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2020-10-09Revert "arm64: initialize per-cpu offsets earlier"Will Deacon
This reverts commit 353e228eb355be5a65a3c0996c774a0f46737fda. Qian Cai reports that TX2 no longer boots with his .config as it appears that task_cpu() gets instrumented and used before KASAN has been initialised. Although Mark has a proposed fix, let's take the safe option of reverting this for now and sorting it out properly later. Link: https://lore.kernel.org/r/711bc57a314d8d646b41307008db2845b7537b3d.camel@redhat.com Reported-by: Qian Cai <cai@redhat.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-10-07Merge branch 'for-next/late-arrivals' into for-next/coreWill Deacon
Late patches for 5.10: MTE selftests, minor KCSAN preparation and removal of some unused prototypes. (Amit Daniel Kachhap and others) * for-next/late-arrivals: arm64: random: Remove no longer needed prototypes arm64: initialize per-cpu offsets earlier kselftest/arm64: Check mte tagged user address in kernel kselftest/arm64: Verify KSM page merge for MTE pages kselftest/arm64: Verify all different mmap MTE options kselftest/arm64: Check forked child mte memory accessibility kselftest/arm64: Verify mte tag inclusion via prctl kselftest/arm64: Add utilities and a test to validate mte memory
2020-10-07arm64: random: Remove no longer needed prototypesAndre Przywara
Commit 9bceb80b3cc4 ("arm64: kaslr: Use standard early random function") removed the direct calls of the __arm64_rndr() and __early_cpu_has_rndr() functions, but left the dummy prototypes in the #else branch of the #ifdef CONFIG_ARCH_RANDOM guard. Remove the redundant prototypes, as they have no users outside of this header file. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20201006194453.36519-1-andre.przywara@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-10-05arm64: initialize per-cpu offsets earlierMark Rutland
The current initialization of the per-cpu offset register is difficult to follow and this initialization is not always early enough for upcoming instrumentation with KCSAN, where the instrumentation callbacks use the per-cpu offset. To make it possible to support KCSAN, and to simplify reasoning about early bringup code, let's initialize the per-cpu offset earlier, before we run any C code that may consume it. To do so, this patch adds a new init_this_cpu_offset() helper that's called before the usual primary/secondary start functions. For consistency, this is also used to re-initialize the per-cpu offset after the runtime per-cpu areas have been allocated (which can change CPU0's offset). So that init_this_cpu_offset() isn't subject to any instrumentation that might consume the per-cpu offset, it is marked with noinstr, preventing instrumentation. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201005164303.21389-1-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-10-02Merge branch 'for-next/mte' into for-next/coreWill Deacon
Add userspace support for the Memory Tagging Extension introduced by Armv8.5. (Catalin Marinas and others) * for-next/mte: (30 commits) arm64: mte: Fix typo in memory tagging ABI documentation arm64: mte: Add Memory Tagging Extension documentation arm64: mte: Kconfig entry arm64: mte: Save tags when hibernating arm64: mte: Enable swap of tagged pages mm: Add arch hooks for saving/restoring tags fs: Handle intra-page faults in copy_mount_options() arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks arm64: mte: Restore the GCR_EL1 register after a suspend arm64: mte: Allow user control of the generated random tags via prctl() arm64: mte: Allow user control of the tag check mode via prctl() mm: Allow arm64 mmap(PROT_MTE) on RAM-based files arm64: mte: Validate the PROT_MTE request via arch_validate_flags() mm: Introduce arch_validate_flags() arm64: mte: Add PROT_MTE support to mmap() and mprotect() mm: Introduce arch_calc_vm_flag_bits() arm64: mte: Tags-aware aware memcmp_pages() implementation arm64: Avoid unnecessary clear_user_page() indirection ...
2020-10-02Merge branch 'for-next/ghostbusters' into for-next/coreWill Deacon
Fix and subsequently rewrite Spectre mitigations, including the addition of support for PR_SPEC_DISABLE_NOEXEC. (Will Deacon and Marc Zyngier) * for-next/ghostbusters: (22 commits) arm64: Add support for PR_SPEC_DISABLE_NOEXEC prctl() option arm64: Pull in task_stack_page() to Spectre-v4 mitigation code KVM: arm64: Allow patching EL2 vectors even with KASLR is not enabled arm64: Get rid of arm64_ssbd_state KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state() KVM: arm64: Get rid of kvm_arm_have_ssbd() KVM: arm64: Simplify handling of ARCH_WORKAROUND_2 arm64: Rewrite Spectre-v4 mitigation code arm64: Move SSBD prctl() handler alongside other spectre mitigation code arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4 arm64: Treat SSBS as a non-strict system feature arm64: Group start_thread() functions together KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2 arm64: Rewrite Spectre-v2 mitigation code arm64: Introduce separate file for spectre mitigations and reporting arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2 KVM: arm64: Simplify install_bp_hardening_cb() KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE arm64: Remove Spectre-related CONFIG_* options arm64: Run ARCH_WORKAROUND_2 enabling code on all CPUs ...
2020-10-02Merge branches 'for-next/acpi', 'for-next/boot', 'for-next/bpf', ↵Will Deacon
'for-next/cpuinfo', 'for-next/fpsimd', 'for-next/misc', 'for-next/mm', 'for-next/pci', 'for-next/perf', 'for-next/ptrauth', 'for-next/sdei', 'for-next/selftests', 'for-next/stacktrace', 'for-next/svm', 'for-next/topology', 'for-next/tpyos' and 'for-next/vdso' into for-next/core Remove unused functions and parameters from ACPI IORT code. (Zenghui Yu via Lorenzo Pieralisi) * for-next/acpi: ACPI/IORT: Remove the unused inline functions ACPI/IORT: Drop the unused @ops of iort_add_device_replay() Remove redundant code and fix documentation of caching behaviour for the HVC_SOFT_RESTART hypercall. (Pingfan Liu) * for-next/boot: Documentation/kvm/arm: improve description of HVC_SOFT_RESTART arm64/relocate_kernel: remove redundant code Improve reporting of unexpected kernel traps due to BPF JIT failure. (Will Deacon) * for-next/bpf: arm64: Improve diagnostics when trapping BRK with FAULT_BRK_IMM Improve robustness of user-visible HWCAP strings and their corresponding numerical constants. (Anshuman Khandual) * for-next/cpuinfo: arm64/cpuinfo: Define HWCAP name arrays per their actual bit definitions Cleanups to handling of SVE and FPSIMD register state in preparation for potential future optimisation of handling across syscalls. (Julien Grall) * for-next/fpsimd: arm64/sve: Implement a helper to load SVE registers from FPSIMD state arm64/sve: Implement a helper to flush SVE registers arm64/fpsimdmacros: Allow the macro "for" to be used in more cases arm64/fpsimdmacros: Introduce a macro to update ZCR_EL1.LEN arm64/signal: Update the comment in preserve_sve_context arm64/fpsimd: Update documentation of do_sve_acc Miscellaneous changes. (Tian Tao and others) * for-next/misc: arm64/mm: return cpu_all_mask when node is NUMA_NO_NODE arm64: mm: Fix missing-prototypes in pageattr.c arm64/fpsimd: Fix missing-prototypes in fpsimd.c arm64: hibernate: Remove unused including <linux/version.h> arm64/mm: Refactor {pgd, pud, pmd, pte}_ERROR() arm64: Remove the unused include statements arm64: get rid of TEXT_OFFSET arm64: traps: Add str of description to panic() in die() Memory management updates and cleanups. (Anshuman Khandual and others) * for-next/mm: arm64: dbm: Invalidate local TLB when setting TCR_EL1.HD arm64: mm: Make flush_tlb_fix_spurious_fault() a no-op arm64/mm: Unify CONT_PMD_SHIFT arm64/mm: Unify CONT_PTE_SHIFT arm64/mm: Remove CONT_RANGE_OFFSET arm64/mm: Enable THP migration arm64/mm: Change THP helpers to comply with generic MM semantics arm64/mm/ptdump: Add address markers for BPF regions Allow prefetchable PCI BARs to be exposed to userspace using normal non-cacheable mappings. (Clint Sbisa) * for-next/pci: arm64: Enable PCI write-combine resources under sysfs Perf/PMU driver updates. (Julien Thierry and others) * for-next/perf: perf: arm-cmn: Fix conversion specifiers for node type perf: arm-cmn: Fix unsigned comparison to less than zero arm_pmu: arm64: Use NMIs for PMU arm_pmu: Introduce pmu_irq_ops KVM: arm64: pmu: Make overflow handler NMI safe arm64: perf: Defer irq_work to IPI_IRQ_WORK arm64: perf: Remove PMU locking arm64: perf: Avoid PMXEV* indirection arm64: perf: Add missing ISB in armv8pmu_enable_counter() perf: Add Arm CMN-600 PMU driver perf: Add Arm CMN-600 DT binding arm64: perf: Add support caps under sysfs drivers/perf: thunderx2_pmu: Fix memory resource error handling drivers/perf: xgene_pmu: Fix uninitialized resource struct perf: arm_dsu: Support DSU ACPI devices arm64: perf: Remove unnecessary event_idx check drivers/perf: hisi: Add missing include of linux/module.h arm64: perf: Add general hardware LLC events for PMUv3 Support for the Armv8.3 Pointer Authentication enhancements. (By Amit Daniel Kachhap) * for-next/ptrauth: arm64: kprobe: clarify the comment of steppable hint instructions arm64: kprobe: disable probe of fault prone ptrauth instruction arm64: cpufeature: Modify address authentication cpufeature to exact arm64: ptrauth: Introduce Armv8.3 pointer authentication enhancements arm64: traps: Allow force_signal_inject to pass esr error code arm64: kprobe: add checks for ARMv8.3-PAuth combined instructions Tonnes of cleanup to the SDEI driver. (Gavin Shan) * for-next/sdei: firmware: arm_sdei: Remove _sdei_event_unregister() firmware: arm_sdei: Remove _sdei_event_register() firmware: arm_sdei: Introduce sdei_do_local_call() firmware: arm_sdei: Cleanup on cross call function firmware: arm_sdei: Remove while loop in sdei_event_unregister() firmware: arm_sdei: Remove while loop in sdei_event_register() firmware: arm_sdei: Remove redundant error message in sdei_probe() firmware: arm_sdei: Remove duplicate check in sdei_get_conduit() firmware: arm_sdei: Unregister driver on error in sdei_init() firmware: arm_sdei: Avoid nested statements in sdei_init() firmware: arm_sdei: Retrieve event number from event instance firmware: arm_sdei: Common block for failing path in sdei_event_create() firmware: arm_sdei: Remove sdei_is_err() Selftests for Pointer Authentication and FPSIMD/SVE context-switching. (Mark Brown and Boyan Karatotev) * for-next/selftests: selftests: arm64: Add build and documentation for FP tests selftests: arm64: Add wrapper scripts for stress tests selftests: arm64: Add utility to set SVE vector lengths selftests: arm64: Add stress tests for FPSMID and SVE context switching selftests: arm64: Add test for the SVE ptrace interface selftests: arm64: Test case for enumeration of SVE vector lengths kselftests/arm64: add PAuth tests for single threaded consistency and differently initialized keys kselftests/arm64: add PAuth test for whether exec() changes keys kselftests/arm64: add nop checks for PAuth tests kselftests/arm64: add a basic Pointer Authentication test Implementation of ARCH_STACKWALK for unwinding. (Mark Brown) * for-next/stacktrace: arm64: Move console stack display code to stacktrace.c arm64: stacktrace: Convert to ARCH_STACKWALK arm64: stacktrace: Make stack walk callback consistent with generic code stacktrace: Remove reliable argument from arch_stack_walk() callback Support for ASID pinning, which is required when sharing page-tables with the SMMU. (Jean-Philippe Brucker) * for-next/svm: arm64: cpufeature: Export symbol read_sanitised_ftr_reg() arm64: mm: Pin down ASIDs for sharing mm with devices Rely on firmware tables for establishing CPU topology. (Valentin Schneider) * for-next/topology: arm64: topology: Stop using MPIDR for topology information Spelling fixes. (Xiaoming Ni and Yanfei Xu) * for-next/tpyos: arm64/numa: Fix a typo in comment of arm64_numa_init arm64: fix some spelling mistakes in the comments by codespell vDSO cleanups. (Will Deacon) * for-next/vdso: arm64: vdso: Fix unusual formatting in *setup_additional_pages() arm64: vdso32: Remove a bunch of #ifdef CONFIG_COMPAT_VDSO guards
2020-10-01arm64: dbm: Invalidate local TLB when setting TCR_EL1.HDWill Deacon
TCR_EL1.HD is permitted to be cached in a TLB, so invalidate the local TLB after setting the bit when detected support for the feature. Although this isn't strictly necessary, since we can happily operate with the bit effectively clear, the current code uses an ISB in a half-hearted attempt to make the change effective, so let's just fix that up. Link: https://lore.kernel.org/r/20201001110405.18617-1-will@kernel.org Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-10-01arm64: mm: Make flush_tlb_fix_spurious_fault() a no-opWill Deacon
Our use of broadcast TLB maintenance means that spurious page-faults that have been handled already by another CPU do not require additional TLB maintenance. Make flush_tlb_fix_spurious_fault() a no-op and rely on the existing TLB invalidation instead. Add an explicit flush_tlb_page() when making a page dirty, as the TLB is permitted to cache the old read-only entry. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200728092220.GA21800@willie-the-truck Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Add support for PR_SPEC_DISABLE_NOEXEC prctl() optionWill Deacon
The PR_SPEC_DISABLE_NOEXEC option to the PR_SPEC_STORE_BYPASS prctl() allows the SSB mitigation to be enabled only until the next execve(), at which point the state will revert back to PR_SPEC_ENABLE and the mitigation will be disabled. Add support for PR_SPEC_DISABLE_NOEXEC on arm64. Reported-by: Anthony Steinhauser <asteinhauser@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Pull in task_stack_page() to Spectre-v4 mitigation codeWill Deacon
The kbuild robot reports that we're relying on an implicit inclusion to get a definition of task_stack_page() in the Spectre-v4 mitigation code, which is not always in place for some configurations: | arch/arm64/kernel/proton-pack.c:329:2: error: implicit declaration of function 'task_stack_page' [-Werror,-Wimplicit-function-declaration] | task_pt_regs(task)->pstate |= val; | ^ | arch/arm64/include/asm/processor.h:268:36: note: expanded from macro 'task_pt_regs' | ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1) | ^ | arch/arm64/kernel/proton-pack.c:329:2: note: did you mean 'task_spread_page'? Add the missing include to fix the build error. Fixes: a44acf477220 ("arm64: Move SSBD prctl() handler alongside other spectre mitigation code") Reported-by: Anthony Steinhauser <asteinhauser@google.com> Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/202009260013.Ul7AD29w%lkp@intel.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29KVM: arm64: Allow patching EL2 vectors even with KASLR is not enabledWill Deacon
Patching the EL2 exception vectors is integral to the Spectre-v2 workaround, where it can be necessary to execute CPU-specific sequences to nobble the branch predictor before running the hypervisor text proper. Remove the dependency on CONFIG_RANDOMIZE_BASE and allow the EL2 vectors to be patched even when KASLR is not enabled. Fixes: 7a132017e7a5 ("KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE") Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/202009221053.Jv1XsQUZ%lkp@intel.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Get rid of arm64_ssbd_stateMarc Zyngier
Out with the old ghost, in with the new... Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state()Marc Zyngier
Convert the KVM WA2 code to using the Spectre infrastructure, making the code much more readable. It also allows us to take SSBS into account for the mitigation. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29KVM: arm64: Get rid of kvm_arm_have_ssbd()Marc Zyngier
kvm_arm_have_ssbd() is now completely unused, get rid of it. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29KVM: arm64: Simplify handling of ARCH_WORKAROUND_2Marc Zyngier
Owing to the fact that the host kernel is always mitigated, we can drastically simplify the WA2 handling by keeping the mitigation state ON when entering the guest. This means the guest is either unaffected or not mitigated. This results in a nice simplification of the mitigation space, and the removal of a lot of code that was never really used anyway. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Rewrite Spectre-v4 mitigation codeWill Deacon
Rewrite the Spectre-v4 mitigation handling code to follow the same approach as that taken by Spectre-v2. For now, report to KVM that the system is vulnerable (by forcing 'ssbd_state' to ARM64_SSBD_UNKNOWN), as this will be cleared up in subsequent steps. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Move SSBD prctl() handler alongside other spectre mitigation codeWill Deacon
As part of the spectre consolidation effort to shift all of the ghosts into their own proton pack, move all of the horrible SSBD prctl() code out of its own 'ssbd.c' file. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4Will Deacon
In a similar manner to the renaming of ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2, rename ARM64_SSBD to ARM64_SPECTRE_V4. This isn't _entirely_ accurate, as we also need to take into account the interaction with SSBS, but that will be taken care of in subsequent patches. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Treat SSBS as a non-strict system featureWill Deacon
If all CPUs discovered during boot have SSBS, then spectre-v4 will be considered to be "mitigated". However, we still allow late CPUs without SSBS to be onlined, albeit with a "SANITY CHECK" warning. This is problematic for userspace because it means that the system can quietly transition to "Vulnerable" at runtime. Avoid this by treating SSBS as a non-strict system feature: if all of the CPUs discovered during boot have SSBS, then late arriving secondaries better have it as well. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Group start_thread() functions togetherWill Deacon
The is_ttbrX_addr() functions have somehow ended up in the middle of the start_thread() functions, so move them out of the way to keep the code readable. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2Marc Zyngier
If the system is not affected by Spectre-v2, then advertise to the KVM guest that it is not affected, without the need for a safelist in the guest. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Rewrite Spectre-v2 mitigation codeWill Deacon
The Spectre-v2 mitigation code is pretty unwieldy and hard to maintain. This is largely due to it being written hastily, without much clue as to how things would pan out, and also because it ends up mixing policy and state in such a way that it is very difficult to figure out what's going on. Rewrite the Spectre-v2 mitigation so that it clearly separates state from policy and follows a more structured approach to handling the mitigation. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Introduce separate file for spectre mitigations and reportingWill Deacon
The spectre mitigation code is spread over a few different files, which makes it both hard to follow, but also hard to remove it should we want to do that in future. Introduce a new file for housing the spectre mitigations, and populate it with the spectre-v1 reporting code to start with. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2Will Deacon
For better or worse, the world knows about "Spectre" and not about "Branch predictor hardening". Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2 as part of moving all of the Spectre mitigations into their own little corner. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29KVM: arm64: Simplify install_bp_hardening_cb()Will Deacon
Use is_hyp_mode_available() to detect whether or not we need to patch the KVM vectors for branch hardening, which avoids the need to take the vector pointers as parameters. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASEWill Deacon
The removal of CONFIG_HARDEN_BRANCH_PREDICTOR means that CONFIG_KVM_INDIRECT_VECTORS is synonymous with CONFIG_RANDOMIZE_BASE, so replace it. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Remove Spectre-related CONFIG_* optionsWill Deacon
The spectre mitigations are too configurable for their own good, leading to confusing logic trying to figure out when we should mitigate and when we shouldn't. Although the plethora of command-line options need to stick around for backwards compatibility, the default-on CONFIG options that depend on EXPERT can be dropped, as the mitigations only do anything if the system is vulnerable, a mitigation is available and the command-line hasn't disabled it. Remove CONFIG_HARDEN_BRANCH_PREDICTOR and CONFIG_ARM64_SSBD in favour of enabling this code unconditionally. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-29arm64: Run ARCH_WORKAROUND_2 enabling code on all CPUsMarc Zyngier
Commit 606f8e7b27bf ("arm64: capabilities: Use linear array for detection and verification") changed the way we deal with per-CPU errata by only calling the .matches() callback until one CPU is found to be affected. At this point, .matches() stop being called, and .cpu_enable() will be called on all CPUs. This breaks the ARCH_WORKAROUND_2 handling, as only a single CPU will be mitigated. In order to address this, forcefully call the .matches() callback from a .cpu_enable() callback, which brings us back to the original behaviour. Fixes: 606f8e7b27bf ("arm64: capabilities: Use linear array for detection and verification") Cc: <stable@vger.kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28arm64: cpufeature: Export symbol read_sanitised_ftr_reg()Jean-Philippe Brucker
The SMMUv3 driver would like to read the MMFR0 PARANGE field in order to share CPU page tables with devices. Allow the driver to be built as module by exporting the read_sanitized_ftr_reg() cpufeature symbol. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20200918101852.582559-7-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28arm64: mm: Pin down ASIDs for sharing mm with devicesJean-Philippe Brucker
To enable address space sharing with the IOMMU, introduce arm64_mm_context_get() and arm64_mm_context_put(), that pin down a context and ensure that it will keep its ASID after a rollover. Export the symbols to let the modular SMMUv3 driver use them. Pinning is necessary because a device constantly needs a valid ASID, unlike tasks that only require one when running. Without pinning, we would need to notify the IOMMU when we're about to use a new ASID for a task, and it would get complicated when a new task is assigned a shared ASID. Consider the following scenario with no ASID pinned: 1. Task t1 is running on CPUx with shared ASID (gen=1, asid=1) 2. Task t2 is scheduled on CPUx, gets ASID (1, 2) 3. Task tn is scheduled on CPUy, a rollover occurs, tn gets ASID (2, 1) We would now have to immediately generate a new ASID for t1, notify the IOMMU, and finally enable task tn. We are holding the lock during all that time, since we can't afford having another CPU trigger a rollover. The IOMMU issues invalidation commands that can take tens of milliseconds. It gets needlessly complicated. All we wanted to do was schedule task tn, that has no business with the IOMMU. By letting the IOMMU pin tasks when needed, we avoid stalling the slow path, and let the pinning fail when we're out of shareable ASIDs. After a rollover, the allocator expects at least one ASID to be available in addition to the reserved ones (one per CPU). So (NR_ASIDS - NR_CPUS - 1) is the maximum number of ASIDs that can be shared with the IOMMU. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20200918101852.582559-5-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28KVM: arm64: pmu: Make overflow handler NMI safeJulien Thierry
kvm_vcpu_kick() is not NMI safe. When the overflow handler is called from NMI context, defer waking the vcpu to an irq_work queue. A vcpu can be freed while it's not running by kvm_destroy_vm(). Prevent running the irq_work for a non-existent vcpu by calling irq_work_sync() on the PMU destroy path. [Alexandru E.: Added irq_work_sync()] Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox) Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Pouloze <suzuki.poulose@arm.com> Cc: kvm@vger.kernel.org Cc: kvmarm@lists.cs.columbia.edu Link: https://lore.kernel.org/r/20200924110706.254996-6-alexandru.elisei@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28arm64: perf: Defer irq_work to IPI_IRQ_WORKJulien Thierry
When handling events, armv8pmu_handle_irq() calls perf_event_overflow(), and subsequently calls irq_work_run() to handle any work queued by perf_event_overflow(). As perf_event_overflow() raises IPI_IRQ_WORK when queuing the work, this isn't strictly necessary and the work could be handled as part of the IPI_IRQ_WORK handler. In the common case the IPI handler will run immediately after the PMU IRQ handler, and where the PE is heavily loaded with interrupts other handlers may run first, widening the window where some counters are disabled. In practice this window is unlikely to be a significant issue, and removing the call to irq_work_run() would make the PMU IRQ handler NMI safe in addition to making it simpler, so let's do that. [Alexandru E.: Reworded commit message] Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200924110706.254996-5-alexandru.elisei@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28arm64: perf: Remove PMU lockingJulien Thierry
The PMU is disabled and enabled, and the counters are programmed from contexts where interrupts or preemption is disabled. The functions to toggle the PMU and to program the PMU counters access the registers directly and don't access data modified by the interrupt handler. That, and the fact that they're always called from non-preemptible contexts, means that we don't need to disable interrupts or use a spinlock. [Alexandru E.: Explained why locking is not needed, removed WARN_ONs] Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox) Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200924110706.254996-4-alexandru.elisei@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28arm64: perf: Avoid PMXEV* indirectionMark Rutland
Currently we access the counter registers and their respective type registers indirectly. This requires us to write to PMSELR, issue an ISB, then access the relevant PMXEV* registers. This is unfortunate, because: * Under virtualization, accessing one register requires two traps to the hypervisor, even though we could access the register directly with a single trap. * We have to issue an ISB which we could otherwise avoid the cost of. * When we use NMIs, the NMI handler will have to save/restore the select register in case the code it preempted was attempting to access a counter or its type register. We can avoid these issues by directly accessing the relevant registers. This patch adds helpers to do so. In armv8pmu_enable_event() we still need the ISB to prevent the PE from reordering the write to PMINTENSET_EL1 register. If the interrupt is enabled before we disable the counter and the new event is configured, we might get an interrupt triggered by the previously programmed event overflowing, but which we wrongly attribute to the event that we are enabling. Execute an ISB after we disable the counter. In the process, remove the comment that refers to the ARMv7 PMU. [Julien T.: Don't inline read/write functions to avoid big code-size increase, remove unused read_pmevtypern function, fix counter index issue.] [Alexandru E.: Removed comment, removed trailing semicolons in macros, added ISB] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox) Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200924110706.254996-3-alexandru.elisei@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28arm64: perf: Add missing ISB in armv8pmu_enable_counter()Alexandru Elisei
