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/include/crypto/internal/sig.h b/include/crypto/internal/sig.h
new file mode 100644
index 000000000..b16648c1a
--- /dev/null
+++ b/include/crypto/internal/sig.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Public Key Signature Algorithm
+ *
+ * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+#ifndef _CRYPTO_INTERNAL_SIG_H
+#define _CRYPTO_INTERNAL_SIG_H
+
+#include <crypto/algapi.h>
+#include <crypto/sig.h>
+
+struct sig_instance {
+	void (*free)(struct sig_instance *inst);
+	union {
+		struct {
+			char head[offsetof(struct sig_alg, base)];
+			struct crypto_instance base;
+		};
+		struct sig_alg alg;
+	};
+};
+
+struct crypto_sig_spawn {
+	struct crypto_spawn base;
+};
+
+static inline void *crypto_sig_ctx(struct crypto_sig *tfm)
+{
+	return crypto_tfm_ctx(&tfm->base);
+}
+
+/**
+ * crypto_register_sig() -- Register public key signature algorithm
+ *
+ * Function registers an implementation of a public key signature algorithm
+ *
+ * @alg:	algorithm definition
+ *
+ * Return: zero on success; error code in case of error
+ */
+int crypto_register_sig(struct sig_alg *alg);
+
+/**
+ * crypto_unregister_sig() -- Unregister public key signature algorithm
+ *
+ * Function unregisters an implementation of a public key signature algorithm
+ *
+ * @alg:	algorithm definition
+ */
+void crypto_unregister_sig(struct sig_alg *alg);
+
+int sig_register_instance(struct crypto_template *tmpl,
+			  struct sig_instance *inst);
+
+static inline struct sig_instance *sig_instance(struct crypto_instance *inst)
+{
+	return container_of(&inst->alg, struct sig_instance, alg.base);
+}
+
+static inline struct sig_instance *sig_alg_instance(struct crypto_sig *tfm)
+{
+	return sig_instance(crypto_tfm_alg_instance(&tfm->base));
+}
+
+static inline struct crypto_instance *sig_crypto_instance(struct sig_instance
+									*inst)
+{
+	return container_of(&inst->alg.base, struct crypto_instance, alg);
+}
+
+static inline void *sig_instance_ctx(struct sig_instance *inst)
+{
+	return crypto_instance_ctx(sig_crypto_instance(inst));
+}
+
+int crypto_grab_sig(struct crypto_sig_spawn *spawn,
+		    struct crypto_instance *inst,
+		    const char *name, u32 type, u32 mask);
+
+static inline struct crypto_sig *crypto_spawn_sig(struct crypto_sig_spawn
+								   *spawn)
+{
+	return crypto_spawn_tfm2(&spawn->base);
+}
+
+static inline void crypto_drop_sig(struct crypto_sig_spawn *spawn)
+{
+	crypto_drop_spawn(&spawn->base);
+}
+
+static inline struct sig_alg *crypto_spawn_sig_alg(struct crypto_sig_spawn
+								    *spawn)
+{
+	return container_of(spawn->base.alg, struct sig_alg, base);
+}
+#endif