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, 201 insertions, 0 deletions

diff --git a/crypto/mldsa.c b/crypto/mldsa.c
new file mode 100644
index 000000000..d8de082cc
--- /dev/null
+++ b/crypto/mldsa.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * crypto_sig wrapper around ML-DSA library.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <crypto/internal/sig.h>
+#include <crypto/mldsa.h>
+
+struct crypto_mldsa_ctx {
+	u8 pk[MAX(MAX(MLDSA44_PUBLIC_KEY_SIZE,
+		      MLDSA65_PUBLIC_KEY_SIZE),
+		  MLDSA87_PUBLIC_KEY_SIZE)];
+	unsigned int pk_len;
+	enum mldsa_alg strength;
+	bool key_set;
+};
+
+static int crypto_mldsa_sign(struct crypto_sig *tfm,
+			     const void *msg, unsigned int msg_len,
+			     void *sig, unsigned int sig_len)
+{
+	return -EOPNOTSUPP;
+}
+
+static int crypto_mldsa_verify(struct crypto_sig *tfm,
+			       const void *sig, unsigned int sig_len,
+			       const void *msg, unsigned int msg_len)
+{
+	const struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+	if (unlikely(!ctx->key_set))
+		return -EINVAL;
+
+	return mldsa_verify(ctx->strength, sig, sig_len, msg, msg_len,
+			    ctx->pk, ctx->pk_len);
+}
+
+static unsigned int crypto_mldsa_key_size(struct crypto_sig *tfm)
+{
+	struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+	switch (ctx->strength) {
+	case MLDSA44:
+		return MLDSA44_PUBLIC_KEY_SIZE;
+	case MLDSA65:
+		return MLDSA65_PUBLIC_KEY_SIZE;
+	case MLDSA87:
+		return MLDSA87_PUBLIC_KEY_SIZE;
+	default:
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+}
+
+static int crypto_mldsa_set_pub_key(struct crypto_sig *tfm,
+				    const void *key, unsigned int keylen)
+{
+	struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+	unsigned int expected_len = crypto_mldsa_key_size(tfm);
+
+	if (keylen != expected_len)
+		return -EINVAL;
+
+	ctx->pk_len = keylen;
+	memcpy(ctx->pk, key, keylen);
+	ctx->key_set = true;
+	return 0;
+}
+
+static int crypto_mldsa_set_priv_key(struct crypto_sig *tfm,
+				     const void *key, unsigned int keylen)
+{
+	return -EOPNOTSUPP;
+}
+
+static unsigned int crypto_mldsa_max_size(struct crypto_sig *tfm)
+{
+	struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+	switch (ctx->strength) {
+	case MLDSA44:
+		return MLDSA44_SIGNATURE_SIZE;
+	case MLDSA65:
+		return MLDSA65_SIGNATURE_SIZE;
+	case MLDSA87:
+		return MLDSA87_SIGNATURE_SIZE;
+	default:
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+}
+
+static int crypto_mldsa44_alg_init(struct crypto_sig *tfm)
+{
+	struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+	ctx->strength = MLDSA44;
+	ctx->key_set = false;
+	return 0;
+}
+
+static int crypto_mldsa65_alg_init(struct crypto_sig *tfm)
+{
+	struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+	ctx->strength = MLDSA65;
+	ctx->key_set = false;
+	return 0;
+}
+
+static int crypto_mldsa87_alg_init(struct crypto_sig *tfm)
+{
+	struct crypto_mldsa_ctx *ctx = crypto_sig_ctx(tfm);
+
+	ctx->strength = MLDSA87;
+	ctx->key_set = false;
+	return 0;
+}
+
+static void crypto_mldsa_alg_exit(struct crypto_sig *tfm)
+{
+}
+
+static struct sig_alg crypto_mldsa_algs[] = {
+	{
+		.sign			= crypto_mldsa_sign,
+		.verify			= crypto_mldsa_verify,
+		.set_pub_key		= crypto_mldsa_set_pub_key,
+		.set_priv_key		= crypto_mldsa_set_priv_key,
+		.key_size		= crypto_mldsa_key_size,
+		.max_size		= crypto_mldsa_max_size,
+		.init			= crypto_mldsa44_alg_init,
+		.exit			= crypto_mldsa_alg_exit,
+		.base.cra_name		= "mldsa44",
+		.base.cra_driver_name	= "mldsa44-lib",
+		.base.cra_ctxsize	= sizeof(struct crypto_mldsa_ctx),
+		.base.cra_module	= THIS_MODULE,
+		.base.cra_priority	= 5000,
+	}, {
+		.sign			= crypto_mldsa_sign,
+		.verify			= crypto_mldsa_verify,
+		.set_pub_key		= crypto_mldsa_set_pub_key,
+		.set_priv_key		= crypto_mldsa_set_priv_key,
+		.key_size		= crypto_mldsa_key_size,
+		.max_size		= crypto_mldsa_max_size,
+		.init			= crypto_mldsa65_alg_init,
+		.exit			= crypto_mldsa_alg_exit,
+		.base.cra_name		= "mldsa65",
+		.base.cra_driver_name	= "mldsa65-lib",
+		.base.cra_ctxsize	= sizeof(struct crypto_mldsa_ctx),
+		.base.cra_module	= THIS_MODULE,
+		.base.cra_priority	= 5000,
+	}, {
+		.sign			= crypto_mldsa_sign,
+		.verify			= crypto_mldsa_verify,
+		.set_pub_key		= crypto_mldsa_set_pub_key,
+		.set_priv_key		= crypto_mldsa_set_priv_key,
+		.key_size		= crypto_mldsa_key_size,
+		.max_size		= crypto_mldsa_max_size,
+		.init			= crypto_mldsa87_alg_init,
+		.exit			= crypto_mldsa_alg_exit,
+		.base.cra_name		= "mldsa87",
+		.base.cra_driver_name	= "mldsa87-lib",
+		.base.cra_ctxsize	= sizeof(struct crypto_mldsa_ctx),
+		.base.cra_module	= THIS_MODULE,
+		.base.cra_priority	= 5000,
+	},
+};
+
+static int __init mldsa_init(void)
+{
+	int ret, i;
+
+	for (i = 0; i < ARRAY_SIZE(crypto_mldsa_algs); i++) {
+		ret = crypto_register_sig(&crypto_mldsa_algs[i]);
+		if (ret < 0)
+			goto error;
+	}
+	return 0;
+
+error:
+	pr_err("Failed to register (%d)\n", ret);
+	for (i--; i >= 0; i--)
+		crypto_unregister_sig(&crypto_mldsa_algs[i]);
+	return ret;
+}
+module_init(mldsa_init);
+
+static void mldsa_exit(void)
+{
+	for (int i = 0; i < ARRAY_SIZE(crypto_mldsa_algs); i++)
+		crypto_unregister_sig(&crypto_mldsa_algs[i]);
+}
+module_exit(mldsa_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Crypto API support for ML-DSA signature verification");
+MODULE_ALIAS_CRYPTO("mldsa44");
+MODULE_ALIAS_CRYPTO("mldsa65");
+MODULE_ALIAS_CRYPTO("mldsa87");