init/initramfs.c

   1 #include <linux/init.h>
   2 #include <linux/fs.h>
   3 #include <linux/slab.h>
   4 #include <linux/types.h>
   5 #include <linux/fcntl.h>
   6 #include <linux/delay.h>
   7 #include <linux/string.h>
   8 #include <linux/dirent.h>
   9 #include <linux/syscalls.h>
  10 #include <linux/utime.h>
  11 #include <linux/async.h>
  12 #include <linux/export.h>
  13
  14 static __initdata char *message;
  15 static void __init error(char *x)
  16 {
  17         if (!message)
  18                 message = x;
  19 }
  20
  21 /* link hash */
  22
  23 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
  24
  25 static __initdata struct hash {
  26         int ino, minor, major;
  27         mode_t mode;
  28         struct hash *next;
  29         char name[N_ALIGN(PATH_MAX)];
  30 } *head[32];
  31
  32 static inline int hash(int major, int minor, int ino)
  33 {
  34         unsigned long tmp = ino + minor + (major << 3);
  35         tmp += tmp >> 5;
  36         return tmp & 31;
  37 }
  38
  39 static char __init *find_link(int major, int minor, int ino,
  40                               mode_t mode, char *name)
  41 {
  42         struct hash **p, *q;
  43         for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
  44                 if ((*p)->ino != ino)
  45                         continue;
  46                 if ((*p)->minor != minor)
  47                         continue;
  48                 if ((*p)->major != major)
  49                         continue;
  50                 if (((*p)->mode ^ mode) & S_IFMT)
  51                         continue;
  52                 return (*p)->name;
  53         }
  54         q = kmalloc(sizeof(struct hash), GFP_KERNEL);
  55         if (!q)
  56                 panic("can't allocate link hash entry");
  57         q->major = major;
  58         q->minor = minor;
  59         q->ino = ino;
  60         q->mode = mode;
  61         strcpy(q->name, name);
  62         q->next = NULL;
  63         *p = q;
  64         return NULL;
  65 }
  66
  67 static void __init free_hash(void)
  68 {
  69         struct hash **p, *q;
  70         for (p = head; p < head + 32; p++) {
  71                 while (*p) {
  72                         q = *p;
  73                         *p = q->next;
  74                         kfree(q);
  75                 }
  76         }
  77 }
  78
  79 static long __init do_utime(char __user *filename, time_t mtime)
  80 {
  81         struct timespec t[2];
  82
  83         t[0].tv_sec = mtime;
  84         t[0].tv_nsec = 0;
  85         t[1].tv_sec = mtime;
  86         t[1].tv_nsec = 0;
  87
  88         return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
  89 }
  90
  91 static __initdata LIST_HEAD(dir_list);
  92 struct dir_entry {
  93         struct list_head list;
  94         char *name;
  95         time_t mtime;
  96 };
  97
  98 static void __init dir_add(const char *name, time_t mtime)
  99 {
 100         struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
 101         if (!de)
 102                 panic("can't allocate dir_entry buffer");
 103         INIT_LIST_HEAD(&de->list);
 104         de->name = kstrdup(name, GFP_KERNEL);
 105         de->mtime = mtime;
 106         list_add(&de->list, &dir_list);
 107 }
 108
 109 static void __init dir_utime(void)
 110 {
 111         struct dir_entry *de, *tmp;
 112         list_for_each_entry_safe(de, tmp, &dir_list, list) {
 113                 list_del(&de->list);
 114                 do_utime(de->name, de->mtime);
 115                 kfree(de->name);
 116                 kfree(de);
 117         }
 118 }
 119
 120 static __initdata time_t mtime;
 121
 122 /* cpio header parsing */
 123
 124 static __initdata unsigned long ino, major, minor, nlink;
 125 static __initdata mode_t mode;
 126 static __initdata unsigned long body_len, name_len;
 127 static __initdata uid_t uid;
 128 static __initdata gid_t gid;
 129 static __initdata unsigned rdev;
 130
 131 static void __init parse_header(char *s)
 132 {
 133         unsigned long parsed[12];
 134         char buf[9];
 135         int i;
 136
 137         buf[8] = '\0';
 138         for (i = 0, s += 6; i < 12; i++, s += 8) {
 139                 memcpy(buf, s, 8);
 140                 parsed[i] = simple_strtoul(buf, NULL, 16);
 141         }
 142         ino = parsed[0];
 143         mode = parsed[1];
 144         uid = parsed[2];
 145         gid = parsed[3];
 146         nlink = parsed[4];
 147         mtime = parsed[5];
 148         body_len = parsed[6];
 149         major = parsed[7];
 150         minor = parsed[8];
 151         rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
 152         name_len = parsed[11];
 153 }
 154
 155 /* FSM */
 156
 157 static __initdata enum state {
 158         Start,
 159         Collect,
 160         GotHeader,
 161         SkipIt,
 162         GotName,
 163         CopyFile,
 164         GotSymlink,
 165         Reset
 166 } state, next_state;
 167
 168 static __initdata char *victim;
 169 static __initdata unsigned count;
 170 static __initdata loff_t this_header, next_header;
 171
 172 static inline void __init eat(unsigned n)
 173 {
 174         victim += n;
 175         this_header += n;
 176         count -= n;
 177 }
 178
 179 static __initdata char *vcollected;
 180 static __initdata char *collected;
 181 static __initdata int remains;
 182 static __initdata char *collect;
 183
 184 static void __init read_into(char *buf, unsigned size, enum state next)
 185 {
 186         if (count >= size) {
 187                 collected = victim;
 188                 eat(size);
 189                 state = next;
 190         } else {
 191                 collect = collected = buf;
 192                 remains = size;
 193                 next_state = next;
 194                 state = Collect;
 195         }
 196 }
 197
 198 static __initdata char *header_buf, *symlink_buf, *name_buf;
 199
 200 static int __init do_start(void)
 201 {
 202         read_into(header_buf, 110, GotHeader);
 203         return 0;
 204 }
 205
 206 static int __init do_collect(void)
 207 {
 208         unsigned n = remains;
 209         if (count < n)
 210                 n = count;
 211         memcpy(collect, victim, n);
 212         eat(n);
 213         collect += n;
 214         if ((remains -= n) != 0)
 215                 return 1;
 216         state = next_state;
 217         return 0;
 218 }
 219
 220 static int __init do_header(void)
 221 {
 222         if (memcmp(collected, "070707", 6)==0) {
 223                 error("incorrect cpio method used: use -H newc option");
 224                 return 1;
 225         }
 226         if (memcmp(collected, "070701", 6)) {
 227                 error("no cpio magic");
 228                 return 1;
 229         }
 230         parse_header(collected);
 231         next_header = this_header + N_ALIGN(name_len) + body_len;
 232         next_header = (next_header + 3) & ~3;
 233         state = SkipIt;
 234         if (name_len <= 0 || name_len > PATH_MAX)
 235                 return 0;
 236         if (S_ISLNK(mode)) {
 237                 if (body_len > PATH_MAX)
 238                         return 0;
 239                 collect = collected = symlink_buf;
 240                 remains = N_ALIGN(name_len) + body_len;
 241                 next_state = GotSymlink;
 242                 state = Collect;
 243                 return 0;
 244         }
 245         if (S_ISREG(mode) || !body_len)
 246                 read_into(name_buf, N_ALIGN(name_len), GotName);
 247         return 0;
 248 }
 249
 250 static int __init do_skip(void)
 251 {
 252         if (this_header + count < next_header) {
 253                 eat(count);
 254                 return 1;
 255         } else {
 256                 eat(next_header - this_header);
 257                 state = next_state;
 258                 return 0;
 259         }
 260 }
 261
 262 static int __init do_reset(void)
 263 {
 264         while(count && *victim == '\0')
 265                 eat(1);
 266         if (count && (this_header & 3))
 267                 error("broken padding");
 268         return 1;
 269 }
 270
 271 static int __init maybe_link(void)
 272 {
 273         if (nlink >= 2) {
 274                 char *old = find_link(major, minor, ino, mode, collected);
 275                 if (old)
 276                         return (sys_link(old, collected) < 0) ? -1 : 1;
 277         }
 278         return 0;
 279 }
 280
 281 static void __init clean_path(char *path, mode_t mode)
 282 {
 283         struct stat st;
 284
 285         if (!sys_newlstat(path, &st) && (st.st_mode^mode) & S_IFMT) {
 286                 if (S_ISDIR(st.st_mode))
 287                         sys_rmdir(path);
 288                 else
 289                         sys_unlink(path);
 290         }
 291 }
 292
 293 static __initdata int wfd;
 294
 295 static int __init do_name(void)
 296 {
 297         state = SkipIt;
 298         next_state = Reset;
 299         if (strcmp(collected, "TRAILER!!!") == 0) {
 300                 free_hash();
 301                 return 0;
 302         }
 303         clean_path(collected, mode);
 304         if (S_ISREG(mode)) {
 305                 int ml = maybe_link();
 306                 if (ml >= 0) {
 307                         int openflags = O_WRONLY|O_CREAT;
 308                         if (ml != 1)
 309                                 openflags |= O_TRUNC;
 310                         wfd = sys_open(collected, openflags, mode);
 311
 312                         if (wfd >= 0) {
 313                                 sys_fchown(wfd, uid, gid);
 314                                 sys_fchmod(wfd, mode);
 315                                 if (body_len)
 316                                         sys_ftruncate(wfd, body_len);
 317                                 vcollected = kstrdup(collected, GFP_KERNEL);
 318                                 state = CopyFile;
 319                         }
 320                 }
 321         } else if (S_ISDIR(mode)) {
 322                 sys_mkdir(collected, mode);
 323                 sys_chown(collected, uid, gid);
 324                 sys_chmod(collected, mode);
 325                 dir_add(collected, mtime);
 326         } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
 327                    S_ISFIFO(mode) || S_ISSOCK(mode)) {
 328                 if (maybe_link() == 0) {
 329                         sys_mknod(collected, mode, rdev);
 330                         sys_chown(collected, uid, gid);
 331                         sys_chmod(collected, mode);
 332                         do_utime(collected, mtime);
 333                 }
 334         }
 335         return 0;
 336 }
 337
 338 static int __init do_copy(void)
 339 {
 340         if (count >= body_len) {
 341                 sys_write(wfd, victim, body_len);
 342                 sys_close(wfd);
 343                 do_utime(vcollected, mtime);
 344                 kfree(vcollected);
 345                 eat(body_len);
 346                 state = SkipIt;
 347                 return 0;
 348         } else {
 349                 sys_write(wfd, victim, count);
 350                 body_len -= count;
 351                 eat(count);
 352                 return 1;
 353         }
 354 }
 355
 356 static int __init do_symlink(void)
 357 {
 358         collected[N_ALIGN(name_len) + body_len] = '\0';
 359         clean_path(collected, 0);
 360         sys_symlink(collected + N_ALIGN(name_len), collected);
 361         sys_lchown(collected, uid, gid);
 362         do_utime(collected, mtime);
 363         state = SkipIt;
 364         next_state = Reset;
 365         return 0;
 366 }
 367
 368 static __initdata int (*actions[])(void) = {
 369         [Start]         = do_start,
 370         [Collect]       = do_collect,
 371         [GotHeader]     = do_header,
 372         [SkipIt]        = do_skip,
 373         [GotName]       = do_name,
 374         [CopyFile]      = do_copy,
 375         [GotSymlink]    = do_symlink,
 376         [Reset]         = do_reset,
 377 };
 378
 379 static int __init write_buffer(char *buf, unsigned len)
 380 {
 381         count = len;
 382         victim = buf;
 383
 384         while (!actions[state]())
 385                 ;
 386         return len - count;
 387 }
 388
 389 static int __init flush_buffer(void *bufv, unsigned len)
 390 {
 391         char *buf = (char *) bufv;
 392         int written;
 393         int origLen = len;
 394         if (message)
 395                 return -1;
 396         while ((written = write_buffer(buf, len)) < len && !message) {
 397                 char c = buf[written];
 398                 if (c == '0') {
 399                         buf += written;
 400                         len -= written;
 401                         state = Start;
 402                 } else if (c == 0) {
 403                         buf += written;
 404                         len -= written;
 405                         state = Reset;
 406                 } else
 407                         error("junk in compressed archive");
 408         }
 409         return origLen;
 410 }
 411
 412 static unsigned my_inptr;   /* index of next byte to be processed in inbuf */
 413
 414 #include <linux/decompress/generic.h>
 415
 416 static char * __init unpack_to_rootfs(char *buf, unsigned len)
 417 {
 418         int written, res;
 419         decompress_fn decompress;
 420         const char *compress_name;
 421         static __initdata char msg_buf[64];
 422
 423         header_buf = kmalloc(110, GFP_KERNEL);
 424         symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
 425         name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
 426
 427         if (!header_buf || !symlink_buf || !name_buf)
 428                 panic("can't allocate buffers");
 429
 430         state = Start;
 431         this_header = 0;
 432         message = NULL;
 433         while (!message && len) {
 434                 loff_t saved_offset = this_header;
 435                 if (*buf == '0' && !(this_header & 3)) {
 436                         state = Start;
 437                         written = write_buffer(buf, len);
 438                         buf += written;
 439                         len -= written;
 440                         continue;
 441                 }
 442                 if (!*buf) {
 443                         buf++;
 444                         len--;
 445                         this_header++;
 446                         continue;
 447                 }
 448                 this_header = 0;
 449                 decompress = decompress_method(buf, len, &compress_name);
 450                 if (decompress) {
 451                         res = decompress(buf, len, NULL, flush_buffer, NULL,
 452                                    &my_inptr, error);
 453                         if (res)
 454                                 error("decompressor failed");
 455                 } else if (compress_name) {
 456                         if (!message) {
 457                                 snprintf(msg_buf, sizeof msg_buf,
 458                                          "compression method %s not configured",
 459                                          compress_name);
 460                                 message = msg_buf;
 461                         }
 462                 } else
 463                         error("junk in compressed archive");
 464                 if (state != Reset)
 465                         error("junk in compressed archive");
 466                 this_header = saved_offset + my_inptr;
 467                 buf += my_inptr;
 468                 len -= my_inptr;
 469         }
 470         dir_utime();
 471         kfree(name_buf);
 472         kfree(symlink_buf);
 473         kfree(header_buf);
 474         return message;
 475 }
 476
 477 static int __initdata do_retain_initrd;
 478
 479 static int __init retain_initrd_param(char *str)
 480 {
 481         if (*str)
 482                 return 0;
 483         do_retain_initrd = 1;
 484         return 1;
 485 }
 486 __setup("retain_initrd", retain_initrd_param);
 487
 488 extern char __initramfs_start[];
 489 extern unsigned long __initramfs_size;
 490 #include <linux/initrd.h>
 491 #include <linux/kexec.h>
 492
 493 static void __init free_initrd(void)
 494 {
 495 #ifdef CONFIG_KEXEC
 496         unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
 497         unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
 498 #endif
 499         if (do_retain_initrd)
 500                 goto skip;
 501
 502 #ifdef CONFIG_KEXEC
 503         /*
 504          * If the initrd region is overlapped with crashkernel reserved region,
 505          * free only memory that is not part of crashkernel region.
 506          */
 507         if (initrd_start < crashk_end && initrd_end > crashk_start) {
 508                 /*
 509                  * Initialize initrd memory region since the kexec boot does
 510                  * not do.
 511                  */
 512                 memset((void *)initrd_start, 0, initrd_end - initrd_start);
 513                 if (initrd_start < crashk_start)
 514                         free_initrd_mem(initrd_start, crashk_start);
 515                 if (initrd_end > crashk_end)
 516                         free_initrd_mem(crashk_end, initrd_end);
 517         } else
 518 #endif
 519                 free_initrd_mem(initrd_start, initrd_end);
 520 skip:
 521         initrd_start = 0;
 522         initrd_end = 0;
 523 }
 524
 525 #ifdef CONFIG_BLK_DEV_RAM
 526 #define BUF_SIZE 1024
 527 static void __init clean_rootfs(void)
 528 {
 529         int fd;
 530         void *buf;
 531         struct linux_dirent64 *dirp;
 532         int num;
 533
 534         fd = sys_open((const char __user __force *) "/", O_RDONLY, 0);
 535         WARN_ON(fd < 0);
 536         if (fd < 0)
 537                 return;
 538         buf = kzalloc(BUF_SIZE, GFP_KERNEL);
 539         WARN_ON(!buf);
 540         if (!buf) {
 541                 sys_close(fd);
 542                 return;
 543         }
 544
 545         dirp = buf;
 546         num = sys_getdents64(fd, dirp, BUF_SIZE);
 547         while (num > 0) {
 548                 while (num > 0) {
 549                         struct stat st;
 550                         int ret;
 551
 552                         ret = sys_newlstat(dirp->d_name, &st);
 553                         WARN_ON_ONCE(ret);
 554                         if (!ret) {
 555                                 if (S_ISDIR(st.st_mode))
 556                                         sys_rmdir(dirp->d_name);
 557                                 else
 558                                         sys_unlink(dirp->d_name);
 559                         }
 560
 561                         num -= dirp->d_reclen;
 562                         dirp = (void *)dirp + dirp->d_reclen;
 563                 }
 564                 dirp = buf;
 565                 memset(buf, 0, BUF_SIZE);
 566                 num = sys_getdents64(fd, dirp, BUF_SIZE);
 567         }
 568
 569         sys_close(fd);
 570         kfree(buf);
 571 }
 572 #endif
 573
 574 LIST_HEAD(populate_rootfs_domain);
 575
 576 void populate_rootfs_wait(void)
 577 {
 578         async_synchronize_full_domain(&populate_rootfs_domain);
 579 }
 580 EXPORT_SYMBOL(populate_rootfs_wait);
 581
 582 static void __init async_populate_rootfs(void)
 583 {
 584         char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
 585         if (err)
 586                 panic(err);     /* Failed to decompress INTERNAL initramfs */
 587         if (initrd_start) {
 588 #ifdef CONFIG_BLK_DEV_RAM
 589                 int fd;
 590                 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
 591                 err = unpack_to_rootfs((char *)initrd_start,
 592                         initrd_end - initrd_start);
 593                 if (!err) {
 594                         free_initrd();
 595                         return;
 596                 } else {
 597                         clean_rootfs();
 598                         unpack_to_rootfs(__initramfs_start, __initramfs_size);
 599                 }
 600                 printk(KERN_INFO "rootfs image is not initramfs (%s)"
 601                                 "; looks like an initrd\n", err);
 602                 fd = sys_open((const char __user __force *) "/initrd.image",
 603                               O_WRONLY|O_CREAT, 0700);
 604                 if (fd >= 0) {
 605                         sys_write(fd, (char *)initrd_start,
 606                                         initrd_end - initrd_start);
 607                         sys_close(fd);
 608                         free_initrd();
 609                 }
 610 #else
 611                 printk(KERN_INFO "Unpacking initramfs...\n");
 612                 err = unpack_to_rootfs((char *)initrd_start,
 613                         initrd_end - initrd_start);
 614                 if (err)
 615                         printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
 616                 free_initrd();
 617 #endif
 618         }
 619         return;
 620 }
 621
 622 static int __initdata rootfs_populated;
 623
 624 static int __init populate_rootfs_early(void)
 625 {
 626         if (num_online_cpus() > 1) {
 627                 rootfs_populated = 1;
 628                 async_schedule_domain(async_populate_rootfs, NULL,
 629                                                 &populate_rootfs_domain);
 630         }
 631 }
 632 static int __init populate_rootfs(void)
 633 {
 634         if (!rootfs_populated)
 635                 async_schedule_domain(async_populate_rootfs, NULL,
 636                                                 &populate_rootfs_domain);
 637 }
 638
 639 earlyrootfs_initcall(populate_rootfs_early);
 640 rootfs_initcall(populate_rootfs);