mirror_ubuntu-kernels/arch/powerpc
Linus Torvalds 2d9db778dd Timers and timekeeping updates:
- Core code:
 
    - Make timekeeping and VDSO time readouts resilent against math overflow:
 
      In guest context the kernel is prone to math overflow when the host
      defers the timer interrupt due to overload, malfunction or malice.
 
      This can be mitigated by checking the clocksource delta for the
      maximum deferrement which is readily available. If that value is
      exceeded then the code uses a slowpath function which can handle the
      multiplication overflow.
 
      This functionality is enabled unconditionally in the kernel, but made
      conditional in the VDSO code. The latter is conditional because it
      allows architectures to optimize the check so it is not causing
      performance regressions.
 
      On X86 this is achieved by reworking the existing check for negative
      TSC deltas as a negative delta obviously exceeds the maximum
      deferrement when it is evaluated as an unsigned value. That avoids two
      conditionals in the hotpath and allows to hide both the negative delta
      and the large delta handling in the same slow path.
 
    - Add an initial minimal ktime_t abstraction for Rust
 
    - The usual boring cleanups and enhancements
 
  - Drivers:
 
    - Boring updates to device trees and trivial enhancements in various
      drivers.
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Merge tag 'timers-core-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timers and timekeeping updates from Thomas Gleixner:
 "Core code:

   - Make timekeeping and VDSO time readouts resilent against math
     overflow:

     In guest context the kernel is prone to math overflow when the host
     defers the timer interrupt due to overload, malfunction or malice.

     This can be mitigated by checking the clocksource delta for the
     maximum deferrement which is readily available. If that value is
     exceeded then the code uses a slowpath function which can handle
     the multiplication overflow.

     This functionality is enabled unconditionally in the kernel, but
     made conditional in the VDSO code. The latter is conditional
     because it allows architectures to optimize the check so it is not
     causing performance regressions.

     On X86 this is achieved by reworking the existing check for
     negative TSC deltas as a negative delta obviously exceeds the
     maximum deferrement when it is evaluated as an unsigned value. That
     avoids two conditionals in the hotpath and allows to hide both the
     negative delta and the large delta handling in the same slow path.

   - Add an initial minimal ktime_t abstraction for Rust

   - The usual boring cleanups and enhancements

  Drivers:

   - Boring updates to device trees and trivial enhancements in various
     drivers"

* tag 'timers-core-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  clocksource/drivers/arm_arch_timer: Mark hisi_161010101_oem_info const
  clocksource/drivers/timer-ti-dm: Remove an unused field in struct dmtimer
  clocksource/drivers/renesas-ostm: Avoid reprobe after successful early probe
  clocksource/drivers/renesas-ostm: Allow OSTM driver to reprobe for RZ/V2H(P) SoC
  dt-bindings: timer: renesas: ostm: Document Renesas RZ/V2H(P) SoC
  rust: time: doc: Add missing C header links
  clocksource: Make the int help prompt unit readable in ncurses
  hrtimer: Rename __hrtimer_hres_active() to hrtimer_hres_active()
  timerqueue: Remove never used function timerqueue_node_expires()
  rust: time: Add Ktime
  vdso: Fix powerpc build U64_MAX undeclared error
  clockevents: Convert s[n]printf() to sysfs_emit()
  clocksource: Convert s[n]printf() to sysfs_emit()
  clocksource: Make watchdog and suspend-timing multiplication overflow safe
  timekeeping: Let timekeeping_cycles_to_ns() handle both under and overflow
  timekeeping: Make delta calculation overflow safe
  timekeeping: Prepare timekeeping_cycles_to_ns() for overflow safety
  timekeeping: Fold in timekeeping_delta_to_ns()
  timekeeping: Consolidate timekeeping helpers
  timekeeping: Refactor timekeeping helpers
  ...
2024-05-14 09:27:40 -07:00
..
boot USB/Thunderbolt changes for 6.9-rc1 2024-03-21 12:35:20 -07:00
configs powerpc: Add allmodconfig for all 32-bit sub-arches 2024-03-03 22:20:29 +11:00
crypto powerpc/crypto/chacha-p10: Fix failure on non Power10 2024-04-05 00:02:18 +11:00
include Timers and timekeeping updates: 2024-05-14 09:27:40 -07:00
kernel Scheduler changes for v6.10: 2024-05-13 17:18:51 -07:00
kexec powerpc/kdump: Split KEXEC_CORE and CRASH_DUMP dependency 2024-03-17 13:34:00 +11:00
kvm powerpc updates for 6.9 2024-03-15 17:53:48 -07:00
lib powerpc: xor_vmx: Add '-mhard-float' to CFLAGS 2024-03-07 00:13:28 +11:00
math-emu powerpc/math-emu: Inhibit W=1 warnings 2022-09-08 11:11:18 +10:00
mm powerpc: Handle error in mark_rodata_ro() and mark_initmem_nx() 2024-03-17 13:33:21 +11:00
net powerpc/bpf: use bpf_jit_binary_pack_[alloc|finalize|free] 2023-10-23 20:33:19 +11:00
perf powerpc/hv-gpci: Fix the H_GET_PERF_COUNTER_INFO hcall return value checks 2024-03-03 23:05:21 +11:00
platforms powerpc/pseries/iommu: LPAR panics during boot up with a frozen PE 2024-04-23 14:34:00 +10:00
purgatory powerpc/purgatory: remove PGO flags 2023-06-12 11:31:50 -07:00
sysdev powerpc updates for 6.9 2024-03-15 17:53:48 -07:00
tools powerpc/tools: Pass -mabi=elfv2 to gcc-check-mprofile-kernel.sh 2023-10-20 17:46:33 +11:00
xmon powerpc updates for 6.9 2024-03-15 17:53:48 -07:00
Kbuild
Kconfig Replace macro "ARCH_HAVE_EXTRA_ELF_NOTES" with kconfig 2024-04-15 11:02:51 -07:00
Kconfig.debug powerpc/ps3: move udbg_shutdown_ps3gelic prototype 2023-11-21 12:06:50 +11:00
Makefile powerpc updates for 6.9 2024-03-15 17:53:48 -07:00
Makefile.postlink kbuild: remove ARCH_POSTLINK from module builds 2023-10-28 21:10:08 +09:00