linux-stable.git/drivers/uio, branch v5.9.8 Linux kernel stable tree uio: free uio id after uio file node is freed 2020-11-05T10:51:22+00:00 Lang Dai lang.dai@intel.com 2020-09-14T03:26:41+00:00 1737a0bd8f5ecdd2774f31fe41c7454c355e09c1 [ Upstream commit 8fd0e2a6df262539eaa28b0a2364cca10d1dc662 ] uio_register_device() do two things. 1) get an uio id from a global pool, e.g. the id is <A> 2) create file nodes like /sys/class/uio/uio<A> uio_unregister_device() do two things. 1) free the uio id <A> and return it to the global pool 2) free the file node /sys/class/uio/uio<A> There is a situation is that one worker is calling uio_unregister_device(), and another worker is calling uio_register_device(). If the two workers are X and Y, they go as below sequence, 1) X free the uio id <AAA> 2) Y get an uio id <AAA> 3) Y create file node /sys/class/uio/uio<AAA> 4) X free the file note /sys/class/uio/uio<AAA> Then it will failed at the 3rd step and cause the phenomenon we saw as it is creating a duplicated file node. Failure reports as follows: sysfs: cannot create duplicate filename '/class/uio/uio10' Call Trace: sysfs_do_create_link_sd.isra.2+0x9e/0xb0 sysfs_create_link+0x25/0x40 device_add+0x2c4/0x640 __uio_register_device+0x1c5/0x576 [uio] adf_uio_init_bundle_dev+0x231/0x280 [intel_qat] adf_uio_register+0x1c0/0x340 [intel_qat] adf_dev_start+0x202/0x370 [intel_qat] adf_dev_start_async+0x40/0xa0 [intel_qat] process_one_work+0x14d/0x410 worker_thread+0x4b/0x460 kthread+0x105/0x140 ? process_one_work+0x410/0x410 ? kthread_bind+0x40/0x40 ret_from_fork+0x1f/0x40 Code: 85 c0 48 89 c3 74 12 b9 00 10 00 00 48 89 c2 31 f6 4c 89 ef e8 ec c4 ff ff 4c 89 e2 48 89 de 48 c7 c7 e8 b4 ee b4 e8 6a d4 d7 ff <0f> 0b 48 89 df e8 20 fa f3 ff 5b 41 5c 41 5d 5d c3 66 0f 1f 84 ---[ end trace a7531c1ed5269e84 ]--- c6xxvf b002:00:00.0: Failed to register UIO devices c6xxvf b002:00:00.0: Failed to register UIO devices Signed-off-by: Lang Dai <lang.dai@intel.com> Link: https://lore.kernel.org/r/1600054002-17722-1-git-send-email-lang.dai@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8fd0e2a6df262539eaa28b0a2364cca10d1dc662 ]

uio_register_device() do two things.
1) get an uio id from a global pool, e.g. the id is <A>
2) create file nodes like /sys/class/uio/uio<A>

uio_unregister_device() do two things.
1) free the uio id <A> and return it to the global pool
2) free the file node /sys/class/uio/uio<A>

There is a situation is that one worker is calling uio_unregister_device(),
and another worker is calling uio_register_device().
If the two workers are X and Y, they go as below sequence,
1) X free the uio id <AAA>
2) Y get an uio id <AAA>
3) Y create file node /sys/class/uio/uio<AAA>
4) X free the file note /sys/class/uio/uio<AAA>
Then it will failed at the 3rd step and cause the phenomenon we saw as it
is creating a duplicated file node.

Failure reports as follows:
sysfs: cannot create duplicate filename '/class/uio/uio10'
Call Trace:
   sysfs_do_create_link_sd.isra.2+0x9e/0xb0
   sysfs_create_link+0x25/0x40
   device_add+0x2c4/0x640
   __uio_register_device+0x1c5/0x576 [uio]
   adf_uio_init_bundle_dev+0x231/0x280 [intel_qat]
   adf_uio_register+0x1c0/0x340 [intel_qat]
   adf_dev_start+0x202/0x370 [intel_qat]
   adf_dev_start_async+0x40/0xa0 [intel_qat]
   process_one_work+0x14d/0x410
   worker_thread+0x4b/0x460
   kthread+0x105/0x140
 ? process_one_work+0x410/0x410
 ? kthread_bind+0x40/0x40
 ret_from_fork+0x1f/0x40
 Code: 85 c0 48 89 c3 74 12 b9 00 10 00 00 48 89 c2 31 f6 4c 89 ef
 e8 ec c4 ff ff 4c 89 e2 48 89 de 48 c7 c7 e8 b4 ee b4 e8 6a d4 d7
 ff <0f> 0b 48 89 df e8 20 fa f3 ff 5b 41 5c 41 5d 5d c3 66 0f 1f 84
---[ end trace a7531c1ed5269e84 ]---
 c6xxvf b002:00:00.0: Failed to register UIO devices
 c6xxvf b002:00:00.0: Failed to register UIO devices

Signed-off-by: Lang Dai <lang.dai@intel.com>

Link: https://lore.kernel.org/r/1600054002-17722-1-git-send-email-lang.dai@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Merge branch 'char-misc-linus' into 'char-misc-next' 2020-07-10T11:42:33+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2020-07-10T11:42:33+00:00 2d41d2ab85d414f6ea9eac2f853b1aa31ba0820f We need the virtbox changes in here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
We need the virtbox changes in here as well to build on top of.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uio: disable lazy irq disable to avoid double fire 2020-07-03T09:02:21+00:00 Thommy Jakobsson thommyj@gmail.com 2020-06-28T14:12:29+00:00 415abcdfd4b8326d679cd0c78bee00b5ceac9718 uio_pdrv_genirq and uio_dmem_genirq interrupts are handled in userspace. So the condition for the interrupt hasn't normally not been cleared when top half returns. disable_irq_nosync is called in top half, but since that normally is lazy the irq isn't actually disabled. For level triggered interrupts this will always result in a spurious additional fire since the level in to the interrupt controller still is active. The actual interrupt handler isn't run though since this spurious irq is just recorded, and later on discared (for level). This commit disables lazy masking for level triggered interrupts. It leaves edge triggered interrupts as before, because they work with the lazy scheme. All other UIO drivers already seem to clear the interrupt cause at driver levels. Example of double fire. First goes all the way up to uio_pdrv_genirq_handler, second is terminated in handle_fasteoi_irq and marked as pending. <idle>-0 [000] d... 8.245870: gic_handle_irq: irq 29 <idle>-0 [000] d.h. 8.245873: uio_pdrv_genirq_handler: disable irq 29 <idle>-0 [000] d... 8.245878: gic_handle_irq: irq 29 <idle>-0 [000] d.h. 8.245880: handle_fasteoi_irq: irq 29 PENDING HInt-34 [001] d... 8.245897: uio_pdrv_genirq_irqcontrol: enable irq 29 Tested on 5.7rc2 using uio_pdrv_genirq and a custom Xilinx MPSoC board. Signed-off-by: Thommy Jakobsson <thommyj@gmail.com> Link: https://lore.kernel.org/r/20200628141229.16121-1-thommyj@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
uio_pdrv_genirq and uio_dmem_genirq interrupts are handled in
userspace. So the condition for the interrupt hasn't normally not been
cleared when top half returns. disable_irq_nosync is called in top half,
but since that normally is lazy the irq isn't actually disabled.

For level triggered interrupts this will always result in a spurious
additional fire since the level in to the interrupt controller still is
active. The actual interrupt handler isn't run though since this
spurious irq is just recorded, and later on discared (for level).

This commit disables lazy masking for level triggered interrupts. It
leaves edge triggered interrupts as before, because they work with the
lazy scheme.

All other UIO drivers already seem to clear the interrupt cause at
driver levels.

Example of double fire. First goes all the way up to
uio_pdrv_genirq_handler, second is terminated in handle_fasteoi_irq and
marked as pending.

<idle>-0 [000] d... 8.245870: gic_handle_irq: irq 29
<idle>-0 [000] d.h. 8.245873: uio_pdrv_genirq_handler: disable irq 29
<idle>-0 [000] d... 8.245878: gic_handle_irq: irq 29
<idle>-0 [000] d.h. 8.245880: handle_fasteoi_irq: irq 29 PENDING
HInt-34  [001] d... 8.245897: uio_pdrv_genirq_irqcontrol: enable irq 29

Tested on 5.7rc2 using uio_pdrv_genirq and a custom Xilinx MPSoC board.

Signed-off-by: Thommy Jakobsson <thommyj@gmail.com>
Link: https://lore.kernel.org/r/20200628141229.16121-1-thommyj@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uio_pdrv_genirq: Allow use with non-page-aligned memory resources 2020-07-03T09:01:50+00:00 Esben Haabendal esben@geanix.com 2020-07-01T14:56:59+00:00 7aca462b133300c16213e214bb96e516f1f2784e Similar to the changes made in 270579d95f82 ("uio_mf624: Align memory regions to page size and set correct offsets"), this will allow uio_pdrv_genirq devices to expose memory regions that is not page-aligned, requiring the users to respect the offset sysfs attribute (as implemented in libuio). Signed-off-by: Esben Haabendal <esben@geanix.com> Link: https://lore.kernel.org/r/20200701145659.3978-4-esben@geanix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Similar to the changes made in 270579d95f82 ("uio_mf624: Align memory
regions to page size and set correct offsets"), this will allow
uio_pdrv_genirq devices to expose memory regions that is not page-aligned,
requiring the users to respect the offset sysfs attribute (as implemented
in libuio).

