[linux-block.git] / kernel / stacktrace.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * kernel/stacktrace.c
 *
 * Stack trace management functions
 *
 *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 */
#include <linux/sched/task_stack.h>
#include <linux/sched/debug.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>

/**
 * stack_trace_print - Print the entries in the stack trace
 * @entries:	Pointer to storage array
 * @nr_entries:	Number of entries in the storage array
 * @spaces:	Number of leading spaces to print
 */
void stack_trace_print(const unsigned long *entries, unsigned int nr_entries,
		       int spaces)
{
	unsigned int i;

	if (WARN_ON(!entries))
		return;

	for (i = 0; i < nr_entries; i++)
		printk("%*c%pS\n", 1 + spaces, ' ', (void *)entries[i]);
}
EXPORT_SYMBOL_GPL(stack_trace_print);

/**
 * stack_trace_snprint - Print the entries in the stack trace into a buffer
 * @buf:	Pointer to the print buffer
 * @size:	Size of the print buffer
 * @entries:	Pointer to storage array
 * @nr_entries:	Number of entries in the storage array
 * @spaces:	Number of leading spaces to print
 *
 * Return: Number of bytes printed.
 */
int stack_trace_snprint(char *buf, size_t size, const unsigned long *entries,
			unsigned int nr_entries, int spaces)
{
	unsigned int generated, i, total = 0;

	if (WARN_ON(!entries))
		return 0;

	for (i = 0; i < nr_entries && size; i++) {
		generated = snprintf(buf, size, "%*c%pS\n", 1 + spaces, ' ',
				     (void *)entries[i]);

		total += generated;
		if (generated >= size) {
			buf += size;
			size = 0;
		} else {
			buf += generated;
			size -= generated;
		}
	}

	return total;
}
EXPORT_SYMBOL_GPL(stack_trace_snprint);

#ifdef CONFIG_ARCH_STACKWALK

struct stacktrace_cookie {
	unsigned long	*store;
	unsigned int	size;
	unsigned int	skip;
	unsigned int	len;
};

static bool stack_trace_consume_entry(void *cookie, unsigned long addr,
				      bool reliable)
{
	struct stacktrace_cookie *c = cookie;

	if (c->len >= c->size)
		return false;

	if (c->skip > 0) {
		c->skip--;
		return true;
	}
	c->store[c->len++] = addr;
	return c->len < c->size;
}

static bool stack_trace_consume_entry_nosched(void *cookie, unsigned long addr,
					      bool reliable)
{
	if (in_sched_functions(addr))
		return true;
	return stack_trace_consume_entry(cookie, addr, reliable);
}

/**
 * stack_trace_save - Save a stack trace into a storage array
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 * @skipnr:	Number of entries to skip at the start of the stack trace
 *
 * Return: Number of trace entries stored.
 */
unsigned int stack_trace_save(unsigned long *store, unsigned int size,
			      unsigned int skipnr)
{
	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	struct stacktrace_cookie c = {
		.store	= store,
		.size	= size,
		.skip	= skipnr + 1,
	};

	arch_stack_walk(consume_entry, &c, current, NULL);
	return c.len;
}
EXPORT_SYMBOL_GPL(stack_trace_save);

/**
 * stack_trace_save_tsk - Save a task stack trace into a storage array
 * @task:	The task to examine
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 * @skipnr:	Number of entries to skip at the start of the stack trace
 *
 * Return: Number of trace entries stored.
 */
unsigned int stack_trace_save_tsk(struct task_struct *tsk, unsigned long *store,
				  unsigned int size, unsigned int skipnr)
{
	stack_trace_consume_fn consume_entry = stack_trace_consume_entry_nosched;
	struct stacktrace_cookie c = {
		.store	= store,
		.size	= size,
		/* skip this function if they are tracing us */
		.skip	= skipnr + (current == tsk),
	};

	if (!try_get_task_stack(tsk))
		return 0;

	arch_stack_walk(consume_entry, &c, tsk, NULL);
	put_task_stack(tsk);
	return c.len;
}

