linux-stable.git/drivers/base, branch linux-5.19.y Linux kernel stable tree arm64: topology: move store_cpu_topology() to shared code 2022-10-24T07:56:45+00:00 Conor Dooley conor.dooley@microchip.com 2022-07-15T17:51:55+00:00 32863f41ee774d3e1fc787e07bf31bdf9d9953f9 commit 456797da792fa7cbf6698febf275fe9b36691f78 upstream. arm64's method of defining a default cpu topology requires only minimal changes to apply to RISC-V also. The current arm64 implementation exits early in a uniprocessor configuration by reading MPIDR & claiming that uniprocessor can rely on the default values. This is appears to be a hangover from prior to '3102bc0e6ac7 ("arm64: topology: Stop using MPIDR for topology information")', because the current code just assigns default values for multiprocessor systems. With the MPIDR references removed, store_cpu_topolgy() can be moved to the common arch_topology code. Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 456797da792fa7cbf6698febf275fe9b36691f78 upstream.

arm64's method of defining a default cpu topology requires only minimal
changes to apply to RISC-V also. The current arm64 implementation exits
early in a uniprocessor configuration by reading MPIDR & claiming that
uniprocessor can rely on the default values.

This is appears to be a hangover from prior to '3102bc0e6ac7 ("arm64:
topology: Stop using MPIDR for topology information")', because the
current code just assigns default values for multiprocessor systems.

With the MPIDR references removed, store_cpu_topolgy() can be moved to
the common arch_topology code.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
regmap: spi: Reserve space for register address/padding 2022-09-15T08:47:12+00:00 Cristian Ciocaltea cristian.ciocaltea@collabora.com 2022-08-18T10:48:51+00:00 15ff1f17847c19174b260bd7dd0de33edcebd45e [ Upstream commit f5723cfc01932c7a8d5c78dbf7e067e537c91439 ] Currently the max_raw_read and max_raw_write limits in regmap_spi struct do not take into account the additional size of the transmitted register address and padding. This may result in exceeding the maximum permitted SPI message size, which could cause undefined behaviour, e.g. data corruption. Fix regmap_get_spi_bus() to properly adjust the above mentioned limits by reserving space for the register address/padding as set in the regmap configuration. Fixes: f231ff38b7b2 ("regmap: spi: Set regmap max raw r/w from max_transfer_size") Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com> Reviewed-by: Lucas Tanure <tanureal@opensource.cirrus.com> Link: https://lore.kernel.org/r/20220818104851.429479-1-cristian.ciocaltea@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f5723cfc01932c7a8d5c78dbf7e067e537c91439 ]

Currently the max_raw_read and max_raw_write limits in regmap_spi struct
do not take into account the additional size of the transmitted register
address and padding.  This may result in exceeding the maximum permitted
SPI message size, which could cause undefined behaviour, e.g. data
corruption.

Fix regmap_get_spi_bus() to properly adjust the above mentioned limits
by reserving space for the register address/padding as set in the regmap
configuration.

Fixes: f231ff38b7b2 ("regmap: spi: Set regmap max raw r/w from max_transfer_size")

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220818104851.429479-1-cristian.ciocaltea@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
driver core: fix driver_set_override() issue with empty strings 2022-09-15T08:47:11+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2022-09-01T16:37:34+00:00 7ea6589d0ff6d12805af6b0ee919c2a1c369f0cb commit 5666a274a6d54372d6b79b1f78682a9d827e679e upstream. Python likes to send an empty string for some sysfs files, including the driver_override field. When commit 23d99baf9d72 ("PCI: Use driver_set_override() instead of open-coding") moved the PCI core to use the driver core function instead of hand-rolling their own handler, this showed up as a regression from some userspace tools, like DPDK. Fix this up by actually looking at the length of the string first instead of trusting that userspace got it correct. Fixes: 23d99baf9d72 ("PCI: Use driver_set_override() instead of open-coding") Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: stable <stable@kernel.org> Reported-by: Stephen Hemminger <stephen@networkplumber.org> Tested-by: Huisong Li <lihuisong@huawei.com> Reviewed-by: Stephen Hemminger <stephen@networkplumber.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20220901163734.3583106-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5666a274a6d54372d6b79b1f78682a9d827e679e upstream.

