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2017-11-06m68k: allow ColdFire m5441x parts to run with MMU enabledGreg Ungerer
The Freescale ColdFire M5441x system-on-chip parts have full paged MMU hardware support. So far though we have only allowed them to be configured for use in non-MMU mode. All required kernel changes to support operation of the M5441x parts with MMU enabled have been pushed into the kernel, so now we can allow it to be configured and used with the MMU enabled. Tested-by: Angelo Dureghello <angelo@sysam.it> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2017-11-06m68k: fix ColdFire node shift size calculationGreg Ungerer
The m68k pg_data_table is a fix size array defined in arch/m68k/mm/init.c. Index numbers within it are defined based on memory size. But for Coldfire these don't take into account a non-zero physical RAM base address, and this causes us to access past the end of this array at system start time. Change the node shift calculation so that we keep the index inside its range. Reported-by: Angelo Dureghello <angelo@sysam.it> Tested-by: Angelo Dureghello <angelo@sysam.it> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2017-11-06m68k: move coldfire MMU initialization codeGreg Ungerer
The M54[78]x ColdFire parts are not the only members of the ColdFire family that have an MMU. But currently some of the early MMU initialization code is inside the startup code specific to only the ColdFire M54[78]x parts. Move that early ColdFire MMU init code so that it is run for other ColdFire parts running with MMU enabled. Specifically this means that the MMU initialization code will now also be run for the ColdFire M5441x parts when running with MMU enabled. The code move meant that the extern definition for the mmu_context_init() function had to be moved as well. To make it clear that is ColdFire specific I have renamed that with a "cf_" in front of it and put its extern definition in the mcfmmu.h (which is already included by the setup code). Reported-by: Angelo Dureghello <angelo@sysam.it> Tested-by: Angelo Dureghello <angelo@sysam.it> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2017-11-05Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Two fixes: - A PCID related revert that fixes power management and performance regressions. - The module loader robustization and sanity check commit is rather fresh, but it looked like a good idea to apply because of the hidden data corruption problem such invalid modules could cause" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/module: Detect and skip invalid relocations Revert "x86/mm: Stop calling leave_mm() in idle code"
2017-11-05Merge branch 'ras-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RAS fix from Ingo Molnar: "Fix an RCU warning that triggers when /dev/mcelog is used" * 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mcelog: Get rid of RCU remnants
2017-11-05x86/module: Detect and skip invalid relocationsJosh Poimboeuf
There have been some cases where external tooling (e.g., kpatch-build) creates a corrupt relocation which targets the wrong address. This is a silent failure which can corrupt memory in unexpected places. On x86, the bytes of data being overwritten by relocations are always initialized to zero beforehand. Use that knowledge to add sanity checks to detect such cases before they corrupt memory. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: jeyu@kernel.org Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/37450d6c6225e54db107fba447ce9e56e5f758e9.1509713553.git.jpoimboe@redhat.com [ Restructured the messages, as it's unclear whether the relocation or the target is corrupted. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-04Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds
Pull ARM fixes from Russell King: - omit EFI memory map sorting, which was recently introduced, but caused problems with the decompressor due to additional sections being emitted. - avoid unaligned load fault-generating instructions in the decompressor by switching to a private unaligned implementation. - add a symbol into the decompressor to further debug non-boot situations (ld's documentation is extremely poor for how "." works, ld doesn't seem to follow its own documentation!) - parse endian information to sparse * 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: add debug ".edata_real" symbol ARM: 8716/1: pass endianness info to sparse efi/libstub: arm: omit sorting of the UEFI memory map ARM: 8715/1: add a private asm/unaligned.h
