aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel
AgeCommit message (Collapse)AuthorFilesLines
2018-01-14x86/idt: Mark IDT tables __initconstAndi Kleen1-6/+6
const variables must use __initconst, not __initdata. Fix this up for the IDT tables, which got it consistently wrong. Fixes: 16bc18d895ce ("x86/idt: Move 32-bit idt_descr to C code") Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20171222001821.2157-7-andi@firstfloor.org
2018-01-14Revert "x86/apic: Remove init_bsp_APIC()"Ville Syrjälä2-0/+52
This reverts commit b371ae0d4a194b178817b0edfb6a7395c7aec37a. It causes boot hangs on old P3/P4 systems when the local APIC is enforced in UP mode. Reported-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: yinghai@kernel.org Cc: bhe@redhat.com Link: https://lkml.kernel.org/r/20171128145350.21560-1-ville.syrjala@linux.intel.com
2018-01-14x86/tsc: Print tsc_khz, when it differs from cpu_khzLen Brown1-0/+6
If CPU and TSC frequency are the same the printout of the CPU frequency is valid for the TSC as well: tsc: Detected 2900.000 MHz processor If the TSC frequency is different there is no information in dmesg. Add a conditional printout: tsc: Detected 2904.000 MHz TSC Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: peterz@infradead.org Link: https://lkml.kernel.org/r/537b342debcd8e8aebc8d631015dcdf9f9ba8a26.1513920414.git.len.brown@intel.com
2018-01-14x86/tsc: Fix erroneous TSC rate on Skylake XeonLen Brown1-1/+0
The INTEL_FAM6_SKYLAKE_X hardcoded crystal_khz value of 25MHZ is problematic: - SKX workstations (with same model # as server variants) use a 24 MHz crystal. This results in a -4.0% time drift rate on SKX workstations. - SKX servers subject the crystal to an EMI reduction circuit that reduces its actual frequency by (approximately) -0.25%. This results in -1 second per 10 minute time drift as compared to network time. This issue can also trigger a timer and power problem, on configurations that use the LAPIC timer (versus the TSC deadline timer). Clock ticks scheduled with the LAPIC timer arrive a few usec before the time they are expected (according to the slow TSC). This causes Linux to poll-idle, when it should be in an idle power saving state. The idle and clock code do not graciously recover from this error, sometimes resulting in significant polling and measurable power impact. Stop using native_calibrate_tsc() for INTEL_FAM6_SKYLAKE_X. native_calibrate_tsc() will return 0, boot will run with tsc_khz = cpu_khz, and the TSC refined calibration will update tsc_khz to correct for the difference. [ tglx: Sanitized change log ] Fixes: 6baf3d61821f ("x86/tsc: Add additional Intel CPU models to the crystal quirk list") Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: peterz@infradead.org Cc: Prarit Bhargava <prarit@redhat.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/ff6dcea166e8ff8f2f6a03c17beab2cb436aa779.1513920414.git.len.brown@intel.com
2018-01-14x86/tsc: Future-proof native_calibrate_tsc()Len Brown1-0/+2
If the crystal frequency cannot be determined via CPUID(15).crystal_khz or the built-in table then native_calibrate_tsc() will still set the X86_FEATURE_TSC_KNOWN_FREQ flag which prevents the refined TSC calibration. As a consequence such systems use cpu_khz for the TSC frequency which is incorrect when cpu_khz != tsc_khz resulting in time drift. Return early when the crystal frequency cannot be retrieved without setting the X86_FEATURE_TSC_KNOWN_FREQ flag. This ensures that the refined TSC calibration is invoked. [ tglx: Steam-blastered changelog. Sigh ] Fixes: 4ca4df0b7eb0 ("x86/tsc: Mark TSC frequency determined by CPUID as known") Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: peterz@infradead.org Cc: Bin Gao <bin.gao@intel.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/0fe2503aa7d7fc69137141fc705541a78101d2b9.1513920414.git.len.brown@intel.com
2018-01-06x86/microcode/intel: Extend BDW late-loading with a revision checkJia Zhang1-2/+11
Instead of blacklisting all model 79 CPUs when attempting a late microcode loading, limit that only to CPUs with microcode revisions < 0x0b000021 because only on those late loading may cause a system hang. For such processors either: a) a BIOS update which might contain a newer microcode revision or b) the early microcode loading method should be considered. Processors with revisions 0x0b000021 or higher will not experience such hangs. For more details, see erratum BDF90 in document #334165 (Intel Xeon Processor E7-8800/4800 v4 Product Family Specification Update) from September 2017. [ bp: Heavily massage commit message and pr_* statements. ] Fixes: 723f2828a98c ("x86/microcode/intel: Disable late loading on model 79") Signed-off-by: Jia Zhang <qianyue.zj@alibaba-inc.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Cc: <stable@vger.kernel.org> # v4.14 Link: http://lkml.kernel.org/r/1514772287-92959-1-git-send-email-qianyue.zj@alibaba-inc.com
2018-01-05Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more x86 pti fixes from Thomas Gleixner: "Another small stash of fixes for fallout from the PTI work: - Fix the modules vs. KASAN breakage which was caused by making MODULES_END depend of the fixmap size. That was done when the cpu entry area moved into the fixmap, but now that we have a separate map space for that this is causing more issues than it solves. - Use the proper cache flush methods for the debugstore buffers as they are mapped/unmapped during runtime and not statically mapped at boot time like the rest of the cpu entry area. - Make the map layout of the cpu_entry_area consistent for 4 and 5 level paging and fix the KASLR vaddr_end wreckage. - Use PER_CPU_EXPORT for per cpu variable and while at it unbreak nvidia gfx drivers by dropping the GPL export. The subject line of the commit tells it the other way around, but I noticed that too late. - Fix the ASM alternative macros so they can be used in the middle of an inline asm block. - Rename the BUG_CPU_INSECURE flag to BUG_CPU_MELTDOWN so the attack vector is properly identified. The Spectre mitigations will come with their own bug bits later" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pti: Rename BUG_CPU_INSECURE to BUG_CPU_MELTDOWN x86/alternatives: Add missing '\n' at end of ALTERNATIVE inline asm x86/tlb: Drop the _GPL from the cpu_tlbstate export x86/events/intel/ds: Use the proper cache flush method for mapping ds buffers x86/kaslr: Fix the vaddr_end mess x86/mm: Map cpu_entry_area at the same place on 4/5 level x86/mm: Set MODULES_END to 0xffffffffff000000
