linux-stable.git/drivers/base, branch v4.19.26

cacheinfo: Keep the old value if of_property_read_u32 fails

2019-02-12T18:47:26+00:00

commit 3a34c986324c07dde32903f7bb262e6138e77c2a upstream.

Commit 448a5a552f336bd7b847b1951 ("drivers: base: cacheinfo: use OF
property_read_u32 instead of get_property,read_number") makes cache
size and number_of_sets be 0 if DT doesn't provide there values. I
think this is unreasonable so make them keep the old values, which is
the same as old kernels.

Fixes: 448a5a552f33 ("drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number")
Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen 
Reviewed-by: Sudeep Holla 
Signed-off-by: Greg Kroah-Hartman

kobject: return error code if writing /sys/.../uevent fails

2019-02-12T18:47:06+00:00

[ Upstream commit df44b479654f62b478c18ee4d8bc4e9f897a9844 ]

Propagate error code back to userspace if writing the /sys/.../uevent
file fails. Before, the write operation always returned with success,
even if we failed to recognize the input string or if we failed to
generate the uevent itself.

With the error codes properly propagated back to userspace, we are
able to react in userspace accordingly by not assuming and awaiting
a uevent that is not delivered.

Signed-off-by: Peter Rajnoha 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

driver core: Move async_synchronize_full call

2019-02-12T18:47:06+00:00

[ Upstream commit c37d721c68ad88925ba0e72f6e14acb829a8c6bb ]

Move the async_synchronize_full call out of __device_release_driver and
into driver_detach.

The idea behind this is that the async_synchronize_full call will only
guarantee that any existing async operations are flushed. This doesn't do
anything to guarantee that a hotplug event that may occur while we are
doing the release of the driver will not be asynchronously scheduled.

By moving this into the driver_detach path we can avoid potential deadlocks
as we aren't holding the device lock at this point and we should not have
the driver we want to flush loaded so the flush will take care of any
asynchronous events the driver we are detaching might have scheduled.

Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers")
Reviewed-by: Bart Van Assche 
Reviewed-by: Dan Williams 
Signed-off-by: Alexander Duyck 
Reviewed-by: Luis Chamberlain 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

devres: Align data[] to ARCH_KMALLOC_MINALIGN

2019-02-12T18:46:56+00:00

commit a66d972465d15b1d89281258805eb8b47d66bd36 upstream.

Initially we bumped into problem with 32-bit aligned atomic64_t
on ARC, see [1]. And then during quite lengthly discussion Peter Z.
mentioned ARCH_KMALLOC_MINALIGN which IMHO makes perfect sense.
If allocation is done by plain kmalloc() obtained buffer will be
ARCH_KMALLOC_MINALIGN aligned and then why buffer obtained via
devm_kmalloc() should have any other alignment?

This way we at least get the same behavior for both types of
allocation.

[1] http://lists.infradead.org/pipermail/linux-snps-arc/2018-July/004009.html
[2] http://lists.infradead.org/pipermail/linux-snps-arc/2018-July/004036.html

Signed-off-by: Alexey Brodkin 
Cc: Greg Kroah-Hartman 
Cc: Geert Uytterhoeven 
Cc: David Laight 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Greg KH 
Cc:  # 4.8+
Signed-off-by: Greg Kroah-Hartman

sysfs: Disable lockdep for driver bind/unbind files

2019-01-26T08:32:42+00:00

[ Upstream commit 4f4b374332ec0ae9c738ff8ec9bed5cd97ff9adc ]

This is the much more correct fix for my earlier attempt at:

https://lkml.org/lkml/2018/12/10/118

Short recap:

- There's not actually a locking issue, it's just lockdep being a bit
  too eager to complain about a possible deadlock.

- Contrary to what I claimed the real problem is recursion on
  kn->count. Greg pointed me at sysfs_break_active_protection(), used
  by the scsi subsystem to allow a sysfs file to unbind itself. That
  would be a real deadlock, which isn't what's happening here. Also,
  breaking the active protection means we'd need to manually handle
  all the lifetime fun.

- With Rafael we discussed the task_work approach, which kinda works,
  but has two downsides: It's a functional change for a lockdep
  annotation issue, and it won't work for the bind file (which needs
  to get the errno from the driver load function back to userspace).

- Greg also asked why this never showed up: To hit this you need to
  unregister a 2nd driver from the unload code of your first driver. I
  guess only gpus do that. The bug has always been there, but only
  with a recent patch series did we add more locks so that lockdep
  built a chain from unbinding the snd-hda driver to the
  acpi_video_unregister call.