2017-11-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "Fixes for interrupt controller emulation in ARM/ARM64 and x86, plus a one-liner x86 KVM guest fix" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Update APICv on APIC reset KVM: VMX: Do not fully reset PI descriptor on vCPU reset kvm: Return -ENODEV from update_persistent_clock KVM: arm/arm64: vgic-its: Check GITS_BASER Valid bit before saving tables KVM: arm/arm64: vgic-its: Check CBASER/BASER validity before enabling the ITS KVM: arm/arm64: vgic-its: Fix vgic_its_restore_collection_table returned value KVM: arm/arm64: vgic-its: Fix return value for device table restore arm/arm64: kvm: Disable branch profiling in HYP code arm/arm64: kvm: Move initialization completion message arm/arm64: KVM: set right LR register value for 32 bit guest when inject abort KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table
2017-11-04Merge tag 'armsoc-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC fixes from Arnd Bergmann: "Only two patches came in over the last two weeks: Uniphier USB support needs additional clocks enabled (on both 32-bit and 64-bit ARM), and a Marvell MVEBU stability issue has been fixed" * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: ARM: dts: mvebu: pl310-cache disable double-linefill arm64: dts: uniphier: add STDMAC clock to EHCI nodes ARM: dts: uniphier: add STDMAC clock to EHCI nodes
2017-11-04Merge tag 'mips_fixes_4.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips Pull MIPS fixes from James Hogan: "A selection of important MIPS fixes for 4.14, and some MAINTAINERS / email address updates: Maintainership updates: - imgtec.com -> mips.com email addresses (this trivially updates comments in quite a few files, as well as MAINTAINERS) - Pistachio SoC maintainership update Fixes: - NI 169445 build (new platform in 4.14) - EVA regression (4.14) - SMP-CPS build & preemption regressions (4.14) - SMP/hotplug deadlock & race (deadlock reintroduced 4.13) - ebpf_jit error return (4.13) - SMP-CMP build regressions (4.11 and 4.14) - bad UASM microMIPS encoding (3.16) - CM definitions (3.15)" [ I had taken the email address updates separately, because I didn't expect James to send a pull request, so those got applied twice. - Linus] * tag 'mips_fixes_4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips: MIPS: Update email address for Marcin Nowakowski MIPS: smp-cmp: Fix vpe_id build error MAINTAINERS: Update Pistachio platform maintainers MIPS: smp-cmp: Use right include for task_struct MIPS: Update Goldfish RTC driver maintainer email address MIPS: Update RINT emulation maintainer email address MIPS: CPS: Fix use of current_cpu_data in preemptible code MIPS: SMP: Fix deadlock & online race MIPS: bpf: Fix a typo in build_one_insn() MIPS: microMIPS: Fix incorrect mask in insn_table_MM MIPS: Fix CM region target definitions MIPS: generic: Fix compilation error from include asm/mips-cpc.h MIPS: Fix exception entry when CONFIG_EVA enabled MIPS: generic: Fix NI 169445 its build Update MIPS email addresses
2017-11-04Revert "x86/mm: Stop calling leave_mm() in idle code"Andy Lutomirski
This reverts commit 43858b4f25cf0adc5c2ca9cf5ce5fdf2532941e5. The reason I removed the leave_mm() calls in question is because the heuristic wasn't needed after that patch. With the original version of my PCID series, we never flushed a "lazy cpu" (i.e. a CPU running kernel thread) due a flush on the loaded mm. Unfortunately, that caused architectural issues, so now I've reinstated these flushes on non-PCID systems in: commit b956575bed91 ("x86/mm: Flush more aggressively in lazy TLB mode"). That, in turn, gives us a power management and occasionally performance regression as compared to old kernels: a process that goes into a deep idle state on a given CPU and gets its mm flushed due to activity on a different CPU will wake the idle CPU. Reinstate the old ugly heuristic: if a CPU goes into ACPI C3 or an intel_idle state that is likely to cause a TLB flush gets its mm switched to init_mm before going idle. FWIW, this heuristic is lousy. Whether we should change CR3 before idle isn't a good hint except insofar as the performance hit is a bit lower if the TLB is getting flushed by the idle code anyway. What we really want to know is whether we anticipate being idle long enough that the mm is likely to be flushed before we wake up. This is more a matter of the expected latency than the idle state that gets chosen. This heuristic also completely fails on systems that don't know whether the TLB will be flushed (e.g. AMD systems?). OTOH it may be a bit obsolete anyway -- PCID systems don't presently benefit from this heuristic at all. We also shouldn't do this callback from innermost bit of the idle code due to the RCU nastiness it causes. All the information need is available before rcu_idle_enter() needs to happen. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 43858b4f25cf "x86/mm: Stop calling leave_mm() in idle code" Link: http://lkml.kernel.org/r/c513bbd4e653747213e05bc7062de000bf0202a5.1509793738.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-04arm64: dts: actions: s900-bubblegum-96: Add fake uart5 clockAndreas Färber
Give the serial driver a fixed-clock as input for baudrate 115200. Signed-off-by: Andreas Färber <afaerber@suse.de>
