| c274f6ef1c6665632767d32e4ab912aad839ce27 |
|
10-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Hold termios_rwsem for tcflow(TCIxxx)
While transmitting a START/STOP char for tcflow(TCION/TCIOFF), prevent
a termios change. Otherwise, a garbage in-band flow control char
may be sent, if the termios change overlaps the transmission setup.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 136d5258b2bc4ffae99cb69874a76624c26fbfad |
|
10-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Move and rename send_prio_char() as tty_send_xchar()
Relocate the file-scope function, send_prio_char(), as a global
helper tty_send_xchar(). Remove the global declarations for
tty_write_lock()/tty_write_unlock(), as these are file-scope only now.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| c545b66c6922b002b5fe224a6eaec58c913650b5 |
|
10-Sep-2014 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Serialize tcflow() with other tty flow control changes
Use newly-introduced tty->flow_lock to serialize updates to
tty->flow_stopped (via tcflow()) and with concurrent tty flow
control changes from other sources.
Merge the storage for ->stopped and ->flow_stopped, now that both
flags are serialized by ->flow_lock.
The padding bits are necessary to force the compiler to allocate the
type specified; otherwise, gcc will ignore the type specifier and
allocate the minimum number of bytes necessary to store the bitfield.
In turn, this would allow Alpha EV4 and EV5 cpus to corrupt adjacent
byte storage because those cpus use RMW to store byte and short data.
gcc versions < 4.7.2 will also corrupt storage adjacent to bitfields
smaller than unsigned long on ia64, ppc64, hppa64 and sparc64, thus
requiring more than unsigned int storage (which would otherwise be
sufficient to workaround the Alpha non-atomic byte/short storage problem).
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| a1d51aa2214cea3f91611893610a2f769cada0e7 |
|
08-Aug-2014 |
Matthias Brugger <matthias.bgg@gmail.com> |
tty: fix typo in comment of tty_termios_encode_baud_rate
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 5cec7bf699c61d14f0538345076480bb8c8ebfbb |
|
26-Sep-2013 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Fix SIGTTOU not sent with tcflush()
Commit 'e7f3880cd9b98c5bf9391ae7acdec82b75403776'
tty: Fix recursive deadlock in tty_perform_flush()
introduced a regression where tcflush() does not generate
SIGTTOU for background process groups.
Make sure ioctl(TCFLSH) calls tty_check_change() when
invoked from the line discipline.
Cc: stable@vger.kernel.org # v3.10+
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| d8c1f929aa8164cd8eaa830068d2fa3159c0764a |
|
15-Jun-2013 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Only guarantee termios read safety for throttle/unthrottle
No tty driver modifies termios during throttle() or unthrottle().
Therefore, only read safety is required.
However, tty_throttle_safe and tty_unthrottle_safe must still be
mutually exclusive; introduce throttle_mutex for that purpose.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 6a1c0680cf3ba94356ecd58833e1540c93472a57 |
|
15-Jun-2013 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Convert termios_mutex to termios_rwsem
termios is commonly accessed unsafely (especially by N_TTY)
because the existing mutex forces exclusive access.
Convert existing usage.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 579a00a5c2f0a85fb4602a53e2c1beb77a646528 |
|
15-Apr-2013 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Fix unsafe bit ops in tty_throttle_safe/unthrottle_safe
tty->flags needs to be atomically modified.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| e7f3880cd9b98c5bf9391ae7acdec82b75403776 |
|
11-Mar-2013 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Fix recursive deadlock in tty_perform_flush()
tty_perform_flush() can deadlock when called while holding
a line discipline reference. By definition, all ldisc drivers
hold a ldisc reference, so calls originating from ldisc drivers
must not block for a ldisc reference.
The deadlock can occur when:
CPU 0 | CPU 1
|
tty_ldisc_ref(tty) |
.... | <line discipline halted>
tty_ldisc_ref_wait(tty) |
|
CPU 0 cannot progess because it cannot obtain an ldisc reference
with the line discipline has been halted (thus no new references
are granted).
CPU 1 cannot progress because an outstanding ldisc reference
has not been released.
An in-tree call-tree audit of tty_perform_flush() [1] shows 5
ldisc drivers calling tty_perform_flush() indirectly via
n_tty_ioctl_helper() and 2 ldisc drivers calling directly.
