fs/binfmt_flat.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /****************************************************************************/
   3 /*
   4  *  linux/fs/binfmt_flat.c
   5  *
   6  *      Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
   7  *      Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
   8  *      Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
   9  *      Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
  10  *  based heavily on:
  11  *
  12  *  linux/fs/binfmt_aout.c:
  13  *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
  14  *  linux/fs/binfmt_flat.c for 2.0 kernel
  15  *          Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
  16  *      JAN/99 -- coded full program relocation (gerg@snapgear.com)
  17  */
  18
  19 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/kernel.h>
  22 #include <linux/sched.h>
  23 #include <linux/sched/task_stack.h>
  24 #include <linux/mm.h>
  25 #include <linux/mman.h>
  26 #include <linux/errno.h>
  27 #include <linux/signal.h>
  28 #include <linux/string.h>
  29 #include <linux/fs.h>
  30 #include <linux/file.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/user.h>
  33 #include <linux/slab.h>
  34 #include <linux/binfmts.h>
  35 #include <linux/personality.h>
  36 #include <linux/init.h>
  37 #include <linux/flat.h>
  38 #include <linux/uaccess.h>
  39 #include <linux/vmalloc.h>
  40
  41 #include <asm/byteorder.h>
  42 #include <asm/unaligned.h>
  43 #include <asm/cacheflush.h>
  44 #include <asm/page.h>
  45 #include <asm/flat.h>
  46
  47 #ifndef flat_get_relocate_addr
  48 #define flat_get_relocate_addr(rel)     (rel)
  49 #endif
  50
  51 /****************************************************************************/
  52
  53 /*
  54  * User data (data section and bss) needs to be aligned.
  55  * We pick 0x20 here because it is the max value elf2flt has always
  56  * used in producing FLAT files, and because it seems to be large
  57  * enough to make all the gcc alignment related tests happy.
  58  */
  59 #define FLAT_DATA_ALIGN (0x20)
  60
  61 /*
  62  * User data (stack) also needs to be aligned.
  63  * Here we can be a bit looser than the data sections since this
  64  * needs to only meet arch ABI requirements.
  65  */
  66 #define FLAT_STACK_ALIGN        max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
  67
  68 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  69 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  70
  71 #ifdef CONFIG_BINFMT_SHARED_FLAT
  72 #define MAX_SHARED_LIBS                 (4)
  73 #else
  74 #define MAX_SHARED_LIBS                 (1)
  75 #endif
  76
  77 struct lib_info {
  78         struct {
  79                 unsigned long start_code;               /* Start of text segment */
  80                 unsigned long start_data;               /* Start of data segment */
  81                 unsigned long start_brk;                /* End of data segment */
  82                 unsigned long text_len;                 /* Length of text segment */
  83                 unsigned long entry;                    /* Start address for this module */
  84                 unsigned long build_date;               /* When this one was compiled */
  85                 bool loaded;                            /* Has this library been loaded? */
  86         } lib_list[MAX_SHARED_LIBS];
  87 };
  88
  89 #ifdef CONFIG_BINFMT_SHARED_FLAT
  90 static int load_flat_shared_library(int id, struct lib_info *p);
  91 #endif
  92
  93 static int load_flat_binary(struct linux_binprm *);
  94 static int flat_core_dump(struct coredump_params *cprm);
  95
  96 static struct linux_binfmt flat_format = {
  97         .module         = THIS_MODULE,
  98         .load_binary    = load_flat_binary,
  99         .core_dump      = flat_core_dump,
 100         .min_coredump   = PAGE_SIZE
 101 };
 102
 103 /****************************************************************************/
 104 /*
 105  * Routine writes a core dump image in the current directory.
 106  * Currently only a stub-function.
 107  */
 108
 109 static int flat_core_dump(struct coredump_params *cprm)
 110 {
 111         pr_warn("Process %s:%d received signr %d and should have core dumped\n",
 112                 current->comm, current->pid, cprm->siginfo->si_signo);
 113         return 1;
 114 }
 115
 116 /****************************************************************************/
 117 /*
 118  * create_flat_tables() parses the env- and arg-strings in new user
 119  * memory and creates the pointer tables from them, and puts their
 120  * addresses on the "stack", recording the new stack pointer value.
 121  */
 122
 123 static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
 124 {
 125         char __user *p;
 126         unsigned long __user *sp;
 127         long i, len;
 128
 129         p = (char __user *)arg_start;
 130         sp = (unsigned long __user *)current->mm->start_stack;
 131
 132         sp -= bprm->envc + 1;
 133         sp -= bprm->argc + 1;
 134         if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
 135                 sp -= 2; /* argvp + envp */
 136         sp -= 1;  /* &argc */
 137
 138         current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
 139         sp = (unsigned long __user *)current->mm->start_stack;
 140
 141         __put_user(bprm->argc, sp++);
 142         if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
 143                 unsigned long argv, envp;
 144                 argv = (unsigned long)(sp + 2);
 145                 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
 146                 __put_user(argv, sp++);
 147                 __put_user(envp, sp++);
 148         }
 149
 150         current->mm->arg_start = (unsigned long)p;
 151         for (i = bprm->argc; i > 0; i--) {
 152                 __put_user((unsigned long)p, sp++);
 153                 len = strnlen_user(p, MAX_ARG_STRLEN);
 154                 if (!len || len > MAX_ARG_STRLEN)
 155                         return -EINVAL;
 156                 p += len;
 157         }
 158         __put_user(0, sp++);
 159         current->mm->arg_end = (unsigned long)p;
 160
 161         current->mm->env_start = (unsigned long) p;
 162         for (i = bprm->envc; i > 0; i--) {
 163                 __put_user((unsigned long)p, sp++);
 164                 len = strnlen_user(p, MAX_ARG_STRLEN);
 165                 if (!len || len > MAX_ARG_STRLEN)
 166                         return -EINVAL;
 167                 p += len;
 168         }
 169         __put_user(0, sp++);
 170         current->mm->env_end = (unsigned long)p;
 171
 172         return 0;
 173 }
 174
 175 /****************************************************************************/
 176
 177 #ifdef CONFIG_BINFMT_ZFLAT
 178
 179 #include <linux/zlib.h>
 180
 181 #define LBUFSIZE        4000
 182
 183 /* gzip flag byte */
 184 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 185 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 186 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 187 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 188 #define COMMENT      0x10 /* bit 4 set: file comment present */
 189 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 190 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 191
 192 static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
 193                 long len, int fd)
 194 {
 195         unsigned char *buf;
 196         z_stream strm;
 197         int ret, retval;
 198
 199         pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
 200
 201         memset(&strm, 0, sizeof(strm));
 202         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 203         if (!strm.workspace)
 204                 return -ENOMEM;
 205
 206         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 207         if (!buf) {
 208                 retval = -ENOMEM;
 209                 goto out_free;
 210         }
 211
 212         /* Read in first chunk of data and parse gzip header. */
 213         ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
 214
 215         strm.next_in = buf;
 216         strm.avail_in = ret;
 217         strm.total_in = 0;
 218
 219         retval = -ENOEXEC;
 220
 221         /* Check minimum size -- gzip header */
 222         if (ret < 10) {
 223                 pr_debug("file too small?\n");
 224                 goto out_free_buf;
 225         }
 226
 227         /* Check gzip magic number */
 228         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 229                 pr_debug("unknown compression magic?\n");
 230                 goto out_free_buf;
 231         }
 232
 233         /* Check gzip method */
 234         if (buf[2] != 8) {
 235                 pr_debug("unknown compression method?\n");
 236                 goto out_free_buf;
 237         }
 238         /* Check gzip flags */
 239         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 240             (buf[3] & RESERVED)) {
 241                 pr_debug("unknown flags?\n");
 242                 goto out_free_buf;
 243         }
 244
 245         ret = 10;
 246         if (buf[3] & EXTRA_FIELD) {
 247                 ret += 2 + buf[10] + (buf[11] << 8);
 248                 if (unlikely(ret >= LBUFSIZE)) {
 249                         pr_debug("buffer overflow (EXTRA)?\n");
 250                         goto out_free_buf;
 251                 }
 252         }
 253         if (buf[3] & ORIG_NAME) {
 254                 while (ret < LBUFSIZE && buf[ret++] != 0)
 255                         ;
 256                 if (unlikely(ret == LBUFSIZE)) {
 257                         pr_debug("buffer overflow (ORIG_NAME)?\n");
 258                         goto out_free_buf;
 259                 }
 260         }
 261         if (buf[3] & COMMENT) {
 262                 while (ret < LBUFSIZE && buf[ret++] != 0)
 263                         ;
 264                 if (unlikely(ret == LBUFSIZE)) {
 265                         pr_debug("buffer overflow (COMMENT)?\n");
 266                         goto out_free_buf;
 267                 }
 268         }
 269
 270         strm.next_in += ret;
 271         strm.avail_in -= ret;
 272
 273         strm.next_out = dst;
 274         strm.avail_out = len;
 275         strm.total_out = 0;
 276
 277         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 278                 pr_debug("zlib init failed?\n");
 279                 goto out_free_buf;
 280         }
 281
 282         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 283                 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
 284                 if (ret <= 0)
 285                         break;
 286                 len -= ret;
 287
 288                 strm.next_in = buf;
 289                 strm.avail_in = ret;
 290                 strm.total_in = 0;
 291         }
 292
 293         if (ret < 0) {
 294                 pr_debug("decompression failed (%d), %s\n",
 295                         ret, strm.msg);
 296                 goto out_zlib;
 297         }
 298
 299         retval = 0;
 300 out_zlib:
 301         zlib_inflateEnd(&strm);
 302 out_free_buf:
 303         kfree(buf);
 304 out_free:
 305         kfree(strm.workspace);
 306         return retval;
 307 }
 308
 309 #endif /* CONFIG_BINFMT_ZFLAT */
 310
 311 /****************************************************************************/
 312
 313 static unsigned long
 314 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 315 {
 316         unsigned long addr;
 317         int id;
 318         unsigned long start_brk;
 319         unsigned long start_data;
 320         unsigned long text_len;
 321         unsigned long start_code;
 322
 323 #ifdef CONFIG_BINFMT_SHARED_FLAT
 324         if (r == 0)
 325                 id = curid;     /* Relocs of 0 are always self referring */
 326         else {
 327                 id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 328                 r &= 0x00ffffff;        /* Trim ID off here */
 329         }
 330         if (id >= MAX_SHARED_LIBS) {
 331                 pr_err("reference 0x%lx to shared library %d", r, id);
 332                 goto failed;
 333         }
 334         if (curid != id) {
 335                 if (internalp) {
 336                         pr_err("reloc address 0x%lx not in same module "
 337                                "(%d != %d)", r, curid, id);
 338                         goto failed;
 339                 } else if (!p->lib_list[id].loaded &&
 340                            load_flat_shared_library(id, p) < 0) {
 341                         pr_err("failed to load library %d", id);
 342                         goto failed;
 343                 }
 344                 /* Check versioning information (i.e. time stamps) */
 345                 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 346                                 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 347                         pr_err("library %d is younger than %d", id, curid);
 348                         goto failed;
 349                 }
 350         }
 351 #else
 352         id = 0;
 353 #endif
 354
 355         start_brk = p->lib_list[id].start_brk;
 356         start_data = p->lib_list[id].start_data;
 357         start_code = p->lib_list[id].start_code;
 358         text_len = p->lib_list[id].text_len;
 359
 360         if (r > start_brk - start_data + text_len) {
 361                 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
 362                        r, start_brk-start_data+text_len, text_len);
 363                 goto failed;
 364         }
 365
 366         if (r < text_len)                       /* In text segment */
 367                 addr = r + start_code;
 368         else                                    /* In data segment */
 369                 addr = r - text_len + start_data;
 370
 371         /* Range checked already above so doing the range tests is redundant...*/
 372         return addr;
 373
 374 failed:
 375         pr_cont(", killing %s!\n", current->comm);
 376         send_sig(SIGSEGV, current, 0);
 377
 378         return RELOC_FAILED;
 379 }
 380
 381 /****************************************************************************/
 382
 383 #ifdef CONFIG_BINFMT_FLAT_OLD
 384 static void old_reloc(unsigned long rl)
 385 {
 386         static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 387         flat_v2_reloc_t r;
 388         unsigned long __user *ptr;
 389         unsigned long val;
 390
 391         r.value = rl;
 392 #if defined(CONFIG_COLDFIRE)
 393         ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
 394 #else
 395         ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
 396 #endif
 397         get_user(val, ptr);
 398
 399         pr_debug("Relocation of variable at DATASEG+%x "
 400                  "(address %p, currently %lx) into segment %s\n",
 401                  r.reloc.offset, ptr, val, segment[r.reloc.type]);
 402
 403         switch (r.reloc.type) {
 404         case OLD_FLAT_RELOC_TYPE_TEXT:
 405                 val += current->mm->start_code;
 406                 break;
 407         case OLD_FLAT_RELOC_TYPE_DATA:
 408                 val += current->mm->start_data;
 409                 break;
 410         case OLD_FLAT_RELOC_TYPE_BSS:
 411                 val += current->mm->end_data;
 412                 break;
 413         default:
 414                 pr_err("Unknown relocation type=%x\n", r.reloc.type);
 415                 break;
 416         }
 417         put_user(val, ptr);