2017-11-04ARM: dts: owl-s500: Add CubieBoard6Andreas Färber
Add a Device Tree for Cubietech CubieBoard6. Cc: support@cubietech.com Signed-off-by: Andreas Färber <afaerber@suse.de>
2017-11-04ARM: dts: owl-s500-guitar-bb-rev-b: Add fake uart3 clockAndreas Färber
Add a fixed-clock for baudrate 115200. Signed-off-by: Andreas Färber <afaerber@suse.de>
2017-11-04ARM: dts: owl-s500: Set power domains for CPU2 and CPU3Andreas Färber
CPU2 has its own power domain PD_CPU2, and CPU3 has PD_CPU3. Signed-off-by: Andreas Färber <afaerber@suse.de>
2017-11-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-03xen: support priv-mapping in an HVM tools domainPaul Durrant
If the domain has XENFEAT_auto_translated_physmap then use of the PV- specific HYPERVISOR_mmu_update hypercall is clearly incorrect. This patch adds checks in xen_remap_domain_gfn_array() and xen_unmap_domain_gfn_array() which call through to the approprate xlate_mmu function if the feature is present. A check is also added to xen_remap_domain_gfn_range() to fail with -EOPNOTSUPP since this should not be used in an HVM tools domain. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-11-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
Pull arch/tile fixes from Chris Metcalf: "Two one-line bug fixes" * git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: arch/tile: Implement ->set_state_oneshot_stopped() tile: pass machine size to sparse
2017-11-03arch/tile: Implement ->set_state_oneshot_stopped()Chris Metcalf
set_state_oneshot_stopped() is called by the clkevt core, when the next event is required at an expiry time of 'KTIME_MAX'. This normally happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes. This patch makes the clockevent device to stop on such an event, to avoid spurious interrupts, as explained by: commit 8fff52fd5093 ("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state"). Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
2017-11-03Merge tag 'powerpc-4.14-6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Some more powerpc fixes for 4.14. This is bigger than I like to send at rc7, but that's at least partly because I didn't send any fixes last week. If it wasn't for the IMC driver, which is new and getting heavy testing, the diffstat would look a bit better. I've also added ftrace on big endian to my test suite, so we shouldn't break that again in future. - A fix to the handling of misaligned paste instructions (P9 only), where a change to a #define has caused the check for the instruction to always fail. - The preempt handling was unbalanced in the radix THP flush (P9 only). Though we don't generally use preempt we want to keep it working as much as possible. - Two fixes for IMC (P9 only), one when booting with restricted number of CPUs and one in the error handling when initialisation fails due to firmware etc. - A revert to fix function_graph on big endian machines, and then a rework of the reverted patch to fix kprobes blacklist handling on big endian machines. Thanks to: Anju T Sudhakar, Guilherme G. Piccoli, Madhavan Srinivasan, Naveen N. Rao, Nicholas Piggin, Paul Mackerras" * tag 'powerpc-4.14-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/perf: Fix core-imc hotplug callback failure during imc initialization powerpc/kprobes: Dereference function pointers only if the address does not belong to kernel text Revert "powerpc64/elfv1: Only dereference function descriptor for non-text symbols" powerpc/64s/radix: Fix preempt imbalance in TLB flush powerpc: Fix check for copy/paste instructions in alignment handler powerpc/perf: Fix IMC allocation routine
2017-11-03Update MIPS email addressesPaul Burton
MIPS will soon not be a part of Imagination Technologies, and as such many @imgtec.com email addresses will no longer be valid. This patch updates the addresses for those who: - Have 10 or more patches in mainline authored using an @imgtec.com email address, or any patches dated within the past year. - Are still with Imagination but leaving as part of the MIPS business unit, as determined from an internal email address list. - Haven't already updated their email address (ie. JamesH) or expressed a desire to be excluded (ie. Maciej). - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt & myself. New addresses are of the form firstname.lastname@mips.com, and all verified against an internal email address list. An entry is added to .mailmap for each person such that get_maintainer.pl will report the new addresses rather than @imgtec.com addresses which will soon be dead. Instances of the affected addresses throughout the tree are then mechanically replaced with the new @mips.com address. Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@mips.com> Acked-by: Dengcheng Zhu <dengcheng.zhu@mips.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Matt Redfearn <matt.redfearn@mips.com> Acked-by: Matt Redfearn <matt.redfearn@mips.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: trivial@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-03x86: CPU: Fix up "cpu MHz" in /proc/cpuinfoRafael J. Wysocki
Commit 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"") is not sufficient to restore the previous behavior of "cpu MHz" in /proc/cpuinfo on x86 due to some changes made after the commit it has reverted. To address this, make the code in question use arch_freq_get_on_cpu() which also is used by cpufreq for reporting the current frequency of CPUs and since that function doesn't really depend on cpufreq in any way, drop the CONFIG_CPU_FREQ dependency for the object file containing it. Also refactor arch_freq_get_on_cpu() somewhat to avoid IPIs and return cached values right away if it is called very often over a short time (to prevent user space from triggering IPI storms through it). Fixes: 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"") Cc: stable@kernel.org # 4.13 - together with 890da9cf0983 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-03xen/time: Return -ENODEV from xen_get_wallclock()Boris Ostrovsky
For any other error sync_cmos_clock() will reschedule itself every second or so, for no good reason. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-11-03arm64: support __int128 on gcc 5+Jason A. Donenfeld
Versions of gcc prior to gcc 5 emitted a __multi3 function call when dealing with TI types, resulting in failures when trying to link to libgcc, and more generally, bad performance. However, since gcc 5, the compiler supports actually emitting fast instructions, which means we can at long last enable this option and receive the speedups. The gcc commit that added proper Aarch64 support is: https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=d1ae7bb994f49316f6f63e6173f2931e837a351d This commit appears to be part of the gcc 5 release. There are still a few instructions, __ashlti3 and __ashrti3, which require libgcc, which is fine. Rather than linking to libgcc, we simply provide them ourselves, since they're not that complicated. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Add documentationDave Martin
This patch adds basic documentation of the user/kernel interface provided by the for SVE. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alan Hayward <alan.hayward@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Szabolcs Nagy <szabolcs.nagy@arm.com> Cc: linux-api@vger.kernel.org Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Detect SVE and activate runtime supportDave Martin
This patch enables detection of hardware SVE support via the cpufeatures framework, and reports its presence to the kernel and userspace via the new ARM64_SVE cpucap and HWCAP_SVE hwcap respectively. Userspace can also detect SVE using ID_AA64PFR0_EL1, using the cpufeatures MRS emulation. When running on hardware that supports SVE, this enables runtime kernel support for SVE, and allows user tasks to execute SVE instructions and make of the of the SVE-specific user/kernel interface extensions implemented by this series. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: KVM: Hide SVE from CPU features exposed to guestsDave Martin
KVM guests cannot currently use SVE, because SVE is always configured to trap to EL2. However, a guest that sees SVE reported as present in ID_AA64PFR0_EL1 may legitimately expect that SVE works and try to use it. Instead of working, the guest will receive an injected undef exception, which may cause the guest to oops or go into a spin. To avoid misleading the guest into believing that SVE will work, this patch masks out the SVE field from ID_AA64PFR0_EL1 when a guest attempts to read this register. No support is explicitly added for ID_AA64ZFR0_EL1 either, so that is still emulated as reading as zero, which is consistent with SVE not being implemented. This is a temporary measure, and will be removed in a later series when full KVM support for SVE is implemented. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: KVM: Treat guest SVE use as undefined instruction executionDave Martin
When trapping forbidden attempts by a guest to use SVE, we want the guest to see a trap consistent with SVE not being implemented. This patch injects an undefined instruction exception into the guest in response to such an exception. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: KVM: Prevent guests from using SVEDave Martin
