lockdep: Simplify stack trace handling (c120bce7) · Commits · e / devices / android_kernel_fairphone_FP5

include/linux/lockdep.h

+7 −2

Original line number	Original line	Diff line number	Diff line
	@@ -66,6 +66,11 @@ struct lock_class_key {

	extern struct lock_class_key __lockdep_no_validate__;		extern struct lock_class_key __lockdep_no_validate__;

			struct lock_trace {
			unsigned int nr_entries;
			unsigned int offset;
			};

	#define LOCKSTAT_POINTS 4		#define LOCKSTAT_POINTS 4

	/*		/*
	@@ -100,7 +105,7 @@ struct lock_class {
	* IRQ/softirq usage tracking bits:		* IRQ/softirq usage tracking bits:
	*/		*/
	unsigned long usage_mask;		unsigned long usage_mask;
	struct stack_trace usage_traces[XXX_LOCK_USAGE_STATES];		struct lock_trace usage_traces[XXX_LOCK_USAGE_STATES];

	/*		/*
	* Generation counter, when doing certain classes of graph walking,		* Generation counter, when doing certain classes of graph walking,
	@@ -188,7 +193,7 @@ struct lock_list {
	struct list_head entry;		struct list_head entry;
	struct lock_class *class;		struct lock_class *class;
	struct lock_class *links_to;		struct lock_class *links_to;
	struct stack_trace trace;		struct lock_trace trace;
	int distance;		int distance;

	/*		/*

kernel/locking/lockdep.c

+28 −27

Original line number	Original line	Diff line number	Diff line
	@@ -434,18 +434,14 @@ static void print_lockdep_off(const char *bug_msg)
	#endif		#endif
	}		}

	static int save_trace(struct stack_trace *trace)		static int save_trace(struct lock_trace *trace)
	{		{
	trace->nr_entries = 0;		unsigned long *entries = stack_trace + nr_stack_trace_entries;
	trace->max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries;		unsigned int max_entries;
	trace->entries = stack_trace + nr_stack_trace_entries;

	trace->skip = 3;

	save_stack_trace(trace);

	trace->max_entries = trace->nr_entries;

			trace->offset = nr_stack_trace_entries;
			max_entries = MAX_STACK_TRACE_ENTRIES - nr_stack_trace_entries;
			trace->nr_entries = stack_trace_save(entries, max_entries, 3);
	nr_stack_trace_entries += trace->nr_entries;		nr_stack_trace_entries += trace->nr_entries;

	if (nr_stack_trace_entries >= MAX_STACK_TRACE_ENTRIES-1) {		if (nr_stack_trace_entries >= MAX_STACK_TRACE_ENTRIES-1) {
	@@ -1196,7 +1192,7 @@ static struct lock_list *alloc_list_entry(void)
	static int add_lock_to_list(struct lock_class *this,		static int add_lock_to_list(struct lock_class *this,
	struct lock_class links_to, struct list_head head,		struct lock_class links_to, struct list_head head,
	unsigned long ip, int distance,		unsigned long ip, int distance,
	struct stack_trace *trace)		struct lock_trace *trace)
	{		{
	struct lock_list *entry;		struct lock_list *entry;
	/*		/*
	@@ -1415,6 +1411,13 @@ static inline int __bfs_backwards(struct lock_list *src_entry,
	* checking.		* checking.
	*/		*/

			static void print_lock_trace(struct lock_trace *trace, unsigned int spaces)
			{
			unsigned long *entries = stack_trace + trace->offset;

			stack_trace_print(entries, trace->nr_entries, spaces);
			}

	/*		/*
	* Print a dependency chain entry (this is only done when a deadlock		* Print a dependency chain entry (this is only done when a deadlock
	* has been detected):		* has been detected):
	@@ -1427,8 +1430,7 @@ print_circular_bug_entry(struct lock_list *target, int depth)
	printk("\n-> #%u", depth);		printk("\n-> #%u", depth);
	print_lock_name(target->class);		print_lock_name(target->class);
	printk(KERN_CONT ":\n");		printk(KERN_CONT ":\n");
	print_stack_trace(&target->trace, 6);		print_lock_trace(&target->trace, 6);

	return 0;		return 0;
	}		}

	@@ -1740,7 +1742,7 @@ static void print_lock_class_header(struct lock_class *class, int depth)

	len += printk("%*s %s", depth, "", usage_str[bit]);		len += printk("%*s %s", depth, "", usage_str[bit]);
	len += printk(KERN_CONT " at:\n");		len += printk(KERN_CONT " at:\n");
	print_stack_trace(class->usage_traces + bit, len);		print_lock_trace(class->usage_traces + bit, len);
	}		}
	}		}
	printk("%*s }\n", depth, "");		printk("%*s }\n", depth, "");
	@@ -1765,7 +1767,7 @@ print_shortest_lock_dependencies(struct lock_list *leaf,
	do {		do {
	print_lock_class_header(entry->class, depth);		print_lock_class_header(entry->class, depth);
	printk("%*s ... acquired at:\n", depth, "");		printk("%*s ... acquired at:\n", depth, "");
	print_stack_trace(&entry->trace, 2);		print_lock_trace(&entry->trace, 2);
	printk("\n");		printk("\n");

	if (depth == 0 && (entry != root)) {		if (depth == 0 && (entry != root)) {
	@@ -1878,14 +1880,14 @@ print_bad_irq_dependency(struct task_struct *curr,
	print_lock_name(backwards_entry->class);		print_lock_name(backwards_entry->class);
	pr_warn("\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);		print_lock_trace(backwards_entry->class->usage_traces + bit1, 1);

	pr_warn("\nto a %s-irq-unsafe lock:\n", irqclass);		pr_warn("\nto a %s-irq-unsafe lock:\n", irqclass);
	print_lock_name(forwards_entry->class);		print_lock_name(forwards_entry->class);
	pr_warn("\n... which became %s-irq-unsafe at:\n", irqclass);		pr_warn("\n... which became %s-irq-unsafe at:\n", irqclass);
	pr_warn("...");		pr_warn("...");

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

	pr_warn("\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,		print_irq_lock_scenario(backwards_entry, forwards_entry,
	@@ -2158,7 +2160,7 @@ check_deadlock(struct task_struct curr, struct held_lock next,
	*/		*/
	static int		static int
	check_prev_add(struct task_struct curr, struct held_lock prev,		check_prev_add(struct task_struct curr, struct held_lock prev,
	struct held_lock next, int distance, struct stack_trace trace)		struct held_lock next, int distance, struct lock_trace trace)
	{		{
	struct lock_list *uninitialized_var(target_entry);		struct lock_list *uninitialized_var(target_entry);
	struct lock_list *entry;		struct lock_list *entry;
	@@ -2196,7 +2198,7 @@ check_prev_add(struct task_struct curr, struct held_lock prev,
	this.parent = NULL;		this.parent = NULL;
	ret = check_noncircular(&this, hlock_class(prev), &target_entry);		ret = check_noncircular(&this, hlock_class(prev), &target_entry);
	if (unlikely(!ret)) {		if (unlikely(!ret)) {
	if (!trace->entries) {		if (!trace->nr_entries) {
	/*		/*
	* If save_trace fails here, the printing might		* If save_trace fails here, the printing might
	* trigger a WARN but because of the !nr_entries it		* trigger a WARN but because of the !nr_entries it
	@@ -2252,7 +2254,7 @@ check_prev_add(struct task_struct curr, struct held_lock prev,
	return print_bfs_bug(ret);		return print_bfs_bug(ret);


	if (!trace->entries && !save_trace(trace))		if (!trace->nr_entries && !save_trace(trace))
	return 0;		return 0;

	/*		/*
	@@ -2284,14 +2286,9 @@ check_prev_add(struct task_struct curr, struct held_lock prev,
	static int		static int
	check_prevs_add(struct task_struct curr, struct held_lock next)		check_prevs_add(struct task_struct curr, struct held_lock next)
	{		{
			struct lock_trace trace = { .nr_entries = 0 };
	int depth = curr->lockdep_depth;		int depth = curr->lockdep_depth;
	struct held_lock *hlock;		struct held_lock *hlock;
	struct stack_trace trace = {
	.nr_entries = 0,
	.max_entries = 0,
	.entries = NULL,
	.skip = 0,
	};

	/*		/*
	* Debugging checks.		* Debugging checks.
	@@ -2719,6 +2716,10 @@ static inline int validate_chain(struct task_struct *curr,
	{		{
	return 1;		return 1;
	}		}

			static void print_lock_trace(struct lock_trace *trace, unsigned int spaces)
			{
			}
	#endif		#endif

	/*		/*
	@@ -2815,7 +2816,7 @@ print_usage_bug(struct task_struct curr, struct held_lock this,
	print_lock(this);		print_lock(this);

	pr_warn("{%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_lock_trace(hlock_class(this)->usage_traces + prev_bit, 1);

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