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2015-12-30arch/x86/xen/suspend.c: include xen/xen.hAndrew Morton1-0/+1
Fix the build warning: arch/x86/xen/suspend.c: In function 'xen_arch_pre_suspend': arch/x86/xen/suspend.c:70:9: error: implicit declaration of function 'xen_pv_domain' [-Werror=implicit-function-declaration] if (xen_pv_domain()) ^ Reported-by: kbuild test robot <fengguang.wu@intel.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-23Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds5-15/+41
Pull kvm fixes from Paolo Bonzini: - A series of fixes to the MTRR emulation, tested in the BZ by several users so they should be safe this late - A fix for a division by zero - Two very simple ARM and PPC fixes * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Reload pit counters for all channels when restoring state KVM: MTRR: treat memory as writeback if MTRR is disabled in guest CPUID KVM: MTRR: observe maxphyaddr from guest CPUID, not host KVM: MTRR: fix fixed MTRR segment look up KVM: VMX: Fix host initiated access to guest MSR_TSC_AUX KVM: arm/arm64: vgic: Fix kvm_vgic_map_is_active's dist check kvm: x86: move tracepoints outside extended quiescent state KVM: PPC: Book3S HV: Prohibit setting illegal transaction state in MSR
2015-12-23um: Fix pointer castMickaël Salaün1-1/+1
Fix a pointer cast typo introduced in v4.4-rc5 especially visible for the i386 subarchitecture where it results in a kernel crash. [ Also removed pointless cast as per Al Viro - Linus ] Fixes: 8090bfd2bb9a ("um: Fix fpstate handling") Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Jeff Dike <jdike@addtoit.com> Acked-by: Richard Weinberger <richard@nod.at> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-22KVM: x86: Reload pit counters for all channels when restoring stateAndrew Honig1-2/+6
Currently if userspace restores the pit counters with a count of 0 on channels 1 or 2 and the guest attempts to read the count on those channels, then KVM will perform a mod of 0 and crash. This will ensure that 0 values are converted to 65536 as per the spec. This is CVE-2015-7513. Signed-off-by: Andy Honig <ahonig@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-22KVM: MTRR: treat memory as writeback if MTRR is disabled in guest CPUIDPaolo Bonzini2-3/+19
Virtual machines can be run with CPUID such that there are no MTRRs. In that case, the firmware will never enable MTRRs and it is obviously undesirable to run the guest entirely with UC memory. Check out guest CPUID, and use WB memory if MTRR do not exist. Cc: qemu-stable@nongnu.org Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=107561 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-22KVM: MTRR: observe maxphyaddr from guest CPUID, not hostPaolo Bonzini1-2/+7
Conversion of MTRRs to ranges used the maxphyaddr from the boot CPU. This is wrong, because var_mtrr_range's mask variable then is discontiguous (like FF00FFFF000, where the first run of 0s corresponds to the bits between host and guest maxphyaddr). Instead always set up the masks to be full 64-bit values---we know that the reserved bits at the top are zero, and we can restore them when reading the MSR. This way var_mtrr_range gets a mask that just works. Fixes: a13842dc668b40daef4327294a6d3bdc8bd30276 Cc: qemu-stable@nongnu.org Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=107561 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-22KVM: MTRR: fix fixed MTRR segment look upAlexis Dambricourt1-1/+1
This fixes the slow-down of VM running with pci-passthrough, since some MTRR range changed from MTRR_TYPE_WRBACK to MTRR_TYPE_UNCACHABLE. Memory in the 0K-640K range was incorrectly treated as uncacheable. Fixes: f7bfb57b3e89ff89c0da9f93dedab89f68d6ca27 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=107561 Cc: qemu-stable@nongnu.org Signed-off-by: Alexis Dambricourt <alexis.dambricourt@gmail.com> [Use correct BZ for "Fixes" annotation. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-18Merge tag 'for-linus-4.4-rc5-tag' of ↵Linus Torvalds2-17/+12
