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, 85 insertions, 0 deletions

diff --git a/include/crypto/gcm.h b/include/crypto/gcm.h
new file mode 100644
index 000000000..1d5f39ff1
--- /dev/null
+++ b/include/crypto/gcm.h
@@ -0,0 +1,85 @@
+#ifndef _CRYPTO_GCM_H
+#define _CRYPTO_GCM_H
+
+#include <linux/errno.h>
+
+#include <crypto/aes.h>
+#include <crypto/gf128hash.h>
+
+#define GCM_AES_IV_SIZE 12
+#define GCM_RFC4106_IV_SIZE 8
+#define GCM_RFC4543_IV_SIZE 8
+
+/*
+ * validate authentication tag for GCM
+ */
+static inline int crypto_gcm_check_authsize(unsigned int authsize)
+{
+	switch (authsize) {
+	case 4:
+	case 8:
+	case 12:
+	case 13:
+	case 14:
+	case 15:
+	case 16:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * validate authentication tag for RFC4106
+ */
+static inline int crypto_rfc4106_check_authsize(unsigned int authsize)
+{
+	switch (authsize) {
+	case 8:
+	case 12:
+	case 16:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * validate assoclen for RFC4106/RFC4543
+ */
+static inline int crypto_ipsec_check_assoclen(unsigned int assoclen)
+{
+	switch (assoclen) {
+	case 16:
+	case 20:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+struct aesgcm_ctx {
+	struct ghash_key	ghash_key;
+	struct aes_enckey	aes_key;
+	unsigned int		authsize;
+};
+
+int aesgcm_expandkey(struct aesgcm_ctx *ctx, const u8 *key,
+		     unsigned int keysize, unsigned int authsize);
+
+void aesgcm_encrypt(const struct aesgcm_ctx *ctx, u8 *dst, const u8 *src,
+		    int crypt_len, const u8 *assoc, int assoc_len,
+		    const u8 iv[GCM_AES_IV_SIZE], u8 *authtag);
+
+bool __must_check aesgcm_decrypt(const struct aesgcm_ctx *ctx, u8 *dst,
+				 const u8 *src, int crypt_len, const u8 *assoc,
+				 int assoc_len, const u8 iv[GCM_AES_IV_SIZE],
+				 const u8 *authtag);
+
+#endif