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, 77 insertions, 0 deletions

diff --git a/tools/lib/thermal/sampling.c b/tools/lib/thermal/sampling.c
new file mode 100644
index 000000000..f67c1f9ea
--- /dev/null
+++ b/tools/lib/thermal/sampling.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: LGPL-2.1+
+// Copyright (C) 2022, Linaro Ltd - Daniel Lezcano <daniel.lezcano@linaro.org>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <thermal.h>
+#include "thermal_nl.h"
+
+static int handle_thermal_sample(struct nl_msg *n, void *arg)
+{
+	struct nlmsghdr *nlh = nlmsg_hdr(n);
+	struct genlmsghdr *genlhdr = genlmsg_hdr(nlh);
+	struct nlattr *attrs[THERMAL_GENL_ATTR_MAX + 1];
+	struct thermal_handler_param *thp = arg;
+	struct thermal_handler *th = thp->th;
+
+	arg = thp->arg;
+
+	genlmsg_parse(nlh, 0, attrs, THERMAL_GENL_ATTR_MAX, NULL);
+
+	switch (genlhdr->cmd) {
+
+	case THERMAL_GENL_SAMPLING_TEMP:
+		return th->ops->sampling.tz_temp(
+			nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_ID]),
+			nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_TEMP]), arg);
+	default:
+		return THERMAL_ERROR;
+	}
+}
+
+thermal_error_t thermal_sampling_handle(struct thermal_handler *th, void *arg)
+{
+	struct thermal_handler_param thp = { .th = th, .arg = arg };
+
+	if (!th)
+		return THERMAL_ERROR;
+
+	if (nl_cb_set(th->cb_sampling, NL_CB_VALID, NL_CB_CUSTOM,
+		      handle_thermal_sample, &thp))
+		return THERMAL_ERROR;
+
+	return nl_recvmsgs(th->sk_sampling, th->cb_sampling);
+}
+
+int thermal_sampling_fd(struct thermal_handler *th)
+{
+	if (!th)
+		return -1;
+
+	return nl_socket_get_fd(th->sk_sampling);
+}
+
+thermal_error_t thermal_sampling_exit(struct thermal_handler *th)
+{
+	if (nl_unsubscribe_thermal(th->sk_sampling, th->cb_sampling,
+				   THERMAL_GENL_SAMPLING_GROUP_NAME))
+		return THERMAL_ERROR;
+
+	nl_thermal_disconnect(th->sk_sampling, th->cb_sampling);
+
+	return THERMAL_SUCCESS;
+}
+
+thermal_error_t thermal_sampling_init(struct thermal_handler *th)
+{
+	if (nl_thermal_connect(&th->sk_sampling, &th->cb_sampling))
+		return THERMAL_ERROR;
+
+	if (nl_subscribe_thermal(th->sk_sampling, th->cb_sampling,
+				 THERMAL_GENL_SAMPLING_GROUP_NAME))
+		return THERMAL_ERROR;
+
+	return THERMAL_SUCCESS;
+}