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen bug fixes from David Vrabel: - XSA-155 security fixes to backend drivers. - XSA-157 security fixes to pciback. * tag 'for-linus-4.4-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-pciback: fix up cleanup path when alloc fails xen/pciback: Don't allow MSI-X ops if PCI_COMMAND_MEMORY is not set. xen/pciback: For XEN_PCI_OP_disable_msi[|x] only disable if device has MSI(X) enabled. xen/pciback: Do not install an IRQ handler for MSI interrupts. xen/pciback: Return error on XEN_PCI_OP_enable_msix when device has MSI or MSI-X enabled xen/pciback: Return error on XEN_PCI_OP_enable_msi when device has MSI or MSI-X enabled xen/pciback: Save xen_pci_op commands before processing it xen-scsiback: safely copy requests xen-blkback: read from indirect descriptors only once xen-blkback: only read request operation from shared ring once xen-netback: use RING_COPY_REQUEST() throughout xen-netback: don't use last request to determine minimum Tx credit xen: Add RING_COPY_REQUEST() xen/x86/pvh: Use HVM's flush_tlb_others op xen: Resume PMU from non-atomic context xen/events/fifo: Consume unprocessed events when a CPU dies
2015-12-15Fix user-visible spelling errorLinus Torvalds1-1/+1
Pavel Machek reports a warning about W+X pages found in the "Persisent" kmap area. After grepping for it (using the correct spelling), and not finding it, I noticed how the debug printk was just misspelled. Fix it. The actual mapping bug that Pavel reported is still open. It's apparently a separate issue from the known EFI page tables, looks like it's related to the HIGHMEM mappings. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-14KVM: VMX: Fix host initiated access to guest MSR_TSC_AUXHaozhong Zhang1-2/+2
The current handling of accesses to guest MSR_TSC_AUX returns error if vcpu does not support rdtscp, though those accesses are initiated by host. This can result in the reboot failure of some versions of QEMU. This patch fixes this issue by passing those host initiated accesses for further handling instead. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-14xen/x86/pvh: Use HVM's flush_tlb_others opBoris Ostrovsky1-7/+2
Using MMUEXT_TLB_FLUSH_MULTI doesn't buy us much since the hypervisor will likely perform same IPIs as would have the guest. More importantly, using MMUEXT_INVLPG_MULTI may not to invalidate the guest's address on remote CPU (when, for example, VCPU from another guest is running there). Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-12-11kvm: x86: move tracepoints outside extended quiescent statePaolo Bonzini3-5/+6
Invoking tracepoints within kvm_guest_enter/kvm_guest_exit causes a lockdep splat. Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-09Merge branch 'for-linus-4.4-rc5' of ↵Linus Torvalds1-8/+10
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull uml fixes from Richard Weinberger: "This contains various bug fixes, most of them are fall out from the merge window" * 'for-linus-4.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: fix returns without va_end um: Fix fpstate handling arch: um: fix error when linking vmlinux. um: Fix get_signal() usage
2015-12-09um: Fix fpstate handlingRichard Weinberger1-8/+10
The x86 FPU cleanup changed fpstate to a plain integer. UML on x86 has to deal with that too. Signed-off-by: Richard Weinberger <richard@nod.at>
2015-12-09Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds6-7/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This tree includes four core perf fixes for misc bugs, three fixes to x86 PMU drivers, and two updates to old email addresses" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Do not send exit event twice perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macro perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on Haswell perf: Fix PERF_EVENT_IOC_PERIOD deadlock treewide: Remove old email address perf/x86: Fix LBR call stack save/restore perf: Update email address in MAINTAINERS perf/core: Robustify the perf_cgroup_from_task() RCU checks perf/core: Fix RCU problem with cgroup context switching code
2015-12-06Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds12-36/+54
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thoma Gleixner: "Another round of fixes for x86: - Move the initialization of the microcode driver to late_initcall to make sure everything that init function needs is available. - Make sure that lockdep knows about interrupts being off in the entry code before calling into c-code. - Undo the cpu hotplug init delay regression. - Use the proper conditionals in the mpx instruction decoder. - Fixup restart_syscall for x32 tasks. - Fix the hugepage regression on PAE kernels which was introduced with the latest PAT changes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/signal: Fix restart_syscall number for x32 tasks x86/mpx: Fix instruction decoder condition x86/mm: Fix regression with huge pages on PAE x86 smpboot: Re-enable init_udelay=0 by default on modern CPUs x86/entry/64: Fix irqflag tracing wrt context tracking x86/microcode: Initialize the driver late when facilities are up
2015-12-06perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macroJiri Olsa1-1/+1
We need to add rest of the flags to the constraint mask instead of another INTEL_ARCH_EVENT_MASK, fixing a typo. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1447061071-28085-1-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-06perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on HaswellYuanfang Chen1-1/+1
There was a mistake in the Haswell constraints table. Signed-off-by: Yuanfang Chen <cheny@udel.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1448384701-9110-1-git-send-email-cheny@udel.edu Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-05x86/signal: Fix restart_syscall number for x32 tasksDmitry V. Levin1-7/+10
When restarting a syscall with regs->ax == -ERESTART_RESTARTBLOCK, regs->ax is assigned to a restart_syscall number. For x32 tasks, this syscall number must have __X32_SYSCALL_BIT set, otherwise it will be an x86_64 syscall number instead of a valid x32 syscall number. This issue has been there since the introduction of x32. Reported-by: strace/tests/restart_syscall.test Reported-and-tested-by: Elvira Khabirova <lineprinter0@gmail.com> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Cc: Elvira Khabirova <lineprinter0@gmail.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20151130215436.GA25996@altlinux.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-05x86/mpx: Fix instruction decoder conditionDave Hansen1-3/+3
MPX decodes instructions in order to tell which bounds register was violated. Part of this decoding involves looking at the "REX prefix" which is a special instrucion prefix used to retrofit support for new registers in to old instructions. The X86_REX_*() macros are defined to return actual bit values: #define X86_REX_R(rex) ((rex) & 4) *not* boolean values. However, the MPX code was checking for them like they were booleans. This might have led to us mis-decoding the "REX prefix" and giving false information out to userspace about bounds violations. X86_REX_B() actually is bit 1, so this is really only broken for the X86_REX_X() case. Fix the conditionals up to tolerate the non-boolean values. Fixes: fcc7ffd67991 "x86, mpx: Decode MPX instruction to get bound violation information" Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: x86@kernel.org Cc: Dave Hansen <dave@sr71.net> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20151201003113.D800C1E0@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-04Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds1-0/+12
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: - NFIT parsing regression fixes from Linda. The nvdimm hot-add implementation merged in 4.4-rc1 interpreted the specification in a way that breaks actual HPE platforms. We are also closing the loop with the ACPI Working Group to get this clarification added to the spec. - Andy pointed out that his laptop without nvdimm resources is loading the e820-nvdimm module by default, fix that up to only load the module when an e820-type-12 range is present. * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: nfit: Adjust for different _FIT and NFIT headers nfit: Fix the check for a successful NFIT merge nfit: Account for table size length variation libnvdimm, e820: skip module loading when no type-12
2015-12-04Merge branches 'acpi-pci' and 'pm-pci'Rafael J. Wysocki218-4722/+8555
* acpi-pci: x86/PCI/ACPI: Fix regression caused by commit 4d6b4e69a245 * pm-pci: PCI / PM: Tune down retryable runtime suspend error messages
2015-12-04x86/mm: Fix regression with huge pages on PAEKirill A. Shutemov6-19/+17
Recent PAT patchset has caused issue on 32-bit PAE machines: page:eea45000 count:0 mapcount:-128 mapping: (null) index:0x0 flags: 0x40000000() page dumped because: VM_BUG_ON_PAGE(page_mapcount(page) < 0) ------------[ cut here ]------------ kernel BUG at /home/build/linux-boris/mm/huge_memory.c:1485! invalid opcode: 0000 [#1] SMP [...] Call Trace: unmap_single_vma ? __wake_up unmap_vmas unmap_region do_munmap vm_munmap SyS_munmap do_fast_syscall_32 ? __do_page_fault sysenter_past_esp Code: ... EIP: [<c11bde80>] zap_huge_pmd+0x240/0x260 SS:ESP 0068:f6459d98 The problem is in pmd_pfn_mask() and pmd_flags_mask(). These helpers use PMD_PAGE_MASK to calculate resulting mask. PMD_PAGE_MASK is 'unsigned long', not 'unsigned long long' as phys_addr_t is on 32-bit PAE (ARCH_PHYS_ADDR_T_64BIT). As a result, the upper bits of resulting mask get truncated. pud_pfn_mask() and pud_flags_mask() aren't problematic since we don't have PUD page table level on 32-bit systems, but it's reasonable to keep them consistent with PMD counterpart. Introduce PHYSICAL_PMD_PAGE_MASK and PHYSICAL_PUD_PAGE_MASK in addition to existing PHYSICAL_PAGE_MASK and reworks helpers to use them. Reported-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> [ Fix -Woverflow warnings from the realmode code. ] Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jürgen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: elliott@hpe.com Cc: konrad.wilk@oracle.com Cc: linux-mm <linux-mm@kvack.org> Fixes: f70abb0fc3da ("x86/asm: Fix pud/pmd interfaces to handle large PAT bit") Link: http://lkml.kernel.org/r/1448878233-11390-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-02xen: Resume PMU from non-atomic contextBoris Ostrovsky1-10/+10
Resuming PMU currently triggers a warning from ___might_sleep() (assuming CONFIG_DEBUG_ATOMIC_SLEEP is set) when xen_pmu_init() allocates GFP_KERNEL page because we are in state resembling atomic context. Move resuming PMU to xen_arch_resume() which is called in regular context. For symmetry move suspending PMU to xen_arch_suspend() as well. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: <stable@vger.kernel.org> # 4.3 Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-12-02x86/PCI/ACPI: Fix regression caused by commit 4d6b4e69a245Liu Jiang1-11/+2
Commit 4d6b4e69a245 ("x86/PCI/ACPI: Use common interface to support PCI host bridge") converted x86 to use the common interface acpi_pci_root_create, but the conversion missed on code piece in arch/x86/pci/bus_numa.c, which causes regression on some legacy AMD platforms as reported by Arthur Marsh <arthur.marsh@internode.on.net>. The root causes is that acpi_pci_root_create() fails to insert host bridge resources into iomem_resource/ioport_resource because x86_pci_root_bus_resources() has already inserted those resources. So change x86_pci_root_bus_resources() to not insert resources into iomem_resource/ioport_resource. Fixes: 4d6b4e69a245 ("x86/PCI/ACPI: Use common interface to support PCI host bridge") Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Reported-and-tested-by: Arthur Marsh <arthur.marsh@internode.on.net> Reported-and-tested-by: Krzysztof Kolasa <kkolasa@winsoft.pl> Reported-and-tested-by: Keith Busch <keith.busch@intel.com> Reported-and-tested-by: Hans de Bruin <jmdebruin@xmsnet.nl> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-30libnvdimm, e820: skip module loading when no type-12Dan Williams1-0/+12
If there are no persistent memory ranges present then don't bother creating the platform device. Otherwise, it loads the full libnvdimm sub-system only to discover no resources present. Reported-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-11-26x86 smpboot: Re-enable init_udelay=0 by default on modern CPUsLen Brown1-4/+5
commit f1ccd249319e allowed the cmdline "cpu_init_udelay=" to work with all values, including the default of 10000. But in setting the default of 10000, it over-rode the code that sets the delay 0 on modern processors. Also, tidy up use of INT/UINT. Fixes: f1ccd249319e "x86/smpboot: Fix cpu_init_udelay=10000 corner case boot parameter misbehavior" Reported-by: Shane <shrybman@teksavvy.com> Signed-off-by: Len Brown <len.brown@intel.com> Cc: dparsons@brightdsl.net Cc: stable@kernel.org Link: http://lkml.kernel.org/r/9082eb809ef40dad02db714759c7aaf618c518d4.1448232494.git.len.brown@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-11-25KVM: nVMX: remove incorrect vpid check in nested invvpid emulationHaozhong Zhang1-5/+0
This patch removes the vpid check when emulating nested invvpid instruction of type all-contexts invalidation. The existing code is incorrect because: (1) According to Intel SDM Vol 3, Section "INVVPID - Invalidate Translations Based on VPID", invvpid instruction does not check vpid in the invvpid descriptor when its type is all-contexts invalidation. (2) According to the same document, invvpid of type all-contexts invalidation does not require there is an active VMCS, so/and get_vmcs12() in the existing code may result in a NULL-pointer dereference. In practice, it can crash both KVM itself and L1 hypervisors that use invvpid (e.g. Xen). Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-24Merge tag 'kvm-arm-for-v4.4-rc3' of ↵Paolo Bonzini6-17/+54
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/ARM Fixes for v4.4-rc3. Includes some timer fixes, properly unmapping PTEs, an errata fix, and two tweaks to the EL2 panic code.
