fs/binfmt_flat.c

   1 /****************************************************************************/
   2 /*
   3  *  linux/fs/binfmt_flat.c
   4  *
   5  *      Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
   6  *      Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
   7  *      Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
   8  *      Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
   9  *  based heavily on:
  10  *
  11  *  linux/fs/binfmt_aout.c:
  12  *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
  13  *  linux/fs/binfmt_flat.c for 2.0 kernel
  14  *          Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
  15  *      JAN/99 -- coded full program relocation (gerg@snapgear.com)
  16  */
  17
  18 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/mm.h>
  23 #include <linux/mman.h>
  24 #include <linux/errno.h>
  25 #include <linux/signal.h>
  26 #include <linux/string.h>
  27 #include <linux/fs.h>
  28 #include <linux/file.h>
  29 #include <linux/ptrace.h>
  30 #include <linux/user.h>
  31 #include <linux/slab.h>
  32 #include <linux/binfmts.h>
  33 #include <linux/personality.h>
  34 #include <linux/init.h>
  35 #include <linux/flat.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/vmalloc.h>
  38
  39 #include <asm/byteorder.h>
  40 #include <asm/unaligned.h>
  41 #include <asm/cacheflush.h>
  42 #include <asm/page.h>
  43
  44 /****************************************************************************/
  45
  46 /*
  47  * User data (data section and bss) needs to be aligned.
  48  * We pick 0x20 here because it is the max value elf2flt has always
  49  * used in producing FLAT files, and because it seems to be large
  50  * enough to make all the gcc alignment related tests happy.
  51  */
  52 #define FLAT_DATA_ALIGN (0x20)
  53
  54 /*
  55  * User data (stack) also needs to be aligned.
  56  * Here we can be a bit looser than the data sections since this
  57  * needs to only meet arch ABI requirements.
  58  */
  59 #define FLAT_STACK_ALIGN        max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
  60
  61 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  62 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  63
  64 struct lib_info {
  65         struct {
  66                 unsigned long start_code;               /* Start of text segment */
  67                 unsigned long start_data;               /* Start of data segment */
  68                 unsigned long start_brk;                /* End of data segment */
  69                 unsigned long text_len;                 /* Length of text segment */
  70                 unsigned long entry;                    /* Start address for this module */
  71                 unsigned long build_date;               /* When this one was compiled */
  72                 bool loaded;                            /* Has this library been loaded? */
  73         } lib_list[MAX_SHARED_LIBS];
  74 };
  75
  76 #ifdef CONFIG_BINFMT_SHARED_FLAT
  77 static int load_flat_shared_library(int id, struct lib_info *p);
  78 #endif
  79
  80 static int load_flat_binary(struct linux_binprm *);
  81 static int flat_core_dump(struct coredump_params *cprm);
  82
  83 static struct linux_binfmt flat_format = {
  84         .module         = THIS_MODULE,
  85         .load_binary    = load_flat_binary,
  86         .core_dump      = flat_core_dump,
  87         .min_coredump   = PAGE_SIZE
  88 };
  89
  90 /****************************************************************************/
  91 /*
  92  * Routine writes a core dump image in the current directory.
  93  * Currently only a stub-function.
  94  */
  95
  96 static int flat_core_dump(struct coredump_params *cprm)
  97 {
  98         pr_warn("Process %s:%d received signr %d and should have core dumped\n",
  99                 current->comm, current->pid, cprm->siginfo->si_signo);
 100         return 1;
 101 }
 102
 103 /****************************************************************************/
 104 /*
 105  * create_flat_tables() parses the env- and arg-strings in new user
 106  * memory and creates the pointer tables from them, and puts their
 107  * addresses on the "stack", recording the new stack pointer value.
