linux-stable.git/drivers/acpi/processor_idle.c, branch linux-5.4.y

ACPI: processor: idle: Fix memory leak when register cpuidle device failed

2025-10-29T12:59:46+00:00

[ Upstream commit 11b3de1c03fa9f3b5d17e6d48050bc98b3704420 ]

The cpuidle device's memory is leaked when cpuidle device registration
fails in acpi_processor_power_init().  Free it as appropriate.

Fixes: 3d339dcbb56d ("cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure")
Signed-off-by: Huisong Li 
Link: https://patch.msgid.link/20250728070612.1260859-2-lihuisong@huawei.com
[ rjw: Changed the order of the new statements, added empty line after if () ]
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

ACPI: processor: idle: Check acpi_fetch_acpi_dev() return value

2025-08-28T14:21:33+00:00

commit 2437513a814b3e93bd02879740a8a06e52e2cf7d upstream.

The return value of acpi_fetch_acpi_dev() could be NULL, which would
cause a NULL pointer dereference to occur in acpi_device_hid().

Signed-off-by: Li Zhong 
[ rjw: Subject and changelog edits, added empty line after if () ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Teddy Astie 
Signed-off-by: Yann Sionneau 
Reported-by: Dillon C 
Tested-by: Dillon C 
Signed-off-by: Greg Kroah-Hartman

ACPI: processor_idle: Fix invalid comparison with insertion sort for latency

2024-07-27T08:38:32+00:00

commit 233323f9b9f828cd7cd5145ad811c1990b692542 upstream.

The acpi_cst_latency_cmp() comparison function currently used for
sorting C-state latencies does not satisfy transitivity, causing
incorrect sorting results.

Specifically, if there are two valid acpi_processor_cx elements A and B
and one invalid element C, it may occur that A < B, A = C, and B = C.
Sorting algorithms assume that if A < B and A = C, then C < B, leading
to incorrect ordering.

Given the small size of the array (<=8), we replace the library sort
function with a simple insertion sort that properly ignores invalid
elements and sorts valid ones based on latency. This change ensures
correct ordering of the C-state latencies.

Fixes: 65ea8f2c6e23 ("ACPI: processor idle: Fix up C-state latency if not ordered")
Reported-by: Julian Sikorski 
Closes: https://lore.kernel.org/lkml/70674dc7-5586-4183-8953-8095567e73df@gmail.com
Signed-off-by: Kuan-Wei Chiu 
Tested-by: Julian Sikorski 
Cc: All applicable 
Link: https://patch.msgid.link/20240701205639.117194-1-visitorckw@gmail.com
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Kuan-Wei Chiu 
Signed-off-by: Greg Kroah-Hartman

ACPI: processor_idle: Fix memory leak in acpi_processor_power_exit()

2024-03-26T22:22:15+00:00

[ Upstream commit e18afcb7b2a12b635ac10081f943fcf84ddacc51 ]

After unregistering the CPU idle device, the memory associated with
it is not freed, leading to a memory leak:

unreferenced object 0xffff896282f6c000 (size 1024):
  comm "swapper/0", pid 1, jiffies 4294893170
  hex dump (first 32 bytes):
    00 00 00 00 0b 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 8836a742):
    [] kmalloc_trace+0x29d/0x340
    [] acpi_processor_power_init+0xf3/0x1c0
    [] __acpi_processor_start+0xd3/0xf0
    [] acpi_processor_start+0x2c/0x50
    [] really_probe+0xe2/0x480
    [] __driver_probe_device+0x78/0x160
    [] driver_probe_device+0x1f/0x90
    [] __driver_attach+0xce/0x1c0
    [] bus_for_each_dev+0x70/0xc0
    [] bus_add_driver+0x112/0x210
    [] driver_register+0x55/0x100
    [] acpi_processor_driver_init+0x3b/0xc0
    [] do_one_initcall+0x41/0x300
    [] kernel_init_freeable+0x320/0x470
    [] kernel_init+0x16/0x1b0
    [] ret_from_fork+0x2d/0x50

Fix this by freeing the CPU idle device after unregistering it.

