If the WDIOF_PRETIMEOUT flag is not set when registering the device the
driver will not show the sysfs entries or register the default governor.
By moving the registering after the decision whether pretimeout is
supported this gets fixed.
This driver's remove path calls del_timer(). However, that function
does not wait until the timer handler finishes. This means that the
timer handler may still be running after the driver's remove function
has finished, which would result in a use-after-free.
Fix by calling del_timer_sync(), which makes sure the timer handler
has finished, and unable to re-schedule itself.
Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Vladimir Zapolskiy <vz@mleia.com> Link: https://lore.kernel.org/r/1620802676-19701-1-git-send-email-zou_wei@huawei.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This module's remove path calls del_timer(). However, that function
does not wait until the timer handler finishes. This means that the
timer handler may still be running after the driver's remove function
has finished, which would result in a use-after-free.
Fix by calling del_timer_sync(), which makes sure the timer handler
has finished, and unable to re-schedule itself.
Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/1620716691-108460-1-git-send-email-zou_wei@huawei.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This module's remove path calls del_timer(). However, that function
does not wait until the timer handler finishes. This means that the
timer handler may still be running after the driver's remove function
has finished, which would result in a use-after-free.
Fix by calling del_timer_sync(), which makes sure the timer handler
has finished, and unable to re-schedule itself.
Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/1620716495-108352-1-git-send-email-zou_wei@huawei.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
In order to use upstream_bridge_distance_warn() from a dma_map function, it
must not sleep. However, pci_get_slot() takes the pci_bus_sem so it might
sleep.
In order to avoid this, try to get the host bridge's device from the first
element in the device list. It should be impossible for the host bridge's
device to go away while references are held on child devices, so the first
element should not be able to change and, thus, this should be safe.
Introduce a static function called pci_host_bridge_dev() to obtain the host
bridge's root device.
Link: https://github.com/ClangBuiltLinux/linux/issues/1309 Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Jian Cai <jiancai@google.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.
Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Bixuan Cui <cuibixuan@huawei.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Interrupt line can be configured on different hardware in different way,
even inverted. Therefore driver should not enforce specific trigger
type - edge falling - but instead rely on Devicetree to configure it.
The Maxim 17047/77693 datasheets describe the interrupt line as active
low with a requirement of acknowledge from the CPU therefore the edge
falling is not correct.
The interrupt line is shared between PMIC and RTC driver, so using level
sensitive interrupt is here especially important to avoid races. With
an edge configuration in case if first PMIC signals interrupt followed
shortly after by the RTC, the interrupt might not be yet cleared/acked
thus the second one would not be noticed.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Sometimes the code will crash because we haven't enabled
AC or USB charging and thus not created the corresponding
psy device. Fix it by checking that it is there before
notifying.
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.
So drop the hardware modification from the .remove() callback.
This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.
Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.
Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
lz4 compatible decompressor is simple. The format is underspecified and
relies on EOF notification to determine when to stop. Initramfs buffer
format[1] explicitly states that it can have arbitrary number of zero
padding. Thus when operating without a fill function, be extra careful to
ensure that sizes less than 4, or apperantly empty chunksizes are treated
as EOF.
To test this I have created two cpio initrds, first a normal one,
main.cpio. And second one with just a single /test-file with content
"second" second.cpio. Then i compressed both of them with gzip, and with
lz4 -l. Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1
count=4). To create four testcase initrds:
The pad4 test-cases replicate the initrd load by grub, as it pads and
aligns every initrd it loads.
All of the above boot, however /test-file was not accessible in the initrd
for the testcase #4, as decoding in lz4 decompressor failed. Also an
error message printed which usually is harmless.
Whith a patched kernel, all of the above testcases now pass, and
/test-file is accessible.
This fixes lz4 initrd decompress warning on every boot with grub. And
more importantly this fixes inability to load multiple lz4 compressed
initrds with grub. This patch has been shipping in Ubuntu kernels since
January 2021.
If an i2c client receives an interrupt during reboot or shutdown it may
be too late to service it by making an i2c transaction on the bus
because the i2c controller has already been shutdown. This can lead to
system hangs if the i2c controller tries to make a transfer that is
doomed to fail because the access to the i2c pins is already shut down,
or an iommu translation has been torn down so i2c controller register
access doesn't work.
Let's simply disable the irq if there isn't a shutdown callback for an
i2c client when there is an irq associated with the device. This will
make sure that irqs don't come in later than the time that we can handle
it. We don't do this if the i2c client device already has a shutdown
callback because presumably they're doing the right thing and quieting
the device so irqs don't come in after the shutdown callback returns.
Reported-by: kernel test robot <lkp@intel.com>
[swboyd@chromium.org: Dropped newline, added commit text, added
interrupt.h for robot build error] Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Some devices don't drain their pipelines if we don't make sure that
the corresponding output port is in reset before programming it for
a new trace capture, resulting in bits of old trace appearing in the
new trace capture. Fix that by explicitly making sure the reset is
asserted before programming new trace capture.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Link: https://lore.kernel.org/r/20210621151246.31891-5-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The function hda_tegra_first_init() neglects to check the return
value after executing platform_get_irq().
hda_tegra_first_init() should check the return value (if negative
error number) for errors so as to not pass a negative value to
the devm_request_irq().
