Commit Graph

127624 Commits

Author SHA1 Message Date
Jike Song 871b7ef2a1 kvm/page_track: export symbols for external usage
Signed-off-by: Jike Song <jike.song@intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-04 12:13:20 +01:00
Jike Song d126363d8f kvm/page_track: call notifiers with kvm_page_track_notifier_node
The user of page_track might needs extra information, so pass
the kvm_page_track_notifier_node to callbacks.

Signed-off-by: Jike Song <jike.song@intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-04 12:13:20 +01:00
Xiaoguang Chen ae7cd87372 KVM: x86: add track_flush_slot page track notifier
When a memory slot is being moved or removed users of page track
can be notified. So users can drop write-protection for the pages
in that memory slot.

This notifier type is needed by KVMGT to sync up its shadow page
table when memory slot is being moved or removed.

Register the notifier type track_flush_slot to receive memslot move
and remove event.

Reviewed-by: Xiao Guangrong <guangrong.xiao@intel.com>
Signed-off-by: Chen Xiaoguang <xiaoguang.chen@intel.com>
[Squashed commits to avoid bisection breakage and reworded the subject.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-04 12:13:19 +01:00
Owen Hofmann d9092f52d7 kvm: x86: Check memopp before dereference (CVE-2016-8630)
Commit 41061cdb98 ("KVM: emulate: do not initialize memopp") removes a
check for non-NULL under incorrect assumptions. An undefined instruction
with a ModR/M byte with Mod=0 and R/M-5 (e.g. 0xc7 0x15) will attempt
to dereference a null pointer here.

Fixes: 41061cdb98
Message-Id: <1477592752-126650-2-git-send-email-osh@google.com>
Signed-off-by: Owen Hofmann <osh@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02 21:31:53 +01:00
Jim Mattson 355f4fb140 kvm: nVMX: VMCLEAR an active shadow VMCS after last use
After a successful VM-entry with the "VMCS shadowing" VM-execution
control set, the shadow VMCS referenced by the VMCS link pointer field
in the current VMCS becomes active on the logical processor.

A VMCS that is made active on more than one logical processor may become
corrupted. Therefore, before an active VMCS can be migrated to another
logical processor, the first logical processor must execute a VMCLEAR
for the active VMCS. VMCLEAR both ensures that all VMCS data are written
to memory and makes the VMCS inactive.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-By: David Matlack <dmatlack@google.com>
Message-Id: <1477668579-22555-1-git-send-email-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02 20:03:17 +01:00
Paolo Bonzini ea26e4ec08 KVM: x86: drop TSC offsetting kvm_x86_ops to fix KVM_GET/SET_CLOCK
Since commit a545ab6a00 ("kvm: x86: add tsc_offset field to struct
kvm_vcpu_arch", 2016-09-07) the offset between host and L1 TSC is
cached and need not be fished out of the VMCS or VMCB.  This means
that we can implement adjust_tsc_offset_guest and read_l1_tsc
entirely in generic code.  The simplification is particularly
significant for VMX code, where vmx->nested.vmcs01_tsc_offset
was duplicating what is now in vcpu->arch.tsc_offset.  Therefore
the vmcs01_tsc_offset can be dropped completely.

More importantly, this fixes KVM_GET_CLOCK/KVM_SET_CLOCK
which, after commit 108b249c45 ("KVM: x86: introduce get_kvmclock_ns",
2016-09-01) called read_l1_tsc while the VMCS was not loaded.
It thus returned bogus values on Intel CPUs.

Fixes: 108b249c45
Reported-by: Roman Kagan <rkagan@virtuozzo.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02 20:03:07 +01:00
Ido Yariv bd768e1466 KVM: x86: fix wbinvd_dirty_mask use-after-free
vcpu->arch.wbinvd_dirty_mask may still be used after freeing it,
corrupting memory. For example, the following call trace may set a bit
in an already freed cpu mask:
    kvm_arch_vcpu_load
    vcpu_load
    vmx_free_vcpu_nested
    vmx_free_vcpu
    kvm_arch_vcpu_free

Fix this by deferring freeing of wbinvd_dirty_mask.

Cc: stable@vger.kernel.org
Signed-off-by: Ido Yariv <ido@wizery.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-10-28 11:35:21 +02:00
Borislav Petkov 796f4687bd kvm/x86: Show WRMSR data is in hex
Add the "0x" prefix to the error messages format to make it unambiguous
about what kind of value we're talking about.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Message-Id: <20161027181445.25319-1-bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-27 20:31:25 +02:00
Paolo Bonzini b5149a5fd1 KVM: s390: Fix wrong memory allocation
With commit d86bd1bece ("mm/slub: support left redzone") or
 with slab debugging the allocation of our diag224 buffer is not
 aligned properly. Let's fix this.
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Merge tag 'kvm-s390-master-4.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Fix wrong memory allocation

With commit d86bd1bece ("mm/slub: support left redzone") or
with slab debugging the allocation of our diag224 buffer is not
aligned properly. Let's fix this.
2016-10-27 13:22:54 +02:00
Jim Mattson 85c856b39b kvm: nVMX: Fix kernel panics induced by illegal INVEPT/INVVPID types
Bitwise shifts by amounts greater than or equal to the width of the left
operand are undefined. A malicious guest can exploit this to crash a
32-bit host, due to the BUG_ON(1)'s in handle_{invept,invvpid}.

Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <1477496318-17681-1-git-send-email-jmattson@google.com>
[Change 1UL to 1, to match the range check on the shift count. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-27 12:15:27 +02:00
Janosch Frank 45c7ee43a5 KVM: s390: Fix STHYI buffer alignment for diag224
Diag224 requires a page-aligned 4k buffer to store the name table
into. kmalloc does not guarantee page alignment, hence we replace it
with __get_free_page for the buffer allocation.

Cc: stable@vger.kernel.org # v4.8+
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-10-26 13:46:44 +02:00
James Hogan e1e575f6b0 KVM: MIPS: Precalculate MMIO load resume PC
The advancing of the PC when completing an MMIO load is done before
re-entering the guest, i.e. before restoring the guest ASID. However if
the load is in a branch delay slot it may need to access guest code to
read the prior branch instruction. This isn't safe in TLB mapped code at
the moment, nor in the future when we'll access unmapped guest segments
using direct user accessors too, as it could read the branch from host
user memory instead.

Therefore calculate the resume PC in advance while we're still in the
right context and save it in the new vcpu->arch.io_pc (replacing the no
longer needed vcpu->arch.pending_load_cause), and restore it on MMIO
completion.

Fixes: e685c689f3 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: <stable@vger.kernel.org> # 3.10.x-
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-26 13:43:55 +02:00
James Hogan ede5f3e7b5 KVM: MIPS: Make ERET handle ERL before EXL
The ERET instruction to return from exception is used for returning from
exception level (Status.EXL) and error level (Status.ERL). If both bits
are set however we should be returning from ERL first, as ERL can
interrupt EXL, for example when an NMI is taken. KVM however checks EXL
first.

Fix the order of the checks to match the pseudocode in the instruction
set manual.

Fixes: e685c689f3 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: <stable@vger.kernel.org> # 3.10.x-
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-26 13:43:48 +02:00
James Hogan 9078210ef4 KVM: MIPS: Fix lazy user ASID regenerate for SMP
kvm_mips_check_asids() runs before entering the guest and performs lazy
regeneration of host ASID for guest usermode, using last_user_gasid to
track the last guest ASID in the VCPU that was used by guest usermode on
any host CPU.

last_user_gasid is reset after performing the lazy ASID regeneration on
the current CPU, and by kvm_arch_vcpu_load() if the host ASID for guest
usermode is regenerated due to staleness (to cancel outstanding lazy
ASID regenerations). Unfortunately neither case handles SMP hosts
correctly:

 - When the lazy ASID regeneration is performed it should apply to all
   CPUs (as last_user_gasid does), so reset the ASID on other CPUs to
   zero to trigger regeneration when the VCPU is next loaded on those
   CPUs.

 - When the ASID is found to be stale on the current CPU, we should not
   cancel lazy ASID regenerations globally, so drop the reset of
   last_user_gasid altogether here.

Both cases would require a guest ASID change and two host CPU migrations
(and in the latter case one of the CPUs to start a new ASID cycle)
before guest usermode could potentially access stale user pages from a
previously running ASID in the same VCPU.

Fixes: 25b08c7fb0 ("KVM: MIPS: Invalidate TLB by regenerating ASIDs")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-26 13:43:41 +02:00
Linus Torvalds 3e9679a365 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Three fixes, a hw-enablement and a cross-arch fix/enablement change:

   - SGI/UV fix for older platforms

   - x32 signal handling fix

   - older x86 platform bootup APIC fix

   - AVX512-4VNNIW (Neural Network Instructions) and AVX512-4FMAPS
     (Multiply Accumulation Single precision instructions) enablement.

   - move thread_info back into x86 specific code, to make life easier
     for other architectures trying to make use of
     CONFIG_THREAD_INFO_IN_TASK_STRUCT=y"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/smp: Don't try to poke disabled/non-existent APIC
  sched/core, x86: Make struct thread_info arch specific again
  x86/signal: Remove bogus user_64bit_mode() check from sigaction_compat_abi()
  x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates
  x86/cpufeature: Add AVX512_4VNNIW and AVX512_4FMAPS features
  x86/vmware: Skip timer_irq_works() check on VMware
2016-10-22 09:58:49 -07:00
Ville Syrjälä ff8560512b x86/boot/smp: Don't try to poke disabled/non-existent APIC
Apparently trying to poke a disabled or non-existent APIC
leads to a box that doesn't even boot. Let's not do that.

No real clue if this is the right fix, but at least my
P3 machine boots again.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: dyoung@redhat.com
Cc: kexec@lists.infradead.org
Cc: stable@vger.kernel.org
Fixes: 2a51fe083e ("arch/x86: Handle non enumerated CPU after physical hotplug")
Link: http://lkml.kernel.org/r/1477102684-5092-1-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-22 10:47:54 +02:00
Linus Torvalds dcd4693cf4 powerpc fixes for 4.9 #3
Fixes marked for stable:
  - Prevent unlikely crash in copro_calculate_slb() (Frederic Barrat)
  - cxl: Prevent adapter reset if an active context exists (Vaibhav Jain)
 
 Fixes for code merged this cycle:
  - Fix boot on systems with uncompressed kernel image (Heiner Kallweit)
  - Drop dump_numa_memory_topology() (Michael Ellerman)
  - Fix numa topology console print (Aneesh Kumar K.V)
  - Ignore the pkey system calls for now (Stephen Rothwell)
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Merge tag 'powerpc-4.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Fixes marked for stable:
   - Prevent unlikely crash in copro_calculate_slb() (Frederic Barrat)
   - cxl: Prevent adapter reset if an active context exists (Vaibhav Jain)

