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/config.h>
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/mm.h>
  23 #include <linux/mman.h>
  24 #include <linux/a.out.h>
  25 #include <linux/errno.h>
  26 #include <linux/signal.h>
  27 #include <linux/string.h>
  28 #include <linux/fs.h>
  29 #include <linux/file.h>
  30 #include <linux/stat.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/ptrace.h>
  33 #include <linux/user.h>
  34 #include <linux/slab.h>
  35 #include <linux/binfmts.h>
  36 #include <linux/personality.h>
  37 #include <linux/init.h>
  38 #include <linux/flat.h>
  39
  40 #include <asm/byteorder.h>
  41 #include <asm/system.h>
  42 #include <asm/uaccess.h>
  43 #include <asm/unaligned.h>
  44 #include <asm/cacheflush.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 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  59 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  60
  61 struct lib_info {
  62         struct {
  63                 unsigned long start_code;               /* Start of text segment */
  64                 unsigned long start_data;               /* Start of data segment */
  65                 unsigned long start_brk;                /* End of data segment */
  66                 unsigned long text_len;                 /* Length of text segment */
  67                 unsigned long entry;                    /* Start address for this module */
  68                 unsigned long build_date;               /* When this one was compiled */
  69                 short loaded;                           /* Has this library been loaded? */
  70         } lib_list[MAX_SHARED_LIBS];
  71 };
  72
  73 #ifdef CONFIG_BINFMT_SHARED_FLAT
  74 static int load_flat_shared_library(int id, struct lib_info *p);
  75 #endif
  76
  77 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
  78 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file);
  79
  80 extern void dump_thread(struct pt_regs *, struct user *);
  81
  82 static struct linux_binfmt flat_format = {
  83         .module         = THIS_MODULE,
  84         .load_binary    = load_flat_binary,
  85         .core_dump      = flat_core_dump,
  86         .min_coredump   = PAGE_SIZE
  87 };
  88
  89 /****************************************************************************/
  90 /*
  91  * Routine writes a core dump image in the current directory.
  92  * Currently only a stub-function.
  93  */
  94
  95 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file)
  96 {
  97         printk("Process %s:%d received signr %d and should have core dumped\n",
  98                         current->comm, current->pid, (int) signr);
  99         return(1);
 100 }
 101
 102 /****************************************************************************/
 103 /*
 104  * create_flat_tables() parses the env- and arg-strings in new user
 105  * memory and creates the pointer tables from them, and puts their
 106  * addresses on the "stack", returning the new stack pointer value.
 107  */
 108
 109 static unsigned long create_flat_tables(
 110         unsigned long pp,
 111         struct linux_binprm * bprm)
 112 {
 113         unsigned long *argv,*envp;
 114         unsigned long * sp;
 115         char * p = (char*)pp;
 116         int argc = bprm->argc;
 117         int envc = bprm->envc;
 118         char dummy;
 119
 120         sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);
 121
 122         sp -= envc+1;
 123         envp = sp;
 124         sp -= argc+1;
 125         argv = sp;
 126
 127         flat_stack_align(sp);
 128         if (flat_argvp_envp_on_stack()) {
 129                 --sp; put_user((unsigned long) envp, sp);
 130                 --sp; put_user((unsigned long) argv, sp);
 131         }
 132
 133         put_user(argc,--sp);
 134         current->mm->arg_start = (unsigned long) p;
 135         while (argc-->0) {
 136                 put_user((unsigned long) p, argv++);
 137                 do {
 138                         get_user(dummy, p); p++;
 139                 } while (dummy);
 140         }
 141         put_user((unsigned long) NULL, argv);
 142         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 143         while (envc-->0) {
 144                 put_user((unsigned long)p, envp); envp++;
 145                 do {
 146                         get_user(dummy, p); p++;
 147                 } while (dummy);
 148         }
 149         put_user((unsigned long) NULL, envp);
 150         current->mm->env_end = (unsigned long) p;
 151         return (unsigned long)sp;
 152 }
 153
 154 /****************************************************************************/
 155
 156 #ifdef CONFIG_BINFMT_ZFLAT
 157
 158 #include <linux/zlib.h>
 159
 160 #define LBUFSIZE        4000
 161
 162 /* gzip flag byte */
 163 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 164 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 165 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 166 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 167 #define COMMENT      0x10 /* bit 4 set: file comment present */
 168 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 169 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 170
 171 static int decompress_exec(
 172         struct linux_binprm *bprm,
 173         unsigned long offset,
 174         char *dst,
 175         long len,
 176         int fd)
 177 {
 178         unsigned char *buf;
 179         z_stream strm;
 180         loff_t fpos;
 181         int ret, retval;
 182
 183         DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 184
 185         memset(&strm, 0, sizeof(strm));
 186         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 187         if (strm.workspace == NULL) {
 188                 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 189                 return -ENOMEM;
 190         }
 191         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 192         if (buf == NULL) {
 193                 DBG_FLT("binfmt_flat: no memory for read buffer\n");
 194                 retval = -ENOMEM;
 195                 goto out_free;
 196         }
 197
 198         /* Read in first chunk of data and parse gzip header. */
 199         fpos = offset;
 200         ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 201
 202         strm.next_in = buf;
 203         strm.avail_in = ret;
 204         strm.total_in = 0;
 205
 206         retval = -ENOEXEC;
 207
 208         /* Check minimum size -- gzip header */
 209         if (ret < 10) {
 210                 DBG_FLT("binfmt_flat: file too small?\n");
 211                 goto out_free_buf;
 212         }
 213
 214         /* Check gzip magic number */
 215         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 216                 DBG_FLT("binfmt_flat: unknown compression magic?\n");
 217                 goto out_free_buf;
 218         }
 219
 220         /* Check gzip method */
 221         if (buf[2] != 8) {
 222                 DBG_FLT("binfmt_flat: unknown compression method?\n");
 223                 goto out_free_buf;
 224         }
 225         /* Check gzip flags */
 226         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 227             (buf[3] & RESERVED)) {
 228                 DBG_FLT("binfmt_flat: unknown flags?\n");
 229                 goto out_free_buf;
 230         }
 231
 232         ret = 10;
 233         if (buf[3] & EXTRA_FIELD) {
 234                 ret += 2 + buf[10] + (buf[11] << 8);
 235                 if (unlikely(LBUFSIZE == ret)) {
 236                         DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
 237                         goto out_free_buf;
 238                 }
 239         }
 240         if (buf[3] & ORIG_NAME) {
 241                 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
 242                         ;
 243                 if (unlikely(LBUFSIZE == ret)) {
 244                         DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
 245                         goto out_free_buf;
 246                 }
 247         }
 248         if (buf[3] & COMMENT) {
 249                 for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
 250                         ;
 251                 if (unlikely(LBUFSIZE == ret)) {
 252                         DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
 253                         goto out_free_buf;
 254                 }
 255         }
 256
 257         strm.next_in += ret;
 258         strm.avail_in -= ret;
 259
 260         strm.next_out = dst;
 261         strm.avail_out = len;
 262         strm.total_out = 0;
 263
 264         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 265                 DBG_FLT("binfmt_flat: zlib init failed?\n");
 266                 goto out_free_buf;
 267         }
 268
 269         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 270                 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 271                 if (ret <= 0)
 272                         break;
 273                 if (ret >= (unsigned long) -4096)
 274                         break;
 275                 len -= ret;
 276
 277                 strm.next_in = buf;
 278                 strm.avail_in = ret;
 279                 strm.total_in = 0;
 280         }
 281
 282         if (ret < 0) {
 283                 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
 284                         ret, strm.msg);
 285                 goto out_zlib;
 286         }
 287
 288         retval = 0;
 289 out_zlib:
 290         zlib_inflateEnd(&strm);
 291 out_free_buf:
 292         kfree(buf);
 293 out_free:
 294         kfree(strm.workspace);
 295 out:
 296         return retval;
 297 }
 298
 299 #endif /* CONFIG_BINFMT_ZFLAT */
 300
 301 /****************************************************************************/
 302
 303 static unsigned long
 304 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 305 {
 306         unsigned long addr;
 307         int id;
 308         unsigned long start_brk;
 309         unsigned long start_data;
 310         unsigned long text_len;
 311         unsigned long start_code;
 312
 313 #ifdef CONFIG_BINFMT_SHARED_FLAT
 314         if (r == 0)
 315                 id = curid;     /* Relocs of 0 are always self referring */
 316         else {
 317                 id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 318                 r &= 0x00ffffff;        /* Trim ID off here */
 319         }
 320         if (id >= MAX_SHARED_LIBS) {
 321                 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
 322                                 (unsigned) r, id);
 323                 goto failed;
 324         }
 325         if (curid != id) {
 326                 if (internalp) {
 327                         printk("BINFMT_FLAT: reloc address 0x%x not in same module "
 328                                         "(%d != %d)", (unsigned) r, curid, id);
 329                         goto failed;
 330                 } else if ( ! p->lib_list[id].loaded &&
 331                                 load_flat_shared_library(id, p) > (unsigned long) -4096) {
 332                         printk("BINFMT_FLAT: failed to load library %d", id);
 333                         goto failed;
 334                 }
 335                 /* Check versioning information (i.e. time stamps) */
 336                 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 337                                 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 338                         printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
 339                         goto failed;
 340                 }
 341         }
 342 #else
 343         id = 0;
 344 #endif
 345
 346         start_brk = p->lib_list[id].start_brk;
 347         start_data = p->lib_list[id].start_data;
 348         start_code = p->lib_list[id].start_code;
 349         text_len = p->lib_list[id].text_len;
 350
 351         if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 352                 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
 353                        (int) r,(int)(start_brk-start_code),(int)text_len);
 354                 goto failed;
 355         }
 356
 357         if (r < text_len)                       /* In text segment */
 358                 addr = r + start_code;
 359         else                                    /* In data segment */
 360                 addr = r - text_len + start_data;
 361
 362         /* Range checked already above so doing the range tests is redundant...*/
 363         return(addr);
 364
 365 failed:
 366         printk(", killing %s!\n", current->comm);
 367         send_sig(SIGSEGV, current, 0);
 368
 369         return RELOC_FAILED;
 370 }
 371
 372 /****************************************************************************/
 373
 374 void old_reloc(unsigned long rl)
 375 {
 376 #ifdef DEBUG
 377         char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 378 #endif
 379         flat_v2_reloc_t r;
 380         unsigned long *ptr;
 381
 382         r.value = rl;
 383 #if defined(CONFIG_COLDFIRE)
 384         ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
 385 #else
 386         ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
 387 #endif
 388
 389 #ifdef DEBUG
 390         printk("Relocation of variable at DATASEG+%x "
 391                 "(address %p, currently %x) into segment %s\n",
 392                 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
 393 #endif
 394
 395         switch (r.reloc.type) {
 396         case OLD_FLAT_RELOC_TYPE_TEXT:
 397                 *ptr += current->mm->start_code;
 398                 break;
 399         case OLD_FLAT_RELOC_TYPE_DATA:
 400                 *ptr += current->mm->start_data;
 401                 break;
 402         case OLD_FLAT_RELOC_TYPE_BSS:
 403                 *ptr += current->mm->end_data;
 404                 break;
 405         default:
 406                 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
 407                 break;
 408         }
 409
 410 #ifdef DEBUG
 411         printk("Relocation became %x\n", (int)*ptr);
 412 #endif
 413 }
 414
 415 /****************************************************************************/
 416
 417 static int load_flat_file(struct linux_binprm * bprm,
 418                 struct lib_info *libinfo, int id, unsigned long *extra_stack)
 419 {
 420         struct flat_hdr * hdr;
 421         unsigned long textpos = 0, datapos = 0, result;
 422         unsigned long realdatastart = 0;
 423         unsigned long text_len, data_len, bss_len, stack_len, flags;
 424         unsigned long memp = 0; /* for finding the brk area */
 425         unsigned long extra, rlim;
 426         unsigned long *reloc = 0, *rp;
 427         struct inode *inode;
 428         int i, rev, relocs = 0;
 429         loff_t fpos;
 430         unsigned long start_code, end_code;
 431
 432         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 433         inode = bprm->file->f_dentry->d_inode;
 434
 435         text_len  = ntohl(hdr->data_start);
 436         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 437         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 438         stack_len = ntohl(hdr->stack_size);
 439         if (extra_stack) {
 440                 stack_len += *extra_stack;
 441                 *extra_stack = stack_len;
 442         }
 443         relocs    = ntohl(hdr->reloc_count);
 444         flags     = ntohl(hdr->flags);
 445         rev       = ntohl(hdr->rev);
 446
 447         if (flags & FLAT_FLAG_KTRACE)
 448                 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 449
 450         if (strncmp(hdr->magic, "bFLT", 4) ||
 451                         (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION)) {
 452                 /*
 453                  * because a lot of people do not manage to produce good
 454                  * flat binaries,  we leave this printk to help them realise
 455                  * the problem.  We only print the error if its not a script file
 456                  */
 457                 if (strncmp(hdr->magic, "#!", 2))
 458                         printk("BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",
 459                                         rev, (int) FLAT_VERSION);
 460                 return -ENOEXEC;
 461         }
 462
 463         /* Don't allow old format executables to use shared libraries */
 464         if (rev == OLD_FLAT_VERSION && id != 0) {
 465                 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
 466                                 (int) FLAT_VERSION);
 467                 return -ENOEXEC;
 468         }
 469
 470         /*
 471          * fix up the flags for the older format,  there were all kinds
 472          * of endian hacks,  this only works for the simple cases
 473          */
 474         if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 475                 flags = FLAT_FLAG_RAM;
 476
 477 #ifndef CONFIG_BINFMT_ZFLAT
 478         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 479                 printk("Support for ZFLAT executables is not enabled.\n");
 480                 return -ENOEXEC;
 481         }
 482 #endif
 483
 484         /*
 485          * Check initial limits. This avoids letting people circumvent
 486          * size limits imposed on them by creating programs with large
 487          * arrays in the data or bss.
 488          */
 489         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 490         if (rlim >= RLIM_INFINITY)
 491                 rlim = ~0;
 492         if (data_len + bss_len > rlim)
 493                 return -ENOMEM;
 494
 495         /* Flush all traces of the currently running executable */
 496         if (id == 0) {
 497                 result = flush_old_exec(bprm);
 498                 if (result)
 499                         return result;
 500
 501                 /* OK, This is the point of no return */
 502                 set_personality(PER_LINUX);
 503         }
 504
 505         /*
 506          * calculate the extra space we need to map in
 507          */
 508         extra = max(bss_len + stack_len, relocs * sizeof(unsigned long));
 509
 510         /*
 511          * there are a couple of cases here,  the separate code/data
 512          * case,  and then the fully copied to RAM case which lumps
 513          * it all together.
 514          */
 515         if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 516                 /*
 517                  * this should give us a ROM ptr,  but if it doesn't we don't
 518                  * really care
 519                  */
 520                 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 521
 522                 down_write(&current->mm->mmap_sem);
 523                 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, 0, 0);
 524                 up_write(&current->mm->mmap_sem);
 525                 if (!textpos  || textpos >= (unsigned long) -4096) {
 526                         if (!textpos)
 527                                 textpos = (unsigned long) -ENOMEM;
 528                         printk("Unable to mmap process text, errno %d\n", (int)-textpos);
 529                         return(textpos);
 530                 }
 531
 532                 down_write(&current->mm->mmap_sem);
 533                 realdatastart = do_mmap(0, 0, data_len + extra +
 534                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 535                                 PROT_READ|PROT_WRITE|PROT_EXEC, 0, 0);
 536                 up_write(&current->mm->mmap_sem);
 537
 538                 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
 539                         if (!realdatastart)
 540                                 realdatastart = (unsigned long) -ENOMEM;
 541                         printk("Unable to allocate RAM for process data, errno %d\n",
 542                                         (int)-datapos);
 543                         do_munmap(current->mm, textpos, text_len);
 544                         return realdatastart;
 545                 }
 546                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 547
 548                 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 549                                 (int)(data_len + bss_len + stack_len), (int)datapos);
 550
 551                 fpos = ntohl(hdr->data_start);
 552 #ifdef CONFIG_BINFMT_ZFLAT
 553                 if (flags & FLAT_FLAG_GZDATA) {
 554                         result = decompress_exec(bprm, fpos, (char *) datapos,