Full lockdep splat:

[12301.898799] ============================================
[12301.898805] WARNING: possible recursive locking detected
[12301.898811] 4.20.0-rc7+ #84 Not tainted
[12301.898815] --------------------------------------------
[12301.898821] bash/5297 is trying to acquire lock:
[12301.898826] 00000000f61c6093 (kn->count#39){++++}, at: kernfs_remove_by_name_ns+0x3b/0x80
[12301.898841] but task is already holding lock:
[12301.898847] 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190
[12301.898856] other info that might help us debug this:
[12301.898862]  Possible unsafe locking scenario:
[12301.898867]        CPU0
[12301.898870]        ----
[12301.898874]   lock(kn->count#39);
[12301.898879]   lock(kn->count#39);
[12301.898883] *** DEADLOCK ***
[12301.898891]  May be due to missing lock nesting notation
[12301.898899] 5 locks held by bash/5297:
[12301.898903]  #0: 00000000cd800e54 (sb_writers#4){.+.+}, at: vfs_write+0x17f/0x1b0
[12301.898915]  #1: 000000000465e7c2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xd3/0x190
[12301.898925]  #2: 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190
[12301.898936]  #3: 00000000414ef7ac (&dev->mutex){....}, at: device_release_driver_internal+0x34/0x240
[12301.898950]  #4: 000000003218fbdf (register_count_mutex){+.+.}, at: acpi_video_unregister+0xe/0x40
[12301.898960] stack backtrace:
[12301.898968] CPU: 1 PID: 5297 Comm: bash Not tainted 4.20.0-rc7+ #84
[12301.898974] Hardware name: Hewlett-Packard HP EliteBook 8460p/161C, BIOS 68SCF Ver. F.01 03/11/2011
[12301.898982] Call Trace:
[12301.898989]  dump_stack+0x67/0x9b
[12301.898997]  __lock_acquire+0x6ad/0x1410
[12301.899003]  ? kernfs_remove_by_name_ns+0x3b/0x80
[12301.899010]  ? find_held_lock+0x2d/0x90
[12301.899017]  ? mutex_spin_on_owner+0xe4/0x150
[12301.899023]  ? find_held_lock+0x2d/0x90
[12301.899030]  ? lock_acquire+0x90/0x180
[12301.899036]  lock_acquire+0x90/0x180
[12301.899042]  ? kernfs_remove_by_name_ns+0x3b/0x80
[12301.899049]  __kernfs_remove+0x296/0x310
[12301.899055]  ? kernfs_remove_by_name_ns+0x3b/0x80
[12301.899060]  ? kernfs_name_hash+0xd/0x80
[12301.899066]  ? kernfs_find_ns+0x6c/0x100
[12301.899073]  kernfs_remove_by_name_ns+0x3b/0x80
[12301.899080]  bus_remove_driver+0x92/0xa0
[12301.899085]  acpi_video_unregister+0x24/0x40
[12301.899127]  i915_driver_unload+0x42/0x130 [i915]
[12301.899160]  i915_pci_remove+0x19/0x30 [i915]
[12301.899169]  pci_device_remove+0x36/0xb0
[12301.899176]  device_release_driver_internal+0x185/0x240
[12301.899183]  unbind_store+0xaf/0x180
[12301.899189]  kernfs_fop_write+0x104/0x190
[12301.899195]  __vfs_write+0x31/0x180
[12301.899203]  ? rcu_read_lock_sched_held+0x6f/0x80
[12301.899209]  ? rcu_sync_lockdep_assert+0x29/0x50
[12301.899216]  ? __sb_start_write+0x13c/0x1a0
[12301.899221]  ? vfs_write+0x17f/0x1b0
[12301.899227]  vfs_write+0xb9/0x1b0
[12301.899233]  ksys_write+0x50/0xc0
[12301.899239]  do_syscall_64+0x4b/0x180
[12301.899247]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[12301.899253] RIP: 0033:0x7f452ac7f7a4
[12301.899259] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 aa f0 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
[12301.899273] RSP: 002b:00007ffceafa6918 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[12301.899282] RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f452ac7f7a4
[12301.899288] RDX: 000000000000000d RSI: 00005612a1abf7c0 RDI: 0000000000000001
[12301.899295] RBP: 00005612a1abf7c0 R08: 000000000000000a R09: 00005612a1c46730
[12301.899301] R10: 000000000000000a R11: 0000000000000246 R12: 000000000000000d
[12301.899308] R13: 0000000000000001 R14: 00007f452af4a740 R15: 000000000000000d

Looking around I've noticed that usb and i2c already handle similar
recursion problems, where a sysfs file can unbind the same type of
sysfs somewhere else in the hierarchy. Relevant commits are:

commit 356c05d58af05d582e634b54b40050c73609617b
Author: Alan Stern 
Date:   Mon May 14 13:30:03 2012 -0400

    sysfs: get rid of some lockdep false positives

commit e9b526fe704812364bca07edd15eadeba163ebfb
Author: Alexander Sverdlin 
Date:   Fri May 17 14:56:35 2013 +0200

    i2c: suppress lockdep warning on delete_device

Implement the same trick for driver bind/unbind.

v2: Put the macro into bus.c (Greg).

