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.

3 files changed, 47 insertions, 0 deletions

diff --git a/tools/include/uapi/asm/bitsperlong.h b/tools/include/uapi/asm/bitsperlong.h
new file mode 100644
index 000000000..c65267afc
--- /dev/null
+++ b/tools/include/uapi/asm/bitsperlong.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if defined(__i386__) || defined(__x86_64__)
+#include "../../../arch/x86/include/uapi/asm/bitsperlong.h"
+#elif defined(__powerpc__)
+#include "../../../arch/powerpc/include/uapi/asm/bitsperlong.h"
+#elif defined(__s390__)
+#include "../../../arch/s390/include/uapi/asm/bitsperlong.h"
+#elif defined(__sparc__)
+#include "../../../arch/sparc/include/uapi/asm/bitsperlong.h"
+#elif defined(__mips__)
+#include "../../../arch/mips/include/uapi/asm/bitsperlong.h"
+#elif defined(__ia64__)
+#include "../../../arch/ia64/include/uapi/asm/bitsperlong.h"
+#elif defined(__alpha__)
+#include "../../../arch/alpha/include/uapi/asm/bitsperlong.h"
+#else
+#include <asm-generic/bitsperlong.h>
+#endif
diff --git a/tools/include/uapi/asm/bpf_perf_event.h b/tools/include/uapi/asm/bpf_perf_event.h
new file mode 100644
index 000000000..ff52668ab
--- /dev/null
+++ b/tools/include/uapi/asm/bpf_perf_event.h
@@ -0,0 +1,13 @@
+#if defined(__aarch64__)
+#include "../../arch/arm64/include/uapi/asm/bpf_perf_event.h"
+#elif defined(__arc__)
+#include "../../arch/arc/include/uapi/asm/bpf_perf_event.h"
+#elif defined(__s390__)
+#include "../../arch/s390/include/uapi/asm/bpf_perf_event.h"
+#elif defined(__riscv)
+#include "../../arch/riscv/include/uapi/asm/bpf_perf_event.h"
+#elif defined(__loongarch__)
+#include "../../arch/loongarch/include/uapi/asm/bpf_perf_event.h"
+#else
+#include <uapi/asm-generic/bpf_perf_event.h>
+#endif
diff --git a/tools/include/uapi/asm/errno.h b/tools/include/uapi/asm/errno.h
new file mode 100644
index 000000000..869379f91
--- /dev/null
+++ b/tools/include/uapi/asm/errno.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if defined(__i386__) || defined(__x86_64__)
+#include "../../../arch/x86/include/uapi/asm/errno.h"
+#elif defined(__powerpc__)
+#include "../../../arch/powerpc/include/uapi/asm/errno.h"
+#elif defined(__sparc__)
+#include "../../../arch/sparc/include/uapi/asm/errno.h"
+#elif defined(__alpha__)
+#include "../../../arch/alpha/include/uapi/asm/errno.h"
+#elif defined(__mips__)
+#include "../../../arch/mips/include/uapi/asm/errno.h"
+#elif defined(__hppa__)
+#include "../../../arch/parisc/include/uapi/asm/errno.h"
+#else
+#include <asm-generic/errno.h>
+#endif