/**
 * stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array
 * @regs:	Pointer to pt_regs to examine
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 * @skipnr:	Number of entries to skip at the start of the stack trace
 *
 * Return: Number of trace entries stored.
 */
unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store,
				   unsigned int size, unsigned int skipnr)
{
	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	struct stacktrace_cookie c = {
		.store	= store,
		.size	= size,
		.skip	= skipnr,
	};

	arch_stack_walk(consume_entry, &c, current, regs);
	return c.len;
}

#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
/**
 * stack_trace_save_tsk_reliable - Save task stack with verification
 * @tsk:	Pointer to the task to examine
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 *
 * Return:	An error if it detects any unreliable features of the
 *		stack. Otherwise it guarantees that the stack trace is
 *		reliable and returns the number of entries stored.
 *
 * If the task is not 'current', the caller *must* ensure the task is inactive.
 */
int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store,
				  unsigned int size)
{
	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	struct stacktrace_cookie c = {
		.store	= store,
		.size	= size,
	};
	int ret;

	/*
	 * If the task doesn't have a stack (e.g., a zombie), the stack is
	 * "reliably" empty.
	 */
	if (!try_get_task_stack(tsk))
		return 0;

	ret = arch_stack_walk_reliable(consume_entry, &c, tsk);
	put_task_stack(tsk);
	return ret ? ret : c.len;
}
#endif

#ifdef CONFIG_USER_STACKTRACE_SUPPORT
/**
 * stack_trace_save_user - Save a user space stack trace into a storage array
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 *
 * Return: Number of trace entries stored.
 */
unsigned int stack_trace_save_user(unsigned long *store, unsigned int size)
{
	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	struct stacktrace_cookie c = {
		.store	= store,
		.size	= size,
	};
	mm_segment_t fs;

	/* Trace user stack if not a kernel thread */
	if (current->flags & PF_KTHREAD)
		return 0;

	fs = force_uaccess_begin();
	arch_stack_walk_user(consume_entry, &c, task_pt_regs(current));
	force_uaccess_end(fs);

	return c.len;
}
#endif

#else /* CONFIG_ARCH_STACKWALK */

/*
 * Architectures that do not implement save_stack_trace_*()
 * get these weak aliases and once-per-bootup warnings
 * (whenever this facility is utilized - for example by procfs):
 */
__weak void
save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
}

__weak void
save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
{
	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
}

/**
 * stack_trace_save - Save a stack trace into a storage array
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 * @skipnr:	Number of entries to skip at the start of the stack trace
 *
 * Return: Number of trace entries stored
 */
unsigned int stack_trace_save(unsigned long *store, unsigned int size,
			      unsigned int skipnr)
{
	struct stack_trace trace = {
		.entries	= store,
		.max_entries	= size,
		.skip		= skipnr + 1,
	};

	save_stack_trace(&trace);
	return trace.nr_entries;
}
EXPORT_SYMBOL_GPL(stack_trace_save);

/**
 * stack_trace_save_tsk - Save a task stack trace into a storage array
 * @task:	The task to examine
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 * @skipnr:	Number of entries to skip at the start of the stack trace
 *
 * Return: Number of trace entries stored
 */
unsigned int stack_trace_save_tsk(struct task_struct *task,
				  unsigned long *store, unsigned int size,
				  unsigned int skipnr)
{
	struct stack_trace trace = {
		.entries	= store,
		.max_entries	= size,
		/* skip this function if they are tracing us */
		.skip	= skipnr + (current == task),
	};

