microsoft
/
WSL2-Linux-Kernel
зеркало из https://github.com/microsoft/WSL2-Linux-Kernel.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность
The source for the Linux kernel used in Windows Subsystem for Linux 2 (WSL2)
1 046 831 коммит 10 Ветки 3 162 Теги 3,2 GiB
C 97.7%
Assembly 1.2%
Shell 0.4%
Makefile 0.3%
Python 0.2%
Разное 0.1%
Перейти к файлу
Mike Tipton ad4adbbf66 clk: Don't parent clks until the parent is fully registered 
[ Upstream commit 54baf56eaa ]

Before commit fc0c209c14 ("clk: Allow parents to be specified without
string names") child clks couldn't find their parent until the parent
clk was added to a list in __clk_core_init(). After that commit, child
clks can reference their parent clks directly via a clk_hw pointer, or
they can lookup that clk_hw pointer via DT if the parent clk is
registered with an OF clk provider.

The common clk framework treats hw->core being non-NULL as "the clk is
registered" per the logic within clk_core_fill_parent_index():

	parent = entry->hw->core;
	/*
	 * We have a direct reference but it isn't registered yet?
	 * Orphan it and let clk_reparent() update the orphan status
	 * when the parent is registered.
	 */
	if (!parent)

Therefore we need to be extra careful to not set hw->core until the clk
is fully registered with the clk framework. Otherwise we can get into a
situation where a child finds a parent clk and we move the child clk off
the orphan list when the parent isn't actually registered, wrecking our
enable accounting and breaking critical clks.

Consider the following scenario:

  CPU0                                     CPU1
  ----                                     ----
  struct clk_hw clkBad;
  struct clk_hw clkA;

  clkA.init.parent_hws = { &clkBad };

  clk_hw_register(&clkA)                   clk_hw_register(&clkBad)
   ...                                      __clk_register()
					     hw->core = core
					     ...
   __clk_register()
    __clk_core_init()
     clk_prepare_lock()
     __clk_init_parent()
      clk_core_get_parent_by_index()
       clk_core_fill_parent_index()
        if (entry->hw) {
	 parent = entry->hw->core;

At this point, 'parent' points to clkBad even though clkBad hasn't been
fully registered yet. Ouch! A similar problem can happen if a clk
controller registers orphan clks that are referenced in the DT node of
another clk controller.

Let's fix all this by only setting the hw->core pointer underneath the
clk prepare lock in __clk_core_init(). This way we know that
clk_core_fill_parent_index() can't see hw->core be non-NULL until the
clk is fully registered.

Fixes: fc0c209c14 ("clk: Allow parents to be specified without string names")
Signed-off-by: Mike Tipton <quic_mdtipton@quicinc.com>
Link: https://lore.kernel.org/r/20211109043438.4639-1-quic_mdtipton@quicinc.com
[sboyd@kernel.org: Reword commit text, update comment]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
 		2021-12-22 09:32:39 +01:00
Documentation dt-bindings: media: nxp,imx7-mipi-csi2: Drop bad if/then schema 2021-12-17 10:30:13 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
arch arm64: dts: imx8mq: remove interconnect property from lcdif 2021-12-22 09:32:39 +01:00
block block: fix ioprio_get(IOPRIO_WHO_PGRP) vs setuid(2) 2021-12-14 10:57:16 +01:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto crypto: pcrypt - Delay write to padata->info 2021-11-18 19:16:44 +01:00
drivers clk: Don't parent clks until the parent is fully registered 2021-12-22 09:32:39 +01:00
fs ceph: initialize pathlen variable in reconnect_caps_cb 2021-12-22 09:32:38 +01:00
include bus: mhi: core: Add support for forced PM resume 2021-12-14 10:57:22 +01:00
init init: make unknown command line param message clearer 2021-11-18 19:17:11 +01:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-11-25 09:48:42 +01:00
kernel audit: improve robustness of the audit queue handling 2021-12-22 09:32:36 +01:00
lib siphash: use _unaligned version by default 2021-12-08 09:04:47 +01:00
mm mm: bdi: initialize bdi_min_ratio when bdi is unregistered 2021-12-14 10:57:11 +01:00
net mac80211: track only QoS data frames for admission control 2021-12-22 09:32:38 +01:00
samples samples/bpf: Fix incorrect use of strlen in xdp_redirect_cpu 2021-11-25 09:48:33 +01:00
scripts recordmcount.pl: look for jgnop instruction as well as bcrl on s390 2021-12-22 09:32:36 +01:00
security selinux: fix NULL-pointer dereference when hashtab allocation fails 2021-11-25 09:49:07 +01:00
sound ALSA: hda/hdmi: fix HDA codec entry table order for ADL-P 2021-12-17 10:30:15 +01:00
tools bpf, selftests: Update test case for atomic cmpxchg on r0 with pointer 2021-12-22 09:32:35 +01:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt KVM: downgrade two BUG_ONs to WARN_ON_ONCE 2021-12-22 09:32:34 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS drm fixes for 5.15 final 2021-10-28 12:17:01 -07:00
Makefile Linux 5.15.10 2021-12-17 10:30:17 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

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 Restructured Text 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.