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6 years agoposix-timers: Handle relative posix-timers correctly
Thomas Gleixner [Mon, 12 Jun 2017 17:39:49 +0000 (19:39 +0200)]
posix-timers: Handle relative posix-timers correctly

The recent rework of the posix timer internals broke the magic posix
mechanism, which requires that relative timers are not affected by
modifications of the underlying clock. That means relative CLOCK_REALTIME
timers cannot use CLOCK_REALTIME, because that can be set and adjusted. The
underlying hrtimer switches the clock for these timers to CLOCK_MONOTONIC.

That still works, but reading the remaining time of such a timer has been
broken in the rework. The old code used the hrtimer internals directly and
avoided the posix clock callbacks. Now common_timer_get() uses the
underlying kclock->timer_get() callback, which is still CLOCK_REALTIME
based. So the remaining time of such a timer is calculated against the
wrong time base.

Handle it by switching the k_itimer->kclock pointer according to the
resulting hrtimer mode. k_itimer->it_clock still contains CLOCK_REALTIME
because the timer might be set with ABSTIME later and then it needs to
switch back to the realtime posix clock implementation.

Fixes: eae1c4ae275f ("posix-timers: Make use of cancel/arm callbacks")
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/20170609201156.GB21491@outlook.office365.com
6 years agoposix-timers: Zero out oldval itimerspec
Thomas Gleixner [Mon, 12 Jun 2017 17:44:09 +0000 (19:44 +0200)]
posix-timers: Zero out oldval itimerspec

The recent posix timer rework moved the clearing of the itimerspec to the
real syscall implementation, but forgot that the kclock->timer_get() is
used by timer_settime() as well. That results in an uninitialized variable
and bogus values returned to user space.

Add the missing memset to timer_settime().

Fixes: eabdec043853 ("posix-timers: Zero settings value in common code")
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/20170609201156.GB21491@outlook.office365.com
6 years agoposix-timers: Fix inverted SIGEV_NONE logic in common_timer_get()
Thomas Gleixner [Mon, 12 Jun 2017 15:21:26 +0000 (17:21 +0200)]
posix-timers: Fix inverted SIGEV_NONE logic in common_timer_get()

The refactoring of the posix-timer core to allow better code sharing
introduced inverted logic vs. SIGEV_NONE timers in common_timer_get().

That causes hrtimer_forward() to be called on active timers, which
rightfully triggers the warning hrtimer_forward().

Make sig_none what it says: signal mode == SIGEV_NONE.

Fixes: 91d57bae0868 ("posix-timers: Make use of forward/remaining callbacks")
Reported-by: Ye Xiaolong <xiaolong.ye@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170609104457.GA39907@inn.lkp.intel.com
6 years agoalarmtimer: Switch over to generic set/get/rearm routine
Thomas Gleixner [Tue, 30 May 2017 21:15:59 +0000 (23:15 +0200)]
alarmtimer: Switch over to generic set/get/rearm routine

All required callbacks are in place. Switch the alarm timer based posix
interval timer callbacks to the common implementation and remove the
incorrect private implementation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.825471962@linutronix.de
6 years agoalarmtimer: Implement arm callback
Thomas Gleixner [Tue, 30 May 2017 21:15:58 +0000 (23:15 +0200)]
alarmtimer: Implement arm callback

Preparatory change to utilize the common posix timer mechanisms.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.747567162@linutronix.de
6 years agoalarmtimer: Implement try_to_cancel callback
Thomas Gleixner [Tue, 30 May 2017 21:15:57 +0000 (23:15 +0200)]
alarmtimer: Implement try_to_cancel callback

Preparatory change to utilize the common posix timer mechanisms.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.670026824@linutronix.de
6 years agoalarmtimer: Implement remaining callback
Thomas Gleixner [Tue, 30 May 2017 21:15:56 +0000 (23:15 +0200)]
alarmtimer: Implement remaining callback

Preparatory change to utilize the common posix timer mechanisms.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.592676753@linutronix.de
6 years agoalarmtimer: Implement forward callback
Thomas Gleixner [Tue, 30 May 2017 21:15:55 +0000 (23:15 +0200)]
alarmtimer: Implement forward callback

Preparatory change to utilize the common posix timer mechanisms.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.513694229@linutronix.de
6 years agoalarmtimer: Implement timer_rearm() callback
Thomas Gleixner [Tue, 30 May 2017 21:15:54 +0000 (23:15 +0200)]
alarmtimer: Implement timer_rearm() callback

Preparatory change to utilize the common posix timer mechanisms.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.434598989@linutronix.de
6 years agoposix-timers: Make use of cancel/arm callbacks
Thomas Gleixner [Tue, 30 May 2017 21:15:53 +0000 (23:15 +0200)]
posix-timers: Make use of cancel/arm callbacks

Replace the hrtimer calls by calls to the new try_to_cancel()/arm() kclock
callbacks and move the hrtimer specific implementation into the
corresponding callback functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.355396667@linutronix.de
6 years agoposix-timers: Add cancel/arm callbacks
Thomas Gleixner [Tue, 30 May 2017 21:15:52 +0000 (23:15 +0200)]
posix-timers: Add cancel/arm callbacks

Add timer_try_to_cancel() and timer_arm() callbacks to kclock which allow
to make common_timer_set() usable by both hrtimer and alarmtimer based
clocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.278022962@linutronix.de
6 years agoposix-timers: Zero settings value in common code
Thomas Gleixner [Tue, 30 May 2017 21:15:51 +0000 (23:15 +0200)]
posix-timers: Zero settings value in common code

Zero out the settings struct in the common code so the callbacks do not
have to do it themself.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.200870713@linutronix.de
6 years agoposix-timers: Make use of forward/remaining callbacks
Thomas Gleixner [Tue, 30 May 2017 21:15:50 +0000 (23:15 +0200)]
posix-timers: Make use of forward/remaining callbacks

Replace the hrtimer calls by calls to the new forward/remaining kclock
callbacks and move the hrtimer specific implementation into the
corresponding callback functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.121437232@linutronix.de
6 years agoposix-timers: Add forward/remaining callbacks
Thomas Gleixner [Tue, 30 May 2017 21:15:49 +0000 (23:15 +0200)]
posix-timers: Add forward/remaining callbacks

Add two callbacks to kclock which allow using common_)timer_get() for both
hrtimer and alarm timer based clocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.044915536@linutronix.de
6 years agoposix-timers: Add active flag to k_itimer
Thomas Gleixner [Tue, 30 May 2017 21:15:48 +0000 (23:15 +0200)]
posix-timers: Add active flag to k_itimer

Keep track of the activation state of posix timers. This is a preparatory
change for making common_timer_get() usable by both hrtimer and alarm timer
implementations.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.967783982@linutronix.de
6 years agoposix-timers: Use timer_rearm() callback in posixtimer_rearm()
Thomas Gleixner [Tue, 30 May 2017 21:15:47 +0000 (23:15 +0200)]
posix-timers: Use timer_rearm() callback in posixtimer_rearm()

Use the new timer_rearm() callback to replace the conditional hardcoded
calls into the hrtimer and cpu timer code.

This allows later to bring the same logic to alarmtimers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.889661919@linutronix.de
6 years agoposix-timers: Rename do_schedule_next_timer
Thomas Gleixner [Tue, 30 May 2017 21:15:46 +0000 (23:15 +0200)]
posix-timers: Rename do_schedule_next_timer

That function is a misnomer. Rename it with a proper prefix to
posixtimer_rearm().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.811362578@linutronix.de
6 years agoposix-timers: Add timer_rearm() callback
Thomas Gleixner [Tue, 30 May 2017 21:15:45 +0000 (23:15 +0200)]
posix-timers: Add timer_rearm() callback

Add a timer_rearm() callback which is used to make the rescheduling of
posix interval timers independent of the underlying clock implementation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.732632167@linutronix.de
6 years agoposix-timers: Store k_clock pointer in k_itimer
Thomas Gleixner [Tue, 30 May 2017 21:15:44 +0000 (23:15 +0200)]
posix-timers: Store k_clock pointer in k_itimer

Having the k_clock pointer in the k_itimer struct avoids the lookup in
several code pathes and makes the next steps of unification of the hrtimer
and alarmtimer based posix timers simpler.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.641222072@linutronix.de
6 years agoposix-timers: Move interval out of the union
Thomas Gleixner [Tue, 30 May 2017 21:15:43 +0000 (23:15 +0200)]
posix-timers: Move interval out of the union

Preparatory patch to unify the alarm timer and hrtimer based posix interval
timer handling.

The interval is used as a criteria for rearming decisions so moving it out
of the clock specific data structures allows later unification.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.563922908@linutronix.de
6 years agoposix-timers: Unify overrun/requeue_pending handling
Thomas Gleixner [Tue, 30 May 2017 21:15:42 +0000 (23:15 +0200)]
posix-timers: Unify overrun/requeue_pending handling

hrtimer based posix-timers and posix-cpu-timers handle the update of the
rearming and overflow related status fields differently.

Move that update to the common rearming code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.484936964@linutronix.de
6 years agoposix-timers: Move posix-timer internals to core
Thomas Gleixner [Tue, 30 May 2017 21:15:41 +0000 (23:15 +0200)]
posix-timers: Move posix-timer internals to core

None of these declarations is required outside of kernel/time. Move them to
an internal header.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170530211656.394803853@linutronix.de
6 years agoposix-timers: Cleanup struct k_itimer
Thomas Gleixner [Tue, 30 May 2017 21:15:40 +0000 (23:15 +0200)]
posix-timers: Cleanup struct k_itimer

As a preparation for further changes, cleanup the formatting of the
k_itimer structure and add kernel doc comments.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.316574129@linutronix.de
6 years agoposix-timers: Avoid gazillions of forward declarations
Thomas Gleixner [Tue, 30 May 2017 21:15:39 +0000 (23:15 +0200)]
posix-timers: Avoid gazillions of forward declarations

Move it below the actual implementations as there are new callbacks coming
which would require even more forward declarations.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.238209952@linutronix.de
6 years agoposix-clocks: Remove interval timer facility and mmap/fasync callbacks
Thomas Gleixner [Tue, 30 May 2017 21:15:38 +0000 (23:15 +0200)]
posix-clocks: Remove interval timer facility and mmap/fasync callbacks

The only user of this facility is ptp_clock, which does not implement any of
those functions.

Remove them to prevent accidental users. Especially the interval timer
interfaces are now more or less impossible to implement because the
necessary infrastructure has been confined to the core code. Aside of that
it's really complex to make these callbacks implemented according to spec
as the alarm timer implementation demonstrates. If at all then a nanosleep
callback might be a reasonable extension. For now keep just what ptp_clock
needs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.145036286@linutronix.de
6 years agoposix-timers: Remove unused export of posix_timer_event()
Thomas Gleixner [Tue, 30 May 2017 21:15:37 +0000 (23:15 +0200)]
posix-timers: Remove unused export of posix_timer_event()

Since the removal of the mmtimer driver the export is not longer needed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.052744418@linutronix.de
6 years agoalarmtimer: Remove pointless config conditional
Thomas Gleixner [Tue, 30 May 2017 21:15:36 +0000 (23:15 +0200)]
alarmtimer: Remove pointless config conditional

Having a IF_ENABLED(CONFIG_POSIX_TIMERS) inside of a
#ifdef CONFIG_POSIX_TIMERS section is pointless.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211655.975218056@linutronix.de
6 years agoMerge branch 'timers/urgent' into WIP.timers
Thomas Gleixner [Sun, 4 Jun 2017 13:21:52 +0000 (15:21 +0200)]
Merge branch 'timers/urgent' into WIP.timers

Pick up urgent fixes to avoid conflicts.