Signed-off-by: Esben Haabendal <esben@geanix.com>
Link: https://lore.kernel.org/r/20200701145659.3978-4-esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uio_pdrv_genirq: fix use without device tree and no interrupt 2020-07-03T08:52:02+00:00 Esben Haabendal esben@geanix.com 2020-07-01T14:56:58+00:00 bf12fdf0ab728ca8e5933aac46dd972c0dd0421e While e3a3c3a20555 ("UIO: fix uio_pdrv_genirq with device tree but no interrupt") added support for using uio_pdrv_genirq for devices without interrupt for device tree platforms, the removal of uio_pdrv in 26dac3c49d56 ("uio: Remove uio_pdrv and use uio_pdrv_genirq instead") broke the support for non device tree platforms. This change fixes this, so that uio_pdrv_genirq can be used without interrupt on all platforms. This still leaves the support that uio_pdrv had for custom interrupt handler lacking, as uio_pdrv_genirq does not handle it (yet). Fixes: 26dac3c49d56 ("uio: Remove uio_pdrv and use uio_pdrv_genirq instead") Signed-off-by: Esben Haabendal <esben@geanix.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200701145659.3978-3-esben@geanix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
While e3a3c3a20555 ("UIO: fix uio_pdrv_genirq with device tree but no
interrupt") added support for using uio_pdrv_genirq for devices without
interrupt for device tree platforms, the removal of uio_pdrv in
26dac3c49d56 ("uio: Remove uio_pdrv and use uio_pdrv_genirq instead")
broke the support for non device tree platforms.

This change fixes this, so that uio_pdrv_genirq can be used without
interrupt on all platforms.

This still leaves the support that uio_pdrv had for custom interrupt
handler lacking, as uio_pdrv_genirq does not handle it (yet).

Fixes: 26dac3c49d56 ("uio: Remove uio_pdrv and use uio_pdrv_genirq instead")
Signed-off-by: Esben Haabendal <esben@geanix.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200701145659.3978-3-esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uio_pdrv_genirq: Remove warning when irq is not specified 2020-07-03T08:52:01+00:00 Esben Haabendal esben@geanix.com 2020-07-01T14:56:57+00:00 324ac45f25e634eca6346953ae531e8da3e0c73d Since e3a3c3a20555 ("UIO: fix uio_pdrv_genirq with device tree but no interrupt"), the uio_pdrv_genirq has supported use without interrupt, so the change in 7723f4c5ecdb ("driver core: platform: Add an error message to") added false warnings for those cases. Fixes: 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()") Signed-off-by: Esben Haabendal <esben@geanix.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200701145659.3978-2-esben@geanix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Since e3a3c3a20555 ("UIO: fix uio_pdrv_genirq with device tree but no
interrupt"), the uio_pdrv_genirq has supported use without interrupt,
so the change in 7723f4c5ecdb ("driver core: platform: Add an error
message to") added false warnings for those cases.

Fixes: 7723f4c5ecdb ("driver core: platform: Add an error message to platform_get_irq*()")
Signed-off-by: Esben Haabendal <esben@geanix.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200701145659.3978-2-esben@geanix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uio_hv_generic: add missed sysfs_remove_bin_file 2020-05-15T14:13:19+00:00 Chuhong Yuan hslester96@gmail.com 2020-05-07T15:13:43+00:00 7066c2f61ce49b131026fec68ed1c9b0d0d9a05a This driver calls sysfs_create_bin_file() in probe, but forgets to call sysfs_remove_bin_file() in remove. Add the missed call to fix it. Signed-off-by: Chuhong Yuan <hslester96@gmail.com> Link: https://lore.kernel.org/r/20200507151343.792816-1-hslester96@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This driver calls sysfs_create_bin_file() in probe, but forgets to
call sysfs_remove_bin_file() in remove.
Add the missed call to fix it.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Link: https://lore.kernel.org/r/20200507151343.792816-1-hslester96@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uio: remove unneeded variable "ret" in uio_dmem_genirq_open 2020-04-28T13:55:15+00:00 Jason Yan yanaijie@huawei.com 2020-04-28T06:31:55+00:00 161309788e426203e1d436abf9a5a845cc19d20c Fix the following coccicheck warning: drivers/uio/uio_dmem_genirq.c:47:5-8: Unneeded variable: "ret". Return "0" on line 71 Signed-off-by: Jason Yan <yanaijie@huawei.com> Link: https://lore.kernel.org/r/20200428063155.42349-1-yanaijie@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Fix the following coccicheck warning:

drivers/uio/uio_dmem_genirq.c:47:5-8: Unneeded variable: "ret". Return
"0" on line 71

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200428063155.42349-1-yanaijie@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers: uio: remove redundant assignment to variable retval 2020-04-28T13:55:15+00:00 Colin Ian King colin.king@canonical.com 2020-04-25T12:44:48+00:00 56731c68f335ff0ce49e7d8f4fb45eb7805629be The variable retval is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/r/20200425124448.139532-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The variable retval is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200425124448.139532-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uio: uio_pdrv_genirq: use new devm_uio_register_device() function 2020-03-18T11:34:10+00:00 Alexandru Ardelean alexandru.ardelean@analog.com 2020-03-06T16:18:53+00:00 eff1dd87fae2448f02f368ac6ed6215ea1d447ac This change makes use of the new devm_uio_register_device() initializer. This cleans up the exit path quite nicely, and removes the remove function of the driver. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20200306161853.25368-2-alexandru.ardelean@analog.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This change makes use of the new devm_uio_register_device() initializer.
This cleans up the exit path quite nicely, and removes the remove function
of the driver.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200306161853.25368-2-alexandru.ardelean@analog.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>