aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2015-10-10 11:09:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-10-10 11:09:55 -0700
commit97d0c931c043646abd1f4c5446a8dfcaba162004 (patch)
tree10f3d4d845d8785b8c3202bfa3a47ee5084fa1f6
parent91dbc047e9c1284634ae3570c0382c2288c5548b (diff)
parent0c55627167870255158db1cde0d28366f91c8872 (diff)
downloadlinux-linaro-stable-97d0c931c043646abd1f4c5446a8dfcaba162004.tar.gz
Merge tag 'tty-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver fixes from Greg KH: "Here are a few bug fixes for the tty core that resolve reported issues, and some serial driver fixes as well (including the much-reported imx driver problem) All of these have been in linux-next with no reported problems" * tag 'tty-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: drivers/tty: require read access for controlling terminal serial: 8250: add uart_config entry for PORT_RT2880 tty: fix data race on tty_buffer.commit tty: fix data race in tty_buffer_flush tty: fix data race in flush_to_ldisc tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c serial: atmel: fix error path of probe function tty: don't leak cdev in tty_cdev_add() Revert "serial: imx: remove unbalanced clk_prepare"
-rw-r--r--drivers/tty/n_tty.c15
-rw-r--r--drivers/tty/serial/8250/8250_port.c8
-rw-r--r--drivers/tty/serial/atmel_serial.c2
-rw-r--r--drivers/tty/serial/imx.c20
-rw-r--r--drivers/tty/tty_buffer.c22
-rw-r--r--drivers/tty/tty_io.c40
6 files changed, 79 insertions, 28 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 20932cc9c8f7..b09023b07169 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -343,8 +343,7 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty)
spin_lock_irqsave(&tty->ctrl_lock, flags);
tty->ctrl_status |= TIOCPKT_FLUSHREAD;
spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- if (waitqueue_active(&tty->link->read_wait))
- wake_up_interruptible(&tty->link->read_wait);
+ wake_up_interruptible(&tty->link->read_wait);
}
}
@@ -1382,8 +1381,7 @@ handle_newline:
put_tty_queue(c, ldata);
smp_store_release(&ldata->canon_head, ldata->read_head);
kill_fasync(&tty->fasync, SIGIO, POLL_IN);
- if (waitqueue_active(&tty->read_wait))
- wake_up_interruptible_poll(&tty->read_wait, POLLIN);
+ wake_up_interruptible_poll(&tty->read_wait, POLLIN);
return 0;
}
}
@@ -1667,8 +1665,7 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
if ((read_cnt(ldata) >= ldata->minimum_to_wake) || L_EXTPROC(tty)) {
kill_fasync(&tty->fasync, SIGIO, POLL_IN);
- if (waitqueue_active(&tty->read_wait))
- wake_up_interruptible_poll(&tty->read_wait, POLLIN);
+ wake_up_interruptible_poll(&tty->read_wait, POLLIN);
}
}
@@ -1887,10 +1884,8 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
}
/* The termios change make the tty ready for I/O */
- if (waitqueue_active(&tty->write_wait))
- wake_up_interruptible(&tty->write_wait);
- if (waitqueue_active(&tty->read_wait))
- wake_up_interruptible(&tty->read_wait);
+ wake_up_interruptible(&tty->write_wait);
+ wake_up_interruptible(&tty->read_wait);
}
/**
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index b1e0ba3e525b..0bbf34035d6a 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -261,6 +261,14 @@ configured less than Maximum supported fifo bytes */
UART_FCR7_64BYTE,
.flags = UART_CAP_FIFO,
},
+ [PORT_RT2880] = {
+ .name = "Palmchip BK-3103",
+ .fifo_size = 16,
+ .tx_loadsz = 16,
+ .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+ .rxtrig_bytes = {1, 4, 8, 14},
+ .flags = UART_CAP_FIFO,
+ },
};
/* Uart divisor latch read */
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 5ca5cf3e9359..538ea03bc101 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2786,7 +2786,7 @@ static int atmel_serial_probe(struct platform_device *pdev)
ret = atmel_init_gpios(port, &pdev->dev);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to initialize GPIOs.");
- goto err;
+ goto err_clear_bit;
}
ret = atmel_init_port(port, pdev);
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index fe3d41cc8416..d0388a071ba1 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1631,12 +1631,12 @@ imx_console_write(struct console *co, const char *s, unsigned int count)
int locked = 1;
int retval;
- retval = clk_prepare_enable(sport->clk_per);
+ retval = clk_enable(sport->clk_per);
if (retval)
return;
- retval = clk_prepare_enable(sport->clk_ipg);
+ retval = clk_enable(sport->clk_ipg);
if (retval) {
- clk_disable_unprepare(sport->clk_per);
+ clk_disable(sport->clk_per);
return;
}
@@ -1675,8 +1675,8 @@ imx_console_write(struct console *co, const char *s, unsigned int count)
if (locked)
spin_unlock_irqrestore(&sport->port.lock, flags);
- clk_disable_unprepare(sport->clk_ipg);
- clk_disable_unprepare(sport->clk_per);
+ clk_disable(sport->clk_ipg);
+ clk_disable(sport->clk_per);
}
/*
@@ -1777,7 +1777,15 @@ imx_console_setup(struct console *co, char *options)
retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
- clk_disable_unprepare(sport->clk_ipg);
+ clk_disable(sport->clk_ipg);
+ if (retval) {
+ clk_unprepare(sport->clk_ipg);
+ goto error_console;
+ }
+
+ retval = clk_prepare(sport->clk_per);
+ if (retval)
+ clk_disable_unprepare(sport->clk_ipg);
error_console:
return retval;
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 5a3fa8913880..a660ab181cca 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -242,7 +242,10 @@ void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld)
atomic_inc(&buf->priority);
mutex_lock(&buf->lock);
- while ((next = buf->head->next) != NULL) {
+ /* paired w/ release in __tty_buffer_request_room; ensures there are
+ * no pending memory accesses to the freed buffer
+ */
+ while ((next = smp_load_acquire(&buf->head->next)) != NULL) {
tty_buffer_free(port, buf->head);
buf->head = next;
}
@@ -290,7 +293,10 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size,
if (n != NULL) {
n->flags = flags;
buf->tail = n;
- b->commit = b->used;
+ /* paired w/ acquire in flush_to_ldisc(); ensures
+ * flush_to_ldisc() sees buffer data.
