From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934621Ab0EEKki (ORCPT ); Wed, 5 May 2010 06:40:38 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:54770 "EHLO bob.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S934533Ab0EEKkg (ORCPT ); Wed, 5 May 2010 06:40:36 -0400 From: Alan Cox Subject: [PATCH 05/20] rocket: kill BKL To: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, arnd@arndb.de Date: Wed, 05 May 2010 11:02:08 +0100 Message-ID: <20100505100207.3595.74716.stgit@localhost.localdomain> In-Reply-To: <20100505100144.3595.65633.stgit@localhost.localdomain> References: <20100505100144.3595.65633.stgit@localhost.localdomain> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We can use the port mutex for this and also for the hangup path so removing the problematic use of the hangup mutex in this driver. Fix up the locking on the various port flags while we are at it. Ultimately this driver needs to be using tty_port_ helpers which would sort this out far better. Signed-off-by: Alan Cox --- drivers/char/rocket.c | 28 +++++++++++++++++++--------- 1 files changed, 19 insertions(+), 9 deletions(-) diff --git a/drivers/char/rocket.c b/drivers/char/rocket.c index 0e29a23..79c3bc6 100644 --- a/drivers/char/rocket.c +++ b/drivers/char/rocket.c @@ -73,7 +73,6 @@ #include #include #include -#include #include #include #include @@ -1017,6 +1016,7 @@ static void rp_close(struct tty_struct *tty, struct file *filp) if (tty_port_close_start(port, tty, filp) == 0) return; + mutex_lock(&port->mutex); cp = &info->channel; /* * Before we drop DTR, make sure the UART transmitter @@ -1060,9 +1060,13 @@ static void rp_close(struct tty_struct *tty, struct file *filp) info->xmit_buf = NULL; } } + spin_lock_irq(&port->lock); info->port.flags &= ~(ASYNC_INITIALIZED | ASYNC_CLOSING | ASYNC_NORMAL_ACTIVE); tty->closing = 0; + spin_unlock_irq(&port->lock); + mutex_unlock(&port->mutex); tty_port_tty_set(port, NULL); + wake_up_interruptible(&port->close_wait); complete_all(&info->close_wait); atomic_dec(&rp_num_ports_open); @@ -1210,11 +1214,13 @@ static int get_config(struct r_port *info, struct rocket_config __user *retinfo) if (!retinfo) return -EFAULT; memset(&tmp, 0, sizeof (tmp)); + mutex_lock(&info->port.mutex); tmp.line = info->line; tmp.flags = info->flags; tmp.close_delay = info->port.close_delay; tmp.closing_wait = info->port.closing_wait; tmp.port = rcktpt_io_addr[(info->line >> 5) & 3]; + mutex_unlock(&info->port.mutex); if (copy_to_user(retinfo, &tmp, sizeof (*retinfo))) return -EFAULT; @@ -1229,10 +1235,13 @@ static int set_config(struct tty_struct *tty, struct r_port *info, if (copy_from_user(&new_serial, new_info, sizeof (new_serial))) return -EFAULT; + mutex_lock(&info->port.mutex); if (!capable(CAP_SYS_ADMIN)) { - if ((new_serial.flags & ~ROCKET_USR_MASK) != (info->flags & ~ROCKET_USR_MASK)) + if ((new_serial.flags & ~ROCKET_USR_MASK) != (info->flags & ~ROCKET_USR_MASK)) { + mutex_unlock(&info->port.mutex); return -EPERM; + } info->flags = ((info->flags & ~ROCKET_USR_MASK) | (new_serial.flags & ROCKET_USR_MASK)); configure_r_port(tty, info, NULL); return 0; @@ -1250,6 +1259,7 @@ static int set_config(struct tty_struct *tty, struct r_port *info, tty->alt_speed = 230400; if ((info->flags & ROCKET_SPD_MASK) == ROCKET_SPD_WARP) tty->alt_speed = 460800; + mutex_unlock(&info->port.mutex); configure_r_port(tty, info, NULL); return 0; @@ -1325,8 +1335,6 @@ static int rp_ioctl(struct tty_struct *tty, struct file *file, if (cmd != RCKP_GET_PORTS && rocket_paranoia_check(info, "rp_ioctl")) return -ENXIO; - lock_kernel(); - switch (cmd) { case RCKP_GET_STRUCT: if (copy_to_user(argp, info, sizeof (struct r_port))) @@ -1350,7 +1358,6 @@ static int rp_ioctl(struct tty_struct *tty, struct file *file, default: ret = -ENOIOCTLCMD; } - unlock_kernel(); return ret; } @@ -1471,7 +1478,6 @@ static void rp_wait_until_sent(struct tty_struct *tty, int timeout) jiffies); printk(KERN_INFO "cps=%d...\n", info->cps); #endif - lock_kernel(); while (1) { txcnt = sGetTxCnt(cp); if (!txcnt) { @@ -1499,7 +1505,6 @@ static void rp_wait_until_sent(struct tty_struct *tty, int timeout) break; } __set_current_state(TASK_RUNNING); - unlock_kernel(); #ifdef ROCKET_DEBUG_WAIT_UNTIL_SENT printk(KERN_INFO "txcnt = %d (jiff=%lu)...done\n", txcnt, jiffies); #endif @@ -1512,6 +1517,7 @@ static void rp_hangup(struct tty_struct *tty) { CHANNEL_t *cp; struct r_port *info = tty->driver_data; + unsigned long flags; if (rocket_paranoia_check(info, "rp_hangup")) return; @@ -1520,11 +1526,15 @@ static void rp_hangup(struct tty_struct *tty) printk(KERN_INFO "rp_hangup of ttyR%d...\n", info->line); #endif rp_flush_buffer(tty); - if (info->port.flags & ASYNC_CLOSING) + spin_lock_irqsave(&info->port.lock, flags); + if (info->port.flags & ASYNC_CLOSING) { + spin_unlock_irqrestore(&info->port.lock, flags); return; + } if (info->port.count) atomic_dec(&rp_num_ports_open); clear_bit((info->aiop * 8) + info->chan, (void *) &xmit_flags[info->board]); + spin_unlock_irqrestore(&info->port.lock, flags); tty_port_hangup(&info->port); @@ -1535,7 +1545,7 @@ static void rp_hangup(struct tty_struct *tty) sDisCTSFlowCtl(cp); sDisTxSoftFlowCtl(cp); sClrTxXOFF(cp); - info->port.flags &= ~ASYNC_INITIALIZED; + clear_bit(ASYNCB_INITIALIZED, &info->port.flags); wake_up_interruptible(&info->port.open_wait); }