1 /****************************************************************************/ 2 /* 3 * QEMU bFLT binary loader. Based on linux/fs/binfmt_flat.c 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, see <http://www.gnu.org/licenses/>. 17 * 18 * Copyright (C) 2006 CodeSourcery. 19 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> 20 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> 21 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> 22 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> 23 * based heavily on: 24 * 25 * linux/fs/binfmt_aout.c: 26 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 27 * linux/fs/binfmt_flat.c for 2.0 kernel 28 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> 29 * JAN/99 -- coded full program relocation (gerg@snapgear.com) 30 */ 31 32 /* ??? ZFLAT and shared library support is currently disabled. */ 33 34 /****************************************************************************/ 35 36 #include "qemu/osdep.h" 37 #include <sys/mman.h> 38 39 #include "qemu.h" 40 #include "flat.h" 41 #include <target_flat.h> 42 43 //#define DEBUG 44 45 #ifdef DEBUG 46 #define DBG_FLT(...) printf(__VA_ARGS__) 47 #else 48 #define DBG_FLT(...) 49 #endif 50 51 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 52 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 53 54 struct lib_info { 55 abi_ulong start_code; /* Start of text segment */ 56 abi_ulong start_data; /* Start of data segment */ 57 abi_ulong end_data; /* Start of bss section */ 58 abi_ulong start_brk; /* End of data segment */ 59 abi_ulong text_len; /* Length of text segment */ 60 abi_ulong entry; /* Start address for this module */ 61 abi_ulong build_date; /* When this one was compiled */ 62 short loaded; /* Has this library been loaded? */ 63 }; 64 65 #ifdef CONFIG_BINFMT_SHARED_FLAT 66 static int load_flat_shared_library(int id, struct lib_info *p); 67 #endif 68 69 struct linux_binprm; 70 71 /****************************************************************************/ 72 /* 73 * create_flat_tables() parses the env- and arg-strings in new user 74 * memory and creates the pointer tables from them, and puts their 75 * addresses on the "stack", returning the new stack pointer value. 76 */ 77 78 /* Push a block of strings onto the guest stack. */ 79 static abi_ulong copy_strings(abi_ulong p, int n, char **s) 80 { 81 int len; 82 83 while (n-- > 0) { 84 len = strlen(s[n]) + 1; 85 p -= len; 86 memcpy_to_target(p, s[n], len); 87 } 88 89 return p; 90 } 91 92 static int target_pread(int fd, abi_ulong ptr, abi_ulong len, 93 abi_ulong offset) 94 { 95 void *buf; 96 int ret; 97 98 buf = lock_user(VERIFY_WRITE, ptr, len, 0); 99 ret = pread(fd, buf, len, offset); 100 unlock_user(buf, ptr, len); 101 return ret; 102 } 103 /****************************************************************************/ 104 105 #ifdef CONFIG_BINFMT_ZFLAT 106 107 #include <linux/zlib.h> 108 109 #define LBUFSIZE 4000 110 111 /* gzip flag byte */ 112 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 113 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 114 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 115 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 116 #define COMMENT 0x10 /* bit 4 set: file comment present */ 117 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 118 #define RESERVED 0xC0 /* bit 6,7: reserved */ 119 120 static int decompress_exec( 121 struct linux_binprm *bprm, 122 unsigned long offset, 123 char *dst, 124 long len, 125 int fd) 126 { 127 unsigned char *buf; 128 z_stream strm; 129 loff_t fpos; 130 int ret, retval; 131 132 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 133 134 memset(&strm, 0, sizeof(strm)); 135 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 136 if (strm.workspace == NULL) { 137 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 138 return -ENOMEM; 139 } 140 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 141 if (buf == NULL) { 142 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 143 retval = -ENOMEM; 144 goto out_free; 145 } 146 147 /* Read in first chunk of data and parse gzip header. */ 148 fpos = offset; 149 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 150 151 strm.next_in = buf; 152 strm.avail_in = ret; 153 strm.total_in = 0; 154 155 retval = -ENOEXEC; 156 157 /* Check minimum size -- gzip header */ 158 if (ret < 10) { 159 DBG_FLT("binfmt_flat: file too small?