linux-user/flatload.c

   1 /****************************************************************************/
   2 /*
   3  *  QEMU bFLT binary loader.  Based on linux/fs/binfmt_flat.c
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  *
  18  *      Copyright (C) 2006 CodeSourcery.
  19  *      Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
  20  *      Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
  21  *      Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
  22  *      Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
  23  *  based heavily on:
  24  *
  25  *  linux/fs/binfmt_aout.c:
  26  *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
  27  *  linux/fs/binfmt_flat.c for 2.0 kernel
  28  *          Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
  29  *      JAN/99 -- coded full program relocation (gerg@snapgear.com)
  30  */
  31
  32 /* ??? ZFLAT and shared library support is currently disabled.  */
  33
  34 /****************************************************************************/
  35
  36 #include "qemu/osdep.h"
  37 #include <sys/mman.h>
  38
  39 #include "qemu.h"
  40 #include "flat.h"
  41 #define ntohl(x) be32_to_cpu(x)
  42 #include <target_flat.h>
  43
  44 //#define DEBUG
  45
  46 #ifdef DEBUG
  47 #define DBG_FLT(...)    printf(__VA_ARGS__)
  48 #else
  49 #define DBG_FLT(...)
  50 #endif
  51
  52 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  53 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  54
  55 struct lib_info {
  56     abi_ulong start_code;       /* Start of text segment */
  57     abi_ulong start_data;       /* Start of data segment */
  58     abi_ulong end_data;         /* Start of bss section */
  59     abi_ulong start_brk;        /* End of data segment */
  60     abi_ulong text_len;         /* Length of text segment */
  61     abi_ulong entry;            /* Start address for this module */
  62     abi_ulong build_date;       /* When this one was compiled */
  63     short loaded;               /* Has this library been loaded? */
  64 };
  65
  66 #ifdef CONFIG_BINFMT_SHARED_FLAT
  67 static int load_flat_shared_library(int id, struct lib_info *p);
  68 #endif
  69
  70 struct linux_binprm;
  71
  72 /****************************************************************************/
  73 /*
  74  * create_flat_tables() parses the env- and arg-strings in new user
  75  * memory and creates the pointer tables from them, and puts their
  76  * addresses on the "stack", returning the new stack pointer value.
  77  */
  78
  79 /* Push a block of strings onto the guest stack.  */
  80 static abi_ulong copy_strings(abi_ulong p, int n, char **s)
  81 {
  82     int len;
  83
  84     while (n-- > 0) {
  85         len = strlen(s[n]) + 1;
  86         p -= len;
  87         memcpy_to_target(p, s[n], len);
  88     }
  89
  90     return p;
  91 }
  92
  93 static int target_pread(int fd, abi_ulong ptr, abi_ulong len,
  94                         abi_ulong offset)
  95 {
  96     void *buf;
  97     int ret;
  98
  99     buf = lock_user(VERIFY_WRITE, ptr, len, 0);
 100     ret = pread(fd, buf, len, offset);
 101     unlock_user(buf, ptr, len);
 102     return ret;
 103 }
 104 /****************************************************************************/
 105
 106 #ifdef CONFIG_BINFMT_ZFLAT
 107
 108 #include <linux/zlib.h>
 109
 110 #define LBUFSIZE        4000
 111
 112 /* gzip flag byte */
 113 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 114 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 115 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 116 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 117 #define COMMENT      0x10 /* bit 4 set: file comment present */
 118 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 119 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 120
 121 static int decompress_exec(
 122         struct linux_binprm *bprm,
 123         unsigned long offset,
 124         char *dst,
 125         long len,
 126         int fd)
 127 {
 128         unsigned char *buf;
 129         z_stream strm;
 130         loff_t fpos;
 131         int ret, retval;
 132
 133         DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 134
 135         memset(&strm, 0, sizeof(strm));
 136         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 137         if (strm.workspace == NULL) {
 138                 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 139                 return -ENOMEM;
