Commit graph

4509 commits

Author SHA1 Message Date
Paolo Bonzini
5834816829 KVM/arm64 fixes for 6.1, take #1
- Fix for stage-2 invalidation holding the VM MMU lock
   for too long by limiting the walk to the largest
   block mapping size
 
 - Enable stack protection and branch profiling for VHE
 
 - Two selftest fixes
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Merge tag 'kvmarm-fixes-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.1, take #1

- Fix for stage-2 invalidation holding the VM MMU lock
  for too long by limiting the walk to the largest
  block mapping size

- Enable stack protection and branch profiling for VHE

- Two selftest fixes
2022-10-22 03:32:23 -04:00
Linus Torvalds
1df046ab1c arm64 fixes:
- Cortex-A55 errata workaround (repeat TLBI).
 
 - AMPERE1 added to the Spectre-BHB affected list.
 
 - MTE fix to avoid setting PG_mte_tagged if no tags have been touched on
   a page.
 
 - Fixed typo in the SCTLR_EL1.SPINTMASK bit naming (the commit log has
   other typos).
 
 - perf: return value check in ali_drw_pmu_probe(),
   ALIBABA_UNCORE_DRW_PMU dependency on ACPI.
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Cortex-A55 errata workaround (repeat TLBI)

 - AMPERE1 added to the Spectre-BHB affected list

 - MTE fix to avoid setting PG_mte_tagged if no tags have been touched
   on a page

 - Fixed typo in the SCTLR_EL1.SPINTMASK bit naming (the commit log has
   other typos)

 - perf: return value check in ali_drw_pmu_probe(),
   ALIBABA_UNCORE_DRW_PMU dependency on ACPI

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Add AMPERE1 to the Spectre-BHB affected list
  arm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored
  MAINTAINERS: rectify file entry in ALIBABA PMU DRIVER
  drivers/perf: ALIBABA_UNCORE_DRW_PMU should depend on ACPI
  drivers/perf: fix return value check in ali_drw_pmu_probe()
  arm64: errata: Add Cortex-A55 to the repeat tlbi list
  arm64/sysreg: Fix typo in SCTR_EL1.SPINTMASK
2022-10-14 12:38:03 -07:00
Linus Torvalds
676cb49573 - hfs and hfsplus kmap API modernization from Fabio Francesco
- Valentin Schneider makes crash-kexec work properly when invoked from
   an NMI-time panic.
 
 - ntfs bugfixes from Hawkins Jiawei
 
 - Jiebin Sun improves IPC msg scalability by replacing atomic_t's with
   percpu counters.
 
 - nilfs2 cleanups from Minghao Chi
 
 - lots of other single patches all over the tree!
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Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...
2022-10-12 11:00:22 -07:00
D Scott Phillips
0e5d5ae837 arm64: Add AMPERE1 to the Spectre-BHB affected list
Per AmpereOne erratum AC03_CPU_12, "Branch history may allow control of
speculative execution across software contexts," the AMPERE1 core needs the
bhb clearing loop to mitigate Spectre-BHB, with a loop iteration count of
11.

Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20221011022140.432370-1-scott@os.amperecomputing.com
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-10-12 17:36:06 +01:00
Linus Torvalds
f311d498be ARM:
* Fixes for single-stepping in the presence of an async
   exception as well as the preservation of PSTATE.SS
 
 * Better handling of AArch32 ID registers on AArch64-only
   systems
 
 * Fixes for the dirty-ring API, allowing it to work on
   architectures with relaxed memory ordering
 
 * Advertise the new kvmarm mailing list
 
 * Various minor cleanups and spelling fixes
 
 RISC-V:
 
 * Improved instruction encoding infrastructure for
   instructions not yet supported by binutils
 
 * Svinval support for both KVM Host and KVM Guest
 
 * Zihintpause support for KVM Guest
 
 * Zicbom support for KVM Guest
 
 * Record number of signal exits as a VCPU stat
 
 * Use generic guest entry infrastructure
 
 x86:
 
 * Misc PMU fixes and cleanups.
 
 * selftests: fixes for Hyper-V hypercall
 
 * selftests: fix nx_huge_pages_test on TDP-disabled hosts
 
 * selftests: cleanups for fix_hypercall_test
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull more kvm updates from Paolo Bonzini:
 "The main batch of ARM + RISC-V changes, and a few fixes and cleanups
  for x86 (PMU virtualization and selftests).

  ARM:

   - Fixes for single-stepping in the presence of an async exception as
     well as the preservation of PSTATE.SS

   - Better handling of AArch32 ID registers on AArch64-only systems

   - Fixes for the dirty-ring API, allowing it to work on architectures
     with relaxed memory ordering

   - Advertise the new kvmarm mailing list

   - Various minor cleanups and spelling fixes

  RISC-V:

   - Improved instruction encoding infrastructure for instructions not
     yet supported by binutils

   - Svinval support for both KVM Host and KVM Guest

   - Zihintpause support for KVM Guest

   - Zicbom support for KVM Guest

   - Record number of signal exits as a VCPU stat

   - Use generic guest entry infrastructure

  x86:

   - Misc PMU fixes and cleanups.

   - selftests: fixes for Hyper-V hypercall

   - selftests: fix nx_huge_pages_test on TDP-disabled hosts

   - selftests: cleanups for fix_hypercall_test"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (57 commits)
  riscv: select HAVE_POSIX_CPU_TIMERS_TASK_WORK
  RISC-V: KVM: Use generic guest entry infrastructure
  RISC-V: KVM: Record number of signal exits as a vCPU stat
  RISC-V: KVM: add __init annotation to riscv_kvm_init()
  RISC-V: KVM: Expose Zicbom to the guest
  RISC-V: KVM: Provide UAPI for Zicbom block size
  RISC-V: KVM: Make ISA ext mappings explicit
  RISC-V: KVM: Allow Guest use Zihintpause extension
  RISC-V: KVM: Allow Guest use Svinval extension
  RISC-V: KVM: Use Svinval for local TLB maintenance when available
  RISC-V: Probe Svinval extension form ISA string
  RISC-V: KVM: Change the SBI specification version to v1.0
  riscv: KVM: Apply insn-def to hlv encodings
  riscv: KVM: Apply insn-def to hfence encodings
  riscv: Introduce support for defining instructions
  riscv: Add X register names to gpr-nums
  KVM: arm64: Advertise new kvmarm mailing list
  kvm: vmx: keep constant definition format consistent
  kvm: mmu: fix typos in struct kvm_arch
  KVM: selftests: Fix nx_huge_pages_test on TDP-disabled hosts
  ...
2022-10-11 20:07:44 -07:00
Linus Torvalds
27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Oliver Upton
5994bc9e05 KVM: arm64: Limit stage2_apply_range() batch size to largest block
Presently stage2_apply_range() works on a batch of memory addressed by a
stage 2 root table entry for the VM. Depending on the IPA limit of the
VM and PAGE_SIZE of the host, this could address a massive range of
memory. Some examples:

  4 level, 4K paging -> 512 GB batch size

  3 level, 64K paging -> 4TB batch size

Unsurprisingly, working on such a large range of memory can lead to soft
lockups. When running dirty_log_perf_test:

  ./dirty_log_perf_test -m -2 -s anonymous_thp -b 4G -v 48

  watchdog: BUG: soft lockup - CPU#0 stuck for 45s! [dirty_log_perf_:16703]
  Modules linked in: vfat fat cdc_ether usbnet mii xhci_pci xhci_hcd sha3_generic gq(O)
  CPU: 0 PID: 16703 Comm: dirty_log_perf_ Tainted: G           O       6.0.0-smp-DEV #1
  pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : dcache_clean_inval_poc+0x24/0x38
  lr : clean_dcache_guest_page+0x28/0x4c
  sp : ffff800021763990
  pmr_save: 000000e0
  x29: ffff800021763990 x28: 0000000000000005 x27: 0000000000000de0
  x26: 0000000000000001 x25: 00400830b13bc77f x24: ffffad4f91ead9c0
  x23: 0000000000000000 x22: ffff8000082ad9c8 x21: 0000fffafa7bc000
  x20: ffffad4f9066ce50 x19: 0000000000000003 x18: ffffad4f92402000
  x17: 000000000000011b x16: 000000000000011b x15: 0000000000000124
  x14: ffff07ff8301d280 x13: 0000000000000000 x12: 00000000ffffffff
  x11: 0000000000010001 x10: fffffc0000000000 x9 : ffffad4f9069e580
  x8 : 000000000000000c x7 : 0000000000000000 x6 : 000000000000003f
  x5 : ffff07ffa2076980 x4 : 0000000000000001 x3 : 000000000000003f
  x2 : 0000000000000040 x1 : ffff0830313bd000 x0 : ffff0830313bcc40
  Call trace:
   dcache_clean_inval_poc+0x24/0x38
   stage2_unmap_walker+0x138/0x1ec
   __kvm_pgtable_walk+0x130/0x1d4
   __kvm_pgtable_walk+0x170/0x1d4
   __kvm_pgtable_walk+0x170/0x1d4
   __kvm_pgtable_walk+0x170/0x1d4
   kvm_pgtable_stage2_unmap+0xc4/0xf8
   kvm_arch_flush_shadow_memslot+0xa4/0x10c
   kvm_set_memslot+0xb8/0x454
   __kvm_set_memory_region+0x194/0x244
   kvm_vm_ioctl_set_memory_region+0x58/0x7c
   kvm_vm_ioctl+0x49c/0x560
   __arm64_sys_ioctl+0x9c/0xd4
   invoke_syscall+0x4c/0x124
   el0_svc_common+0xc8/0x194
   do_el0_svc+0x38/0xc0
   el0_svc+0x2c/0xa4
   el0t_64_sync_handler+0x84/0xf0
   el0t_64_sync+0x1a0/0x1a4

Use the largest supported block mapping for the configured page size as
the batch granularity. In so doing the walker is guaranteed to visit a
leaf only once.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221007234151.461779-3-oliver.upton@linux.dev
2022-10-09 02:33:49 +01:00
Oliver Upton
3b5c082bbf KVM: arm64: Work out supported block level at compile time
Work out the minimum page table level where KVM supports block mappings
at compile time. While at it, rewrite the comment around supported block
mappings to directly describe what KVM supports instead of phrasing in
terms of what it does not.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221007234151.461779-2-oliver.upton@linux.dev
2022-10-09 02:33:49 +01:00
Linus Torvalds
a09476668e Char/Misc and other driver changes for 6.1-rc1
Here is the large set of char/misc and other small driver subsystem
 changes for 6.1-rc1.  Loads of different things in here:
   - IIO driver updates, additions, and changes.  Probably the largest
     part of the diffstat
   - habanalabs driver update with support for new hardware and features,
     the second largest part of the diff.
   - fpga subsystem driver updates and additions
   - mhi subsystem updates
   - Coresight driver updates
   - gnss subsystem updates
   - extcon driver updates
   - icc subsystem updates
   - fsi subsystem updates
   - nvmem subsystem and driver updates
   - misc driver updates
   - speakup driver additions for new features
   - lots of tiny driver updates and cleanups
 
 All of these have been in the linux-next tree for a while with no
 reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc and other driver updates from Greg KH:
 "Here is the large set of char/misc and other small driver subsystem
  changes for 6.1-rc1. Loads of different things in here:

   - IIO driver updates, additions, and changes. Probably the largest
     part of the diffstat

   - habanalabs driver update with support for new hardware and
     features, the second largest part of the diff.