 108  */
 109
 110 static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
 111 {
 112         char __user *p;
 113         unsigned long __user *sp;
 114         long i, len;
 115
 116         p = (char __user *)arg_start;
 117         sp = (unsigned long __user *)current->mm->start_stack;
 118
 119         sp -= bprm->envc + 1;
 120         sp -= bprm->argc + 1;
 121         sp -= flat_argvp_envp_on_stack() ? 2 : 0;
 122         sp -= 1;  /* &argc */
 123
 124         current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
 125         sp = (unsigned long __user *)current->mm->start_stack;
 126
 127         __put_user(bprm->argc, sp++);
 128         if (flat_argvp_envp_on_stack()) {
 129                 unsigned long argv, envp;
 130                 argv = (unsigned long)(sp + 2);
 131                 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
 132                 __put_user(argv, sp++);
 133                 __put_user(envp, sp++);
 134         }
 135
 136         current->mm->arg_start = (unsigned long)p;
 137         for (i = bprm->argc; i > 0; i--) {
 138                 __put_user((unsigned long)p, sp++);
 139                 len = strnlen_user(p, MAX_ARG_STRLEN);
 140                 if (!len || len > MAX_ARG_STRLEN)
 141                         return -EINVAL;
 142                 p += len;
 143         }
 144         __put_user(0, sp++);
 145         current->mm->arg_end = (unsigned long)p;
 146
 147         current->mm->env_start = (unsigned long) p;
 148         for (i = bprm->envc; i > 0; i--) {
 149                 __put_user((unsigned long)p, sp++);
 150                 len = strnlen_user(p, MAX_ARG_STRLEN);
 151                 if (!len || len > MAX_ARG_STRLEN)
 152                         return -EINVAL;
 153                 p += len;
 154         }
 155         __put_user(0, sp++);
 156         current->mm->env_end = (unsigned long)p;
 157
 158         return 0;
 159 }
 160
 161 /****************************************************************************/
 162
 163 #ifdef CONFIG_BINFMT_ZFLAT
 164
 165 #include <linux/zlib.h>
 166
 167 #define LBUFSIZE        4000
 168
 169 /* gzip flag byte */
 170 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 171 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 172 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 173 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 174 #define COMMENT      0x10 /* bit 4 set: file comment present */
 175 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 176 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 177
 178 static int decompress_exec(
 179         struct linux_binprm *bprm,
 180         unsigned long offset,
 181         char *dst,
 182         long len,
 183         int fd)
 184 {
 185         unsigned char *buf;
 186         z_stream strm;
 187         loff_t fpos;
 188         int ret, retval;
 189
 190         pr_debug("decompress_exec(offset=%lx,buf=%p,len=%lx)\n", offset, dst, len);
 191
 192         memset(&strm, 0, sizeof(strm));
 193         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 194         if (strm.workspace == NULL) {
 195                 pr_debug("no memory for decompress workspace\n");
 196                 return -ENOMEM;
 197         }
 198         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 199         if (buf == NULL) {
 200                 pr_debug("no memory for read buffer\n");
 201                 retval = -ENOMEM;
 202                 goto out_free;
 203         }
 204
 205         /* Read in first chunk of data and parse gzip header. */
 206         fpos = offset;
 207         ret = kernel_read(bprm->file, offset, buf, LBUFSIZE);
 208
 209         strm.next_in = buf;
 210         strm.avail_in = ret;
 211         strm.total_in = 0;
 212         fpos += ret;
 213
 214         retval = -ENOEXEC;
 215
 216         /* Check minimum size -- gzip header */
 217         if (ret < 10) {
 218                 pr_debug("file too small?\n");
 219                 goto out_free_buf;
 220         }
 221
 222         /* Check gzip magic number */
 223         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 224                 pr_debug("unknown compression magic?\n");
 225                 goto out_free_buf;
 226         }
 227
 228         /* Check gzip method */
 229         if (buf[2] != 8) {
 230                 pr_debug("unknown compression method?\n");
 231                 goto out_free_buf;
 232         }
 233         /* Check gzip flags */
 234         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 235             (buf[3] & RESERVED)) {
 236                 pr_debug("unknown flags?\n");
 237                 goto out_free_buf;
 238         }
 239
 240         ret = 10;
 241         if (buf[3] & EXTRA_FIELD) {
 242                 ret += 2 + buf[10] + (buf[11] << 8);
 243                 if (unlikely(ret >= LBUFSIZE)) {
 244                         pr_debug("buffer overflow (EXTRA)?\n");
 245                         goto out_free_buf;
 246                 }
 247         }
 248         if (buf[3] & ORIG_NAME) {
 249                 while (ret < LBUFSIZE && buf[ret++] != 0)
 250                         ;
 251                 if (unlikely(ret == LBUFSIZE)) {
 252                         pr_debug("buffer overflow (ORIG_NAME)?\n");
 253                         goto out_free_buf;
 254                 }
 255         }
 256         if (buf[3] & COMMENT) {