2018-01-05Merge branch 'efi-urgent-for-linus' of ↵Linus Torvalds1-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Thomas Gleixner: - A fix for a add_efi_memmap parameter regression which ensures that the parameter is parsed before it is used. - Reinstate the virtual capsule mapping as the cached copy turned out to break Quark and other things - Remove Matt Fleming as EFI co-maintainer. He stepped back a few days ago. Thanks Matt for all your great work! * 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: MAINTAINERS: Remove Matt Fleming as EFI co-maintainer efi/capsule-loader: Reinstate virtual capsule mapping x86/efi: Fix kernel param add_efi_memmap regression
2018-01-05x86/pti: Rename BUG_CPU_INSECURE to BUG_CPU_MELTDOWNThomas Gleixner1-1/+1
Use the name associated with the particular attack which needs page table isolation for mitigation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Cc: Jiri Koshina <jikos@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Lutomirski <luto@amacapital.net> Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Turner <pjt@google.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Greg KH <gregkh@linux-foundation.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801051525300.1724@nanos
2018-01-03Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds4-13/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 page table isolation fixes from Thomas Gleixner: "A couple of urgent fixes for PTI: - Fix a PTE mismatch between user and kernel visible mapping of the cpu entry area (differs vs. the GLB bit) and causes a TLB mismatch MCE on older AMD K8 machines - Fix the misplaced CR3 switch in the SYSCALL compat entry code which causes access to unmapped kernel memory resulting in double faults. - Fix the section mismatch of the cpu_tss_rw percpu storage caused by using a different mechanism for declaration and definition. - Two fixes for dumpstack which help to decode entry stack issues better - Enable PTI by default in Kconfig. We should have done that earlier, but it slipped through the cracks. - Exclude AMD from the PTI enforcement. Not necessarily a fix, but if AMD is so confident that they are not affected, then we should not burden users with the overhead" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/process: Define cpu_tss_rw in same section as declaration x86/pti: Switch to kernel CR3 at early in entry_SYSCALL_compat() x86/dumpstack: Print registers for first stack frame x86/dumpstack: Fix partial register dumps x86/pti: Make sure the user/kernel PTEs match x86/cpu, x86/pti: Do not enable PTI on AMD processors x86/pti: Enable PTI by default
2018-01-03x86/process: Define cpu_tss_rw in same section as declarationNick Desaulniers1-1/+1
cpu_tss_rw is declared with DECLARE_PER_CPU_PAGE_ALIGNED but then defined with DEFINE_PER_CPU_SHARED_ALIGNED leading to section mismatch warnings. Use DEFINE_PER_CPU_PAGE_ALIGNED consistently. This is necessary because it's mapped to the cpu entry area and must be page aligned. [ tglx: Massaged changelog a bit ] Fixes: 1a935bc3d4ea ("x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: thomas.lendacky@amd.com Cc: Borislav Petkov <bpetkov@suse.de> Cc: tklauser@distanz.ch Cc: minipli@googlemail.com Cc: me@kylehuey.com Cc: namit@vmware.com Cc: luto@kernel.org Cc: jpoimboe@redhat.com Cc: tj@kernel.org Cc: cl@linux.com Cc: bp@suse.de Cc: thgarnie@google.com Cc: kirill.shutemov@linux.intel.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180103203954.183360-1-ndesaulniers@google.com
2018-01-03x86/dumpstack: Print registers for first stack frameJosh Poimboeuf1-1/+2
In the stack dump code, if the frame after the starting pt_regs is also a regs frame, the registers don't get printed. Fix that. Reported-by: Andy Lutomirski <luto@amacapital.net> Tested-by: Alexander Tsoy <alexander@tsoy.me> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toralf Förster <toralf.foerster@gmx.de> Cc: stable@vger.kernel.org Fixes: 3b3fa11bc700 ("x86/dumpstack: Print any pt_regs found on the stack") Link: http://lkml.kernel.org/r/396f84491d2f0ef64eda4217a2165f5712f6a115.1514736742.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-03x86/dumpstack: Fix partial register dumpsJosh Poimboeuf2-9/+21
The show_regs_safe() logic is wrong. When there's an iret stack frame, it prints the entire pt_regs -- most of which is random stack data -- instead of just the five registers at the end. show_regs_safe() is also poorly named: the on_stack() checks aren't for safety. Rename the function to show_regs_if_on_stack() and add a comment to explain why the checks are needed. These issues were introduced with the "partial register dump" feature of the following commit: b02fcf9ba121 ("x86/unwinder: Handle stack overflows more gracefully") That patch had gone through a few iterations of development, and the above issues were artifacts from a previous iteration of the patch where 'regs' pointed directly to the iret frame rather than to the (partially empty) pt_regs. Tested-by: Alexander Tsoy <alexander@tsoy.me> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toralf Förster <toralf.foerster@gmx.de> Cc: stable@vger.kernel.org Fixes: b02fcf9ba121 ("x86/unwinder: Handle stack overflows more gracefully") Link: http://lkml.kernel.org/r/5b05b8b344f59db2d3d50dbdeba92d60f2304c54.1514736742.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-03x86/cpu, x86/pti: Do not enable PTI on AMD processorsTom Lendacky1-2/+2
AMD processors are not subject to the types of attacks that the kernel page table isolation feature protects against. The AMD microarchitecture does not allow memory references, including speculative references, that access higher privileged data when running in a lesser privileged mode when that access would result in a page fault. Disable page table isolation by default on AMD processors by not setting the X86_BUG_CPU_INSECURE feature, which controls whether X86_FEATURE_PTI is set. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20171227054354.20369.94587.stgit@tlendack-t1.amdoffice.net
2018-01-03x86/efi: Fix kernel param add_efi_memmap regressionDave Young1-3/+2
'add_efi_memmap' is an early param, but do_add_efi_memmap() has no chance to run because the code path is before parse_early_param(). I believe it worked when the param was introduced but probably later some other changes caused the wrong order and nobody noticed it. Move efi_memblock_x86_reserve_range() after parse_early_param() to fix it. Signed-off-by: Dave Young <dyoung@redhat.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie> Cc: Ge Song <ge.song@hxt-semitech.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180102172110.17018-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-31Merge branch 'x86/urgent' of ↵Linus Torvalds9-15/+15
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A couple of fixlets for x86: - Fix the ESPFIX double fault handling for 5-level pagetables - Fix the commandline parsing for 'apic=' on 32bit systems and update documentation - Make zombie stack traces reliable - Fix kexec with stack canary - Fix the delivery mode for APICs which was missed when the x86 vector management was converted to single target delivery. Caused a regression due to the broken hardware which ignores affinity settings in lowest prio delivery mode. - Unbreak modules when AMD memory encryption is enabled - Remove an unused parameter of prepare_switch_to" * 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Switch all APICs to Fixed delivery mode x86/apic: Update the 'apic=' description of setting APIC driver x86/apic: Avoid wrong warning when parsing 'apic=' in X86-32 case x86-32: Fix kexec with stack canary (CONFIG_CC_STACKPROTECTOR) x86: Remove unused parameter of prepare_switch_to x86/stacktrace: Make zombie stack traces reliable x86/mm: Unbreak modules that use the DMA API x86/build: Make isoimage work on Debian x86/espfix/64: Fix espfix double-fault handling on 5-level systems
2017-12-31Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2-10/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 page table isolation fixes from Thomas Gleixner: "Four patches addressing the PTI fallout as discussed and debugged yesterday: - Remove stale and pointless TLB flush invocations from the hotplug code - Remove stale preempt_disable/enable from __native_flush_tlb() - Plug the memory leak in the write_ldt() error path" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/ldt: Make LDT pgtable free conditional x86/ldt: Plug memory leak in error path x86/mm: Remove preempt_disable/enable() from __native_flush_tlb() x86/smpboot: Remove stale TLB flush invocations
2017-12-31Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds2-5/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "A rather large update after the kaisered maintainer finally found time to handle regression reports. - The larger part addresses a regression caused by the x86 vector management rework. The reservation based model does not work reliably for MSI interrupts, if they cannot be masked (yes, yet another hw engineering trainwreck). The reason is that the reservation mode assigns a dummy vector when the interrupt is allocated and switches to a real vector when the interrupt is requested. If the MSI entry cannot be masked then the initialization might raise an interrupt before the interrupt is requested, which ends up as spurious interrupt and causes device malfunction and worse. The fix is to exclude MSI interrupts which do not support masking from reservation mode and assign a real vector right away. - Extend the extra lockdep class setup for nested interrupts with a class for the recently added irq_desc::request_mutex so lockdep can differeniate and does not emit false positive warnings. - A ratelimit guard for the bad irq printout so in case a bad irq comes back immediately the system does not drown in dmesg spam" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/msi, x86/vector: Prevent reservation mode for non maskable MSI genirq/irqdomain: Rename early argument of irq_domain_activate_irq() x86/vector: Use IRQD_CAN_RESERVE flag genirq: Introduce IRQD_CAN_RESERVE flag genirq/msi: Handle reactivation only on success gpio: brcmstb: Make really use of the new lockdep class genirq: Guard handle_bad_irq log messages kernel/irq: Extend lockdep class for request mutex
2017-12-31x86/ldt: Make LDT pgtable free conditionalThomas Gleixner1-1/+2
Andy prefers to be paranoid about the pagetable free in the error path of write_ldt(). Make it conditional and warn whenever the installment of a secondary LDT fails. Requested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-12-31x86/ldt: Plug memory leak in error pathThomas Gleixner1-1/+7
The error path in write_ldt() tries to free 'old_ldt' instead of the newly allocated 'new_ldt', resulting in a memory leak. It also misses to clean up a half populated LDT pagetable, which is not a leak as it gets cleaned up when the process exits. Free both the potentially half populated LDT pagetable and the newly allocated LDT struct. This can be done unconditionally because once an LDT is mapped subsequent maps will succeed, because the PTE page is already populated and the two LDTs fit into that single page. Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: f55f0501cbf6 ("x86/pti: Put the LDT in its own PGD if PTI is on") Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1712311121340.1899@nanos Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-31x86/smpboot: Remove stale TLB flush invocationsThomas Gleixner1-9/+0
smpboot_setup_warm_reset_vector() and smpboot_restore_warm_reset_vector() invoke local_flush_tlb() for no obvious reason. Digging in history revealed that the original code in the 2.1 era added those because the code manipulated a swapper_pg_dir pagetable entry. The pagetable manipulation was removed long ago in the 2.3 timeframe, but the TLB flush invocations stayed around forever. Remove them along with the pointless pr_debug()s which come from the same 2.1 change. Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20171230211829.586548655@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-29Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds7-18/+194
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 page table isolation updates from Thomas Gleixner: "This is the final set of enabling page table isolation on x86: - Infrastructure patches for handling the extra page tables. - Patches which map the various bits and pieces which are required to get in and out of user space into the user space visible page tables. - The required changes to have CR3 switching in the entry/exit code. - Optimizations for the CR3 switching along with documentation how the ASID/PCID mechanism works. - Updates to dump pagetables to cover the user space page tables for W+X scans and extra debugfs files to analyze both the kernel and the user space visible page tables The whole functionality is compile time controlled via a config switch and can be turned on/off on the command line as well" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) x86/ldt: Make the LDT mapping RO x86/mm/dump_pagetables: Allow dumping current pagetables x86/mm/dump_pagetables: Check user space page table for WX pages x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy x86/mm/pti: Add Kconfig x86/dumpstack: Indicate in Oops whether PTI is configured and enabled x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming x86/mm: Use INVPCID for __native_flush_tlb_single() x86/mm: Optimize RESTORE_CR3 x86/mm: Use/Fix PCID to optimize user/kernel switches x86/mm: Abstract switching CR3 x86/mm: Allow flushing for future ASID switches x86/pti: Map the vsyscall page if needed x86/pti: Put the LDT in its own PGD if PTI is on x86/mm/64: Make a full PGD-entry size hole in the memory map x86/events/intel/ds: Map debug buffers in cpu_entry_area x86/cpu_entry_area: Add debugstore entries to cpu_entry_area x86/mm/pti: Map ESPFIX into user space x86/mm/pti: Share entry text PMD x86/entry: Align entry text section to PMD boundary ...
2017-12-29genirq/msi, x86/vector: Prevent reservation mode for non maskable MSIThomas Gleixner1-1/+11
The new reservation mode for interrupts assigns a dummy vector when the interrupt is allocated and assigns a real vector when the interrupt is requested. The reservation mode prevents vector pressure when devices with a large amount of queues/interrupts are initialized, but only a minimal subset of those queues/interrupts is actually used. This mode has an issue with MSI interrupts which cannot be masked. If the driver is not careful or the hardware emits an interrupt before the device irq is requestd by the driver then the interrupt ends up on the dummy vector as a spurious interrupt which can cause malfunction of the device or in the worst case a lockup of the machine. Change the logic for the reservation mode so that the early activation of MSI interrupts checks whether: - the device is a PCI/MSI device - the reservation mode of the underlying irqdomain is activated - PCI/MSI masking is globally enabled - the PCI/MSI device uses either MSI-X, which supports masking, or MSI with the maskbit supported. If one of those conditions is false, then clear the reservation mode flag in the irq data of the interrupt and invoke irq_domain_activate_irq() with the reserve argument cleared. In the x86 vector code, clear the can_reserve flag in the vector allocation data so a subsequent free_irq() won't create the same situation again. The interrupt stays assigned to a real vector until pci_disable_msi() is invoked and all allocations are undone. Fixes: 4900be83602b ("x86/vector/msi: Switch to global reservation mode") Reported-by: Alexandru Chirvasitu <achirvasub@gmail.com> Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexandru Chirvasitu <achirvasub@gmail.com> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Mikael Pettersson <mikpelinux@gmail.com> Cc: Josh Poulson <jopoulso@microsoft.com> Cc: Mihai Costache <v-micos@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-pci@vger.kernel.org Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Simon Xiao <sixiao@microsoft.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: devel@linuxdriverproject.org Cc: KY Srinivasan <kys@microsoft.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Sakari Ailus <sakari.ailus@intel.com>, Cc: linux-media@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712291406420.1899@nanos Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712291409460.1899@nanos
2017-12-29genirq/irqdomain: Rename early argument of irq_domain_activate_irq()Thomas Gleixner2-4/+4
The 'early' argument of irq_domain_activate_irq() is actually used to denote reservation mode. To avoid confusion, rename it before abuse happens. No functional change. Fixes: 72491643469a ("genirq/irqdomain: Update irq_domain_ops.activate() signature") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexandru Chirvasitu <achirvasub@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Mikael Pettersson <mikpelinux@gmail.com> Cc: Josh Poulson <jopoulso@microsoft.com> Cc: Mihai Costache <v-micos@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-pci@vger.kernel.org Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Simon Xiao <sixiao@microsoft.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: devel@linuxdriverproject.org Cc: KY Srinivasan <kys@microsoft.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Sakari Ailus <sakari.ailus@intel.com>, Cc: linux-media@vger.kernel.org
2017-12-29x86/vector: Use IRQD_CAN_RESERVE flagThomas Gleixner1-0/+2
Set the new CAN_RESERVE flag when the initial reservation for an interrupt happens. The flag is used in a subsequent patch to disable reservation mode for a certain class of MSI devices. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexandru Chirvasitu <achirvasub@gmail.com> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Mikael Pettersson <mikpelinux@gmail.com> Cc: Josh Poulson <jopoulso@microsoft.com> Cc: Mihai Costache <v-micos@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-pci@vger.kernel.org Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Simon Xiao <sixiao@microsoft.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: devel@linuxdriverproject.org Cc: KY Srinivasan <kys@microsoft.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Sakari Ailus <sakari.ailus@intel.com>, Cc: linux-media@vger.kernel.org
2017-12-29x86/apic: Switch all APICs to Fixed delivery modeThomas Gleixner5-10/+6
Some of the APIC incarnations are operating in lowest priority delivery mode. This worked as long as the vector management code allocated the same vector on all possible CPUs for each interrupt. Lowest priority delivery mode does not necessarily respect the affinity setting and may redirect to some other online CPU. This was documented somewhere in the old code and the conversion to single target delivery missed to update the delivery mode of the affected APIC drivers which results in spurious interrupts on some of the affected CPU/Chipset combinations. Switch the APIC drivers over to Fixed delivery mode and remove all leftovers of lowest priority delivery mode. Switching to Fixed delivery mode is not a problem on these CPUs because the kernel already uses Fixed delivery mode for IPIs. The reason for this is that th SDM explicitely forbids lowest prio mode for IPIs. The reason is obvious: If the irq routing does not honor destination targets in lowest prio mode then an IPI targeted at CPU1 might end up on CPU0, which would be a fatal problem in many cases. As a consequence of this change, the apic::irq_delivery_mode field is now pointless, but this needs to be cleaned up in a separate patch. Fixes: fdba46ffb4c2 ("x86/apic: Get rid of multi CPU affinity") Reported-by: vcaputo@pengaru.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: vcaputo@pengaru.com Cc: Pavel Machek <pavel@ucw.cz> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712281140440.1688@nanos
2017-12-28x86/apic: Avoid wrong warning when parsing 'apic=' in X86-32 caseDou Liyang1-0/+2
There are two consumers of apic=: apic_set_verbosity() for setting the APIC debug level; parse_apic() for registering APIC driver by hand. X86-32 supports both of them, but sometimes, kernel issues a weird warning. eg: when kernel was booted up with 'apic=bigsmp' in command line, early_param would warn like that: ... [ 0.000000] APIC Verbosity level bigsmp not recognised use apic=verbose or apic=debug [ 0.000000] Malformed early option 'apic' ... Wrap the warning code in CONFIG_X86_64 case to avoid this. Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: peterz@infradead.org Cc: rdunlap@infradead.org Cc: corbet@lwn.net Link: https://lkml.kernel.org/r/20171204040313.24824-1-douly.fnst@cn.fujitsu.com
2017-12-27x86-32: Fix kexec with stack canary (CONFIG_CC_STACKPROTECTOR)Linus Torvalds1-3/+1
Commit e802a51ede91 ("x86/idt: Consolidate IDT invalidation") cleaned up and unified the IDT invalidation that existed in a couple of places. It changed no actual real code. Despite not changing any actual real code, it _did_ change code generation: by implementing the common idt_invalidate() function in archx86/kernel/idt.c, it made the use of the function in arch/x86/kernel/machine_kexec_32.c be a real function call rather than an (accidental) inlining of the function. That, in turn, exposed two issues: - in load_segments(), we had incorrectly reset all the segment registers, which then made the stack canary load (which gcc does using offset of %gs) cause a trap. Instead of %gs pointing to the stack canary, it will be the normal zero-based kernel segment, and the stack canary load will take a page fault at address 0x14. - to make this even harder to debug, we had invalidated the GDT just before calling idt_invalidate(), which meant that the fault happened with an invalid GDT, which in turn causes a triple fault and immediate reboot. Fix this by (a) not reloading the special segments in load_segments(). We currently don't do any percpu accesses (which would require %fs on x86-32) in this area, but there's no reason to think that we might not want to do them, and like %gs, it's pointless to break it. (b) doing idt_invalidate() before invalidating the GDT, to keep things at least _slightly_ more debuggable for a bit longer. Without a IDT, traps will not work. Without a GDT, traps also will not work, but neither will any segment loads etc. So in a very real sense, the GDT is even more core than the IDT. Fixes: e802a51ede91 ("x86/idt: Consolidate IDT invalidation") Reported-and-tested-by: Alexandru Chirvasitu <achirvasub@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.LFD.2.21.1712271143180.8572@i7.lan
2017-12-23x86/ldt: Make the LDT mapping ROThomas Gleixner2-10/+8
Now that the LDT mapping is in a known area when PAGE_TABLE_ISOLATION is enabled its a primary target for attacks, if a user space interface fails to validate a write address correctly. That can never happen, right? The SDM states: If the segment descriptors in the GDT or an LDT are placed in ROM, the processor can enter an indefinite loop if software or the processor attempts to update (write to) the ROM-based segment descriptors. To prevent this problem, set the accessed bits for all segment descriptors placed in a ROM. Also, remove operating-system or executive code that attempts to modify segment descriptors located in ROM. So its a valid approach to set the ACCESS bit when setting up the LDT entry and to map the table RO. Fixup the selftest so it can handle that new mode. Remove the manual ACCESS bit setter in set_tls_desc() as this is now pointless. Folded the patch from Peter Ziljstra. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23x86/dumpstack: Indicate in Oops whether PTI is configured and enabledVlastimil Babka1-2/+4
CONFIG_PAGE_TABLE_ISOLATION is relatively new and intrusive feature that may still have some corner cases which could take some time to manifest and be fixed. It would be useful to have Oops messages indicate whether it was enabled for building the kernel, and whether it was disabled during boot. Example of fully enabled: Oops: 0001 [#1] SMP PTI Example of enabled during build, but disabled during boot: Oops: 0001 [#1] SMP NOPTI We can decide to remove this after the feature has been tested in the field long enough. [ tglx: Made it use boot_cpu_has() as requested by Borislav ] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Eduardo Valentin <eduval@amazon.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: bpetkov@suse.de Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: jkosina@suse.cz Cc: keescook@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23x86/mm: Use/Fix PCID to optimize user/kernel switchesPeter Zijlstra1-0/+4
We can use PCID to retain the TLBs across CR3 switches; including those now part of the user/kernel switch. This increases performance of kernel entry/exit at the cost of more expensive/complicated TLB flushing. Now that we have two address spaces, one for kernel and one for user space, we need two PCIDs per mm. We use the top PCID bit to indicate a user PCID (just like we use the PFN LSB for the PGD). Since we do TLB invalidation from kernel space, the existing code will only invalidate the kernel PCID, we augment that by marking the corresponding user PCID invalid, and upon switching back to userspace, use a flushing CR3 write for the switch. In order to access the user_pcid_flush_mask we use PER_CPU storage, which means the previously established SWAPGS vs CR3 ordering is now mandatory and required. Having to do this memory access does require additional registers, most sites have a functioning stack and we can spill one (RAX), sites without functional stack need to otherwise provide the second scratch register. Note: PCID is generally available on Intel Sandybridge and later CPUs. Note: Up until this point TLB flushing was broken in this series. Based-on-code-from: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23x86/pti: Put the LDT in its own PGD if PTI is onAndy Lutomirski1-3/+136
With PTI enabled, the LDT must be mapped in the usermode tables somewhere. The LDT is per process, i.e. per mm. An earlier approach mapped the LDT on context switch into a fixmap area, but that's a big overhead and exhausted the fixmap space when NR_CPUS got big. Take advantage of the fact that there is an address space hole which provides a completely unused pgd. Use this pgd to manage per-mm LDT mappings. This has a down side: the LDT isn't (currently) randomized, and an attack that can write the LDT is instant root due to call gates (thanks, AMD, for leaving call gates in AMD64 but designing them wrong so they're only useful for exploits). This can be mitigated by making the LDT read-only or randomizing the mapping, either of which is strightforward on top of this patch. This will significantly slow down LDT users, but that shouldn't matter for important workloads -- the LDT is only used by DOSEMU(2), Wine, and very old libc implementations. [ tglx: Cleaned it up. ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23x86/entry: Align entry text section to PMD boundaryThomas Gleixner1-0/+8
The (irq)entry text must be visible in the user space page tables. To allow simple PMD based sharing, make the entry text PMD aligned. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23x86/mm/pti: Force entry through trampoline when PTI activeThomas Gleixner1-1/+4
Force the entry through the trampoline only when PTI is active. Otherwise go through the normal entry code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23x86/mm/pti: Allocate a separate user PGDDave Hansen1-3/+27
Kernel page table isolation requires to have two PGDs. One for the kernel, which contains the full kernel mapping plus the user space mapping and one for user space which contains the user space mappings and the minimal set of kernel mappings which are required by the architecture to be able to transition from and to user space. Add the necessary preliminaries. [ tglx: Split out from the big kaiser dump. EFI fixup from Kirill ] Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23x86/cpufeatures: Add X86_BUG_CPU_INSECUREThomas Gleixner1-0/+4
Many x86 CPUs leak information to user space due to missing isolation of user space and kernel space page tables. There are many well documented ways to exploit that. The upcoming software migitation of isolating the user and kernel space page tables needs a misfeature flag so code can be made runtime conditional. Add the BUG bits which indicates that the CPU is affected and add a feature bit which indicates that the software migitation is enabled. Assume for now that _ALL_ x86 CPUs are affected by this. Exceptions can be made later. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-23Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds10-154/+53
