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, 44 insertions, 0 deletions

diff --git a/drivers/base/init.c b/drivers/base/init.c
new file mode 100644
index 000000000..af8014416
--- /dev/null
+++ b/drivers/base/init.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2002-3 Patrick Mochel
+ * Copyright (c) 2002-3 Open Source Development Labs
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/memory.h>
+#include <linux/of.h>
+#include <linux/backing-dev.h>
+
+#include "base.h"
+
+/**
+ * driver_init - initialize driver model.
+ *
+ * Call the driver model init functions to initialize their
+ * subsystems. Called early from init/main.c.
+ */
+void __init driver_init(void)
+{
+	/* These are the core pieces */
+	bdi_init(&noop_backing_dev_info);
+	devtmpfs_init();
+	devices_init();
+	buses_init();
+	classes_init();
+	firmware_init();
+	hypervisor_init();
+
+	/* These are also core pieces, but must come after the
+	 * core core pieces.
+	 */
+	faux_bus_init();
+	of_core_init();
+	software_node_init();
+	platform_bus_init();
+	auxiliary_bus_init();
+	memory_dev_init();
+	node_dev_init();
+	cpu_dev_init();
+	container_dev_init();
+}