\n"); 160 goto out_free_buf; 161 } 162 163 /* Check gzip magic number */ 164 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 165 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 166 goto out_free_buf; 167 } 168 169 /* Check gzip method */ 170 if (buf[2] != 8) { 171 DBG_FLT("binfmt_flat: unknown compression method?\n"); 172 goto out_free_buf; 173 } 174 /* Check gzip flags */ 175 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 176 (buf[3] & RESERVED)) { 177 DBG_FLT("binfmt_flat: unknown flags?\n"); 178 goto out_free_buf; 179 } 180 181 ret = 10; 182 if (buf[3] & EXTRA_FIELD) { 183 ret += 2 + buf[10] + (buf[11] << 8); 184 if (unlikely(LBUFSIZE == ret)) { 185 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 186 goto out_free_buf; 187 } 188 } 189 if (buf[3] & ORIG_NAME) { 190 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 191 ; 192 if (unlikely(LBUFSIZE == ret)) { 193 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 194 goto out_free_buf; 195 } 196 } 197 if (buf[3] & COMMENT) { 198 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 199 ; 200 if (unlikely(LBUFSIZE == ret)) { 201 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 202 goto out_free_buf; 203 } 204 } 205 206 strm.next_in += ret; 207 strm.avail_in -= ret; 208 209 strm.next_out = dst; 210 strm.avail_out = len; 211 strm.total_out = 0; 212 213 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 214 DBG_FLT("binfmt_flat: zlib init failed?\n"); 215 goto out_free_buf; 216 } 217 218 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 219 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 220 if (ret <= 0) 221 break; 222 if (ret >= (unsigned long) -4096) 223 break; 224 len -= ret; 225 226 strm.next_in = buf; 227 strm.avail_in = ret; 228 strm.total_in = 0; 229 } 230 231 if (ret < 0) { 232 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 233 ret, strm.msg); 234 goto out_zlib; 235 } 236 237 retval = 0; 238 out_zlib: 239 zlib_inflateEnd(&strm); 240 out_free_buf: 241 kfree(buf); 242 out_free: 243 kfree(strm.workspace); 244 out: 245 return retval; 246 } 247 248 #endif /* CONFIG_BINFMT_ZFLAT */ 249 250 /****************************************************************************/ 251 252 static abi_ulong 253 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp) 254 { 255 abi_ulong addr; 256 int id; 257 abi_ulong start_brk; 258 abi_ulong start_data; 259 abi_ulong text_len; 260 abi_ulong start_code; 261 262 #ifdef CONFIG_BINFMT_SHARED_FLAT 263 #error needs checking 264 if (r == 0) 265 id = curid; /* Relocs of 0 are always self referring */ 266 else { 267 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 268 r &= 0x00ffffff; /* Trim ID off here */ 269 } 270 if (id >= MAX_SHARED_LIBS) { 271 fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n", 272 (unsigned) r, id); 273 goto failed; 274 } 275 if (curid != id) { 276 if (internalp) { 277 fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not " 278 "in same module (%d != %d)\n", 279 (unsigned) r, curid, id); 280 goto failed; 281 } else if ( ! p[id].loaded && 282 load_flat_shared_library(id, p) > (unsigned long) -4096) { 283 fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id); 284 goto failed; 285 } 286 /* Check versioning information (i.e. time stamps) */ 287 if (p[id].build_date && p[curid].build_date 288 && p[curid].build_date < p[id].build_date) { 289 fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n", 290 id, curid); 291 goto failed; 292 } 293 } 294 #else 295 id = 0; 296 #endif 297 298 start_brk = p[id].start_brk; 299 start_data = p[id].start_data; 300 start_code = p[id].start_code; 301 text_len = p[id].text_len; 302 303 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 304 fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x " 305 "(0 - 0x%x/0x%x)\n", 306 (int) r,(int)(start_brk-start_code),(int)text_len); 307 goto failed; 308 } 309 310 if (r < text_len) /* In text segment */ 311 addr = r + start_code; 312 else /* In data segment */ 313 addr = r - text_len + start_data; 314 315 /* Range checked already above so doing the range tests is redundant...