1 /****************************************************************************/ 2 /* 3 * linux/fs/binfmt_flat.c 4 * 5 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> 6 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> 7 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> 8 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> 9 * based heavily on: 10 * 11 * linux/fs/binfmt_aout.c: 12 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 13 * linux/fs/binfmt_flat.c for 2.0 kernel 14 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> 15 * JAN/99 -- coded full program relocation (gerg@snapgear.com) 16 */ 17 18 #include <linux/module.h> 19 #include <linux/kernel.h> 20 #include <linux/sched.h> 21 #include <linux/mm.h> 22 #include <linux/mman.h> 23 #include <linux/errno.h> 24 #include <linux/signal.h> 25 #include <linux/string.h> 26 #include <linux/fs.h> 27 #include <linux/file.h> 28 #include <linux/stat.h> 29 #include <linux/fcntl.h> 30 #include <linux/ptrace.h> 31 #include <linux/user.h> 32 #include <linux/slab.h> 33 #include <linux/binfmts.h> 34 #include <linux/personality.h> 35 #include <linux/init.h> 36 #include <linux/flat.h> 37 #include <linux/syscalls.h> 38 39 #include <asm/byteorder.h> 40 #include <asm/system.h> 41 #include <asm/uaccess.h> 42 #include <asm/unaligned.h> 43 #include <asm/cacheflush.h> 44 45 /****************************************************************************/ 46 47 #if 0 48 #define DEBUG 1 49 #endif 50 51 #ifdef DEBUG 52 #define DBG_FLT(a...) printk(a) 53 #else 54 #define DBG_FLT(a...) 55 #endif 56 57 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 58 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 59 60 struct lib_info { 61 struct { 62 unsigned long start_code; /* Start of text segment */ 63 unsigned long start_data; /* Start of data segment */ 64 unsigned long start_brk; /* End of data segment */ 65 unsigned long text_len; /* Length of text segment */ 66 unsigned long entry; /* Start address for this module */ 67 unsigned long build_date; /* When this one was compiled */ 68 short loaded; /* Has this library been loaded? */ 69 } lib_list[MAX_SHARED_LIBS]; 70 }; 71 72 #ifdef CONFIG_BINFMT_SHARED_FLAT 73 static int load_flat_shared_library(int id, struct lib_info *p); 74 #endif 75 76 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs); 77 static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit); 78 79 static struct linux_binfmt flat_format = { 80 .module = THIS_MODULE, 81 .load_binary = load_flat_binary, 82 .core_dump = flat_core_dump, 83 .min_coredump = PAGE_SIZE 84 }; 85 86 /****************************************************************************/ 87 /* 88 * Routine writes a core dump image in the current directory. 89 * Currently only a stub-function. 90 */ 91 92 static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit) 93 { 94 printk("Process %s:%d received signr %d and should have core dumped\n", 95 current->comm, current->pid, (int) signr); 96 return(1); 97 } 98 99 /****************************************************************************/ 100 /* 101 * create_flat_tables() parses the env- and arg-strings in new user 102 * memory and creates the pointer tables from them, and puts their 103 * addresses on the "stack", returning the new stack pointer value. 104 */ 105 106 static unsigned long create_flat_tables( 107 unsigned long pp, 108 struct linux_binprm * bprm) 109 { 110 unsigned long *argv,*envp; 111 unsigned long * sp; 112 char * p = (char*)pp; 113 int argc = bprm->argc; 114 int envc = bprm->envc; 115 char uninitialized_var(dummy); 116 117 sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p); 118 119 sp -= envc+1; 120 envp = sp; 121 sp -= argc+1; 122 argv = sp; 123 124 flat_stack_align(sp); 125 if (flat_argvp_envp_on_stack()) { 126 --sp; put_user((unsigned long) envp, sp); 127 --sp; put_user((unsigned long) argv, sp); 128 } 129 130 put_user(argc,--sp); 131 current->mm->arg_start = (unsigned long) p; 132 while (argc-->0) { 133 put_user((unsigned long) p, argv++); 134 do { 135 get_user(dummy, p); p++; 136 } while (dummy); 137 } 138 put_user((unsigned long) NULL, argv); 139 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 140 while (envc-->0) { 141 put_user((unsigned long)p, envp); envp++; 142 do { 143 get_user(dummy, p); p++; 144 } while (dummy); 145 } 146 put_user((unsigned long) NULL, envp); 147 current->mm->env_end = (unsigned long) p; 148 return (unsigned long)sp; 149 } 150 151 /****************************************************************************/ 152 153 #ifdef CONFIG_BINFMT_ZFLAT 154 155 #include <linux/zlib.h> 156 157 #define LBUFSIZE 4000 158 159 /* gzip flag byte */ 160 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 161 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 162 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 163 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 164 #define COMMENT 0x10 /* bit 4 set: file comment present */ 165 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 166 #define RESERVED 0xC0 /* bit 6,7: reserved */ 167 168 static int decompress_exec( 169 struct linux_binprm *bprm, 170 unsigned long offset, 171 char *dst, 172 long len, 173 int fd) 174 { 175 unsigned char *buf; 176 z_stream strm; 177 loff_t fpos; 178 int ret, retval; 179 180 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 181 182 memset(&strm, 0, sizeof(strm)); 183 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 184 if (strm.workspace == NULL) { 185 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 186 return -ENOMEM; 187 } 188 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 189 if (buf == NULL) { 190 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 191 retval = -ENOMEM; 192 goto out_free; 193 } 194 195 /* Read in first chunk of data and parse gzip header. */ 196 fpos = offset; 197 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 198 199 strm.next_in = buf; 200 strm.avail_in = ret; 201 strm.total_in = 0; 202 203 retval = -ENOEXEC; 204 205 /* Check minimum size -- gzip header */ 206 if (ret < 10) { 207 DBG_FLT("binfmt_flat: file too small?\n"); 208 goto out_free_buf; 209 } 210 211 /* Check gzip magic number */ 212 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 213 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 214 goto out_free_buf; 215 } 216 217 /* Check gzip method */ 218 if (buf[2] != 8) { 219 DBG_FLT("binfmt_flat: unknown compression method?\n"); 220 goto out_free_buf; 221 } 222 /* Check gzip flags */ 223 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 224 (buf[3] & RESERVED)) { 225 DBG_FLT("binfmt_flat: unknown flags?\n"); 226 goto out_free_buf; 227 } 228 229 ret = 10; 230 if (buf[3] & EXTRA_FIELD) { 231 ret += 2 + buf[10] + (buf[11] << 8); 232 if (unlikely(LBUFSIZE == ret)) { 233 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 234 goto out_free_buf; 235 } 236 } 237 if (buf[3] & ORIG_NAME) { 238 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 239 ; 240 if (unlikely(LBUFSIZE == ret)) { 241 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 242 goto out_free_buf; 243 } 244 } 245 if (buf[3] & COMMENT) { 246 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 247 ; 248 if (unlikely(LBUFSIZE == ret)) { 249 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 250 goto out_free_buf; 251 } 252 } 253 254 strm.next_in += ret; 255 strm.avail_in -= ret; 256 257 strm.next_out = dst; 258 strm.avail_out = len; 259 strm.total_out = 0; 260 261 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 262 DBG_FLT("binfmt_flat: zlib init failed?\n"); 263 goto out_free_buf; 264 } 265 266 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 267 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 268 if (ret <= 0) 269 break; 270 if (ret >= (unsigned long) -4096) 271 break; 272 len -= ret; 273 274 strm.next_in = buf; 275 strm.avail_in = ret; 276 strm.total_in = 0; 277 } 278 279 if (ret < 0) { 280 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 281 ret, strm.msg); 282 goto out_zlib; 283 } 284 285 retval = 0; 286 out_zlib: 287 zlib_inflateEnd(&strm); 288 out_free_buf: 289 kfree(buf); 290 out_free: 291 kfree(strm.workspace); 292 return retval; 293 } 294 295 #endif /* CONFIG_BINFMT_ZFLAT */ 296 297 /****************************************************************************/ 298 299 static unsigned long 300 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 301 { 302 unsigned long addr; 303 int id; 304 unsigned long start_brk; 305 unsigned long start_data; 306 unsigned long text_len; 307 unsigned long start_code; 308 309 #ifdef CONFIG_BINFMT_SHARED_FLAT 310 if (r == 0) 311 id = curid; /* Relocs of 0 are always self referring */ 312 else { 313 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 314 r &= 0x00ffffff; /* Trim ID off here */ 315 } 316 if (id >= MAX_SHARED_LIBS) { 317 printk("BINFMT_FLAT: reference 0x%x to shared library %d", 318 (unsigned) r, id); 319 goto failed; 320 } 321 if (curid != id) { 322 if (internalp) { 323 printk("BINFMT_FLAT: reloc address 0x%x not in same module " 324 "(%d != %d)", (unsigned) r, curid, id); 325 goto failed; 326 } else if ( ! p->lib_list[id].loaded && 327 load_flat_shared_library(id, p) > (unsigned long) -4096) { 328 printk("BINFMT_FLAT: failed to load library %d", id); 329 goto failed; 330 } 331 /* Check versioning information (i.e. time stamps) */ 332 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 333 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 334 printk("BINFMT_FLAT: library %d is younger than %d", id, curid); 335 goto failed; 336 } 337 } 338 #else 339 id = 0; 340 #endif 341 342 start_brk = p->lib_list[id].start_brk; 343 start_data = p->lib_list[id].start_data; 344 start_code = p->lib_list[id].start_code; 345 text_len = p->lib_list[id].text_len; 346 347 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 348 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)", 349 (int) r,(int)(start_brk-start_code),(int)text_len); 350 goto failed; 351 } 352 353 if (r < text_len) /* In text segment */ 354 addr = r + start_code; 355 else /* In data segment */ 356 addr = r - text_len + start_data; 357 358 /* Range checked already above so doing the range tests is redundant...*/ 359 return(addr); 360 361 failed: 362 printk(", killing %s!\n", current->comm); 363 send_sig(SIGSEGV, current, 0); 364 365 return RELOC_FAILED; 366 } 367 368 /****************************************************************************/ 369 370 void old_reloc(unsigned long rl) 371 { 372 #ifdef DEBUG 373 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 374 #endif 375 flat_v2_reloc_t r; 376 unsigned long *ptr; 377 378 r.value = rl; 379 #if defined(CONFIG_COLDFIRE) 380 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset); 381 #else 382 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset); 383 #endif 384 385 #ifdef DEBUG 386 printk("Relocation of variable at DATASEG+%x " 387 "(address %p, currently %x) into segment %s\n", 388 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]); 389 #endif 390 391 switch (r.reloc.type) { 392 case OLD_FLAT_RELOC_TYPE_TEXT: 393 *ptr += current->mm->start_code; 394 break; 395 case OLD_FLAT_RELOC_TYPE_DATA: 396 *ptr += current->mm->start_data; 397 break; 398 case OLD_FLAT_RELOC_TYPE_BSS: 399 *ptr += current->mm->end_data; 400 break; 401 default: 402 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type); 403 break; 404 } 405 406 #ifdef DEBUG 407 printk("Relocation became %x\n", (int)*ptr); 408 #endif 409 } 410 411 /****************************************************************************/ 412 413 static int load_flat_file(struct linux_binprm * bprm, 414 struct lib_info *libinfo, int id, unsigned long *extra_stack) 415 { 416 struct flat_hdr * hdr; 417 unsigned long textpos = 0, datapos = 0, result; 418 unsigned long realdatastart = 0; 419 unsigned long text_len, data_len, bss_len, stack_len, flags; 420 unsigned long len, reallen, memp = 0; 421 unsigned long extra, rlim; 422 unsigned long *reloc = 0, *rp; 423 struct inode *inode; 424 int i, rev, relocs = 0; 425 loff_t fpos; 426 unsigned long start_code, end_code; 427 int ret; 428 429 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 430 inode = bprm->file->f_path.dentry->d_inode; 431 432 text_len = ntohl(hdr->data_start); 433 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 434 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 435 stack_len = ntohl(hdr->stack_size); 436 if (extra_stack) { 437 stack_len += *extra_stack; 438 *extra_stack = stack_len; 439 } 440 relocs = ntohl(hdr->reloc_count); 441 flags = ntohl(hdr->flags); 442 rev = ntohl(hdr->rev); 443 444 if (strncmp(hdr->magic, "bFLT", 4)) { 445 /* 446 * Previously, here was a printk to tell people 447 * "BINFMT_FLAT: bad header magic". 448 * But for the kernel which also use ELF FD-PIC format, this 449 * error message is confusing. 450 * because a lot of people do not manage to produce good 451 */ 452 ret = -ENOEXEC; 453 goto err; 454 } 455 456 if (flags & FLAT_FLAG_KTRACE) 457 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 458 459 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 460 printk("BINFMT_FLAT: bad flat file version 0x%x (supported " 461 "0x%lx and 0x%lx)\n", 462 rev, FLAT_VERSION, OLD_FLAT_VERSION); 463 ret = -ENOEXEC; 464 goto err; 465 } 466 467 /* Don't allow old format executables to use shared libraries */ 468 if (rev == OLD_FLAT_VERSION && id != 0) { 469 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n", 470 (int) FLAT_VERSION); 471 ret = -ENOEXEC; 472 goto err; 473 } 474 475 /* 476 * fix up the flags for the older format, there were all kinds 477 * of endian hacks, this only works for the simple cases 478 */ 479 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 480 flags = FLAT_FLAG_RAM; 481 482 #ifndef CONFIG_BINFMT_ZFLAT 483 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 484 printk("Support for ZFLAT executables is not enabled.\n"); 485 ret = -ENOEXEC; 486 goto err; 487 } 488 #endif 489 490 /* 491 * Check initial limits. This avoids letting people circumvent 492 * size limits imposed on them by creating programs with large 493 * arrays in the data or bss. 494 */ 495 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; 496 if (rlim >= RLIM_INFINITY) 497 rlim = ~0; 498 if (data_len + bss_len > rlim) { 499 ret = -ENOMEM; 500 goto err; 501 } 502 503 /* Flush all traces of the currently running executable */ 504 if (id == 0) { 505 result = flush_old_exec(bprm); 506 if (result) { 507 ret = result; 508 goto err; 509 } 510 511 /* OK, This is the point of no return */ 512 set_personality(PER_LINUX_32BIT); 513 } 514 515 /* 516 * calculate the extra space we need to map in 517 */ 518 extra = max_t(unsigned long, bss_len + stack_len, 519 relocs * sizeof(unsigned long)); 520 521 /* 522 * there are a couple of cases here, the separate code/data 523 * case, and then the fully copied to RAM case which lumps 524 * it all together. 525 */ 526 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 527 /* 528 * this should give us a ROM ptr, but if it doesn't we don't 529 * really care 530 */ 531 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 532 533 down_write(¤t->mm->mmap_sem); 534 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, 535 MAP_PRIVATE|MAP_EXECUTABLE, 0); 536 up_write(¤t->mm->mmap_sem); 537 if (!textpos || textpos >= (unsigned long) -4096) { 538 if (!textpos) 539 textpos = (unsigned long) -ENOMEM; 540 printk("Unable to mmap process text, errno %d\n", (int)-textpos); 541 ret = textpos; 542 goto err; 543 } 544 545 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 546 down_write(¤t->mm->mmap_sem); 547 realdatastart = do_mmap(0, 0, len, 548 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 549 /* Remap to use all availabe slack region space */ 550 if (realdatastart && (realdatastart < (unsigned long)-4096)) { 551 reallen = kobjsize((void *)realdatastart); 552 if (reallen > len) { 553 realdatastart = do_mremap(realdatastart, len, 554 reallen, MREMAP_FIXED, realdatastart); 555 } 556 } 557 up_write(¤t->mm->mmap_sem); 558 559 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) { 560 if (!realdatastart) 561 realdatastart = (unsigned long) -ENOMEM; 562 printk("Unable to allocate RAM for process data, errno %d\n", 563 (int)-realdatastart); 564 do_munmap(current->mm, textpos, text_len); 565 ret = realdatastart; 566 goto err; 567 } 568 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); 569 570 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 571 (int)(data_len + bss_len + stack_len), (int)datapos); 572 573 fpos = ntohl(hdr->data_start); 574 #ifdef CONFIG_BINFMT_ZFLAT 575 if (flags & FLAT_FLAG_GZDATA) { 576 result = decompress_exec(bprm, fpos, (char *) datapos, 577 data_len + (relocs * sizeof(unsigned long)), 0); 578 } else 579 #endif 580 { 581 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 582 data_len + (relocs * sizeof(unsigned long)), &fpos); 583 } 584 if (result >= (unsigned long)-4096) { 585 printk("Unable to read data+bss, errno %d\n", (int)-result); 586 do_munmap(current->mm, textpos, text_len); 587 do_munmap(current->mm, realdatastart, data_len + extra); 588 ret = result; 589 goto err; 590 } 591 592 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len)); 593 memp = realdatastart; 594 595 } else { 596 597 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 598 down_write(¤t->mm->mmap_sem); 599 textpos = do_mmap(0, 0, len, 600 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 601 /* Remap to use all availabe slack region space */ 602 if (textpos && (textpos < (unsigned long) -4096)) { 603 reallen = kobjsize((void *)textpos); 604 if (reallen > len) { 605 textpos = do_mremap(textpos, len, reallen, 606 MREMAP_FIXED, textpos); 607 } 608 } 609 up_write(¤t->mm->mmap_sem); 610 611 if (!textpos || textpos >= (unsigned long) -4096) { 612 if (!textpos) 613 textpos = (unsigned long) -ENOMEM; 614 printk("Unable to allocate RAM for process text/data, errno %d\n", 615 (int)-textpos); 616 ret = textpos; 617 goto err; 618 } 619 620 realdatastart = textpos + ntohl(hdr->data_start); 621 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); 622 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) + 623 MAX_SHARED_LIBS * sizeof(unsigned long)); 624 memp = textpos; 625 626 #ifdef CONFIG_BINFMT_ZFLAT 627 /* 628 * load it all in and treat it like a RAM load from now on 629 */ 630 if (flags & FLAT_FLAG_GZIP) { 631 result = decompress_exec(bprm, sizeof (struct flat_hdr), 632 (((char *) textpos) + sizeof (struct flat_hdr)), 633 (text_len + data_len + (relocs * sizeof(unsigned long)) 634 - sizeof (struct flat_hdr)), 635 0); 636 memmove((void *) datapos, (void *) realdatastart, 637 data_len + (relocs * sizeof(unsigned long))); 638 } else if (flags & FLAT_FLAG_GZDATA) { 639 fpos = 0; 640 result = bprm->file->f_op->read(bprm->file, 641 (char *) textpos, text_len, &fpos); 642 if (result < (unsigned long) -4096) 643 result = decompress_exec(bprm, text_len, (char *) datapos, 644 data_len + (relocs * sizeof(unsigned long)), 0); 645 } 646 else 647 #endif 648 { 649 fpos = 0; 650 result = bprm->file->f_op->read(bprm->file, 651 (char *) textpos, text_len, &fpos); 652 if (result < (unsigned long) -4096) { 653 fpos = ntohl(hdr->data_start); 654 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 655 data_len + (relocs * sizeof(unsigned long)), &fpos); 656 } 657 } 658 if (result >= (unsigned long)-4096) { 659 printk("Unable to read code+data+bss, errno %d\n",(int)-result); 660 do_munmap(current->mm, textpos, text_len + data_len + extra + 661 MAX_SHARED_LIBS * sizeof(unsigned long)); 662 ret = result; 663 goto err; 664 } 665 } 666 667 if (flags & FLAT_FLAG_KTRACE) 668 printk("Mapping is %x, Entry point is %x, data_start is %x\n", 669 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); 670 671 /* The main program needs a little extra setup in the task structure */ 672 start_code = textpos + sizeof (struct flat_hdr); 673 end_code = textpos + text_len; 674 if (id == 0) { 675 current->mm->start_code = start_code; 676 current->mm->end_code = end_code; 677 current->mm->start_data = datapos; 678 current->mm->end_data = datapos + data_len; 679 /* 680 * set up the brk stuff, uses any slack left in data/bss/stack 681 * allocation. We put the brk after the bss (between the bss 682 * and stack) like other platforms. 