1 // SPDX-License-Identifier: GPL-2.0 2 /****************************************************************************/ 3 /* 4 * linux/fs/binfmt_flat.c 5 * 6 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> 7 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> 8 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> 9 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> 10 * based heavily on: 11 * 12 * linux/fs/binfmt_aout.c: 13 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 14 * linux/fs/binfmt_flat.c for 2.0 kernel 15 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> 16 * JAN/99 -- coded full program relocation (gerg@snapgear.com) 17 */ 18 19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #include <linux/kernel.h> 22 #include <linux/sched.h> 23 #include <linux/sched/task_stack.h> 24 #include <linux/mm.h> 25 #include <linux/mman.h> 26 #include <linux/errno.h> 27 #include <linux/signal.h> 28 #include <linux/string.h> 29 #include <linux/fs.h> 30 #include <linux/file.h> 31 #include <linux/ptrace.h> 32 #include <linux/user.h> 33 #include <linux/slab.h> 34 #include <linux/binfmts.h> 35 #include <linux/personality.h> 36 #include <linux/init.h> 37 #include <linux/flat.h> 38 #include <linux/uaccess.h> 39 #include <linux/vmalloc.h> 40 #include <linux/coredump.h> 41 42 #include <asm/byteorder.h> 43 #include <asm/unaligned.h> 44 #include <asm/cacheflush.h> 45 #include <asm/page.h> 46 #include <asm/flat.h> 47 48 #ifndef flat_get_relocate_addr 49 #define flat_get_relocate_addr(rel) (rel) 50 #endif 51 52 /****************************************************************************/ 53 54 /* 55 * User data (data section and bss) needs to be aligned. 56 * We pick 0x20 here because it is the max value elf2flt has always 57 * used in producing FLAT files, and because it seems to be large 58 * enough to make all the gcc alignment related tests happy. 59 */ 60 #define FLAT_DATA_ALIGN (0x20) 61 62 /* 63 * User data (stack) also needs to be aligned. 64 * Here we can be a bit looser than the data sections since this 65 * needs to only meet arch ABI requirements. 66 */ 67 #define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN) 68 69 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 70 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 71 72 #ifdef CONFIG_BINFMT_SHARED_FLAT 73 #define MAX_SHARED_LIBS (4) 74 #else 75 #define MAX_SHARED_LIBS (1) 76 #endif 77 78 #ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET 79 #define DATA_START_OFFSET_WORDS (0) 80 #else 81 #define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) 82 #endif 83 84 struct lib_info { 85 struct { 86 unsigned long start_code; /* Start of text segment */ 87 unsigned long start_data; /* Start of data segment */ 88 unsigned long start_brk; /* End of data segment */ 89 unsigned long text_len; /* Length of text segment */ 90 unsigned long entry; /* Start address for this module */ 91 unsigned long build_date; /* When this one was compiled */ 92 bool loaded; /* Has this library been loaded? */ 93 } lib_list[MAX_SHARED_LIBS]; 94 }; 95 96 #ifdef CONFIG_BINFMT_SHARED_FLAT 97 static int load_flat_shared_library(int id, struct lib_info *p); 98 #endif 99 100 static int load_flat_binary(struct linux_binprm *); 101 #ifdef CONFIG_COREDUMP 102 static int flat_core_dump(struct coredump_params *cprm); 103 #endif 104 105 static struct linux_binfmt flat_format = { 106 .module = THIS_MODULE, 107 .load_binary = load_flat_binary, 108 #ifdef CONFIG_COREDUMP 109 .core_dump = flat_core_dump, 110 .min_coredump = PAGE_SIZE 111 #endif 112 }; 113 114 /****************************************************************************/ 115 /* 116 * Routine writes a core dump image in the current directory. 117 * Currently only a stub-function. 