linux-stable.git/include, branch v5.9.8

PM: runtime: Drop pm_runtime_clean_up_links()

2020-11-10T11:39:10+00:00

commit d6e36668598154820177bfd78c1621d8e6c580a2 upstream.

After commit d12544fb2aa9 ("PM: runtime: Remove link state checks in
rpm_get/put_supplier()") nothing prevents the consumer device's
runtime PM from acquiring additional references to the supplier
device after pm_runtime_clean_up_links() has run (or even while it
is running), so calling this function from __device_release_driver()
may be pointless (or even harmful).

Moreover, it ignores stateless device links, so the runtime PM
handling of managed and stateless device links is inconsistent
because of it, so better get rid of it entirely.

Fixes: d12544fb2aa9 ("PM: runtime: Remove link state checks in rpm_get/put_supplier()")
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Tested-by: Xiang Chen 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

PM: runtime: Drop runtime PM references to supplier on link removal

2020-11-10T11:39:10+00:00

commit e0e398e204634db8fb71bd89cf2f6e3e5bd09b51 upstream.

While removing a device link, drop the supplier device's runtime PM
usage counter as many times as needed to drop all of the runtime PM
references to it from the consumer in addition to dropping the
consumer's link count.

Fixes: baa8809f6097 ("PM / runtime: Optimize the use of device links")
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Tested-by: Xiang Chen 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

mm: always have io_remap_pfn_range() set pgprot_decrypted()

2020-11-10T11:39:00+00:00

commit f8f6ae5d077a9bdaf5cbf2ac960a5d1a04b47482 upstream.

The purpose of io_remap_pfn_range() is to map IO memory, such as a
memory mapped IO exposed through a PCI BAR.  IO devices do not
understand encryption, so this memory must always be decrypted.
Automatically call pgprot_decrypted() as part of the generic
implementation.

This fixes a bug where enabling AMD SME causes subsystems, such as RDMA,
using io_remap_pfn_range() to expose BAR pages to user space to fail.
The CPU will encrypt access to those BAR pages instead of passing
unencrypted IO directly to the device.

Places not mapping IO should use remap_pfn_range().

Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption")
Signed-off-by: Jason Gunthorpe 
Signed-off-by: Andrew Morton 
Cc: Arnd Bergmann 
Cc: Tom Lendacky 
Cc: Thomas Gleixner 
Cc: Andrey Ryabinin 
Cc: Borislav Petkov 
Cc: Brijesh Singh 
Cc: Jonathan Corbet 
Cc: Dmitry Vyukov 
Cc: "Dave Young" 
Cc: Alexander Potapenko 
Cc: Konrad Rzeszutek Wilk 
Cc: Andy Lutomirski 
Cc: Larry Woodman 
Cc: Matt Fleming 
Cc: Ingo Molnar 
Cc: "Michael S. Tsirkin" 
Cc: Paolo Bonzini 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Toshimitsu Kani 
Cc: 
Link: https://lkml.kernel.org/r/0-v1-025d64bdf6c4+e-amd_sme_fix_jgg@nvidia.com
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

time: Prevent undefined behaviour in timespec64_to_ns()

2020-11-05T10:51:57+00:00

commit cb47755725da7b90fecbb2aa82ac3b24a7adb89b upstream.

UBSAN reports:

Undefined behaviour in ./include/linux/time64.h:127:27
signed integer overflow:
17179869187 * 1000000000 cannot be represented in type 'long long int'
Call Trace:
 timespec64_to_ns include/linux/time64.h:127 [inline]
 set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180
 do_setitimer+0x8e/0x740 kernel/time/itimer.c:245
 __x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336
 do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295

Commit bd40a175769d ("y2038: itimer: change implementation to timespec64")
replaced the original conversion which handled time clamping correctly with
timespec64_to_ns() which has no overflow protection.

Fix it in timespec64_to_ns() as this is not necessarily limited to the
usage in itimers.

[ tglx: Added comment and adjusted the fixes tag ]

Fixes: 361a3bf00582 ("time64: Add time64.h header and define struct timespec64")
Signed-off-by: Zeng Tao 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Arnd Bergmann 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com
Signed-off-by: Greg Kroah-Hartman

cpufreq: Introduce cpufreq_driver_test_flags()

2020-11-05T10:51:57+00:00

commit a62f68f5ca53ab61cba2f0a410d0add7a6d54a52 upstream.

Add a helper function to test the flags of the cpufreq driver in use
againt a given flags mask.

In particular, this will be needed to test the
CPUFREQ_NEED_UPDATE_LIMITS cpufreq driver flag in the schedutil
governor.

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

hil/parisc: Disable HIL driver when it gets stuck

2020-11-05T10:51:54+00:00

commit 879bc2d27904354b98ca295b6168718e045c4aa2 upstream.

When starting a HP machine with HIL driver but without an HIL keyboard
or HIL mouse attached, it may happen that data written to the HIL loop
gets stuck (e.g. because the transaction queue is full).  Usually one
will then have to reboot the machine because all you see is and endless
output of:
 Transaction add failed: transaction already queued?

In the higher layers hp_sdc_enqueue_transaction() is called to queued up
a HIL packet. This function returns an error code, and this patch adds
the necessary checks for this return code and disables the HIL driver if
further packets can't be sent.

Tested on a HP 730 and a HP 715/64 machine.

