Commit Graph

17202 Commits

Author SHA1 Message Date
Greg Kurz
ac64115a66 KVM: PPC: Fix oops when checking KVM_CAP_PPC_HTM
The following program causes a kernel oops:

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/kvm.h>

main()
{
    int fd = open("/dev/kvm", O_RDWR);
    ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_PPC_HTM);
}

This happens because when using the global KVM fd with
KVM_CHECK_EXTENSION, kvm_vm_ioctl_check_extension() gets
called with a NULL kvm argument, which gets dereferenced
in is_kvmppc_hv_enabled(). Spotted while reading the code.

Let's use the hv_enabled fallback variable, like everywhere
else in this function.

Fixes: 23528bb21e ("KVM: PPC: Introduce KVM_CAP_PPC_HTM")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-10-14 11:32:53 +11:00
Linus Torvalds
8d473320ee KVM fixes for v4.14-rc4
- fix PPC XIVE interrupt delivery
 - fix x86 RCU breakage from asynchronous page faults when built without
   PREEMPT_COUNT
 - fix x86 build with -frecord-gcc-switches
 - fix x86 build without X86_LOCAL_APIC
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:

 - fix PPC XIVE interrupt delivery

 - fix x86 RCU breakage from asynchronous page faults when built without
   PREEMPT_COUNT

 - fix x86 build with -frecord-gcc-switches

 - fix x86 build without X86_LOCAL_APIC

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: add X86_LOCAL_APIC dependency
  x86/kvm: Move kvm_fastop_exception to .fixup section
  kvm/x86: Avoid async PF preempting the kernel incorrectly
  KVM: PPC: Book3S: Fix server always zero from kvmppc_xive_get_xive()
2017-10-06 11:28:34 -07:00
Linus Torvalds
1249b571ba powerpc fixes for 4.14 #4
Nine small fixes, really nothing that stands out.
 
 A work around for a spurious MCE on Power9. A CXL fault handling fix, some fixes
 to the new XIVE code, and a fix to the new 32-bit STRICT_KERNEL_RWX code.
 
 Fixes for old code/stable: an fix to an incorrect TLB flush on boot but not on
 any current machines, a compile error on 4xx and a fix to memory hotplug when
 using radix (Power9).
 
 Thanks to:
   Anton Blanchard, Cédric Le Goater, Christian Lamparter, Christophe Leroy,
   Christophe Lombard, Guenter Roeck, Jeremy Kerr, Michael Neuling, Nicholas
   Piggin.
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Merge tag 'powerpc-4.14-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Nine small fixes, really nothing that stands out.

  A work-around for a spurious MCE on Power9. A CXL fault handling fix,
  some fixes to the new XIVE code, and a fix to the new 32-bit
  STRICT_KERNEL_RWX code.

  Fixes for old code/stable: an fix to an incorrect TLB flush on boot
  but not on any current machines, a compile error on 4xx and a fix to
  memory hotplug when using radix (Power9).

  Thanks to: Anton Blanchard, Cédric Le Goater, Christian Lamparter,
  Christophe Leroy, Christophe Lombard, Guenter Roeck, Jeremy Kerr,
  Michael Neuling, Nicholas Piggin"

* tag 'powerpc-4.14-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powernv: Increase memory block size to 1GB on radix
  powerpc/mm: Call flush_tlb_kernel_range with interrupts enabled
  powerpc/xive: Clear XIVE internal structures when a CPU is removed
  powerpc/xive: Fix IPI reset
  powerpc/4xx: Fix compile error with 64K pages on 40x, 44x
  powerpc: Fix action argument for cpufeatures-based TLB flush
  cxl: Fix memory page not handled
  powerpc: Fix workaround for spurious MCE on POWER9
  powerpc: Handle MCE on POWER9 with only DSISR bit 30 set
2017-10-06 08:47:21 -07:00
Linus Torvalds
27efed3e83 Merge branch 'core-watchdog-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull watchddog clean-up and fixes from Thomas Gleixner:
 "The watchdog (hard/softlockup detector) code is pretty much broken in
  its current state. The patch series addresses this by removing all
  duct tape and refactoring it into a workable state.

  The reasons why I ask for inclusion that late in the cycle are:

   1) The code causes lockdep splats vs. hotplug locking which get
      reported over and over. Unfortunately there is no easy fix.

   2) The risk of breakage is minimal because it's already broken

   3) As 4.14 is a long term stable kernel, I prefer to have working
      watchdog code in that and the lockdep issues resolved. I wouldn't
      ask you to pull if 4.14 wouldn't be a LTS kernel or if the
      solution would be easy to backport.

   4) The series was around before the merge window opened, but then got
      delayed due to the UP failure caused by the for_each_cpu()
      surprise which we discussed recently.

  Changes vs. V1:

   - Addressed your review points

   - Addressed the warning in the powerpc code which was discovered late

   - Changed two function names which made sense up to a certain point
     in the series. Now they match what they do in the end.

   - Fixed a 'unused variable' warning, which got not detected by the
     intel robot. I triggered it when trying all possible related config
     combinations manually. Randconfig testing seems not random enough.

  The changes have been tested by and reviewed by Don Zickus and tested
  and acked by Micheal Ellerman for powerpc"

* 'core-watchdog-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  watchdog/core: Put softlockup_threads_initialized under ifdef guard
  watchdog/core: Rename some softlockup_* functions
  powerpc/watchdog: Make use of watchdog_nmi_probe()
  watchdog/core, powerpc: Lock cpus across reconfiguration
  watchdog/core, powerpc: Replace watchdog_nmi_reconfigure()
  watchdog/hardlockup/perf: Fix spelling mistake: "permanetely" -> "permanently"
  watchdog/hardlockup/perf: Cure UP damage
  watchdog/hardlockup: Clean up hotplug locking mess
  watchdog/hardlockup/perf: Simplify deferred event destroy
  watchdog/hardlockup/perf: Use new perf CPU enable mechanism
  watchdog/hardlockup/perf: Implement CPU enable replacement
  watchdog/hardlockup/perf: Implement init time detection of perf
  watchdog/hardlockup/perf: Implement init time perf validation
  watchdog/core: Get rid of the racy update loop
  watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage
  watchdog/sysctl: Clean up sysctl variable name space
  watchdog/sysctl: Get rid of the #ifdeffery
  watchdog/core: Clean up header mess
  watchdog/core: Further simplify sysctl handling
  watchdog/core: Get rid of the thread teardown/setup dance
  ...
2017-10-06 08:36:41 -07:00
Anton Blanchard
53ecde0b91 powerpc/powernv: Increase memory block size to 1GB on radix
Memory hot unplug on PowerNV radix hosts is broken. Our memory block
size is 256MB but since we map the linear region with very large
pages, each pte we tear down maps 1GB.

A hot unplug of one 256MB memory block results in 768MB of memory
getting unintentionally unmapped. At this point we are likely to oops.

Fix this by increasing our memory block size to 1GB on PowerNV radix
hosts.

Fixes: 4b5d62ca17 ("powerpc/mm: add radix__remove_section_mapping()")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-06 15:50:45 +11:00
Guenter Roeck
7c6a4f3b16 powerpc/mm: Call flush_tlb_kernel_range with interrupts enabled
flush_tlb_kernel_range() may call smp_call_function_many() which expects
interrupts to be enabled. This results in a traceback.

WARNING: CPU: 0 PID: 1 at kernel/smp.c:416 smp_call_function_many+0xcc/0x2fc
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc1-00009-g0666f56 #1
task: cf830000 task.stack: cf82e000
NIP:  c00a93c8 LR: c00a9634 CTR: 00000001
REGS: cf82fde0 TRAP: 0700   Not tainted  (4.14.0-rc1-00009-g0666f56)
MSR:  00021000 <CE,ME>  CR: 24000082  XER: 00000000

GPR00: c00a9634 cf82fe90 cf830000 c050ad3c c0015a54 00000000 00000001 00000001
GPR08: 00000001 00000000 00000000 cf82e000 24000084 00000000 c0003150 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000001 00000000 c0510000
GPR24: 00000000 c0015a54 00000000 c050ad3c c051823c c050ad3c 00000025 00000000
NIP [c00a93c8] smp_call_function_many+0xcc/0x2fc
LR [c00a9634] smp_call_function+0x3c/0x50
Call Trace:
[cf82fe90] [00000010] 0x10 (unreliable)
[cf82fed0] [c00a9634] smp_call_function+0x3c/0x50
[cf82fee0] [c0015d2c] flush_tlb_kernel_range+0x20/0x38
[cf82fef0] [c001524c] mark_initmem_nx+0x154/0x16c
[cf82ff20] [c001484c] free_initmem+0x20/0x4c
[cf82ff30] [c000316c] kernel_init+0x1c/0x108
[cf82ff40] [c000f3a8] ret_from_kernel_thread+0x5c/0x64
Instruction dump:
7c0803a6 7d808120 38210040 4e800020 3d20c052 812981a0 2f890000 40beffac
3d20c051 8929ac64 2f890000 40beff9c <0fe00000> 4bffff94 7fc3f378 7f64db78

Fixes: 3184cc4b6f ("powerpc/mm: Fix kernel RAM protection after freeing ...")
Fixes: e611939fc8 ("powerpc/mm: Ensure change_page_attr() doesn't ...")
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04 22:15:30 +11:00
Cédric Le Goater
cc56939802 powerpc/xive: Clear XIVE internal structures when a CPU is removed
Commit eac1e731b5 ("powerpc/xive: guest exploitation of the XIVE
interrupt controller") introduced support for the XIVE exploitation
mode of the P9 interrupt controller on the pseries platform.

At that time, support for CPU removal was not complete on PowerVM and
CPU hot unplug remained untested. It appears that some cleanups of the
XIVE internal structures are required before releasing the CPU,
without which the kernel crashes in a RTAS call doing the CPU
isolation.

These changes fix the crash by deconfiguring the IPI interrupt source
and clearing the event queues of the CPU when it is removed.

Fixes: eac1e731b5 ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04 22:01:57 +11:00
Cédric Le Goater
74f1282114 powerpc/xive: Fix IPI reset
When resetting an IPI, hw_ipi should also be set to zero.

Fixes: eac1e731b5 ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-04 22:01:15 +11:00
Thomas Gleixner
34ddaa3e5c powerpc/watchdog: Make use of watchdog_nmi_probe()
The rework of the core hotplug code triggers the WARN_ON in start_wd_cpu()
on powerpc because it is called multiple times for the boot CPU.

The first call is via:

  start_wd_on_cpu+0x80/0x2f0
  watchdog_nmi_reconfigure+0x124/0x170
  softlockup_reconfigure_threads+0x110/0x130
  lockup_detector_init+0xbc/0xe0
  kernel_init_freeable+0x18c/0x37c
  kernel_init+0x2c/0x160
  ret_from_kernel_thread+0x5c/0xbc

And then again via the CPU hotplug registration:

  start_wd_on_cpu+0x80/0x2f0
  cpuhp_invoke_callback+0x194/0x620
  cpuhp_thread_fun+0x7c/0x1b0
  smpboot_thread_fn+0x290/0x2a0
  kthread+0x168/0x1b0
  ret_from_kernel_thread+0x5c/0xbc

This can be avoided by setting up the cpu hotplug state with nocalls and
move the initialization to the watchdog_nmi_probe() function. That
initializes the hotplug callbacks without invoking the callback and the
following core initialization function then configures the watchdog for the
online CPUs (in this case CPU0) via softlockup_reconfigure_threads().

Reported-and-tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
2017-10-04 10:53:54 +02:00
Thomas Gleixner
e31d6883f2 watchdog/core, powerpc: Lock cpus across reconfiguration
Instead of dropping the cpu hotplug lock after stopping NMI watchdog and
threads and reaquiring for restart, the code and the protection rules
become more obvious when holding cpu hotplug lock across the full
reconfiguration.

Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710022105570.2114@nanos
2017-10-04 10:53:54 +02:00
Thomas Gleixner
6b9dc4806b watchdog/core, powerpc: Replace watchdog_nmi_reconfigure()
The recent cleanup of the watchdog code split watchdog_nmi_reconfigure()
into two stages. One to stop the NMI and one to restart it after
reconfiguration. That was done by adding a boolean 'run' argument to the
code, which is functionally correct but not necessarily a piece of art.

Replace it by two explicit functions: watchdog_nmi_stop() and
watchdog_nmi_start().

Fixes: 6592ad2fcc ("watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage")
Requested-by: Linus 'Nursing his pet-peeve' Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Thomas 'Mopping up garbage' Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710021957480.2114@nanos
2017-10-04 10:53:53 +02:00
Ioan Nicu
31d1e130f4 rapidio: remove global irq spinlocks from the subsystem
Locking of config and doorbell operations should be done only if the
underlying hardware requires it.