 257                 while (ret < LBUFSIZE && buf[ret++] != 0)
 258                         ;
 259                 if (unlikely(ret == LBUFSIZE)) {
 260                         pr_debug("buffer overflow (COMMENT)?\n");
 261                         goto out_free_buf;
 262                 }
 263         }
 264
 265         strm.next_in += ret;
 266         strm.avail_in -= ret;
 267
 268         strm.next_out = dst;
 269         strm.avail_out = len;
 270         strm.total_out = 0;
 271
 272         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 273                 pr_debug("zlib init failed?\n");
 274                 goto out_free_buf;
 275         }
 276
 277         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 278                 ret = kernel_read(bprm->file, fpos, buf, LBUFSIZE);
 279                 if (ret <= 0)
 280                         break;
 281                 len -= ret;
 282
 283                 strm.next_in = buf;
 284                 strm.avail_in = ret;
 285                 strm.total_in = 0;
 286                 fpos += ret;
 287         }
 288
 289         if (ret < 0) {
 290                 pr_debug("decompression failed (%d), %s\n",
 291                         ret, strm.msg);
 292                 goto out_zlib;
 293         }
 294
 295         retval = 0;
 296 out_zlib:
 297         zlib_inflateEnd(&strm);
 298 out_free_buf:
 299         kfree(buf);
 300 out_free:
 301         kfree(strm.workspace);
 302         return retval;
 303 }
 304
 305 #endif /* CONFIG_BINFMT_ZFLAT */
 306
 307 /****************************************************************************/
 308
 309 static unsigned long
 310 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 311 {
 312         unsigned long addr;
 313         int id;
 314         unsigned long start_brk;
 315         unsigned long start_data;
 316         unsigned long text_len;
 317         unsigned long start_code;
 318
 319 #ifdef CONFIG_BINFMT_SHARED_FLAT
 320         if (r == 0)
 321                 id = curid;     /* Relocs of 0 are always self referring */
 322         else {
 323                 id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 324                 r &= 0x00ffffff;        /* Trim ID off here */
 325         }
 326         if (id >= MAX_SHARED_LIBS) {
 327                 pr_err("reference 0x%lx to shared library %d", r, id);
 328                 goto failed;
 329         }
 330         if (curid != id) {
 331                 if (internalp) {
 332                         pr_err("reloc address 0x%lx not in same module "
 333                                "(%d != %d)", r, curid, id);
 334                         goto failed;
 335                 } else if (!p->lib_list[id].loaded &&
 336                            load_flat_shared_library(id, p) < 0) {
 337                         pr_err("failed to load library %d", id);
 338                         goto failed;
 339                 }
 340                 /* Check versioning information (i.e. time stamps) */
 341                 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 342                                 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 343                         pr_err("library %d is younger than %d", id, curid);
 344                         goto failed;
 345                 }
 346         }
 347 #else
 348         id = 0;
 349 #endif
 350
 351         start_brk = p->lib_list[id].start_brk;
 352         start_data = p->lib_list[id].start_data;
 353         start_code = p->lib_list[id].start_code;
 354         text_len = p->lib_list[id].text_len;
 355
 356         if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 357                 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
 358                        r, start_brk-start_data+text_len, text_len);
 359                 goto failed;
 360         }
 361
 362         if (r < text_len)                       /* In text segment */
 363                 addr = r + start_code;
 364         else                                    /* In data segment */
 365                 addr = r - text_len + start_data;
 366
 367         /* Range checked already above so doing the range tests is redundant...*/
 368         return addr;
 369
 370 failed:
 371         pr_cont(", killing %s!\n", current->comm);
 372         send_sig(SIGSEGV, current, 0);
 373
 374         return RELOC_FAILED;
 375 }
 376
 377 /****************************************************************************/
 378
 379 static void old_reloc(unsigned long rl)
 380 {
 381         static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 382         flat_v2_reloc_t r;
 383         unsigned long __user *ptr;
 384         unsigned long val;
 385
 386         r.value = rl;
 387 #if defined(CONFIG_COLDFIRE)
 388         ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
 389 #else
 390         ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
 391 #endif
 392         get_user(val, ptr);
 393
 394         pr_debug("Relocation of variable at DATASEG+%x "
 395                  "(address %p, currently %lx) into segment %s\n",
 396                  r.reloc.offset, ptr, val, segment[r.reloc.type]);
 397
 398         switch (r.reloc.type) {
 399         case OLD_FLAT_RELOC_TYPE_TEXT:
 400                 val += current->mm->start_code;
 401                 break;
 402         case OLD_FLAT_RELOC_TYPE_DATA:
 403                 val += current->mm->start_data;