 140         }
 141         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 142         if (buf == NULL) {
 143                 DBG_FLT("binfmt_flat: no memory for read buffer\n");
 144                 retval = -ENOMEM;
 145                 goto out_free;
 146         }
 147
 148         /* Read in first chunk of data and parse gzip header. */
 149         fpos = offset;
 150         ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 151
 152         strm.next_in = buf;
 153         strm.avail_in = ret;
 154         strm.total_in = 0;
 155
 156         retval = -ENOEXEC;
 157
 158         /* Check minimum size -- gzip header */
 159         if (ret < 10) {
 160                 DBG_FLT("binfmt_flat: file too small?\n");
 161                 goto out_free_buf;
 162         }
 163
 164         /* Check gzip magic number */
 165         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 166                 DBG_FLT("binfmt_flat: unknown compression magic?\n");
 167                 goto out_free_buf;
 168         }
 169
 170         /* Check gzip method */
 171         if (buf[2] != 8) {
 172                 DBG_FLT("binfmt_flat: unknown compression method?\n");
 173                 goto out_free_buf;
 174         }
 175         /* Check gzip flags */
 176         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 177             (buf[3] & RESERVED)) {
 178                 DBG_FLT("binfmt_flat: unknown flags?\n");
 179                 goto out_free_buf;
 180         }
 181
 182         ret = 10;
 183         if (buf[3] & EXTRA_FIELD) {
 184                 ret += 2 + buf[10] + (buf[11] << 8);
 185                 if (unlikely(LBUFSIZE == ret)) {
 186                         DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
 187                         goto out_free_buf;
 188                 }
 189         }
 190         if (buf[3] & ORIG_NAME) {
 191                 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
 192                         ;
 193                 if (unlikely(LBUFSIZE == ret)) {
 194                         DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
 195                         goto out_free_buf;
 196                 }
 197         }
 198         if (buf[3] & COMMENT) {
 199                 for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
 200                         ;
 201                 if (unlikely(LBUFSIZE == ret)) {
 202                         DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
 203                         goto out_free_buf;
 204                 }
 205         }
 206
 207         strm.next_in += ret;
 208         strm.avail_in -= ret;
 209
 210         strm.next_out = dst;
 211         strm.avail_out = len;
 212         strm.total_out = 0;
 213
 214         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 215                 DBG_FLT("binfmt_flat: zlib init failed?\n");
 216                 goto out_free_buf;
 217         }
 218
 219         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 220                 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 221                 if (ret <= 0)
 222                         break;
 223                 if (ret >= (unsigned long) -4096)
 224                         break;
 225                 len -= ret;
 226
 227                 strm.next_in = buf;
 228                 strm.avail_in = ret;
 229                 strm.total_in = 0;
 230         }
 231
 232         if (ret < 0) {
 233                 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
 234                         ret, strm.msg);
 235                 goto out_zlib;
 236         }
 237
 238         retval = 0;
 239 out_zlib:
 240         zlib_inflateEnd(&strm);
 241 out_free_buf:
 242         kfree(buf);
 243 out_free:
 244         kfree(strm.workspace);
 245 out:
 246         return retval;
 247 }
 248
 249 #endif /* CONFIG_BINFMT_ZFLAT */
 250
 251 /****************************************************************************/
 252
 253 static abi_ulong
 254 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp)
 255 {
 256     abi_ulong addr;
 257     int id;
 258     abi_ulong start_brk;
 259     abi_ulong start_data;
 260     abi_ulong text_len;
 261     abi_ulong start_code;
 262
 263 #ifdef CONFIG_BINFMT_SHARED_FLAT
 264 #error needs checking
 265     if (r == 0)
 266         id = curid;     /* Relocs of 0 are always self referring */
 267     else {
