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