[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>
#include <linux/interrupt.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)
{
	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)
{
	if (in_sched_functions(addr))
		return true;
	return stack_trace_consume_entry(cookie, addr);
}

/**
 * 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,
	};

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

	arch_stack_walk_user(consume_entry, &c, task_pt_regs(current));

	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 */

static inline bool in_irqentry_text(unsigned long ptr)
{
	return (ptr >= (unsigned long)&__irqentry_text_start &&
		ptr < (unsigned long)&__irqentry_text_end) ||
		(ptr >= (unsigned long)&__softirqentry_text_start &&
		 ptr < (unsigned long)&__softirqentry_text_end);
}

/**
 * filter_irq_stacks - Find first IRQ stack entry in trace
 * @entries:	Pointer to stack trace array
 * @nr_entries:	Number of entries in the storage array
 *
 * Return: Number of trace entries until IRQ stack starts.
 */
unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries)
{
	unsigned int i;

	for (i = 0; i < nr_entries; i++) {
		if (in_irqentry_text(entries[i])) {
			/* Include the irqentry function into the stack. */
			return i + 1;
		}
	}
	return nr_entries;
}
EXPORT_SYMBOL_GPL(filter_irq_stacks);
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>
8637c099 IM	15	#include <linux/stacktrace.h>
f39f21b3	16	#include <linux/interrupt.h>
8637c099	17
e9b98e16 TG	18	/**
	19	* stack_trace_print - Print the entries in the stack trace
	20	* @entries: Pointer to storage array
	21	* @nr_entries: Number of entries in the storage array
	22	* @spaces: Number of leading spaces to print
	23	*/
a2970421	24	void stack_trace_print(const unsigned long *entries, unsigned int nr_entries,
e9b98e16	25	int spaces)
8637c099	26	{
e9b98e16	27	unsigned int i;
8637c099	28
e9b98e16	29	if (WARN_ON(!entries))
bfeeeeb9 JB	30	return;
bfeeeeb9 JB	31
e9b98e16 TG	32	for (i = 0; i < nr_entries; i++)
	33	printk("%c%pS\n", 1 + spaces, ' ', (void )entries[i]);
	34	}
	35	EXPORT_SYMBOL_GPL(stack_trace_print);
	36
e9b98e16 TG	37	/**
	38	* stack_trace_snprint - Print the entries in the stack trace into a buffer
	39	* @buf: Pointer to the print buffer
	40	* @size: Size of the print buffer
	41	* @entries: Pointer to storage array
	42	* @nr_entries: Number of entries in the storage array
	43	* @spaces: Number of leading spaces to print
	44	*
	45	* Return: Number of bytes printed.
	46	*/
a2970421	47	int stack_trace_snprint(char buf, size_t size, const unsigned long entries,
e9b98e16	48	unsigned int nr_entries, int spaces)
9a92a6ce	49	{
e9b98e16	50	unsigned int generated, i, total = 0;
9a92a6ce	51
e9b98e16	52	if (WARN_ON(!entries))
9a92a6ce JK	53	return 0;
9a92a6ce JK	54
e9b98e16	55	for (i = 0; i < nr_entries && size; i++) {
bfeda41d	56	generated = snprintf(buf, size, "%*c%pS\n", 1 + spaces, ' ',
e9b98e16	57	(void *)entries[i]);
9a92a6ce JK	58
9a92a6ce JK	59	total += generated;
9a92a6ce JK	60	if (generated >= size) {
	61	buf += size;
	62	size = 0;
	63	} else {
	64	buf += generated;
	65	size -= generated;
	66	}
	67	}
	68
	69	return total;
	70	}
e9b98e16 TG	71	EXPORT_SYMBOL_GPL(stack_trace_snprint);
e9b98e16 TG	72
214d8ca6 TG	73	#ifdef CONFIG_ARCH_STACKWALK
	74
	75	struct stacktrace_cookie {
	76	unsigned long *store;
	77	unsigned int size;
	78	unsigned int skip;
	79	unsigned int len;
	80	};
	81
264c03a2	82	static bool stack_trace_consume_entry(void *cookie, unsigned long addr)
214d8ca6 TG	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
264c03a2	97	static bool stack_trace_consume_entry_nosched(void *cookie, unsigned long addr)
214d8ca6 TG	98	{
	99	if (in_sched_functions(addr))
	100	return true;
264c03a2	101	return stack_trace_consume_entry(cookie, addr);
214d8ca6 TG	102	}
	103
	104	/**
	105	* stack_trace_save - Save a stack trace into a storage array
	106	* @store: Pointer to storage array
	107	* @size: Size of the storage array
	108	* @skipnr: Number of entries to skip at the start of the stack trace
	109	*
	110	* Return: Number of trace entries stored.
	111	*/
	112	unsigned int stack_trace_save(unsigned long *store, unsigned int size,
	113	unsigned int skipnr)
	114	{
	115	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	116	struct stacktrace_cookie c = {
	117	.store = store,
	118	.size = size,
	119	.skip = skipnr + 1,
	120	};
	121
	122	arch_stack_walk(consume_entry, &c, current, NULL);
	123	return c.len;
	124	}
	125	EXPORT_SYMBOL_GPL(stack_trace_save);
	126
	127	/**
	128	* stack_trace_save_tsk - Save a task stack trace into a storage array
	129	* @task: The task to examine
	130	* @store: Pointer to storage array
	131	* @size: Size of the storage array
	132	* @skipnr: Number of entries to skip at the start of the stack trace
	133	*
	134	* Return: Number of trace entries stored.
	135	*/
	136	unsigned int stack_trace_save_tsk(struct task_struct tsk, unsigned long store,
	137	unsigned int size, unsigned int skipnr)
	138	{
	139	stack_trace_consume_fn consume_entry = stack_trace_consume_entry_nosched;
	140	struct stacktrace_cookie c = {
	141	.store = store,
	142	.size = size,
b0c51f15	143	/* skip this function if they are tracing us */
4b48512c	144	.skip = skipnr + (current == tsk),
214d8ca6 TG	145	};
	146
	147	if (!try_get_task_stack(tsk))
	148	return 0;
	149
	150	arch_stack_walk(consume_entry, &c, tsk, NULL);
	151	put_task_stack(tsk);
	152	return c.len;
	153	}
	154
	155	/**
	156	* stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array
	157	* @regs: Pointer to pt_regs to examine
	158	* @store: Pointer to storage array
	159	* @size: Size of the storage array
	160	* @skipnr: Number of entries to skip at the start of the stack trace
	161	*
	162	* Return: Number of trace entries stored.
	163	*/
	164	unsigned int stack_trace_save_regs(struct pt_regs regs, unsigned long store,
	165	unsigned int size, unsigned int skipnr)
	166	{
	167	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	168	struct stacktrace_cookie c = {
	169	.store = store,
	170	.size = size,
	171	.skip = skipnr,
	172	};
	173
	174	arch_stack_walk(consume_entry, &c, current, regs);
	175	return c.len;
	176	}
	177
	178	#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
	179	/**
	180	* stack_trace_save_tsk_reliable - Save task stack with verification
	181	* @tsk: Pointer to the task to examine
	182	* @store: Pointer to storage array
	183	* @size: Size of the storage array
	184	*
	185	* Return: An error if it detects any unreliable features of the
	186	* stack. Otherwise it guarantees that the stack trace is
	187	* reliable and returns the number of entries stored.
	188	*
	189	* If the task is not 'current', the caller must ensure the task is inactive.
	190	*/
	191	int stack_trace_save_tsk_reliable(struct task_struct tsk, unsigned long store,
	192	unsigned int size)
	193	{
	194	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	195	struct stacktrace_cookie c = {
	196	.store = store,
	197	.size = size,
	198	};
	199	int ret;
	200
	201	/*
	202	* If the task doesn't have a stack (e.g., a zombie), the stack is
	203	* "reliably" empty.
	204	*/
	205	if (!try_get_task_stack(tsk))
	206	return 0;
	207
	208	ret = arch_stack_walk_reliable(consume_entry, &c, tsk);
209	put_task_stack(tsk);
7eaf51a2	210	return ret ? ret : c.len;
214d8ca6 TG	211	}
	212	#endif
	213
	214	#ifdef CONFIG_USER_STACKTRACE_SUPPORT
	215	/**
	216	* stack_trace_save_user - Save a user space stack trace into a storage array
	217	* @store: Pointer to storage array
	218	* @size: Size of the storage array
	219	*
	220	* Return: Number of trace entries stored.
	221	*/
	222	unsigned int stack_trace_save_user(unsigned long *store, unsigned int size)
	223	{
	224	stack_trace_consume_fn consume_entry = stack_trace_consume_entry;
	225	struct stacktrace_cookie c = {
	226	.store = store,
	227	.size = size,
	228	};
	229
	230	/* Trace user stack if not a kernel thread */
7e8e6816	231	if (current->flags & PF_KTHREAD)
214d8ca6 TG	232	return 0;
	233
	234	arch_stack_walk_user(consume_entry, &c, task_pt_regs(current));
cac9b9a4	235
214d8ca6 TG	236	return c.len;
	237	}
	238	#endif
	239
	240	#else /* CONFIG_ARCH_STACKWALK */
	241
9212ddb5	242	/*
af085d90 JP	243	* Architectures that do not implement save_stack_trace_*()
af085d90 JP	244	* get these weak aliases and once-per-bootup warnings
c624d33f	245	* (whenever this facility is utilized - for example by procfs):
9212ddb5 IM	246	*/
	247	__weak void
	248	save_stack_trace_tsk(struct task_struct tsk, struct stack_trace trace)
	249	{
	250	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
	251	}
c624d33f MH	252
	253	__weak void
	254	save_stack_trace_regs(struct pt_regs regs, struct stack_trace trace)
	255	{
	256	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
	257	}
af085d90	258
e9b98e16 TG	259	/**
	260	* stack_trace_save - Save a stack trace into a storage array
	261	* @store: Pointer to storage array