Python likes to send an empty string for some sysfs files, including the
driver_override field.  When commit 23d99baf9d72 ("PCI: Use
driver_set_override() instead of open-coding") moved the PCI core to use
the driver core function instead of hand-rolling their own handler, this
showed up as a regression from some userspace tools, like DPDK.

Fix this up by actually looking at the length of the string first
instead of trusting that userspace got it correct.

Fixes: 23d99baf9d72 ("PCI: Use driver_set_override() instead of open-coding")
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: stable <stable@kernel.org>
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Tested-by: Huisong Li <lihuisong@huawei.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220901163734.3583106-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: Don't probe devices after bus_type.match() probe deferral 2022-09-08T09:24:06+00:00 Isaac J. Manjarres isaacmanjarres@google.com 2022-08-17T18:40:26+00:00 a4c5cc34976883e2b16b2bfdec70c8d33238a20f commit 25e9fbf0fd38868a429feabc38abebfc6dbf6542 upstream. Both __device_attach_driver() and __driver_attach() check the return code of the bus_type.match() function to see if the device needs to be added to the deferred probe list. After adding the device to the list, the logic attempts to bind the device to the driver anyway, as if the device had matched with the driver, which is not correct. If __device_attach_driver() detects that the device in question is not ready to match with a driver on the bus, then it doesn't make sense for the device to attempt to bind with the current driver or continue attempting to match with any of the other drivers on the bus. So, update the logic in __device_attach_driver() to reflect this. If __driver_attach() detects that a driver tried to match with a device that is not ready to match yet, then the driver should not attempt to bind with the device. However, the driver can still attempt to match and bind with other devices on the bus, as drivers can be bound to multiple devices. So, update the logic in __driver_attach() to reflect this. Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()") Cc: stable@vger.kernel.org Cc: Saravana Kannan <saravanak@google.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Saravana Kannan <saravanak@google.com> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com> Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 25e9fbf0fd38868a429feabc38abebfc6dbf6542 upstream.

Both __device_attach_driver() and __driver_attach() check the return
code of the bus_type.match() function to see if the device needs to be
added to the deferred probe list. After adding the device to the list,
the logic attempts to bind the device to the driver anyway, as if the
device had matched with the driver, which is not correct.

If __device_attach_driver() detects that the device in question is not
ready to match with a driver on the bus, then it doesn't make sense for
the device to attempt to bind with the current driver or continue
attempting to match with any of the other drivers on the bus. So, update
the logic in __device_attach_driver() to reflect this.

If __driver_attach() detects that a driver tried to match with a device
that is not ready to match yet, then the driver should not attempt to bind
with the device. However, the driver can still attempt to match and bind
with other devices on the bus, as drivers can be bound to multiple
devices. So, update the logic in __driver_attach() to reflect this.

Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
Cc: stable@vger.kernel.org
Cc: Saravana Kannan <saravanak@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
firmware_loader: Fix memory leak in firmware upload 2022-09-08T09:24:02+00:00 Russ Weight russell.h.weight@intel.com 2022-08-31T00:25:18+00:00 baf92485d111be828e1ab84a995515b604b938e5 commit 789bba82f63c3e81dce426ba457fc7905b30ac6e upstream. In the case of firmware-upload, an instance of struct fw_upload is allocated in firmware_upload_register(). This data needs to be freed in fw_dev_release(). Create a new fw_upload_free() function in sysfs_upload.c to handle the firmware-upload specific memory frees and incorporate the missing kfree call for the fw_upload structure. Fixes: 97730bbb242c ("firmware_loader: Add firmware-upload support") Cc: stable <stable@kernel.org> Signed-off-by: Russ Weight <russell.h.weight@intel.com> Link: https://lore.kernel.org/r/20220831002518.465274-1-russell.h.weight@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 789bba82f63c3e81dce426ba457fc7905b30ac6e upstream.

In the case of firmware-upload, an instance of struct fw_upload is
allocated in firmware_upload_register(). This data needs to be freed
in fw_dev_release(). Create a new fw_upload_free() function in
sysfs_upload.c to handle the firmware-upload specific memory frees
and incorporate the missing kfree call for the fw_upload structure.