Fix it by adding a check for the return value irq_id.
According to <linux/backlight.h> .update_status() is supposed to
return 0 on success and a negative error code otherwise. Adapt
lm3630a_bank_a_update_status() and lm3630a_bank_b_update_status() to
actually do it.
While touching that also add the error code to the failure message.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
The private->vol_updated flag was being checked outside of the
mutex_lock/unlock() of private->data_mutex leading to the volume data
being fetched twice from the device unnecessarily or old volume data
being returned.
Update scarlett2_*_ctl_get() and include the private->vol_updated flag
check inside the critical region.
A user of FFADO project reported the issue of ToneWeal FW66. As a result,
the device is identified as one of applications of BeBoB solution.
I note that in the report the device returns contradictory result in plug
discovery process for audio subunit. Fortunately ALSA BeBoB driver doesn't
perform it thus it's likely to handle the device without issues.
I receive no reaction to test request for this patch yet, however it would
be worth to add support for it.
Inside function hideep_nvm_unlock(), variable "unmask_code" could
be uninitialized if hideep_pgm_r_reg() returns error, however, it
is used in the later if statement after an "and" operation, which
is potentially unsafe.
The tprot() inline asm temporarily changes the program check new psw
to redirect a potential program check on the diag instruction.
Restoring of the program check new psw is done in C code behind the
inline asm.
This can be problematic, especially if the function is inlined, since
the compiler can reorder instructions in such a way that a different
instruction, which may result in a program check, might be executed
before the program check new psw has been restored.
To avoid such a scenario move restoring into the inline asm. For
consistency reasons move also saving of the original program check new
psw into the inline asm.
The __diag260() inline asm temporarily changes the program check new
psw to redirect a potential program check on the diag instruction.
Restoring of the program check new psw is done in C code behind the
inline asm.
This can be problematic, especially if the function is inlined, since
the compiler can reorder instructions in such a way that a different
instruction, which may result in a program check, might be executed
before the program check new psw has been restored.
To avoid such a scenario move restoring into the inline asm. For
consistency reasons move also saving of the original program check new
psw into the inline asm.
The __diag308() inline asm temporarily changes the program check new
psw to redirect a potential program check on the diag instruction.
Restoring of the program check new psw is done in C code behind the
inline asm.
This can be problematic, especially if the function is inlined, since
the compiler can reorder instructions in such a way that a different
instruction, which may result in a program check, might be executed
before the program check new psw has been restored.
To avoid such a scenario move restoring into the inline asm. For
consistency reasons move also saving of the original program check new
psw into the inline asm.
s390 is the only architecture which makes use of the __no_kasan_or_inline
attribute for two functions. Given that both stap() and __load_psw_mask()
are very small functions they can and should be always inlined anyway.
Therefore get rid of __no_kasan_or_inline and always inline these
functions.
The "no_handler_test" in ebb selftests attempts to read the PMU
registers twice via helper function "dump_ebb_state". First dump is
just before closing of event and the second invocation is done after
closing of the event. The original intention of second
dump_ebb_state was to dump the state of registers at the end of
the test when the counters are frozen. But this will be achieved
with the first call itself since sample period is set to low value
and PMU will be frozen by then. Hence patch removes the
dump which was done before closing of the event.
The reference counting issue happens in several exception handling paths
of arm_smmu_iova_to_phys_hard(). When those error scenarios occur, the
function forgets to decrease the refcount of "smmu" increased by
arm_smmu_rpm_get(), causing a refcount leak.
Fix this issue by jumping to "out" label when those error scenarios
occur.
arm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the
refcount of the "smmu" even though the return value is less than 0.
The reference counting issue happens in some error handling paths of
arm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get()
fails, the caller functions forget to decrease the refcount of "smmu"
increased by arm_smmu_rpm_get(), causing a refcount leak.
Fix this issue by calling pm_runtime_resume_and_get() instead of
pm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcount
balanced in case of failure.
Commit f959dcd6ddfd29235030e8026471ac1b022ad2b0 (dma-direct: Fix
potential NULL pointer dereference) added a null check on the
dma_mask pointer of the kernel's device structure.
Add a dma_mask variable to the ps3_dma_region structure and set
the device structure's dma_mask pointer to point to this new variable.
Fixes runtime errors like these:
# WARNING: Fixes tag on line 10 doesn't match correct format
# WARNING: Fixes tag on line 10 doesn't match correct format
ps3_system_bus_match:349: dev=8.0(sb_01), drv=8.0(ps3flash): match
WARNING: CPU: 0 PID: 1 at kernel/dma/mapping.c:151 .dma_map_page_attrs+0x34/0x1e0
ps3flash sb_01: ps3stor_setup:193: map DMA region failed
snd_sb_qsound_destroy() contains the calls of removing the previously
created mixer controls, but it doesn't clear the pointers. As
snd_sb_qsound_destroy() itself may be repeatedly called via ioctl,
this could lead to double-free potentially.
Fix it by clearing the struct fields properly afterwards.
This test will require /dev/rtc0, the default RTC device, or one
specified by user to run. Since this default RTC is not guaranteed to
exist on all of the devices, so check its existence first, otherwise
skip this test with the kselftest skip code 4.
Without this patch this test will fail like this on a s390x zVM:
$ selftests: timers: rtcpie
$ /dev/rtc0: No such file or directory
not ok 1 selftests: timers: rtcpie # exit=22
With this patch:
$ selftests: timers: rtcpie
$ Default RTC /dev/rtc0 does not exist. Test Skipped!
not ok 9 selftests: timers: rtcpie # SKIP
Fixed up change log so "With this patch" text doesn't get dropped.
Shuah Khan <skhan@linuxfoundation.org>
Remove the hack to assign the global console_port variable at probe time.
This assumption that cons->index is -1 is wrong for systems that specify
'console=' in the cmdline (or 'stdout-path' in dts). Hence, on such system
the actual console assignment is ignored, and the first UART that happens
to be probed is used as console instead.
Move the logic to console_setup() and map the console to the correct port
through the array of available ports instead.
pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by replacing it with pm_runtime_resume_and_get to keep usage
counter balanced.
We have started to get a bunch of pointless dmamask not set warnings
that makes the output of dmesg -l err,warn hard to read with many
extra warnings:
cpcap-regulator cpcap-regulator.0: DMA mask not set
cpcap_adc cpcap_adc.0: DMA mask not set
cpcap_battery cpcap_battery.0: DMA mask not set
cpcap-charger cpcap-charger.0: DMA mask not set
cpcap-pwrbutton cpcap-pwrbutton.0: DMA mask not set
cpcap-led cpcap-led.0: DMA mask not set
cpcap-led cpcap-led.1: DMA mask not set
cpcap-led cpcap-led.2: DMA mask not set
cpcap-led cpcap-led.3: DMA mask not set
cpcap-led cpcap-led.4: DMA mask not set
cpcap-rtc cpcap-rtc.0: DMA mask not set
cpcap-usb-phy cpcap-usb-phy.0: DMA mask not set
This seems to have started with commit 4d8bde883bfb ("OF: Don't set
default coherent DMA mask"). We have the parent SPI controller use
DMA, while CPCAP driver and it's children do not. For audio, the
DMA is handled over I2S bus with the McBSP driver.
Cc: Carl Philipp Klemm <philipp@uvos.xyz> Cc: Ivan Jelincic <parazyd@dyne.org> Cc: Merlijn Wajer <merlijn@wizzup.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Sebastian Reichel <sre@kernel.org> Cc: Sicelo A. Mhlongo <absicsz@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This patch adds/modifies MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.
Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
If qedi_process_cmd_cleanup_resp finds the cmd it frees the work and sets
list_tmf_work to NULL, so qedi_tmf_work should check if list_tmf_work is
non-NULL when it wants to force cleanup.
Link: https://lore.kernel.org/r/20210525181821.7617-20-michael.christie@oracle.com Reviewed-by: Manish Rangankar <mrangankar@marvell.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The iscsi offload drivers are setting the shost->max_id to the max number
of sessions they support. The problem is that max_id is not the max number
of targets but the highest identifier the targets can have. To use it to
limit the number of targets we need to set it to max sessions - 1, or we
can end up with a session we might not have preallocated resources for.
If we haven't done a unbind target call we can race where
iscsi_conn_teardown wakes up the EH thread and then frees the conn while
those threads are still accessing the conn ehwait.
We can only do one TMF per session so this just moves the TMF fields from
the conn to the session. We can then rely on the
iscsi_session_teardown->iscsi_remove_session->__iscsi_unbind_session call
to remove the target and it's devices, and know after that point there is
no device or scsi-ml callout trying to access the session.
There are a couple places where we could free the iscsi_cls_conn while it's
still in use. This adds some helpers to get/put a refcount on the struct
and converts an exiting user. Subsequent commits will then use the helpers
to fix 2 bugs in the eh code.
While reenabling the IRQ after IRQ poll there may be a small window for the
firmware to post the replies with interrupts raised. In that case the
driver will not see the interrupts which leads to I/O timeout.
This issue only happens when there are many I/O completions on a single
reply queue. This forces the driver to switch between the interrupt and IRQ
context.
Make the driver process the reply queue one more time after enabling the
IRQ.
Consider the case where a VD is deleted and the targetID of that VD is
assigned to a newly created VD. If the sequence of deletion/addition of VD
happens very quickly there is a possibility that second event (VD add)
occurs even before the driver processes the first event (VD delete). As
event processing is done in deferred context the device list remains the
same (but targetID is re-used) so driver will not learn the VD
deletion/additon. I/Os meant for the older VD will be directed to new VD
which may lead to data corruption.
Make driver detect the deleted VD as soon as possible based on the RaidMap
update and block further I/O to that device.