This patch removes the global spinlocks from the rapidio subsystem and
moves them to the mport drivers (fsl_rio and tsi721), only to the
necessary places.  For example, local config space read and write
operations (lcread/lcwrite) are atomic in all existing drivers, so there
should be no need for locking, while the cread/cwrite operations which
generate maintenance transactions need to be synchronized with a lock.

Later, each driver could chose to use a per-port lock instead of a
global one, or even more granular locking.

Link: http://lkml.kernel.org/r/20170824113023.GD50104@nokia.com
Signed-off-by: Ioan Nicu <ioan.nicu.ext@nokia.com>
Signed-off-by: Frank Kunz <frank.kunz@nokia.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:24 -07:00
Sam Bobroff
2fb1e94645 KVM: PPC: Book3S: Fix server always zero from kvmppc_xive_get_xive()
In KVM's XICS-on-XIVE emulation, kvmppc_xive_get_xive() returns the
value of state->guest_server as "server". However, this value is not
set by it's counterpart kvmppc_xive_set_xive(). When the guest uses
this interface to migrate interrupts away from a CPU that is going
offline, it sees all interrupts as belonging to CPU 0, so they are
left assigned to (now) offline CPUs.

This patch removes the guest_server field from the state, and returns
act_server in it's place (that is, the CPU actually handling the
interrupt, which may differ from the one requested).

Fixes: 5af5099385 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Cc: stable@vger.kernel.org
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-10-03 17:58:16 +02:00
Christian Lamparter
070e004912 powerpc/4xx: Fix compile error with 64K pages on 40x, 44x
The mmu context on the 40x, 44x does not define pte_frag entry. This
causes gcc abort the compilation due to:

  setup-common.c: In function ‘setup_arch’:
  setup-common.c:908: error: ‘mm_context_t’ has no ‘pte_frag’

This patch fixes the issue by removing the pte_frag initialization in
setup-common.c.

This is possible, because the compiler will do the initialization,
since the mm_context is a sub struct of init_mm. init_mm is declared
in mm_types.h as external linkage.

According to C99 6.2.4.3:
  An object whose identifier is declared with external linkage
  [...] has static storage duration.

C99 defines in 6.7.8.10 that:
  If an object that has static storage duration is not
  initialized explicitly, then:
  - if it has pointer type, it is initialized to a null pointer

Fixes: b1923caa6e ("powerpc: Merge 32-bit and 64-bit setup_arch()")
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-03 21:59:48 +11:00
Jeremy Kerr
3b7af5c0fd powerpc: Fix action argument for cpufeatures-based TLB flush
Commit 41d0c2ecde ("powerpc/powernv: Fix local TLB flush for boot
and MCE on POWER9") introduced calls to __flush_tlb_power[89] from the
cpufeatures code, specifying the number of sets to flush.

However, these functions take an action argument, not a number of
sets. This means we hit the BUG() in __flush_tlb_{206,300} when using
cpufeatures-style configuration.

This change passes TLB_INVAL_SCOPE_GLOBAL instead.

Fixes: 41d0c2ecde ("powerpc/powernv: Fix local TLB flush for boot and MCE on POWER9")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-10-03 16:16:55 +11:00
Linus Torvalds
42057e1825 Mixed bugfixes. Perhaps the most interesting one is a latent bug
that was finally triggered by PCID support.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Mixed bugfixes. Perhaps the most interesting one is a latent bug that
  was finally triggered by PCID support"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm/x86: Handle async PF in RCU read-side critical sections
  KVM: nVMX: Fix nested #PF intends to break L1's vmlauch/vmresume
  KVM: VMX: use cmpxchg64
  KVM: VMX: simplify and fix vmx_vcpu_pi_load
  KVM: VMX: avoid double list add with VT-d posted interrupts
  KVM: VMX: extract __pi_post_block
  KVM: PPC: Book3S HV: Check for updated HDSISR on P9 HDSI exception
  KVM: nVMX: fix HOST_CR3/HOST_CR4 cache
2017-09-29 12:18:55 -07:00
Michael Neuling
bca73f595a powerpc: Fix workaround for spurious MCE on POWER9
In the recent commit d8bd9f3f09 ("powerpc: Handle MCE on POWER9 with
only DSISR bit 30 set") I screwed up the bit number. It should be bit
25 (IBM bit 38).

Fixes: d8bd9f3f09 ("powerpc: Handle MCE on POWER9 with only DSISR bit 30 set")
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-29 14:19:44 +10:00
Michael Neuling
d8bd9f3f09 powerpc: Handle MCE on POWER9 with only DSISR bit 30 set
On POWER9 DD2.1 and below, it's possible for a paste instruction to
cause a Machine Check Exception (MCE) where only DSISR bit 30 (IBM 33)
is set. This will result in the MCE handler seeing an unknown event,
which triggers linux to crash.

We change this by detecting unknown events caused by load/stores in
the MCE handler and marking them as handled so that we no longer
crash.

An MCE that occurs like this is spurious, so we don't need to do
anything in terms of servicing it. If there is something that needs to
be serviced, the CPU will raise the MCE again with the correct DSISR
so that it can be serviced properly.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com
Acked-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Expand comment with details from change log, use normal bit #s]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-26 21:01:59 +10:00
Michael Neuling
e001fa78d4 KVM: PPC: Book3S HV: Check for updated HDSISR on P9 HDSI exception
On POWER9 DD2.1 and below, sometimes on a Hypervisor Data Storage
Interrupt (HDSI) the HDSISR is not be updated at all.

To work around this we put a canary value into the HDSISR before
returning to a guest and then check for this canary when we take a
HDSI. If we find the canary on a HDSI, we know the hardware didn't
update the HDSISR. In this case we return to the guest to retake the
HDSI which should correctly update the HDSISR the second time HDSI
entry.

After talking to Paulus we've applied this workaround to all POWER9
CPUs. The workaround of returning to the guest shouldn't ever be
triggered on well behaving CPU. The extra instructions should have
negligible performance impact.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-22 10:45:46 +02:00
Tyrel Datwyler
b537ca6fed powerpc/pseries: Fix parent_dn reference leak in add_dt_node()
A reference to the parent device node is held by add_dt_node() for the
node to be added. If the call to dlpar_configure_connector() fails
add_dt_node() returns ENOENT and that reference is not freed.

Add a call to of_node_put(parent_dn) prior to bailing out after a
failed dlpar_configure_connector() call.

