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