6 years agoalarmtimer: Rate limit periodic intervals
Thomas Gleixner [Tue, 30 May 2017 21:15:35 +0000 (23:15 +0200)]
alarmtimer: Rate limit periodic intervals

The alarmtimer code has another source of potentially rearming itself too
fast. Interval timers with a very samll interval have a similar CPU hog
effect as the previously fixed overflow issue.

The reason is that alarmtimers do not implement the normal protection
against this kind of problem which the other posix timer use:

  timer expires -> queue signal -> deliver signal -> rearm timer

This scheme brings the rearming under scheduler control and prevents
permanently firing timers which hog the CPU.

Bringing this scheme to the alarm timer code is a major overhaul because it
lacks all the necessary mechanisms completely.

So for a quick fix limit the interval to one jiffie. This is not
problematic in practice as alarmtimers are usually backed by an RTC for
suspend which have 1 second resolution. It could be therefor argued that
the resolution of this clock should be set to 1 second in general, but
that's outside the scope of this fix.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kostya Serebryany <kcc@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170530211655.896767100@linutronix.de
6 years agoalarmtimer: Prevent overflow of relative timers
Thomas Gleixner [Tue, 30 May 2017 21:15:34 +0000 (23:15 +0200)]
alarmtimer: Prevent overflow of relative timers

Andrey reported a alartimer related RCU stall while fuzzing the kernel with
syzkaller.

The reason for this is an overflow in ktime_add() which brings the
resulting time into negative space and causes immediate expiry of the
timer. The following rearm with a small interval does not bring the timer
back into positive space due to the same issue.

This results in a permanent firing alarmtimer which hogs the CPU.

Use ktime_add_safe() instead which detects the overflow and clamps the
result to KTIME_SEC_MAX.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kostya Serebryany <kcc@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170530211655.802921648@linutronix.de
6 years agosignal: Remove non-uapi <asm/siginfo.h>
Christoph Hellwig [Sat, 3 Jun 2017 19:01:02 +0000 (21:01 +0200)]
signal: Remove non-uapi <asm/siginfo.h>

By moving the kernel side __SI_* defintions right next to the userspace
ones we can kill the non-uapi versions of <asm/siginfo.h> include
include/asm-generic/siginfo.h and untangle the unholy mess of includes.

[ tglx: Removed uapi/asm/siginfo.h from m32r, microblaze, mn10300 and score ]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: sparclinux@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20170603190102.28866-6-hch@lst.de
6 years agosignal: Move copy_siginfo_to_user to <linux/signal.h>
Christoph Hellwig [Sat, 3 Jun 2017 19:01:01 +0000 (21:01 +0200)]
signal: Move copy_siginfo_to_user to <linux/signal.h>

Having it in asm-generic/siginfo.h doesn't make any sense as it is in no way
architecture specific.  Move it to signal.h instead where several related
functions already reside.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: sparclinux@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20170603190102.28866-5-hch@lst.de
6 years agoposix-timers: Move the do_schedule_next_timer declaration
Christoph Hellwig [Sat, 3 Jun 2017 19:01:00 +0000 (21:01 +0200)]
posix-timers: Move the do_schedule_next_timer declaration

Having it in asm-generic/siginfo.h doesn't make any sense as it is in no way
architecture specific.  Move it to posix-timers.h instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: sparclinux@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20170603190102.28866-4-hch@lst.de
6 years agoia64: Remove HAVE_ARCH_COPY_SIGINFO
Christoph Hellwig [Sat, 3 Jun 2017 19:00:59 +0000 (21:00 +0200)]
ia64: Remove HAVE_ARCH_COPY_SIGINFO

Since ia64 defines __ARCH_SI_PREAMBLE_SIZE it can just use the generic
copy_siginfo implementation, which is identical to the architecture
specific one.

With that support for HAVE_ARCH_COPY_SIGINFO can go away entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: sparclinux@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20170603190102.28866-3-hch@lst.de
6 years agosparc: Simplify <asm/siginfo.h>
Christoph Hellwig [Sat, 3 Jun 2017 19:00:58 +0000 (21:00 +0200)]
sparc: Simplify <asm/siginfo.h>

There is no need for the forward declaration of compat_siginfo provided
here.  We can't yet use the generic header as we need to pull in the
sparc-specific version of the uapi <asm/siginfo.h>, but this prepares
for removing the non-uapi <asm/siginfo.h> entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20170603190102.28866-2-hch@lst.de
6 years agoMerge tag 'acpi-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
Linus Torvalds [Fri, 2 Jun 2017 23:36:23 +0000 (16:36 -0700)]
Merge tag 'acpi-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI fixes from Rafael Wysocki:
 "These revert one more problematic commit related to the ACPI-based
  handling of laptop lids and make some unuseful error messages coming
  from ACPICA go away.

  Specifics:

   - Revert one more commit related to the ACPI-based handling of laptop
     lids that changed the default behavior on laptops that booted with
     closed lids and introduced a regression there (Benjamin Tissoires).

   - Add a missing acpi_put_table() to the code implementing the
     /sys/firmware/acpi/tables interface to prevent a counter in the
     ACPICA core from overflowing (Dan Williams).

   - Drop error messages printed by ACPICA on acpi_get_table() reference
     counting mismatches as they need not indicate real errors at this
     point (Lv Zheng)"

* tag 'acpi-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPICA: Tables: Fix regression introduced by a too early mechanism enabling
  Revert "ACPI / button: Change default behavior to lid_init_state=open"
  ACPI / sysfs: fix acpi_get_table() leak / acpi-sysfs denial of service

6 years agoMerge tag 'pm-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Linus Torvalds [Fri, 2 Jun 2017 23:33:33 +0000 (16:33 -0700)]
Merge tag 'pm-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix two bugs in error code paths in the cpufreq core and in the
  kirkwood-cpufreq driver.

  Specifics:

   - Make cpufreq_register_driver() return an error if the ->init()
     calls fail for all CPUs to prevent non-functional drivers from
     hanging around for no reason (David Arcari).

   - Make kirkwood-cpufreq check the return value of
     clk_prepare_enable() (which may fail) as appropriate (Arvind
     Yadav)"

* tag 'pm-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: kirkwood-cpufreq:- Handle return value of clk_prepare_enable()
  cpufreq: cpufreq_register_driver() should return -ENODEV if init fails

6 years agoMerge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Fri, 2 Jun 2017 23:19:47 +0000 (16:19 -0700)]
Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull /dev/random bug fix from Ted Ts'o:
 "Fix a race on architectures with prioritized interrupts (such as m68k)
  which can causes crashes in drivers/char/random.c:get_reg()"

* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  fix race in drivers/char/random.c:get_reg()

6 years agoMerge branch 'akpm' (patches from Andrew)
Linus Torvalds [Fri, 2 Jun 2017 22:49:46 +0000 (15:49 -0700)]
Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "15 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  scripts/gdb: make lx-dmesg command work (reliably)
  mm: consider memblock reservations for deferred memory initialization sizing
  mm/hugetlb: report -EHWPOISON not -EFAULT when FOLL_HWPOISON is specified
  mlock: fix mlock count can not decrease in race condition
  mm/migrate: fix refcount handling when !hugepage_migration_supported()
  dax: fix race between colliding PMD & PTE entries
  mm: avoid spurious 'bad pmd' warning messages
  mm/page_alloc.c: make sure OOM victim can try allocations with no watermarks once
  pcmcia: remove left-over %Z format
  slub/memcg: cure the brainless abuse of sysfs attributes
  initramfs: fix disabling of initramfs (and its compression)
  mm: clarify why we want kmalloc before falling backto vmallock
  frv: declare jiffies to be located in the .data section
  include/linux/gfp.h: fix ___GFP_NOLOCKDEP value
  ksm: prevent crash after write_protect_page fails

6 years agoscripts/gdb: make lx-dmesg command work (reliably)
André Draszik [Fri, 2 Jun 2017 21:46:51 +0000 (14:46 -0700)]
scripts/gdb: make lx-dmesg command work (reliably)

lx-dmesg needs access to the log_buf symbol from printk.c.
Unfortunately, the symbol log_buf also exists in BPF's verifier.c and
hence gdb can pick one or the other.  If it happens to pick BPF's
log_buf, lx-dmesg doesn't work:

  (gdb) lx-dmesg
  Python Exception <class 'gdb.MemoryError'> Cannot access memory at address 0x0:
  Error occurred in Python command: Cannot access memory at address 0x0
  (gdb) p log_buf
  $15 = 0x0

Luckily, GDB has a way to deal with this, see
  https://sourceware.org/gdb/onlinedocs/gdb/Symbols.html

  (gdb) info variables ^log_buf$
  All variables matching regular expression "^log_buf$":

  File <linux.git>/kernel/bpf/verifier.c:
  static char *log_buf;

  File <linux.git>/kernel/printk/printk.c:
  static char *log_buf;
  (gdb) p 'verifier.c'::log_buf
  $1 = 0x0
  (gdb) p 'printk.c'::log_buf
  $2 = 0x811a6aa0 <__log_buf> ""
  (gdb) p &log_buf
  $3 = (char **) 0x8120fe40 <log_buf>
  (gdb) p &'verifier.c'::log_buf
  $4 = (char **) 0x8120fe40 <log_buf>
  (gdb) p &'printk.c'::log_buf
  $5 = (char **) 0x8048b7d0 <log_buf>

By being explicit about the location of the symbol, we can make lx-dmesg
work again.  While at it, do the same for the other symbols we need from
printk.c

Link: http://lkml.kernel.org/r/20170526112222.3414-1-git@andred.net
Signed-off-by: André Draszik <git@andred.net>
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agomm: consider memblock reservations for deferred memory initialization sizing
Michal Hocko [Fri, 2 Jun 2017 21:46:49 +0000 (14:46 -0700)]
mm: consider memblock reservations for deferred memory initialization sizing

We have seen an early OOM killer invocation on ppc64 systems with
crashkernel=4096M:

kthreadd invoked oom-killer: gfp_mask=0x16040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK), nodemask=7, order=0, oom_score_adj=0
kthreadd cpuset=/ mems_allowed=7
CPU: 0 PID: 2 Comm: kthreadd Not tainted 4.4.68-1.gd7fe927-default #1
Call Trace:
  dump_stack+0xb0/0xf0 (unreliable)
  dump_header+0xb0/0x258
  out_of_memory+0x5f0/0x640
  __alloc_pages_nodemask+0xa8c/0xc80
  kmem_getpages+0x84/0x1a0
  fallback_alloc+0x2a4/0x320
  kmem_cache_alloc_node+0xc0/0x2e0
  copy_process.isra.25+0x260/0x1b30
  _do_fork+0x94/0x470
  kernel_thread+0x48/0x60
  kthreadd+0x264/0x330
  ret_from_kernel_thread+0x5c/0xa4

Mem-Info:
active_anon:0 inactive_anon:0 isolated_anon:0
 active_file:0 inactive_file:0 isolated_file:0
 unevictable:0 dirty:0 writeback:0 unstable:0
 slab_reclaimable:5 slab_unreclaimable:73
 mapped:0 shmem:0 pagetables:0 bounce:0
 free:0 free_pcp:0 free_cma:0
Node 7 DMA free:0kB min:0kB low:0kB high:0kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:52428800kB managed:110016kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:320kB slab_unreclaimable:4672kB kernel_stack:1152kB pagetables:0kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
lowmem_reserve[]: 0 0 0 0
Node 7 DMA: 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 0kB
0 total pagecache pages
0 pages in swap cache
Swap cache stats: add 0, delete 0, find 0/0
Free swap  = 0kB
Total swap = 0kB
819200 pages RAM
0 pages HighMem/MovableOnly
817481 pages reserved
0 pages cma reserved
0 pages hwpoisoned

the reason is that the managed memory is too low (only 110MB) while the
rest of the the 50GB is still waiting for the deferred intialization to
be done.  update_defer_init estimates the initial memoty to initialize
to 2GB at least but it doesn't consider any memory allocated in that
range.  In this particular case we've had

Reserving 4096MB of memory at 128MB for crashkernel (System RAM: 51200MB)

so the low 2GB is mostly depleted.

