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6ad018e3ca
Sparse checking used to be disabled on init/do_mounts.c and a few related
files because "Many of the syscalls used in this file expect some of the
arguments to be __user pointers not __kernel pointers".
However since 28128c61e
("kconfig.h: Include compiler types to avoid
missed struct attributes") the checks are, in fact, not disabled anymore
because of the more early include of "linux/compiler_types.h"
So remove the now ineffective #undefery that was done to disable these
warnings, as well as the associated comment.
Link: http://lkml.kernel.org/r/20180617115355.53799-1-luc.vanoostenryck@gmail.com
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
346 lines
8.1 KiB
C
346 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/minix_fs.h>
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#include <linux/ext2_fs.h>
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#include <linux/romfs_fs.h>
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#include <uapi/linux/cramfs_fs.h>
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#include <linux/initrd.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include "do_mounts.h"
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#include "../fs/squashfs/squashfs_fs.h"
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#include <linux/decompress/generic.h>
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int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */
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static int __init prompt_ramdisk(char *str)
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{
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rd_prompt = simple_strtol(str,NULL,0) & 1;
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return 1;
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}
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__setup("prompt_ramdisk=", prompt_ramdisk);
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int __initdata rd_image_start; /* starting block # of image */
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static int __init ramdisk_start_setup(char *str)
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{
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rd_image_start = simple_strtol(str,NULL,0);
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return 1;
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}
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__setup("ramdisk_start=", ramdisk_start_setup);
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static int __init crd_load(int in_fd, int out_fd, decompress_fn deco);
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/*
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* This routine tries to find a RAM disk image to load, and returns the
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* number of blocks to read for a non-compressed image, 0 if the image
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* is a compressed image, and -1 if an image with the right magic
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* numbers could not be found.
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*
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* We currently check for the following magic numbers:
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* minix
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* ext2
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* romfs
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* cramfs
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* squashfs
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* gzip
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* bzip2
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* lzma
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* xz
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* lzo
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* lz4
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*/
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static int __init
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identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
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{
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const int size = 512;
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struct minix_super_block *minixsb;
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struct romfs_super_block *romfsb;
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struct cramfs_super *cramfsb;
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struct squashfs_super_block *squashfsb;
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int nblocks = -1;
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unsigned char *buf;
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const char *compress_name;
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unsigned long n;
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buf = kmalloc(size, GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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minixsb = (struct minix_super_block *) buf;
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romfsb = (struct romfs_super_block *) buf;
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cramfsb = (struct cramfs_super *) buf;
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squashfsb = (struct squashfs_super_block *) buf;
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memset(buf, 0xe5, size);
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/*
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* Read block 0 to test for compressed kernel
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*/
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ksys_lseek(fd, start_block * BLOCK_SIZE, 0);
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ksys_read(fd, buf, size);
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*decompressor = decompress_method(buf, size, &compress_name);
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if (compress_name) {
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printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
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compress_name, start_block);
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if (!*decompressor)
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printk(KERN_EMERG
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"RAMDISK: %s decompressor not configured!\n",
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compress_name);
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nblocks = 0;
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goto done;
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}
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/* romfs is at block zero too */
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if (romfsb->word0 == ROMSB_WORD0 &&
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romfsb->word1 == ROMSB_WORD1) {
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printk(KERN_NOTICE
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"RAMDISK: romfs filesystem found at block %d\n",
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start_block);
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nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS;
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goto done;
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}
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if (cramfsb->magic == CRAMFS_MAGIC) {
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printk(KERN_NOTICE
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"RAMDISK: cramfs filesystem found at block %d\n",
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start_block);
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nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
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goto done;
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}
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/* squashfs is at block zero too */
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if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) {
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printk(KERN_NOTICE
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"RAMDISK: squashfs filesystem found at block %d\n",
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start_block);
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nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1)
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>> BLOCK_SIZE_BITS;
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goto done;
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}
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/*
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* Read 512 bytes further to check if cramfs is padded
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*/
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ksys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0);
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ksys_read(fd, buf, size);
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if (cramfsb->magic == CRAMFS_MAGIC) {
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printk(KERN_NOTICE
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"RAMDISK: cramfs filesystem found at block %d\n",
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start_block);
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nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
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goto done;
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}
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/*
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* Read block 1 to test for minix and ext2 superblock
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*/
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ksys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0);
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ksys_read(fd, buf, size);
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/* Try minix */
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if (minixsb->s_magic == MINIX_SUPER_MAGIC ||
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minixsb->s_magic == MINIX_SUPER_MAGIC2) {
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printk(KERN_NOTICE
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"RAMDISK: Minix filesystem found at block %d\n",
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start_block);
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nblocks = minixsb->s_nzones << minixsb->s_log_zone_size;
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goto done;
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}
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/* Try ext2 */
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n = ext2_image_size(buf);
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if (n) {
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printk(KERN_NOTICE
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"RAMDISK: ext2 filesystem found at block %d\n",
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start_block);
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nblocks = n;
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goto done;
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}
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printk(KERN_NOTICE
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"RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",
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start_block);
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done:
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ksys_lseek(fd, start_block * BLOCK_SIZE, 0);
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kfree(buf);
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return nblocks;
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}
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int __init rd_load_image(char *from)
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{
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int res = 0;
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int in_fd, out_fd;
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unsigned long rd_blocks, devblocks;
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int nblocks, i, disk;
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char *buf = NULL;
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unsigned short rotate = 0;
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decompress_fn decompressor = NULL;
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#if !defined(CONFIG_S390)
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char rotator[4] = { '|' , '/' , '-' , '\\' };
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#endif
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out_fd = ksys_open("/dev/ram", O_RDWR, 0);
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if (out_fd < 0)
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goto out;
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in_fd = ksys_open(from, O_RDONLY, 0);
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if (in_fd < 0)
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goto noclose_input;
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nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor);
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if (nblocks < 0)
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goto done;
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if (nblocks == 0) {
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if (crd_load(in_fd, out_fd, decompressor) == 0)
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goto successful_load;
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goto done;
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}
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/*
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* NOTE NOTE: nblocks is not actually blocks but
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* the number of kibibytes of data to load into a ramdisk.
