Commit Graph

7819 Commits

Author SHA1 Message Date
Jiri Olsa fcdba07ee3 tty,vcs removing con_buf/conf_buf_mtx
seems there's no longer need for using con_buf/conf_buf_mtx
as vcs_read/vcs_write buffer for user's data.

The do_con_write function, that was the other user of this,
is currently using its own kmalloc-ed buffer.

Not sure when this got changed, as I was able to find this code
in 2.6.9, but it's already gone as far as current git history
goes - 2.6.12-rc2.

AFAICS there's a behaviour change with the current change.
The lseek is not completely mutually exclusive with the
vcs_read/vcs_write - the file->f_pos might get updated
via lseek callback during the vcs_read/vcs_write processing.

I tried to find out if the prefered behaviour is to keep
this in sync within read/write/lseek functions, but I did
not find any pattern on different places.

I guess if user end up calling write/lseek from different
threads she should know what she's doing. If needed we
could use dedicated fd mutex/buffer.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:13:19 -08:00
Jiri Olsa dc1892c4bc tty,vcs: lseek/VC-release race fix
there's a race between vcs's lseek handler and VC release.

The lseek handler does not hold console_lock and touches
VC's size info. If during this the VC got released, there's
an access violation.

Following program triggers the issue for me:

[SNIP]
#define _BSD_SOURCE
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/vt.h>
#include <unistd.h>
#include <errno.h>

static int run_seek(void)
{
        while(1) {
                int fd;
                fd = open("./vcs30", O_RDWR);
                while(lseek(fd, 0, 0) != -1);
                close(fd);
        }
}

static int open_ioctl_tty(void)
{
        return open("/dev/tty1", O_RDWR);
}

static int do_ioctl(int fd, int req, int i)
{
        return ioctl(fd, req, i);
}

#define INIT(i) do_ioctl(ioctl_fd, VT_ACTIVATE, i)
#define SHUT(i) do_ioctl(ioctl_fd, VT_DISALLOCATE, i)

int main(int argc, char **argv)
{
        int ioctl_fd = open_ioctl_tty();

        if (ioctl < 0) {
                perror("open tty1 failed\n");
                return -1;
        }

        if ((-1 == mknod("vcs30", S_IFCHR|0666, makedev(7, 30))) &&
            (errno != EEXIST)) {
                printf("errno %d\n", errno);
                perror("failed to create vcs30");
                return -1;
        }

        do_ioctl(ioctl_fd, VT_LOCKSWITCH, 0);

        if (!fork())
                run_seek();

        while(1) {
                INIT(30);
                SHUT(30);
        }

        return 0;
}
[SNIP]

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:13:19 -08:00
Mandeep Singh Baines 1ffdda9503 TTY: use appropriate printk priority level
printk()s without a priority level default to KERN_WARNING. To reduce
noise at KERN_WARNING, this patch set the priority level appriopriately
for unleveled printks()s. This should be useful to folks that look at
dmesg warnings closely.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:12:40 -08:00
Mike Frysinger 5427bcf5e9 hvc: add Blackfin JTAG console support
This converts the existing bfin_jtag_comm TTY driver to the HVC layer so
that the common HVC code can worry about all of the TTY/polling crap and
leave the Blackfin code to worry about the Blackfin bits.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:12:40 -08:00
Arthur Taylor 9fc3de9c83 vt: Add virtual console keyboard mode OFF
virtual console: add keyboard mode OFF

Add a new mode for the virtual console keyboard OFF in which all input
other than shift keys is ignored. Prevents vt input buffers from
overflowing when a program opens but doesn't read from a tty, like X11
using evdev for input.

Signed-off-by: Arthur Taylor <art@ified.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:12:40 -08:00
Jesper Juhl f95497d9df serial, pch uart: Remove duplicate inclusion of linux/pci.h header
Only include linux/pci.h once in drivers/tty/serial/pch_uart.c