   - fpga subsystem driver updates and additions

   - mhi subsystem updates

   - Coresight driver updates

   - gnss subsystem updates

   - extcon driver updates

   - icc subsystem updates

   - fsi subsystem updates

   - nvmem subsystem and driver updates

   - misc driver updates

   - speakup driver additions for new features

   - lots of tiny driver updates and cleanups

  All of these have been in the linux-next tree for a while with no
  reported issues"

* tag 'char-misc-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (411 commits)
  w1: Split memcpy() of struct cn_msg flexible array
  spmi: pmic-arb: increase SPMI transaction timeout delay
  spmi: pmic-arb: block access for invalid PMIC arbiter v5 SPMI writes
  spmi: pmic-arb: correct duplicate APID to PPID mapping logic
  spmi: pmic-arb: add support to dispatch interrupt based on IRQ status
  spmi: pmic-arb: check apid against limits before calling irq handler
  spmi: pmic-arb: do not ack and clear peripheral interrupts in cleanup_irq
  spmi: pmic-arb: handle spurious interrupt
  spmi: pmic-arb: add a print in cleanup_irq
  drivers: spmi: Directly use ida_alloc()/free()
  MAINTAINERS: add TI ECAP driver info
  counter: ti-ecap-capture: capture driver support for ECAP
  Documentation: ABI: sysfs-bus-counter: add frequency & num_overflows items
  dt-bindings: counter: add ti,am62-ecap-capture.yaml
  counter: Introduce the COUNTER_COMP_ARRAY component type
  counter: Consolidate Counter extension sysfs attribute creation
  counter: Introduce the Count capture component
  counter: 104-quad-8: Add Signal polarity component
  counter: Introduce the Signal polarity component
  counter: interrupt-cnt: Implement watch_validate callback
  ...
2022-10-08 08:56:37 -07:00
Linus Torvalds
18fd049731 arm64 updates for 6.1:
- arm64 perf: DDR PMU driver for Alibaba's T-Head Yitian 710 SoC, SVE
   vector granule register added to the user regs together with SVE perf
   extensions documentation.
 
 - SVE updates: add HWCAP for SVE EBF16, update the SVE ABI documentation
   to match the actual kernel behaviour (zeroing the registers on syscall
   rather than "zeroed or preserved" previously).
 
 - More conversions to automatic system registers generation.
 
 - vDSO: use self-synchronising virtual counter access in gettimeofday()
   if the architecture supports it.
 
 - arm64 stacktrace cleanups and improvements.
 
 - arm64 atomics improvements: always inline assembly, remove LL/SC
   trampolines.
 
 - Improve the reporting of EL1 exceptions: rework BTI and FPAC exception
   handling, better EL1 undefs reporting.
 
 - Cortex-A510 erratum 2658417: remove BF16 support due to incorrect
   result.
 
 - arm64 defconfig updates: build CoreSight as a module, enable options
   necessary for docker, memory hotplug/hotremove, enable all PMUs
   provided by Arm.
 
 - arm64 ptrace() support for TPIDR2_EL0 (register provided with the SME
   extensions).
 
 - arm64 ftraces updates/fixes: fix module PLTs with mcount, remove
   unused function.
 
 - kselftest updates for arm64: simple HWCAP validation, FP stress test
   improvements, validation of ZA regs in signal handlers, include larger
   SVE and SME vector lengths in signal tests, various cleanups.
 
 - arm64 alternatives (code patching) improvements to robustness and
   consistency: replace cpucap static branches with equivalent
   alternatives, associate callback alternatives with a cpucap.
 
 - Miscellaneous updates: optimise kprobe performance of patching
   single-step slots, simplify uaccess_mask_ptr(), move MTE registers
   initialisation to C, support huge vmalloc() mappings, run softirqs on
   the per-CPU IRQ stack, compat (arm32) misalignment fixups for
   multiword accesses.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - arm64 perf: DDR PMU driver for Alibaba's T-Head Yitian 710 SoC, SVE
   vector granule register added to the user regs together with SVE perf
   extensions documentation.

 - SVE updates: add HWCAP for SVE EBF16, update the SVE ABI
   documentation to match the actual kernel behaviour (zeroing the
   registers on syscall rather than "zeroed or preserved" previously).

 - More conversions to automatic system registers generation.

 - vDSO: use self-synchronising virtual counter access in gettimeofday()
   if the architecture supports it.

 - arm64 stacktrace cleanups and improvements.

 - arm64 atomics improvements: always inline assembly, remove LL/SC
   trampolines.

 - Improve the reporting of EL1 exceptions: rework BTI and FPAC
   exception handling, better EL1 undefs reporting.

 - Cortex-A510 erratum 2658417: remove BF16 support due to incorrect
   result.

 - arm64 defconfig updates: build CoreSight as a module, enable options
   necessary for docker, memory hotplug/hotremove, enable all PMUs
   provided by Arm.

 - arm64 ptrace() support for TPIDR2_EL0 (register provided with the SME
   extensions).

 - arm64 ftraces updates/fixes: fix module PLTs with mcount, remove
   unused function.

 - kselftest updates for arm64: simple HWCAP validation, FP stress test
   improvements, validation of ZA regs in signal handlers, include
   larger SVE and SME vector lengths in signal tests, various cleanups.

 - arm64 alternatives (code patching) improvements to robustness and
   consistency: replace cpucap static branches with equivalent
   alternatives, associate callback alternatives with a cpucap.

 - Miscellaneous updates: optimise kprobe performance of patching
   single-step slots, simplify uaccess_mask_ptr(), move MTE registers
   initialisation to C, support huge vmalloc() mappings, run softirqs on
   the per-CPU IRQ stack, compat (arm32) misalignment fixups for
   multiword accesses.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (126 commits)
  arm64: alternatives: Use vdso/bits.h instead of linux/bits.h
  arm64/kprobe: Optimize the performance of patching single-step slot
  arm64: defconfig: Add Coresight as module
  kselftest/arm64: Handle EINTR while reading data from children
  kselftest/arm64: Flag fp-stress as exiting when we begin finishing up
  kselftest/arm64: Don't repeat termination handler for fp-stress
  ARM64: reloc_test: add __init/__exit annotations to module init/exit funcs
  arm64/mm: fold check for KFENCE into can_set_direct_map()
  arm64: ftrace: fix module PLTs with mcount
  arm64: module: Remove unused plt_entry_is_initialized()
  arm64: module: Make plt_equals_entry() static
  arm64: fix the build with binutils 2.27
  kselftest/arm64: Don't enable v8.5 for MTE selftest builds
  arm64: uaccess: simplify uaccess_mask_ptr()
  arm64: asm/perf_regs.h: Avoid C++-style comment in UAPI header
  kselftest/arm64: Fix typo in hwcap check
  arm64: mte: move register initialization to C
  arm64: mm: handle ARM64_KERNEL_USES_PMD_MAPS in vmemmap_populate()
  arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()
  arm64/sve: Add Perf extensions documentation
  ...
2022-10-06 11:51:49 -07:00
Nathan Chancellor
d2995249a2 arm64: alternatives: Use vdso/bits.h instead of linux/bits.h
When building with CONFIG_LTO after commit ba00c2a04f ("arm64: fix the
build with binutils 2.27"), the following build error occurs:

  In file included from arch/arm64/kernel/module-plts.c:6:
  In file included from include/linux/elf.h:6:
  In file included from arch/arm64/include/asm/elf.h:8:
  In file included from arch/arm64/include/asm/hwcap.h:9:
  In file included from arch/arm64/include/asm/cpufeature.h:9:
  In file included from arch/arm64/include/asm/alternative-macros.h:5:
  In file included from include/linux/bits.h:22:
  In file included from include/linux/build_bug.h:5:
  In file included from include/linux/compiler.h:248:
  In file included from arch/arm64/include/asm/rwonce.h:71:
  include/asm-generic/rwonce.h:67:9: error: expected string literal in 'asm'
          return __READ_ONCE(*(unsigned long *)addr);
                ^
  arch/arm64/include/asm/rwonce.h:43:16: note: expanded from macro '__READ_ONCE'
                  asm volatile(__LOAD_RCPC(b, %w0, %1)                    \
                              ^
  arch/arm64/include/asm/rwonce.h:17:2: note: expanded from macro '__LOAD_RCPC'
          ALTERNATIVE(                                                    \
          ^

Similar to the issue resolved by commit 0072dc1b53 ("arm64: avoid
BUILD_BUG_ON() in alternative-macros"), there is a circular include
dependency through <linux/bits.h> when CONFIG_LTO is enabled due to
<asm/rwonce.h> appearing in the include chain before the contents of
<asm/alternative-macros.h>, which results in ALTERNATIVE() not getting
expanded properly because it has not been defined yet.

Avoid this issue by including <vdso/bits.h>, which includes the
definition of the BIT() macro, instead of <linux/bits.h>, as BIT() is the
only macro from bits.h that is relevant to this header.