	save_stack_trace_tsk(task, &trace);
	return trace.nr_entries;
}

/**
 * stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array
 * @regs:	Pointer to pt_regs to examine
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 * @skipnr:	Number of entries to skip at the start of the stack trace
 *
 * Return: Number of trace entries stored
 */
unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store,
				   unsigned int size, unsigned int skipnr)
{
	struct stack_trace trace = {
		.entries	= store,
		.max_entries	= size,
		.skip		= skipnr,
	};

	save_stack_trace_regs(regs, &trace);
	return trace.nr_entries;
}

#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
/**
 * stack_trace_save_tsk_reliable - Save task stack with verification
 * @tsk:	Pointer to the task to examine
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 *
 * Return:	An error if it detects any unreliable features of the
 *		stack. Otherwise it guarantees that the stack trace is
 *		reliable and returns the number of entries stored.
 *
 * If the task is not 'current', the caller *must* ensure the task is inactive.
 */
int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store,
				  unsigned int size)
{
	struct stack_trace trace = {
		.entries	= store,
		.max_entries	= size,
	};
	int ret = save_stack_trace_tsk_reliable(tsk, &trace);

	return ret ? ret : trace.nr_entries;
}
#endif

#ifdef CONFIG_USER_STACKTRACE_SUPPORT
/**
 * stack_trace_save_user - Save a user space stack trace into a storage array
 * @store:	Pointer to storage array
 * @size:	Size of the storage array
 *
 * Return: Number of trace entries stored
 */
unsigned int stack_trace_save_user(unsigned long *store, unsigned int size)
{
	struct stack_trace trace = {
		.entries	= store,
		.max_entries	= size,
	};

	save_stack_trace_user(&trace);
	return trace.nr_entries;
}
#endif /* CONFIG_USER_STACKTRACE_SUPPORT */