Writes to the PMXEVTYPER_EL0 register are not self-synchronising. In armv8pmu_enable_event(), the PE can reorder configuring the event type after we have enabled the counter and the interrupt. This can lead to an interrupt being asserted because of the previous event type that we were counting using the same counter, not the one that we've just configured. The same rationale applies to writes to the PMINTENSET_EL1 register. The PE can reorder enabling the interrupt at any point in the future after we have enabled the event. Prevent both situations from happening by adding an ISB just before we enable the event counter. Fixes: 030896885ade ("arm64: Performance counters support") Reported-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox) Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20200924110706.254996-2-alexandru.elisei@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28arm64: perf: Add support caps under sysfsShaokun Zhang
ARMv8.4-PMU introduces the PMMIR_EL1 registers and some new PMU events, like STALL_SLOT etc, are related to it. Let's add a caps directory to /sys/bus/event_source/devices/armv8_pmuv3_0/ and support slots from PMMIR_EL1 registers in this entry. The user programs can get the slots from sysfs directly. /sys/bus/event_source/devices/armv8_pmuv3_0/caps/slots is exposed under sysfs. Both ARMv8.4-PMU and STALL_SLOT event are implemented, it returns the slots from PMMIR_EL1, otherwise it will return 0. Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/1600754025-53535-1-git-send-email-zhangshaokun@hisilicon.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64/mm: return cpu_all_mask when node is NUMA_NO_NODEZhengyuan Liu
The @node passed to cpumask_of_node() can be NUMA_NO_NODE, in that case it will trigger the following WARN_ON(node >= nr_node_ids) due to mismatched data types of @node and @nr_node_ids. Actually we should return cpu_all_mask just like most other architectures do if passed NUMA_NO_NODE. Also add a similar check to the inline cpumask_of_node() in numa.h. Signed-off-by: Zhengyuan Liu <liuzhengyuan@tj.kylinos.cn> Reviewed-by: Gavin Shan <gshan@redhat.com> Link: https://lore.kernel.org/r/20200921023936.21846-1-liuzhengyuan@tj.kylinos.cn Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64: Move console stack display code to stacktrace.cMark Brown
Currently the code for displaying a stack trace on the console is located in traps.c rather than stacktrace.c, using the unwinding code that is in stacktrace.c. This can be confusing and make the code hard to find since such output is often referred to as a stack trace which might mislead the unwary. Due to this and since traps.c doesn't interact with this code except for via the public interfaces move the code to stacktrace.c to make it easier to find. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200921122341.11280-1-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUsMarc Zyngier
Commit 73f381660959 ("arm64: Advertise mitigation of Spectre-v2, or lack thereof") changed the way we deal with ARCH_WORKAROUND_1, by moving most of the enabling code to the .matches() callback. This has the unfortunate effect that the workaround gets only enabled on the first affected CPU, and no other. In order to address this, forcefully call the .matches() callback from a .cpu_enable() callback, which brings us back to the original behaviour. Fixes: 73f381660959 ("arm64: Advertise mitigation of Spectre-v2, or lack thereof") Cc: <stable@vger.kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64: Make use of ARCH_WORKAROUND_1 even when KVM is not enabledMarc Zyngier
We seem to be pretending that we don't have any firmware mitigation when KVM is not compiled in, which is not quite expected. Bring back the mitigation in this case. Fixes: 4db61fef16a1 ("arm64: kvm: Modernize __smccc_workaround_1_smc_start annotations") Cc: <stable@vger.kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64/sve: Implement a helper to load SVE registers from FPSIMD stateJulien Grall
In a follow-up patch, we may save the FPSIMD rather than the full SVE state when the state has to be zeroed on return to userspace (e.g during a syscall). Introduce an helper to load SVE vectors from FPSIMD state and zero the rest of SVE registers. Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200828181155.17745-7-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64/sve: Implement a helper to flush SVE registersJulien Grall