+ */
+ smp_store_release(&b->commit, b->used);
/* paired w/ acquire in flush_to_ldisc(); ensures the
* latest commit value can be read before the head is
* advanced to the next buffer
@@ -393,7 +399,10 @@ void tty_schedule_flip(struct tty_port *port)
{
struct tty_bufhead *buf = &port->buf;
- buf->tail->commit = buf->tail->used;
+ /* paired w/ acquire in flush_to_ldisc(); ensures
+ * flush_to_ldisc() sees buffer data.
+ */
+ smp_store_release(&buf->tail->commit, buf->tail->used);
schedule_work(&buf->work);
}
EXPORT_SYMBOL(tty_schedule_flip);
@@ -467,7 +476,7 @@ static void flush_to_ldisc(struct work_struct *work)
struct tty_struct *tty;
struct tty_ldisc *disc;
- tty = port->itty;
+ tty = READ_ONCE(port->itty);
if (tty == NULL)
return;
@@ -491,7 +500,10 @@ static void flush_to_ldisc(struct work_struct *work)
* is advancing to the next buffer
*/
next = smp_load_acquire(&head->next);
- count = head->commit - head->read;
+ /* paired w/ release in __tty_buffer_request_room() or in
+ * tty_buffer_flush(); ensures we see the committed buffer data
+ */
+ count = smp_load_acquire(&head->commit) - head->read;
if (!count) {
if (next == NULL) {
check_other_closed(tty);
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 02785d844354..2eefaa6e3e3a 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2128,8 +2128,24 @@ retry_open:
if (!noctty &&
current->signal->leader &&
!current->signal->tty &&
- tty->session == NULL)
- __proc_set_tty(tty);
+ tty->session == NULL) {
+ /*
+ * Don't let a process that only has write access to the tty
+ * obtain the privileges associated with having a tty as
+ * controlling terminal (being able to reopen it with full
+ * access through /dev/tty, being able to perform pushback).
+ * Many distributions set the group of all ttys to "tty" and
+ * grant write-only access to all terminals for setgid tty
+ * binaries, which should not imply full privileges on all ttys.
+ *
+ * This could theoretically break old code that performs open()
+ * on a write-only file descriptor. In that case, it might be
+ * necessary to also permit this if
+ * inode_permission(inode, MAY_READ) == 0.
+ */
+ if (filp->f_mode & FMODE_READ)
+ __proc_set_tty(tty);
+ }
spin_unlock_irq(&current->sighand->siglock);
read_unlock(&tasklist_lock);
tty_unlock(tty);
@@ -2418,7 +2434,7 @@ static int fionbio(struct file *file, int __user *p)
* Takes ->siglock() when updating signal->tty
*/
-static int tiocsctty(struct tty_struct *tty, int arg)
+static int tiocsctty(struct tty_struct *tty, struct file *file, int arg)
{
int ret = 0;
@@ -2452,6 +2468,13 @@ static int tiocsctty(struct tty_struct *tty, int arg)
goto unlock;
}
}
+
+ /* See the comment in tty_open(). */
+ if ((file->f_mode & FMODE_READ) == 0 && !capable(CAP_SYS_ADMIN)) {
+ ret = -EPERM;
+ goto unlock;
+ }
+
proc_set_tty(tty);
unlock:
read_unlock(&tasklist_lock);
@@ -2844,7 +2867,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
no_tty();
return 0;
case TIOCSCTTY:
- return tiocsctty(tty, arg);
+ return tiocsctty(tty, file, arg);
case TIOCGPGRP:
return tiocgpgrp(tty, real_tty, p);
case TIOCSPGRP:
@@ -3151,13 +3174,18 @@ struct class *tty_class;
static int tty_cdev_add(struct tty_driver *driver, dev_t dev,
unsigned int index, unsigned int count)
{
+ int err;
+
/* init here, since reused cdevs cause crashes */
driver->cdevs[index] = cdev_alloc();
if (!driver->cdevs[index])
return -ENOMEM;
- cdev_init(driver->cdevs[index], &tty_fops);
+ driver->cdevs[index]->ops = &tty_fops;
driver->cdevs[index]->owner = driver->owner;
- return cdev_add(driver->cdevs[index], dev, count);
+ err = cdev_add(driver->cdevs[index], dev, count);
+ if (err)
+ kobject_put(&driver->cdevs[index]->kobj);
+ return err;
}
/**