1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Many of the syscalls used in this file expect some of the arguments 4 * to be __user pointers not __kernel pointers. To limit the sparse 5 * noise, turn off sparse checking for this file. 6 */ 7 #ifdef __CHECKER__ 8 #undef __CHECKER__ 9 #warning "Sparse checking disabled for this file" 10 #endif 11 12 #include <linux/kernel.h> 13 #include <linux/fs.h> 14 #include <linux/minix_fs.h> 15 #include <linux/ext2_fs.h> 16 #include <linux/romfs_fs.h> 17 #include <uapi/linux/cramfs_fs.h> 18 #include <linux/initrd.h> 19 #include <linux/string.h> 20 #include <linux/slab.h> 21 22 #include "do_mounts.h" 23 #include "../fs/squashfs/squashfs_fs.h" 24 25 #include <linux/decompress/generic.h> 26 27 28 int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */ 29 30 static int __init prompt_ramdisk(char *str) 31 { 32 rd_prompt = simple_strtol(str,NULL,0) & 1; 33 return 1; 34 } 35 __setup("prompt_ramdisk=", prompt_ramdisk); 36 37 int __initdata rd_image_start; /* starting block # of image */ 38 39 static int __init ramdisk_start_setup(char *str) 40 { 41 rd_image_start = simple_strtol(str,NULL,0); 42 return 1; 43 } 44 __setup("ramdisk_start=", ramdisk_start_setup); 45 46 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco); 47 48 /* 49 * This routine tries to find a RAM disk image to load, and returns the 50 * number of blocks to read for a non-compressed image, 0 if the image 51 * is a compressed image, and -1 if an image with the right magic 52 * numbers could not be found. 53 * 54 * We currently check for the following magic numbers: 55 * minix 56 * ext2 57 * romfs 58 * cramfs 59 * squashfs 60 * gzip 61 * bzip2 62 * lzma 63 * xz 64 * lzo 65 * lz4 66 */ 67 static int __init 68 identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) 69 { 70 const int size = 512; 71 struct minix_super_block *minixsb; 72 struct romfs_super_block *romfsb; 73 struct cramfs_super *cramfsb; 74 struct squashfs_super_block *squashfsb; 75 int nblocks = -1; 76 unsigned char *buf; 77 const char *compress_name; 78 unsigned long n; 79 80 buf = kmalloc(size, GFP_KERNEL); 81 if (!buf) 82 return -ENOMEM; 83 84 minixsb = (struct minix_super_block *) buf; 85 romfsb = (struct romfs_super_block *) buf; 86 cramfsb = (struct cramfs_super *) buf; 87 squashfsb = (struct squashfs_super_block *) buf; 88 memset(buf, 0xe5, size); 89 90 /* 91 * Read block 0 to test for compressed kernel 92 */ 93 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 94 sys_read(fd, buf, size); 95 96 *decompressor = decompress_method(buf, size, &compress_name); 97 if (compress_name) { 98 printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n", 99 compress_name, start_block); 100 if (!*decompressor) 101 printk(KERN_EMERG 102 "RAMDISK: %s decompressor not configured!\n", 103 compress_name); 104 nblocks = 0; 105 goto done; 106 } 107 108 /* romfs is at block zero too */ 109 if (romfsb->word0 == ROMSB_WORD0 && 110 romfsb->word1 == ROMSB_WORD1) { 111 printk(KERN_NOTICE 112 "RAMDISK: romfs filesystem found at block %d\n", 113 start_block); 114 nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS; 115 goto done; 116 } 117 118 if (cramfsb->magic == CRAMFS_MAGIC) { 119 printk(KERN_NOTICE 120 "RAMDISK: cramfs filesystem found at block %d\n", 121 start_block); 122 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 123 goto done; 124 } 125 126 /* squashfs is at block zero too */ 127 if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) { 128 printk(KERN_NOTICE 129 "RAMDISK: squashfs filesystem found at block %d\n", 130 start_block); 131 nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1) 132 >> BLOCK_SIZE_BITS; 133 goto done; 134 } 135 136 /* 137 * Read 512 bytes further to check if cramfs is padded 138 */ 139 sys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0); 140 sys_read(fd, buf, size); 141 142 if (cramfsb->magic == CRAMFS_MAGIC) { 143 printk(KERN_NOTICE 144 "RAMDISK: cramfs filesystem found at block %d\n", 145 start_block); 146 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 147 goto done; 148 } 149 150 /* 151 * Read block 1 to test for minix and ext2 superblock 152 */ 153 sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0); 154 sys_read(fd, buf, size); 155 156 /* Try minix */ 157 if (minixsb->s_magic == MINIX_SUPER_MAGIC || 158 minixsb->s_magic == MINIX_SUPER_MAGIC2) { 159 printk(KERN_NOTICE 160 "RAMDISK: Minix filesystem found at block %d\n", 161 start_block); 162 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; 163 goto done; 164 } 165 166 /* Try ext2 */ 167 n = ext2_image_size(buf); 168 if (n) { 169 printk(KERN_NOTICE 170 "RAMDISK: ext2 filesystem found at block %d\n", 171 start_block); 172 nblocks = n; 173 goto done; 174 } 175 176 printk(KERN_NOTICE 177 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", 178 start_block); 179 180 done: 181 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 182 kfree(buf); 183 return nblocks; 184 } 185 186 int __init rd_load_image(char *from) 187 { 188 int res = 0; 189 int in_fd, out_fd; 190 unsigned long rd_blocks, devblocks; 191 int nblocks, i, disk; 192 char *buf = NULL; 193 unsigned short rotate = 0; 194 decompress_fn decompressor = NULL; 195 #if !defined(CONFIG_S390) 196 char rotator[4] = { '|' , '/' , '-' , '\\' }; 197 #endif 198 199 out_fd = sys_open("/dev/ram", O_RDWR, 0); 200 if (out_fd < 0) 201 goto out; 202 203 in_fd = sys_open(from, O_RDONLY, 0); 204 if (in_fd < 0) 205 goto noclose_input; 206 207 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor); 208 if (nblocks < 0) 209 goto done; 210 211 if (nblocks == 0) { 212 if (crd_load(in_fd, out_fd, decompressor) == 0) 213 goto successful_load; 214 goto done; 215 } 216 217 /* 218 * NOTE NOTE: nblocks is not actually blocks but 219 * the number of kibibytes of data to load into a ramdisk. 220 */ 221 if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) 222 rd_blocks = 0; 223 else 224 rd_blocks >>= 1; 225 226 if (nblocks > rd_blocks) { 227 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", 228 nblocks, rd_blocks); 229 goto done; 230 } 231 232 /* 233 * OK, time to copy in the data 234 */ 235 if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) 236 devblocks = 0; 237 else 238 devblocks >>= 1; 239 240 if (strcmp(from, "/initrd.image") == 0) 241 devblocks = nblocks; 242 243 if (devblocks == 0) { 244 printk(KERN_ERR "RAMDISK: could not determine device size\n"); 245 goto done; 246 } 247 248 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); 249 if (!buf) { 250 printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); 251 goto done; 252 } 253 254 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", 255 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); 256 for (i = 0, disk = 1; i < nblocks; i++) { 257 if (i && (i % devblocks == 0)) { 258 printk("done disk #%d.\n", disk++); 259 rotate = 0; 260 if (sys_close(in_fd)) { 261 printk("Error closing the disk.\n"); 262 goto noclose_input; 263 } 264 change_floppy("disk #%d", disk); 265 in_fd = sys_open(from, O_RDONLY, 0); 266 if (in_fd < 0) { 267 printk("Error opening disk.\n"); 268 goto noclose_input; 269 } 270 printk("Loading disk #%d... ", disk); 271 } 272 sys_read(in_fd, buf, BLOCK_SIZE); 273 sys_write(out_fd, buf, BLOCK_SIZE); 274 #if !defined(CONFIG_S390) 275 if (!(i % 16)) { 276 pr_cont("%c\b", rotator[rotate & 0x3]); 277 rotate++; 278 } 279 #endif 280 } 281 printk("done.\n"); 282 283 successful_load: 284 res = 1; 285 done: 286 sys_close(in_fd); 287 noclose_input: 288 sys_close(out_fd); 289 out: 290 kfree(buf); 291 sys_unlink("/dev/ram"); 292 return res; 293 } 294 295 int __init rd_load_disk(int n) 296 { 297 if (rd_prompt) 298 change_floppy("root floppy disk to be loaded into RAM disk"); 299 create_dev("/dev/root", ROOT_DEV); 300 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n)); 301 return rd_load_image("/dev/root"); 302 } 303 304 static int exit_code; 305 static int decompress_error; 306 static int crd_infd, crd_outfd; 307 308 static long __init compr_fill(void *buf, unsigned long len) 309 { 310 long r = sys_read(crd_infd, buf, len); 311 if (r < 0) 312 printk(KERN_ERR "RAMDISK: error while reading compressed data"); 313 else if (r == 0) 314 printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); 315 return r; 316 } 317 318 static long __init compr_flush(void *window, unsigned long outcnt) 319 { 320 long written = sys_write(crd_outfd, window, outcnt); 321 if (written != outcnt) { 322 if (decompress_error == 0) 323 printk(KERN_ERR 324 "RAMDISK: incomplete write (%ld != %ld)\n", 325 written, outcnt); 326 decompress_error = 1; 327 return -1; 328 } 329 return outcnt; 330 } 331 332 static void __init error(char *x) 333 { 334 printk(KERN_ERR "%s\n", x); 335 exit_code = 1; 336 decompress_error = 1; 337 } 338 339 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) 340 { 341 int result; 342 crd_infd = in_fd; 343 crd_outfd = out_fd; 344 345 if (!deco) { 346 pr_emerg("Invalid ramdisk decompression routine. " 347 "Select appropriate config option.\n"); 348 panic("Could not decompress initial ramdisk image."); 349 } 350 351 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); 352 if (decompress_error) 353 result = 1; 354 return result; 355 } 356