Fix this by considering memblock allocations in the initial static
initialization estimation.  Move the max_initialise to
reset_deferred_meminit and implement a simple memblock_reserved_memory
helper which iterates all reserved blocks and sums the size of all that
start below the given address.  The cumulative size is than added on top
of the initial estimation.  This is still not ideal because
reset_deferred_meminit doesn't consider holes and so reservation might
be above the initial estimation whihch we ignore but let's make the
logic simpler until we really need to handle more complicated cases.

Fixes: 3a80a7fa7989 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set")
Link: http://lkml.kernel.org/r/20170531104010.GI27783@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> [4.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agomm/hugetlb: report -EHWPOISON not -EFAULT when FOLL_HWPOISON is specified
James Morse [Fri, 2 Jun 2017 21:46:46 +0000 (14:46 -0700)]
mm/hugetlb: report -EHWPOISON not -EFAULT when FOLL_HWPOISON is specified

KVM uses get_user_pages() to resolve its stage2 faults.  KVM sets the
FOLL_HWPOISON flag causing faultin_page() to return -EHWPOISON when it
finds a VM_FAULT_HWPOISON.  KVM handles these hwpoison pages as a
special case.  (check_user_page_hwpoison())

When huge pages are involved, this doesn't work so well.
get_user_pages() calls follow_hugetlb_page(), which stops early if it
receives VM_FAULT_HWPOISON from hugetlb_fault(), eventually returning
-EFAULT to the caller.  The step to map this to -EHWPOISON based on the
FOLL_ flags is missing.  The hwpoison special case is skipped, and
-EFAULT is returned to user-space, causing Qemu or kvmtool to exit.

Instead, move this VM_FAULT_ to errno mapping code into a header file
and use it from faultin_page() and follow_hugetlb_page().

With this, KVM works as expected.

This isn't a problem for arm64 today as we haven't enabled
MEMORY_FAILURE, but I can't see any reason this doesn't happen on x86
too, so I think this should be a fix.  This doesn't apply earlier than
stable's v4.11.1 due to all sorts of cleanup.

[james.morse@arm.com: add vm_fault_to_errno() call to faultin_page()]
suggested.
Link: http://lkml.kernel.org/r/20170525171035.16359-1-james.morse@arm.com
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170524160900.28786-1-james.morse@arm.com
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org> [4.11.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agomlock: fix mlock count can not decrease in race condition
Yisheng Xie [Fri, 2 Jun 2017 21:46:43 +0000 (14:46 -0700)]
mlock: fix mlock count can not decrease in race condition

Kefeng reported that when running the follow test, the mlock count in
meminfo will increase permanently:

 [1] testcase
 linux:~ # cat test_mlockal
 grep Mlocked /proc/meminfo
  for j in `seq 0 10`
  do
  for i in `seq 4 15`
  do
  ./p_mlockall >> log &
  done
  sleep 0.2
 done
 # wait some time to let mlock counter decrease and 5s may not enough
 sleep 5
 grep Mlocked /proc/meminfo

 linux:~ # cat p_mlockall.c
 #include <sys/mman.h>
 #include <stdlib.h>
 #include <stdio.h>

 #define SPACE_LEN 4096

 int main(int argc, char ** argv)
 {
  int ret;
  void *adr = malloc(SPACE_LEN);
  if (!adr)
  return -1;

  ret = mlockall(MCL_CURRENT | MCL_FUTURE);
  printf("mlcokall ret = %d\n", ret);

  ret = munlockall();
  printf("munlcokall ret = %d\n", ret);

  free(adr);
  return 0;
 }

In __munlock_pagevec() we should decrement NR_MLOCK for each page where
we clear the PageMlocked flag.  Commit 1ebb7cc6a583 ("mm: munlock: batch
NR_MLOCK zone state updates") has introduced a bug where we don't
decrement NR_MLOCK for pages where we clear the flag, but fail to
isolate them from the lru list (e.g.  when the pages are on some other
cpu's percpu pagevec).  Since PageMlocked stays cleared, the NR_MLOCK
accounting gets permanently disrupted by this.

Fix it by counting the number of page whose PageMlock flag is cleared.

Fixes: 1ebb7cc6a583 (" mm: munlock: batch NR_MLOCK zone state updates")
Link: http://lkml.kernel.org/r/1495678405-54569-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joern Engel <joern@logfs.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: zhongjiang <zhongjiang@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agomm/migrate: fix refcount handling when !hugepage_migration_supported()
Punit Agrawal [Fri, 2 Jun 2017 21:46:40 +0000 (14:46 -0700)]
mm/migrate: fix refcount handling when !hugepage_migration_supported()

On failing to migrate a page, soft_offline_huge_page() performs the
necessary update to the hugepage ref-count.

But when !hugepage_migration_supported() , unmap_and_move_hugepage()
also decrements the page ref-count for the hugepage.  The combined
behaviour leaves the ref-count in an inconsistent state.

This leads to soft lockups when running the overcommitted hugepage test
from mce-tests suite.

  Soft offlining pfn 0x83ed600 at process virtual address 0x400000000000
  soft offline: 0x83ed600: migration failed 1, type 1fffc00000008008 (uptodate|head)
  INFO: rcu_preempt detected stalls on CPUs/tasks:
   Tasks blocked on level-0 rcu_node (CPUs 0-7): P2715
    (detected by 7, t=5254 jiffies, g=963, c=962, q=321)
    thugetlb_overco R  running task        0  2715   2685 0x00000008
    Call trace:
      dump_backtrace+0x0/0x268
      show_stack+0x24/0x30
      sched_show_task+0x134/0x180
      rcu_print_detail_task_stall_rnp+0x54/0x7c
      rcu_check_callbacks+0xa74/0xb08
      update_process_times+0x34/0x60
      tick_sched_handle.isra.7+0x38/0x70
      tick_sched_timer+0x4c/0x98
      __hrtimer_run_queues+0xc0/0x300
      hrtimer_interrupt+0xac/0x228
      arch_timer_handler_phys+0x3c/0x50
      handle_percpu_devid_irq+0x8c/0x290
      generic_handle_irq+0x34/0x50
      __handle_domain_irq+0x68/0xc0
      gic_handle_irq+0x5c/0xb0

Address this by changing the putback_active_hugepage() in
soft_offline_huge_page() to putback_movable_pages().

This only triggers on systems that enable memory failure handling
(ARCH_SUPPORTS_MEMORY_FAILURE) but not hugepage migration
(!ARCH_ENABLE_HUGEPAGE_MIGRATION).

I imagine this wasn't triggered as there aren't many systems running
this configuration.

[akpm@linux-foundation.org: remove dead comment, per Naoya]
Link: http://lkml.kernel.org/r/20170525135146.32011-1-punit.agrawal@arm.com
Reported-by: Manoj Iyer <manoj.iyer@canonical.com>
Tested-by: Manoj Iyer <manoj.iyer@canonical.com>
Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org> [3.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agodax: fix race between colliding PMD & PTE entries
Ross Zwisler [Fri, 2 Jun 2017 21:46:37 +0000 (14:46 -0700)]
dax: fix race between colliding PMD & PTE entries

We currently have two related PMD vs PTE races in the DAX code.  These
can both be easily triggered by having two threads reading and writing
simultaneously to the same private mapping, with the key being that
private mapping reads can be handled with PMDs but private mapping
writes are always handled with PTEs so that we can COW.

Here is the first race:

  CPU 0 CPU 1

  (private mapping write)
  __handle_mm_fault()
    create_huge_pmd() - FALLBACK
    handle_pte_fault()
      passes check for pmd_devmap()

(private mapping read)
__handle_mm_fault()
  create_huge_pmd()
    dax_iomap_pmd_fault() inserts PMD

      dax_iomap_pte_fault() does a PTE fault, but we already have a DAX PMD
         installed in our page tables at this spot.

Here's the second race:

  CPU 0 CPU 1

  (private mapping read)
  __handle_mm_fault()
    passes check for pmd_none()
    create_huge_pmd()
      dax_iomap_pmd_fault() inserts PMD

  (private mapping write)
  __handle_mm_fault()
    create_huge_pmd() - FALLBACK
(private mapping read)
__handle_mm_fault()
  passes check for pmd_none()
  create_huge_pmd()

    handle_pte_fault()
      dax_iomap_pte_fault() inserts PTE
    dax_iomap_pmd_fault() inserts PMD,
       but we already have a PTE at
       this spot.

The core of the issue is that while there is isolation between faults to
the same range in the DAX fault handlers via our DAX entry locking,
there is no isolation between faults in the code in mm/memory.c.  This
means for instance that this code in __handle_mm_fault() can run:

if (pmd_none(*vmf.pmd) && transparent_hugepage_enabled(vma)) {
ret = create_huge_pmd(&vmf);

But by the time we actually get to run the fault handler called by
create_huge_pmd(), the PMD is no longer pmd_none() because a racing PTE
fault has installed a normal PMD here as a parent.  This is the cause of
the 2nd race.  The first race is similar - there is the following check
in handle_pte_fault():

} else {
/* See comment in pte_alloc_one_map() */
if (pmd_devmap(*vmf->pmd) || pmd_trans_unstable(vmf->pmd))
return 0;

So if a pmd_devmap() PMD (a DAX PMD) has been installed at vmf->pmd, we
will bail and retry the fault.  This is correct, but there is nothing
preventing the PMD from being installed after this check but before we
actually get to the DAX PTE fault handlers.

In my testing these races result in the following types of errors:

  BUG: Bad rss-counter state mm:ffff8800a817d280 idx:1 val:1
  BUG: non-zero nr_ptes on freeing mm: 15

Fix this issue by having the DAX fault handlers verify that it is safe
to continue their fault after they have taken an entry lock to block
other racing faults.

[ross.zwisler@linux.intel.com: improve fix for colliding PMD & PTE entries]
Link: http://lkml.kernel.org/r/20170526195932.32178-1-ross.zwisler@linux.intel.com
Link: http://lkml.kernel.org/r/20170522215749.23516-2-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Pawel Lebioda <pawel.lebioda@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Pawel Lebioda <pawel.lebioda@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Xiong Zhou <xzhou@redhat.com>
Cc: Eryu Guan <eguan@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agomm: avoid spurious 'bad pmd' warning messages
Ross Zwisler [Fri, 2 Jun 2017 21:46:34 +0000 (14:46 -0700)]
mm: avoid spurious 'bad pmd' warning messages

When the pmd_devmap() checks were added by 5c7fb56e5e3f ("mm, dax:
dax-pmd vs thp-pmd vs hugetlbfs-pmd") to add better support for DAX huge
pages, they were all added to the end of if() statements after existing
pmd_trans_huge() checks.  So, things like:

  -       if (pmd_trans_huge(*pmd))
  +       if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd))

When further checks were added after pmd_trans_unstable() checks by
commit 7267ec008b5c ("mm: postpone page table allocation until we have
page to map") they were also added at the end of the conditional:

  +       if (pmd_trans_unstable(fe->pmd) || pmd_devmap(*fe->pmd))

This ordering is fine for pmd_trans_huge(), but doesn't work for
pmd_trans_unstable().  This is because DAX huge pages trip the bad_pmd()
check inside of pmd_none_or_trans_huge_or_clear_bad() (called by
pmd_trans_unstable()), which prints out a warning and returns 1.  So, we
do end up doing the right thing, but only after spamming dmesg with
suspicious looking messages:

  mm/pgtable-generic.c:39: bad pmd ffff8808daa49b88(84000001006000a5)

Reorder these checks in a helper so that pmd_devmap() is checked first,
avoiding the error messages, and add a comment explaining why the
ordering is important.

