blob: 312cb89ec3648e7a6224229df45494a039e24cb1 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <asm/setup.h>
#include <asm/types.h>
#include <asm/page.h>
struct buffer {
size_t size;
char data[];
static ssize_t atags_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
struct buffer *b = PDE_DATA(file_inode(file));
return simple_read_from_buffer(buf, count, ppos, b->data, b->size);
static const struct file_operations atags_fops = {
.read = atags_read,
.llseek = default_llseek,
#define BOOT_PARAMS_SIZE 1536
static char __initdata atags_copy[BOOT_PARAMS_SIZE];
void __init save_atags(const struct tag *tags)
memcpy(atags_copy, tags, sizeof(atags_copy));
static int __init init_atags_procfs(void)
* This cannot go into save_atags() because kmalloc and proc don't work
* yet when it is called.
struct proc_dir_entry *tags_entry;
struct tag *tag = (struct tag *)atags_copy;
struct buffer *b;
size_t size;
if (tag->hdr.tag != ATAG_CORE) {
pr_info("No ATAGs?");
return -EINVAL;
for (; tag->hdr.size; tag = tag_next(tag))
/* include the terminating ATAG_NONE */
size = (char *)tag - atags_copy + sizeof(struct tag_header);
WARN_ON(tag->hdr.tag != ATAG_NONE);
b = kmalloc(sizeof(*b) + size, GFP_KERNEL);
if (!b)
goto nomem;
b->size = size;
memcpy(b->data, atags_copy, size);
tags_entry = proc_create_data("atags", 0400, NULL, &atags_fops, b);
if (!tags_entry)
goto nomem;
return 0;
pr_err("Exporting ATAGs: not enough memory\n");
return -ENOMEM;