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-02-17 17:39:37 +01:00
Tejun Heo 58a69cb47e workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable'
There are two spellings in use for 'freeze' + 'able' - 'freezable' and
'freezeable'.  The former is the more prominent one.  The latter is
mostly used by workqueue and in a few other odd places.  Unify the
spelling to 'freezable'.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Steven Whitehouse <swhiteho@redhat.com>
2011-02-16 17:48:59 +01:00
Linus Torvalds 048f039f3e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68knommu: set flow handler for secondary interrupt controller of 5249
  m68knommu: remove use of IRQ_FLG_LOCK from 68360 platform support
  m68knommu: fix dereference of port.tty
  m68knommu: add missing linker __modver section
  m68knommu: fix mis-named variable int set_irq_chip loop
  m68knommu: add optimize memmove() function
  m68k: remove arch specific non-optimized memcmp()
  m68knommu: fix use of un-defined _TIF_WORK_MASK
  m68knommu: Rename m548x_wdt.c to m54xx_wdt.c
  m68knommu: fix m548x_wdt.c compilation after headers renaming
  m68knommu: Remove dependencies on nonexistent M68KNOMMU
2011-02-15 17:51:18 -08:00
Greg Ungerer bc0c36d3c8 m68knommu: fix dereference of port.tty
The struct_tty associated with a port is now a direct pointer
from within the local private driver info struct. So fix all uses
of it.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2011-02-16 09:43:18 +10:00
Linus Torvalds 87450bd55d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: matrix_keypad - increase the limit of rows and columns
  Input: wacom - fix error path in wacom_probe()
  Input: ads7846 - check proper condition when freeing gpio
  Revert "Input: do not pass injected events back to the originating handler"
  Input: sysrq - rework re-inject logic
  Input: serio - clear pending rescans after sysfs driver rebind
  Input: rotary_encoder - use proper irqflags
  Input: wacom_w8001 - report resolution to userland
2011-02-15 09:40:27 -08:00
Jesper Juhl 18fd7315cc Freescale STMP37XX/STMP378X Application UART driver: remove duplicate linux/device.h include
Do not include linux/device.h twice in drivers/tty/serial/mxs-auart.c .
Once is enough.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-02-15 18:35:42 +01:00
Paul Bolle 46a1ca7068 hvcs: fix typo in comment
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Reviewed-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-02-15 10:24:53 +01:00
Paul Mundt 18e9550273 Merge branch 'sh/st-integration' into sh-latest 2011-02-15 16:48:28 +09:00
Sascha Hauer f19693a17c Merge commit 'v2.6.38-rc4' into imx-for-2.6.39
Conflicts:
	arch/arm/mach-mxs/clock-mx28.c

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-02-11 08:33:14 +01:00
Stephen Boyd 8e6d3fe1af hvc_dcc: Simplify assembly for v6 and v7 ARM
The inline assembly differences for v6 vs. v7 in the hvc_dcc
driver are purely optimizations. On a v7 processor, an mrc with
the pc sets the condition codes to the 28-31 bits of the register
being read. It just so happens that the TX/RX full bits the DCC
driver is testing for are high enough in the register to be put
into the condition codes. On a v6 processor, this "feature" isn't
implemented and thus we have to do the usual read, mask, test
operations to check for TX/RX full.

Since we already test the RX/TX full bits before calling
__dcc_getchar() and __dcc_putchar() we don't actually need to do
anything special for v7 over v6. The only difference is in
hvc_dcc_get_chars(). We would test RX full, poll RX full, and
then read a character from the buffer, whereas now we will test
RX full, read a character from the buffer, and then test RX full
again for the second iteration of the loop. It doesn't seem
possible for the buffer to go from full to empty between testing
the RX full and reading a character. Therefore, replace the v7
versions with the v6 versions and everything works the same.

Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:05:43 -08:00
Stephen Boyd bf73bd35a2 hvc_dcc: Simplify put_chars()/get_chars() loops
Casting and anding with 0xff is unnecessary in
hvc_dcc_put_chars() since buf is already a char[].
__dcc_get_char() can't return an int less than 0 since it only
returns a char. Simplify the if statement in hvc_dcc_get_chars()
to take this into account.

Cc: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:05:43 -08:00
Stephen Boyd a996320146 hvc_dcc: Fix bad code generation by marking assembly volatile
Without marking the asm __dcc_getstatus() volatile my compiler
decides it can cache the value of __ret in a register and then
check the value of it continually in hvc_dcc_put_chars() (I had
to replace get_wait/put_wait with 1 and fixup the branch
otherwise my disassembler barfed on __dcc_(get|put)char).

00000000 <hvc_dcc_put_chars>:
   0:   ee103e11        mrc     14, 0, r3, cr0, cr1, {0}
   4:   e3a0c000        mov     ip, #0  ; 0x0
   8:   e2033202        and     r3, r3, #536870912      ; 0x20000000
   c:   ea000006        b       2c <hvc_dcc_put_chars+0x2c>
  10:   e3530000        cmp     r3, #0  ; 0x0
  14:   1afffffd        bne     10 <hvc_dcc_put_chars+0x10>
  18:   e7d1000c        ldrb    r0, [r1, ip]
  1c:   ee10fe11        mrc     14, 0, pc, cr0, cr1, {0}
  20:   2afffffd        bcs     1c <hvc_dcc_put_chars+0x1c>
  24:   ee000e15        mcr     14, 0, r0, cr0, cr5, {0}
  28:   e28cc001        add     ip, ip, #1      ; 0x1
  2c:   e15c0002        cmp     ip, r2
  30:   bafffff6        blt     10 <hvc_dcc_put_chars+0x10>
  34:   e1a00002        mov     r0, r2
  38:   e12fff1e        bx      lr

As you can see, the value of the mrc is checked against
DCC_STATUS_TX (bit 29) and then stored in r3 for later use.
Marking the asm volatile produces the following:

