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linux/drivers/char
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Alan Cox 8077088449 n_tty: Fix echo race 
If a tty in N_TTY mode with echo enabled manages to get itself into a state
where
	- echo characters are pending
	- FASYNC is enabled
	- tty_write_wakeup is called from either
		- a device write path (pty)
		- an IRQ (serial)

then it either deadlocks or explodes taking a mutex in the IRQ path.

On the serial side it is almost impossible to reproduce because you have to
go from a full serial port to a near empty one with echo characters
pending. The pty case happens to have become possible to trigger using
emacs and ptys, the pty changes having created a scenario which shows up
this bug.

The code path is

	n_tty:process_echoes() (takes mutex)
	tty_io:tty_put_char()
	pty:pty_write  (or serial paths)
	tty_wakeup     (from pty_write or serial IRQ)
	n_tty_write_wakeup()
	process_echoes()
	*KABOOM*

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-16 09:19:16 -07:00
..
agp
Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
2009-06-20 10:15:30 -07:00
hw_random
Remove multiple KERN_ prefixes from printk formats
2009-07-08 10:30:03 -07:00
ip2
tty: rewrite the ldisc locking
2009-06-11 08:51:01 -07:00
ipmi
ipmi: remove driver_data direct access of struct device
2009-06-15 21:30:27 -07:00
mwave
mwave: struct device - replace bus_id with dev_name(), dev_set_name()
2009-01-06 10:44:38 -08:00
pcmcia
pcmcia/cm4000: fix lock imbalance
2009-06-22 11:32:24 -07:00
rio
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
tpm
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
xilinx_hwicap
xilinx_hwicap: remove improper wording in license statement
2008-12-17 11:23:07 -08:00
.gitignore
…
amiserial.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
apm-emulation.c
APM emulation: Notify about all suspend events, not just APM invoked ones (v2)
2008-07-16 23:27:02 +02:00
applicom.c
applicom: Auto-load applicom module when device opened.
2009-04-06 14:36:30 -07:00
applicom.h
…
bfin_jtag_comm.c
bfin_jtag_comm: clean up printk usage
2009-06-22 11:32:23 -07:00
bfin-otp.c
…
briq_panel.c
briq_panel: BKL pushdown
2008-06-20 14:05:55 -06:00
bsr.c
powerpc/BSR: Fix BSR to allow mmap of small BSR on 64k kernel
2009-06-26 14:37:26 +10:00
cd1865.h
…
ChangeLog
…
consolemap.c
consolemap: indentation & braces disagree - reindent
2009-01-06 15:59:30 -08:00
cp437.uni
unicode table for cp437
2008-12-13 11:25:49 -08:00
cs5535_gpio.c
Add a bunch of cycle_kernel_lock() calls
2008-06-20 14:05:53 -06:00
cyclades.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
defkeymap.c_shipped
…
defkeymap.map
…
digi1.h
…
digiFep1.h
…
digiPCI.h
…
ds1302.c
rtc: use bcd2bin/bin2bcd
2008-10-20 08:52:41 -07:00
ds1620.c
[ARM] netwinder: clean up GPIO naming
2008-12-13 09:12:07 +00:00
dsp56k.c
device create: char: convert device_create_drvdata to device_create
2008-10-16 09:24:42 -07:00
dtlk.c
dtlk: off by one in {read,write}_tts()
2009-06-19 16:46:06 -07:00
efirtc.c
drivers/char/efirtc.c: removed duplicated #include
2008-08-04 16:59:56 -07:00
epca.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
epca.h
epca: use tty_port
2008-07-20 17:12:36 -07:00
epcaconfig.h
…
esp.c
esp: fix section mismatch warning
2009-04-07 08:31:03 -07:00
generic_nvram.c
driver/char/generic_nvram: fix banner
2008-06-12 18:05:41 -07:00
generic_serial.c
tty: Remove some pointless casts
2009-01-02 10:19:40 -08:00
genrtc.c
genrtc: BKL pushdown
2008-06-20 14:05:57 -06:00
hangcheck-timer.c
…
hpet.c
irq: change ACPI GSI APIs to also take a device argument
2009-04-28 12:21:17 +02:00
hvc_beat.c
powerpc/cell: Use correct types in beat files
2009-01-08 16:25:16 +11:00
hvc_console.c
hvc_console: Remove tty->low_latency
2009-01-16 16:15:16 +11:00
hvc_console.h
powerpc: Make open count variables signed in hvcs/hvsi/hvc_console
2008-12-03 21:04:13 +11:00
hvc_irq.c
hvc_console: Call free_irq() only if request_irq() was successful
2009-01-13 14:48:01 +11:00
hvc_iseries.c
drivers/hvc: Add missing __devexit_p()
2009-06-16 14:15:44 +10:00
hvc_iucv.c
[S390] pm: hvc_iucv power management callbacks
2009-06-16 10:31:19 +02:00
hvc_rtas.c
…
hvc_udbg.c
powerpc: udbg-based backend for hvc_console
2008-11-19 16:04:25 +11:00
hvc_vio.c
drivers/hvc: Add missing __devexit_p()
2009-06-16 14:15:44 +10:00
hvc_xen.c
hvc_console: Add a hangup notifier for backends
2008-10-22 10:59:54 +11:00
hvcs.c
Merge commit 'origin/master' into next
2009-06-18 11:16:55 +10:00
hvsi.c
hvc_console: Remove tty->low_latency on pseries backends
2009-03-11 10:44:26 +11:00
i8k.c
i8k: Add Dell Vostro systems
2009-01-02 10:28:32 -08:00
isicom.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
istallion.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
Kconfig
MIPS: Update VR41xx GPIO driver to use gpiolib
2009-07-03 15:45:25 +01:00
keyboard.c
Input: keyboard - remove warning about raw mode not supported
2009-04-20 21:21:24 -07:00
lp.c
device create: char: convert device_create_drvdata to device_create
2008-10-16 09:24:42 -07:00
Makefile
MIPS: Update VR41xx GPIO driver to use gpiolib
2009-07-03 15:45:25 +01:00
mbcs.c
mbcs: cdev lock_kernel() pushdown
2008-06-20 14:05:48 -06:00
mbcs.h
…
mem.c
drivers/char/mem.c: memory_open() cleanup: lookup minor device number from devlist
2009-06-18 13:03:54 -07:00
misc.c
Driver Core: misc: add nodename support for misc devices.
2009-06-15 21:30:25 -07:00
mmtimer.c
mmtimer: Push BKL down into the ioctl handler
2008-07-17 11:34:49 -07:00
moxa.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
moxa.h
…
mspec.c
mspec: convert nopfn to fault
2008-07-24 10:47:14 -07:00
mxser.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
mxser.h
…
n_hdlc.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
n_r3964.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
n_tty.c
n_tty: Fix echo race
2009-07-16 09:19:16 -07:00
nozomi.c
tty: nozomi, fix tty refcounting bug
2009-07-16 09:19:16 -07:00
nsc_gpio.c
…
nvram.c
[PATCH] nvram - convert PRINT_PROC to seq_file
2008-11-11 09:56:00 +00:00
nwbutton.c
…
nwbutton.h
…
nwflash.c
[ARM] netwinder: clean up GPIO naming
2008-12-13 09:12:07 +00:00
pc8736x_gpio.c
pc8736x_gpio: add support for PC87365 chips
2008-10-20 08:52:40 -07:00
ppdev.c
ppdev: reduce kernel log spam
2009-06-18 13:03:54 -07:00
ps3flash.c
ps3flash: Always read chunks of 256 KiB, and cache them
2009-06-15 16:47:27 +10:00
pty.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
random.c
Avoid ICE in get_random_int() with gcc-3.4.5
2009-05-19 11:25:35 -07:00
raw.c
Driver Core: raw: add nodename for raw devices
2009-06-15 21:30:26 -07:00
riscom8_reg.h
…
riscom8.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
riscom8.h
tty: add more tty_port fields
2008-07-20 17:12:38 -07:00
rocket_int.h
tty: rocketport uses different port flags to everyone else
2009-01-02 10:19:39 -08:00
rocket.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
rocket.h
tty: rocketport uses different port flags to everyone else
2009-01-02 10:19:39 -08:00
rtc.c
RTC: Remove the BKL.
2009-01-08 16:44:03 -07:00
scc.h
m68k: atari - Rename "mfp" to "st_mfp"
2009-02-22 09:23:02 -08:00
scx200_gpio.c
Add a bunch of cycle_kernel_lock() calls
2008-06-20 14:05:53 -06:00
selection.c
tty: rewrite the ldisc locking
2009-06-11 08:51:01 -07:00
ser_a2232.c
m68k: ser_a2232 - Kill warn_unused_result warnings
2009-01-12 20:56:39 +01:00
ser_a2232.h
…
ser_a2232fw.ax
…
ser_a2232fw.h
…
serial167.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
snsc_event.c
byteorder: don't directly include linux/byteorder/generic.h
2008-05-16 12:01:45 -07:00
snsc.c
device create: char: convert device_create_drvdata to device_create
2008-10-16 09:24:42 -07:00
snsc.h
…
sonypi.c
Rationalize fasync return values
2009-03-16 08:34:35 -06:00
specialix_io8.h
tty: add more tty_port fields
2008-07-20 17:12:38 -07:00
specialix.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
stallion.c
tty: Add carrier processing on close to the tty_port core
2009-06-11 08:50:56 -07:00
sx.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
sx.h
…
sxboards.h
…
sxwindow.h
…
synclink_gt.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
synclink.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
synclinkmp.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
sysrq.c
kexec: sysrq: simplify sysrq-c handler
2009-06-18 13:03:59 -07:00
tb0219.c
Update Yoichi Yuasa's e-mail address
2009-07-03 15:45:29 +01:00
tlclk.c
tlckl: BKL pushdown
2008-06-20 14:05:51 -06:00
toshiba.c
…
tty_audit.c
tty: remove buffer special casing
2009-06-11 08:51:02 -07:00
tty_buffer.c
tty: split the buffering from tty_io
2008-10-13 09:51:40 -07:00
tty_io.c
tty: fix sanity check
2009-06-16 12:01:16 -07:00
tty_ioctl.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
tty_ldisc.c
tty: fix close/hangup race
2009-07-16 09:19:16 -07:00
tty_port.c
tty: fix tty_port_block_til_ready waiting
2009-06-24 09:55:50 -07:00
vc_screen.c
vcs: hook sysfs devices into object lifetime instead of "binding"
2009-03-24 16:38:26 -07:00
viotape.c
tape: beyond ARRAY_SIZE of viocd_diskinfo
2009-06-02 10:32:34 +10:00
virtio_console.c
virtio: find_vqs/del_vqs virtio operations
2009-06-12 22:16:36 +09:30
vme_scc.c
m68k: vme_scc - Kill warn_unused_result warnings
2009-01-12 20:56:38 +01:00
vr41xx_giu.c
MIPS: Update VR41xx GPIO driver to use gpiolib
2009-07-03 15:45:25 +01:00
vt_ioctl.c
headers: smp_lock.h redux
2009-07-12 12:22:34 -07:00
vt.c
vt: drop bootmem/slab memory distinction
2009-07-16 09:19:16 -07:00