mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![H. Peter Anvin](/assets/img/avatar_default.png)
Impact: More consistent behaviour, avoid policy in the kernel Upgrade/downgrade initrd/initramfs decompression failure from inconsistently a panic or a KERN_ALERT message to a KERN_EMERG event. It is, however, possible do design a system which can recover from this (using the kernel builtin code and/or the internal initramfs), which means this is policy, not a technical necessity. A good way to handle this would be to have a panic-level=X option, to force a panic on a printk above a certain level. That is a separate patch, however. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
326 lines
8 KiB
C
326 lines
8 KiB
C
|
|
#include <linux/kernel.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/minix_fs.h>
|
|
#include <linux/ext2_fs.h>
|
|
#include <linux/romfs_fs.h>
|
|
#include <linux/cramfs_fs.h>
|
|
#include <linux/initrd.h>
|
|
#include <linux/string.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;
|
|
}
|
|
__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(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
|
|
*/
|
|
static int __init
|
|
identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
|
|
{
|
|
const int size = 512;
|
|
struct minix_super_block *minixsb;
|
|
struct ext2_super_block *ext2sb;
|
|
struct romfs_super_block *romfsb;
|
|
struct cramfs_super *cramfsb;
|
|
struct squashfs_super_block *squashfsb;
|
|
int nblocks = -1;
|
|
unsigned char *buf;
|
|
const char *compress_name;
|
|
|
|
buf = kmalloc(size, GFP_KERNEL);
|
|
if (!buf)
|
|
return -1;
|
|
|
|
minixsb = (struct minix_super_block *) buf;
|
|
ext2sb = (struct ext2_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 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 */
|
|
if (ext2sb->s_magic == cpu_to_le16(EXT2_SUPER_MAGIC)) {
|
|
printk(KERN_NOTICE
|
|
"RAMDISK: ext2 filesystem found at block %d\n",
|
|
start_block);
|
|
nblocks = le32_to_cpu(ext2sb->s_blocks_count) <<
|
|
le32_to_cpu(ext2sb->s_log_block_size);
|
|
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;
|
|
}
|
|
|
|
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) && !defined(CONFIG_PPC_ISERIES)
|
|
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.
|
|
* So any ramdisk block size that is a multiple of 1KiB should
|
|
* work when the appropriate ramdisk_blocksize is specified
|
|
* on the command line.
|
|
*
|
|
* The default ramdisk_blocksize is 1KiB and it is generally
|
|
* silly to use anything else, so make sure to use 1KiB
|
|
* blocksize while generating ext2fs ramdisk-images.
|
|
*/
|
|
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) && !defined(CONFIG_PPC_ISERIES)
|
|
if (!(i % 16)) {
|
|
printk("%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;
|
|
}
|
|
|
|
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");
|
|
}
|
|
|
|
static int exit_code;
|
|
static int decompress_error;
|
|
static int crd_infd, crd_outfd;
|
|
|
|
static int __init compr_fill(void *buf, unsigned int len)
|
|
{
|
|
int 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;
|
|
}
|
|
|
|
static int __init compr_flush(void *window, unsigned int outcnt)
|
|
{
|
|
int written = sys_write(crd_outfd, window, outcnt);
|
|
if (written != outcnt) {
|
|
if (decompress_error == 0)
|
|
printk(KERN_ERR
|
|
"RAMDISK: incomplete write (%d != %d)\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(int in_fd, int out_fd, decompress_fn deco)
|
|
{
|
|
int result;
|
|
crd_infd = in_fd;
|
|
crd_outfd = out_fd;
|
|
result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
|
|
if (decompress_error)
|
|
result = 1;
|
|
return result;
|
|
}
|