1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sh/kernel/stacktrace.c
4 *
5 * Stack trace management functions
6 *
7 *  Copyright (C) 2006 - 2008  Paul Mundt
8 */
9#include <linux/sched.h>
10#include <linux/sched/debug.h>
11#include <linux/stacktrace.h>
12#include <linux/thread_info.h>
13#include <linux/module.h>
14#include <asm/unwinder.h>
15#include <asm/ptrace.h>
16#include <asm/stacktrace.h>
17
18/*
19 * Save stack-backtrace addresses into a stack_trace buffer.
20 */
21static void save_stack_address(void *data, unsigned long addr, int reliable)
22{
23	struct stack_trace *trace = data;
24
25	if (!reliable)
26		return;
27
28	if (trace->skip > 0) {
29		trace->skip--;
30		return;
31	}
32
33	if (trace->nr_entries < trace->max_entries)
34		trace->entries[trace->nr_entries++] = addr;
35}
36
37static const struct stacktrace_ops save_stack_ops = {
38	.address = save_stack_address,
39};
40
41void save_stack_trace(struct stack_trace *trace)
42{
43	unsigned long *sp = (unsigned long *)current_stack_pointer;
44
45	unwind_stack(current, NULL, sp,  &save_stack_ops, trace);
46}
47EXPORT_SYMBOL_GPL(save_stack_trace);
48
49static void
50save_stack_address_nosched(void *data, unsigned long addr, int reliable)
51{
52	struct stack_trace *trace = (struct stack_trace *)data;
53
54	if (!reliable)
55		return;
56
57	if (in_sched_functions(addr))
58		return;
59
60	if (trace->skip > 0) {
61		trace->skip--;
62		return;
63	}
64
65	if (trace->nr_entries < trace->max_entries)
66		trace->entries[trace->nr_entries++] = addr;
67}
68
69static const struct stacktrace_ops save_stack_ops_nosched = {
70	.address = save_stack_address_nosched,
71};
72
73void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
74{
75	unsigned long *sp = (unsigned long *)tsk->thread.sp;
76
77	unwind_stack(current, NULL, sp,  &save_stack_ops_nosched, trace);
78}
79EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
80