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commit 9ec1882df2 (tty: serial: imx: console write routing is unsafe
on SMP) introduced a recursive locking bug in imx_console_write().
The callchain is:
imx_rxint()
spin_lock_irqsave(&sport->port.lock,flags);
...
uart_handle_sysrq_char();
sysrq_function();
printk();
imx_console_write();
spin_lock_irqsave(&sport->port.lock,flags); <--- DEAD
The bad news is that the kernel debugging facilities can dectect the
problem, but the printks never surface on the serial console for
obvious reasons.
There is a similar issue with oops_in_progress. If the kernel crashes
we really don't want to be stuck on the lock and unable to tell what
happened.
In general most UP originated drivers miss these checks and nobody
ever notices because CONFIG_PROVE_LOCKING seems to be still ignored by
a large number of developers.
The solution is to avoid locking in the sysrq case and trylock in the
oops_in_progress case.
This scheme is used in other drivers as well and it would be nice if
we could move this to a common place, so the usual copy/paste/modify
bugs can be avoided.
Now there is another issue with this scheme:
CPU0 CPU1
printk()
rxint()
sysrq_detection() -> sets port->sysrq
return from interrupt
console_write()
if (port->sysrq)
avoid locking
port->sysrq is reset with the next receive character. So as long as
the port->sysrq is not reset and this can take an endless amount of
time if after the break no futher receive character follows, all
console writes happen unlocked.
While the current writer is protected against other console writers by
the console sem, it's unprotected against open/close or other
operations which fiddle with the port. That's what the above mentioned
commit tried to solve.
That's an issue in all drivers which use that scheme and unfortunately
there is no easy workaround. The only solution is to have a separate
indicator port->sysrq_cpu. uart_handle_sysrq_char() then sets it to
smp_processor_id() before calling into handle_sysrq() and resets it to
-1 after that. Then change the locking check to:
if (port->sysrq_cpu == smp_processor_id())
locked = 0;
else if (oops_in_progress)
locked = spin_trylock_irqsave(port->lock, flags);
else
spin_lock_irqsave(port->lock, flags);
That would force all other cpus into the spin_lock path. Problem
solved, but that's way beyond the scope of this fix and really wants
to be implemented in a common function which calls the uart specific
write function to avoid another gazillion of hard to debug
copy/paste/modify bugs.
Reported-and-tested-by: Tim Sander <tim@krieglstein.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@vger.kernel.org> # 3.6+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Convert the synchronous size sense code to an interrupt driven
approach. This allows to set the device online even if the
terminal is not connected. With the new code views can be
registered without a connected terminal, the tty can be opened
as soon as the device is online. After the terminal has been
connected and the size has been determined the tty is resized
to match the device characteristics..
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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hardpps() functionality is provided through the N_PPS line
discipline now. The new function signature was added in commit
025b40ab (2011-01-12). There was no previous macro or
function hardpps(), at least since before the initial commit of
v2.6.12 in 2005. It's unlikely this code has been compiled since.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: George Spelvin <linux@horizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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An extension of the previous commit, there is no semantic change
here, just fewer lines of source code.
Signed-off-by: George Spelvin <linux@horizon.com>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The PPS (Pulse-Per-Second) line discipline has developed a number of
unhealthy attachments to core tty data and functions, ultimately leading
to its breakage.
The previous patches fixed the crashing. This one reduces coupling further
by eliminating the timestamp parameter from the dcd_change ldisc method.
This reduces header file linkage and makes the extension more generic,
and the timestamp read is delayed only slightly, from just before the
ldisc->ops->dcd_change method call to just after.
Fix attendant build breakage in
drivers/tty/n_tty.c
drivers/tty/tty_buffer.c
drivers/staging/speakup/selection.c
drivers/staging/dgrp/dgrp_*.c
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@braille.uwo.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: George Spelvin <linux@horizon.com>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Use big and little endian accessors function to reflect system configuration.
Detection is done via control register in ulite_request_port.
Tested on Microblaze LE, BE, PPC440 and Arm zynq.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Clean coding style and sparse warnings.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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-replace "baud" with "current-speed"
-if uart alias doesn't exist in DT, don't abort, pick 0
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Since SERIAL_CORE needs GENERIC_HARDIRQS (see below) and most serial drivers
select it, just add a GENERIC_HARDIRQS dependency to all serial drivers.