A single tty driver safely uses the function.
[1]
Recursive usage:
/* These functions are line discipline ioctls and thus
* recursive wrt line discipline references */
tty_perform_flush() - ./drivers/tty/tty_ioctl.c
n_tty_ioctl_helper()
hci_uart_tty_ioctl(default) - drivers/bluetooth/hci_ldisc.c (N_HCI)
n_hdlc_tty_ioctl(default) - drivers/tty/n_hdlc.c (N_HDLC)
gsmld_ioctl(default) - drivers/tty/n_gsm.c (N_GSM0710)
n_tty_ioctl(default) - drivers/tty/n_tty.c (N_TTY)
gigaset_tty_ioctl(default) - drivers/isdn/gigaset/ser-gigaset.c (N_GIGASET_M101)
ppp_synctty_ioctl(TCFLSH) - drivers/net/ppp/pps_synctty.c
ppp_asynctty_ioctl(TCFLSH) - drivers/net/ppp/ppp_async.c
Non-recursive use:
tty_perform_flush() - drivers/tty/tty_ioctl.c
ipw_ioctl(TCFLSH) - drivers/tty/ipwireless/tty.c
/* This function is a tty i/o ioctl method, which
* is invoked by tty_ioctl() */
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 6865ff222ccab371c04afce17aec1f7d70b17dbc |
|
07-Mar-2013 |
Jiri Slaby <jslaby@suse.cz> |
TTY: do not warn about setting speed via SPD_*
The warning is there since 2.1.69 and we have not seen anybody
reporting it in the past decade. Remove the warning now.
tty_get_baud_rate can now be inline. This gives us one less
EXPORT_SYMBOL.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 70bc126471af30bb115e635512dcf6d86fe6e29a |
|
06-Mar-2013 |
Peter Hurley <peter@hurleysoftware.com> |
tty: Add safe tty throttle/unthrottle functions
The tty driver can become stuck throttled due to race conditions
between throttle and unthrottle, when the decision to throttle
or unthrottle is conditional. The following example helps to
illustrate the race:
CPU 0 | CPU 1
|
if (condition A) |
| <processing such that A not true>
| if (!condition A)
| unthrottle()
throttle() |
|
Note the converse is also possible; ie.,
CPU 0 | CPU 1
|
| if (!condition A)
<processing such that A true> |
if (condition A) |
throttle() |
| unthrottle()
|
Add new throttle/unthrottle functions based on the familiar model
of task state and schedule/wake. For example,
while (1) {
tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
if (!condition)
break;
if (!tty_throttle_safe(tty))
break;
}
__tty_set_flow_change(tty, 0);
In this example, if an unthrottle occurs after the condition is
evaluated but before tty_throttle_safe(), then tty_throttle_safe()
will return non-zero, looping and forcing the re-evaluation of
condition.
Reported-by: Vincent Pillet <vincentx.pillet@intel.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 183d95cdd834381c594d3aa801c1f9f9c0c54fa9 |
|
29-Jan-2013 |
Oleg Nesterov <oleg@redhat.com> |
tty: set_termios/set_termiox should not return -EINTR
See https://bugzilla.redhat.com/show_bug.cgi?id=904907
read command causes bash to abort with double free or corruption (out).
A simple test-case from Roman:
// Compile the reproducer and send sigchld ti that process.
// EINTR occurs even if SA_RESTART flag is set.
void handler(int sig)
{
}
main()
{
struct sigaction act;
act.sa_handler = handler;
act.sa_flags = SA_RESTART;
sigaction (SIGCHLD, &act, 0);
struct termio ttp;
ioctl(0, TCGETA, &ttp);
while(1)
{
if (ioctl(0, TCSETAW, ttp) < 0)
{
if (errno == EINTR)
{
fprintf(stderr, "BUG!"); return(1);
}
}
}
}
Change set_termios/set_termiox to return -ERESTARTSYS to fix this
particular problem.
I didn't dare to change other EINTR's in drivers/tty/, but they look
equally wrong.
Reported-by: Roman Rakus <rrakus@redhat.com>
Reported-by: Lingzhu Xiang <lxiang@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| a1bf9584429d61b7096f93ae09325e1ba538e9e8 |
|
16-Jan-2013 |
Ilya Zykov <ilya@ilyx.ru> |
tty: Add driver unthrottle in ioctl(...,TCFLSH,..).
