Merging debian version 6.8.9-1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 487 insertions, 0 deletions

diff --git a/debian/patches-rt/0032-lockdep-Mark-emergency-sections-in-lockdep-splats.patch b/debian/patches-rt/0032-lockdep-Mark-emergency-sections-in-lockdep-splats.patch
new file mode 100644
index 0000000000..64cf39b672
--- /dev/null
+++ b/debian/patches-rt/0032-lockdep-Mark-emergency-sections-in-lockdep-splats.patch
@@ -0,0 +1,487 @@
+From: John Ogness <john.ogness@linutronix.de>
+Date: Mon, 18 Sep 2023 20:27:41 +0000
+Subject: [PATCH 32/48] lockdep: Mark emergency sections in lockdep splats
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz
+
+Mark emergency sections wherever multiple lines of
+lock debugging output are generated. In an emergency
+section the CPU will not perform console output for the
+printk() calls. Instead, a flushing of the console
+output is triggered when exiting the emergency section.
+This allows the full message block to be stored as
+quickly as possible in the ringbuffer.
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ kernel/locking/lockdep.c |   91 +++++++++++++++++++++++++++++++++++++++++++++--
+ 1 file changed, 88 insertions(+), 3 deletions(-)
+
+--- a/kernel/locking/lockdep.c
++++ b/kernel/locking/lockdep.c
+@@ -56,6 +56,7 @@
+ #include <linux/kprobes.h>
+ #include <linux/lockdep.h>
+ #include <linux/context_tracking.h>
++#include <linux/console.h>
+ 
+ #include <asm/sections.h>
+ 
+@@ -574,8 +575,10 @@ static struct lock_trace *save_trace(voi
+ 		if (!debug_locks_off_graph_unlock())
+ 			return NULL;
+ 
++		nbcon_cpu_emergency_enter();
+ 		print_lockdep_off("BUG: MAX_STACK_TRACE_ENTRIES too low!");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 
+ 		return NULL;
+ 	}
+@@ -782,6 +785,8 @@ static void lockdep_print_held_locks(str
+ {
+ 	int i, depth = READ_ONCE(p->lockdep_depth);
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	if (!depth)
+ 		printk("no locks held by %s/%d.\n", p->comm, task_pid_nr(p));
+ 	else
+@@ -792,11 +797,13 @@ static void lockdep_print_held_locks(str
+ 	 * and it's not the current task.
+ 	 */
+ 	if (p != current && task_is_running(p))
+-		return;
++		goto out;
+ 	for (i = 0; i < depth; i++) {
+ 		printk(" #%d: ", i);
+ 		print_lock(p->held_locks + i);
+ 	}
++out:
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ static void print_kernel_ident(void)
+@@ -888,11 +895,13 @@ look_up_lock_class(const struct lockdep_
+ 	if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
+ 		instrumentation_begin();
+ 		debug_locks_off();
++		nbcon_cpu_emergency_enter();
+ 		printk(KERN_ERR
+ 			"BUG: looking up invalid subclass: %u\n", subclass);
+ 		printk(KERN_ERR
+ 			"turning off the locking correctness validator.\n");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 		instrumentation_end();
+ 		return NULL;
+ 	}
+@@ -969,11 +978,13 @@ static bool assign_lock_key(struct lockd
+ 	else {
+ 		/* Debug-check: all keys must be persistent! */
+ 		debug_locks_off();
++		nbcon_cpu_emergency_enter();
+ 		pr_err("INFO: trying to register non-static key.\n");
+ 		pr_err("The code is fine but needs lockdep annotation, or maybe\n");
+ 		pr_err("you didn't initialize this object before use?\n");
+ 		pr_err("turning off the locking correctness validator.\n");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 		return false;
+ 	}
+ 
+@@ -1317,8 +1328,10 @@ register_lock_class(struct lockdep_map *
+ 			return NULL;
+ 		}
+ 
++		nbcon_cpu_emergency_enter();