Fixes: 97730bbb242c ("firmware_loader: Add firmware-upload support")
Cc: stable <stable@kernel.org>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20220831002518.465274-1-russell.h.weight@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
firmware_loader: Fix use-after-free during unregister 2022-09-08T09:24:02+00:00 Russ Weight russell.h.weight@intel.com 2022-08-29T17:45:57+00:00 d380d40930a674c520a5b55f3be1eb17dc634ebc commit 8b40c38e37492b5bdf8e95b46b5cca9517a9957a upstream. In the following code within firmware_upload_unregister(), the call to device_unregister() could result in the dev_release function freeing the fw_upload_priv structure before it is dereferenced for the call to module_put(). This bug was found by the kernel test robot using CONFIG_KASAN while running the firmware selftests. device_unregister(&fw_sysfs->dev); module_put(fw_upload_priv->module); The problem is fixed by copying fw_upload_priv->module to a local variable for use when calling device_unregister(). Fixes: 97730bbb242c ("firmware_loader: Add firmware-upload support") Cc: stable <stable@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com> Signed-off-by: Russ Weight <russell.h.weight@intel.com> Link: https://lore.kernel.org/r/20220829174557.437047-1-russell.h.weight@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8b40c38e37492b5bdf8e95b46b5cca9517a9957a upstream.

In the following code within firmware_upload_unregister(), the call to
device_unregister() could result in the dev_release function freeing the
fw_upload_priv structure before it is dereferenced for the call to
module_put(). This bug was found by the kernel test robot using
CONFIG_KASAN while running the firmware selftests.

  device_unregister(&fw_sysfs->dev);
  module_put(fw_upload_priv->module);

The problem is fixed by copying fw_upload_priv->module to a local variable
for use when calling device_unregister().

Fixes: 97730bbb242c ("firmware_loader: Add firmware-upload support")
Cc: stable <stable@kernel.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20220829174557.437047-1-russell.h.weight@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "devcoredump: remove the useless gfp_t parameter in dev_coredumpv and dev_coredumpm" 2022-08-17T13:16:19+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2022-06-27T14:36:57+00:00 d729f0ee99a3c4ef8d515bd1a78dcafb86f3b8f8 commit 38a523a2946d3a0961d141d477a1ee2b1f3bdbb1 upstream. This reverts commit 77515ebaf01920e2db49e04672ef669a7c2907f2 as it causes build problems in linux-next. It needs to be reintroduced in a way that can allow the api to evolve and not require a "flag day" to catch all users. Link: https://lore.kernel.org/r/20220623160723.7a44b573@canb.auug.org.au Cc: Duoming Zhou <duoming@zju.edu.cn> Cc: Brian Norris <briannorris@chromium.org> Cc: Johannes Berg <johannes@sipsolutions.net> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 38a523a2946d3a0961d141d477a1ee2b1f3bdbb1 upstream.

This reverts commit 77515ebaf01920e2db49e04672ef669a7c2907f2 as it
causes build problems in linux-next.  It needs to be reintroduced in a
way that can allow the api to evolve and not require a "flag day" to
catch all users.

Link: https://lore.kernel.org/r/20220623160723.7a44b573@canb.auug.org.au
Cc: Duoming Zhou <duoming@zju.edu.cn>
Cc: Brian Norris <briannorris@chromium.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist 2022-08-17T13:16:06+00:00 Phil Auld pauld@redhat.com 2022-07-15T13:49:24+00:00 03c8facf9dcbee13e169b8b6d82af55ab4119173 commit 7ee951acd31a88f941fd6535fbdee3a1567f1d63 upstream. Using bin_attributes with a 0 size causes fstat and friends to return that 0 size. This breaks userspace code that retrieves the size before reading the file. Rather than reverting 75bd50fa841 ("drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI") let's put in a size value at compile time. For cpulist the maximum size is on the order of NR_CPUS * (ceil(log10(NR_CPUS)) + 1)/2 which for 8192 is 20480 (8192 * 5)/2. In order to get near that you'd need a system with every other CPU on one node. For example: (0,2,4,8, ... ). To simplify the math and support larger NR_CPUS in the future we are using (NR_CPUS * 7)/2. We also set it to a min of PAGE_SIZE to retain the older behavior for smaller NR_CPUS. The cpumap file the size works out to be NR_CPUS/4 + NR_CPUS/32 - 1 (or NR_CPUS * 9/32 - 1) including the ","s. Add a set of macros for these values to cpumask.h so they can be used in multiple places. Apply these to the handful of such files in drivers/base/topology.c as well as node.c. As an example, on an 80 cpu 4-node system (NR_CPUS == 8192): before: -r--r--r--. 1 root root 0 Jul 12 14:08 system/node/node0/cpulist -r--r--r--. 1 root root 0 Jul 11 17:25 system/node/node0/cpumap after: -r--r--r--. 1 root root 28672 Jul 13 11:32 system/node/node0/cpulist -r--r--r--. 1 root root 4096 Jul 13 11:31 system/node/node0/cpumap CONFIG_NR_CPUS = 16384 -r--r--r--. 1 root root 57344 Jul 13 14:03 system/node/node0/cpulist -r--r--r--. 1 root root 4607 Jul 13 14:02 system/node/node0/cpumap The actual number of cpus doesn't matter for the reported size since they are based on NR_CPUS. Fixes: 75bd50fa841d ("drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI") Fixes: bb9ec13d156e ("topology: use bin_attribute to break the size limitation of cpumap ABI") Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Yury Norov <yury.norov@gmail.com> Cc: stable@vger.kernel.org Acked-by: Yury Norov <yury.norov@gmail.com> (for include/linux/cpumask.h) Signed-off-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220715134924.3466194-1-pauld@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7ee951acd31a88f941fd6535fbdee3a1567f1d63 upstream.

