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, 62 insertions, 0 deletions

diff --git a/include/crypto/mldsa.h b/include/crypto/mldsa.h
new file mode 100644
index 000000000..3ef267678
--- /dev/null
+++ b/include/crypto/mldsa.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Support for verifying ML-DSA signatures
+ *
+ * Copyright 2025 Google LLC
+ */
+#ifndef _CRYPTO_MLDSA_H
+#define _CRYPTO_MLDSA_H
+
+#include <linux/types.h>
+
+/* Identifier for an ML-DSA parameter set */
+enum mldsa_alg {
+	MLDSA44, /* ML-DSA-44 */
+	MLDSA65, /* ML-DSA-65 */
+	MLDSA87, /* ML-DSA-87 */
+};
+
+/* Lengths of ML-DSA public keys and signatures in bytes */
+#define MLDSA44_PUBLIC_KEY_SIZE 1312
+#define MLDSA65_PUBLIC_KEY_SIZE 1952
+#define MLDSA87_PUBLIC_KEY_SIZE 2592
+#define MLDSA44_SIGNATURE_SIZE 2420
+#define MLDSA65_SIGNATURE_SIZE 3309
+#define MLDSA87_SIGNATURE_SIZE 4627
+
+/**
+ * mldsa_verify() - Verify an ML-DSA signature
+ * @alg: The ML-DSA parameter set to use
+ * @sig: The signature
+ * @sig_len: Length of the signature in bytes.  Should match the
+ *	     MLDSA*_SIGNATURE_SIZE constant associated with @alg,
+ *	     otherwise -EBADMSG will be returned.
+ * @msg: The message
+ * @msg_len: Length of the message in bytes
+ * @pk: The public key
+ * @pk_len: Length of the public key in bytes.  Should match the
+ *	    MLDSA*_PUBLIC_KEY_SIZE constant associated with @alg,
+ *	    otherwise -EBADMSG will be returned.
+ *
+ * This verifies a signature using pure ML-DSA with the specified parameter set.
+ * The context string is assumed to be empty.  This corresponds to FIPS 204
+ * Algorithm 3 "ML-DSA.Verify" with the ctx parameter set to the empty string
+ * and the lengths of the signature and key given explicitly by the caller.
+ *
+ * Context: Might sleep
+ *
+ * Return:
+ * * 0 if the signature is valid
+ * * -EBADMSG if the signature and/or public key is malformed
+ * * -EKEYREJECTED if the signature is invalid but otherwise well-formed
+ * * -ENOMEM if out of memory so the validity of the signature is unknown
+ */
+int mldsa_verify(enum mldsa_alg alg, const u8 *sig, size_t sig_len,
+		 const u8 *msg, size_t msg_len, const u8 *pk, size_t pk_len);
+
+#if IS_ENABLED(CONFIG_CRYPTO_LIB_MLDSA_KUNIT_TEST)
+/* Internal function, exposed only for unit testing */
+s32 mldsa_use_hint(u8 h, s32 r, s32 gamma2);
+#endif
+
+#endif /* _CRYPTO_MLDSA_H */