Fixes: 8d5ff32076 ("powerpc/pseries: Make dlpar_configure_connector parent node aware")
Cc: stable@vger.kernel.org # v3.12+
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-21 19:33:16 +10:00
Tyrel Datwyler
087ff6a5ae powerpc/pseries: Fix "OF: ERROR: Bad of_node_put() on /cpus" during DLPAR
Commit 215ee763f8 ("powerpc: pseries: remove dlpar_attach_node
dependency on full path") reworked dlpar_attach_node() to no longer
look up the parent node "/cpus", but instead to have the parent node
passed by the caller in the function parameter list.

As a result dlpar_attach_node() is no longer responsible for freeing
the reference to the parent node. However, commit 215ee763f8 failed
to remove the of_node_put(parent) call in dlpar_attach_node(), or to
take into account that the reference to the parent in the caller
dlpar_cpu_add() needs to be held until after dlpar_attach_node()
returns.

As a result doing repeated cpu add/remove dlpar operations will
eventually result in the following error:

  OF: ERROR: Bad of_node_put() on /cpus
  CPU: 0 PID: 10896 Comm: drmgr Not tainted 4.13.0-autotest #1
  Call Trace:
   dump_stack+0x15c/0x1f8 (unreliable)
   of_node_release+0x1a4/0x1c0
   kobject_put+0x1a8/0x310
   kobject_del+0xbc/0xf0
   __of_detach_node_sysfs+0x144/0x210
   of_detach_node+0xf0/0x180
   dlpar_detach_node+0xc4/0x120
   dlpar_cpu_remove+0x280/0x560
   dlpar_cpu_release+0xbc/0x1b0
   arch_cpu_release+0x6c/0xb0
   cpu_release_store+0xa0/0x100
   dev_attr_store+0x68/0xa0
   sysfs_kf_write+0xa8/0xf0
   kernfs_fop_write+0x2cc/0x400
   __vfs_write+0x5c/0x340
   vfs_write+0x1a8/0x3d0
   SyS_write+0xa8/0x1a0
   system_call+0x58/0x6c

Fix the issue by removing the of_node_put(parent) call from
dlpar_attach_node(), and ensuring that the reference to the parent
node is properly held and released by the caller dlpar_cpu_add().

Fixes: 215ee763f8 ("powerpc: pseries: remove dlpar_attach_node dependency on full path")
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
[mpe: Add a comment in the code and frob the change log slightly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-21 19:30:53 +10:00
Benjamin Herrenschmidt
3e77adeea3 powerpc/eeh: Create PHB PEs after EEH is initialized
Otherwise we end up not yet having computed the right diag data size
on powernv where EEH initialization is delayed, thus causing memory
corruption later on when calling OPAL.

Fixes: 5cb1f8fddd ("powerpc/powernv/pci: Dynamically allocate PHB diag data")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-21 14:56:00 +10:00
Naveen N. Rao
8afafa6fba powerpc/kprobes: Update optprobes to use emulate_update_regs()
Optprobes depended on an updated regs->nip from analyse_instr() to
identify the location to branch back from the optprobes trampoline.
However, since commit 3cdfcbfd32 ("powerpc: Change analyse_instr so
it doesn't modify *regs"), analyse_instr() doesn't update the registers
anymore.  Due to this, we end up branching back from the optprobes
trampoline to the same branch into the trampoline resulting in a loop.

Fix this by calling out to emulate_update_regs() before using the nip.
Additionally, explicitly compare the return value from analyse_instr()
to 1, rather than just checking for !0 so as to guard against any
future changes to analyse_instr() that may result in -1 being returned
in more scenarios.

Fixes: 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 20:21:24 +10:00
Michael Ellerman
b134165ead Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into fixes
Merge one commit from Scott which I missed while away.
2017-09-20 20:05:24 +10:00
Gautham R. Shenoy
5d298baa41 powerpc/powernv: Clear LPCR[PECE1] via stop-api only for deep state offline
Commit 24be85a23d ("powerpc/powernv: Clear PECE1 in LPCR via
stop-api only on Hotplug") clears the PECE1 bit of the LPCR via
stop-api during CPU-Hotplug to prevent wakeup due to a decrementer on
an offlined CPU which is in a deep stop state.

In the case where the stop-api support is found to be lacking, the
commit 785a12afdb ("powerpc/powernv/idle: Disable LOSE_FULL_CONTEXT
states when stop-api fails") disables deep states that lose hypervisor
context. Thus in this case, the offlined CPU will be put to some
shallow idle state.

However, we currently unconditionally clear the PECE1 in LPCR via
stop-api during CPU-Hotplug even when deep states are disabled due to
stop-api failure.

Fix this by clearing PECE1 of LPCR via stop-api during CPU-Hotplug
*only* when the offlined CPU will be put to a deep state that loses
hypervisor context.

Fixes: 24be85a23d ("powerpc/powernv: Clear PECE1 in LPCR via stop-api only on Hotplug")
Reported-by: Pavithra Prakash <pavirampu@linux.vnet.ibm.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Pavithra Prakash <pavrampu@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Anton Blanchard
1575fe06f6 powerpc/sstep: mullw should calculate a 64 bit signed result
mullw should do a 32 bit signed multiply and create a 64 bit signed
result. It currently truncates the result to 32 bits.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Anton Blanchard
5bcaa4cc41 powerpc/sstep: Fix issues with mcrf
mcrf broke when we changed analyse_instr() to not modify the register
state. The instruction writes to the CR, so we need to store the result
in op->ccval, not op->val.

Fixes: 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Anton Blanchard
ad47ff3e33 powerpc/sstep: Fix issues with set_cr0()
set_cr0() broke when we changed analyse_instr() to not modify the
register state. Instead of looking at regs->gpr[x] which has not
been updated yet, we need to look at op->val.

Fixes: 3cdfcbfd32 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Gustavo Romero
c1fa0768a8 powerpc/tm: Flush TM only if CPU has TM feature
Commit cd63f3c ("powerpc/tm: Fix saving of TM SPRs in core dump")
added code to access TM SPRs in flush_tmregs_to_thread(). However
flush_tmregs_to_thread() does not check if TM feature is available on
CPU before trying to access TM SPRs in order to copy live state to
thread structures. flush_tmregs_to_thread() is indeed guarded by
CONFIG_PPC_TRANSACTIONAL_MEM but it might be the case that kernel
was compiled with CONFIG_PPC_TRANSACTIONAL_MEM enabled and ran on
a CPU without TM feature available, thus rendering the execution
of TM instructions that are treated by the CPU as illegal instructions.