 268         id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 269         r &= 0x00ffffff;        /* Trim ID off here */
 270     }
 271     if (id >= MAX_SHARED_LIBS) {
 272         fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n",
 273                 (unsigned) r, id);
 274         goto failed;
 275     }
 276     if (curid != id) {
 277         if (internalp) {
 278             fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not "
 279                     "in same module (%d != %d)\n",
 280                     (unsigned) r, curid, id);
 281             goto failed;
 282         } else if ( ! p[id].loaded &&
 283                     load_flat_shared_library(id, p) > (unsigned long) -4096) {
 284             fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id);
 285             goto failed;
 286         }
 287         /* Check versioning information (i.e. time stamps) */
 288         if (p[id].build_date && p[curid].build_date
 289             && p[curid].build_date < p[id].build_date) {
 290             fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n",
 291                     id, curid);
 292             goto failed;
 293         }
 294     }
 295 #else
 296     id = 0;
 297 #endif
 298
 299     start_brk = p[id].start_brk;
 300     start_data = p[id].start_data;
 301     start_code = p[id].start_code;
 302     text_len = p[id].text_len;
 303
 304     if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 305         fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x "
 306                 "(0 - 0x%x/0x%x)\n",
 307                (int) r,(int)(start_brk-start_code),(int)text_len);
 308         goto failed;
 309     }
 310
 311     if (r < text_len)                   /* In text segment */
 312         addr = r + start_code;
 313     else                                        /* In data segment */
 314         addr = r - text_len + start_data;
 315
 316     /* Range checked already above so doing the range tests is redundant...*/
 317     return(addr);
 318
 319 failed:
 320     abort();
 321     return RELOC_FAILED;
 322 }
 323
 324 /****************************************************************************/
 325
 326 /* ??? This does not handle endianness correctly.  */
 327 static void old_reloc(struct lib_info *libinfo, uint32_t rl)
 328 {
 329 #ifdef DEBUG
 330         const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 331 #endif
 332         uint32_t *ptr;
 333         uint32_t offset;
 334         int reloc_type;
 335
 336         offset = rl & 0x3fffffff;
 337         reloc_type = rl >> 30;
 338         /* ??? How to handle this?  */
 339 #if defined(CONFIG_COLDFIRE)
 340         ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset);
 341 #else
 342         ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset);
 343 #endif
 344
 345 #ifdef DEBUG
 346         fprintf(stderr, "Relocation of variable at DATASEG+%x "
 347                 "(address %p, currently %x) into segment %s\n",
 348                 offset, ptr, (int)*ptr, segment[reloc_type]);
 349 #endif
 350
 351         switch (reloc_type) {
 352         case OLD_FLAT_RELOC_TYPE_TEXT:
 353                 *ptr += libinfo->start_code;
 354                 break;
 355         case OLD_FLAT_RELOC_TYPE_DATA:
 356                 *ptr += libinfo->start_data;
 357                 break;
 358         case OLD_FLAT_RELOC_TYPE_BSS:
 359                 *ptr += libinfo->end_data;
 360                 break;
 361         default:
 362                 fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n",
 363                         reloc_type);
 364                 break;
 365         }
 366         DBG_FLT("Relocation became %x\n", (int)*ptr);
 367 }
 368
 369 /****************************************************************************/
 370
 371 static int load_flat_file(struct linux_binprm * bprm,
 372                 struct lib_info *libinfo, int id, abi_ulong *extra_stack)
 373 {
 374     struct flat_hdr * hdr;
 375     abi_ulong textpos = 0, datapos = 0;
 376     abi_long result;
 377     abi_ulong realdatastart = 0;
 378     abi_ulong text_len, data_len, bss_len, stack_len, flags;
 379     abi_ulong extra;
 380     abi_ulong reloc = 0, rp;
 381     int i, rev, relocs = 0;
 382     abi_ulong fpos;
 383     abi_ulong start_code;
 384     abi_ulong indx_len;
 385
 386     hdr = ((struct flat_hdr *) bprm->buf);              /* exec-header */
 387
 388     text_len  = ntohl(hdr->data_start);