683 */ 684 current->mm->start_brk = datapos + data_len + bss_len; 685 current->mm->brk = (current->mm->start_brk + 3) & ~3; 686 current->mm->context.end_brk = memp + kobjsize((void *) memp) - stack_len; 687 } 688 689 if (flags & FLAT_FLAG_KTRACE) 690 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 691 id ? "Lib" : "Load", bprm->filename, 692 (int) start_code, (int) end_code, 693 (int) datapos, 694 (int) (datapos + data_len), 695 (int) (datapos + data_len), 696 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 697 698 text_len -= sizeof(struct flat_hdr); /* the real code len */ 699 700 /* Store the current module values into the global library structure */ 701 libinfo->lib_list[id].start_code = start_code; 702 libinfo->lib_list[id].start_data = datapos; 703 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 704 libinfo->lib_list[id].text_len = text_len; 705 libinfo->lib_list[id].loaded = 1; 706 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 707 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 708 709 /* 710 * We just load the allocations into some temporary memory to 711 * help simplify all this mumbo jumbo 712 * 713 * We've got two different sections of relocation entries. 714 * The first is the GOT which resides at the begining of the data segment 715 * and is terminated with a -1. This one can be relocated in place. 716 * The second is the extra relocation entries tacked after the image's 717 * data segment. These require a little more processing as the entry is 718 * really an offset into the image which contains an offset into the 719 * image. 720 */ 721 if (flags & FLAT_FLAG_GOTPIC) { 722 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) { 723 unsigned long addr; 724 if (*rp) { 725 addr = calc_reloc(*rp, libinfo, id, 0); 726 if (addr == RELOC_FAILED) { 727 ret = -ENOEXEC; 728 goto err; 729 } 730 *rp = addr; 731 } 732 } 733 } 734 735 /* 736 * Now run through the relocation entries. 737 * We've got to be careful here as C++ produces relocatable zero 738 * entries in the constructor and destructor tables which are then 739 * tested for being not zero (which will always occur unless we're 740 * based from address zero). This causes an endless loop as __start 741 * is at zero. The solution used is to not relocate zero addresses. 742 * This has the negative side effect of not allowing a global data 743 * reference to be statically initialised to _stext (I've moved 744 * __start to address 4 so that is okay). 745 */ 746 if (rev > OLD_FLAT_VERSION) { 747 unsigned long persistent = 0; 748 for (i=0; i < relocs; i++) { 749 unsigned long addr, relval; 750 751 /* Get the address of the pointer to be 752 relocated (of course, the address has to be 753 relocated first). */ 754 relval = ntohl(reloc[i]); 755 if (flat_set_persistent (relval, &persistent)) 756 continue; 757 addr = flat_get_relocate_addr(relval); 758 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1); 759 if (rp == (unsigned long *)RELOC_FAILED) { 760 ret = -ENOEXEC; 761 goto err; 762 } 763 764 /* Get the pointer's value. */ 765 addr = flat_get_addr_from_rp(rp, relval, flags, 766 &persistent); 767 if (addr != 0) { 768 /* 769 * Do the relocation. PIC relocs in the data section are 770 * already in target order 771 */ 772 if ((flags & FLAT_FLAG_GOTPIC) == 0) 773 addr = ntohl(addr); 774 addr = calc_reloc(addr, libinfo, id, 0); 775 if (addr == RELOC_FAILED) { 776 ret = -ENOEXEC; 777 goto err; 778 } 779 780 /* Write back the relocated pointer. */ 781 flat_put_addr_at_rp(rp, addr, relval); 782 } 783 } 784 } else { 785 for (i=0; i < relocs; i++) 786 old_reloc(ntohl(reloc[i])); 787 } 788 789 flush_icache_range(start_code, end_code); 790 791 /* zero the BSS, BRK and stack areas */ 792 memset((void*)(datapos + data_len), 0, bss_len + 793 (memp + kobjsize((void *) memp) - stack_len - /* end brk */ 794 libinfo->lib_list[id].start_brk) + /* start brk */ 795 stack_len); 796 797 return 0; 798 err: 799 return ret; 800 } 801 802 803 /****************************************************************************/ 804 #ifdef CONFIG_BINFMT_SHARED_FLAT 805 806 /* 807 * Load a shared library into memory. The library gets its own data 808 * segment (including bss) but not argv/argc/environ. 809 */ 810 811 static int load_flat_shared_library(int id, struct lib_info *libs) 812 { 813 struct linux_binprm bprm; 814 int res; 815 char buf[16]; 816 817 /* Create the file name */ 818 sprintf(buf, "/lib/lib%d.so", id); 819 820 /* Open the file up */ 821 bprm.filename = buf; 822 bprm.file = open_exec(bprm.filename); 823 res = PTR_ERR(bprm.file); 824 if (IS_ERR(bprm.file)) 825 return res; 826 827 res = prepare_binprm(&bprm); 828 829 if (res <= (unsigned long)-4096) 830 res = load_flat_file(&bprm, libs, id, NULL); 831 if (bprm.file) { 832 allow_write_access(bprm.file); 833 fput(bprm.file); 834 bprm.file = NULL; 835 } 836 return(res); 837 } 838 839 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 840 /****************************************************************************/ 841 842 /* 843 * These are the functions used to load flat style executables and shared 844 * libraries. There is no binary dependent code anywhere else. 845 */ 846 847 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) 848 { 849 struct lib_info libinfo; 850 unsigned long p = bprm->p; 851 unsigned long stack_len; 852 unsigned long start_addr; 853 unsigned long *sp; 854 int res; 855 int i, j; 856 857 memset(&libinfo, 0, sizeof(libinfo)); 858 /* 859 * We have to add the size of our arguments to our stack size 860 * otherwise it's too easy for users to create stack overflows 861 * by passing in a huge argument list. And yes, we have to be 862 * pedantic and include space for the argv/envp array as it may have 863 * a lot of entries. 864 */ 865 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *)) 866 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ 867 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 868 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 869 870 871 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 872 if (res > (unsigned long)-4096) 873 return res; 874 875 /* Update data segment pointers for all libraries */ 876 for (i=0; i<MAX_SHARED_LIBS; i++) 877 if (libinfo.lib_list[i].loaded) 878 for (j=0; j<MAX_SHARED_LIBS; j++) 879 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] = 880 (libinfo.lib_list[j].loaded)? 881 libinfo.lib_list[j].start_data:UNLOADED_LIB; 882 883 compute_creds(bprm); 884 current->flags &= ~PF_FORKNOEXEC; 885 886 set_binfmt(&flat_format); 887 888 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 889 DBG_FLT("p=%x\n", (int)p); 890 891 /* copy the arg pages onto the stack, this could be more efficient :-) */ 892 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--) 893 * (char *) --p = 894 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE]; 895 896 sp = (unsigned long *) create_flat_tables(p, bprm); 897 898 /* Fake some return addresses to ensure the call chain will 899 * initialise library in order for us. We are required to call 900 * lib 1 first, then 2, ... and finally the main program (id 0). 901 */ 902 start_addr = libinfo.lib_list[0].entry; 903 904 #ifdef CONFIG_BINFMT_SHARED_FLAT 905 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 906 if (libinfo.lib_list[i].loaded) { 907 /* Push previos first to call address */ 908 --sp; put_user(start_addr, sp); 909 start_addr = libinfo.lib_list[i].entry; 910 } 911 } 912 #endif 913 914 /* Stash our initial stack pointer into the mm structure */ 915 current->mm->start_stack = (unsigned long )sp; 916 917 918 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n", 919 (int)regs, (int)start_addr, (int)current->mm->start_stack); 920 921 start_thread(regs, start_addr, current->mm->start_stack); 922 923 return 0; 924 } 925 926 /****************************************************************************/ 927 928 static int __init init_flat_binfmt(void) 929 { 930 return register_binfmt(&flat_format); 931 } 932 933 /****************************************************************************/ 934 935 core_initcall(init_flat_binfmt); 936 937 /****************************************************************************/ 938