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 #include <asm/page.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 /* 59 * User data (stack, data section and bss) needs to be aligned 60 * for the same reasons as SLAB memory is, and to the same amount. 61 * Avoid duplicating architecture specific code by using the same 62 * macro as with SLAB allocation: 63 */ 64 #ifdef ARCH_SLAB_MINALIGN 65 #define FLAT_DATA_ALIGN (ARCH_SLAB_MINALIGN) 66 #else 67 #define FLAT_DATA_ALIGN (sizeof(void *)) 68 #endif 69 70 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 71 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 72 73 struct lib_info { 74 struct { 75 unsigned long start_code; /* Start of text segment */ 76 unsigned long start_data; /* Start of data segment */ 77 unsigned long start_brk; /* End of data segment */ 78 unsigned long text_len; /* Length of text segment */ 79 unsigned long entry; /* Start address for this module */ 80 unsigned long build_date; /* When this one was compiled */ 81 short loaded; /* Has this library been loaded? */ 82 } lib_list[MAX_SHARED_LIBS]; 83 }; 84 85 #ifdef CONFIG_BINFMT_SHARED_FLAT 86 static int load_flat_shared_library(int id, struct lib_info *p); 87 #endif 88 89 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs); 90 static int flat_core_dump(struct coredump_params *cprm); 91 92 static struct linux_binfmt flat_format = { 93 .module = THIS_MODULE, 94 .load_binary = load_flat_binary, 95 .core_dump = flat_core_dump, 96 .min_coredump = PAGE_SIZE 97 }; 98 99 /****************************************************************************/ 100 /* 101 * Routine writes a core dump image in the current directory. 102 * Currently only a stub-function. 103 */ 104 105 static int flat_core_dump(struct coredump_params *cprm) 106 { 107 printk("Process %s:%d received signr %d and should have core dumped\n", 108 current->comm, current->pid, (int) cprm->signr); 109 return(1); 110 } 111 112 /****************************************************************************/ 113 /* 114 * create_flat_tables() parses the env- and arg-strings in new user 115 * memory and creates the pointer tables from them, and puts their 116 * addresses on the "stack", returning the new stack pointer value. 117 */ 118 119 static unsigned long create_flat_tables( 120 unsigned long pp, 121 struct linux_binprm * bprm) 122 { 123 unsigned long *argv,*envp; 124 unsigned long * sp; 125 char * p = (char*)pp; 126 int argc = bprm->argc; 127 int envc = bprm->envc; 128 char uninitialized_var(dummy); 129 130 sp = (unsigned long *)p; 131 sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); 132 sp = (unsigned long *) ((unsigned long)sp & -FLAT_DATA_ALIGN); 133 argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); 134 envp = argv + (argc + 1); 135 136 if (flat_argvp_envp_on_stack()) { 137 put_user((unsigned long) envp, sp + 2); 138 put_user((unsigned long) argv, sp + 1); 139 } 140 141 put_user(argc, sp); 142 current->mm->arg_start = (unsigned long) p; 143 while (argc-->0) { 144 put_user((unsigned long) p, argv++); 145 do { 146 get_user(dummy, p); p++; 147 } while (dummy); 148 } 149 put_user((unsigned long) NULL, argv); 150 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 151 while (envc-->0) { 152 put_user((unsigned long)p, envp); envp++; 153 do { 154 get_user(dummy, p); p++; 155 } while (dummy); 156 } 157 put_user((unsigned long) NULL, envp); 158 current->mm->env_end = (unsigned long) p; 159 return (unsigned long)sp; 160 } 161 162 /****************************************************************************/ 163 164 #ifdef CONFIG_BINFMT_ZFLAT 165 166 #include <linux/zlib.h> 167 168 #define LBUFSIZE 4000 169 170 /* gzip flag byte */ 171 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 172 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 173 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 174 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 175 #define COMMENT 0x10 /* bit 4 set: file comment present */ 176 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 177 #define RESERVED 0xC0 /* bit 6,7: reserved */ 178 179 static int decompress_exec( 180 struct linux_binprm *bprm, 181 unsigned long offset, 182 char *dst, 183 long len, 184 int fd) 185 { 186 unsigned char *buf; 187 z_stream strm; 188 loff_t fpos; 189 int ret, retval; 190 191 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 192 193 memset(&strm, 0, sizeof(strm)); 194 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 195 if (strm.workspace == NULL) { 196 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 197 return -ENOMEM; 198 } 199 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 200 if (buf == NULL) { 201 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 202 retval = -ENOMEM; 203 goto out_free; 204 } 205 206 /* Read in first chunk of data and parse gzip header. */ 207 fpos = offset; 208 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 209 210 strm.next_in = buf; 211 strm.avail_in = ret; 212 strm.total_in = 0; 213 214 retval = -ENOEXEC; 215 216 /* Check minimum size -- gzip header */ 217 if (ret < 10) { 218 DBG_FLT("binfmt_flat: file too small?\n"); 219 goto out_free_buf; 220 } 221 222 /* Check gzip magic number */ 223 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 224 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 225 goto out_free_buf; 226 } 227 228 /* Check gzip method */ 229 if (buf[2] != 8) { 230 DBG_FLT("binfmt_flat: unknown compression method?\n"); 231 goto out_free_buf; 232 } 233 /* Check gzip flags */ 234 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 235 (buf[3] & RESERVED)) { 236 DBG_FLT("binfmt_flat: unknown flags?\n"); 237 goto out_free_buf; 238 } 239 240 ret = 10; 241 if (buf[3] & EXTRA_FIELD) { 242 ret += 2 + buf[10] + (buf[11] << 8); 243 if (unlikely(LBUFSIZE <= ret)) { 244 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 245 goto out_free_buf; 246 } 247 } 248 if (buf[3] & ORIG_NAME) { 249 while (ret < LBUFSIZE && buf[ret++] != 0) 250 ; 251 if (unlikely(LBUFSIZE == ret)) { 252 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 253 goto out_free_buf; 254 } 255 } 256 if (buf[3] & COMMENT) { 257 while (ret < LBUFSIZE && buf[ret++] != 0) 258 ; 259 if (unlikely(LBUFSIZE == ret)) { 260 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 261 goto out_free_buf; 262 } 263 } 264 265 strm.next_in += ret; 266 strm.avail_in -= ret; 267 268 strm.next_out = dst; 269 strm.avail_out = len; 270 strm.total_out = 0; 271 272 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 273 DBG_FLT("binfmt_flat: zlib init failed?\n"); 274 goto out_free_buf; 275 } 276 277 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 278 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 279 if (ret <= 0) 280 break; 281 len -= ret; 282 283 strm.next_in = buf; 284 strm.avail_in = ret; 285 strm.total_in = 0; 286 } 287 288 if (ret < 0) { 289 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 290 ret, strm.msg); 291 goto out_zlib; 292 } 293 294 retval = 0; 295 out_zlib: 296 zlib_inflateEnd(&strm); 297 out_free_buf: 298 kfree(buf); 299 out_free: 300 kfree(strm.workspace); 301 return retval; 302 } 303 304 #endif /* CONFIG_BINFMT_ZFLAT */ 305 306 /****************************************************************************/ 307 308 static unsigned long 309 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 310 { 311 unsigned long addr; 312 int id; 313 unsigned long start_brk; 314 unsigned long start_data; 315 unsigned long text_len; 316 unsigned long start_code; 317 318 #ifdef CONFIG_BINFMT_SHARED_FLAT 319 if (r == 0) 320 id = curid; /* Relocs of 0 are always self referring */ 321 else { 322 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 323 r &= 0x00ffffff; /* Trim ID off here */ 324 } 325 if (id >= MAX_SHARED_LIBS) { 326 printk("BINFMT_FLAT: reference 0x%x to shared library %d", 327 (unsigned) r, id); 328 goto failed; 329 } 330 if (curid != id) { 331 if (internalp) { 332 printk("BINFMT_FLAT: reloc address 0x%x not in same module " 333 "(%d != %d)", (unsigned) r, curid, id); 334 goto failed; 335 } else if ( ! p->lib_list[id].loaded && 336 IS_ERR_VALUE(load_flat_shared_library(id, p))) { 337 printk("BINFMT_FLAT: failed to load library %d", id); 338 goto failed; 339 } 340 /* Check versioning information (i.e. time stamps) */ 341 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 342 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 343 printk("BINFMT_FLAT: library %d is younger than %d", id, curid); 344 goto failed; 345 } 346 } 347 #else 348 id = 0; 349 #endif 350 351 start_brk = p->lib_list[id].start_brk; 352 start_data = p->lib_list[id].start_data; 353 start_code = p->lib_list[id].start_code; 354 text_len = p->lib_list[id].text_len; 355 356 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 357 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)", 358 (int) r,(int)(start_brk-start_code),(int)text_len); 359 goto failed; 360 } 361 362 if (r < text_len) /* In text segment */ 363 addr = r + start_code; 364 else /* In data segment */ 365 addr = r - text_len + start_data; 366 367 /* Range checked already above so doing the range tests is redundant...