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