Merge tag 'rcu-next-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks

Pull RCU updates from Frederic Weisbecker:

 - RCU torture, locktorture and generic torture infrastructure updates
   that include various fixes, cleanups and consolidations.

   Among the user visible things, ftrace dumps can now be found into
   their own file, and module parameters get better documented and
   reported on dumps.

 - Generic and misc fixes all over the place. Some highlights:

     * Hotplug handling has seen some light cleanups and comments

     * An RCU barrier can now be triggered through sysfs to serialize
       memory stress testing and avoid OOM

     * Object information is now dumped in case of invalid callback
       invocation

     * Also various SRCU issues, too hard to trigger to deserve urgent
       pull requests, have been fixed

 - RCU documentation updates

 - RCU reference scalability test minor fixes and doc improvements.

 - RCU tasks minor fixes

 - Stall detection updates. Introduce RCU CPU Stall notifiers that
   allows a subsystem to provide informations to help debugging. Also
   cure some false positive stalls.

* tag 'rcu-next-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks: (56 commits)
  srcu: Only accelerate on enqueue time
  locktorture: Check the correct variable for allocation failure
  srcu: Fix callbacks acceleration mishandling
  rcu: Comment why callbacks migration can't wait for CPUHP_RCUTREE_PREP
  rcu: Standardize explicit CPU-hotplug calls
  rcu: Conditionally build CPU-hotplug teardown callbacks
  rcu: Remove references to rcu_migrate_callbacks() from diagrams
  rcu: Assume rcu_report_dead() is always called locally
  rcu: Assume IRQS disabled from rcu_report_dead()
  rcu: Use rcu_segcblist_segempty() instead of open coding it
  rcu: kmemleak: Ignore kmemleak false positives when RCU-freeing objects
  srcu: Fix srcu_struct node grpmask overflow on 64-bit systems
  torture: Convert parse-console.sh to mktemp
  rcutorture: Traverse possible cpu to set maxcpu in rcu_nocb_toggle()
  rcutorture: Replace schedule_timeout*() 1-jiffy waits with HZ/20
  torture: Add kvm.sh --debug-info argument
  locktorture: Rename readers_bind/writers_bind to bind_readers/bind_writers
  doc: Catch-up update for locktorture module parameters
  locktorture: Add call_rcu_chains module parameter
  locktorture: Add new module parameters to lock_torture_print_module_parms()
  ...

7 files changed, 58 insertions, 10 deletions

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 4a1dc88ddbff..76121c2bb4f8 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -566,7 +566,7 @@ enum
  *
  * _ RCU:
  * 	1) rcutree_migrate_callbacks() migrates the queue.
- * 	2) rcu_report_dead() reports the final quiescent states.
+ * 	2) rcutree_report_cpu_dead() reports the final quiescent states.
  *
  * _ IRQ_POLL: irq_poll_cpu_dead() migrates the queue
  *
diff --git a/include/linux/rcu_notifier.h b/include/linux/rcu_notifier.h
new file mode 100644
index 000000000000..ebf371364581
--- /dev/null
+++ b/include/linux/rcu_notifier.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Read-Copy Update notifiers, initially RCU CPU stall notifier.
+ * Separate from rcupdate.h to avoid #include loops.
+ *
+ * Copyright (C) 2023 Paul E. McKenney.
+ */
+
+#ifndef __LINUX_RCU_NOTIFIER_H
+#define __LINUX_RCU_NOTIFIER_H
+
+// Actions for RCU CPU stall notifier calls.
+#define RCU_STALL_NOTIFY_NORM	1
+#define RCU_STALL_NOTIFY_EXP	2
+
+#ifdef CONFIG_RCU_STALL_COMMON
+
+#include <linux/notifier.h>
+#include <linux/types.h>
+
+int rcu_stall_chain_notifier_register(struct notifier_block *n);
+int rcu_stall_chain_notifier_unregister(struct notifier_block *n);
+
+#else // #ifdef CONFIG_RCU_STALL_COMMON
+
+// No RCU CPU stall warnings in Tiny RCU.
+static inline int rcu_stall_chain_notifier_register(struct notifier_block *n) { return -EEXIST; }
+static inline int rcu_stall_chain_notifier_unregister(struct notifier_block *n) { return -ENOENT; }
+
+#endif // #else // #ifdef CONFIG_RCU_STALL_COMMON
+
+#endif /* __LINUX_RCU_NOTIFIER_H */
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 5e5f920ade90..f7206b2623c9 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -122,8 +122,6 @@ static inline void call_rcu_hurry(struct rcu_head *head, rcu_callback_t func)
 void rcu_init(void);
 extern int rcu_scheduler_active;
 void rcu_sched_clock_irq(int user);
-void rcu_report_dead(unsigned int cpu);
-void rcutree_migrate_callbacks(int cpu);
 
 #ifdef CONFIG_TASKS_RCU_GENERIC
 void rcu_init_tasks_generic(void);
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 7b949292908a..d9ac7b136aea 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -171,6 +171,6 @@ static inline void rcu_all_qs(void) { barrier(); }
 #define rcutree_offline_cpu      NULL
 #define rcutree_dead_cpu         NULL
 #define rcutree_dying_cpu        NULL
-static inline void rcu_cpu_starting(unsigned int cpu) { }
+static inline void rcutree_report_cpu_starting(unsigned int cpu) { }
 
 #endif /* __LINUX_RCUTINY_H */
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 126f6b418f6a..254244202ea9 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -37,7 +37,6 @@ void synchronize_rcu_expedited(void);
 void kvfree_call_rcu(struct rcu_head *head, void *ptr);
 
 void rcu_barrier(void);
-bool rcu_eqs_special_set(int cpu);
 void rcu_momentary_dyntick_idle(void);
 void kfree_rcu_scheduler_running(void);
 bool rcu_gp_might_be_stalled(void);
@@ -111,9 +110,21 @@ void rcu_all_qs(void);
 /* RCUtree hotplug events */
 int rcutree_prepare_cpu(unsigned int cpu);
 int rcutree_online_cpu(unsigned int cpu);
-int rcutree_offline_cpu(unsigned int cpu);
+void rcutree_report_cpu_starting(unsigned int cpu);
+
+#ifdef CONFIG_HOTPLUG_CPU
 int rcutree_dead_cpu(unsigned int cpu);
 int rcutree_dying_cpu(unsigned int cpu);
-void rcu_cpu_starting(unsigned int cpu);
+int rcutree_offline_cpu(unsigned int cpu);
+#else
+#define rcutree_dead_cpu NULL
+#define rcutree_dying_cpu NULL
+#define rcutree_offline_cpu NULL
+#endif
+
+void rcutree_migrate_callbacks(int cpu);
+
+/* Called from hotplug and also arm64 early secondary boot failure */
+void rcutree_report_cpu_dead(void);
 
 #endif /* __LINUX_RCUTREE_H */
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 8228d1276a2f..ff56ab804bf6 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -245,8 +245,9 @@ DEFINE_FREE(kfree, void *, if (_T) kfree(_T))
 size_t ksize(const void *objp);
 
 #ifdef CONFIG_PRINTK
-bool kmem_valid_obj(void *object);
-void kmem_dump_obj(void *object);
+bool kmem_dump_obj(void *object);
+#else
+static inline bool kmem_dump_obj(void *object) { return false; }
 #endif
 
 /*
diff --git a/include/linux/torture.h b/include/linux/torture.h
index bb466eec01e4..c98d0c83d117 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -81,7 +81,8 @@ static inline void torture_random_init(struct torture_random_state *trsp)
 }
 
 /* Definitions for high-resolution-timer sleeps. */
-int torture_hrtimeout_ns(ktime_t baset_ns, u32 fuzzt_ns, struct torture_random_state *trsp);
+int torture_hrtimeout_ns(ktime_t baset_ns, u32 fuzzt_ns, const enum hrtimer_mode mode,
+			 struct torture_random_state *trsp);
 int torture_hrtimeout_us(u32 baset_us, u32 fuzzt_ns, struct torture_random_state *trsp);
 int torture_hrtimeout_ms(u32 baset_ms, u32 fuzzt_us, struct torture_random_state *trsp);
 int torture_hrtimeout_jiffies(u32 baset_j, struct torture_random_state *trsp);
@@ -120,10 +121,15 @@ void _torture_stop_kthread(char *m, struct task_struct **tp);
 #define torture_stop_kthread(n, tp) \
 	_torture_stop_kthread("Stopping " #n " task", &(tp))
 
+/* Scheduler-related definitions. */
 #ifdef CONFIG_PREEMPTION
 #define torture_preempt_schedule() __preempt_schedule()
 #else
 #define torture_preempt_schedule()	do { } while (0)
 #endif
 
+#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST) || IS_ENABLED(CONFIG_LOCK_TORTURE_TEST) || IS_MODULE(CONFIG_LOCK_TORTURE_TEST)
+long torture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);
+#endif
+
 #endif /* __LINUX_TORTURE_H */