Link: https://lore.kernel.org/r/20210528131307.25683-4-chandrakanth.patil@broadcom.com Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by replacing it with pm_runtime_resume_and_get to keep usage
counter balanced.
The sysfs handling function sdev_store_queue_depth() enforces that the sdev
queue depth cannot exceed shost can_queue. The initial sdev queue depth
comes from shost cmd_per_lun. However, the LLDD may manually set
cmd_per_lun to be larger than can_queue, which leads to an initial sdev
queue depth greater than can_queue.
Such an issue was reported in [0], which caused a hang. That has since been
fixed in commit fc09acb7de31 ("scsi: scsi_debug: Fix cmd_per_lun, set to
max_queue").
Stop this possibly happening for other drivers by capping shost cmd_per_lun
at shost can_queue.
Link: https://lore.kernel.org/r/1621434662-173079-1-git-send-email-john.garry@huawei.com Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The driver is encountering a crash in lpfc_free_iocb_list() while
performing initial attachment.
Code review found this to be an errant failure path that was taken, jumping
to a tag that then referenced structures that were uninitialized.
Fix the failure path.
Link: https://lore.kernel.org/r/20210514195559.119853-9-jsmart2021@gmail.com Co-developed-by: Justin Tee <justin.tee@broadcom.com> Signed-off-by: Justin Tee <justin.tee@broadcom.com> Signed-off-by: James Smart <jsmart2021@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
An 'unexpected timeout' message may be seen in a point-2-point topology.
The message occurs when a PLOGI is received before the driver is notified
of FLOGI completion. The FLOGI completion failure causes discovery to be
triggered for a second time. The discovery timer is restarted but no new
discovery activity is initiated, thus the timeout message eventually
appears.
In point-2-point, when discovery has progressed before the FLOGI completion
is processed, it is not a failure. Add code to FLOGI completion to detect
that discovery has progressed and exit the FLOGI handling (noop'ing it).
Link: https://lore.kernel.org/r/20210514195559.119853-4-jsmart2021@gmail.com Co-developed-by: Justin Tee <justin.tee@broadcom.com> Signed-off-by: Justin Tee <justin.tee@broadcom.com> Signed-off-by: James Smart <jsmart2021@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
After commit 6c11dc060427 ("scsi: hisi_sas: Fix IRQ checks") we have the
error codes returned by platform_get_irq() ready for the propagation
upsream in interrupt_init_v1_hw() -- that will fix still broken deferred
probing. Let's propagate the error codes from devm_request_irq() as well
since I don't see the reason to override them with -ENOENT...
Link: https://lore.kernel.org/r/49ba93a3-d427-7542-d85a-b74fe1a33a73@omp.ru Acked-by: John Garry <john.garry@huawei.com> Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
The purpose of the w1_ds2438_get_page function is to get the register
values at the page passed as the pageno parameter. However, the page0 was
hardcoded, such that the function always returned the page0 contents. Fixed
so that the function can retrieve any page.
I've explained that optional FireWire card for d.2 is also built-in to
d.2 Pro, however it's wrong. The optional card uses DM1000 ASIC and has
'Mackie DJ Mixer' in its model name of configuration ROM. On the other
hand, built-in FireWire card for d.2 Pro and d.4 Pro uses OXFW971 ASIC
and has 'd.Pro' in its model name according to manuals and user
experiences. The former card is not the card for d.2 Pro. They are similar
in appearance but different internally.
probe() error paths after runtime pm is enabled, should disable it.
remove() should not call pm_runtime_put_noidle() as there is no
matching get() to have raised the reference count. This case
has no affect a the runtime pm core protects against going negative.
Whilst here use pm_runtime_resume_and_get() to tidy things up a little.
coccicheck script didn't get this one due to complex code structure so
found by inspection.
In both the probe() error path and remove() pm_runtime_put_noidle()
is called which will decrement the runtime pm reference count.
However, there is no matching function to have raised the reference count.
Not this isn't a fix as the runtime pm core will stop the reference count
going negative anyway.
An alternative would have been to raise the count in these paths, but
it is not clear why that would be necessary.
Whilst we are here replace some boilerplate with pm_runtime_resume_and_get()
Found using coccicheck script under review at:
https://lore.kernel.org/lkml/20210427141946.2478411-1-Julia.Lawall@inria.fr/
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Rui Miguel Silva <rui.silva@linaro.org> Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/20210509113354.660190-2-jic23@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
There is an issue with the ASPM(optional) capability checking function.
A device might be attached to root complex directly, in this case,
bus->self(bridge) will be NULL, thus priv->parent_pdev is NULL.
Since alcor_pci_init_check_aspm(priv->parent_pdev) checks the PCI link's
ASPM capability and populate parent_cap_off, which will be used later by
alcor_pci_aspm_ctrl() to dynamically turn on/off device, what we can do
here is to avoid checking the capability if we are on the root complex.
This will make pdev_cap_off 0 and alcor_pci_aspm_ctrl() will simply
return when bring called, effectively disable ASPM for the device.
