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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
arch Timers and timekeeping updates: 2024-05-14 09:27:40 -07:00
block for-6.10/block-20240511 2024-05-13 13:03:54 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This update includes the following changes: 2024-05-13 14:53:05 -07:00
Documentation Timers and timekeeping updates: 2024-05-14 09:27:40 -07:00
drivers Timers and timekeeping updates: 2024-05-14 09:27:40 -07:00
fs hardening updates for 6.10-rc1 2024-05-13 14:14:05 -07:00
include Timers and timekeeping updates: 2024-05-14 09:27:40 -07:00
init Scheduler changes for v6.10: 2024-05-13 17:18:51 -07:00
io_uring for-6.10/io_uring-20240511 2024-05-13 12:48:06 -07:00
ipc fs: Add FOP_HUGE_PAGES 2024-04-09 10:53:44 +02:00
kernel Timers and timekeeping updates: 2024-05-14 09:27:40 -07:00
lib Timers and timekeeping updates: 2024-05-14 09:27:40 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm for-6.10/io_uring-20240511 2024-05-13 12:48:06 -07:00
net for-6.10/io_uring-20240511 2024-05-13 12:48:06 -07:00
rust Timers and timekeeping updates: 2024-05-14 09:27:40 -07:00
samples rust: sync: update Arc and UniqueArc to take allocation flags 2024-04-16 22:50:04 +02:00
scripts Rust changes for v6.10 2024-05-13 15:13:54 -07:00
security Hi 2024-05-13 10:48:35 -07:00
sound ALSA: hda/realtek: Fix build error without CONFIG_PM 2024-05-02 08:25:06 +02:00
tools x86/cpu changes for v6.10: 2024-05-13 18:44:44 -07:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start() 2024-04-11 12:58:53 -07:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap Another not-too-busy cycle for documentation, including: 2024-05-13 10:51:53 -07:00
.rustfmt.toml
COPYING
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS This update includes the following changes: 2024-05-13 14:53:05 -07:00
Makefile Linux 6.9 2024-05-12 14:12:29 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.