*/ 316 return(addr); 317 318 failed: 319 abort(); 320 return RELOC_FAILED; 321 } 322 323 /****************************************************************************/ 324 325 /* ??? This does not handle endianness correctly. */ 326 static void old_reloc(struct lib_info *libinfo, uint32_t rl) 327 { 328 #ifdef DEBUG 329 const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 330 #endif 331 uint32_t *ptr; 332 uint32_t offset; 333 int reloc_type; 334 335 offset = rl & 0x3fffffff; 336 reloc_type = rl >> 30; 337 /* ??? How to handle this? */ 338 #if defined(CONFIG_COLDFIRE) 339 ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset); 340 #else 341 ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset); 342 #endif 343 344 #ifdef DEBUG 345 fprintf(stderr, "Relocation of variable at DATASEG+%x " 346 "(address %p, currently %x) into segment %s\n", 347 offset, ptr, (int)*ptr, segment[reloc_type]); 348 #endif 349 350 switch (reloc_type) { 351 case OLD_FLAT_RELOC_TYPE_TEXT: 352 *ptr += libinfo->start_code; 353 break; 354 case OLD_FLAT_RELOC_TYPE_DATA: 355 *ptr += libinfo->start_data; 356 break; 357 case OLD_FLAT_RELOC_TYPE_BSS: 358 *ptr += libinfo->end_data; 359 break; 360 default: 361 fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n", 362 reloc_type); 363 break; 364 } 365 DBG_FLT("Relocation became %x\n", (int)*ptr); 366 } 367 368 /****************************************************************************/ 369 370 static int load_flat_file(struct linux_binprm * bprm, 371 struct lib_info *libinfo, int id, abi_ulong *extra_stack) 372 { 373 struct flat_hdr * hdr; 374 abi_ulong textpos = 0, datapos = 0; 375 abi_long result; 376 abi_ulong realdatastart = 0; 377 abi_ulong text_len, data_len, bss_len, stack_len, flags; 378 abi_ulong extra; 379 abi_ulong reloc = 0, rp; 380 int i, rev, relocs = 0; 381 abi_ulong fpos; 382 abi_ulong start_code; 383 abi_ulong indx_len; 384 385 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 386 387 text_len = ntohl(hdr->data_start); 388 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 389 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 390 stack_len = ntohl(hdr->stack_size); 391 if (extra_stack) { 392 stack_len += *extra_stack; 393 *extra_stack = stack_len; 394 } 395 relocs = ntohl(hdr->reloc_count); 396 flags = ntohl(hdr->flags); 397 rev = ntohl(hdr->rev); 398 399 DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 400 401 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 402 fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n", 403 rev, (int) FLAT_VERSION); 404 return -ENOEXEC; 405 } 406 407 /* Don't allow old format executables to use shared libraries */ 408 if (rev == OLD_FLAT_VERSION && id != 0) { 409 fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n"); 410 return -ENOEXEC; 411 } 412 413 /* 414 * fix up the flags for the older format, there were all kinds 415 * of endian hacks, this only works for the simple cases 416 */ 417 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 418 flags = FLAT_FLAG_RAM; 419 420 #ifndef CONFIG_BINFMT_ZFLAT 421 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 422 fprintf(stderr, "Support for ZFLAT executables is not enabled\n"); 423 return -ENOEXEC; 424 } 425 #endif 426 427 /* 428 * calculate the extra space we need to map in 429 */ 430 extra = relocs * sizeof(abi_ulong); 431 if (extra < bss_len + stack_len) 432 extra = bss_len + stack_len; 433 434 /* Add space for library base pointers. Make sure this does not 435 misalign the doesn't misalign the data segment. */ 436 indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong); 437 indx_len = (indx_len + 15) & ~(abi_ulong)15; 438 439 /* 440 * there are a couple of cases here, the separate code/data 441 * case, and then the fully copied to RAM case which lumps 442 * it all together. 