 389     data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 390     bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 391     stack_len = ntohl(hdr->stack_size);
 392     if (extra_stack) {
 393         stack_len += *extra_stack;
 394         *extra_stack = stack_len;
 395     }
 396     relocs    = ntohl(hdr->reloc_count);
 397     flags     = ntohl(hdr->flags);
 398     rev       = ntohl(hdr->rev);
 399
 400     DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 401
 402     if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 403         fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",
 404                 rev, (int) FLAT_VERSION);
 405         return -ENOEXEC;
 406     }
 407
 408     /* Don't allow old format executables to use shared libraries */
 409     if (rev == OLD_FLAT_VERSION && id != 0) {
 410         fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n");
 411         return -ENOEXEC;
 412     }
 413
 414     /*
 415      * fix up the flags for the older format,  there were all kinds
 416      * of endian hacks,  this only works for the simple cases
 417      */
 418     if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 419         flags = FLAT_FLAG_RAM;
 420
 421 #ifndef CONFIG_BINFMT_ZFLAT
 422     if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 423         fprintf(stderr, "Support for ZFLAT executables is not enabled\n");
 424         return -ENOEXEC;
 425     }
 426 #endif
 427
 428     /*
 429      * calculate the extra space we need to map in
 430      */
 431     extra = relocs * sizeof(abi_ulong);
 432     if (extra < bss_len + stack_len)
 433         extra = bss_len + stack_len;
 434
 435     /* Add space for library base pointers.  Make sure this does not
 436        misalign the  doesn't misalign the data segment.  */
 437     indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong);
 438     indx_len = (indx_len + 15) & ~(abi_ulong)15;
 439
 440     /*
 441      * there are a couple of cases here,  the separate code/data
 442      * case,  and then the fully copied to RAM case which lumps
 443      * it all together.
 444      */
 445     if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 446         /*
 447          * this should give us a ROM ptr,  but if it doesn't we don't
 448          * really care
 449          */
 450         DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 451
 452         textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC,
 453                               MAP_PRIVATE, bprm->fd, 0);
 454         if (textpos == -1) {
 455             fprintf(stderr, "Unable to mmap process text\n");
 456             return -1;
 457         }
 458
 459         realdatastart = target_mmap(0, data_len + extra + indx_len,
 460                                     PROT_READ|PROT_WRITE|PROT_EXEC,
 461                                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 462
 463         if (realdatastart == -1) {
 464             fprintf(stderr, "Unable to allocate RAM for process data\n");
 465             return realdatastart;
 466         }
 467         datapos = realdatastart + indx_len;
 468
 469         DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 470                         (int)(data_len + bss_len + stack_len), (int)datapos);
 471
 472         fpos = ntohl(hdr->data_start);
 473 #ifdef CONFIG_BINFMT_ZFLAT
 474         if (flags & FLAT_FLAG_GZDATA) {
 475             result = decompress_exec(bprm, fpos, (char *) datapos,
 476                                      data_len + (relocs * sizeof(abi_ulong)))
 477         } else
 478 #endif
 479         {
 480             result = target_pread(bprm->fd, datapos,
 481                                   data_len + (relocs * sizeof(abi_ulong)),
 482                                   fpos);
 483         }
 484         if (result < 0) {
 485             fprintf(stderr, "Unable to read data+bss\n");
 486             return result;
 487         }
 488
 489         reloc = datapos + (ntohl(hdr->reloc_start) - text_len);
 490
 491     } else {
 492
 493         textpos = target_mmap(0, text_len + data_len + extra + indx_len,
 494                               PROT_READ | PROT_EXEC | PROT_WRITE,
 495                               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 496         if (textpos == -1 ) {
 497             fprintf(stderr, "Unable to allocate RAM for process text/data\n");
 498             return -1;
 499         }
 500
 501         realdatastart = textpos + ntohl(hdr->data_start);