 404                 break;
 405         case OLD_FLAT_RELOC_TYPE_BSS:
 406                 val += current->mm->end_data;
 407                 break;
 408         default:
 409                 pr_err("Unknown relocation type=%x\n", r.reloc.type);
 410                 break;
 411         }
 412         put_user(val, ptr);
 413
 414         pr_debug("Relocation became %lx\n", val);
 415 }
 416
 417 /****************************************************************************/
 418
 419 static int load_flat_file(struct linux_binprm *bprm,
 420                 struct lib_info *libinfo, int id, unsigned long *extra_stack)
 421 {
 422         struct flat_hdr *hdr;
 423         unsigned long textpos, datapos, realdatastart;
 424         unsigned long text_len, data_len, bss_len, stack_len, full_data, flags;
 425         unsigned long len, memp, memp_size, extra, rlim;
 426         unsigned long __user *reloc, *rp;
 427         struct inode *inode;
 428         int i, rev, relocs;
 429         loff_t fpos;
 430         unsigned long start_code, end_code;
 431         ssize_t result;
 432         int ret;
 433
 434         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 435         inode = file_inode(bprm->file);
 436
 437         text_len  = ntohl(hdr->data_start);
 438         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 439         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 440         stack_len = ntohl(hdr->stack_size);
 441         if (extra_stack) {
 442                 stack_len += *extra_stack;
 443                 *extra_stack = stack_len;
 444         }
 445         relocs    = ntohl(hdr->reloc_count);
 446         flags     = ntohl(hdr->flags);
 447         rev       = ntohl(hdr->rev);
 448         full_data = data_len + relocs * sizeof(unsigned long);
 449
 450         if (strncmp(hdr->magic, "bFLT", 4)) {
 451                 /*
 452                  * Previously, here was a printk to tell people
 453                  *   "BINFMT_FLAT: bad header magic".
 454                  * But for the kernel which also use ELF FD-PIC format, this
 455                  * error message is confusing.
 456                  * because a lot of people do not manage to produce good
 457                  */
 458                 ret = -ENOEXEC;
 459                 goto err;
 460         }
 461
 462         if (flags & FLAT_FLAG_KTRACE)
 463                 pr_info("Loading file: %s\n", bprm->filename);
 464
 465         if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 466                 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
 467                        rev, FLAT_VERSION, OLD_FLAT_VERSION);
 468                 ret = -ENOEXEC;
 469                 goto err;
 470         }
 471
 472         /* Don't allow old format executables to use shared libraries */
 473         if (rev == OLD_FLAT_VERSION && id != 0) {
 474                 pr_err("shared libraries are not available before rev 0x%lx\n",
 475                        FLAT_VERSION);
 476                 ret = -ENOEXEC;
 477                 goto err;
 478         }
 479
 480         /*
 481          * Make sure the header params are sane.
 482          * 28 bits (256 MB) is way more than reasonable in this case.
 483          * If some top bits are set we have probable binary corruption.
 484         */
 485         if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
 486                 pr_err("bad header\n");
 487                 ret = -ENOEXEC;
 488                 goto err;
 489         }
 490
 491         /*
 492          * fix up the flags for the older format,  there were all kinds
 493          * of endian hacks,  this only works for the simple cases
 494          */
 495         if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 496                 flags = FLAT_FLAG_RAM;
 497
 498 #ifndef CONFIG_BINFMT_ZFLAT
 499         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 500                 pr_err("Support for ZFLAT executables is not enabled.\n");
 501                 ret = -ENOEXEC;
 502                 goto err;
 503         }
 504 #endif
 505
 506         /*
 507          * Check initial limits. This avoids letting people circumvent
 508          * size limits imposed on them by creating programs with large
 509          * arrays in the data or bss.
 510          */
 511         rlim = rlimit(RLIMIT_DATA);
 512         if (rlim >= RLIM_INFINITY)
 513                 rlim = ~0;
 514         if (data_len + bss_len > rlim) {
 515                 ret = -ENOMEM;
 516                 goto err;
 517         }
 518
 519         /* Flush all traces of the currently running executable */
 520         if (id == 0) {
 521                 ret = flush_old_exec(bprm);
 522                 if (ret)
 523                         goto err;
 524
 525                 /* OK, This is the point of no return */
 526                 set_personality(PER_LINUX_32BIT);
 527                 setup_new_exec(bprm);
 528         }
 529
 530         /*
 531          * calculate the extra space we need to map in
 532          */
 533         extra = max_t(unsigned long, bss_len + stack_len,
 534                         relocs * sizeof(unsigned long));
 535
 536         /*
 537          * there are a couple of cases here,  the separate code/data
 538          * case,  and then the fully copied to RAM case which lumps
 539          * it all together.