#endif /* !CONFIG_ARCH_STACKWALK */
Commit	Line	Data
457c8996	1	// SPDX-License-Identifier: GPL-2.0-only
8637c099 IM	2	/*
	3	* kernel/stacktrace.c
	4	*
	5	* Stack trace management functions
	6	*
	7	* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
	8	*/
214d8ca6 TG	9	#include <linux/sched/task_stack.h>
214d8ca6 TG	10	#include <linux/sched/debug.h>
8637c099	11	#include <linux/sched.h>
9212ddb5	12	#include <linux/kernel.h>
9984de1a	13	#include <linux/export.h>
8637c099 IM	14	#include <linux/kallsyms.h>
	15	#include <linux/stacktrace.h>
	16
e9b98e16 TG	17	/**
	18	* stack_trace_print - Print the entries in the stack trace
	19	* @entries: Pointer to storage array
	20	* @nr_entries: Number of entries in the storage array
	21	* @spaces: Number of leading spaces to print
	22	*/
a2970421	23	void stack_trace_print(const unsigned long *entries, unsigned int nr_entries,
e9b98e16	24	int spaces)
8637c099	25	{
e9b98e16	26	unsigned int i;
8637c099	27
e9b98e16	28	if (WARN_ON(!entries))
bfeeeeb9 JB	29	return;
bfeeeeb9 JB	30
e9b98e16 TG	31	for (i = 0; i < nr_entries; i++)
	32	printk("%c%pS\n", 1 + spaces, ' ', (void )entries[i]);
	33	}
	34	EXPORT_SYMBOL_GPL(stack_trace_print);
	35
e9b98e16 TG	36	/**
	37	* stack_trace_snprint - Print the entries in the stack trace into a buffer
	38	* @buf: Pointer to the print buffer
	39	* @size: Size of the print buffer
	40	* @entries: Pointer to storage array
	41	* @nr_entries: Number of entries in the storage array
	42	* @spaces: Number of leading spaces to print
	43	*
	44	* Return: Number of bytes printed.
	45	*/
a2970421	46	int stack_trace_snprint(char buf, size_t size, const unsigned long entries,
e9b98e16	47	unsigned int nr_entries, int spaces)
9a92a6ce	48	{
e9b98e16	49	unsigned int generated, i, total = 0;
9a92a6ce	50
e9b98e16	51	if (WARN_ON(!entries))
9a92a6ce JK	52	return 0;
9a92a6ce JK	53
e9b98e16	54	for (i = 0; i < nr_entries && size; i++) {
bfeda41d	55	generated = snprintf(buf, size, "%*c%pS\n", 1 + spaces, ' ',
e9b98e16	56	(void *)entries[i]);
9a92a6ce JK	57
9a92a6ce JK	58	total += generated;
9a92a6ce JK	59	if (generated >= size) {
	60	buf += size;
	61	size = 0;
	62	} else {
	63	buf += generated;
	64	size -= generated;
	65	}
	66	}
	67
	68	return total;
	69	}
e9b98e16 TG	70	EXPORT_SYMBOL_GPL(stack_trace_snprint);
e9b98e16 TG	71
214d8ca6 TG	72	#ifdef CONFIG_ARCH_STACKWALK
	73
	74	struct stacktrace_cookie {
	75	unsigned long *store;
	76	unsigned int size;
	77	unsigned int skip;
	78	unsigned int len;
	79	};
	80
	81	static bool stack_trace_consume_entry(void *cookie, unsigned long addr,
	82	bool reliable)
	83	{
	84	struct stacktrace_cookie *c = cookie;
	85
	86	if (c->len >= c->size)
	87	return false;
	88
	89	if (c->skip > 0) {
	90	c->skip--;
	91	return true;
	92	}
	93	c->store[c->len++] = addr;
	94	return c->len < c->size;
	95	}
	96
	97	static bool stack_trace_consume_entry_nosched(void *cookie, unsigned long addr,
	98	bool reliable)
	99	{
	100	if (in_sched_functions(addr))
	101	return true;
	102	return stack_trace_consume_entry(cookie, addr, reliable);
	103	}
	104
	105	/**
	106	* stack_trace_save - Save a stack trace into a storage array
	107	* @store: Pointer to storage array
	108	* @size: Size of the storage array
	109	* @skipnr: Number of entries to skip at the start of the stack trace
	110	*
	111	* Return: Number of trace entries stored.
	112	*/
	113	unsigned int stack_trace_save(unsigned long *store, unsigned int size,
	114	unsigned int skipnr)
	115	{
	116	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	117	struct stacktrace_cookie c = {
	118	.store = store,
	119	.size = size,
	120	.skip = skipnr + 1,
	121	};
	122
	123	arch_stack_walk(consume_entry, &c, current, NULL);
	124	return c.len;
	125	}
	126	EXPORT_SYMBOL_GPL(stack_trace_save);
	127
	128	/**
	129	* stack_trace_save_tsk - Save a task stack trace into a storage array
	130	* @task: The task to examine
	131	* @store: Pointer to storage array
	132	* @size: Size of the storage array
	133	* @skipnr: Number of entries to skip at the start of the stack trace
	134	*
	135	* Return: Number of trace entries stored.
136	*/
137	unsigned int stack_trace_save_tsk(struct task_struct tsk, unsigned long store,
138	unsigned int size, unsigned int skipnr)
139	{
140	stack_trace_consume_fn consume_entry = stack_trace_consume_entry_nosched;
141	struct stacktrace_cookie c = {
142	.store = store,
143	.size = size,
b0c51f15	144	/* skip this function if they are tracing us */
4b48512c	145	.skip = skipnr + (current == tsk),
214d8ca6 TG	146	};
	147
	148	if (!try_get_task_stack(tsk))
	149	return 0;
	150
	151	arch_stack_walk(consume_entry, &c, tsk, NULL);
	152	put_task_stack(tsk);
	153	return c.len;
	154	}
	155
	156	/**
	157	* stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array
	158	* @regs: Pointer to pt_regs to examine
	159	* @store: Pointer to storage array
	160	* @size: Size of the storage array
	161	* @skipnr: Number of entries to skip at the start of the stack trace
	162	*
	163	* Return: Number of trace entries stored.
	164	*/
	165	unsigned int stack_trace_save_regs(struct pt_regs regs, unsigned long store,
	166	unsigned int size, unsigned int skipnr)
	167	{
	168	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	169	struct stacktrace_cookie c = {
	170	.store = store,
	171	.size = size,
	172	.skip = skipnr,
	173	};
	174
	175	arch_stack_walk(consume_entry, &c, current, regs);
	176	return c.len;
	177	}
	178
	179	#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
	180	/**
	181	* stack_trace_save_tsk_reliable - Save task stack with verification
	182	* @tsk: Pointer to the task to examine
	183	* @store: Pointer to storage array
	184	* @size: Size of the storage array
	185	*
	186	* Return: An error if it detects any unreliable features of the
	187	* stack. Otherwise it guarantees that the stack trace is
	188	* reliable and returns the number of entries stored.
	189	*
	190	* If the task is not 'current', the caller must ensure the task is inactive.
	191	*/
	192	int stack_trace_save_tsk_reliable(struct task_struct tsk, unsigned long store,
	193	unsigned int size)
	194	{
	195	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	196	struct stacktrace_cookie c = {
	197	.store = store,
	198	.size = size,
	199	};
	200	int ret;
	201
	202	/*
	203	* If the task doesn't have a stack (e.g., a zombie), the stack is
	204	* "reliably" empty.
	205	*/
	206	if (!try_get_task_stack(tsk))
	207	return 0;
	208
	209	ret = arch_stack_walk_reliable(consume_entry, &c, tsk);
210	put_task_stack(tsk);
7eaf51a2	211	return ret ? ret : c.len;
214d8ca6 TG	212	}
	213	#endif
	214
	215	#ifdef CONFIG_USER_STACKTRACE_SUPPORT
	216	/**
	217	* stack_trace_save_user - Save a user space stack trace into a storage array
	218	* @store: Pointer to storage array
	219	* @size: Size of the storage array
	220	*
	221	* Return: Number of trace entries stored.
	222	*/
	223	unsigned int stack_trace_save_user(unsigned long *store, unsigned int size)
	224	{
	225	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	226	struct stacktrace_cookie c = {
	227	.store = store,
	228	.size = size,
	229	};
cac9b9a4	230	mm_segment_t fs;
214d8ca6 TG	231
214d8ca6 TG	232	/* Trace user stack if not a kernel thread */
7e8e6816	233	if (current->flags & PF_KTHREAD)
214d8ca6 TG	234	return 0;
214d8ca6 TG	235
3d13f313	236	fs = force_uaccess_begin();
214d8ca6	237	arch_stack_walk_user(consume_entry, &c, task_pt_regs(current));
3d13f313	238	force_uaccess_end(fs);
cac9b9a4	239
214d8ca6 TG	240	return c.len;
	241	}
	242	#endif
	243
	244	#else /* CONFIG_ARCH_STACKWALK */
	245
9212ddb5	246	/*
af085d90 JP	247	* Architectures that do not implement save_stack_trace_*()
af085d90 JP	248	* get these weak aliases and once-per-bootup warnings
c624d33f	249	* (whenever this facility is utilized - for example by procfs):
9212ddb5 IM	250	*/
	251	__weak void
	252	save_stack_trace_tsk(struct task_struct tsk, struct stack_trace trace)
	253	{
	254	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
	255	}
c624d33f MH	256
	257	__weak void
	258	save_stack_trace_regs(struct pt_regs regs, struct stack_trace trace)
	259	{
	260	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
	261	}
af085d90	262
e9b98e16 TG	263	/**
	264	* stack_trace_save - Save a stack trace into a storage array
	265	* @store: Pointer to storage array
	266	* @size: Size of the storage array
	267	* @skipnr: Number of entries to skip at the start of the stack trace
	268	*
	269	* Return: Number of trace entries stored
	270	*/
	271	unsigned int stack_trace_save(unsigned long *store, unsigned int size,
	272	unsigned int skipnr)
	273	{
	274	struct stack_trace trace = {
	275	.entries = store,
	276	.max_entries = size,
	277	.skip = skipnr + 1,
	278	};
	279
	280	save_stack_trace(&trace);
	281	return trace.nr_entries;
	282	}
	283	EXPORT_SYMBOL_GPL(stack_trace_save);
	284
	285	/**
	286	* stack_trace_save_tsk - Save a task stack trace into a storage array
	287	* @task: The task to examine
	288	* @store: Pointer to storage array
	289	* @size: Size of the storage array
	290	* @skipnr: Number of entries to skip at the start of the stack trace
	291	*
	292	* Return: Number of trace entries stored
	293	*/
	294	unsigned int stack_trace_save_tsk(struct task_struct *task,
	295	unsigned long *store, unsigned int size,
	296	unsigned int skipnr)
	297	{
	298	struct stack_trace trace = {
	299	.entries = store,
	300	.max_entries = size,
b0c51f15	301	/* skip this function if they are tracing us */
4b48512c	302	.skip = skipnr + (current == task),
e9b98e16 TG	303	};
	304
	305	save_stack_trace_tsk(task, &trace);
	306	return trace.nr_entries;
	307	}
	308
	309	/**
	310	* stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array
	311	* @regs: Pointer to pt_regs to examine
	312	* @store: Pointer to storage array
	313	* @size: Size of the storage array
	314	* @skipnr: Number of entries to skip at the start of the stack trace
	315	*
	316	* Return: Number of trace entries stored
	317	*/
	318	unsigned int stack_trace_save_regs(struct pt_regs regs, unsigned long store,
	319	unsigned int size, unsigned int skipnr)
	320	{
	321	struct stack_trace trace = {
	322	.entries = store,
	323	.max_entries = size,
	324	.skip = skipnr,
	325	};
	326
	327	save_stack_trace_regs(regs, &trace);
	328	return trace.nr_entries;
	329	}
	330
	331	#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
	332	/**
	333	* stack_trace_save_tsk_reliable - Save task stack with verification
	334	* @tsk: Pointer to the task to examine
	335	* @store: Pointer to storage array
	336	* @size: Size of the storage array
	337	*
	338	* Return: An error if it detects any unreliable features of the
	339	* stack. Otherwise it guarantees that the stack trace is
	340	* reliable and returns the number of entries stored.
	341	*
	342	* If the task is not 'current', the caller must ensure the task is inactive.
	343	*/
	344	int stack_trace_save_tsk_reliable(struct task_struct tsk, unsigned long store,
	345	unsigned int size)
	346	{
	347	struct stack_trace trace = {
	348	.entries = store,
	349	.max_entries = size,
	350	};
	351	int ret = save_stack_trace_tsk_reliable(tsk, &trace);
	352
	353	return ret ? ret : trace.nr_entries;
	354	}
	355	#endif
	356
	357	#ifdef CONFIG_USER_STACKTRACE_SUPPORT
	358	/**
	359	* stack_trace_save_user - Save a user space stack trace into a storage array
	360	* @store: Pointer to storage array
	361	* @size: Size of the storage array
	362	*
	363	* Return: Number of trace entries stored
	364	*/
	365	unsigned int stack_trace_save_user(unsigned long *store, unsigned int size)
	366	{
367	struct stack_trace trace = {
368	.entries = store,
369	.max_entries = size,
370	};
371
372	save_stack_trace_user(&trace);
373	return trace.nr_entries;
374	}
375	#endif /* CONFIG_USER_STACKTRACE_SUPPORT */
214d8ca6 TG	376
214d8ca6 TG	377	#endif /* !CONFIG_ARCH_STACKWALK */