118 */ 119 120 #ifdef CONFIG_COREDUMP 121 static int flat_core_dump(struct coredump_params *cprm) 122 { 123 pr_warn("Process %s:%d received signr %d and should have core dumped\n", 124 current->comm, current->pid, cprm->siginfo->si_signo); 125 return 1; 126 } 127 #endif 128 129 /****************************************************************************/ 130 /* 131 * create_flat_tables() parses the env- and arg-strings in new user 132 * memory and creates the pointer tables from them, and puts their 133 * addresses on the "stack", recording the new stack pointer value. 134 */ 135 136 static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start) 137 { 138 char __user *p; 139 unsigned long __user *sp; 140 long i, len; 141 142 p = (char __user *)arg_start; 143 sp = (unsigned long __user *)current->mm->start_stack; 144 145 sp -= bprm->envc + 1; 146 sp -= bprm->argc + 1; 147 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) 148 sp -= 2; /* argvp + envp */ 149 sp -= 1; /* &argc */ 150 151 current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN; 152 sp = (unsigned long __user *)current->mm->start_stack; 153 154 if (put_user(bprm->argc, sp++)) 155 return -EFAULT; 156 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) { 157 unsigned long argv, envp; 158 argv = (unsigned long)(sp + 2); 159 envp = (unsigned long)(sp + 2 + bprm->argc + 1); 160 if (put_user(argv, sp++) || put_user(envp, sp++)) 161 return -EFAULT; 162 } 163 164 current->mm->arg_start = (unsigned long)p; 165 for (i = bprm->argc; i > 0; i--) { 166 if (put_user((unsigned long)p, sp++)) 167 return -EFAULT; 168 len = strnlen_user(p, MAX_ARG_STRLEN); 169 if (!len || len > MAX_ARG_STRLEN) 170 return -EINVAL; 171 p += len; 172 } 173 if (put_user(0, sp++)) 174 return -EFAULT; 175 current->mm->arg_end = (unsigned long)p; 176 177 current->mm->env_start = (unsigned long) p; 178 for (i = bprm->envc; i > 0; i--) { 179 if (put_user((unsigned long)p, sp++)) 180 return -EFAULT; 181 len = strnlen_user(p, MAX_ARG_STRLEN); 182 if (!len || len > MAX_ARG_STRLEN) 183 return -EINVAL; 184 p += len; 185 } 186 if (put_user(0, sp++)) 187 return -EFAULT; 188 current->mm->env_end = (unsigned long)p; 189 190 return 0; 191 } 192 193 /****************************************************************************/ 194 195 #ifdef CONFIG_BINFMT_ZFLAT 196 197 #include <linux/zlib.h> 198 199 #define LBUFSIZE 4000 200 201 /* gzip flag byte */ 202 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 203 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 204 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 205 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 206 #define COMMENT 0x10 /* bit 4 set: file comment present */ 207 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 208 #define RESERVED 0xC0 /* bit 6,7: reserved */ 209 210 static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst, 211 long len, int fd) 212 { 213 unsigned char *buf; 214 z_stream strm; 215 int ret, retval; 216 217 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len); 218 219 memset(&strm, 0, sizeof(strm)); 220 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 221 if (!strm.workspace) 222 return -ENOMEM; 223 224 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 225 if (!buf) { 226 retval = -ENOMEM; 227 goto out_free; 228 } 229 230 /* Read in first chunk of data and parse gzip header. */ 231 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos); 232 233 strm.next_in = buf; 234 strm.avail_in = ret; 235 strm.total_in = 0; 236 237 retval = -ENOEXEC; 238 239 /* Check minimum size -- gzip header */ 240 if (ret < 10) { 241 pr_debug("file too small?\n"); 242 goto out_free_buf; 243 } 244 245 /* Check gzip magic number */ 246 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 247 pr_debug("unknown compression magic?\n"); 248 goto out_free_buf; 249 } 250 251 /* Check gzip method */ 252 if (buf[2] != 8) { 253 pr_debug("unknown compression method?\n"); 254 goto out_free_buf; 255 } 256 /* Check gzip flags */ 257 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 258 (buf[3] & RESERVED)) { 259 pr_debug("unknown flags?\n"); 260 goto out_free_buf; 261 } 262 263 ret = 10; 264 if (buf[3] & EXTRA_FIELD) { 265 ret += 2 + buf[10] + (buf[11] << 8); 266 if (unlikely(ret >= LBUFSIZE)) { 267 pr_debug("buffer overflow (EXTRA)?\n"); 268 goto out_free_buf; 269 } 270 } 271 if (buf[3] & ORIG_NAME) { 272 while (ret < LBUFSIZE && buf[ret++] != 0) 273 ; 274 if (unlikely(ret == LBUFSIZE)) { 275 pr_debug("buffer overflow (ORIG_NAME)?\n"); 276 goto out_free_buf; 277 } 278 } 279 if (buf[3] & COMMENT) { 280 while (ret < LBUFSIZE && buf[ret++] != 0) 281 ; 282 if (unlikely(ret == LBUFSIZE)) { 283 pr_debug("buffer overflow (COMMENT)?\n"); 284 goto out_free_buf; 285 } 286 } 287 288 strm.next_in += ret; 289 strm.avail_in -= ret; 290 291 strm.next_out = dst; 292 strm.avail_out = len; 293 strm.total_out = 0; 294 295 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 296 pr_debug("zlib init failed?\n"); 297 goto out_free_buf; 298 } 299 300 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 301 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos); 302 if (ret <= 0) 303 break; 304 len -= ret; 305 306 strm.next_in = buf; 307 strm.avail_in = ret; 308 strm.total_in = 0; 309 } 310 311 if (ret < 0) { 312 pr_debug("decompression failed (%d), %s\n", 313 ret, strm.msg); 314 goto out_zlib; 315 } 316 317 retval = 0; 318 out_zlib: 319 zlib_inflateEnd(&strm); 320 out_free_buf: 321 kfree(buf); 322 out_free: 323 kfree(strm.workspace); 324 return retval; 325 } 326 327 #endif /* CONFIG_BINFMT_ZFLAT */ 328 329 /****************************************************************************/ 330 331 static unsigned long 332 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 333 { 334 unsigned long addr; 335 int id; 336 unsigned long start_brk; 337 unsigned long start_data; 338 unsigned long text_len; 339 unsigned long start_code; 340 341 #ifdef CONFIG_BINFMT_SHARED_FLAT 342 if (r == 0) 343 id = curid; /* Relocs of 0 are always self referring */ 344 else { 345 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 346 r &= 0x00ffffff; /* Trim ID off here */ 347 } 348 if (id >= MAX_SHARED_LIBS) { 349 pr_err("reference 0x%lx to shared library %d", r, id); 350 goto failed; 351 } 352 if (curid != id) { 353 if (internalp) { 354 pr_err("reloc address 0x%lx not in same module " 355 "(%d != %d)", r, curid, id); 356 goto failed; 357 } else if (!p->lib_list[id].loaded && 358 load_flat_shared_library(id, p) < 0) { 359 pr_err("failed to load library %d", id); 360 goto failed; 361 } 362 /* Check versioning information (i.e. time stamps) */ 363 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 364 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 365 pr_err("library %d is younger than %d", id, curid); 366 goto failed; 367 } 368 } 369 #else 370 id = 0; 371 #endif 372 373 start_brk = p->lib_list[id].start_brk; 374 start_data = p->lib_list[id].start_data; 375 start_code = p->lib_list[id].start_code; 376 text_len = p->lib_list[id].text_len; 377 378 if (r > start_brk - start_data + text_len) { 379 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)", 380 r, start_brk-start_data+text_len, text_len); 381 goto failed; 382 } 383 384 if (r < text_len) /* In text segment */ 385 addr = r + start_code; 386 else /* In data segment */ 387 addr = r - text_len + start_data; 388 389 /* Range checked already above so doing the range tests is redundant...*/ 390 return addr; 391 392 failed: 393 pr_cont(", killing %s!