Fixes: ba00c2a04f ("arm64: fix the build with binutils 2.27")
Link: https://github.com/ClangBuiltLinux/linux/issues/1728
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221003193759.1141709-1-nathan@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-10-05 10:44:44 +01:00
Paolo Bonzini
fe4d9e4abf KVM/arm64 updates for v6.1
- Fixes for single-stepping in the presence of an async
   exception as well as the preservation of PSTATE.SS
 
 - Better handling of AArch32 ID registers on AArch64-only
   systems
 
 - Fixes for the dirty-ring API, allowing it to work on
   architectures with relaxed memory ordering
 
 - Advertise the new kvmarm mailing list
 
 - Various minor cleanups and spelling fixes
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Merge tag 'kvmarm-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for v6.1

- Fixes for single-stepping in the presence of an async
  exception as well as the preservation of PSTATE.SS

- Better handling of AArch32 ID registers on AArch64-only
  systems

- Fixes for the dirty-ring API, allowing it to work on
  architectures with relaxed memory ordering

- Advertise the new kvmarm mailing list

- Various minor cleanups and spelling fixes
2022-10-03 15:33:32 -04:00
Catalin Marinas
53630a1f61 Merge branch 'for-next/misc' into for-next/core
* for-next/misc:
  : Miscellaneous patches
  arm64/kprobe: Optimize the performance of patching single-step slot
  ARM64: reloc_test: add __init/__exit annotations to module init/exit funcs
  arm64/mm: fold check for KFENCE into can_set_direct_map()
  arm64: uaccess: simplify uaccess_mask_ptr()
  arm64: mte: move register initialization to C
  arm64: mm: handle ARM64_KERNEL_USES_PMD_MAPS in vmemmap_populate()
  arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()
  arm64: support huge vmalloc mappings
  arm64: spectre: increase parameters that can be used to turn off bhb mitigation individually
  arm64: run softirqs on the per-CPU IRQ stack
  arm64: compat: Implement misalignment fixups for multiword loads
2022-09-30 09:18:26 +01:00
Catalin Marinas
c704cf27a1 Merge branch 'for-next/alternatives' into for-next/core
* for-next/alternatives:
  : Alternatives (code patching) improvements
  arm64: fix the build with binutils 2.27
  arm64: avoid BUILD_BUG_ON() in alternative-macros
  arm64: alternatives: add shared NOP callback
  arm64: alternatives: add alternative_has_feature_*()
  arm64: alternatives: have callbacks take a cap
  arm64: alternatives: make alt_region const
  arm64: alternatives: hoist print out of __apply_alternatives()
  arm64: alternatives: proton-pack: prepare for cap changes
  arm64: alternatives: kvm: prepare for cap changes
  arm64: cpufeature: make cpus_have_cap() noinstr-safe
2022-09-30 09:18:22 +01:00
Catalin Marinas
b23ec74cbd Merge branches 'for-next/doc', 'for-next/sve', 'for-next/sysreg', 'for-next/gettimeofday', 'for-next/stacktrace', 'for-next/atomics', 'for-next/el1-exceptions', 'for-next/a510-erratum-2658417', 'for-next/defconfig', 'for-next/tpidr2_el0' and 'for-next/ftrace', remote-tracking branch 'arm64/for-next/perf' into for-next/core
* arm64/for-next/perf:
  arm64: asm/perf_regs.h: Avoid C++-style comment in UAPI header
  arm64/sve: Add Perf extensions documentation
  perf: arm64: Add SVE vector granule register to user regs
  MAINTAINERS: add maintainers for Alibaba' T-Head PMU driver
  drivers/perf: add DDR Sub-System Driveway PMU driver for Yitian 710 SoC
  docs: perf: Add description for Alibaba's T-Head PMU driver

* for-next/doc:
  : Documentation/arm64 updates
  arm64/sve: Document our actual ABI for clearing registers on syscall

* for-next/sve:
  : SVE updates
  arm64/sysreg: Add hwcap for SVE EBF16

* for-next/sysreg: (35 commits)
  : arm64 system registers generation (more conversions)
  arm64/sysreg: Fix a few missed conversions
  arm64/sysreg: Convert ID_AA64AFRn_EL1 to automatic generation
  arm64/sysreg: Convert ID_AA64DFR1_EL1 to automatic generation
  arm64/sysreg: Convert ID_AA64FDR0_EL1 to automatic generation
  arm64/sysreg: Use feature numbering for PMU and SPE revisions
  arm64/sysreg: Add _EL1 into ID_AA64DFR0_EL1 definition names
  arm64/sysreg: Align field names in ID_AA64DFR0_EL1 with architecture
  arm64/sysreg: Add defintion for ALLINT
  arm64/sysreg: Convert SCXTNUM_EL1 to automatic generation
  arm64/sysreg: Convert TIPDR_EL1 to automatic generation
  arm64/sysreg: Convert ID_AA64PFR1_EL1 to automatic generation
  arm64/sysreg: Convert ID_AA64PFR0_EL1 to automatic generation
  arm64/sysreg: Convert ID_AA64MMFR2_EL1 to automatic generation
  arm64/sysreg: Convert ID_AA64MMFR1_EL1 to automatic generation
  arm64/sysreg: Convert ID_AA64MMFR0_EL1 to automatic generation
  arm64/sysreg: Convert HCRX_EL2 to automatic generation
  arm64/sysreg: Standardise naming of ID_AA64PFR1_EL1 SME enumeration
  arm64/sysreg: Standardise naming of ID_AA64PFR1_EL1 BTI enumeration
  arm64/sysreg: Standardise naming of ID_AA64PFR1_EL1 fractional version fields
  arm64/sysreg: Standardise naming for MTE feature enumeration
  ...

* for-next/gettimeofday:
  : Use self-synchronising counter access in gettimeofday() (if FEAT_ECV)
  arm64: vdso: use SYS_CNTVCTSS_EL0 for gettimeofday
  arm64: alternative: patch alternatives in the vDSO
  arm64: module: move find_section to header

* for-next/stacktrace:
  : arm64 stacktrace cleanups and improvements
  arm64: stacktrace: track hyp stacks in unwinder's address space
  arm64: stacktrace: track all stack boundaries explicitly
  arm64: stacktrace: remove stack type from fp translator
  arm64: stacktrace: rework stack boundary discovery
  arm64: stacktrace: add stackinfo_on_stack() helper
  arm64: stacktrace: move SDEI stack helpers to stacktrace code
  arm64: stacktrace: rename unwind_next_common() -> unwind_next_frame_record()
  arm64: stacktrace: simplify unwind_next_common()
  arm64: stacktrace: fix kerneldoc comments

* for-next/atomics:
  : arm64 atomics improvements
  arm64: atomic: always inline the assembly
  arm64: atomics: remove LL/SC trampolines

* for-next/el1-exceptions:
  : Improve the reporting of EL1 exceptions
  arm64: rework BTI exception handling
  arm64: rework FPAC exception handling
  arm64: consistently pass ESR_ELx to die()
  arm64: die(): pass 'err' as long
  arm64: report EL1 UNDEFs better

* for-next/a510-erratum-2658417:
  : Cortex-A510: 2658417: remove BF16 support due to incorrect result
  arm64: errata: remove BF16 HWCAP due to incorrect result on Cortex-A510
  arm64: cpufeature: Expose get_arm64_ftr_reg() outside cpufeature.c
  arm64: cpufeature: Force HWCAP to be based on the sysreg visible to user-space

* for-next/defconfig:
  : arm64 defconfig updates
  arm64: defconfig: Add Coresight as module
  arm64: Enable docker support in defconfig
  arm64: defconfig: Enable memory hotplug and hotremove config
  arm64: configs: Enable all PMUs provided by Arm

* for-next/tpidr2_el0:
  : arm64 ptrace() support for TPIDR2_EL0
  kselftest/arm64: Add coverage of TPIDR2_EL0 ptrace interface
  arm64/ptrace: Support access to TPIDR2_EL0
  arm64/ptrace: Document extension of NT_ARM_TLS to cover TPIDR2_EL0
  kselftest/arm64: Add test coverage for NT_ARM_TLS

* for-next/ftrace:
  : arm64 ftraces updates/fixes
  arm64: ftrace: fix module PLTs with mcount
  arm64: module: Remove unused plt_entry_is_initialized()
  arm64: module: Make plt_equals_entry() static
2022-09-30 09:17:57 +01:00
Li Huafei
5de2291605 arm64: module: Remove unused plt_entry_is_initialized()
Since commit f1a54ae9af ("arm64: module/ftrace: intialize PLT at load
time"), plt_entry_is_initialized() is unused anymore , so remove it.

Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220929094134.99512-3-lihuafei1@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-29 17:47:18 +01:00
Li Huafei
3fb420f56c arm64: module: Make plt_equals_entry() static
Since commit 4e69ecf4da ("arm64/module: ftrace: deal with place
relative nature of PLTs"), plt_equals_entry() is not used outside of
module-plts.c, so make it static.

Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220929094134.99512-2-lihuafei1@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-29 17:47:18 +01:00
Mark Rutland
ba00c2a04f arm64: fix the build with binutils 2.27
Jon Hunter reports that for some toolchains the build has been broken
since commit:

  4c0bd995d7 ("arm64: alternatives: have callbacks take a cap")

... with a stream of build-time splats of the form:

|   CC      arch/arm64/kvm/hyp/vhe/debug-sr.o
| /tmp/ccY3kbki.s: Assembler messages:
| /tmp/ccY3kbki.s:1600: Error: found 'L', expected: ')'
| /tmp/ccY3kbki.s:1600: Error: found 'L', expected: ')'
| /tmp/ccY3kbki.s:1600: Error: found 'L', expected: ')'
| /tmp/ccY3kbki.s:1600: Error: found 'L', expected: ')'
| /tmp/ccY3kbki.s:1600: Error: junk at end of line, first unrecognized character
| is `L'
| /tmp/ccY3kbki.s:1723: Error: found 'L', expected: ')'
| /tmp/ccY3kbki.s:1723: Error: found 'L', expected: ')'
| /tmp/ccY3kbki.s:1723: Error: found 'L', expected: ')'
| /tmp/ccY3kbki.s:1723: Error: found 'L', expected: ')'
| /tmp/ccY3kbki.s:1723: Error: junk at end of line, first unrecognized character
| is `L'
| scripts/Makefile.build:249: recipe for target
| 'arch/arm64/kvm/hyp/vhe/debug-sr.o' failed

The issue here is that older versions of binutils (up to and including
2.27.0) don't like an 'L' suffix on constants. For plain assembly files,
UL() avoids this suffix, but in C files this gets added, and so for
inline assembly we can't directly use a constant defined with `UL()`.

We could avoid this by passing the constant as an input parameter, but
this isn't practical given the way we use the alternative macros.
Instead, just open code the constant without the `UL` suffix, and for
consistency do this for both the inline assembly macro and the regular
assembly macro.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 4c0bd995d7 ("arm64: alternatives: have callbacks take a cap")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/linux-arm-kernel/3cecc3a5-30b0-f0bd-c3de-9e09bd21909b@nvidia.com/
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220929150227.1028556-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-29 17:43:32 +01:00
Yu Zhao
e1fd09e3d1 mm: x86, arm64: add arch_has_hw_pte_young()
Patch series "Multi-Gen LRU Framework", v14.

What's new
==========
1. OpenWrt, in addition to Android, Arch Linux Zen, Armbian, ChromeOS,
   Liquorix, post-factum and XanMod, is now shipping MGLRU on 5.15.
2. Fixed long-tailed direct reclaim latency seen on high-memory (TBs)
   machines. The old direct reclaim backoff, which tries to enforce a
   minimum fairness among all eligible memcgs, over-swapped by about
   (total_mem>>DEF_PRIORITY)-nr_to_reclaim. The new backoff, which
   pulls the plug on swapping once the target is met, trades some
   fairness for curtailed latency:
   https://lore.kernel.org/r/20220918080010.2920238-10-yuzhao@google.com/
3. Fixed minior build warnings and conflicts. More comments and nits.