 555                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 556                 } else
 557 #endif
 558                 {
 559                         result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 560                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 561                 }
 562                 if (result >= (unsigned long)-4096) {
 563                         printk("Unable to read data+bss, errno %d\n", (int)-result);
 564                         do_munmap(current->mm, textpos, text_len);
 565                         do_munmap(current->mm, realdatastart, data_len + extra);
 566                         return result;
 567                 }
 568
 569                 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
 570                 memp = realdatastart;
 571
 572         } else {
 573
 574                 down_write(&current->mm->mmap_sem);
 575                 textpos = do_mmap(0, 0, text_len + data_len + extra +
 576                                         MAX_SHARED_LIBS * sizeof(unsigned long),
 577                                 PROT_READ | PROT_EXEC | PROT_WRITE, 0, 0);
 578                 up_write(&current->mm->mmap_sem);
 579                 if (!textpos  || textpos >= (unsigned long) -4096) {
 580                         if (!textpos)
 581                                 textpos = (unsigned long) -ENOMEM;
 582                         printk("Unable to allocate RAM for process text/data, errno %d\n",
 583                                         (int)-textpos);
 584                         return(textpos);
 585                 }
 586
 587                 realdatastart = textpos + ntohl(hdr->data_start);
 588                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 589                 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
 590                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 591                 memp = textpos;
 592
 593 #ifdef CONFIG_BINFMT_ZFLAT
 594                 /*
 595                  * load it all in and treat it like a RAM load from now on
 596                  */
 597                 if (flags & FLAT_FLAG_GZIP) {
 598                         result = decompress_exec(bprm, sizeof (struct flat_hdr),
 599                                          (((char *) textpos) + sizeof (struct flat_hdr)),
 600                                          (text_len + data_len + (relocs * sizeof(unsigned long))
 601                                                   - sizeof (struct flat_hdr)),
 602                                          0);
 603                         memmove((void *) datapos, (void *) realdatastart,
 604                                         data_len + (relocs * sizeof(unsigned long)));
 605                 } else if (flags & FLAT_FLAG_GZDATA) {
 606                         fpos = 0;
 607                         result = bprm->file->f_op->read(bprm->file,
 608                                         (char *) textpos, text_len, &fpos);
 609                         if (result < (unsigned long) -4096)
 610                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 611                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 612                 }
 613                 else
 614 #endif
 615                 {
 616                         fpos = 0;
 617                         result = bprm->file->f_op->read(bprm->file,
 618                                         (char *) textpos, text_len, &fpos);
 619                         if (result < (unsigned long) -4096) {
 620                                 fpos = ntohl(hdr->data_start);
 621                                 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 622                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 623                         }
 624                 }
 625                 if (result >= (unsigned long)-4096) {
 626                         printk("Unable to read code+data+bss, errno %d\n",(int)-result);
 627                         do_munmap(current->mm, textpos, text_len + data_len + extra +
 628                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 629                         return result;
 630                 }
 631         }
 632
 633         if (flags & FLAT_FLAG_KTRACE)
 634                 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
 635                         (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 636
 637         /* The main program needs a little extra setup in the task structure */
 638         start_code = textpos + sizeof (struct flat_hdr);
 639         end_code = textpos + text_len;
 640         if (id == 0) {
 641                 current->mm->start_code = start_code;
 642                 current->mm->end_code = end_code;
 643                 current->mm->start_data = datapos;
 644                 current->mm->end_data = datapos + data_len;
 645                 /*
 646                  * set up the brk stuff, uses any slack left in data/bss/stack
 647                  * allocation.  We put the brk after the bss (between the bss
 648                  * and stack) like other platforms.
 649                  */
 650                 current->mm->start_brk = datapos + data_len + bss_len;
 651                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 652                 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len;
 653                 set_mm_counter(current->mm, rss, 0);
 654         }
 655
 656         if (flags & FLAT_FLAG_KTRACE)
 657                 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 658                         id ? "Lib" : "Load", bprm->filename,
 659                         (int) start_code, (int) end_code,
 660                         (int) datapos,
 661                         (int) (datapos + data_len),
 662                         (int) (datapos + data_len),
 663                         (int) (((datapos + data_len + bss_len) + 3) & ~3));
 664
 665         text_len -= sizeof(struct flat_hdr); /* the real code len */
 666
 667         /* Store the current module values into the global library structure */
 668         libinfo->lib_list[id].start_code = start_code;
 669         libinfo->lib_list[id].start_data = datapos;
 670         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 671         libinfo->lib_list[id].text_len = text_len;
 672         libinfo->lib_list[id].loaded = 1;
 673         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 674         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 675
 676         /*
 677          * We just load the allocations into some temporary memory to
 678          * help simplify all this mumbo jumbo
 679          *
 680          * We've got two different sections of relocation entries.
 681          * The first is the GOT which resides at the begining of the data segment
 682          * and is terminated with a -1.  This one can be relocated in place.
 683          * The second is the extra relocation entries tacked after the image's
 684          * data segment. These require a little more processing as the entry is
 685          * really an offset into the image which contains an offset into the
 686          * image.
 687          */
 688         if (flags & FLAT_FLAG_GOTPIC) {
 689                 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
 690                         unsigned long addr;
 691                         if (*rp) {
 692                                 addr = calc_reloc(*rp, libinfo, id, 0);
 693                                 if (addr == RELOC_FAILED)
 694                                         return -ENOEXEC;
 695                                 *rp = addr;
 696                         }
 697                 }
 698         }
 699
 700         /*
 701          * Now run through the relocation entries.
 702          * We've got to be careful here as C++ produces relocatable zero
 703          * entries in the constructor and destructor tables which are then
 704          * tested for being not zero (which will always occur unless we're
 705          * based from address zero).  This causes an endless loop as __start
 706          * is at zero.  The solution used is to not relocate zero addresses.
 707          * This has the negative side effect of not allowing a global data
 708          * reference to be statically initialised to _stext (I've moved
 709          * __start to address 4 so that is okay).
 710          */
 711         if (rev > OLD_FLAT_VERSION) {
 712                 for (i=0; i < relocs; i++) {
 713                         unsigned long addr, relval;
 714
 715                         /* Get the address of the pointer to be
 716                            relocated (of course, the address has to be
 717                            relocated first).  */
 718                         relval = ntohl(reloc[i]);
 719                         addr = flat_get_relocate_addr(relval);
 720                         rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
 721                         if (rp == (unsigned long *)RELOC_FAILED)
 722                                 return -ENOEXEC;
 723
 724                         /* Get the pointer's value.  */
 725                         addr = flat_get_addr_from_rp(rp, relval, flags);
 726                         if (addr != 0) {
 727                                 /*
 728                                  * Do the relocation.  PIC relocs in the data section are
 729                                  * already in target order
 730                                  */
 731                                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 732                                         addr = ntohl(addr);
 733                                 addr = calc_reloc(addr, libinfo, id, 0);
 734                                 if (addr == RELOC_FAILED)
 735                                         return -ENOEXEC;
 736
 737                                 /* Write back the relocated pointer.  */
 738                                 flat_put_addr_at_rp(rp, addr, relval);
 739                         }
 740                 }
 741         } else {
 742                 for (i=0; i < relocs; i++)
 743                         old_reloc(ntohl(reloc[i]));
 744         }
 745
 746         flush_icache_range(start_code, end_code);
 747
 748         /* zero the BSS,  BRK and stack areas */
 749         memset((void*)(datapos + data_len), 0, bss_len +
 750                         (memp + ksize((void *) memp) - stack_len -      /* end brk */
 751                         libinfo->lib_list[id].start_brk) +              /* start brk */
 752                         stack_len);
 753
 754         return 0;
 755 }
 756
 757
 758 /****************************************************************************/
 759 #ifdef CONFIG_BINFMT_SHARED_FLAT
 760
 761 /*
 762  * Load a shared library into memory.  The library gets its own data
 763  * segment (including bss) but not argv/argc/environ.
 764  */
 765
 766 static int load_flat_shared_library(int id, struct lib_info *libs)
 767 {
 768         struct linux_binprm bprm;
 769         int res;
 770         char buf[16];
 771
 772         /* Create the file name */
 773         sprintf(buf, "/lib/lib%d.so", id);
 774
 775         /* Open the file up */
 776         bprm.filename = buf;
 777         bprm.file = open_exec(bprm.filename);
 778         res = PTR_ERR(bprm.file);
 779         if (IS_ERR(bprm.file))
 780                 return res;
 781
 782         res = prepare_binprm(&bprm);
 783
 784         if (res <= (unsigned long)-4096)
 785                 res = load_flat_file(&bprm, libs, id, NULL);
 786         if (bprm.file) {
 787                 allow_write_access(bprm.file);
 788                 fput(bprm.file);
 789                 bprm.file = NULL;
 790         }
 791         return(res);
 792 }
 793
 794 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 795 /****************************************************************************/
 796
 797 /*
 798  * These are the functions used to load flat style executables and shared
 799  * libraries.  There is no binary dependent code anywhere else.
 800  */
 801
 802 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 803 {
 804         struct lib_info libinfo;
 805         unsigned long p = bprm->p;
 806         unsigned long stack_len;
 807         unsigned long start_addr;
 808         unsigned long *sp;
 809         int res;
 810         int i, j;
 811
 812         memset(&libinfo, 0, sizeof(libinfo));
 813         /*
 814          * We have to add the size of our arguments to our stack size
 815          * otherwise it's too easy for users to create stack overflows
 816          * by passing in a huge argument list.  And yes,  we have to be
 817          * pedantic and include space for the argv/envp array as it may have
 818          * a lot of entries.
 819          */
 820 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
 821         stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
 822         stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
 823         stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
 824
 825
 826         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 827         if (res > (unsigned long)-4096)
 828                 return res;
 829
 830         /* Update data segment pointers for all libraries */
 831         for (i=0; i<MAX_SHARED_LIBS; i++)
 832                 if (libinfo.lib_list[i].loaded)
 833                         for (j=0; j<MAX_SHARED_LIBS; j++)
 834                                 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
 835                                         (libinfo.lib_list[j].loaded)?
 836                                                 libinfo.lib_list[j].start_data:UNLOADED_LIB;
 837
 838         compute_creds(bprm);
 839         current->flags &= ~PF_FORKNOEXEC;
 840
 841         set_binfmt(&flat_format);
 842
 843         p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 844         DBG_FLT("p=%x\n", (int)p);
 845
 846         /* copy the arg pages onto the stack, this could be more efficient :-) */
 847         for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
 848                 * (char *) --p =
 849                         ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
 850
 851         sp = (unsigned long *) create_flat_tables(p, bprm);
 852
 853         /* Fake some return addresses to ensure the call chain will
 854          * initialise library in order for us.  We are required to call
 855          * lib 1 first, then 2, ... and finally the main program (id 0).
 856          */
 857         start_addr = libinfo.lib_list[0].entry;
 858
 859 #ifdef CONFIG_BINFMT_SHARED_FLAT
 860         for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 861                 if (libinfo.lib_list[i].loaded) {
 862                         /* Push previos first to call address */
 863                         --sp;   put_user(start_addr, sp);
 864                         start_addr = libinfo.lib_list[i].entry;
 865                 }
 866         }
 867 #endif
 868
 869         /* Stash our initial stack pointer into the mm structure */
 870         current->mm->start_stack = (unsigned long )sp;
 871
 872
 873         DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
 874                 (int)regs, (int)start_addr, (int)current->mm->start_stack);
 875
 876         start_thread(regs, start_addr, current->mm->start_stack);
 877
 878         if (current->ptrace & PT_PTRACED)
 879                 send_sig(SIGTRAP, current, 0);
 880
 881         return 0;
 882 }
 883
 884 /****************************************************************************/
 885
 886 static int __init init_flat_binfmt(void)
 887 {
 888         return register_binfmt(&flat_format);
 889 }
 890
 891 static void __exit exit_flat_binfmt(void)
 892 {
 893         unregister_binfmt(&flat_format);
 894 }
 895
 896 /****************************************************************************/
 897
 898 core_initcall(init_flat_binfmt);
 899 module_exit(exit_flat_binfmt);
 900
 901 /****************************************************************************/