linux-stable.git, branch v4.16.8

Linux 4.16.8

2018-05-09T07:53:14+00:00

tracing: Fix bad use of igrab in trace_uprobe.c

2018-05-09T07:53:13+00:00

commit 0c92c7a3c5d416f47b32c5f20a611dfeca5d5f2e upstream.

As Miklos reported and suggested:

  This pattern repeats two times in trace_uprobe.c and in
  kernel/events/core.c as well:

      ret = kern_path(filename, LOOKUP_FOLLOW, &path);
      if (ret)
          goto fail_address_parse;

      inode = igrab(d_inode(path.dentry));
      path_put(&path);

  And it's wrong.  You can only hold a reference to the inode if you
  have an active ref to the superblock as well (which is normally
  through path.mnt) or holding s_umount.

  This way unmounting the containing filesystem while the tracepoint is
  active will give you the "VFS: Busy inodes after unmount..." message
  and a crash when the inode is finally put.

  Solution: store path instead of inode.

This patch fixes two instances in trace_uprobe.c. struct path is added to
struct trace_uprobe to keep the inode and containing mount point
referenced.

Link: http://lkml.kernel.org/r/20180423172135.4050588-1-songliubraving@fb.com

Fixes: f3f096cfedf8 ("tracing: Provide trace events interface for uprobes")
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
Cc: stable@vger.kernel.org
Cc: Ingo Molnar 
Cc: Howard McLauchlan 
Cc: Josef Bacik 
Cc: Srikar Dronamraju 
Acked-by: Miklos Szeredi 
Reported-by: Miklos Szeredi 
Signed-off-by: Song Liu 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

clocksource: Consistent de-rate when marking unstable

2018-05-09T07:53:13+00:00

commit cd2af07d823e5287cd6c91d54337348c2a873462 upstream.

When a registered clocksource gets marked unstable the watchdog_kthread
will de-rate and re-select the clocksource. Ensure it also de-rates
when getting called on an unregistered clocksource.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Rafael J. Wysocki 
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: diego.viola@gmail.com
Cc: rui.zhang@intel.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180430100344.594904898@infradead.org
Signed-off-by: Greg Kroah-Hartman

clocksource: Initialize cs->wd_list

2018-05-09T07:53:13+00:00

commit 5b9e886a4af97574ca3ce1147f35545da0e7afc7 upstream.

A number of places relies on list_empty(&cs->wd_list), however the
list_head does not get initialized. Do so upon registration, such that
thereafter it is possible to rely on list_empty() correctly reflecting
the list membership status.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Tested-by: Diego Viola 
Reviewed-by: Rafael J. Wysocki 
Cc: stable@vger.kernel.org
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20180430100344.472662715@infradead.org
Signed-off-by: Greg Kroah-Hartman

clocksource: Allow clocksource_mark_unstable() on unregistered clocksources

2018-05-09T07:53:13+00:00

commit 2aae7bcfa4104b770e6f612356adb8d66c6144d6 upstream.

Because of how the code flips between tsc-early and tsc clocksources
it might need to mark one or both unstable. The current code in
mark_tsc_unstable() only worked because previously it registered the
tsc clocksource once and then never touched it.

Since it now unregisters the tsc-early clocksource, it needs to know
if a clocksource got unregistered and the current cs->mult test
doesn't work for that. Instead use list_empty(&cs->list) to test for
registration.

Furthermore, since clocksource_mark_unstable() needs to place the cs
on the wd_list, it links the cs->list and cs->wd_list serialization.
It must not see a clocsource registered (!empty cs->list) but already
past dequeue_watchdog(). So place {en,de}queue{,_watchdog}() under the
same lock.

Provided cs->list is initialized to empty, this then allows us to
unconditionally use clocksource_mark_unstable(), regardless of the
registration state.

Fixes: aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource")
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Rafael J. Wysocki 
Tested-by: Diego Viola 
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: diego.viola@gmail.com
Cc: rui.zhang@intel.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180502135312.GS12217@hirez.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman

irqchip/qcom: Fix check for spurious interrupts

2018-05-09T07:53:13+00:00

commit 1bc2463cee92ef0e2034c813d5e511adeb58b5fd upstream.

When the interrupts for a combiner span multiple registers it must be
checked if any interrupts have been asserted on each register before
checking for spurious interrupts.

Checking each register seperately leads to false positive warnings.

[ tglx: Massaged changelog ]

Fixes: f20cc9b00c7b ("irqchip/qcom: Add IRQ combiner driver")
Signed-off-by: Agustin Vega-Frias 
Signed-off-by: Thomas Gleixner 
Cc: Jason Cooper 
Cc: Marc Zyngier 
Cc: timur@codeaurora.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1525184090-26143-1-git-send-email-agustinv@codeaurora.org
Signed-off-by: Greg Kroah-Hartman

x86/tsc: Fix mark_tsc_unstable()

2018-05-09T07:53:12+00:00

commit e3b4f79025e0a4eb7e2a2c7d24dadfa1e38893b0 upstream.

mark_tsc_unstable() also needs to affect tsc_early, Now that
clocksource_mark_unstable() can be used on a clocksource irrespective of
its registration state, use it on both tsc_early and tsc.