TLDR
====
The current page reclaim is too expensive in terms of CPU usage and it
often makes poor choices about what to evict. This patchset offers an
alternative solution that is performant, versatile and
straightforward.

Patchset overview
=================
The design and implementation overview is in patch 14:
https://lore.kernel.org/r/20220918080010.2920238-15-yuzhao@google.com/

01. mm: x86, arm64: add arch_has_hw_pte_young()
02. mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
Take advantage of hardware features when trying to clear the accessed
bit in many PTEs.

03. mm/vmscan.c: refactor shrink_node()
04. Revert "include/linux/mm_inline.h: fold __update_lru_size() into
    its sole caller"
Minor refactors to improve readability for the following patches.

05. mm: multi-gen LRU: groundwork
Adds the basic data structure and the functions that insert pages to
and remove pages from the multi-gen LRU (MGLRU) lists.

06. mm: multi-gen LRU: minimal implementation
A minimal implementation without optimizations.

07. mm: multi-gen LRU: exploit locality in rmap
Exploits spatial locality to improve efficiency when using the rmap.

08. mm: multi-gen LRU: support page table walks
Further exploits spatial locality by optionally scanning page tables.

09. mm: multi-gen LRU: optimize multiple memcgs
Optimizes the overall performance for multiple memcgs running mixed
types of workloads.

10. mm: multi-gen LRU: kill switch
Adds a kill switch to enable or disable MGLRU at runtime.

11. mm: multi-gen LRU: thrashing prevention
12. mm: multi-gen LRU: debugfs interface
Provide userspace with features like thrashing prevention, working set
estimation and proactive reclaim.

13. mm: multi-gen LRU: admin guide
14. mm: multi-gen LRU: design doc
Add an admin guide and a design doc.

Benchmark results
=================
Independent lab results
-----------------------
Based on the popularity of searches [01] and the memory usage in
Google's public cloud, the most popular open-source memory-hungry
applications, in alphabetical order, are:
      Apache Cassandra      Memcached
      Apache Hadoop         MongoDB
      Apache Spark          PostgreSQL
      MariaDB (MySQL)       Redis

An independent lab evaluated MGLRU with the most widely used benchmark
suites for the above applications. They posted 960 data points along
with kernel metrics and perf profiles collected over more than 500
hours of total benchmark time. Their final reports show that, with 95%
confidence intervals (CIs), the above applications all performed
significantly better for at least part of their benchmark matrices.

On 5.14:
1. Apache Spark [02] took 95% CIs [9.28, 11.19]% and [12.20, 14.93]%
   less wall time to sort three billion random integers, respectively,
   under the medium- and the high-concurrency conditions, when
   overcommitting memory. There were no statistically significant
   changes in wall time for the rest of the benchmark matrix.
2. MariaDB [03] achieved 95% CIs [5.24, 10.71]% and [20.22, 25.97]%
   more transactions per minute (TPM), respectively, under the medium-
   and the high-concurrency conditions, when overcommitting memory.
   There were no statistically significant changes in TPM for the rest
   of the benchmark matrix.
3. Memcached [04] achieved 95% CIs [23.54, 32.25]%, [20.76, 41.61]%
   and [21.59, 30.02]% more operations per second (OPS), respectively,
   for sequential access, random access and Gaussian (distribution)
   access, when THP=always; 95% CIs [13.85, 15.97]% and
   [23.94, 29.92]% more OPS, respectively, for random access and
   Gaussian access, when THP=never. There were no statistically
   significant changes in OPS for the rest of the benchmark matrix.
4. MongoDB [05] achieved 95% CIs [2.23, 3.44]%, [6.97, 9.73]% and
   [2.16, 3.55]% more operations per second (OPS), respectively, for
   exponential (distribution) access, random access and Zipfian
   (distribution) access, when underutilizing memory; 95% CIs
   [8.83, 10.03]%, [21.12, 23.14]% and [5.53, 6.46]% more OPS,
   respectively, for exponential access, random access and Zipfian
   access, when overcommitting memory.

On 5.15:
5. Apache Cassandra [06] achieved 95% CIs [1.06, 4.10]%, [1.94, 5.43]%
   and [4.11, 7.50]% more operations per second (OPS), respectively,
   for exponential (distribution) access, random access and Zipfian
   (distribution) access, when swap was off; 95% CIs [0.50, 2.60]%,
   [6.51, 8.77]% and [3.29, 6.75]% more OPS, respectively, for
   exponential access, random access and Zipfian access, when swap was
   on.
6. Apache Hadoop [07] took 95% CIs [5.31, 9.69]% and [2.02, 7.86]%
   less average wall time to finish twelve parallel TeraSort jobs,
   respectively, under the medium- and the high-concurrency
   conditions, when swap was on. There were no statistically
   significant changes in average wall time for the rest of the
   benchmark matrix.
7. PostgreSQL [08] achieved 95% CI [1.75, 6.42]% more transactions per
   minute (TPM) under the high-concurrency condition, when swap was
   off; 95% CIs [12.82, 18.69]% and [22.70, 46.86]% more TPM,
   respectively, under the medium- and the high-concurrency
   conditions, when swap was on. There were no statistically
   significant changes in TPM for the rest of the benchmark matrix.
8. Redis [09] achieved 95% CIs [0.58, 5.94]%, [6.55, 14.58]% and
   [11.47, 19.36]% more total operations per second (OPS),
   respectively, for sequential access, random access and Gaussian
   (distribution) access, when THP=always; 95% CIs [1.27, 3.54]%,
   [10.11, 14.81]% and [8.75, 13.64]% more total OPS, respectively,
   for sequential access, random access and Gaussian access, when
   THP=never.

Our lab results
---------------
To supplement the above results, we ran the following benchmark suites
on 5.16-rc7 and found no regressions [10].
      fs_fio_bench_hdd_mq      pft
      fs_lmbench               pgsql-hammerdb
      fs_parallelio            redis
      fs_postmark              stream
      hackbench                sysbenchthread
      kernbench                tpcc_spark
      memcached                unixbench
      multichase               vm-scalability
      mutilate                 will-it-scale
      nginx

[01] https://trends.google.com
[02] https://lore.kernel.org/r/20211102002002.92051-1-bot@edi.works/
[03] https://lore.kernel.org/r/20211009054315.47073-1-bot@edi.works/
[04] https://lore.kernel.org/r/20211021194103.65648-1-bot@edi.works/
[05] https://lore.kernel.org/r/20211109021346.50266-1-bot@edi.works/
[06] https://lore.kernel.org/r/20211202062806.80365-1-bot@edi.works/
[07] https://lore.kernel.org/r/20211209072416.33606-1-bot@edi.works/
[08] https://lore.kernel.org/r/20211218071041.24077-1-bot@edi.works/
[09] https://lore.kernel.org/r/20211122053248.57311-1-bot@edi.works/
[10] https://lore.kernel.org/r/20220104202247.2903702-1-yuzhao@google.com/

Read-world applications
=======================
Third-party testimonials
------------------------
Konstantin reported [11]:
   I have Archlinux with 8G RAM + zswap + swap. While developing, I
   have lots of apps opened such as multiple LSP-servers for different
   langs, chats, two browsers, etc... Usually, my system gets quickly
   to a point of SWAP-storms, where I have to kill LSP-servers,
   restart browsers to free memory, etc, otherwise the system lags
   heavily and is barely usable.
   
   1.5 day ago I migrated from 5.11.15 kernel to 5.12 + the LRU
   patchset, and I started up by opening lots of apps to create memory
   pressure, and worked for a day like this. Till now I had not a
   single SWAP-storm, and mind you I got 3.4G in SWAP. I was never
   getting to the point of 3G in SWAP before without a single
   SWAP-storm.

Vaibhav from IBM reported [12]:
   In a synthetic MongoDB Benchmark, seeing an average of ~19%
   throughput improvement on POWER10(Radix MMU + 64K Page Size) with
   MGLRU patches on top of 5.16 kernel for MongoDB + YCSB across
   three different request distributions, namely, Exponential, Uniform
   and Zipfan.

Shuang from U of Rochester reported [13]:
   With the MGLRU, fio achieved 95% CIs [38.95, 40.26]%, [4.12, 6.64]%
   and [9.26, 10.36]% higher throughput, respectively, for random
   access, Zipfian (distribution) access and Gaussian (distribution)
   access, when the average number of jobs per CPU is 1; 95% CIs
   [42.32, 49.15]%, [9.44, 9.89]% and [20.99, 22.86]% higher
   throughput, respectively, for random access, Zipfian access and
   Gaussian access, when the average number of jobs per CPU is 2.

Daniel from Michigan Tech reported [14]:
   With Memcached allocating ~100GB of byte-addressable Optante,
   performance improvement in terms of throughput (measured as queries
   per second) was about 10% for a series of workloads.

Large-scale deployments
-----------------------
We've rolled out MGLRU to tens of millions of ChromeOS users and
about a million Android users. Google's fleetwide profiling [15] shows
an overall 40% decrease in kswapd CPU usage, in addition to
improvements in other UX metrics, e.g., an 85% decrease in the number
of low-memory kills at the 75th percentile and an 18% decrease in
app launch time at the 50th percentile.

The downstream kernels that have been using MGLRU include:
1. Android [16]
2. Arch Linux Zen [17]
3. Armbian [18]
4. ChromeOS [19]
5. Liquorix [20]
6. OpenWrt [21]
7. post-factum [22]
8. XanMod [23]

[11] https://lore.kernel.org/r/140226722f2032c86301fbd326d91baefe3d7d23.camel@yandex.ru/
[12] https://lore.kernel.org/r/87czj3mux0.fsf@vajain21.in.ibm.com/
[13] https://lore.kernel.org/r/20220105024423.26409-1-szhai2@cs.rochester.edu/
[14] https://lore.kernel.org/r/CA+4-3vksGvKd18FgRinxhqHetBS1hQekJE2gwco8Ja-bJWKtFw@mail.gmail.com/
[15] https://dl.acm.org/doi/10.1145/2749469.2750392
[16] https://android.com
[17] https://archlinux.org
[18] https://armbian.com
[19] https://chromium.org
[20] https://liquorix.net
[21] https://openwrt.org
[22] https://codeberg.org/pf-kernel
[23] https://xanmod.org

Summary
=======
The facts are:
1. The independent lab results and the real-world applications
   indicate substantial improvements; there are no known regressions.
2. Thrashing prevention, working set estimation and proactive reclaim
   work out of the box; there are no equivalent solutions.
3. There is a lot of new code; no smaller changes have been
   demonstrated similar effects.