	262	* @size: Size of the storage array
	263	* @skipnr: Number of entries to skip at the start of the stack trace
	264	*
	265	* Return: Number of trace entries stored
	266	*/
	267	unsigned int stack_trace_save(unsigned long *store, unsigned int size,
	268	unsigned int skipnr)
	269	{
	270	struct stack_trace trace = {
	271	.entries = store,
	272	.max_entries = size,
	273	.skip = skipnr + 1,
	274	};
	275
	276	save_stack_trace(&trace);
	277	return trace.nr_entries;
	278	}
	279	EXPORT_SYMBOL_GPL(stack_trace_save);
	280
	281	/**
	282	* stack_trace_save_tsk - Save a task stack trace into a storage array
	283	* @task: The task to examine
	284	* @store: Pointer to storage array
	285	* @size: Size of the storage array
	286	* @skipnr: Number of entries to skip at the start of the stack trace
	287	*
	288	* Return: Number of trace entries stored
	289	*/
	290	unsigned int stack_trace_save_tsk(struct task_struct *task,
	291	unsigned long *store, unsigned int size,
	292	unsigned int skipnr)
	293	{
	294	struct stack_trace trace = {
	295	.entries = store,
	296	.max_entries = size,
b0c51f15	297	/* skip this function if they are tracing us */
4b48512c	298	.skip = skipnr + (current == task),
e9b98e16 TG	299	};
	300
	301	save_stack_trace_tsk(task, &trace);
	302	return trace.nr_entries;
	303	}
	304
	305	/**
	306	* stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array
	307	* @regs: Pointer to pt_regs to examine
	308	* @store: Pointer to storage array
	309	* @size: Size of the storage array
	310	* @skipnr: Number of entries to skip at the start of the stack trace
	311	*
	312	* Return: Number of trace entries stored
	313	*/
	314	unsigned int stack_trace_save_regs(struct pt_regs regs, unsigned long store,
	315	unsigned int size, unsigned int skipnr)
	316	{
	317	struct stack_trace trace = {
	318	.entries = store,
	319	.max_entries = size,
	320	.skip = skipnr,
	321	};
	322
	323	save_stack_trace_regs(regs, &trace);
	324	return trace.nr_entries;
	325	}
	326
	327	#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
	328	/**
	329	* stack_trace_save_tsk_reliable - Save task stack with verification
	330	* @tsk: Pointer to the task to examine
	331	* @store: Pointer to storage array
	332	* @size: Size of the storage array
	333	*
	334	* Return: An error if it detects any unreliable features of the
	335	* stack. Otherwise it guarantees that the stack trace is
	336	* reliable and returns the number of entries stored.
	337	*
	338	* If the task is not 'current', the caller must ensure the task is inactive.
	339	*/
	340	int stack_trace_save_tsk_reliable(struct task_struct tsk, unsigned long store,
	341	unsigned int size)
	342	{
	343	struct stack_trace trace = {
	344	.entries = store,
	345	.max_entries = size,
	346	};
	347	int ret = save_stack_trace_tsk_reliable(tsk, &trace);
	348
	349	return ret ? ret : trace.nr_entries;
	350	}
	351	#endif
	352
	353	#ifdef CONFIG_USER_STACKTRACE_SUPPORT
	354	/**
	355	* stack_trace_save_user - Save a user space stack trace into a storage array
	356	* @store: Pointer to storage array
	357	* @size: Size of the storage array
	358	*
	359	* Return: Number of trace entries stored
	360	*/
	361	unsigned int stack_trace_save_user(unsigned long *store, unsigned int size)
	362	{
363	struct stack_trace trace = {
364	.entries = store,
365	.max_entries = size,
366	};
367
368	save_stack_trace_user(&trace);
369	return trace.nr_entries;
370	}
371	#endif /* CONFIG_USER_STACKTRACE_SUPPORT */
214d8ca6 TG	372
214d8ca6 TG	373	#endif /* !CONFIG_ARCH_STACKWALK */
f39f21b3 ME	374
	375	static inline bool in_irqentry_text(unsigned long ptr)
	376	{
	377	return (ptr >= (unsigned long)&__irqentry_text_start &&
	378	ptr < (unsigned long)&__irqentry_text_end) \|\|
	379	(ptr >= (unsigned long)&__softirqentry_text_start &&
	380	ptr < (unsigned long)&__softirqentry_text_end);
	381	}
	382
	383	/**
	384	* filter_irq_stacks - Find first IRQ stack entry in trace
	385	* @entries: Pointer to stack trace array
	386	* @nr_entries: Number of entries in the storage array
	387	*
	388	* Return: Number of trace entries until IRQ stack starts.
	389	*/
	390	unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries)
	391	{
	392	unsigned int i;
	393
	394	for (i = 0; i < nr_entries; i++) {
	395	if (in_irqentry_text(entries[i])) {
	396	/* Include the irqentry function into the stack. */
	397	return i + 1;
	398	}
	399	}
	400	return nr_entries;
	401	}
	402	EXPORT_SYMBOL_GPL(filter_irq_stacks);