This does however require cs->list to be initialized empty, otherwise it
cannot tell the registation state before registation.

Fixes: aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource")
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Tested-by: Diego Viola 
Reviewed-by: Rafael J. Wysocki 
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: rui.zhang@intel.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180430100344.533326547@infradead.org
Signed-off-by: Greg Kroah-Hartman

x86/tsc: Always unregister clocksource_tsc_early

2018-05-09T07:53:12+00:00

commit e9088adda13cd23249d4b0abb97ff8a81bf5573a upstream.

Don't leave the tsc-early clocksource registered if it errors out
early.

This was reported by Diego, who on his Core2 era machine got TSC
invalidated while it was running with tsc-early (due to C-states).
This results in keeping tsc-early with very bad effects.

Reported-and-Tested-by: Diego Viola 
Fixes: aa83c45762a2 ("x86/tsc: Introduce early tsc clocksource")
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Rafael J. Wysocki 
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: diego.viola@gmail.com
Cc: rui.zhang@intel.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180430100344.350507853@infradead.org
Signed-off-by: Greg Kroah-Hartman

KVM: x86: remove APIC Timer periodic/oneshot spikes

2018-05-09T07:53:12+00:00

commit ecf08dad723d3e000aecff6c396f54772d124733 upstream.

Since the commit "8003c9ae204e: add APIC Timer periodic/oneshot mode VMX
preemption timer support", a Windows 10 guest has some erratic timer
spikes.

Here the results on a 150000 times 1ms timer without any load:
	  Before 8003c9ae204e | After 8003c9ae204e
Max           1834us          |  86000us
Mean          1100us          |   1021us
Deviation       59us          |    149us
Here the results on a 150000 times 1ms timer with a cpu-z stress test:
	  Before 8003c9ae204e | After 8003c9ae204e
Max          32000us          | 140000us
Mean          1006us          |   1997us
Deviation      140us          |  11095us

The root cause of the problem is starting hrtimer with an expiry time
already in the past can take more than 20 milliseconds to trigger the
timer function.  It can be solved by forward such past timers
immediately, rather than submitting them to hrtimer_start().
In case the timer is periodic, update the target expiration and call
hrtimer_start with it.

v2: Check if the tsc deadline is already expired. Thank you Mika.
v3: Execute the past timers immediately rather than submitting them to
hrtimer_start().
v4: Rearm the periodic timer with advance_periodic_target_expiration() a
simpler version of set_target_expiration(). Thank you Paolo.

Cc: Mika Penttilä 
Cc: Wanpeng Li 
Cc: Paolo Bonzini 
Cc: stable@vger.kernel.org
Signed-off-by: Anthoine Bourgeois 
8003c9ae204e ("KVM: LAPIC: add APIC Timer periodic/oneshot mode VMX preemption timer support")
Signed-off-by: Radim Krčmář 
Signed-off-by: Greg Kroah-Hartman

platform/x86: Kconfig: Fix dell-laptop dependency chain.

2018-05-09T07:53:12+00:00

commit 7fe3fa3b5ec8e75389cce4bf5d052a52e6198d59 upstream.

As reported by Randy Dunlap:
>> WARNING: unmet direct dependencies detected for DELL_SMBIOS
>>   Depends on [m]: X86 [=y] && X86_PLATFORM_DEVICES [=y]
>>	&& (DCDBAS [=m] ||
>> DCDBAS [=m]=n) && (ACPI_WMI [=n] || ACPI_WMI [=n]=n)
>>   Selected by [y]:
>>   - DELL_LAPTOP [=y] && X86 [=y] && X86_PLATFORM_DEVICES [=y]
>> && DMI [=y]
>> && BACKLIGHT_CLASS_DEVICE [=y] && (ACPI_VIDEO [=n] ||
>>	ACPI_VIDEO [=n]=n)
>> && (RFKILL [=n] || RFKILL [=n]=n) && SERIO_I8042 [=y]
>>

Right now it's possible to set dell laptop to compile in but this
causes dell-smbios to compile in which breaks if dcdbas is a module.

Dell laptop shouldn't select dell-smbios anymore, but depend on it.

Fixes: 32d7b19bad96 (platform/x86: dell-smbios: Resolve dependency error on DCDBAS)
Reported-by: Randy Dunlap 
Signed-off-by: Mario Limonciello 
Cc: stable@vger.kernel.org
Signed-off-by: Darren Hart (VMware) 
Signed-off-by: Greg Kroah-Hartman