1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Based on arch/arm/kernel/atags_proc.c
 4 */
 5
 6#include <linux/fs.h>
 7#include <linux/init.h>
 8#include <linux/printk.h>
 9#include <linux/proc_fs.h>
10#include <linux/slab.h>
11#include <linux/string.h>
12
13#include <asm/bootinfo.h>
14#include <asm/byteorder.h>
15
16
17static char bootinfo_tmp[1536] __initdata;
18
19static void *bootinfo_copy;
20static size_t bootinfo_size;
21
22static ssize_t bootinfo_read(struct file *file, char __user *buf,
23			  size_t count, loff_t *ppos)
24{
25	return simple_read_from_buffer(buf, count, ppos, bootinfo_copy,
26				       bootinfo_size);
27}
28
29static const struct proc_ops bootinfo_proc_ops = {
30	.proc_read	= bootinfo_read,
31	.proc_lseek	= default_llseek,
32};
33
34void __init save_bootinfo(const struct bi_record *bi)
35{
36	const void *start = bi;
37	size_t size = sizeof(bi->tag);
38
39	while (be16_to_cpu(bi->tag) != BI_LAST) {
40		uint16_t n = be16_to_cpu(bi->size);
41		size += n;
42		bi = (struct bi_record *)((unsigned long)bi + n);
43	}
44
45	if (size > sizeof(bootinfo_tmp)) {
46		pr_err("Cannot save %zu bytes of bootinfo\n", size);
47		return;
48	}
49
50	pr_info("Saving %zu bytes of bootinfo\n", size);
51	memcpy(bootinfo_tmp, start, size);
52	bootinfo_size = size;
53}
54
55static int __init init_bootinfo_procfs(void)
56{
57	/*
58	 * This cannot go into save_bootinfo() because kmalloc and proc don't
59	 * work yet when it is called.
60	 */
61	struct proc_dir_entry *pde;
62
63	if (!bootinfo_size)
64		return -EINVAL;
65
66	bootinfo_copy = kmemdup(bootinfo_tmp, bootinfo_size, GFP_KERNEL);
67	if (!bootinfo_copy)
68		return -ENOMEM;
69
70	pde = proc_create_data("bootinfo", 0400, NULL, &bootinfo_proc_ops, NULL);
71	if (!pde) {
72		kfree(bootinfo_copy);
73		return -ENOMEM;
74	}
75
76	return 0;
77}
78
79arch_initcall(init_bootinfo_procfs);

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Based on arch/arm/kernel/atags_proc.c
 4 */
 5
 6#include <linux/fs.h>
 7#include <linux/init.h>
 8#include <linux/printk.h>
 9#include <linux/proc_fs.h>
10#include <linux/slab.h>
11#include <linux/string.h>
12
13#include <asm/bootinfo.h>
14#include <asm/byteorder.h>
15
16
17static char bootinfo_tmp[1536] __initdata;
18
19static void *bootinfo_copy;
20static size_t bootinfo_size;
21
22static ssize_t bootinfo_read(struct file *file, char __user *buf,
23			  size_t count, loff_t *ppos)
24{
25	return simple_read_from_buffer(buf, count, ppos, bootinfo_copy,
26				       bootinfo_size);
27}
28
29static const struct proc_ops bootinfo_proc_ops = {
30	.proc_read	= bootinfo_read,
31	.proc_lseek	= default_llseek,
32};
33
34void __init save_bootinfo(const struct bi_record *bi)
35{
36	const void *start = bi;
37	size_t size = sizeof(bi->tag);
38
39	while (be16_to_cpu(bi->tag) != BI_LAST) {
40		uint16_t n = be16_to_cpu(bi->size);
41		size += n;
42		bi = (struct bi_record *)((unsigned long)bi + n);
43	}
44
45	if (size > sizeof(bootinfo_tmp)) {
46		pr_err("Cannot save %zu bytes of bootinfo\n", size);
47		return;
48	}
49
50	pr_info("Saving %zu bytes of bootinfo\n", size);
51	memcpy(bootinfo_tmp, start, size);
52	bootinfo_size = size;
53}
54
55static int __init init_bootinfo_procfs(void)
56{
57	/*
58	 * This cannot go into save_bootinfo() because kmalloc and proc don't
59	 * work yet when it is called.
60	 */
61	struct proc_dir_entry *pde;
62
63	if (!bootinfo_size)
64		return -EINVAL;
65
66	bootinfo_copy = kmemdup(bootinfo_tmp, bootinfo_size, GFP_KERNEL);
67	if (!bootinfo_copy)
68		return -ENOMEM;
69
70	pde = proc_create_data("bootinfo", 0400, NULL, &bootinfo_proc_ops, NULL);
71	if (!pde) {
72		kfree(bootinfo_copy);
73		return -ENOMEM;
74	}
75
76	return 0;
77}
78
79arch_initcall(init_bootinfo_procfs);