Any sysfs "show" read access from the client app will result in reading
all registers (8 with ina226). Depending on the host this can limit the
best achievable read rate.
This changeset allows for individual register accesses through regmap.
Tested with BeagleBone Black (Baylibre-ACME) and ina226.
Signed-off-by: Marc Titinger <mtitinger@baylibre.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
A new limit selected arbitrarily as power of two greater than
required minimum for Xeon Phi processor (72 for Knights Landing).
Currently driver is not able to handle cores with core ID greater than 32.
Such attempt ends up with the following error in dmesg:
coretemp coretemp.0: Adding Core XXX failed
Signed-off-by: Lukasz Odzioba <lukasz.odzioba@intel.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The TMP75C has a different control register layout and only supports
12-bit temperature samples (0.0625 deg C).
The continuous sample rate is ~12 Hz.
Signed-off-by: Ben Gardner <gardner.ben@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Fix module autoload for IBM and Open power platforms.
Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The description in the driver states: "ABX500 does not provide auto ADC,
so to monitor the required temperatures, a periodic work is used. It is
more important to not wake up the CPU... If the chip gets too hot during
a sleep state it's most likely due to external factors, such as the
surrounding temperature and nothing can be done in S/W."
So it makes no sense to keep IRQs enabled as it need not be wakeup
source. This patch removes the use of IRQF_NO_SUSPEND flag
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
max31790_update_device() return the error code in ERR_PTR. We were
checking if it has returned error or not but before checking we have
dereferenced it.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Pull SCSI fixes from James Bottomley:
"This is a set of three bug fixes, two of which are regressions from
recent updates (the 3ware one from 4.1 and the device handler fixes
from 4.2)"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
3w-9xxx: don't unmap bounce buffered commands
scsi_dh: Use the correct module name when loading device handler
libiscsi: Fix iscsi_check_transport_timeouts possible infinite loop
Pull md bugfix from Neil Brown:
"One bug fix for raid1/raid10.
Very careless bug earler in 4.3-rc, now fixed :-)"
* tag 'md/4.3-rc4-fix' of git://neil.brown.name/md:
crash in md-raid1 and md-raid10 due to incorrect list manipulation
Pull USB fixes from Greg KH:
"Here are some small USB and PHY fixes and quirk updates for 4.3-rc5.
Nothing major here, full details in the shortlog, and all of these
have been in linux-next for a while"
* tag 'usb-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: Add device quirk for Logitech PTZ cameras
USB: chaoskey read offset bug
USB: Add reset-resume quirk for two Plantronics usb headphones.
usb: renesas_usbhs: Add support for R-Car H3
usb: renesas_usbhs: fix build warning if 64-bit architecture
usb: gadget: bdc: fix memory leak
phy: berlin-sata: Fix module autoload for OF platform driver
phy: rockchip-usb: power down phy when rockchip phy probe
phy: qcom-ufs: fix build error when the component is built as a module
Pull tty/serial driver fixes from Greg KH:
"Here are a few bug fixes for the tty core that resolve reported
issues, and some serial driver fixes as well (including the
much-reported imx driver problem)
All of these have been in linux-next with no reported problems"
* tag 'tty-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
drivers/tty: require read access for controlling terminal
serial: 8250: add uart_config entry for PORT_RT2880
tty: fix data race on tty_buffer.commit
tty: fix data race in tty_buffer_flush
tty: fix data race in flush_to_ldisc
tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c
serial: atmel: fix error path of probe function
tty: don't leak cdev in tty_cdev_add()
Revert "serial: imx: remove unbalanced clk_prepare"
Pull staging fixes from Greg KH:
"Here are two tiny staging tree fixes for 4.3-rc5.
