1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* arch/arm64/kernel/return_address.c
*
* Copyright (C) 2013 Linaro Limited
* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
*/
#include <linux/export.h>
#include <linux/ftrace.h>
#include <linux/kprobes.h>
#include <linux/stacktrace.h>
#include <asm/stack_pointer.h>
struct return_address_data {
unsigned int level;
void *addr;
};
static bool save_return_addr(void *d, unsigned long pc)
{
struct return_address_data *data = d;
if (!data->level) {
data->addr = (void *)pc;
return false;
} else {
--data->level;
return true;
}
}
NOKPROBE_SYMBOL(save_return_addr);
void *return_address(unsigned int level)
{
struct return_address_data data;
data.level = level + 2;
data.addr = NULL;
arch_stack_walk(save_return_addr, &data, current, NULL);
if (!data.level)
return data.addr;
else
return NULL;
}
EXPORT_SYMBOL_GPL(return_address);
NOKPROBE_SYMBOL(return_address);
|
