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, 139 insertions, 0 deletions

diff --git a/tools/perf/util/jitdump.h b/tools/perf/util/jitdump.h
new file mode 100644
index 000000000..f57bfebb2
--- /dev/null
+++ b/tools/perf/util/jitdump.h
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * jitdump.h: jitted code info encapsulation file format
+ *
+ * Adapted from OProfile GPLv2 support jidump.h:
+ * Copyright 2007 OProfile authors
+ * Jens Wilke
+ * Daniel Hansel
+ * Copyright IBM Corporation 2007
+ */
+#ifndef JITDUMP_H
+#define JITDUMP_H
+
+#include <stdint.h>
+#include <string.h>
+
+/* JiTD */
+#define JITHEADER_MAGIC		0x4A695444
+#define JITHEADER_MAGIC_SW	0x4454694A
+
+#define PADDING_8ALIGNED(x) ((((x) + 7) & 7) ^ 7)
+#define ALIGN_8(x) (((x) + 7) & (~7))
+
+#define JITHEADER_VERSION 1
+
+enum jitdump_flags_bits {
+	JITDUMP_FLAGS_ARCH_TIMESTAMP_BIT,
+	JITDUMP_FLAGS_MAX_BIT,
+};
+
+#define JITDUMP_FLAGS_ARCH_TIMESTAMP	(1ULL << JITDUMP_FLAGS_ARCH_TIMESTAMP_BIT)
+
+#define JITDUMP_FLAGS_RESERVED (JITDUMP_FLAGS_MAX_BIT < 64 ? \
+				(~((1ULL << JITDUMP_FLAGS_MAX_BIT) - 1)) : 0)
+
+struct jitheader {
+	uint32_t magic;		/* characters "jItD" */
+	uint32_t version;	/* header version */
+	uint32_t total_size;	/* total size of header */
+	uint32_t elf_mach;	/* elf mach target */
+	uint32_t pad1;		/* reserved */
+	uint32_t pid;		/* JIT process id */
+	uint64_t timestamp;	/* timestamp */
+	uint64_t flags;		/* flags */
+};
+
+enum jit_record_type {
+	JIT_CODE_LOAD		= 0,
+        JIT_CODE_MOVE           = 1,
+	JIT_CODE_DEBUG_INFO	= 2,
+	JIT_CODE_CLOSE		= 3,
+	JIT_CODE_UNWINDING_INFO	= 4,
+
+	JIT_CODE_MAX,
+};
+
+/* record prefix (mandatory in each record) */
+struct jr_prefix {
+	uint32_t id;
+	uint32_t total_size;
+	uint64_t timestamp;
+};
+
+struct jr_code_load {
+	struct jr_prefix p;
+
+	uint32_t pid;
+	uint32_t tid;
+	uint64_t vma;
+	uint64_t code_addr;
+	uint64_t code_size;
+	uint64_t code_index;
+};
+
+struct jr_code_close {
+	struct jr_prefix p;
+};
+
+struct jr_code_move {
+	struct jr_prefix p;
+
+	uint32_t pid;
+	uint32_t tid;
+	uint64_t vma;
+	uint64_t old_code_addr;
+	uint64_t new_code_addr;
+	uint64_t code_size;
+	uint64_t code_index;
+};
+
+struct debug_entry {
+	uint64_t addr;
+	int lineno;	    /* source line number starting at 1 */
+	int discrim;	    /* column discriminator, 0 is default */
+	const char name[]; /* null terminated filename, \xff\0 if same as previous entry */
+};
+
+struct jr_code_debug_info {
+	struct jr_prefix p;
+
+	uint64_t code_addr;
+	uint64_t nr_entry;
+	struct debug_entry entries[];
+};
+
+struct jr_code_unwinding_info {
+	struct jr_prefix p;
+
+	uint64_t unwinding_size;
+	uint64_t eh_frame_hdr_size;
+	uint64_t mapped_size;
+	const char unwinding_data[];
+};
+
+union jr_entry {
+        struct jr_code_debug_info info;
+        struct jr_code_close close;
+        struct jr_code_load load;
+        struct jr_code_move move;
+        struct jr_prefix prefix;
+        struct jr_code_unwinding_info unwinding;
+};
+
+static inline struct debug_entry *
+debug_entry_next(struct debug_entry *ent)
+{
+	void *a = ent + 1;
+	size_t l = strlen(ent->name) + 1;
+	return a + l;
+}
+
+static inline char *
+debug_entry_file(struct debug_entry *ent)
+{
+	void *a = ent + 1;
+	return a;
+}
+
+#endif /* !JITDUMP_H */