linux-stable.git/drivers/base/dd.c, branch linux-5.17.y

driver core: Fix wait_for_device_probe() & deferred_probe_timeout interaction

2022-06-14T16:41:25+00:00

[ Upstream commit 5ee76c256e928455212ab759c51d198fedbe7523 ]

Mounting NFS rootfs was timing out when deferred_probe_timeout was
non-zero [1].  This was because ip_auto_config() initcall times out
waiting for the network interfaces to show up when
deferred_probe_timeout was non-zero. While ip_auto_config() calls
wait_for_device_probe() to make sure any currently running deferred
probe work or asynchronous probe finishes, that wasn't sufficient to
account for devices being deferred until deferred_probe_timeout.

Commit 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits
until the deferred_probe_timeout fires") tried to fix that by making
sure wait_for_device_probe() waits for deferred_probe_timeout to expire
before returning.

However, if wait_for_device_probe() is called from the kernel_init()
context:

- Before deferred_probe_initcall() [2], it causes the boot process to
  hang due to a deadlock.

- After deferred_probe_initcall() [3], it blocks kernel_init() from
  continuing till deferred_probe_timeout expires and beats the point of
  deferred_probe_timeout that's trying to wait for userspace to load
  modules.

Neither of this is good. So revert the changes to
wait_for_device_probe().

[1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/
[2] - https://lore.kernel.org/lkml/YowHNo4sBjr9ijZr@dev-arch.thelio-3990X/
[3] - https://lore.kernel.org/lkml/Yo3WvGnNk3LvLb7R@linutronix.de/

Fixes: 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires")
Cc: John Stultz 
Cc: "David S. Miller" 
Cc: Alexey Kuznetsov 
Cc: Hideaki YOSHIFUJI 
Cc: Jakub Kicinski 
Cc: Rob Herring 
Cc: Geert Uytterhoeven 
Cc: Yoshihiro Shimoda 
Cc: Robin Murphy 
Cc: Andy Shevchenko 
Cc: Sudeep Holla 
Cc: Andy Shevchenko 
Cc: Naresh Kamboju 
Cc: Basil Eljuse 
Cc: Ferry Toth 
Cc: Arnd Bergmann 
Cc: Anders Roxell 
Cc: linux-pm@vger.kernel.org
Reported-by: Nathan Chancellor 
Reported-by: Sebastian Andrzej Siewior 
Tested-by: Geert Uytterhoeven 
Acked-by: John Stultz 
Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20220526034609.480766-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman 
Reviewed-by: Rafael J. Wysocki 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

driver core: fix deadlock in __device_attach

2022-06-14T16:41:19+00:00

[ Upstream commit b232b02bf3c205b13a26dcec08e53baddd8e59ed ]

In __device_attach function, The lock holding logic is as follows:
...
__device_attach
device_lock(dev)      // get lock dev
  async_schedule_dev(__device_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
	   __device_attach_async_helper will get lock dev as
	   well, 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 shown above, when it is allowed to do async probes, because of
out of memory or work limit, async work is not allowed, to do
sync execute instead. it will lead to A-A deadlock because of
__device_attach_async_helper getting lock dev.

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: 765230b5f084 ("driver-core: add asynchronous probing support for drivers")
Signed-off-by: Zhang Wensheng 
Link: https://lore.kernel.org/r/20220518074516.1225580-1-zhangwensheng5@huawei.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

net: mdio: don't defer probe forever if PHY IRQ provider is missing

2022-04-20T07:36:13+00:00

[ Upstream commit 74befa447e6839cdd90ed541159ec783726946f9 ]

When a driver for an interrupt controller is missing, of_irq_get()
returns -EPROBE_DEFER ad infinitum, causing
fwnode_mdiobus_phy_device_register(), and ultimately, the entire
of_mdiobus_register() call, to fail. In turn, any phy_connect() call
towards a PHY on this MDIO bus will also fail.

This is not what is expected to happen, because the PHY library falls
back to poll mode when of_irq_get() returns a hard error code, and the
MDIO bus, PHY and attached Ethernet controller work fine, albeit
suboptimally, when the PHY library polls for link status. However,
-EPROBE_DEFER has special handling given the assumption that at some
point probe deferral will stop, and the driver for the supplier will
kick in and create the IRQ domain.

