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 <stdio.h> 37 #include <stdlib.h> 38 #include <errno.h> 39 #include <sys/mman.h> 40 #include <unistd.h> 41 42 #include "qemu.h" 43 #include "flat.h" 44 45 //#define DEBUG 46 47 #ifdef DEBUG 48 #define DBG_FLT(...) printf(__VA_ARGS__) 49 #else 50 #define DBG_FLT(...) 51 #endif 52 53 #define flat_reloc_valid(reloc, size) ((reloc) <= (size)) 54 #define flat_old_ram_flag(flag) (flag) 55 #ifdef TARGET_WORDS_BIGENDIAN 56 #define flat_get_relocate_addr(relval) (relval) 57 #else 58 #define flat_get_relocate_addr(relval) bswap32(relval) 59 #endif 60 61 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 62 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 63 64 struct lib_info { 65 abi_ulong start_code; /* Start of text segment */ 66 abi_ulong start_data; /* Start of data segment */ 67 abi_ulong end_data; /* Start of bss section */ 68 abi_ulong start_brk; /* End of data segment */ 69 abi_ulong text_len; /* Length of text segment */ 70 abi_ulong entry; /* Start address for this module */ 71 abi_ulong build_date; /* When this one was compiled */ 72 short loaded; /* Has this library been loaded? */ 73 }; 74 75 #ifdef CONFIG_BINFMT_SHARED_FLAT 76 static int load_flat_shared_library(int id, struct lib_info *p); 77 #endif 78 79 struct linux_binprm; 80 81 #define ntohl(x) be32_to_cpu(x) 82 83 /****************************************************************************/ 84 /* 85 * create_flat_tables() parses the env- and arg-strings in new user 86 * memory and creates the pointer tables from them, and puts their 87 * addresses on the "stack", returning the new stack pointer value. 88 */ 89 90 /* Push a block of strings onto the guest stack. */ 91 static abi_ulong copy_strings(abi_ulong p, int n, char **s) 92 { 93 int len; 94 95 while (n-- > 0) { 96 len = strlen(s[n]) + 1; 97 p -= len; 98 memcpy_to_target(p, s[n], len); 99 } 100 101 return p; 102 } 103 104 static int target_pread(int fd, abi_ulong ptr, abi_ulong len, 105 abi_ulong offset) 106 { 107 void *buf; 108 int ret; 109 110 buf = lock_user(VERIFY_WRITE, ptr, len, 0); 111 ret = pread(fd, buf, len, offset); 112 unlock_user(buf, ptr, len); 113 return ret; 114 } 115 /****************************************************************************/ 116 117 #ifdef CONFIG_BINFMT_ZFLAT 118 119 #include <linux/zlib.h> 120 121 #define LBUFSIZE 4000 122 123 /* gzip flag byte */ 124 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 125 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 126 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 127 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 128 #define COMMENT 0x10 /* bit 4 set: file comment present */ 129 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 130 #define RESERVED 0xC0 /* bit 6,7: reserved */ 131 132 static int decompress_exec( 133 struct linux_binprm *bprm, 134 unsigned long offset, 135 char *dst, 136 long len, 137 int fd) 138 { 139 unsigned char *buf; 140 z_stream strm; 141 loff_t fpos; 142 int ret, retval; 143 144 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 145 146 memset(&strm, 0, sizeof(strm)); 147 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 148 if (strm.workspace == NULL) { 149 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 150 return -ENOMEM; 151 } 152 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 153 if (buf == NULL) { 154 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 155 retval = -ENOMEM; 156 goto out_free; 157 } 158 159 /* Read in first chunk of data and parse gzip header. */ 160 fpos = offset; 161 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 162 163 strm.next_in = buf; 164 strm.avail_in = ret; 165 strm.total_in = 0; 166 167 retval = -ENOEXEC; 168 169 /* Check minimum size -- gzip header */ 170 if (ret < 10) { 171 DBG_FLT("binfmt_flat: file too small?\n"); 172 goto out_free_buf; 173 } 174 175 /* Check gzip magic number */ 176 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 177 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 178 goto out_free_buf; 179 } 180 181 /* Check gzip method */ 182 if (buf[2] != 8) { 183 DBG_FLT("binfmt_flat: unknown compression method?\n"); 184 goto out_free_buf; 185 } 186 /* Check gzip flags */ 187 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 188 (buf[3] & RESERVED)) { 189 DBG_FLT("binfmt_flat: unknown flags?\n"); 190 goto out_free_buf; 191 } 192 193 ret = 10; 194 if (buf[3] & EXTRA_FIELD) { 195 ret += 2 + buf[10] + (buf[11] << 8); 196 if (unlikely(LBUFSIZE == ret)) { 197 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 198 goto out_free_buf; 199 } 200 } 201 if (buf[3] & ORIG_NAME) { 202 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 203 ; 204 if (unlikely(LBUFSIZE == ret)) { 205 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 206 goto out_free_buf; 207 } 208 } 209 if (buf[3] & COMMENT) { 210 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 211 ; 212 if (unlikely(LBUFSIZE == ret)) { 213 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 214 goto out_free_buf; 215 } 216 } 217 218 strm.next_in += ret; 219 strm.avail_in -= ret; 220 221 strm.next_out = dst; 222 strm.avail_out = len; 223 strm.total_out = 0; 224 225 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 226 DBG_FLT("binfmt_flat: zlib init failed?\n"); 227 goto out_free_buf; 228 } 229 230 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 231 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 232 if (ret <= 0) 233 break; 234 if (ret >= (unsigned long) -4096) 235 break; 236 len -= ret; 237 238 strm.next_in = buf; 239 strm.avail_in = ret; 240 strm.total_in = 0; 241 } 242 243 if (ret < 0) { 244 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 245 ret, strm.msg); 246 goto out_zlib; 247 } 248 249 retval = 0; 250 out_zlib: 251 zlib_inflateEnd(&strm); 252 out_free_buf: 253 kfree(buf); 254 out_free: 255 kfree(strm.workspace); 256 out: 257 return retval; 258 } 259 260 #endif /* CONFIG_BINFMT_ZFLAT */ 261 262 /****************************************************************************/ 263 264 static abi_ulong 265 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp) 266 { 267 abi_ulong addr; 268 int id; 269 abi_ulong start_brk; 270 abi_ulong start_data; 271 abi_ulong text_len; 272 abi_ulong start_code; 273 274 #ifdef CONFIG_BINFMT_SHARED_FLAT 275 #error needs checking 276 if (r == 0) 277 id = curid; /* Relocs of 0 are always self referring */ 278 else { 279 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 280 r &= 0x00ffffff; /* Trim ID off here */ 281 } 282 if (id >= MAX_SHARED_LIBS) { 283 fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n", 284 (unsigned) r, id); 285 goto failed; 286 } 287 if (curid != id) { 288 if (internalp) { 289 fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not " 290 "in same module (%d != %d)\n", 291 (unsigned) r, curid, id); 292 goto failed; 293 } else if ( ! p[id].loaded && 294 load_flat_shared_library(id, p) > (unsigned long) -4096) { 295 fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id); 296 goto failed; 297 } 298 /* Check versioning information (i.e. time stamps) */ 299 if (p[id].build_date && p[curid].build_date 300 && p[curid].build_date < p[id].build_date) { 301 fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n", 302 id, curid); 303 goto failed; 304 } 305 } 306 #else 307 id = 0; 308 #endif 309 310 start_brk = p[id].start_brk; 311 start_data = p[id].start_data; 312 start_code = p[id].start_code; 313 text_len = p[id].text_len; 314 315 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 316 fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x " 317 "(0 - 0x%x/0x%x)\n", 318 (int) r,(int)(start_brk-start_code),(int)text_len); 319 goto failed; 320 } 321 322 if (r < text_len) /* In text segment */ 323 addr = r + start_code; 324 else /* In data segment */ 325 addr = r - text_len + start_data; 326 327 /* Range checked already above so doing the range tests is redundant...*/ 328 return(addr); 329 330 failed: 331 abort(); 332 return RELOC_FAILED; 333 } 334 335 /****************************************************************************/ 336 337 /* ??? This does not handle endianness correctly. */ 338 static void old_reloc(struct lib_info *libinfo, uint32_t rl) 339 { 340 #ifdef DEBUG 341 const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 342 #endif 343 uint32_t *ptr; 344 uint32_t offset; 345 int reloc_type; 346 347 offset = rl & 0x3fffffff; 348 reloc_type = rl >> 30; 349 /* ??? How to handle this? */ 350 #if defined(CONFIG_COLDFIRE) 351 ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset); 352 #else 353 ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset); 354 #endif 355 356 #ifdef DEBUG 357 fprintf(stderr, "Relocation of variable at DATASEG+%x " 358 "(address %p, currently %x) into segment %s\n", 359 offset, ptr, (int)*ptr, segment[reloc_type]); 360 #endif 361 362 switch (reloc_type) { 363 case OLD_FLAT_RELOC_TYPE_TEXT: 364 *ptr += libinfo->start_code; 365 break; 366 case OLD_FLAT_RELOC_TYPE_DATA: 367 *ptr += libinfo->start_data; 368 break; 369 case OLD_FLAT_RELOC_TYPE_BSS: 370 *ptr += libinfo->end_data; 371 break; 372 default: 373 fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n", 374 reloc_type); 375 break; 376 } 377 DBG_FLT("Relocation became %x\n", (int)*ptr); 378 } 379 380 /****************************************************************************/ 381 382 static int load_flat_file(struct linux_binprm * bprm, 383 struct lib_info *libinfo, int id, abi_ulong *extra_stack) 384 { 385 struct flat_hdr * hdr; 386 abi_ulong textpos = 0, datapos = 0; 387 abi_long result; 388 abi_ulong realdatastart = 0; 389 abi_ulong text_len, data_len, bss_len, stack_len, flags; 390 abi_ulong memp = 0; /* for finding the brk area */ 391 abi_ulong extra; 392 abi_ulong reloc = 0, rp; 393 int i, rev, relocs = 0; 394 abi_ulong fpos; 395 abi_ulong start_code, end_code; 396 abi_ulong indx_len; 397 398 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 399 400 text_len = ntohl(hdr->data_start); 401 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 402 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 403 stack_len = ntohl(hdr->stack_size); 404 if (extra_stack) { 405 stack_len += *extra_stack; 406 *extra_stack = stack_len; 407 } 408 relocs = ntohl(hdr->reloc_count); 409 flags = ntohl(hdr->flags); 410 rev = ntohl(hdr->rev); 411 412 DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 413 414 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 415 fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n", 416 rev, (int) FLAT_VERSION); 417 return -ENOEXEC; 418 } 419 420 /* Don't allow old format executables to use shared libraries */ 421 if (rev == OLD_FLAT_VERSION && id != 0) { 422 fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n"); 423 return -ENOEXEC; 424 } 425 426 /* 427 * fix up the flags for the older format, there were all kinds 428 * of endian hacks, this only works for the simple cases 429 */ 430 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 431 flags = FLAT_FLAG_RAM; 432 433 #ifndef CONFIG_BINFMT_ZFLAT 434 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 435 fprintf(stderr, "Support for ZFLAT executables is not enabled\n"); 436 return -ENOEXEC; 437 } 438 #endif 439 440 /* 441 * calculate the extra space we need to map in 442 */ 443 extra = relocs * sizeof(abi_ulong); 444 if (extra < bss_len + stack_len) 445 extra = bss_len + stack_len; 446 447 /* Add space for library base pointers. Make sure this does not 448 misalign the doesn't misalign the data segment. */ 449 indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong); 450 indx_len = (indx_len + 15) & ~(abi_ulong)15; 451 452 /* 453 * there are a couple of cases here, the separate code/data 454 * case, and then the fully copied to RAM case which lumps 455 * it all together. 456 */ 457 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 458 /* 459 * this should give us a ROM ptr, but if it doesn't we don't 460 * really care 461 */ 462 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 463 464 textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC, 465 MAP_PRIVATE, bprm->fd, 0); 466 if (textpos == -1) { 467 fprintf(stderr, "Unable to mmap process text\n"); 468 return -1; 469 } 470 471 realdatastart = target_mmap(0, data_len + extra + indx_len, 472 PROT_READ|PROT_WRITE|PROT_EXEC, 473 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 474 475 if (realdatastart == -1) { 476 fprintf(stderr, "Unable to allocate RAM for process data\n"); 477 return realdatastart; 478 } 479 datapos = realdatastart + indx_len; 480 481 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 482 (int)(data_len + bss_len + stack_len), (int)datapos); 483 484 fpos = ntohl(hdr->data_start); 485 #ifdef CONFIG_BINFMT_ZFLAT 486 if (flags & FLAT_FLAG_GZDATA) { 487 result = decompress_exec(bprm, fpos, (char *) datapos, 488 data_len + (relocs * sizeof(abi_ulong))) 489 } else 490 #endif 491 { 492 result = target_pread(bprm->fd, datapos, 493 data_len + (relocs * sizeof(abi_ulong)), 494 fpos); 495 } 496 if (result < 0) { 497 fprintf(stderr, "Unable to read data+bss\n"); 498 return result; 499 } 500 501 reloc = datapos + (ntohl(hdr->reloc_start) - text_len); 502 memp = realdatastart; 503 504 } else { 505 506 textpos = target_mmap(0, text_len + data_len + extra + indx_len, 507 PROT_READ | PROT_EXEC | PROT_WRITE, 508 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 509 if (textpos == -1 ) { 510 fprintf(stderr, "Unable to allocate RAM for process text/data\n"); 511 return -1; 512 } 513 514 realdatastart = textpos + ntohl(hdr->data_start); 515 datapos = realdatastart + indx_len; 516 reloc = (textpos + ntohl(hdr->reloc_start) + indx_len); 517 memp = textpos; 518 519 #ifdef CONFIG_BINFMT_ZFLAT 520 #error code needs checking 521 /* 522 * load it all in and treat it like a RAM load from now on 523 */ 524 if (flags & FLAT_FLAG_GZIP) { 525 result = decompress_exec(bprm, sizeof (struct flat_hdr), 526 (((char *) textpos) + sizeof (struct flat_hdr)), 527 (text_len + data_len + (relocs * sizeof(unsigned long)) 528 - sizeof (struct flat_hdr)), 529 0); 530 memmove((void *) datapos, (void *) realdatastart, 531 data_len + (relocs * sizeof(unsigned long))); 532 } else if (flags & FLAT_FLAG_GZDATA) { 533 fpos = 0; 534 result = bprm->file->f_op->read(bprm->file, 535 (char *) textpos, text_len, &fpos); 536 if (result < (unsigned long) -4096) 537 result = decompress_exec(bprm, text_len, (char *) datapos, 538 data_len + (relocs * sizeof(unsigned long)), 0); 539 } 540 else 541 #endif 542 { 543 result = target_pread(bprm->fd, textpos, 544 text_len, 0); 545 if (result >= 0) { 546 result = target_pread(bprm->fd, datapos, 547 data_len + (relocs * sizeof(abi_ulong)), 548 ntohl(hdr->data_start)); 549 } 550 } 551 if (result < 0) { 552 fprintf(stderr, "Unable to read code+data+bss\n"); 553 return result; 554 } 555 } 556 557 DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n", 558 (int)textpos, 0x00ffffff&ntohl(hdr->entry), 559 ntohl(hdr->data_start)); 560 561 /* The main program needs a little extra setup in the task structure */ 562 start_code = textpos + sizeof (struct flat_hdr); 563 end_code = textpos + text_len; 564 565 DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 566 id ? "Lib" : "Load", bprm->filename, 567 (int) start_code, (int) end_code, 568 (int) datapos, 569 (int) (datapos + data_len), 570 (int) (datapos + data_len), 571 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 572 573 text_len -= sizeof(struct flat_hdr); /* the real code len */ 574 575 /* Store the current module values into the global library structure */ 576 libinfo[id].start_code = start_code; 577 libinfo[id].start_data = datapos; 578 libinfo[id].end_data = datapos + data_len; 579 libinfo[id].start_brk = datapos + data_len + bss_len; 580 libinfo[id].text_len = text_len; 581 libinfo[id].loaded = 1; 582 libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 583 libinfo[id].build_date = ntohl(hdr->build_date); 584 585 /* 586 * We just load the allocations into some temporary memory to 587 * help simplify all this mumbo jumbo 588 * 589 * We've got two different sections of relocation entries. 590 * The first is the GOT which resides at the begining of the data segment 591 * and is terminated with a -1. This one can be relocated in place. 592 * The second is the extra relocation entries tacked after the image's 593 * data segment. These require a little more processing as the entry is 594 * really an offset into the image which contains an offset into the 595 * image. 596 */ 597 if (flags & FLAT_FLAG_GOTPIC) { 598 rp = datapos; 599 while (1) { 600 abi_ulong addr; 601 if (get_user_ual(addr, rp)) 602 return -EFAULT; 603 if (addr == -1) 604 break; 605 if (addr) { 606 addr = calc_reloc(addr, libinfo, id, 0); 607 if (addr == RELOC_FAILED) 608 return -ENOEXEC; 609 if (put_user_ual(addr, rp)) 610 return -EFAULT; 611 } 612 rp += sizeof(abi_ulong); 613 } 614 } 615 616 /* 617 * Now run through the relocation entries. 618 * We've got to be careful here as C++ produces relocatable zero 619 * entries in the constructor and destructor tables which are then 620 * tested for being not zero (which will always occur unless we're 621 * based from address zero). This causes an endless loop as __start 622 * is at zero. The solution used is to not relocate zero addresses. 623 * This has the negative side effect of not allowing a global data 624 * reference to be statically initialised to _stext (I've moved 625 * __start to address 4 so that is okay). 626 */ 627 if (rev > OLD_FLAT_VERSION) { 628 for (i = 0; i < relocs; i++) { 629 abi_ulong addr, relval; 630 631 /* Get the address of the pointer to be 632 relocated (of course, the address has to be 633 relocated first). */ 634 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) 635 return -EFAULT; 636 addr = flat_get_relocate_addr(relval); 637 rp = calc_reloc(addr, libinfo, id, 1); 638 if (rp == RELOC_FAILED) 639 return -ENOEXEC; 640 641 /* Get the pointer's value. */ 642 if (get_user_ual(addr, rp)) 643 return -EFAULT; 644 if (addr != 0) { 645 /* 646 * Do the relocation. PIC relocs in the data section are 647 * already in target order 648 */ 649 650 #ifndef TARGET_WORDS_BIGENDIAN 651 if ((flags & FLAT_FLAG_GOTPIC) == 0) 652 addr = bswap32(addr); 653 #endif 654 addr = calc_reloc(addr, libinfo, id, 0); 655 if (addr == RELOC_FAILED) 656 return -ENOEXEC; 657 658 /* Write back the relocated pointer. */ 659 if (put_user_ual(addr, rp)) 660 return -EFAULT; 661 } 662 } 663 } else { 664 for (i = 0; i < relocs; i++) { 665 abi_ulong relval; 666 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong))) 667 return -EFAULT; 668 old_reloc(&libinfo[0], relval); 669 } 670 } 671 672 /* zero the BSS. */ 673 memset((void *)((unsigned long)datapos + data_len), 0, bss_len); 674 675 return 0; 676 } 677 678 679 /****************************************************************************/ 680 #ifdef CONFIG_BINFMT_SHARED_FLAT 681 682 /* 683 * Load a shared library into memory. The library gets its own data 684 * segment (including bss) but not argv/argc/environ. 685 */ 686 687 static int load_flat_shared_library(int id, struct lib_info *libs) 688 { 689 struct linux_binprm bprm; 690 int res; 691 char buf[16]; 692 693 /* Create the file name */ 694 sprintf(buf, "/lib/lib%d.so", id); 695 696 /* Open the file up */ 697 bprm.filename = buf; 698 bprm.file = open_exec(bprm.filename); 699 res = PTR_ERR(bprm.file); 700 if (IS_ERR(bprm.file)) 701 return res; 702 703 res = prepare_binprm(&bprm); 704 705 if (res <= (unsigned long)-4096) 706 res = load_flat_file(&bprm, libs, id, NULL); 707 if (bprm.file) { 708 allow_write_access(bprm.file); 709 fput(bprm.file); 710 bprm.file = NULL; 711 } 712 return(res); 713 } 714 715 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 716 717 int load_flt_binary(struct linux_binprm * bprm, struct target_pt_regs * regs, 718 struct image_info * info) 719 { 720 struct lib_info libinfo[MAX_SHARED_LIBS]; 721 abi_ulong p = bprm->p; 722 abi_ulong stack_len; 723 abi_ulong start_addr; 724 abi_ulong sp; 725 int res; 726 int i, j; 727 728 memset(libinfo, 0, sizeof(libinfo)); 729 /* 730 * We have to add the size of our arguments to our stack size 731 * otherwise it's too easy for users to create stack overflows 732 * by passing in a huge argument list. And yes, we have to be 733 * pedantic and include space for the argv/envp array as it may have 734 * a lot of entries. 735 */ 736 #define TOP_OF_ARGS (TARGET_PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *)) 737 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ 738 stack_len += (bprm->argc + 1) * 4; /* the argv array */ 739 stack_len += (bprm->envc + 1) * 4; /* the envp array */ 740 741 742 res = load_flat_file(bprm, libinfo, 0, &stack_len); 743 if (res > (unsigned long)-4096) 744 return res; 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 += 3; /* argc, arvg, argp */ 775 stack_len *= sizeof(abi_ulong); 776 if ((sp + stack_len) & 15) 777 sp -= 16 - ((sp + stack_len) & 15); 778 sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, 1); 779 780 /* Fake some return addresses to ensure the call chain will 781 * initialise library in order for us. We are required to call 782 * lib 1 first, then 2, ... and finally the main program (id 0). 783 */ 784 start_addr = libinfo[0].entry; 785 786 #ifdef CONFIG_BINFMT_SHARED_FLAT 787 #error here 788 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 789 if (libinfo[i].loaded) { 790 /* Push previos first to call address */ 791 --sp; 792 if (put_user_ual(start_addr, sp)) 793 return -EFAULT; 794 start_addr = libinfo[i].entry; 795 } 796 } 797 #endif 798 799 /* Stash our initial stack pointer into the mm structure */ 800 info->start_code = libinfo[0].start_code; 801 info->end_code = libinfo[0].start_code = libinfo[0].text_len; 802 info->start_data = libinfo[0].start_data; 803 info->end_data = libinfo[0].end_data; 804 info->start_brk = libinfo[0].start_brk; 805 info->start_stack = sp; 806 info->stack_limit = libinfo[0].start_brk; 807 info->entry = start_addr; 808 info->code_offset = info->start_code; 809 info->data_offset = info->start_data - libinfo[0].text_len; 810 811 DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n", 812 (int)info->entry, (int)info->start_stack); 813 814 return 0; 815 } 816