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