Signed-off-by: Helge Deller 
Cc: 
Signed-off-by: Greg Kroah-Hartman

cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS driver flag

2020-11-05T10:51:51+00:00

commit 1c534352f47fd83eb08075ac2474f707e74bf7f7 upstream.

Generally, a cpufreq driver may need to update some internal upper
and lower frequency boundaries on policy max and min changes,
respectively, but currently this does not work if the target
frequency does not change along with the policy limit.

Namely, if the target frequency does not change along with the
policy min or max, the "target_freq == policy->cur" check in
__cpufreq_driver_target() prevents driver callbacks from being
invoked and they do not even have a chance to update the
corresponding internal boundary.

This particularly affects the "powersave" and "performance"
governors that always set the target frequency to one of the
policy limits and it never changes when the other limit is updated.

To allow cpufreq the drivers needing to update internal frequency
boundaries on policy limits changes to avoid this issue, introduce
a new driver flag, CPUFREQ_NEED_UPDATE_LIMITS, that (when set) will
neutralize the check mentioned above.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Viresh Kumar 
Signed-off-by: Greg Kroah-Hartman

NFSv4.2: support EXCHGID4_FLAG_SUPP_FENCE_OPS 4.2 EXCHANGE_ID flag

2020-11-05T10:51:46+00:00

commit 8c39076c276be0b31982e44654e2c2357473258a upstream.

RFC 7862 introduced a new flag that either client or server is
allowed to set: EXCHGID4_FLAG_SUPP_FENCE_OPS.

Client needs to update its bitmask to allow for this flag value.

v2: changed minor version argument to unsigned int

Signed-off-by: Olga Kornievskaia 
CC: 
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

rcu-tasks: Fix grace-period/unlock race in RCU Tasks Trace

2020-11-05T10:51:43+00:00

commit ba3a86e47232ad9f76160929f33ac9c64e4d0567 upstream.

The more intense grace-period processing resulting from the 50x RCU
Tasks Trace grace-period speedups exposed the following race condition:

o	Task A running on CPU 0 executes rcu_read_lock_trace(),
	entering a read-side critical section.

o	When Task A eventually invokes rcu_read_unlock_trace()
	to exit its read-side critical section, this function
	notes that the ->trc_reader_special.s flag is zero and
	and therefore invoke wil set ->trc_reader_nesting to zero
	using WRITE_ONCE().  But before that happens...

o	The RCU Tasks Trace grace-period kthread running on some other
	CPU interrogates Task A, but this fails because this task is
	currently running.  This kthread therefore sends an IPI to CPU 0.

o	CPU 0 receives the IPI, and thus invokes trc_read_check_handler().
	Because Task A has not yet cleared its ->trc_reader_nesting
	counter, this function sees that Task A is still within its
	read-side critical section.  This function therefore sets the
	->trc_reader_nesting.b.need_qs flag, AKA the .need_qs flag.

	Except that Task A has already checked the .need_qs flag, which
	is part of the ->trc_reader_special.s flag.  The .need_qs flag
	therefore remains set until Task A's next rcu_read_unlock_trace().

o	Task A now invokes synchronize_rcu_tasks_trace(), which cannot
	start a new grace period until the current grace period completes.
	And thus cannot return until after that time.

	But Task A's .need_qs flag is still set, which prevents the current
	grace period from completing.  And because Task A is blocked, it
	will never execute rcu_read_unlock_trace() until its call to
	synchronize_rcu_tasks_trace() returns.

	We are therefore deadlocked.

This race is improbable, but 80 hours of rcutorture made it happen twice.
The race was possible before the grace-period speedup, but roughly 50x
less probable.  Several thousand hours of rcutorture would have been
necessary to have a reasonable chance of making this happen before this
50x speedup.

This commit therefore eliminates this deadlock by setting
->trc_reader_nesting to a large negative number before checking the
.need_qs and zeroing (or decrementing with respect to its initial
value) ->trc_reader_nesting.  For its part, the IPI handler's
trc_read_check_handler() function adds a check for negative values,
deferring evaluation of the task in this case.  Taken together, these
changes avoid this deadlock scenario.

Fixes: 276c410448db ("rcu-tasks: Split ->trc_reader_need_end")
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: Jiri Olsa 
Cc: 
Cc:  # 5.7.x
Signed-off-by: Paul E. McKenney 
Signed-off-by: Greg Kroah-Hartman

btrfs: tree-checker: fix false alert caused by legacy btrfs root item

2020-11-05T10:51:37+00:00

commit 1465af12e254a68706e110846f59cf0f09683184 upstream.

Commit 259ee7754b67 ("btrfs: tree-checker: Add ROOT_ITEM check")
introduced btrfs root item size check, however btrfs root item has two
versions, the legacy one which just ends before generation_v2 member, is
smaller than current btrfs root item size.

This caused btrfs kernel to reject valid but old tree root leaves.

Fix this problem by also allowing legacy root item, since kernel can
already handle them pretty well and upgrade to newer root item format
when needed.

Reported-by: Martin Steigerwald 
Fixes: 259ee7754b67 ("btrfs: tree-checker: Add ROOT_ITEM check")
CC: stable@vger.kernel.org # 5.4+
Tested-By: Martin Steigerwald 
Reviewed-by: Josef Bacik 
Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman