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
  45 /****************************************************************************/
  46
  47 #if 0
  48 #define DEBUG 1
  49 #endif
  50
  51 #ifdef DEBUG
  52 #define DBG_FLT(a...)   printk(a)
  53 #else
  54 #define DBG_FLT(a...)
  55 #endif
  56
  57 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  58 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  59
  60 struct lib_info {
  61         struct {
  62                 unsigned long start_code;               /* Start of text segment */
  63                 unsigned long start_data;               /* Start of data segment */
  64                 unsigned long start_brk;                /* End of data segment */
  65                 unsigned long text_len;                 /* Length of text segment */
  66                 unsigned long entry;                    /* Start address for this module */
  67                 unsigned long build_date;               /* When this one was compiled */
  68                 short loaded;                           /* Has this library been loaded? */
  69         } lib_list[MAX_SHARED_LIBS];
  70 };
  71
  72 #ifdef CONFIG_BINFMT_SHARED_FLAT
  73 static int load_flat_shared_library(int id, struct lib_info *p);
  74 #endif
  75
  76 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
  77 static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
  78
  79 static struct linux_binfmt flat_format = {
  80         .module         = THIS_MODULE,
  81         .load_binary    = load_flat_binary,
  82         .core_dump      = flat_core_dump,
  83         .min_coredump   = PAGE_SIZE
  84 };
  85
  86 /****************************************************************************/
  87 /*
  88  * Routine writes a core dump image in the current directory.
  89  * Currently only a stub-function.
  90  */
  91
  92 static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
  93 {
  94         printk("Process %s:%d received signr %d and should have core dumped\n",
  95                         current->comm, current->pid, (int) signr);
  96         return(1);
  97 }
  98
  99 /****************************************************************************/
 100 /*
 101  * create_flat_tables() parses the env- and arg-strings in new user
 102  * memory and creates the pointer tables from them, and puts their
 103  * addresses on the "stack", returning the new stack pointer value.
 104  */
 105
 106 static unsigned long create_flat_tables(
 107         unsigned long pp,
 108         struct linux_binprm * bprm)
 109 {
 110         unsigned long *argv,*envp;
 111         unsigned long * sp;
 112         char * p = (char*)pp;
 113         int argc = bprm->argc;
 114         int envc = bprm->envc;
 115         char uninitialized_var(dummy);
 116
 117         sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);
 118
 119         sp -= envc+1;
 120         envp = sp;
 121         sp -= argc+1;
 122         argv = sp;
 123
 124         flat_stack_align(sp);
 125         if (flat_argvp_envp_on_stack()) {
 126                 --sp; put_user((unsigned long) envp, sp);
 127                 --sp; put_user((unsigned long) argv, sp);
 128         }
 129
 130         put_user(argc,--sp);
 131         current->mm->arg_start = (unsigned long) p;
 132         while (argc-->0) {
 133                 put_user((unsigned long) p, argv++);
 134                 do {
 135                         get_user(dummy, p); p++;
 136                 } while (dummy);
 137         }
 138         put_user((unsigned long) NULL, argv);
 139         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 140         while (envc-->0) {
 141                 put_user((unsigned long)p, envp); envp++;
 142                 do {
 143                         get_user(dummy, p); p++;
 144                 } while (dummy);
 145         }
 146         put_user((unsigned long) NULL, envp);
 147         current->mm->env_end = (unsigned long) p;
 148         return (unsigned long)sp;
 149 }
 150
 151 /****************************************************************************/
 152
 153 #ifdef CONFIG_BINFMT_ZFLAT
 154
 155 #include <linux/zlib.h>
 156
 157 #define LBUFSIZE        4000
 158
 159 /* gzip flag byte */
 160 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 161 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 162 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 163 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 164 #define COMMENT      0x10 /* bit 4 set: file comment present */
 165 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 166 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 167
 168 static int decompress_exec(
 169         struct linux_binprm *bprm,
 170         unsigned long offset,
 171         char *dst,
 172         long len,
 173         int fd)
 174 {
 175         unsigned char *buf;
 176         z_stream strm;
 177         loff_t fpos;
 178         int ret, retval;
 179
 180         DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 181
 182         memset(&strm, 0, sizeof(strm));
 183         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 184         if (strm.workspace == NULL) {
 185                 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 186                 return -ENOMEM;
 187         }
 188         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 189         if (buf == NULL) {
 190                 DBG_FLT("binfmt_flat: no memory for read buffer\n");
 191                 retval = -ENOMEM;
 192                 goto out_free;
 193         }
 194
 195         /* Read in first chunk of data and parse gzip header. */
 196         fpos = offset;
 197         ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 198
 199         strm.next_in = buf;
 200         strm.avail_in = ret;
 201         strm.total_in = 0;
 202
 203         retval = -ENOEXEC;
 204
 205         /* Check minimum size -- gzip header */
 206         if (ret < 10) {
 207                 DBG_FLT("binfmt_flat: file too small?\n");
 208                 goto out_free_buf;
 209         }
 210
 211         /* Check gzip magic number */
 212         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 213                 DBG_FLT("binfmt_flat: unknown compression magic?\n");
 214                 goto out_free_buf;
 215         }
 216
 217         /* Check gzip method */
 218         if (buf[2] != 8) {
 219                 DBG_FLT("binfmt_flat: unknown compression method?\n");
 220                 goto out_free_buf;
 221         }
 222         /* Check gzip flags */
 223         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 224             (buf[3] & RESERVED)) {
 225                 DBG_FLT("binfmt_flat: unknown flags?\n");
 226                 goto out_free_buf;
 227         }
 228
 229         ret = 10;
 230         if (buf[3] & EXTRA_FIELD) {
 231                 ret += 2 + buf[10] + (buf[11] << 8);
 232                 if (unlikely(LBUFSIZE == ret)) {
 233                         DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
 234                         goto out_free_buf;
 235                 }
 236         }
 237         if (buf[3] & ORIG_NAME) {
 238                 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
 239                         ;
 240                 if (unlikely(LBUFSIZE == ret)) {
 241                         DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
 242                         goto out_free_buf;
 243                 }
 244         }
 245         if (buf[3] & COMMENT) {
 246                 for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
 247                         ;
 248                 if (unlikely(LBUFSIZE == ret)) {
 249                         DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
 250                         goto out_free_buf;
 251                 }
 252         }
 253
 254         strm.next_in += ret;
 255         strm.avail_in -= ret;
 256
 257         strm.next_out = dst;
 258         strm.avail_out = len;
 259         strm.total_out = 0;
 260
 261         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 262                 DBG_FLT("binfmt_flat: zlib init failed?\n");
 263                 goto out_free_buf;
 264         }
 265
 266         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 267                 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 268                 if (ret <= 0)
 269                         break;
 270                 if (ret >= (unsigned long) -4096)
 271                         break;
 272                 len -= ret;
 273
 274                 strm.next_in = buf;
 275                 strm.avail_in = ret;
 276                 strm.total_in = 0;
 277         }
 278
 279         if (ret < 0) {
 280                 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
 281                         ret, strm.msg);
 282                 goto out_zlib;
 283         }
 284
 285         retval = 0;
 286 out_zlib:
 287         zlib_inflateEnd(&strm);
 288 out_free_buf:
 289         kfree(buf);
 290 out_free:
 291         kfree(strm.workspace);
 292         return retval;
 293 }
 294
 295 #endif /* CONFIG_BINFMT_ZFLAT */
 296
 297 /****************************************************************************/
 298
 299 static unsigned long
 300 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 301 {
 302         unsigned long addr;
 303         int id;
 304         unsigned long start_brk;
 305         unsigned long start_data;
 306         unsigned long text_len;
 307         unsigned long start_code;
 308
 309 #ifdef CONFIG_BINFMT_SHARED_FLAT
 310         if (r == 0)
 311                 id = curid;     /* Relocs of 0 are always self referring */
 312         else {
 313                 id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 314                 r &= 0x00ffffff;        /* Trim ID off here */
 315         }
 316         if (id >= MAX_SHARED_LIBS) {
 317                 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
 318                                 (unsigned) r, id);
 319                 goto failed;
 320         }
 321         if (curid != id) {
 322                 if (internalp) {
 323                         printk("BINFMT_FLAT: reloc address 0x%x not in same module "
 324                                         "(%d != %d)", (unsigned) r, curid, id);
 325                         goto failed;
 326                 } else if ( ! p->lib_list[id].loaded &&
 327                                 load_flat_shared_library(id, p) > (unsigned long) -4096) {
 328                         printk("BINFMT_FLAT: failed to load library %d", id);
 329                         goto failed;
 330                 }
 331                 /* Check versioning information (i.e. time stamps) */
 332                 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 333                                 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 334                         printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
 335                         goto failed;
 336                 }
 337         }
 338 #else
 339         id = 0;
 340 #endif
 341
 342         start_brk = p->lib_list[id].start_brk;
 343         start_data = p->lib_list[id].start_data;
 344         start_code = p->lib_list[id].start_code;
 345         text_len = p->lib_list[id].text_len;
 346
 347         if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 348                 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
 349                        (int) r,(int)(start_brk-start_code),(int)text_len);
 350                 goto failed;
 351         }
 352
 353         if (r < text_len)                       /* In text segment */
 354                 addr = r + start_code;
 355         else                                    /* In data segment */
 356                 addr = r - text_len + start_data;
 357
 358         /* Range checked already above so doing the range tests is redundant...*/
 359         return(addr);
 360
 361 failed:
 362         printk(", killing %s!\n", current->comm);
 363         send_sig(SIGSEGV, current, 0);
 364
 365         return RELOC_FAILED;
 366 }
 367
 368 /****************************************************************************/
 369
 370 void old_reloc(unsigned long rl)
 371 {
 372 #ifdef DEBUG
 373         char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 374 #endif
 375         flat_v2_reloc_t r;
 376         unsigned long *ptr;
 377
 378         r.value = rl;
 379 #if defined(CONFIG_COLDFIRE)
 380         ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
 381 #else
 382         ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
 383 #endif
 384
 385 #ifdef DEBUG
 386         printk("Relocation of variable at DATASEG+%x "
 387                 "(address %p, currently %x) into segment %s\n",
 388                 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
 389 #endif
 390
 391         switch (r.reloc.type) {
 392         case OLD_FLAT_RELOC_TYPE_TEXT:
 393                 *ptr += current->mm->start_code;
 394                 break;
 395         case OLD_FLAT_RELOC_TYPE_DATA:
 396                 *ptr += current->mm->start_data;
 397                 break;
 398         case OLD_FLAT_RELOC_TYPE_BSS:
 399                 *ptr += current->mm->end_data;
 400                 break;
 401         default:
 402                 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
 403                 break;
 404         }
 405
 406 #ifdef DEBUG
 407         printk("Relocation became %x\n", (int)*ptr);
 408 #endif
 409 }
 410
 411 /****************************************************************************/
 412
 413 static int load_flat_file(struct linux_binprm * bprm,
 414                 struct lib_info *libinfo, int id, unsigned long *extra_stack)
 415 {
 416         struct flat_hdr * hdr;
 417         unsigned long textpos = 0, datapos = 0, result;
 418         unsigned long realdatastart = 0;
 419         unsigned long text_len, data_len, bss_len, stack_len, flags;
 420         unsigned long len, reallen, memp = 0;
 421         unsigned long extra, rlim;
 422         unsigned long *reloc = 0, *rp;
 423         struct inode *inode;
 424         int i, rev, relocs = 0;
 425         loff_t fpos;
 426         unsigned long start_code, end_code;
 427         int ret;
 428
 429         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 430         inode = bprm->file->f_path.dentry->d_inode;
 431
 432         text_len  = ntohl(hdr->data_start);
 433         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 434         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 435         stack_len = ntohl(hdr->stack_size);
 436         if (extra_stack) {
 437                 stack_len += *extra_stack;
 438                 *extra_stack = stack_len;
 439         }
 440         relocs    = ntohl(hdr->reloc_count);
 441         flags     = ntohl(hdr->flags);
 442         rev       = ntohl(hdr->rev);
 443
 444         if (strncmp(hdr->magic, "bFLT", 4)) {
 445                 /*
 446                  * Previously, here was a printk to tell people
 447                  *   "BINFMT_FLAT: bad header magic".
 448                  * But for the kernel which also use ELF FD-PIC format, this
 449                  * error message is confusing.
 450                  * because a lot of people do not manage to produce good
 451                  */
 452                 ret = -ENOEXEC;
 453                 goto err;
 454         }
 455
 456         if (flags & FLAT_FLAG_KTRACE)
 457                 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 458
 459         if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 460                 printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
 461                         "0x%lx and 0x%lx)\n",
 462                         rev, FLAT_VERSION, OLD_FLAT_VERSION);
 463                 ret = -ENOEXEC;
 464                 goto err;
 465         }
 466
 467         /* Don't allow old format executables to use shared libraries */
 468         if (rev == OLD_FLAT_VERSION && id != 0) {
 469                 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
 470                                 (int) FLAT_VERSION);
 471                 ret = -ENOEXEC;
 472                 goto err;
 473         }
 474
 475         /*
 476          * fix up the flags for the older format,  there were all kinds
 477          * of endian hacks,  this only works for the simple cases
 478          */
 479         if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 480                 flags = FLAT_FLAG_RAM;
 481
 482 #ifndef CONFIG_BINFMT_ZFLAT
 483         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 484                 printk("Support for ZFLAT executables is not enabled.\n");
 485                 ret = -ENOEXEC;
 486                 goto err;
 487         }
 488 #endif
 489
 490         /*
 491          * Check initial limits. This avoids letting people circumvent
 492          * size limits imposed on them by creating programs with large
 493          * arrays in the data or bss.
 494          */
 495         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 496         if (rlim >= RLIM_INFINITY)
 497                 rlim = ~0;
 498         if (data_len + bss_len > rlim) {
 499                 ret = -ENOMEM;
 500                 goto err;
 501         }
 502
 503         /* Flush all traces of the currently running executable */
 504         if (id == 0) {
 505                 result = flush_old_exec(bprm);
 506                 if (result) {
 507                         ret = result;
 508                         goto err;
 509                 }
 510
 511                 /* OK, This is the point of no return */
 512                 set_personality(PER_LINUX_32BIT);
 513         }
 514
 515         /*
 516          * calculate the extra space we need to map in
 517          */
 518         extra = max_t(unsigned long, bss_len + stack_len,
 519                         relocs * sizeof(unsigned long));
 520
 521         /*
 522          * there are a couple of cases here,  the separate code/data
 523          * case,  and then the fully copied to RAM case which lumps
 524          * it all together.
 525          */
 526         if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 527                 /*
 528                  * this should give us a ROM ptr,  but if it doesn't we don't
 529                  * really care
 530                  */
 531                 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 532
 533                 down_write(&current->mm->mmap_sem);
 534                 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0);
 535                 up_write(&current->mm->mmap_sem);
 536                 if (!textpos  || textpos >= (unsigned long) -4096) {
 537                         if (!textpos)
 538                                 textpos = (unsigned long) -ENOMEM;
 539                         printk("Unable to mmap process text, errno %d\n", (int)-textpos);
 540                         ret = textpos;
 541                         goto err;
 542                 }
 543
 544                 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 545                 down_write(&current->mm->mmap_sem);
 546                 realdatastart = do_mmap(0, 0, len,
 547                         PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 548                 /* Remap to use all availabe slack region space */
 549                 if (realdatastart && (realdatastart < (unsigned long)-4096)) {
 550                         reallen = ksize((void *)realdatastart);
 551                         if (reallen > len) {
 552                                 realdatastart = do_mremap(realdatastart, len,
 553                                         reallen, MREMAP_FIXED, realdatastart);
 554                         }
 555                 }
 556                 up_write(&current->mm->mmap_sem);
 557
 558                 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
 559                         if (!realdatastart)
 560                                 realdatastart = (unsigned long) -ENOMEM;
 561                         printk("Unable to allocate RAM for process data, errno %d\n",
 562                                         (int)-realdatastart);
 563                         do_munmap(current->mm, textpos, text_len);
 564                         ret = realdatastart;
 565                         goto err;
 566                 }
 567                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 568
 569                 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 570                                 (int)(data_len + bss_len + stack_len), (int)datapos);
 571
 572                 fpos = ntohl(hdr->data_start);
 573 #ifdef CONFIG_BINFMT_ZFLAT
 574                 if (flags & FLAT_FLAG_GZDATA) {
 575                         result = decompress_exec(bprm, fpos, (char *) datapos,
 576                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 577                 } else
 578 #endif
 579                 {
 580                         result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 581                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 582                 }
 583                 if (result >= (unsigned long)-4096) {
 584                         printk("Unable to read data+bss, errno %d\n", (int)-result);
 585                         do_munmap(current->mm, textpos, text_len);
 586                         do_munmap(current->mm, realdatastart, data_len + extra);
 587                         ret = result;
 588                         goto err;
 589                 }
 590
 591                 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
 592                 memp = realdatastart;
 593
 594         } else {
 595
 596                 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 597                 down_write(&current->mm->mmap_sem);
 598                 textpos = do_mmap(0, 0, len,
 599                         PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 600                 /* Remap to use all availabe slack region space */
 601                 if (textpos && (textpos < (unsigned long) -4096)) {
 602                         reallen = ksize((void *)textpos);
 603                         if (reallen > len) {
 604                                 textpos = do_mremap(textpos, len, reallen,
 605                                         MREMAP_FIXED, textpos);
 606                         }
 607                 }
 608                 up_write(&current->mm->mmap_sem);
 609
 610                 if (!textpos  || textpos >= (unsigned long) -4096) {
 611                         if (!textpos)
 612                                 textpos = (unsigned long) -ENOMEM;
 613                         printk("Unable to allocate RAM for process text/data, errno %d\n",
 614                                         (int)-textpos);
 615                         ret = textpos;
 616                         goto err;
 617                 }
 618
 619                 realdatastart = textpos + ntohl(hdr->data_start);
 620                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 621                 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
 622                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 623                 memp = textpos;
 624
 625 #ifdef CONFIG_BINFMT_ZFLAT
 626                 /*
 627                  * load it all in and treat it like a RAM load from now on
 628                  */
 629                 if (flags & FLAT_FLAG_GZIP) {
 630                         result = decompress_exec(bprm, sizeof (struct flat_hdr),
 631                                          (((char *) textpos) + sizeof (struct flat_hdr)),
 632                                          (text_len + data_len + (relocs * sizeof(unsigned long))
 633                                                   - sizeof (struct flat_hdr)),
 634                                          0);
 635                         memmove((void *) datapos, (void *) realdatastart,
 636                                         data_len + (relocs * sizeof(unsigned long)));
 637                 } else if (flags & FLAT_FLAG_GZDATA) {
 638                         fpos = 0;
 639                         result = bprm->file->f_op->read(bprm->file,
 640                                         (char *) textpos, text_len, &fpos);
 641                         if (result < (unsigned long) -4096)
 642                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 643                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 644                 }
 645                 else
 646 #endif
 647                 {
 648                         fpos = 0;
 649                         result = bprm->file->f_op->read(bprm->file,
 650                                         (char *) textpos, text_len, &fpos);
 651                         if (result < (unsigned long) -4096) {
 652                                 fpos = ntohl(hdr->data_start);
 653                                 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 654                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 655                         }
 656                 }
 657                 if (result >= (unsigned long)-4096) {
 658                         printk("Unable to read code+data+bss, errno %d\n",(int)-result);
 659                         do_munmap(current->mm, textpos, text_len + data_len + extra +
 660                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 661                         ret = result;
 662                         goto err;
 663                 }
 664         }
 665
 666         if (flags & FLAT_FLAG_KTRACE)
 667                 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
 668                         (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 669
 670         /* The main program needs a little extra setup in the task structure */
 671         start_code = textpos + sizeof (struct flat_hdr);
 672         end_code = textpos + text_len;
 673         if (id == 0) {
 674                 current->mm->start_code = start_code;
 675                 current->mm->end_code = end_code;
 676                 current->mm->start_data = datapos;
 677                 current->mm->end_data = datapos + data_len;
 678                 /*
 679                  * set up the brk stuff, uses any slack left in data/bss/stack
 680                  * allocation.  We put the brk after the bss (between the bss
 681                  * and stack) like other platforms.
 682                  */
 683                 current->mm->start_brk = datapos + data_len + bss_len;
 684                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 685                 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len;
 686         }
 687
 688         if (flags & FLAT_FLAG_KTRACE)
 689                 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 690                         id ? "Lib" : "Load", bprm->filename,
 691                         (int) start_code, (int) end_code,
 692                         (int) datapos,
 693                         (int) (datapos + data_len),
 694                         (int) (datapos + data_len),
 695                         (int) (((datapos + data_len + bss_len) + 3) & ~3));
 696
 697         text_len -= sizeof(struct flat_hdr); /* the real code len */
 698
 699         /* Store the current module values into the global library structure */
 700         libinfo->lib_list[id].start_code = start_code;
 701         libinfo->lib_list[id].start_data = datapos;
 702         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 703         libinfo->lib_list[id].text_len = text_len;
 704         libinfo->lib_list[id].loaded = 1;
 705         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 706         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 707
 708         /*
 709          * We just load the allocations into some temporary memory to
 710          * help simplify all this mumbo jumbo
 711          *
 712          * We've got two different sections of relocation entries.
 713          * The first is the GOT which resides at the begining of the data segment
 714          * and is terminated with a -1.  This one can be relocated in place.
 715          * The second is the extra relocation entries tacked after the image's
 716          * data segment. These require a little more processing as the entry is
 717          * really an offset into the image which contains an offset into the
 718          * image.
 719          */
 720         if (flags & FLAT_FLAG_GOTPIC) {
 721                 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
 722                         unsigned long addr;
 723                         if (*rp) {
 724                                 addr = calc_reloc(*rp, libinfo, id, 0);
 725                                 if (addr == RELOC_FAILED) {
 726                                         ret = -ENOEXEC;
 727                                         goto err;
 728                                 }
 729                                 *rp = addr;
 730                         }
 731                 }
 732         }
 733
 734         /*
 735          * Now run through the relocation entries.
 736          * We've got to be careful here as C++ produces relocatable zero
 737          * entries in the constructor and destructor tables which are then
 738          * tested for being not zero (which will always occur unless we're
 739          * based from address zero).  This causes an endless loop as __start
 740          * is at zero.  The solution used is to not relocate zero addresses.
 741          * This has the negative side effect of not allowing a global data
 742          * reference to be statically initialised to _stext (I've moved
 743          * __start to address 4 so that is okay).
 744          */
 745         if (rev > OLD_FLAT_VERSION) {
 746                 unsigned long persistent = 0;
 747                 for (i=0; i < relocs; i++) {
 748                         unsigned long addr, relval;
 749
 750                         /* Get the address of the pointer to be
 751                            relocated (of course, the address has to be
 752                            relocated first).  */
 753                         relval = ntohl(reloc[i]);
 754                         if (flat_set_persistent (relval, &persistent))
 755                                 continue;
 756                         addr = flat_get_relocate_addr(relval);
 757                         rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
 758                         if (rp == (unsigned long *)RELOC_FAILED) {
 759                                 ret = -ENOEXEC;
 760                                 goto err;
 761                         }
 762
 763                         /* Get the pointer's value.  */
 764                         addr = flat_get_addr_from_rp(rp, relval, flags,
 765                                                         &persistent);
 766                         if (addr != 0) {
 767                                 /*
 768                                  * Do the relocation.  PIC relocs in the data section are
 769                                  * already in target order
 770                                  */
 771                                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 772                                         addr = ntohl(addr);
 773                                 addr = calc_reloc(addr, libinfo, id, 0);
 774                                 if (addr == RELOC_FAILED) {
 775                                         ret = -ENOEXEC;
 776                                         goto err;
 777                                 }
 778
 779                                 /* Write back the relocated pointer.  */
 780                                 flat_put_addr_at_rp(rp, addr, relval);
 781                         }
 782                 }
 783         } else {
 784                 for (i=0; i < relocs; i++)
 785                         old_reloc(ntohl(reloc[i]));
 786         }
 787
 788         flush_icache_range(start_code, end_code);
 789
 790         /* zero the BSS,  BRK and stack areas */
 791         memset((void*)(datapos + data_len), 0, bss_len +
 792                         (memp + ksize((void *) memp) - stack_len -      /* end brk */
 793                         libinfo->lib_list[id].start_brk) +              /* start brk */
 794                         stack_len);
 795
 796         return 0;
 797 err:
 798         return ret;
 799 }
 800
 801
 802 /****************************************************************************/
 803 #ifdef CONFIG_BINFMT_SHARED_FLAT
 804
 805 /*
 806  * Load a shared library into memory.  The library gets its own data
 807  * segment (including bss) but not argv/argc/environ.
 808  */
 809
 810 static int load_flat_shared_library(int id, struct lib_info *libs)
 811 {
 812         struct linux_binprm bprm;
 813         int res;
 814         char buf[16];
 815
 816         /* Create the file name */
 817         sprintf(buf, "/lib/lib%d.so", id);
 818
 819         /* Open the file up */
 820         bprm.filename = buf;
 821         bprm.file = open_exec(bprm.filename);
 822         res = PTR_ERR(bprm.file);
 823         if (IS_ERR(bprm.file))
 824                 return res;
 825
 826         res = prepare_binprm(&bprm);
 827
 828         if (res <= (unsigned long)-4096)
 829                 res = load_flat_file(&bprm, libs, id, NULL);
 830         if (bprm.file) {
 831                 allow_write_access(bprm.file);
 832                 fput(bprm.file);
 833                 bprm.file = NULL;
 834         }
 835         return(res);
 836 }
 837
 838 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 839 /****************************************************************************/
 840
 841 /*
 842  * These are the functions used to load flat style executables and shared
 843  * libraries.  There is no binary dependent code anywhere else.
 844  */
 845
 846 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 847 {
 848         struct lib_info libinfo;
 849         unsigned long p = bprm->p;
 850         unsigned long stack_len;
 851         unsigned long start_addr;
 852         unsigned long *sp;
 853         int res;
 854         int i, j;
 855
 856         memset(&libinfo, 0, sizeof(libinfo));
 857         /*
 858          * We have to add the size of our arguments to our stack size
 859          * otherwise it's too easy for users to create stack overflows
 860          * by passing in a huge argument list.  And yes,  we have to be
 861          * pedantic and include space for the argv/envp array as it may have
 862          * a lot of entries.
 863          */
 864 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
 865         stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
 866         stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
 867         stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
 868
 869
 870         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 871         if (res > (unsigned long)-4096)
 872                 return res;
 873
 874         /* Update data segment pointers for all libraries */
 875         for (i=0; i<MAX_SHARED_LIBS; i++)
 876                 if (libinfo.lib_list[i].loaded)
 877                         for (j=0; j<MAX_SHARED_LIBS; j++)
 878                                 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
 879                                         (libinfo.lib_list[j].loaded)?
 880                                                 libinfo.lib_list[j].start_data:UNLOADED_LIB;
 881
 882         compute_creds(bprm);
 883         current->flags &= ~PF_FORKNOEXEC;
 884
 885         set_binfmt(&flat_format);
 886
 887         p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 888         DBG_FLT("p=%x\n", (int)p);
 889
 890         /* copy the arg pages onto the stack, this could be more efficient :-) */
 891         for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
 892                 * (char *) --p =
 893                         ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
 894
 895         sp = (unsigned long *) create_flat_tables(p, bprm);
 896
 897         /* Fake some return addresses to ensure the call chain will
 898          * initialise library in order for us.  We are required to call
 899          * lib 1 first, then 2, ... and finally the main program (id 0).
 900          */
 901         start_addr = libinfo.lib_list[0].entry;
 902
 903 #ifdef CONFIG_BINFMT_SHARED_FLAT
 904         for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 905                 if (libinfo.lib_list[i].loaded) {
 906                         /* Push previos first to call address */
 907                         --sp;   put_user(start_addr, sp);
 908                         start_addr = libinfo.lib_list[i].entry;
 909                 }
 910         }
 911 #endif
 912
 913         /* Stash our initial stack pointer into the mm structure */
 914         current->mm->start_stack = (unsigned long )sp;
 915
 916
 917         DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
 918                 (int)regs, (int)start_addr, (int)current->mm->start_stack);
 919
 920         start_thread(regs, start_addr, current->mm->start_stack);
 921
 922         if (current->ptrace & PT_PTRACED)
 923                 send_sig(SIGTRAP, current, 0);
 924
 925         return 0;
 926 }
 927
 928 /****************************************************************************/
 929
 930 static int __init init_flat_binfmt(void)
 931 {
 932         return register_binfmt(&flat_format);
 933 }
 934
 935 static void __exit exit_flat_binfmt(void)
 936 {
 937         unregister_binfmt(&flat_format);
 938 }
 939
 940 /****************************************************************************/
 941
 942 core_initcall(init_flat_binfmt);
 943 module_exit(exit_flat_binfmt);
 944
 945 /****************************************************************************/