*/ 368 return(addr); 369 370 failed: 371 printk(", killing %s!\n", current->comm); 372 send_sig(SIGSEGV, current, 0); 373 374 return RELOC_FAILED; 375 } 376 377 /****************************************************************************/ 378 379 void old_reloc(unsigned long rl) 380 { 381 #ifdef DEBUG 382 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 383 #endif 384 flat_v2_reloc_t r; 385 unsigned long *ptr; 386 387 r.value = rl; 388 #if defined(CONFIG_COLDFIRE) 389 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset); 390 #else 391 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset); 392 #endif 393 394 #ifdef DEBUG 395 printk("Relocation of variable at DATASEG+%x " 396 "(address %p, currently %x) into segment %s\n", 397 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]); 398 #endif 399 400 switch (r.reloc.type) { 401 case OLD_FLAT_RELOC_TYPE_TEXT: 402 *ptr += current->mm->start_code; 403 break; 404 case OLD_FLAT_RELOC_TYPE_DATA: 405 *ptr += current->mm->start_data; 406 break; 407 case OLD_FLAT_RELOC_TYPE_BSS: 408 *ptr += current->mm->end_data; 409 break; 410 default: 411 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type); 412 break; 413 } 414 415 #ifdef DEBUG 416 printk("Relocation became %x\n", (int)*ptr); 417 #endif 418 } 419 420 /****************************************************************************/ 421 422 static int load_flat_file(struct linux_binprm * bprm, 423 struct lib_info *libinfo, int id, unsigned long *extra_stack) 424 { 425 struct flat_hdr * hdr; 426 unsigned long textpos = 0, datapos = 0, result; 427 unsigned long realdatastart = 0; 428 unsigned long text_len, data_len, bss_len, stack_len, flags; 429 unsigned long len, memp = 0; 430 unsigned long memp_size, extra, rlim; 431 unsigned long *reloc = 0, *rp; 432 struct inode *inode; 433 int i, rev, relocs = 0; 434 loff_t fpos; 435 unsigned long start_code, end_code; 436 int ret; 437 438 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 439 inode = bprm->file->f_path.dentry->d_inode; 440 441 text_len = ntohl(hdr->data_start); 442 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 443 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 444 stack_len = ntohl(hdr->stack_size); 445 if (extra_stack) { 446 stack_len += *extra_stack; 447 *extra_stack = stack_len; 448 } 449 relocs = ntohl(hdr->reloc_count); 450 flags = ntohl(hdr->flags); 451 rev = ntohl(hdr->rev); 452 453 if (strncmp(hdr->magic, "bFLT", 4)) { 454 /* 455 * Previously, here was a printk to tell people 456 * "BINFMT_FLAT: bad header magic". 457 * But for the kernel which also use ELF FD-PIC format, this 458 * error message is confusing. 459 * because a lot of people do not manage to produce good 460 */ 461 ret = -ENOEXEC; 462 goto err; 463 } 464 465 if (flags & FLAT_FLAG_KTRACE) 466 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 467 468 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 469 printk("BINFMT_FLAT: bad flat file version 0x%x (supported " 470 "0x%lx and 0x%lx)\n", 471 rev, FLAT_VERSION, OLD_FLAT_VERSION); 472 ret = -ENOEXEC; 473 goto err; 474 } 475 476 /* Don't allow old format executables to use shared libraries */ 477 if (rev == OLD_FLAT_VERSION && id != 0) { 478 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n", 479 (int) FLAT_VERSION); 480 ret = -ENOEXEC; 481 goto err; 482 } 483 484 /* 485 * fix up the flags for the older format, there were all kinds 486 * of endian hacks, this only works for the simple cases 487 */ 488 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 489 flags = FLAT_FLAG_RAM; 490 491 #ifndef CONFIG_BINFMT_ZFLAT 492 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 493 printk("Support for ZFLAT executables is not enabled.\n"); 494 ret = -ENOEXEC; 495 goto err; 496 } 497 #endif 498 499 /* 500 * Check initial limits. This avoids letting people circumvent 501 * size limits imposed on them by creating programs with large 502 * arrays in the data or bss. 503 */ 504 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; 505 if (rlim >= RLIM_INFINITY) 506 rlim = ~0; 507 if (data_len + bss_len > rlim) { 508 ret = -ENOMEM; 509 goto err; 510 } 511 512 /* Flush all traces of the currently running executable */ 513 if (id == 0) { 514 result = flush_old_exec(bprm); 515 if (result) { 516 ret = result; 517 goto err; 518 } 519 520 /* OK, This is the point of no return */ 521 set_personality(PER_LINUX_32BIT); 522 } 523 524 /* 525 * calculate the extra space we need to map in 526 */ 527 extra = max_t(unsigned long, bss_len + stack_len, 528 relocs * sizeof(unsigned long)); 529 530 /* 531 * there are a couple of cases here, the separate code/data 532 * case, and then the fully copied to RAM case which lumps 533 * it all together. 534 */ 535 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 536 /* 537 * this should give us a ROM ptr, but if it doesn't we don't 538 * really care 539 */ 540 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 541 542 down_write(¤t->mm->mmap_sem); 543 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, 544 MAP_PRIVATE|MAP_EXECUTABLE, 0); 545 up_write(¤t->mm->mmap_sem); 546 if (!textpos || IS_ERR_VALUE(textpos)) { 547 if (!textpos) 548 textpos = (unsigned long) -ENOMEM; 549 printk("Unable to mmap process text, errno %d\n", (int)-textpos); 550 ret = textpos; 551 goto err; 552 } 553 554 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 555 len = PAGE_ALIGN(len); 556 down_write(¤t->mm->mmap_sem); 557 realdatastart = do_mmap(0, 0, len, 558 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 559 up_write(¤t->mm->mmap_sem); 560 561 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) { 562 if (!realdatastart) 563 realdatastart = (unsigned long) -ENOMEM; 564 printk("Unable to allocate RAM for process data, errno %d\n", 565 (int)-realdatastart); 566 do_munmap(current->mm, textpos, text_len); 567 ret = realdatastart; 568 goto err; 569 } 570 datapos = ALIGN(realdatastart + 571 MAX_SHARED_LIBS * sizeof(unsigned long), 572 FLAT_DATA_ALIGN); 573 574 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 575 (int)(data_len + bss_len + stack_len), (int)datapos); 576 577 fpos = ntohl(hdr->data_start); 578 #ifdef CONFIG_BINFMT_ZFLAT 579 if (flags & FLAT_FLAG_GZDATA) { 580 result = decompress_exec(bprm, fpos, (char *) datapos, 581 data_len + (relocs * sizeof(unsigned long)), 0); 582 } else 583 #endif 584 { 585 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 586 data_len + (relocs * sizeof(unsigned long)), &fpos); 587 } 588 if (IS_ERR_VALUE(result)) { 589 printk("Unable to read data+bss, errno %d\n", (int)-result); 590 do_munmap(current->mm, textpos, text_len); 591 do_munmap(current->mm, realdatastart, data_len + extra); 592 ret = result; 593 goto err; 594 } 595 596 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len)); 597 memp = realdatastart; 598 memp_size = len; 599 } else { 600 601 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 602 len = PAGE_ALIGN(len); 603 down_write(¤t->mm->mmap_sem); 604 textpos = do_mmap(0, 0, len, 605 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 606 up_write(¤t->mm->mmap_sem); 607 608 if (!textpos || IS_ERR_VALUE(textpos)) { 609 if (!textpos) 610 textpos = (unsigned long) -ENOMEM; 611 printk("Unable to allocate RAM for process text/data, errno %d\n", 612 (int)-textpos); 613 ret = textpos; 614 goto err; 615 } 616 617 realdatastart = textpos + ntohl(hdr->data_start); 618 datapos = ALIGN(realdatastart + 619 MAX_SHARED_LIBS * sizeof(unsigned long), 620 FLAT_DATA_ALIGN); 621 622 reloc = (unsigned long *) 623 (datapos + (ntohl(hdr->reloc_start) - text_len)); 624 memp = textpos; 625 memp_size = len; 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 (!IS_ERR_VALUE(result)) 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 (!IS_ERR_VALUE(result)) { 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 (IS_ERR_VALUE(result)) { 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 * Userspace code relies on the stack pointer starting out at 684 * an address right at the end of a page. 685 */ 686 current->mm->start_brk = datapos + data_len + bss_len; 687 current->mm->brk = (current->mm->start_brk + 3) & ~3; 688 current->mm->context.end_brk = memp + memp_size - stack_len; 689 } 690 691 if (flags & FLAT_FLAG_KTRACE) 692 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 693 id ? "Lib" : "Load", bprm->filename, 694 (int) start_code, (int) end_code, 695 (int) datapos, 696 (int) (datapos + data_len), 697 (int) (datapos + data_len), 698 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 699 700 text_len -= sizeof(struct flat_hdr); /* the real code len */ 701 702 /* Store the current module values into the global library structure */ 703 libinfo->lib_list[id].start_code = start_code; 704 libinfo->lib_list[id].start_data = datapos; 705 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 706 libinfo->lib_list[id].text_len = text_len; 707 libinfo->lib_list[id].loaded = 1; 708 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 709 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 710 711 /* 712 * We just load the allocations into some temporary memory to 713 * help simplify all this mumbo jumbo 714 * 715 * We've got two different sections of relocation entries. 716 * The first is the GOT which resides at the begining of the data segment 717 * and is terminated with a -1. This one can be relocated in place. 718 * The second is the extra relocation entries tacked after the image's 719 * data segment. These require a little more processing as the entry is 720 * really an offset into the image which contains an offset into the 721 * image. 722 */ 723 if (flags & FLAT_FLAG_GOTPIC) { 724 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) { 725 unsigned long addr; 726 if (*rp) { 727 addr = calc_reloc(*rp, libinfo, id, 0); 728 if (addr == RELOC_FAILED) { 729 ret = -ENOEXEC; 730 goto err; 731 } 732 *rp = addr; 733 } 734 } 735 } 736 737 /* 738 * Now run through the relocation entries. 739 * We've got to be careful here as C++ produces relocatable zero 740 * entries in the constructor and destructor tables which are then 741 * tested for being not zero (which will always occur unless we're 742 * based from address zero). This causes an endless loop as __start 743 * is at zero. The solution used is to not relocate zero addresses. 744 * This has the negative side effect of not allowing a global data 745 * reference to be statically initialised to _stext (I've moved 746 * __start to address 4 so that is okay). 747 */ 748 if (rev > OLD_FLAT_VERSION) { 749 unsigned long persistent = 0; 750 for (i=0; i < relocs; i++) { 751 unsigned long addr, relval; 752 753 /* Get the address of the pointer to be 754 relocated (of course, the address has to be 755 relocated first). */ 756 relval = ntohl(reloc[i]); 757 if (flat_set_persistent (relval, &persistent)) 758 continue; 759 addr = flat_get_relocate_addr(relval); 760 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1); 761 if (rp == (unsigned long *)RELOC_FAILED) { 762 ret = -ENOEXEC; 763 goto err; 764 } 765 766 /* Get the pointer's value. */ 767 addr = flat_get_addr_from_rp(rp, relval, flags, 768 &persistent); 769 if (addr != 0) { 770 /* 771 * Do the relocation. PIC relocs in the data section are 772 * already in target order 773 */ 774 if ((flags & FLAT_FLAG_GOTPIC) == 0) 775 addr = ntohl(addr); 776 addr = calc_reloc(addr, libinfo, id, 0); 777 if (addr == RELOC_FAILED) { 778 ret = -ENOEXEC; 779 goto err; 780 } 781 782 /* Write back the relocated pointer. */ 783 flat_put_addr_at_rp(rp, addr, relval); 784 } 785 } 786 } else { 787 for (i=0; i < relocs; i++) 788 old_reloc(ntohl(reloc[i])); 789 } 790 791 flush_icache_range(start_code, end_code); 792 793 /* zero the BSS, BRK and stack areas */ 794 memset((void*)(datapos + data_len), 0, bss_len + 795 (memp + memp_size - stack_len - /* end brk */ 796 libinfo->lib_list[id].start_brk) + /* start brk */ 797 stack_len); 798 799 return 0; 800 err: 801 return ret; 802 } 803 804 805 /****************************************************************************/ 806 #ifdef CONFIG_BINFMT_SHARED_FLAT 807 808 /* 809 * Load a shared library into memory. The library gets its own data 810 * segment (including bss) but not argv/argc/environ. 811 */ 812 813 static int load_flat_shared_library(int id, struct lib_info *libs) 814 { 815 struct linux_binprm bprm; 816 int res; 817 char buf[16]; 818 819 /* Create the file name */ 820 sprintf(buf, "/lib/lib%d.so", id); 821 822 /* Open the file up */ 823 bprm.filename = buf; 824 bprm.file = open_exec(bprm.filename); 825 res = PTR_ERR(bprm.file); 826 if (IS_ERR(bprm.file)) 827 return res; 828 829 bprm.cred = prepare_exec_creds(); 830 res = -ENOMEM; 831 if (!bprm.cred) 832 goto out; 833 834 res = prepare_binprm(&bprm); 835 836 if (!IS_ERR_VALUE(res)) 837 res = load_flat_file(&bprm, libs, id, NULL); 838 839 abort_creds(bprm.cred); 840 841 out: 842 allow_write_access(bprm.file); 843 fput(bprm.file); 844 845 return(res); 846 } 847 848 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 849 /****************************************************************************/ 850 851 /* 852 * These are the functions used to load flat style executables and shared 853 * libraries. There is no binary dependent code anywhere else. 854 */ 855 856 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) 857 { 858 struct lib_info libinfo; 859 unsigned long p = bprm->p; 860 unsigned long stack_len; 861 unsigned long start_addr; 862 unsigned long *sp; 863 int res; 864 int i, j; 865 866 memset(&libinfo, 0, sizeof(libinfo)); 867 /* 868 * We have to add the size of our arguments to our stack size 869 * otherwise it's too easy for users to create stack overflows 870 * by passing in a huge argument list. And yes, we have to be 871 * pedantic and include space for the argv/envp array as it may have 872 * a lot of entries. 873 */ 874 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *)) 875 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ 876 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 877 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 878 stack_len += FLAT_DATA_ALIGN - 1; /* reserve for upcoming alignment */ 879 880 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 881 if (IS_ERR_VALUE(res)) 882 return res; 883 884 /* Update data segment pointers for all libraries */ 885 for (i=0; i<MAX_SHARED_LIBS; i++) 886 if (libinfo.lib_list[i].loaded) 887 for (j=0; j<MAX_SHARED_LIBS; j++) 888 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] = 889 (libinfo.lib_list[j].loaded)? 890 libinfo.lib_list[j].start_data:UNLOADED_LIB; 891 892 install_exec_creds(bprm); 893 current->flags &= ~PF_FORKNOEXEC; 894 895 set_binfmt(&flat_format); 896 897 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 898 DBG_FLT("p=%x\n", (int)p); 899 900 /* copy the arg pages onto the stack, this could be more efficient :-) */ 901 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--) 902 * (char *) --p = 903 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE]; 904 905 sp = (unsigned long *) create_flat_tables(p, bprm); 906 907 /* Fake some return addresses to ensure the call chain will 908 * initialise library in order for us. We are required to call 909 * lib 1 first, then 2, ... and finally the main program (id 0). 910 */ 911 start_addr = libinfo.lib_list[0].entry; 912 913 #ifdef CONFIG_BINFMT_SHARED_FLAT 914 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 915 if (libinfo.lib_list[i].loaded) { 916 /* Push previos first to call address */ 917 --sp; put_user(start_addr, sp); 918 start_addr = libinfo.lib_list[i].entry; 919 } 920 } 921 #endif 922 923 /* Stash our initial stack pointer into the mm structure */ 924 current->mm->start_stack = (unsigned long )sp; 925 926 #ifdef FLAT_PLAT_INIT 927 FLAT_PLAT_INIT(regs); 928 #endif 929 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n", 930 (int)regs, (int)start_addr, (int)current->mm->start_stack); 931 932 start_thread(regs, start_addr, current->mm->start_stack); 933 934 return 0; 935 } 936 937 /****************************************************************************/ 938 939 static int __init init_flat_binfmt(void) 940 { 941 return register_binfmt(&flat_format); 942 } 943 944 /****************************************************************************/ 945 946 core_initcall(init_flat_binfmt); 947 948 /****************************************************************************/ 949