The fix is just to add proper checking in flush_tmregs_to_thread()
if CPU has the TM feature before accessing any TM-specific resource,
returning immediately if TM is no available on the CPU. Adding
that checking in flush_tmregs_to_thread() instead of in places
where it is called, like in vsr_get() and vsr_set(), is better because
avoids the same problem cropping up elsewhere.

Cc: stable@vger.kernel.org # v4.13+
Fixes: cd63f3c ("powerpc/tm: Fix saving of TM SPRs in core dump")
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Ravi Bangoria
4917fcb58c powerpc/sysrq: Fix oops whem ppmu is not registered
Kernel crashes if power pmu is not registered and user tries to dump
regs with 'echo p > /proc/sysrq-trigger'. Sample log:

  Unable to handle kernel paging request for data at address 0x00000008
  Faulting instruction address: 0xc0000000000d52f0

  NIP [c0000000000d52f0] perf_event_print_debug+0x10/0x230
  LR [c00000000058a938] sysrq_handle_showregs+0x38/0x50
  Call Trace:
   printk+0x38/0x4c (unreliable)
   __handle_sysrq+0xe4/0x270
   write_sysrq_trigger+0x64/0x80
   proc_reg_write+0x80/0xd0
   __vfs_write+0x40/0x200
   vfs_write+0xc8/0x240
   SyS_write+0x60/0x110
   system_call+0x58/0x6c

Fixes: 5f6d0380c6 ("powerpc/perf: Define perf_event_print_debug() to print PMU register values")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Michael Ellerman
8632ec8cdc powerpc/configs: Update for CONFIG_SND changes
Commit eb3b705aae ("ALSA: Make CONFIG_SND_OSSEMUL user-selectable")
means we need to set CONFIG_SND_OSSEMUL in our configs, otherwise we
lose some of the SND symbols.

And commit 0181307abc ("ALSA: seq: Reorganize kconfig and build")
reorganised things, which causes the churn.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-20 13:30:09 +10:00
Linus Torvalds
9db59599ae * PPC bugfixes
* RCU splat fix
 * swait races fix
 * pointless userspace-triggerable BUG() fix
 * misc fixes for KVM_RUN corner cases
 * nested virt correctness fixes + one host DoS
 * some cleanups
 * clang build fix
 * fix AMD AVIC with default QEMU command line options
 * x86 bugfixes
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull more KVM updates from Paolo Bonzini:
 - PPC bugfixes
 - RCU splat fix
 - swait races fix
 - pointless userspace-triggerable BUG() fix
 - misc fixes for KVM_RUN corner cases
 - nested virt correctness fixes + one host DoS
 - some cleanups
 - clang build fix
 - fix AMD AVIC with default QEMU command line options
 - x86 bugfixes

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
  kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly
  kvm: vmx: Handle VMLAUNCH/VMRESUME failure properly
  kvm: nVMX: Remove nested_vmx_succeed after successful VM-entry
  kvm,mips: Fix potential swait_active() races
  kvm,powerpc: Serialize wq active checks in ops->vcpu_kick
  kvm: Serialize wq active checks in kvm_vcpu_wake_up()
  kvm,x86: Fix apf_task_wake_one() wq serialization
  kvm,lapic: Justify use of swait_active()
  kvm,async_pf: Use swq_has_sleeper()
  sched/wait: Add swq_has_sleeper()
  KVM: VMX: Do not BUG() on out-of-bounds guest IRQ
  KVM: Don't accept obviously wrong gsi values via KVM_IRQFD
  kvm: nVMX: Don't allow L2 to access the hardware CR8
  KVM: trace events: update list of exit reasons
  KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously
  KVM: X86: Don't block vCPU if there is pending exception
  KVM: SVM: Add irqchip_split() checks before enabling AVIC
  KVM: Add struct kvm_vcpu pointer parameter to get_enable_apicv()
  KVM: SVM: Refactor AVIC vcpu initialization into avic_init_vcpu()
  KVM: x86: fix clang build
  ...
2017-09-15 15:43:55 -07:00
Linus Torvalds
418702b910 powerpc fixes for 4.14 #2
Just one fix, for the handling of alignment interrupts on dcbz instructions.
 
 Thanks to:
   Paul Mackerras, Christian Zigotzky, Michal Sojka.
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Merge tag 'powerpc-4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fix from Michael Ellerman:
 "Just one fix, for the handling of alignment interrupts on dcbz
  instructions.

  Thanks to Paul Mackerras, Christian Zigotzky, Michal Sojka"

* tag 'powerpc-4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Fix handling of alignment interrupt on dcbz instruction
2017-09-15 12:44:59 -07:00
Davidlohr Bueso
267ad7bc2d kvm,powerpc: Serialize wq active checks in ops->vcpu_kick
Particularly because kvmppc_fast_vcpu_kick_hv() is a callback,
ensure that we properly serialize wq active checks in order to
avoid potentially missing a wakeup due to racing with the waiter
side.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-15 16:57:13 +02:00
Paul Mackerras
1bc944cee6 powerpc: Fix handling of alignment interrupt on dcbz instruction
This fixes the emulation of the dcbz instruction in the alignment
interrupt handler.  The error was that we were comparing just the
instruction type field of op.type rather than the whole thing,
and therefore the comparison "type != CACHEOP + DCBZ" was always
true.

Fixes: 31bfdb036f ("powerpc: Use instruction emulation infrastructure to handle alignment faults")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Tested-by: Michal Sojka <sojkam1@fel.cvut.cz>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-09-15 08:41:18 +10:00
Radim Krčmář
648d453dd4 Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
Bug fixes for stable.
2017-09-14 17:21:10 +02:00
Thomas Gleixner
ab5fe3ff38 watchdog/hardlockup: Clean up hotplug locking mess
All watchdog thread related functions are delegated to the smpboot thread
infrastructure, which handles serialization against CPU hotplug correctly.

The sysctl interface is completely decoupled from anything which requires
CPU hotplug protection.

No need to protect the sysctl writes against cpu hotplug anymore. Remove it
and add the now required protection to the powerpc arch_nmi_watchdog
implementation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170912194148.418497420@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-14 11:41:09 +02:00
Thomas Gleixner
6592ad2fcc watchdog/core, powerpc: Make watchdog_nmi_reconfigure() two stage
Both the perf reconfiguration and the powerpc watchdog_nmi_reconfigure()
need to be done in two steps.

     1) Stop all NMIs
     2) Read the new parameters and start NMIs

Right now watchdog_nmi_reconfigure() is a combination of both. To allow a
clean reconfiguration add a 'run' argument and split the functionality in
powerpc.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170912194147.862865570@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-14 11:41:07 +02:00
Thomas Gleixner
5490125d77 watchdog/core: Remove broken suspend/resume interfaces
This interface has several issues:

 - It's causing recursive locking of the hotplug lock.

