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, 147 insertions, 0 deletions

diff --git a/net/rxrpc/sysctl.c b/net/rxrpc/sysctl.c
new file mode 100644
index 000000000..46a20cf4c
--- /dev/null
+++ b/net/rxrpc/sysctl.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* sysctls for configuring RxRPC operating parameters
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/sysctl.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static struct ctl_table_header *rxrpc_sysctl_reg_table;
+static const unsigned int rxrpc_rx_mtu_min = 500;
+static const unsigned int rxrpc_jumbo_max = RXRPC_MAX_NR_JUMBO;
+static const unsigned int four = 4;
+static const unsigned int max_backlog = RXRPC_BACKLOG_MAX - 1;
+static const unsigned int n_65535 = 65535;
+static const unsigned int n_max_acks = 255;
+static const unsigned long one_ms = 1;
+static const unsigned long max_ms = 1000;
+static const unsigned long one_jiffy = 1;
+static const unsigned long max_jiffies = MAX_JIFFY_OFFSET;
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+static const unsigned long max_500 = 500;
+#endif
+
+/*
+ * RxRPC operating parameters.
+ *
+ * See Documentation/networking/rxrpc.rst and the variable definitions for more
+ * information on the individual parameters.
+ */
+static struct ctl_table rxrpc_sysctl_table[] = {
+	/* Values measured in milliseconds */
+	{
+		.procname	= "soft_ack_delay",
+		.data		= &rxrpc_soft_ack_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= (void *)&one_ms,
+		.extra2		= (void *)&max_ms,
+	},
+	{
+		.procname	= "idle_ack_delay",
+		.data		= &rxrpc_idle_ack_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= (void *)&one_ms,
+		.extra2		= (void *)&max_ms,
+	},
+	{
+		.procname	= "idle_conn_expiry",
+		.data		= &rxrpc_conn_idle_client_expiry,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+	{
+		.procname	= "idle_conn_fast_expiry",
+		.data		= &rxrpc_conn_idle_client_fast_expiry,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+
+	/* Values used in milliseconds */
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+	{
+		.procname	= "inject_rx_delay",
+		.data		= &rxrpc_inject_rx_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= (void *)SYSCTL_LONG_ZERO,
+		.extra2		= (void *)&max_500,
+	},
+#endif
+
+	/* Non-time values */
+	{
+		.procname	= "reap_client_conns",
+		.data		= &rxrpc_reap_client_connections,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&n_65535,
+	},
+	{
+		.procname	= "max_backlog",
+		.data		= &rxrpc_max_backlog,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)&four,
+		.extra2		= (void *)&max_backlog,
+	},
+	{
+		.procname	= "rx_window_size",
+		.data		= &rxrpc_rx_window_size,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&n_max_acks,
+	},
+	{
+		.procname	= "rx_mtu",
+		.data		= &rxrpc_rx_mtu,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)&rxrpc_rx_mtu_min,
+		.extra2		= (void *)&n_65535,
+	},
+	{
+		.procname	= "rx_jumbo_max",
+		.data		= &rxrpc_rx_jumbo_max,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&rxrpc_jumbo_max,
+	},
+};
+
+int __init rxrpc_sysctl_init(void)
+{
+	rxrpc_sysctl_reg_table = register_net_sysctl(&init_net, "net/rxrpc",
+						     rxrpc_sysctl_table);
+	if (!rxrpc_sysctl_reg_table)
+		return -ENOMEM;
+	return 0;
+}
+
+void rxrpc_sysctl_exit(void)
+{
+	if (rxrpc_sysctl_reg_table)
+		unregister_net_sysctl_table(rxrpc_sysctl_reg_table);
+}