Fixes: commit 7267ec008b5c ("mm: postpone page table allocation until we have page to map")
Link: http://lkml.kernel.org/r/20170522215749.23516-1-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Pawel Lebioda <pawel.lebioda@intel.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Xiong Zhou <xzhou@redhat.com>
Cc: Eryu Guan <eguan@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agomm/page_alloc.c: make sure OOM victim can try allocations with no watermarks once
Tetsuo Handa [Fri, 2 Jun 2017 21:46:31 +0000 (14:46 -0700)]
mm/page_alloc.c: make sure OOM victim can try allocations with no watermarks once

Roman Gushchin has reported that the OOM killer can trivially selects
next OOM victim when a thread doing memory allocation from page fault
path was selected as first OOM victim.

    allocate invoked oom-killer: gfp_mask=0x14280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=(null),  order=0, oom_score_adj=0
    allocate cpuset=/ mems_allowed=0
    CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
    Call Trace:
     oom_kill_process+0x219/0x3e0
     out_of_memory+0x11d/0x480
     __alloc_pages_slowpath+0xc84/0xd40
     __alloc_pages_nodemask+0x245/0x260
     alloc_pages_vma+0xa2/0x270
     __handle_mm_fault+0xca9/0x10c0
     handle_mm_fault+0xf3/0x210
     __do_page_fault+0x240/0x4e0
     trace_do_page_fault+0x37/0xe0
     do_async_page_fault+0x19/0x70
     async_page_fault+0x28/0x30
    ...
    Out of memory: Kill process 492 (allocate) score 899 or sacrifice child
    Killed process 492 (allocate) total-vm:2052368kB, anon-rss:1894576kB, file-rss:4kB, shmem-rss:0kB
    allocate: page allocation failure: order:0, mode:0x14280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=(null)
    allocate cpuset=/ mems_allowed=0
    CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
    Call Trace:
     __alloc_pages_slowpath+0xd32/0xd40
     __alloc_pages_nodemask+0x245/0x260
     alloc_pages_vma+0xa2/0x270
     __handle_mm_fault+0xca9/0x10c0
     handle_mm_fault+0xf3/0x210
     __do_page_fault+0x240/0x4e0
     trace_do_page_fault+0x37/0xe0
     do_async_page_fault+0x19/0x70
     async_page_fault+0x28/0x30
    ...
    oom_reaper: reaped process 492 (allocate), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
    ...
    allocate invoked oom-killer: gfp_mask=0x0(), nodemask=(null),  order=0, oom_score_adj=0
    allocate cpuset=/ mems_allowed=0
    CPU: 1 PID: 492 Comm: allocate Not tainted 4.12.0-rc1-mm1+ #181
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
    Call Trace:
     oom_kill_process+0x219/0x3e0
     out_of_memory+0x11d/0x480
     pagefault_out_of_memory+0x68/0x80
     mm_fault_error+0x8f/0x190
     ? handle_mm_fault+0xf3/0x210
     __do_page_fault+0x4b2/0x4e0
     trace_do_page_fault+0x37/0xe0
     do_async_page_fault+0x19/0x70
     async_page_fault+0x28/0x30
    ...
    Out of memory: Kill process 233 (firewalld) score 10 or sacrifice child
    Killed process 233 (firewalld) total-vm:246076kB, anon-rss:20956kB, file-rss:0kB, shmem-rss:0kB

There is a race window that the OOM reaper completes reclaiming the
first victim's memory while nothing but mutex_trylock() prevents the
first victim from calling out_of_memory() from pagefault_out_of_memory()
after memory allocation for page fault path failed due to being selected
as an OOM victim.

This is a side effect of commit 9a67f6488eca926f ("mm: consolidate
GFP_NOFAIL checks in the allocator slowpath") because that commit
silently changed the behavior from

    /* Avoid allocations with no watermarks from looping endlessly */

to

    /*
     * Give up allocations without trying memory reserves if selected
     * as an OOM victim
     */

in __alloc_pages_slowpath() by moving the location to check TIF_MEMDIE
flag.  I have noticed this change but I didn't post a patch because I
thought it is an acceptable change other than noise by warn_alloc()
because !__GFP_NOFAIL allocations are allowed to fail.  But we
overlooked that failing memory allocation from page fault path makes
difference due to the race window explained above.

While it might be possible to add a check to pagefault_out_of_memory()
that prevents the first victim from calling out_of_memory() or remove
out_of_memory() from pagefault_out_of_memory(), changing
pagefault_out_of_memory() does not suppress noise by warn_alloc() when
allocating thread was selected as an OOM victim.  There is little point
with printing similar backtraces and memory information from both
out_of_memory() and warn_alloc().

Instead, if we guarantee that current thread can try allocations with no
watermarks once when current thread looping inside
__alloc_pages_slowpath() was selected as an OOM victim, we can follow "who
can use memory reserves" rules and suppress noise by warn_alloc() and
prevent memory allocations from page fault path from calling
pagefault_out_of_memory().

If we take the comment literally, this patch would do

  -    if (test_thread_flag(TIF_MEMDIE))
  -        goto nopage;
  +    if (alloc_flags == ALLOC_NO_WATERMARKS || (gfp_mask & __GFP_NOMEMALLOC))
  +        goto nopage;

because gfp_pfmemalloc_allowed() returns false if __GFP_NOMEMALLOC is
given.  But if I recall correctly (I couldn't find the message), the
condition is meant to apply to only OOM victims despite the comment.
Therefore, this patch preserves TIF_MEMDIE check.

Fixes: 9a67f6488eca926f ("mm: consolidate GFP_NOFAIL checks in the allocator slowpath")
Link: http://lkml.kernel.org/r/201705192112.IAF69238.OQOHSJLFOFFMtV@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Roman Gushchin <guro@fb.com>
Tested-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org> [4.11]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agopcmcia: remove left-over %Z format
Nicolas Iooss [Fri, 2 Jun 2017 21:46:28 +0000 (14:46 -0700)]
pcmcia: remove left-over %Z format

Commit 5b5e0928f742 ("lib/vsprintf.c: remove %Z support") removed some
usages of format %Z but forgot "%.2Zx".  This makes clang 4.0 reports a
-Wformat-extra-args warning because it does not know about %Z.

Replace %Z with %z.

Link: http://lkml.kernel.org/r/20170520090946.22562-1-nicolas.iooss_linux@m4x.org
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: Harald Welte <laforge@gnumonks.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org> [4.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agoslub/memcg: cure the brainless abuse of sysfs attributes
Thomas Gleixner [Fri, 2 Jun 2017 21:46:25 +0000 (14:46 -0700)]
slub/memcg: cure the brainless abuse of sysfs attributes

memcg_propagate_slab_attrs() abuses the sysfs attribute file functions
to propagate settings from the root kmem_cache to a newly created
kmem_cache.  It does that with:

     attr->show(root, buf);
     attr->store(new, buf, strlen(bug);

Aside of being a lazy and absurd hackery this is broken because it does
not check the return value of the show() function.

Some of the show() functions return 0 w/o touching the buffer.  That
means in such a case the store function is called with the stale content
of the previous show().  That causes nonsense like invoking
kmem_cache_shrink() on a newly created kmem_cache.  In the worst case it
would cause handing in an uninitialized buffer.

This should be rewritten proper by adding a propagate() callback to
those slub_attributes which must be propagated and avoid that insane
conversion to and from ASCII, but that's too large for a hot fix.

Check at least the return value of the show() function, so calling
store() with stale content is prevented.

Steven said:
 "It can cause a deadlock with get_online_cpus() that has been uncovered
  by recent cpu hotplug and lockdep changes that Thomas and Peter have
  been doing.

     Possible unsafe locking scenario:

           CPU0                    CPU1
           ----                    ----
      lock(cpu_hotplug.lock);
                                   lock(slab_mutex);
                                   lock(cpu_hotplug.lock);
      lock(slab_mutex);

     *** DEADLOCK ***"

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705201244540.2255@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agoinitramfs: fix disabling of initramfs (and its compression)
Florian Fainelli [Fri, 2 Jun 2017 21:46:22 +0000 (14:46 -0700)]
initramfs: fix disabling of initramfs (and its compression)

Commit db2aa7fd15e8 ("initramfs: allow again choice of the embedded
initram compression algorithm") introduced the possibility to select the
initramfs compression algorithm from Kconfig and while this is a nice
feature it broke the use case described below.

Here is what my build system does:

 - kernel is initially configured not to have an initramfs included

 - build the user space root file system

 - re-configure the kernel to have an initramfs included
   (CONFIG_INITRAMFS_SOURCE="/path/to/romfs") and set relevant
   CONFIG_INITRAMFS options, in my case, no compression option
   (CONFIG_INITRAMFS_COMPRESSION_NONE)

 - kernel is re-built with these options -> kernel+initramfs image is
   copied

 - kernel is re-built again without these options -> kernel image is
   copied

Building a kernel without an initramfs means setting this option:

  CONFIG_INITRAMFS_SOURCE="" (and this one only)

whereas building a kernel with an initramfs means setting these options:

  CONFIG_INITRAMFS_SOURCE="/home/fainelli/work/uclinux-rootfs/romfs /home/fainelli/work/uclinux-rootfs/misc/initramfs.dev"
  CONFIG_INITRAMFS_ROOT_UID=1000
  CONFIG_INITRAMFS_ROOT_GID=1000
  CONFIG_INITRAMFS_COMPRESSION_NONE=y
  CONFIG_INITRAMFS_COMPRESSION=""

Commit db2aa7fd15e85 ("initramfs: allow again choice of the embedded
initram compression algorithm") is problematic because
CONFIG_INITRAMFS_COMPRESSION which is used to determine the
initramfs_data.cpio extension/compression is a string, and due to how
Kconfig works it will evaluate in order, how to assign it.

Setting CONFIG_INITRAMFS_COMPRESSION_NONE with CONFIG_INITRAMFS_SOURCE=""
cannot possibly work (because of the depends on INITRAMFS_SOURCE!=""
imposed on CONFIG_INITRAMFS_COMPRESSION ) yet we still get
CONFIG_INITRAMFS_COMPRESSION assigned to ".gz" because CONFIG_RD_GZIP=y
is set in my kernel, even when there is no initramfs being built.

So we basically end-up generating two initramfs_data.cpio* files, one
without extension, and one with .gz.  This causes usr/Makefile to track
usr/initramfs_data.cpio.gz, and not usr/initramfs_data.cpio anymore,
that is also largely problematic after 9e3596b0c6539e ("kbuild:
initramfs cleanup, set target from Kconfig") because we used to track
all possible initramfs_data files in the $(targets) variable before that
commit.

The end result is that the kernel with an initramfs clearly does not
contain what we expect it to, it has a stale initramfs_data.cpio file
built into it, and we keep re-generating an initramfs_data.cpio.gz file
which is not the one that we want to include in the kernel image proper.

The fix consists in hiding CONFIG_INITRAMFS_COMPRESSION when
CONFIG_INITRAMFS_SOURCE="".  This puts us back in a state to the
pre-4.10 behavior where we can properly disable and re-enable initramfs
within the same kernel .config file, and be in control of what
CONFIG_INITRAMFS_COMPRESSION is set to.

Fixes: db2aa7fd15e8 ("initramfs: allow again choice of the embedded initram compression algorithm")
Fixes: 9e3596b0c653 ("kbuild: initramfs cleanup, set target from Kconfig")
Link: http://lkml.kernel.org/r/20170521033337.6197-1-f.fainelli@gmail.com
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Cc: P J P <ppandit@redhat.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agomm: clarify why we want kmalloc before falling backto vmallock
Michal Hocko [Fri, 2 Jun 2017 21:46:19 +0000 (14:46 -0700)]
mm: clarify why we want kmalloc before falling backto vmallock

While converting drm_[cm]alloc* helpers to kvmalloc* variants Chris
Wilson has wondered why we want to try kmalloc before vmalloc fallback
even for larger allocations requests.  Let's clarify that one larger
physically contiguous block is less likely to fragment memory than many
scattered pages which can prevent more large blocks from being created.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170517080932.21423-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agofrv: declare jiffies to be located in the .data section
Matthias Kaehlcke [Fri, 2 Jun 2017 21:46:16 +0000 (14:46 -0700)]
frv: declare jiffies to be located in the .data section

Commit 7c30f352c852 ("jiffies.h: declare jiffies and jiffies_64 with
____cacheline_aligned_in_smp") removed a section specification from the
jiffies declaration that caused conflicts on some platforms.

Unfortunately this change broke the build for frv:

  kernel/built-in.o: In function `__do_softirq': (.text+0x6460): relocation truncated to fit: R_FRV_GPREL12 against symbol
      `jiffies' defined in *ABS* section in .tmp_vmlinux1
  kernel/built-in.o: In function `__do_softirq': (.text+0x6574): relocation truncated to fit: R_FRV_GPREL12 against symbol
      `jiffies' defined in *ABS* section in .tmp_vmlinux1
  kernel/built-in.o: In function `pwq_activate_delayed_work': workqueue.c:(.text+0x15b9c): relocation truncated to fit: R_FRV_GPREL12 against
      symbol `jiffies' defined in *ABS* section in .tmp_vmlinux1
  ...

Add __jiffy_arch_data to the declaration of jiffies and use it on frv to
include the section specification.  For all other platforms
__jiffy_arch_data (currently) has no effect.

Fixes: 7c30f352c852 ("jiffies.h: declare jiffies and jiffies_64 with ____cacheline_aligned_in_smp")
Link: http://lkml.kernel.org/r/20170516221333.177280-1-mka@chromium.org
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agoinclude/linux/gfp.h: fix ___GFP_NOLOCKDEP value
Michal Hocko [Fri, 2 Jun 2017 21:46:13 +0000 (14:46 -0700)]
include/linux/gfp.h: fix ___GFP_NOLOCKDEP value

Igor Stoppa has noticed that __GFP_NOLOCKDEP can use a lower bit.  At
the time commit 7e7844226f10 ("lockdep: allow to disable reclaim lockup
detection") was written we still had __GFP_OTHER_NODE but I have removed
it in commit 41b6167e8f74 ("mm: get rid of __GFP_OTHER_NODE") and forgot
to lower the bit value.

The current value is outside of __GFP_BITS_SHIFT so it cannot be used
actually.

Fixes: 7e7844226f10 ("lockdep: allow to disable reclaim lockup detection")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Igor Stoppa <igor.stoppa@nokia.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agoksm: prevent crash after write_protect_page fails
Andrea Arcangeli [Fri, 2 Jun 2017 21:46:11 +0000 (14:46 -0700)]
ksm: prevent crash after write_protect_page fails

"err" needs to be left set to -EFAULT if split_huge_page succeeds.
Otherwise if "err" gets clobbered with zero and write_protect_page
fails, try_to_merge_one_page() will succeed instead of returning -EFAULT
and then try_to_merge_with_ksm_page() will continue thinking kpage is a
PageKsm when in fact it's still an anonymous page.  Eventually it'll
crash in page_add_anon_rmap.

This has been reproduced on Fedora25 kernel but I can reproduce with
upstream too.

The bug was introduced in commit f765f540598a ("ksm: prepare to new THP
semantics") introduced in v4.5.

    page:fffff67546ce1cc0 count:4 mapcount:2 mapping:ffffa094551e36e1 index:0x7f0f46673
    flags: 0x2ffffc0004007c(referenced|uptodate|dirty|lru|active|swapbacked)
    page dumped because: VM_BUG_ON_PAGE(!PageLocked(page))
    page->mem_cgroup:ffffa09674bf0000
    ------------[ cut here ]------------
    kernel BUG at mm/rmap.c:1222!
    CPU: 1 PID: 76 Comm: ksmd Not tainted 4.9.3-200.fc25.x86_64 #1
    RIP: do_page_add_anon_rmap+0x1c4/0x240
    Call Trace:
      page_add_anon_rmap+0x18/0x20
      try_to_merge_with_ksm_page+0x50b/0x780
      ksm_scan_thread+0x1211/0x1410
      ? prepare_to_wait_event+0x100/0x100
      ? try_to_merge_with_ksm_page+0x780/0x780
      kthread+0xd9/0xf0
      ? kthread_park+0x60/0x60
      ret_from_fork+0x25/0x30

Fixes: f765f54059 ("ksm: prepare to new THP semantics")
Link: http://lkml.kernel.org/r/20170513131040.21732-1-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Federico Simoncelli <fsimonce@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
6 years agoMerge branches 'acpi-button', 'acpica' and 'acpi-sysfs'
Rafael J. Wysocki [Fri, 2 Jun 2017 22:03:29 +0000 (00:03 +0200)]
Merge branches 'acpi-button', 'acpica' and 'acpi-sysfs'

* acpi-button:
  Revert "ACPI / button: Change default behavior to lid_init_state=open"

* acpica:
  ACPICA: Tables: Fix regression introduced by a too early mechanism enabling

* acpi-sysfs:
  ACPI / sysfs: fix acpi_get_table() leak / acpi-sysfs denial of service

6 years agoMerge branch 'pm-cpufreq'
Rafael J. Wysocki [Fri, 2 Jun 2017 22:01:45 +0000 (00:01 +0200)]
Merge branch 'pm-cpufreq'

* pm-cpufreq:
  cpufreq: kirkwood-cpufreq:- Handle return value of clk_prepare_enable()
  cpufreq: cpufreq_register_driver() should return -ENODEV if init fails

6 years agoMerge tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Linus Torvalds [Fri, 2 Jun 2017 19:29:03 +0000 (12:29 -0700)]
Merge tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull XFS fix from Darrick Wong:
 "I've one more bugfix for you for 4.12-rc4: Fix an unmount hang due to
  a race in io buffer accounting"

* tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: use ->b_state to fix buffer I/O accounting release race

6 years agoMerge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Linus Torvalds [Fri, 2 Jun 2017 19:06:27 +0000 (12:06 -0700)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:
 "ACPI-related fixes for arm64:

   - GICC MADT entry validity check fix

   - Skip IRQ registration with pmu=off in an ACPI guest

   - struct acpi_pci_root_ops freeing on error path"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  ARM64/ACPI: Fix BAD_MADT_GICC_ENTRY() macro implementation
  drivers/perf: arm_pmu_acpi: avoid perf IRQ init when guest PMU is off
  ARM64: PCI: Fix struct acpi_pci_root_ops allocation failure path

6 years agoMerge tag 'ceph-for-4.12-rc4' of git://github.com/ceph/ceph-client
Linus Torvalds [Fri, 2 Jun 2017 19:03:07 +0000 (12:03 -0700)]
Merge tag 'ceph-for-4.12-rc4' of git://github.com/ceph/ceph-client

Pull ceph fix from Ilya Dryomov:
 "A small fix for rbd FALLOC_FL_ZERO_RANGE/PUNCH_HOLE handling breakage
  introduced in -rc1"

* tag 'ceph-for-4.12-rc4' of git://github.com/ceph/ceph-client:
  rbd: implement REQ_OP_WRITE_ZEROES

6 years agoMerge tag 'for-4.12/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Fri, 2 Jun 2017 18:50:37 +0000 (11:50 -0700)]
Merge tag 'for-4.12/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - a DM verity fix for a mode when no salt is used

 - a fix to DM to account for the possibility that PREFLUSH or FUA are
   used without the SYNC flag if the underlying storage doesn't have a
   volatile write-cache

 - a DM ioctl memory allocation flag fix to use __GFP_HIGH to allow
   emergency forward progress (by using memory reserves as last resort)

 - a small DM integrity cleanup to use kvmalloc() instead of duplicating
   the same

* tag 'for-4.12/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: make flush bios explicitly sync
  dm ioctl: restore __GFP_HIGH in copy_params()
  dm integrity: use kvmalloc() instead of dm_integrity_kvmalloc()
  dm verity: fix no salt use case

6 years agoMerge tag 'md/4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Linus Torvalds [Fri, 2 Jun 2017 18:47:24 +0000 (11:47 -0700)]
Merge tag 'md/4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md

Pull MD fixes from Shaohua Li:
 "Several patches for MD. One notable is making flush bios sync, others
  fix small issues"

* tag 'md/4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md: Make flush bios explicitely sync
  md: report sector of stripes with check mismatches
  md: uuid debug statement now in processor byte order.
  md-cluster: fix potential lock issue in add_new_disk

6 years agoMerge branch 'for-linus' of git://git.kernel.dk/linux-block
Linus Torvalds [Fri, 2 Jun 2017 18:44:46 +0000 (11:44 -0700)]
Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A set of fixes that should go into the next -rc. This contains:

   - A use-after-free in the request_list exit for the legacy IO path,
     from Bart.

   - A fix for CFQ, fixing a recent regression with the conversion to
     higher resolution timing for iops mode. From Hou Tao.

   - A single fix for nbd, split in two patches, fixing a leak of a data
     structure.

   - A regression fix from Keith, ensuring that callers of
     blk_mq_update_nr_hw_queues() hold the right lock"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: Avoid that blk_exit_rl() triggers a use-after-free
  cfq-iosched: fix the delay of cfq_group's vdisktime under iops mode
  blk-mq: Take tagset lock when updating hw queues
  nbd: don't leak nbd_config
  nbd: nbd_reset() call in nbd_dev_add() is redundant

6 years agoMerge tag 'drm-dp-quirk-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux
Linus Torvalds [Fri, 2 Jun 2017 18:32:38 +0000 (11:32 -0700)]
Merge tag 'drm-dp-quirk-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux

Pull drm displayport quirk support:
 "DP quirk for usb c dongles.

  As mentioned I have a separate request for fixing a regression, but
  also keeping the broken hw working, for certain USB-C DP adapters they
  require a minimised n/m parameters, but an attempt to do this
  generically has failed, we need to quirk these specific adapters.
  However doing it generically regressed some eDP panels.

  This pull adds the infrastructure and a quirk for the adapter"

* tag 'drm-dp-quirk-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: Detect USB-C specific dongles before reducing M and N
  drm/dp: start a DPCD based DP sink/branch device quirk database
  drm/i915: use drm DP helper to read DPCD desc
  drm/dp: add helper for reading DP sink/branch device desc from DPCD

6 years agoMerge tag 'sound-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...
Linus Torvalds [Fri, 2 Jun 2017 16:40:47 +0000 (09:40 -0700)]
Merge tag 'sound-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
 "This contains the fixes for a few reported regression for HD-audio and
  USB-audio. All small, trivial, and boring"

* tag 'sound-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Fix applying MSI dual-codec mobo quirk
  ALSA: usb: Avoid VLA in mixer_us16x08.c
  ALSA: usb: Fix a typo in Tascam US-16x08 mixer element
  Revert "ALSA: usb-audio: purge needless variable length array"

6 years agoMerge tag 'dmaengine-fix-4.12-rc4' of git://git.infradead.org/users/vkoul/slave-dma
Linus Torvalds [Fri, 2 Jun 2017 16:26:42 +0000 (09:26 -0700)]
Merge tag 'dmaengine-fix-4.12-rc4' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine fixes from Vinod Koul:
 "Here is the dmaengine fixes request for 4.12. Fixes bunch of issues in
  the driver, npthing exciting though..