00000000 <hvc_dcc_put_chars>:
   0:   e3a03000        mov     r3, #0  ; 0x0
   4:   ea000007        b       28 <hvc_dcc_put_chars+0x28>
   8:   ee100e11        mrc     14, 0, r0, cr0, cr1, {0}
   c:   e3100202        tst     r0, #536870912  ; 0x20000000
  10:   1afffffc        bne     8 <hvc_dcc_put_chars+0x8>
  14:   e7d10003        ldrb    r0, [r1, r3]
  18:   ee10fe11        mrc     14, 0, pc, cr0, cr1, {0}
  1c:   2afffffd        bcs     18 <hvc_dcc_put_chars+0x18>
  20:   ee000e15        mcr     14, 0, r0, cr0, cr5, {0}
  24:   e2833001        add     r3, r3, #1      ; 0x1
  28:   e1530002        cmp     r3, r2
  2c:   bafffff5        blt     8 <hvc_dcc_put_chars+0x8>
  30:   e1a00002        mov     r0, r2
  34:   e12fff1e        bx      lr

which looks better and actually works. Mark all the inline
assembly in this file as volatile since we don't want the
compiler to optimize away these statements or move them around
in any way.

Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 16:05:43 -08:00
Sonic Zhang 0f66e50af5 serial: bfin_5xx: split uart RX lock from uart port lock to avoid deadlock
The RX lock is used to protect the RX buffer from concurrent access in DMA
mode between the timer and RX interrupt routines.  It is independent from
the uart lock which is used to protect the TX buffer.  It is possible for
a uart TX transfer to be started up from the RX interrupt handler if low
latency is enabled.  So we need to split the locks to avoid deadlocking in
this situation.

In PIO mode, the RX lock is not necessary because the handle_simple_irq
and handle_level_irq functions ensure driver interrupt handlers are called
once on one core.

And now that the RX path has its own lock, the TX interrupt has nothing to
do with the RX path, so disabling it at the same time.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:44:54 -08:00
Ben Hutchings 3e517f4b1d 68360serial: Plumb in rs_360_get_icount()
Commit 0587102cf9 replaced a direct
implementation of SIOCGICOUNT with an implementation of
tty_operations::get_icount, but it did not actually set
rs_360_ops.get_icount.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@kernel.org [2.6.37]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:44:23 -08:00
Ken Mills 91f78f3669 n_gsm: copy mtu over when configuring via ioctl interface
This field is settable but did not get copied.

Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:43:43 -08:00
Amit Shah 51df0acc3d virtio: console: Move file back to drivers/char/
Commit 728674a7e4 moved virtio_console.c
to drivers/tty/hvc/ under the perception of this being an hvc driver.
It was such once, but these days it has generic communication
capabilities as well, so move it to drivers/char/.

In the future, the hvc part from this file can be split off and moved
under drivers/tty/hvc/.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:43:12 -08:00
Tomoya MORINAGA 380042f2db serial: pch_uart: revert Kconfig for non-DMA mode
PCH_DMA is not always enabled when a user uses PCH_UART.
Since overhead of DMA is not small, in case of low frequent
communication, without DMA is better.
Thus, "select PCH_DMA" and DMADEVICES are unnecessary

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:19:33 -08:00
Tomoya MORINAGA 4564e1ef21 serial: pch_uart: support new device ML7213
Support ML7213 device of OKI SEMICONDUCTOR.
ML7213 is companion chip of Intel Atom E6xx series for IVI(In-Vehicle Infotainment).
ML7213 is completely compatible for Intel EG20T PCH.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:18:33 -08:00
Tejun Heo f094298bae 68328serial: remove unsed m68k_serial->tqueue_hangup
m68k_serial->tqueue_hangup is unused.  Remove it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:16:49 -08:00
Yin Kangkai 5933a161ab serial-core: reset the console speed on resume
On some platforms, we need to restore the console speed on resume even
it was not suspended (no_console_suspend), and on others we don't have
to do that.

So don't care about the "console_suspend_enabled" and unconditionally
reset the console speed if it is a console.

This is actually a redo of ba15ab0 (Set proper console speed on resume
if console suspend is disabled) from Deepak Saxena.  I also tried to
investigate more to find out if this change will break others, here is
what I've found out:

commit 891b9dd107
Author: Jason Wang <jason77.wang@gmail.com>
    serial-core: restore termios settings when resume console ports

commit ca2e71aa8c
Author: Jason Wang <jason77.wang@gmail.com>
    serial-core: skip call set_termios/console_start when no_console_suspend

commit 4547be7809
Author: Stanislav Brabec <sbrabec@suse.cz>
    serial-core: resume serial hardware with no_console_suspend

commit ba15ab0e8d
Author: Deepak Saxena <dsaxena@laptop.org>
    Set proper console speed on resume if console suspend is disabled

from ba15ab0, we learned that, even if the console suspend is disabled
(when no_console_suspend is set), we may still need to "reset the port
to the state it was in before we suspended."

Then with 4547be7, this piece of code is removed.

And then Jason Wang added that back in ca2e71a and 891b9dd, to fix
some breakage on OMAP3EVM platform. From ca2e71a we learned that the
"set_termios" things is actually needed by both console is suspended
and not suspended.

That's why I removed the console_suspended_enabled condition, and only
call console_start() when we actually suspeneded it.

