Release 4.14 init/do_mounts_rd.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Many of the syscalls used in this file expect some of the arguments
 * to be __user pointers not __kernel pointers.  To limit the sparse
 * noise, turn off sparse checking for this file.
 */
#ifdef __CHECKER__

#undef __CHECKER__
#warning "Sparse checking disabled for this file"
#endif

#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>



int __initdata rd_prompt = 1;
/* 1 = prompt for RAM disk, 0 = don't prompt */



static int __init prompt_ramdisk(char *str)
{
	rd_prompt = simple_strtol(str,NULL,0) & 1;
	return 1;
}
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__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;
}
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__setup("ramdisk_start=", ramdisk_start_setup);

static int __init crd_load(int in_fd, int out_fd, 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(int fd, int start_block, 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;

	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
         */
	sys_lseek(fd, start_block * BLOCK_SIZE, 0);
	sys_read(fd, buf, size);

	*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
         */
	sys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0);
	sys_read(fd, buf, size);

	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
         */
	sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0);
	sys_read(fd, buf, size);

	/* 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:
	sys_lseek(fd, start_block * BLOCK_SIZE, 0);
	kfree(buf);
	return nblocks;
}

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Neil Armstrong
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11.65%
1
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Phillip Lougher
54
10.84%
1
7.69%
James Bottomley
51
10.24%
1
7.69%
H. Peter Anvin
37
7.43%
4
30.77%
Alain Knaff
21
4.22%
1
7.69%
Al Viro
13
2.61%
1
7.69%
Andrew Morton
5
1.00%
1
7.69%
Stephen Hemminger
1
0.20%
1
7.69%
Davidlohr Bueso A
1
0.20%
1
7.69%
Total
498
100.00%
13
100.00%



int __init rd_load_image(char *from)
{
	int res = 0;
	int in_fd, out_fd;
	unsigned long rd_blocks, devblocks;
	int nblocks, i, disk;
	char *buf = NULL;
	unsigned short rotate = 0;
	decompress_fn decompressor = NULL;
#if !defined(CONFIG_S390)
	char rotator[4] = { '|' , '/' , '-' , '\\' };
#endif

	out_fd = sys_open("/dev/ram", O_RDWR, 0);
	if (out_fd < 0)
		goto out;

	in_fd = sys_open(from, O_RDONLY, 0);
	if (in_fd < 0)
		goto noclose_input;

	nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor);
	if (nblocks < 0)
		goto done;

	if (nblocks == 0) {
		if (crd_load(in_fd, out_fd, 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.
         */
	if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0)
		rd_blocks = 0;
	else
		rd_blocks >>= 1;

	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 (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0)
		devblocks = 0;
	else
		devblocks >>= 1;

	if (strcmp(from, "/initrd.image") == 0)
		devblocks = nblocks;

	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, disk = 1; i < nblocks; i++) {
		if (i && (i % devblocks == 0)) {
			printk("done disk #%d.\n", disk++);
			rotate = 0;
			if (sys_close(in_fd)) {
				printk("Error closing the disk.\n");
				goto noclose_input;
			}
			change_floppy("disk #%d", disk);
			in_fd = sys_open(from, O_RDONLY, 0);
			if (in_fd < 0)  {
				printk("Error opening disk.\n");
				goto noclose_input;
			}
			printk("Loading disk #%d... ", disk);
		}
		sys_read(in_fd, buf, BLOCK_SIZE);
		sys_write(out_fd, buf, BLOCK_SIZE);
#if !defined(CONFIG_S390)
		if (!(i % 16)) {
			pr_cont("%c\b", rotator[rotate & 0x3]);
			rotate++;
		}
#endif
	}
	printk("done.\n");

successful_load:
	res = 1;
done:
	sys_close(in_fd);
noclose_input:
	sys_close(out_fd);
out:
	kfree(buf);
	sys_unlink("/dev/ram");
	return res;
}

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2.88%
2
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Alain Knaff
10
1.92%
1
10.00%
Eric W. Biedermann
2
0.38%
1
10.00%
Martin Schwidefsky
2
0.38%
1
10.00%
Harvey Harrison
1
0.19%
1
10.00%
Robert Elliott
1
0.19%
1
10.00%
Al Viro
1
0.19%
1
10.00%
Nicolas Schichan
1
0.19%
1
10.00%
Total
520
100.00%
10
100.00%



int __init rd_load_disk(int n)
{
	if (rd_prompt)
		change_floppy("root floppy disk to be loaded into RAM disk");
	create_dev("/dev/root", ROOT_DEV);
	create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
	return rd_load_image("/dev/root");
}

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static int exit_code;

static int decompress_error;


static int crd_infd, crd_outfd;



static long __init compr_fill(void *buf, unsigned long len)
{
	long r = sys_read(crd_infd, buf, len);
	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;
}

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23
41.82%
1
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Yinghai Lu
3
5.45%
1
20.00%
Andrew Morton
1
1.82%
1
20.00%
Andries E. Brouwer
1
1.82%
1
20.00%
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55
100.00%
5
100.00%



static long __init compr_flush(void *window, unsigned long outcnt)
{
	long written = sys_write(crd_outfd, window, outcnt);
	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;
}

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20
32.26%
1
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Yinghai Lu
4
6.45%
1
25.00%
Andrew Morton
1
1.61%
1
25.00%
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4
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static void __init error(char *x)
{
	printk(KERN_ERR "%s\n", x);
	exit_code = 1;
	decompress_error = 1;
}

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33.33%
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33.33%
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1
3.70%
1
33.33%
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27
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3
100.00%



static int __init crd_load(int in_fd, int out_fd, decompress_fn deco)
{
	int result;
	crd_infd = in_fd;
	crd_outfd = out_fd;

	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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33.33%
P J P
18
24.00%
1
33.33%
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17
22.67%
1
33.33%
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75
100.00%
3
100.00%

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6.06%
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103
7.17%
1
3.03%
Neil Armstrong
58
4.04%
1
3.03%
Phillip Lougher
55
3.83%
1
3.03%
James Bottomley
53
3.69%
1
3.03%
H. Peter Anvin
37
2.57%
4
12.12%
Andrew Morton
23
1.60%
3
9.09%
P J P
19
1.32%
2
6.06%
Al Viro
15
1.04%
3
9.09%
H Hartley Sweeten
12
0.84%
1
3.03%
Yinghai Lu
7
0.49%
1
3.03%
Adrian Bunk
3
0.21%
1
3.03%
Christoph Hellwig
3
0.21%
1
3.03%
Tejun Heo
3
0.21%
1
3.03%
Martin Schwidefsky
2
0.14%
1
3.03%
Ingo Molnar
2
0.14%
1
3.03%
Eric W. Biedermann
2
0.14%
1
3.03%
Nicolas Schichan
1
0.07%
1
3.03%
Greg Kroah-Hartman
1
0.07%
1
3.03%
Davidlohr Bueso A
1
0.07%
1
3.03%
Harvey Harrison
1
0.07%
1
3.03%
Andries E. Brouwer
1
0.07%
1
3.03%
Robert Elliott
1
0.07%
1
3.03%
Stephen Hemminger
1
0.07%
1
3.03%
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