path: root/kernel/stacktrace.c (plain)
blob: 9c15a9124e83b50661414fa425393cdb51866313

1	/*
2	* kernel/stacktrace.c
3	*
4	* Stack trace management functions
5	*
6	* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
7	*/
8	#include <linux/sched.h>
9	#include <linux/kernel.h>
10	#include <linux/export.h>
11	#include <linux/kallsyms.h>
12	#include <linux/stacktrace.h>
13
14	void print_stack_trace(struct stack_trace *trace, int spaces)
15	{
16	int i;
17
18	if (WARN_ON(!trace->entries))
19	return;
20
21	for (i = 0; i < trace->nr_entries; i++)
22	printk("%*c%pS\n", 1 + spaces, ' ', (void *)trace->entries[i]);
23	}
24	EXPORT_SYMBOL_GPL(print_stack_trace);
25
26	int snprint_stack_trace(char *buf, size_t size,
27	struct stack_trace *trace, int spaces)
28	{
29	int i;
30	int generated;
31	int total = 0;
32
33	if (WARN_ON(!trace->entries))
34	return 0;
35
36	for (i = 0; i < trace->nr_entries; i++) {
37	generated = snprintf(buf, size, "%*c%pS\n", 1 + spaces, ' ',
38	(void *)trace->entries[i]);
39
40	total += generated;
41
42	/* Assume that generated isn't a negative number */
43	if (generated >= size) {
44	buf += size;
45	size = 0;
46	} else {
47	buf += generated;
48	size -= generated;
49	}
50	}
51
52	return total;
53	}
54	EXPORT_SYMBOL_GPL(snprint_stack_trace);
55
56	/*
57	* Architectures that do not implement save_stack_trace_tsk or
58	* save_stack_trace_regs get this weak alias and a once-per-bootup warning
59	* (whenever this facility is utilized - for example by procfs):
60	*/
61	__weak void
62	save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
63	{
64	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
65	}
66
67	__weak void
68	save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
69	{
70	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
71	}
72