Reasons for which the interrupt controller may be missing:

- It is not yet written. This may happen if a more recent DT blob (with
  an interrupt-parent for the PHY) is used to boot an old kernel where
  the driver didn't exist, and that kernel worked with the
  vintage-correct DT blob using poll mode.

- It is compiled out. Behavior is the same as above.

- It is compiled as a module. The kernel will wait for a number of
  seconds specified in the "deferred_probe_timeout" boot parameter for
  user space to load the required module. The current default is 0,
  which times out at the end of initcalls. It is possible that this
  might cause regressions unless users adjust this boot parameter.

The proposed solution is to use the driver_deferred_probe_check_state()
helper function provided by the driver core, which gives up after some
-EPROBE_DEFER attempts, taking "deferred_probe_timeout" into consideration.
The return code is changed from -EPROBE_DEFER into -ENODEV or
-ETIMEDOUT, depending on whether the kernel is compiled with support for
modules or not.

Fixes: 66bdede495c7 ("of_mdio: Fix broken PHY IRQ in case of probe deferral")
Suggested-by: Robin Murphy 
Signed-off-by: Vladimir Oltean 
Acked-by: Greg Kroah-Hartman 
Reviewed-by: Florian Fainelli 
Link: https://lore.kernel.org/r/20220407165538.4084809-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

driver core: dd: fix return value of __setup handler

2022-04-08T11:58:30+00:00

[ Upstream commit f2aad54703dbe630f9d8b235eb58e8c8cc78f37d ]

When "driver_async_probe=nulltty" is used on the kernel boot command line,
it causes an Unknown parameter message and the string is added to init's
environment strings, polluting them.

  Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6
  driver_async_probe=nulltty", will be passed to user space.

 Run /sbin/init as init process
   with arguments:
     /sbin/init
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc6
     driver_async_probe=nulltty

Change the return value of the __setup function to 1 to indicate
that the __setup option has been handled.

Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Fixes: 1ea61b68d0f8 ("async: Add cmdline option to specify drivers to be async probed")
Cc: Feng Tang 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Reported-by: Igor Zhbanov 
Reviewed-by: Feng Tang 
Signed-off-by: Randy Dunlap 
Link: https://lore.kernel.org/r/20220301041829.15137-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

driver core: Free DMA range map when device is released

2022-02-22T07:40:02+00:00

When unbinding/binding a driver with DMA mapped memory, the DMA map is
not freed before the driver is reloaded. This leads to a memory leak
when the DMA map is overwritten when reprobing the driver.

This can be reproduced with a platform driver having a dma-range:

dummy {
	...
	#address-cells = <0x2>;
	#size-cells = <0x2>;
	ranges;
	dma-ranges = <...>;
	...
};

and then unbinding/binding it:

~# echo soc:dummy >/sys/bus/platform/drivers//unbind

DMA map object 0xffffff800b0ae540 still being held by &pdev->dev

~# echo soc:dummy >/sys/bus/platform/drivers//bind
~# echo scan > /sys/kernel/debug/kmemleak
~# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffffff800b0ae540 (size 64):
  comm "sh", pid 833, jiffies 4295174550 (age 2535.352s)
  hex dump (first 32 bytes):
    00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 80 00 00 00 00 00 00 00 80 00 00 00 00  ................
  backtrace:
    [] create_object.isra.0+0x108/0x344
    [] kmemleak_alloc+0x8c/0xd0
    [] __kmalloc+0x440/0x6f0
    [] of_dma_get_range+0x124/0x220
    [] of_dma_configure_id+0x40/0x2d0
    [] platform_dma_configure+0x5c/0xa4
    [] really_probe+0x8c/0x514
    [] __driver_probe_device+0x9c/0x19c
    [] device_driver_attach+0x54/0xbc
    [] bind_store+0xc4/0x120
    [] drv_attr_store+0x30/0x44
    [] sysfs_kf_write+0x50/0x60
    [] kernfs_fop_write_iter+0x124/0x1b4
    [] new_sync_write+0xdc/0x160
    [] vfs_write+0x23c/0x2a0
    [] ksys_write+0x64/0xec

To prevent this we should free the dma_range_map when the device is
released.

Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset")
Cc: stable 
Suggested-by: Rob Herring 
Reviewed-by: Rob Herring 
Signed-off-by: Mårten Lindahl 
Link: https://lore.kernel.org/r/20220216094128.4025861-1-marten.lindahl@axis.com
Signed-off-by: Greg Kroah-Hartman

driver core: Make bus notifiers in right order in really_probe()

2022-01-06T14:47:41+00:00

If a driver cannot be bound to a device, the correct bus notifier order
should be:

 - BUS_NOTIFY_BIND_DRIVER: driver is about to be bound
 - BUS_NOTIFY_DRIVER_NOT_BOUND: driver failed to be bound

or no notifier if the failure happens before the actual binding.

The really_probe() notifies a BUS_NOTIFY_DRIVER_NOT_BOUND event without
a BUS_NOTIFY_BIND_DRIVER if .dma_configure() returns failure. This
change makes the notifiers in order.

Signed-off-by: Lu Baolu 
Link: https://lore.kernel.org/r/20211231033901.2168664-3-baolu.lu@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

driver core: Move driver_sysfs_remove() after driver_sysfs_add()

2022-01-06T14:47:41+00:00

The driver_sysfs_remove() should be called after driver_sysfs_add() in
really_probe(). The out-of-order driver_sysfs_remove() tries to remove
some nonexistent nodes under the device and driver sysfs nodes. This is
allowed, hence this change doesn't fix any problem, just a cleanup.

Signed-off-by: Lu Baolu 
Link: https://lore.kernel.org/r/20211231033901.2168664-2-baolu.lu@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

Merge 5.14-rc5 into driver-core-next

2021-08-09T07:03:47+00:00

We need the driver core fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

drivers core: Fix oops when driver probe fails

2021-07-27T12:44:43+00:00

dma_range_map is freed to early, which might cause an oops when
a driver probe fails.
 Call trace:
  is_free_buddy_page+0xe4/0x1d4
  __free_pages+0x2c/0x88
  dma_free_contiguous+0x64/0x80
  dma_direct_free+0x38/0xb4
  dma_free_attrs+0x88/0xa0
  dmam_release+0x28/0x34
  release_nodes+0x78/0x8c
  devres_release_all+0xa8/0x110
  really_probe+0x118/0x2d0
  __driver_probe_device+0xc8/0xe0
  driver_probe_device+0x54/0xec
  __driver_attach+0xe0/0xf0
  bus_for_each_dev+0x7c/0xc8
  driver_attach+0x30/0x3c
  bus_add_driver+0x17c/0x1c4
  driver_register+0xc0/0xf8
  __platform_driver_register+0x34/0x40
  ...

This issue is introduced by commit d0243bbd5dd3 ("drivers core:
Free dma_range_map when driver probe failed"). It frees
dma_range_map before the call to devres_release_all, which is too
early. The solution is to free dma_range_map only after
devres_release_all.

Fixes: d0243bbd5dd3 ("drivers core: Free dma_range_map when driver probe failed")
Cc: stable 
Signed-off-by: Filip Schauer 
Link: https://lore.kernel.org/r/20210727112311.GA7645@DESKTOP-E8BN1B0.localdomain
Signed-off-by: Greg Kroah-Hartman

driver core: Fix error return code in really_probe()

2021-07-21T14:16:23+00:00

In the case of error handling, the error code returned by the subfunction
should be propagated instead of 0.

Fixes: 1901fb2604fb ("Driver core: fix "driver" symlink timing")
Fixes: 23b6904442d0 ("driver core: add dev_groups to all drivers")
Fixes: 8fd456ec0cf0 ("driver core: Add state_synced sysfs file for devices that support it")
Reported-by: Hulk Robot 
Signed-off-by: Zhen Lei 
Link: https://lore.kernel.org/r/20210707074301.2722-1-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman