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, 76 insertions, 0 deletions

diff --git a/scripts/dtc/fstree.c b/scripts/dtc/fstree.c
new file mode 100644
index 000000000..0f9a534ba
--- /dev/null
+++ b/scripts/dtc/fstree.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation.  2005.
+ */
+
+#include "dtc.h"
+
+#include <dirent.h>
+#include <sys/stat.h>
+
+static struct node *read_fstree(const char *dirname)
+{
+	DIR *d;
+	struct dirent *de;
+	struct stat st;
+	struct node *tree;
+
+	d = opendir(dirname);
+	if (!d)
+		die("Couldn't opendir() \"%s\": %s\n", dirname, strerror(errno));
+
+	tree = build_node(NULL, NULL, NULL);
+
+	while ((de = readdir(d)) != NULL) {
+		char *tmpname;
+
+		if (streq(de->d_name, ".")
+		    || streq(de->d_name, ".."))
+			continue;
+
+		tmpname = join_path(dirname, de->d_name);
+
+		if (stat(tmpname, &st) < 0)
+			die("stat(%s): %s\n", tmpname, strerror(errno));
+
+		if (S_ISREG(st.st_mode)) {
+			struct property *prop;
+			FILE *pfile;
+
+			pfile = fopen(tmpname, "rb");
+			if (! pfile) {
+				fprintf(stderr,
+					"WARNING: Cannot open %s: %s\n",
+					tmpname, strerror(errno));
+			} else {
+				prop = build_property(de->d_name,
+						      data_copy_file(pfile,
+								     st.st_size),
+						      NULL);
+				add_property(tree, prop);
+				fclose(pfile);
+			}
+		} else if (S_ISDIR(st.st_mode)) {
+			struct node *newchild;
+
+			newchild = read_fstree(tmpname);
+			newchild = name_node(newchild, xstrdup(de->d_name));
+			add_child(tree, newchild);
+		}
+
+		free(tmpname);
+	}
+
+	closedir(d);
+	return tree;
+}
+
+struct dt_info *dt_from_fs(const char *dirname)
+{
+	struct node *tree;
+
+	tree = read_fstree(dirname);
+	tree = name_node(tree, "");
+
+	return build_dt_info(DTSF_V1, NULL, tree, guess_boot_cpuid(tree));
+}