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, 209 insertions, 0 deletions

diff --git a/include/crypto/sha1.h b/include/crypto/sha1.h
new file mode 100644
index 000000000..4d973e016
--- /dev/null
+++ b/include/crypto/sha1.h
@@ -0,0 +1,209 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common values for SHA-1 algorithms
+ */
+
+#ifndef _CRYPTO_SHA1_H
+#define _CRYPTO_SHA1_H
+
+#include <linux/types.h>
+
+#define SHA1_DIGEST_SIZE        20
+#define SHA1_BLOCK_SIZE         64
+#define SHA1_STATE_SIZE         offsetof(struct sha1_state, buffer)
+
+#define SHA1_H0		0x67452301UL
+#define SHA1_H1		0xefcdab89UL
+#define SHA1_H2		0x98badcfeUL
+#define SHA1_H3		0x10325476UL
+#define SHA1_H4		0xc3d2e1f0UL
+
+extern const u8 sha1_zero_message_hash[SHA1_DIGEST_SIZE];
+
+struct sha1_state {
+	u32 state[SHA1_DIGEST_SIZE / 4];
+	u64 count;
+	u8 buffer[SHA1_BLOCK_SIZE];
+};
+
+/* State for the SHA-1 compression function */
+struct sha1_block_state {
+	u32 h[SHA1_DIGEST_SIZE / 4];
+};
+
+/**
+ * struct sha1_ctx - Context for hashing a message with SHA-1
+ * @state: the compression function state
+ * @bytecount: number of bytes processed so far
+ * @buf: partial block buffer; bytecount % SHA1_BLOCK_SIZE bytes are valid
+ */
+struct sha1_ctx {
+	struct sha1_block_state state;
+	u64 bytecount;
+	u8 buf[SHA1_BLOCK_SIZE];
+};
+
+/**
+ * sha1_init() - Initialize a SHA-1 context for a new message
+ * @ctx: the context to initialize
+ *
+ * If you don't need incremental computation, consider sha1() instead.
+ *
+ * Context: Any context.
+ */
+void sha1_init(struct sha1_ctx *ctx);
+
+/**
+ * sha1_update() - Update a SHA-1 context with message data
+ * @ctx: the context to update; must have been initialized
+ * @data: the message data
+ * @len: the data length in bytes
+ *
+ * This can be called any number of times.
+ *
+ * Context: Any context.
+ */
+void sha1_update(struct sha1_ctx *ctx, const u8 *data, size_t len);
+
+/**
+ * sha1_final() - Finish computing a SHA-1 message digest
+ * @ctx: the context to finalize; must have been initialized
+ * @out: (output) the resulting SHA-1 message digest
+ *
+ * After finishing, this zeroizes @ctx.  So the caller does not need to do it.
+ *
+ * Context: Any context.
+ */
+void sha1_final(struct sha1_ctx *ctx, u8 out[at_least SHA1_DIGEST_SIZE]);
+
+/**
+ * sha1() - Compute SHA-1 message digest in one shot
+ * @data: the message data
+ * @len: the data length in bytes
+ * @out: (output) the resulting SHA-1 message digest
+ *
+ * Context: Any context.
+ */
+void sha1(const u8 *data, size_t len, u8 out[at_least SHA1_DIGEST_SIZE]);
+
+/**
+ * struct hmac_sha1_key - Prepared key for HMAC-SHA1
+ * @istate: private
+ * @ostate: private
+ */
+struct hmac_sha1_key {
+	struct sha1_block_state istate;
+	struct sha1_block_state ostate;
+};
+
+/**
+ * struct hmac_sha1_ctx - Context for computing HMAC-SHA1 of a message
+ * @sha_ctx: private
+ * @ostate: private
+ */
+struct hmac_sha1_ctx {
+	struct sha1_ctx sha_ctx;
+	struct sha1_block_state ostate;
+};
+
+/**
+ * hmac_sha1_preparekey() - Prepare a key for HMAC-SHA1
+ * @key: (output) the key structure to initialize
+ * @raw_key: the raw HMAC-SHA1 key
+ * @raw_key_len: the key length in bytes.  All key lengths are supported.
