1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2022 Huawei Device Co., Ltd.
4 */
5
6 #include <linux/ptrace.h>
7 #include <linux/sched/mm.h>
8 #include "internal.h"
9
10 #define XPM_REGION_LEN 48
xpm_region_open(struct inode * inode,struct file * file)11 static int xpm_region_open(struct inode *inode, struct file *file)
12 {
13 struct mm_struct *mm = proc_mem_open(inode, PTRACE_MODE_READ);
14
15 if (IS_ERR(mm))
16 return PTR_ERR(mm);
17
18 file->private_data = mm;
19 return 0;
20 }
21
xpm_region_read(struct file * file,char __user * buf,size_t count,loff_t * pos)22 static ssize_t xpm_region_read(struct file *file, char __user *buf,
23 size_t count, loff_t *pos)
24 {
25 struct mm_struct *mm = file->private_data;
26 char xpm_region[XPM_REGION_LEN] = {0};
27 size_t len;
28
29 if (!mm)
30 return 0;
31
32 len = snprintf(xpm_region, XPM_REGION_LEN - 1, "%lx-%lx",
33 mm->xpm_region.addr_start,
34 mm->xpm_region.addr_end);
35
36 return simple_read_from_buffer(buf, count, pos, xpm_region, len);
37 }
38
xpm_region_release(struct inode * inode,struct file * file)39 static int xpm_region_release(struct inode *inode, struct file *file)
40 {
41 struct mm_struct *mm = file->private_data;
42
43 if (mm)
44 mmdrop(mm);
45
46 return 0;
47 }
48
49 const struct file_operations proc_xpm_region_operations = {
50 .open = xpm_region_open,
51 .read = xpm_region_read,
52 .llseek = generic_file_llseek,
53 .release = xpm_region_release,
54 };