I also noticed in this thread:
http://marc.info/?t=129079257100004&r=1&w=2, which talked about on
some platforms, UART HW will be cut power whether or not we set
no_console_suspend, and then on resume it does not work quite well. I
have a similar HW, and this patch fixed this issue, don't know if this
patch also works on their platforms.

[Update: Stanislav tested this patch on Zaurus and reported it improves the
situation. Thanks.]

CC: Greg KH <greg@kroah.com>
CC: Deepak Saxena <dsaxena@laptop.org>
CC: Jason Wang <jason77.wang@gmail.com>
CC: Stanislav Brabec <sbrabec@suse.cz>
CC: Daniel Drake <dsd@laptop.org>
Signed-off-by: Yin Kangkai <kangkai.yin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:14:00 -08:00
Dan Carpenter d8653d305e serial: mrst_max3110: make buffer larger
This is used to store the spi_device ->modalias so they have to be the same
size.  SPI_NAME_SIZE is 32.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:13:17 -08:00
Tejun Heo 0a1f1a0b62 tty_ldisc: don't use flush_scheduled_work()
flush_scheduled_work() is scheduled to be deprecated.  Explicitly sync
flush the used work items instead.  Note that before this change,
flush_scheduled_work() wouldn't have properly flushed tty->buf.work if
it were on timer.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:12:25 -08:00
Jarkko Nikula 78841462d7 serial: omap-serial: Enable the UART wake-up bits always
OMAP can do also dynamic idling so wake-up enable register should be set
also while system is running. If UART_OMAP_WER is not set, then for instance
the RX activity cannot wake up the UART port that is sleeping.

This RX wake-up feature was working when the 8250 driver was used instead
of omap-serial. Reason for this is that the 8250 doesn't set the
UART_OMAP_WER and then arch/arm/mach-omap2/pm34xx.c ends up saving and
restoring the reset default which is the same than value
OMAP_UART_WER_MOD_WKUP here.

Fix this by moving the conditional UART_OMAP_WER write from serial_omap_pm
into serial_omap_startup where wake-up bits are set unconditionally.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Cc: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 14:10:22 -08:00
Thomas Weber 364a6ece62 OMAP: Enable Magic SysRq on serial console ttyOx
Magic SysRq key is not working for OMAP on new serial
console ttyOx because SUPPORT_SYSRQ is not defined
for omap-serial.

This patch defines SUPPORT_SYSRQ in omap-serial and
enables handling of Magic SysRq character.

Further there is an issue of losing first break character.
Removing the reset of the lsr_break_flag fixes this issue.

Signed-off-by: Thomas Weber <weber@corscience.de>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Tested-by: Manjunath G Kondaiah <manjugk@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 11:43:11 -08:00
Russ Gorby 2f1522eccb serial: ifx6x60: expanded info available from platform data
Some platform attributes (e.g. max_hz, use_dma) were being intuited
from the modem type. These things should be specified by the platform
data.

Added max_hz, use_dma to ifx_modem_platform_data definition,
replaced is_6160 w/ modem_type, and changed clients accordingly

Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 11:43:10 -08:00
Feng Tang a5f4dbf0ae serial: mfd: remove the timeout workaround for A0
This is kind of a revert for commit 669b7a0938 "hsu: add a periodic
timer to check dma rx channel", which is a workaround for a bug in A0
stepping silicon, where a dma rx data timeout is missing for some case.
Since new silicon has fixed it and the old version is phasing out, no
need to carry on it any more.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 11:40:46 -08:00
Vasiliy Kulikov 940f3be405 tty: serial: bfin_sport_uart: fix signedness error
sport->port.irq is unsigned, check for <0 doesn't make sense.
Explicitly cast it to int to check for error.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-03 11:40:46 -08:00
Paul Mundt 17292ecc07 Merge branch 'sh/urgent' into sh-latest 2011-02-01 19:38:49 +09:00
Linus Torvalds abfa44b5fd Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  tty/serial: fix apbuart build
  n_hdlc: fix read and write locking
  serial: unbreak billionton CF card
  tty: use for_each_console() and WARN() on sysfs failures
  vt: fix issue when fbcon wants to takeover a second time.

Fix up trivial conflict in drivers/tty/tty_io.c
2011-02-01 08:05:19 +10:00
Paul Mundt 6b620478e5 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into common/serial-rework 2011-01-26 18:23:27 +09:00
Linus Torvalds 6fb1b30425 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: wacom - pass touch resolution to clients through input_absinfo
  Input: wacom - add 2 Bamboo Pen and touch models
  Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent
  Input: sparse-keymap - fix KEY_VSW handling in sparse_keymap_setup
  Input: tegra-kbc - add tegra keyboard driver
  Input: gpio_keys - switch to using request_any_context_irq
  Input: serio - allow registered drivers to get status flag
  Input: ct82710c - return proper error code for ct82c710_open
  Input: bu21013_ts - added regulator support
  Input: bu21013_ts - remove duplicate resolution parameters
  Input: tnetv107x-ts - don't treat NULL clk as an error
  Input: tnetv107x-keypad - don't treat NULL clk as an error

Fix up trivial conflicts in drivers/input/keyboard/Makefile due to
additions of tc3589x/Tegra drivers
2011-01-26 16:31:44 +10:00
Torben Hohn ac751efa6a console: rename acquire/release_console_sem() to console_lock/unlock()
The -rt patches change the console_semaphore to console_mutex.  As a
result, a quite large chunk of the patches changes all
acquire/release_console_sem() to acquire/release_console_mutex()

This commit makes things use more neutral function names which dont make
implications about the underlying lock.