One fixes the broken speakup subsystem as reported by a user, and the
other removes an entry in the MAINTAINERS file for a developer that
doesn't want to be listed anymore"
* tag 'staging-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: speakup: fix speakup-r regression
MAINTAINERS: Remove myself as nvec co-maintainer
Pull char/misc driver fixes from Greg KH:
"Here are some small fixes for some misc drivers that resolve some
reported issues. All of these have been linux-next for a while"
* tag 'char-misc-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
mcb: Fix error handling in mcb_pci_probe()
mei: hbm: fix error in state check logic
nvmem: sunxi: Check for memory allocation failure
nvmem: core: Fix memory leak in nvmem_cell_write
nvmem: core: Handle shift bits in-place if cell->nbits is non-zero
nvmem: core: fix the out-of-range leak in read/write()
Pull power management and ACPI fixes from Rafael Wysocki:
"These are four fixes for bugs in the devfreq and cpufreq subsystems,
including two regression fixes (one for a recent regression and one
for a problem introduced in 4.2).
Specifics:
- Two fixes for cpufreq regressions, an acpi-cpufreq driver one
introduced during the 4.2 cycle when we started to preserve cpufreq
directories for offline CPUs and a general one introduced recently
(Srinivas Pandruvada).
- Two devfreq fixes, one for a double kfree() in an error code path
and one for a confusing sysfs-related failure (Geliang Tang, Tobias
Jakobi)"
* tag 'pm+acpi-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: prevent lockup on reading scaling_available_frequencies
cpufreq: acpi_cpufreq: prevent crash on reading freqdomain_cpus
PM / devfreq: fix double kfree
PM / devfreq: Fix governor_store()
Pull clk fixes from Stephen Boyd:
"A Samsung driver fix and a handful of TI driver fixes"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: ti: dflt: fix enable_reg validity check
clk: ti: fix dual-registration of uart4_ick
clk: ti: clk-7xx: Remove hardwired ABE clock configuration
clk: samsung: fix cpu clock's flags checking
Pull dm fixes from Mike Snitzer:
"Three stable fixes:
- DM core AB-BA deadlock fix in the device destruction path (vs
device creation's DM table swap).
- DM raid fix to properly round up the region_size to the next
power-of-2.
- DM cache fix for a NULL pointer seen while switching from the
"cleaner" cache policy.
Two fixes for regressions introduced during the 4.3 merge:
- request-based DM error propagation regressed due to incorrect
changes introduced when adding the bi_error field to bio.
- DM snapshot fix to only support snapshots that overflow if the
client (e.g. lvm2) is prepared to deal with the associated
snapshot status interface change"
* tag 'dm-4.3-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm snapshot: add new persistent store option to support overflow
dm cache: fix NULL pointer when switching from cleaner policy
dm: fix request-based dm error reporting
dm raid: fix round up of default region size
dm: fix AB-BA deadlock in __dm_destroy()
Pull ARM SoC fixes from Arnd Bergmann:
"The fixes for this week include one small patch that was years in the
making and that finally fixes using all eight CPUs on exynos542x.
The rest are lots of minor changes for sunxi, imx, exynos and shmobile
- fixing the minimum voltage for Allwinner A20
- thermal boot issue on SMDK5250.
- invalid clock used for FIMD IOMMU.
- audio on Renesas r8a7790/r8a7791
- invalid clock used for FIMD IOMMU
- LEDs on exynos5422-odroidxu3-common
- usb pin control for imx-rex
- imx53: fix PMIC interrupt level
- a Makefile typo"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: dts: Fix wrong clock binding for sysmmu_fimd1_1 on exynos5420
ARM: dts: Fix bootup thermal issue on smdk5250
ARM: shmobile: r8a7791 dtsi: Add CPG/MSTP Clock Domain for sound
ARM: shmobile: r8a7790 dtsi: Add CPG/MSTP Clock Domain for sound
arm-cci500: Don't enable PMU driver by default
ARM: dts: fix usb pin control for imx-rex dts
ARM: imx53: qsrb: fix PMIC interrupt level
ARM: imx53: include IRQ dt-bindings header
ARM: dts: add suspend opp to exynos4412
ARM: dts: Fix LEDs on exynos5422-odroidxu3
ARM: EXYNOS: reset Little cores when cpu is up
ARM: dts: Fix Makefile target for sun4i-a10-itead-iteaduino-plus
ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications
Commit 76c44f6d80 introduced the possibly for "Overflow" to be reported
by the snapshot device's status. Older userspace (e.g. lvm2) does not
handle the "Overflow" status response.