Until KVM has full SVE support, guests must not be allowed to execute SVE instructions. This patch enables the necessary traps, and also ensures that the traps are disabled again on exit from the guest so that the host can still use SVE if it wants to. On guest exit, high bits of the SVE Zn registers may have been clobbered as a side-effect the execution of FPSIMD instructions in the guest. The existing KVM host FPSIMD restore code is not sufficient to restore these bits, so this patch explicitly marks the CPU as not containing cached vector state for any task, thus forcing a reload on the next return to userspace. This is an interim measure, in advance of adding full SVE awareness to KVM. This marking of cached vector state in the CPU as invalid is done using __this_cpu_write(fpsimd_last_state, NULL) in fpsimd.c. Due to the repeated use of this rather obscure operation, it makes sense to factor it out as a separate helper with a clearer name. This patch factors it out as fpsimd_flush_cpu_state(), and ports all callers to use it. As a side effect of this refactoring, a this_cpu_write() in fpsimd_cpu_pm_notifier() is changed to __this_cpu_write(). This should be fine, since cpu_pm_enter() is supposed to be called only with interrupts disabled. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Add sysctl to set the default vector length for new processesDave Martin
Because of the effect of SVE on the size of the signal frame, the default vector length used for new processes involves a tradeoff between performance of SVE-enabled software on the one hand, and reliability of non-SVE-aware software on the other hand. For this reason, the best choice depends on the repertoire of userspace software in use and is thus best left up to distro maintainers, sysadmins and developers. If CONFIG_SYSCTL and CONFIG_PROC_SYSCTL are enabled, this patch exposes the default vector length in /proc/sys/abi/sve_default_vector_length, where boot scripts or the adventurous can poke it. In common with other arm64 ABI sysctls, this control is currently global: setting it requires CAP_SYS_ADMIN in the root user namespace, but the value set is effective for subsequent execs in all namespaces. The control only affects _new_ processes, however: changing it does not affect the vector length of any existing process. The intended usage model is that if userspace is known to be fully SVE-tolerant (or a developer is curious to find out) then this parameter can be cranked up during system startup. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Add prctl controls for userspace vector length managementDave Martin
This patch adds two arm64-specific prctls, to permit userspace to control its vector length: * PR_SVE_SET_VL: set the thread's SVE vector length and vector length inheritance mode. * PR_SVE_GET_VL: get the same information. Although these prctls resemble instruction set features in the SVE architecture, they provide additional control: the vector length inheritance mode is Linux-specific and nothing to do with the architecture, and the architecture does not permit EL0 to set its own vector length directly. Both can be used in portable tools without requiring the use of SVE instructions. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> [will: Fixed up prctl constants to avoid clash with PDEATHSIG] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: ptrace and ELF coredump supportDave Martin
This patch defines and implements a new regset NT_ARM_SVE, which describes a thread's SVE register state. This allows a debugger to manipulate the SVE state, as well as being included in ELF coredumps for post-mortem debugging. Because the regset size and layout are dependent on the thread's current vector length, it is not possible to define a C struct to describe the regset contents as is done for existing regsets. Instead, and for the same reasons, NT_ARM_SVE is based on the freeform variable-layout approach used for the SVE signal frame. Additionally, to reduce debug overhead when debugging threads that might or might not have live SVE register state, NT_ARM_SVE may be presented in one of two different formats: the old struct user_fpsimd_state format is embedded for describing the state of a thread with no live SVE state, whereas a new variable-layout structure is embedded for describing live SVE state. This avoids a debugger needing to poll NT_PRFPREG in addition to NT_ARM_SVE, and allows existing userspace code to handle the non-SVE case without too much modification. For this to work, NT_ARM_SVE is defined with a fixed-format header of type struct user_sve_header, which the recipient can use to figure out the content, size and layout of the reset of the regset. Accessor macros are defined to allow the vector-length-dependent parts of the regset to be manipulated. Signed-off-by: Alan Hayward <alan.hayward@arm.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Cc: Okamoto Takayuki <tokamoto@jp.fujitsu.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Preserve SVE registers around EFI runtime service callsDave Martin