 502         datapos = realdatastart + indx_len;
 503         reloc = (textpos + ntohl(hdr->reloc_start) + indx_len);
 504
 505 #ifdef CONFIG_BINFMT_ZFLAT
 506 #error code needs checking
 507         /*
 508          * load it all in and treat it like a RAM load from now on
 509          */
 510         if (flags & FLAT_FLAG_GZIP) {
 511                 result = decompress_exec(bprm, sizeof (struct flat_hdr),
 512                                  (((char *) textpos) + sizeof (struct flat_hdr)),
 513                                  (text_len + data_len + (relocs * sizeof(unsigned long))
 514                                           - sizeof (struct flat_hdr)),
 515                                  0);
 516                 memmove((void *) datapos, (void *) realdatastart,
 517                                 data_len + (relocs * sizeof(unsigned long)));
 518         } else if (flags & FLAT_FLAG_GZDATA) {
 519                 fpos = 0;
 520                 result = bprm->file->f_op->read(bprm->file,
 521                                 (char *) textpos, text_len, &fpos);
 522                 if (result < (unsigned long) -4096)
 523                         result = decompress_exec(bprm, text_len, (char *) datapos,
 524                                          data_len + (relocs * sizeof(unsigned long)), 0);
 525         }
 526         else
 527 #endif
 528         {
 529             result = target_pread(bprm->fd, textpos,
 530                                   text_len, 0);
 531             if (result >= 0) {
 532                 result = target_pread(bprm->fd, datapos,
 533                     data_len + (relocs * sizeof(abi_ulong)),
 534                     ntohl(hdr->data_start));
 535             }
 536         }
 537         if (result < 0) {
 538             fprintf(stderr, "Unable to read code+data+bss\n");
 539             return result;
 540         }
 541     }
 542
 543     DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n",
 544             (int)textpos, 0x00ffffff&ntohl(hdr->entry),
 545             ntohl(hdr->data_start));
 546
 547     /* The main program needs a little extra setup in the task structure */
 548     start_code = textpos + sizeof (struct flat_hdr);
 549
 550     DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 551             id ? "Lib" : "Load", bprm->filename,
 552             (int) start_code, (int) (textpos + text_len),
 553             (int) datapos,
 554             (int) (datapos + data_len),
 555             (int) (datapos + data_len),
 556             (int) (((datapos + data_len + bss_len) + 3) & ~3));
 557
 558     text_len -= sizeof(struct flat_hdr); /* the real code len */
 559
 560     /* Store the current module values into the global library structure */
 561     libinfo[id].start_code = start_code;
 562     libinfo[id].start_data = datapos;
 563     libinfo[id].end_data = datapos + data_len;
 564     libinfo[id].start_brk = datapos + data_len + bss_len;
 565     libinfo[id].text_len = text_len;
 566     libinfo[id].loaded = 1;
 567     libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 568     libinfo[id].build_date = ntohl(hdr->build_date);
 569
 570     /*
 571      * We just load the allocations into some temporary memory to
 572      * help simplify all this mumbo jumbo
 573      *
 574      * We've got two different sections of relocation entries.
 575      * The first is the GOT which resides at the beginning of the data segment
 576      * and is terminated with a -1.  This one can be relocated in place.
 577      * The second is the extra relocation entries tacked after the image's
 578      * data segment. These require a little more processing as the entry is
 579      * really an offset into the image which contains an offset into the
 580      * image.
 581      */
 582     if (flags & FLAT_FLAG_GOTPIC) {
 583         rp = datapos;
 584         while (1) {
 585             abi_ulong addr;
 586             if (get_user_ual(addr, rp))
 587                 return -EFAULT;
 588             if (addr == -1)
 589                 break;
 590             if (addr) {
 591                 addr = calc_reloc(addr, libinfo, id, 0);
 592                 if (addr == RELOC_FAILED)
 593                     return -ENOEXEC;
 594                 if (put_user_ual(addr, rp))
 595                     return -EFAULT;
 596             }
 597             rp += sizeof(abi_ulong);
 598         }
 599     }
 600
 601     /*
 602      * Now run through the relocation entries.
 603      * We've got to be careful here as C++ produces relocatable zero
 604      * entries in the constructor and destructor tables which are then
 605      * tested for being not zero (which will always occur unless we're
 606      * based from address zero).  This causes an endless loop as __start
 607      * is at zero.  The solution used is to not relocate zero addresses.
 608      * This has the negative side effect of not allowing a global data
 609      * reference to be statically initialised to _stext (I've moved
 610      * __start to address 4 so that is okay).
 611      */
 612     if (rev > OLD_FLAT_VERSION) {
 613         abi_ulong persistent = 0;
 614         for (i = 0; i < relocs; i++) {
 615             abi_ulong addr, relval;
 616
 617             /* Get the address of the pointer to be
 618                relocated (of course, the address has to be
 619                relocated first).  */
 620             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
 621                 return -EFAULT;
 622             relval = ntohl(relval);
 623             if (flat_set_persistent(relval, &persistent))
 624                 continue;
 625             addr = flat_get_relocate_addr(relval);
 626             rp = calc_reloc(addr, libinfo, id, 1);
 627             if (rp == RELOC_FAILED)
 628                 return -ENOEXEC;
 629
 630             /* Get the pointer's value.  */
 631             if (get_user_ual(addr, rp))
 632                 return -EFAULT;
 633             addr = flat_get_addr_from_rp(addr, relval, flags, &persistent);
 634             if (addr != 0) {
 635                 /*
 636                  * Do the relocation.  PIC relocs in the data section are
 637                  * already in target order
 638                  */
 639                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 640                     addr = ntohl(addr);
 641                 addr = calc_reloc(addr, libinfo, id, 0);
 642                 if (addr == RELOC_FAILED)
 643                     return -ENOEXEC;
 644
 645                 /* Write back the relocated pointer.  */
 646                 if (flat_put_addr_at_rp(rp, addr, relval))
 647                     return -EFAULT;
 648             }
 649         }
 650     } else {
 651         for (i = 0; i < relocs; i++) {
 652             abi_ulong relval;
 653             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
 654                 return -EFAULT;
 655             old_reloc(&libinfo[0], relval);
 656         }
 657     }
 658
 659     /* zero the BSS.  */
 660     memset(g2h(datapos + data_len), 0, bss_len);
 661
 662     return 0;
 663 }
 664
 665
 666 /****************************************************************************/
 667 #ifdef CONFIG_BINFMT_SHARED_FLAT
 668
 669 /*
 670  * Load a shared library into memory.  The library gets its own data
 671  * segment (including bss) but not argv/argc/environ.
 672  */
 673
 674 static int load_flat_shared_library(int id, struct lib_info *libs)
 675 {
 676         struct linux_binprm bprm;
 677         int res;
 678         char buf[16];
 679
 680         /* Create the file name */
 681         sprintf(buf, "/lib/lib%d.so", id);
 682
 683         /* Open the file up */
 684         bprm.filename = buf;
 685         bprm.file = open_exec(bprm.filename);
 686         res = PTR_ERR(bprm.file);
 687         if (IS_ERR(bprm.file))
 688                 return res;
 689
 690         res = prepare_binprm(&bprm);
 691
 692         if (res <= (unsigned long)-4096)
 693                 res = load_flat_file(&bprm, libs, id, NULL);
 694         if (bprm.file) {
 695                 allow_write_access(bprm.file);
 696                 fput(bprm.file);
 697                 bprm.file = NULL;
 698         }
 699         return(res);
 700 }
 701
 702 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 703
 704 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info)
 705 {
 706     struct lib_info libinfo[MAX_SHARED_LIBS];
 707     abi_ulong p;
 708     abi_ulong stack_len;
 709     abi_ulong start_addr;
 710     abi_ulong sp;
 711     int res;
 712     int i, j;
 713
 714     memset(libinfo, 0, sizeof(libinfo));
 715     /*
 716      * We have to add the size of our arguments to our stack size
 717      * otherwise it's too easy for users to create stack overflows
 718      * by passing in a huge argument list.  And yes,  we have to be
 719      * pedantic and include space for the argv/envp array as it may have
 720      * a lot of entries.