The only real change is the return value of console_trylock which is
inverted from try_acquire_console_sem()

This patch also paves the way to switching console_sem from a semaphore to
a mutex.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Thomas Gleixner <tglx@tglx.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:06 +10:00
David Brown c243e52843 Merge branch 'msm-uart' into for-next
* msm-uart:
  serial: msm: Add support for UARTDM cores
  msm: Add name field to UART resources
2011-01-24 11:16:43 -08:00
Russell King 82e6923e18 ARM: lh7a40x: remove unmaintained platform support
lh7a40x has only been receiving updates for updates to generic code.
The last involvement from the maintainer according to the git logs was
in 2006.  As such, it is a maintainence burden with no benefit.

This gets rid of two defconfigs.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-24 19:05:19 +00:00
Randy Dunlap fed7bb324c tty/serial: fix apbuart build
Fix build errors by selecting SERIAL_CORE:

ERROR: "uart_register_driver" [drivers/tty/serial/apbuart.ko] undefined!
ERROR: "uart_write_wakeup" [drivers/tty/serial/apbuart.ko] undefined!
ERROR: "uart_update_timeout" [drivers/tty/serial/apbuart.ko] undefined!
ERROR: "uart_get_divisor" [drivers/tty/serial/apbuart.ko] undefined!
ERROR: "uart_get_baud_rate" [drivers/tty/serial/apbuart.ko] undefined!
ERROR: "uart_add_one_port" [drivers/tty/serial/apbuart.ko] undefined!
ERROR: "uart_unregister_driver" [drivers/tty/serial/apbuart.ko] undefined!
ERROR: "uart_remove_one_port" [drivers/tty/serial/apbuart.ko] undefined!

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-22 19:15:02 -08:00
Paul Fulghum 1035b63d3c n_hdlc: fix read and write locking
Fix locking in read and write code of n_hdlc line discipline.

2.6.36 replaced lock_kernel() with tty_lock().  The tty mutex is not
dropped automatically when the thread sleeps like the BKL.  This results
in a blocked read or write holding the tty mutex and stalling operations
by other devices that use the tty mutex.

A review of n_hdlc read and write code shows:
1. neither BKL or tty mutex are required for correct operation
2. read can block while read data is available if data is posted
   between availability check and call to interruptible_sleep_on()
3. write does not set process state to TASK_INTERRUPTIBLE
   on each pass through the processing loop which can cause
   unneeded scheduling of the thread

The unnecessary tty mutex references have been removed.

Read changed to use same code as n_tty read
for completing reads and blocking.

Write corrected to set process state to TASK_INTERRUPTIBLE on each pass
through processing loop.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-22 19:15:01 -08:00
Pavel Machek d0694e2aeb serial: unbreak billionton CF card
Unbreak Billionton CF bluetooth card. This actually fixes a regression
on zaurus.

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-22 19:15:01 -08:00
Kay Sievers a2a6a822ad tty: use for_each_console() and WARN() on sysfs failures
This fixes the build warnings in the tty code, and uses the proper
function for iterating over the console devices.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-22 19:15:00 -08:00
Dave Airlie c55c63c653 vt: fix issue when fbcon wants to takeover a second time.
With framebuffer handover and multiple GPUs, we get into a
position where the fbcon unbinds the vesafb framebuffer for GPU 1,
but we still have a radeon framebuffer bound from GPU 0, so
we don't unregister the console driver. Then when we tried to bind
the new radeon framebuffer for GPU1 we never get to the bind
call as we fail due to the console being registered already.

