframe; } + lock_kernel(); + add_wait_queue(&tty->write_wait, &wait); set_current_state(TASK_INTERRUPTIBLE); @@ -695,7 +707,7 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file, n_hdlc_buf_put(&n_hdlc->tx_buf_list,tbuf); n_hdlc_send_frames(n_hdlc,tty); } - + unlock_kernel(); return error; } /* end of n_hdlc_tty_write() */ diff --git a/drivers/char/n_r3964.c b/drivers/char/n_r3964.c index 6b918b80f73e..3f6486e9f1ec 100644 --- a/drivers/char/n_r3964.c +++ b/drivers/char/n_r3964.c @@ -1075,12 +1075,15 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, TRACE_L("read()"); + lock_kernel(); + pClient = findClient(pInfo, task_pid(current)); if (pClient) { pMsg = remove_msg(pInfo, pClient); if (pMsg == NULL) { /* no messages available. */ if (file->f_flags & O_NONBLOCK) { + unlock_kernel(); return -EAGAIN; } /* block until there is a message: */ @@ -1090,8 +1093,10 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, /* If we still haven't got a message, we must have been signalled */ - if (!pMsg) + if (!pMsg) { + unlock_kernel(); return -EINTR; + } /* deliver msg to client process: */ theMsg.msg_id = pMsg->msg_id; @@ -1102,12 +1107,15 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, kfree(pMsg); TRACE_M("r3964_read - msg kfree %p", pMsg); - if (copy_to_user(buf, &theMsg, count)) + if (copy_to_user(buf, &theMsg, count)) { + unlock_kernel(); return -EFAULT; + } TRACE_PS("read - return %d", count); return count; } + unlock_kernel(); return -EPERM; } @@ -1156,6 +1164,8 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file, pHeader->locks = 0; pHeader->owner = NULL; + lock_kernel(); + pClient = findClient(pInfo, task_pid(current)); if (pClient) { pHeader->owner = pClient; @@ -1173,6 +1183,8 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file, add_tx_queue(pInfo, pHeader); trigger_transmit(pInfo); + unlock_kernel(); + return 0; } diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index 0c09409fa45d..001d9d875387 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -183,22 +183,24 @@ static void reset_buffer_flags(struct tty_struct *tty) * at hangup) or when the N_TTY line discipline internally has to * clean the pending queue (for example some signals). * - * FIXME: tty->ctrl_status is not spinlocked and relies on - * lock_kernel() still. + * Locking: ctrl_lock */ static void n_tty_flush_buffer(struct tty_struct *tty) { + unsigned long flags; /* clear everything and unthrottle the driver */ reset_buffer_flags(tty); if (!tty->link) return; + spin_lock_irqsave(&tty->ctrl_lock, flags); if (tty->link->packet) { tty->ctrl_status |= TIOCPKT_FLUSHREAD; wake_up_interruptible(&tty->link->read_wait); } + spin_unlock_irqrestore(&tty->ctrl_lock, flags); } /** @@ -264,7 +266,7 @@ static inline int is_continuation(unsigned char c, struct tty_struct *tty) * relevant in the world today. If you ever need them, add them here. * * Called from both the receive and transmit sides and can be called - * re-entrantly. Relies on lock_kernel() still. + * re-entrantly. Relies on lock_kernel() for tty->column state. */ static int opost(unsigned char c, struct tty_struct *tty) @@ -275,6 +277,7 @@ static int opost(unsigned char c, struct tty_struct *tty) if (!space) return -1; + lock_kernel(); if (O_OPOST(tty)) { switch (c) { case '\n': @@ -323,6 +326,7 @@ static int opost(unsigned char c, struct tty_struct *tty) } } tty->driver->put_char(tty, c); + unlock_kernel(); return 0; } @@ -337,7 +341,8 @@ static int opost(unsigned char c, struct tty_struct *tty) * the simple cases normally found and helps to generate blocks of * symbols for the console driver and thus improve performance. * - * Called from write_chan under the tty layer write lock. + * Called from write_chan under the tty layer write lock. Relies + * on lock_kernel for the tty->column state. */ static ssize_t opost_block(struct tty_struct *tty, @@ -353,6 +358,7 @@ static ssize_t opost_block(struct tty_struct *tty, if (nr > space) nr = space; + lock_kernel(); for (i = 0, cp = buf; i < nr; i++, cp++) { switch (*cp) { case '\n': @@ -387,6 +393,7 @@ break_out: if (tty->driver->flush_chars) tty->driver->flush_chars(tty); i = tty->driver->write(tty, buf, i); + unlock_kernel(); return i; } @@ -1194,6 +1201,11 @@ extern ssize_t redirected_tty_write(struct file *, const char __user *, * Perform job control management checks on this file/tty descriptor * and if appropriate send any needed signals and return a negative * error code if action should be taken. + * + * FIXME: + * Locking: None - redirected write test is safe, testing + * current->signal should possibly lock current->sighand + * pgrp locking ? */ static int job_control(struct tty_struct *tty, struct file *file) @@ -1246,6 +1258,7 @@ static ssize_t read_chan(struct tty_struct *tty, struct file *file, ssize_t size; long timeout; unsigned long flags; + int packet; do_it_again: @@ -1289,16 +1302,19 @@ do_it_again: if (mutex_lock_interruptible(&tty->atomic_read_lock)) return -ERESTARTSYS; } + packet = tty->packet; add_wait_queue(&tty->read_wait, &wait); while (nr) { /* First test for status change. */ - if (tty->packet && tty->link->ctrl_status) { + if (packet && tty->link->ctrl_status) { unsigned char cs; if (b != buf) break; + spin_lock_irqsave(&tty->link->ctrl_lock, flags); cs = tty->link->ctrl_status; tty->link->ctrl_status = 0; + spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); if (tty_put_user(tty, cs, b++)) { retval = -EFAULT; b--; @@ -1333,6 +1349,7 @@ do_it_again: retval = -ERESTARTSYS; break; } + /* FIXME: does n_tty_set_room need locking ? */ n_tty_set_room(tty); timeout = schedule_timeout(timeout); continue; @@ -1340,7 +1357,7 @@ do_it_again: __set_current_state(TASK_RUNNING); /* Deal with packet mode. */ - if (tty->packet && b == buf) { + if (packet && b == buf) { if (tty_put_user(tty, TIOCPKT_DATA, b++)) { retval = -EFAULT; b--; @@ -1388,6 +1405,8 @@ do_it_again: break; } else { int uncopied; + /* The copy function takes the read lock and handles + locking internally for this case */ uncopied = copy_from_read_buf(tty, &b, &nr); uncopied += copy_from_read_buf(tty, &b, &nr); if (uncopied) { @@ -1429,7 +1448,6 @@ do_it_again: goto do_it_again; n_tty_set_room(tty); - return retval; } diff --git a/drivers/char/pty.c b/drivers/char/pty.c index 706ff34728f1..6288356b769d 100644 --- a/drivers/char/pty.c +++ b/drivers/char/pty.c @@ -181,6 +181,7 @@ static int pty_set_lock(struct tty_struct *tty, int __user * arg) static void pty_flush_buffer(struct tty_struct *tty) { struct tty_struct *to = tty->link; + unsigned long flags; if (!to) return; @@ -189,8 +190,10 @@ static void pty_flush_buffer(struct tty_struct *tty) to->ldisc.flush_buffer(to); if (to->packet) { + spin_lock_irqsave(&tty->ctrl_lock, flags); tty->ctrl_status |= TIOCPKT_FLUSHWRITE; wake_up_interruptible(&to->read_wait); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); } } diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 2fa6856706ab..0b0354bc28d6 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -152,8 +152,7 @@ ssize_t redirected_tty_write(struct file *, const char __user *, 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 *); -int tty_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg); +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, unsigned long arg); @@ -1205,7 +1204,7 @@ EXPORT_SYMBOL_GPL(tty_find_polling_driver); * not in the foreground, send a SIGTTOU. If the signal is blocked or * ignored, go ahead and perform the operation. (POSIX 7.2) * - * Locking: none + * Locking: none - FIXME: review this */ int tty_check_change(struct tty_struct *tty) @@ -1247,8 +1246,8 @@ static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; } -static int hung_up_tty_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) +static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) { return cmd == TIOCSPGRP ? -ENOTTY : -EIO; } @@ -1264,7 +1263,7 @@ static const struct file_operations tty_fops = { .read = tty_read, .write = tty_write, .poll = tty_poll, - .ioctl = tty_ioctl, + .unlocked_ioctl = tty_ioctl, .compat_ioctl = tty_compat_ioctl, .open = tty_open, .release = tty_release, @@ -1277,7 +1276,7 @@ static const struct file_operations