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 #define ntohl(x) be32_to_cpu(x) 42 #include <target_flat.h> 43 44 //#define DEBUG 45 46 #ifdef DEBUG 47 #define DBG_FLT(...) printf(__VA_ARGS__) 48 #else 49 #define DBG_FLT(...) 50 #endif 51 52 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 53 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 54 55 struct lib_info { 56 abi_ulong start_code; /* Start of text segment */ 57 abi_ulong start_data; /* Start of data segment */ 58 abi_ulong end_data; /* Start of bss section */ 59 abi_ulong start_brk; /* End of data segment */ 60 abi_ulong text_len; /* Length of text segment */ 61 abi_ulong entry; /* Start address for this module */ 62 abi_ulong build_date; /* When this one was compiled */ 63 short loaded; /* Has this library been loaded? */ 64 }; 65 66 #ifdef CONFIG_BINFMT_SHARED_FLAT 67 static int load_flat_shared_library(int id, struct lib_info *p); 68 #endif 69 70 struct linux_binprm; 71 72 /****************************************************************************/ 73 /* 74 * create_flat_tables() parses the env- and arg-strings in new user 75 * memory and creates the pointer tables from them, and puts their 76 * addresses on the "stack", returning the new stack pointer value. 77 */ 78 79 /* Push a block of strings onto the guest stack. */ 80 static abi_ulong copy_strings(abi_ulong p, int n, char **s) 81 { 82 int len; 83 84 while (n-- > 0) { 85 len = strlen(s[n]) + 1; 86 p -= len; 87 memcpy_to_target(p, s[n], len); 88 } 89 90 return p; 91 } 92 93 static int target_pread(int fd, abi_ulong ptr, abi_ulong len, 94 abi_ulong offset) 95 { 96 void *buf; 97 int ret; 98 99 buf = lock_user(VERIFY_WRITE, ptr, len, 0); 100 ret = pread(fd, buf, len, offset); 101 unlock_user(buf, ptr, len); 102 return ret; 103 } 104 /****************************************************************************/ 105 106 #ifdef CONFIG_BINFMT_ZFLAT 107 108 #include <linux/zlib.h> 109 110 #define LBUFSIZE 4000 111 112 /* gzip flag byte */ 113 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 114 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 115 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 116 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 117 #define COMMENT 0x10 /* bit 4 set: file comment present */ 118 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 119 #define RESERVED 0xC0 /* bit 6,7: reserved */ 120 121 static int decompress_exec( 122 struct linux_binprm *bprm, 123 unsigned long offset, 124 char *dst, 125 long len, 126 int fd) 127 { 128 unsigned char *buf; 129 z_stream strm; 130 loff_t fpos; 131 int ret, retval; 132 133 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 134 135 memset(&strm, 0, sizeof(strm)); 136 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 137 if (strm.workspace == NULL) { 138 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 139 return -ENOMEM; 140 } 141 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 142 if (buf == NULL) { 143 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 144 retval = -ENOMEM; 145 goto out_free; 146 } 147 148 /* Read in first chunk of data and parse gzip header. */ 149 fpos = offset; 150 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 151 152 strm.next_in = buf; 153 strm.avail_in = ret; 154 strm.total_in = 0; 155 156 retval = -ENOEXEC; 157 158 /* Check minimum size -- gzip header */ 159 if (ret < 10) { 160 DBG_FLT("binfmt_flat: file too small?\n"); 161 goto out_free_buf; 162 } 163 164 /* Check gzip magic number */ 165 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 166 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 167 goto out_free_buf; 168 } 169 170 /* Check gzip method */ 171 if (buf[2] != 8) { 172 DBG_FLT("binfmt_flat: unknown compression method?\n"); 173 goto out_free_buf; 174 } 175 /* Check gzip flags */ 176 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 177 (buf[3] & RESERVED)) { 178 DBG_FLT("binfmt_flat: unknown flags?\n"); 179 goto out_free_buf; 180 } 181 182 ret = 10; 183 if (buf[3] & EXTRA_FIELD) { 184 ret += 2 + buf[10] + (buf[11] << 8); 185 if (unlikely(LBUFSIZE == ret)) { 186 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 187 goto out_free_buf; 188 } 189 } 190 if (buf[3] & ORIG_NAME) { 191 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 192 ; 193 if (unlikely(LBUFSIZE == ret)) { 194 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 195 goto out_free_buf; 196 } 197 } 198 if (buf[3] & COMMENT) { 199 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 200 ; 201 if (unlikely(LBUFSIZE == ret)) { 202 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 203 goto out_free_buf; 204 } 205 } 206 207 strm.next_in += ret; 208 strm.avail_in -= ret; 209 210 strm.next_out = dst; 211 strm.avail_out = len; 212 strm.total_out = 0; 213 214 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 215 DBG_FLT("binfmt_flat: zlib init failed?\n"); 216 goto out_free_buf; 217 } 218 219 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 220 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 221 if (ret <= 0) 222 break; 223 if (ret >= (unsigned long) -4096) 224 break; 225 len -= ret; 226 227 strm.next_in = buf; 228 strm.avail_in = ret; 229 strm.total_in = 0; 230 } 231 232 if (ret < 0) { 233 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 234 ret, strm.msg); 235 goto out_zlib; 236 } 237 238 retval = 0; 239 out_zlib: 240 zlib_inflateEnd(&strm); 241 out_free_buf: 242 kfree(buf); 243 out_free: 244 kfree(strm.workspace); 245 out: 246 return retval; 247 } 248 249 #endif /* CONFIG_BINFMT_ZFLAT */ 250 251 /****************************************************************************/ 252 253 static abi_ulong 254 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp) 255 { 256 abi_ulong addr; 257 int id; 258 abi_ulong start_brk; 259 abi_ulong start_data; 260 abi_ulong text_len; 261 abi_ulong start_code; 262 263 #ifdef CONFIG_BINFMT_SHARED_FLAT 264 #error needs checking 265 if (r == 0) 266 id = curid; /* Relocs of 0 are always self referring */ 267 else { 268 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 269 r &= 0x00ffffff; /* Trim ID off here */ 270 } 271 if (id >= MAX_SHARED_LIBS) { 272 fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n", 273 (unsigned) r, id); 274 goto failed; 275 } 276 if (curid != id) { 277 if (internalp) { 278 fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not " 279 "in same module (%d != %d)\n", 280 (unsigned) r, curid, id); 281 goto failed; 282 } else if ( ! p[id].loaded && 283 load_flat_shared_library(id, p) > (unsigned long) -4096) { 284 fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id); 285 goto failed; 286 } 287 /* Check versioning information (i.e. time stamps) */ 288 if (p[id].build_date && p[curid].build_date 289 && p[curid].build_date < p[id].build_date) { 290 fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n", 291 id, curid); 292 goto failed; 293 } 294 } 295 #else 296 id = 0; 297 #endif 298 299 start_brk = p[id].start_brk; 300 start_data = p[id].start_data; 301 start_code = p[id].start_code; 302 text_len = p[id].text_len; 303 304 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 305 fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x " 306 "(0 - 0x%x/0x%x)\n", 307 (int) r,(int)(start_brk-start_code),(int)text_len); 308 goto failed; 309 } 310 311 if (r < text_len) /* In text segment */ 312 addr = r + start_code; 313 else /* In data segment */ 314 addr = r - text_len + start_data; 315 316 /* Range checked already above so doing the range tests is redundant...*/ 317 return(addr); 318 319 failed: 320 abort(); 321 return RELOC_FAILED; 322 } 323 324 /****************************************************************************/ 325 326 /* ??? This does not handle endianness correctly. */ 327 static void old_reloc(struct lib_info *libinfo, uint32_t rl) 328 { 329 #ifdef DEBUG 330 const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 331 #endif 332 uint32_t *ptr; 333 uint32_t offset; 334 int reloc_type; 335 336 offset = rl & 0x3fffffff; 337 reloc_type = rl >> 30; 338 /* ??? How to handle this? */ 339 #if defined(CONFIG_COLDFIRE) 340 ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset); 341 #else 342 ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset); 343 #endif 344 345 #ifdef DEBUG 346 fprintf(stderr, "Relocation of variable at DATASEG+%x " 347 "(address %p, currently %x) into segment %s\n", 348 offset, ptr, (int)*ptr, segment[reloc_type]); 349 #endif 350 351 switch (reloc_type) { 352 case OLD_FLAT_RELOC_TYPE_TEXT: 353 *ptr += libinfo->start_code; 354 break; 355 case OLD_FLAT_RELOC_TYPE_DATA: 356 *ptr += libinfo->start_data; 357 break; 358 case OLD_FLAT_RELOC_TYPE_BSS: 359 *ptr += libinfo->end_data; 360 break; 361 default: 362 fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n", 363 reloc_type); 364 break; 365 } 366 DBG_FLT("Relocation became %x\n", (int)*ptr); 367 } 368 369 /****************************************************************************/ 370 371 static int load_flat_file(struct linux_binprm * bprm, 372 struct lib_info *libinfo, int id, abi_ulong *extra_stack) 373 { 374 struct flat_hdr * hdr; 375 abi_ulong textpos = 0, datapos = 0; 376 abi_long result; 377 abi_ulong realdatastart = 0; 378 abi_ulong text_len, data_len, bss_len, stack_len, flags; 379 abi_ulong extra; 380 abi_ulong reloc = 0, rp; 381 int i, rev, relocs = 0; 382 abi_ulong fpos; 383 abi_ulong start_code; 384 abi_ulong indx_len; 385 386 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 387 388 text_len = ntohl(hdr->data_start); 389 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 390 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 391 stack_len = ntohl(hdr->stack_size); 392 if (extra_stack) { 393 stack_len += *extra_stack; 394 *extra_stack = stack_len; 395 } 396 relocs = ntohl(hdr->reloc_count); 397 flags = ntohl(hdr->flags); 398 rev = ntohl(hdr->rev); 399 400 DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 401 402 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 403 fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n", 404 rev, (int) FLAT_VERSION); 405 return -ENOEXEC; 406 } 407 408 /* Don't allow old format executables to use shared libraries */ 409 if (rev == OLD_FLAT_VERSION && id != 0) { 410 fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n"); 411 return -ENOEXEC; 412 } 413 414 /* 415 * fix up the flags for the older format, there were all kinds 416 * of endian hacks, this only works for the simple cases 417 */ 418 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 419 flags = FLAT_FLAG_RAM; 420 421 #ifndef CONFIG_BINFMT_ZFLAT 422 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 423 fprintf(stderr, "Support for ZFLAT executables is not enabled\n"); 424 return -ENOEXEC; 425 } 426 #endif 427 428 /* 429 * calculate the extra space we need to map in 430 */ 431 extra = relocs * sizeof(abi_ulong); 432 if (extra < bss_len + stack_len) 433 extra = bss_len + stack_len; 434 435 /* Add space for library base pointers. Make sure this does not 436 misalign the doesn't misalign the data segment. */ 437 indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong); 438 indx_len = (indx_len + 15) & ~(abi_ulong)15; 439 440 /* 441 * there are a couple of cases here, the separate code/data 442 * case, and then the fully copied to RAM case which lumps 443 * it all together. 444 */ 445 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 446 /* 447 * this should give us a ROM ptr, but if it doesn't we don't 448 * really care 449 */ 450 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 451 452 textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC, 453 MAP_PRIVATE, bprm->fd, 0); 454 if (textpos == -1) { 455 fprintf(stderr, "Unable to mmap process text\n"); 456 return -1; 457 } 458 459 realdatastart = target_mmap(0, data_len + extra + indx_len, 460 PROT_READ|PROT_WRITE|PROT_EXEC, 461 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 462 463 if (realdatastart == -1) { 464 fprintf(stderr, "Unable to allocate RAM for process data\n"); 465 return realdatastart; 466 } 467 datapos = realdatastart + indx_len; 468 469 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 470 (int)(data_len + bss_len + stack_len), (int)datapos); 471 472 fpos = ntohl(hdr->data_start); 473 #ifdef CONFIG_BINFMT_ZFLAT 474 if (flags & FLAT_FLAG_GZDATA) { 475 result = decompress_exec(bprm, fpos, (char *) datapos, 476 data_len + (relocs * sizeof(abi_ulong))) 477 } else 478 #endif 479 { 480 result = target_pread(bprm->fd, datapos, 481 data_len + (relocs * sizeof(abi_ulong)), 482 fpos); 483 } 484 if (result < 0) { 485 fprintf(stderr, "Unable to read data+bss\n"); 486 return result; 487 } 488 489 reloc = datapos + (ntohl(hdr->reloc_start) - text_len); 490 491 } else { 492 493 textpos = target_mmap(0, text_len + data_len + extra + indx_len, 494 PROT_READ | PROT_EXEC | PROT_WRITE, 495 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 496 if (textpos == -1 ) { 497 fprintf(stderr, "Unable to allocate RAM for process text/data\n"); 498 return -1; 499 } 500 501 realdatastart = textpos + ntohl(hdr->data_start); 502 datapos = realdatastart + indx_len; 503 reloc = (textpos + ntohl(hdr->reloc_start) + indx_len); 504 505 #ifdef CONFIG_BINFMT_ZFLAT 506 #error code needs checking 507 /* 508 * load it all in and treat it like a RAM load from now on 509 */ 510 if (flags & FLAT_FLAG_GZIP) { 511 result = decompress_exec(bprm, sizeof (struct flat_hdr), 512 (((char *) textpos) + sizeof (struct flat_hdr)), 513 (text_len + data_len + (relocs * sizeof(unsigned long)) 514 - sizeof (struct flat_hdr)), 515 0); 516 memmove((void *) datapos, (void *) realdatastart, 517 data_len + (relocs * sizeof(unsigned long))); 518 } else if (flags & FLAT_FLAG_GZDATA) { 519 fpos = 0; 520 result = bprm->file->f_op->read(bprm->file, 521 (char *) textpos, text_len, &fpos); 522 if (result < (unsigned long) -4096) 523 result = decompress_exec(bprm, text_len, (char *) datapos, 524 data_len + (relocs * sizeof(unsigned long)), 0); 525 } 526 else 527 #endif 528 { 529 result = target_pread(bprm->fd, textpos, 530 text_len, 0); 531 if (result >= 0) { 532 result = target_pread(bprm->fd, datapos, 533 data_len + (relocs * sizeof(abi_ulong)), 534 ntohl(hdr->data_start)); 535 } 536 } 537 if (result < 0) { 538 fprintf(stderr, "Unable to read code+data+bss\n"); 539 return result; 540 } 541 } 542 543 DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n", 544 (int)textpos, 0x00ffffff&ntohl(hdr->entry), 545 ntohl(hdr->data_start)); 546 547 /* The main program needs a little extra setup in the task structure */ 548 start_code = textpos + sizeof (struct flat_hdr); 549 550 DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 551 id ? "Lib" : "Load", bprm->filename, 552 (int) start_code, (int) (textpos + text_len), 553 (int) datapos, 554 (int) (datapos + data_len), 555 (int) (datapos + data_len), 556 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 557 558 text_len -= sizeof(struct flat_hdr); /* the real code len */ 559 560 /* Store the current module values into the global library structure */ 561 libinfo[id].start_code = start_code; 562 libinfo[id].start_data = datapos; 563 libinfo[id].end_data = datapos + data_len; 564 libinfo[id].start_brk = datapos + data_len + bss_len; 565 libinfo[id].text_len = text_len; 566 libinfo[id].loaded = 1; 567 libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 568 libinfo[id].build_date = ntohl(hdr->build_date); 569 570 /* 571 * We just load the allocations into some temporary memory to 572 * help simplify all this mumbo jumbo 573 * 574 * We've got two different sections of relocation entries. 575 * The first is the GOT which resides at the beginning of the data segment 576 * and is terminated with a -1. This one can be relocated in place. 577 * The second is the extra relocation entries tacked after the image's 578 * data segment. These require a little more processing as the entry is 579 * really an offset into the image which contains an offset into the 580 * image. 581 */ 582 if (flags & FLAT_FLAG_GOTPIC) { 583 rp = datapos; 584 while (1) { 585 abi_ulong addr; 586 if (get_user_ual(addr, rp)) 587 return -EFAULT; 588 if (addr == -1) 589 break; 590 if (addr) { 591 addr = calc_reloc(addr, libinfo, id, 0); 592 if (addr == RELOC_FAILED) 593 return -ENOEXEC; 594 if (put_user_ual(addr, rp)) 595 return -EFAULT; 596 } 597 rp += sizeof(abi_ulong); 598 } 599 } 600 601 /* 602 * Now run through the relocation entries. 603 * We've got to be careful here as C++ produces relocatable zero 604 * entries in the constructor and destructor tables which are then 605 * tested for being not zero (which will always occur unless we're 606 * based from address zero). This causes an endless loop as __start 607 * is at zero. The solution used is to not relocate zero addresses. 608 * This has the negative side effect of not allowing a global data 609 * reference to be statically initialised to _stext (I've moved 610 * __start to address 4 so that is okay). 611 */ 612 if (rev > OLD_FLAT_VERSION) { 613 abi_ulong persistent = 0; 614 for (i = 0; i < relocs; i++) { 615 abi_ulong addr, relval; 616 617 /* Get the address of the pointer to be 618 relocated (of course, the address has to be 619 relocated first). */ 620 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) 621 return -EFAULT; 622 relval = ntohl(relval); 623 if (flat_set_persistent(relval, &persistent)) 624 continue; 625 addr = flat_get_relocate_addr(relval); 626 rp = calc_reloc(addr, libinfo, id, 1); 627 if (rp == RELOC_FAILED) 628 return -ENOEXEC; 629 630 /* Get the pointer's value. */ 631 if (get_user_ual(addr, rp)) 632 return -EFAULT; 633 addr = flat_get_addr_from_rp(addr, relval, flags, &persistent); 634 if (addr != 0) { 635 /* 636 * Do the relocation. PIC relocs in the data section are 637 * already in target order 638 */ 639 if ((flags & FLAT_FLAG_GOTPIC) == 0) 640 addr = ntohl(addr); 641 addr = calc_reloc(addr, libinfo, id, 0); 642 if (addr == RELOC_FAILED) 643 return -ENOEXEC; 644 645 /* Write back the relocated pointer. */ 646 if (flat_put_addr_at_rp(rp, addr, relval)) 647 return -EFAULT; 648 } 649 } 650 } else { 651 for (i = 0; i < relocs; i++) { 652 abi_ulong relval; 653 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) 654 return -EFAULT; 655 old_reloc(&libinfo[0], relval); 656 } 657 } 658 659 /* zero the BSS. */ 660 memset(g2h(datapos + data_len), 0, bss_len); 661 662 return 0; 663 } 664 665 666 /****************************************************************************/ 667 #ifdef CONFIG_BINFMT_SHARED_FLAT 668 669 /* 670 * Load a shared library into memory. The library gets its own data 671 * segment (including bss) but not argv/argc/environ. 672 */ 673 674 static int load_flat_shared_library(int id, struct lib_info *libs) 675 { 676 struct linux_binprm bprm; 677 int res; 678 char buf[16]; 679 680 /* Create the file name */ 681 sprintf(buf, "/lib/lib%d.so", id); 682 683 /* Open the file up */ 684 bprm.filename = buf; 685 bprm.file = open_exec(bprm.filename); 686 res = PTR_ERR(bprm.file); 687 if (IS_ERR(bprm.file)) 688 return res; 689 690 res = prepare_binprm(&bprm); 691 692 if (res <= (unsigned long)-4096) 693 res = load_flat_file(&bprm, libs, id, NULL); 694 if (bprm.file) { 695 allow_write_access(bprm.file); 696 fput(bprm.file); 697 bprm.file = NULL; 698 } 699 return(res); 700 } 701 702 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 703 704 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info) 705 { 706 struct lib_info libinfo[MAX_SHARED_LIBS]; 707 abi_ulong p; 708 abi_ulong stack_len; 709 abi_ulong start_addr; 710 abi_ulong sp; 711 int res; 712 int i, j; 713 714 memset(libinfo, 0, sizeof(libinfo)); 715 /* 716 * We have to add the size of our arguments to our stack size 717 * otherwise it's too easy for users to create stack overflows 718 * by passing in a huge argument list. And yes, we have to be 719 * pedantic and include space for the argv/envp array as it may have 720 * a lot of entries. 721 */ 722 stack_len = 0; 723 for (i = 0; i < bprm->argc; ++i) { 724 /* the argv strings */ 725 stack_len += strlen(bprm->argv[i]); 726 } 727 for (i = 0; i < bprm->envc; ++i) { 728 /* the envp strings */ 729 stack_len += strlen(bprm->envp[i]); 730 } 731 stack_len += (bprm->argc + 1) * 4; /* the argv array */ 732 stack_len += (bprm->envc + 1) * 4; /* the envp array */ 733 734 735 res = load_flat_file(bprm, libinfo, 0, &stack_len); 736 if (res > (unsigned long)-4096) 737 return res; 738 739 /* Update data segment pointers for all libraries */ 740 for (i=0; i<MAX_SHARED_LIBS; i++) { 741 if (libinfo[i].loaded) { 742 abi_ulong p; 743 p = libinfo[i].start_data; 744 for (j=0; j<MAX_SHARED_LIBS; j++) { 745 p -= 4; 746 /* FIXME - handle put_user() failures */ 747 if (put_user_ual(libinfo[j].loaded 748 ? libinfo[j].start_data 749 : UNLOADED_LIB, 750 p)) 751 return -EFAULT; 752 } 753 } 754 } 755 756 p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4; 757 DBG_FLT("p=%x\n", (int)p); 758 759 /* Copy argv/envp. */ 760 p = copy_strings(p, bprm->envc, bprm->envp); 761 p = copy_strings(p, bprm->argc, bprm->argv); 762 /* Align stack. */ 763 sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1); 764 /* Enforce final stack alignment of 16 bytes. This is sufficient 765 for all current targets, and excess alignment is harmless. */ 766 stack_len = bprm->envc + bprm->argc + 2; 767 stack_len += 3; /* argc, arvg, argp */ 768 stack_len *= sizeof(abi_ulong); 769 if ((sp + stack_len) & 15) 770 sp -= 16 - ((sp + stack_len) & 15); 771 sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, 772 flat_argvp_envp_on_stack()); 773 774 /* Fake some return addresses to ensure the call chain will 775 * initialise library in order for us. We are required to call 776 * lib 1 first, then 2, ... and finally the main program (id 0). 777 */ 778 start_addr = libinfo[0].entry; 779 780 #ifdef CONFIG_BINFMT_SHARED_FLAT 781 #error here 782 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 783 if (libinfo[i].loaded) { 784 /* Push previos first to call address */ 785 --sp; 786 if (put_user_ual(start_addr, sp)) 787 return -EFAULT; 788 start_addr = libinfo[i].entry; 789 } 790 } 791 #endif 792 793 /* Stash our initial stack pointer into the mm structure */ 794 info->start_code = libinfo[0].start_code; 795 info->end_code = libinfo[0].start_code = libinfo[0].text_len; 796 info->start_data = libinfo[0].start_data; 797 info->end_data = libinfo[0].end_data; 798 info->start_brk = libinfo[0].start_brk; 799 info->start_stack = sp; 800 info->stack_limit = libinfo[0].start_brk; 801 info->entry = start_addr; 802 info->code_offset = info->start_code; 803 info->data_offset = info->start_data - libinfo[0].text_len; 804 805 DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n", 806 (int)info->entry, (int)info->start_stack); 807 808 return 0; 809 } 810