kernel/linux.git/drivers/base/dd.c, branch v6.1.168

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

2023-11-28T17:07:13+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: Greg Kroah-Hartman

driver core: Call dma_cleanup() on the test_remove path

2023-09-13T07:42:53+00:00

[ Upstream commit f429378a9bf84d79a7e2cae05d2e3384cf7d68ba ] When test_remove is enabled really_probe() does not properly pair dma_configure() with dma_remove(), it will end up calling dma_configure() twice. This corrupts the owner_cnt and renders the group unusable with VFIO/etc. Add the missing cleanup before going back to re_probe. Fixes: 25f3bcfc54bc ("driver core: Add dma_cleanup callback in bus_type") Reported-by: Zenghui Yu Tested-by: Zenghui Yu Closes: https://lore.kernel.org/all/6472f254-c3c4-8610-4a37-8d9dfdd54ce8@huawei.com/ Signed-off-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/0-v2-4deed94e283e+40948-really_probe_dma_cleanup_jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

driver core: Don't require dynamic_debug for initcall_debug probe timing

2023-04-30T23:26:27+00:00

commit e2f06aa885081e1391916367f53bad984714b4db upstream. Don't require the use of dynamic debug (or modification of the kernel to add a #define DEBUG to the top of this file) to get the printk message about driver probe timing. This printk is only emitted when initcall_debug is enabled on the kernel commandline, and it isn't immediately obvious that you have to do something else to debug boot timing issues related to driver probe. Add a comment too so it doesn't get converted back to pr_debug(). Fixes: eb7fbc9fb118 ("driver core: Add missing '\n' in log messages") Cc: stable Cc: Christophe JAILLET Cc: Brian Norris Reviewed-by: Brian Norris Acked-by: Randy Dunlap Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20230412225842.3196599-1-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman

drivers: base: dd: fix memory leak with using debugfs_lookup()

2023-03-11T12:55:39+00:00

[ Upstream commit 36c893d3a759ae7c91ee7d4871ebfc7504f08c40 ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230202141621.2296458-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

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

2023-01-07T10:11:54+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

Merge 6.0-rc5 into driver-core-next

2022-09-12T14:51:22+00:00

We need the driver core and debugfs changes in this branch. Signed-off-by: Greg Kroah-Hartman

driver_core: move from strlcpy with unused retval to strscpy

2022-09-01T16:15:32+00:00

Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20220818205956.6528-1-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman

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

2022-09-01T13:57:13+00:00

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

Revert "driver core: Delete driver_deferred_probe_check_state()"

2022-08-23T11:14:02+00:00

This reverts commit 9cbffc7a59561be950ecc675d19a3d2b45202b2b. There are a few more issues to fix that have been reported in the thread for the original series [1]. We'll need to fix those before this will work. So, revert it for now. [1] - https://lore.kernel.org/lkml/20220601070707.3946847-1-saravanak@google.com/ Fixes: 9cbffc7a5956 ("driver core: Delete driver_deferred_probe_check_state()") Tested-by: Tony Lindgren Tested-by: Peng Fan Tested-by: Douglas Anderson Tested-by: Alexander Stein Reviewed-by: Tony Lindgren Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20220819221616.2107893-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: fix potential deadlock in __driver_attach

2022-06-27T14:43:51+00:00

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] [ 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 Link: https://lore.kernel.org/r/20220622074327.497102-1-zhangwensheng5@huawei.com Signed-off-by: Greg Kroah-Hartman