Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 89 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led
new file mode 100644
index 000000000..d4c918cc1
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led
@@ -0,0 +1,89 @@
+What:		/sys/class/leds/<led>/brightness
+Date:		March 2006
+KernelVersion:	2.6.17
+Contact:	Richard Purdie <rpurdie@rpsys.net>
+Description:
+		Set the brightness of the LED.
+
+		Most LEDs don't have hardware brightness support, so will
+		just be turned on for non-zero brightness settings.
+
+		.. Note::
+
+		  For multicolor LEDs, writing to this file will update all
+		  LEDs within the group to a calculated percentage of what
+		  each color LED intensity is set to.
+
+		  The percentage is calculated for each grouped LED via
+		  the equation below::
+
+		    led_brightness = brightness * multi_intensity/max_brightness
+
+		  For additional details please refer to
+		  Documentation/leds/leds-class-multicolor.rst.
+
+		The value is between 0 and /sys/class/leds/<led>/max_brightness
+		and is represented by as a decimal.
+
+		Writing 0 to this file clears active trigger.
+
+		Writing non-zero to this file while trigger is active changes the
+		top brightness trigger is going to use.
+
+
+
+What:		/sys/class/leds/<led>/max_brightness
+Date:		March 2006
+KernelVersion:	2.6.17
+Contact:	Richard Purdie <rpurdie@rpsys.net>
+Description:
+		Maximum brightness level for this LED, default is 255 (LED_FULL).
+
+		If the LED does not support different brightness levels, this
+		should be 1.
+
+What:		/sys/class/leds/<led>/brightness_hw_changed
+Date:		January 2017
+KernelVersion:	4.11
+Description:
+		Last hardware set brightness level for this LED. Some LEDs
+		may be changed autonomously by hardware/firmware. Only LEDs
+		where this happens and the driver can detect this, will have
+		this file.
+
+		This file supports poll() to detect when the hardware changes
+		the brightness.
+
+		Reading this file will return the last brightness level set
+		by the hardware, this may be different from the current
+		brightness. Reading this file when no hw brightness change
+		event has happened will return an ENODATA error.
+
+What:		/sys/class/leds/<led>/trigger
+Date:		March 2006
+KernelVersion:	2.6.17
+Contact:	Richard Purdie <rpurdie@rpsys.net>
+Description:
+		Set the trigger for this LED. A trigger is a kernel based source
+		of LED events.
+
+		You can change triggers in a similar manner to the way an IO
+		scheduler is chosen. Trigger specific parameters can appear in
+		/sys/class/leds/<led> once a given trigger is selected. For
+		their documentation see `sysfs-class-led-trigger-*`.
+
+		Writing "none" removes the trigger for this LED.
+
+		Writing "default" sets the trigger to the LED's default trigger
+		(which would often be configured in the device tree for the
+		hardware).
+
+What:		/sys/class/leds/<led>/inverted
+Date:		January 2011
+KernelVersion:	2.6.38
+Contact:	Richard Purdie <rpurdie@rpsys.net>
+Description:
+		Invert the LED on/off state. This parameter is specific to
+		gpio and backlight triggers. In case of the backlight trigger,
+		it is useful when driving a LED which is intended to indicate
+		a device in a standby like state.