\n", current->comm); 394 send_sig(SIGSEGV, current, 0); 395 396 return RELOC_FAILED; 397 } 398 399 /****************************************************************************/ 400 401 #ifdef CONFIG_BINFMT_FLAT_OLD 402 static void old_reloc(unsigned long rl) 403 { 404 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 405 flat_v2_reloc_t r; 406 unsigned long __user *ptr; 407 unsigned long val; 408 409 r.value = rl; 410 #if defined(CONFIG_COLDFIRE) 411 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset); 412 #else 413 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset); 414 #endif 415 get_user(val, ptr); 416 417 pr_debug("Relocation of variable at DATASEG+%x " 418 "(address %p, currently %lx) into segment %s\n", 419 r.reloc.offset, ptr, val, segment[r.reloc.type]); 420 421 switch (r.reloc.type) { 422 case OLD_FLAT_RELOC_TYPE_TEXT: 423 val += current->mm->start_code; 424 break; 425 case OLD_FLAT_RELOC_TYPE_DATA: 426 val += current->mm->start_data; 427 break; 428 case OLD_FLAT_RELOC_TYPE_BSS: 429 val += current->mm->end_data; 430 break; 431 default: 432 pr_err("Unknown relocation type=%x\n", r.reloc.type); 433 break; 434 } 435 put_user(val, ptr); 436 437 pr_debug("Relocation became %lx\n", val); 438 } 439 #endif /* CONFIG_BINFMT_FLAT_OLD */ 440 441 /****************************************************************************/ 442 443 static int load_flat_file(struct linux_binprm *bprm, 444 struct lib_info *libinfo, int id, unsigned long *extra_stack) 445 { 446 struct flat_hdr *hdr; 447 unsigned long textpos, datapos, realdatastart; 448 u32 text_len, data_len, bss_len, stack_len, full_data, flags; 449 unsigned long len, memp, memp_size, extra, rlim; 450 __be32 __user *reloc; 451 u32 __user *rp; 452 int i, rev, relocs; 453 loff_t fpos; 454 unsigned long start_code, end_code; 455 ssize_t result; 456 int ret; 457 458 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 459 460 text_len = ntohl(hdr->data_start); 461 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 462 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 463 stack_len = ntohl(hdr->stack_size); 464 if (extra_stack) { 465 stack_len += *extra_stack; 466 *extra_stack = stack_len; 467 } 468 relocs = ntohl(hdr->reloc_count); 469 flags = ntohl(hdr->flags); 470 rev = ntohl(hdr->rev); 471 full_data = data_len + relocs * sizeof(unsigned long); 472 473 if (strncmp(hdr->magic, "bFLT", 4)) { 474 /* 475 * Previously, here was a printk to tell people 476 * "BINFMT_FLAT: bad header magic". 477 * But for the kernel which also use ELF FD-PIC format, this 478 * error message is confusing. 479 * because a lot of people do not manage to produce good 480 */ 481 ret = -ENOEXEC; 482 goto err; 483 } 484 485 if (flags & FLAT_FLAG_KTRACE) 486 pr_info("Loading file: %s\n", bprm->filename); 487 488 #ifdef CONFIG_BINFMT_FLAT_OLD 489 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 490 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n", 491 rev, FLAT_VERSION, OLD_FLAT_VERSION); 492 ret = -ENOEXEC; 493 goto err; 494 } 495 496 /* Don't allow old format executables to use shared libraries */ 497 if (rev == OLD_FLAT_VERSION && id != 0) { 498 pr_err("shared libraries are not available before rev 0x%lx\n", 499 FLAT_VERSION); 500 ret = -ENOEXEC; 501 goto err; 502 } 503 504 /* 505 * fix up the flags for the older format, there were all kinds 506 * of endian hacks, this only works for the simple cases 507 */ 508 if (rev == OLD_FLAT_VERSION && 509 (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM))) 510 flags = FLAT_FLAG_RAM; 511 512 #else /* CONFIG_BINFMT_FLAT_OLD */ 513 if (rev != FLAT_VERSION) { 514 pr_err("bad flat file version 0x%x (supported 0x%lx)\n", 515 rev, FLAT_VERSION); 516 ret = -ENOEXEC; 517 goto err; 518 } 519 #endif /* !CONFIG_BINFMT_FLAT_OLD */ 520 521 /* 522 * Make sure the header params are sane. 523 * 28 bits (256 MB) is way more than reasonable in this case. 524 * If some top bits are set we have probable binary corruption. 525 */ 526 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) { 527 pr_err("bad header\n"); 528 ret = -ENOEXEC; 529 goto err; 530 } 531 532 #ifndef CONFIG_BINFMT_ZFLAT 533 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 534 pr_err("Support for ZFLAT executables is not enabled.\n"); 535 ret = -ENOEXEC; 536 goto err; 537 } 538 #endif 539 540 /* 541 * Check initial limits. This avoids letting people circumvent 542 * size limits imposed on them by creating programs with large 543 * arrays in the data or bss. 544 */ 545 rlim = rlimit(RLIMIT_DATA); 546 if (rlim >= RLIM_INFINITY) 547 rlim = ~0; 548 if (data_len + bss_len > rlim) { 549 ret = -ENOMEM; 550 goto err; 551 } 552 553 /* Flush all traces of the currently running executable */ 554 if (id == 0) { 555 ret = begin_new_exec(bprm); 556 if (ret) 557 goto err; 558 559 /* OK, This is the point of no return */ 560 set_personality(PER_LINUX_32BIT); 561 setup_new_exec(bprm); 562 } 563 564 /* 565 * calculate the extra space we need to map in 566 */ 567 extra = max_t(unsigned long, bss_len + stack_len, 568 relocs * sizeof(unsigned long)); 569 570 /* 571 * there are a couple of cases here, the separate code/data 572 * case, and then the fully copied to RAM case which lumps 573 * it all together. 574 */ 575 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { 576 /* 577 * this should give us a ROM ptr, but if it doesn't we don't 578 * really care 579 */ 580 pr_debug("ROM mapping of file (we hope)\n"); 581 582 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, 583 MAP_PRIVATE, 0); 584 if (!textpos || IS_ERR_VALUE(textpos)) { 585 ret = textpos; 586 if (!textpos) 587 ret = -ENOMEM; 588 pr_err("Unable to mmap process text, errno %d\n", ret); 589 goto err; 590 } 591 592 len = data_len + extra + 593 DATA_START_OFFSET_WORDS * sizeof(unsigned long); 594 len = PAGE_ALIGN(len); 595 realdatastart = vm_mmap(NULL, 0, len, 596 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 597 598 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) { 599 ret = realdatastart; 600 if (!realdatastart) 601 ret = -ENOMEM; 602 pr_err("Unable to allocate RAM for process data, " 603 "errno %d\n", ret); 604 vm_munmap(textpos, text_len); 605 goto err; 606 } 607 datapos = ALIGN(realdatastart + 608 DATA_START_OFFSET_WORDS * sizeof(unsigned long), 609 FLAT_DATA_ALIGN); 610 611 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", 612 data_len + bss_len + stack_len, datapos); 613 614 fpos = ntohl(hdr->data_start); 615 #ifdef CONFIG_BINFMT_ZFLAT 616 if (flags & FLAT_FLAG_GZDATA) { 617 result = decompress_exec(bprm, fpos, (char *)datapos, 618 full_data, 0); 619 } else 620 #endif 621 { 622 result = read_code(bprm->file, datapos, fpos, 623 full_data); 624 } 625 if (IS_ERR_VALUE(result)) { 626 ret = result; 627 pr_err("Unable to read data+bss, errno %d\n", ret); 628 vm_munmap(textpos, text_len); 629 vm_munmap(realdatastart, len); 630 goto err; 631 } 632 633 reloc = (__be32 __user *) 634 (datapos + (ntohl(hdr->reloc_start) - text_len)); 635 memp = realdatastart; 636 memp_size = len; 637 } else { 638 639 len = text_len + data_len + extra + 640 DATA_START_OFFSET_WORDS * sizeof(u32); 641 len = PAGE_ALIGN(len); 642 textpos = vm_mmap(NULL, 0, len, 643 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 644 645 if (!textpos || IS_ERR_VALUE(textpos)) { 646 ret = textpos; 647 if (!textpos) 648 ret = -ENOMEM; 649 pr_err("Unable to allocate RAM for process text/data, " 650 "errno %d\n", ret); 651 goto err; 652 } 653 654 realdatastart = textpos + ntohl(hdr->data_start); 655 datapos = ALIGN(realdatastart + 656 DATA_START_OFFSET_WORDS * sizeof(u32), 657 FLAT_DATA_ALIGN); 658 659 reloc = (__be32 __user *) 660 (datapos + (ntohl(hdr->reloc_start) - text_len)); 661 memp = textpos; 662 memp_size = len; 663 #ifdef CONFIG_BINFMT_ZFLAT 664 /* 665 * load it all in and treat it like a RAM load from now on 666 */ 667 if (flags & FLAT_FLAG_GZIP) { 668 #ifndef CONFIG_MMU 669 result = decompress_exec(bprm, sizeof(struct flat_hdr), 670 (((char *)textpos) + sizeof(struct flat_hdr)), 671 (text_len + full_data 672 - sizeof(struct flat_hdr)), 673 0); 674 memmove((void *) datapos, (void *) realdatastart, 675 full_data); 676 #else 677 /* 678 * This is used on MMU systems mainly for testing. 