kernel.git/arch/arm64/kernel/traps.c, branch linux-6.15.y

arm64: Mark kernel as tainted on SAE and SError panic

2025-08-20T16:36:03Z

[ Upstream commit d7ce7e3a84642aadf7c4787f7ec4f58eb163d129 ] 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 Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20250716-vmcore_hw_error-v2-1-f187f7d62aba@debian.org Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

arm64: Rely on generic printing of preemption model

2025-03-17T10:23:39Z

__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 Signed-off-by: Peter Zijlstra (Intel) Acked-by: Will Deacon Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20250314160810.2373416-5-bigeasy@linutronix.de

Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-11-23T17:58:07Z

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 ...

Merge branch 'for-next/mops' into for-next/core

2024-11-14T12:07:28Z

* 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

asm-generic: introduce text-patching.h

2024-11-07T22:25:15Z

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) Reviewed-by: Christoph Hellwig Acked-by: Geert Uytterhoeven # m68k Acked-by: Arnd Bergmann Reviewed-by: Luis Chamberlain Tested-by: kdevops Cc: Andreas Larsson Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Borislav Petkov (AMD) Cc: Brian Cain Cc: Catalin Marinas Cc: Christophe Leroy Cc: Dave Hansen Cc: Dinh Nguyen Cc: Guo Ren Cc: Helge Deller Cc: Huacai Chen Cc: Ingo Molnar Cc: Johannes Berg Cc: John Paul Adrian Glaubitz Cc: Kent Overstreet Cc: Liam R. Howlett Cc: Mark Rutland Cc: Masami Hiramatsu (Google) Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Oleg Nesterov Cc: Palmer Dabbelt Cc: Peter Zijlstra Cc: Richard Weinberger Cc: Russell King Cc: Song Liu Cc: Stafford Horne Cc: Steven Rostedt (Google) Cc: Suren Baghdasaryan Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Uladzislau Rezki (Sony) Cc: Vineet Gupta Cc: Will Deacon Signed-off-by: Andrew Morton

arm64: mops: Handle MOPS exceptions from EL1

2024-10-17T15:42:51Z

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 Link: https://lore.kernel.org/r/20240930161051.3777828-3-kristina.martsenko@arm.com Signed-off-by: Catalin Marinas

arm64/traps: Handle GCS exceptions

2024-10-04T11:04:37Z

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 Reviewed-by: Catalin Marinas Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-19-222b78d87eee@kernel.org Signed-off-by: Catalin Marinas

Merge branch 'for-next/timers' into for-next/core

2024-09-12T12:44:03Z

* for-next/timers: arm64: Implement prctl(PR_{G,S}ET_TSC)

arm64: handle PKEY/POE faults

2024-09-04T11:53:44Z

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 Cc: Catalin Marinas Cc: Will Deacon Reviewed-by: Catalin Marinas 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

arm64: Implement prctl(PR_{G,S}ET_TSC)

2024-08-27T12:38:56Z

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 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