 721      */
 722     stack_len = 0;
 723     for (i = 0; i < bprm->argc; ++i) {
 724         /* the argv strings */
 725         stack_len += strlen(bprm->argv[i]);
 726     }
 727     for (i = 0; i < bprm->envc; ++i) {
 728         /* the envp strings */
 729         stack_len += strlen(bprm->envp[i]);
 730     }
 731     stack_len += (bprm->argc + 1) * 4; /* the argv array */
 732     stack_len += (bprm->envc + 1) * 4; /* the envp array */
 733
 734
 735     res = load_flat_file(bprm, libinfo, 0, &stack_len);
 736     if (res > (unsigned long)-4096)
 737             return res;
 738
 739     /* Update data segment pointers for all libraries */
 740     for (i=0; i<MAX_SHARED_LIBS; i++) {
 741         if (libinfo[i].loaded) {
 742             abi_ulong p;
 743             p = libinfo[i].start_data;
 744             for (j=0; j<MAX_SHARED_LIBS; j++) {
 745                 p -= 4;
 746                 /* FIXME - handle put_user() failures */
 747                 if (put_user_ual(libinfo[j].loaded
 748                                  ? libinfo[j].start_data
 749                                  : UNLOADED_LIB,
 750                                  p))
 751                     return -EFAULT;
 752             }
 753         }
 754     }
 755
 756     p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4;
 757     DBG_FLT("p=%x\n", (int)p);
 758
 759     /* Copy argv/envp.  */
 760     p = copy_strings(p, bprm->envc, bprm->envp);
 761     p = copy_strings(p, bprm->argc, bprm->argv);
 762     /* Align stack.  */
 763     sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1);
 764     /* Enforce final stack alignment of 16 bytes.  This is sufficient
 765        for all current targets, and excess alignment is harmless.  */
 766     stack_len = bprm->envc + bprm->argc + 2;
 767     stack_len += 3;     /* argc, arvg, argp */
 768     stack_len *= sizeof(abi_ulong);
 769     if ((sp + stack_len) & 15)
 770         sp -= 16 - ((sp + stack_len) & 15);
 771     sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p,
 772                              flat_argvp_envp_on_stack());
 773
 774     /* Fake some return addresses to ensure the call chain will
 775      * initialise library in order for us.  We are required to call
 776      * lib 1 first, then 2, ... and finally the main program (id 0).
 777      */
 778     start_addr = libinfo[0].entry;
 779
 780 #ifdef CONFIG_BINFMT_SHARED_FLAT
 781 #error here
 782     for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 783             if (libinfo[i].loaded) {
 784                     /* Push previos first to call address */
 785                     --sp;
 786                     if (put_user_ual(start_addr, sp))
 787                         return -EFAULT;
 788                     start_addr = libinfo[i].entry;
 789             }
 790     }
 791 #endif
 792
 793     /* Stash our initial stack pointer into the mm structure */
 794     info->start_code = libinfo[0].start_code;
 795     info->end_code = libinfo[0].start_code = libinfo[0].text_len;
 796     info->start_data = libinfo[0].start_data;
 797     info->end_data = libinfo[0].end_data;
 798     info->start_brk = libinfo[0].start_brk;
 799     info->start_stack = sp;
 800     info->stack_limit = libinfo[0].start_brk;
 801     info->entry = start_addr;
 802     info->code_offset = info->start_code;
 803     info->data_offset = info->start_data - libinfo[0].text_len;
 804
 805     DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n",
 806             (int)info->entry, (int)info->start_stack);
 807
 808     return 0;
 809 }