// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/minix_fs.h>
#include <linux/ext2_fs.h>
#include <linux/romfs_fs.h>
#include <uapi/linux/cramfs_fs.h>
#include <linux/initrd.h>
#include <linux/string.h>
#include <linux/slab.h>
#include "do_mounts.h"
#include "../fs/squashfs/squashfs_fs.h"
#include <linux/decompress/generic.h>
static struct file *in_file, *out_file;
static loff_t in_pos, out_pos;
static int __init prompt_ramdisk(char *str)
{
pr_warn("ignoring the deprecated prompt_ramdisk= option\n");
return 1;
}
__setup("prompt_ramdisk=", prompt_ramdisk);
int __initdata rd_image_start; /* starting block # of image */
static int __init ramdisk_start_setup(char *str)
{
rd_image_start = simple_strtol(str,NULL,0);
return 1;
}
__setup("ramdisk_start=", ramdisk_start_setup);
static int __init crd_load(decompress_fn deco);
/*
* This routine tries to find a RAM disk image to load, and returns the
* number of blocks to read for a non-compressed image, 0 if the image
* is a compressed image, and -1 if an image with the right magic
* numbers could not be found.
*
* We currently check for the following magic numbers:
* minix
* ext2
* romfs
* cramfs
* squashfs
* gzip
* bzip2
* lzma
* xz
* lzo
* lz4
*/
static int __init
identify_ramdisk_image(struct file *file, loff_t pos,
decompress_fn *decompressor)
{
const int size = 512;
struct minix_super_block *minixsb;
struct romfs_super_block *romfsb;
struct cramfs_super *cramfsb;
struct squashfs_super_block *squashfsb;
int nblocks = -1;
unsigned char *buf;
const char *compress_name;
unsigned long n;
int start_block = rd_image_start;
buf = kmalloc(size, GFP_KERNEL);
if (!buf)
return -ENOMEM;
minixsb = (struct minix_super_block *) buf;
romfsb = (struct romfs_super_block *) buf;
cramfsb = (struct cramfs_super *) buf;
squashfsb = (struct squashfs_super_block *) buf;
memset(buf, 0xe5, size);
/*
* Read block 0 to test for compressed kernel
*/
pos = start_block * BLOCK_SIZE;
kernel_read(file, buf, size, &pos);
*decompressor = decompress_method(buf, size, &compress_name);
if (compress_name) {
printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
compress_name, start_block);
if (!*decompressor)
printk(KERN_EMERG
"RAMDISK: %s decompressor not configured!\n",
compress_name);
nblocks = 0;
goto done;
}
/* romfs is at block zero too */
if (romfsb->word0 == ROMSB_WORD0 &&
romfsb->word1 == ROMSB_WORD1) {
printk(KERN_NOTICE
"RAMDISK: romfs filesystem found at block %d\n",
start_block);
nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS;
goto done;
}
if (cramfsb->magic == CRAMFS_MAGIC) {
printk(KERN_NOTICE
"RAMDISK: cramfs filesystem found at block %d\n",
start_block);
nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
goto done;
}
/* squashfs is at block zero too */
if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) {
printk(KERN_NOTICE
"RAMDISK: squashfs filesystem found at block %d\n",
start_block);
nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1)
>> BLOCK_SIZE_BITS;
goto done;
}
/*
* Read 512 bytes further to check if cramfs is padded
*/
pos = start_block * BLOCK_SIZE + 0x200;
kernel_read(file, buf, size, &pos);
if (cramfsb->magic == CRAMFS_MAGIC) {
printk(KERN_NOTICE
"RAMDISK: cramfs filesystem found at block %d\n",
start_block);
nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
goto done;
}
/*
* Read block 1 to test for minix and ext2 superblock
*/
pos = (start_block + 1) * BLOCK_SIZE;
kernel_read(file, buf, size, &pos);
/* Try minix */
if (minixsb->s_magic == MINIX_SUPER_MAGIC ||
minixsb->s_magic == MINIX_SUPER_MAGIC2) {
printk(KERN_NOTICE
"RAMDISK: Minix filesystem found at block %d\n",
start_block);
nblocks = minixsb->s_nzones << minixsb->s_log_zone_size;
goto done;
}
/* Try ext2 */
n = ext2_image_size(buf);
if (n) {
printk(KERN_NOTICE
"RAMDISK: ext2 filesystem found at block %d\n",
start_block);
nblocks = n;
goto done;
}
printk(KERN_NOTICE
"RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",
start_block);
done:
kfree(buf);
return nblocks;
}
static unsigned long nr_blocks(struct file *file)
{
struct inode *inode = file->f_mapping->host;
if (!S_ISBLK(inode->i_mode))
return 0;
return i_size_read(inode) >> 10;
}
int __init rd_load_image(char *from)
{
int res = 0;
unsigned long rd_blocks, devblocks;
int nblocks, i;
char *buf = NULL;
unsigned short rotate = 0;
decompress_fn decompressor = NULL;
#if !defined(CONFIG_S390)
char rotator[4] = { '|' , '/' , '-' , '\\' };
#endif
out_file = filp_open("/dev/ram", O_RDWR, 0);
if (IS_ERR(out_file))
goto out;
in_file = filp_open(from, O_RDONLY, 0);
if (IS_ERR(in_file))
goto noclose_input;
in_pos = rd_image_start * BLOCK_SIZE;
nblocks = identify_ramdisk_image(in_file, in_pos, &decompressor);
if (nblocks < 0)
goto done;
if (nblocks == 0) {
if (crd_load(decompressor) == 0)
goto successful_load;
goto done;
}
/*
* NOTE NOTE: nblocks is not actually blocks but
* the number of kibibytes of data to load into a ramdisk.
*/
rd_blocks = nr_blocks(out_file);
if (nblocks > rd_blocks) {
printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n",
nblocks, rd_blocks);
goto done;
}
/*
* OK, time to copy in the data
*/
if (strcmp(from, "/initrd.image") == 0)
devblocks = nblocks;
else
devblocks = nr_blocks(in_file);
if (devblocks == 0) {
printk(KERN_ERR "RAMDISK: could not determine device size\n");
goto done;
}
buf = kmalloc(BLOCK_SIZE, GFP_KERNEL);
if (!buf) {
printk(KERN_ERR "RAMDISK: could not allocate buffer\n");
goto done;
}
printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ",
nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : "");
for (i = 0; i < nblocks; i++) {
if (i && (i % devblocks == 0)) {
pr_cont("done disk #1.\n");
rotate = 0;
fput(in_file);
break;
}
kernel_read(in_file, buf, BLOCK_SIZE, &in_pos);
kernel_write(out_file, buf, BLOCK_SIZE, &out_pos);
#if !defined(CONFIG_S390)
if (!(i % 16)) {
pr_cont("%c\b", rotator[rotate & 0x3]);
rotate++;
}
#endif
}
pr_cont("done.\n");
successful_load:
res = 1;
done:
fput(in_file);
noclose_input:
fput(out_file);
out:
kfree(buf);
init_unlink("/dev/ram");
return res;
}
int __init rd_load_disk(int n)
{
create_dev("/dev/root", ROOT_DEV);
create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
return rd_load_image("/dev/root");
}
static int exit_code;
static int decompress_error;
static long __init compr_fill(void *buf, unsigned long len)
{
long r = kernel_read(in_file, buf, len, &in_pos);
if (r < 0)
printk(KERN_ERR "RAMDISK: error while reading compressed data");
else if (r == 0)
printk(KERN_ERR "RAMDISK: EOF while reading compressed data");
return r;
}
static long __init compr_flush(void *window, unsigned long outcnt)
{
long written = kernel_write(out_file, window, outcnt, &out_pos);
if (written != outcnt) {
if (decompress_error == 0)
printk(KERN_ERR
"RAMDISK: incomplete write (%ld != %ld)\n",
written, outcnt);
decompress_error = 1;
return -1;
}
return outcnt;
}
static void __init error(char *x)
{
printk(KERN_ERR "%s\n", x);
exit_code = 1;
decompress_error = 1;
}
static int __init crd_load(decompress_fn deco)
{
int result;
if (!deco) {
pr_emerg("Invalid ramdisk decompression routine. "
"Select appropriate config option.\n");
panic("Could not decompress initial ramdisk image.");
}
result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
if (decompress_error)
result = 1;
return result;
}
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