 540          */
 541         if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
 542                 /*
 543                  * this should give us a ROM ptr,  but if it doesn't we don't
 544                  * really care
 545                  */
 546                 pr_debug("ROM mapping of file (we hope)\n");
 547
 548                 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
 549                                   MAP_PRIVATE|MAP_EXECUTABLE, 0);
 550                 if (!textpos || IS_ERR_VALUE(textpos)) {
 551                         ret = textpos;
 552                         if (!textpos)
 553                                 ret = -ENOMEM;
 554                         pr_err("Unable to mmap process text, errno %d\n", ret);
 555                         goto err;
 556                 }
 557
 558                 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 559                 len = PAGE_ALIGN(len);
 560                 realdatastart = vm_mmap(NULL, 0, len,
 561                         PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 562
 563                 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
 564                         ret = realdatastart;
 565                         if (!realdatastart)
 566                                 ret = -ENOMEM;
 567                         pr_err("Unable to allocate RAM for process data, "
 568                                "errno %d\n", ret);
 569                         vm_munmap(textpos, text_len);
 570                         goto err;
 571                 }
 572                 datapos = ALIGN(realdatastart +
 573                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 574                                 FLAT_DATA_ALIGN);
 575
 576                 pr_debug("Allocated data+bss+stack (%ld bytes): %lx\n",
 577                          data_len + bss_len + stack_len, datapos);
 578
 579                 fpos = ntohl(hdr->data_start);
 580 #ifdef CONFIG_BINFMT_ZFLAT
 581                 if (flags & FLAT_FLAG_GZDATA) {
 582                         result = decompress_exec(bprm, fpos, (char *)datapos,
 583                                                  full_data, 0);
 584                 } else
 585 #endif
 586                 {
 587                         result = read_code(bprm->file, datapos, fpos,
 588                                         full_data);
 589                 }
 590                 if (IS_ERR_VALUE(result)) {
 591                         ret = result;
 592                         pr_err("Unable to read data+bss, errno %d\n", ret);
 593                         vm_munmap(textpos, text_len);
 594                         vm_munmap(realdatastart, len);
 595                         goto err;
 596                 }
 597
 598                 reloc = (unsigned long __user *)
 599                         (datapos + (ntohl(hdr->reloc_start) - text_len));
 600                 memp = realdatastart;
 601                 memp_size = len;
 602         } else {
 603
 604                 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 605                 len = PAGE_ALIGN(len);
 606                 textpos = vm_mmap(NULL, 0, len,
 607                         PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 608
 609                 if (!textpos || IS_ERR_VALUE(textpos)) {
 610                         ret = textpos;
 611                         if (!textpos)
 612                                 ret = -ENOMEM;
 613                         pr_err("Unable to allocate RAM for process text/data, "
 614                                "errno %d\n", ret);
 615                         goto err;
 616                 }
 617
 618                 realdatastart = textpos + ntohl(hdr->data_start);
 619                 datapos = ALIGN(realdatastart +
 620                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 621                                 FLAT_DATA_ALIGN);
 622
 623                 reloc = (unsigned long __user *)
 624                         (datapos + (ntohl(hdr->reloc_start) - text_len));
 625                 memp = textpos;
 626                 memp_size = len;
 627 #ifdef CONFIG_BINFMT_ZFLAT
 628                 /*
 629                  * load it all in and treat it like a RAM load from now on
 630                  */
 631                 if (flags & FLAT_FLAG_GZIP) {
 632 #ifndef CONFIG_MMU
 633                         result = decompress_exec(bprm, sizeof(struct flat_hdr),
 634                                          (((char *)textpos) + sizeof(struct flat_hdr)),
 635                                          (text_len + full_data
 636                                                   - sizeof(struct flat_hdr)),
 637                                          0);
 638                         memmove((void *) datapos, (void *) realdatastart,
 639                                         full_data);
 640 #else
 641                         /*
 642                          * This is used on MMU systems mainly for testing.
 643                          * Let's use a kernel buffer to simplify things.
