linux.git/arch/x86/kernel, branch v4.12 Linux kernel source tree Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-01T16:10:17+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-07-01T16:10:17+00:00 e18aca0236a2dac4a134ace4685e97ad09d3605b Pull x86 fixes from Thomas Gleixner: "Fixlets for x86: - Prevent kexec crash when KASLR is enabled, which was caused by an address calculation bug - Restore the freeing of PUDs on memory hot remove - Correct a negated pointer check in the intel uncore performance monitoring driver - Plug a memory leak in an error exit path in the RDT code" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/intel_rdt: Fix memory leak on mount failure x86/boot/KASLR: Fix kexec crash due to 'virt_addr' calculation bug x86/boot/KASLR: Add checking for the offset of kernel virtual address randomization perf/x86/intel/uncore: Fix wrong box pointer check x86/mm/hotplug: Fix BUG_ON() after hot-remove by not freeing PUD 
Pull x86 fixes from Thomas Gleixner:
 "Fixlets for x86:

   - Prevent kexec crash when KASLR is enabled, which was caused by an
     address calculation bug

   - Restore the freeing of PUDs on memory hot remove

   - Correct a negated pointer check in the intel uncore performance
     monitoring driver

   - Plug a memory leak in an error exit path in the RDT code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel_rdt: Fix memory leak on mount failure
  x86/boot/KASLR: Fix kexec crash due to 'virt_addr' calculation bug
  x86/boot/KASLR: Add checking for the offset of kernel virtual address randomization
  perf/x86/intel/uncore: Fix wrong box pointer check
  x86/mm/hotplug: Fix BUG_ON() after hot-remove by not freeing PUD
x86/intel_rdt: Fix memory leak on mount failure 2017-06-30T19:20:00+00:00 Vikas Shivappa vikas.shivappa@linux.intel.com 2017-06-26T18:55:49+00:00 79298acc4ba097e9ab78644e3e38902d73547c92 If mount fails, the kn_info directory is not freed causing memory leak. Add the missing error handling path. Fixes: 4e978d06dedb ("x86/intel_rdt: Add "info" files to resctrl file system") Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ravi.v.shankar@intel.com Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: peterz@infradead.org Cc: vikas.shivappa@intel.com Cc: andi.kleen@intel.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1498503368-20173-3-git-send-email-vikas.shivappa@linux.intel.com 
If mount fails, the kn_info directory is not freed causing memory leak.

Add the missing error handling path.

Fixes: 4e978d06dedb ("x86/intel_rdt: Add "info" files to resctrl file system")
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: vikas.shivappa@intel.com
Cc: andi.kleen@intel.com
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1498503368-20173-3-git-send-email-vikas.shivappa@linux.intel.com
Merge tag 'iommu-fixes-v4.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu 2017-06-30T17:37:48+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-06-30T17:37:48+00:00 27ab862a3afdd7a0285b69a7475f8af7bd2434c4 Pull IOMMU fixes from Joerg Roedel: "Two fixes: - A fix for AMD IOMMU interrupt remapping code when IRQs are forwarded directly to KVM guests - Fixed check in the recently merged code to allow tboot with Intel VT-d disabled" * tag 'iommu-fixes-v4.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: iommu/amd: Fix interrupt remapping when disable guest_mode iommu/vt-d: Correctly disable Intel IOMMU force on 
Pull IOMMU fixes from Joerg Roedel:
 "Two fixes:

   - A fix for AMD IOMMU interrupt remapping code when IRQs are
     forwarded directly to KVM guests

   - Fixed check in the recently merged code to allow tboot with
     Intel VT-d disabled"

* tag 'iommu-fixes-v4.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Fix interrupt remapping when disable guest_mode
  iommu/vt-d: Correctly disable Intel IOMMU force on
arch: remove unused macro/function thread_saved_pc() 2017-06-28T23:13:57+00:00 Tobias Klauser tklauser@distanz.ch 2017-06-28T13:30:02+00:00 6474924e2b5ddb0030c355558966adcbe3b49022 The only user of thread_saved_pc() in non-arch-specific code was removed in commit 8243d5597793 ("sched/core: Remove pointless printout in sched_show_task()"). Remove the implementations as well. Some architectures use thread_saved_pc() in their arch-specific code. Leave their thread_saved_pc() intact. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
The only user of thread_saved_pc() in non-arch-specific code was removed
in commit 8243d5597793 ("sched/core: Remove pointless printout in
sched_show_task()").  Remove the implementations as well.

Some architectures use thread_saved_pc() in their arch-specific code.
Leave their thread_saved_pc() intact.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: larger stack guard gap, between vmas 2017-06-19T13:50:20+00:00 Hugh Dickins hughd@google.com 2017-06-19T11:03:24+00:00 1be7107fbe18eed3e319a6c3e83c78254b693acb Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.

This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.

Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.

One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications.  For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).

Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.

Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.

Original-patch-by: Oleg Nesterov <oleg@redhat.com>
Original-patch-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
iommu/vt-d: Correctly disable Intel IOMMU force on 2017-06-15T14:41:10+00:00 Shaohua Li shli@fb.com 2017-06-08T18:27:14+00:00 7304e8f28bb2f3cb2baf37c1bb2caa0f54ca4e43 I made a mistake in commit bfd20f1. We should skip the force on with the option enabled instead of vice versa. Not sure why this passed our performance test, sorry. Fixes: bfd20f1cc850 ('x86, iommu/vt-d: Add an option to disable Intel IOMMU force on') Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> 
I made a mistake in commit bfd20f1. We should skip the force on with the
option enabled instead of vice versa. Not sure why this passed our
performance test, sorry.