2015-11-24x86/entry/64: Fix irqflag tracing wrt context trackingAndy Lutomirski1-1/+18
Paolo pointed out that enter_from_user_mode could be called while irqflags were traced as though IRQs were on. In principle, this could confuse lockdep. It doesn't cause any problems that I've seen in any configuration, but if I build with CONFIG_DEBUG_LOCKDEP=y, enable a nohz_full CPU, and add code like: if (irqs_disabled()) { spin_lock(&something); spin_unlock(&something); } to the top of enter_from_user_mode, then lockdep will complain without this fix. It seems that lockdep's irqflags sanity checks are too weak to detect this bug without forcing the issue. This patch adds one byte to normal kernels, and it's IMO a bit ugly. I haven't spotted a better way to do this yet, though. The issue is that we can't do TRACE_IRQS_OFF until after SWAPGS (if needed), but we're also supposed to do it before calling C code. An alternative approach would be to call trace_hardirqs_off in enter_from_user_mode. That would be less code and would not bloat normal kernels at all, but it would be harder to see how the code worked. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/86237e362390dfa6fec12de4d75a238acb0ae787.1447361906.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23x86/microcode: Initialize the driver late when facilities are upBorislav Petkov2-2/+1
Running microcode_init() from setup_arch() is a bad idea because not even kmalloc() is ready at that point and the loader does all kinds of allocations and init/registration with various subsystems. Make it a late initcall when required facilities are initialized so that the microcode driver initialization can succeed too. Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20151120112400.GC4028@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23treewide: Remove old email addressPeter Zijlstra3-3/+3
There were still a number of references to my old Red Hat email address in the kernel source. Remove these while keeping the Red Hat copyright notices intact. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23perf/x86: Fix LBR call stack save/restoreAndi Kleen2-1/+4
This fixes a bug I added in the following commit: 90405aa02247 ("perf/x86/intel/lbr: Limit LBR accesses to TOS in callstack mode") The bug could lead to lost LBR call stacks. When restoring the LBR state we need to use the TOS of the previous context, not the current context. To do that we need to save/restore the TOS. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1445366797-30894-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23perf/core: Robustify the perf_cgroup_from_task() RCU checksStephane Eranian1-1/+1
This patch reinforces the lockdep checks performed by perf_cgroup_from_tsk() by passing the perf_event_context whenever possible. It is okay to not hold the RCU read lock when we know we hold the ctx->lock. This patch makes sure this property holds. In some functions, such as perf_cgroup_sched_in(), we do not pass the context because we are sure we are holding the RCU read lock. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: edumazet@google.com Link: http://lkml.kernel.org/r/1447322404-10920-3-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-22Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds5-15/+53
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "This update contains: - MPX updates for handling 32bit processes - A fix for a long standing bug in 32bit signal frame handling related to FPU/XSAVE state - Handle get_xsave_addr() correctly in KVM - Fix SMAP check under paravirtualization - Add a comment to the static function trace entry to avoid further confusion about the difference to dynamic tracing" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Fix SMAP check in PVOPS environments x86/ftrace: Add comment on static function tracing x86/fpu: Fix get_xsave_addr() behavior under virtualization x86/fpu: Fix 32-bit signal frame handling x86/mpx: Fix 32-bit address space calculation x86/mpx: Do proper get_user() when running 32-bit binaries on 64-bit kernels
2015-11-19x86/cpu: Fix SMAP check in PVOPS environmentsAndrew Cooper1-2/+1
There appears to be no formal statement of what pv_irq_ops.save_fl() is supposed to return precisely. Native returns the full flags, while lguest and Xen only return the Interrupt Flag, and both have comments by the implementations stating that only the Interrupt Flag is looked at. This may have been true when initially implemented, but no longer is. To make matters worse, the Xen PVOP leaves the upper bits undefined, making the BUG_ON() undefined behaviour. Experimentally, this now trips for 32bit PV guests on Broadwell hardware. The BUG_ON() is consistent for an individual build, but not consistent for all builds. It has also been a sitting timebomb since SMAP support was introduced. Use native_save_fl() instead, which will obtain an accurate view of the AC flag. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Tested-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: <lguest@lists.ozlabs.org> Cc: Xen-devel <xen-devel@lists.xen.org> CC: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1433323874-6927-1-git-send-email-andrew.cooper3@citrix.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-11-19x86/ftrace: Add comment on static function tracingNamhyung Kim1-0/+6