 644                          */
 645                         long unz_text_len = text_len - sizeof(struct flat_hdr);
 646                         long unz_len = unz_text_len + full_data;
 647                         char *unz_data = vmalloc(unz_len);
 648                         if (!unz_data) {
 649                                 result = -ENOMEM;
 650                         } else {
 651                                 result = decompress_exec(bprm, sizeof(struct flat_hdr),
 652                                                          unz_data, unz_len, 0);
 653                                 if (result == 0 &&
 654                                     (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
 655                                                   unz_data, unz_text_len) ||
 656                                      copy_to_user((void __user *)datapos,
 657                                                   unz_data + unz_text_len, full_data)))
 658                                         result = -EFAULT;
 659                                 vfree(unz_data);
 660                         }
 661 #endif
 662                 } else if (flags & FLAT_FLAG_GZDATA) {
 663                         result = read_code(bprm->file, textpos, 0, text_len);
 664                         if (!IS_ERR_VALUE(result)) {
 665 #ifndef CONFIG_MMU
 666                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 667                                                  full_data, 0);
 668 #else
 669                                 char *unz_data = vmalloc(full_data);
 670                                 if (!unz_data) {
 671                                         result = -ENOMEM;
 672                                 } else {
 673                                         result = decompress_exec(bprm, text_len,
 674                                                        unz_data, full_data, 0);
 675                                         if (result == 0 &&
 676                                             copy_to_user((void __user *)datapos,
 677                                                          unz_data, full_data))
 678                                                 result = -EFAULT;
 679                                         vfree(unz_data);
 680                                 }
 681 #endif
 682                         }
 683                 } else
 684 #endif /* CONFIG_BINFMT_ZFLAT */
 685                 {
 686                         result = read_code(bprm->file, textpos, 0, text_len);
 687                         if (!IS_ERR_VALUE(result))
 688                                 result = read_code(bprm->file, datapos,
 689                                                    ntohl(hdr->data_start),
 690                                                    full_data);
 691                 }
 692                 if (IS_ERR_VALUE(result)) {
 693                         ret = result;
 694                         pr_err("Unable to read code+data+bss, errno %d\n", ret);
 695                         vm_munmap(textpos, text_len + data_len + extra +
 696                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 697                         goto err;
 698                 }
 699         }
 700
 701         start_code = textpos + sizeof(struct flat_hdr);
 702         end_code = textpos + text_len;
 703         text_len -= sizeof(struct flat_hdr); /* the real code len */
 704
 705         /* The main program needs a little extra setup in the task structure */
 706         if (id == 0) {
 707                 current->mm->start_code = start_code;
 708                 current->mm->end_code = end_code;
 709                 current->mm->start_data = datapos;
 710                 current->mm->end_data = datapos + data_len;
 711                 /*
 712                  * set up the brk stuff, uses any slack left in data/bss/stack
 713                  * allocation.  We put the brk after the bss (between the bss
 714                  * and stack) like other platforms.
 715                  * Userspace code relies on the stack pointer starting out at
 716                  * an address right at the end of a page.
 717                  */
 718                 current->mm->start_brk = datapos + data_len + bss_len;
 719                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 720 #ifndef CONFIG_MMU
 721                 current->mm->context.end_brk = memp + memp_size - stack_len;
 722 #endif
 723         }
 724
 725         if (flags & FLAT_FLAG_KTRACE) {
 726                 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
 727                         textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 728                 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
 729                         id ? "Lib" : "Load", bprm->filename,
 730                         start_code, end_code, datapos, datapos + data_len,
 731                         datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
 732         }
 733
 734         /* Store the current module values into the global library structure */
 735         libinfo->lib_list[id].start_code = start_code;
 736         libinfo->lib_list[id].start_data = datapos;
 737         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 738         libinfo->lib_list[id].text_len = text_len;
 739         libinfo->lib_list[id].loaded = 1;
 740         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 741         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 742
 743         /*
 744          * We just load the allocations into some temporary memory to
 745          * help simplify all this mumbo jumbo
 746          *
 747          * We've got two different sections of relocation entries.
 748          * The first is the GOT which resides at the beginning of the data segment
 749          * and is terminated with a -1.  This one can be relocated in place.
 750          * The second is the extra relocation entries tacked after the image's
 751          * data segment. These require a little more processing as the entry is
 752          * really an offset into the image which contains an offset into the
 753          * image.
 754          */
 755         if (flags & FLAT_FLAG_GOTPIC) {
 756                 for (rp = (unsigned long __user *)datapos; ; rp++) {
 757                         unsigned long addr, rp_val;
 758                         if (get_user(rp_val, rp))
 759                                 return -EFAULT;
 760                         if (rp_val == 0xffffffff)
 761                                 break;
 762                         if (rp_val) {
 763                                 addr = calc_reloc(rp_val, libinfo, id, 0);
 764                                 if (addr == RELOC_FAILED) {
 765                                         ret = -ENOEXEC;
 766                                         goto err;
 767                                 }
 768                                 if (put_user(addr, rp))
 769                                         return -EFAULT;
 770                         }
 771                 }
 772         }
 773
 774         /*
 775          * Now run through the relocation entries.
 776          * We've got to be careful here as C++ produces relocatable zero
 777          * entries in the constructor and destructor tables which are then
 778          * tested for being not zero (which will always occur unless we're
 779          * based from address zero).  This causes an endless loop as __start
 780          * is at zero.  The solution used is to not relocate zero addresses.
 781          * This has the negative side effect of not allowing a global data
 782          * reference to be statically initialised to _stext (I've moved
 783          * __start to address 4 so that is okay).
 784          */
 785         if (rev > OLD_FLAT_VERSION) {
 786                 unsigned long __maybe_unused persistent = 0;
 787                 for (i = 0; i < relocs; i++) {
 788                         unsigned long addr, relval;
 789
 790                         /*
 791                          * Get the address of the pointer to be
 792                          * relocated (of course, the address has to be
 793                          * relocated first).
 794                          */
 795                         if (get_user(relval, reloc + i))
 796                                 return -EFAULT;
 797                         relval = ntohl(relval);
 798                         if (flat_set_persistent(relval, &persistent))
 799                                 continue;
 800                         addr = flat_get_relocate_addr(relval);
 801                         rp = (unsigned long __user *)calc_reloc(addr, libinfo, id, 1);
 802                         if (rp == (unsigned long __user *)RELOC_FAILED) {
 803                                 ret = -ENOEXEC;
 804                                 goto err;
 805                         }
 806
 807                         /* Get the pointer's value.  */
 808                         addr = flat_get_addr_from_rp(rp, relval, flags,
 809                                                         &persistent);
 810                         if (addr != 0) {
 811                                 /*
 812                                  * Do the relocation.  PIC relocs in the data section are
 813                                  * already in target order
 814                                  */
 815                                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 816                                         addr = ntohl(addr);
 817                                 addr = calc_reloc(addr, libinfo, id, 0);
 818                                 if (addr == RELOC_FAILED) {
 819                                         ret = -ENOEXEC;
 820                                         goto err;
 821                                 }
 822
 823                                 /* Write back the relocated pointer.  */
 824                                 flat_put_addr_at_rp(rp, addr, relval);
 825                         }
 826                 }
 827         } else {
 828                 for (i = 0; i < relocs; i++) {
 829                         unsigned long relval;
 830                         if (get_user(relval, reloc + i))
 831                                 return -EFAULT;
 832                         relval = ntohl(relval);
 833                         old_reloc(relval);
 834                 }
 835         }
 836
 837         flush_icache_range(start_code, end_code);
 838
 839         /* zero the BSS,  BRK and stack areas */
 840         if (clear_user((void __user *)(datapos + data_len), bss_len +
 841                        (memp + memp_size - stack_len -          /* end brk */
 842                        libinfo->lib_list[id].start_brk) +       /* start brk */
 843                        stack_len))
 844                 return -EFAULT;
 845
 846         return 0;
 847 err:
 848         return ret;
 849 }
 850
 851
 852 /****************************************************************************/
 853 #ifdef CONFIG_BINFMT_SHARED_FLAT
 854
 855 /*
 856  * Load a shared library into memory.  The library gets its own data
 857  * segment (including bss) but not argv/argc/environ.
 858  */
 859
 860 static int load_flat_shared_library(int id, struct lib_info *libs)
 861 {
 862         struct linux_binprm bprm;
 863         int res;
 864         char buf[16];
 865
 866         memset(&bprm, 0, sizeof(bprm));
 867
 868         /* Create the file name */
 869         sprintf(buf, "/lib/lib%d.so", id);
 870
 871         /* Open the file up */
 872         bprm.filename = buf;
 873         bprm.file = open_exec(bprm.filename);
 874         res = PTR_ERR(bprm.file);
 875         if (IS_ERR(bprm.file))
 876                 return res;
 877
 878         bprm.cred = prepare_exec_creds();
 879         res = -ENOMEM;
 880         if (!bprm.cred)
 881                 goto out;
 882
 883         /* We don't really care about recalculating credentials at this point
 884          * as we're past the point of no return and are dealing with shared
 885          * libraries.