Reviewed-by: Rafael J. Wysocki 
Cc: Ramalingam C 
Cc: Arend van Spriel 
Cc: Andy Shevchenko 
Cc: Geert Uytterhoeven 
Cc: Bartosz Golaszewski 
Cc: Heikki Krogerus 
Cc: Vivek Gautam 
Cc: Joe Perches 
Signed-off-by: Daniel Vetter 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

driver core: Add missing dev->bus->need_parent_lock checks

2019-01-13T08:51:06+00:00

commit e121a833745b4708b660e3fe6776129c2956b041 upstream.

__device_release_driver() has to check dev->bus->need_parent_lock
before dropping the parent lock and acquiring it again as it may
attempt to drop a lock that hasn't been acquired or lock a device
that shouldn't be locked and create a lock imbalance.

Fixes: 8c97a46af04b (driver core: hold dev's parent lock when needed)
Signed-off-by: Rafael J. Wysocki 
Cc: stable 
Reviewed-by: Daniel Vetter 
Signed-off-by: Greg Kroah-Hartman

platform-msi: Free descriptors in platform_msi_domain_free()

2019-01-09T16:38:42+00:00

commit 81b1e6e6a8590a19257e37a1633bec098d499c57 upstream.

Since the addition of platform MSI support, there were two helpers
supposed to allocate/free IRQs for a device:

    platform_msi_domain_alloc_irqs()
    platform_msi_domain_free_irqs()

In these helpers, IRQ descriptors are allocated in the "alloc" routine
while they are freed in the "free" one.

Later, two other helpers have been added to handle IRQ domains on top
of MSI domains:

    platform_msi_domain_alloc()
    platform_msi_domain_free()

Seen from the outside, the logic is pretty close with the former
helpers and people used it with the same logic as before: a
platform_msi_domain_alloc() call should be balanced with a
platform_msi_domain_free() call. While this is probably what was
intended to do, the platform_msi_domain_free() does not remove/free
the IRQ descriptor(s) created/inserted in
platform_msi_domain_alloc().

One effect of such situation is that removing a module that requested
an IRQ will let one orphaned IRQ descriptor (with an allocated MSI
entry) in the device descriptors list. Next time the module will be
inserted back, one will observe that the allocation will happen twice
in the MSI domain, one time for the remaining descriptor, one time for
the new one. It also has the side effect to quickly overshoot the
maximum number of allocated MSI and then prevent any module requesting
an interrupt in the same domain to be inserted anymore.

This situation has been met with loops of insertion/removal of the
mvpp2.ko module (requesting 15 MSIs each time).

Fixes: 552c494a7666 ("platform-msi: Allow creation of a MSI-based stacked irq domain")
Cc: stable@vger.kernel.org
Signed-off-by: Miquel Raynal 
Signed-off-by: Marc Zyngier 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2018-10-07T06:15:57+00:00

I wrote:
  "Char/Misc fixes for 4.19-rc7

   Here are 8 small fixes for some char/misc driver issues

   Included here are:
	- fpga driver fixes
	- thunderbolt bugfixes
	- firmware core revert/fix
	- hv core fix
	- hv tool fix

   All of these have been in linux-next with no reported issues."

* tag 'char-misc-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  thunderbolt: Initialize after IOMMUs
  thunderbolt: Do not handle ICM events after domain is stopped
  firmware: Always initialize the fw_priv list object
  docs: fpga: document fpga manager flags
  fpga: bridge: fix obvious function documentation error
  tools: hv: fcopy: set 'error' in case an unknown operation was requested
  fpga: do not access region struct after fpga_region_unregister
  Drivers: hv: vmbus: Use get/put_cpu() in vmbus_connect()

PM / core: Clear the direct_complete flag on errors

2018-10-04T17:39:31+00:00

If __device_suspend() runs asynchronously (in which case the device
passed to it is in dpm_suspended_list at that point) and it returns
early on an error or pending wakeup, and the power.direct_complete
flag has been set for the device already, the subsequent
device_resume() will be confused by that and it will call
pm_runtime_enable() incorrectly, as runtime PM has not been
disabled for the device by __device_suspend().

To avoid that, clear power.direct_complete if __device_suspend()
is not going to disable runtime PM for the device before returning.

Fixes: aae4518b3124 (PM / sleep: Mechanism to avoid resuming runtime-suspended devices unnecessarily)
Reported-by: Al Cooper 
Tested-by: Al Cooper 
Reviewed-by: Ulf Hansson 
Cc: 3.16+  # 3.16+
Signed-off-by: Rafael J. Wysocki

firmware: Always initialize the fw_priv list object

2018-09-30T15:49:55+00:00

When freeing the fw_priv the item is taken off the list. This causes an
oops in the FW_OPT_NOCACHE case as the list object is not initialized.

Make sure to initialize the list object regardless of this flag.

Fixes: 422b3db2a503 ("firmware: Fix security issue with request_firmware_into_buf()")
Cc: stable@vger.kernel.org
Cc: Rishabh Bhatnagar 
Signed-off-by: Bjorn Andersson 
Reviewed-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman