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2025-11-12arm64: Fix typos and spelling errors in commentsmrigendrachaubey1-1/+1
This patch corrects several minor typographical and spelling errors in comments across multiple arm64 source files. No functional changes. Signed-off-by: mrigendrachaubey <mrigendra.chaubey@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-10-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-6/+9
Pull kvm updates from Paolo Bonzini: "This excludes the bulk of the x86 changes, which I will send separately. They have two not complex but relatively unusual conflicts so I will wait for other dust to settle. guest_memfd: - Add support for host userspace mapping of guest_memfd-backed memory for VM types that do NOT use support KVM_MEMORY_ATTRIBUTE_PRIVATE (which isn't precisely the same thing as CoCo VMs, since x86's SEV-MEM and SEV-ES have no way to detect private vs. shared). This lays the groundwork for removal of guest memory from the kernel direct map, as well as for limited mmap() for guest_memfd-backed memory. For more information see: - commit a6ad54137af9 ("Merge branch 'guest-memfd-mmap' into HEAD") - guest_memfd in Firecracker: https://github.com/firecracker-microvm/firecracker/tree/feature/secret-hiding - direct map removal: https://lore.kernel.org/all/20250221160728.1584559-1-roypat@amazon.co.uk/ - mmap support: https://lore.kernel.org/all/20250328153133.3504118-1-tabba@google.com/ ARM: - Add support for FF-A 1.2 as the secure memory conduit for pKVM, allowing more registers to be used as part of the message payload. - Change the way pKVM allocates its VM handles, making sure that the privileged hypervisor is never tricked into using uninitialised data. - Speed up MMIO range registration by avoiding unnecessary RCU synchronisation, which results in VMs starting much quicker. - Add the dump of the instruction stream when panic-ing in the EL2 payload, just like the rest of the kernel has always done. This will hopefully help debugging non-VHE setups. - Add 52bit PA support to the stage-1 page-table walker, and make use of it to populate the fault level reported to the guest on failing to translate a stage-1 walk. - Add NV support to the GICv3-on-GICv5 emulation code, ensuring feature parity for guests, irrespective of the host platform. - Fix some really ugly architecture problems when dealing with debug in a nested VM. This has some bad performance impacts, but is at least correct. - Add enough infrastructure to be able to disable EL2 features and give effective values to the EL2 control registers. This then allows a bunch of features to be turned off, which helps cross-host migration. - Large rework of the selftest infrastructure to allow most tests to transparently run at EL2. This is the first step towards enabling NV testing. - Various fixes and improvements all over the map, including one BE fix, just in time for the removal of the feature. LoongArch: - Detect page table walk feature on new hardware - Add sign extension with kernel MMIO/IOCSR emulation - Improve in-kernel IPI emulation - Improve in-kernel PCH-PIC emulation - Move kvm_iocsr tracepoint out of generic code RISC-V: - Added SBI FWFT extension for Guest/VM with misaligned delegation and pointer masking PMLEN features - Added ONE_REG interface for SBI FWFT extension - Added Zicbop and bfloat16 extensions for Guest/VM - Enabled more common KVM selftests for RISC-V - Added SBI v3.0 PMU enhancements in KVM and perf driver s390: - Improve interrupt cpu for wakeup, in particular the heuristic to decide which vCPU to deliver a floating interrupt to. - Clear the PTE when discarding a swapped page because of CMMA; this bug was introduced in 6.16 when refactoring gmap code. x86 selftests: - Add #DE coverage in the fastops test (the only exception that's guest- triggerable in fastop-emulated instructions). - Fix PMU selftests errors encountered on Granite Rapids (GNR), Sierra Forest (SRF) and Clearwater Forest (CWF). - Minor cleanups and improvements x86 (guest side): - For the legacy PCI hole (memory between TOLUD and 4GiB) to UC when overriding guest MTRR for TDX/SNP to fix an issue where ACPI auto-mapping could map devices as WB and prevent the device drivers from mapping their devices with UC/UC-. - Make kvm_async_pf_task_wake() a local static helper and remove its export. - Use native qspinlocks when running in a VM with dedicated vCPU=>pCPU bindings even when PV_UNHALT is unsupported. Generic: - Remove a redundant __GFP_NOWARN from kvm_setup_async_pf() as __GFP_NOWARN is now included in GFP_NOWAIT. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (178 commits) KVM: s390: Fix to clear PTE when discarding a swapped page KVM: arm64: selftests: Cover ID_AA64ISAR3_EL1 in set_id_regs KVM: arm64: selftests: Remove a duplicate register listing in set_id_regs KVM: arm64: selftests: Cope with arch silliness in EL2 selftest KVM: arm64: selftests: Add basic test for running in VHE EL2 KVM: arm64: selftests: Enable EL2 by default KVM: arm64: selftests: Initialize HCR_EL2 KVM: arm64: selftests: Use the vCPU attr for setting nr of PMU counters KVM: arm64: selftests: Use hyp timer IRQs when test runs at EL2 KVM: arm64: selftests: Select SMCCC conduit based on current EL KVM: arm64: selftests: Provide helper for getting default vCPU target KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts KVM: arm64: selftests: Create a VGICv3 for 'default' VMs KVM: arm64: selftests: Add unsanitised helpers for VGICv3 creation KVM: arm64: selftests: Add helper to check for VGICv3 support KVM: arm64: selftests: Initialize VGICv3 only once KVM: arm64: selftests: Provide kvm_arch_vm_post_create() in library code KVM: selftests: Add ex_str() to print human friendly name of exception vectors selftests/kvm: remove stale TODO in xapic_state_test KVM: selftests: Handle Intel Atom errata that leads to PMU event overcount ...
2025-09-24kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFIKees Cook1-2/+2
The kernel's CFI implementation uses the KCFI ABI specifically, and is not strictly tied to a particular compiler. In preparation for GCC supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with associated options). Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will enable CONFIG_CFI during olddefconfig. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-09-15KVM: arm64: Dump instruction on hyp panicMostafa Saleh1-6/+9
Similar to the kernel panic, where the instruction code is printed, we can do the same for hypervisor panics. This patch does that only in case of “CONFIG_NVHE_EL2_DEBUG” or nvhe. The next patch adds support for pKVM. Also, remove the hardcoded argument dump_kernel_instr(). Signed-off-by: Mostafa Saleh <smostafa@google.com> Tested-by: Kunwu Chan <chentao@kylinos.cn> Reviewed-by: Kunwu Chan <chentao@kylinos.cn> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-07-24Merge branches 'for-next/livepatch', 'for-next/user-contig-bbml2', ↵Catalin Marinas1-76/+8
'for-next/misc', 'for-next/acpi', 'for-next/debug-entry', 'for-next/feat_mte_tagged_far', 'for-next/kselftest', 'for-next/mdscr-cleanup' and 'for-next/vmap-stack', remote-tracking branch 'arm64/for-next/perf' into for-next/core * arm64/for-next/perf: (23 commits) drivers/perf: hisi: Support PMUs with no interrupt drivers/perf: hisi: Relax the event number check of v2 PMUs drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver drivers/perf: hisi: Simplify the probe process for each DDRC version perf/arm-ni: Support sharing IRQs within an NI instance perf/arm-ni: Consolidate CPU affinity handling perf/cxlpmu: Fix typos in cxl_pmu.c comments and documentation perf/cxlpmu: Remove unintended newline from IRQ name format string perf/cxlpmu: Fix devm_kcalloc() argument order in cxl_pmu_probe() perf: arm_spe: Relax period restriction perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE) KVM: arm64: nvhe: Disable branch generation in nVHE guests arm64: Handle BRBE booting requirements arm64/sysreg: Add BRBE registers and fields perf/arm: Add missing .suppress_bind_attrs perf/arm-cmn: Reduce stack usage during discovery perf: imx9_perf: make the read-only array mask static const perf/arm-cmn: Broaden module description for wider interconnect support ... * for-next/livepatch: : Support for HAVE_LIVEPATCH on arm64 arm64: Kconfig: Keep selects somewhat alphabetically ordered arm64: Implement HAVE_LIVEPATCH arm64: stacktrace: Implement arch_stack_walk_reliable() arm64: stacktrace: Check kretprobe_find_ret_addr() return value arm64/module: Use text-poke API for late relocations. * for-next/user-contig-bbml2: : Optimise the TLBI when folding/unfolding contigous PTEs on hardware with BBML2 and no TLB conflict aborts arm64/mm: Elide tlbi in contpte_convert() under BBML2 iommu/arm: Add BBM Level 2 smmu feature arm64: Add BBM Level 2 cpu feature arm64: cpufeature: Introduce MATCH_ALL_EARLY_CPUS capability type * for-next/misc: : Miscellaneous arm64 patches arm64/gcs: task_gcs_el0_enable() should use passed task arm64: signal: Remove ISB when resetting POR_EL0 arm64/mm: Drop redundant addr increment in set_huge_pte_at() arm64: Mark kernel as tainted on SAE and SError panic arm64/gcs: Don't call gcs_free() when releasing task_struct arm64: fix unnecessary rebuilding when CONFIG_DEBUG_EFI=y arm64/mm: Optimize loop to reduce redundant operations of contpte_ptep_get arm64: pi: use 'targets' instead of extra-y in Makefile * for-next/acpi: : Various ACPI arm64 changes ACPI: Suppress misleading SPCR console message when SPCR table is absent ACPI: Return -ENODEV from acpi_parse_spcr() when SPCR support is disabled * for-next/debug-entry: : Simplify the debug exception entry path arm64: debug: remove debug exception registration infrastructure arm64: debug: split bkpt32 exception entry arm64: debug: split brk64 exception entry arm64: debug: split hardware watchpoint exception entry arm64: debug: split single stepping exception entry arm64: debug: refactor reinstall_suspended_bps() arm64: debug: split hardware breakpoint exception entry arm64: entry: Add entry and exit functions for debug exceptions arm64: debug: remove break/step handler registration infrastructure arm64: debug: call step handlers statically arm64: debug: call software breakpoint handlers statically arm64: refactor aarch32_break_handler() arm64: debug: clean up single_step_handler logic * for-next/feat_mte_tagged_far: : Support for reporting the non-address bits during a synchronous MTE tag check fault kselftest/arm64/mte: Add mtefar tests on check_mmap_options kselftest/arm64/mte: Refactor check_mmap_option test kselftest/arm64/mte: Add verification for address tag in signal handler kselftest/arm64/mte: Add address tag related macro and function kselftest/arm64/mte: Check MTE_FAR feature is supported kselftest/arm64/mte: Register mte signal handler with SA_EXPOSE_TAGBITS kselftest/arm64: Add MTE_FAR hwcap test KVM: arm64: Expose FEAT_MTE_TAGGED_FAR feature to guest arm64: Report address tag when FEAT_MTE_TAGGED_FAR is supported arm64/cpufeature: Add FEAT_MTE_TAGGED_FAR feature * for-next/kselftest: : Kselftest updates for arm64 kselftest/arm64: Handle attempts to disable SM on SME only systems kselftest/arm64: Fix SVE write data generation for SME only systems kselftest/arm64: Test SME on SME only systems in fp-ptrace kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace kselftest/arm64: Allow sve-ptrace to run on SME only systems kselftest/arm4: Provide local defines for AT_HWCAP3 kselftest/arm64: Specify SVE data when testing VL set in sve-ptrace kselftest/arm64: Fix test for streaming FPSIMD write in sve-ptrace kselftest/arm64: Fix check for setting new VLs in sve-ptrace kselftest/arm64: Convert tpidr2 test to use kselftest.h * for-next/mdscr-cleanup: : Drop redundant DBG_MDSCR_* macros KVM: selftests: Change MDSCR_EL1 register holding variables as uint64_t arm64/debug: Drop redundant DBG_MDSCR_* macros * for-next/vmap-stack: : Force VMAP_STACK on arm64 arm64: remove CONFIG_VMAP_STACK checks from entry code arm64: remove CONFIG_VMAP_STACK checks from SDEI stack handling arm64: remove CONFIG_VMAP_STACK checks from stacktrace overflow logic arm64: remove CONFIG_VMAP_STACK conditionals from traps overflow stack arm64: remove CONFIG_VMAP_STACK conditionals from irq stack setup arm64: Remove CONFIG_VMAP_STACK conditionals from THREAD_SHIFT and THREAD_ALIGN arm64: efi: Remove CONFIG_VMAP_STACK check arm64: Mandate VMAP_STACK arm64: efi: Fix KASAN false positive for EFI runtime stack arm64/ptrace: Fix stack-out-of-bounds read in regs_get_kernel_stack_nth() arm64/gcs: Don't call gcs_free() during flush_gcs() arm64: Restrict pagetable teardown to avoid false warning docs: arm64: Fix ICC_SRE_EL2 register typo in booting.rst
2025-07-17arm64: Mark kernel as tainted on SAE and SError panicBreno Leitao1-0/+1
Set TAINT_MACHINE_CHECK when SError or Synchronous External Abort (SEA) interrupts trigger a panic to flag potential hardware faults. This tainting mechanism aids in debugging and enables correlation of hardware-related crashes in large-scale deployments. This change aligns with similar patches[1] that mark machine check events when the system crashes due to hardware errors. Link: https://lore.kernel.org/all/20250702-add_tain-v1-1-9187b10914b9@debian.org/ [1] Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20250716-vmcore_hw_error-v2-1-f187f7d62aba@debian.org Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08arm64: remove CONFIG_VMAP_STACK conditionals from traps overflow stackBreno Leitao1-3/+0
With VMAP_STACK now always enabled on arm64, remove the CONFIG_VMAP_STACK checks from overflow stack definitions and related code in arch/arm64/kernel/traps.c. The overflow_stack and panic_bad_stack() logic are now unconditionally included, simplifying the source and matching the mandatory stack model. Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-5-8de98ca0f91c@debian.org Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08arm64: debug: remove debug exception registration infrastructureAda Couprie Diaz1-27/+0
Now that debug exceptions are handled individually and without the need for dynamic registration, remove the unused registration infrastructure. This removes the external caller for `debug_exception_enter()` and `debug_exception_exit()`. Make them static again and remove them from the header. Remove `early_brk64()` as it has been made redundant by (arm64: debug: split brk64 exception entry) and is not used anymore. Note : in `early_brk64()` `bug_brk_handler()` is called unconditionally as a fall-through, but now `call_break_hook()` only calls it if the immediate matches. This does not change the behaviour in early boot, as if `bug_brk_handler()` was called on a non-BUG immediate it would return DBG_HOOK_ERROR anyway, which `call_break_hook()` will do if no immediate matches. Remove `trap_init()`, as it would be empty and a weak definition already exists in `init/main.c`. Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com> Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Reviewed-by: Will Deacon <will@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20250707114109.35672-14-ada.coupriediaz@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08arm64: debug: call software breakpoint handlers staticallyAda Couprie Diaz1-49/+10
Software breakpoints pass an immediate value in ESR ("comment") that can be used to call a specialized handler (KGDB, KASAN...). We do so in two different ways : - During early boot, `early_brk64` statically checks against known immediates and calls the corresponding handler, - During init, handlers are dynamically registered into a list. When called, the generic software breakpoint handler will iterate over the list to find the appropriate handler. The dynamic registration does not provide any benefit here as it is not exported and all its uses are within the arm64 tree. It also depends on an RCU list, whose safe access currently relies on the non-preemptible state of `do_debug_exception`. Replace the list iteration logic in `call_break_hooks` to call the breakpoint handlers statically if they are enabled, like in `early_brk64`. Expose the handlers in their respective headers to be reachable from `arch/arm64/kernel/debug-monitors.c` at link time. Unify the naming of the software breakpoint handlers to XXX_brk_handler(), making it clear they are related and to differentiate from the hardware breakpoints. Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com> Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Reviewed-by: Will Deacon <will@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20250707114109.35672-4-ada.coupriediaz@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2025-07-08arm64: refactor aarch32_break_handler()Ada Couprie Diaz1-1/+1
`aarch32_break_handler()` is called in `do_el0_undef()` when we are trying to handle an exception whose Exception Syndrome is unknown. It checks if the instruction hit might be a 32-bit arm break (be it A32 or T2), and sends a SIGTRAP to userspace if it is so that it can be handled. However, this is badly represented in the naming of the function, and is not consistent with the other functions called with the same logic in `do_el0_undef()`. Rename it `try_handle_aarch32_break()` and change the return value to a boolean to align with the logic of the other tentative handlers in `do_el0_undef()`, the previous error code being ignored anyway. Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com> Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20250707114109.35672-3-ada.coupriediaz@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2025-05-07ubsan: Remove regs from report_ubsan_failure()Mostafa Saleh1-1/+1
report_ubsan_failure() doesn't use argument regs, and soon it will be called from the hypervisor context were regs are not available. So, remove the unused argument. Signed-off-by: Mostafa Saleh <smostafa@google.com> Acked-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250430162713.1997569-3-smostafa@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-07arm64: Introduce esr_is_ubsan_brk()Mostafa Saleh1-1/+1
Soon, KVM is going to use this logic for hypervisor panics, so add it in a wrapper that can be used by the hypervisor exit handler to decode hyp panics. Signed-off-by: Mostafa Saleh <smostafa@google.com> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250430162713.1997569-2-smostafa@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-03-17arm64: Rely on generic printing of preemption modelSebastian Andrzej Siewior1-9/+1
__die() invokes later show_regs() -> show_regs_print_info() which prints the current preemption model. Remove it from the initial line. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20250314160810.2373416-5-bigeasy@linutronix.de
2024-11-23Merge tag 'mm-stable-2024-11-18-19-27' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "zram: optimal post-processing target selection" from Sergey Senozhatsky improves zram's post-processing selection algorithm. This leads to improved memory savings. - Wei Yang has gone to town on the mapletree code, contributing several series which clean up the implementation: - "refine mas_mab_cp()" - "Reduce the space to be cleared for maple_big_node" - "maple_tree: simplify mas_push_node()" - "Following cleanup after introduce mas_wr_store_type()" - "refine storing null" - The series "selftests/mm: hugetlb_fault_after_madv improvements" from David Hildenbrand fixes this selftest for s390. - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng implements some rationaizations and cleanups in the page mapping code. - The series "mm: optimize shadow entries removal" from Shakeel Butt optimizes the file truncation code by speeding up the handling of shadow entries. - The series "Remove PageKsm()" from Matthew Wilcox completes the migration of this flag over to being a folio-based flag. - The series "Unify hugetlb into arch_get_unmapped_area functions" from Oscar Salvador implements a bunch of consolidations and cleanups in the hugetlb code. - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain takes away the wp-fault time practice of turning a huge zero page into small pages. Instead we replace the whole thing with a THP. More consistent cleaner and potentiall saves a large number of pagefaults. - The series "percpu: Add a test case and fix for clang" from Andy Shevchenko enhances and fixes the kernel's built in percpu test code. - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett optimizes mremap() by avoiding doing things which we didn't need to do. - The series "Improve the tmpfs large folio read performance" from Baolin Wang teaches tmpfs to copy data into userspace at the folio size rather than as individual pages. A 20% speedup was observed. - The series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting. - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt removes the long-deprecated memcgv2 charge moving feature. - The series "fix error handling in mmap_region() and refactor" from Lorenzo Stoakes cleanup up some of the mmap() error handling and addresses some potential performance issues. - The series "x86/module: use large ROX pages for text allocations" from Mike Rapoport teaches x86 to use large pages for read-only-execute module text. - The series "page allocation tag compression" from Suren Baghdasaryan is followon maintenance work for the new page allocation profiling feature. - The series "page->index removals in mm" from Matthew Wilcox remove most references to page->index in mm/. A slow march towards shrinking struct page. - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs interface tests" from Andrew Paniakin performs maintenance work for DAMON's self testing code. - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar improves zswap's batching of compression and decompression. It is a step along the way towards using Intel IAA hardware acceleration for this zswap operation. - The series "kasan: migrate the last module test to kunit" from Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests over to the KUnit framework. - The series "implement lightweight guard pages" from Lorenzo Stoakes permits userapace to place fault-generating guard pages within a single