443 */ 444 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 445 /* 446 * this should give us a ROM ptr, but if it doesn't we don't 447 * really care 448 */ 449 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 450 451 textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC, 452 MAP_PRIVATE, bprm->fd, 0); 453 if (textpos == -1) { 454 fprintf(stderr, "Unable to mmap process text\n"); 455 return -1; 456 } 457 458 realdatastart = target_mmap(0, data_len + extra + indx_len, 459 PROT_READ|PROT_WRITE|PROT_EXEC, 460 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 461 462 if (realdatastart == -1) { 463 fprintf(stderr, "Unable to allocate RAM for process data\n"); 464 return realdatastart; 465 } 466 datapos = realdatastart + indx_len; 467 468 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 469 (int)(data_len + bss_len + stack_len), (int)datapos); 470 471 fpos = ntohl(hdr->data_start); 472 #ifdef CONFIG_BINFMT_ZFLAT 473 if (flags & FLAT_FLAG_GZDATA) { 474 result = decompress_exec(bprm, fpos, (char *) datapos, 475 data_len + (relocs * sizeof(abi_ulong))) 476 } else 477 #endif 478 { 479 result = target_pread(bprm->fd, datapos, 480 data_len + (relocs * sizeof(abi_ulong)), 481 fpos); 482 } 483 if (result < 0) { 484 fprintf(stderr, "Unable to read data+bss\n"); 485 return result; 486 } 487 488 reloc = datapos + (ntohl(hdr->reloc_start) - text_len); 489 490 } else { 491 492 textpos = target_mmap(0, text_len + data_len + extra + indx_len, 493 PROT_READ | PROT_EXEC | PROT_WRITE, 494 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 495 if (textpos == -1 ) { 496 fprintf(stderr, "Unable to allocate RAM for process text/data\n"); 497 return -1; 498 } 499 500 realdatastart = textpos + ntohl(hdr->data_start); 501 datapos = realdatastart + indx_len; 502 reloc = (textpos + ntohl(hdr->reloc_start) + indx_len); 503 504 #ifdef CONFIG_BINFMT_ZFLAT 505 #error code needs checking 506 /* 507 * load it all in and treat it like a RAM load from now on 508 */ 509 if (flags & FLAT_FLAG_GZIP) { 510 result = decompress_exec(bprm, sizeof (struct flat_hdr), 511 (((char *) textpos) + sizeof (struct flat_hdr)), 512 (text_len + data_len + (relocs * sizeof(unsigned long)) 513 - sizeof (struct flat_hdr)), 514 0); 515 memmove((void *) datapos, (void *) realdatastart, 516 data_len + (relocs * sizeof(unsigned long))); 517 } else if (flags & FLAT_FLAG_GZDATA) { 518 fpos = 0; 519 result = bprm->file->f_op->read(bprm->file, 520 (char *) textpos, text_len, &fpos); 521 if (result < (unsigned long) -4096) 522 result = decompress_exec(bprm, text_len, (char *) datapos, 523 data_len + (relocs * sizeof(unsigned long)), 0); 524 } 525 else 526 #endif 527 { 528 result = target_pread(bprm->fd, textpos, 529 text_len, 0); 530 if (result >= 0) { 531 result = target_pread(bprm->fd, datapos, 532 data_len + (relocs * sizeof(abi_ulong)), 533 ntohl(hdr->data_start)); 534 } 535 } 536 if (result < 0) { 537 fprintf(stderr, "Unable to read code+data+bss\n"); 538 return result; 539 } 540 } 541 542 DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n", 543 (int)textpos, 0x00ffffff&ntohl(hdr->entry), 544 ntohl(hdr->data_start)); 545 546 /* The main program needs a little extra setup in the task structure */ 547 start_code = textpos + sizeof (struct flat_hdr); 548 549 DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 550 id ? "Lib" : "Load", bprm->filename, 551 (int) start_code, (int) (textpos + text_len), 552 (int) datapos, 553 (int) (datapos + data_len), 554 (int) (datapos + data_len), 555 