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22ae19c6e3
kernel-ark/drivers
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Dmitry Torokhov 22ae19c6e3 Input: uinput - fix race that can block nonblocking read 
Consider two threads calling read() on the same uinput-fd, both
non-blocking. Assume there is data-available so both will simultaneously
pass:
	udev->head == udev->tail

Then the first thread goes to sleep and the second one pops the message
from the queue. Now assume udev->head == udev->tail. If the first thread
wakes up it will call wait_event_*() and sleep in the waitq. This
effectively turns the non-blocking FD into a blocking one.

We fix this by attempting to fetch events from the queue first and only
if we fail to retrieve any events we either return -EAGAIN (in case of
non-blocing read) or wait until there are more events.

This also fixes incorrect return code (we were returning 0 instead of
 -EAGAIN for non-blocking reads) when an event is "stolen" by another
thread. Blocking reads will now continue to wait instead of returning 0
in this scenario.

Count of 0 continues to be a special case, as per spec: we will check for
device existence and whether there are events in the queue, but no events
will be actually retrieved.

Reported-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2012-08-21 22:29:53 -07:00
..
accessibility
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-06-30 11:11:58 -07:00
amba arm-soc: driver specific updates 2012-05-26 12:22:27 -07:00
ata Viresh has moved 2012-06-20 14:39:36 -07:00
atm solos-pci: Fix DMA support 2012-05-24 16:22:53 -04:00
auxdisplay
base PM / Sleep: Prevent waiting forever on asynchronous suspend after abort 2012-06-24 23:31:09 +02:00
bcma bcma: fix null pointer in bcma_core_pci_irq_ctl 2012-06-08 13:47:07 -04:00
block mtip32xx: Changes to sysfs entries 2012-05-31 08:46:50 +02:00
bluetooth Bluetooth: btmrvl: Do not send vendor events to bluetooth stack 2012-06-19 00:19:11 -03:00
cdrom
char Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2012-06-18 12:20:36 -07:00
clk clk: mxs: fix clock lookup after freeing init memory 2012-06-25 16:51:48 -07:00
clocksource clocksource: sh_tmu: Use clockevents_config_and_register(). 2012-06-11 17:10:16 +09:00
connector
cpufreq
cpuidle
crypto arm-soc: clock driver changes 2012-05-26 12:42:29 -07:00
dca
devfreq Power management updates for 3.5 2012-05-23 14:07:06 -07:00
dio
dma Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma 2012-06-20 22:12:52 -07:00
edac edac: Do alignment logic properly in edac_align_ptr() 2012-06-11 12:43:16 -03:00
eisa
extcon extcon: max8997: Add missing kfree for info->edev in max8997_muic_remove() 2012-06-18 16:30:42 -07:00
firewire IEEE 1394 (FireWire) subsystem updates post v3.4: 2012-05-24 12:57:47 -07:00
firmware
gpio gpio/samsung: fix the typo 'exynos5_xxx' instead of 'exonys5_xxx' 2012-06-03 21:21:01 -07:00
gpu Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel into drm-fixes 2012-06-27 19:56:20 +01:00
hid Merge branch 'upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2012-06-26 11:23:41 -07:00
hsi
hv Driver core pull for 3.5-rc1 2012-05-22 16:02:13 -07:00
hwmon Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-06-29 10:29:54 -07:00
hwspinlock
i2c i2c: Add generic I2C multiplexer using pinctrl API 2012-06-04 16:49:43 +02:00
ide drivers/ide/ide-cs.c: adjust suspicious bit operation 2012-06-12 15:51:41 -07:00
idle
ieee802154
iio iio: drop wrong reference from Kconfig 2012-06-14 17:28:46 -07:00
infiniband Merge branches 'cma' and 'ocrdma' into for-linus 2012-06-24 04:59:59 -07:00
input Input: uinput - fix race that can block nonblocking read 2012-08-21 22:29:53 -07:00
iommu iommu/amd: Fix deadlock in ppr-handling error path 2012-06-04 12:47:44 +02:00
isdn Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-05-24 11:54:29 -07:00
leds leds: Make LEDS_ASIC3 and LEDS_RENESAS_TPU depend on LEDS_CLASS=y 2012-06-12 10:56:25 +08:00
lguest
macintosh
md md: 2 fixes for 3.5-rc 2012-06-06 09:49:28 -07:00
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-06-25 14:53:09 -07:00
memory
memstick
message Merge branch 'akpm' (Andrew's patch-bomb) 2012-05-31 18:10:18 -07:00
mfd Viresh has moved 2012-06-20 14:39:36 -07:00
misc misc: mei: set WDIOF_ALARMONLY on mei watchdog 2012-06-13 15:34:31 -07:00
mmc Revert "mmc: omap_hsmmc: Enable Auto CMD12" 2012-06-26 16:10:30 -04:00
mtd Fix the debugfs regression - we never enable it because incorrect 2012-06-28 11:41:43 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-06-28 11:20:31 -07:00
nfc NFC: potential integer overflow problem in check_crc() 2012-05-25 11:16:16 -04:00
nubus
of Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2012-05-29 18:27:19 -07:00
oprofile oprofile: perf: use NR_CPUS instead or nr_cpumask_bits for static array 2012-06-21 16:15:11 +02:00
parisc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-05-22 19:22:50 -07:00
parport Driver core pull for 3.5-rc1 2012-05-22 16:02:13 -07:00
pci USB: add NO_D3_DURING_SLEEP flag and revert 151b612847 2012-06-13 13:11:39 -07:00
pcmcia
pinctrl Merge branch 'akpm' (Andrew's patch-bomb) 2012-06-20 14:41:57 -07:00
platform drivers/platform/x86/acerhdf.c: correct Boris' mail address 2012-06-07 14:43:55 -07:00
pnp
power A bunch of fixes for v3.5, nothing extraordinary. 2012-05-31 12:10:15 -07:00
pps
ps3
ptp Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-05-22 19:22:50 -07:00
rapidio rapidio/tsi721: add DMA engine support 2012-05-31 17:49:31 -07:00
regulator regulator: palmas: fix regmap offsets for enable/disable 2012-06-23 11:37:28 +01:00
remoteproc remoteproc/omap: fix dev_err typo 2012-06-17 10:31:03 +03:00
rpmsg
rtc Merge branches 'bugfix-battery', 'bugfix-misc', 'bugfix-rafael', 'bugfix-turbostat', 'bugfix-video' and 'workaround-pss' into release 2012-06-04 00:48:41 -04:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2012-05-31 10:51:10 -07:00
sbus
scsi SCSI & usb-storage: add try_rc_10_first flag 2012-06-22 22:05:31 -07:00
sfi
sh sh: intc: Kill off special reservation interface. 2012-05-22 19:07:55 +09:00
sn
spi SPI: fix over-eager devm_xxx() conversion 2012-06-18 11:27:04 +01:00
ssb
staging Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-06-25 14:53:09 -07:00
target target: Return error to initiator if SET TARGET PORT GROUPS emulation fails 2012-06-12 20:12:25 -07:00
tc
thermal
tty Serial driver fixes for 3.5-rc4 2012-06-20 15:13:13 -07:00
uio
usb USB: CP210x Add 10 Device IDs 2012-06-26 16:14:34 -07:00
uwb
vhost vhost: use USER_DS in vhost_worker thread 2012-06-26 21:10:56 -07:00
video fbdev fixes for 3.5 2012-06-16 16:59:05 -07:00
virt
virtio virtio-mmio: Devices parameter parsing 2012-05-22 12:16:15 +09:30
vlynq
vme
w1 arm-soc: clock driver changes 2012-05-26 12:42:29 -07:00
watchdog watchdog: core: fix WDIOC_GETSTATUS return value 2012-06-28 20:40:56 +02:00
xen Five bug-fixes: 2012-06-15 17:17:15 -07:00
zorro
Kconfig Staging tree pull request for 3.5-rc1 2012-05-22 16:34:21 -07:00
Makefile arm-soc: driver specific updates 2012-05-26 12:22:27 -07:00