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
14void 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", 1 + spaces, ' ');
23		print_ip_sym(trace->entries[i]);
24	}
25}
26EXPORT_SYMBOL_GPL(print_stack_trace);
27
28int snprint_stack_trace(char *buf, size_t size,
29			struct stack_trace *trace, int spaces)
30{
31	int i;
32	unsigned long ip;
33	int generated;
34	int total = 0;
35
36	if (WARN_ON(!trace->entries))
37		return 0;
38
39	for (i = 0; i < trace->nr_entries; i++) {
40		ip = trace->entries[i];
41		generated = snprintf(buf, size, "%*c[<%p>] %pS\n",
42				1 + spaces, ' ', (void *) ip, (void *) ip);
43
44		total += generated;
45
46		/* Assume that generated isn't a negative number */
47		if (generated >= size) {
48			buf += size;
49			size = 0;
50		} else {
51			buf += generated;
52			size -= generated;
53		}
54	}
55
56	return total;
57}
58EXPORT_SYMBOL_GPL(snprint_stack_trace);
59
60/*
61 * Architectures that do not implement save_stack_trace_tsk or
62 * save_stack_trace_regs get this weak alias and a once-per-bootup warning
63 * (whenever this facility is utilized - for example by procfs):
64 */
65__weak void
66save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
67{
68	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
69}
70
71__weak void
72save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
73{
74	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
75}
76