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, 97 insertions, 0 deletions

diff --git a/drivers/net/netdevsim/tc.c b/drivers/net/netdevsim/tc.c
new file mode 100644
index 000000000..a415e02a6
--- /dev/null
+++ b/drivers/net/netdevsim/tc.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/netdevice.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+
+#include "netdevsim.h"
+
+static int
+nsim_setup_tc_block_cb(enum tc_setup_type type, void *type_data, void *cb_priv)
+{
+	struct flow_cls_common_offload *common = type_data;
+	int err = 0;
+
+	switch (type) {
+	case TC_SETUP_CLSBPF:
+		err = nsim_bpf_setup_tc_block_cb(type, type_data, cb_priv);
+		break;
+	case TC_SETUP_CLSFLOWER:
+		break;
+	default:
+		NSIM_EA(common->extack, "offload type not supported");
+		err = -EOPNOTSUPP;
+		break;
+	}
+
+	return err;
+}
+
+static void nsim_taprio_stats(struct tc_taprio_qopt_stats *stats)
+{
+	stats->window_drops = 0;
+	stats->tx_overruns = 0;
+}
+
+static int nsim_setup_tc_taprio(struct net_device *dev,
+				struct tc_taprio_qopt_offload *offload)
+{
+	int err = 0;
+
+	switch (offload->cmd) {
+	case TAPRIO_CMD_REPLACE:
+	case TAPRIO_CMD_DESTROY:
+		break;
+	case TAPRIO_CMD_STATS:
+		nsim_taprio_stats(&offload->stats);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+	}
+
+	return err;
+}
+
+static int nsim_setup_tc_ets(struct net_device *dev,
+			     struct tc_ets_qopt_offload *offload)
+{
+	int err = 0;
+
+	switch (offload->command) {
+	case TC_ETS_REPLACE:
+	case TC_ETS_DESTROY:
+		break;
+	case TC_ETS_STATS:
+		_bstats_update(offload->stats.bstats, 0, 0);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+	}
+
+	return err;
+}
+
+static LIST_HEAD(nsim_block_cb_list);
+
+int
+nsim_setup_tc(struct net_device *dev, enum tc_setup_type type, void *type_data)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	switch (type) {
+	case TC_SETUP_QDISC_TAPRIO:
+		return nsim_setup_tc_taprio(dev, type_data);
+	case TC_SETUP_QDISC_ETS:
+		return nsim_setup_tc_ets(dev, type_data);
+	case TC_SETUP_BLOCK:
+		return flow_block_cb_setup_simple(type_data,
+						  &nsim_block_cb_list,
+						  nsim_setup_tc_block_cb,
+						  ns, ns, true);
+	case TC_SETUP_FT:
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+ALLOW_ERROR_INJECTION(nsim_setup_tc, ERRNO);