Fixes the compile error below:
drivers/tty/serial/serial_core.c: In function ‘uart_set_info’:
drivers/tty/serial/serial_core.c:725:2: error: implicit declaration of function ‘irq_canonicalize’
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(not the fbcon maintainer pull 2)
fix bug in vgacon on bootup and fbcon losing fonts on startup.
* console-fixes: (50 commits)
fbcon: don't lose the console font across generic->chip driver switch
vgacon/vt: clear buffer attributes when we load a 512 character font (v2)
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I've still got lockdep warnings even after Alan's patch, and it seems that
yet more band aids are required to paper over similar paths for
unbind_con_driver() and unregister_con_driver(). After this hack, lockdep
warnings are finally gone.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: stable <stable@vger.kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Adjust the console layer to allow a take over call where the caller
already holds the locks. Make the fb layer lock in order.
This is partly a band aid, the fb layer is terminally confused about the
locking rules it uses for its notifiers it seems.
[akpm@linux-foundation.org: remove stray non-ascii char, tidy comment]
[akpm@linux-foundation.org: export do_take_over_console()]
[airlied: cleanup another non-ascii char]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: stable <stable@vger.kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Move rt scheduler definitions out of include/linux/sched.h into
new file include/linux/sched/rt.h
Signed-off-by: Clark Williams <williams@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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When we switch from 256->512 byte font rendering mode, it means the
current contents of the screen is being reinterpreted. The bit that holds
the high bit of the 9-bit font, may have been previously set, and thus
the new font misrenders.
The problem case we see is grub2 writes spaces with the bit set, so it
ends up with data like 0x820, which gets reinterpreted into 0x120 char
which the font translates into G with a circumflex. This flashes up on
screen at boot and is quite ugly.
A current side effect of this patch though is that any rendering on the
screen changes color to a slightly darker color, but at least the screen
no longer corrupts.
v2: as suggested by hpa, always clear the attribute space, whether we
are are going to or from 512 chars.
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
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Michał's previous patch missed this tty check to fix up the
class_find_device() arguments.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This reverts commit cdc8da3998dcc50cee2f81904c16ebdbd7ec2cee.
In my attempt to fix a build warning on arm randconfig a build error on
imx_v6_v7_defconfig was introduced, so revert it for now.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Getting the tty kref in dashtty_timer() is no longer necessary since it
isn't needed in fetch_data() any longer (due to changes which make the
tty flip functions refer to tty_ports instead of tty_structs), so just
pass around a channel number instead.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Add a TTY driver for communicating over a Meta DA (Debug Adapter)
channel using the bios channel SWITCH operation.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If CONFIG_CONSOLE_POLL is not defined, the following build warning happens:
drivers/tty/serial/imx.c:274:13: warning: 'imx_port_ucrs_save' defined but not used [-Wunused-function]
drivers/tty/serial/imx.c:283:13: warning: 'imx_port_ucrs_restore' defined but not used [-Wunused-function]
Move imx_port_ucrs_saver/restore under CONFIG_CONSOLE_POLL ifdef block to fix it.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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No need for two separate return statements, consolidate them.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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No need for two separate return statements, consolidate them.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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and Tx FIFO IRQ generation
Original configuration of Rx FIFO threshold contained an error
that resulted Rx threshold to be effectively set to 1 character
instead of 16 characters, as noted in comments.
Checking LSR to contain UART_LSR_THRE bit set caused issue when
not all UART_IER_THRI interrupts have been properly handled.
This caused gap in Tx data, visible on high baud rates using
oscilloscope.
Setting OMAP_UART_SCR_TX_EMPTY bit in SCR caused UART_IER_THRI
interrupt to be raised only when Tx FIFO and Tx shift registers
are empty.
Signed-off-by: Alexey Pelykh <alexey.pelykh@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Tegra is only booted through device-tree now; there are no board files
left that use this function. Hence, don't export it. Move the static
inline definition into of_serial.c, so we can delete of_serial.h too.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Multiple slave pty opens may be performed in parallel with the
master open. Of course, all the slave opens will fail because the
master pty is still locked but during this time the slave pty
count will be artificially greater than 1. This is should not
cause the master pty open to fail.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If the master and slave ptys are opened in parallel, the slave open
fails because the pty is still locked. This is as designed.
However, pty_close() is still called for the slave pty which sets
TTY_OTHER_CLOSED in the master pty. This can cause the master open
to fail as well.