VMA, rather than requiring that multiple VMAs be created for this. Improved efficiencies for userspace memory allocators are expected. - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses tracepoints to provide increased visibility into memcg stats flushing activity. - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky fixes a zram buglet which potentially affected performance. - The series "mm: add more kernel parameters to control mTHP" from Maíra Canal enhances our ability to control/configuremultisize THP from the kernel boot command line. - The series "kasan: few improvements on kunit tests" from Sabyrzhan Tasbolatov has a couple of fixups for the KASAN KUnit tests. - The series "mm/list_lru: Split list_lru lock into per-cgroup scope" from Kairui Song optimizes list_lru memory utilization when lockdep is enabled. * tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits) cma: enforce non-zero pageblock_order during cma_init_reserved_mem() mm/kfence: add a new kunit test test_use_after_free_read_nofault() zram: fix NULL pointer in comp_algorithm_show() memcg/hugetlb: add hugeTLB counters to memcg vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount zram: ZRAM_DEF_COMP should depend on ZRAM MAINTAINERS/MEMORY MANAGEMENT: add document files for mm Docs/mm/damon: recommend academic papers to read and/or cite mm: define general function pXd_init() kmemleak: iommu/iova: fix transient kmemleak false positive mm/list_lru: simplify the list_lru walk callback function mm/list_lru: split the lock to per-cgroup scope mm/list_lru: simplify reparenting and initial allocation mm/list_lru: code clean up for reparenting mm/list_lru: don't export list_lru_add mm/list_lru: don't pass unnecessary key parameters kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols ...
2024-11-14Merge branch 'for-next/mops' into for-next/coreCatalin Marinas1-0/+7
* for-next/mops: : More FEAT_MOPS (memcpy instructions) uses - in-kernel routines arm64: mops: Document requirements for hypervisors arm64: lib: Use MOPS for copy_page() and clear_page() arm64: lib: Use MOPS for memcpy() routines arm64: mops: Document booting requirement for HCR_EL2.MCE2 arm64: mops: Handle MOPS exceptions from EL1 arm64: probes: Disable kprobes/uprobes on MOPS instructions # Conflicts: # arch/arm64/kernel/entry-common.c
2024-11-07asm-generic: introduce text-patching.hMike Rapoport (Microsoft)1-1/+1
Several architectures support text patching, but they name the header files that declare patching functions differently. Make all such headers consistently named text-patching.h and add an empty header in asm-generic for architectures that do not support text patching. Link: https://lkml.kernel.org/r/20241023162711.2579610-4-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Tested-by: kdevops <kdevops@lists.linux.dev> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Song Liu <song@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-17arm64: mops: Handle MOPS exceptions from EL1Kristina Martsenko1-0/+7
We will soon be using MOPS instructions in the kernel, so wire up the exception handler to handle exceptions from EL1 caused by the copy/set operation being stopped and resumed on a different type of CPU. Add a helper for advancing the single step state machine, similarly to what the EL0 exception handler does. Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Link: https://lore.kernel.org/r/20240930161051.3777828-3-kristina.martsenko@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-10-04arm64/traps: Handle GCS exceptionsMark Brown1-0/+11
A new exception code is defined for GCS specific faults other than standard load/store faults, for example GCS token validation failures, add handling for this. These faults are reported to userspace as segfaults with code SEGV_CPERR (protection error), mirroring the reporting for x86 shadow stack errors. GCS faults due to memory load/store operations generate data aborts with a flag set, these will be handled separately as part of the data abort handling. Since we do not currently enable GCS for EL1 we should not get any faults there but while we're at it we wire things up there, treating any GCS fault as fatal. Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-19-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-09-12Merge branch 'for-next/timers' into for-next/coreWill Deacon1-6/+14
* for-next/timers: arm64: Implement prctl(PR_{G,S}ET_TSC)
2024-09-04arm64: handle PKEY/POE faultsJoey Gouly1-0/+6
If a memory fault occurs that is due to an overlay/pkey fault, report that to userspace with a SEGV_PKUERR. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20240822151113.1479789-17-joey.gouly@arm.com [will: Add ESR.FSC check to data abort handler] Signed-off-by: Will Deacon <will@kernel.org>
2024-08-27arm64: Implement prctl(PR_{G,S}ET_TSC)Peter Collingbourne1-6/+14
