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
  38 #include "qemu.h"
  39 #include "flat.h"
  40 #include "target_flat.h"
  41
  42 //#define DEBUG
  43
  44 #ifdef DEBUG
  45 #define DBG_FLT(...)    printf(__VA_ARGS__)
  46 #else
  47 #define DBG_FLT(...)
  48 #endif
  49
  50 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  51 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  52
  53 struct lib_info {
  54     abi_ulong start_code;       /* Start of text segment */
  55     abi_ulong start_data;       /* Start of data segment */
  56     abi_ulong end_data;         /* Start of bss section */
  57     abi_ulong start_brk;        /* End of data segment */
  58     abi_ulong text_len;         /* Length of text segment */
  59     abi_ulong entry;            /* Start address for this module */
  60     abi_ulong build_date;       /* When this one was compiled */
  61     short loaded;               /* Has this library been loaded? */
  62 };
  63
  64 #ifdef CONFIG_BINFMT_SHARED_FLAT
  65 static int load_flat_shared_library(int id, struct lib_info *p);
  66 #endif
  67
  68 struct linux_binprm;
  69
  70 /****************************************************************************/
  71 /*
  72  * create_flat_tables() parses the env- and arg-strings in new user
  73  * memory and creates the pointer tables from them, and puts their
  74  * addresses on the "stack", returning the new stack pointer value.
  75  */
  76
  77 /* Push a block of strings onto the guest stack.  */
  78 static abi_ulong copy_strings(abi_ulong p, int n, char **s)
  79 {
  80     int len;
  81
  82     while (n-- > 0) {
  83         len = strlen(s[n]) + 1;
  84         p -= len;
  85         memcpy_to_target(p, s[n], len);
  86     }
  87
  88     return p;
  89 }
  90
  91 static int target_pread(int fd, abi_ulong ptr, abi_ulong len,
  92                         abi_ulong offset)
  93 {
  94     void *buf;
  95     int ret;
  96
  97     buf = lock_user(VERIFY_WRITE, ptr, len, 0);
  98     if (!buf) {
  99         return -EFAULT;
 100     }
 101     ret = pread(fd, buf, len, offset);
 102     if (ret < 0) {
 103         ret = -errno;
 104     }
 105     unlock_user(buf, ptr, len);
 106     return ret;
 107 }
 108 /****************************************************************************/
 109
 110 #ifdef CONFIG_BINFMT_ZFLAT
 111
 112 #include <linux/zlib.h>
 113
 114 #define LBUFSIZE        4000
 115
 116 /* gzip flag byte */
 117 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 118 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 119 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 120 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 121 #define COMMENT      0x10 /* bit 4 set: file comment present */
 122 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 123 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 124
 125 static int decompress_exec(
 126         struct linux_binprm *bprm,
 127         unsigned long offset,
 128         char *dst,
 129         long len,
 130         int fd)
 131 {
 132         unsigned char *buf;
 133         z_stream strm;
 134         loff_t fpos;
 135         int ret, retval;
 136
 137         DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 138
 139         memset(&strm, 0, sizeof(strm));
 140         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 141         if (strm.workspace == NULL) {
 142                 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 143                 return -ENOMEM;
 144         }
 145         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 146         if (buf == NULL) {
 147                 DBG_FLT("binfmt_flat: no memory for read buffer\n");
 148                 retval = -ENOMEM;
 149                 goto out_free;
 150         }
 151
 152         /* Read in first chunk of data and parse gzip header. */
 153         fpos = offset;
 154         ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 155
 156         strm.next_in = buf;
 157         strm.avail_in = ret;
 158         strm.total_in = 0;
 159
 160         retval = -ENOEXEC;
 161
 162         /* Check minimum size -- gzip header */
 163         if (ret < 10) {
 164                 DBG_FLT("binfmt_flat: file too small?\n");
 165                 goto out_free_buf;
 166         }
 167
 168         /* Check gzip magic number */
 169         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 170                 DBG_FLT("binfmt_flat: unknown compression magic?\n");
 171                 goto out_free_buf;
 172         }
 173
 174         /* Check gzip method */
 175         if (buf[2] != 8) {
 176                 DBG_FLT("binfmt_flat: unknown compression method?\n");
 177                 goto out_free_buf;
 178         }
 179         /* Check gzip flags */
 180         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 181             (buf[3] & RESERVED)) {
 182                 DBG_FLT("binfmt_flat: unknown flags?\n");
 183                 goto out_free_buf;
 184         }
 185
 186         ret = 10;
 187         if (buf[3] & EXTRA_FIELD) {
 188                 ret += 2 + buf[10] + (buf[11] << 8);
 189                 if (unlikely(LBUFSIZE == ret)) {
 190                         DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
 191                         goto out_free_buf;
 192                 }
 193         }
 194         if (buf[3] & ORIG_NAME) {
 195                 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
 196                         ;
 197                 if (unlikely(LBUFSIZE == ret)) {
 198                         DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
 199                         goto out_free_buf;
 200                 }
 201         }
 202         if (buf[3] & COMMENT) {
 203                 for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
 204                         ;
 205                 if (unlikely(LBUFSIZE == ret)) {
 206                         DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
 207                         goto out_free_buf;
 208                 }
 209         }
 210
 211         strm.next_in += ret;
 212         strm.avail_in -= ret;
 213
 214         strm.next_out = dst;
 215         strm.avail_out = len;
 216         strm.total_out = 0;
 217
 218         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 219                 DBG_FLT("binfmt_flat: zlib init failed?\n");
 220                 goto out_free_buf;
 221         }
 222
 223         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 224                 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 225                 if (ret <= 0)
 226                         break;
 227                 if (is_error(ret)) {
 228                         break;
 229                 }
 230                 len -= ret;
 231
 232                 strm.next_in = buf;
 233                 strm.avail_in = ret;
 234                 strm.total_in = 0;
 235         }
 236
 237         if (ret < 0) {
 238                 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
 239                         ret, strm.msg);
 240                 goto out_zlib;
 241         }
 242
 243         retval = 0;
 244 out_zlib:
 245         zlib_inflateEnd(&strm);
 246 out_free_buf:
 247         kfree(buf);
 248 out_free:
 249         kfree(strm.workspace);
 250 out:
 251         return retval;
 252 }
 253
 254 #endif /* CONFIG_BINFMT_ZFLAT */
 255
 256 /****************************************************************************/
 257
 258 static abi_ulong
 259 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp)
 260 {
 261     abi_ulong addr;
 262     int id;
 263     abi_ulong start_brk;
 264     abi_ulong start_data;
 265     abi_ulong text_len;
 266     abi_ulong start_code;
 267
 268 #ifdef CONFIG_BINFMT_SHARED_FLAT
 269 #error needs checking
 270     if (r == 0)
 271         id = curid;     /* Relocs of 0 are always self referring */
 272     else {
 273         id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 274         r &= 0x00ffffff;        /* Trim ID off here */
 275     }
 276     if (id >= MAX_SHARED_LIBS) {
 277         fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n",
 278                 (unsigned) r, id);
 279         goto failed;
 280     }
 281     if (curid != id) {
 282         if (internalp) {
 283             fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not "
 284                     "in same module (%d != %d)\n",
 285                     (unsigned) r, curid, id);
 286             goto failed;
 287         } else if (!p[id].loaded && is_error(load_flat_shared_library(id, p))) {
 288             fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id);
 289             goto failed;
 290         }
 291         /* Check versioning information (i.e. time stamps) */
 292         if (p[id].build_date && p[curid].build_date
 293             && p[curid].build_date < p[id].build_date) {
 294             fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n",
 295                     id, curid);
 296             goto failed;
 297         }
 298     }
 299 #else
 300     id = 0;
 301 #endif
 302
 303     start_brk = p[id].start_brk;
 304     start_data = p[id].start_data;
 305     start_code = p[id].start_code;
 306     text_len = p[id].text_len;
 307
 308     if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 309         fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x "
 310                 "(0 - 0x%x/0x%x)\n",
 311                (int) r,(int)(start_brk-start_code),(int)text_len);
 312         goto failed;
 313     }
 314
 315     if (r < text_len)                   /* In text segment */
 316         addr = r + start_code;
 317     else                                        /* In data segment */
 318         addr = r - text_len + start_data;
 319
 320     /* Range checked already above so doing the range tests is redundant...*/
 321     return(addr);
 322
 323 failed:
 324     abort();
 325     return RELOC_FAILED;
 326 }
 327
 328 /****************************************************************************/
 329
 330 /* ??? This does not handle endianness correctly.  */
 331 static void old_reloc(struct lib_info *libinfo, uint32_t rl)
 332 {
 333 #ifdef DEBUG
 334         const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 335 #endif
 336         uint32_t *ptr;
 337         uint32_t offset;
 338         int reloc_type;
 339
 340         offset = rl & 0x3fffffff;
 341         reloc_type = rl >> 30;
 342         /* ??? How to handle this?  */
 343 #if defined(CONFIG_COLDFIRE)
 344         ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset);
 345 #else
 346         ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset);
 347 #endif
 348
 349 #ifdef DEBUG
 350         fprintf(stderr, "Relocation of variable at DATASEG+%x "
 351                 "(address %p, currently %x) into segment %s\n",
 352                 offset, ptr, (int)*ptr, segment[reloc_type]);
 353 #endif
 354
 355         switch (reloc_type) {
 356         case OLD_FLAT_RELOC_TYPE_TEXT:
 357                 *ptr += libinfo->start_code;
 358                 break;
 359         case OLD_FLAT_RELOC_TYPE_DATA:
 360                 *ptr += libinfo->start_data;
 361                 break;
 362         case OLD_FLAT_RELOC_TYPE_BSS:
 363                 *ptr += libinfo->end_data;
 364                 break;
 365         default:
 366                 fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n",
 367                         reloc_type);
 368                 break;
 369         }
 370         DBG_FLT("Relocation became %x\n", (int)*ptr);
 371 }
 372
 373 /****************************************************************************/
 374
 375 static int load_flat_file(struct linux_binprm * bprm,
 376                 struct lib_info *libinfo, int id, abi_ulong *extra_stack)
 377 {
 378     struct flat_hdr * hdr;
 379     abi_ulong textpos = 0, datapos = 0;
 380     abi_long result;
 381     abi_ulong realdatastart = 0;
 382     abi_ulong text_len, data_len, bss_len, stack_len, flags;
 383     abi_ulong extra;
 384     abi_ulong reloc = 0, rp;
 385     int i, rev, relocs = 0;
 386     abi_ulong fpos;
 387     abi_ulong start_code;
 388     abi_ulong indx_len;
 389
 390     hdr = ((struct flat_hdr *) bprm->buf);              /* exec-header */
 391
 392     text_len  = ntohl(hdr->data_start);
 393     data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 394     bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 395     stack_len = ntohl(hdr->stack_size);
 396     if (extra_stack) {
 397         stack_len += *extra_stack;
 398         *extra_stack = stack_len;
 399     }
 400     relocs    = ntohl(hdr->reloc_count);
 401     flags     = ntohl(hdr->flags);
 402     rev       = ntohl(hdr->rev);
 403
 404     DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 405
 406     if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 407         fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",
 408                 rev, (int) FLAT_VERSION);
 409         return -ENOEXEC;
 410     }
 411
 412     /* Don't allow old format executables to use shared libraries */
 413     if (rev == OLD_FLAT_VERSION && id != 0) {
 414         fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n");
 415         return -ENOEXEC;
 416     }
 417
 418     /*
 419      * fix up the flags for the older format,  there were all kinds
 420      * of endian hacks,  this only works for the simple cases
 421      */
 422     if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 423         flags = FLAT_FLAG_RAM;
 424
 425 #ifndef CONFIG_BINFMT_ZFLAT
 426     if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 427         fprintf(stderr, "Support for ZFLAT executables is not enabled\n");
 428         return -ENOEXEC;
 429     }
 430 #endif
 431
 432     /*
 433      * calculate the extra space we need to map in
 434      */
 435     extra = relocs * sizeof(abi_ulong);
 436     if (extra < bss_len + stack_len)
 437         extra = bss_len + stack_len;
 438
 439     /* Add space for library base pointers.  Make sure this does not
 440        misalign the  doesn't misalign the data segment.  */
 441     indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong);
 442     indx_len = (indx_len + 15) & ~(abi_ulong)15;
 443
 444     /*
 445      * Allocate the address space.
 446      */
 447     probe_guest_base(bprm->filename, 0,
 448                      text_len + data_len + extra + indx_len);
 449
 450     /*
 451      * there are a couple of cases here,  the separate code/data
 452      * case,  and then the fully copied to RAM case which lumps
 453      * it all together.