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 PTI preparatory patches from Thomas Gleixner: "Todays Advent calendar window contains twentyfour easy to digest patches. The original plan was to have twenty three matching the date, but a late fixup made that moot. - Move the cpu_entry_area mapping out of the fixmap into a separate address space. That's necessary because the fixmap becomes too big with NRCPUS=8192 and this caused already subtle and hard to diagnose failures. The top most patch is fresh from today and cures a brain slip of that tall grumpy german greybeard, who ignored the intricacies of 32bit wraparounds. - Limit the number of CPUs on 32bit to 64. That's insane big already, but at least it's small enough to prevent address space issues with the cpu_entry_area map, which have been observed and debugged with the fixmap code - A few TLB flush fixes in various places plus documentation which of the TLB functions should be used for what. - Rename the SYSENTER stack to CPU_ENTRY_AREA stack as it is used for more than sysenter now and keeping the name makes backtraces confusing. - Prevent LDT inheritance on exec() by moving it to arch_dup_mmap(), which is only invoked on fork(). - Make vysycall more robust. - A few fixes and cleanups of the debug_pagetables code. Check PAGE_PRESENT instead of checking the PTE for 0 and a cleanup of the C89 initialization of the address hint array which already was out of sync with the index enums. - Move the ESPFIX init to a different place to prepare for PTI. - Several code moves with no functional change to make PTI integration simpler and header files less convoluted. - Documentation fixes and clarifications" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/cpu_entry_area: Prevent wraparound in setup_cpu_entry_area_ptes() on 32bit init: Invoke init_espfix_bsp() from mm_init() x86/cpu_entry_area: Move it out of the fixmap x86/cpu_entry_area: Move it to a separate unit x86/mm: Create asm/invpcid.h x86/mm: Put MMU to hardware ASID translation in one place x86/mm: Remove hard-coded ASID limit checks x86/mm: Move the CR3 construction functions to tlbflush.h x86/mm: Add comments to clarify which TLB-flush functions are supposed to flush what x86/mm: Remove superfluous barriers x86/mm: Use __flush_tlb_one() for kernel memory x86/microcode: Dont abuse the TLB-flush interface x86/uv: Use the right TLB-flush API x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stack x86/doc: Remove obvious weirdnesses from the x86 MM layout documentation x86/mm/64: Improve the memory map documentation x86/ldt: Prevent LDT inheritance on exec x86/ldt: Rework locking arch, mm: Allow arch_dup_mmap() to fail x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode ...
2017-12-22init: Invoke init_espfix_bsp() from mm_init()Thomas Gleixner1-5/+1
init_espfix_bsp() needs to be invoked before the page table isolation initialization. Move it into mm_init() which is the place where pti_init() will be added. While at it get rid of the #ifdeffery and provide proper stub functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/cpu_entry_area: Move it out of the fixmapThomas Gleixner2-2/+4
Put the cpu_entry_area into a separate P4D entry. The fixmap gets too big and 0-day already hit a case where the fixmap PTEs were cleared by cleanup_highmap(). Aside of that the fixmap API is a pain as it's all backwards. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/cpu_entry_area: Move it to a separate unitThomas Gleixner2-94/+1
Separate the cpu_entry_area code out of cpu/common.c and the fixmap. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/microcode: Dont abuse the TLB-flush interfacePeter Zijlstra1-13/+0
Commit: ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU") ... grubbed into tlbflush internals without coherent explanation. Since it says its a precaution and the SDM doesn't mention anything like this, take it out back. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: fenghua.yu@intel.com Cc: hughd@google.com Cc: keescook@google.com Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stackDave Hansen6-21/+27
If the kernel oopses while on the trampoline stack, it will print "<SYSENTER>" even if SYSENTER is not involved. That is rather confusing. The "SYSENTER" stack is used for a lot more than SYSENTER now. Give it a better string to display in stack dumps, and rename the kernel code to match. Also move the 32-bit code over to the new naming even though it still uses the entry stack only for SYSENTER. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> 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: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/ldt: Prevent LDT inheritance on execThomas Gleixner1-13/+5
The LDT is inherited across fork() or exec(), but that makes no sense at all because exec() is supposed to start the process clean. The reason why this happens is that init_new_context_ldt() is called from init_new_context() which obviously needs to be called for both fork() and exec(). It would be surprising if anything relies on that behaviour, so it seems to be safe to remove that misfeature. Split the context initialization into two parts. Clear the LDT pointer and initialize the mutex from the general context init and move the LDT duplication to arch_dup_mmap() which is only called on fork(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: dan.j.williams@intel.com Cc: hughd@google.com Cc: keescook@google.com Cc: kirill.shutemov@linux.intel.com Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-22x86/ldt: Rework lockingPeter Zijlstra1-12/+21