 - It's complete overkill to teardown all threads and then recreate them

The same can be achieved with the simple hardlockup_detector_perf_stop /
restart() interfaces. The abuse from the busy looping poweroff() loop of
PARISC has been solved as well.

Remove the cruft.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.487537732@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-14 11:41:04 +02:00
Michal Hocko
0ee931c4e3 mm: treewide: remove GFP_TEMPORARY allocation flag
GFP_TEMPORARY was introduced by commit e12ba74d8f ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation.  As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.

The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory.  So
this is rather misleading and hard to evaluate for any benefits.

I have checked some random users and none of them has added the flag
with a specific justification.  I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring.  This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.

I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL.  Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.

I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.

This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
seems to be a heuristic without any measured advantage for most (if not
all) its current users.  The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers.  So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.

[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org

[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
  Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-13 18:53:16 -07:00
Paul Mackerras
67f8a8c115 KVM: PPC: Book3S HV: Fix bug causing host SLB to be restored incorrectly
Aneesh Kumar reported seeing host crashes when running recent kernels
on POWER8.  The symptom was an oops like this:

Unable to handle kernel paging request for data at address 0xf00000000786c620
Faulting instruction address: 0xc00000000030e1e4
Oops: Kernel access of bad area, sig: 11 [#1]
LE SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in: powernv_op_panel
CPU: 24 PID: 6663 Comm: qemu-system-ppc Tainted: G        W 4.13.0-rc7-43932-gfc36c59 #2
task: c000000fdeadfe80 task.stack: c000000fdeb68000
NIP:  c00000000030e1e4 LR: c00000000030de6c CTR: c000000000103620
REGS: c000000fdeb6b450 TRAP: 0300   Tainted: G        W        (4.13.0-rc7-43932-gfc36c59)
MSR:  9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 24044428  XER: 20000000
CFAR: c00000000030e134 DAR: f00000000786c620 DSISR: 40000000 SOFTE: 0
GPR00: 0000000000000000 c000000fdeb6b6d0 c0000000010bd000 000000000000e1b0
GPR04: c00000000115e168 c000001fffa6e4b0 c00000000115d000 c000001e1b180386
GPR08: f000000000000000 c000000f9a8913e0 f00000000786c600 00007fff587d0000
GPR12: c000000fdeb68000 c00000000fb0f000 0000000000000001 00007fff587cffff
GPR16: 0000000000000000 c000000000000000 00000000003fffff c000000fdebfe1f8
GPR20: 0000000000000004 c000000fdeb6b8a8 0000000000000001 0008000000000040
GPR24: 07000000000000c0 00007fff587cffff c000000fdec20bf8 00007fff587d0000
GPR28: c000000fdeca9ac0 00007fff587d0000 00007fff587c0000 00007fff587d0000
NIP [c00000000030e1e4] __get_user_pages_fast+0x434/0x1070
LR [c00000000030de6c] __get_user_pages_fast+0xbc/0x1070
Call Trace:
[c000000fdeb6b6d0] [c00000000139dab8] lock_classes+0x0/0x35fe50 (unreliable)
[c000000fdeb6b7e0] [c00000000030ef38] get_user_pages_fast+0xf8/0x120
[c000000fdeb6b830] [c000000000112318] kvmppc_book3s_hv_page_fault+0x308/0xf30
[c000000fdeb6b960] [c00000000010e10c] kvmppc_vcpu_run_hv+0xfdc/0x1f00
[c000000fdeb6bb20] [c0000000000e915c] kvmppc_vcpu_run+0x2c/0x40
[c000000fdeb6bb40] [c0000000000e5650] kvm_arch_vcpu_ioctl_run+0x110/0x300
[c000000fdeb6bbe0] [c0000000000d6468] kvm_vcpu_ioctl+0x528/0x900
[c000000fdeb6bd40] [c0000000003bc04c] do_vfs_ioctl+0xcc/0x950
[c000000fdeb6bde0] [c0000000003bc930] SyS_ioctl+0x60/0x100
[c000000fdeb6be30] [c00000000000b96c] system_call+0x58/0x6c
Instruction dump:
7ca81a14 2fa50000 41de0010 7cc8182a 68c60002 78c6ffe2 0b060000 3cc2000a
794a3664 390610d8 e9080000 7d485214 <e90a0020> 7d435378 790507e1 408202f0
---[ end trace fad4a342d0414aa2 ]---

It turns out that what has happened is that the SLB entry for the
vmmemap region hasn't been reloaded on exit from a guest, and it has
the wrong page size.  Then, when the host next accesses the vmemmap
region, it gets a page fault.

Commit a25bd72bad ("powerpc/mm/radix: Workaround prefetch issue with
KVM", 2017-07-24) modified the guest exit code so that it now only clears
out the SLB for hash guest.  The code tests the radix flag and puts the
result in a non-volatile CR field, CR2, and later branches based on CR2.

Unfortunately, the kvmppc_save_tm function, which gets called between
those two points, modifies all the user-visible registers in the case
where the guest was in transactional or suspended state, except for a
few which it restores (namely r1, r2, r9 and r13).  Thus the hash/radix indication in CR2 gets corrupted.

This fixes the problem by re-doing the comparison just before the
result is needed.  For good measure, this also adds comments next to
the call sites of kvmppc_save_tm and kvmppc_restore_tm pointing out
that non-volatile register state will be lost.

Cc: stable@vger.kernel.org # v4.13
Fixes: a25bd72bad ("powerpc/mm/radix: Workaround prefetch issue with KVM")
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-09-12 16:02:46 +10:00
Paul Mackerras
cf5f6f3125 KVM: PPC: Book3S HV: Hold kvm->lock around call to kvmppc_update_lpcr
Commit 468808bd35 ("KVM: PPC: Book3S HV: Set process table for HPT
guests on POWER9", 2017-01-30) added a call to kvmppc_update_lpcr()
which doesn't hold the kvm->lock mutex around the call, as required.
This adds the lock/unlock pair, and for good measure, includes
the kvmppc_setup_partition_table() call in the locked region, since
it is altering global state of the VM.

This error appears not to have any fatal consequences for the host;
the consequences would be that the VCPUs could end up running with
different LPCR values, or an update to the LPCR value by userspace
using the one_reg interface could get overwritten, or the update
done by kvmhv_configure_mmu() could get overwritten.

