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, 58 insertions, 0 deletions

diff --git a/io_uring/opdef.h b/io_uring/opdef.h
new file mode 100644
index 000000000..667f981e6
--- /dev/null
+++ b/io_uring/opdef.h
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef IOU_OP_DEF_H
+#define IOU_OP_DEF_H
+
+struct io_uring_bpf_ctx;
+
+struct io_issue_def {
+	/* needs req->file assigned */
+	unsigned		needs_file : 1;
+	/* should block plug */
+	unsigned		plug : 1;
+	/* supports ioprio */
+	unsigned		ioprio : 1;
+	/* supports iopoll */
+	unsigned		iopoll : 1;
+	/* op supports buffer selection */
+	unsigned		buffer_select : 1;
+	/* hash wq insertion if file is a regular file */
+	unsigned		hash_reg_file : 1;
+	/* unbound wq insertion if file is a non-regular file */
+	unsigned		unbound_nonreg_file : 1;
+	/* set if opcode supports polled "wait" */
+	unsigned		pollin : 1;
+	unsigned		pollout : 1;
+	unsigned		poll_exclusive : 1;
+	/* skip auditing */
+	unsigned		audit_skip : 1;
+	/* vectored opcode, set if 1) vectored, and 2) handler needs to know */
+	unsigned		vectored : 1;
+	/* set to 1 if this opcode uses 128b sqes in a mixed sq */
+	unsigned		is_128 : 1;
+
+	/* size of async data needed, if any */
+	unsigned short		async_size;
+
+	/* bpf filter pdu size, if any */
+	unsigned short		filter_pdu_size;
+
+	int (*issue)(struct io_kiocb *, unsigned int);
+	int (*prep)(struct io_kiocb *, const struct io_uring_sqe *);
+	void (*filter_populate)(struct io_uring_bpf_ctx *, struct io_kiocb *);
+};
+
+struct io_cold_def {
+	const char		*name;
+
+	void (*sqe_copy)(struct io_kiocb *);
+	void (*cleanup)(struct io_kiocb *);
+	void (*fail)(struct io_kiocb *);
+};
+
+extern const struct io_issue_def io_issue_defs[];
+extern const struct io_cold_def io_cold_defs[];
+
+bool io_uring_op_supported(u8 opcode);
+
+void io_uring_optable_init(void);
+#endif