Fix this incompatibility by requiring newer userspace code, that can
cope with "Overflow", request the persistent store with overflow support
by using "PO" (Persistent with Overflow) for the snapshot store type.
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Fixes: 76c44f6d80 ("dm snapshot: don't invalidate on-disk image on snapshot write overflow")
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The cleaner policy doesn't make use of the per cache block hint space in
the metadata (unlike the other policies). When switching from the
cleaner policy to mq or smq a NULL pointer crash (in dm_tm_new_block)
was observed. The crash was caused by bugs in dm-cache-metadata.c
when trying to skip creation of the hint btree.
The minimal fix is to change hint size for the cleaner policy to 4 bytes
(only hint size supported).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
The commit 55ce74d4bf (md/raid1: ensure
device failure recorded before write request returns) is causing crash in
the LVM2 testsuite test shell/lvchange-raid.sh. For me the crash is 100%
reproducible.
The reason for the crash is that the newly added code in raid1d moves the
list from conf->bio_end_io_list to tmp, then tests if tmp is non-empty and
then incorrectly pops the bio from conf->bio_end_io_list (which is empty
because the list was alrady moved).
Raid-10 has a similar bug.
Kernel Fault: Code=15 regs=000000006ccb8640 (Addr=0000000100000000)
CPU: 3 PID: 1930 Comm: mdX_raid1 Not tainted 4.2.0-rc5-bisect+ #35
task: 000000006cc1f258 ti: 000000006ccb8000 task.ti: 000000006ccb8000
YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001001111111000001111 Not tainted
r00-03 000000ff0804fe0f 000000001059d000 000000001059f818 000000007f16be38
r04-07 000000001059d000 000000007f16be08 0000000000200200 0000000000000001
r08-11 000000006ccb8260 000000007b7934d0 0000000000000001 0000000000000000
r12-15 000000004056f320 0000000000000000 0000000000013dd0 0000000000000000
r16-19 00000000f0d00ae0 0000000000000000 0000000000000000 0000000000000001
r20-23 000000000800000f 0000000042200390 0000000000000000 0000000000000000
r24-27 0000000000000001 000000000800000f 000000007f16be08 000000001059d000
r28-31 0000000100000000 000000006ccb8560 000000006ccb8640 0000000000000000
sr00-03 0000000000249800 0000000000000000 0000000000000000 0000000000249800
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000
IASQ: 0000000000000000 0000000000000000 IAOQ: 000000001059f61c 000000001059f620
IIR: 0f8010c6 ISR: 0000000000000000 IOR: 0000000100000000
CPU: 3 CR30: 000000006ccb8000 CR31: 0000000000000000
ORIG_R28: 000000001059d000
IAOQ[0]: call_bio_endio+0x34/0x1a8 [raid1]
IAOQ[1]: call_bio_endio+0x38/0x1a8 [raid1]
RP(r2): raid_end_bio_io+0x88/0x168 [raid1]
Backtrace:
[<000000001059f818>] raid_end_bio_io+0x88/0x168 [raid1]
[<00000000105a4f64>] raid1d+0x144/0x1640 [raid1]
[<000000004017fd5c>] kthread+0x144/0x160
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 55ce74d4bf ("md/raid1: ensure device failure recorded before write request returns.")
Fixes: 95af587e95 ("md/raid10: ensure device failure recorded before write request returns.")