In ibmasm_init_one, it calls ibmasm_init_remote_input_dev().
Inside ibmasm_init_remote_input_dev, mouse_dev and keybd_dev are
allocated by input_allocate_device(), and assigned to
sp->remote.mouse_dev and sp->remote.keybd_dev respectively.
In the err_free_devices error branch of ibmasm_init_one,
mouse_dev and keybd_dev are freed by input_free_device(), and return
error. Then the execution runs into error_send_message error branch
of ibmasm_init_one, where ibmasm_free_remote_input_dev(sp) is called
to unregister the freed sp->remote.mouse_dev and sp->remote.keybd_dev.
My patch add a "error_init_remote" label to handle the error of
ibmasm_init_remote_input_dev(), to avoid the uaf bugs.
We should be very careful about the register values that will be used
for division or modulo operations, althrough the possibility that the
UARTBAUD register value is zero is very low, but we had better to deal
with the "bad data" of hardware in advance to avoid division or modulo
by zero leading to undefined kernel behavior.
An srcu_struct structure that is initialized before rcu_init_geometry()
will have its srcu_node hierarchy based on CONFIG_NR_CPUS. Once
rcu_init_geometry() is called, this hierarchy is compressed as needed
for the actual maximum number of CPUs for this system.
Later on, that srcu_struct structure is confused, sometimes referring
to its initial CONFIG_NR_CPUS-based hierarchy, and sometimes instead
to the new num_possible_cpus() hierarchy. For example, each of its
->mynode fields continues to reference the original leaf rcu_node
structures, some of which might no longer exist. On the other hand,
srcu_for_each_node_breadth_first() traverses to the new node hierarchy.
There are at least two bad possible outcomes to this:
1) a) A callback enqueued early on an srcu_data structure (call it
*sdp) is recorded pending on sdp->mynode->srcu_data_have_cbs in
srcu_funnel_gp_start() with sdp->mynode pointing to a deep leaf
(say 3 levels).
b) The grace period ends after rcu_init_geometry() shrinks the
nodes level to a single one. srcu_gp_end() walks through the new
srcu_node hierarchy without ever reaching the old leaves so the
callback is never executed.
This is easily reproduced on an 8 CPUs machine with CONFIG_NR_CPUS >= 32
and "rcupdate.rcu_self_test=1". The srcu_barrier() after early tests
verification never completes and the boot hangs:
2) An srcu_struct structure that is initialized before rcu_init_geometry()
and used afterward will always have stale rdp->mynode references,
resulting in callbacks to be missed in srcu_gp_end(), just like in
the previous scenario.
This commit therefore causes init_srcu_struct_nodes to initialize the
geometry, if needed. This ensures that the srcu_node hierarchy is
properly built and distributed from the get-go.
Suggested-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Neeraj Upadhyay <neeraju@codeaurora.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Use devm_platform_get_and_ioremap_resource() to simplify
code and avoid a null-ptr-deref by checking 'res' in it.
[yyl: since devm_platform_get_and_ioremap_resource() is introduced
in linux-5.7, so just check the return value after calling
platform_get_resource()]
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The execution of fb_delete_videomode() is not based on the result of the
previous fbcon_mode_deleted(). As a result, the mode is directly deleted,
regardless of whether it is still in use, which may cause UAF.
==================================================================
BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \
drivers/video/fbdev/core/modedb.c:924
Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962
The following sequence can be used to trigger a UAF:
int fscontext_fd = fsopen("cgroup");
int fd_null = open("/dev/null, O_RDONLY);
int fsconfig(fscontext_fd, FSCONFIG_SET_FD, "source", fd_null);
close_range(3, ~0U, 0);
The cgroup v1 specific fs parser expects a string for the "source"
parameter. However, it is perfectly legitimate to e.g. specify a file
descriptor for the "source" parameter. The fs parser doesn't know what
a filesystem allows there. So it's a bug to assume that "source" is
always of type fs_value_is_string when it can reasonably also be
fs_value_is_file.
This assumption in the cgroup code causes a UAF because struct
fs_parameter uses a union for the actual value. Access to that union is
guarded by the param->type member. Since the cgroup paramter parser
didn't check param->type but unconditionally moved param->string into
fc->source a close on the fscontext_fd would trigger a UAF during
put_fs_context() which frees fc->source thereby freeing the file stashed
in param->file causing a UAF during a close of the fd_null.
Fix this by verifying that param->type is actually a string and report
an error if not.
In follow up patches I'll add a new generic helper that can be used here
and by other filesystems instead of this error-prone copy-pasta fix.
But fixing it in here first makes backporting a it to stable a lot
easier.
Fixes: 8d2451f4994f ("cgroup1: switch to option-by-option parsing") Reported-by: syzbot+283ce5a46486d6acdbaf@syzkaller.appspotmail.com Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@kernel.org> Cc: syzkaller-bugs <syzkaller-bugs@googlegroups.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 66a834d09293 ("scsi: core: Fix error handling of scsi_host_alloc()")
changed the allocation logic to call put_device() to perform host cleanup
with the assumption that IDA removal and stopping the kthread would
properly be performed in scsi_host_dev_release(). However, in the unlikely
case that the error handler thread fails to spawn, shost->ehandler is set
to ERR_PTR(-ENOMEM).
The error handler cleanup code in scsi_host_dev_release() will call
kthread_stop() if shost->ehandler != NULL which will always be the case
whether the kthread was successfully spawned or not. In the case that it
failed to spawn this has the nasty side effect of trying to dereference an
invalid pointer when kthread_stop() is called. The following splat provides
an example of this behavior in the wild:
When the host is using debug registers but the guest is not using them
nor is the guest in guest-debug state, the kvm code does not reset
the host debug registers before kvm_x86->run(). Rather, it relies on
the hardware vmentry instruction to automatically reset the dr7 registers
which ensures that the host breakpoints do not affect the guest.
This however violates the non-instrumentable nature around VM entry
and exit; for example, when a host breakpoint is set on vcpu->arch.cr2,
Another issue is consistency. When the guest debug registers are active,
the host breakpoints are reset before kvm_x86->run(). But when the
guest debug registers are inactive, the host breakpoints are delayed to
be disabled. The host tracing tools may see different results depending
on what the guest is doing.
To fix the problems, we clear %db7 unconditionally before kvm_x86->run()
if the host has set any breakpoints, no matter if the guest is using
them or not.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20210628172632.81029-1-jiangshanlai@gmail.com> Cc: stable@vger.kernel.org
[Only clear %db7 instead of reloading all debug registers. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ignore the guest MAXPHYADDR reported by CPUID.0x8000_0008 if TDP, i.e.
NPT, is disabled, and instead use the host's MAXPHYADDR. Per AMD'S APM:
Maximum guest physical address size in bits. This number applies only
to guests using nested paging. When this field is zero, refer to the
PhysAddrSize field for the maximum guest physical address size.
BUG: KASAN: use-after-free in kvm_vm_ioctl_unregister_coalesced_mmio+0x7c/0x1ec arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:183
Read of size 8 at addr ffff0000c03a2500 by task syz-executor083/4269
If kvm_io_bus_unregister_dev() return -ENOMEM, we already call kvm_iodevice_destructor()
inside this function to delete 'struct kvm_coalesced_mmio_dev *dev' from list
and free the dev, but kvm_iodevice_destructor() is called again, it will lead
the above issue.
Let's check the the return value of kvm_io_bus_unregister_dev(), only call
kvm_iodevice_destructor() if the return value is 0.
Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: kvm@vger.kernel.org Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Message-Id: <20210626070304.143456-1-wangkefeng.wang@huawei.com> Cc: stable@vger.kernel.org Fixes: 5d3c4c79384a ("KVM: Stop looking for coalesced MMIO zones if the bus is destroyed", 2021-04-20) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 7ef4c19d245f3dc2 ("smackfs: restrict bytes count in smackfs write
functions") missed that count > SMK_CIPSOMAX check applies to only
format == SMK_FIXED24_FMT case.
The Elgato Cam Link 4K HDMI video capture card reports to support three
different pixel formats, where the first format depends on the connected
HDMI device.
Changing the pixel format to anything besides the first pixel format
does not work:
```
$ v4l2-ctl -d /dev/video0 --try-fmt-video pixelformat=YU12
Format Video Capture:
Width/Height : 3840/2160
Pixel Format : 'NV12' (Y/CbCr 4:2:0)
Field : None
Bytes per Line : 3840
Size Image : 12441600
Colorspace : sRGB
Transfer Function : Rec. 709
YCbCr/HSV Encoding: Rec. 709
Quantization : Default (maps to Limited Range)
Flags :
```
User space applications like VLC might show an error message on the
terminal in that case:
```
libv4l2: error set_fmt gave us a different result than try_fmt!
```
Depending on the error handling of the user space applications, they
might display a distorted video, because they use the wrong pixel format
for decoding the stream.
The Elgato Cam Link 4K responds to the USB video probe
VS_PROBE_CONTROL/VS_COMMIT_CONTROL with a malformed data structure: The
second byte contains bFormatIndex (instead of being the second byte of
bmHint). The first byte is always zero. The third byte is always 1.
The firmware bug was reported to Elgato on 2020-12-01 and it was
forwarded by the support team to the developers as feature request.
There is no firmware update available since then. The latest firmware
for Elgato Cam Link 4K as of 2021-03-23 has MCU 20.02.19 and FPGA 67.
Therefore correct the malformed data structure for this device. The
change was successfully tested with VLC, OBS, and Chromium using
different pixel formats (YUYV, NV12, YU12), resolutions (3840x2160,
1920x1080), and frame rates (29.970 and 59.940 fps).
The direction of the pipe argument must match the request-type direction
bit or control requests may fail depending on the host-controller-driver
implementation.
Control transfers without a data stage are treated as OUT requests by
the USB stack and should be using usb_sndctrlpipe(). Failing to do so
will now trigger a warning.
Fix the single zero-length control request which was using the
read-register helper, and update the helper so that zero-length reads
fail with an error message instead.
Fixes: 6a7eba24e4f0 ("V4L/DVB (8157): gspca: all subdrivers") Cc: stable@vger.kernel.org # 2.6.27 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The direction of the pipe argument must match the request-type direction
bit or control requests may fail depending on the host-controller-driver
implementation.
Fix the USB_REQ_SYNCH_FRAME request which erroneously used
usb_sndctrlpipe().
Fixes: 27d35fc3fb06 ("V4L/DVB (10639): gspca - sq905: New subdriver.") Cc: stable@vger.kernel.org # 2.6.30 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The direction of the pipe argument must match the request-type direction
bit or control requests may fail depending on the host-controller-driver
implementation.
Fix the control requests which erroneously used usb_rcvctrlpipe().
Fixes: 8466028be792 ("V4L/DVB (8734): Initial support for AME DTV-5100 USB2.0 DVB-T") Cc: stable@vger.kernel.org # 2.6.28 Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The saa6588_ioctl() function expects to get called from other kernel
functions with a 'saa6588_command' pointer, but I found nothing stops it
from getting called from user space instead, which seems rather dangerous.
The same thing happens in the davinci vpbe driver with its VENC_GET_FLD
command.
As a quick fix, add a separate .command() callback pointer for this
driver and change the two callers over to that. This change can easily
get backported to stable kernels if necessary, but since there are only
two drivers, we may want to eventually replace this with a set of more
specialized callbacks in the long run.
On Macbook 2013, resuming from suspend-to-idle or standby resulted in the
external monitor no longer being detected, a stacktrace, and errors like
this in dmesg:
pcieport 0000:06:00.0: can't change power state from D3hot to D0 (config space inaccessible)
The reason is that we know how to turn power to the Thunderbolt controller
*off* via the SXIO/SXFP/SXLF methods, but we don't know how to turn power
back on. We have to rely on firmware to turn the power back on.
When going to the "suspend-to-idle" or "standby" system sleep states,
firmware is not involved either on the suspend side or the resume side, so
we can't use SXIO/SXFP/SXLF to turn the power off.
Skip SXIO/SXFP/SXLF when firmware isn't involved in suspend, e.g., when
we're going to the "suspend-to-idle" or "standby" system sleep states.
Fixes: 1df5172c5c25 ("PCI: Suspend/resume quirks for Apple thunderbolt")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212767 Link: https://lore.kernel.org/r/20210520235501.917397-1-Hi-Angel@yandex.ru Signed-off-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
remove_raw() in dm_btree_remove() may fail due to IO read error
(e.g. read the content of origin block fails during shadowing),
and the value of shadow_spine::root is uninitialized, but
the uninitialized value is still assign to new_root in the
end of dm_btree_remove().
For dm-thin, the value of pmd->details_root or pmd->root will become
an uninitialized value, so if trying to read details_info tree again
out-of-bound memory may occur as showed below:
general protection fault, probably for non-canonical address 0x3fdcb14c8d7520
CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6
Hardware name: QEMU Standard PC
RIP: 0010:metadata_ll_load_ie+0x14/0x30
Call Trace:
sm_metadata_count_is_more_than_one+0xb9/0xe0
dm_tm_shadow_block+0x52/0x1c0
shadow_step+0x59/0xf0
remove_raw+0xb2/0x170
dm_btree_remove+0xf4/0x1c0
dm_pool_delete_thin_device+0xc3/0x140
pool_message+0x218/0x2b0
target_message+0x251/0x290
ctl_ioctl+0x1c4/0x4d0
dm_ctl_ioctl+0xe/0x20
__x64_sys_ioctl+0x7b/0xb0
do_syscall_64+0x40/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fixing it by only assign new_root when removal succeeds
Signed-off-by: Hou Tao <houtao1@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6f755e85c332 ("coresight: Add helper for inserting synchronization
packets") removed trailing '\0' from barrier_pkt array and updated the
call sites like etb_update_buffer() to have proper checks for barrier_pkt
size before read but missed updating tmc_update_etf_buffer() which still
reads barrier_pkt past the array size resulting in KASAN out-of-bounds
bug. Fix this by adding a check for barrier_pkt size before accessing
like it is done in etb_update_buffer().
BUG: KASAN: global-out-of-bounds in tmc_update_etf_buffer+0x4b8/0x698
Read of size 4 at addr ffffffd05b7d1030 by task perf/2629
The buggy address belongs to the variable:
barrier_pkt+0x10/0x40
Memory state around the buggy address: ffffffd05b7d0f00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00 ffffffd05b7d0f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffd05b7d1000: 00 00 00 00 00 00 fa fa fa fa fa fa 00 00 00 03
^ ffffffd05b7d1080: fa fa fa fa 00 02 fa fa fa fa fa fa 03 fa fa fa ffffffd05b7d1100: fa fa fa fa 00 00 00 00 05 fa fa fa fa fa fa fa
==================================================================
In the out_err_bus_register error branch of tpci200_pci_probe,
tpci200->info->cfg_regs is freed by tpci200_uninstall()->
tpci200_unregister()->pci_iounmap(..,tpci200->info->cfg_regs)
in the first time.