Our options, accordingly, are:
1. Given the amount of evidence, the reported improvements will likely
   materialize for a wide range of workloads.
2. Gauging the interest from the past discussions, the new features
   will likely be put to use for both personal computers and data
   centers.
3. Based on Google's track record, the new code will likely be well
   maintained in the long term. It'd be more difficult if not
   impossible to achieve similar effects with other approaches.


This patch (of 14):

Some architectures automatically set the accessed bit in PTEs, e.g., x86
and arm64 v8.2.  On architectures that do not have this capability,
clearing the accessed bit in a PTE usually triggers a page fault following
the TLB miss of this PTE (to emulate the accessed bit).

Being aware of this capability can help make better decisions, e.g.,
whether to spread the work out over a period of time to reduce bursty page
faults when trying to clear the accessed bit in many PTEs.

Note that theoretically this capability can be unreliable, e.g.,
hotplugged CPUs might be different from builtin ones.  Therefore it should
not be used in architecture-independent code that involves correctness,
e.g., to determine whether TLB flushes are required (in combination with
the accessed bit).

Link: https://lkml.kernel.org/r/20220918080010.2920238-1-yuzhao@google.com
Link: https://lkml.kernel.org/r/20220918080010.2920238-2-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: Brian Geffon <bgeffon@google.com>
Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Acked-by: Steven Barrett <steven@liquorix.net>
Acked-by: Suleiman Souhlal <suleiman@google.com>
Acked-by: Will Deacon <will@kernel.org>
Tested-by: Daniel Byrne <djbyrne@mtu.edu>
Tested-by: Donald Carr <d@chaos-reins.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>
Tested-by: Shuang Zhai <szhai2@cs.rochester.edu>
Tested-by: Sofia Trinh <sofia.trinh@edi.works>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Larabel <Michael@MichaelLarabel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:08 -07:00
Sami Tolvanen
607289a7cd treewide: Drop function_nocfi
With -fsanitize=kcfi, we no longer need function_nocfi() as
the compiler won't change function references to point to a
jump table. Remove all implementations and uses of the macro.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-14-samitolvanen@google.com
2022-09-26 10:13:14 -07:00
Sami Tolvanen
5f20997c19 arm64: Drop unneeded __nocfi attributes
With -fsanitize=kcfi, CONFIG_CFI_CLANG no longer has issues
with address space confusion in functions that switch to linear
mapping. Now that the indirectly called assembly functions have
type annotations, drop the __nocfi attributes.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-12-samitolvanen@google.com
2022-09-26 10:13:14 -07:00
Sami Tolvanen
b26e484b8b arm64: Add CFI error handling
With -fsanitize=kcfi, CFI always traps. Add arm64 support for handling CFI
failures. The registers containing the target address and the expected type
are encoded in the first ten bits of the ESR as follows:

 - 0-4: n, where the register Xn contains the target address
 - 5-9: m, where the register Wm contains the type hash

This produces the following oops on CFI failure (generated using lkdtm):

[   21.885179] CFI failure at lkdtm_indirect_call+0x2c/0x44 [lkdtm]
(target: lkdtm_increment_int+0x0/0x1c [lkdtm]; expected type: 0x7e0c52a)
[   21.886593] Internal error: Oops - CFI: 0 [#1] PREEMPT SMP
[   21.891060] Modules linked in: lkdtm
[   21.893363] CPU: 0 PID: 151 Comm: sh Not tainted
5.19.0-rc1-00021-g852f4e48dbab #1
[   21.895560] Hardware name: linux,dummy-virt (DT)
[   21.896543] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   21.897583] pc : lkdtm_indirect_call+0x2c/0x44 [lkdtm]
[   21.898551] lr : lkdtm_CFI_FORWARD_PROTO+0x3c/0x6c [lkdtm]
[   21.899520] sp : ffff8000083a3c50
[   21.900191] x29: ffff8000083a3c50 x28: ffff0000027e0ec0 x27: 0000000000000000
[   21.902453] x26: 0000000000000000 x25: ffffc2aa3d07e7b0 x24: 0000000000000002
[   21.903736] x23: ffffc2aa3d079088 x22: ffffc2aa3d07e7b0 x21: ffff000003379000
[   21.905062] x20: ffff8000083a3dc0 x19: 0000000000000012 x18: 0000000000000000
[   21.906371] x17: 000000007e0c52a5 x16: 000000003ad55aca x15: ffffc2aa60d92138
[   21.907662] x14: ffffffffffffffff x13: 2e2e2e2065707974 x12: 0000000000000018
[   21.909775] x11: ffffc2aa62322b88 x10: ffffc2aa62322aa0 x9 : c7e305fb5195d200
[   21.911898] x8 : ffffc2aa3d077e20 x7 : 6d20676e696c6c61 x6 : 43203a6d74646b6c
[   21.913108] x5 : ffffc2aa6266c9df x4 : ffffc2aa6266c9e1 x3 : ffff8000083a3968
[   21.914358] x2 : 80000000fffff122 x1 : 00000000fffff122 x0 : ffffc2aa3d07e8f8
[   21.915827] Call trace:
[   21.916375]  lkdtm_indirect_call+0x2c/0x44 [lkdtm]
[   21.918060]  lkdtm_CFI_FORWARD_PROTO+0x3c/0x6c [lkdtm]
[   21.919030]  lkdtm_do_action+0x34/0x4c [lkdtm]
[   21.919920]  direct_entry+0x170/0x1ac [lkdtm]
[   21.920772]  full_proxy_write+0x84/0x104
[   21.921759]  vfs_write+0x188/0x3d8
[   21.922387]  ksys_write+0x78/0xe8
[   21.922986]  __arm64_sys_write+0x1c/0x2c
[   21.923696]  invoke_syscall+0x58/0x134
[   21.924554]  el0_svc_common+0xb4/0xf4
[   21.925603]  do_el0_svc+0x2c/0xb4
[   21.926563]  el0_svc+0x2c/0x7c
[   21.927147]  el0t_64_sync_handler+0x84/0xf0
[   21.927985]  el0t_64_sync+0x18c/0x190
[   21.929133] Code: 728a54b1 72afc191 6b11021f 54000040 (d4304500)
[   21.930690] ---[ end trace 0000000000000000 ]---
[   21.930971] Kernel panic - not syncing: Oops - CFI: Fatal exception

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-11-samitolvanen@google.com
2022-09-26 10:13:14 -07:00
Sami Tolvanen
c50d32859e arm64: Add types to indirect called assembly functions
With CONFIG_CFI_CLANG, assembly functions indirectly called from C
code must be annotated with type identifiers to pass CFI checking. Use
SYM_TYPED_FUNC_START for the indirectly called functions, and ensure
we emit `bti c` also with SYM_TYPED_FUNC_START.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-10-samitolvanen@google.com
2022-09-26 10:13:13 -07:00
Mark Rutland
2305b809be arm64: uaccess: simplify uaccess_mask_ptr()
We introduced uaccess pointer masking for arm64 in commit:

  4d8efc2d5e ("arm64: Use pointer masking to limit uaccess speculation")

Which was intended to prevent speculative uaccesses to kernel memory on
CPUs where access permissions were not respected under speculation.

At the time, the uaccess primitives were occasionally used to access
kernel memory, with the maximum permitted address held in
thread_info::addr_limit. Consequently, the address masking needed to
take this dynamic limit into account.

Subsequently the uaccess primitives were reworked such that they are
only used for user memory, and as of commit:

  3d2403fd10 ("arm64: uaccess: remove set_fs()")

... the address limit was made a compile-time constant, but the logic
was otherwise unchanged.

Regardless of the configured VA size or whether TBI is in use, the
address space can be divided into three ranges:

* The TTBR0 VA range, for which any valid pointer has bit 55 *clear*,
  and any non-tag bits [63-56] must match bit 55 (i.e. must be clear).

* The TTBR1 VA range, for which any valid pointer has bit 55 *set*, and
  any non-tag bits [63-56] must match bit 55 (i.e. must be set).

* The gap between the TTBR0 and TTBR1 ranges, where bit 55 may be set or
  clear, but any access will result in a fault.

As the uaccess primitives are now only used for user memory in the TTBR0
VA range, we can prevent generation of TTBR1 addresses by clearing bit
55, which will either result in a TTBR0 address or a faulting address
between the TTBR VA ranges.

This is beneficial for code generation as:

* We no longer clobber the condition codes.

* We no longer burn a register on (TASK_SIZE_MAX - 1).

* We no longer need to consume the untagged pointer.

When building a defconfig v6.0-rc3 with GCC 12.1.0, this change makes
the resulting Image 64KiB smaller.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220922151053.3520750-1-mark.rutland@arm.com
[catalin.marinas@arm.com: remove csdb() as the bit clearing is unconditional]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-23 14:39:20 +01:00
Will Deacon
aa3e49b606 arm64: asm/perf_regs.h: Avoid C++-style comment in UAPI header
An arm64 'allmodconfig' build fails with GCC due to use of a C++-style
comment for the new SVE vector granule 'enum perf_event_arm_regs' entry:

  | /usr/include/asm/perf_regs.h:42:26: error: C++ style comments are not allowed in ISO C90

Use good ol' /* */ comment syntax to keep things rosey.

Link: https://lore.kernel.org/r/632cceb2.170a0220.599ec.0a3a@mx.google.com
Fixes: cbb0c02caf ("perf: arm64: Add SVE vector granule register to user regs")
Signed-off-by: Will Deacon <will@kernel.org>
2022-09-22 22:15:33 +01:00
Peter Collingbourne
973b9e3733 arm64: mte: move register initialization to C
If FEAT_MTE2 is disabled via the arm64.nomte command line argument on a
CPU that claims to support FEAT_MTE2, the kernel will use Tagged Normal
in the MAIR. If we interpret arm64.nomte to mean that the CPU does not
in fact implement FEAT_MTE2, setting the system register like this may
lead to UNSPECIFIED behavior. Fix it by arranging for MAIR to be set
in the C function cpu_enable_mte which is called based on the sanitized
version of the system register.

There is no need for the rest of the MTE-related system register
initialization to happen from assembly, with the exception of TCR_EL1,
which must be set to include at least TBI1 because the secondary CPUs
access KASan-allocated data structures early. Therefore, make the TCR_EL1
initialization unconditional and move the rest of the initialization to
cpu_enable_mte so that we no longer have a dependency on the unsanitized
ID register value.

Co-developed-by: Evgenii Stepanov <eugenis@google.com>
Signed-off-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: Evgenii Stepanov <eugenis@google.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 3b714d24ef ("arm64: mte: CPU feature detection and initial sysreg configuration")
Cc: <stable@vger.kernel.org> # 5.10.x
Link: https://lore.kernel.org/r/20220915222053.3484231-1-eugenis@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-22 18:02:50 +01:00
James Clark
cbb0c02caf perf: arm64: Add SVE vector granule register to user regs
Dwarf based unwinding in a function that pushes SVE registers onto
the stack requires the unwinder to know the length of the SVE register
to calculate the stack offsets correctly. This was added to the Arm
specific Dwarf spec as the VG pseudo register[1].