There was a confusion between update_ftrace_function() and static function tracing trampoline regarding 3rd parameter (ftrace_ops). Add a comment for clarification. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1447721004-2551-1-git-send-email-namhyung@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-11-18KVM: x86: request interrupt window when IRQ chip is splitMatt Gingell1-2/+4
Before this patch, we incorrectly enter the guest without requesting an interrupt window if the IRQ chip is split between user space and the kernel. Because lapic_in_kernel no longer implies the PIC is in the kernel, this patch tests pic_in_kernel to determining whether an interrupt window should be requested when entering the guest. If the APIC is in the kernel and we request an interrupt window the guest will return immediately. If the APIC is masked the guest will not not make forward progress and unmask it, leading to a loop when KVM reenters and requests again. This patch adds a check to ensure the APIC is ready to accept an interrupt before requesting a window. Reviewed-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Matt Gingell <gingell@google.com> [Use the other newly introduced functions. - Paolo] Fixes: 1c1a9ce973a7863dd46767226bce2a5f12d48bc6 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-18KVM: x86: set KVM_REQ_EVENT on local interrupt request from user spaceMatt Gingell1-0/+1
Set KVM_REQ_EVENT when a PIC in user space injects a local interrupt. Currently a request is only made when neither the PIC nor the APIC is in the kernel, which is not sufficient in the split IRQ chip case. This addresses a problem in QEMU where interrupts are delayed until another path invokes the event loop. Reviewed-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Matt Gingell <gingell@google.com> Fixes: 1c1a9ce973a7863dd46767226bce2a5f12d48bc6 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-18KVM: x86: split kvm_vcpu_ready_for_interrupt_injection out of ↵Matt Gingell1-24/+19
dm_request_for_irq_injection This patch breaks out a new function kvm_vcpu_ready_for_interrupt_injection. This routine encapsulates the logic required to determine whether a vcpu is ready to accept an interrupt injection, which is now required on multiple paths. Reviewed-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Matt Gingell <gingell@google.com> Fixes: 1c1a9ce973a7863dd46767226bce2a5f12d48bc6 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-18KVM: x86: fix interrupt window handling in split IRQ chip caseMatt Gingell1-14/+19
This patch ensures that dm_request_for_irq_injection and post_kvm_run_save are in sync, avoiding that an endless ping-pong between userspace (who correctly notices that IF=0) and the kernel (who insists that userspace handles its request for the interrupt window). To synchronize them, it also adds checks for kvm_arch_interrupt_allowed and !kvm_event_needs_reinjection. These are always needed, not just for in-kernel LAPIC. Signed-off-by: Matt Gingell <gingell@google.com> [A collage of two patches from Matt. - Paolo] Fixes: 1c1a9ce973a7863dd46767226bce2a5f12d48bc6 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-17Merge branch 'pm-tools'Rafael J. Wysocki1-2/+1
* pm-tools: x86: remove unused definition of MSR_NHM_PLATFORM_INFO tools/power turbostat: use new name for MSR_PLATFORM_INFO
2015-11-15Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-6/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Thomas Gleixner: "Mostly updates to the perf tool plus two fixes to the kernel core code: - Handle tracepoint filters correctly for inherited events (Peter Zijlstra) - Prevent a deadlock in perf_lock_task_context (Paul McKenney) - Add missing newlines to some pr_err() calls (Arnaldo Carvalho de Melo) - Print full source file paths when using 'perf annotate --print-line --full-paths' (Michael Petlan) - Fix 'perf probe -d' when just one out of uprobes and kprobes is enabled (Wang Nan) - Add compiler.h to list.h to fix 'make perf-tar-src-pkg' generated tarballs, i.e. out of tree building (Arnaldo Carvalho de Melo) - Add the llvm-src-base.c and llvm-src-kbuild.c files, generated by the 'perf test' LLVM entries, when running it in-tree, to .gitignore (Yunlong Song) - libbpf error reporting improvements, using a strerror interface to more precisely tell the user about problems with the provided scriptlet, be it in C or as a ready made object file (Wang Nan) - Do not be case sensitive when searching for matching 'perf test' entries (Arnaldo Carvalho de Melo) - Inform the user about objdump failures in 'perf annotate' (Andi Kleen) - Improve the LLVM 'perf test' entry, introduce a new ones for BPF and kbuild tests to check the environment used by clang to compile .c scriptlets (Wang Nan)" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) perf/x86/intel/rapl: Remove the unused RAPL_EVENT_DESC() macro tools include: Add compiler.h to list.h perf probe: Verify parameters in two functions perf session: Add missing newlines to some pr_err() calls perf annotate: Support full source file paths for srcline fix perf test: Add llvm-src-base.c and llvm-src-kbuild.c to .gitignore perf: Fix inherited events vs. tracepoint filters perf: Disable IRQs across RCU RS CS that acquires scheduler lock perf test: Do not be case sensitive when searching for matching tests perf test: Add 'perf test BPF' perf test: Enhance the LLVM tests: add kbuild test perf test: Enhance the LLVM test: update basic BPF test program perf bpf: Improve BPF related error messages perf tools: Make fetch_kernel_version() publicly available bpf tools: Add new API bpf_object__get_kversion() bpf tools: Improve libbpf error reporting perf probe: Cleanup find_perf_probe_point_from_map to reduce redundancy perf annotate: Inform the user about objdump failures in --stdio perf stat: Make stat options global perf sched latency: Fix thread pid reuse issue ...
2015-11-15Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds9-16/+73
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A couple of fixes and updates related to x86: - Fix the W+X check regression on XEN - The real fix for the low identity map trainwreck - Probe legacy PIC early instead of unconditionally allocating legacy irqs - Add cpu verification to long mode entry - Adjust the cache topology to AMD Fam17H systems - Let Merrifield use the TSC across S3" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Call verify_cpu() after having entered long mode too x86/setup: Fix low identity map for >= 2GB kernel range x86/mm: Skip the hypervisor range when walking PGD x86/AMD: Fix last level cache topology for AMD Fam17h systems x86/irq: Probe for PIC presence before allocating descs for legacy IRQs x86/cpu/intel: Enable X86_FEATURE_NONSTOP_TSC_S3 for Merrifield
2015-11-14x86: remove unused definition of MSR_NHM_PLATFORM_INFOLen Brown1-2/+1
MSR_NHM_PLATFORM_INFO has been replaced by... MSR_PLATFORM_INFO Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds10-211/+223
Pull second batch of kvm updates from Paolo Bonzini: "Four changes: - x86: work around two nasty cases where a benign exception occurs while another is being delivered. The endless stream of exceptions causes an infinite loop in the processor, which not even NMIs or SMIs can interrupt; in the virt case, there is no possibility to exit to the host either. - x86: support for Skylake per-guest TSC rate. Long supported by AMD, the patches mostly move things from there to common arch/x86/kvm/ code. - generic: remove local_irq_save/restore from the guest entry and exit paths when context tracking is enabled. The patches are a few months old, but we discussed them again at kernel summit. Andy will pick up from here and, in 4.5, try to remove it from the user entry/exit paths. - PPC: Two bug fixes, see merge commit 370289756becc for details" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits) KVM: x86: rename update_db_bp_intercept to update_bp_intercept KVM: svm: unconditionally intercept #DB KVM: x86: work around infinite loop in microcode when #AC is delivered context_tracking: avoid irq_save/irq_restore on guest entry and exit context_tracking: remove duplicate enabled check KVM: VMX: Dump TSC multiplier in dump_vmcs() KVM: VMX: Use a scaled host TSC for guest readings of MSR_IA32_TSC KVM: VMX: Setup TSC scaling ratio when a vcpu is loaded KVM: VMX: Enable and initialize VMX TSC scaling KVM: x86: Use the correct vcpu's TSC rate to compute time scale KVM: x86: Move TSC scaling logic out of call-back read_l1_tsc() KVM: x86: Move TSC scaling logic out of call-back adjust_tsc_offset() KVM: x86: Replace call-back compute_tsc_offset() with a common function KVM: x86: Replace call-back set_tsc_khz() with a common function KVM: x86: Add a common TSC scaling function KVM: x86: Add a common TSC scaling ratio field in kvm_vcpu_arch KVM: x86: Collect information for setting TSC scaling ratio KVM: x86: declare a few variables as __read_mostly KVM: x86: merge handle_mmio_page_fault and handle_mmio_page_fault_common KVM: PPC: Book3S HV: Don't dynamically split core when already split ...
2015-11-12perf/x86/intel/rapl: Remove the unused RAPL_EVENT_DESC() macroHuang Rui1-6/+0
Signed-off-by: Huang Rui <ray.huang@amd.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Li <tony.li@amd.com> Link: http://lkml.kernel.org/r/1446630233-3166-1-git-send-email-ray.huang@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-12x86/fpu: Fix get_xsave_addr() behavior under virtualizationHuaitong Han1-1/+0
KVM uses the get_xsave_addr() function in a different fashion from the native kernel, in that the 'xsave' parameter belongs to guest vcpu, not the currently running task. But 'xsave' is replaced with current task's (host) xsave structure, so get_xsave_addr() will incorrectly return the bad xsave address to KVM. Fix it so that the passed in 'xsave' address is used - as intended originally. Signed-off-by: Huaitong Han <huaitong.han@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave.hansen@intel.com Link: http://lkml.kernel.org/r/1446800423-21622-1-git-send-email-huaitong.han@intel.com [ Tidied up the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-12x86/fpu: Fix 32-bit signal frame handlingDave Hansen1-6/+5
(This should have gone to LKML originally. Sorry for the extra noise, folks on the cc.) Background: Signal frames on x86 have two formats: 1. For 32-bit executables (whether on a real 32-bit kernel or under 32-bit emulation on a 64-bit kernel) we have a 'fpregset_t' that includes the "FSAVE" registers. 2. For 64-bit executables (on 64-bit kernels obviously), the 'fpregset_t' is smaller and does not contain the "FSAVE" state. When creating the signal frame, we have to be aware of whether we are running a 32 or 64-bit executable so we create the correct format signal frame. Problem: save_xstate_epilog() uses 'fx_sw_reserved_ia32' whenever it is called for a 32-bit executable. This is for real 32-bit and ia32 emulation. But, fpu__init_prepare_fx_sw_frame() only initializes 'fx_sw_reserved_ia32' when emulation is enabled, *NOT* for real 32-bit kernels. This leads to really wierd situations where 32-bit programs lose their extended state when returning from a signal handler. The kernel copies the uninitialized (zero) 'fx_sw_reserved_ia32' out to userspace in save_xstate_epilog(). But when returning from the signal, the kernel errors out in check_for_xstate() when it does not see FP_XSTATE_MAGIC1 present (because it was zeroed). This leads to the FPU/XSAVE state being initialized. For MPX, this leads to the most permissive state and means we silently lose bounds violations. I think this would also mean that we could lose *ANY* FPU/SSE/AVX state. I'm not sure why no one has spotted this bug. I believe this was broken by: 72a671ced66d ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels") way back in 2012. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@sr71.net Cc: fenghua.yu@intel.com Cc: yu-cheng.yu@intel.com Link: http://lkml.kernel.org/r/20151111002354.A0799571@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-12x86/mpx: Fix 32-bit address space calculationDave Hansen1-5/+17
I received a bug report that running 32-bit MPX binaries on 64-bit kernels was broken. I traced it down to this little code snippet. We were switching our "number of bounds directory entries" calculation correctly. But, we didn't switch the other side of the calculation: the virtual space size. This meant that we were calculating an absurd size for bd_entry_virt_space() on 32-bit because we used the 64-bit virt_space. This was _also_ broken for 32-bit kernels running on 64-bit hardware since boot_cpu_data.x86_virt_bits=48 even when running in 32-bit mode. Correct that and properly handle all 3 possible cases: 1. 32-bit binary on 64-bit kernel 2. 64-bit binary on 64-bit kernel 3. 32-bit binary on 32-bit kernel This manifested in having bounds tables not properly unmapped. It "leaked" memory but had no functional impact otherwise. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> 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/20151111181934.FA7FAC34@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>