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/checkversion.pl b/scripts/checkversion.pl
new file mode 100755
index 000000000..94cd49eff
--- /dev/null
+++ b/scripts/checkversion.pl
@@ -0,0 +1,76 @@
+#! /usr/bin/env perl
+# SPDX-License-Identifier: GPL-2.0
+#
+# checkversion finds uses of all macros in <linux/version.h>
+# where the source files do not #include <linux/version.h>; or cases
+# of including <linux/version.h> where it is not needed.
+# Copyright (C) 2003, Randy Dunlap <rdunlap@infradead.org>
+
+use strict;
+
+$| = 1;
+
+my $debugging;
+
+foreach my $file (@ARGV) {
+    next if $file =~ "include/generated/uapi/linux/version\.h";
+    next if $file =~ "usr/include/linux/version\.h";
+    # Open this file.
+    open( my $f, '<', $file )
+      or die "Can't open $file: $!\n";
+
+    # Initialize variables.
+    my ($fInComment, $fInString, $fUseVersion);
+    my $iLinuxVersion = 0;
+
+    while (<$f>) {
+	# Strip comments.
+	$fInComment && (s+^.*?\*/+ +o ? ($fInComment = 0) : next);
+	m+/\*+o && (s+/\*.*?\*/+ +go, (s+/\*.*$+ +o && ($fInComment = 1)));
+
+	# Pick up definitions.
+	if ( m/^\s*#/o ) {
+	    $iLinuxVersion      = $. if m/^\s*#\s*include\s*"linux\/version\.h"/o;
+	}
+
+	# Strip strings.
+	$fInString && (s+^.*?"+ +o ? ($fInString = 0) : next);
+	m+"+o && (s+".*?"+ +go, (s+".*$+ +o && ($fInString = 1)));
+
+	# Pick up definitions.
+	if ( m/^\s*#/o ) {
+	    $iLinuxVersion      = $. if m/^\s*#\s*include\s*<linux\/version\.h>/o;
+	}
+
+	# Look for uses: LINUX_VERSION_CODE, KERNEL_VERSION,
+	# LINUX_VERSION_MAJOR, LINUX_VERSION_PATCHLEVEL, LINUX_VERSION_SUBLEVEL
+	if (($_ =~ /LINUX_VERSION_CODE/) || ($_ =~ /\WKERNEL_VERSION/) ||
+	    ($_ =~ /LINUX_VERSION_MAJOR/) || ($_ =~ /LINUX_VERSION_PATCHLEVEL/) ||
+	    ($_ =~ /LINUX_VERSION_SUBLEVEL/)) {
+	    $fUseVersion = 1;
+            last if $iLinuxVersion;
+        }
+    }
+
+    # Report used version IDs without include?
+    if ($fUseVersion && ! $iLinuxVersion) {
+	print "$file: $.: need linux/version.h\n";
+    }
+
+    # Report superfluous includes.
+    if ($iLinuxVersion && ! $fUseVersion) {
+	print "$file: $iLinuxVersion linux/version.h not needed.\n";
+    }
+
+    # debug: report OK results:
+    if ($debugging) {
+        if ($iLinuxVersion && $fUseVersion) {
+	    print "$file: version use is OK ($iLinuxVersion)\n";
+        }
+        if (! $iLinuxVersion && ! $fUseVersion) {
+	    print "$file: version use is OK (none)\n";
+        }
+    }
+
+    close($f);
+}