The EFI runtime services ABI allows EFI to make free use of the FPSIMD registers during EFI runtime service calls, subject to the callee-save requirements of the AArch64 procedure call standard. However, the SVE architecture allows upper bits of the SVE vector registers to be zeroed as a side-effect of FPSIMD V-register writes. This means that the SVE vector registers must be saved in their entirety in order to avoid data loss: non-SVE-aware EFI implementations cannot restore them correctly. The non-IRQ case is already handled gracefully by kernel_neon_begin(). For the IRQ case, this patch allocates a suitable per-CPU stash buffer for the full SVE register state and uses it to preserve the affected registers around EFI calls. It is currently unclear how the EFI runtime services ABI will be clarified with respect to SVE, so it safest to assume that the predicate registers and FFR must be saved and restored too. No attempt is made to restore the restore the vector length after a call, for now. It is deemed rather insane for EFI to change it, and contemporary EFI implementations certainly won't. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Preserve SVE registers around kernel-mode NEON useDave Martin
Kernel-mode NEON will corrupt the SVE vector registers, due to the way they alias the FPSIMD vector registers in the hardware. This patch ensures that any live SVE register content for the task is saved by kernel_neon_begin(). The data will be restored in the usual way on return to userspace. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Probe SVE capabilities and usable vector lengthsDave Martin
This patch uses the cpufeatures framework to determine common SVE capabilities and vector lengths, and configures the runtime SVE support code appropriately. ZCR_ELx is not really a feature register, but it is convenient to use it as a template for recording the maximum vector length supported by a CPU, using the LEN field. This field is similar to a feature field in that it is a contiguous bitfield for which we want to determine the minimum system-wide value. This patch adds ZCR as a pseudo-register in cpuinfo/cpufeatures, with appropriate custom code to populate it. Finding the minimum supported value of the LEN field is left to the cpufeatures framework in the usual way. The meaning of ID_AA64ZFR0_EL1 is not architecturally defined yet, so for now we just require it to be zero. Note that much of this code is dormant and SVE still won't be used yet, since system_supports_sve() remains hardwired to false. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64: cpufeature: Move sys_caps_initialised declarationsDave Martin
update_cpu_features() currently cannot tell whether it is being called during early or late secondary boot. This doesn't desperately matter for anything it currently does. However, SVE will need to know here whether the set of available vector lengths is known or still to be determined when booting a CPU, so that it can be updated appropriately. This patch simply moves the sys_caps_initialised stuff to the top of the file so that it can be used more widely. There doesn't seem to be a more obvious place to put it. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Backend logic for setting the vector lengthDave Martin
This patch implements the core logic for changing a task's vector length on request from userspace. This will be used by the ptrace and prctl frontends that are implemented in later patches. The SVE architecture permits, but does not require, implementations to support vector lengths that are not a power of two. To handle this, logic is added to check a requested vector length against a possibly sparse bitmap of available vector lengths at runtime, so that the best supported value can be chosen. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Signal handling supportDave Martin
This patch implements support for saving and restoring the SVE registers around signals. A fixed-size header struct sve_context is always included in the signal frame encoding the thread's vector length at the time of signal delivery, optionally followed by a variable-layout structure encoding the SVE registers. Because of the need to preserve backwards compatibility, the FPSIMD view of the SVE registers is always dumped as a struct fpsimd_context in the usual way, in addition to any sve_context. The SVE vector registers are dumped in full, including bits 127:0 of each register which alias the corresponding FPSIMD vector registers in the hardware. To avoid any ambiguity about which alias to restore during sigreturn, the kernel always restores bits 127:0 of each SVE vector register from the fpsimd_context in the signal frame (which must be present): userspace needs to take this into account if it wants to modify the SVE vector register contents on return from a signal. FPSR and FPCR, which are used by both FPSIMD and SVE, are not included in sve_context because they are always present in fpsimd_context anyway. For signal delivery, a new helper fpsimd_signal_preserve_current_state() is added to update _both_ the FPSIMD and SVE views in the task struct, to make it easier to populate this information into the signal frame. Because of the redundancy between the two views of the state, only one is updated otherwise. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Support vector length resetting for new processesDave Martin