On arm64, this prctl controls access to CNTVCT_EL0, CNTVCTSS_EL0 and CNTFRQ_EL0 via CNTKCTL_EL1.EL0VCTEN. Since this bit is also used to implement various erratum workarounds, check whether the CPU needs a workaround whenever we potentially need to change it. This is needed for a correct implementation of non-instrumenting record-replay debugging on arm64 (i.e. rr; https://rr-project.org/). rr must trap and record any sources of non-determinism from the userspace program's perspective so it can be replayed later. This includes the results of syscalls as well as the results of access to architected timers exposed directly to the program. This prctl was originally added for x86 by commit 8fb402bccf20 ("generic, x86: add prctl commands PR_GET_TSC and PR_SET_TSC"), and rr uses it to trap RDTSC on x86 for the same reason. We also considered exposing this as a PTRACE_EVENT. However, prctl seems like a better choice for these reasons: 1) In general an in-process control seems more useful than an out-of-process control, since anything that you would be able to do with ptrace could also be done with prctl (tracer can inject a call to the prctl and handle signal-delivery-stops), and it avoids needing an additional process (which will complicate debugging of the ptraced process since it cannot have more than one tracer, and will be incompatible with ptrace_scope=3) in cases where that is not otherwise necessary. 2) Consistency with x86_64. Note that on x86_64, RDTSC has been there since the start, so it's the same situation as on arm64. Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/I233a1867d1ccebe2933a347552e7eae862344421 Link: https://lore.kernel.org/r/20240824015415.488474-1-pcc@google.com Signed-off-by: Will Deacon <will@kernel.org>
2024-06-20arm64: Introduce esr_brk_comment, esr_is_cfi_brkPierre-Clément Tosi1-5/+3
As it is already used in two places, move esr_comment() to a header for re-use, with a clearer name. Introduce esr_is_cfi_brk() to detect kCFI BRK syndromes, currently used by early_brk64() but soon to also be used by hypervisor code. Signed-off-by: Pierre-Clément Tosi <ptosi@google.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20240610063244.2828978-7-ptosi@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-11-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-47/+1
Pull kvm updates from Paolo Bonzini: "ARM: - Generalized infrastructure for 'writable' ID registers, effectively allowing userspace to opt-out of certain vCPU features for its guest - Optimization for vSGI injection, opportunistically compressing MPIDR to vCPU mapping into a table - Improvements to KVM's PMU emulation, allowing userspace to select the number of PMCs available to a VM - Guest support for memory operation instructions (FEAT_MOPS) - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing bugs and getting rid of useless code - Changes to the way the SMCCC filter is constructed, avoiding wasted memory allocations when not in use - Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing the overhead of errata mitigations - Miscellaneous kernel and selftest fixes LoongArch: - New architecture for kvm. The hardware uses the same model as x86, s390 and RISC-V, where guest/host mode is orthogonal to supervisor/user mode. The virtualization extensions are very similar to MIPS, therefore the code also has some similarities but it's been cleaned up to avoid some of the historical bogosities that are found in arch/mips. The kernel emulates MMU, timer and CSR accesses, while interrupt controllers are only emulated in userspace, at least for now. RISC-V: - Support for the Smstateen and Zicond extensions - Support for virtualizing senvcfg - Support for virtualized SBI debug console (DBCN) S390: - Nested page table management can be monitored through tracepoints and statistics x86: - Fix incorrect handling of VMX posted interrupt descriptor in KVM_SET_LAPIC, which could result in a dropped timer IRQ - Avoid WARN on systems with Intel IPI virtualization - Add CONFIG_KVM_MAX_NR_VCPUS, to allow supporting up to 4096 vCPUs without forcing more common use cases to eat the extra memory overhead. - Add virtualization support for AMD SRSO mitigation (IBPB_BRTYPE and SBPB, aka Selective Branch Predictor Barrier). - Fix a bug where restoring a vCPU snapshot that was taken within 1 second of creating the original vCPU would cause KVM to try to synchronize the vCPU's TSC and thus clobber the correct TSC being set by userspace. - Compute guest wall clock using a single TSC read to avoid generating an inaccurate time, e.g. if the vCPU is preempted between multiple TSC reads. - "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which complain about a "Firmware Bug" if the bit isn't set for select F/M/S combos. Likewise "virtualize" (ignore) MSR_AMD64_TW_CFG to appease Windows Server 2022. - Don't apply side effects to Hyper-V's synthetic timer on writes from userspace to fix an issue where the auto-enable behavior can trigger spurious interrupts, i.e. do auto-enabling only for guest writes. - Remove an unnecessary kick of all vCPUs when synchronizing the dirty log without PML enabled. - Advertise "support" for non-serializing FS/GS base MSR writes as appropriate. - Harden the fast page fault path to guard against encountering an invalid root when walking SPTEs. - Omit "struct kvm_vcpu_xen" entirely when CONFIG_KVM_XEN=n. - Use the fast path directly from the timer callback when delivering Xen timer events, instead of waiting for the next iteration of the run loop. This was not done so far because previously proposed code had races, but now care is taken to stop the hrtimer at critical points such as restarting the timer or saving the timer information for userspace. - Follow the lead of upstream Xen and ignore the VCPU_SSHOTTMR_future flag. - Optimize injection of PMU interrupts that are simultaneous with NMIs. - Usual handful of fixes for typos and other warts. x86 - MTRR/PAT fixes and optimizations: - Clean up code that deals with honoring guest MTRRs when the VM has