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 556 557 text_len -= sizeof(struct flat_hdr); /* the real code len */ 558 559 /* Store the current module values into the global library structure */ 560 libinfo[id].start_code = start_code; 561 libinfo[id].start_data = datapos; 562 libinfo[id].end_data = datapos + data_len; 563 libinfo[id].start_brk = datapos + data_len + bss_len; 564 libinfo[id].text_len = text_len; 565 libinfo[id].loaded = 1; 566 libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 567 libinfo[id].build_date = ntohl(hdr->build_date); 568 569 /* 570 * We just load the allocations into some temporary memory to 571 * help simplify all this mumbo jumbo 572 * 573 * We've got two different sections of relocation entries. 574 * The first is the GOT which resides at the beginning of the data segment 575 * and is terminated with a -1. This one can be relocated in place. 576 * The second is the extra relocation entries tacked after the image's 577 * data segment. These require a little more processing as the entry is 578 * really an offset into the image which contains an offset into the 579 * image. 580 */ 581 if (flags & FLAT_FLAG_GOTPIC) { 582 rp = datapos; 583 while (1) { 584 abi_ulong addr; 585 if (get_user_ual(addr, rp)) 586 return -EFAULT; 587 if (addr == -1) 588 break; 589 if (addr) { 590 addr = calc_reloc(addr, libinfo, id, 0); 591 if (addr == RELOC_FAILED) 592 return -ENOEXEC; 593 if (put_user_ual(addr, rp)) 594 return -EFAULT; 595 } 596 rp += sizeof(abi_ulong); 597 } 598 } 599 600 /* 601 * Now run through the relocation entries. 602 * We've got to be careful here as C++ produces relocatable zero 603 * entries in the constructor and destructor tables which are then 604 * tested for being not zero (which will always occur unless we're 605 * based from address zero). This causes an endless loop as __start 606 * is at zero. The solution used is to not relocate zero addresses. 607 * This has the negative side effect of not allowing a global data 608 * reference to be statically initialised to _stext (I've moved 609 * __start to address 4 so that is okay). 610 */ 611 if (rev > OLD_FLAT_VERSION) { 612 abi_ulong persistent = 0; 613 for (i = 0; i < relocs; i++) { 614 abi_ulong addr, relval; 615 616 /* Get the address of the pointer to be 617 relocated (of course, the address has to be 618 relocated first). */ 619 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) 620 return -EFAULT; 621 relval = ntohl(relval); 622 if (flat_set_persistent(relval, &persistent)) 623 continue; 624 addr = flat_get_relocate_addr(relval); 625 rp = calc_reloc(addr, libinfo, id, 1); 626 if (rp == RELOC_FAILED) 627 return -ENOEXEC; 628 629 /* Get the pointer's value. */ 630 if (get_user_ual(addr, rp)) 631 return -EFAULT; 632 addr = flat_get_addr_from_rp(addr, relval, flags, &persistent); 633 if (addr != 0) { 634 /* 635 * Do the relocation. PIC relocs in the data section are 636 * already in target order 637 */ 638 if ((flags & FLAT_FLAG_GOTPIC) == 0) 639 addr = ntohl(addr); 640 addr = calc_reloc(addr, libinfo, id, 0); 641 if (addr == RELOC_FAILED) 642 return -ENOEXEC; 643 644 /* Write back the relocated pointer. */ 645 if (flat_put_addr_at_rp(rp, addr, relval)) 646 return -EFAULT; 647 } 648 } 649 } else { 650 for (i = 0; i < relocs; i++) { 651 abi_ulong relval; 652 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) 653 return -EFAULT; 654 old_reloc(&libinfo[0], relval); 655 } 656 } 657 658 /* zero the BSS. */ 659 memset(g2h(datapos + data_len), 0, bss_len); 660 661 return 0; 662 } 663 664 665 /****************************************************************************/ 666 #ifdef CONFIG_BINFMT_SHARED_FLAT 667 668 /* 669 * Load a shared library into memory. The library gets its own data 670 * segment (including bss) but not argv/argc/environ. 671 */ 672 673 static int load_flat_shared_library(int id, struct lib_info *libs) 674 { 675 struct linux_binprm bprm; 676 int res; 677 char buf[16]; 678 679 /* Create the file name */ 680 sprintf(buf, "/lib/lib%d.so", id); 681 682 /* Open the file up */ 683 bprm.filename = buf; 684 bprm.file = open_exec(bprm.filename); 685 res = PTR_ERR(bprm.file); 686 if (IS_ERR(bprm.file)) 687 return res; 688 689 res = prepare_binprm(&bprm); 690 691 if (res <= (unsigned long)-4096) 692 res = load_flat_file(&bprm, libs, id, NULL); 693 if (bprm.file) { 694 allow_write_access(bprm.file); 695 fput(bprm.file); 696 bprm.file = NULL; 697 } 698 return(res); 699 } 700 701 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 702 703 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info) 704 { 705 struct lib_info libinfo[MAX_SHARED_LIBS]; 706 abi_ulong p; 707 abi_ulong stack_len; 708 abi_ulong start_addr; 709 abi_ulong sp; 710 int res; 711 int i, j; 712 713 memset(libinfo, 0, sizeof(libinfo)); 714 /* 715 * We have to add the size of our arguments to our stack size 716 * otherwise it's too easy for users to create stack overflows 717 * by passing in a huge argument list. And yes, we have to be 718 * pedantic and include space for the argv/envp array as it may have 719 * a lot of entries. 720 */ 721 stack_len = 0; 722 for (i = 0; i < bprm->argc; ++i) { 723 /* the argv strings */ 724 stack_len += strlen(bprm->argv[i]); 725 } 726 for (i = 0; i < bprm->envc; ++i) { 727 /* the envp strings */ 728 stack_len += strlen(bprm->envp[i]); 729 } 730 stack_len += (bprm->argc + 1) * 4; /* the argv array */ 731 stack_len += (bprm->envc + 1) * 4; /* the envp array */ 732 733 734 res = load_flat_file(bprm, libinfo, 0, &stack_len); 735 if (res > (unsigned long)-4096) 736 return res; 737 738 /* Update data segment pointers for all libraries */ 739 for (i=0; i<MAX_SHARED_LIBS; i++) { 740 if (libinfo[i].loaded) { 741 abi_ulong p; 742 p = libinfo[i].start_data; 743 for (j=0; j<MAX_SHARED_LIBS; j++) { 744 p -= 4; 745 /* FIXME - handle put_user() failures */ 746 if (put_user_ual(libinfo[j].loaded 747 ? libinfo[j].start_data 748 : UNLOADED_LIB, 749 p)) 750 return -EFAULT; 751 } 752 } 753 } 754 755 p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4; 756 DBG_FLT("p=%x\n", (int)p); 757 758 /* Copy argv/envp. */ 759 p = copy_strings(p, bprm->envc, bprm->envp); 760 p = copy_strings(p, bprm->argc, bprm->argv); 761 /* Align stack. */ 762 sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1); 763 /* Enforce final stack alignment of 16 bytes. This is sufficient 764 for all current targets, and excess alignment is harmless. */ 765 stack_len = bprm->envc + bprm->argc + 2; 766 stack_len += 3; /* argc, arvg, argp */ 767 stack_len *= sizeof(abi_ulong); 768 if ((sp + stack_len) & 15) 769 sp -= 16 - ((sp + stack_len) & 15); 770 sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, 771 flat_argvp_envp_on_stack()); 772 773 /* Fake some return addresses to ensure the call chain will 774 * initialise library in order for us. We are required to call 775 * lib 1 first, then 2, ... and finally the main program (id 0). 776 */ 777 start_addr = libinfo[0].entry; 778 779 #ifdef CONFIG_BINFMT_SHARED_FLAT 780 #error here 781 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 782 if (libinfo[i].loaded) { 783 /* Push previos first to call address */ 784 --sp; 785 if (put_user_ual(start_addr, sp)) 786 return -EFAULT; 787 start_addr = libinfo[i].entry; 788 } 789 } 790 #endif 791 792 /* Stash our initial stack pointer into the mm structure */ 793 info->start_code = libinfo[0].start_code; 794 info->end_code = libinfo[0].start_code = libinfo[0].text_len; 795 info->start_data = libinfo[0].start_data; 796 info->end_data = libinfo[0].end_data; 797 info->start_brk = libinfo[0].start_brk; 798 info->start_stack = sp; 799 info->stack_limit = libinfo[0].start_brk; 800 info->entry = start_addr; 801 info->code_offset = info->start_code; 802 info->data_offset = info->start_data - libinfo[0].text_len; 803 804 DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n", 805 (int)info->entry, (int)info->start_stack); 806 807 return 0; 808 } 809