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, 62 insertions, 0 deletions

diff --git a/drivers/accessibility/speakup/thread.c b/drivers/accessibility/speakup/thread.c
new file mode 100644
index 000000000..2fc75e60f
--- /dev/null
+++ b/drivers/accessibility/speakup/thread.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kthread.h>
+#include <linux/wait.h>
+
+#include "spk_types.h"
+#include "speakup.h"
+#include "spk_priv.h"
+
+DECLARE_WAIT_QUEUE_HEAD(speakup_event);
+EXPORT_SYMBOL_GPL(speakup_event);
+
+int speakup_thread(void *data)
+{
+	unsigned long flags;
+	int should_break;
+	struct bleep our_sound;
+
+	our_sound.active = 0;
+	our_sound.freq = 0;
+	our_sound.jiffies = 0;
+
+	mutex_lock(&spk_mutex);
+	while (1) {
+		DEFINE_WAIT(wait);
+
+		while (1) {
+			spin_lock_irqsave(&speakup_info.spinlock, flags);
+			our_sound = spk_unprocessed_sound;
+			spk_unprocessed_sound.active = 0;
+			prepare_to_wait(&speakup_event, &wait,
+					TASK_INTERRUPTIBLE);
+			should_break = kthread_should_stop() ||
+				our_sound.active ||
+				(synth && synth->catch_up && synth->alive &&
+					(speakup_info.flushing ||
+					!synth_buffer_empty()));
+			spin_unlock_irqrestore(&speakup_info.spinlock, flags);
+			if (should_break)
+				break;
+			mutex_unlock(&spk_mutex);
+			schedule();
+			mutex_lock(&spk_mutex);
+		}
+		finish_wait(&speakup_event, &wait);
+		if (kthread_should_stop())
+			break;
+
+		if (our_sound.active)
+			kd_mksound(our_sound.freq, our_sound.jiffies);
+		if (synth && synth->catch_up && synth->alive) {
+			/*
+			 * It is up to the callee to take the lock, so that it
+			 * can sleep whenever it likes
+			 */
+			synth->catch_up(synth);
+		}
+
+		speakup_start_ttys();
+	}
+	mutex_unlock(&spk_mutex);
+	return 0;
+}