Use a common pattern in other tty drivers by setting TTY_IO_ERROR
until the open is successful and only closing the pty if not set.
Note: the master pty always closes regardless of whether the open
was successful, so that proper cleanup can occur.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If pmtx_open() fails to get a slave inode or fails the pty_open(),
the tty is released as part of the error cleanup. As evidenced by the
first BUG stacktrace below, pty_close() assumes that the linked pty has
a valid, initialized inode* stored in driver_data.
Also, as evidenced by the second BUG stacktrace below, pty_unix98_shutdown()
assumes that the master pty's driver_data has been initialized.
1) Fix the invalid assumption in pty_close().
2) Initialize driver_data immediately so proper devpts fs cleanup occurs.
Fixes this BUG:
[ 815.868844] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
[ 815.869018] IP: [<ffffffff81207bcc>] devpts_pty_kill+0x1c/0xa0
[ 815.869190] PGD 7c775067 PUD 79deb067 PMD 0
[ 815.869315] Oops: 0000 [#1] PREEMPT SMP
[ 815.869443] Modules linked in: kvm_intel kvm snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi microcode snd_rawmidi psmouse serio_raw snd_seq_midi_event snd_seq snd_timer$
[ 815.870025] CPU 0
[ 815.870143] Pid: 27819, comm: stress_test_tty Tainted: G W 3.8.0-next-20130125+ttypatch-2-xeon #2 Bochs Bochs
[ 815.870386] RIP: 0010:[<ffffffff81207bcc>] [<ffffffff81207bcc>] devpts_pty_kill+0x1c/0xa0
[ 815.870540] RSP: 0018:ffff88007d3e1ac8 EFLAGS: 00010282
[ 815.870661] RAX: ffff880079c20800 RBX: 0000000000000000 RCX: 0000000000000000
[ 815.870804] RDX: ffff880079c209a8 RSI: 0000000000000286 RDI: 0000000000000000
[ 815.870933] RBP: ffff88007d3e1ae8 R08: 0000000000000000 R09: 0000000000000000
[ 815.871078] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88007bfb7e00
[ 815.871209] R13: 0000000000000005 R14: ffff880079c20c00 R15: ffff880079c20c00
[ 815.871343] FS: 00007f2e86206700(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
[ 815.871495] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 815.871617] CR2: 0000000000000028 CR3: 000000007ae56000 CR4: 00000000000006f0
[ 815.871752] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 815.871902] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 815.872012] Process stress_test_tty (pid: 27819, threadinfo ffff88007d3e0000, task ffff88007c874530)
[ 815.872012] Stack:
[ 815.872012] ffff88007bfb7e00 ffff880079c20c00 ffff88007bfb7e00 0000000000000005
[ 815.872012] ffff88007d3e1b08 ffffffff81417be7 ffff88007caa9bd8 ffff880079c20800
[ 815.872012] ffff88007d3e1bc8 ffffffff8140e5f8 0000000000000000 0000000000000000
[ 815.872012] Call Trace:
[ 815.872012] [<ffffffff81417be7>] pty_close+0x157/0x170
[ 815.872012] [<ffffffff8140e5f8>] tty_release+0x138/0x580
[ 815.872012] [<ffffffff816d29f3>] ? _raw_spin_lock+0x23/0x30
[ 815.872012] [<ffffffff816d267a>] ? _raw_spin_unlock+0x1a/0x40
[ 815.872012] [<ffffffff816d0178>] ? __mutex_unlock_slowpath+0x48/0x60
[ 815.872012] [<ffffffff81417dff>] ptmx_open+0x11f/0x180
[ 815.872012] [<ffffffff8119394b>] chrdev_open+0x9b/0x1c0
[ 815.872012] [<ffffffff8118d643>] do_dentry_open+0x203/0x290
[ 815.872012] [<ffffffff811938b0>] ? cdev_put+0x30/0x30
[ 815.872012] [<ffffffff8118d705>] finish_open+0x35/0x50
[ 815.872012] [<ffffffff8119dcce>] do_last+0x6fe/0xe90
[ 815.872012] [<ffffffff8119a7af>] ? link_path_walk+0x7f/0x880
[ 815.872012] [<ffffffff810909d5>] ? cpuacct_charge+0x75/0x80
[ 815.872012] [<ffffffff8119e51c>] path_openat+0xbc/0x4e0
[ 815.872012] [<ffffffff816d0fd0>] ? __schedule+0x400/0x7f0
[ 815.872012] [<ffffffff8140e956>] ? tty_release+0x496/0x580
