1 /* 2 * Many of the syscalls used in this file expect some of the arguments 3 * to be __user pointers not __kernel pointers. To limit the sparse 4 * noise, turn off sparse checking for this file. 5 */ 6 #ifdef __CHECKER__ 7 #undef __CHECKER__ 8 #warning "Sparse checking disabled for this file" 9 #endif 10 11 #include <linux/kernel.h> 12 #include <linux/fs.h> 13 #include <linux/minix_fs.h> 14 #include <linux/ext2_fs.h> 15 #include <linux/romfs_fs.h> 16 #include <uapi/linux/cramfs_fs.h> 17 #include <linux/initrd.h> 18 #include <linux/string.h> 19 #include <linux/slab.h> 20 21 #include "do_mounts.h" 22 #include "../fs/squashfs/squashfs_fs.h" 23 24 #include <linux/decompress/generic.h> 25 26 27 int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */ 28 29 static int __init prompt_ramdisk(char *str) 30 { 31 rd_prompt = simple_strtol(str,NULL,0) & 1; 32 return 1; 33 } 34 __setup("prompt_ramdisk=", prompt_ramdisk); 35 36 int __initdata rd_image_start; /* starting block # of image */ 37 38 static int __init ramdisk_start_setup(char *str) 39 { 40 rd_image_start = simple_strtol(str,NULL,0); 41 return 1; 42 } 43 __setup("ramdisk_start=", ramdisk_start_setup); 44 45 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco); 46 47 /* 48 * This routine tries to find a RAM disk image to load, and returns the 49 * number of blocks to read for a non-compressed image, 0 if the image 50 * is a compressed image, and -1 if an image with the right magic 51 * numbers could not be found. 52 * 53 * We currently check for the following magic numbers: 54 * minix 55 * ext2 56 * romfs 57 * cramfs 58 * squashfs 59 * gzip 60 * bzip2 61 * lzma 62 * xz 63 * lzo 64 * lz4 65 */ 66 static int __init 67 identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) 68 { 69 const int size = 512; 70 struct minix_super_block *minixsb; 71 struct romfs_super_block *romfsb; 72 struct cramfs_super *cramfsb; 73 struct squashfs_super_block *squashfsb; 74 int nblocks = -1; 75 unsigned char *buf; 76 const char *compress_name; 77 unsigned long n; 78 79 buf = kmalloc(size, GFP_KERNEL); 80 if (!buf) 81 return -ENOMEM; 82 83 minixsb = (struct minix_super_block *) buf; 84 romfsb = (struct romfs_super_block *) buf; 85 cramfsb = (struct cramfs_super *) buf; 86 squashfsb = (struct squashfs_super_block *) buf; 87 memset(buf, 0xe5, size); 88 89 /* 90 * Read block 0 to test for compressed kernel 91 */ 92 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 93 sys_read(fd, buf, size); 94 95 *decompressor = decompress_method(buf, size, &compress_name); 96 if (compress_name) { 97 printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n", 98 compress_name, start_block); 99 if (!*decompressor) 100 printk(KERN_EMERG 101 "RAMDISK: %s decompressor not configured!\n", 102 compress_name); 103 nblocks = 0; 104 goto done; 105 } 106 107 /* romfs is at block zero too */ 108 if (romfsb->word0 == ROMSB_WORD0 && 109 romfsb->word1 == ROMSB_WORD1) { 110 printk(KERN_NOTICE 111 "RAMDISK: romfs filesystem found at block %d\n", 112 start_block); 113 nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS; 114 goto done; 115 } 116 117 if (cramfsb->magic == CRAMFS_MAGIC) { 118 printk(KERN_NOTICE 119 "RAMDISK: cramfs filesystem found at block %d\n", 120 start_block); 121 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 122 goto done; 123 } 124 125 /* squashfs is at block zero too */ 126 if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) { 127 printk(KERN_NOTICE 128 "RAMDISK: squashfs filesystem found at block %d\n", 129 start_block); 130 nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1) 131 >> BLOCK_SIZE_BITS; 132 goto done; 133 } 134 135 /* 136 * Read 512 bytes further to check if cramfs is padded 137 */ 138 sys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0); 139 sys_read(fd, buf, size); 140 141 if (cramfsb->magic == CRAMFS_MAGIC) { 142 printk(KERN_NOTICE 143 "RAMDISK: cramfs filesystem found at block %d\n", 144 start_block); 145 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 146 goto done; 147 } 148 149 /* 150 * Read block 1 to test for minix and ext2 superblock 151 */ 152 sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0); 153 sys_read(fd, buf, size); 154 155 /* Try minix */ 156 if (minixsb->s_magic == MINIX_SUPER_MAGIC || 157 minixsb->s_magic == MINIX_SUPER_MAGIC2) { 158 printk(KERN_NOTICE 159 "RAMDISK: Minix filesystem found at block %d\n", 160 start_block); 161 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; 162 goto done; 163 } 164 165 /* Try ext2 */ 166 n = ext2_image_size(buf); 167 if (n) { 168 printk(KERN_NOTICE 169 "RAMDISK: ext2 filesystem found at block %d\n", 170 start_block); 171 nblocks = n; 172 goto done; 173 } 174 175 printk(KERN_NOTICE 176 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", 177 start_block); 178 179 done: 180 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 181 kfree(buf); 182 return nblocks; 183 } 184 185 int __init rd_load_image(char *from) 186 { 187 int res = 0; 188 int in_fd, out_fd; 189 unsigned long rd_blocks, devblocks; 190 int nblocks, i, disk; 191 char *buf = NULL; 192 unsigned short rotate = 0; 193 decompress_fn decompressor = NULL; 194 #if !defined(CONFIG_S390) 195 char rotator[4] = { '|' , '/' , '-' , '\\' }; 196 #endif 197 198 out_fd = sys_open("/dev/ram", O_RDWR, 0); 199 if (out_fd < 0) 200 goto out; 201 202 in_fd = sys_open(from, O_RDONLY, 0); 203 if (in_fd < 0) 204 goto noclose_input; 205 206 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor); 207 if (nblocks < 0) 208 goto done; 209 210 if (nblocks == 0) { 211 if (crd_load(in_fd, out_fd, decompressor) == 0) 212 goto successful_load; 213 goto done; 214 } 215 216 /* 217 * NOTE NOTE: nblocks is not actually blocks but 218 * the number of kibibytes of data to load into a ramdisk. 219 */ 220 if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) 221 rd_blocks = 0; 222 else 223 rd_blocks >>= 1; 224 225 if (nblocks > rd_blocks) { 226 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", 227 nblocks, rd_blocks); 228 goto done; 229 } 230 231 /* 232 * OK, time to copy in the data 233 */ 234 if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) 235 devblocks = 0; 236 else 237 devblocks >>= 1; 238 239 if (strcmp(from, "/initrd.image") == 0) 240 devblocks = nblocks; 241 242 if (devblocks == 0) { 243 printk(KERN_ERR "RAMDISK: could not determine device size\n"); 244 goto done; 245 } 246 247 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); 248 if (!buf) { 249 printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); 250 goto done; 251 } 252 253 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", 254 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); 255 for (i = 0, disk = 1; i < nblocks; i++) { 256 if (i && (i % devblocks == 0)) { 257 printk("done disk #%d.\n", disk++); 258 rotate = 0; 259 if (sys_close(in_fd)) { 260 printk("Error closing the disk.\n"); 261 goto noclose_input; 262 } 263 change_floppy("disk #%d", disk); 264 in_fd = sys_open(from, O_RDONLY, 0); 265 if (in_fd < 0) { 266 printk("Error opening disk.\n"); 267 goto noclose_input; 268 } 269 printk("Loading disk #%d... ", disk); 270 } 271 sys_read(in_fd, buf, BLOCK_SIZE); 272 sys_write(out_fd, buf, BLOCK_SIZE); 273 #if !defined(CONFIG_S390) 274 if (!(i % 16)) { 275 pr_cont("%c\b", rotator[rotate & 0x3]); 276 rotate++; 277 } 278 #endif 279 } 280 printk("done.\n"); 281 282 successful_load: 283 res = 1; 284 done: 285 sys_close(in_fd); 286 noclose_input: 287 sys_close(out_fd); 288 out: 289 kfree(buf); 290 sys_unlink("/dev/ram"); 291 return res; 292 } 293 294 int __init rd_load_disk(int n) 295 { 296 if (rd_prompt) 297 change_floppy("root floppy disk to be loaded into RAM disk"); 298 create_dev("/dev/root", ROOT_DEV); 299 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n)); 300 return rd_load_image("/dev/root"); 301 } 302 303 static int exit_code; 304 static int decompress_error; 305 static int crd_infd, crd_outfd; 306 307 static long __init compr_fill(void *buf, unsigned long len) 308 { 309 long r = sys_read(crd_infd, buf, len); 310 if (r < 0) 311 printk(KERN_ERR "RAMDISK: error while reading compressed data"); 312 else if (r == 0) 313 printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); 314 return r; 315 } 316 317 static long __init compr_flush(void *window, unsigned long outcnt) 318 { 319 long written = sys_write(crd_outfd, window, outcnt); 320 if (written != outcnt) { 321 if (decompress_error == 0) 322 printk(KERN_ERR 323 "RAMDISK: incomplete write (%ld != %ld)\n", 324 written, outcnt); 325 decompress_error = 1; 326 return -1; 327 } 328 return outcnt; 329 } 330 331 static void __init error(char *x) 332 { 333 printk(KERN_ERR "%s\n", x); 334 exit_code = 1; 335 decompress_error = 1; 336 } 337 338 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) 339 { 340 int result; 341 crd_infd = in_fd; 342 crd_outfd = out_fd; 343 344 if (!deco) { 345 pr_emerg("Invalid ramdisk decompression routine. " 346 "Select appropriate config option.\n"); 347 panic("Could not decompress initial ramdisk image."); 348 } 349 350 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); 351 if (decompress_error) 352 result = 1; 353 return result; 354 } 355