  Fixes for code merged this cycle:
   - Fix boot on systems with uncompressed kernel image (Heiner Kallweit)
   - Drop dump_numa_memory_topology() (Michael Ellerman)
   - Fix numa topology console print (Aneesh Kumar K.V)
   - Ignore the pkey system calls for now (Stephen Rothwell)"

* tag 'powerpc-4.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Ignore the pkey system calls for now
  powerpc: Fix numa topology console print
  powerpc/mm: Drop dump_numa_memory_topology()
  cxl: Prevent adapter reset if an active context exists
  powerpc/boot: Fix boot on systems with uncompressed kernel image
  powerpc/mm: Prevent unlikely crash in copro_calculate_slb()
2016-10-21 19:13:00 -07:00
Linus Torvalds a23b27ae12 KVM fixes for v4.9-rc2
ARM:
  - avoid livelock when walking guest page tables
  - fix HYP mode static keys without CC_HAVE_ASM_GOTO
 
 MIPS:
  - fix a build error without TRACEPOINTS_ENABLED
 
 s390:
  - reject a malformed userspace configuration
 
 x86:
  - suppress a warning without CONFIG_CPU_FREQ
  - initialize whole irq_eoi array
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - avoid livelock when walking guest page tables
   - fix HYP mode static keys without CC_HAVE_ASM_GOTO

  MIPS:
   - fix a build error without TRACEPOINTS_ENABLED

  s390:
   - reject a malformed userspace configuration

  x86:
   - suppress a warning without CONFIG_CPU_FREQ
   - initialize whole irq_eoi array"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  arm/arm64: KVM: Map the BSS at HYP
  arm64: KVM: Take S1 walks into account when determining S2 write faults
  KVM: s390: reject invalid modes for runtime instrumentation
  kvm: x86: memset whole irq_eoi
  kvm/x86: Fix unused variable warning in kvm_timer_init()
  KVM: MIPS: Add missing uaccess.h include
2016-10-21 19:09:29 -07:00
Radim Krčmář 658f7c4bb7 KVM/ARM updates for 4.9-rc2
- Handle faults generated by the page table walker as being writes
 - Map the BSS at EL2
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Merge tag 'kvm-arm-for-4.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm

KVM/ARM updates for 4.9-rc2

- Handle faults generated by the page table walker as being writes
- Map the BSS at EL2
2016-10-21 18:49:53 +02:00
Marc Zyngier c8ea0395ff arm/arm64: KVM: Map the BSS at HYP
When used with a compiler that doesn't implement "asm goto"
(such as the AArch64 port of GCC 4.8), jump labels generate a
memory access to find out about the value of the key (instead
of just patching the code). The key itself is likely to be
stored in the BSS.

This is perfectly fine, except that we don't map the BSS at HYP,
leading to an exploding kernel at the first access. The obvious
fix is simply to map the BSS there (which should have been done
a long while ago, but hey...).

Reported-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-10-21 17:26:24 +01:00
Will Deacon 60e21a0ef5 arm64: KVM: Take S1 walks into account when determining S2 write faults
The WnR bit in the HSR/ESR_EL2 indicates whether a data abort was
generated by a read or a write instruction. For stage 2 data aborts
generated by a stage 1 translation table walk (i.e. the actual page
table access faults at EL2), the WnR bit therefore reports whether the
instruction generating the walk was a load or a store, *not* whether the
page table walker was reading or writing the entry.

For page tables marked as read-only at stage 2 (e.g. due to KSM merging
them with the tables from another guest), this could result in livelock,
where a page table walk generated by a load instruction attempts to
set the access flag in the stage 1 descriptor, but fails to trigger
CoW in the host since only a read fault is reported.

This patch modifies the arm64 kvm_vcpu_dabt_iswrite function to
take into account stage 2 faults in stage 1 walks. Since DBM cannot be
disabled at EL2 for CPUs that implement it, we assume that these faults
are always causes by writes, avoiding the livelock situation at the
expense of occasional, spurious CoWs.

We could, in theory, do a bit better by checking the guest TCR
configuration and inspecting the page table to see why the PTE faulted.
However, I doubt this is measurable in practice, and the threat of
livelock is real.

Cc: <stable@vger.kernel.org>
Cc: Julien Grall <julien.grall@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-21 17:25:47 +01:00
Radim Krčmář 3633031db5 KVM: s390: Fix for user-triggerable WARN_ON
A malicious user space can provide an invalid mode for runtime
 instrumentation via the interfaces that are normally used on
 the target host during migration. This would trigger a WARN_ON
 via validity intercept. Let's detect this special case.
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Merge tag 'kvm-s390-master-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux

KVM: s390: Fix for user-triggerable WARN_ON

A malicious user space can provide an invalid mode for runtime
instrumentation via the interfaces that are normally used on
the target host during migration. This would trigger a WARN_ON
via validity intercept. Let's detect this special case.
2016-10-20 20:31:01 +02:00
Christian Borntraeger a5efb6b6c9 KVM: s390: reject invalid modes for runtime instrumentation
Usually a validity intercept is a programming error of the host
because of invalid entries in the state description.
We can get a validity intercept if the mode of the runtime
instrumentation control block is wrong. As the host does not know
which modes are valid, this can be used by userspace to trigger
a WARN.
Instead of printing a WARN let's return an error to userspace as
this can only happen if userspace provides a malformed initial
value (e.g. on migration). The kernel should never warn on bogus
input. Instead let's log it into the s390 debug feature.