Cc: stable@vger.kernel.org # v4.10+
Fixes: 468808bd35 ("KVM: PPC: Book3S HV: Set process table for HPT guests on POWER9")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-09-12 16:02:27 +10:00
Benjamin Herrenschmidt
d222af0723 KVM: PPC: Book3S HV: Don't access XIVE PIPR register using byte accesses
The XIVE interrupt controller on POWER9 machines doesn't support byte
accesses to any register in the thread management area other than the
CPPR (current processor priority register).  In particular, when
reading the PIPR (pending interrupt priority register), we need to
do a 32-bit or 64-bit load.

Cc: stable@vger.kernel.org # v4.13
Fixes: 2c4fb78f78 ("KVM: PPC: Book3S HV: Workaround POWER9 DD1.0 bug causing IPB bit loss")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-09-12 16:02:07 +10:00
Linus Torvalds
dd198ce714 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman:
 "Life has been busy and I have not gotten half as much done this round
  as I would have liked. I delayed it so that a minor conflict
  resolution with the mips tree could spend a little time in linux-next
  before I sent this pull request.

  This includes two long delayed user namespace changes from Kirill
  Tkhai. It also includes a very useful change from Serge Hallyn that
  allows the security capability attribute to be used inside of user
  namespaces. The practical effect of this is people can now untar
  tarballs and install rpms in user namespaces. It had been suggested to
  generalize this and encode some of the namespace information
  information in the xattr name. Upon close inspection that makes the
  things that should be hard easy and the things that should be easy
  more expensive.

  Then there is my bugfix/cleanup for signal injection that removes the
  magic encoding of the siginfo union member from the kernel internal
  si_code. The mips folks reported the case where I had used FPE_FIXME
  me is impossible so I have remove FPE_FIXME from mips, while at the
  same time including a return statement in that case to keep gcc from
  complaining about unitialized variables.

  I almost finished the work to get make copy_siginfo_to_user a trivial
  copy to user. The code is available at:

     git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git neuter-copy_siginfo_to_user-v3

  But I did not have time/energy to get the code posted and reviewed
  before the merge window opened.

  I was able to see that the security excuse for just copying fields
  that we know are initialized doesn't work in practice there are buggy
  initializations that don't initialize the proper fields in siginfo. So
  we still sometimes copy unitialized data to userspace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  Introduce v3 namespaced file capabilities
  mips/signal: In force_fcr31_sig return in the impossible case
  signal: Remove kernel interal si_code magic
  fcntl: Don't use ambiguous SIG_POLL si_codes
  prctl: Allow local CAP_SYS_ADMIN changing exe_file
  security: Use user_namespace::level to avoid redundant iterations in cap_capable()
  userns,pidns: Verify the userns for new pid namespaces
  signal/testing: Don't look for __SI_FAULT in userspace
  signal/mips: Document a conflict with SI_USER with SIGFPE
  signal/sparc: Document a conflict with SI_USER with SIGFPE
  signal/ia64: Document a conflict with SI_USER with SIGFPE
  signal/alpha: Document a conflict with SI_USER for SIGTRAP
2017-09-11 18:34:47 -07:00
Linus Torvalds
fbf4432ff7 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - most of the rest of MM

 - a small number of misc things

 - lib/ updates

 - checkpatch

 - autofs updates

 - ipc/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (126 commits)
  ipc: optimize semget/shmget/msgget for lots of keys
  ipc/sem: play nicer with large nsops allocations
  ipc/sem: drop sem_checkid helper
  ipc: convert kern_ipc_perm.refcount from atomic_t to refcount_t
  ipc: convert sem_undo_list.refcnt from atomic_t to refcount_t
  ipc: convert ipc_namespace.count from atomic_t to refcount_t
  kcov: support compat processes
  sh: defconfig: cleanup from old Kconfig options
  mn10300: defconfig: cleanup from old Kconfig options
  m32r: defconfig: cleanup from old Kconfig options
  drivers/pps: use surrounding "if PPS" to remove numerous dependency checks
  drivers/pps: aesthetic tweaks to PPS-related content
  cpumask: make cpumask_next() out-of-line
  kmod: move #ifdef CONFIG_MODULES wrapper to Makefile
  kmod: split off umh headers into its own file
  MAINTAINERS: clarify kmod is just a kernel module loader
  kmod: split out umh code into its own file
  test_kmod: flip INT checks to be consistent
  test_kmod: remove paranoid UINT_MAX check on uint range processing
  vfat: deduplicate hex2bin()
  ...
2017-09-09 10:30:07 -07:00
Alexey Dobriyan
9b130ad5bb treewide: make "nr_cpu_ids" unsigned
First, number of CPUs can't be negative number.

Second, different signnnedness leads to suboptimal code in the following
cases:

1)
	kmalloc(nr_cpu_ids * sizeof(X));

"int" has to be sign extended to size_t.

2)
	while (loff_t *pos < nr_cpu_ids)

MOVSXD is 1 byte longed than the same MOV.

Other cases exist as well. Basically compiler is told that nr_cpu_ids
can't be negative which can't be deduced if it is "int".

Code savings on allyesconfig kernel: -3KB

	add/remove: 0/0 grow/shrink: 25/264 up/down: 261/-3631 (-3370)
	function                                     old     new   delta
	coretemp_cpu_online                          450     512     +62
	rcu_init_one                                1234    1272     +38
	pci_device_probe                             374     399     +25

				...

	pgdat_reclaimable_pages                      628     556     -72
	select_fallback_rq                           446     369     -77
	task_numa_find_cpu                          1923    1807    -116

Link: http://lkml.kernel.org/r/20170819114959.GA30580@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Matthew Wilcox
ac036f9570 vga: optimise console scrolling
Where possible, call memset16(), memmove() or memcpy() instead of using
open-coded loops.  I don't like the calling convention that uses a byte
count instead of a count of u16s, but it's a little late to change that.
Reduces code size of fbcon.o by almost 400 bytes on my laptop build.