Add the vector length at position 46 if it's requested by userspace and
SVE is supported. If it's not supported then fail to open the event.

The vector length must be on each sample because it can be changed
at runtime via a prctl or ptrace call. Also by adding it as a register
rather than a separate attribute, minimal changes will be required in an
unwinder that already indexes into the register list.

[1]: https://github.com/ARM-software/abi-aa/blob/main/aadwarf64/aadwarf64.rst

Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20220901132658.1024635-2-james.clark@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2022-09-22 15:06:02 +01:00
Greg Kroah-Hartman
8be7dfc6a8 coresight: Changes for v6.1
Coresight trace subsystem updates for v6.1 includes:
   - Support for HiSilicon PTT trace
   - Coresight cleanup of sysfs accessor functions, reduced
     code size.
   - Expose coresight timestamp source for ETMv4+
   - DT binding updates to include missing properties
   - Minor documentation, Kconfig text fixes.
 
 Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
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Merge tag 'coresight-next-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux into char-misc-next

Suzuki writes:
  "coresight: Changes for v6.1

   Coresight trace subsystem updates for v6.1 includes:
     - Support for HiSilicon PTT trace
     - Coresight cleanup of sysfs accessor functions, reduced
       code size.
     - Expose coresight timestamp source for ETMv4+
     - DT binding updates to include missing properties
     - Minor documentation, Kconfig text fixes.

   Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>"

* tag 'coresight-next-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux:
  hwtracing: hisi_ptt: Fix up for "iommu/dma: Make header private"
  MAINTAINERS: Add maintainer for HiSilicon PTT driver
  docs: trace: Add HiSilicon PTT device driver documentation
  hwtracing: hisi_ptt: Add tune function support for HiSilicon PCIe Tune and Trace device
  hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device
  iommu/arm-smmu-v3: Make default domain type of HiSilicon PTT device to identity
  coresight: cti-sysfs: Mark coresight_cti_reg_store() as __maybe_unused
  coresight: Make new csdev_access offsets unsigned
  coresight: cti-sysfs: Re-use same functions for similar sysfs register accessors
  coresight: Re-use same function for similar sysfs register accessors
  coresight: Simplify sysfs accessors by using csdev_access abstraction
  coresight: Remove unused function parameter
  coresight: etm4x: docs: Add documentation for 'ts_source' sysfs interface
  coresight: etm4x: Expose default timestamp source in sysfs
  dt-bindings: arm: coresight-tmc: Add 'iommu' property
  dt-bindings: arm: coresight: Add 'power-domains' property
  coresight: docs: Fix a broken reference
  coresight: trbe: fix Kconfig "its" grammar
2022-09-21 16:16:03 +02:00
Mark Rutland
0072dc1b53 arm64: avoid BUILD_BUG_ON() in alternative-macros
Nathan reports that the build fails when using clang and LTO:

|  In file included from kernel/bounds.c:10:
|  In file included from ./include/linux/page-flags.h:10:
|  In file included from ./include/linux/bug.h:5:
|  In file included from ./arch/arm64/include/asm/bug.h:26:
|  In file included from ./include/asm-generic/bug.h:5:
|  In file included from ./include/linux/compiler.h:248:
|  In file included from ./arch/arm64/include/asm/rwonce.h:11:
|  ./arch/arm64/include/asm/alternative-macros.h:224:2: error: call to undeclared function 'BUILD_BUG_ON'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
|          BUILD_BUG_ON(feature >= ARM64_NCAPS);
|          ^
|  ./arch/arm64/include/asm/alternative-macros.h:241:2: error: call to undeclared function 'BUILD_BUG_ON'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
|          BUILD_BUG_ON(feature >= ARM64_NCAPS);
|          ^
|  2 errors generated.

... the problem being that when LTO is enabled, <asm/rwonce.h> includes
<asm/alternative-macros.h>, and causes a circular include dependency
through <linux/bug.h>. This manifests as BUILD_BUG_ON() not being
defined when used within <asm/alternative-macros.h>.

This patch avoids the problem and simplifies the include dependencies by
using compiletime_assert() instead of BUILD_BUG_ON().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 21fb26bfb0 ("arm64: alternatives: add alternative_has_feature_*()")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: http://lore.kernel.org/r/YyigTrxhE3IRPzjs@dev-arch.thelio-3990X
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220920140044.1709073-1-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-21 12:41:50 +01:00
Marc Zyngier
bb0cca240a Merge branch kvm-arm64/single-step-async-exception into kvmarm-master/next
* kvm-arm64/single-step-async-exception:
  : .
  : Single-step fixes from Reiji Watanabe:
  :
  : "This series fixes two bugs of single-step execution enabled by
  : userspace, and add a test case for KVM_GUESTDBG_SINGLESTEP to
  : the debug-exception test to verify the single-step behavior."
  : .
  KVM: arm64: selftests: Add a test case for KVM_GUESTDBG_SINGLESTEP
  KVM: arm64: selftests: Refactor debug-exceptions to make it amenable to new test cases
  KVM: arm64: Clear PSTATE.SS when the Software Step state was Active-pending
  KVM: arm64: Preserve PSTATE.SS for the guest while single-step is enabled

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-09-19 10:59:29 +01:00
Reiji Watanabe
370531d1e9 KVM: arm64: Clear PSTATE.SS when the Software Step state was Active-pending
While userspace enables single-step, if the Software Step state at the
last guest exit was "Active-pending", clear PSTATE.SS on guest entry
to restore the state.

Currently, KVM sets PSTATE.SS to 1 on every guest entry while userspace
enables single-step for the vCPU (with KVM_GUESTDBG_SINGLESTEP).
It means KVM always makes the vCPU's Software Step state
"Active-not-pending" on the guest entry, which lets the VCPU perform
single-step (then Software Step exception is taken). This could cause
extra single-step (without returning to userspace) if the Software Step
state at the last guest exit was "Active-pending" (i.e. the last
exit was triggered by an asynchronous exception after the single-step
is performed, but before the Software Step exception is taken.
See "Figure D2-3 Software step state machine" and "D2.12.7 Behavior
in the active-pending state" in ARM DDI 0487I.a for more info about
this behavior).

Fix this by clearing PSTATE.SS on guest entry if the Software Step state
at the last exit was "Active-pending" so that KVM restore the state (and
the exception is taken before further single-step is performed).

Fixes: 337b99bf7e ("KVM: arm64: guest debug, add support for single-step")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220917010600.532642-3-reijiw@google.com
2022-09-19 10:48:53 +01:00
Reiji Watanabe
34fbdee086 KVM: arm64: Preserve PSTATE.SS for the guest while single-step is enabled
Preserve the PSTATE.SS value for the guest while userspace enables
single-step (i.e. while KVM manipulates the PSTATE.SS) for the vCPU.

Currently, while userspace enables single-step for the vCPU
(with KVM_GUESTDBG_SINGLESTEP), KVM sets PSTATE.SS to 1 on every
guest entry, not saving its original value.
When userspace disables single-step, KVM doesn't restore the original
value for the subsequent guest entry (use the current value instead).
Exception return instructions copy PSTATE.SS from SPSR_ELx.SS
only in certain cases when single-step is enabled (and set it to 0
in other cases). So, the value matters only when the guest enables
single-step (and when the guest's Software step state isn't affected
by single-step enabled by userspace, practically), though.

Fix this by preserving the original PSTATE.SS value while userspace
enables single-step, and restoring the value once it is disabled.

This fix modifies the behavior of GET_ONE_REG/SET_ONE_REG for the
PSTATE.SS while single-step is enabled by userspace.
Presently, GET_ONE_REG/SET_ONE_REG gets/sets the current PSTATE.SS
value, which KVM will override on the next guest entry (i.e. the
value userspace gets/sets is not used for the next guest entry).
With this patch, GET_ONE_REG/SET_ONE_REG will get/set the guest's
preserved value, which KVM will preserve and try to restore after
single-step is disabled.

Fixes: 337b99bf7e ("KVM: arm64: guest debug, add support for single-step")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220917010600.532642-2-reijiw@google.com
2022-09-19 10:48:53 +01:00
Mark Rutland
d926079f17 arm64: alternatives: add shared NOP callback
For each instance of an alternative, the compiler outputs a distinct
copy of the alternative instructions into a subsection. As the compiler
doesn't have special knowledge of alternatives, it cannot coalesce these
to save space.

In a defconfig kernel built with GCC 12.1.0, there are approximately
10,000 instances of alternative_has_feature_likely(), where the
replacement instruction is always a NOP. As NOPs are
position-independent, we don't need a unique copy per alternative
sequence.

This patch adds a callback to patch an alternative sequence with NOPs,
and make use of this in alternative_has_feature_likely(). So that this
can be used for other sites in future, this is written to patch multiple
instructions up to the original sequence length.

For NVHE, an alias is added to image-vars.h.

For modules, the callback is exported. Note that as modules are loaded
within 2GiB of the kernel, an alt_instr entry in a module can always
refer directly to the callback, and no special handling is necessary.

When building with GCC 12.1.0, the vmlinux is ~158KiB smaller, though
the resulting Image size is unchanged due to alignment constraints and
padding:

| % ls -al vmlinux-*
| -rwxr-xr-x 1 mark mark 134644592 Sep  1 14:52 vmlinux-after
| -rwxr-xr-x 1 mark mark 134486232 Sep  1 14:50 vmlinux-before
| % ls -al Image-*
| -rw-r--r-- 1 mark mark 37108224 Sep  1 14:52 Image-after
| -rw-r--r-- 1 mark mark 37108224 Sep  1 14:50 Image-before

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220912162210.3626215-9-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 17:15:03 +01:00
Mark Rutland
21fb26bfb0 arm64: alternatives: add alternative_has_feature_*()
Currrently we use a mixture of alternative sequences and static branches
to handle features detected at boot time. For ease of maintenance we
generally prefer to use static branches in C code, but this has a few
downsides:

* Each static branch has metadata in the __jump_table section, which is
  not discarded after features are finalized. This wastes some space,
  and slows down the patching of other static branches.

* The static branches are patched at a different point in time from the
  alternatives, so changes are not atomic. This leaves a transient
  period where there could be a mismatch between the behaviour of
  alternatives and static branches, which could be problematic for some
  features (e.g. pseudo-NMI).

* More (instrumentable) kernel code is executed to patch each static
  branch, which can be risky when patching certain features (e.g.
  irqflags management for pseudo-NMI).

* When CONFIG_JUMP_LABEL=n, static branches are turned into a load of a
  flag and a conditional branch. This means it isn't safe to use such
  static branches in an alternative address space (e.g. the NVHE/PKVM
  hyp code), where the generated address isn't safe to acccess.

