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, 66 insertions, 0 deletions

diff --git a/include/trace/events/siox.h b/include/trace/events/siox.h
new file mode 100644
index 000000000..68a43fc2c
--- /dev/null
+++ b/include/trace/events/siox.h
@@ -0,0 +1,66 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM siox
+
+#if !defined(_TRACE_SIOX_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SIOX_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(siox_set_data,
+	    TP_PROTO(const struct siox_master *smaster,
+		     const struct siox_device *sdevice,
+		     unsigned int devno, size_t bufoffset),
+	    TP_ARGS(smaster, sdevice, devno, bufoffset),
+	    TP_STRUCT__entry(
+			     __field(int, busno)
+			     __field(unsigned int, devno)
+			     __field(size_t, inbytes)
+			     __dynamic_array(u8, buf, sdevice->inbytes)
+			    ),
+	    TP_fast_assign(
+			   __entry->busno = smaster->busno;
+			   __entry->devno = devno;
+			   __entry->inbytes = sdevice->inbytes;
+			   memcpy(__get_dynamic_array(buf),
+				  smaster->buf + bufoffset, sdevice->inbytes);
+			  ),
+	    TP_printk("siox-%d-%u [%*phD]",
+		      __entry->busno,
+		      __entry->devno,
+		      (int)__entry->inbytes, __get_dynamic_array(buf)
+		     )
+);
+
+TRACE_EVENT(siox_get_data,
+	    TP_PROTO(const struct siox_master *smaster,
+		     const struct siox_device *sdevice,
+		     unsigned int devno, u8 status_clean,
+		     size_t bufoffset),
+	    TP_ARGS(smaster, sdevice, devno, status_clean, bufoffset),
+	    TP_STRUCT__entry(
+			     __field(int, busno)
+			     __field(unsigned int, devno)
+			     __field(u8, status_clean)
+			     __field(size_t, outbytes)
+			     __dynamic_array(u8, buf, sdevice->outbytes)
+			    ),
+	    TP_fast_assign(
+			   __entry->busno = smaster->busno;
+			   __entry->devno = devno;
+			   __entry->status_clean = status_clean;
+			   __entry->outbytes = sdevice->outbytes;
+			   memcpy(__get_dynamic_array(buf),
+				  smaster->buf + bufoffset, sdevice->outbytes);
+			  ),
+	    TP_printk("siox-%d-%u (%02hhx) [%*phD]",
+		      __entry->busno,
+		      __entry->devno,
+		      __entry->status_clean,
+		      (int)__entry->outbytes, __get_dynamic_array(buf)
+		     )
+);
+
+#endif /* if !defined(_TRACE_SIOX_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>