ptmx_fops = { .read = tty_read, .write = tty_write, .poll = tty_poll, - .ioctl = tty_ioctl, + .unlocked_ioctl = tty_ioctl, .compat_ioctl = tty_compat_ioctl, .open = ptmx_open, .release = tty_release, @@ -1290,7 +1289,7 @@ static const struct file_operations console_fops = { .read = tty_read, .write = redirected_tty_write, .poll = tty_poll, - .ioctl = tty_ioctl, + .unlocked_ioctl = tty_ioctl, .compat_ioctl = tty_compat_ioctl, .open = tty_open, .release = tty_release, @@ -1302,7 +1301,7 @@ static const struct file_operations hung_up_tty_fops = { .read = hung_up_tty_read, .write = hung_up_tty_write, .poll = hung_up_tty_poll, - .ioctl = hung_up_tty_ioctl, + .unlocked_ioctl = hung_up_tty_ioctl, .compat_ioctl = hung_up_tty_compat_ioctl, .release = tty_release, }; @@ -1626,16 +1625,17 @@ void disassociate_ctty(int on_exit) struct tty_struct *tty; struct pid *tty_pgrp = NULL; - lock_kernel(); mutex_lock(&tty_mutex); tty = get_current_tty(); if (tty) { tty_pgrp = get_pid(tty->pgrp); mutex_unlock(&tty_mutex); + lock_kernel(); /* XXX: here we race, there is nothing protecting tty */ if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) tty_vhangup(tty); + unlock_kernel(); } else if (on_exit) { struct pid *old_pgrp; spin_lock_irq(¤t->sighand->siglock); @@ -1648,7 +1648,6 @@ void disassociate_ctty(int on_exit) put_pid(old_pgrp); } mutex_unlock(&tty_mutex); - unlock_kernel(); return; } if (tty_pgrp) { @@ -1683,7 +1682,6 @@ void disassociate_ctty(int on_exit) read_lock(&tasklist_lock); session_clear_tty(task_session(current)); read_unlock(&tasklist_lock); - unlock_kernel(); } /** @@ -1693,8 +1691,10 @@ void disassociate_ctty(int on_exit) void no_tty(void) { struct task_struct *tsk = current; + lock_kernel(); if (tsk->signal->leader) disassociate_ctty(0); + unlock_kernel(); proc_clear_tty(tsk); } @@ -1714,19 +1714,24 @@ void no_tty(void) * but not always. * * Locking: - * Broken. Relies on BKL which is unsafe here. + * Uses the tty control lock internally */ void stop_tty(struct tty_struct *tty) { - if (tty->stopped) + unsigned long flags; + spin_lock_irqsave(&tty->ctrl_lock, flags); + if (tty->stopped) { + spin_unlock_irqrestore(&tty->ctrl_lock, flags); return; + } tty->stopped = 1; if (tty->link && tty->link->packet) { tty->ctrl_status &= ~TIOCPKT_START; tty->ctrl_status |= TIOCPKT_STOP; wake_up_interruptible(&tty->link->read_wait); } + spin_unlock_irqrestore(&tty->ctrl_lock, flags); if (tty->driver->stop) (tty->driver->stop)(tty); } @@ -1743,19 +1748,24 @@ EXPORT_SYMBOL(stop_tty); * driver start method is invoked and the line discipline woken. * * Locking: - * Broken. Relies on BKL which is unsafe here. + * ctrl_lock */ void start_tty(struct tty_struct *tty) { - if (!tty->stopped || tty->flow_stopped) + unsigned long flags; + spin_lock_irqsave(&tty->ctrl_lock, flags); + if (!tty->stopped || tty->flow_stopped) { + spin_unlock_irqrestore(&tty->ctrl_lock, flags); return; + } tty->stopped = 0; if (tty->link && tty->link->packet) { tty->ctrl_status &= ~TIOCPKT_STOP; tty->ctrl_status |= TIOCPKT_START; wake_up_interruptible(&tty->link->read_wait); } + spin_unlock_irqrestore(&tty->ctrl_lock, flags); if (tty->driver->start) (tty->driver->start)(tty); /* If we have a running line discipline it may need kicking */ @@ -1799,13 +1809,11 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count, /* We want to wait for the line discipline to sort out in this situation */ ld = tty_ldisc_ref_wait(tty); - lock_kernel(); if (ld->read) i = (ld->read)(tty, file, buf, count); else i = -EIO; tty_ldisc_deref(ld); - unlock_kernel(); if (i > 0) inode->i_atime = current_fs_time(inode->i_sb); return i; @@ -1893,9 +1901,7 @@ static inline ssize_t do_tty_write( ret = -EFAULT; if (copy_from_user(tty->write_buf, buf, size)) break; - lock_kernel(); ret = write(tty, file, tty->write_buf, size); - unlock_kernel(); if (ret <= 0) break; written += ret; @@ -3070,10 +3076,13 @@ static int fionbio(struct file *file, int __user *p) if (get_user(nonblock, p)) return -EFAULT; + /* file->f_flags is still BKL protected in the fs layer - vomit */ + lock_kernel(); if (nonblock) file->f_flags |= O_NONBLOCK; else file->f_flags &= ~O_NONBLOCK; + unlock_kernel(); return 0; } @@ -3162,7 +3171,7 @@ static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t * Set the process group of the tty to the session passed. Only * permitted where the tty session is our session. * - * Locking: None + * Locking: RCU */ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) @@ -3237,10 +3246,16 @@ static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t _ static int tiocsetd(struct tty_struct *tty, int __user *p) { int ldisc; + int ret; if (get_user(ldisc, p)) return -EFAULT; - return tty_set_ldisc(tty, ldisc); + + lock_kernel(); + ret = tty_set_ldisc(tty, ldisc); + unlock_kernel(); + + return ret; } /** @@ -3258,16 +3273,21 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) static int send_break(struct tty_struct *tty, unsigned int duration) { + int retval = -EINTR; + + lock_kernel(); if (tty_write_lock(tty, 0) < 0) - return -EINTR; + goto out; tty->driver->break_ctl(tty, -1); if (!signal_pending(current)) msleep_interruptible(duration); tty->driver->break_ctl(tty, 0); tty_write_unlock(tty); - if (signal_pending(current)) - return -EINTR; - return 0; + if (!signal_pending(current)) + retval = 0; +out: + unlock_kernel(); + return retval; } /** @@ -3287,7 +3307,9 @@ static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p int retval = -EINVAL; if (tty->driver->tiocmget) { + lock_kernel(); retval = tty->driver->tiocmget(tty, file); + unlock_kernel(); if (retval >= 0) retval = put_user(retval, p); @@ -3337,7 +3359,9 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; + lock_kernel(); retval = tty->driver->tiocmset(tty, file, set, clear); + unlock_kernel(); } return retval; } @@ -3345,20 +3369,18 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int /* * Split this up, as gcc can choke on it otherwise.. */ -int tty_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) +long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct tty_struct *tty, *real_tty; void __user *p = (void __user *)arg; int retval; struct tty_ldisc *ld; + struct inode *inode = file->f_dentry->d_inode; tty = (struct tty_struct *)file->private_data; if (tty_paranoia_check(tty, inode, "tty_ioctl")) return -EINVAL; - /* CHECKME: is this safe as one end closes ? */ - real_tty = tty; if (tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER) @@ -3367,13 +3389,19 @@ int tty_ioctl(struct inode *inode, struct file *file, /* * Break handling by driver */ + + retval = -EINVAL; + if (!tty->driver->break_ctl) { switch (cmd) { case TIOCSBRK: case TIOCCBRK: - if (tty->driver->ioctl) - return tty->driver->ioctl(tty, file, cmd, arg); - return -EINVAL; + if (tty->driver->ioctl) { + lock_kernel(); + retval = tty->driver->ioctl(tty, file, cmd, arg); + unlock_kernel(); + } + return retval; /* These two ioctl's always return success; even if */ /* the driver doesn't support them. */ @@ -3381,7 +3409,9 @@ int tty_ioctl(struct inode *inode, struct file *file, case TCSBRKP: if (!tty->driver->ioctl) return 0; + lock_kernel(); retval = tty->driver->ioctl(tty, file, cmd, arg); + unlock_kernel(); if (retval == -ENOIOCTLCMD) retval = 0; return retval; @@ -3401,7 +3431,9 @@ int tty_ioctl(struct inode *inode, struct file *file, if (retval) return retval; if (cmd != TIOCCBRK) { + lock_kernel(); tty_wait_until_sent(tty, 0); + unlock_kernel(); if (signal_pending(current)) return -EINTR; } @@ -3451,11 +3483,15 @@ int tty_ioctl(struct inode *inode, struct file *file, * Break handling */ case TIOCSBRK: /* Turn break on, unconditionally */ + lock_kernel(); tty->driver->break_ctl(tty, -1); + unlock_kernel(); return 0; case TIOCCBRK: /* Turn break off, unconditionally */ + lock_kernel(); tty->driver->break_ctl(tty, 0); + unlock_kernel(); return 0; case TCSBRK: /* SVID version: non-zero arg --> no break */ /* non-zero arg means wait for all output data @@ -3485,14 +3521,18 @@ int tty_ioctl(struct inode *inode, struct file *file, break; } if (tty->driver->ioctl) { + lock_kernel(); retval = (tty->driver->ioctl)(tty, file, cmd, arg); + unlock_kernel(); if (retval != -ENOIOCTLCMD) return retval; } ld = tty_ldisc_ref_wait(tty); retval = -EINVAL; if (ld->ioctl) { + lock_kernel(); retval = ld->ioctl(tty, file, cmd, arg); + unlock_kernel(); if (retval == -ENOIOCTLCMD) retval = -EINVAL; } @@ -3770,6 +3810,7 @@ static void initialize_tty_struct(struct tty_struct *tty) mutex_init(&tty->atomic_read_lock); mutex_init(&tty->atomic_write_lock); spin_lock_init(&tty->read_lock); + spin_lock_init(&tty->ctrl_lock); INIT_LIST_HEAD(&tty->tty_files); INIT_WORK(&tty->SAK_work, do_SAK_work); } diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c index f95a80b2265f..d6353d89b451 100644 --- a/drivers/char/tty_ioctl.c +++ b/drivers/char/tty_ioctl.c @@ -395,6 +395,7 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios) int canon_change; struct ktermios old_termios = *tty->termios; struct tty_ldisc *ld; + unsigned long flags; /* * Perform the actual termios internal changes under lock. @@ -429,11 +430,13 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios) STOP_CHAR(tty) == '\023' && START_CHAR(tty) == '\021'); if (old_flow != new_flow) { + spin_lock_irqsave(&tty->ctrl_lock, flags); tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP); if (new_flow) tty->ctrl_status |= TIOCPKT_DOSTOP; else tty->ctrl_status |= TIOCPKT_NOSTOP; + spin_unlock_irqrestore(&tty->ctrl_lock, flags); wake_up_interruptible(&tty->link->read_wait); } } @@ -905,6 +908,7 @@ int n_tty_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg) { struct tty_struct *real_tty; + unsigned long flags; int retval; if (tty->driver->type == TTY_DRIVER_TYPE_PTY && @@ -963,6 +967,7 @@ int n_tty_ioctl(struct tty_struct *tty, struct file *file, return -ENOTTY; if (get_user(pktmode, (int __user *) arg)) return -EFAULT; + spin_lock_irqsave(&tty->ctrl_lock, flags); if (pktmode) { if (!tty->packet) { tty->packet = 1; @@ -970,6 +975,7 @@ int n_tty_ioctl(struct tty_struct *tty, struct file *file, } } else tty->packet = 0; + spin_unlock_irqrestore(&tty->ctrl_lock, flags); return 0; } default: diff --git a/drivers/char/vt.c b/drivers/char/vt.c index 1c2660477135..e64f0bf3624e 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -2541,6 +2541,9 @@ int tioclinux(struct tty_struct *tty, unsigned long arg) if (get_user(type, p)) return -EFAULT; ret = 0; + + lock_kernel(); + switch (type) { case TIOCL_SETSEL: @@ -2560,7 +2563,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg) ret = sel_loadlut(p); break; case TIOCL_GETSHIFTSTATE: - + /* * Make it possible to react to Shift+Mousebutton. * Note that 'shift_state' is an undocumented @@ -2615,6 +2618,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg) ret = -EINVAL; break; } + unlock_kernel(); return ret; } @@ -3829,7 +3833,7 @@ static int con_font_get(struct vc_data *vc, struct console_font_op *op) goto out; c = (font.width+7)/8 * 32 * font.charcount; - + if (op->data && font.charcount > op->charcount) rc = -ENOSPC; if (!(op->flags & KD_FONT_FLAG_OLD)) { diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index c6e72aebd16b..9663e8776724 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -1046,7 +1046,7 @@ static int vt_check(struct file *file) struct inode *inode = file->f_path.dentry->d_inode; struct vc_data *vc; - if (file->f_op->ioctl != tty_ioctl) + if (file->f_op->unlocked_ioctl != tty_ioctl) return -EINVAL; tty = (struct tty_struct *)file->private_data; diff --git a/include/linux/tty.h b/include/linux/tty.h index 265831ccaa88..4d3702bade03 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -183,6 +183,7 @@ struct tty_struct { int index; struct tty_ldisc ldisc; struct mutex termios_mutex; + spinlock_t ctrl_lock; struct ktermios *termios, *termios_locked; char name[64]; struct pid *pgrp; @@ -323,8 +324,7 @@ extern void tty_ldisc_put(int); extern void tty_wakeup(struct tty_struct *tty); extern void tty_ldisc_flush(struct tty_struct *tty); -extern int tty_ioctl(struct inode *inode, struct file *file, unsigned int cmd, - unsigned long arg); +extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg); extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg); -- 2.20.1