Fixes: bfd20f1cc850 ('x86, iommu/vt-d: Add an option to disable Intel IOMMU force on')
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
x86/debug: Handle early WARN_ONs proper 2017-06-12T19:17:48+00:00 Peter Zijlstra peterz@infradead.org 2017-06-12T11:52:46+00:00 8a524f803a3e0290cdba6d373361b2cef9752934 Hans managed to trigger a WARN very early in the boot which killed his (Virtual) box. The reason is that the recent rework of WARN() to use UD0 forgot to add the fixup_bug() call to early_fixup_exception(). As a result the kernel does not handle the WARN_ON injected UD0 exception and panics. Add the missing fixup call, so early UD's injected by WARN() get handled. Fixes: 9a93848fe787 ("x86/debug: Implement __WARN() using UD0") Reported-and-tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frank Mehnert <frank.mehnert@oracle.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Michael Thayer <michael.thayer@oracle.com> Link: http://lkml.kernel.org/r/20170612180108.w4vgu2ckucmllf3a@hirez.programming.kicks-ass.net 
Hans managed to trigger a WARN very early in the boot which killed his
(Virtual) box.

The reason is that the recent rework of WARN() to use UD0 forgot to add the
fixup_bug() call to early_fixup_exception(). As a result the kernel does
not handle the WARN_ON injected UD0 exception and panics.

Add the missing fixup call, so early UD's injected by WARN() get handled.

Fixes: 9a93848fe787 ("x86/debug: Implement __WARN() using UD0")
Reported-and-tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frank Mehnert <frank.mehnert@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Michael Thayer <michael.thayer@oracle.com>
Link: http://lkml.kernel.org/r/20170612180108.w4vgu2ckucmllf3a@hirez.programming.kicks-ass.net
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2017-06-11T18:07:25+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-06-11T18:07:25+00:00 9d0eb4624601ac978b9e89be4aeadbd51ab2c830 Pull KVM fixes from Paolo Bonzini: "Bug fixes (ARM, s390, x86)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: async_pf: avoid async pf injection when in guest mode KVM: cpuid: Fix read/write out-of-bounds vulnerability in cpuid emulation arm: KVM: Allow unaligned accesses at HYP arm64: KVM: Allow unaligned accesses at EL2 arm64: KVM: Preserve RES1 bits in SCTLR_EL2 KVM: arm/arm64: Handle possible NULL stage2 pud when ageing pages KVM: nVMX: Fix exception injection kvm: async_pf: fix rcu_irq_enter() with irqs enabled KVM: arm/arm64: vgic-v3: Fix nr_pre_bits bitfield extraction KVM: s390: fix ais handling vs cpu model KVM: arm/arm64: Fix isues with GICv2 on GICv3 migration 
Pull KVM fixes from Paolo Bonzini:
 "Bug fixes (ARM, s390, x86)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: async_pf: avoid async pf injection when in guest mode
  KVM: cpuid: Fix read/write out-of-bounds vulnerability in cpuid emulation
  arm: KVM: Allow unaligned accesses at HYP
  arm64: KVM: Allow unaligned accesses at EL2
  arm64: KVM: Preserve RES1 bits in SCTLR_EL2
  KVM: arm/arm64: Handle possible NULL stage2 pud when ageing pages
  KVM: nVMX: Fix exception injection
  kvm: async_pf: fix rcu_irq_enter() with irqs enabled
  KVM: arm/arm64: vgic-v3: Fix nr_pre_bits bitfield extraction
  KVM: s390: fix ais handling vs cpu model
  KVM: arm/arm64: Fix isues with GICv2 on GICv3 migration
x86/microcode/intel: Clear patch pointer before jettisoning the initrd 2017-06-08T08:03:05+00:00 Dominik Brodowski linux@dominikbrodowski.net 2017-06-07T09:58:19+00:00 5b0bc9ac2ce4881ee318a21f31140584ce4dbdad During early boot, load_ucode_intel_ap() uses __load_ucode_intel() to obtain a pointer to the relevant microcode patch (embedded in the initrd), and stores this value in 'intel_ucode_patch' to speed up the microcode patch application for subsequent CPUs. On resuming from suspend-to-RAM, however, load_ucode_ap() calls load_ucode_intel_ap() for each non-boot-CPU. By then the initramfs is long gone so the pointer stored in 'intel_ucode_patch' no longer points to a valid microcode patch. Clear that pointer so that we effectively fall back to the CPU hotplug notifier callbacks to update the microcode. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> [ Edit and massage commit message. ] Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> # 4.10.. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170607095819.9754-1-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org> 
During early boot, load_ucode_intel_ap() uses __load_ucode_intel()
to obtain a pointer to the relevant microcode patch (embedded in the
initrd), and stores this value in 'intel_ucode_patch' to speed up the
microcode patch application for subsequent CPUs.

On resuming from suspend-to-RAM, however, load_ucode_ap() calls
load_ucode_intel_ap() for each non-boot-CPU. By then the initramfs is
long gone so the pointer stored in 'intel_ucode_patch' no longer points to
a valid microcode patch.

Clear that pointer so that we effectively fall back to the CPU hotplug
notifier callbacks to update the microcode.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
[ Edit and massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.10..
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170607095819.9754-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kvm: async_pf: fix rcu_irq_enter() with irqs enabled 2017-06-06T12:43:16+00:00 Paolo Bonzini pbonzini@redhat.com 2017-04-26T14:56:26+00:00 bbaf0e2b1c1b4f88abd6ef49576f0efb1734eae5 native_safe_halt enables interrupts, and you just shouldn't call rcu_irq_enter() with interrupts enabled. Reorder the call with the following local_irq_disable() to respect the invariant. Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> 
native_safe_halt enables interrupts, and you just shouldn't
call rcu_irq_enter() with interrupts enabled.  Reorder the
call with the following local_irq_disable() to respect the
invariant.

Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>