[ 815.872012] [<ffffffff8119ec11>] do_filp_open+0x41/0xa0
[ 815.872012] [<ffffffff816d267a>] ? _raw_spin_unlock+0x1a/0x40
[ 815.872012] [<ffffffff811abe39>] ? __alloc_fd+0xe9/0x140
[ 815.872012] [<ffffffff8118ea44>] do_sys_open+0xf4/0x1e0
[ 815.872012] [<ffffffff8118eb51>] sys_open+0x21/0x30
[ 815.872012] [<ffffffff816da499>] system_call_fastpath+0x16/0x1b
[ 815.872012] Code: 0f 1f 80 00 00 00 00 45 31 e4 eb d7 0f 0b 90 0f 1f 44 00 00 55 48 89 e5 48 83 ec 20 48 89 5d e8 48 89 fb 4c 89 65 f0 4c 89 6d f8 <48> 8b 47 28 48 81 78 58 d1 1c 0$
[ 815.872012] RIP [<ffffffff81207bcc>] devpts_pty_kill+0x1c/0xa0
[ 815.872012] RSP <ffff88007d3e1ac8>
[ 815.872012] CR2: 0000000000000028
[ 815.897036] ---[ end trace eadf50b7f34e47d5 ]---
Fixes this BUG also:
[ 608.366836] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
[ 608.366948] IP: [<ffffffff812078d8>] devpts_kill_index+0x18/0x70
[ 608.367050] PGD 7c75b067 PUD 7b919067 PMD 0
[ 608.367135] Oops: 0000 [#1] PREEMPT SMP
[ 608.367201] Modules linked in: kvm_intel kvm snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event microcode snd_seq psmouse snd_timer snd_seq_device serio_raw snd mac_hid soundcore snd_page_alloc rfcomm virtio_balloon parport_pc bnep bluetooth ppdev i2c_piix4 lp parport floppy
[ 608.367617] CPU 2
[ 608.367669] Pid: 1918, comm: stress_test_tty Tainted: G W 3.8.0-next-20130125+ttypatch-2-xeon #2 Bochs Bochs
[ 608.367796] RIP: 0010:[<ffffffff812078d8>] [<ffffffff812078d8>] devpts_kill_index+0x18/0x70
[ 608.367885] RSP: 0018:ffff88007ae41a88 EFLAGS: 00010286
[ 608.367951] RAX: ffffffff81417e80 RBX: ffff880036472400 RCX: 0000000180400028
[ 608.368010] RDX: ffff880036470004 RSI: 0000000000000004 RDI: 0000000000000000
[ 608.368010] RBP: ffff88007ae41a98 R08: 0000000000000000 R09: 0000000000000001
[ 608.368010] R10: ffffea0001f22e40 R11: ffffffff814151d5 R12: 0000000000000004
[ 608.368010] R13: ffff880036470000 R14: 0000000000000004 R15: ffff880036472400
[ 608.368010] FS: 00007ff7a5268700(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000
[ 608.368010] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 608.368010] CR2: 0000000000000028 CR3: 000000007a0fd000 CR4: 00000000000006e0
[ 608.368010] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 608.368010] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 608.368010] Process stress_test_tty (pid: 1918, threadinfo ffff88007ae40000, task ffff88003688dc40)
[ 608.368010] Stack:
[ 608.368010] ffff880036472400 0000000000000001 ffff88007ae41aa8 ffffffff81417e98
[ 608.368010] ffff88007ae41ac8 ffffffff8140c42b ffff88007ac73100 ffff88007ac73100
[ 608.368010] ffff88007ae41b98 ffffffff8140ead5 ffff88007ae41b38 ffff88007ca40e40
[ 608.368010] Call Trace:
[ 608.368010] [<ffffffff81417e98>] pty_unix98_shutdown+0x18/0x20
[ 608.368010] [<ffffffff8140c42b>] release_tty+0x3b/0xe0
[ 608.368010] [<ffffffff8140ead5>] __tty_release+0x575/0x5d0
[ 608.368010] [<ffffffff816d2c63>] ? _raw_spin_lock+0x23/0x30
[ 608.368010] [<ffffffff816d28ea>] ? _raw_spin_unlock+0x1a/0x40
[ 608.368010] [<ffffffff816d03e8>] ? __mutex_unlock_slowpath+0x48/0x60
[ 608.368010] [<ffffffff8140ef79>] tty_open+0x449/0x5f0
[ 608.368010] [<ffffffff8119394b>] chrdev_open+0x9b/0x1c0
[ 608.368010] [<ffffffff8118d643>] do_dentry_open+0x203/0x290
[ 608.368010] [<ffffffff811938b0>] ? cdev_put+0x30/0x30
[ 608.368010] [<ffffffff8118d705>] finish_open+0x35/0x50
[ 608.368010] [<ffffffff8119dcce>] do_last+0x6fe/0xe90
[ 608.368010] [<ffffffff8119a7af>] ? link_path_walk+0x7f/0x880
[ 608.368010] [<ffffffff8119e51c>] path_openat+0xbc/0x4e0
[ 608.368010] [<ffffffff8119ec11>] do_filp_open+0x41/0xa0