+ 		print_lockdep_off("BUG: MAX_LOCKDEP_KEYS too low!");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 		return NULL;
+ 	}
+ 	nr_lock_classes++;
+@@ -1350,11 +1363,13 @@ register_lock_class(struct lockdep_map *
+ 	if (verbose(class)) {
+ 		graph_unlock();
+ 
++		nbcon_cpu_emergency_enter();
+ 		printk("\nnew class %px: %s", class->key, class->name);
+ 		if (class->name_version > 1)
+ 			printk(KERN_CONT "#%d", class->name_version);
+ 		printk(KERN_CONT "\n");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 
+ 		if (!graph_lock()) {
+ 			return NULL;
+@@ -1393,8 +1408,10 @@ static struct lock_list *alloc_list_entr
+ 		if (!debug_locks_off_graph_unlock())
+ 			return NULL;
+ 
++		nbcon_cpu_emergency_enter();
+ 		print_lockdep_off("BUG: MAX_LOCKDEP_ENTRIES too low!");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 		return NULL;
+ 	}
+ 	nr_list_entries++;
+@@ -2040,6 +2057,8 @@ static noinline void print_circular_bug(
+ 
+ 	depth = get_lock_depth(target);
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	print_circular_bug_header(target, depth, check_src, check_tgt);
+ 
+ 	parent = get_lock_parent(target);
+@@ -2058,6 +2077,8 @@ static noinline void print_circular_bug(
+ 
+ 	printk("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ static noinline void print_bfs_bug(int ret)
+@@ -2570,6 +2591,8 @@ print_bad_irq_dependency(struct task_str
+ 	if (!debug_locks_off_graph_unlock() || debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("=====================================================\n");
+ 	pr_warn("WARNING: %s-safe -> %s-unsafe lock order detected\n",
+@@ -2619,11 +2642,13 @@ print_bad_irq_dependency(struct task_str
+ 	pr_warn(" and %s-irq-unsafe lock:\n", irqclass);
+ 	next_root->trace = save_trace();
+ 	if (!next_root->trace)
+-		return;
++		goto out;
+ 	print_shortest_lock_dependencies(forwards_entry, next_root);
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++out:
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ static const char *state_names[] = {
+@@ -2988,6 +3013,8 @@ print_deadlock_bug(struct task_struct *c
+ 	if (!debug_locks_off_graph_unlock() || debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("============================================\n");
+ 	pr_warn("WARNING: possible recursive locking detected\n");
+@@ -3010,6 +3037,8 @@ print_deadlock_bug(struct task_struct *c
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ /*
+@@ -3607,6 +3636,8 @@ static void print_collision(struct task_
+ 			struct held_lock *hlock_next,
+ 			struct lock_chain *chain)
+ {
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("============================\n");
+ 	pr_warn("WARNING: chain_key collision\n");
+@@ -3623,6 +3654,8 @@ static void print_collision(struct task_
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ #endif
+ 
+@@ -3713,8 +3746,10 @@ static inline int add_chain_cache(struct
+ 		if (!debug_locks_off_graph_unlock())
+ 			return 0;
+ 
++		nbcon_cpu_emergency_enter();
+ 		print_lockdep_off("BUG: MAX_LOCKDEP_CHAINS too low!");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 		return 0;
+ 	}
+ 	chain->chain_key = chain_key;
+@@ -3731,8 +3766,10 @@ static inline int add_chain_cache(struct
+ 		if (!debug_locks_off_graph_unlock())
+ 			return 0;
+ 
++		nbcon_cpu_emergency_enter();
+ 		print_lockdep_off("BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 		return 0;
+ 	}
+ 
+@@ -3971,6 +4008,8 @@ print_usage_bug(struct task_struct *curr
+ 	if (!debug_locks_off() || debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("================================\n");