While at it, let's return -EINVAL for all validity intercepts as
this will trigger an error in QEMU like

error: kvm run failed Invalid argument
PSW=mask 0404c00180000000 addr 000000000063c226 cc 00
R00=000000000000004f R01=0000000000000004 R02=0000000000760005 R03=000000007fe0a000
R04=000000000064ba2a R05=000000049db73dd0 R06=000000000082c4b0 R07=0000000000000041
R08=0000000000000002 R09=000003e0804042a8 R10=0000000496152c42 R11=000000007fe0afb0
[...]

This will avoid an endless loop of validity intercepts.

Cc: stable@vger.kernel.org # v4.5+
Fixes: c6e5f16637 ("KVM: s390: implement the RI support of guest")
Acked-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-10-20 20:06:12 +02:00
Linus Torvalds f4814e6183 arm64 fixes:
- Fix ACPI boot due to recent broken NUMA changes
 - Fix remote enabling of CPU features requiring PSTATE bit manipulation
 - Add address range check when emulating user cache maintenance
 - Fix LL/SC loops that allow compiler to introduce memory accesses
 - Fix recently added write_sysreg_s macro
 - Ensure MDCR_EL2 is initialised on qemu targets without a PMU
 - Avoid kaslr breakage due to MODVERSIONs and DYNAMIC_FTRACE
 - Correctly drive recent ld when building relocatable Image
 - Remove junk IS_ERR check from xgene PMU driver added during merge window
 - pr_cont fixes after core changes in the merge window
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "Most of these are CC'd for stable, but there are a few fixing issues
  introduced during the recent merge window too.

  There's also a fix for the xgene PMU driver, but it seemed daft to
  send as a separate pull request, so I've included it here with the
  rest of the fixes.

   - Fix ACPI boot due to recent broken NUMA changes
   - Fix remote enabling of CPU features requiring PSTATE bit manipulation
   - Add address range check when emulating user cache maintenance
   - Fix LL/SC loops that allow compiler to introduce memory accesses
   - Fix recently added write_sysreg_s macro
   - Ensure MDCR_EL2 is initialised on qemu targets without a PMU
   - Avoid kaslr breakage due to MODVERSIONs and DYNAMIC_FTRACE
   - Correctly drive recent ld when building relocatable Image
   - Remove junk IS_ERR check from xgene PMU driver added during merge window
   - pr_cont fixes after core changes in the merge window"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: remove pr_cont abuse from mem_init
  arm64: fix show_regs fallout from KERN_CONT changes
  arm64: kernel: force ET_DYN ELF type for CONFIG_RELOCATABLE=y
  arm64: suspend: Reconfigure PSTATE after resume from idle
  arm64: mm: Set PSTATE.PAN from the cpu_enable_pan() call
  arm64: cpufeature: Schedule enable() calls instead of calling them via IPI
  arm64: Cortex-A53 errata workaround: check for kernel addresses
  arm64: percpu: rewrite ll/sc loops in assembly
  arm64: swp emulation: bound LL/SC retries before rescheduling
  arm64: sysreg: Fix use of XZR in write_sysreg_s
  arm64: kaslr: keep modules close to the kernel when DYNAMIC_FTRACE=y
  arm64: kernel: Init MDCR_EL2 even in the absence of a PMU
  perf: xgene: Remove bogus IS_ERR() check
  arm64: kernel: numa: fix ACPI boot cpu numa node mapping
  arm64: kaslr: fix breakage with CONFIG_MODVERSIONS=y
2016-10-20 10:17:13 -07:00
Radim Krčmář f6bbf1b7ac MIPS KVM fix for v4.9-rc2
- Fix build error introduced during the 4.9 merge window when
   tracepoints are disabled.
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Merge tag 'kvm_mips_4.9_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/kvm-mips

MIPS KVM fix for v4.9-rc2

- Fix build error introduced during the 4.9 merge window when
  tracepoints are disabled.
2016-10-20 17:26:53 +02:00
Mark Rutland f7881bd644 arm64: remove pr_cont abuse from mem_init
All the lines printed by mem_init are independent, with each ending with
a newline. While they logically form a large block, none are actually
continuations of previous lines.

The kernel-side printk code and the userspace demsg tool differ in their
handling of KERN_CONT following a newline, and while this isn't always a
problem kernel-side, it does cause difficulty for userspace. Using
pr_cont causes the userspace tool to not print line prefix (e.g.
timestamps) even when following a newline, mis-aligning the output and
making it harder to read, e.g.

[    0.000000] Virtual kernel memory layout:
[    0.000000]     modules : 0xffff000000000000 - 0xffff000008000000   (   128 MB)
    vmalloc : 0xffff000008000000 - 0xffff7dffbfff0000   (129022 GB)
      .text : 0xffff000008080000 - 0xffff0000088b0000   (  8384 KB)
    .rodata : 0xffff0000088b0000 - 0xffff000008c50000   (  3712 KB)
      .init : 0xffff000008c50000 - 0xffff000008d50000   (  1024 KB)
      .data : 0xffff000008d50000 - 0xffff000008e25200   (   853 KB)
       .bss : 0xffff000008e25200 - 0xffff000008e6bec0   (   284 KB)
    fixed   : 0xffff7dfffe7fd000 - 0xffff7dfffec00000   (  4108 KB)
    PCI I/O : 0xffff7dfffee00000 - 0xffff7dffffe00000   (    16 MB)
    vmemmap : 0xffff7e0000000000 - 0xffff800000000000   (  2048 GB maximum)
              0xffff7e0000000000 - 0xffff7e0026000000   (   608 MB actual)
    memory  : 0xffff800000000000 - 0xffff800980000000   ( 38912 MB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=6, Nodes=1

Fix this by using pr_notice consistently for all lines, which both the
kernel and userspace are happy with.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 15:27:56 +01:00
Mark Rutland db4b0710fa arm64: fix show_regs fallout from KERN_CONT changes
Recently in commit 4bcc595ccd ("printk: reinstate KERN_CONT for
printing continuation lines"), the behaviour of printk changed w.r.t.
KERN_CONT. Now, KERN_CONT is mandatory to continue existing lines.
Without this, prefixes are inserted, making output illegible, e.g.

