fs/binfmt_flat.c

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