679 * Let's use a kernel buffer to simplify things. 680 */ 681 long unz_text_len = text_len - sizeof(struct flat_hdr); 682 long unz_len = unz_text_len + full_data; 683 char *unz_data = vmalloc(unz_len); 684 if (!unz_data) { 685 result = -ENOMEM; 686 } else { 687 result = decompress_exec(bprm, sizeof(struct flat_hdr), 688 unz_data, unz_len, 0); 689 if (result == 0 && 690 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr), 691 unz_data, unz_text_len) || 692 copy_to_user((void __user *)datapos, 693 unz_data + unz_text_len, full_data))) 694 result = -EFAULT; 695 vfree(unz_data); 696 } 697 #endif 698 } else if (flags & FLAT_FLAG_GZDATA) { 699 result = read_code(bprm->file, textpos, 0, text_len); 700 if (!IS_ERR_VALUE(result)) { 701 #ifndef CONFIG_MMU 702 result = decompress_exec(bprm, text_len, (char *) datapos, 703 full_data, 0); 704 #else 705 char *unz_data = vmalloc(full_data); 706 if (!unz_data) { 707 result = -ENOMEM; 708 } else { 709 result = decompress_exec(bprm, text_len, 710 unz_data, full_data, 0); 711 if (result == 0 && 712 copy_to_user((void __user *)datapos, 713 unz_data, full_data)) 714 result = -EFAULT; 715 vfree(unz_data); 716 } 717 #endif 718 } 719 } else 720 #endif /* CONFIG_BINFMT_ZFLAT */ 721 { 722 result = read_code(bprm->file, textpos, 0, text_len); 723 if (!IS_ERR_VALUE(result)) 724 result = read_code(bprm->file, datapos, 725 ntohl(hdr->data_start), 726 full_data); 727 } 728 if (IS_ERR_VALUE(result)) { 729 ret = result; 730 pr_err("Unable to read code+data+bss, errno %d\n", ret); 731 vm_munmap(textpos, text_len + data_len + extra + 732 DATA_START_OFFSET_WORDS * sizeof(u32)); 733 goto err; 734 } 735 } 736 737 start_code = textpos + sizeof(struct flat_hdr); 738 end_code = textpos + text_len; 739 text_len -= sizeof(struct flat_hdr); /* the real code len */ 740 741 /* The main program needs a little extra setup in the task structure */ 742 if (id == 0) { 743 current->mm->start_code = start_code; 744 current->mm->end_code = end_code; 745 current->mm->start_data = datapos; 746 current->mm->end_data = datapos + data_len; 747 /* 748 * set up the brk stuff, uses any slack left in data/bss/stack 749 * allocation. We put the brk after the bss (between the bss 750 * and stack) like other platforms. 751 * Userspace code relies on the stack pointer starting out at 752 * an address right at the end of a page. 753 */ 754 current->mm->start_brk = datapos + data_len + bss_len; 755 current->mm->brk = (current->mm->start_brk + 3) & ~3; 756 #ifndef CONFIG_MMU 757 current->mm->context.end_brk = memp + memp_size - stack_len; 758 #endif 759 } 760 761 if (flags & FLAT_FLAG_KTRACE) { 762 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n", 763 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); 764 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n", 765 id ? "Lib" : "Load", bprm->filename, 766 start_code, end_code, datapos, datapos + data_len, 767 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3); 768 } 769 770 /* Store the current module values into the global library structure */ 771 libinfo->lib_list[id].start_code = start_code; 772 libinfo->lib_list[id].start_data = datapos; 773 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 774 libinfo->lib_list[id].text_len = text_len; 775 libinfo->lib_list[id].loaded = 1; 776 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 777 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 778 779 /* 780 * We just load the allocations into some temporary memory to 781 * help simplify all this mumbo jumbo 782 * 783 * We've got two different sections of relocation entries. 784 * The first is the GOT which resides at the beginning of the data segment 785 * and is terminated with a -1. This one can be relocated in place. 