Commit 681fbec8 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

lockdep: Use consistent printing primitives 



Commit a5dd63ef ("lockdep: Use "WARNING" tag on lockdep splats")
substituted pr_warn() for printk() in places called out by Dmitry Vyukov.
However, this resulted in an ugly mix of pr_warn() and printk().  This
commit therefore changes printk() to pr_warn() or pr_cont(), depending
on the absence or presence of KERN_CONT.  This is done in all functions
that had printk() changed to pr_warn() by the aforementioned commit.

Reported-by: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent 2464dd94

kernel/locking/lockdep.c

+86 −86
Original line number Diff line number Diff line
@@ -1157,18 +1157,18 @@ print_circular_bug_header(struct lock_list *entry, unsigned int depth, 
	if (debug_locks_silent)

		return 0;



	printk("\n");

	pr_warn("\n");

	pr_warn("======================================================\n");

	pr_warn("WARNING: possible circular locking dependency detected\n");

	print_kernel_ident();

	pr_warn("------------------------------------------------------\n");

	printk("%s/%d is trying to acquire lock:\n",

	pr_warn("%s/%d is trying to acquire lock:\n",

		curr->comm, task_pid_nr(curr));

	print_lock(check_src);

	printk("\nbut task is already holding lock:\n");

	pr_warn("\nbut task is already holding lock:\n");

	print_lock(check_tgt);

	printk("\nwhich lock already depends on the new lock.\n\n");

	printk("\nthe existing dependency chain (in reverse order) is:\n");

	pr_warn("\nwhich lock already depends on the new lock.\n\n");

	pr_warn("\nthe existing dependency chain (in reverse order) is:\n");



	print_circular_bug_entry(entry, depth);
@@ -1495,13 +1495,13 @@ print_bad_irq_dependency(struct task_struct *curr, 
	if (!debug_locks_off_graph_unlock() || debug_locks_silent)

		return 0;



	printk("\n");

	pr_warn("\n");

	pr_warn("=====================================================\n");

	pr_warn("WARNING: %s-safe -> %s-unsafe lock order detected\n",

		irqclass, irqclass);

	print_kernel_ident();

	pr_warn("-----------------------------------------------------\n");

	printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",

	pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",

		curr->comm, task_pid_nr(curr),

		curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,

		curr->softirq_context, softirq_count() >> SOFTIRQ_SHIFT,
@@ -1509,46 +1509,46 @@ print_bad_irq_dependency(struct task_struct *curr, 
		curr->softirqs_enabled);

	print_lock(next);



	printk("\nand this task is already holding:\n");

	pr_warn("\nand this task is already holding:\n");

	print_lock(prev);

	printk("which would create a new lock dependency:\n");

	pr_warn("which would create a new lock dependency:\n");

	print_lock_name(hlock_class(prev));

	printk(KERN_CONT " ->");

	pr_cont(" ->");

	print_lock_name(hlock_class(next));

	printk(KERN_CONT "\n");

	pr_cont("\n");



	printk("\nbut this new dependency connects a %s-irq-safe lock:\n",

	pr_warn("\nbut this new dependency connects a %s-irq-safe lock:\n",

		irqclass);

	print_lock_name(backwards_entry->class);

	printk("\n... which became %s-irq-safe at:\n", irqclass);

	pr_warn("\n... which became %s-irq-safe at:\n", irqclass);



	print_stack_trace(backwards_entry->class->usage_traces + bit1, 1);



	printk("\nto a %s-irq-unsafe lock:\n", irqclass);

	pr_warn("\nto a %s-irq-unsafe lock:\n", irqclass);

	print_lock_name(forwards_entry->class);

	printk("\n... which became %s-irq-unsafe at:\n", irqclass);

	printk("...");

	pr_warn("\n... which became %s-irq-unsafe at:\n", irqclass);

	pr_warn("...");



	print_stack_trace(forwards_entry->class->usage_traces + bit2, 1);



	printk("\nother info that might help us debug this:\n\n");

	pr_warn("\nother info that might help us debug this:\n\n");

	print_irq_lock_scenario(backwards_entry, forwards_entry,

				hlock_class(prev), hlock_class(next));



	lockdep_print_held_locks(curr);



	printk("\nthe dependencies between %s-irq-safe lock and the holding lock:\n", irqclass);

	pr_warn("\nthe dependencies between %s-irq-safe lock and the holding lock:\n", irqclass);

	if (!save_trace(&prev_root->trace))

		return 0;

	print_shortest_lock_dependencies(backwards_entry, prev_root);



	printk("\nthe dependencies between the lock to be acquired");

	printk(" and %s-irq-unsafe lock:\n", irqclass);

	pr_warn("\nthe dependencies between the lock to be acquired");

	pr_warn(" and %s-irq-unsafe lock:\n", irqclass);

	if (!save_trace(&next_root->trace))

		return 0;

	print_shortest_lock_dependencies(forwards_entry, next_root);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();



	return 0;
@@ -1724,22 +1724,22 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev, 
	if (!debug_locks_off_graph_unlock() || debug_locks_silent)

		return 0;



	printk("\n");

	pr_warn("\n");

	pr_warn("============================================\n");

	pr_warn("WARNING: possible recursive locking detected\n");

	print_kernel_ident();

	pr_warn("--------------------------------------------\n");

	printk("%s/%d is trying to acquire lock:\n",

	pr_warn("%s/%d is trying to acquire lock:\n",

		curr->comm, task_pid_nr(curr));

	print_lock(next);

	printk("\nbut task is already holding lock:\n");

	pr_warn("\nbut task is already holding lock:\n");

	print_lock(prev);



	printk("\nother info that might help us debug this:\n");

	pr_warn("\nother info that might help us debug this:\n");

	print_deadlock_scenario(next, prev);

	lockdep_print_held_locks(curr);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();



	return 0;
@@ -2074,21 +2074,21 @@ static void print_collision(struct task_struct *curr, 
			struct held_lock *hlock_next,

			struct lock_chain *chain)

{

	printk("\n");

	pr_warn("\n");

	pr_warn("============================\n");

	pr_warn("WARNING: chain_key collision\n");

	print_kernel_ident();

	pr_warn("----------------------------\n");

	printk("%s/%d: ", current->comm, task_pid_nr(current));

	printk("Hash chain already cached but the contents don't match!\n");

	pr_warn("%s/%d: ", current->comm, task_pid_nr(current));

	pr_warn("Hash chain already cached but the contents don't match!\n");



	printk("Held locks:");

	pr_warn("Held locks:");

	print_chain_keys_held_locks(curr, hlock_next);



	printk("Locks in cached chain:");

	pr_warn("Locks in cached chain:");

	print_chain_keys_chain(chain);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();

}

#endif
@@ -2373,16 +2373,16 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this, 
	if (!debug_locks_off_graph_unlock() || debug_locks_silent)

		return 0;



	printk("\n");

	pr_warn("\n");

	pr_warn("================================\n");

	pr_warn("WARNING: inconsistent lock state\n");

	print_kernel_ident();

	pr_warn("--------------------------------\n");



	printk("inconsistent {%s} -> {%s} usage.\n",

	pr_warn("inconsistent {%s} -> {%s} usage.\n",

		usage_str[prev_bit], usage_str[new_bit]);



	printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",

	pr_warn("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] takes:\n",

		curr->comm, task_pid_nr(curr),

		trace_hardirq_context(curr), hardirq_count() >> HARDIRQ_SHIFT,

		trace_softirq_context(curr), softirq_count() >> SOFTIRQ_SHIFT,
@@ -2390,16 +2390,16 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this, 
		trace_softirqs_enabled(curr));

	print_lock(this);



	printk("{%s} state was registered at:\n", usage_str[prev_bit]);

	pr_warn("{%s} state was registered at:\n", usage_str[prev_bit]);

	print_stack_trace(hlock_class(this)->usage_traces + prev_bit, 1);



	print_irqtrace_events(curr);

	printk("\nother info that might help us debug this:\n");

	pr_warn("\nother info that might help us debug this:\n");

	print_usage_bug_scenario(this);



	lockdep_print_held_locks(curr);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();



	return 0;
@@ -2438,28 +2438,28 @@ print_irq_inversion_bug(struct task_struct *curr, 
	if (!debug_locks_off_graph_unlock() || debug_locks_silent)

		return 0;



	printk("\n");

	pr_warn("\n");

	pr_warn("========================================================\n");

	pr_warn("WARNING: possible irq lock inversion dependency detected\n");

	print_kernel_ident();

	pr_warn("--------------------------------------------------------\n");

	printk("%s/%d just changed the state of lock:\n",

	pr_warn("%s/%d just changed the state of lock:\n",

		curr->comm, task_pid_nr(curr));

	print_lock(this);

	if (forwards)

		printk("but this lock took another, %s-unsafe lock in the past:\n", irqclass);

		pr_warn("but this lock took another, %s-unsafe lock in the past:\n", irqclass);

	else

		printk("but this lock was taken by another, %s-safe lock in the past:\n", irqclass);

		pr_warn("but this lock was taken by another, %s-safe lock in the past:\n", irqclass);

	print_lock_name(other->class);

	printk("\n\nand interrupts could create inverse lock ordering between them.\n\n");

	pr_warn("\n\nand interrupts could create inverse lock ordering between them.\n\n");



	printk("\nother info that might help us debug this:\n");

	pr_warn("\nother info that might help us debug this:\n");



	/* Find a middle lock (if one exists) */

	depth = get_lock_depth(other);

	do {

		if (depth == 0 && (entry != root)) {

			printk("lockdep:%s bad path found in chain graph\n", __func__);

			pr_warn("lockdep:%s bad path found in chain graph\n", __func__);

			break;

		}

		middle = entry;
@@ -2475,12 +2475,12 @@ print_irq_inversion_bug(struct task_struct *curr, 


	lockdep_print_held_locks(curr);



	printk("\nthe shortest dependencies between 2nd lock and 1st lock:\n");

	pr_warn("\nthe shortest dependencies between 2nd lock and 1st lock:\n");

	if (!save_trace(&root->trace))

		return 0;

	print_shortest_lock_dependencies(other, root);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();



	return 0;
@@ -3189,25 +3189,25 @@ print_lock_nested_lock_not_held(struct task_struct *curr, 
	if (debug_locks_silent)

		return 0;



	printk("\n");

	pr_warn("\n");

	pr_warn("==================================\n");

	pr_warn("WARNING: Nested lock was not taken\n");

	print_kernel_ident();

	pr_warn("----------------------------------\n");



	printk("%s/%d is trying to lock:\n", curr->comm, task_pid_nr(curr));

	pr_warn("%s/%d is trying to lock:\n", curr->comm, task_pid_nr(curr));

	print_lock(hlock);



	printk("\nbut this task is not holding:\n");

	printk("%s\n", hlock->nest_lock->name);

	pr_warn("\nbut this task is not holding:\n");

	pr_warn("%s\n", hlock->nest_lock->name);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();



	printk("\nother info that might help us debug this:\n");

	pr_warn("\nother info that might help us debug this:\n");

	lockdep_print_held_locks(curr);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();



	return 0;
@@ -3402,21 +3402,21 @@ print_unlock_imbalance_bug(struct task_struct *curr, struct lockdep_map *lock, 
	if (debug_locks_silent)

		return 0;



	printk("\n");

	pr_warn("\n");

	pr_warn("=====================================\n");

	pr_warn("WARNING: bad unlock balance detected!\n");

	print_kernel_ident();

	pr_warn("-------------------------------------\n");

	printk("%s/%d is trying to release lock (",

	pr_warn("%s/%d is trying to release lock (",

		curr->comm, task_pid_nr(curr));

	print_lockdep_cache(lock);

	printk(KERN_CONT ") at:\n");

	pr_cont(") at:\n");

	print_ip_sym(ip);

	printk("but there are no more locks to release!\n");

	printk("\nother info that might help us debug this:\n");

	pr_warn("but there are no more locks to release!\n");

	pr_warn("\nother info that might help us debug this:\n");

	lockdep_print_held_locks(curr);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();



	return 0;
@@ -3974,21 +3974,21 @@ print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock, 
	if (debug_locks_silent)

		return 0;



	printk("\n");

	pr_warn("\n");

	pr_warn("=================================\n");

	pr_warn("WARNING: bad contention detected!\n");

	print_kernel_ident();

	pr_warn("---------------------------------\n");

	printk("%s/%d is trying to contend lock (",

	pr_warn("%s/%d is trying to contend lock (",

		curr->comm, task_pid_nr(curr));

	print_lockdep_cache(lock);

	printk(KERN_CONT ") at:\n");

	pr_cont(") at:\n");

	print_ip_sym(ip);

	printk("but there are no locks held!\n");

	printk("\nother info that might help us debug this:\n");

	pr_warn("but there are no locks held!\n");

	pr_warn("\nother info that might help us debug this:\n");

	lockdep_print_held_locks(curr);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();



	return 0;
@@ -4318,17 +4318,17 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from, 
	if (debug_locks_silent)

		return;



	printk("\n");

	pr_warn("\n");

	pr_warn("=========================\n");

	pr_warn("WARNING: held lock freed!\n");

	print_kernel_ident();

	pr_warn("-------------------------\n");

	printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n",

	pr_warn("%s/%d is freeing memory %p-%p, with a lock still held there!\n",

		curr->comm, task_pid_nr(curr), mem_from, mem_to-1);

	print_lock(hlock);

	lockdep_print_held_locks(curr);