 886          */
 887         bprm.cred_prepared = 1;
 888
 889         res = prepare_binprm(&bprm);
 890
 891         if (!res)
 892                 res = load_flat_file(&bprm, libs, id, NULL);
 893
 894         abort_creds(bprm.cred);
 895
 896 out:
 897         allow_write_access(bprm.file);
 898         fput(bprm.file);
 899
 900         return res;
 901 }
 902
 903 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 904 /****************************************************************************/
 905
 906 /*
 907  * These are the functions used to load flat style executables and shared
 908  * libraries.  There is no binary dependent code anywhere else.
 909  */
 910
 911 static int load_flat_binary(struct linux_binprm *bprm)
 912 {
 913         struct lib_info libinfo;
 914         struct pt_regs *regs = current_pt_regs();
 915         unsigned long stack_len = 0;
 916         unsigned long start_addr;
 917         int res;
 918         int i, j;
 919
 920         memset(&libinfo, 0, sizeof(libinfo));
 921
 922         /*
 923          * We have to add the size of our arguments to our stack size
 924          * otherwise it's too easy for users to create stack overflows
 925          * by passing in a huge argument list.  And yes,  we have to be
 926          * pedantic and include space for the argv/envp array as it may have
 927          * a lot of entries.
 928          */
 929 #ifndef CONFIG_MMU
 930         stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
 931 #endif
 932         stack_len += (bprm->argc + 1) * sizeof(char *);   /* the argv array */
 933         stack_len += (bprm->envc + 1) * sizeof(char *);   /* the envp array */
 934         stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
 935
 936         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 937         if (res < 0)
 938                 return res;
 939
 940         /* Update data segment pointers for all libraries */
 941         for (i = 0; i < MAX_SHARED_LIBS; i++) {
 942                 if (!libinfo.lib_list[i].loaded)
 943                         continue;
 944                 for (j = 0; j < MAX_SHARED_LIBS; j++) {
 945                         unsigned long val = libinfo.lib_list[j].loaded ?
 946                                 libinfo.lib_list[j].start_data : UNLOADED_LIB;
 947                         unsigned long __user *p = (unsigned long __user *)
 948                                 libinfo.lib_list[i].start_data;
 949                         p -= j + 1;
 950                         if (put_user(val, p))
 951                                 return -EFAULT;
 952                 }
 953         }
 954
 955         install_exec_creds(bprm);
 956
 957         set_binfmt(&flat_format);
 958
 959 #ifdef CONFIG_MMU
 960         res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
 961         if (!res)
 962                 res = create_flat_tables(bprm, bprm->p);
 963 #else
 964         /* Stash our initial stack pointer into the mm structure */
 965         current->mm->start_stack =
 966                 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 967         pr_debug("sp=%lx\n", current->mm->start_stack);
 968
 969         /* copy the arg pages onto the stack */
 970         res = transfer_args_to_stack(bprm, &current->mm->start_stack);
 971         if (!res)
 972                 res = create_flat_tables(bprm, current->mm->start_stack);
 973 #endif
 974         if (res)
 975                 return res;
 976
 977         /* Fake some return addresses to ensure the call chain will
 978          * initialise library in order for us.  We are required to call
 979          * lib 1 first, then 2, ... and finally the main program (id 0).
 980          */
 981         start_addr = libinfo.lib_list[0].entry;
 982
 983 #ifdef CONFIG_BINFMT_SHARED_FLAT
 984         for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
 985                 if (libinfo.lib_list[i].loaded) {
 986                         /* Push previos first to call address */
 987                         unsigned long __user *sp;
 988                         current->mm->start_stack -= sizeof(unsigned long);
 989                         sp = (unsigned long __user *)current->mm->start_stack;
 990                         __put_user(start_addr, sp);
 991                         start_addr = libinfo.lib_list[i].entry;
 992                 }
 993         }
 994 #endif
 995
 996 #ifdef FLAT_PLAT_INIT
 997         FLAT_PLAT_INIT(regs);
 998 #endif
 999
1000         pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
1001                  regs, start_addr, current->mm->start_stack);
1002         start_thread(regs, start_addr, current->mm->start_stack);
1003
1004         return 0;
1005 }
1006
1007 /****************************************************************************/
1008
1009 static int __init init_flat_binfmt(void)
1010 {
1011         register_binfmt(&flat_format);
1012         return 0;
1013 }
1014 core_initcall(init_flat_binfmt);
1015
1016 /****************************************************************************/