It's desirable to be able to reset the vector length to some sane default for new processes, since the new binary and its libraries may or may not be SVE-aware. This patch tracks the desired post-exec vector length (if any) in a new thread member sve_vl_onexec, and adds a new thread flag TIF_SVE_VL_INHERIT to control whether to inherit or reset the vector length. Currently these are inactive. Subsequent patches will provide the capability to configure them. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Core task context handlingDave Martin
This patch adds the core support for switching and managing the SVE architectural state of user tasks. Calls to the existing FPSIMD low-level save/restore functions are factored out as new functions task_fpsimd_{save,load}(), since SVE now dynamically may or may not need to be handled at these points depending on the kernel configuration, hardware features discovered at boot, and the runtime state of the task. To make these decisions as fast as possible, const cpucaps are used where feasible, via the system_supports_sve() helper. The SVE registers are only tracked for threads that have explicitly used SVE, indicated by the new thread flag TIF_SVE. Otherwise, the FPSIMD view of the architectural state is stored in thread.fpsimd_state as usual. When in use, the SVE registers are not stored directly in thread_struct due to their potentially large and variable size. Because the task_struct slab allocator must be configured very early during kernel boot, it is also tricky to configure it correctly to match the maximum vector length provided by the hardware, since this depends on examining secondary CPUs as well as the primary. Instead, a pointer sve_state in thread_struct points to a dynamically allocated buffer containing the SVE register data, and code is added to allocate and free this buffer at appropriate times. TIF_SVE is set when taking an SVE access trap from userspace, if suitable hardware support has been detected. This enables SVE for the thread: a subsequent return to userspace will disable the trap accordingly. If such a trap is taken without sufficient system- wide hardware support, SIGILL is sent to the thread instead as if an undefined instruction had been executed: this may happen if userspace tries to use SVE in a system where not all CPUs support it for example. The kernel will clear TIF_SVE and disable SVE for the thread whenever an explicit syscall is made by userspace. For backwards compatibility reasons and conformance with the spirit of the base AArch64 procedure call standard, the subset of the SVE register state that aliases the FPSIMD registers is still preserved across a syscall even if this happens. The remainder of the SVE register state logically becomes zero at syscall entry, though the actual zeroing work is currently deferred until the thread next tries to use SVE, causing another trap to the kernel. This implementation is suboptimal: in the future, the fastpath case may be optimised to zero the registers in-place and leave SVE enabled for the task, where beneficial. TIF_SVE is also cleared in the following slowpath cases, which are taken as reasonable hints that the task may no longer use SVE: * exec * fork and clone Code is added to sync data between thread.fpsimd_state and thread.sve_state whenever enabling/disabling SVE, in a manner consistent with the SVE architectural programmer's model. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Alex Bennée <alex.bennee@linaro.org> [will: added #include to fix allnoconfig build] [will: use enable_daif in do_sve_acc] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Low-level CPU setupDave Martin
To enable the kernel to use SVE, SVE traps from EL1 to EL2 must be disabled. To take maximum advantage of the hardware, the full available vector length also needs to be enabled for EL1 by programming ZCR_EL2.LEN. (The kernel will program ZCR_EL1.LEN as required, but this cannot override the limit set by ZCR_EL2.) This patch makes the appropriate changes to the EL2 early setup code. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Signal frame and context structure definitionDave Martin
This patch defines the representation that will be used for the SVE register state in the signal frame, and implements support for saving and restoring the SVE registers around signals. The same layout will also be used for the in-kernel task state. Due to the variability of the SVE vector length, it is not possible to define a fixed C struct to describe all the registers. Instead, Macros are defined in sigcontext.h to facilitate access to the parts of the structure. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Kconfig update and conditional compilation supportDave Martin
