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, 47 insertions, 0 deletions

diff --git a/samples/Makefile b/samples/Makefile
new file mode 100644
index 000000000..07641e177
--- /dev/null
+++ b/samples/Makefile
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for Linux samples code
+
+subdir-$(CONFIG_SAMPLE_AUXDISPLAY)	+= auxdisplay
+subdir-$(CONFIG_SAMPLE_ANDROID_BINDERFS) += binderfs
+subdir-$(CONFIG_SAMPLE_CHECK_EXEC)	+= check-exec
+subdir-$(CONFIG_SAMPLE_CGROUP) += cgroup
+obj-$(CONFIG_SAMPLE_CONFIGFS)		+= configfs/
+obj-$(CONFIG_SAMPLE_CONNECTOR)		+= connector/
+obj-$(CONFIG_SAMPLE_FANOTIFY_ERROR)	+= fanotify/
+subdir-$(CONFIG_SAMPLE_HIDRAW)		+= hidraw
+obj-$(CONFIG_SAMPLE_HW_BREAKPOINT)	+= hw_breakpoint/
+obj-$(CONFIG_SAMPLE_KDB)		+= kdb/
+obj-$(CONFIG_SAMPLE_KFIFO)		+= kfifo/
+obj-$(CONFIG_SAMPLE_KOBJECT)		+= kobject/
+obj-$(CONFIG_SAMPLE_KPROBES)		+= kprobes/
+subdir-$(CONFIG_SAMPLE_LANDLOCK)	+= landlock
+obj-$(CONFIG_SAMPLE_LIVEPATCH)		+= livepatch/
+subdir-$(CONFIG_SAMPLE_PIDFD)		+= pidfd
+obj-$(CONFIG_SAMPLE_QMI_CLIENT)		+= qmi/
+obj-$(CONFIG_SAMPLE_RPMSG_CLIENT)	+= rpmsg/
+subdir-$(CONFIG_SAMPLE_SECCOMP)		+= seccomp
+subdir-$(CONFIG_SAMPLE_TIMER)		+= timers
+obj-$(CONFIG_SAMPLE_TRACE_EVENTS)	+= trace_events/
+obj-$(CONFIG_SAMPLE_TRACE_CUSTOM_EVENTS) += trace_events/
+obj-$(CONFIG_SAMPLE_TRACE_PRINTK)	+= trace_printk/
+obj-$(CONFIG_SAMPLE_FTRACE_DIRECT)	+= ftrace/
+obj-$(CONFIG_SAMPLE_FTRACE_DIRECT_MULTI) += ftrace/
+obj-$(CONFIG_SAMPLE_FTRACE_OPS)		+= ftrace/
+obj-$(CONFIG_SAMPLE_TRACE_ARRAY)	+= ftrace/
+subdir-$(CONFIG_SAMPLE_UHID)		+= uhid
+obj-$(CONFIG_VIDEO_PCI_SKELETON)	+= v4l/
+obj-y					+= vfio-mdev/
+subdir-$(CONFIG_SAMPLE_VFS)		+= vfs
+obj-$(CONFIG_SAMPLE_INTEL_MEI)		+= mei/
+obj-$(CONFIG_SAMPLE_TPS6594_PFSM)	+= pfsm/
+subdir-$(CONFIG_SAMPLE_WATCHDOG)	+= watchdog
+subdir-$(CONFIG_SAMPLE_WATCH_QUEUE)	+= watch_queue
+obj-$(CONFIG_SAMPLE_KMEMLEAK)		+= kmemleak/
+obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG)	+= coresight/
+obj-$(CONFIG_SAMPLE_FPROBE)		+= fprobe/
+obj-$(CONFIG_SAMPLES_RUST)		+= rust/
+obj-$(CONFIG_SAMPLE_DAMON_WSSE)		+= damon/
+obj-$(CONFIG_SAMPLE_DAMON_PRCL)		+= damon/
+obj-$(CONFIG_SAMPLE_DAMON_MTIER)	+= damon/
+obj-$(CONFIG_SAMPLE_HUNG_TASK)		+= hung_task/
+obj-$(CONFIG_SAMPLE_TSM_MR)		+= tsm-mr/