   - mv_xor_v2 driver fixes for handling descriptors, tx_submit
     implementation, removing interrupt coalescing and setting DMA mask
     properly

   - fix usb-dmac DMAOR AE bit definition

   - fix ep93xx start buffer from BASE0 and not drain the transfers in
     terminate_all

   - fix rcar-dmac to use right descriptor pointer for residue
     calculation

   - pl330 fix warn for irq freeup"

* tag 'dmaengine-fix-4.12-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: pl330: fix warning in pl330_remove
  rcar-dmac: fixup descriptor pointer for descriptor mode
  dmaengine: ep93xx: Don't drain the transfers in terminate_all()
  dmaengine: ep93xx: Always start from BASE0
  dmaengine: usb-dmac: Fix DMAOR AE bit definition
  dmaengine: mv_xor_v2: set DMA mask to 40 bits
  dmaengine: mv_xor_v2: remove interrupt coalescing
  dmaengine: mv_xor_v2: fix tx_submit() implementation
  dmaengine: mv_xor_v2: enable XOR engine after its configuration
  dmaengine: mv_xor_v2: do not use descriptors not acked by async_tx
  dmaengine: mv_xor_v2: properly handle wrapping in the array of HW descriptors
  dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly

6 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Linus Torvalds [Fri, 2 Jun 2017 16:23:56 +0000 (09:23 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid

Pull HID fixes from Jiri Kosina:

 - corner-case oops fixes for Asus and Wacom drivers from Carlo Caione
   and Jason Gerecke

 - power management fix (reported on SIS0817 touchscreen) for i2c-hid
   devices from Hans de Goede

 - device-id-specific fixes and quirks from Hans de Goede, Diego Elio
   Pettenò and Che-Liang Chiou

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: asus: Stop underlying hardware on remove
  HID: i2c: Call acpi_device_fix_up_power for ACPI-enumerated devices
  HID: asus: Add support for T100 keyboard
  HID: elecom: extend to fix the descriptor for DEFT trackballs
  HID: magicmouse: Set multi-touch keybits for Magic Mouse
  HID: wacom: Have wacom_tpc_irq guard against possible NULL dereference

6 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livep...
Linus Torvalds [Fri, 2 Jun 2017 15:59:17 +0000 (08:59 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching

Pull livepatching fix from Jiri Kosina:
 "Kconfig dependency fix for livepatching infrastructure from Miroslav
  Benes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: Make livepatch dependent on !TRIM_UNUSED_KSYMS

6 years agoMerge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Fri, 2 Jun 2017 15:53:42 +0000 (08:53 -0700)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - revert a broken PAT commit that broke a number of systems

   - fix two preemptability warnings/bugs that can trigger under certain
     circumstances, in the debug code and in the microcode loader"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "x86/PAT: Fix Xorg regression on CPUs that don't support PAT"
  x86/debug/32: Convert a smp_processor_id() call to raw to avoid DEBUG_PREEMPT warning
  x86/microcode/AMD: Change load_microcode_amd()'s param to bool to fix preemptibility bug

6 years agoMerge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Fri, 2 Jun 2017 15:51:53 +0000 (08:51 -0700)]
Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI fixes from Ingo Molnar:
 "Misc fixes:

   - three boot crash fixes for uncommon configurations

   - silence a boot warning under virtualization

   - plus a GCC 7 related (harmless) build warning fix"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/bgrt: Skip efi_bgrt_init() in case of non-EFI boot
  x86/efi: Correct EFI identity mapping under 'efi=old_map' when KASLR is enabled
  x86/efi: Disable runtime services on kexec kernel if booted with efi=old_map
  efi: Remove duplicate 'const' specifiers
  efi: Don't issue error message when booted under Xen

6 years agoARM64/ACPI: Fix BAD_MADT_GICC_ENTRY() macro implementation
Lorenzo Pieralisi [Fri, 26 May 2017 16:40:02 +0000 (17:40 +0100)]
ARM64/ACPI: Fix BAD_MADT_GICC_ENTRY() macro implementation

The BAD_MADT_GICC_ENTRY() macro checks if a GICC MADT entry passes
muster from an ACPI specification standpoint. Current macro detects the
MADT GICC entry length through ACPI firmware version (it changed from 76
to 80 bytes in the transition from ACPI 5.1 to ACPI 6.0 specification)
but always uses (erroneously) the ACPICA (latest) struct (ie struct
acpi_madt_generic_interrupt - that is 80-bytes long) length to check if
the current GICC entry memory record exceeds the MADT table end in
memory as defined by the MADT table header itself, which may result in
false negatives depending on the ACPI firmware version and how the MADT
entries are laid out in memory (ie on ACPI 5.1 firmware MADT GICC
entries are 76 bytes long, so by adding 80 to a GICC entry start address
in memory the resulting address may well be past the actual MADT end,
triggering a false negative).

Fix the BAD_MADT_GICC_ENTRY() macro by reshuffling the condition checks
and update them to always use the firmware version specific MADT GICC
entry length in order to carry out boundary checks.

Fixes: b6cfb277378e ("ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro")
Reported-by: Julien Grall <julien.grall@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Julien Grall <julien.grall@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Al Stone <ahs3@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
6 years agoHID: asus: Stop underlying hardware on remove
Carlo Caione [Tue, 30 May 2017 20:39:46 +0000 (22:39 +0200)]
HID: asus: Stop underlying hardware on remove

We are missing a call to hid_hw_stop() on the remove hook.
Among other things this is causing an Oops when (re-)starting GNOME /
upowerd / ... after the module has been already rmmod-ed.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
6 years agodmaengine: pl330: fix warning in pl330_remove
Jean-Philippe Brucker [Thu, 1 Jun 2017 18:22:01 +0000 (19:22 +0100)]
dmaengine: pl330: fix warning in pl330_remove

When removing a device with less than 9 IRQs (AMBA_NR_IRQS), we'll get a
big WARN_ON from devres.c because pl330_remove calls devm_free_irqs for
unallocated irqs. Similarly to pl330_probe, check that IRQ number is
present before calling devm_free_irq.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
6 years agoMerge tag 'topic/dp-quirks-2017-05-31' of git://anongit.freedesktop.org/git/drm-intel...
Dave Airlie [Fri, 2 Jun 2017 02:57:32 +0000 (12:57 +1000)]
Merge tag 'topic/dp-quirks-2017-05-31' of git://anongit.freedesktop.org/git/drm-intel into drm-fixes

DP sink specific quirks

* tag 'topic/dp-quirks-2017-05-31' of git://anongit.freedesktop.org/git/drm-intel:
  drm/i915: Detect USB-C specific dongles before reducing M and N
  drm/dp: start a DPCD based DP sink/branch device quirk database
  drm/i915: use drm DP helper to read DPCD desc
  drm/dp: add helper for reading DP sink/branch device desc from DPCD

6 years agoMerge tag 'nfsd-4.12-1' of git://linux-nfs.org/~bfields/linux
Linus Torvalds [Thu, 1 Jun 2017 23:24:48 +0000 (16:24 -0700)]
Merge tag 'nfsd-4.12-1' of git://linux-nfs.org/~bfields/linux

Pull nfsd fixes from Bruce Fields:
 "Revert patch accidentally included in the merge window pull request,
  and fix a crash that was likely a result of buggy client behavior"

* tag 'nfsd-4.12-1' of git://linux-nfs.org/~bfields/linux:
  nfsd4: fix null dereference on replay
  nfsd: Revert "nfsd: check for oversized NFSv2/v3 arguments"

6 years agoMerge tag 'gcc-plugins-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Thu, 1 Jun 2017 23:17:42 +0000 (16:17 -0700)]
Merge tag 'gcc-plugins-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull gcc-plugin prepwork from Kees Cook:
 "Use designated initializers for mtk-vcodec, powerplay, amdgpu, and
  sgi-xp. Use ERR_CAST() to avoid cross-structure cast in ocf2, ntfs,
  and NFS.

  Christoph Hellwig recommended that I send these fixes now, rather than
  waiting for the v4.13 merge window. These are all initializer and cast
  fixes needed for the future randstruct plugin that haven't been picked
  up by the respective maintainers"

* tag 'gcc-plugins-v4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  mtk-vcodec: Use designated initializers
  drm/amd/powerplay: Use designated initializers
  drm/amdgpu: Use designated initializers
  sgi-xp: Use designated initializers
  ocfs2: Use ERR_CAST() to avoid cross-structure cast
  ntfs: Use ERR_CAST() to avoid cross-structure cast
  NFS: Use ERR_CAST() to avoid cross-structure cast

6 years agoblock: Avoid that blk_exit_rl() triggers a use-after-free
Bart Van Assche [Wed, 31 May 2017 21:43:45 +0000 (14:43 -0700)]
block: Avoid that blk_exit_rl() triggers a use-after-free

Since the introduction of .init_rq_fn() and .exit_rq_fn() it is
essential that the memory allocated for struct request_queue
stays around until all blk_exit_rl() calls have finished. Hence
make blk_init_rl() take a reference on struct request_queue.

This patch fixes the following crash:

general protection fault: 0000 [#2] SMP
CPU: 3 PID: 28 Comm: ksoftirqd/3 Tainted: G      D         4.12.0-rc2-dbg+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
task: ffff88013a108040 task.stack: ffffc9000071c000
RIP: 0010:free_request_size+0x1a/0x30
RSP: 0018:ffffc9000071fd38 EFLAGS: 00010202
RAX: 6b6b6b6b6b6b6b6b RBX: ffff880067362a88 RCX: 0000000000000003
RDX: ffff880067464178 RSI: ffff880067362a88 RDI: ffff880135ea4418
RBP: ffffc9000071fd40 R08: 0000000000000000 R09: 0000000100180009
R10: ffffc9000071fd38 R11: ffffffff81110800 R12: ffff88006752d3d8
R13: ffff88006752d3d8 R14: ffff88013a108040 R15: 000000000000000a
FS:  0000000000000000(0000) GS:ffff88013fd80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa8ec1edb00 CR3: 0000000138ee8000 CR4: 00000000001406e0
Call Trace:
 mempool_destroy.part.10+0x21/0x40
 mempool_destroy+0xe/0x10
 blk_exit_rl+0x12/0x20
 blkg_free+0x4d/0xa0
 __blkg_release_rcu+0x59/0x170
 rcu_process_callbacks+0x260/0x4e0
 __do_softirq+0x116/0x250
 smpboot_thread_fn+0x123/0x1e0
 kthread+0x109/0x140
 ret_from_fork+0x31/0x40

Fixes: commit e9c787e65c0c ("scsi: allocate scsi_cmnd structures as part of struct request")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Jens Axboe <axboe@fb.com>
6 years agoMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Linus Torvalds [Thu, 1 Jun 2017 17:48:09 +0000 (10:48 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "Many small x86 bug fixes: SVM segment registers access rights, nested
  VMX, preempt notifiers, LAPIC virtual wire mode, NMI injection"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Fix nmi injection failure when vcpu got blocked
  KVM: SVM: do not zero out segment attributes if segment is unusable or not present
  KVM: SVM: ignore type when setting segment registers
  KVM: nVMX: fix nested_vmx_check_vmptr failure paths under debugging
  KVM: x86: Fix virtual wire mode
  KVM: nVMX: Fix handling of lmsw instruction
  KVM: X86: Fix preempt the preemption timer cancel

6 years agoMerge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Linus Torvalds [Thu, 1 Jun 2017 17:45:27 +0000 (10:45 -0700)]
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull Reiserfs and GFS2 fixes from Jan Kara:
 "Fixes to GFS2 & Reiserfs for the fallout of the recent WRITE_FUA
  cleanup from Christoph.

  Fixes for other filesystems were already merged by respective
  maintainers."