	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();

}
@@ -4376,14 +4376,14 @@ static void print_held_locks_bug(void) 
	if (debug_locks_silent)

		return;



	printk("\n");

	pr_warn("\n");

	pr_warn("====================================\n");

	pr_warn("WARNING: %s/%d still has locks held!\n",

	       current->comm, task_pid_nr(current));

	print_kernel_ident();

	pr_warn("------------------------------------\n");

	lockdep_print_held_locks(current);

	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();

}
@@ -4402,10 +4402,10 @@ void debug_show_all_locks(void) 
	int unlock = 1;



	if (unlikely(!debug_locks)) {

		printk("INFO: lockdep is turned off.\n");

		pr_warn("INFO: lockdep is turned off.\n");

		return;

	}

	printk("\nShowing all locks held in the system:\n");

	pr_warn("\nShowing all locks held in the system:\n");



	/*

	 * Here we try to get the tasklist_lock as hard as possible,
@@ -4416,18 +4416,18 @@ void debug_show_all_locks(void) 
retry:

	if (!read_trylock(&tasklist_lock)) {

		if (count == 10)

			printk("hm, tasklist_lock locked, retrying... ");

			pr_warn("hm, tasklist_lock locked, retrying... ");

		if (count) {

			count--;

			printk(" #%d", 10-count);

			pr_cont(" #%d", 10-count);

			mdelay(200);

			goto retry;

		}

		printk(" ignoring it.\n");

		pr_cont(" ignoring it.\n");

		unlock = 0;

	} else {

		if (count != 10)

			printk(KERN_CONT " locked it.\n");

			pr_cont(" locked it.\n");

	}



	do_each_thread(g, p) {
@@ -4445,7 +4445,7 @@ retry: 
				unlock = 1;

	} while_each_thread(g, p);



	printk("\n");

	pr_warn("\n");

	pr_warn("=============================================\n\n");



	if (unlock)
@@ -4475,12 +4475,12 @@ asmlinkage __visible void lockdep_sys_exit(void) 
	if (unlikely(curr->lockdep_depth)) {

		if (!debug_locks_off())

			return;

		printk("\n");

		pr_warn("\n");

		pr_warn("================================================\n");

		pr_warn("WARNING: lock held when returning to user space!\n");

		print_kernel_ident();

		pr_warn("------------------------------------------------\n");

		printk("%s/%d is leaving the kernel with locks still held!\n",

		pr_warn("%s/%d is leaving the kernel with locks still held!\n",

				curr->comm, curr->pid);

		lockdep_print_held_locks(curr);

	}
@@ -4495,14 +4495,14 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) 
		return;

#endif /* #ifdef CONFIG_PROVE_RCU_REPEATEDLY */

	/* Note: the following can be executed concurrently, so be careful. */

	printk("\n");

	pr_warn("\n");

	pr_warn("=============================\n");

	pr_warn("WARNING: suspicious RCU usage\n");

	print_kernel_ident();

	pr_warn("-----------------------------\n");

	printk("%s:%d %s!\n", file, line, s);

	printk("\nother info that might help us debug this:\n\n");

	printk("\n%srcu_scheduler_active = %d, debug_locks = %d\n",

	pr_warn("%s:%d %s!\n", file, line, s);

	pr_warn("\nother info that might help us debug this:\n\n");

	pr_warn("\n%srcu_scheduler_active = %d, debug_locks = %d\n",

	       !rcu_lockdep_current_cpu_online()

			? "RCU used illegally from offline CPU!\n"

			: !rcu_is_watching()
@@ -4529,10 +4529,10 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) 
	 * rcu_read_lock_bh() and so on from extended quiescent states.

	 */

	if (!rcu_is_watching())

		printk("RCU used illegally from extended quiescent state!\n");

		pr_warn("RCU used illegally from extended quiescent state!\n");



	lockdep_print_held_locks(curr);

	printk("\nstack backtrace:\n");

	pr_warn("\nstack backtrace:\n");

	dump_stack();

}

EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious);

CRA Git | Maintained and supported by SUSTech CRA and CCSE