 418
 419         pr_debug("Relocation became %lx\n", val);
 420 }
 421 #endif /* CONFIG_BINFMT_FLAT_OLD */
 422
 423 /****************************************************************************/
 424
 425 static int load_flat_file(struct linux_binprm *bprm,
 426                 struct lib_info *libinfo, int id, unsigned long *extra_stack)
 427 {
 428         struct flat_hdr *hdr;
 429         unsigned long textpos, datapos, realdatastart;
 430         u32 text_len, data_len, bss_len, stack_len, full_data, flags;
 431         unsigned long len, memp, memp_size, extra, rlim;
 432         __be32 __user *reloc;
 433         u32 __user *rp;
 434         int i, rev, relocs;
 435         loff_t fpos;
 436         unsigned long start_code, end_code;
 437         ssize_t result;
 438         int ret;
 439
 440         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 441
 442         text_len  = ntohl(hdr->data_start);
 443         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 444         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 445         stack_len = ntohl(hdr->stack_size);
 446         if (extra_stack) {
 447                 stack_len += *extra_stack;
 448                 *extra_stack = stack_len;
 449         }
 450         relocs    = ntohl(hdr->reloc_count);
 451         flags     = ntohl(hdr->flags);
 452         rev       = ntohl(hdr->rev);
 453         full_data = data_len + relocs * sizeof(unsigned long);
 454
 455         if (strncmp(hdr->magic, "bFLT", 4)) {
 456                 /*
 457                  * Previously, here was a printk to tell people
 458                  *   "BINFMT_FLAT: bad header magic".
 459                  * But for the kernel which also use ELF FD-PIC format, this
 460                  * error message is confusing.
 461                  * because a lot of people do not manage to produce good
 462                  */
 463                 ret = -ENOEXEC;
 464                 goto err;
 465         }
 466
 467         if (flags & FLAT_FLAG_KTRACE)
 468                 pr_info("Loading file: %s\n", bprm->filename);
 469
 470 #ifdef CONFIG_BINFMT_FLAT_OLD
 471         if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 472                 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
 473                        rev, FLAT_VERSION, OLD_FLAT_VERSION);
 474                 ret = -ENOEXEC;
 475                 goto err;
 476         }
 477
 478         /* Don't allow old format executables to use shared libraries */
 479         if (rev == OLD_FLAT_VERSION && id != 0) {
 480                 pr_err("shared libraries are not available before rev 0x%lx\n",
 481                        FLAT_VERSION);
 482                 ret = -ENOEXEC;
 483                 goto err;
 484         }
 485
 486         /*
 487          * fix up the flags for the older format,  there were all kinds
 488          * of endian hacks,  this only works for the simple cases
 489          */
 490         if (rev == OLD_FLAT_VERSION &&
 491            (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
 492                 flags = FLAT_FLAG_RAM;
 493
 494 #else /* CONFIG_BINFMT_FLAT_OLD */
 495         if (rev != FLAT_VERSION) {
 496                 pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
 497                        rev, FLAT_VERSION);
 498                 ret = -ENOEXEC;
 499                 goto err;
 500         }
 501 #endif /* !CONFIG_BINFMT_FLAT_OLD */
 502
 503         /*
 504          * Make sure the header params are sane.
 505          * 28 bits (256 MB) is way more than reasonable in this case.
 506          * If some top bits are set we have probable binary corruption.
 507         */
 508         if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
 509                 pr_err("bad header\n");
 510                 ret = -ENOEXEC;
 511                 goto err;
 512         }
 513
 514 #ifndef CONFIG_BINFMT_ZFLAT
 515         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 516                 pr_err("Support for ZFLAT executables is not enabled.\n");
 517                 ret = -ENOEXEC;
 518                 goto err;
 519         }
 520 #endif
 521
 522         /*
 523          * Check initial limits. This avoids letting people circumvent
 524          * size limits imposed on them by creating programs with large
 525          * arrays in the data or bss.
 526          */
 527         rlim = rlimit(RLIMIT_DATA);
 528         if (rlim >= RLIM_INFINITY)
 529                 rlim = ~0;
 530         if (data_len + bss_len > rlim) {
 531                 ret = -ENOMEM;
 532                 goto err;
 533         }
 534
 535         /* Flush all traces of the currently running executable */
 536         if (id == 0) {
 537                 ret = flush_old_exec(bprm);
 538                 if (ret)
 539                         goto err;
 540
 541                 /* OK, This is the point of no return */
 542                 set_personality(PER_LINUX_32BIT);
 543                 setup_new_exec(bprm);
 544         }
 545
 546         /*
 547          * calculate the extra space we need to map in
 548          */
 549         extra = max_t(unsigned long, bss_len + stack_len,
 550                         relocs * sizeof(unsigned long));
 551
 552         /*
 553          * there are a couple of cases here,  the separate code/data
 554          * case,  and then the fully copied to RAM case which lumps
 555          * it all together.
 556          */
 557         if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
 558                 /*
 559                  * this should give us a ROM ptr,  but if it doesn't we don't
 560                  * really care
 561                  */
 562                 pr_debug("ROM mapping of file (we hope)\n");
 563
 564                 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
 565                                   MAP_PRIVATE|MAP_EXECUTABLE, 0);
 566                 if (!textpos || IS_ERR_VALUE(textpos)) {
 567                         ret = textpos;
 568                         if (!textpos)
 569                                 ret = -ENOMEM;
 570                         pr_err("Unable to mmap process text, errno %d\n", ret);
 571                         goto err;
 572                 }
 573
 574                 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 575                 len = PAGE_ALIGN(len);
 576                 realdatastart = vm_mmap(NULL, 0, len,
 577                         PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 578
 579                 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
 580                         ret = realdatastart;
 581                         if (!realdatastart)
 582                                 ret = -ENOMEM;
 583                         pr_err("Unable to allocate RAM for process data, "
 584                                "errno %d\n", ret);
 585                         vm_munmap(textpos, text_len);
 586                         goto err;
 587                 }
 588                 datapos = ALIGN(realdatastart +
 589                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 590                                 FLAT_DATA_ALIGN);
 591
 592                 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
 593                          data_len + bss_len + stack_len, datapos);
 594
 595                 fpos = ntohl(hdr->data_start);
 596 #ifdef CONFIG_BINFMT_ZFLAT
 597                 if (flags & FLAT_FLAG_GZDATA) {
 598                         result = decompress_exec(bprm, fpos, (char *)datapos,
 599                                                  full_data, 0);
 600                 } else
 601 #endif
 602                 {
 603                         result = read_code(bprm->file, datapos, fpos,
 604                                         full_data);
 605                 }
 606                 if (IS_ERR_VALUE(result)) {
 607                         ret = result;
 608                         pr_err("Unable to read data+bss, errno %d\n", ret);
 609                         vm_munmap(textpos, text_len);
 610                         vm_munmap(realdatastart, len);
 611                         goto err;
 612                 }
 613
 614                 reloc = (__be32 __user *)
 615                         (datapos + (ntohl(hdr->reloc_start) - text_len));
 616                 memp = realdatastart;
 617                 memp_size = len;
 618         } else {
 619
 620                 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
 621                 len = PAGE_ALIGN(len);
 622                 textpos = vm_mmap(NULL, 0, len,
 623                         PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 624
 625                 if (!textpos || IS_ERR_VALUE(textpos)) {
 626                         ret = textpos;
 627                         if (!textpos)
 628                                 ret = -ENOMEM;
 629                         pr_err("Unable to allocate RAM for process text/data, "
 630                                "errno %d\n", ret);
 631                         goto err;
 632                 }
 633
 634                 realdatastart = textpos + ntohl(hdr->data_start);
 635                 datapos = ALIGN(realdatastart +
 636                                 MAX_SHARED_LIBS * sizeof(u32),
 637                                 FLAT_DATA_ALIGN);
 638
 639                 reloc = (__be32 __user *)
 640                         (datapos + (ntohl(hdr->reloc_start) - text_len));
 641                 memp = textpos;
 642                 memp_size = len;
 643 #ifdef CONFIG_BINFMT_ZFLAT
 644                 /*
 645                  * load it all in and treat it like a RAM load from now on
 646                  */
 647                 if (flags & FLAT_FLAG_GZIP) {
 648 #ifndef CONFIG_MMU
 649                         result = decompress_exec(bprm, sizeof(struct flat_hdr),
 650                                          (((char *)textpos) + sizeof(struct flat_hdr)),
 651                                          (text_len + full_data
 652                                                   - sizeof(struct flat_hdr)),
 653                                          0);
 654                         memmove((void *) datapos, (void *) realdatastart,
 655                                         full_data);
 656 #else
 657                         /*
 658                          * This is used on MMU systems mainly for testing.
 659                          * Let's use a kernel buffer to simplify things.
 660                          */
 661                         long unz_text_len = text_len - sizeof(struct flat_hdr);
 662                         long unz_len = unz_text_len + full_data;
 663                         char *unz_data = vmalloc(unz_len);
 664                         if (!unz_data) {
 665                                 result = -ENOMEM;
 666                         } else {
 667                                 result = decompress_exec(bprm, sizeof(struct flat_hdr),
 668                                                          unz_data, unz_len, 0);
 669                                 if (result == 0 &&
 670                                     (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
 671                                                   unz_data, unz_text_len) ||
 672                                      copy_to_user((void __user *)datapos,
 673                                                   unz_data + unz_text_len, full_data)))
 674                                         result = -EFAULT;
 675                                 vfree(unz_data);
 676                         }
 677 #endif
 678                 } else if (flags & FLAT_FLAG_GZDATA) {
 679                         result = read_code(bprm->file, textpos, 0, text_len);
 680                         if (!IS_ERR_VALUE(result)) {
 681 #ifndef CONFIG_MMU
 682                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 683                                                  full_data, 0);
 684 #else
 685                                 char *unz_data = vmalloc(full_data);
 686                                 if (!unz_data) {
 687                                         result = -ENOMEM;
 688                                 } else {
 689                                         result = decompress_exec(bprm, text_len,
 690                                                        unz_data, full_data, 0);
 691                                         if (result == 0 &&
 692                                             copy_to_user((void __user *)datapos,
 693                                                          unz_data, full_data))
 694                                                 result = -EFAULT;
 695                                         vfree(unz_data);
 696                                 }
 697 #endif
 698                         }
 699                 } else
 700 #endif /* CONFIG_BINFMT_ZFLAT */
 701                 {
 702                         result = read_code(bprm->file, textpos, 0, text_len);
 703                         if (!IS_ERR_VALUE(result))
 704                                 result = read_code(bprm->file, datapos,
 705                                                    ntohl(hdr->data_start),
 706                                                    full_data);
 707                 }
 708                 if (IS_ERR_VALUE(result)) {
 709                         ret = result;
 710                         pr_err("Unable to read code+data+bss, errno %d\n", ret);
 711                         vm_munmap(textpos, text_len + data_len + extra +
 712                                 MAX_SHARED_LIBS * sizeof(u32));
 713                         goto err;
 714                 }
 715         }
 716
 717         start_code = textpos + sizeof(struct flat_hdr);
 718         end_code = textpos + text_len;
 719         text_len -= sizeof(struct flat_hdr); /* the real code len */
 720
 721         /* The main program needs a little extra setup in the task structure */
 722         if (id == 0) {
 723                 current->mm->start_code = start_code;
 724                 current->mm->end_code = end_code;
 725                 current->mm->start_data = datapos;
 726                 current->mm->end_data = datapos + data_len;
 727                 /*
 728                  * set up the brk stuff, uses any slack left in data/bss/stack
 729                  * allocation.  We put the brk after the bss (between the bss
 730                  * and stack) like other platforms.
 731                  * Userspace code relies on the stack pointer starting out at
 732                  * an address right at the end of a page.
 733                  */
 734                 current->mm->start_brk = datapos + data_len + bss_len;
 735                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 736 #ifndef CONFIG_MMU
 737                 current->mm->context.end_brk = memp + memp_size - stack_len;
 738 #endif
 739         }
 740
 741         if (flags & FLAT_FLAG_KTRACE) {
 742                 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
 743                         textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 744                 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
 745                         id ? "Lib" : "Load", bprm->filename,
 746                         start_code, end_code, datapos, datapos + data_len,
 747                         datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
 748         }
 749
 750         /* Store the current module values into the global library structure */
 751         libinfo->lib_list[id].start_code = start_code;
 752         libinfo->lib_list[id].start_data = datapos;
 753         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 754         libinfo->lib_list[id].text_len = text_len;
 755         libinfo->lib_list[id].loaded = 1;
 756         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 757         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 758
 759         /*
 760          * We just load the allocations into some temporary memory to
 761          * help simplify all this mumbo jumbo
 762          *
 763          * We've got two different sections of relocation entries.
 764          * The first is the GOT which resides at the beginning of the data segment
 765          * and is terminated with a -1.  This one can be relocated in place.
 766          * The second is the extra relocation entries tacked after the image's
 767          * data segment. These require a little more processing as the entry is
 768          * really an offset into the image which contains an offset into the
 769          * image.
 770          */
 771         if (flags & FLAT_FLAG_GOTPIC) {
 772                 for (rp = (u32 __user *)datapos; ; rp++) {
 773                         u32 addr, rp_val;
 774                         if (get_user(rp_val, rp))
 775                                 return -EFAULT;
 776                         if (rp_val == 0xffffffff)
 777                                 break;
 778                         if (rp_val) {
 779                                 addr = calc_reloc(rp_val, libinfo, id, 0);
 780                                 if (addr == RELOC_FAILED) {
 781                                         ret = -ENOEXEC;
 782                                         goto err;
 783                                 }
 784                                 if (put_user(addr, rp))
 785                                         return -EFAULT;
 786                         }
 787                 }
 788         }
 789
 790         /*
 791          * Now run through the relocation entries.
 792          * We've got to be careful here as C++ produces relocatable zero
 793          * entries in the constructor and destructor tables which are then
 794          * tested for being not zero (which will always occur unless we're
 795          * based from address zero).  This causes an endless loop as __start
 796          * is at zero.  The solution used is to not relocate zero addresses.
 797          * This has the negative side effect of not allowing a global data
 798          * reference to be statically initialised to _stext (I've moved
 799          * __start to address 4 so that is okay).
 800          */
 801         if (rev > OLD_FLAT_VERSION) {
 802                 for (i = 0; i < relocs; i++) {
 803                         u32 addr, relval;
 804                         __be32 tmp;
 805
 806                         /*
 807                          * Get the address of the pointer to be
 808                          * relocated (of course, the address has to be
 809                          * relocated first).
 810                          */
 811                         if (get_user(tmp, reloc + i))
 812                                 return -EFAULT;
 813                         relval = ntohl(tmp);
 814                         addr = flat_get_relocate_addr(relval);
 815                         rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
 816                         if (rp == (u32 __user *)RELOC_FAILED) {
 817                                 ret = -ENOEXEC;
 818                                 goto err;
 819                         }
 820
 821                         /* Get the pointer's value.  */
 822                         ret = flat_get_addr_from_rp(rp, relval, flags, &addr);
 823                         if (unlikely(ret))
 824                                 goto err;
 825
 826                         if (addr != 0) {
 827                                 /*
 828                                  * Do the relocation.  PIC relocs in the data section are
 829                                  * already in target order
 830                                  */
 831                                 if ((flags & FLAT_FLAG_GOTPIC) == 0) {
 832                                         /*
 833                                          * Meh, the same value can have a different
 834                                          * byte order based on a flag..
 835                                          */
 836                                         addr = ntohl((__force __be32)addr);
 837                                 }
 838                                 addr = calc_reloc(addr, libinfo, id, 0);
 839                                 if (addr == RELOC_FAILED) {
 840                                         ret = -ENOEXEC;
 841                                         goto err;
 842                                 }
 843
 844                                 /* Write back the relocated pointer.  */
 845                                 ret = flat_put_addr_at_rp(rp, addr, relval);
 846                                 if (unlikely(ret))
 847                                         goto err;
 848                         }
 849                 }
 850 #ifdef CONFIG_BINFMT_FLAT_OLD
 851         } else {
 852                 for (i = 0; i < relocs; i++) {
 853                         __be32 relval;
 854                         if (get_user(relval, reloc + i))
 855                                 return -EFAULT;
 856                         old_reloc(ntohl(relval));
 857                 }
 858 #endif /* CONFIG_BINFMT_FLAT_OLD */
 859         }
 860
 861         flush_icache_range(start_code, end_code);
 862
 863         /* zero the BSS,  BRK and stack areas */
 864         if (clear_user((void __user *)(datapos + data_len), bss_len +
 865                        (memp + memp_size - stack_len -          /* end brk */
 866                        libinfo->lib_list[id].start_brk) +       /* start brk */
 867                        stack_len))
 868                 return -EFAULT;
 869
 870         return 0;
 871 err:
 872         return ret;
 873 }
 874
 875
 876 /****************************************************************************/
 877 #ifdef CONFIG_BINFMT_SHARED_FLAT
 878
 879 /*
 880  * Load a shared library into memory.  The library gets its own data
 881  * segment (including bss) but not argv/argc/environ.
 882  */
 883
 884 static int load_flat_shared_library(int id, struct lib_info *libs)
 885 {
 886         /*
 887          * This is a fake bprm struct; only the members "buf", "file" and
 888          * "filename" are actually used.
 889          */
 890         struct linux_binprm bprm;
 891         int res;
 892         char buf[16];
 893         loff_t pos = 0;
 894
 895         memset(&bprm, 0, sizeof(bprm));
 896
 897         /* Create the file name */
 898         sprintf(buf, "/lib/lib%d.so", id);
 899
 900         /* Open the file up */
 901         bprm.filename = buf;
 902         bprm.file = open_exec(bprm.filename);
 903         res = PTR_ERR(bprm.file);
 904         if (IS_ERR(bprm.file))
 905                 return res;
 906
 907         res = kernel_read(bprm.file, bprm.buf, BINPRM_BUF_SIZE, &pos);
 908
 909         if (res >= 0)
 910                 res = load_flat_file(&bprm, libs, id, NULL);
 911
 912         allow_write_access(bprm.file);
 913         fput(bprm.file);
 914
 915         return res;
 916 }
 917
 918 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 919 /****************************************************************************/
 920
 921 /*
 922  * These are the functions used to load flat style executables and shared
 923  * libraries.  There is no binary dependent code anywhere else.
 924  */
 925
 926 static int load_flat_binary(struct linux_binprm *bprm)
 927 {
 928         struct lib_info libinfo;
 929         struct pt_regs *regs = current_pt_regs();
 930         unsigned long stack_len = 0;
 931         unsigned long start_addr;
 932         int res;
 933         int i, j;
 934
 935         memset(&libinfo, 0, sizeof(libinfo));
 936
 937         /*
 938          * We have to add the size of our arguments to our stack size
 939          * otherwise it's too easy for users to create stack overflows
 940          * by passing in a huge argument list.  And yes,  we have to be
 941          * pedantic and include space for the argv/envp array as it may have
 942          * a lot of entries.
 943          */
 944 #ifndef CONFIG_MMU
 945         stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
 946 #endif
 947         stack_len += (bprm->argc + 1) * sizeof(char *);   /* the argv array */
 948         stack_len += (bprm->envc + 1) * sizeof(char *);   /* the envp array */
 949         stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
 950
 951         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 952         if (res < 0)
 953                 return res;
 954
 955         /* Update data segment pointers for all libraries */
 956         for (i = 0; i < MAX_SHARED_LIBS; i++) {
 957                 if (!libinfo.lib_list[i].loaded)
 958                         continue;
 959                 for (j = 0; j < MAX_SHARED_LIBS; j++) {
 960                         unsigned long val = libinfo.lib_list[j].loaded ?
 961                                 libinfo.lib_list[j].start_data : UNLOADED_LIB;
 962                         unsigned long __user *p = (unsigned long __user *)
 963                                 libinfo.lib_list[i].start_data;
 964                         p -= j + 1;
 965                         if (put_user(val, p))
 966                                 return -EFAULT;
 967                 }
 968         }
 969
 970         install_exec_creds(bprm);
 971
 972         set_binfmt(&flat_format);
 973
 974 #ifdef CONFIG_MMU
 975         res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
 976         if (!res)
 977                 res = create_flat_tables(bprm, bprm->p);
 978 #else
 979         /* Stash our initial stack pointer into the mm structure */
 980         current->mm->start_stack =
 981                 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 982         pr_debug("sp=%lx\n", current->mm->start_stack);
 983
 984         /* copy the arg pages onto the stack */
 985         res = transfer_args_to_stack(bprm, &current->mm->start_stack);
 986         if (!res)
 987                 res = create_flat_tables(bprm, current->mm->start_stack);
 988 #endif
 989         if (res)
 990                 return res;
 991
 992         /* Fake some return addresses to ensure the call chain will
 993          * initialise library in order for us.  We are required to call
 994          * lib 1 first, then 2, ... and finally the main program (id 0).
 995          */
 996         start_addr = libinfo.lib_list[0].entry;
 997
 998 #ifdef CONFIG_BINFMT_SHARED_FLAT
 999         for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
1000                 if (libinfo.lib_list[i].loaded) {
1001                         /* Push previos first to call address */
1002                         unsigned long __user *sp;
1003                         current->mm->start_stack -= sizeof(unsigned long);
1004                         sp = (unsigned long __user *)current->mm->start_stack;
1005                         __put_user(start_addr, sp);
1006                         start_addr = libinfo.lib_list[i].entry;
1007                 }
1008         }
1009 #endif
1010
1011 #ifdef FLAT_PLAT_INIT
1012         FLAT_PLAT_INIT(regs);
1013 #endif
1014
1015         finalize_exec(bprm);
1016         pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
1017                  regs, start_addr, current->mm->start_stack);
1018         start_thread(regs, start_addr, current->mm->start_stack);
1019
1020         return 0;
1021 }
1022
1023 /****************************************************************************/
1024
1025 static int __init init_flat_binfmt(void)
1026 {
1027         register_binfmt(&flat_format);
1028         return 0;
1029 }
1030 core_initcall(init_flat_binfmt);
1031
1032 /****************************************************************************/