non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled. - Zap EPT entries when non-coherent DMA assignment stops/start to prevent using stale entries with the wrong memtype. - Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y This was done as a workaround for virtual machine BIOSes that did not bother to clear CR0.CD (because ancient KVM/QEMU did not bother to set it, in turn), and there's zero reason to extend the quirk to also ignore guest PAT. x86 - SEV fixes: - Report KVM_EXIT_SHUTDOWN instead of EINVAL if KVM intercepts SHUTDOWN while running an SEV-ES guest. - Clean up the recognition of emulation failures on SEV guests, when KVM would like to "skip" the instruction but it had already been partially emulated. This makes it possible to drop a hack that second guessed the (insufficient) information provided by the emulator, and just do the right thing. Documentation: - Various updates and fixes, mostly for x86 - MTRR and PAT fixes and optimizations" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (164 commits) KVM: selftests: Avoid using forced target for generating arm64 headers tools headers arm64: Fix references to top srcdir in Makefile KVM: arm64: Add tracepoint for MMIO accesses where ISV==0 KVM: arm64: selftest: Perform ISB before reading PAR_EL1 KVM: arm64: selftest: Add the missing .guest_prepare() KVM: arm64: Always invalidate TLB for stage-2 permission faults KVM: x86: Service NMI requests after PMI requests in VM-Enter path KVM: arm64: Handle AArch32 SPSR_{irq,abt,und,fiq} as RAZ/WI KVM: arm64: Do not let a L1 hypervisor access the *32_EL2 sysregs KVM: arm64: Refine _EL2 system register list that require trap reinjection arm64: Add missing _EL2 encodings arm64: Add missing _EL12 encodings KVM: selftests: aarch64: vPMU test for validating user accesses KVM: selftests: aarch64: vPMU register test for unimplemented counters KVM: selftests: aarch64: vPMU register test for implemented counters KVM: selftests: aarch64: Introduce vpmu_counter_access test tools: Import arm_pmuv3.h KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} ...
2023-10-16arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_1542419Mark Rutland1-1/+1
We use cpus_have_const_cap() to check for ARM64_WORKAROUND_1542419 but this is not necessary and cpus_have_final_cap() would be preferable. For historical reasons, cpus_have_const_cap() is more complicated than it needs to be. Before cpucaps are finalized, it will perform a bitmap test of the system_cpucaps bitmap, and once cpucaps are finalized it will use an alternative branch. This used to be necessary to handle some race conditions in the window between cpucap detection and the subsequent patching of alternatives and static branches, where different branches could be out-of-sync with one another (or w.r.t. alternative sequences). Now that we use alternative branches instead of static branches, these are all patched atomically w.r.t. one another, and there are only a handful of cases that need special care in the window between cpucap detection and alternative patching. Due to the above, it would be nice to remove cpus_have_const_cap(), and migrate callers over to alternative_has_cap_*(), cpus_have_final_cap(), or cpus_have_cap() depending on when their requirements. This will remove redundant instructions and improve code generation, and will make it easier to determine how each callsite will behave before, during, and after alternative patching. The ARM64_WORKAROUND_1542419 cpucap is detected and patched before any userspace code can run, and the both __do_compat_cache_op() and ctr_read_handler() are only reachable from exceptions taken from userspace. Thus it is not necessary for either to use cpus_have_const_cap(), and cpus_have_final_cap() is equivalent. This patch replaces the use of cpus_have_const_cap() with cpus_have_final_cap(), which will avoid generating code to test the system_cpucaps bitmap and should be better for all subsequent calls at runtime. Using cpus_have_final_cap() clearly documents that we do not expect this code to run before cpucaps are finalized, and will make it easier to spot issues if code is changed in future to allow these functions to be reached earlier. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-10-09KVM: arm64: Add handler for MOPS exceptionsKristina Martsenko1-47/+1
An Armv8.8 FEAT_MOPS main or epilogue instruction will take an exception if executed on a CPU with a different MOPS implementation option (A or B) than the CPU where the preceding prologue instruction ran. In this case the OS exception handler is expected to reset the registers and restart execution from the prologue instruction. A KVM guest may use the instructions at EL1 at times when the guest is not able to handle the exception, expecting that the instructions will only run on one CPU (e.g. when running UEFI boot services in the guest). As KVM may reschedule the guest between different types of CPUs at any time (on an asymmetric system), it needs to also handle the resulting exception itself in case the guest is not able to. A similar situation will also occur in the future when live migrating a guest from one type of CPU to another. Add handling for the MOPS exception to KVM. The handling can be shared with the EL0 exception handler, as the logic and register layouts are the same. The exception can be handled right after exiting a guest, which avoids the cost of returning to the host exit handler. Similarly to the EL0 exception handler, in case the main or epilogue instruction is being single stepped, it makes sense to finish the step before executing the prologue instruction, so advance the single step state machine. Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230922112508.1774352-2-kristina.martsenko@arm.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-28Merge tag 'mm-stable-2023-06-24-19-15' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: - Yosry Ahmed brought back some cgroup v1 stats in OOM logs - Yosry has also eliminated cgroup's atomic rstat flushing - Nhat Pham adds the new cachestat() syscall. It provides userspace with the ability to query pagecache status - a similar concept to mincore() but more powerful and with improved usability - Mel Gorman provides more optimizations for compaction, reducing the prevalence of page rescanning - Lorenzo Stoakes has done some maintanance work on the get_user_pages() interface - Liam Howlett continues with cleanups and maintenance work to the maple tree code. Peng Zhang also does some work on maple tree - Johannes Weiner has done some cleanup work on the compaction code - David Hildenbrand has contributed additional selftests for get_user_pages() - Thomas Gleixner has contributed some maintenance and optimization work for the vmalloc code - Baolin Wang has provided some compaction cleanups, - SeongJae Park continues maintenance work on the DAMON code - Huang Ying has done some maintenance on the swap code's usage of device refcounting - Christoph Hellwig has some cleanups for the filemap/directio code - Ryan Roberts provides two patch series which yield some rationalization of the kernel's access to pte entries - use the provided APIs rather than open-coding accesses - Lorenzo Stoakes has some fixes to the interaction between pagecache and directio access to file mappings - John Hubbard has a series of fixes to the MM selftesting code - ZhangPeng continues the folio conversion campaign - Hugh Dickins has been working on the pagetable handling code, mainly with a view to reducing the load on the mmap_lock - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from 128 to 8 - Domenico Cerasuolo has improved the zswap reclaim mechanism by reorganizing the LRU management - Matthew Wilcox provides some fixups to make gfs2 work better with the buffer_head code - Vishal Moola also has done some folio conversion work - Matthew Wilcox has removed the remnants of the pagevec code - their functionality is migrated over to struct folio_batch * tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits) mm/hugetlb: remove hugetlb_set_page_subpool() mm: nommu: correct the range of mmap_sem_read_lock in task_mem() hugetlb: revert use of page_cache_next_miss() Revert "page cache: fix page_cache_next/prev_miss off by one" mm/vmscan: fix root proactive reclaim unthrottling unbalanced node mm: memcg: rename and document global_reclaim() mm: kill [add|del]_page_to_lru_list() mm: compaction: convert to use a folio in isolate_migratepages_block() mm: zswap: fix double invalidate with exclusive loads mm: remove unnecessary pagevec includes mm: remove references to pagevec mm: rename invalidate_mapping_pagevec to mapping_try_invalidate mm: remove struct pagevec net: convert sunrpc from pagevec to folio_batch i915: convert i915_gpu_error to use a folio_batch pagevec: rename fbatch_count() mm: remove check_move_unevictable_pages() drm: convert drm_gem_put_pages() to use a folio_batch i915: convert shmem_sg_free_table() to use a folio_batch scatterlist: add sg_set_folio() ...
2023-06-23Merge branches 'for-next/kpti', 'for-next/missing-proto-warn', ↵Catalin Marinas1-1/+60
'for-next/iss2-decode', 'for-next/kselftest', 'for-next/misc', 'for-next/feat_mops', 'for-next/module-alloc', 'for-next/sysreg', 'for-next/cpucap', 'for-next/acpi', 'for-next/kdump', 'for-next/acpi-doc', 'for-next/doc' and 'for-next/tpidr2-fix', remote-tracking branch 'arm64/for-next/perf' into for-next/core * arm64/for-next/perf: docs: perf: Fix warning from 'make htmldocs' in hisi-pmu.rst docs: perf: Add new description for HiSilicon UC PMU drivers/perf: hisi: Add support for HiSilicon UC PMU driver drivers/perf: hisi: Add support for HiSilicon H60PA and PAv3 PMU driver perf: arm_cspmu: Add missing MODULE_DEVICE_TABLE perf/arm-cmn: Add sysfs identifier perf/arm-cmn: Revamp model detection perf/arm_dmc620: Add cpumask dt-bindings: perf: fsl-imx-ddr: Add i.MX93 compatible drivers/perf: imx_ddr: Add support for NXP i.MX9 SoC DDRC PMU driver perf/arm_cspmu: Decouple APMT dependency perf/arm_cspmu: Clean up ACPI dependency ACPI/APMT: Don't register invalid resource perf/arm_cspmu: Fix event attribute type perf: arm_cspmu: Set irq affinitiy only if overflow interrupt is used drivers/perf: hisi: Don't migrate perf to the CPU going to teardown drivers/perf: apple_m1: Force 63bit counters for M2 CPUs perf/arm-cmn: Fix DTC reset perf: qcom_l2_pmu: Make l2_cache_pmu_probe_cluster() more robust perf/arm-cci: Slightly optimize cci_pmu_sync_counters() * for-next/kpti: : Simplify KPTI trampoline exit code arm64: entry: Simplify tramp_alias macro and tramp_exit routine arm64: entry: Preserve/restore X29 even for compat tasks * for-next/missing-proto-warn: : Address -Wmissing-prototype warnings arm64: add alt_cb_patch_nops prototype arm64: move early_brk64 prototype to header arm64: signal: include asm/exception.h arm64: kaslr: add kaslr_early_init() declaration arm64: flush: