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, 117 insertions, 0 deletions

diff --git a/net/ethtool/debug.c b/net/ethtool/debug.c
new file mode 100644
index 000000000..6043916b4
--- /dev/null
+++ b/net/ethtool/debug.c
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "bitset.h"
+#include "common.h"
+#include "netlink.h"
+
+struct debug_req_info {
+	struct ethnl_req_info		base;
+};
+
+struct debug_reply_data {
+	struct ethnl_reply_data		base;
+	u32				msg_mask;
+};
+
+#define DEBUG_REPDATA(__reply_base) \
+	container_of(__reply_base, struct debug_reply_data, base)
+
+const struct nla_policy ethnl_debug_get_policy[] = {
+	[ETHTOOL_A_DEBUG_HEADER]	=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+static int debug_prepare_data(const struct ethnl_req_info *req_base,
+			      struct ethnl_reply_data *reply_base,
+			      const struct genl_info *info)
+{
+	struct debug_reply_data *data = DEBUG_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	int ret;
+
+	if (!dev->ethtool_ops->get_msglevel)
+		return -EOPNOTSUPP;
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+	data->msg_mask = dev->ethtool_ops->get_msglevel(dev);
+	ethnl_ops_complete(dev);
+
+	return 0;
+}
+
+static int debug_reply_size(const struct ethnl_req_info *req_base,
+			    const struct ethnl_reply_data *reply_base)
+{
+	const struct debug_reply_data *data = DEBUG_REPDATA(reply_base);
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+
+	return ethnl_bitset32_size(&data->msg_mask, NULL, NETIF_MSG_CLASS_COUNT,
+				   netif_msg_class_names, compact);
+}
+
+static int debug_fill_reply(struct sk_buff *skb,
+			    const struct ethnl_req_info *req_base,
+			    const struct ethnl_reply_data *reply_base)
+{
+	const struct debug_reply_data *data = DEBUG_REPDATA(reply_base);
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+
+	return ethnl_put_bitset32(skb, ETHTOOL_A_DEBUG_MSGMASK, &data->msg_mask,
+				  NULL, NETIF_MSG_CLASS_COUNT,
+				  netif_msg_class_names, compact);
+}
+
+/* DEBUG_SET */
+
+const struct nla_policy ethnl_debug_set_policy[] = {
+	[ETHTOOL_A_DEBUG_HEADER]	=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_DEBUG_MSGMASK]	= { .type = NLA_NESTED },
+};
+
+static int
+ethnl_set_debug_validate(struct ethnl_req_info *req_info,
+			 struct genl_info *info)
+{
+	const struct ethtool_ops *ops = req_info->dev->ethtool_ops;
+
+	return ops->get_msglevel && ops->set_msglevel ? 1 : -EOPNOTSUPP;
+}
+
+static int
+ethnl_set_debug(struct ethnl_req_info *req_info, struct genl_info *info)
+{
+	struct net_device *dev = req_info->dev;
+	struct nlattr **tb = info->attrs;
+	bool mod = false;
+	u32 msg_mask;
+	int ret;
+
+	msg_mask = dev->ethtool_ops->get_msglevel(dev);
+	ret = ethnl_update_bitset32(&msg_mask, NETIF_MSG_CLASS_COUNT,
+				    tb[ETHTOOL_A_DEBUG_MSGMASK],
+				    netif_msg_class_names, info->extack, &mod);
+	if (ret < 0 || !mod)
+		return ret;
+
+	dev->ethtool_ops->set_msglevel(dev, msg_mask);
+	return 1;
+}
+
+const struct ethnl_request_ops ethnl_debug_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_DEBUG_GET,
+	.reply_cmd		= ETHTOOL_MSG_DEBUG_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_DEBUG_HEADER,
+	.req_info_size		= sizeof(struct debug_req_info),
+	.reply_data_size	= sizeof(struct debug_reply_data),
+
+	.prepare_data		= debug_prepare_data,
+	.reply_size		= debug_reply_size,
+	.fill_reply		= debug_fill_reply,
+
+	.set_validate		= ethnl_set_debug_validate,
+	.set			= ethnl_set_debug,
+	.set_ntf_cmd		= ETHTOOL_MSG_DEBUG_NTF,
+};