linux-stable.git/drivers/base/dd.c, branch v4.19.321

driver core: Release all resources during unbind before updating device links

2023-12-08T07:43:22+00:00

commit 2e84dc37920012b458e9458b19fc4ed33f81bc74 upstream.

This commit fixes a bug in commit 9ed9895370ae ("driver core: Functional
dependencies tracking support") where the device link status was
incorrectly updated in the driver unbind path before all the device's
resources were released.

Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support")
Cc: stable 
Reported-by: Uwe Kleine-König 
Closes: https://lore.kernel.org/all/20231014161721.f4iqyroddkcyoefo@pengutronix.de/
Signed-off-by: Saravana Kannan 
Cc: Thierry Reding 
Cc: Yang Yingliang 
Cc: Andy Shevchenko 
Cc: Mark Brown 
Cc: Matti Vaittinen 
Cc: James Clark 
Acked-by: "Rafael J. Wysocki" 
Tested-by: Uwe Kleine-König 
Acked-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20231018013851.3303928-1-saravanak@google.com
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman

driver core: Fix bus_type.match() error handling in __driver_attach()

2023-01-18T10:30:51+00:00

commit 27c0d217340e47ec995557f61423ef415afba987 upstream.

When a driver registers with a bus, it will attempt to match with every
device on the bus through the __driver_attach() function. Currently, if
the bus_type.match() function encounters an error that is not
-EPROBE_DEFER, __driver_attach() will return a negative error code, which
causes the driver registration logic to stop trying to match with the
remaining devices on the bus.

This behavior is not correct; a failure while matching a driver to a
device does not mean that the driver won't be able to match and bind
with other devices on the bus. 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 
Signed-off-by: Isaac J. Manjarres 
Link: https://lore.kernel.org/r/20220921001414.4046492-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman

driver core: Set deferred_probe_timeout to a longer default if CONFIG_MODULES is set

2023-01-18T10:30:47+00:00

[ Upstream commit e2cec7d6853712295cef5377762165a489b2957f ]

When using modules, its common for the modules not to be loaded
until quite late by userland. With the current code,
driver_deferred_probe_check_state() will stop returning
EPROBE_DEFER after late_initcall, which can cause module
dependency resolution to fail after that.

So allow a longer window of 30 seconds (picked somewhat
arbitrarily, but influenced by the similar regulator core
timeout value) in the case where modules are enabled.

Cc: linux-pm@vger.kernel.org
Cc: Greg Kroah-Hartman 
Cc: Linus Walleij 
Cc: Thierry Reding 
Cc: Mark Brown 
Cc: Liam Girdwood 
Cc: Bjorn Andersson 
Cc: Saravana Kannan 
Cc: Todd Kjos 
Cc: Len Brown 
Cc: Pavel Machek 
Cc: Ulf Hansson 
Cc: Kevin Hilman 
Cc: "Rafael J. Wysocki" 
Cc: Rob Herring 
Reviewed-by: Bjorn Andersson 
Reviewed-by: Rafael J. Wysocki 
Signed-off-by: John Stultz 
Link: https://lore.kernel.org/r/20200225050828.56458-3-john.stultz@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

driver core: Don't probe devices after bus_type.match() probe deferral

2022-09-15T10:17:02+00:00

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 
Reported-by: Guenter Roeck 
Tested-by: Guenter Roeck 
Tested-by: Linus Walleij 
Reviewed-by: Saravana Kannan 
Signed-off-by: Isaac J. Manjarres 
Link: https://lore.kernel.org/r/20220817184026.3468620-1-isaacmanjarres@google.com
Signed-off-by: Greg Kroah-Hartman

driver core: Fix locking bug in deferred_probe_timeout_work_func()

2021-04-16T09:49:31+00:00

commit eed6e41813deb9ee622cd9242341f21430d7789f upstream.

list_for_each_entry_safe() is only useful if we are deleting nodes in a
linked list within the loop. It doesn't protect against other threads
adding/deleting nodes to the list in parallel. We need to grab
deferred_probe_mutex when traversing the deferred_probe_pending_list.

Cc: stable@vger.kernel.org
Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init")
Signed-off-by: Saravana Kannan 
Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman

PM: runtime: Resume the device earlier in __device_release_driver()

2020-11-10T11:36:01+00:00

commit 9226c504e364158a17a68ff1fe9d67d266922f50 upstream.

Since the device is resumed from runtime-suspend in
__device_release_driver() anyway, it is better to do that before
looking for busy managed device links from it to consumers, because
if there are any, device_links_unbind_consumers() will be called
and it will cause the consumer devices' drivers to unbind, so the
consumer devices will be runtime-resumed.  In turn, resuming each
consumer device will cause the supplier to be resumed and when the
runtime PM references from the given consumer to it are dropped, it
may be suspended.  Then, the runtime-resume of the next consumer
will cause the supplier to resume again and so on.

Update the code accordingly.

Signed-off-by: Rafael J. Wysocki 
Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support")
Cc: All applicable  # All applicable
Tested-by: Xiang Chen 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

driver core: Fix probe_count imbalance in really_probe()

2020-10-14T08:31:22+00:00

commit b292b50b0efcc7095d8bf15505fba6909bb35dce upstream.

syzbot is reporting hung task in wait_for_device_probe() [1]. At least,
we always need to decrement probe_count if we incremented probe_count in
really_probe().

However, since I can't find "Resources present before probing" message in
the console log, both "this message simply flowed off" and "syzbot is not
hitting this path" will be possible. Therefore, while we are at it, let's
also prepare for concurrent wait_for_device_probe() calls by replacing
wake_up() with wake_up_all().

[1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c0f

Reported-by: syzbot 
Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()")
Cc: Geert Uytterhoeven 
Signed-off-by: Tetsuo Handa 
Cc: stable 
Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKURA.ne.jp
[iwamatsu: Drop patch for deferred_probe_timeout_work_func()]
Signed-off-by: Nobuhiro Iwamatsu (CIP) 
Signed-off-by: Greg Kroah-Hartman

driver core: Avoid binding drivers to dead devices

2020-08-21T09:05:32+00:00

commit 654888327e9f655a9d55ad477a9583e90e8c9b5c upstream.

Commit 3451a495ef24 ("driver core: Establish order of operations for
device_add and device_del via bitflag") sought to prevent asynchronous
driver binding to a device which is being removed.  It added a
per-device "dead" flag which is checked in the following code paths:

* asynchronous binding in __driver_attach_async_helper()
*  synchronous binding in device_driver_attach()
* asynchronous binding in __device_attach_async_helper()

It did *not* check the flag upon:

*  synchronous binding in __device_attach()

However __device_attach() may also be called asynchronously from:

deferred_probe_work_func()
  bus_probe_device()
    device_initial_probe()
      __device_attach()

So if the commit's intention was to check the "dead" flag in all
asynchronous code paths, then a check is also necessary in
__device_attach().  Add the missing check.

Fixes: 3451a495ef24 ("driver core: Establish order of operations for device_add and device_del via bitflag")
Signed-off-by: Lukas Wunner 
Cc: stable@vger.kernel.org # v5.1+
Cc: Alexander Duyck 
Link: https://lore.kernel.org/r/de88a23a6fe0ef70f7cfd13c8aea9ab51b4edab6.1594214103.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman

driver core: Add device link flag DL_FLAG_AUTOPROBE_CONSUMER

2020-03-20T10:55:58+00:00

commit e7dd40105aac9ba051e44ad711123bc53a5e4c71 upstream.

Add a new device link flag, DL_FLAG_AUTOPROBE_CONSUMER, to request the
driver core to probe for a consumer driver automatically after binding
a driver to the supplier device on a persistent managed device link.

As unbinding the supplier driver on a managed device link causes the
consumer driver to be detached from its device automatically, this
flag provides a complementary mechanism which is needed to address
some "composite device" use cases.

Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Saravana Kannan 
Signed-off-by: Greg Kroah-Hartman

driver core: Print device when resources present in really_probe()

2020-02-24T07:34:47+00:00

[ Upstream commit 7c35e699c88bd60734277b26962783c60e04b494 ]

If a device already has devres items attached before probing, a warning
backtrace is printed.  However, this backtrace does not reveal the
offending device, leaving the user uninformed.  Furthermore, using
WARN_ON() causes systems with panic-on-warn to reboot.

Fix this by replacing the WARN_ON() by a dev_crit() message.
Abort probing the device, to prevent doing more damage to the device's
resources.

Signed-off-by: Geert Uytterhoeven 
Link: https://lore.kernel.org/r/20191206132219.28908-1-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin