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Rafael J. Wysocki fbf6074d19 ACPI: battery: Add synchronization between interface updates
commit 399dbcadc0 upstream.

There is no synchronization between different code paths in the ACPI
battery driver that update its sysfs interface or its power supply
class device interface.  In some cases this results to functional
failures due to race conditions.

One example of this is when two ACPI notifications:

  - ACPI_BATTERY_NOTIFY_STATUS (0x80)
  - ACPI_BATTERY_NOTIFY_INFO   (0x81)

are triggered (by the platform firmware) in a row with a little delay
in between after removing and reinserting a laptop battery.  Both
notifications cause acpi_battery_update() to be called and if the delay
between them is sufficiently small, sysfs_add_battery() can be re-entered
before battery->bat is set which leads to a duplicate sysfs entry error:

 sysfs: cannot create duplicate filename '/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BAT1'
 CPU: 1 UID: 0 PID: 185 Comm: kworker/1:4 Kdump: loaded Not tainted 6.12.38+deb13-amd64 #1  Debian 6.12.38-1
 Hardware name: Gateway          NV44             /SJV40-MV        , BIOS V1.3121 04/08/2009
 Workqueue: kacpi_notify acpi_os_execute_deferred
 Call Trace:
  <TASK>
  dump_stack_lvl+0x5d/0x80
  sysfs_warn_dup.cold+0x17/0x23
  sysfs_create_dir_ns+0xce/0xe0
  kobject_add_internal+0xba/0x250
  kobject_add+0x96/0xc0
  ? get_device_parent+0xde/0x1e0
  device_add+0xe2/0x870
  __power_supply_register.part.0+0x20f/0x3f0
  ? wake_up_q+0x4e/0x90
  sysfs_add_battery+0xa4/0x1d0 [battery]
  acpi_battery_update+0x19e/0x290 [battery]
  acpi_battery_notify+0x50/0x120 [battery]
  acpi_ev_notify_dispatch+0x49/0x70
  acpi_os_execute_deferred+0x1a/0x30
  process_one_work+0x177/0x330
  worker_thread+0x251/0x390
  ? __pfx_worker_thread+0x10/0x10
  kthread+0xd2/0x100
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x34/0x50
  ? __pfx_kthread+0x10/0x10
  ret_from_fork_asm+0x1a/0x30
  </TASK>
 kobject: kobject_add_internal failed for BAT1 with -EEXIST, don't try to register things with the same name in the same directory.

There are also other scenarios in which analogous issues may occur.

Address this by using a common lock in all of the code paths leading
to updates of driver interfaces: ACPI Notify () handler, system resume
callback and post-resume notification, device addition and removal.

This new lock replaces sysfs_lock that has been used only in
sysfs_remove_battery() which now is going to be always called under
the new lock, so it doesn't need any internal locking any more.

Fixes: 1066625155 ("ACPI: battery: Install Notify() handler directly")
Closes: https://lore.kernel.org/linux-acpi/20250910142653.313360-1-luogf2025@163.com/
Reported-by: GuangFei Luo <luogf2025@163.com>
Tested-by: GuangFei Luo <luogf2025@163.com>
Cc: 6.6+ <stable@vger.kernel.org> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-10-19 16:37:16 +02:00
arch s390/vmlinux.lds.S: Move .vmlinux.info to end of allocatable sections 2025-10-19 16:37:16 +02:00
block blk-throttle: fix throtl_data leak during disk release 2025-10-15 12:03:34 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: essiv - Check ssize for decryption and in-place encryption 2025-10-19 16:37:14 +02:00
Documentation Documentation: trace: historgram-design: Separate sched_waking histogram section heading and the following diagram 2025-10-15 12:04:01 +02:00
drivers
fs cifs: Query EA $LXMOD in cifs_query_path_info() for WSL reparse points 2025-10-19 16:37:15 +02:00
include kbuild: keep .modinfo section in vmlinux.unstripped 2025-10-19 16:37:15 +02:00
init Fix CC_HAS_ASM_GOTO_OUTPUT on non-x86 architectures 2025-10-15 12:03:13 +02:00
io_uring io_uring/zcrx: increment fallback loop src offset 2025-10-19 16:37:14 +02:00
ipc vfs-6.17-rc1.mmap_prepare 2025-07-28 13:43:25 -07:00
kernel bpf: Avoid RCU context warning when unpinning htab with internal structs 2025-10-19 16:37:15 +02:00
lib vdso/datastore: Gate time data behind CONFIG_GENERIC_GETTIMEOFDAY 2025-10-15 12:03:24 +02:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm memcg: skip cgroup_file_notify if spinning is not allowed 2025-10-19 16:37:00 +02:00
net bridge: br_vlan_fill_forward_path_pvid: use br_vlan_group_rcu() 2025-10-19 16:37:13 +02:00
rust cpufreq: Make drivers using CPUFREQ_ETERNAL specify transition latency 2025-10-19 16:37:00 +02:00
samples 15 hotfixes. 11 are cc:stable and the remainder address post-6.16 issues 2025-09-17 21:34:26 -07:00
scripts kbuild: Add '.rel.*' strip pattern for vmlinux 2025-10-19 16:37:15 +02:00
security lsm: CONFIG_LSM can depend on CONFIG_SECURITY 2025-10-15 12:03:17 +02:00
sound ASoC: SOF: Intel: Read the LLP via the associated Link DMA channel 2025-10-19 16:37:09 +02:00
tools ACPICA: acpidump: drop ACPI_NONSTRING attribute from file_name 2025-10-19 16:37:16 +02:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge tag 'kvm-x86-no_assignment-6.17' of https://github.com/kvm-x86/linux into HEAD 2025-07-29 08:36:42 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore gitignore: allow .pylintrc to be tracked 2025-07-02 17:10:04 -06:00
.mailmap 7 hotfixes. 4 are cc:stable and the remainder address post-6.16 issues or 2025-09-28 09:32:00 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: retire Boris from TLS maintainers 2025-08-26 17:36:01 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS i2c-for-6.17-rc8 2025-09-28 13:19:23 -07:00
Makefile Linux 6.17.3 2025-10-15 12:04:23 +02:00
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.