Introduce a new helper that will zero all SVE registers but the first 128-bits of each vector. This will be used by subsequent patches to avoid costly store/maipulate/reload sequences in places like do_sve_acc(). Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200828181155.17745-6-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64/fpsimdmacros: Allow the macro "for" to be used in more casesJulien Grall
The current version of the macro "for" is not able to work when the counter is used to generate registers using mnemonics. This is because gas is not able to evaluate the expression generated if used in register's name (i.e x\n). Gas offers a way to evaluate macro arguments by using % in front of them under the alternate macro mode. The implementation of "for" is updated to use the alternate macro mode and %, so we can use the macro in more cases. As the alternate macro mode may have side-effects, this is disabled when expanding the body. While it is enough to prefix the argument of the macro "__for_body" with %, the arguments of "__for" are also prefixed to get a more bearable value in case of compilation error. Suggested-by: Dave Martin <dave.martin@arm.com> Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200828181155.17745-4-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64/fpsimdmacros: Introduce a macro to update ZCR_EL1.LENJulien Grall
A follow-up patch will need to update ZCR_EL1.LEN. Add a macro that could be re-used in the current and new places to avoid code duplication. Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200828181155.17745-5-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64/signal: Update the comment in preserve_sve_contextJulien Grall
The SVE state is saved by fpsimd_signal_preserve_current_state() and not preserve_fpsimd_context(). Update the comment in preserve_sve_context to reflect the current behavior. Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200828181155.17745-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21arm64/fpsimd: Update documentation of do_sve_accJulien Grall
fpsimd_restore_current_state() enables and disables the SVE access trap based on TIF_SVE, not task_fpsimd_load(). Update the documentation of do_sve_acc to reflect this behavior. Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200828181155.17745-2-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-18arm64: Improve diagnostics when trapping BRK with FAULT_BRK_IMMWill Deacon
When generating instructions at runtime, for example due to kernel text patching or the BPF JIT, we can emit a trapping BRK instruction if we are asked to encode an invalid instruction such as an out-of-range] branch. This is indicative of a bug in the caller, and will result in a crash on executing the generated code. Unfortunately, the message from the crash is really unhelpful, and mumbles something about ptrace: | Unexpected kernel BRK exception at EL1 | Internal error: ptrace BRK handler: f2000100 [#1] SMP We can do better than this. Install a break handler for FAULT_BRK_IMM, which is the immediate used to encode the "I've been asked to generate an invalid instruction" error, and triage the faulting PC to determine whether or not the failure occurred in the BPF JIT. Link: https://lore.kernel.org/r/20200915141707.GB26439@willie-the-truck Reported-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-18arm64: mm: Fix missing-prototypes in pageattr.cTian Tao
Fix the following warnings. ‘set_memory_valid’ [-Wmissing-prototypes] int set_memory_valid(unsigned long addr, int numpages, int enable) ^ ‘set_direct_map_invalid_noflush’ [-Wmissing-prototypes] int set_direct_map_invalid_noflush(struct page *page) ^ ‘set_direct_map_default_noflush’ [-Wmissing-prototypes] int set_direct_map_default_noflush(struct page *page) ^ Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Link: https://lore.kernel.org/r/1600222847-56792-1-git-send-email-tiantao6@hisilicon.com arch/arm64/mm/pageattr.c:138:5: warning: no previous prototype for arch/arm64/mm/pageattr.c:150:5: warning: no previous prototype for arch/arm64/mm/pageattr.c:165:5: warning: no previous prototype for Signed-off-by: Will Deacon <will@kernel.org>
2020-09-18arm64/fpsimd: Fix missing-prototypes in fpsimd.cTian Tao
Fix the following warnings. arch/arm64/kernel/fpsimd.c:935:6: warning: no previous prototype for ‘do_sve_acc’ [-Wmissing-prototypes] arch/arm64/kernel/fpsimd.c:962:6: warning: no previous prototype for ‘do_fpsimd_acc’ [-Wmissing-prototypes] arch/arm64/kernel/fpsimd.c:971:6: warning: no previous prototype for ‘do_fpsimd_exc’ [-Wmissing-prototypes] arch/arm64/kernel/fpsimd.c:1266:6: warning: no previous prototype for ‘kernel_neon_begin’ [-Wmissing-prototypes] arch/arm64/kernel/fpsimd.c:1292:6: warning: no previous prototype for ‘kernel_neon_end’ [-Wmissing-prototypes] Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/1600157999-14802-1-git-send-email-tiantao6@hisilicon.com Signed-off-by: Will Deacon <will@kernel.org>