This patch adds CONFIG_ARM64_SVE to control building of SVE support into the kernel, and adds a stub predicate system_supports_sve() to control conditional compilation and runtime SVE support. system_supports_sve() just returns false for now: it will be replaced with a non-trivial implementation in a later patch, once SVE support is complete enough to be enabled safely. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Low-level SVE architectural state manipulation functionsDave Martin
Manipulating the SVE architectural state, including the vector and predicate registers, first-fault register and the vector length, requires the use of dedicated instructions added by SVE. This patch adds suitable assembly functions for saving and restoring the SVE registers and querying the vector length. Setting of the vector length is done as part of register restore. Since people building kernels may not all get an SVE-enabled toolchain for a while, this patch uses macros that generate explicit opcodes in place of assembler mnemonics. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: System register and exception syndrome definitionsDave Martin
The SVE architecture adds some system registers, ID register fields and a dedicated ESR exception class. This patch adds the appropriate definitions that will be needed by the kernel. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64: fpsimd: Simplify uses of {set,clear}_ti_thread_flag()Dave Martin
The existing FPSIMD context switch code contains a couple of instances of {set,clear}_ti_thread(task_thread_info(task)). Since there are thread flag manipulators that operate directly on task_struct, this verbosity isn't strictly needed. For consistency, this patch simplifies the affected calls. This should have no impact on behaviour. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64: Port deprecated instruction emulation to new sysctl interfaceDave Martin
Currently, armv8_deprected.c takes charge of the "abi" sysctl directory, which makes life difficult for other code that wants to register sysctls in the same directory. There is a "new" [1] sysctl registration interface that removes the need to define ctl_tables for parent directories explicitly, which is ideal here. This patch ports register_insn_emulation_sysctl() over to the register_sysctl() interface and removes the redundant ctl_table for "abi". Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> [1] fea478d4101a (sysctl: Add register_sysctl for normal sysctl users) The commit message notes an intent to port users of the pre-existing interfaces over to register_sysctl(), though the number of users of the new interface currently appears negligible. Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64: efi: Add missing Kconfig dependency on KERNEL_MODE_NEONDave Martin
The EFI runtime services ABI permits calls to EFI to clobber certain FPSIMD/NEON registers, as per the AArch64 procedure call standard. Saving/restoring the clobbered registers around such calls needs KERNEL_MODE_NEON, but the dependency is missing from Kconfig. This patch adds the missing dependency. This will aid bisection of the patches implementing support for the ARM Scalable Vector Extension (SVE). Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64: KVM: Hide unsupported AArch64 CPU features from guestsDave Martin
Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64: signal: Verify extra data is user-readable in sys_rt_sigreturnDave Martin
Currently sys_rt_sigreturn() verifies that the base sigframe is readable, but no similar check is performed on the extra data to which an extra_context record points. This matters because the extra data will be read with the unprotected user accessors. However, this is not a problem at present because the extra data base address is required to be exactly at the end of the base sigframe. So, there would need to be a non-user-readable kernel address within about 59K (SIGFRAME_MAXSZ - sizeof(struct rt_sigframe)) of some address for which access_ok(VERIFY_READ) returns true, in order for sigreturn to be able to read kernel memory that should be inaccessible to the user task. This is currently impossible due to the untranslatable address hole between the TTBR0 and TTBR1 address ranges. Disappearance of the hole between the TTBR0 and TTBR1 mapping ranges would require the VA size for TTBR0 and TTBR1 to grow to at least 55 bits, and either the disabling of tagged pointers for userspace or enabling of tagged pointers for kernel space; none of which is currently envisaged. Even so, it is wrong to use the unprotected user accessors without an accompanying access_ok() check. To avoid the potential for future surprises, this patch does an explicit access_ok() check on the extra data space when parsing an extra_context record. Fixes: 33f082614c34 ("arm64: signal: Allow expansion of the signal frame") Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>