To deal with these issues, this patch introduces new
alternative_has_feature_*() helpers, which work like static branches but
are patched using alternatives. This ensures the patching is performed
at the same time as other alternative patching, allows the metadata to
be freed after patching, and is safe for use in alternative address
spaces.

Note that all supported toolchains have asm goto support, and since
commit:

  a0a12c3ed0 ("asm goto: eradicate CC_HAS_ASM_GOTO)"

... the CC_HAS_ASM_GOTO Kconfig symbol has been removed, so no feature
check is necessary, and we can always make use of asm goto.

Additionally, note that:

* This has no impact on cpus_have_cap(), which is a dynamic check.

* This has no functional impact on cpus_have_const_cap(). The branches
  are patched slightly later than before this patch, but these branches
  are not reachable until caps have been finalised.

* It is now invalid to use cpus_have_final_cap() in the window between
  feature detection and patching. All existing uses are only expected
  after patching anyway, so this should not be a problem.

* The LSE atomics will now be enabled during alternatives patching
  rather than immediately before. As the LL/SC an LSE atomics are
  functionally equivalent this should not be problematic.

When building defconfig with GCC 12.1.0, the resulting Image is 64KiB
smaller:

| % ls -al Image-*
| -rw-r--r-- 1 mark mark 37108224 Aug 23 09:56 Image-after
| -rw-r--r-- 1 mark mark 37173760 Aug 23 09:54 Image-before

According to bloat-o-meter.pl:

| add/remove: 44/34 grow/shrink: 602/1294 up/down: 39692/-61108 (-21416)
| Function                                     old     new   delta
| [...]
| Total: Before=16618336, After=16596920, chg -0.13%
| add/remove: 0/2 grow/shrink: 0/0 up/down: 0/-1296 (-1296)
| Data                                         old     new   delta
| arm64_const_caps_ready                        16       -     -16
| cpu_hwcap_keys                              1280       -   -1280
| Total: Before=8987120, After=8985824, chg -0.01%
| add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0)
| RO Data                                      old     new   delta
| Total: Before=18408, After=18408, chg +0.00%

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220912162210.3626215-8-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 17:15:03 +01:00
Mark Rutland
4c0bd995d7 arm64: alternatives: have callbacks take a cap
Today, callback alternatives are special-cased within
__apply_alternatives(), and are applied alongside patching for system
capabilities as ARM64_NCAPS is not part of the boot_capabilities feature
mask.

This special-casing is less than ideal. Giving special meaning to
ARM64_NCAPS for this requires some structures and loops to use
ARM64_NCAPS + 1 (AKA ARM64_NPATCHABLE), while others use ARM64_NCAPS.
It's also not immediately clear callback alternatives are only applied
when applying alternatives for system-wide features.

To make this a bit clearer, changes the way that callback alternatives
are identified to remove the special-casing of ARM64_NCAPS, and to allow
callback alternatives to be associated with a cpucap as with all other
alternatives.

New cpucaps, ARM64_ALWAYS_BOOT and ARM64_ALWAYS_SYSTEM are added which
are always detected alongside boot cpu capabilities and system
capabilities respectively. All existing callback alternatives are made
to use ARM64_ALWAYS_SYSTEM, and so will be patched at the same point
during the boot flow as before.

Subsequent patches will make more use of these new cpucaps.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220912162210.3626215-7-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 17:15:03 +01:00
Mark Rutland
92b4b5619f arm64: cpufeature: make cpus_have_cap() noinstr-safe
Currently it isn't safe to use cpus_have_cap() from noinstr code as
test_bit() is explicitly instrumented, and were cpus_have_cap() placed
out-of-line, cpus_have_cap() itself could be instrumented.

Make cpus_have_cap() noinstr safe by marking it __always_inline and
using arch_test_bit().

Aside from the prevention of instrumentation, there should be no
functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220912162210.3626215-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 17:15:02 +01:00
James Morse
445c953e4a arm64: cpufeature: Expose get_arm64_ftr_reg() outside cpufeature.c
get_arm64_ftr_reg() returns the properties of a system register based
on its instruction encoding.

This is needed by erratum workaround in cpu_errata.c to modify the
user-space visible view of id registers.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220909165938.3931307-3-james.morse@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 15:16:34 +01:00
Mark Brown
10453bf149 arm64/sysreg: Convert ID_AA64AFRn_EL1 to automatic generation
Convert ID_AA64AFRn_EL1 to automatic generation as per DDI0487I.a, no
functional changes.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220910163354.860255-7-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:38:58 +01:00
Mark Brown
c65c617806 arm64/sysreg: Convert ID_AA64DFR1_EL1 to automatic generation
Convert ID_AA64FDR1_EL1 to automatic generation as per DDI0487I.a, no
functional changes.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220910163354.860255-6-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:38:58 +01:00
Mark Brown
e62a2d2610 arm64/sysreg: Convert ID_AA64FDR0_EL1 to automatic generation
Convert ID_AA64DFR0_EL1 to automatic generation as per DDI0487I.a, no
functional changes.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220910163354.860255-5-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:38:58 +01:00
Mark Brown
121a8fc088 arm64/sysreg: Use feature numbering for PMU and SPE revisions
Currently the kernel refers to the versions of the PMU and SPE features by
the version of the architecture where those features were updated but the
ARM refers to them using the FEAT_ names for the features. To improve
consistency and help with updating for newer features and since v9 will
make our current naming scheme a bit more confusing update the macros
identfying features to use the FEAT_ based scheme.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220910163354.860255-4-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:38:57 +01:00
Mark Brown
fcf37b38ff arm64/sysreg: Add _EL1 into ID_AA64DFR0_EL1 definition names
Normally we include the full register name in the defines for fields within
registers but this has not been followed for ID registers. In preparation
for automatic generation of defines add the _EL1s into the defines for
ID_AA64DFR0_EL1 to follow the convention. No functional changes.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220910163354.860255-3-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:38:57 +01:00
Mark Brown
c0357a73fa arm64/sysreg: Align field names in ID_AA64DFR0_EL1 with architecture
The naming scheme the architecture uses for the fields in ID_AA64DFR0_EL1
does not align well with kernel conventions, using as it does a lot of
MixedCase in various arrangements. In preparation for automatically
generating the defines for this register rename the defines used to match
what is in the architecture.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220910163354.860255-2-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:38:57 +01:00
Mark Rutland
830a2a4d85 arm64: rework BTI exception handling
If a BTI exception is taken from EL1, the entry code will treat this as
an unhandled exception and will panic() the kernel. This is inconsistent
with the way we handle FPAC exceptions, which have a dedicated handler
and only necessarily kill the thread from which the exception was taken
from, and we don't log all the information that could be relevant to
debug the issue.

The code in do_bti() has:

	BUG_ON(!user_mode(regs));

... and it seems like the intent was to call this for EL1 BTI
exceptions, as with FPAC, but this was omitted due to an oversight.

This patch adds separate EL0 and EL1 BTI exception handlers, with the
latter calling die() directly to report the original context the BTI
exception was taken from. This matches our handling of FPAC exceptions.

Prior to this patch, a BTI failure is reported as:

| Unhandled 64-bit el1h sync exception on CPU0, ESR 0x0000000034000002 -- BTI
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00131-g7d937ff0221d-dirty #9
| Hardware name: linux,dummy-virt (DT)
| pstate: 20400809 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=-c)
| pc : test_bti_callee+0x4/0x10
| lr : test_bti_caller+0x1c/0x28
| sp : ffff80000800bdf0
| x29: ffff80000800bdf0 x28: 0000000000000000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffff80000a2b8000 x22: 0000000000000000 x21: 0000000000000000
| x20: ffff8000099fa5b0 x19: ffff800009ff7000 x18: fffffbfffda37000
| x17: 3120676e696d7573 x16: 7361202c6e6f6974 x15: 0000000041a90000
| x14: 0040000000000041 x13: 0040000000000001 x12: ffff000001a90000
| x11: fffffbfffda37480 x10: 0068000000000703 x9 : 0001000040000000
| x8 : 0000000000090000 x7 : 0068000000000f03 x6 : 0060000000000f83
| x5 : ffff80000a2b6000 x4 : ffff0000028d0000 x3 : ffff800009f78378
| x2 : 0000000000000000 x1 : 0000000040210000 x0 : ffff8000080257e4
| Kernel panic - not syncing: Unhandled exception
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00131-g7d937ff0221d-dirty #9
| Hardware name: linux,dummy-virt (DT)
| Call trace:
|  dump_backtrace.part.0+0xcc/0xe0
|  show_stack+0x18/0x5c
|  dump_stack_lvl+0x64/0x80
|  dump_stack+0x18/0x34
|  panic+0x170/0x360
|  arm64_exit_nmi.isra.0+0x0/0x80
|  el1h_64_sync_handler+0x64/0xd0
|  el1h_64_sync+0x64/0x68
|  test_bti_callee+0x4/0x10
|  smp_cpus_done+0xb0/0xbc
|  smp_init+0x7c/0x8c
|  kernel_init_freeable+0x128/0x28c
|  kernel_init+0x28/0x13c
|  ret_from_fork+0x10/0x20

With this patch applied, a BTI failure is reported as:

| Internal error: Oops - BTI: 0000000034000002 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00132-g0ad98265d582-dirty #8
| Hardware name: linux,dummy-virt (DT)
| pstate: 20400809 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=-c)
| pc : test_bti_callee+0x4/0x10
| lr : test_bti_caller+0x1c/0x28
| sp : ffff80000800bdf0
| x29: ffff80000800bdf0 x28: 0000000000000000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffff80000a2b8000 x22: 0000000000000000 x21: 0000000000000000
| x20: ffff8000099fa5b0 x19: ffff800009ff7000 x18: fffffbfffda37000
| x17: 3120676e696d7573 x16: 7361202c6e6f6974 x15: 0000000041a90000
| x14: 0040000000000041 x13: 0040000000000001 x12: ffff000001a90000
| x11: fffffbfffda37480 x10: 0068000000000703 x9 : 0001000040000000
| x8 : 0000000000090000 x7 : 0068000000000f03 x6 : 0060000000000f83
| x5 : ffff80000a2b6000 x4 : ffff0000028d0000 x3 : ffff800009f78378
| x2 : 0000000000000000 x1 : 0000000040210000 x0 : ffff800008025804
| Call trace:
|  test_bti_callee+0x4/0x10
|  smp_cpus_done+0xb0/0xbc
|  smp_init+0x7c/0x8c
|  kernel_init_freeable+0x128/0x28c
|  kernel_init+0x28/0x13c
|  ret_from_fork+0x10/0x20
| Code: d50323bf d53cd040 d65f03c0 d503233f (d50323bf)

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220913101732.3925290-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:17:03 +01:00
Mark Rutland
a1fafa3b24 arm64: rework FPAC exception handling
If an FPAC exception is taken from EL1, the entry code will call
do_ptrauth_fault(), where due to:

	BUG_ON(!user_mode(regs))

... the kernel will report a problem within do_ptrauth_fault() rather
than reporting the original context the FPAC exception was taken from.
The pt_regs and ESR value reported will be from within
do_ptrauth_fault() and the code dump will be for the BRK in BUG_ON(),
which isn't sufficient to debug the cause of the original exception.