Using bin_attributes with a 0 size causes fstat and friends to return that
0 size. This breaks userspace code that retrieves the size before reading
the file. Rather than reverting 75bd50fa841 ("drivers/base/node.c: use
bin_attribute to break the size limitation of cpumap ABI") let's put in a
size value at compile time.

For cpulist the maximum size is on the order of
	NR_CPUS * (ceil(log10(NR_CPUS)) + 1)/2

which for 8192 is 20480 (8192 * 5)/2. In order to get near that you'd need
a system with every other CPU on one node. For example: (0,2,4,8, ... ).
To simplify the math and support larger NR_CPUS in the future we are using
(NR_CPUS * 7)/2. We also set it to a min of PAGE_SIZE to retain the older
behavior for smaller NR_CPUS.

The cpumap file the size works out to be NR_CPUS/4 + NR_CPUS/32 - 1
(or NR_CPUS * 9/32 - 1) including the ","s.

Add a set of macros for these values to cpumask.h so they can be used in
multiple places. Apply these to the handful of such files in
drivers/base/topology.c as well as node.c.

As an example, on an 80 cpu 4-node system (NR_CPUS == 8192):

before:

-r--r--r--. 1 root root 0 Jul 12 14:08 system/node/node0/cpulist
-r--r--r--. 1 root root 0 Jul 11 17:25 system/node/node0/cpumap

after:

-r--r--r--. 1 root root 28672 Jul 13 11:32 system/node/node0/cpulist
-r--r--r--. 1 root root  4096 Jul 13 11:31 system/node/node0/cpumap

CONFIG_NR_CPUS = 16384
-r--r--r--. 1 root root 57344 Jul 13 14:03 system/node/node0/cpulist
-r--r--r--. 1 root root  4607 Jul 13 14:02 system/node/node0/cpumap

The actual number of cpus doesn't matter for the reported size since they
are based on NR_CPUS.