+ 	pr_warn("WARNING: inconsistent lock state\n");
+@@ -3999,6 +4038,8 @@ print_usage_bug(struct task_struct *curr
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ /*
+@@ -4033,6 +4074,8 @@ print_irq_inversion_bug(struct task_stru
+ 	if (!debug_locks_off_graph_unlock() || debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("========================================================\n");
+ 	pr_warn("WARNING: possible irq lock inversion dependency detected\n");
+@@ -4073,11 +4116,13 @@ print_irq_inversion_bug(struct task_stru
+ 	pr_warn("\nthe shortest dependencies between 2nd lock and 1st lock:\n");
+ 	root->trace = save_trace();
+ 	if (!root->trace)
+-		return;
++		goto out;
+ 	print_shortest_lock_dependencies(other, root);
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++out:
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ /*
+@@ -4154,6 +4199,8 @@ void print_irqtrace_events(struct task_s
+ {
+ 	const struct irqtrace_events *trace = &curr->irqtrace;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	printk("irq event stamp: %u\n", trace->irq_events);
+ 	printk("hardirqs last  enabled at (%u): [<%px>] %pS\n",
+ 		trace->hardirq_enable_event, (void *)trace->hardirq_enable_ip,
+@@ -4167,6 +4214,8 @@ void print_irqtrace_events(struct task_s
+ 	printk("softirqs last disabled at (%u): [<%px>] %pS\n",
+ 		trace->softirq_disable_event, (void *)trace->softirq_disable_ip,
+ 		(void *)trace->softirq_disable_ip);
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ static int HARDIRQ_verbose(struct lock_class *class)
+@@ -4687,10 +4736,12 @@ static int mark_lock(struct task_struct
+ 	 * We must printk outside of the graph_lock:
+ 	 */
+ 	if (ret == 2) {
++		nbcon_cpu_emergency_enter();
+ 		printk("\nmarked lock as {%s}:\n", usage_str[new_bit]);
+ 		print_lock(this);
+ 		print_irqtrace_events(curr);
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 	}
+ 
+ 	return ret;
+@@ -4731,6 +4782,8 @@ print_lock_invalid_wait_context(struct t
+ 	if (debug_locks_silent)
+ 		return 0;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("=============================\n");
+ 	pr_warn("[ BUG: Invalid wait context ]\n");
+@@ -4750,6 +4803,8 @@ print_lock_invalid_wait_context(struct t
+ 	pr_warn("stack backtrace:\n");
+ 	dump_stack();
+ 
++	nbcon_cpu_emergency_exit();
++
+ 	return 0;
+ }
+ 
+@@ -4954,6 +5009,8 @@ print_lock_nested_lock_not_held(struct t
+ 	if (debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("==================================\n");
+ 	pr_warn("WARNING: Nested lock was not taken\n");
+@@ -4974,6 +5031,8 @@ print_lock_nested_lock_not_held(struct t
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ static int __lock_is_held(const struct lockdep_map *lock, int read);
+@@ -5019,11 +5078,13 @@ static int __lock_acquire(struct lockdep
+ 	debug_class_ops_inc(class);
+ 
+ 	if (very_verbose(class)) {
++		nbcon_cpu_emergency_enter();
+ 		printk("\nacquire class [%px] %s", class->key, class->name);
+ 		if (class->name_version > 1)
+ 			printk(KERN_CONT "#%d", class->name_version);
+ 		printk(KERN_CONT "\n");
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 	}
+ 
+ 	/*
+@@ -5150,6 +5211,7 @@ static int __lock_acquire(struct lockdep
+ #endif
+ 	if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) {
+ 		debug_locks_off();
++		nbcon_cpu_emergency_enter();
+ 		print_lockdep_off("BUG: MAX_LOCK_DEPTH too low!");
+ 		printk(KERN_DEBUG "depth: %i  max: %lu!\n",
+ 		       curr->lockdep_depth, MAX_LOCK_DEPTH);
+@@ -5157,6 +5219,7 @@ static int __lock_acquire(struct lockdep
+ 		lockdep_print_held_locks(current);
+ 		debug_show_all_locks();
+ 		dump_stack();
++		nbcon_cpu_emergency_exit();
+ 
+ 		return 0;
+ 	}
+@@ -5176,6 +5239,8 @@ static void print_unlock_imbalance_bug(s
+ 	if (debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("=====================================\n");
+ 	pr_warn("WARNING: bad unlock balance detected!\n");
+@@ -5192,6 +5257,8 @@ static void print_unlock_imbalance_bug(s
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ static noinstr int match_held_lock(const struct held_lock *hlock,
+@@ -5895,6 +5962,8 @@ static void print_lock_contention_bug(st
+ 	if (debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("=================================\n");
+ 	pr_warn("WARNING: bad contention detected!\n");
+@@ -5911,6 +5980,8 @@ static void print_lock_contention_bug(st
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ static void
+@@ -6524,6 +6595,8 @@ print_freed_lock_bug(struct task_struct
+ 	if (debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("=========================\n");
+ 	pr_warn("WARNING: held lock freed!\n");
+@@ -6536,6 +6609,8 @@ print_freed_lock_bug(struct task_struct
+ 
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ static inline int not_in_range(const void* mem_from, unsigned long mem_len,
+@@ -6582,6 +6657,8 @@ static void print_held_locks_bug(void)
+ 	if (debug_locks_silent)
+ 		return;
+ 
++	nbcon_cpu_emergency_enter();
++
+ 	pr_warn("\n");
+ 	pr_warn("====================================\n");
+ 	pr_warn("WARNING: %s/%d still has locks held!\n",
+@@ -6591,6 +6668,8 @@ static void print_held_locks_bug(void)
+ 	lockdep_print_held_locks(current);
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++
++	nbcon_cpu_emergency_exit();
+ }
+ 
+ void debug_check_no_locks_held(void)
+@@ -6609,6 +6688,7 @@ void debug_show_all_locks(void)
+ 		pr_warn("INFO: lockdep is turned off.\n");
+ 		return;
+ 	}
++	nbcon_cpu_emergency_enter();
+ 	pr_warn("\nShowing all locks held in the system:\n");
+ 
+ 	rcu_read_lock();
+@@ -6623,6 +6703,7 @@ void debug_show_all_locks(void)
+ 
+ 	pr_warn("\n");
+ 	pr_warn("=============================================\n\n");
++	nbcon_cpu_emergency_exit();
+ }
+ EXPORT_SYMBOL_GPL(debug_show_all_locks);
+ #endif
+@@ -6648,6 +6729,7 @@ asmlinkage __visible void lockdep_sys_ex
+ 	if (unlikely(curr->lockdep_depth)) {
+ 		if (!debug_locks_off())
+ 			return;
++		nbcon_cpu_emergency_enter();
+ 		pr_warn("\n");
+ 		pr_warn("================================================\n");
+ 		pr_warn("WARNING: lock held when returning to user space!\n");
+@@ -6656,6 +6738,7 @@ asmlinkage __visible void lockdep_sys_ex
+ 		pr_warn("%s/%d is leaving the kernel with locks still held!\n",
+ 				curr->comm, curr->pid);
+ 		lockdep_print_held_locks(curr);
++		nbcon_cpu_emergency_exit();
+ 	}
+ 
+ 	/*
+@@ -6672,6 +6755,7 @@ void lockdep_rcu_suspicious(const char *
+ 	bool rcu = warn_rcu_enter();
+ 
+ 	/* Note: the following can be executed concurrently, so be careful. */
++	nbcon_cpu_emergency_enter();
+ 	pr_warn("\n");
+ 	pr_warn("=============================\n");
+ 	pr_warn("WARNING: suspicious RCU usage\n");
+@@ -6710,6 +6794,7 @@ void lockdep_rcu_suspicious(const char *
+ 	lockdep_print_held_locks(curr);
+ 	pr_warn("\nstack backtrace:\n");
+ 	dump_stack();
++	nbcon_cpu_emergency_exit();
+ 	warn_rcu_exit(rcu);
+ }
+ EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious);