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