This changes the return value to -EBUSY when the driver is
already registered and continues to bind for -EBUSY.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-22 19:15:00 -08:00
Linus Torvalds 8d99641f6c Merge branch 'akpm'
* akpm:
  kernel/smp.c: consolidate writes in smp_call_function_interrupt()
  kernel/smp.c: fix smp_call_function_many() SMP race
  memcg: correctly order reading PCG_USED and pc->mem_cgroup
  backlight: fix 88pm860x_bl macro collision
  drivers/leds/ledtrig-gpio.c: make output match input, tighten input checking
  MAINTAINERS: update Atmel AT91 entry
  mm: fix truncate_setsize() comment
  memcg: fix rmdir, force_empty with THP
  memcg: fix LRU accounting with THP
  memcg: fix USED bit handling at uncharge in THP
  memcg: modify accounting function for supporting THP better
  fs/direct-io.c: don't try to allocate more than BIO_MAX_PAGES in a bio
  mm: compaction: prevent division-by-zero during user-requested compaction
  mm/vmscan.c: remove duplicate include of compaction.h
  memblock: fix memblock_is_region_memory()
  thp: keep highpte mapped until it is no longer needed
  kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT
2011-01-20 17:02:14 -08:00
Linus Torvalds fc887b15d9 Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  tty: update MAINTAINERS file due to driver movement
  tty: move drivers/serial/ to drivers/tty/serial/
  tty: move hvc drivers to drivers/tty/hvc/
2011-01-20 16:39:23 -08:00
Greg Kroah-Hartman ab4382d274 tty: move drivers/serial/ to drivers/tty/serial/
The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-13 12:10:18 -08:00
Greg Kroah-Hartman 728674a7e4 tty: move hvc drivers to drivers/tty/hvc/
As requested by Arnd Bergmann, the hvc drivers are now
moved to the drivers/tty/hvc/ directory.  The virtio_console.c driver
was also moved, as it required the hvc_console.h file to be able to be
built, and it really is a hvc driver.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-13 12:03:00 -08:00
Linus Torvalds 56b85f32d5 Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (36 commits)
  serial: apbuart: Fixup apbuart_console_init()
  TTY: Add tty ioctl to figure device node of the system console.
  tty: add 'active' sysfs attribute to tty0 and console device
  drivers: serial: apbuart: Handle OF failures gracefully
  Serial: Avoid unbalanced IRQ wake disable during resume
  tty: fix typos/errors in tty_driver.h comments
  pch_uart : fix warnings for 64bit compile
  8250: fix uninitialized FIFOs
  ip2: fix compiler warning on ip2main_pci_tbl
  specialix: fix compiler warning on specialix_pci_tbl
  rocket: fix compiler warning on rocket_pci_ids
  8250: add a UPIO_DWAPB32 for 32 bit accesses
  8250: use container_of() instead of casting
  serial: omap-serial: Add support for kernel debugger
  serial: fix pch_uart kconfig & build
  drivers: char: hvc: add arm JTAG DCC console support
  RS485 documentation: add 16C950 UART description
  serial: ifx6x60: fix memory leak
  serial: ifx6x60: free IRQ on error
  Serial: EG20T: add PCH_UART driver
  ...

Fixed up conflicts in drivers/serial/apbuart.c with evil merge that
makes the code look fairly sane (unlike either side).
2011-01-07 14:39:20 -08:00
Werner Fink b7b8de0873 TTY: Add tty ioctl to figure device node of the system console.
This has been in the SuSE kernels for a very long time.

Signed-off-by: Werner Fink <werner@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-12-16 16:18:28 -08:00
Kay Sievers fbc92a3455 tty: add 'active' sysfs attribute to tty0 and console device
tty: add 'active' sysfs attribute to tty0 and console device

Userspace can query the actual virtual console, and the configured
console devices behind /dev/tt0 and /dev/console.

The last entry in the list of devices is the active device, analog
to the console= kernel command line option.

The attribute supports poll(), which is raised when the virtual
console is changed or /dev/console is reconfigured.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

index 0000000..b138b66
2010-12-16 16:15:34 -08:00
Ken Mills 093d804611 n_gsm: gsm_data_alloc buffer allocation could fail and it is not being checked
gsm_data_alloc buffer allocation could fail and it is not being checked.

Add check for allocated buffer and return if the buffer allocation
fails.

Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-12-16 13:03:13 -08:00
Ken Mills be7a7411d6 n_gsm: Fix message length handling when building header
Fix message length handling when building header

When the message length is greater than 127, the length field in the header
is built incorrectly. According to the spec, when the length is less than 128
the length field is a single byte formatted as: bbbbbbb1. When it is greater
than 127 then the field is two bytes of the format: bbbbbbb0 bbbbbbbb.

Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-12-16 13:03:12 -08:00
Linus Torvalds eed5ee1a3a Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  serial: mfd: adjust the baud rate setting
  TTY: open/hangup race fixup
  TTY: don't allow reopen when ldisc is changing
  NET: wan/x25, fix ldisc->open retval
  TTY: ldisc, fix open flag handling
  serial8250: Mark console as CON_ANYTIME
2010-12-02 12:58:16 -08:00
Jiri Slaby acfa747baf TTY: open/hangup race fixup
Like in the "TTY: don't allow reopen when ldisc is changing" patch,
this one fixes a TTY WARNING as described in the option 1) there:
1) __tty_hangup from tty_ldisc_hangup to tty_ldisc_enable. During this
section tty_lock is held. However tty_lock is temporarily dropped in
the middle of the function by tty_ldisc_hangup.

The fix is to introduce a new flag which we set during the unlocked
window and check it in tty_reopen too. The flag is TTY_HUPPING and is
cleared after TTY_HUPPED is set.

While at it, remove duplicate TTY_HUPPED set_bit. The one after
calling ops->hangup seems to be more correct. But anyway, we hold
tty_lock, so there should be no difference.

Also document the function it does that kind of crap.