786 * The second is the extra relocation entries tacked after the image's 787 * data segment. These require a little more processing as the entry is 788 * really an offset into the image which contains an offset into the 789 * image. 790 */ 791 if (flags & FLAT_FLAG_GOTPIC) { 792 for (rp = (u32 __user *)datapos; ; rp++) { 793 u32 addr, rp_val; 794 if (get_user(rp_val, rp)) 795 return -EFAULT; 796 if (rp_val == 0xffffffff) 797 break; 798 if (rp_val) { 799 addr = calc_reloc(rp_val, libinfo, id, 0); 800 if (addr == RELOC_FAILED) { 801 ret = -ENOEXEC; 802 goto err; 803 } 804 if (put_user(addr, rp)) 805 return -EFAULT; 806 } 807 } 808 } 809 810 /* 811 * Now run through the relocation entries. 812 * We've got to be careful here as C++ produces relocatable zero 813 * entries in the constructor and destructor tables which are then 814 * tested for being not zero (which will always occur unless we're 815 * based from address zero). This causes an endless loop as __start 816 * is at zero. The solution used is to not relocate zero addresses. 817 * This has the negative side effect of not allowing a global data 818 * reference to be statically initialised to _stext (I've moved 819 * __start to address 4 so that is okay). 820 */ 821 if (rev > OLD_FLAT_VERSION) { 822 for (i = 0; i < relocs; i++) { 823 u32 addr, relval; 824 __be32 tmp; 825 826 /* 827 * Get the address of the pointer to be 828 * relocated (of course, the address has to be 829 * relocated first). 830 */ 831 if (get_user(tmp, reloc + i)) 832 return -EFAULT; 833 relval = ntohl(tmp); 834 addr = flat_get_relocate_addr(relval); 835 rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1); 836 if (rp == (u32 __user *)RELOC_FAILED) { 837 ret = -ENOEXEC; 838 goto err; 839 } 840 841 /* Get the pointer's value. */ 842 ret = flat_get_addr_from_rp(rp, relval, flags, &addr); 843 if (unlikely(ret)) 844 goto err; 845 846 if (addr != 0) { 847 /* 848 * Do the relocation. PIC relocs in the data section are 849 * already in target order 850 */ 851 if ((flags & FLAT_FLAG_GOTPIC) == 0) { 852 /* 853 * Meh, the same value can have a different 854 * byte order based on a flag.. 855 */ 856 addr = ntohl((__force __be32)addr); 857 } 858 addr = calc_reloc(addr, libinfo, id, 0); 859 if (addr == RELOC_FAILED) { 860 ret = -ENOEXEC; 861 goto err; 862 } 863 864 /* Write back the relocated pointer. */ 865 ret = flat_put_addr_at_rp(rp, addr, relval); 866 if (unlikely(ret)) 867 goto err; 868 } 869 } 870 #ifdef CONFIG_BINFMT_FLAT_OLD 871 } else { 872 for (i = 0; i < relocs; i++) { 873 __be32 relval; 874 if (get_user(relval, reloc + i)) 875 return -EFAULT; 876 old_reloc(ntohl(relval)); 877 } 878 #endif /* CONFIG_BINFMT_FLAT_OLD */ 879 } 880 881 flush_icache_user_range(start_code, end_code); 882 883 /* zero the BSS, BRK and stack areas */ 884 if (clear_user((void __user *)(datapos + data_len), bss_len + 885 (memp + memp_size - stack_len - /* end brk */ 886 libinfo->lib_list[id].start_brk) + /* start brk */ 887 stack_len)) 888 return -EFAULT; 889 890 return 0; 891 err: 892 return ret; 893 } 894 895 896 /****************************************************************************/ 897 #ifdef CONFIG_BINFMT_SHARED_FLAT 898 899 /* 900 * Load a shared library into memory. The library gets its own data 901 * segment (including bss) but not argv/argc/environ. 902 */ 903 904 static int load_flat_shared_library(int id, struct lib_info *libs) 905 { 906 /* 907 * This is a fake bprm struct; only the members "buf", "file" and 908 * "filename" are actually used. 909 */ 910 struct linux_binprm bprm; 911 int res; 912 char buf[16]; 913 loff_t pos = 0; 914 915 memset(&bprm, 0, sizeof(bprm)); 916 917 /* Create the file name */ 918 sprintf(buf, "/lib/lib%d.so", id); 919 920 /* Open the file up */ 921 bprm.filename = buf; 922 bprm.file = open_exec(bprm.filename); 923 res = PTR_ERR(bprm.file); 924 if (IS_ERR(bprm.file)) 925 return res; 926 927 res = kernel_read(bprm.file, bprm.buf, BINPRM_BUF_SIZE, &pos); 