This patch makes the reporting better by having separate EL0 and EL1
FPAC exception handlers, with the latter calling die() directly to
report the original context the FPAC exception was taken from.

Note that we only need to prevent kprobes of the EL1 FPAC handler, since
the EL0 FPAC handler cannot be called recursively.

For consistency with do_el0_svc*(), I've named the split functions
do_el{0,1}_fpac() rather than do_el{0,1}_ptrauth_fault(). I've also
clarified the comment to not imply there are casues other than FPAC
exceptions.

Prior to this patch FPAC exceptions are reported as:

| kernel BUG at arch/arm64/kernel/traps.c:517!
| Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00130-g9c8a180a1cdf-dirty #12
| Hardware name: FVP Base RevC (DT)
| pstate: 00400009 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : do_ptrauth_fault+0x3c/0x40
| lr : el1_fpac+0x34/0x54
| sp : ffff80000a3bbc80
| x29: ffff80000a3bbc80 x28: ffff0008001d8000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: 0000000020400009 x22: ffff800008f70fa4 x21: ffff80000a3bbe00
| x20: 0000000072000000 x19: ffff80000a3bbcb0 x18: fffffbfffda37000
| x17: 3120676e696d7573 x16: 7361202c6e6f6974 x15: 0000000081a90000
| x14: 0040000000000041 x13: 0040000000000001 x12: ffff000001a90000
| x11: fffffbfffda37480 x10: 0068000000000703 x9 : 0001000080000000
| x8 : 0000000000090000 x7 : 0068000000000f03 x6 : 0060000000000783
| x5 : ffff80000a3bbcb0 x4 : ffff0008001d8000 x3 : 0000000072000000
| x2 : 0000000000000000 x1 : 0000000020400009 x0 : ffff80000a3bbcb0
| Call trace:
|  do_ptrauth_fault+0x3c/0x40
|  el1h_64_sync_handler+0xc4/0xd0
|  el1h_64_sync+0x64/0x68
|  test_pac+0x8/0x10
|  smp_init+0x7c/0x8c
|  kernel_init_freeable+0x128/0x28c
|  kernel_init+0x28/0x13c
|  ret_from_fork+0x10/0x20
| Code: 97fffe5e a8c17bfd d50323bf d65f03c0 (d4210000)

With this patch applied FPAC exceptions are reported as:

| Internal error: Oops - FPAC: 0000000072000000 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00132-g78846e1c4757-dirty #11
| Hardware name: FVP Base RevC (DT)
| pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : test_pac+0x8/0x10
| lr : 0x0
| sp : ffff80000a3bbe00
| x29: ffff80000a3bbe00 x28: 0000000000000000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffff80000a2c8000 x22: 0000000000000000 x21: 0000000000000000
| x20: ffff8000099fa5b0 x19: ffff80000a007000 x18: fffffbfffda37000
| x17: 3120676e696d7573 x16: 7361202c6e6f6974 x15: 0000000081a90000
| x14: 0040000000000041 x13: 0040000000000001 x12: ffff000001a90000
| x11: fffffbfffda37480 x10: 0068000000000703 x9 : 0001000080000000
| x8 : 0000000000090000 x7 : 0068000000000f03 x6 : 0060000000000783
| x5 : ffff80000a2c6000 x4 : ffff0008001d8000 x3 : ffff800009f88378
| x2 : 0000000000000000 x1 : 0000000080210000 x0 : ffff000001a90000
| Call trace:
|  test_pac+0x8/0x10
|  smp_init+0x7c/0x8c
|  kernel_init_freeable+0x128/0x28c
|  kernel_init+0x28/0x13c
|  ret_from_fork+0x10/0x20
| Code: d50323bf d65f03c0 d503233f aa1f03fe (d50323bf)

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220913101732.3925290-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:17:03 +01:00
Mark Rutland
0f2cb928a1 arm64: consistently pass ESR_ELx to die()
Currently, bug_handler() and kasan_handler() call die() with '0' as the
'err' value, whereas die_kernel_fault() passes the ESR_ELx value.

For consistency, this patch ensures we always pass the ESR_ELx value to
die(). As this is only called for exceptions taken from kernel mode,
there should be no user-visible change as a result of this patch.

For UNDEFINED exceptions, I've had to modify do_undefinstr() and its
callers to pass the ESR_ELx value. In all cases the ESR_ELx value had
already been read and was available.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220913101732.3925290-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:17:03 +01:00
Mark Rutland
18906ff9af arm64: die(): pass 'err' as long
Recently, we reworked a lot of code to consistentlt pass ESR_ELx as a
64-bit quantity. However, we missed that this can be passed into die()
and __die() as the 'err' parameter where it is truncated to a 32-bit
int.

As notify_die() already takes 'err' as a long, this patch changes die()
and __die() to also take 'err' as a long, ensuring that the full value
of ESR_ELx is retained.

At the same time, die() is updated to consistently log 'err' as a
zero-padded 64-bit quantity.

Subsequent patches will pass the ESR_ELx value to die() for a number of
exceptions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220913101732.3925290-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-16 12:17:03 +01:00
Kefeng Wang
2be9880dc8 kernel: exit: cleanup release_thread()
Only x86 has own release_thread(), introduce a new weak release_thread()
function to clean empty definitions in other ARCHs.

Link: https://lkml.kernel.org/r/20220819014406.32266-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Guo Ren <guoren@kernel.org>				[csky]
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Brian Cain <bcain@quicinc.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>			[powerpc]
Acked-by: Stafford Horne <shorne@gmail.com>			[openrisc]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>		[arm64]
Acked-by: Huacai Chen <chenhuacai@kernel.org>			[LoongArch]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org> [csky]
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Xuerui Wang <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 21:55:07 -07:00
Mark Rutland
78f6f5c994 arm64: atomic: always inline the assembly
The __lse_*() and __ll_sc_*() atomic implementations are marked as
inline rather than __always_inline, permitting a compiler to generate
out-of-line versions, which may be instrumented.

We marked the atomic wrappers as __always_inline in commit:

  c35a824c31 ("arm64: make atomic helpers __always_inline")

... but did not think to do the same for the underlying implementations.

If the compiler were to out-of-line an LSE or LL/SC atomic, this could
break noinstr code. Ensure this doesn't happen by marking the underlying
implementations as __always_inline.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220817155914.3975112-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-09 13:58:33 +01:00
Mark Rutland
b2c3ccbd00 arm64: atomics: remove LL/SC trampolines
When CONFIG_ARM64_LSE_ATOMICS=y, each use of an LL/SC atomic results in
a fragment of code being generated in a subsection without a clear
association with its caller. A trampoline in the caller branches to the
LL/SC atomic with with a direct branch, and the atomic directly branches
back into its trampoline.

This breaks backtracing, as any PC within the out-of-line fragment will
be symbolized as an offset from the nearest prior symbol (which may not
be the function using the atomic), and since the atomic returns with a
direct branch, the caller's PC may be missing from the backtrace.

For example, with secondary_start_kernel() hacked to contain
atomic_inc(NULL), the resulting exception can be reported as being taken
from cpus_are_stuck_in_kernel():

| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
| Mem abort info:
|   ESR = 0x0000000096000004
|   EC = 0x25: DABT (current EL), IL = 32 bits
|   SET = 0, FnV = 0
|   EA = 0, S1PTW = 0
|   FSC = 0x04: level 0 translation fault
| Data abort info:
|   ISV = 0, ISS = 0x00000004
|   CM = 0, WnR = 0
| [0000000000000000] user address but active_mm is swapper
| Internal error: Oops: 96000004 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.19.0-11219-geb555cb5b794-dirty #3
| Hardware name: linux,dummy-virt (DT)
| pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : cpus_are_stuck_in_kernel+0xa4/0x120
| lr : secondary_start_kernel+0x164/0x170
| sp : ffff80000a4cbe90
| x29: ffff80000a4cbe90 x28: 0000000000000000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000000
| x20: 0000000000000001 x19: 0000000000000001 x18: 0000000000000008
| x17: 3030383832343030 x16: 3030303030307830 x15: ffff80000a4cbab0
| x14: 0000000000000001 x13: 5d31666130663133 x12: 3478305b20313030
| x11: 3030303030303078 x10: 3020726f73736563 x9 : 726f737365636f72
| x8 : ffff800009ff2ef0 x7 : 0000000000000003 x6 : 0000000000000000
| x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000100
| x2 : 0000000000000000 x1 : ffff0000029bd880 x0 : 0000000000000000
| Call trace:
|  cpus_are_stuck_in_kernel+0xa4/0x120
|  __secondary_switched+0xb0/0xb4
| Code: 35ffffa3 17fffc6c d53cd040 f9800011 (885f7c01)
| ---[ end trace 0000000000000000 ]---

This is confusing and hinders debugging, and will be problematic for
CONFIG_LIVEPATCH as these cases cannot be unwound reliably.

This is very similar to recent issues with out-of-line exception fixups,
which were removed in commits:

  35d67794b8 ("arm64: lib: __arch_clear_user(): fold fixups into body")
  4012e0e227 ("arm64: lib: __arch_copy_from_user(): fold fixups into body")
  139f9ab73d ("arm64: lib: __arch_copy_to_user(): fold fixups into body")

When the trampolines were introduced in commit:

  addfc38672 ("arm64: atomics: avoid out-of-line ll/sc atomics")

The rationale was to improve icache performance by grouping the LL/SC
atomics together. This has never been measured, and this theoretical
benefit is outweighed by other factors:

* As the subsections are collapsed into sections at object file
  granularity, these are spread out throughout the kernel and can share
  cachelines with unrelated code regardless.

* GCC 12.1.0 has been observed to place the trampoline out-of-line in
  specialised __ll_sc_*() functions, introducing more branching than was
  intended.

* Removing the trampolines has been observed to shrink a defconfig
  kernel Image by 64KiB when building with GCC 12.1.0.

This patch removes the LL/SC trampolines, meaning that the LL/SC atomics
will be inlined into their callers (or placed in out-of line functions
using regular BL/RET pairs). When CONFIG_ARM64_LSE_ATOMICS=y, the LL/SC
atomics are always called in an unlikely branch, and will be placed in a
cold portion of the function, so this should have minimal impact to the
hot paths.

Other than the improved backtracing, there should be no functional
change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220817155914.3975112-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-09 13:58:28 +01:00