[ 1007.069010] pc : [<ffff00000871898c>] lr : [<ffff000008718948>] pstate: 40000145
[ 1007.076329] sp : ffff000008d53ec0
[ 1007.079606] x29: ffff000008d53ec0 [ 1007.082797] x28: 0000000080c50018
[ 1007.086160]
[ 1007.087630] x27: ffff000008e0c7f8 [ 1007.090820] x26: ffff80097631ca00
[ 1007.094183]
[ 1007.095653] x25: 0000000000000001 [ 1007.098843] x24: 000000ea68b61cac
[ 1007.102206]

... or when dumped with the userpace dmesg tool, which has slightly
different implicit newline behaviour. e.g.

[ 1007.069010] pc : [<ffff00000871898c>] lr : [<ffff000008718948>] pstate: 40000145
[ 1007.076329] sp : ffff000008d53ec0
[ 1007.079606] x29: ffff000008d53ec0
[ 1007.082797] x28: 0000000080c50018
[ 1007.086160]
[ 1007.087630] x27: ffff000008e0c7f8
[ 1007.090820] x26: ffff80097631ca00
[ 1007.094183]
[ 1007.095653] x25: 0000000000000001
[ 1007.098843] x24: 000000ea68b61cac
[ 1007.102206]

We can't simply always use KERN_CONT for lines which may or may not be
continuations. That causes line prefixes (e.g. timestamps) to be
supressed, and the alignment of all but the first line will be broken.

For even more fun, we can't simply insert some dummy empty-string printk
calls, as GCC warns for an empty printk string, and even if we pass
KERN_DEFAULT explcitly to silence the warning, the prefix gets swallowed
unless there is an additional part to the string.

Instead, we must manually iterate over pairs of registers, which gives
us the legible output we want in either case, e.g.

[  169.771790] pc : [<ffff00000871898c>] lr : [<ffff000008718948>] pstate: 40000145
[  169.779109] sp : ffff000008d53ec0
[  169.782386] x29: ffff000008d53ec0 x28: 0000000080c50018
[  169.787650] x27: ffff000008e0c7f8 x26: ffff80097631de00
[  169.792913] x25: 0000000000000001 x24: 00000027827b2cf4

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 15:27:56 +01:00
Jiri Slaby 8678654e3c kvm: x86: memset whole irq_eoi
gcc 7 warns:
arch/x86/kvm/ioapic.c: In function 'kvm_ioapic_reset':
arch/x86/kvm/ioapic.c:597:2: warning: 'memset' used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size]

And it is right. Memset whole array using sizeof operator.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
[Added x86 subject tag]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-10-20 14:54:11 +02:00
Borislav Petkov 758f588d6f kvm/x86: Fix unused variable warning in kvm_timer_init()
When CONFIG_CPU_FREQ is not set, int cpu is unused and gcc rightfully
warns about it:

  arch/x86/kvm/x86.c: In function ‘kvm_timer_init’:
  arch/x86/kvm/x86.c:5697:6: warning: unused variable ‘cpu’ [-Wunused-variable]
    int cpu;
        ^~~

But since it is used only in the CONFIG_CPU_FREQ block, simply move it
there, thus squashing the warning too.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-10-20 14:49:52 +02:00
Heiko Carstens c8061485a0 sched/core, x86: Make struct thread_info arch specific again
The following commit:

  c65eacbe29 ("sched/core: Allow putting thread_info into task_struct")

... made 'struct thread_info' a generic struct with only a
single ::flags member, if CONFIG_THREAD_INFO_IN_TASK_STRUCT=y is
selected.

This change however seems to be quite x86 centric, since at least the
generic preemption code (asm-generic/preempt.h) assumes that struct
thread_info also has a preempt_count member, which apparently was not
true for x86.

We could add a bit more #ifdefs to solve this problem too, but it seems
to be much simpler to make struct thread_info arch specific
again. This also makes the conversion to THREAD_INFO_IN_TASK_STRUCT a
bit easier for architectures that have a couple of arch specific stuff
in their thread_info definition.

The arch specific stuff _could_ be moved to thread_struct. However
keeping them in thread_info makes it easier: accessing thread_info
members is simple, since it is at the beginning of the task_struct,
while the thread_struct is at the end. At least on s390 the offsets
needed to access members of the thread_struct (with task_struct as
base) are too large for various asm instructions.  This is not a
problem when keeping these members within thread_info.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: keescook@chromium.org
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/1476901693-8492-2-git-send-email-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-20 13:27:47 +02:00
Dmitry Safonov ed1e7db33c x86/signal: Remove bogus user_64bit_mode() check from sigaction_compat_abi()
The recent introduction of SA_X32/IA32 sa_flags added a check for
user_64bit_mode() into sigaction_compat_abi(). user_64bit_mode() is true
for native 64-bit processes and x32 processes.

Due to that the function returns w/o setting the SA_X32_ABI flag for X32
processes. In consequence the kernel attempts to deliver the signal to the
X32 process in native 64-bit mode causing the process to segfault.

Remove the check, so the actual check for X32 mode which sets the ABI flag
can be reached. There is no side effect for native 64-bit mode.

[ tglx: Rewrote changelog ]

Fixes: 6846351052 ("x86/signal: Add SA_{X32,IA32}_ABI sa_flags")
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Tested-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: linux-mm@kvack.org
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Link: http://lkml.kernel.org/r/CAJwJo6Z8ZWPqNfT6t-i8GW1MKxQrKDUagQqnZ%2B0%2B697%3DMyVeGg@mail.gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-20 13:05:15 +02:00
Ard Biesheuvel b9dce7f1ba arm64: kernel: force ET_DYN ELF type for CONFIG_RELOCATABLE=y
GNU ld used to set the ELF file type to ET_DYN for PIE executables, which
is the same file type used for shared libraries. However, this was changed
recently, and now PIE executables are emitted as ET_EXEC instead.

The distinction is only relevant for ELF loaders, and so there is little
reason to care about the difference when building the kernel, which is
why the change has gone unnoticed until now.

However, debuggers do use the ELF binary, and expect ET_EXEC type files
to appear in memory at the exact offset described in the ELF metadata.
This means source level debugging is no longer possible when KASLR is in
effect or when executing the stub.

So add the -shared LD option when building with CONFIG_RELOCATABLE=y. This
forces the ELF file type to be set to ET_DYN (which is what you get when
building with binutils 2.24 and earlier anyway), and has no other ill
effects.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 11:37:25 +01:00
James Morse d08544127d arm64: suspend: Reconfigure PSTATE after resume from idle
The suspend/resume path in kernel/sleep.S, as used by cpu-idle, does not
save/restore PSTATE. As a result of this cpufeatures that were detected
and have bits in PSTATE get lost when we resume from idle.

UAO gets set appropriately on the next context switch. PAN will be
re-enabled next time we return from user-space, but on a preemptible
kernel we may run work accessing user space before this point.

Add code to re-enable theses two features in __cpu_suspend_exit().
We re-use uao_thread_switch() passing current.

Signed-off-by: James Morse <james.morse@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 09:50:54 +01:00
James Morse 7209c86860 arm64: mm: Set PSTATE.PAN from the cpu_enable_pan() call
Commit 338d4f49d6 ("arm64: kernel: Add support for Privileged Access
Never") enabled PAN by enabling the 'SPAN' feature-bit in SCTLR_EL1.
This means the PSTATE.PAN bit won't be set until the next return to the
kernel from userspace. On a preemptible kernel we may schedule work that
accesses userspace on a CPU before it has done this.

Now that cpufeature enable() calls are scheduled via stop_machine(), we
can set PSTATE.PAN from the cpu_enable_pan() call.

Add WARN_ON_ONCE(in_interrupt()) to check the PSTATE value we updated
is not immediately discarded.

Reported-by: Tony Thompson <anthony.thompson@arm.com>
Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
[will: fixed typo in comment]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 09:50:53 +01:00
James Morse 2a6dcb2b5f arm64: cpufeature: Schedule enable() calls instead of calling them via IPI
The enable() call for a cpufeature/errata is called using on_each_cpu().
This issues a cross-call IPI to get the work done. Implicitly, this
stashes the running PSTATE in SPSR when the CPU receives the IPI, and
restores it when we return. This means an enable() call can never modify
PSTATE.

To allow PAN to do this, change the on_each_cpu() call to use
stop_machine(). This schedules the work on each CPU which allows
us to modify PSTATE.

This involves changing the protype of all the enable() functions.

enable_cpu_capabilities() is called during boot and enables the feature
on all online CPUs. This path now uses stop_machine(). CPU features for
hotplug'd CPUs are enabled by verify_local_cpu_features() which only
acts on the local CPU, and can already modify the running PSTATE as it
is called from secondary_start_kernel().

Reported-by: Tony Thompson <anthony.thompson@arm.com>
Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 09:50:53 +01:00
Andre Przywara 87261d1904 arm64: Cortex-A53 errata workaround: check for kernel addresses
Commit 7dd01aef05 ("arm64: trap userspace "dc cvau" cache operation on
errata-affected core") adds code to execute cache maintenance instructions
in the kernel on behalf of userland on CPUs with certain ARM CPU errata.
It turns out that the address hasn't been checked to be a valid user
space address, allowing userland to clean cache lines in kernel space.
Fix this by introducing an address check before executing the
instructions on behalf of userland.

Since the address doesn't come via a syscall parameter, we can't just
reject tagged pointers and instead have to remove the tag when checking
against the user address limit.

Cc: <stable@vger.kernel.org>
Fixes: 7dd01aef05 ("arm64: trap userspace "dc cvau" cache operation on errata-affected core")
Reported-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[will: rework commit message + replace access_ok with max_user_addr()]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 09:50:49 +01:00
Alex Thorlton caef78b6cd x86/platform/UV: Fix support for EFI_OLD_MEMMAP after BIOS callback updates
Some time ago, we brought our UV BIOS callback code up to speed with the
new EFI memory mapping scheme, in commit:

    d1be84a232 ("x86/uv: Update uv_bios_call() to use efi_call_virt_pointer()")

By leveraging some changes that I made to a few of the EFI runtime
callback mechanisms, in commit:

    80e7559607 ("efi: Convert efi_call_virt() to efi_call_virt_pointer()")

This got everything running smoothly on UV, with the new EFI mapping
code.  However, this left one, small loose end, in that EFI_OLD_MEMMAP
(a.k.a. efi=old_map) will no longer work on UV, on kernels that include
the aforementioned changes.

At the time this was not a major issue (in fact, it still really isn't),
but there's no reason that EFI_OLD_MEMMAP *shouldn't* work on our
systems.  This commit adds a check into uv_bios_call(), to see if we have
the EFI_OLD_MEMMAP bit set in efi.flags.  If it is set, we fall back to
using our old callback method, which uses efi_call() directly on the __va()
of our function pointer.

Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Acked-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: <stable@vger.kernel.org> # v4.7 and later
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1476928131-170101-1-git-send-email-athorlton@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-20 08:47:58 +02:00
Linus Torvalds 147fdd8cf1 Minor changes to improve J2 support and match Kconfig expectations of
other subsystems.
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Merge tag 'sh-for-4.9' of git://git.libc.org/linux-sh

Pull arch/sh updates from Rich Felker:
 "Minor changes to improve J2 support and match Kconfig expectations of
  other subsystems"

* tag 'sh-for-4.9' of git://git.libc.org/linux-sh:
  sh: add earlycon support to j2_defconfig
  sh: add Kconfig option for J-Core SoC core drivers
  sh: support CPU_J2 when compiler lacks -mj2
2016-10-19 11:21:06 -07:00
Linus Torvalds 63ae602cea Merge branch 'gup_flag-cleanups'
Merge the gup_flags cleanups from Lorenzo Stoakes:
 "This patch series adjusts functions in the get_user_pages* family such
  that desired FOLL_* flags are passed as an argument rather than
  implied by flags.

  The purpose of this change is to make the use of FOLL_FORCE explicit
  so it is easier to grep for and clearer to callers that this flag is
  being used.  The use of FOLL_FORCE is an issue as it overrides missing
  VM_READ/VM_WRITE flags for the VMA whose pages we are reading
  from/writing to, which can result in surprising behaviour.

  The patch series came out of the discussion around commit 38e0885465
  ("mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing"),
  which addressed a BUG_ON() being triggered when a page was faulted in
  with PROT_NONE set but having been overridden by FOLL_FORCE.
  do_numa_page() was run on the assumption the page _must_ be one marked
  for NUMA node migration as an actual PROT_NONE page would have been
  dealt with prior to this code path, however FOLL_FORCE introduced a
  situation where this assumption did not hold.

  See

      https://marc.info/?l=linux-mm&m=147585445805166

  for the patch proposal"

Additionally, there's a fix for an ancient bug related to FOLL_FORCE and
FOLL_WRITE by me.

[ This branch was rebased recently to add a few more acked-by's and
  reviewed-by's ]

* gup_flag-cleanups:
  mm: replace access_process_vm() write parameter with gup_flags
  mm: replace access_remote_vm() write parameter with gup_flags
  mm: replace __access_remote_vm() write parameter with gup_flags
  mm: replace get_user_pages_remote() write/force parameters with gup_flags
  mm: replace get_user_pages() write/force parameters with gup_flags
  mm: replace get_vaddr_frames() write/force parameters with gup_flags
  mm: replace get_user_pages_locked() write/force parameters with gup_flags
  mm: replace get_user_pages_unlocked() write/force parameters with gup_flags
  mm: remove write/force parameters from __get_user_pages_unlocked()
  mm: remove write/force parameters from __get_user_pages_locked()
  mm: remove gup_flags FOLL_WRITE games from __get_user_pages()
2016-10-19 08:39:47 -07:00
Piotr Luc 8214899342 x86/cpufeature: Add AVX512_4VNNIW and AVX512_4FMAPS features
AVX512_4VNNIW  - Vector instructions for deep learning enhanced word
variable precision.
AVX512_4FMAPS - Vector instructions for deep learning floating-point
single precision.

These new instructions are to be used in future Intel Xeon & Xeon Phi
processors. The bits 2&3 of CPUID[level:0x07, EDX] inform that new
instructions are supported by a processor.

The spec can be found in the Intel Software Developer Manual (SDM) or in
the Instruction Set Extensions Programming Reference (ISE).

Define new feature flags to enumerate the new instructions in /proc/cpuinfo
accordingly to CPUID bits and add the required xsave extensions which are
required for proper operation.

Signed-off-by: Piotr Luc <piotr.luc@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20161018150111.29926-1-piotr.luc@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-19 17:37:13 +02:00
Renat Valiullin 854dd54245 x86/vmware: Skip timer_irq_works() check on VMware
The timer_irq_works() boot check may sometimes fail in a VM, when
the Host is overcommitted or when the Guest is running nested.

Since the intended check is unnecessary on VMware's virtual
hardware, by-pass it.

Signed-off-by: Renat Valiullin <rvaliullin@vmware.com>
Acked-by: Alok N Kataria <akataria@vmware.com>
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20161013184539.GA11497@rvaliullin-vm
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-19 17:36:33 +02:00
Lorenzo Stoakes f307ab6dce mm: replace access_process_vm() write parameter with gup_flags
This removes the 'write' argument from access_process_vm() and replaces
it with 'gup_flags' as use of this function previously silently implied
FOLL_FORCE, whereas after this patch callers explicitly pass this flag.

We make this explicit as use of FOLL_FORCE can result in surprising
behaviour (and hence bugs) within the mm subsystem.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-19 08:31:25 -07:00
Lorenzo Stoakes 768ae309a9 mm: replace get_user_pages() write/force parameters with gup_flags
This removes the 'write' and 'force' from get_user_pages() and replaces
them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers
as use of this flag can result in surprising behaviour (and hence bugs)
within the mm subsystem.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-19 08:11:43 -07:00
Will Deacon 1e6e57d9b3 arm64: percpu: rewrite ll/sc loops in assembly
Writing the outer loop of an LL/SC sequence using do {...} while
constructs potentially allows the compiler to hoist memory accesses
between the STXR and the branch back to the LDXR. On CPUs that do not
guarantee forward progress of LL/SC loops when faced with memory
accesses to the same ERG (up to 2k) between the failed STXR and the
branch back, we may end up livelocking.

This patch avoids this issue in our percpu atomics by rewriting the
outer loop as part of the LL/SC inline assembly block.

Cc: <stable@vger.kernel.org>
Fixes: f97fc81079 ("arm64: percpu: Implement this_cpu operations")
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-19 15:37:29 +01:00
Will Deacon 1c5b51dfb7 arm64: swp emulation: bound LL/SC retries before rescheduling
If a CPU does not implement a global monitor for certain memory types,
then userspace can attempt a kernel DoS by issuing SWP instructions
targetting the problematic memory (for example, a framebuffer mapped
with non-cacheable attributes).

The SWP emulation code protects against these sorts of attacks by
checking for pending signals and potentially rescheduling when the STXR
instruction fails during the emulation. Whilst this is good for avoiding
livelock, it harms emulation of legitimate SWP instructions on CPUs
where forward progress is not guaranteed if there are memory accesses to
the same reservation granule (up to 2k) between the failing STXR and
the retry of the LDXR.

This patch solves the problem by retrying the STXR a bounded number of
times (4) before breaking out of the LL/SC loop and looking for
something else to do.

Cc: <stable@vger.kernel.org>
Fixes: bd35a4adc4 ("arm64: Port SWP/SWPB emulation support from arm")
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-19 15:37:23 +01:00
Stephen Rothwell 78914ff084 powerpc: Ignore the pkey system calls for now
Eliminates warning messages:

<stdin>:1316:2: warning: #warning syscall pkey_mprotect not implemented [-Wcpp]
<stdin>:1319:2: warning: #warning syscall pkey_alloc not implemented [-Wcpp]
<stdin>:1322:2: warning: #warning syscall pkey_free not implemented [-Wcpp]

Hopefully we will remember to revert this commit if we ever implement
them.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-19 20:36:24 +11:00
Aneesh Kumar K.V 8467801cc8 powerpc: Fix numa topology console print
With recent update to printk, we get console output like below:

[    0.550639] Brought up 160 CPUs
[    0.550718] Node 0 CPUs:
[    0.550721]  0
[    0.550754] -39

[    0.550794] Node 1 CPUs:
[    0.550798]  40
[    0.550817] -79

[    0.550856] Node 16 CPUs:
[    0.550860]  80
[    0.550880] -119

[    0.550917] Node 17 CPUs:
[    0.550923]  120
[    0.550942] -159

Fix this by properly using pr_cont(), ie. KERN_CONT.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-19 20:35:41 +11:00
Michael Ellerman 08b5e79ebd powerpc/mm: Drop dump_numa_memory_topology()
At boot we dump the NUMA memory topology in dump_numa_memory_topology(),
at KERN_DEBUG level, resulting in output like:

  Node 0 Memory: 0x0-0x100000000
  Node 1 Memory: 0x100000000-0x200000000

Which is nice enough, but immediately after that we iterate over each
node and call setup_node_data(), which also prints out the node ranges,
at KERN_INFO, giving eg:

  numa: Initmem setup node 0 [mem 0x00000000-0xffffffff]
  numa: Initmem setup node 1 [mem 0x100000000-0x1ffffffff]

Additionally dump_numa_memory_topology() does not use KERN_CONT
correctly, resulting in split output lines on recent kernels.

So drop dump_numa_memory_topology() as superfluous chatter.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-19 20:35:40 +11:00
Heiner Kallweit 65bc3ece84 powerpc/boot: Fix boot on systems with uncompressed kernel image
This commit broke boot on systems with an uncompressed kernel image,
namely systems using a cuImage. On such systems the compressed boot
image (boot wrapper, uncompressed kernel image, ..) is decompressed
by u-boot already, therefore the boot wrapper code sees an
uncompressed kernel image.

The old decompression code silently assumed an uncompressed kernel
image if it found no valid gzip signature, whilst the new code
bailed out in this case.

Fix this by re-introducing such a fallback if no valid compressed
image is found.

Fixes: 1b7898ee27 ("Use the pre-boot decompression API")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-19 20:35:34 +11:00
Frederic Barrat d2cf909cda powerpc/mm: Prevent unlikely crash in copro_calculate_slb()
If a cxl adapter faults on an invalid address for a kernel context, we
may enter copro_calculate_slb() with a NULL mm pointer (kernel
context) and an effective address which looks like a user
address. Which will cause a crash when dereferencing mm. It is clearly
an AFU bug, but there's no reason to crash either. So return an error,
so that cxl can ack the interrupt with an address error.

Fixes: 73d16a6e0e ("powerpc/cell: Move data segment faulting code out of cell platform")
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-19 20:32:49 +11:00