But later, iounmap() is called to free tpci200->info->cfg_regs
again.
My patch sets tpci200->info->cfg_regs to NULL after tpci200_uninstall()
to avoid the double free.
Fixes: cea2f7cdff2af ("Staging: ipack/bridges/tpci200: Use the TPCI200 in big endian mode") Cc: stable <stable@vger.kernel.org> Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> Link: https://lore.kernel.org/r/20210524093205.8333-1-lyl2019@mail.ustc.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently tgid_map is sized at PID_MAX_DEFAULT entries, which means that
on systems where pid_max is configured higher than PID_MAX_DEFAULT the
ftrace record-tgid option doesn't work so well. Any tasks with PIDs
higher than PID_MAX_DEFAULT are simply not recorded in tgid_map, and
don't show up in the saved_tgids file.
In particular since systemd v243 & above configure pid_max to its
highest possible 1<<22 value by default on 64 bit systems this renders
the record-tgids option of little use.
Increase the size of tgid_map to the configured pid_max instead,
allowing it to cover the full range of PIDs up to the maximum value of
PID_MAX_LIMIT if the system is configured that way.
On 64 bit systems with pid_max == PID_MAX_LIMIT this will increase the
size of tgid_map from 256KiB to 16MiB. Whilst this 64x increase in
memory overhead sounds significant 64 bit systems are presumably best
placed to accommodate it, and since tgid_map is only allocated when the
record-tgid option is actually used presumably the user would rather it
spends sufficient memory to actually record the tgids they expect.
The size of tgid_map could also increase for CONFIG_BASE_SMALL=y
configurations, but these seem unlikely to be systems upon which people
are both configuring a large pid_max and running ftrace with record-tgid
anyway.
Of note is that we only allocate tgid_map once, the first time that the
record-tgid option is enabled. Therefore its size is only set once, to
the value of pid_max at the time the record-tgid option is first
enabled. If a user increases pid_max after that point, the saved_tgids
file will not contain entries for any tasks with pids beyond the earlier
value of pid_max.
Link: https://lkml.kernel.org/r/20210701172407.889626-2-paulburton@google.com Fixes: d914ba37d714 ("tracing: Add support for recording tgid of tasks") Cc: Ingo Molnar <mingo@redhat.com> Cc: Joel Fernandes <joelaf@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Paul Burton <paulburton@google.com>
[ Fixed comment coding style ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tgid_map array records a mapping from pid to tgid, where the index
of an entry within the array is the pid & the value stored at that index
is the tgid.
The saved_tgids_next() function iterates over pointers into the tgid_map
array & dereferences the pointers which results in the tgid, but then it
passes that dereferenced value to trace_find_tgid() which treats it as a
pid & does a further lookup within the tgid_map array. It seems likely
that the intent here was to skip over entries in tgid_map for which the
recorded tgid is zero, but instead we end up skipping over entries for
which the thread group leader hasn't yet had its own tgid recorded in
tgid_map.
A minimal fix would be to remove the call to trace_find_tgid, turning:
if (trace_find_tgid(*ptr))
into:
if (*ptr)
..but it seems like this logic can be much simpler if we simply let
seq_read() iterate over the whole tgid_map array & filter out empty
entries by returning SEQ_SKIP from saved_tgids_show(). Here we take that
approach, removing the incorrect logic here entirely.
Link: https://lkml.kernel.org/r/20210630003406.4013668-1-paulburton@google.com Fixes: d914ba37d714 ("tracing: Add support for recording tgid of tasks") Cc: Ingo Molnar <mingo@redhat.com> Cc: Joel Fernandes <joelaf@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Paul Burton <paulburton@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle")
tried to fix a problem that a process could be sleeping in rq_qos_wait()
without anyone to wake it up. However the fix is not complete and the
following can still happen:
completes IOs, inflight
decreased
prepare_to_wait_exclusive()
prepare_to_wait_exclusive()
has_sleeper = !wq_has_single_sleeper() -> true as there are two sleepers
has_sleeper = !wq_has_single_sleeper() -> true
io_schedule() io_schedule()
Deadlock as now there's nobody to wakeup the two waiters. The logic
automatically blocking when there are already sleepers is really subtle
and the only way to make it work reliably is that we check whether there
are some waiters in the queue when adding ourselves there. That way, we
are guaranteed that at least the first process to enter the wait queue
will recheck the waiting condition before going to sleep and thus
guarantee forward progress.
Fixes: 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210607112613.25344-1-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There's two variables being increased in that loop (i and j), and i
follows the raw data, and j follows what is being written into the buffer.
We should compare 'i' to MAX_MEMHEX_BYTES or compare 'j' to HEX_CHARS.
Otherwise, if 'j' goes bigger than HEX_CHARS, it will overflow the
destination buffer.
projects / thirdparty / kernel / stable.git / log