Signed-off-by: NeilBrown <neilb@suse.com>
When scaling_available_frequencies is read on an offlined cpu, then
either lockup or junk values are displayed. This is caused by
freed freq_table, which policy is using.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The Atmel sdhci device needs the
SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST quirk. Without it, the
internal clock could never stabilised when changing the sd clock
frequency.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The Atmel sdhci device needs a new quirk. sdhci_set_clock set the Clock
Control Register to 0 before computing the new value and writing it.
It disables the internal clock which causes a reset mecanism. If we
write the new value before this reset mecanism is done, it will prevent
the stabilisation of the internal clock, so a delay is needed. This
delay is about 2-3 cycles of the base clock. To be safe, a 1 ms delay is
used.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
According to 'FE-2946959' erratum the clock inversion option is
needed to support slow frequencies when the card input hold time
requirement is high. This setting is not required for high speed
MMC and might cause timing violation.
Signed-off-by: Nadav Haklai <nadavh@marvell.com>
Cc: <stable@vger.kernel.org> # v4.2
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Starting with commit 7d607f9170 ("mmc: host: omap_hsmmc: use
devm_regulator_get_optional() for vmmc") MMC on omap3 stopped working
for legacy booting.
This is because legacy booting sets up some of the resource in the
platform init code, and for optional regulators always seem to
return -EPROBE_DEFER for the legacy booting.
Let's fix the issue by checking for device tree based booting for
now. Then when omap3 boots in device tree only mode, this patch
can be just reverted.
Fixes: 7d607f9170 ("mmc: host: omap_hsmmc: use
devm_regulator_get_optional() for vmmc")
Cc: Felipe Balbi <balbi@ti.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This reverts commit c55d7a0553.
Without reverting this commit we get "unbalanced disables for pbias_mmc_omap4"
errors on omap4430. It seems that 4430 and 4460 behave in a different way for
the PBIAS regulator registers and until that has been debugged further we
cannot rely on the regulator status registers in hardare on 4430.
Fixes: 7d607f9170 ("mmc: host: omap_hsmmc: use
devm_regulator_get_optional() for vmmc")
Cc: Felipe Balbi <balbi@ti.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
3w controller don't dma map small single SGL entry commands but instead
bounce buffer them. Add a helper to identify these commands and don't
call scsi_dma_unmap for them.
Based on an earlier patch from James Bottomley.
Fixes: 118c85 ("3w-9xxx: fix command completion race")
Reported-by: Tóth Attila <atoth@atoth.sote.hu>
Tested-by: Tóth Attila <atoth@atoth.sote.hu>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Pull fbdev fixes from Tomi Valkeinen:
- fbdev: Minor fixes to broadsheetfb, fsl-diu-fb, mb862xxfb, tridentfb,
omapfb
- display-timing: Fix memory leak in error path
* tag 'fbdev-fixes-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
video: of: fix memory leak
fbdev: broadsheetfb: fix memory leak
OMAPDSS: panel-sony-acx565akm: Export OF module alias information
fbdev: omap2: connector-dvi: use of_get_i2c_adapter_by_node interface
tridentfb: Fix set_lwidth on TGUI9440 and CYBER9320
tridentfb: fix hang on Blade3D with CONFIG_CC_OPTIMIZE_FOR_SIZE
video: fbdev: mb862xx: Fix module autoload for OF platform driver
video: fbdev: fsl: Fix the sleep function for FSL DIU module
Pull regmap fixes from Mark Brown:
"A couple of fixes for the debugfs information on the register map,
fixing issues with very small reads potentially causing underflows and
wraparounds"
* tag 'regmap-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: debugfs: Don't bother actually printing when calculating max length
regmap: debugfs: Ensure we don't underflow when printing access masks
Pull spi fixes from Mark Brown:
"A couple of very minor fixes, one for error handling in the Davinci
driver probe function and another making the Renesas sh-msiof DT
binding documentation correspond to what's actually implemented"
* tag 'spi-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: sh-msiof: Match renesas,rx-fifo-size in DT bindings doc with driver
spi: davinci: fix handling platform_get_irq result
Pull regulator fixes from Mark Brown:
"Two fixes here, one device specific fix for axp20x and a core fix for
cases where one regulator is supplying another which broke probe
deferral, substituting in a dummy regulator too aggressively"
* tag 'regulator-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: core: Handle probe deferral from DT when resolving supplies
regulator: axp20x: Fix enable bit indexes for DCDC4 and DCDC5
If of_parse_display_timing() fails we are printing an error message and
jumping to the error path but we missed freeing "dt".
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Pull MTD fixes from Brian Norris:
"A few MTD fixes:
- mxc_nand: a "refactoring only" change in 4.3-rc1 had some bad
pointer (array) arithmetic. Fix that
- sunxi_nand:
- Fix an old list manipulation / memory management bug in the device
release() code path
- Correct a few mistakes in OOB write support"
* tag 'for-linus-20151006' of git://git.infradead.org/linux-mtd:
mxc_nand: fix copy_spare
mtd: nand: sunxi: fix sunxi_nand_chips_cleanup()
mtd: nand: sunxi: fix OOB handling in ->write_xxx() functions
end_clone_bio() is a endio callback for clone bio and should check
and save the clone's bi_error for error reporting. However,
4246a0b63b ("block: add a bi_error field to struct bio") changed
the function to check the original bio's bi_error, which is 0.
Without this fix, clone's error is ignored and reported to the
original request as success. Thus data corruption will be observed.
Fixes: 4246a0b63b ("block: add a bi_error field to struct bio")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If a MCB PCI Carrier device is IO mapped insted of memory-mapped,
the memory of the PCI device is still not unmapped.
Also the patch adds deallocation of the bus
if chameleon_parse_cells() fails.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is a patch to make speakup-r work again.
It broke in 3.6 due to commit 4369c64c79
"Input: Send events one packet at a time)
The problem was that the fakekey.c routine to fake a down arrow no
longer functioned properly and putting the input_sync fixed it.
Fixes: 4369c64c79
Cc: stable <stable@vger.kernel.org>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: John Covici <covici@ccs.covici.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is mostly a hardening fix, given that write-only access to other
users' ttys is usually only given through setgid tty executables.
Signed-off-by: Jann Horn <jann@thejh.net>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds an entry to the uart_config table for PORT_RT2880
enabling rx/tx FIFOs. The UART is actually a Palmchip BK-3103
which is found in several devices from Alchemy/RMI, Ralink, and
Sigma Designs.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Race on buffer data happens when newly committed data is
picked up by an old flush work in the following scenario:
__tty_buffer_request_room does a plain write of tail->commit,
no barriers were executed before that.
At this point flush_to_ldisc reads this new value of commit,
and reads buffer data, no barriers in between.
The committed buffer data is not necessary visible to flush_to_ldisc.
Similar bug happens when tty_schedule_flip commits data.
Update commit with smp_store_release and read commit with
smp_load_acquire, as it is commit that signals data readiness.
This is orthogonal to the existing synchronization on tty_buffer.next,
which is required to not dismiss a buffer with unconsumed data.
The data race was found with KernelThreadSanitizer (KTSAN).
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_buffer_flush frees not acquired buffers.
As the result, for example, read of b->size in tty_buffer_free
can return garbage value which will lead to a huge buffer
hanging in the freelist. This is just the benignest
manifestation of freeing of a not acquired object.
If the object is passed to kfree, heap can be corrupted.
Acquire visibility over the buffer before freeing it.
The data race was found with KernelThreadSanitizer (KTSAN).
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
flush_to_ldisc reads port->itty and checks that it is not NULL,
concurrently release_tty sets port->itty to NULL. It is possible
that flush_to_ldisc loads port->itty once, ensures that it is
not NULL, but then reloads it again and uses. The second load
can already return NULL, which will cause a crash.
Use READ_ONCE to read port->itty.
The data race was found with KernelThreadSanitizer (KTSAN).
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
