x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 164 insertions, 0 deletions

diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
new file mode 100644
index 000000000..c11282a74
--- /dev/null
+++ b/drivers/leds/trigger/Kconfig
@@ -0,0 +1,164 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig LEDS_TRIGGERS
+	bool "LED Trigger support"
+	depends on LEDS_CLASS
+	help
+	  This option enables trigger support for the leds class.
+	  These triggers allow kernel events to drive the LEDs and can
+	  be configured via sysfs. If unsure, say Y.
+
+if LEDS_TRIGGERS
+
+config LEDS_TRIGGER_TIMER
+	tristate "LED Timer Trigger"
+	help
+	  This allows LEDs to be controlled by a programmable timer
+	  via sysfs. Some LED hardware can be programmed to start
+	  blinking the LED without any further software interaction.
+	  For more details read Documentation/leds/leds-class.rst.
+
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_ONESHOT
+	tristate "LED One-shot Trigger"
+	help
+	  This allows LEDs to blink in one-shot pulses with parameters
+	  controlled via sysfs.  It's useful to notify the user on
+	  sporadic events, when there are no clear begin and end trap points,
+	  or on dense events, where this blinks the LED at constant rate if
+	  rearmed continuously.
+
+	  It also shows how to use the led_blink_set_oneshot() function.
+
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_DISK
+	bool "LED Disk Trigger"
+	depends on ATA
+	help
+	  This allows LEDs to be controlled by disk activity.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_MTD
+	bool "LED MTD (NAND/NOR) Trigger"
+	depends on MTD
+	help
+	  This allows LEDs to be controlled by MTD activity.
+	  If unsure, say N.
+
+config LEDS_TRIGGER_HEARTBEAT
+	tristate "LED Heartbeat Trigger"
+	help
+	  This allows LEDs to be controlled by a CPU load average.
+	  The flash frequency is a hyperbolic function of the 1-minute
+	  load average.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_BACKLIGHT
+	tristate "LED backlight Trigger"
+	help
+	  This allows LEDs to be controlled as a backlight device: they
+	  turn off and on when the display is blanked and unblanked.
+
+	  If unsure, say N.
+
+config LEDS_TRIGGER_CPU
+	bool "LED CPU Trigger"
+	depends on !PREEMPT_RT
+	help
+	  This allows LEDs to be controlled by active CPUs. This shows
+	  the active CPUs across an array of LEDs so you can see which
+	  CPUs are active on the system at any given moment.
+
+	  If unsure, say N.
+
+config LEDS_TRIGGER_ACTIVITY
+	tristate "LED activity Trigger"
+	help
+	  This allows LEDs to be controlled by an immediate CPU usage.
+	  The flash frequency and duty cycle varies from faint flashes to
+	  intense brightness depending on the instant CPU load.
+	  If unsure, say N.
+
+config LEDS_TRIGGER_GPIO
+	tristate "LED GPIO Trigger"
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	  This allows LEDs to be controlled by gpio events. It's good
+	  when using gpios as switches and triggering the needed LEDs
+	  from there. Triggers are defined as device properties.
+
+	  If unsure, say N.
+
+config LEDS_TRIGGER_DEFAULT_ON
+	tristate "LED Default ON Trigger"
+	help
+	  This allows LEDs to be initialised in the ON state.
+	  If unsure, say Y.
+
+comment "iptables trigger is under Netfilter config (LED target)"
+	depends on LEDS_TRIGGERS
+
+config LEDS_TRIGGER_TRANSIENT
+	tristate "LED Transient Trigger"
+	help
+	  This allows one time activation of a transient state on
+	  GPIO/PWM based hardware.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_CAMERA
+	tristate "LED Camera Flash/Torch Trigger"
+	help
+	  This allows LEDs to be controlled as a camera flash/torch device.
+	  This enables direct flash/torch on/off by the driver, kernel space.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_PANIC
+	bool "LED Panic Trigger"
+	help
+	  This allows LEDs to be configured to blink on a kernel panic.
+	  Enabling this option will allow to mark certain LEDs as panic indicators,
+	  allowing to blink them on a kernel panic, even if they are set to
+	  a different trigger.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_NETDEV
+	tristate "LED Netdev Trigger"
+	depends on NET
+	help
+	  This allows LEDs to be controlled by network device activity.
+	  If unsure, say Y.
+
+config LEDS_TRIGGER_PATTERN
+	tristate "LED Pattern Trigger"
+	help
+	  This allows LEDs to be controlled by a software or hardware pattern
+	  which is a series of tuples, of brightness and duration (ms).
+	  If unsure, say N
+
+config LEDS_TRIGGER_TTY
+	tristate "LED Trigger for TTY devices"
+	depends on TTY
+	help
+	  This allows LEDs to be controlled by activity on ttys which includes
+	  serial devices like /dev/ttyS0.
+
+	  When build as a module this driver will be called ledtrig-tty.
+
+config LEDS_TRIGGER_INPUT_EVENTS
+	tristate "LED Input events trigger"
+	depends on INPUT
+	help
+	  Turn LEDs on when there is input (/dev/input/event*) activity and turn
+	  them back off again after there has been no activity for 5 seconds.
+
+	  This is primarily intended to control LEDs which are a backlight for
+	  capacitive touch-buttons, such as e.g. the menu / home / back buttons
+	  found on the bottom bezel of many older smartphones and tablets.
+
+	  This can also be used to turn on the keyboard backlight LED on
+	  input events and turn the keyboard backlight off again when idle.
+
+	  When build as a module this driver will be called ledtrig-input-events.
+
+endif # LEDS_TRIGGERS