Fixes: 75bd50fa841d ("drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI")
Fixes: bb9ec13d156e ("topology: use bin_attribute to break the size limitation of cpumap ABI")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: stable@vger.kernel.org
Acked-by: Yury Norov <yury.norov@gmail.com> (for include/linux/cpumask.h)
Signed-off-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220715134924.3466194-1-pauld@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver core: fix potential deadlock in __driver_attach 2022-08-17T13:15:23+00:00 Zhang Wensheng zhangwensheng5@huawei.com 2022-06-22T07:43:27+00:00 37f908038402c9b8325763f306a1c65d88757e15 [ Upstream commit 70fe758352cafdee72a7b13bf9db065f9613ced8 ] In __driver_attach function, There are also AA deadlock problem, like the commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). stack like commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). list below: In __driver_attach function, The lock holding logic is as follows: ... __driver_attach if (driver_allows_async_probing(drv)) device_lock(dev) // get lock dev async_schedule_dev(__driver_attach_async_helper, dev); // func async_schedule_node async_schedule_node_domain(func) entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC); /* when fail or work limit, sync to execute func, but __driver_attach_async_helper will get lock dev as will, which will lead to A-A deadlock. */ if (!entry || atomic_read(&entry_count) > MAX_WORK) { func; else queue_work_node(node, system_unbound_wq, &entry->work) device_unlock(dev) As above show, when it is allowed to do async probes, because of out of memory or work limit, async work is not be allowed, to do sync execute instead. it will lead to A-A deadlock because of __driver_attach_async_helper getting lock dev. Reproduce: and it can be reproduce by make the condition (if (!entry || atomic_read(&entry_count) > MAX_WORK)) untenable, like below: [ 370.785650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 370.787154] task:swapper/0 state:D stack: 0 pid: 1 ppid: 0 flags:0x00004000 [ 370.788865] Call Trace: [ 370.789374] <TASK> [ 370.789841] __schedule+0x482/0x1050 [ 370.790613] schedule+0x92/0x1a0 [ 370.791290] schedule_preempt_disabled+0x2c/0x50 [ 370.792256] __mutex_lock.isra.0+0x757/0xec0 [ 370.793158] __mutex_lock_slowpath+0x1f/0x30 [ 370.794079] mutex_lock+0x50/0x60 [ 370.794795] __device_driver_lock+0x2f/0x70 [ 370.795677] ? driver_probe_device+0xd0/0xd0 [ 370.796576] __driver_attach_async_helper+0x1d/0xd0 [ 370.797318] ? driver_probe_device+0xd0/0xd0 [ 370.797957] async_schedule_node_domain+0xa5/0xc0 [ 370.798652] async_schedule_node+0x19/0x30 [ 370.799243] __driver_attach+0x246/0x290 [ 370.799828] ? driver_allows_async_probing+0xa0/0xa0 [ 370.800548] bus_for_each_dev+0x9d/0x130 [ 370.801132] driver_attach+0x22/0x30 [ 370.801666] bus_add_driver+0x290/0x340 [ 370.802246] driver_register+0x88/0x140 [ 370.802817] ? virtio_scsi_init+0x116/0x116 [ 370.803425] scsi_register_driver+0x1a/0x30 [ 370.804057] init_sd+0x184/0x226 [ 370.804533] do_one_initcall+0x71/0x3a0 [ 370.805107] kernel_init_freeable+0x39a/0x43a [ 370.805759] ? rest_init+0x150/0x150 [ 370.806283] kernel_init+0x26/0x230 [ 370.806799] ret_from_fork+0x1f/0x30 To fix the deadlock, move the async_schedule_dev outside device_lock, as we can see, in async_schedule_node_domain, the parameter of queue_work_node is system_unbound_wq, so it can accept concurrent operations. which will also not change the code logic, and will not lead to deadlock. Fixes: ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver") Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com> Link: https://lore.kernel.org/r/20220622074327.497102-1-zhangwensheng5@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 70fe758352cafdee72a7b13bf9db065f9613ced8 ]

In __driver_attach function, There are also AA deadlock problem,
like the commit b232b02bf3c2 ("driver core: fix deadlock in
__device_attach").

stack like commit b232b02bf3c2 ("driver core: fix deadlock in
__device_attach").
list below:
    In __driver_attach function, The lock holding logic is as follows:
    ...
    __driver_attach
    if (driver_allows_async_probing(drv))
      device_lock(dev)      // get lock dev
        async_schedule_dev(__driver_attach_async_helper, dev); // func
          async_schedule_node
            async_schedule_node_domain(func)
              entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC);
              /* when fail or work limit, sync to execute func, but
                 __driver_attach_async_helper will get lock dev as
                 will, which will lead to A-A deadlock.  */
              if (!entry || atomic_read(&entry_count) > MAX_WORK) {
                func;
              else
                queue_work_node(node, system_unbound_wq, &entry->work)
      device_unlock(dev)

    As above show, when it is allowed to do async probes, because of
    out of memory or work limit, async work is not be allowed, to do
    sync execute instead. it will lead to A-A deadlock because of
    __driver_attach_async_helper getting lock dev.