[akpm@linux-foundation.org: fix build]
Link: http://lkml.kernel.org/r/20170720184539.31609-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Linus Torvalds
0756b7fbb6 First batch of KVM changes for 4.14
Common:
  - improve heuristic for boosting preempted spinlocks by ignoring VCPUs
    in user mode
 
 ARM:
  - fix for decoding external abort types from guests
 
  - added support for migrating the active priority of interrupts when
    running a GICv2 guest on a GICv3 host
 
  - minor cleanup
 
 PPC:
  - expose storage keys to userspace
 
  - merge powerpc/topic/ppc-kvm branch that contains
    find_linux_pte_or_hugepte and POWER9 thread management cleanup
 
  - merge kvm-ppc-fixes with a fix that missed 4.13 because of vacations
 
  - fixes
 
 s390:
  - merge of topic branch tlb-flushing from the s390 tree to get the
    no-dat base features
 
  - merge of kvm/master to avoid conflicts with additional sthyi fixes
 
  - wire up the no-dat enhancements in KVM
 
  - multiple epoch facility (z14 feature)
 
  - Configuration z/Architecture Mode
 
  - more sthyi fixes
 
  - gdb server range checking fix
 
  - small code cleanups
 
 x86:
  - emulate Hyper-V TSC frequency MSRs
 
  - add nested INVPCID
 
  - emulate EPTP switching VMFUNC
 
  - support Virtual GIF
 
  - support 5 level page tables
 
  - speedup nested VM exits by packing byte operations
 
  - speedup MMIO by using hardware provided physical address
 
  - a lot of fixes and cleanups, especially nested
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Merge tag 'kvm-4.14-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "First batch of KVM changes for 4.14

  Common:
   - improve heuristic for boosting preempted spinlocks by ignoring
     VCPUs in user mode

  ARM:
   - fix for decoding external abort types from guests

   - added support for migrating the active priority of interrupts when
     running a GICv2 guest on a GICv3 host

   - minor cleanup

  PPC:
   - expose storage keys to userspace

   - merge kvm-ppc-fixes with a fix that missed 4.13 because of
     vacations

   - fixes

  s390:
   - merge of kvm/master to avoid conflicts with additional sthyi fixes

   - wire up the no-dat enhancements in KVM

   - multiple epoch facility (z14 feature)

   - Configuration z/Architecture Mode

   - more sthyi fixes

   - gdb server range checking fix

   - small code cleanups

  x86:
   - emulate Hyper-V TSC frequency MSRs

   - add nested INVPCID

   - emulate EPTP switching VMFUNC

   - support Virtual GIF

   - support 5 level page tables

   - speedup nested VM exits by packing byte operations

   - speedup MMIO by using hardware provided physical address

   - a lot of fixes and cleanups, especially nested"

* tag 'kvm-4.14-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (67 commits)
  KVM: arm/arm64: Support uaccess of GICC_APRn
  KVM: arm/arm64: Extract GICv3 max APRn index calculation
  KVM: arm/arm64: vITS: Drop its_ite->lpi field
  KVM: arm/arm64: vgic: constify seq_operations and file_operations
  KVM: arm/arm64: Fix guest external abort matching
  KVM: PPC: Book3S HV: Fix memory leak in kvm_vm_ioctl_get_htab_fd
  KVM: s390: vsie: cleanup mcck reinjection
  KVM: s390: use WARN_ON_ONCE only for checking
  KVM: s390: guestdbg: fix range check
  KVM: PPC: Book3S HV: Report storage key support to userspace
  KVM: PPC: Book3S HV: Fix case where HDEC is treated as 32-bit on POWER9
  KVM: PPC: Book3S HV: Fix invalid use of register expression
  KVM: PPC: Book3S HV: Fix H_REGISTER_VPA VPA size validation
  KVM: PPC: Book3S HV: Fix setting of storage key in H_ENTER
  KVM: PPC: e500mc: Fix a NULL dereference
  KVM: PPC: e500: Fix some NULL dereferences on error
  KVM: PPC: Book3S HV: Protect updates to spapr_tce_tables list
  KVM: s390: we are always in czam mode
  KVM: s390: expose no-DAT to guest and migration support
  KVM: s390: sthyi: remove invalid guest write access
  ...
2017-09-08 15:18:36 -07:00
Radim Krčmář
5f54c8b2d4 Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
This fix was intended for 4.13, but didn't get in because both
maintainers were on vacation.

Paul Mackerras:
 "It adds mutual exclusion between list_add_rcu and list_del_rcu calls
  on the kvm->arch.spapr_tce_tables list.  Without this, userspace could
  potentially trigger corruption of the list and cause a host crash or
  worse."
2017-09-08 14:40:43 +02:00
Linus Torvalds
a0725ab0c7 Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
 "This is the first pull request for 4.14, containing most of the code
  changes. It's a quiet series this round, which I think we needed after
  the churn of the last few series. This contains:

   - Fix for a registration race in loop, from Anton Volkov.

   - Overflow complaint fix from Arnd for DAC960.

   - Series of drbd changes from the usual suspects.

   - Conversion of the stec/skd driver to blk-mq. From Bart.

   - A few BFQ improvements/fixes from Paolo.

   - CFQ improvement from Ritesh, allowing idling for group idle.

   - A few fixes found by Dan's smatch, courtesy of Dan.

   - A warning fixup for a race between changing the IO scheduler and
     device remova. From David Jeffery.

   - A few nbd fixes from Josef.

   - Support for cgroup info in blktrace, from Shaohua.

   - Also from Shaohua, new features in the null_blk driver to allow it
     to actually hold data, among other things.

   - Various corner cases and error handling fixes from Weiping Zhang.

   - Improvements to the IO stats tracking for blk-mq from me. Can
     drastically improve performance for fast devices and/or big
     machines.

   - Series from Christoph removing bi_bdev as being needed for IO
     submission, in preparation for nvme multipathing code.

   - Series from Bart, including various cleanups and fixes for switch
     fall through case complaints"

* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
  kernfs: checking for IS_ERR() instead of NULL
  drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
  drbd: Fix allyesconfig build, fix recent commit
  drbd: switch from kmalloc() to kmalloc_array()
  drbd: abort drbd_start_resync if there is no connection
  drbd: move global variables to drbd namespace and make some static
  drbd: rename "usermode_helper" to "drbd_usermode_helper"
  drbd: fix race between handshake and admin disconnect/down
  drbd: fix potential deadlock when trying to detach during handshake
  drbd: A single dot should be put into a sequence.
  drbd: fix rmmod cleanup, remove _all_ debugfs entries
  drbd: Use setup_timer() instead of init_timer() to simplify the code.
  drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
  drbd: new disk-option disable-write-same
  drbd: Fix resource role for newly created resources in events2
  drbd: mark symbols static where possible
  drbd: Send P_NEG_ACK upon write error in protocol != C
  drbd: add explicit plugging when submitting batches
  drbd: change list_for_each_safe to while(list_first_entry_or_null)
  drbd: introduce drbd_recv_header_maybe_unplug
  ...
2017-09-07 11:59:42 -07:00