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, 206 insertions, 0 deletions

diff --git a/include/trace/events/rtc.h b/include/trace/events/rtc.h
new file mode 100644
index 000000000..621333f1c
--- /dev/null
+++ b/include/trace/events/rtc.h
@@ -0,0 +1,206 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rtc
+
+#if !defined(_TRACE_RTC_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_RTC_H
+
+#include <linux/rtc.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(rtc_time_alarm_class,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err),
+
+	TP_STRUCT__entry(
+		__field(time64_t, secs)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->secs = secs;
+		__entry->err = err;
+	),
+
+	TP_printk("UTC (%lld) (%d)",
+		  __entry->secs, __entry->err
+	)
+);
+
+DEFINE_EVENT(rtc_time_alarm_class, rtc_set_time,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err)
+);
+
+DEFINE_EVENT(rtc_time_alarm_class, rtc_read_time,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err)
+);
+
+DEFINE_EVENT(rtc_time_alarm_class, rtc_set_alarm,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err)
+);
+
+DEFINE_EVENT(rtc_time_alarm_class, rtc_read_alarm,
+
+	TP_PROTO(time64_t secs, int err),
+
+	TP_ARGS(secs, err)
+);
+
+TRACE_EVENT(rtc_irq_set_freq,
+
+	TP_PROTO(int freq, int err),
+
+	TP_ARGS(freq, err),
+
+	TP_STRUCT__entry(
+		__field(int, freq)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->freq = freq;
+		__entry->err = err;
+	),
+
+	TP_printk("set RTC periodic IRQ frequency:%u (%d)",
+		  __entry->freq, __entry->err
+	)
+);
+
+TRACE_EVENT(rtc_irq_set_state,
+
+	TP_PROTO(int enabled, int err),
+
+	TP_ARGS(enabled, err),
+
+	TP_STRUCT__entry(
+		__field(int, enabled)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->enabled = enabled;
+		__entry->err = err;
+	),
+
+	TP_printk("%s RTC 2^N Hz periodic IRQs (%d)",
+		  __entry->enabled ? "enable" : "disable",
+		  __entry->err
+	)
+);
+
+TRACE_EVENT(rtc_alarm_irq_enable,
+
+	TP_PROTO(unsigned int enabled, int err),
+
+	TP_ARGS(enabled, err),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, enabled)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->enabled = enabled;
+		__entry->err = err;
+	),
+
+	TP_printk("%s RTC alarm IRQ (%d)",
+		  __entry->enabled ? "enable" : "disable",
+		  __entry->err
+	)
+);
+
+DECLARE_EVENT_CLASS(rtc_offset_class,
+
+	TP_PROTO(long offset, int err),
+
+	TP_ARGS(offset, err),
+
+	TP_STRUCT__entry(
+		__field(long, offset)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__entry->offset = offset;
+		__entry->err = err;
+	),
+
+	TP_printk("RTC offset: %ld (%d)",
+		  __entry->offset, __entry->err
+	)
+);
+
+DEFINE_EVENT(rtc_offset_class, rtc_set_offset,
+
+	TP_PROTO(long offset, int err),
+
+	TP_ARGS(offset, err)
+);
+
+DEFINE_EVENT(rtc_offset_class, rtc_read_offset,
+
+	TP_PROTO(long offset, int err),
+
+	TP_ARGS(offset, err)
+);
+
+DECLARE_EVENT_CLASS(rtc_timer_class,
+
+	TP_PROTO(struct rtc_timer *timer),
+
+	TP_ARGS(timer),
+
+	TP_STRUCT__entry(
+		__field(struct rtc_timer *, timer)
+		__field(ktime_t, expires)
+		__field(ktime_t, period)
+	),
+
+	TP_fast_assign(
+		__entry->timer = timer;
+		__entry->expires = timer->node.expires;
+		__entry->period = timer->period;
+	),
+
+	TP_printk("RTC timer:(%p) expires:%lld period:%lld",
+		  __entry->timer, __entry->expires, __entry->period
+	)
+);
+
+DEFINE_EVENT(rtc_timer_class, rtc_timer_enqueue,
+
+	TP_PROTO(struct rtc_timer *timer),
+
+	TP_ARGS(timer)
+);
+
+DEFINE_EVENT(rtc_timer_class, rtc_timer_dequeue,
+
+	TP_PROTO(struct rtc_timer *timer),
+
+	TP_ARGS(timer)
+);
+
+DEFINE_EVENT(rtc_timer_class, rtc_timer_fired,
+
+	TP_PROTO(struct rtc_timer *timer),
+
+	TP_ARGS(timer)
+);
+
+#endif /* _TRACE_RTC_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>