Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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 | * So any ramdisk block size that is a multiple of 1KiB should |
| 220 | * work when the appropriate ramdisk_blocksize is specified |
| 221 | * on the command line. |
| 222 | * |
| 223 | * The default ramdisk_blocksize is 1KiB and it is generally |
| 224 | * silly to use anything else, so make sure to use 1KiB |
| 225 | * blocksize while generating ext2fs ramdisk-images. |
| 226 | */ |
| 227 | if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) |
| 228 | rd_blocks = 0; |
| 229 | else |
| 230 | rd_blocks >>= 1; |
| 231 | |
| 232 | if (nblocks > rd_blocks) { |
| 233 | printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", |
| 234 | nblocks, rd_blocks); |
| 235 | goto done; |
| 236 | } |
| 237 | |
| 238 | /* |
| 239 | * OK, time to copy in the data |
| 240 | */ |
| 241 | if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) |
| 242 | devblocks = 0; |
| 243 | else |
| 244 | devblocks >>= 1; |
| 245 | |
| 246 | if (strcmp(from, "/initrd.image") == 0) |
| 247 | devblocks = nblocks; |
| 248 | |
| 249 | if (devblocks == 0) { |
| 250 | printk(KERN_ERR "RAMDISK: could not determine device size\n"); |
| 251 | goto done; |
| 252 | } |
| 253 | |
| 254 | buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); |
| 255 | if (!buf) { |
| 256 | printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); |
| 257 | goto done; |
| 258 | } |
| 259 | |
| 260 | printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", |
| 261 | nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); |
| 262 | for (i = 0, disk = 1; i < nblocks; i++) { |
| 263 | if (i && (i % devblocks == 0)) { |
| 264 | printk("done disk #%d.\n", disk++); |
| 265 | rotate = 0; |
| 266 | if (sys_close(in_fd)) { |
| 267 | printk("Error closing the disk.\n"); |
| 268 | goto noclose_input; |
| 269 | } |
| 270 | change_floppy("disk #%d", disk); |
| 271 | in_fd = sys_open(from, O_RDONLY, 0); |
| 272 | if (in_fd < 0) { |
| 273 | printk("Error opening disk.\n"); |
| 274 | goto noclose_input; |
| 275 | } |
| 276 | printk("Loading disk #%d... ", disk); |
| 277 | } |
| 278 | sys_read(in_fd, buf, BLOCK_SIZE); |
| 279 | sys_write(out_fd, buf, BLOCK_SIZE); |
| 280 | #if !defined(CONFIG_S390) |
| 281 | if (!(i % 16)) { |
| 282 | printk("%c\b", rotator[rotate & 0x3]); |
| 283 | rotate++; |
| 284 | } |
| 285 | #endif |
| 286 | } |
| 287 | printk("done.\n"); |
| 288 | |
| 289 | successful_load: |
| 290 | res = 1; |
| 291 | done: |
| 292 | sys_close(in_fd); |
| 293 | noclose_input: |
| 294 | sys_close(out_fd); |
| 295 | out: |
| 296 | kfree(buf); |
| 297 | sys_unlink("/dev/ram"); |
| 298 | return res; |
| 299 | } |
| 300 | |
| 301 | int __init rd_load_disk(int n) |
| 302 | { |
| 303 | if (rd_prompt) |
| 304 | change_floppy("root floppy disk to be loaded into RAM disk"); |
| 305 | create_dev("/dev/root", ROOT_DEV); |
| 306 | create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n)); |
| 307 | return rd_load_image("/dev/root"); |
| 308 | } |
| 309 | |
| 310 | static int exit_code; |
| 311 | static int decompress_error; |
| 312 | static int crd_infd, crd_outfd; |
| 313 | |
| 314 | static long __init compr_fill(void *buf, unsigned long len) |
| 315 | { |
| 316 | long r = sys_read(crd_infd, buf, len); |
| 317 | if (r < 0) |
| 318 | printk(KERN_ERR "RAMDISK: error while reading compressed data"); |
| 319 | else if (r == 0) |
| 320 | printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); |
| 321 | return r; |
| 322 | } |
| 323 | |
| 324 | static long __init compr_flush(void *window, unsigned long outcnt) |
| 325 | { |
| 326 | long written = sys_write(crd_outfd, window, outcnt); |
| 327 | if (written != outcnt) { |
| 328 | if (decompress_error == 0) |
| 329 | printk(KERN_ERR |
| 330 | "RAMDISK: incomplete write (%ld != %ld)\n", |
| 331 | written, outcnt); |
| 332 | decompress_error = 1; |
| 333 | return -1; |
| 334 | } |
| 335 | return outcnt; |
| 336 | } |
| 337 | |
| 338 | static void __init error(char *x) |
| 339 | { |
| 340 | printk(KERN_ERR "%s\n", x); |
| 341 | exit_code = 1; |
| 342 | decompress_error = 1; |
| 343 | } |
| 344 | |
| 345 | static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) |
| 346 | { |
| 347 | int result; |
| 348 | crd_infd = in_fd; |
| 349 | crd_outfd = out_fd; |
| 350 | |
| 351 | if (!deco) { |
| 352 | pr_emerg("Invalid ramdisk decompression routine. " |
| 353 | "Select appropriate config option.\n"); |
| 354 | panic("Could not decompress initial ramdisk image."); |
| 355 | } |
| 356 | |
| 357 | result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); |
| 358 | if (decompress_error) |
| 359 | result = 1; |
| 360 | return result; |
| 361 | } |