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  reiserfs: Make flush bios explicitely sync
  gfs2: Make flush bios explicitely sync

6 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Linus Torvalds [Thu, 1 Jun 2017 17:40:41 +0000 (10:40 -0700)]
Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

Pull SCSI target fixes from Nicholas Bellinger:
 "Here are the target-pending fixes for v4.12-rc4:

   - ibmviscsis ABORT_TASK handling fixes that missed the v4.12 merge
     window. (Bryant Ly and Michael Cyr)

   - Re-add a target-core check enforcing WRITE overflow reject that was
     relaxed in v4.3, to avoid unsupported iscsi-target immediate data
     overflow. (nab)

   - Fix a target-core-user OOPs during device removal. (MNC + Bryant
     Ly)

   - Fix a long standing iscsi-target potential issue where kthread exit
     did not wait for kthread_should_stop(). (Jiang Yi)

   - Fix a iscsi-target v3.12.y regression OOPs involving initial login
     PDU processing during asynchronous TCP connection close. (MNC +
     nab)

  This is a little larger than usual for an -rc4, primarily due to the
  iscsi-target v3.12.y regression OOPs bug-fix.

  However, it's an important patch as MNC + Hannes where both able to
  trigger it using a reduced iscsi initiator login timeout combined with
  a backend taking a long time to complete I/Os during iscsi login
  driven session reinstatement"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  iscsi-target: Always wait for kthread_should_stop() before kthread exit
  iscsi-target: Fix initial login PDU asynchronous socket close OOPs
  tcmu: fix crash during device removal
  target: Re-add check to reject control WRITEs with overflow data
  ibmvscsis: Fix the incorrect req_lim_delta
  ibmvscsis: Clear left-over abort_cmd pointers

6 years agoRevert "x86/PAT: Fix Xorg regression on CPUs that don't support PAT"
Ingo Molnar [Thu, 1 Jun 2017 13:52:23 +0000 (15:52 +0200)]
Revert "x86/PAT: Fix Xorg regression on CPUs that don't support PAT"

This reverts commit cbed27cdf0e3f7ea3b2259e86b9e34df02be3fe4.

As Andy Lutomirski observed:

 "I think this patch is bogus. pat_enabled() sure looks like it's
  supposed to return true if PAT is *enabled*, and these days PAT is
  'enabled' even if there's no HW PAT support."

Reported-by: Bernhard Held <berny156@gmx.de>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: stable@vger.kernel.org # v4.2+
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
6 years agoKVM: x86: Fix nmi injection failure when vcpu got blocked
ZhuangYanying [Fri, 26 May 2017 05:16:48 +0000 (13:16 +0800)]
KVM: x86: Fix nmi injection failure when vcpu got blocked

When spin_lock_irqsave() deadlock occurs inside the guest, vcpu threads,
other than the lock-holding one, would enter into S state because of
pvspinlock. Then inject NMI via libvirt API "inject-nmi", the NMI could
not be injected into vm.

The reason is:
1 It sets nmi_queued to 1 when calling ioctl KVM_NMI in qemu, and sets
cpu->kvm_vcpu_dirty to true in do_inject_external_nmi() meanwhile.
2 It sets nmi_queued to 0 in process_nmi(), before entering guest, because
cpu->kvm_vcpu_dirty is true.

It's not enough just to check nmi_queued to decide whether to stay in
vcpu_block() or not. NMI should be injected immediately at any situation.
Add checking nmi_pending, and testing KVM_REQ_NMI replaces nmi_queued
in vm_vcpu_has_events().

Do the same change for SMIs.

Signed-off-by: Zhuang Yanying <ann.zhuangyanying@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
6 years agoKVM: SVM: do not zero out segment attributes if segment is unusable or not present
Roman Pen [Thu, 1 Jun 2017 08:55:03 +0000 (10:55 +0200)]
KVM: SVM: do not zero out segment attributes if segment is unusable or not present

This is a fix for the problem [1], where VMCB.CPL was set to 0 and interrupt
was taken on userspace stack.  The root cause lies in the specific AMD CPU
behaviour which manifests itself as unusable segment attributes on SYSRET.
The corresponding work around for the kernel is the following:

61f01dd941ba ("x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue")

In other turn virtualization side treated unusable segment incorrectly and
restored CPL from SS attributes, which were zeroed out few lines above.

In current patch it is assured only that P bit is cleared in VMCB.save state
and segment attributes are not zeroed out if segment is not presented or is
unusable, therefore CPL can be safely restored from DPL field.

This is only one part of the fix, since QEMU side should be fixed accordingly
not to zero out attributes on its side.  Corresponding patch will follow.

[1] Message id: CAJrWOzD6Xq==b-zYCDdFLgSRMPM-NkNuTSDFEtX=7MreT45i7Q@mail.gmail.com

Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com>
Signed-off-by: Mikhail Sennikovskii <mikhail.sennikovskii@profitbricks.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
6 years agoALSA: hda - Fix applying MSI dual-codec mobo quirk
Takashi Iwai [Thu, 1 Jun 2017 07:35:30 +0000 (09:35 +0200)]
ALSA: hda - Fix applying MSI dual-codec mobo quirk

The previous commit [63691587f7b0: ALSA: hda - Apply dual-codec quirk
for MSI Z270-Gaming mobo] attempted to apply the existing dual-codec
quirk for a MSI mobo.  But it turned out that this isn't applied
properly due to the MSI-vendor quirk before this entry.  I overlooked
such two MSI entries just because they were put in the wrong position,
although we have a list ordered by PCI SSID numbers.

This patch fixes it by rearranging the unordered entries.

Fixes: 63691587f7b0 ("ALSA: hda - Apply dual-codec quirk for MSI Z270-Gaming mobo")
Reported-by: Rudolf Schmidt <info@rudolfschmidt.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
6 years agoMerge tag 'drm-fixes-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux
Linus Torvalds [Thu, 1 Jun 2017 04:53:49 +0000 (21:53 -0700)]
Merge tag 'drm-fixes-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
 "This is the main set of fixes for rc4, one amdgpu fix, some exynos
  regression fixes, some msm fixes and some i915 and GVT fixes.

  I've got a second regression fix for some DP chips that might be a
  bit large, but I think we'd like to land it now, I'll send it along
  tomorrow, once you are happy with this set"

* tag 'drm-fixes-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux: (24 commits)
  drm/amdgpu: Program ring for vce instance 1 at its register space
  drm/exynos: clean up description of exynos_drm_crtc
  drm/exynos: dsi: Remove bridge node reference in removal
  drm/exynos: dsi: Fix the parse_dt function
  drm/exynos: Merge pre/postclose hooks
  drm/msm: Fix the check for the command size
  drm/msm: Take the mutex before calling msm_gem_new_impl
  drm/msm: for array in-fences, check if all backing fences are from our own context before waiting
  drm/msm: constify irq_domain_ops
  drm/msm/mdp5: release hwpipe(s) for unused planes
  drm/msm: Reuse dma_fence_release.
  drm/msm: Expose our reservation object when exporting a dmabuf.
  drm/msm/gpu: check legacy clk names in get_clocks()
  drm/msm/mdp5: use __drm_atomic_helper_plane_duplicate_state()
  drm/msm: select PM_OPP
  drm/i915: Stop pretending to mask/unmask LPE audio interrupts
  drm/i915/selftests: Silence compiler warning in igt_ctx_exec
  Revert "drm/i915: Restore lost "Initialized i915" welcome message"
  drm/i915/gvt: clean up unsubmited workloads before destroying kmem cache
  drm/i915/gvt: Disable compression workaround for Gen9
  ...

6 years agoMerge tag 'exynos-drm-fixes-for-v4.12' of git://git.kernel.org/pub/scm/linux/kernel...
Dave Airlie [Thu, 1 Jun 2017 02:07:48 +0000 (12:07 +1000)]
Merge tag 'exynos-drm-fixes-for-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-fixes

- Fix a regression to description of exynos_drm_crtc
- Remove preclose hook of Exynos
  . This was a exynos change of the patch series[1] merged already.
- Fix one dt broken issue
- Make sure to release bridge_node of Exynos MIPI-DSI driver.

[1] https://lists.freedesktop.org/archives/dri-devel/2017-March/135111.html

* tag 'exynos-drm-fixes-for-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
  drm/exynos: clean up description of exynos_drm_crtc
  drm/exynos: dsi: Remove bridge node reference in removal
  drm/exynos: dsi: Fix the parse_dt function
  drm/exynos: Merge pre/postclose hooks

6 years agoMerge branch 'drm-fixes-4.12' of git://people.freedesktop.org/~agd5f/linux into drm...
Dave Airlie [Thu, 1 Jun 2017 02:07:18 +0000 (12:07 +1000)]
Merge branch 'drm-fixes-4.12' of git://people.freedesktop.org/~agd5f/linux into drm-fixes

* 'drm-fixes-4.12' of git://people.freedesktop.org/~agd5f/linux:
  drm/amdgpu: Program ring for vce instance 1 at its register space

6 years agoMerge branch 'msm-fixes-4.12-rc4' of git://people.freedesktop.org/~robclark/linux...
Dave Airlie [Thu, 1 Jun 2017 02:06:34 +0000 (12:06 +1000)]
Merge branch 'msm-fixes-4.12-rc4' of git://people.freedesktop.org/~robclark/linux into drm-fixes

a few fixes for 4.12..

* 'msm-fixes-4.12-rc4' of git://people.freedesktop.org/~robclark/linux:
  drm/msm: Fix the check for the command size
  drm/msm: Take the mutex before calling msm_gem_new_impl
  drm/msm: for array in-fences, check if all backing fences are from our own context before waiting
  drm/msm: constify irq_domain_ops
  drm/msm/mdp5: release hwpipe(s) for unused planes
  drm/msm: Reuse dma_fence_release.
  drm/msm: Expose our reservation object when exporting a dmabuf.
  drm/msm/gpu: check legacy clk names in get_clocks()
  drm/msm/mdp5: use __drm_atomic_helper_plane_duplicate_state()
  drm/msm: select PM_OPP

6 years agoMerge tag 'drm-intel-fixes-2017-05-29' of git://anongit.freedesktop.org/git/drm-intel...
Dave Airlie [Thu, 1 Jun 2017 01:53:34 +0000 (11:53 +1000)]
Merge tag 'drm-intel-fixes-2017-05-29' of git://anongit.freedesktop.org/git/drm-intel into drm-fixes

drm/i915 fixes for v4.12-rc4

* tag 'drm-intel-fixes-2017-05-29' of git://anongit.freedesktop.org/git/drm-intel:
  drm/i915: Stop pretending to mask/unmask LPE audio interrupts
  drm/i915/selftests: Silence compiler warning in igt_ctx_exec
  Revert "drm/i915: Restore lost "Initialized i915" welcome message"
  drm/i915/gvt: clean up unsubmited workloads before destroying kmem cache
  drm/i915/gvt: Disable compression workaround for Gen9
  drm/i915: set initialised only when init_context callback is NULL
  drm/i915: Fix new -Wint-in-bool-context gcc compiler warning
  drm/i915: use vma->size for appgtt allocate_va_range
  drm/i915: Do not sync RCU during shrinking

6 years agoiscsi-target: Always wait for kthread_should_stop() before kthread exit
Jiang Yi [Tue, 16 May 2017 09:57:55 +0000 (17:57 +0800)]
iscsi-target: Always wait for kthread_should_stop() before kthread exit

There are three timing problems in the kthread usages of iscsi_target_mod:

 - np_thread of struct iscsi_np
 - rx_thread and tx_thread of struct iscsi_conn

In iscsit_close_connection(), it calls

 send_sig(SIGINT, conn->tx_thread, 1);
 kthread_stop(conn->tx_thread);

In conn->tx_thread, which is iscsi_target_tx_thread(), when it receive
SIGINT the kthread will exit without checking the return value of
kthread_should_stop().