Regression 'tty: fix "IRQ45: nobody cared"'
Regression commit 7b292b4bf9a9d6098440d85616d6ca4c608b8304
Function reset_buffer_flags() also invoked during the ioctl(...,TCFLSH,..).
At the time of request we can have full buffers and throttled driver too.
If we don't unthrottle driver, we can get forever throttled driver, because,
after request, we will have empty buffers and throttled driver and
there is no place to unthrottle driver.
It simple reproduce with "pty" pair then one side sleep on tty->write_wait,
and other side do ioctl(...,TCFLSH,..). Then there is no place to do writers wake up.
Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 06026d911c31dfa602e14e635a3489b8d67cc786 |
|
24-Oct-2012 |
Cyrill Gorcunov <gorcunov@openvz.org> |
tty: pty - Move TIOCPKT handling into pty.c
Since this ioctl is for pty devices only move it to pty.c.
v2:
- drop PTY_TYPE_MASTER test since it's master peer
ioctl anyway (by jslaby@)
Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Pavel Emelyanov <xemul@parallels.com>
CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 9833facf90c625f9757295bda6d970f82132b7be |
|
17-Jul-2012 |
Alan Cox <alan@linux.intel.com> |
tty: Fix up PPC fallout from the termios move
This fixes up the problem Stephen Rothwell reported when trying to merge -next
Signed-off-by: Alan Cox <alan@linux.intel.com>
Reported-by: Stephen Rothwell <sfr@cab.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| adc8d746caa67fff4b53ba3e5163a6cbacc3b523 |
|
14-Jul-2012 |
Alan Cox <alan@linux.intel.com> |
tty: move the termios object into the tty
This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| 9ffc93f203c18a70623f21950f1dd473c9ec48cd |
|
28-Mar-2012 |
David Howells <dhowells@redhat.com> |
Remove all #inclusions of asm/system.h
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:
perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: David Howells <dhowells@redhat.com>
|
| 8193c4290620d9b2a6ac116719f11aa99053a90d |
|
05-Oct-2011 |
Thomas Meyer <thomas@m3y3r.de> |
tty: Support compat_ioctl get/set termios_locked
When running a Fedora 15 (x86) on an x86_64 kernel, in the boot process
plymouthd complains about those two missing ioctls:
[ 2.581783] ioctl32(plymouthd:186): Unknown cmd fd(10) cmd(00005457){t:'T';sz:0} arg(ffb6a5d0) on /dev/tty1
[ 2.581803] ioctl32(plymouthd:186): Unknown cmd fd(10) cmd(00005456){t:'T';sz:0} arg(ffb6a680) on /dev/tty1
both ioctl functions work on the 'struct termios' resp. 'struct termios2',
which has the same size (36 bytes resp. 44 bytes) on x86 and x86_64,
so it's just a matter of converting the pointer from userland.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
|
| 99edb3d10a9d384d69557bd09cc39b9ec62aa04e |
|
30-Mar-2011 |
Jovi Zhang <bookjovi@gmail.com> |
tty: remove invalid location line in file header
remove invalid location line in each file header after location
moved from driver/char to driver/tty
Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
|
| f98e5b80add20ec20b9a3e450c3378eb9a163848 |
|
12-Apr-2011 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
tty: fix typo in descripton of tty_termios_encode_baud_rate
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
|
| 25985edcedea6396277003854657b5f3cb31a628 |
|
31-Mar-2011 |
Lucas De Marchi <lucas.demarchi@profusion.mobi> |
Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
|
| 8d075b199b9a66ad90296f898f1f15c0ae1511b8 |
|
14-Feb-2011 |
Alan Cox <alan@linux.intel.com> |
tty: add a helper for setting termios data from kernel side
This basically encapsulates the small bit of locking knowledge needed. While
we are at it make sure we blow up on any more abusers and unsafe misuses of
ioctl for this kind of stuff.
We change the function to return an argument as at some point it needs to
honour the POSIX 'I asked for changes but got none of them' error reporting
corner case.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
|
| 96fd7ce58ffb5c7bf376796b5525ba3ea1c9d69f |
|
04-Nov-2010 |
Greg Kroah-Hartman <gregkh@suse.de> |
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>
|