Nicely reproducible with two forked children:
static void do_work(const char *tty)
{
	if (signal(SIGHUP, SIG_IGN) == SIG_ERR) exit(1);
	setsid();
	while (1) {
		int fd = open(tty, O_RDWR|O_NOCTTY);
		if (fd < 0) continue;
		if (ioctl(fd, TIOCSCTTY)) continue;
		if (vhangup()) continue;
		close(fd);
	}
	exit(0);
}

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: <Valdis.Kletnieks@vt.edu>
Reported-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-29 14:52:48 -08:00
Jiri Slaby e2efafbf13 TTY: don't allow reopen when ldisc is changing
There are many WARNINGs like the following reported nowadays:
WARNING: at drivers/tty/tty_io.c:1331 tty_open+0x2a2/0x49a()
Hardware name: Latitude E6500
Modules linked in:
Pid: 1207, comm: plymouthd Not tainted 2.6.37-rc3-mmotm1123 #3
Call Trace:
 [<ffffffff8103b189>] warn_slowpath_common+0x80/0x98
 [<ffffffff8103b1b6>] warn_slowpath_null+0x15/0x17
 [<ffffffff8128a3ab>] tty_open+0x2a2/0x49a
 [<ffffffff810fd53f>] chrdev_open+0x11d/0x146
...

This means tty_reopen is called without TTY_LDISC set. For further
considerations, note tty_lock is held in tty_open. TTY_LDISC is cleared in:
1) __tty_hangup from tty_ldisc_hangup to tty_ldisc_enable. During this
section tty_lock is held. However tty_lock is temporarily dropped in
the middle of the function by tty_ldisc_hangup.

2) tty_release via tty_ldisc_release till the end of tty existence. If
tty->count <= 1, tty_lock is taken, TTY_CLOSING bit set and then
tty_ldisc_release called. tty_reopen checks TTY_CLOSING before checking
TTY_LDISC.

3) tty_set_ldisc from tty_ldisc_halt to tty_ldisc_enable. We:
   * take tty_lock, set TTY_LDISC_CHANGING, put tty_lock
   * call tty_ldisc_halt (clear TTY_LDISC), tty_lock is _not_ held
   * do some other work
   * take tty_lock, call tty_ldisc_enable (set TTY_LDISC), put
     tty_lock

I cannot see how 2) can be a problem, as there I see no race. OTOH, 1)
and 3) can happen without problems. This patch the case 3) by checking
TTY_LDISC_CHANGING along with TTY_CLOSING in tty_reopen. 1) will be
fixed in the following patch.

Nicely reproducible with two processes:
while (1) {
	fd = open("/dev/ttyS1", O_RDWR);
	if (fd < 0) {
		warn("open");
		continue;
	}
	close(fd);
}
--------
while (1) {
        fd = open("/dev/ttyS1", O_RDWR);
        ld1 = 0; ld2 = 2;
        while (1) {
                ioctl(fd, TIOCSETD, &ld1);
                ioctl(fd, TIOCSETD, &ld2);
        }
        close(fd);
}

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: <Valdis.Kletnieks@vt.edu>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-29 14:52:48 -08:00
Jiri Slaby 7f90cfc505 TTY: ldisc, fix open flag handling
When a concrete ldisc open fails in tty_ldisc_open, we forget to clear
TTY_LDISC_OPEN. This causes a false warning on the next ldisc open:
WARNING: at drivers/char/tty_ldisc.c:445 tty_ldisc_open+0x26/0x38()
Hardware name: System Product Name
Modules linked in: ...
Pid: 5251, comm: a.out Tainted: G        W  2.6.32-5-686 #1
Call Trace:
 [<c1030321>] ? warn_slowpath_common+0x5e/0x8a
 [<c1030357>] ? warn_slowpath_null+0xa/0xc
 [<c119311c>] ? tty_ldisc_open+0x26/0x38
 [<c11936c5>] ? tty_set_ldisc+0x218/0x304
...

So clear the bit when failing...

Introduced in c65c9bc3ef (tty: rewrite the ldisc locking) back in
2.6.31-rc1.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Reported-by: Sergey Lapin <slapin@ossfans.org>
Tested-by: Sergey Lapin <slapin@ossfans.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-29 14:51:54 -08:00
Linus Torvalds 864ee6cb22 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: fix typo in keycode validation supporting large scancodes
  Input: aiptek - tighten up permissions on sysfs attributes
  Input: sysrq - pass along lone Alt + SysRq
2010-11-19 10:31:04 -08:00
Alan Cox 5f9a31d631 n_gsm: clean up printks
[Original From Ken Mills but I redid it using pr_ helpers instead]

Also fix up coding style, there are two warnings left but that is where
the CodingStyle tools blow up because they cannot handle

	if (blah) {
		foo
	} else switch (x) {
		case 1:
		}

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-11 11:35:58 -08:00
Alan Cox c2f2f0000b n_gsm: Fix support for legacy encoding
The mux supports several encoding schemes. Encoding 0 is a "not
recommended" mode still sometimes used. This has now been tested with
hardware that supports this mode, and found wanting.

Fix the FCS handling in this mode and correct the state machine.

Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-11 11:35:58 -08:00
Ken Mills 40e3465db2 n_gsm: Fix length handling
If the mux is configured with a large mru/mtu the existing code gets the
byte ordering wrong for the header.

Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-11 11:06:09 -08:00
Ken Mills 820e62ef3d n_gsm: Copy n2 over when configuring via ioctl interface
The n2 field is settable but didn't get propogated

Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-11 11:06:08 -08:00
Nicolas Pitre 47c344d0bd vcs: make proper usage of the poll flags
Kay Sievers pointed out that usage of POLLIN is well defined by POSIX,
and the current usage here doesn't follow that definition.  So let's
duplicate the same semantics as implemented by sysfs_poll() instead.

Signed-off-by: Nicolas Pitre <nicolas.pitre@canonical.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-11 10:51:35 -08:00
Philippe Rétornaz 1c95ba1e1d tty_ldisc: Fix BUG() on hangup
A kernel BUG when bluetooth rfcomm connection drop while the associated
serial port is open is sometime triggered.

It seems that the line discipline can disappear between the
tty_ldisc_put and tty_ldisc_get. This patch fall back to the N_TTY line
discipline if the previous discipline is not available anymore.

Signed-off-by: Philippe Retornaz <philippe.retornaz@epfl.ch>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-09 15:05:50 -08:00
Jiri Slaby 100eeae2c5 TTY: restore tty_ldisc_wait_idle
It was removed in 65b770468e (tty-ldisc: turn ldisc user count into
a proper refcount), but we need to wait for last user to quit the
ldisc before we close it in tty_set_ldisc.

Otherwise weird things start to happen. There might be processes
waiting in tty_read->n_tty_read on tty->read_wait for input to appear
and at that moment, a change of ldisc is fatal. n_tty_close is called,
it frees read_buf and the waiting process is still in the middle of
reading and goes nuts after it is woken.

Previously we prevented close to happen when others are in ldisc ops
by tty_ldisc_wait_idle in tty_set_ldisc. But the commit above removed
that. So revoke the change and test whether there is 1 user (=we), and
allow the close then.

We can do that without ldisc/tty locks, because nobody else can open
the device due to TTY_LDISC_CHANGING bit set, so we in fact wait for
everybody to leave.

I don't understand why tty_ldisc_lock would be needed either when the
counter is an atomic variable, so this is a lockless
tty_ldisc_wait_idle.

On the other hand, if we fail to wait (timeout or signal), we have to
reenable the halted ldiscs, so we take ldisc lock and reuse the setup
path at the end of tty_set_ldisc.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Sebastian Andrzej Siewior <bigeasy@breakpoint.cc>
LKML-Reference: <20101031104136.GA511@Chamillionaire.breakpoint.cc>
LKML-Reference: <1287669539-22644-1-git-send-email-jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org [32, 33, 36]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-09 15:04:21 -08:00
Jiri Olsa e045fec489 tty: prevent DOS in the flush_to_ldisc
There's a small window inside the flush_to_ldisc function,
where the tty is unlocked and calling ldisc's receive_buf
function. If in this window new buffer is added to the tty,
the processing might never leave the flush_to_ldisc function.

This scenario will hog the cpu, causing other tty processing
starving, and making it impossible to interface the computer
via tty.

I was able to exploit this via pty interface by sending only
control characters to the master input, causing the flush_to_ldisc
to be scheduled, but never actually generate any output.

To reproduce, please run multiple instances of following code.

- SNIP
#define _XOPEN_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(int argc, char **argv)
{
        int i, slave, master = getpt();
        char buf[8192];

        sprintf(buf, "%s", ptsname(master));
        grantpt(master);
        unlockpt(master);

        slave = open(buf, O_RDWR);
        if (slave < 0) {
                perror("open slave failed");
                return 1;
        }

        for(i = 0; i < sizeof(buf); i++)
                buf[i] = rand() % 32;

        while(1) {
                write(master, buf, sizeof(buf));
        }

        return 0;
}
- SNIP

The attached patch (based on -next tree) fixes this by checking on the
tty buffer tail. Once it's reached, the current work is rescheduled
and another could run.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: stable <stable@kernel.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-09 15:02:02 -08:00
Greg Kroah-Hartman 1db01135df TTY: move .gitignore from drivers/char/ to drivers/tty/vt/
The autogenerated files (consolemap_deftbl.c and defkeymap.c) need to
be ignored by git, so move the .gitignore file that was doing it to the
properly location now that the files have moved as well.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-05 22:18:23 -07:00
Greg Kroah-Hartman 60d4ae8d43 TTY: create drivers/tty/vt and move the vt code there
The vt and other related code is moved into the drivers/tty/vt directory.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-05 08:16:52 -07:00
Greg Kroah-Hartman 96fd7ce58f TTY: create drivers/tty and move the tty core files there
The tty code should be in its own subdirectory and not in the char
driver with all of the cruft that is currently there.

Based on work done by Arnd Bergmann <arnd@arndb.de>

Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-05 08:10:33 -07:00