So if iscsi_target_tx_thread() exit right between send_sig(SIGINT...)
and kthread_stop(...), the kthread_stop() will try to stop an already
stopped kthread.

This is invalid according to the documentation of kthread_stop().

(Fix -ECONNRESET logout handling in iscsi_target_tx_thread and
 early iscsi_target_rx_thread failure case - nab)

Signed-off-by: Jiang Yi <jiangyilism@gmail.com>
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
6 years agoiscsi-target: Fix initial login PDU asynchronous socket close OOPs
Nicholas Bellinger [Thu, 25 May 2017 04:47:09 +0000 (21:47 -0700)]
iscsi-target: Fix initial login PDU asynchronous socket close OOPs

This patch fixes a OOPs originally introduced by:

   commit bb048357dad6d604520c91586334c9c230366a14
   Author: Nicholas Bellinger <nab@linux-iscsi.org>
   Date:   Thu Sep 5 14:54:04 2013 -0700

   iscsi-target: Add sk->sk_state_change to cleanup after TCP failure

which would trigger a NULL pointer dereference when a TCP connection
was closed asynchronously via iscsi_target_sk_state_change(), but only
when the initial PDU processing in iscsi_target_do_login() from iscsi_np
process context was blocked waiting for backend I/O to complete.

To address this issue, this patch makes the following changes.

First, it introduces some common helper functions used for checking
socket closing state, checking login_flags, and atomically checking
socket closing state + setting login_flags.

Second, it introduces a LOGIN_FLAGS_INITIAL_PDU bit to know when a TCP
connection has dropped via iscsi_target_sk_state_change(), but the
initial PDU processing within iscsi_target_do_login() in iscsi_np
context is still running.  For this case, it sets LOGIN_FLAGS_CLOSED,
but doesn't invoke schedule_delayed_work().

The original NULL pointer dereference case reported by MNC is now handled
by iscsi_target_do_login() doing a iscsi_target_sk_check_close() before
transitioning to FFP to determine when the socket has already closed,
or iscsi_target_start_negotiation() if the login needs to exchange
more PDUs (eg: iscsi_target_do_login returned 0) but the socket has
closed.  For both of these cases, the cleanup up of remaining connection
resources will occur in iscsi_target_start_negotiation() from iscsi_np
process context once the failure is detected.

Finally, to handle to case where iscsi_target_sk_state_change() is
called after the initial PDU procesing is complete, it now invokes
conn->login_work -> iscsi_target_do_login_rx() to perform cleanup once
existing iscsi_target_sk_check_close() checks detect connection failure.
For this case, the cleanup of remaining connection resources will occur
in iscsi_target_do_login_rx() from delayed workqueue process context
once the failure is detected.

Reported-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Tested-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Reported-by: Hannes Reinecke <hare@suse.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Varun Prakash <varun@chelsio.com>
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
6 years agodrm/amdgpu: Program ring for vce instance 1 at its register space
Leo Liu [Mon, 29 May 2017 17:13:59 +0000 (13:13 -0400)]
drm/amdgpu: Program ring for vce instance 1 at its register space

We need program ring buffer on instance 1 register space domain,
when only if instance 1 available, with two instances or instance 0,
and we need only program instance 0 regsiter space domain for ring.

Signed-off-by: Leo Liu <leo.liu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
6 years agomd: Make flush bios explicitely sync
Jan Kara [Wed, 31 May 2017 07:44:33 +0000 (09:44 +0200)]
md: Make flush bios explicitely sync

Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

CC: linux-raid@vger.kernel.org
CC: Shaohua Li <shli@kernel.org>
Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Shaohua Li <shli@fb.com>
6 years agoMerge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszer...
Linus Torvalds [Wed, 31 May 2017 15:29:02 +0000 (08:29 -0700)]
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fixes from Miklos Szeredi:
 "Fix regressions:

   - missing CONFIG_EXPORTFS dependency

   - failure if upper fs doesn't support xattr

   - bad error cleanup

  This also adds the concept of "impure" directories complementing the
  "origin" marking introduced in -rc1. Together they enable getting
  consistent st_ino and d_ino for directory listings.

  And there's a bug fix and a cleanup as well"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: filter trusted xattr for non-admin
  ovl: mark upper merge dir with type origin entries "impure"
  ovl: mark upper dir with type origin entries "impure"
  ovl: remove unused arg from ovl_lookup_temp()
  ovl: handle rename when upper doesn't support xattr
  ovl: don't fail copy-up if upper doesn't support xattr
  ovl: check on mount time if upper fs supports setting xattr
  ovl: fix creds leak in copy up error path
  ovl: select EXPORTFS

6 years agocfq-iosched: fix the delay of cfq_group's vdisktime under iops mode
Hou Tao [Wed, 1 Mar 2017 01:02:33 +0000 (09:02 +0800)]
cfq-iosched: fix the delay of cfq_group's vdisktime under iops mode

When adding a cfq_group into the cfq service tree, we use CFQ_IDLE_DELAY
as the delay of cfq_group's vdisktime if there have been other cfq_groups
already.

When cfq is under iops mode, commit 9a7f38c42c2b ("cfq-iosched: Convert
from jiffies to nanoseconds") could result in a large iops delay and
lead to an abnormal io schedule delay for the added cfq_group. To fix
it, we just need to revert to the old CFQ_IDLE_DELAY value: HZ / 5
when iops mode is enabled.

Despite having the same value, the delay of a cfq_queue in idle class
and the delay of cfq_group are different things, so I define two new
macros for the delay of a cfq_group under time-slice mode and iops mode.

Fixes: 9a7f38c42c2b ("cfq-iosched: Convert from jiffies to nanoseconds")
Cc: <stable@vger.kernel.org> # 4.8+
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
6 years agoxfs: use ->b_state to fix buffer I/O accounting release race
Brian Foster [Wed, 31 May 2017 15:22:52 +0000 (08:22 -0700)]
xfs: use ->b_state to fix buffer I/O accounting release race

We've had user reports of unmount hangs in xfs_wait_buftarg() that
analysis shows is due to btp->bt_io_count == -1. bt_io_count
represents the count of in-flight asynchronous buffers and thus
should always be >= 0. xfs_wait_buftarg() waits for this value to
stabilize to zero in order to ensure that all untracked (with
respect to the lru) buffers have completed I/O processing before
unmount proceeds to tear down in-core data structures.

The value of -1 implies an I/O accounting decrement race. Indeed,
the fact that xfs_buf_ioacct_dec() is called from xfs_buf_rele()
(where the buffer lock is no longer held) means that bp->b_flags can
be updated from an unsafe context. While a user-level reproducer is
currently not available, some intrusive hacks to run racing buffer
lookups/ioacct/releases from multiple threads was used to
successfully manufacture this problem.

Existing callers do not expect to acquire the buffer lock from
xfs_buf_rele(). Therefore, we can not safely update ->b_flags from
this context. It turns out that we already have separate buffer
state bits and associated serialization for dealing with buffer LRU
state in the form of ->b_state and ->b_lock. Therefore, replace the
_XBF_IN_FLIGHT flag with a ->b_state variant, update the I/O
accounting wrappers appropriately and make sure they are used with
the correct locking. This ensures that buffer in-flight state can be
modified at buffer release time without racing with modifications
from a buffer lock holder.

Fixes: 9c7504aa72b6 ("xfs: track and serialize in-flight async buffers against unmount")
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Libor Pechacek <lpechacek@suse.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
6 years agodm: make flush bios explicitly sync
Jan Kara [Wed, 31 May 2017 07:44:32 +0000 (09:44 +0200)]
dm: make flush bios explicitly sync

Commit b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as
synchronous") removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions.

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

Fixes: b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as synchronous")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
6 years agoALSA: usb: Avoid VLA in mixer_us16x08.c
Takashi Iwai [Tue, 30 May 2017 21:24:45 +0000 (23:24 +0200)]
ALSA: usb: Avoid VLA in mixer_us16x08.c

This is another attempt to work around the VLA used in
mixer_us16x08.c.  Basically the temporary array is used individually
for two cases, and we can declare locally in each block, instead of
hackish max() usage.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
6 years agoALSA: usb: Fix a typo in Tascam US-16x08 mixer element
Takashi Iwai [Tue, 30 May 2017 21:21:07 +0000 (23:21 +0200)]
ALSA: usb: Fix a typo in Tascam US-16x08 mixer element

A mixer element created in a quirk for Tascam US-16x08 contains a
typo: it should be "EQ MidLow Q" instead of "EQ MidQLow Q".

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195875
Fixes: d2bb390a2081 ("ALSA: usb-audio: Tascam US-16x08 DSP mixer quirk")
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
6 years agoRevert "ALSA: usb-audio: purge needless variable length array"
Takashi Iwai [Tue, 30 May 2017 07:23:41 +0000 (09:23 +0200)]
Revert "ALSA: usb-audio: purge needless variable length array"

This reverts commit 89b593c30e83 ("ALSA: usb-audio: purge needless
variable length array").  The patch turned out to cause a severe
regression, triggering an Oops at snd_usb_ctl_msg().  It was overseen
that snd_usb_ctl_msg() writes back the response to the given buffer,
while the patch changed it to a read-only const buffer.  (One should
always double-check when an extra pointer cast is present...)

As a simple fix, just revert the affected commit.  It was merely a
cleanup.  Although it brings VLA again, it's clearer as a fix.  We'll
address the VLA later in another patch.

Fixes: 89b593c30e83 ("ALSA: usb-audio: purge needless variable length array")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195875
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
6 years ago"Yes, people use FOLL_FORCE ;)"
Linus Torvalds [Tue, 30 May 2017 19:38:59 +0000 (12:38 -0700)]
"Yes, people use FOLL_FORCE ;)"

This effectively reverts commit 8ee74a91ac30 ("proc: try to remove use
of FOLL_FORCE entirely")

It turns out that people do depend on FOLL_FORCE for the /proc/<pid>/mem
case, and we're talking not just debuggers. Talking to the affected people, the use-cases are:

Keno Fischer:
 "We used these semantics as a hardening mechanism in the julia JIT. By
  opening /proc/self/mem and using these semantics, we could avoid
  needing RWX pages, or a dual mapping approach. We do have fallbacks to
  these other methods (though getting EIO here actually causes an assert
  in released versions - we'll updated that to make sure to take the
  fall back in that case).

  Nevertheless the /proc/self/mem approach was our favored approach
  because it a) Required an attacker to be able to execute syscalls
  which is a taller order than getting memory write and b) didn't double
  the virtual address space requirements (as a dual mapping approach
  would).

  I think in general this feature is very useful for anybody who needs
  to precisely control the execution of some other process. Various
  debuggers (gdb/lldb/rr) certainly fall into that category, but there's
  another class of such processes (wine, various emulators) which may
  want to do that kind of thing.

  Now, I suspect most of these will have the other process under ptrace
  control, so maybe allowing (same_mm || ptraced) would be ok, but at
  least for the sandbox/remote-jit use case, it would be perfectly
  reasonable to not have the jit server be a ptracer"

Robert O'Callahan:
 "We write to readonly code and data mappings via /proc/.../mem in lots
  of different situations, particularly when we're adjusting program
  state during replay to match the recorded execution.

  Like Julia, we can add workarounds, but they could be expensive."

so not only do people use FOLL_FORCE for both reads and writes, but they
use it for both the local mm and remote mm.

With these comments in mind, we likely also cannot add the "are we
actively ptracing" check either, so this keeps the new code organization
and does not do a real revert that would add back the original comment
about "Maybe we should limit FOLL_FORCE to actual ptrace users?"

Reported-by: Keno Fischer <keno@juliacomputing.com>
Reported-by: Robert O'Callahan <robert@ocallahan.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>