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 <stdio.h>
  37 #include <stdlib.h>
  38 #include <errno.h>
  39 #include <sys/mman.h>
  40 #include <unistd.h>
  41
  42 #include "qemu.h"
  43 #include "flat.h"
  44
  45 //#define DEBUG
  46
  47 #ifdef DEBUG
  48 #define DBG_FLT(...)    printf(__VA_ARGS__)
  49 #else
  50 #define DBG_FLT(...)
  51 #endif
  52
  53 #define flat_reloc_valid(reloc, size)             ((reloc) <= (size))
  54 #define flat_old_ram_flag(flag)                   (flag)
  55 #ifdef TARGET_WORDS_BIGENDIAN
  56 #define flat_get_relocate_addr(relval)            (relval)
  57 #else
  58 #define flat_get_relocate_addr(relval)            bswap32(relval)
  59 #endif
  60
  61 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  62 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  63
  64 struct lib_info {
  65     abi_ulong start_code;       /* Start of text segment */
  66     abi_ulong start_data;       /* Start of data segment */
  67     abi_ulong end_data;         /* Start of bss section */
  68     abi_ulong start_brk;        /* End of data segment */
  69     abi_ulong text_len;         /* Length of text segment */
  70     abi_ulong entry;            /* Start address for this module */
  71     abi_ulong build_date;       /* When this one was compiled */
  72     short loaded;               /* Has this library been loaded? */
  73 };
  74
  75 #ifdef CONFIG_BINFMT_SHARED_FLAT
  76 static int load_flat_shared_library(int id, struct lib_info *p);
  77 #endif
  78
  79 struct linux_binprm;
  80
  81 #define ntohl(x) be32_to_cpu(x)
  82
  83 /****************************************************************************/
  84 /*
  85  * create_flat_tables() parses the env- and arg-strings in new user
  86  * memory and creates the pointer tables from them, and puts their
  87  * addresses on the "stack", returning the new stack pointer value.
  88  */
  89
  90 /* Push a block of strings onto the guest stack.  */
  91 static abi_ulong copy_strings(abi_ulong p, int n, char **s)
  92 {
  93     int len;
  94
  95     while (n-- > 0) {
  96         len = strlen(s[n]) + 1;
  97         p -= len;
  98         memcpy_to_target(p, s[n], len);
  99     }
 100
 101     return p;
 102 }
 103
 104 static int target_pread(int fd, abi_ulong ptr, abi_ulong len,
 105                         abi_ulong offset)
 106 {
 107     void *buf;
 108     int ret;
 109
 110     buf = lock_user(VERIFY_WRITE, ptr, len, 0);
 111     ret = pread(fd, buf, len, offset);
 112     unlock_user(buf, ptr, len);
 113     return ret;
 114 }
 115 /****************************************************************************/
 116
 117 #ifdef CONFIG_BINFMT_ZFLAT
 118
 119 #include <linux/zlib.h>
 120
 121 #define LBUFSIZE        4000
 122
 123 /* gzip flag byte */
 124 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 125 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 126 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 127 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 128 #define COMMENT      0x10 /* bit 4 set: file comment present */
 129 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 130 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 131
 132 static int decompress_exec(
 133         struct linux_binprm *bprm,
 134         unsigned long offset,
 135         char *dst,
 136         long len,
 137         int fd)
 138 {
 139         unsigned char *buf;
 140         z_stream strm;
 141         loff_t fpos;
 142         int ret, retval;
 143
 144         DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 145
 146         memset(&strm, 0, sizeof(strm));
 147         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 148         if (strm.workspace == NULL) {
 149                 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 150                 return -ENOMEM;
 151         }
 152         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 153         if (buf == NULL) {
 154                 DBG_FLT("binfmt_flat: no memory for read buffer\n");
 155                 retval = -ENOMEM;
 156                 goto out_free;
 157         }
 158
 159         /* Read in first chunk of data and parse gzip header. */
 160         fpos = offset;
 161         ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 162
 163         strm.next_in = buf;
 164         strm.avail_in = ret;
 165         strm.total_in = 0;
 166
 167         retval = -ENOEXEC;
 168
 169         /* Check minimum size -- gzip header */
 170         if (ret < 10) {
 171                 DBG_FLT("binfmt_flat: file too small?\n");
 172                 goto out_free_buf;
 173         }
 174
 175         /* Check gzip magic number */
 176         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 177                 DBG_FLT("binfmt_flat: unknown compression magic?\n");
 178                 goto out_free_buf;
 179         }
 180
 181         /* Check gzip method */
 182         if (buf[2] != 8) {
 183                 DBG_FLT("binfmt_flat: unknown compression method?\n");
 184                 goto out_free_buf;
 185         }
 186         /* Check gzip flags */
 187         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 188             (buf[3] & RESERVED)) {
 189                 DBG_FLT("binfmt_flat: unknown flags?\n");
 190                 goto out_free_buf;
 191         }
 192
 193         ret = 10;
 194         if (buf[3] & EXTRA_FIELD) {
 195                 ret += 2 + buf[10] + (buf[11] << 8);
 196                 if (unlikely(LBUFSIZE == ret)) {
 197                         DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
 198                         goto out_free_buf;
 199                 }
 200         }
 201         if (buf[3] & ORIG_NAME) {
 202                 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
 203                         ;
 204                 if (unlikely(LBUFSIZE == ret)) {
 205                         DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
 206                         goto out_free_buf;
 207                 }
 208         }
 209         if (buf[3] & COMMENT) {
 210                 for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
 211                         ;
 212                 if (unlikely(LBUFSIZE == ret)) {
 213                         DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
 214                         goto out_free_buf;
 215                 }
 216         }
 217
 218         strm.next_in += ret;
 219         strm.avail_in -= ret;
 220
 221         strm.next_out = dst;
 222         strm.avail_out = len;
 223         strm.total_out = 0;
 224
 225         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 226                 DBG_FLT("binfmt_flat: zlib init failed?\n");
 227                 goto out_free_buf;
 228         }
 229
 230         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 231                 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 232                 if (ret <= 0)
 233                         break;
 234                 if (ret >= (unsigned long) -4096)
 235                         break;
 236                 len -= ret;
 237
 238                 strm.next_in = buf;
 239                 strm.avail_in = ret;
 240                 strm.total_in = 0;
 241         }
 242
 243         if (ret < 0) {
 244                 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
 245                         ret, strm.msg);
 246                 goto out_zlib;
 247         }
 248
 249         retval = 0;
 250 out_zlib:
 251         zlib_inflateEnd(&strm);
 252 out_free_buf:
 253         kfree(buf);
 254 out_free:
 255         kfree(strm.workspace);
 256 out:
 257         return retval;
 258 }
 259
 260 #endif /* CONFIG_BINFMT_ZFLAT */
 261
 262 /****************************************************************************/
 263
 264 static abi_ulong
 265 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp)
 266 {
 267     abi_ulong addr;
 268     int id;
 269     abi_ulong start_brk;
 270     abi_ulong start_data;
 271     abi_ulong text_len;
 272     abi_ulong start_code;
 273
 274 #ifdef CONFIG_BINFMT_SHARED_FLAT
 275 #error needs checking
 276     if (r == 0)
 277         id = curid;     /* Relocs of 0 are always self referring */
 278     else {
 279         id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 280         r &= 0x00ffffff;        /* Trim ID off here */
 281     }
 282     if (id >= MAX_SHARED_LIBS) {
 283         fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n",
 284                 (unsigned) r, id);
 285         goto failed;
 286     }
 287     if (curid != id) {
 288         if (internalp) {
 289             fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not "
 290                     "in same module (%d != %d)\n",
 291                     (unsigned) r, curid, id);
 292             goto failed;
 293         } else if ( ! p[id].loaded &&
 294                     load_flat_shared_library(id, p) > (unsigned long) -4096) {
 295             fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id);
 296             goto failed;
 297         }
 298         /* Check versioning information (i.e. time stamps) */
 299         if (p[id].build_date && p[curid].build_date
 300             && p[curid].build_date < p[id].build_date) {
 301             fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n",
 302                     id, curid);
 303             goto failed;
 304         }
 305     }
 306 #else
 307     id = 0;
 308 #endif
 309
 310     start_brk = p[id].start_brk;
 311     start_data = p[id].start_data;
 312     start_code = p[id].start_code;
 313     text_len = p[id].text_len;
 314
 315     if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 316         fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x "
 317                 "(0 - 0x%x/0x%x)\n",
 318                (int) r,(int)(start_brk-start_code),(int)text_len);
 319         goto failed;
 320     }
 321
 322     if (r < text_len)                   /* In text segment */
 323         addr = r + start_code;
 324     else                                        /* In data segment */
 325         addr = r - text_len + start_data;
 326
 327     /* Range checked already above so doing the range tests is redundant...*/
 328     return(addr);
 329
 330 failed:
 331     abort();
 332     return RELOC_FAILED;
 333 }
 334
 335 /****************************************************************************/
 336
 337 /* ??? This does not handle endianness correctly.  */
 338 static void old_reloc(struct lib_info *libinfo, uint32_t rl)
 339 {
 340 #ifdef DEBUG
 341         char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 342 #endif
 343         uint32_t *ptr;
 344         uint32_t offset;
 345         int reloc_type;
 346
 347         offset = rl & 0x3fffffff;
 348         reloc_type = rl >> 30;
 349         /* ??? How to handle this?  */
 350 #if defined(CONFIG_COLDFIRE)
 351         ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset);
 352 #else
 353         ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset);
 354 #endif
 355
 356 #ifdef DEBUG
 357         fprintf(stderr, "Relocation of variable at DATASEG+%x "
 358                 "(address %p, currently %x) into segment %s\n",
 359                 offset, ptr, (int)*ptr, segment[reloc_type]);
 360 #endif
 361
 362         switch (reloc_type) {
 363         case OLD_FLAT_RELOC_TYPE_TEXT:
 364                 *ptr += libinfo->start_code;
 365                 break;
 366         case OLD_FLAT_RELOC_TYPE_DATA:
 367                 *ptr += libinfo->start_data;
 368                 break;
 369         case OLD_FLAT_RELOC_TYPE_BSS:
 370                 *ptr += libinfo->end_data;
 371                 break;
 372         default:
 373                 fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n",
 374                         reloc_type);
 375                 break;
 376         }
 377         DBG_FLT("Relocation became %x\n", (int)*ptr);
 378 }
 379
 380 /****************************************************************************/
 381
 382 static int load_flat_file(struct linux_binprm * bprm,
 383                 struct lib_info *libinfo, int id, abi_ulong *extra_stack)
 384 {
 385     struct flat_hdr * hdr;
 386     abi_ulong textpos = 0, datapos = 0, result;
 387     abi_ulong realdatastart = 0;
 388     abi_ulong text_len, data_len, bss_len, stack_len, flags;
 389     abi_ulong memp = 0; /* for finding the brk area */
 390     abi_ulong extra;
 391     abi_ulong reloc = 0, rp;
 392     int i, rev, relocs = 0;
 393     abi_ulong fpos;
 394     abi_ulong start_code, end_code;
 395     abi_ulong indx_len;
 396
 397     hdr = ((struct flat_hdr *) bprm->buf);              /* exec-header */
 398
 399     text_len  = ntohl(hdr->data_start);
 400     data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 401     bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 402     stack_len = ntohl(hdr->stack_size);
 403     if (extra_stack) {
 404         stack_len += *extra_stack;
 405         *extra_stack = stack_len;
 406     }
 407     relocs    = ntohl(hdr->reloc_count);
 408     flags     = ntohl(hdr->flags);
 409     rev       = ntohl(hdr->rev);
 410
 411     DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 412
 413     if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 414         fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",
 415                 rev, (int) FLAT_VERSION);
 416         return -ENOEXEC;
 417     }
 418
 419     /* Don't allow old format executables to use shared libraries */
 420     if (rev == OLD_FLAT_VERSION && id != 0) {
 421         fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n");
 422         return -ENOEXEC;
 423     }
 424
 425     /*
 426      * fix up the flags for the older format,  there were all kinds
 427      * of endian hacks,  this only works for the simple cases
 428      */
 429     if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 430         flags = FLAT_FLAG_RAM;
 431
 432 #ifndef CONFIG_BINFMT_ZFLAT
 433     if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 434         fprintf(stderr, "Support for ZFLAT executables is not enabled\n");
 435         return -ENOEXEC;
 436     }
 437 #endif
 438
 439     /*
 440      * calculate the extra space we need to map in
 441      */
 442     extra = relocs * sizeof(abi_ulong);
 443     if (extra < bss_len + stack_len)
 444         extra = bss_len + stack_len;
 445
 446     /* Add space for library base pointers.  Make sure this does not
 447        misalign the  doesn't misalign the data segment.  */
 448     indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong);
 449     indx_len = (indx_len + 15) & ~(abi_ulong)15;
 450
 451     /*
 452      * there are a couple of cases here,  the separate code/data
 453      * case,  and then the fully copied to RAM case which lumps
 454      * it all together.
 455      */
 456     if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 457         /*
 458          * this should give us a ROM ptr,  but if it doesn't we don't
 459          * really care
 460          */
 461         DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 462
 463         textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC,
 464                               MAP_PRIVATE, bprm->fd, 0);
 465         if (textpos == -1) {
 466             fprintf(stderr, "Unable to mmap process text\n");
 467             return -1;
 468         }
 469
 470         realdatastart = target_mmap(0, data_len + extra + indx_len,
 471                                     PROT_READ|PROT_WRITE|PROT_EXEC,
 472                                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 473
 474         if (realdatastart == -1) {
 475             fprintf(stderr, "Unable to allocate RAM for process data\n");
 476             return realdatastart;
 477         }
 478         datapos = realdatastart + indx_len;
 479
 480         DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 481                         (int)(data_len + bss_len + stack_len), (int)datapos);
 482
 483         fpos = ntohl(hdr->data_start);
 484 #ifdef CONFIG_BINFMT_ZFLAT
 485         if (flags & FLAT_FLAG_GZDATA) {
 486             result = decompress_exec(bprm, fpos, (char *) datapos,
 487                                      data_len + (relocs * sizeof(abi_ulong)))
 488         } else
 489 #endif
 490         {
 491             result = target_pread(bprm->fd, datapos,
 492                                   data_len + (relocs * sizeof(abi_ulong)),
 493                                   fpos);
 494         }
 495         if (result < 0) {
 496             fprintf(stderr, "Unable to read data+bss\n");
 497             return result;
 498         }
 499
 500         reloc = datapos + (ntohl(hdr->reloc_start) - text_len);
 501         memp = realdatastart;
 502
 503     } else {
 504
 505         textpos = target_mmap(0, text_len + data_len + extra + indx_len,
 506                               PROT_READ | PROT_EXEC | PROT_WRITE,
 507                               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 508         if (textpos == -1 ) {
 509             fprintf(stderr, "Unable to allocate RAM for process text/data\n");
 510             return -1;
 511         }
 512
 513         realdatastart = textpos + ntohl(hdr->data_start);
 514         datapos = realdatastart + indx_len;
 515         reloc = (textpos + ntohl(hdr->reloc_start) + indx_len);
 516         memp = textpos;
 517
 518 #ifdef CONFIG_BINFMT_ZFLAT
 519 #error code needs checking
 520         /*
 521          * load it all in and treat it like a RAM load from now on
 522          */
 523         if (flags & FLAT_FLAG_GZIP) {
 524                 result = decompress_exec(bprm, sizeof (struct flat_hdr),
 525                                  (((char *) textpos) + sizeof (struct flat_hdr)),
 526                                  (text_len + data_len + (relocs * sizeof(unsigned long))
 527                                           - sizeof (struct flat_hdr)),
 528                                  0);
 529                 memmove((void *) datapos, (void *) realdatastart,
 530                                 data_len + (relocs * sizeof(unsigned long)));
 531         } else if (flags & FLAT_FLAG_GZDATA) {
 532                 fpos = 0;
 533                 result = bprm->file->f_op->read(bprm->file,
 534                                 (char *) textpos, text_len, &fpos);
 535                 if (result < (unsigned long) -4096)
 536                         result = decompress_exec(bprm, text_len, (char *) datapos,
 537                                          data_len + (relocs * sizeof(unsigned long)), 0);
 538         }
 539         else
 540 #endif
 541         {
 542             result = target_pread(bprm->fd, textpos,
 543                                   text_len, 0);
 544             if (result >= 0) {
 545                 result = target_pread(bprm->fd, datapos,
 546                     data_len + (relocs * sizeof(abi_ulong)),
 547                     ntohl(hdr->data_start));
 548             }
 549         }
 550         if (result < 0) {
 551             fprintf(stderr, "Unable to read code+data+bss\n");
 552             return result;
 553         }
 554     }
 555
 556     DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n",
 557             (int)textpos, 0x00ffffff&ntohl(hdr->entry),
 558             ntohl(hdr->data_start));
 559
 560     /* The main program needs a little extra setup in the task structure */
 561     start_code = textpos + sizeof (struct flat_hdr);
 562     end_code = textpos + text_len;
 563
 564     DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 565             id ? "Lib" : "Load", bprm->filename,
 566             (int) start_code, (int) end_code,
 567             (int) datapos,
 568             (int) (datapos + data_len),
 569             (int) (datapos + data_len),
 570             (int) (((datapos + data_len + bss_len) + 3) & ~3));
 571
 572     text_len -= sizeof(struct flat_hdr); /* the real code len */
 573
 574     /* Store the current module values into the global library structure */
 575     libinfo[id].start_code = start_code;
 576     libinfo[id].start_data = datapos;
 577     libinfo[id].end_data = datapos + data_len;
 578     libinfo[id].start_brk = datapos + data_len + bss_len;
 579     libinfo[id].text_len = text_len;
 580     libinfo[id].loaded = 1;
 581     libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 582     libinfo[id].build_date = ntohl(hdr->build_date);
 583
 584     /*
 585      * We just load the allocations into some temporary memory to
 586      * help simplify all this mumbo jumbo
 587      *
 588      * We've got two different sections of relocation entries.
 589      * The first is the GOT which resides at the begining of the data segment
 590      * and is terminated with a -1.  This one can be relocated in place.
 591      * The second is the extra relocation entries tacked after the image's
 592      * data segment. These require a little more processing as the entry is
 593      * really an offset into the image which contains an offset into the
 594      * image.
 595      */
 596     if (flags & FLAT_FLAG_GOTPIC) {
 597         rp = datapos;
 598         while (1) {
 599             abi_ulong addr;
 600             if (get_user_ual(addr, rp))
 601                 return -EFAULT;
 602             if (addr == -1)
 603                 break;
 604             if (addr) {
 605                 addr = calc_reloc(addr, libinfo, id, 0);
 606                 if (addr == RELOC_FAILED)
 607                     return -ENOEXEC;
 608                 if (put_user_ual(addr, rp))
 609                     return -EFAULT;
 610             }
 611             rp += sizeof(abi_ulong);
 612         }
 613     }
 614
 615     /*
 616      * Now run through the relocation entries.
 617      * We've got to be careful here as C++ produces relocatable zero
 618      * entries in the constructor and destructor tables which are then
 619      * tested for being not zero (which will always occur unless we're
 620      * based from address zero).  This causes an endless loop as __start
 621      * is at zero.  The solution used is to not relocate zero addresses.
 622      * This has the negative side effect of not allowing a global data
 623      * reference to be statically initialised to _stext (I've moved
 624      * __start to address 4 so that is okay).
 625      */
 626     if (rev > OLD_FLAT_VERSION) {
 627         for (i = 0; i < relocs; i++) {
 628             abi_ulong addr, relval;
 629
 630             /* Get the address of the pointer to be
 631                relocated (of course, the address has to be
 632                relocated first).  */
 633             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
 634                 return -EFAULT;
 635             addr = flat_get_relocate_addr(relval);
 636             rp = calc_reloc(addr, libinfo, id, 1);
 637             if (rp == RELOC_FAILED)
 638                 return -ENOEXEC;
 639
 640             /* Get the pointer's value.  */
 641             if (get_user_ual(addr, rp))
 642                 return -EFAULT;
 643             if (addr != 0) {
 644                 /*
 645                  * Do the relocation.  PIC relocs in the data section are
 646                  * already in target order
 647                  */
 648
 649 #ifndef TARGET_WORDS_BIGENDIAN
 650                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 651                     addr = bswap32(addr);
 652 #endif
 653                 addr = calc_reloc(addr, libinfo, id, 0);
 654                 if (addr == RELOC_FAILED)
 655                     return -ENOEXEC;
 656
 657                 /* Write back the relocated pointer.  */
 658                 if (put_user_ual(addr, rp))
 659                     return -EFAULT;
 660             }
 661         }
 662     } else {
 663         for (i = 0; i < relocs; i++) {
 664             abi_ulong relval;
 665             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
 666                 return -EFAULT;
 667             old_reloc(&libinfo[0], relval);
 668         }
 669     }
 670
 671     /* zero the BSS.  */
 672     memset((void *)((unsigned long)datapos + data_len), 0, bss_len);
 673
 674     return 0;
 675 }
 676
 677
 678 /****************************************************************************/
 679 #ifdef CONFIG_BINFMT_SHARED_FLAT
 680
 681 /*
 682  * Load a shared library into memory.  The library gets its own data
 683  * segment (including bss) but not argv/argc/environ.
 684  */
 685
 686 static int load_flat_shared_library(int id, struct lib_info *libs)
 687 {
 688         struct linux_binprm bprm;
 689         int res;
 690         char buf[16];
 691
 692         /* Create the file name */
 693         sprintf(buf, "/lib/lib%d.so", id);
 694
 695         /* Open the file up */
 696         bprm.filename = buf;
 697         bprm.file = open_exec(bprm.filename);
 698         res = PTR_ERR(bprm.file);
 699         if (IS_ERR(bprm.file))
 700                 return res;
 701
 702         res = prepare_binprm(&bprm);
 703
 704         if (res <= (unsigned long)-4096)
 705                 res = load_flat_file(&bprm, libs, id, NULL);
 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 target_pt_regs * regs,
 717                     struct image_info * info)
 718 {
 719     struct lib_info libinfo[MAX_SHARED_LIBS];
 720     abi_ulong p = bprm->p;
 721     abi_ulong stack_len;
 722     abi_ulong start_addr;
 723     abi_ulong sp;
 724     int res;
 725     int i, j;
 726
 727     memset(libinfo, 0, sizeof(libinfo));
 728     /*
 729      * We have to add the size of our arguments to our stack size
 730      * otherwise it's too easy for users to create stack overflows
 731      * by passing in a huge argument list.  And yes,  we have to be
 732      * pedantic and include space for the argv/envp array as it may have
 733      * a lot of entries.
 734      */
 735 #define TOP_OF_ARGS (TARGET_PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
 736     stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
 737     stack_len += (bprm->argc + 1) * 4; /* the argv array */
 738     stack_len += (bprm->envc + 1) * 4; /* the envp array */
 739
 740
 741     res = load_flat_file(bprm, libinfo, 0, &stack_len);
 742     if (res > (unsigned long)-4096)
 743             return res;
 744
 745     /* Update data segment pointers for all libraries */
 746     for (i=0; i<MAX_SHARED_LIBS; i++) {
 747         if (libinfo[i].loaded) {
 748             abi_ulong p;
 749             p = libinfo[i].start_data;
 750             for (j=0; j<MAX_SHARED_LIBS; j++) {
 751                 p -= 4;
 752                 /* FIXME - handle put_user() failures */
 753                 if (put_user_ual(libinfo[j].loaded
 754                                  ? libinfo[j].start_data
 755                                  : UNLOADED_LIB,
 756                                  p))
 757                     return -EFAULT;
 758             }
 759         }
 760     }
 761
 762     p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4;
 763     DBG_FLT("p=%x\n", (int)p);
 764
 765     /* Copy argv/envp.  */
 766     p = copy_strings(p, bprm->envc, bprm->envp);
 767     p = copy_strings(p, bprm->argc, bprm->argv);
 768     /* Align stack.  */
 769     sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1);
 770     /* Enforce final stack alignment of 16 bytes.  This is sufficient
 771        for all current targets, and excess alignment is harmless.  */
 772     stack_len = bprm->envc + bprm->argc + 2;
 773     stack_len += 3;     /* argc, arvg, argp */
 774     stack_len *= sizeof(abi_ulong);
 775     if ((sp + stack_len) & 15)
 776         sp -= 16 - ((sp + stack_len) & 15);
 777     sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, 1);
 778
 779     /* Fake some return addresses to ensure the call chain will
 780      * initialise library in order for us.  We are required to call
 781      * lib 1 first, then 2, ... and finally the main program (id 0).
 782      */
 783     start_addr = libinfo[0].entry;
 784
 785 #ifdef CONFIG_BINFMT_SHARED_FLAT
 786 #error here
 787     for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 788             if (libinfo[i].loaded) {
 789                     /* Push previos first to call address */
 790                     --sp;
 791                     if (put_user_ual(start_addr, sp))
 792                         return -EFAULT;
 793                     start_addr = libinfo[i].entry;
 794             }
 795     }
 796 #endif
 797
 798     /* Stash our initial stack pointer into the mm structure */
 799     info->start_code = libinfo[0].start_code;
 800     info->end_code = libinfo[0].start_code = libinfo[0].text_len;
 801     info->start_data = libinfo[0].start_data;
 802     info->end_data = libinfo[0].end_data;
 803     info->start_brk = libinfo[0].start_brk;
 804     info->start_stack = sp;
 805     info->entry = start_addr;
 806     info->code_offset = info->start_code;
 807     info->data_offset = info->start_data - libinfo[0].text_len;
 808
 809     DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n",
 810             (int)info->entry, (int)info->start_stack);
 811
 812     return 0;
 813 }