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, 107 insertions, 0 deletions

diff --git a/include/net/sctp/auth.h b/include/net/sctp/auth.h
new file mode 100644
index 000000000..6f2cd562b
--- /dev/null
+++ b/include/net/sctp/auth.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* SCTP kernel implementation
+ * (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ *
+ * This file is part of the SCTP kernel implementation
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ *    lksctp developers <linux-sctp@vger.kernel.org>
+ *
+ * Written or modified by:
+ *   Vlad Yasevich     <vladislav.yasevich@hp.com>
+ */
+
+#ifndef __sctp_auth_h__
+#define __sctp_auth_h__
+
+#include <linux/list.h>
+#include <linux/refcount.h>
+
+struct sctp_endpoint;
+struct sctp_association;
+struct sctp_authkey;
+struct sctp_hmacalgo;
+
+/* Defines an HMAC algorithm supported by SCTP chunk authentication */
+struct sctp_hmac {
+	__u16 hmac_id;		/* one of SCTP_AUTH_HMAC_ID_* */
+	__u16 hmac_len;		/* length of the HMAC value in bytes */
+};
+
+/* This is generic structure that containst authentication bytes used
+ * as keying material.  It's a what is referred to as byte-vector all
+ * over SCTP-AUTH
+ */
+struct sctp_auth_bytes {
+	refcount_t refcnt;
+	__u32 len;
+	__u8  data[];
+};
+
+/* Definition for a shared key, weather endpoint or association */
+struct sctp_shared_key {
+	struct list_head key_list;
+	struct sctp_auth_bytes *key;
+	refcount_t refcnt;
+	__u16 key_id;
+	__u8 deactivated;
+};
+
+#define key_for_each(__key, __list_head) \
+	list_for_each_entry(__key, __list_head, key_list)
+
+#define key_for_each_safe(__key, __tmp, __list_head) \
+	list_for_each_entry_safe(__key, __tmp, __list_head, key_list)
+
+static inline void sctp_auth_key_hold(struct sctp_auth_bytes *key)
+{
+	if (!key)
+		return;
+
+	refcount_inc(&key->refcnt);
+}
+
+void sctp_auth_key_put(struct sctp_auth_bytes *key);
+struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp);
+void sctp_auth_destroy_keys(struct list_head *keys);
+int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp);
+struct sctp_shared_key *sctp_auth_get_shkey(
+				const struct sctp_association *asoc,
+				__u16 key_id);
+int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
+				struct sctp_association *asoc,
+				gfp_t gfp);
+const struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id);
+const struct sctp_hmac *
+sctp_auth_asoc_get_hmac(const struct sctp_association *asoc);
+void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
+				     struct sctp_hmac_algo_param *hmacs);
+int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
+				    __be16 hmac_id);
+int sctp_auth_send_cid(enum sctp_cid chunk,
+		       const struct sctp_association *asoc);
+int sctp_auth_recv_cid(enum sctp_cid chunk,
+		       const struct sctp_association *asoc);
+void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
+			      struct sk_buff *skb, struct sctp_auth_chunk *auth,
+			      struct sctp_shared_key *ep_key, gfp_t gfp);
+void sctp_auth_shkey_release(struct sctp_shared_key *sh_key);
+void sctp_auth_shkey_hold(struct sctp_shared_key *sh_key);
+
+/* API Helpers */
+int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id);
+int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
+			    struct sctp_hmacalgo *hmacs);
+int sctp_auth_set_key(struct sctp_endpoint *ep, struct sctp_association *asoc,
+		      struct sctp_authkey *auth_key);
+int sctp_auth_set_active_key(struct sctp_endpoint *ep,
+			     struct sctp_association *asoc, __u16 key_id);
+int sctp_auth_del_key_id(struct sctp_endpoint *ep,
+			 struct sctp_association *asoc, __u16 key_id);
+int sctp_auth_deact_key_id(struct sctp_endpoint *ep,
+			   struct sctp_association *asoc, __u16 key_id);
+int sctp_auth_init(struct sctp_endpoint *ep, gfp_t gfp);
+void sctp_auth_free(struct sctp_endpoint *ep);
+
+#endif