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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-10-10 11:09:55 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-10-10 11:09:55 -0700 |
commit | 97d0c931c043646abd1f4c5446a8dfcaba162004 (patch) | |
tree | 10f3d4d845d8785b8c3202bfa3a47ee5084fa1f6 /drivers | |
parent | 91dbc047e9c1284634ae3570c0382c2288c5548b (diff) | |
parent | 0c55627167870255158db1cde0d28366f91c8872 (diff) | |
download | linux-97d0c931c043646abd1f4c5446a8dfcaba162004.tar.bz2 |
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"
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/tty/n_tty.c | 15 | ||||
-rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 8 | ||||
-rw-r--r-- | drivers/tty/serial/atmel_serial.c | 2 | ||||
-rw-r--r-- | drivers/tty/serial/imx.c | 20 | ||||
-rw-r--r-- | drivers/tty/tty_buffer.c | 22 | ||||
-rw-r--r-- | drivers/tty/tty_io.c | 40 |
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(¤t->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; } /** |