Reproduce:
and it can be reproduce by make the condition
(if (!entry || atomic_read(&entry_count) > MAX_WORK)) untenable, like
below:

[  370.785650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
this message.
[  370.787154] task:swapper/0       state:D stack:    0 pid:    1 ppid:
0 flags:0x00004000
[  370.788865] Call Trace:
[  370.789374]  <TASK>
[  370.789841]  __schedule+0x482/0x1050
[  370.790613]  schedule+0x92/0x1a0
[  370.791290]  schedule_preempt_disabled+0x2c/0x50
[  370.792256]  __mutex_lock.isra.0+0x757/0xec0
[  370.793158]  __mutex_lock_slowpath+0x1f/0x30
[  370.794079]  mutex_lock+0x50/0x60
[  370.794795]  __device_driver_lock+0x2f/0x70
[  370.795677]  ? driver_probe_device+0xd0/0xd0
[  370.796576]  __driver_attach_async_helper+0x1d/0xd0
[  370.797318]  ? driver_probe_device+0xd0/0xd0
[  370.797957]  async_schedule_node_domain+0xa5/0xc0
[  370.798652]  async_schedule_node+0x19/0x30
[  370.799243]  __driver_attach+0x246/0x290
[  370.799828]  ? driver_allows_async_probing+0xa0/0xa0
[  370.800548]  bus_for_each_dev+0x9d/0x130
[  370.801132]  driver_attach+0x22/0x30
[  370.801666]  bus_add_driver+0x290/0x340
[  370.802246]  driver_register+0x88/0x140
[  370.802817]  ? virtio_scsi_init+0x116/0x116
[  370.803425]  scsi_register_driver+0x1a/0x30
[  370.804057]  init_sd+0x184/0x226
[  370.804533]  do_one_initcall+0x71/0x3a0
[  370.805107]  kernel_init_freeable+0x39a/0x43a
[  370.805759]  ? rest_init+0x150/0x150
[  370.806283]  kernel_init+0x26/0x230
[  370.806799]  ret_from_fork+0x1f/0x30

To fix the deadlock, move the async_schedule_dev outside device_lock,
as we can see, in async_schedule_node_domain, the parameter of
queue_work_node is system_unbound_wq, so it can accept concurrent
operations. which will also not change the code logic, and will
not lead to deadlock.

Fixes: ef0ff68351be ("driver core: Probe devices asynchronously instead of the driver")
Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com>
Link: https://lore.kernel.org/r/20220622074327.497102-1-zhangwensheng5@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
devcoredump: remove the useless gfp_t parameter in dev_coredumpv and dev_coredumpm 2022-08-17T13:15:21+00:00 Duoming Zhou duoming@zju.edu.cn 2022-06-07T03:26:25+00:00 e6a4d422002bf46bca0ae350782e03da5fd28188 [ Upstream commit 77515ebaf01920e2db49e04672ef669a7c2907f2 ] The dev_coredumpv() and dev_coredumpm() could not be used in atomic context, because they call kvasprintf_const() and kstrdup() with GFP_KERNEL parameter. The process is shown below: dev_coredumpv(.., gfp_t gfp) dev_coredumpm(.., gfp_t gfp) dev_set_name kobject_set_name_vargs kvasprintf_const(GFP_KERNEL, ...); //may sleep kstrdup(s, GFP_KERNEL); //may sleep This patch removes gfp_t parameter of dev_coredumpv() and dev_coredumpm() and changes the gfp_t parameter of kzalloc() in dev_coredumpm() to GFP_KERNEL in order to show they could not be used in atomic context. Fixes: 833c95456a70 ("device coredump: add new device coredump class") Reviewed-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Link: https://lore.kernel.org/r/df72af3b1862bac7d8e793d1f3931857d3779dfd.1654569290.git.duoming@zju.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 77515ebaf01920e2db49e04672ef669a7c2907f2 ]

The dev_coredumpv() and dev_coredumpm() could not be used in atomic
context, because they call kvasprintf_const() and kstrdup() with
GFP_KERNEL parameter. The process is shown below:

dev_coredumpv(.., gfp_t gfp)
  dev_coredumpm(.., gfp_t gfp)
    dev_set_name
      kobject_set_name_vargs
        kvasprintf_const(GFP_KERNEL, ...); //may sleep
          kstrdup(s, GFP_KERNEL); //may sleep

This patch removes gfp_t parameter of dev_coredumpv() and dev_coredumpm()
and changes the gfp_t parameter of kzalloc() in dev_coredumpm() to
GFP_KERNEL in order to show they could not be used in atomic context.

Fixes: 833c95456a70 ("device coredump: add new device coredump class")
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Link: https://lore.kernel.org/r/df72af3b1862bac7d8e793d1f3931857d3779dfd.1654569290.git.duoming@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>