928 929 if (res >= 0) 930 res = load_flat_file(&bprm, libs, id, NULL); 931 932 allow_write_access(bprm.file); 933 fput(bprm.file); 934 935 return res; 936 } 937 938 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 939 /****************************************************************************/ 940 941 /* 942 * These are the functions used to load flat style executables and shared 943 * libraries. There is no binary dependent code anywhere else. 944 */ 945 946 static int load_flat_binary(struct linux_binprm *bprm) 947 { 948 struct lib_info libinfo; 949 struct pt_regs *regs = current_pt_regs(); 950 unsigned long stack_len = 0; 951 unsigned long start_addr; 952 int res; 953 int i, j; 954 955 memset(&libinfo, 0, sizeof(libinfo)); 956 957 /* 958 * We have to add the size of our arguments to our stack size 959 * otherwise it's too easy for users to create stack overflows 960 * by passing in a huge argument list. And yes, we have to be 961 * pedantic and include space for the argv/envp array as it may have 962 * a lot of entries. 963 */ 964 #ifndef CONFIG_MMU 965 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */ 966 #endif 967 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 968 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 969 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN); 970 971 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 972 if (res < 0) 973 return res; 974 975 /* Update data segment pointers for all libraries */ 976 for (i = 0; i < MAX_SHARED_LIBS; i++) { 977 if (!libinfo.lib_list[i].loaded) 978 continue; 979 for (j = 0; j < MAX_SHARED_LIBS; j++) { 980 unsigned long val = libinfo.lib_list[j].loaded ? 981 libinfo.lib_list[j].start_data : UNLOADED_LIB; 982 unsigned long __user *p = (unsigned long __user *) 983 libinfo.lib_list[i].start_data; 984 p -= j + 1; 985 if (put_user(val, p)) 986 return -EFAULT; 987 } 988 } 989 990 set_binfmt(&flat_format); 991 992 #ifdef CONFIG_MMU 993 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); 994 if (!res) 995 res = create_flat_tables(bprm, bprm->p); 996 #else 997 /* Stash our initial stack pointer into the mm structure */ 998 current->mm->start_stack = 999 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 1000 pr_debug("sp=%lx\n", current->mm->start_stack); 1001 1002 /* copy the arg pages onto the stack */ 1003 res = transfer_args_to_stack(bprm, ¤t->mm->start_stack); 1004 if (!res) 1005 res = create_flat_tables(bprm, current->mm->start_stack); 1006 #endif 1007 if (res) 1008 return res; 1009 1010 /* Fake some return addresses to ensure the call chain will 1011 * initialise library in order for us. We are required to call 1012 * lib 1 first, then 2, ... and finally the main program (id 0). 1013 */ 1014 start_addr = libinfo.lib_list[0].entry; 1015 1016 #ifdef CONFIG_BINFMT_SHARED_FLAT 1017 for (i = MAX_SHARED_LIBS-1; i > 0; i--) { 1018 if (libinfo.lib_list[i].loaded) { 1019 /* Push previos first to call address */ 1020 unsigned long __user *sp; 1021 current->mm->start_stack -= sizeof(unsigned long); 1022 sp = (unsigned long __user *)current->mm->start_stack; 1023 if (put_user(start_addr, sp)) 1024 return -EFAULT; 1025 start_addr = libinfo.lib_list[i].entry; 1026 } 1027 } 1028 #endif 1029 1030 #ifdef FLAT_PLAT_INIT 1031 FLAT_PLAT_INIT(regs); 1032 #endif 1033 1034 finalize_exec(bprm); 1035 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n", 1036 regs, start_addr, current->mm->start_stack); 1037 start_thread(regs, start_addr, current->mm->start_stack); 1038 1039 return 0; 1040 } 1041 1042 /****************************************************************************/ 1043 1044 static int __init init_flat_binfmt(void) 1045 { 1046 register_binfmt(&flat_format); 1047 return 0; 1048 } 1049 core_initcall(init_flat_binfmt); 1050 1051 /****************************************************************************/ 1052