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, 82 insertions, 0 deletions

diff --git a/tools/perf/util/libbfd.h b/tools/perf/util/libbfd.h
new file mode 100644
index 000000000..953886f3d
--- /dev/null
+++ b/tools/perf/util/libbfd.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_LIBBFD_H
+#define __PERF_LIBBFD_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+struct annotate_args;
+struct build_id;
+struct dso;
+struct inline_node;
+struct symbol;
+
+#ifdef HAVE_LIBBFD_SUPPORT
+int libbfd__addr2line(const char *dso_name, u64 addr,
+		char **file, unsigned int *line, struct dso *dso,
+		bool unwind_inlines, struct inline_node *node,
+		struct symbol *sym);
+
+
+void dso__free_a2l_libbfd(struct dso *dso);
+
+int symbol__disassemble_libbfd(const char *filename, struct symbol *sym,
+			     struct annotate_args *args);
+
+int libbfd__read_build_id(const char *filename, struct build_id *bid);
+
+int libbfd_filename__read_debuglink(const char *filename, char *debuglink, size_t size);
+
+int symbol__disassemble_bpf_libbfd(struct symbol *sym, struct annotate_args *args);
+
+#else // !defined(HAVE_LIBBFD_SUPPORT)
+#include "annotate.h"
+
+static inline int libbfd__addr2line(const char *dso_name __always_unused,
+				u64 addr __always_unused,
+				char **file __always_unused,
+				unsigned int *line __always_unused,
+				struct dso *dso __always_unused,
+				bool unwind_inlines __always_unused,
+				struct inline_node *node __always_unused,
+				struct symbol *sym __always_unused)
+{
+	return -1;
+}
+
+
+static inline void dso__free_a2l_libbfd(struct dso *dso __always_unused)
+{
+}
+
+static inline int symbol__disassemble_libbfd(const char *filename __always_unused,
+					struct symbol *sym __always_unused,
+					struct annotate_args *args __always_unused)
+{
+	return -1;
+}
+
+static inline int libbfd__read_build_id(const char *filename __always_unused,
+					struct build_id *bid __always_unused)
+{
+	return -1;
+}
+
+static inline int libbfd_filename__read_debuglink(const char *filename __always_unused,
+						char *debuglink __always_unused,
+						size_t size __always_unused)
+{
+	return -1;
+}
+
+static inline int symbol__disassemble_bpf_libbfd(struct symbol *sym __always_unused,
+						 struct annotate_args *args __always_unused)
+{
+	return SYMBOL_ANNOTATE_ERRNO__NO_LIBOPCODES_FOR_BPF;
+}
+
+#endif // defined(HAVE_LIBBFD_SUPPORT)
+
+#endif /* __PERF_LIBBFD_H */