linux-stable.git/drivers/powercap, branch linux-5.10.y

powercap: fix sscanf() error return value handling

2026-01-19T12:12:12+00:00

[ Upstream commit efc4c35b741af973de90f6826bf35d3b3ac36bf1 ]

Fix inconsistent error handling for sscanf() return value check.

Implicit boolean conversion is used instead of explicit return
value checks. The code checks if (!sscanf(...)) which is incorrect
because:
 1. sscanf returns the number of successfully parsed items
 2. On success, it returns 1 (one item passed)
 3. On failure, it returns 0 or EOF
 4. The check 'if (!sscanf(...))' is wrong because it treats
    success (1) as failure

All occurrences of sscanf() now uses explicit return value check.
With this behavior it returns '-EINVAL' when parsing fails (returns
0 or EOF), and continues when parsing succeeds (returns 1).

Signed-off-by: Sumeet Pawnikar 
[ rjw: Subject and changelog edits ]
Link: https://patch.msgid.link/20251207151549.202452-1-sumeet4linux@gmail.com
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

powercap: fix race condition in register_control_type()

2026-01-19T12:12:11+00:00

[ Upstream commit 7bda1910c4bccd4b8d4726620bb3d6bbfb62286e ]

The device becomes visible to userspace via device_register()
even before it fully initialized by idr_init(). If userspace
or another thread tries to register a zone immediately after
device_register(), the control_type_valid() will fail because
the control_type is not yet in the list. The IDR is not yet
initialized, so this race condition causes zone registration
failure.

Move idr_init() and list addition before device_register()
fix the race condition.

Signed-off-by: Sumeet Pawnikar 
[ rjw: Subject adjustment, empty line added ]
Link: https://patch.msgid.link/20251205190216.5032-1-sumeet4linux@gmail.com
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

powercap: call put_device() on an error path in powercap_register_control_type()

2025-04-10T12:30:49+00:00

[ Upstream commit 93c66fbc280747ea700bd6199633d661e3c819b3 ]

powercap_register_control_type() calls device_register(), but does not
release the refcount of the device when it fails.

Call put_device() before returning an error to balance the refcount.

Since the kfree(control_type) will be done by powercap_release(), remove
the lines in powercap_register_control_type() before returning the error.

This bug was found by an experimental verifier that I am developing.

Signed-off-by: Joe Hattori 
Link: https://patch.msgid.link/20250110010554.1583411-1-joe@pf.is.s.u-tokyo.ac.jp
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

powercap: RAPL: fix invalid initialization for pl4_supported field

2024-10-17T13:07:58+00:00

commit d05b5e0baf424c8c4b4709ac11f66ab726c8deaf upstream.

The current initialization of the struct x86_cpu_id via
pl4_support_ids[] is partial and wrong. It is initializing
"stepping" field with "X86_FEATURE_ANY" instead of "feature" field.

Use X86_MATCH_INTEL_FAM6_MODEL macro instead of initializing
each field of the struct x86_cpu_id for pl4_supported list of CPUs.
This X86_MATCH_INTEL_FAM6_MODEL macro internally uses another macro
X86_MATCH_VENDOR_FAM_MODEL_FEATURE for X86 based CPU matching with
appropriate initialized values.

Reported-by: Dave Hansen 
Link: https://lore.kernel.org/lkml/28ead36b-2d9e-1a36-6f4e-04684e420260@intel.com
Fixes: eb52bc2ae5b8 ("powercap: RAPL: Add Power Limit4 support for Meteor Lake SoC")
Fixes: b08b95cf30f5 ("powercap: RAPL: Add Power Limit4 support for Alder Lake-N and Raptor Lake-P")
Fixes: 515755906921 ("powercap: RAPL: Add Power Limit4 support for RaptorLake")
Fixes: 1cc5b9a411e4 ("powercap: Add Power Limit4 support for Alder Lake SoC")
Fixes: 8365a898fe53 ("powercap: Add Power Limit4 support")
Signed-off-by: Sumeet Pawnikar 
Signed-off-by: Rafael J. Wysocki 
[ Ricardo: I only kept TIGERLAKE in pl4_support_ids as only this model is
  enumerated before this changeset. ]
Signed-off-by: Ricardo Neri 
Signed-off-by: Greg Kroah-Hartman

powercap: RAPL: Fix CONFIG_IOSF_MBI dependency

2023-07-27T06:43:34+00:00

[ Upstream commit 4658fe81b3f8afe8adf37734ec5fe595d90415c6 ]

After commit 3382388d7148 ("intel_rapl: abstract RAPL common code"),
accessing to IOSF_MBI interface is done in the RAPL common code.

Thus it is the CONFIG_INTEL_RAPL_CORE that has dependency of
CONFIG_IOSF_MBI, while CONFIG_INTEL_RAPL_MSR does not.

This problem was not exposed previously because all the previous RAPL
common code users, aka, the RAPL MSR and MMIO I/F drivers, have
CONFIG_IOSF_MBI selected.

Fix the CONFIG_IOSF_MBI dependency in RAPL code. This also fixes a build
time failure when the RAPL TPMI I/F driver is introduced without
selecting CONFIG_IOSF_MBI.

x86_64-linux-ld: vmlinux.o: in function `set_floor_freq_atom':
intel_rapl_common.c:(.text+0x2dac9b8): undefined reference to `iosf_mbi_write'
x86_64-linux-ld: intel_rapl_common.c:(.text+0x2daca66): undefined reference to `iosf_mbi_read'

Reference to iosf_mbi.h is also removed from the RAPL MSR I/F driver.

Fixes: 3382388d7148 ("intel_rapl: abstract RAPL common code")
Reported-by: Arnd Bergmann 
Link: https://lore.kernel.org/all/20230601213246.3271412-1-arnd@kernel.org
Signed-off-by: Zhang Rui 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

powercap: fix possible name leak in powercap_register_zone()

2023-03-11T15:39:23+00:00

[ Upstream commit 1b6599f741a4525ca761ecde46e5885ff1e6ba58 ]

In the error path after calling dev_set_name(), the device
name is leaked. To fix this, calling dev_set_name() before
device_register(), and call put_device() if it returns error.

All the resources is released in powercap_release(), so it
can return from powercap_register_zone() directly.

Fixes: 75d2364ea0ca ("PowerCap: Add class driver")
Signed-off-by: Yang Yingliang 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

powercap: intel_rapl: fix UBSAN shift-out-of-bounds issue

2022-10-26T11:25:44+00:00

[ Upstream commit 2d93540014387d1c73b9ccc4d7895320df66d01b ]

When value < time_unit, the parameter of ilog2() will be zero and
the return value is -1. u64(-1) is too large for shift exponent
and then will trigger shift-out-of-bounds:

shift exponent 18446744073709551615 is too large for 32-bit type 'int'
Call Trace:
 rapl_compute_time_window_core
 rapl_write_data_raw
 set_time_window
 store_constraint_time_window_us

Signed-off-by: Chao Qin 
Acked-by: Zhang Rui 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin

powercap: intel_rapl: Use standard Energy Unit for SPR Dram RAPL domain

2022-10-26T11:25:11+00:00

commit 4c081324df5608b73428662ca54d5221ea03a6bd upstream.

Intel Xeon servers used to use a fixed energy resolution (15.3uj) for
Dram RAPL domain. But on SPR, Dram RAPL domain follows the standard
energy resolution as described in MSR_RAPL_POWER_UNIT.

Remove the SPR dram_domain_energy_unit quirk.

Fixes: 2d798d9f5967 ("powercap: intel_rapl: add support for Sapphire Rapids")
Signed-off-by: Zhang Rui 
Tested-by: Wang Wendy 
Cc: 5.9+  # 5.9+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux

2020-11-10T18:02:31+00:00

Pull turbostat updates from Len Brown:
 "Update update to version 20.09.30, one kernel side fix"

* 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  tools/power turbostat: update version number
  powercap: restrict energy meter to root access
  tools/power turbostat: harden against cpu hotplug
  tools/power turbostat: adjust for temperature offset
  tools/power turbostat: Build with _FILE_OFFSET_BITS=64
  tools/power turbostat: Support AMD Family 19h
  tools/power turbostat: Remove empty columns for Jacobsville
  tools/power turbostat: Add a new GFXAMHz column that exposes gt_act_freq_mhz.
  tools/power x86_energy_perf_policy: Input/output error in a VM
  tools/power turbostat: Skip pc8, pc9, pc10 columns, if they are disabled
  tools/power turbostat: Support additional CPU model numbers
  tools/power turbostat: Fix output formatting for ACPI CST enumeration
  tools/power turbostat: Replace HTTP links with HTTPS ones: TURBOSTAT UTILITY
  tools/power turbostat: Use sched_getcpu() instead of hardcoded cpu 0
  tools/power turbostat: Enable accumulate RAPL display
  tools/power turbostat: Introduce functions to accumulate RAPL consumption
  tools/power turbostat: Make the energy variable to be 64 bit
  tools/power turbostat: Always print idle in the system configuration header
  tools/power turbostat: Print /dev/cpu_dma_latency

powercap: restrict energy meter to root access

2020-11-10T16:40:57+00:00

Remove non-privileged user access to power data contained in
/sys/class/powercap/intel-rapl*/*/energy_uj

Non-privileged users currently have read access to power data and can
use this data to form a security attack. Some privileged
drivers/applications need read access to this data, but don't expose it
to non-privileged users.

For example, thermald uses this data to ensure that power management
works correctly. Thus removing non-privileged access is preferred over
completely disabling this power reporting capability with
CONFIG_INTEL_RAPL=n.

Fixes: 95677a9a3847 ("PowerCap: Fix mode for energy counter")

Signed-off-by: Len Brown 
Cc: stable@vger.kernel.org