[ 608.368010] [<ffffffff816d28ea>] ? _raw_spin_unlock+0x1a/0x40
[ 608.368010] [<ffffffff811abe39>] ? __alloc_fd+0xe9/0x140
[ 608.368010] [<ffffffff8118ea44>] do_sys_open+0xf4/0x1e0
[ 608.368010] [<ffffffff816d2c63>] ? _raw_spin_lock+0x23/0x30
[ 608.368010] [<ffffffff8118eb51>] sys_open+0x21/0x30
[ 608.368010] [<ffffffff816da719>] system_call_fastpath+0x16/0x1b
[ 608.368010] Code: ec 48 83 c4 10 5b 41 5c 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 48 83 ec 10 4c 89 65 f8 41 89 f4 48 89 5d f0 <48> 8b 47 28 48 81 78 58 d1 1c 00 00 74 0b 48 8b 05 4b 66 cf 00
[ 608.368010] RIP [<ffffffff812078d8>] devpts_kill_index+0x18/0x70
[ 608.368010] RSP <ffff88007ae41a88>
[ 608.368010] CR2: 0000000000000028
[ 608.394153] ---[ end trace afe83b0fb5fbda93 ]---
Reported-by: Ilya Zykov <ilya@ilyx.ru>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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There's no reason kgdb.h itself needs to include the 8250 serial port
header file. So push it down to the _very_ limited number of individual
drivers that need the values in that file, and fix up the places where
people really wanted serial_core.h and platform_device.h.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The "normal" spin lock that guards the N_TTY line discipline read section
is replaced by a raw spin lock.
On a PREEMP_RT system this prevents unwanted scheduling overhead when data is
read at the same time as data is being received: while RX IRQ threaded handling
is busy a TTY read call is performed from a RT priority > threaded IRQ priority.
The read call tries to take the read section spin lock (held by the threaded
IRQ) which blocks and causes a context switch to/from the threaded IRQ handler
until the spin lock is unlocked.
Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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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>
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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This change fixes a deadlock when the multiplexer is closed while there
are still client side ports open.
When the multiplexer is closed and there are active tty's it tries to
close them with tty_vhangup. This has a problem though, because
tty_vhangup needs the tty_lock. This patch changes it to unlock the
tty_lock before attempting the hangup and relocks afterwards. The
additional call to tty_port_tty_set is needed because otherwise the
port stays active because of the reference counter.
This change also exposed another problem that other code paths don't
expect that the multiplexer could have been closed. This patch also adds
checks for these cases in the gsmtty_ class of function that could be
called.
The documentation explicitly states that "first close all virtual ports
before closing the physical port" but we've found this to not always
reality in our field situations. The GPRS / UTMS modem sometimes crashes
and needs a power cycle in that case which means cleanly shutting down
everything is not always possible. This change makes it much more robust
for our situation where at least the system is recoverable with this patch
and doesn't hang in a deadlock situation inside the kernel.
The patch is against the long term support kernel (3.4.27) and should
apply cleanly to more recent branches. Tested with a Telit GE864-QUADV2
and Telit HE910 modem.
Signed-off-by: Dirkjan Bussink <dirkjan.bussink@nedap.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The MIPS based Ralink WiSoC platform has 1 or more 8250 compatible serial cores.