+ *
+ * Note: the caller is responsible for zeroizing both the struct hmac_sha1_key
+ * and the raw key once they are no longer needed.
+ *
+ * Context: Any context.
+ */
+void hmac_sha1_preparekey(struct hmac_sha1_key *key,
+			  const u8 *raw_key, size_t raw_key_len);
+
+/**
+ * hmac_sha1_init() - Initialize an HMAC-SHA1 context for a new message
+ * @ctx: (output) the HMAC context to initialize
+ * @key: the prepared HMAC key
+ *
+ * If you don't need incremental computation, consider hmac_sha1() instead.
+ *
+ * Context: Any context.
+ */
+void hmac_sha1_init(struct hmac_sha1_ctx *ctx, const struct hmac_sha1_key *key);
+
+/**
+ * hmac_sha1_init_usingrawkey() - Initialize an HMAC-SHA1 context for a new
+ *				  message, using a raw key
+ * @ctx: (output) the HMAC context to initialize
+ * @raw_key: the raw HMAC-SHA1 key
+ * @raw_key_len: the key length in bytes.  All key lengths are supported.
+ *
+ * If you don't need incremental computation, consider hmac_sha1_usingrawkey()
+ * instead.
+ *
+ * Context: Any context.
+ */
+void hmac_sha1_init_usingrawkey(struct hmac_sha1_ctx *ctx,
+				const u8 *raw_key, size_t raw_key_len);
+
+/**
+ * hmac_sha1_update() - Update an HMAC-SHA1 context with message data
+ * @ctx: the HMAC context to update; must have been initialized
+ * @data: the message data
+ * @data_len: the data length in bytes
+ *
+ * This can be called any number of times.
+ *
+ * Context: Any context.
+ */
+static inline void hmac_sha1_update(struct hmac_sha1_ctx *ctx,
+				    const u8 *data, size_t data_len)
+{
+	sha1_update(&ctx->sha_ctx, data, data_len);
+}
+
+/**
+ * hmac_sha1_final() - Finish computing an HMAC-SHA1 value
+ * @ctx: the HMAC context to finalize; must have been initialized
+ * @out: (output) the resulting HMAC-SHA1 value
+ *
+ * After finishing, this zeroizes @ctx.  So the caller does not need to do it.
+ *
+ * Context: Any context.
+ */
+void hmac_sha1_final(struct hmac_sha1_ctx *ctx,
+		     u8 out[at_least SHA1_DIGEST_SIZE]);
+
+/**
+ * hmac_sha1() - Compute HMAC-SHA1 in one shot, using a prepared key
+ * @key: the prepared HMAC key
+ * @data: the message data
+ * @data_len: the data length in bytes
+ * @out: (output) the resulting HMAC-SHA1 value
+ *
+ * If you're using the key only once, consider using hmac_sha1_usingrawkey().
+ *
+ * Context: Any context.
+ */
+void hmac_sha1(const struct hmac_sha1_key *key,
+	       const u8 *data, size_t data_len,
+	       u8 out[at_least SHA1_DIGEST_SIZE]);
+
+/**
+ * hmac_sha1_usingrawkey() - Compute HMAC-SHA1 in one shot, using a raw key
+ * @raw_key: the raw HMAC-SHA1 key
+ * @raw_key_len: the key length in bytes.  All key lengths are supported.
+ * @data: the message data
+ * @data_len: the data length in bytes
+ * @out: (output) the resulting HMAC-SHA1 value
+ *
+ * If you're using the key multiple times, prefer to use hmac_sha1_preparekey()
+ * followed by multiple calls to hmac_sha1() instead.
+ *
+ * Context: Any context.
+ */
+void hmac_sha1_usingrawkey(const u8 *raw_key, size_t raw_key_len,
+			   const u8 *data, size_t data_len,
+			   u8 out[at_least SHA1_DIGEST_SIZE]);
+
+#endif /* _CRYPTO_SHA1_H */