1/*
2 * arch/sh/kernel/stacktrace.c
3 *
4 * Stack trace management functions
5 *
6 *  Copyright (C) 2006 - 2008  Paul Mundt
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License.  See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12#include <linux/sched.h>
13#include <linux/stacktrace.h>
14#include <linux/thread_info.h>
15#include <linux/module.h>
16#include <asm/unwinder.h>
17#include <asm/ptrace.h>
18#include <asm/stacktrace.h>
19
20static int save_stack_stack(void *data, char *name)
21{
22	return 0;
23}
24
25/*
26 * Save stack-backtrace addresses into a stack_trace buffer.
27 */
28static void save_stack_address(void *data, unsigned long addr, int reliable)
29{
30	struct stack_trace *trace = data;
31
32	if (!reliable)
33		return;
34
35	if (trace->skip > 0) {
36		trace->skip--;
37		return;
38	}
39
40	if (trace->nr_entries < trace->max_entries)
41		trace->entries[trace->nr_entries++] = addr;
42}
43
44static const struct stacktrace_ops save_stack_ops = {
45	.stack = save_stack_stack,
46	.address = save_stack_address,
47};
48
49void save_stack_trace(struct stack_trace *trace)
50{
51	unsigned long *sp = (unsigned long *)current_stack_pointer;
52
53	unwind_stack(current, NULL, sp,  &save_stack_ops, trace);
54	if (trace->nr_entries < trace->max_entries)
55		trace->entries[trace->nr_entries++] = ULONG_MAX;
56}
57EXPORT_SYMBOL_GPL(save_stack_trace);
58
59static void
60save_stack_address_nosched(void *data, unsigned long addr, int reliable)
61{
62	struct stack_trace *trace = (struct stack_trace *)data;
63
64	if (!reliable)
65		return;
66
67	if (in_sched_functions(addr))
68		return;
69
70	if (trace->skip > 0) {
71		trace->skip--;
72		return;
73	}
74
75	if (trace->nr_entries < trace->max_entries)
76		trace->entries[trace->nr_entries++] = addr;
77}
78
79static const struct stacktrace_ops save_stack_ops_nosched = {
80	.stack = save_stack_stack,
81	.address = save_stack_address_nosched,
82};
83
84void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
85{
86	unsigned long *sp = (unsigned long *)tsk->thread.sp;
87
88	unwind_stack(current, NULL, sp,  &save_stack_ops_nosched, trace);
89	if (trace->nr_entries < trace->max_entries)
90		trace->entries[trace->nr_entries++] = ULONG_MAX;
91}
92EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
93