The LDT is duplicated on fork() and on exec(), which is wrong as exec() should start from a clean state, i.e. without LDT. To fix this the LDT duplication code will be moved into arch_dup_mmap() which is only called for fork(). This introduces a locking problem. arch_dup_mmap() holds mmap_sem of the parent process, but the LDT duplication code needs to acquire mm->context.lock to access the LDT data safely, which is the reverse lock order of write_ldt() where mmap_sem nests into context.lock. Solve this by introducing a new rw semaphore which serializes the read/write_ldt() syscall operations and use context.lock to protect the actual installment of the LDT descriptor. So context.lock stabilizes mm->context.ldt and can nest inside of the new semaphore or mmap_sem. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: dan.j.williams@intel.com Cc: hughd@google.com Cc: keescook@google.com Cc: kirill.shutemov@linux.intel.com Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-19x86/stacktrace: Make zombie stack traces reliableJosh Poimboeuf1-1/+5
Commit: 1959a60182f4 ("x86/dumpstack: Pin the target stack when dumping it") changed the behavior of stack traces for zombies. Before that commit, /proc/<pid>/stack reported the last execution path of the zombie before it died: [<ffffffff8105b877>] do_exit+0x6f7/0xa80 [<ffffffff8105bc79>] do_group_exit+0x39/0xa0 [<ffffffff8105bcf0>] __wake_up_parent+0x0/0x30 [<ffffffff8152dd09>] system_call_fastpath+0x16/0x1b [<00007fd128f9c4f9>] 0x7fd128f9c4f9 [<ffffffffffffffff>] 0xffffffffffffffff After the commit, it just reports an empty stack trace. The new behavior is actually probably more correct. If the stack refcount has gone down to zero, then the task has already gone through do_exit() and isn't going to run anymore. The stack could be freed at any time and is basically gone, so reporting an empty stack makes sense. However, save_stack_trace_tsk_reliable() treats such a missing stack condition as an error. That can cause livepatch transition stalls if there are any unreaped zombies. Instead, just treat it as a reliable, empty stack. Reported-and-tested-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Fixes: af085d9084b4 ("stacktrace/x86: add function for detecting reliable stack traces") Link: http://lkml.kernel.org/r/e4b09e630e99d0c1080528f0821fc9d9dbaeea82.1513631620.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-18Merge branch 'WIP.x86-pti.entry-for-linus' of ↵Linus Torvalds18-196/+336
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 syscall entry code changes for PTI from Ingo Molnar: "The main changes here are Andy Lutomirski's changes to switch the x86-64 entry code to use the 'per CPU entry trampoline stack'. This, besides helping fix KASLR leaks (the pending Page Table Isolation (PTI) work), also robustifies the x86 entry code" * 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) x86/cpufeatures: Make CPU bugs sticky x86/paravirt: Provide a way to check for hypervisors x86/paravirt: Dont patch flush_tlb_single x86/entry/64: Make cpu_entry_area.tss read-only x86/entry: Clean up the SYSENTER_stack code x86/entry/64: Remove the SYSENTER stack canary x86/entry/64: Move the IST stacks into struct cpu_entry_area x86/entry/64: Create a per-CPU SYSCALL entry trampoline x86/entry/64: Return to userspace from the trampoline stack x86/entry/64: Use a per-CPU trampoline stack for IDT entries x86/espfix/64: Stop assuming that pt_regs is on the entry stack x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0 x86/entry: Remap the TSS into the CPU entry area x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct x86/dumpstack: Handle stack overflow on all stacks x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss x86/kasan/64: Teach KASAN about the cpu_entry_area x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area x86/entry/gdt: Put per-CPU GDT remaps in ascending order x86/dumpstack: Add get_stack_info() support for the SYSENTER stack ...
2017-12-17x86/cpufeatures: Make CPU bugs stickyThomas Gleixner1-3/+3
There is currently no way to force CPU bug bits like CPU feature bits. That makes it impossible to set a bug bit once at boot and have it stick for all upcoming CPUs. Extend the force set/clear arrays to handle bug bits as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150606.992156574@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-17x86/paravirt: Dont patch flush_tlb_singleThomas Gleixner1-2/+0
native_flush_tlb_single() will be changed with the upcoming PAGE_TABLE_ISOLATION feature. This requires to have more code in there than INVLPG. Remove the paravirt patching for it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: linux-mm@kvack.org Cc: michael.schwarz@iaik.tugraz.at Cc: moritz.lipp@iaik.tugraz.at Cc: richard.fellner@student.tugraz.at Link: https://lkml.kernel.org/r/20171204150606.828111617@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-17x86/entry/64: Make cpu_entry_area.tss read-onlyAndy Lutomirski8-23/+31
The TSS is a fairly juicy target for exploits, and, now that the TSS is in the cpu_entry_area, it's no longer protected by kASLR. Make it read-only on x86_64. On x86_32, it can't be RO because it's written by the CPU during task switches, and we use a task gate for double faults. I'd also be nervous about errata if we tried to make it RO even on configurations without double fault handling. [ tglx: AMD confirmed that there is no problem on 64-bit with TSS RO. So it's probably safe to assume that it's a non issue, though Intel might have been creative in that area. Still waiting for confirmation. ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bpetkov@suse.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150606.733700132@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-17x86/entry: Clean up the SYSENTER_stack codeAndy Lutomirski3-19/+8
The existing code was a mess, mainly because C arrays are nasty. Turn SYSENTER_stack into a struct, add a helper to find it, and do all the obvious cleanups this enables. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bpetkov@suse.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150606.653244723@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>