Fixes: 3d339dcbb56d ("cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure")
Signed-off-by: Armin Wolf 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

ACPI: processor idle: Check for architectural support for LPI

2022-04-15T12:18:41+00:00

commit eb087f305919ee8169ad65665610313e74260463 upstream.

When `osc_pc_lpi_support_confirmed` is set through `_OSC` and `_LPI` is
populated then the cpuidle driver assumes that LPI is fully functional.

However currently the kernel only provides architectural support for LPI
on ARM.  This leads to high power consumption on X86 platforms that
otherwise try to enable LPI.

So probe whether or not LPI support is implemented before enabling LPI in
the kernel.  This is done by overloading `acpi_processor_ffh_lpi_probe` to
check whether it returns `-EOPNOTSUPP`. It also means that all future
implementations of `acpi_processor_ffh_lpi_probe` will need to follow
these semantics as well.

Reviewed-by: Sudeep Holla 
Signed-off-by: Mario Limonciello 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ACPI: processor idle: Fix up C-state latency if not ordered

2021-07-14T14:53:16+00:00

[ Upstream commit 65ea8f2c6e230bdf71fed0137cf9e9d1b307db32 ]

Generally, the C-state latency is provided by the _CST method or
FADT, but some OEM platforms using AMD Picasso, Renoir, Van Gogh,
and Cezanne set the C2 latency greater than C3's which causes the
C2 state to be skipped.

That will block the core entering PC6, which prevents S0ix working
properly on Linux systems.

In other operating systems, the latency values are not validated and
this does not cause problems by skipping states.

To avoid this issue on Linux, detect when latencies are not an
arithmetic progression and sort them.

Link: https://gitlab.freedesktop.org/agd5f/linux/-/commit/026d186e4592c1ee9c1cb44295912d0294508725
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1230#note_712174
Suggested-by: Prike Liang 
Suggested-by: Alex Deucher 
Signed-off-by: Mario Limonciello 
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

ACPI, x86: Add Zhaoxin processors support for NONSTOP TSC

2019-06-22T09:45:57+00:00

Zhaoxin CPUs have NONSTOP TSC feature, so enable the ACPI
driver support for it.

Signed-off-by: Tony W Wang-oc 
Signed-off-by: Thomas Gleixner 
Cc: "hpa@zytor.com" 
Cc: "gregkh@linuxfoundation.org" 
Cc: "rjw@rjwysocki.net" 
Cc: "lenb@kernel.org" 
Cc: David Wang 
Cc: "Cooper Yan(BJ-RD)" 
Cc: "Qiyuan Wang(BJ-RD)" 
Cc: "Herry Yang(BJ-RD)" 
Link: https://lkml.kernel.org/r/d1cfd937dabc44518d42038b55522c53@zhaoxin.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

2019-05-30T18:26:37+00:00

Based on 3 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Reviewed-by: Kate Stewart 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman

ACPI / processor: Set P_LVL{2,3} idle state descriptions

2019-02-18T10:29:13+00:00

The ACPI idle driver will fallback to using the legacy P_LVL* SystemIO
method of entering C-states if the _CST method is disabled and P_BLK is
defined. However, in this case the C2 and C3 states won't have a
description set, so the user will see "" when reading the
description from sysfs.

Give each of these states a description.

Signed-off-by: Yazen Ghannam 
Signed-off-by: Rafael J. Wysocki

ACPI: Add Hygon Dhyana support

2018-09-27T16:29:00+00:00

The Hygon Dhyana CPU has NONSTOP TSC feature, so enable the ACPI driver
support to it.

Signed-off-by: Pu Wen 
Signed-off-by: Borislav Petkov 
Acked-by: Rafael J. Wysocki 
Cc: rjw@rjwysocki.net
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: thomas.lendacky@amd.com
Cc: lenb@kernel.org
Cc: rafael@kernel.org
Cc: linux-acpi@vger.kernel.org
Link: https://lkml.kernel.org/r/cce6ee26f4e2ebbab493433264d89d7cea661284.1537533369.git.puwen@hygon.cn