To make them work we require the same quirks that are used by AU1x00.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Dan Carpenter noticed a missing set of parentheses
around a multiple field addition.
https://lkml.org/lkml/2013/1/27/166
His original commit message:
There is a kind of precedence problem here, but it doesn't affect how
the code works because ->serial_signals is unsigned char. We want to
clear two flags here.
#define SerialSignal_RTS 0x20 /* Request to Send */
#define SerialSignal_DTR 0x80 /* Data Terminal Ready */
Without the parenthesis then it does:
info->serial_signals &= 0x5f;
With the parenthesis it does:
info->serial_signals &= 0xffffff5f;
info->serial_signals is an unsigned char so the two statements are
equivalent, but it's cleaner to add the parenthesis. In other dtr_rts()
functions the parenthesis are there so this makes it more consistent.
Other changes:
Convert all + uses to | for these bit operations.
Reorder the multiple fields for consistency.
Update the comments too.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Add support for later SUNIX (TIMEDIA) Universal PCI Single and Multi-Port
Communications Boards.
These boards have PCI Vendor ID 1fd4 with device ID 1999 but otherwise
appear to be the same as the TIMEDIA boards already supported by 8250_pci
and parport_serial.
Tested with:
a. the two port serial board part number SER5037A,
b. the two port serial and one port parallel board part number
MIO5079A.
Signed-off-by: Stephen Chivers <schivers@csc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This reverts commit 58f82be334ede87aa6ff6fa1afdb05552be907be.
This was fixed by a previous patch already.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Conflicts:
drivers/devfreq/exynos4_bus.c
Sync with Linus' tree to be able to apply patches that are
against newer code (mvneta).
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This resolves a gpio driver merge issue pointed out in linux-next.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This resolves a number of tty driver merge issues found in linux-next
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Fix compilation error, by adding the correct header file
for Tegra clocks.
Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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1) add clk_enable/disable in serial_pxa_console_write()
2) add clk_prepare() to follow common clock driver
Signed-off-by: Yi Zhang <yizhang@marvell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When PCH_UART_CONSOLE and SERIAL_CORE_CONSOLE is not set neither, the
uart_port will have no 'sysrq' member hence their will need a '#ifdef'
in pch_uart.c to handle the case, otherwise we'll see compile error
like this:
CC [M] drivers/tty/serial/pch_uart.o
drivers/tty/serial/pch_uart.c: In function 'pch_uart_hal_read':
drivers/tty/serial/pch_uart.c:572:11: error: 'struct uart_port' has no member named 'sysrq'
make[4]: *** [drivers/tty/serial/pch_uart.o] Error 1
Reported-by: Randy Dunlap <rdunlap@infradead.org>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Liang Li <liang.li@windriver.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When the tty input buffer is full and thereby throttled,
flushing/resetting the read buffer should unthrottle to allow more
data to be received.
Signed-off-by: Karthik Manamcheri <Karthik.Manamcheri@ni.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Sorry forgot to merge this in the original submission. Resync
with the tty tree changes moving the buffers into the tty_port
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.
devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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__exit_p() need to be removed after the __devexit
removal from the driver.
Warning log:
drivers/tty/serial/xilinx_uartps.c:996:12:
warning: 'xuartps_remove' defined but not used [-Wunused-function]
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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There is no need to memset 0 to SPI frame memory before preparing
transfer frame bits, because SPI frame header are encoded with valid
data size, so don't need to worry about adopting dirty bits, more,
memset zero for each SPI frame may impact the spi throughput efficiency.
Signed-off-by: Chen Jun <jun.d.chen@intel.com>
Signed-off-by: channing <chao.bi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This provides a console driver for the Goldfish virtual platform. The original
is from Arve with changes from Jun Nakajima and Tom Keel. This has been then
been ported to the current kernel and to the tty port mechanism by Alan Cox.
In the process it gained proper POSIX semantics and vhangup works. The default
name is not ttyS as this belongs to the 8250 driver. Instead ttyGFx is now used.
In the normal usage case the first port serves as a kernel logging console and
the second one carries various other data streams for the emulation.
Signed-off-by: Arve Hjønnevåg <arve@google.com>
[Cleaned up to handle x86]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
[Moved to 3.7 and chunks rewritten to use tty_port layer]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This struct is used only for driver, so it should be static.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This patch adds a hardware reset the break and overflow bits for
these events. Without resetting the bits they will be reported to
the core every time, when once occur.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The non-dt probing allowed passing the location via platform data from
the beginning. So make up leeway for device tree probing.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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