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*/
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if (ksys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0)
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rd_blocks = 0;
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else
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rd_blocks >>= 1;
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if (nblocks > rd_blocks) {
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printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n",
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nblocks, rd_blocks);
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goto done;
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}
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/*
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* OK, time to copy in the data
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*/
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if (ksys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0)
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devblocks = 0;
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else
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devblocks >>= 1;
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if (strcmp(from, "/initrd.image") == 0)
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devblocks = nblocks;
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if (devblocks == 0) {
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printk(KERN_ERR "RAMDISK: could not determine device size\n");
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goto done;
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}
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buf = kmalloc(BLOCK_SIZE, GFP_KERNEL);
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if (!buf) {
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printk(KERN_ERR "RAMDISK: could not allocate buffer\n");
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goto done;
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}
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printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ",
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nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : "");
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for (i = 0, disk = 1; i < nblocks; i++) {
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if (i && (i % devblocks == 0)) {
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pr_cont("done disk #%d.\n", disk++);
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rotate = 0;
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if (ksys_close(in_fd)) {
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printk("Error closing the disk.\n");
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goto noclose_input;
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}
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change_floppy("disk #%d", disk);
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in_fd = ksys_open(from, O_RDONLY, 0);
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if (in_fd < 0) {
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printk("Error opening disk.\n");
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goto noclose_input;
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}
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printk("Loading disk #%d... ", disk);
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}
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ksys_read(in_fd, buf, BLOCK_SIZE);
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ksys_write(out_fd, buf, BLOCK_SIZE);
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#if !defined(CONFIG_S390)
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if (!(i % 16)) {
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pr_cont("%c\b", rotator[rotate & 0x3]);
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rotate++;
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}
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#endif
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}
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pr_cont("done.\n");
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successful_load:
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res = 1;
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done:
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ksys_close(in_fd);
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noclose_input:
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ksys_close(out_fd);
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out:
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kfree(buf);
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ksys_unlink("/dev/ram");
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return res;
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}
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int __init rd_load_disk(int n)
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{
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if (rd_prompt)
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change_floppy("root floppy disk to be loaded into RAM disk");
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create_dev("/dev/root", ROOT_DEV);
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create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
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return rd_load_image("/dev/root");
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}
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static int exit_code;
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static int decompress_error;
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static int crd_infd, crd_outfd;
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static long __init compr_fill(void *buf, unsigned long len)
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{
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long r = ksys_read(crd_infd, buf, len);
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if (r < 0)
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printk(KERN_ERR "RAMDISK: error while reading compressed data");
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else if (r == 0)
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printk(KERN_ERR "RAMDISK: EOF while reading compressed data");
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return r;
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}
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static long __init compr_flush(void *window, unsigned long outcnt)
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{
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long written = ksys_write(crd_outfd, window, outcnt);
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if (written != outcnt) {
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if (decompress_error == 0)
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printk(KERN_ERR
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"RAMDISK: incomplete write (%ld != %ld)\n",
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written, outcnt);
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decompress_error = 1;
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return -1;
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}
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return outcnt;
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}
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static void __init error(char *x)
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{
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printk(KERN_ERR "%s\n", x);
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exit_code = 1;
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decompress_error = 1;
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}
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static int __init crd_load(int in_fd, int out_fd, decompress_fn deco)
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{
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int result;
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crd_infd = in_fd;
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crd_outfd = out_fd;
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if (!deco) {
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pr_emerg("Invalid ramdisk decompression routine. "
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"Select appropriate config option.\n");
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panic("Could not decompress initial ramdisk image.");
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}
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result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
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if (decompress_error)
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result = 1;
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return result;
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}
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