 454      */
 455     if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 456         /*
 457          * this should give us a ROM ptr,  but if it doesn't we don't
 458          * really care
 459          */
 460         DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 461
 462         textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC,
 463                               MAP_PRIVATE, bprm->fd, 0);
 464         if (textpos == -1) {
 465             fprintf(stderr, "Unable to mmap process text\n");
 466             return -1;
 467         }
 468
 469         realdatastart = target_mmap(0, data_len + extra + indx_len,
 470                                     PROT_READ|PROT_WRITE|PROT_EXEC,
 471                                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 472
 473         if (realdatastart == -1) {
 474             fprintf(stderr, "Unable to allocate RAM for process data\n");
 475             return realdatastart;
 476         }
 477         datapos = realdatastart + indx_len;
 478
 479         DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 480                         (int)(data_len + bss_len + stack_len), (int)datapos);
 481
 482         fpos = ntohl(hdr->data_start);
 483 #ifdef CONFIG_BINFMT_ZFLAT
 484         if (flags & FLAT_FLAG_GZDATA) {
 485             result = decompress_exec(bprm, fpos, (char *) datapos,
 486                                      data_len + (relocs * sizeof(abi_ulong)))
 487         } else
 488 #endif
 489         {
 490             result = target_pread(bprm->fd, datapos,
 491                                   data_len + (relocs * sizeof(abi_ulong)),
 492                                   fpos);
 493         }
 494         if (result < 0) {
 495             fprintf(stderr, "Unable to read data+bss\n");
 496             return result;
 497         }
 498
 499         reloc = datapos + (ntohl(hdr->reloc_start) - text_len);
 500
 501     } else {
 502
 503         textpos = target_mmap(0, text_len + data_len + extra + indx_len,
 504                               PROT_READ | PROT_EXEC | PROT_WRITE,
 505                               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 506         if (textpos == -1 ) {
 507             fprintf(stderr, "Unable to allocate RAM for process text/data\n");
 508             return -1;
 509         }
 510
 511         realdatastart = textpos + ntohl(hdr->data_start);
 512         datapos = realdatastart + indx_len;
 513         reloc = (textpos + ntohl(hdr->reloc_start) + indx_len);
 514
 515 #ifdef CONFIG_BINFMT_ZFLAT
 516 #error code needs checking
 517         /*
 518          * load it all in and treat it like a RAM load from now on
 519          */
 520         if (flags & FLAT_FLAG_GZIP) {
 521                 result = decompress_exec(bprm, sizeof (struct flat_hdr),
 522                                  (((char *) textpos) + sizeof (struct flat_hdr)),
 523                                  (text_len + data_len + (relocs * sizeof(unsigned long))
 524                                           - sizeof (struct flat_hdr)),
 525                                  0);
 526                 memmove((void *) datapos, (void *) realdatastart,
 527                                 data_len + (relocs * sizeof(unsigned long)));
 528         } else if (flags & FLAT_FLAG_GZDATA) {
 529                 fpos = 0;
 530                 result = bprm->file->f_op->read(bprm->file,
 531                                 (char *) textpos, text_len, &fpos);
 532                 if (!is_error(result)) {
 533                         result = decompress_exec(bprm, text_len, (char *) datapos,
 534                                          data_len + (relocs * sizeof(unsigned long)), 0);
 535                 }
 536         }
 537         else
 538 #endif
 539         {
 540             result = target_pread(bprm->fd, textpos,
 541                                   text_len, 0);
 542             if (result >= 0) {
 543                 result = target_pread(bprm->fd, datapos,
 544                     data_len + (relocs * sizeof(abi_ulong)),
 545                     ntohl(hdr->data_start));
 546             }
 547         }
 548         if (result < 0) {
 549             fprintf(stderr, "Unable to read code+data+bss\n");
 550             return result;
 551         }
 552     }
 553
 554     DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n",
 555             (int)textpos, 0x00ffffff&ntohl(hdr->entry),
 556             ntohl(hdr->data_start));
 557
 558     /* The main program needs a little extra setup in the task structure */
 559     start_code = textpos + sizeof (struct flat_hdr);
 560
 561     DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 562             id ? "Lib" : "Load", bprm->filename,
 563             (int) start_code, (int) (textpos + text_len),
 564             (int) datapos,
 565             (int) (datapos + data_len),
 566             (int) (datapos + data_len),
 567             (int) (((datapos + data_len + bss_len) + 3) & ~3));
 568
 569     text_len -= sizeof(struct flat_hdr); /* the real code len */
 570
 571     /* Store the current module values into the global library structure */
 572     libinfo[id].start_code = start_code;
 573     libinfo[id].start_data = datapos;
 574     libinfo[id].end_data = datapos + data_len;
 575     libinfo[id].start_brk = datapos + data_len + bss_len;
 576     libinfo[id].text_len = text_len;
 577     libinfo[id].loaded = 1;
 578     libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 579     libinfo[id].build_date = ntohl(hdr->build_date);
 580
 581     /*
 582      * We just load the allocations into some temporary memory to
 583      * help simplify all this mumbo jumbo
 584      *
 585      * We've got two different sections of relocation entries.
 586      * The first is the GOT which resides at the beginning of the data segment
 587      * and is terminated with a -1.  This one can be relocated in place.
 588      * The second is the extra relocation entries tacked after the image's
 589      * data segment. These require a little more processing as the entry is
 590      * really an offset into the image which contains an offset into the
 591      * image.
 592      */
 593     if (flags & FLAT_FLAG_GOTPIC) {
 594         rp = datapos;
 595         while (1) {
 596             abi_ulong addr;
 597             if (get_user_ual(addr, rp))
 598                 return -EFAULT;
 599             if (addr == -1)
 600                 break;
 601             if (addr) {
 602                 addr = calc_reloc(addr, libinfo, id, 0);
 603                 if (addr == RELOC_FAILED)
 604                     return -ENOEXEC;
 605                 if (put_user_ual(addr, rp))
 606                     return -EFAULT;
 607             }
 608             rp += sizeof(abi_ulong);
 609         }
 610     }
 611
 612     /*
 613      * Now run through the relocation entries.
 614      * We've got to be careful here as C++ produces relocatable zero
 615      * entries in the constructor and destructor tables which are then
 616      * tested for being not zero (which will always occur unless we're
 617      * based from address zero).  This causes an endless loop as __start
 618      * is at zero.  The solution used is to not relocate zero addresses.
 619      * This has the negative side effect of not allowing a global data
 620      * reference to be statically initialised to _stext (I've moved
 621      * __start to address 4 so that is okay).
 622      */
 623     if (rev > OLD_FLAT_VERSION) {
 624         abi_ulong persistent = 0;
 625         for (i = 0; i < relocs; i++) {
 626             abi_ulong addr, relval;
 627
 628             /* Get the address of the pointer to be
 629                relocated (of course, the address has to be
 630                relocated first).  */
 631             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
 632                 return -EFAULT;
 633             relval = ntohl(relval);
 634             if (flat_set_persistent(relval, &persistent))
 635                 continue;
 636             addr = flat_get_relocate_addr(relval);
 637             rp = calc_reloc(addr, libinfo, id, 1);
 638             if (rp == RELOC_FAILED)
 639                 return -ENOEXEC;
 640
 641             /* Get the pointer's value.  */
 642             if (get_user_ual(addr, rp))
 643                 return -EFAULT;
 644             addr = flat_get_addr_from_rp(addr, relval, flags, &persistent);
 645             if (addr != 0) {
 646                 /*
 647                  * Do the relocation.  PIC relocs in the data section are
 648                  * already in target order
 649                  */
 650                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 651                     addr = ntohl(addr);
 652                 addr = calc_reloc(addr, libinfo, id, 0);
 653                 if (addr == RELOC_FAILED)
 654                     return -ENOEXEC;
 655
 656                 /* Write back the relocated pointer.  */
 657                 if (flat_put_addr_at_rp(rp, addr, relval))
 658                     return -EFAULT;
 659             }
 660         }
 661     } else {
 662         for (i = 0; i < relocs; i++) {
 663             abi_ulong relval;
 664             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
 665                 return -EFAULT;
 666             old_reloc(&libinfo[0], relval);
 667         }
 668     }
 669
 670     /* zero the BSS.  */
 671     memset(g2h_untagged(datapos + data_len), 0, bss_len);
 672
 673     return 0;
 674 }
 675
 676
 677 /****************************************************************************/
 678 #ifdef CONFIG_BINFMT_SHARED_FLAT
 679
 680 /*
 681  * Load a shared library into memory.  The library gets its own data
 682  * segment (including bss) but not argv/argc/environ.
 683  */
 684
 685 static int load_flat_shared_library(int id, struct lib_info *libs)
 686 {
 687         struct linux_binprm bprm;
 688         int res;
 689         char buf[16];
 690
 691         /* Create the file name */
 692         sprintf(buf, "/lib/lib%d.so", id);
 693
 694         /* Open the file up */
 695         bprm.filename = buf;
 696         bprm.file = open_exec(bprm.filename);
 697         res = PTR_ERR(bprm.file);
 698         if (IS_ERR(bprm.file))
 699                 return res;
 700
 701         res = prepare_binprm(&bprm);
 702
 703         if (!is_error(res)) {
 704                 res = load_flat_file(&bprm, libs, id, NULL);
 705         }
 706         if (bprm.file) {
 707                 allow_write_access(bprm.file);
 708                 fput(bprm.file);
 709                 bprm.file = NULL;
 710         }
 711         return(res);
 712 }
 713
 714 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 715
 716 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info)
 717 {
 718     struct lib_info libinfo[MAX_SHARED_LIBS];
 719     abi_ulong p;
 720     abi_ulong stack_len;
 721     abi_ulong start_addr;
 722     abi_ulong sp;
 723     int res;
 724     int i, j;
 725
 726     memset(libinfo, 0, sizeof(libinfo));
 727     /*
 728      * We have to add the size of our arguments to our stack size
 729      * otherwise it's too easy for users to create stack overflows
 730      * by passing in a huge argument list.  And yes,  we have to be
 731      * pedantic and include space for the argv/envp array as it may have
 732      * a lot of entries.
 733      */
 734     stack_len = 0;
 735     for (i = 0; i < bprm->argc; ++i) {
 736         /* the argv strings */
 737         stack_len += strlen(bprm->argv[i]);
 738     }
 739     for (i = 0; i < bprm->envc; ++i) {
 740         /* the envp strings */
 741         stack_len += strlen(bprm->envp[i]);
 742     }
 743     stack_len += (bprm->argc + 1) * 4; /* the argv array */
 744     stack_len += (bprm->envc + 1) * 4; /* the envp array */
 745
 746
 747     res = load_flat_file(bprm, libinfo, 0, &stack_len);
 748     if (is_error(res)) {
 749             return res;
 750     }
 751
 752     /* Update data segment pointers for all libraries */
 753     for (i=0; i<MAX_SHARED_LIBS; i++) {
 754         if (libinfo[i].loaded) {
 755             abi_ulong p;
 756             p = libinfo[i].start_data;
 757             for (j=0; j<MAX_SHARED_LIBS; j++) {
 758                 p -= 4;
 759                 /* FIXME - handle put_user() failures */
 760                 if (put_user_ual(libinfo[j].loaded
 761                                  ? libinfo[j].start_data
 762                                  : UNLOADED_LIB,
 763                                  p))
 764                     return -EFAULT;
 765             }
 766         }
 767     }
 768
 769     p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4;
 770     DBG_FLT("p=%x\n", (int)p);
 771
 772     /* Copy argv/envp.  */
 773     p = copy_strings(p, bprm->envc, bprm->envp);
 774     p = copy_strings(p, bprm->argc, bprm->argv);
 775     /* Align stack.  */
 776     sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1);
 777     /* Enforce final stack alignment of 16 bytes.  This is sufficient
 778        for all current targets, and excess alignment is harmless.  */
 779     stack_len = bprm->envc + bprm->argc + 2;
 780     stack_len += flat_argvp_envp_on_stack() ? 2 : 0; /* arvg, argp */
 781     stack_len += 1; /* argc */
 782     stack_len *= sizeof(abi_ulong);
 783     sp -= (sp - stack_len) & 15;
 784     sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p,
 785                              flat_argvp_envp_on_stack());
 786
 787     /* Fake some return addresses to ensure the call chain will
 788      * initialise library in order for us.  We are required to call
 789      * lib 1 first, then 2, ... and finally the main program (id 0).
 790      */
 791     start_addr = libinfo[0].entry;
 792
 793 #ifdef CONFIG_BINFMT_SHARED_FLAT
 794 #error here
 795     for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 796             if (libinfo[i].loaded) {
 797                     /* Push previous first to call address */
 798                     --sp;
 799                     if (put_user_ual(start_addr, sp))
 800                         return -EFAULT;
 801                     start_addr = libinfo[i].entry;
 802             }
 803     }
 804 #endif
 805
 806     /* Stash our initial stack pointer into the mm structure */
 807     info->start_code = libinfo[0].start_code;
 808     info->end_code = libinfo[0].start_code = libinfo[0].text_len;
 809     info->start_data = libinfo[0].start_data;
 810     info->end_data = libinfo[0].end_data;
 811     info->start_brk = libinfo[0].start_brk;
 812     info->start_stack = sp;
 813     info->stack_limit = libinfo[0].start_brk;
 814     info->entry = start_addr;
 815     info->code_offset = info->start_code;
 816     info->data_offset = info->start_data - libinfo[0].text_len;
 817
 818     DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n",
 819             (int)info->entry, (int)info->start_stack);
 820
 821     return 0;
 822 }