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 if (!buf) { 99 return -EFAULT; 100 } 101 ret = pread(fd, buf, len, offset); 102 if (ret < 0) { 103 ret = -errno; 104 } 105 unlock_user(buf, ptr, len); 106 return ret; 107 } 108 /****************************************************************************/ 109 110 #ifdef CONFIG_BINFMT_ZFLAT 111 112 #include <linux/zlib.h> 113 114 #define LBUFSIZE 4000 115 116 /* gzip flag byte */ 117 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 118 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 119 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 120 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 121 #define COMMENT 0x10 /* bit 4 set: file comment present */ 122 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 123 #define RESERVED 0xC0 /* bit 6,7: reserved */ 124 125 static int decompress_exec( 126 struct linux_binprm *bprm, 127 unsigned long offset, 128 char *dst, 129 long len, 130 int fd) 131 { 132 unsigned char *buf; 133 z_stream strm; 134 loff_t fpos; 135 int ret, retval; 136 137 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 138 139 memset(&strm, 0, sizeof(strm)); 140 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 141 if (strm.workspace == NULL) { 142 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 143 return -ENOMEM; 144 } 145 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 146 if (buf == NULL) { 147 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 148 retval = -ENOMEM; 149 goto out_free; 150 } 151 152 /* Read in first chunk of data and parse gzip header. */ 153 fpos = offset; 154 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 155 156 strm.next_in = buf; 157 strm.avail_in = ret; 158 strm.total_in = 0; 159 160 retval = -ENOEXEC; 161 162 /* Check minimum size -- gzip header */ 163 if (ret < 10) { 164 DBG_FLT("binfmt_flat: file too small?\n"); 165 goto out_free_buf; 166 } 167 168 /* Check gzip magic number */ 169 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 170 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 171 goto out_free_buf; 172 } 173 174 /* Check gzip method */ 175 if (buf[2] != 8) { 176 DBG_FLT("binfmt_flat: unknown compression method?\n"); 177 goto out_free_buf; 178 } 179 /* Check gzip flags */ 180 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 181 (buf[3] & RESERVED)) { 182 DBG_FLT("binfmt_flat: unknown flags?\n"); 183 goto out_free_buf; 184 } 185 186 ret = 10; 187 if (buf[3] & EXTRA_FIELD) { 188 ret += 2 + buf[10] + (buf[11] << 8); 189 if (unlikely(LBUFSIZE == ret)) { 190 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 191 goto out_free_buf; 192 } 193 } 194 if (buf[3] & ORIG_NAME) { 195 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 196 ; 197 if (unlikely(LBUFSIZE == ret)) { 198 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 199 goto out_free_buf; 200 } 201 } 202 if (buf[3] & COMMENT) { 203 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 204 ; 205 if (unlikely(LBUFSIZE == ret)) { 206 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 207 goto out_free_buf; 208 } 209 } 210 211 strm.next_in += ret; 212 strm.avail_in -= ret; 213 214 strm.next_out = dst; 215 strm.avail_out = len; 216 strm.total_out = 0; 217 218 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 219 DBG_FLT("binfmt_flat: zlib init failed?\n"); 220 goto out_free_buf; 221 } 222 223 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 224 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 225 if (ret <= 0) 226 break; 227 if (is_error(ret)) { 228 break; 229 } 230 len -= ret; 231 232 strm.next_in = buf; 233 strm.avail_in = ret; 234 strm.total_in = 0; 235 } 236 237 if (ret < 0) { 238 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 239 ret, strm.msg); 240 goto out_zlib; 241 } 242 243 retval = 0; 244 out_zlib: 245 zlib_inflateEnd(&strm); 246 out_free_buf: 247 kfree(buf); 248 out_free: 249 kfree(strm.workspace); 250 out: 251 return retval; 252 } 253 254 #endif /* CONFIG_BINFMT_ZFLAT */ 255 256 /****************************************************************************/ 257 258 static abi_ulong 259 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp) 260 { 261 abi_ulong addr; 262 int id; 263 abi_ulong start_brk; 264 abi_ulong start_data; 265 abi_ulong text_len; 266 abi_ulong start_code; 267 268 #ifdef CONFIG_BINFMT_SHARED_FLAT 269 #error needs checking 270 if (r == 0) 271 id = curid; /* Relocs of 0 are always self referring */ 272 else { 273 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 274 r &= 0x00ffffff; /* Trim ID off here */ 275 } 276 if (id >= MAX_SHARED_LIBS) { 277 fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n", 278 (unsigned) r, id); 279 goto failed; 280 } 281 if (curid != id) { 282 if (internalp) { 283 fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not " 284 "in same module (%d != %d)\n", 285 (unsigned) r, curid, id); 286 goto failed; 287 } else if (!p[id].loaded && is_error(load_flat_shared_library(id, p))) { 288 fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id); 289 goto failed; 290 } 291 /* Check versioning information (i.e. time stamps) */ 292 if (p[id].build_date && p[curid].build_date 293 && p[curid].build_date < p[id].build_date) { 294 fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n", 295 id, curid); 296 goto failed; 297 } 298 } 299 #else 300 id = 0; 301 #endif 302 303 start_brk = p[id].start_brk; 304 start_data = p[id].start_data; 305 start_code = p[id].start_code; 306 text_len = p[id].text_len; 307 308 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 309 fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x " 310 "(0 - 0x%x/0x%x)\n", 311 (int) r,(int)(start_brk-start_code),(int)text_len); 312 goto failed; 313 } 314 315 if (r < text_len) /* In text segment */ 316 addr = r + start_code; 317 else /* In data segment */ 318 addr = r - text_len + start_data; 319 320 /* Range checked already above so doing the range tests is redundant...*/ 321 return(addr); 322 323 failed: 324 abort(); 325 return RELOC_FAILED; 326 } 327 328 /****************************************************************************/ 329 330 /* ??? This does not handle endianness correctly. */ 331 static void old_reloc(struct lib_info *libinfo, uint32_t rl) 332 { 333 #ifdef DEBUG 334 const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 335 #endif 336 uint32_t *ptr; 337 uint32_t offset; 338 int reloc_type; 339 340 offset = rl & 0x3fffffff; 341 reloc_type = rl >> 30; 342 /* ??? How to handle this? */ 343 #if defined(CONFIG_COLDFIRE) 344 ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset); 345 #else 346 ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset); 347 #endif 348 349 #ifdef DEBUG 350 fprintf(stderr, "Relocation of variable at DATASEG+%x " 351 "(address %p, currently %x) into segment %s\n", 352 offset, ptr, (int)*ptr, segment[reloc_type]); 353 #endif 354 355 switch (reloc_type) { 356 case OLD_FLAT_RELOC_TYPE_TEXT: 357 *ptr += libinfo->start_code; 358 break; 359 case OLD_FLAT_RELOC_TYPE_DATA: 360 *ptr += libinfo->start_data; 361 break; 362 case OLD_FLAT_RELOC_TYPE_BSS: 363 *ptr += libinfo->end_data; 364 break; 365 default: 366 fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n", 367 reloc_type); 368 break; 369 } 370 DBG_FLT("Relocation became %x\n", (int)*ptr); 371 } 372 373 /****************************************************************************/ 374 375 static int load_flat_file(struct linux_binprm * bprm, 376 struct lib_info *libinfo, int id, abi_ulong *extra_stack) 377 { 378 struct flat_hdr * hdr; 379 abi_ulong textpos = 0, datapos = 0; 380 abi_long result; 381 abi_ulong realdatastart = 0; 382 abi_ulong text_len, data_len, bss_len, stack_len, flags; 383 abi_ulong extra; 384 abi_ulong reloc = 0, rp; 385 int i, rev, relocs = 0; 386 abi_ulong fpos; 387 abi_ulong start_code; 388 abi_ulong indx_len; 389 390 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 391 392 text_len = ntohl(hdr->data_start); 393 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 394 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 395 stack_len = ntohl(hdr->stack_size); 396 if (extra_stack) { 397 stack_len += *extra_stack; 398 *extra_stack = stack_len; 399 } 400 relocs = ntohl(hdr->reloc_count); 401 flags = ntohl(hdr->flags); 402 rev = ntohl(hdr->rev); 403 404 DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 405 406 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 407 fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n", 408 rev, (int) FLAT_VERSION); 409 return -ENOEXEC; 410 } 411 412 /* Don't allow old format executables to use shared libraries */ 413 if (rev == OLD_FLAT_VERSION && id != 0) { 414 fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n"); 415 return -ENOEXEC; 416 } 417 418 /* 419 * fix up the flags for the older format, there were all kinds 420 * of endian hacks, this only works for the simple cases 421 */ 422 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 423 flags = FLAT_FLAG_RAM; 424 425 #ifndef CONFIG_BINFMT_ZFLAT 426 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 427 fprintf(stderr, "Support for ZFLAT executables is not enabled\n"); 428 return -ENOEXEC; 429 } 430 #endif 431 432 /* 433 * calculate the extra space we need to map in 434 */ 435 extra = relocs * sizeof(abi_ulong); 436 if (extra < bss_len + stack_len) 437 extra = bss_len + stack_len; 438 439 /* Add space for library base pointers. Make sure this does not 440 misalign the doesn't misalign the data segment. */ 441 indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong); 442 indx_len = (indx_len + 15) & ~(abi_ulong)15; 443 444 /* 445 * there are a couple of cases here, the separate code/data 446 * case, and then the fully copied to RAM case which lumps 447 * it all together. 448 */ 449 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 450 /* 451 * this should give us a ROM ptr, but if it doesn't we don't 452 * really care 453 */ 454 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 455 456 textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC, 457 MAP_PRIVATE, bprm->fd, 0); 458 if (textpos == -1) { 459 fprintf(stderr, "Unable to mmap process text\n"); 460 return -1; 461 } 462 463 realdatastart = target_mmap(0, data_len + extra + indx_len, 464 PROT_READ|PROT_WRITE|PROT_EXEC, 465 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 466 467 if (realdatastart == -1) { 468 fprintf(stderr, "Unable to allocate RAM for process data\n"); 469 return realdatastart; 470 } 471 datapos = realdatastart + indx_len; 472 473 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 474 (int)(data_len + bss_len + stack_len), (int)datapos); 475 476 fpos = ntohl(hdr->data_start); 477 #ifdef CONFIG_BINFMT_ZFLAT 478 if (flags & FLAT_FLAG_GZDATA) { 479 result = decompress_exec(bprm, fpos, (char *) datapos, 480 data_len + (relocs * sizeof(abi_ulong))) 481 } else 482 #endif 483 { 484 result = target_pread(bprm->fd, datapos, 485 data_len + (relocs * sizeof(abi_ulong)), 486 fpos); 487 } 488 if (result < 0) { 489 fprintf(stderr, "Unable to read data+bss\n"); 490 return result; 491 } 492 493 reloc = datapos + (ntohl(hdr->reloc_start) - text_len); 494 495 } else { 496 497 textpos = target_mmap(0, text_len + data_len + extra + indx_len, 498 PROT_READ | PROT_EXEC | PROT_WRITE, 499 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 500 if (textpos == -1 ) { 501 fprintf(stderr, "Unable to allocate RAM for process text/data\n"); 502 return -1; 503 } 504 505 realdatastart = textpos + ntohl(hdr->data_start); 506 datapos = realdatastart + indx_len; 507 reloc = (textpos + ntohl(hdr->reloc_start) + indx_len); 508 509 #ifdef CONFIG_BINFMT_ZFLAT 510 #error code needs checking 511 /* 512 * load it all in and treat it like a RAM load from now on 513 */ 514 if (flags & FLAT_FLAG_GZIP) { 515 result = decompress_exec(bprm, sizeof (struct flat_hdr), 516 (((char *) textpos) + sizeof (struct flat_hdr)), 517 (text_len + data_len + (relocs * sizeof(unsigned long)) 518 - sizeof (struct flat_hdr)), 519 0); 520 memmove((void *) datapos, (void *) realdatastart, 521 data_len + (relocs * sizeof(unsigned long))); 522 } else if (flags & FLAT_FLAG_GZDATA) { 523 fpos = 0; 524 result = bprm->file->f_op->read(bprm->file, 525 (char *) textpos, text_len, &fpos); 526 if (!is_error(result)) { 527 result = decompress_exec(bprm, text_len, (char *) datapos, 528 data_len + (relocs * sizeof(unsigned long)), 0); 529 } 530 } 531 else 532 #endif 533 { 534 result = target_pread(bprm->fd, textpos, 535 text_len, 0); 536 if (result >= 0) { 537 result = target_pread(bprm->fd, datapos, 538 data_len + (relocs * sizeof(abi_ulong)), 539 ntohl(hdr->data_start)); 540 } 541 } 542 if (result < 0) { 543 fprintf(stderr, "Unable to read code+data+bss\n"); 544 return result; 545 } 546 } 547 548 DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n", 549 (int)textpos, 0x00ffffff&ntohl(hdr->entry), 550 ntohl(hdr->data_start)); 551 552 /* The main program needs a little extra setup in the task structure */ 553 start_code = textpos + sizeof (struct flat_hdr); 554 555 DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 556 id ? "Lib" : "Load", bprm->filename, 557 (int) start_code, (int) (textpos + text_len), 558 (int) datapos, 559 (int) (datapos + data_len), 560 (int) (datapos + data_len), 561 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 562 563 text_len -= sizeof(struct flat_hdr); /* the real code len */ 564 565 /* Store the current module values into the global library structure */ 566 libinfo[id].start_code = start_code; 567 libinfo[id].start_data = datapos; 568 libinfo[id].end_data = datapos + data_len; 569 libinfo[id].start_brk = datapos + data_len + bss_len; 570 libinfo[id].text_len = text_len; 571 libinfo[id].loaded = 1; 572 libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 573 libinfo[id].build_date = ntohl(hdr->build_date); 574 575 /* 576 * We just load the allocations into some temporary memory to 577 * help simplify all this mumbo jumbo 578 * 579 * We've got two different sections of relocation entries. 580 * The first is the GOT which resides at the beginning of the data segment 581 * and is terminated with a -1. This one can be relocated in place. 582 * The second is the extra relocation entries tacked after the image's 583 * data segment. These require a little more processing as the entry is 584 * really an offset into the image which contains an offset into the 585 * image. 586 */ 587 if (flags & FLAT_FLAG_GOTPIC) { 588 rp = datapos; 589 while (1) { 590 abi_ulong addr; 591 if (get_user_ual(addr, rp)) 592 return -EFAULT; 593 if (addr == -1) 594 break; 595 if (addr) { 596 addr = calc_reloc(addr, libinfo, id, 0); 597 if (addr == RELOC_FAILED) 598 return -ENOEXEC; 599 if (put_user_ual(addr, rp)) 600 return -EFAULT; 601 } 602 rp += sizeof(abi_ulong); 603 } 604 } 605 606 /* 607 * Now run through the relocation entries. 608 * We've got to be careful here as C++ produces relocatable zero 609 * entries in the constructor and destructor tables which are then 610 * tested for being not zero (which will always occur unless we're 611 * based from address zero). This causes an endless loop as __start 612 * is at zero. The solution used is to not relocate zero addresses. 613 * This has the negative side effect of not allowing a global data 614 * reference to be statically initialised to _stext (I've moved 615 * __start to address 4 so that is okay). 616 */ 617 if (rev > OLD_FLAT_VERSION) { 618 abi_ulong persistent = 0; 619 for (i = 0; i < relocs; i++) { 620 abi_ulong addr, relval; 621 622 /* Get the address of the pointer to be 623 relocated (of course, the address has to be 624 relocated first). */ 625 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) 626 return -EFAULT; 627 relval = ntohl(relval); 628 if (flat_set_persistent(relval, &persistent)) 629 continue; 630 addr = flat_get_relocate_addr(relval); 631 rp = calc_reloc(addr, libinfo, id, 1); 632 if (rp == RELOC_FAILED) 633 return -ENOEXEC; 634 635 /* Get the pointer's value. */ 636 if (get_user_ual(addr, rp)) 637 return -EFAULT; 638 addr = flat_get_addr_from_rp(addr, relval, flags, &persistent); 639 if (addr != 0) { 640 /* 641 * Do the relocation. PIC relocs in the data section are 642 * already in target order 643 */ 644 if ((flags & FLAT_FLAG_GOTPIC) == 0) 645 addr = ntohl(addr); 646 addr = calc_reloc(addr, libinfo, id, 0); 647 if (addr == RELOC_FAILED) 648 return -ENOEXEC; 649 650 /* Write back the relocated pointer. */ 651 if (flat_put_addr_at_rp(rp, addr, relval)) 652 return -EFAULT; 653 } 654 } 655 } else { 656 for (i = 0; i < relocs; i++) { 657 abi_ulong relval; 658 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) 659 return -EFAULT; 660 old_reloc(&libinfo[0], relval); 661 } 662 } 663 664 /* zero the BSS. */ 665 memset(g2h(datapos + data_len), 0, bss_len); 666 667 return 0; 668 } 669 670 671 /****************************************************************************/ 672 #ifdef CONFIG_BINFMT_SHARED_FLAT 673 674 /* 675 * Load a shared library into memory. The library gets its own data 676 * segment (including bss) but not argv/argc/environ. 677 */ 678 679 static int load_flat_shared_library(int id, struct lib_info *libs) 680 { 681 struct linux_binprm bprm; 682 int res; 683 char buf[16]; 684 685 /* Create the file name */ 686 sprintf(buf, "/lib/lib%d.so", id); 687 688 /* Open the file up */ 689 bprm.filename = buf; 690 bprm.file = open_exec(bprm.filename); 691 res = PTR_ERR(bprm.file); 692 if (IS_ERR(bprm.file)) 693 return res; 694 695 res = prepare_binprm(&bprm); 696 697 if (!is_error(res)) { 698 res = load_flat_file(&bprm, libs, id, NULL); 699 } 700 if (bprm.file) { 701 allow_write_access(bprm.file); 702 fput(bprm.file); 703 bprm.file = NULL; 704 } 705 return(res); 706 } 707 708 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 709 710 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info) 711 { 712 struct lib_info libinfo[MAX_SHARED_LIBS]; 713 abi_ulong p; 714 abi_ulong stack_len; 715 abi_ulong start_addr; 716 abi_ulong sp; 717 int res; 718 int i, j; 719 720 memset(libinfo, 0, sizeof(libinfo)); 721 /* 722 * We have to add the size of our arguments to our stack size 723 * otherwise it's too easy for users to create stack overflows 724 * by passing in a huge argument list. And yes, we have to be 725 * pedantic and include space for the argv/envp array as it may have 726 * a lot of entries. 727 */ 728 stack_len = 0; 729 for (i = 0; i < bprm->argc; ++i) { 730 /* the argv strings */ 731 stack_len += strlen(bprm->argv[i]); 732 } 733 for (i = 0; i < bprm->envc; ++i) { 734 /* the envp strings */ 735 stack_len += strlen(bprm->envp[i]); 736 } 737 stack_len += (bprm->argc + 1) * 4; /* the argv array */ 738 stack_len += (bprm->envc + 1) * 4; /* the envp array */ 739 740 741 res = load_flat_file(bprm, libinfo, 0, &stack_len); 742 if (is_error(res)) { 743 return res; 744 } 745 746 /* Update data segment pointers for all libraries */ 747 for (i=0; i<MAX_SHARED_LIBS; i++) { 748 if (libinfo[i].loaded) { 749 abi_ulong p; 750 p = libinfo[i].start_data; 751 for (j=0; j<MAX_SHARED_LIBS; j++) { 752 p -= 4; 753 /* FIXME - handle put_user() failures */ 754 if (put_user_ual(libinfo[j].loaded 755 ? libinfo[j].start_data 756 : UNLOADED_LIB, 757 p)) 758 return -EFAULT; 759 } 760 } 761 } 762 763 p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4; 764 DBG_FLT("p=%x\n", (int)p); 765 766 /* Copy argv/envp. */ 767 p = copy_strings(p, bprm->envc, bprm->envp); 768 p = copy_strings(p, bprm->argc, bprm->argv); 769 /* Align stack. */ 770 sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1); 771 /* Enforce final stack alignment of 16 bytes. This is sufficient 772 for all current targets, and excess alignment is harmless. */ 773 stack_len = bprm->envc + bprm->argc + 2; 774 stack_len += flat_argvp_envp_on_stack() ? 2 : 0; /* arvg, argp */ 775 stack_len += 1; /* argc */ 776 stack_len *= sizeof(abi_ulong); 777 sp -= (sp - stack_len) & 15; 778 sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, 779 flat_argvp_envp_on_stack()); 780 781 /* Fake some return addresses to ensure the call chain will 782 * initialise library in order for us. We are required to call 783 * lib 1 first, then 2, ... and finally the main program (id 0). 784 */ 785 start_addr = libinfo[0].entry; 786 787 #ifdef CONFIG_BINFMT_SHARED_FLAT 788 #error here 789 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 790 if (libinfo[i].loaded) { 791 /* Push previos first to call address */ 792 --sp; 793 if (put_user_ual(start_addr, sp)) 794 return -EFAULT; 795 start_addr = libinfo[i].entry; 796 } 797 } 798 #endif 799 800 /* Stash our initial stack pointer into the mm structure */ 801 info->start_code = libinfo[0].start_code; 802 info->end_code = libinfo[0].start_code = libinfo[0].text_len; 803 info->start_data = libinfo[0].start_data; 804 info->end_data = libinfo[0].end_data; 805 info->start_brk = libinfo[0].start_brk; 806 info->start_stack = sp; 807 info->stack_limit = libinfo[0].start_brk; 808 info->entry = start_addr; 809 info->code_offset = info->start_code; 810 info->data_offset = info->start_data - libinfo[0].text_len; 811 812 DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n", 813 (int)info->entry, (int)info->start_stack); 814 815 return 0; 816 } 817