1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format 2 * 3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * Derived from binfmt_elf.c 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13 #include <linux/module.h> 14 15 #include <linux/fs.h> 16 #include <linux/stat.h> 17 #include <linux/sched.h> 18 #include <linux/mm.h> 19 #include <linux/mman.h> 20 #include <linux/errno.h> 21 #include <linux/signal.h> 22 #include <linux/binfmts.h> 23 #include <linux/string.h> 24 #include <linux/file.h> 25 #include <linux/fcntl.h> 26 #include <linux/slab.h> 27 #include <linux/pagemap.h> 28 #include <linux/highmem.h> 29 #include <linux/highuid.h> 30 #include <linux/personality.h> 31 #include <linux/ptrace.h> 32 #include <linux/init.h> 33 #include <linux/elf.h> 34 #include <linux/elf-fdpic.h> 35 #include <linux/elfcore.h> 36 37 #include <asm/uaccess.h> 38 #include <asm/param.h> 39 #include <asm/pgalloc.h> 40 41 typedef char *elf_caddr_t; 42 43 #if 0 44 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 45 #else 46 #define kdebug(fmt, ...) do {} while(0) 47 #endif 48 49 #if 0 50 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 51 #else 52 #define kdcore(fmt, ...) do {} while(0) 53 #endif 54 55 MODULE_LICENSE("GPL"); 56 57 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *); 58 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 59 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 60 struct mm_struct *, const char *); 61 62 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 63 struct elf_fdpic_params *, 64 struct elf_fdpic_params *); 65 66 #ifndef CONFIG_MMU 67 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, 68 unsigned long *); 69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 70 struct file *, 71 struct mm_struct *); 72 #endif 73 74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 75 struct file *, struct mm_struct *); 76 77 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 78 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit); 79 #endif 80 81 static struct linux_binfmt elf_fdpic_format = { 82 .module = THIS_MODULE, 83 .load_binary = load_elf_fdpic_binary, 84 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 85 .core_dump = elf_fdpic_core_dump, 86 #endif 87 .min_coredump = ELF_EXEC_PAGESIZE, 88 }; 89 90 static int __init init_elf_fdpic_binfmt(void) 91 { 92 return register_binfmt(&elf_fdpic_format); 93 } 94 95 static void __exit exit_elf_fdpic_binfmt(void) 96 { 97 unregister_binfmt(&elf_fdpic_format); 98 } 99 100 core_initcall(init_elf_fdpic_binfmt); 101 module_exit(exit_elf_fdpic_binfmt); 102 103 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) 104 { 105 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 106 return 0; 107 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 108 return 0; 109 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) 110 return 0; 111 if (!file->f_op || !file->f_op->mmap) 112 return 0; 113 return 1; 114 } 115 116 /*****************************************************************************/ 117 /* 118 * read the program headers table into memory 119 */ 120 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 121 struct file *file) 122 { 123 struct elf32_phdr *phdr; 124 unsigned long size; 125 int retval, loop; 126 127 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 128 return -ENOMEM; 129 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 130 return -ENOMEM; 131 132 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 133 params->phdrs = kmalloc(size, GFP_KERNEL); 134 if (!params->phdrs) 135 return -ENOMEM; 136 137 retval = kernel_read(file, params->hdr.e_phoff, 138 (char *) params->phdrs, size); 139 if (unlikely(retval != size)) 140 return retval < 0 ? retval : -ENOEXEC; 141 142 /* determine stack size for this binary */ 143 phdr = params->phdrs; 144 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 145 if (phdr->p_type != PT_GNU_STACK) 146 continue; 147 148 if (phdr->p_flags & PF_X) 149 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 150 else 151 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 152 153 params->stack_size = phdr->p_memsz; 154 break; 155 } 156 157 return 0; 158 } 159 160 /*****************************************************************************/ 161 /* 162 * load an fdpic binary into various bits of memory 163 */ 164 static int load_elf_fdpic_binary(struct linux_binprm *bprm, 165 struct pt_regs *regs) 166 { 167 struct elf_fdpic_params exec_params, interp_params; 168 struct elf_phdr *phdr; 169 unsigned long stack_size, entryaddr; 170 #ifndef CONFIG_MMU 171 unsigned long fullsize; 172 #endif 173 #ifdef ELF_FDPIC_PLAT_INIT 174 unsigned long dynaddr; 175 #endif 176 struct file *interpreter = NULL; /* to shut gcc up */ 177 char *interpreter_name = NULL; 178 int executable_stack; 179 int retval, i; 180 181 kdebug("____ LOAD %d ____", current->pid); 182 183 memset(&exec_params, 0, sizeof(exec_params)); 184 memset(&interp_params, 0, sizeof(interp_params)); 185 186 exec_params.hdr = *(struct elfhdr *) bprm->buf; 187 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 188 189 /* check that this is a binary we know how to deal with */ 190 retval = -ENOEXEC; 191 if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) 192 goto error; 193 194 /* read the program header table */ 195 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 196 if (retval < 0) 197 goto error; 198 199 /* scan for a program header that specifies an interpreter */ 200 phdr = exec_params.phdrs; 201 202 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 203 switch (phdr->p_type) { 204 case PT_INTERP: 205 retval = -ENOMEM; 206 if (phdr->p_filesz > PATH_MAX) 207 goto error; 208 retval = -ENOENT; 209 if (phdr->p_filesz < 2) 210 goto error; 211 212 /* read the name of the interpreter into memory */ 213 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 214 if (!interpreter_name) 215 goto error; 216 217 retval = kernel_read(bprm->file, 218 phdr->p_offset, 219 interpreter_name, 220 phdr->p_filesz); 221 if (unlikely(retval != phdr->p_filesz)) { 222 if (retval >= 0) 223 retval = -ENOEXEC; 224 goto error; 225 } 226 227 retval = -ENOENT; 228 if (interpreter_name[phdr->p_filesz - 1] != '\0') 229 goto error; 230 231 kdebug("Using ELF interpreter %s", interpreter_name); 232 233 /* replace the program with the interpreter */ 234 interpreter = open_exec(interpreter_name); 235 retval = PTR_ERR(interpreter); 236 if (IS_ERR(interpreter)) { 237 interpreter = NULL; 238 goto error; 239 } 240 241 /* 242 * If the binary is not readable then enforce 243 * mm->dumpable = 0 regardless of the interpreter's 244 * permissions. 245 */ 246 if (file_permission(interpreter, MAY_READ) < 0) 247 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; 248 249 retval = kernel_read(interpreter, 0, bprm->buf, 250 BINPRM_BUF_SIZE); 251 if (unlikely(retval != BINPRM_BUF_SIZE)) { 252 if (retval >= 0) 253 retval = -ENOEXEC; 254 goto error; 255 } 256 257 interp_params.hdr = *((struct elfhdr *) bprm->buf); 258 break; 259 260 case PT_LOAD: 261 #ifdef CONFIG_MMU 262 if (exec_params.load_addr == 0) 263 exec_params.load_addr = phdr->p_vaddr; 264 #endif 265 break; 266 } 267 268 } 269 270 if (elf_check_const_displacement(&exec_params.hdr)) 271 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 272 273 /* perform insanity checks on the interpreter */ 274 if (interpreter_name) { 275 retval = -ELIBBAD; 276 if (!is_elf_fdpic(&interp_params.hdr, interpreter)) 277 goto error; 278 279 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 280 281 /* read the interpreter's program header table */ 282 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 283 if (retval < 0) 284 goto error; 285 } 286 287 stack_size = exec_params.stack_size; 288 if (stack_size < interp_params.stack_size) 289 stack_size = interp_params.stack_size; 290 291 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 292 executable_stack = EXSTACK_ENABLE_X; 293 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 294 executable_stack = EXSTACK_DISABLE_X; 295 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 296 executable_stack = EXSTACK_ENABLE_X; 297 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 298 executable_stack = EXSTACK_DISABLE_X; 299 else 300 executable_stack = EXSTACK_DEFAULT; 301 302 retval = -ENOEXEC; 303 if (stack_size == 0) 304 goto error; 305 306 if (elf_check_const_displacement(&interp_params.hdr)) 307 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 308 309 /* flush all traces of the currently running executable */ 310 retval = flush_old_exec(bprm); 311 if (retval) 312 goto error; 313 314 /* there's now no turning back... the old userspace image is dead, 315 * defunct, deceased, etc. after this point we have to exit via 316 * error_kill */ 317 set_personality(PER_LINUX_FDPIC); 318 set_binfmt(&elf_fdpic_format); 319 320 current->mm->start_code = 0; 321 current->mm->end_code = 0; 322 current->mm->start_stack = 0; 323 current->mm->start_data = 0; 324 current->mm->end_data = 0; 325 current->mm->context.exec_fdpic_loadmap = 0; 326 current->mm->context.interp_fdpic_loadmap = 0; 327 328 current->flags &= ~PF_FORKNOEXEC; 329 330 #ifdef CONFIG_MMU 331 elf_fdpic_arch_lay_out_mm(&exec_params, 332 &interp_params, 333 ¤t->mm->start_stack, 334 ¤t->mm->start_brk); 335 336 retval = setup_arg_pages(bprm, current->mm->start_stack, 337 executable_stack); 338 if (retval < 0) { 339 send_sig(SIGKILL, current, 0); 340 goto error_kill; 341 } 342 #endif 343 344 /* load the executable and interpreter into memory */ 345 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 346 "executable"); 347 if (retval < 0) 348 goto error_kill; 349 350 if (interpreter_name) { 351 retval = elf_fdpic_map_file(&interp_params, interpreter, 352 current->mm, "interpreter"); 353 if (retval < 0) { 354 printk(KERN_ERR "Unable to load interpreter\n"); 355 goto error_kill; 356 } 357 358 allow_write_access(interpreter); 359 fput(interpreter); 360 interpreter = NULL; 361 } 362 363 #ifdef CONFIG_MMU 364 if (!current->mm->start_brk) 365 current->mm->start_brk = current->mm->end_data; 366 367 current->mm->brk = current->mm->start_brk = 368 PAGE_ALIGN(current->mm->start_brk); 369 370 #else 371 /* create a stack and brk area big enough for everyone 372 * - the brk heap starts at the bottom and works up 373 * - the stack starts at the top and works down 374 */ 375 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 376 if (stack_size < PAGE_SIZE * 2) 377 stack_size = PAGE_SIZE * 2; 378 379 down_write(¤t->mm->mmap_sem); 380 current->mm->start_brk = do_mmap(NULL, 0, stack_size, 381 PROT_READ | PROT_WRITE | PROT_EXEC, 382 MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN, 383 0); 384 385 if (IS_ERR_VALUE(current->mm->start_brk)) { 386 up_write(¤t->mm->mmap_sem); 387 retval = current->mm->start_brk; 388 current->mm->start_brk = 0; 389 goto error_kill; 390 } 391 392 /* expand the stack mapping to use up the entire allocation granule */ 393 fullsize = kobjsize((char *) current->mm->start_brk); 394 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size, 395 fullsize, 0, 0))) 396 stack_size = fullsize; 397 up_write(¤t->mm->mmap_sem); 398 399 current->mm->brk = current->mm->start_brk; 400 current->mm->context.end_brk = current->mm->start_brk; 401 current->mm->context.end_brk += 402 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; 403 current->mm->start_stack = current->mm->start_brk + stack_size; 404 #endif 405 406 compute_creds(bprm); 407 current->flags &= ~PF_FORKNOEXEC; 408 if (create_elf_fdpic_tables(bprm, current->mm, 409 &exec_params, &interp_params) < 0) 410 goto error_kill; 411 412 kdebug("- start_code %lx", current->mm->start_code); 413 kdebug("- end_code %lx", current->mm->end_code); 414 kdebug("- start_data %lx", current->mm->start_data); 415 kdebug("- end_data %lx", current->mm->end_data); 416 kdebug("- start_brk %lx", current->mm->start_brk); 417 kdebug("- brk %lx", current->mm->brk); 418 kdebug("- start_stack %lx", current->mm->start_stack); 419 420 #ifdef ELF_FDPIC_PLAT_INIT 421 /* 422 * The ABI may specify that certain registers be set up in special 423 * ways (on i386 %edx is the address of a DT_FINI function, for 424 * example. This macro performs whatever initialization to 425 * the regs structure is required. 426 */ 427 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 428 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 429 dynaddr); 430 #endif 431 432 /* everything is now ready... get the userspace context ready to roll */ 433 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 434 start_thread(regs, entryaddr, current->mm->start_stack); 435 436 retval = 0; 437 438 error: 439 if (interpreter) { 440 allow_write_access(interpreter); 441 fput(interpreter); 442 } 443 kfree(interpreter_name); 444 kfree(exec_params.phdrs); 445 kfree(exec_params.loadmap); 446 kfree(interp_params.phdrs); 447 kfree(interp_params.loadmap); 448 return retval; 449 450 /* unrecoverable error - kill the process */ 451 error_kill: 452 send_sig(SIGSEGV, current, 0); 453 goto error; 454 455 } 456 457 /*****************************************************************************/ 458 /* 459 * present useful information to the program 460 */ 461 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 462 struct mm_struct *mm, 463 struct elf_fdpic_params *exec_params, 464 struct elf_fdpic_params *interp_params) 465 { 466 unsigned long sp, csp, nitems; 467 elf_caddr_t __user *argv, *envp; 468 size_t platform_len = 0, len; 469 char *k_platform; 470 char __user *u_platform, *p; 471 long hwcap; 472 int loop; 473 int nr; /* reset for each csp adjustment */ 474 475 /* we're going to shovel a whole load of stuff onto the stack */ 476 #ifdef CONFIG_MMU 477 sp = bprm->p; 478 #else 479 sp = mm->start_stack; 480 481 /* stack the program arguments and environment */ 482 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 483 return -EFAULT; 484 #endif 485 486 /* get hold of platform and hardware capabilities masks for the machine 487 * we are running on. In some cases (Sparc), this info is impossible 488 * to get, in others (i386) it is merely difficult. 489 */ 490 hwcap = ELF_HWCAP; 491 k_platform = ELF_PLATFORM; 492 u_platform = NULL; 493 494 if (k_platform) { 495 platform_len = strlen(k_platform) + 1; 496 sp -= platform_len; 497 u_platform = (char __user *) sp; 498 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 499 return -EFAULT; 500 } 501 502 #if defined(__i386__) && defined(CONFIG_SMP) 503 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 504 * by the processes running on the same package. One thing we can do is 505 * to shuffle the initial stack for them. 506 * 507 * the conditionals here are unneeded, but kept in to make the code 508 * behaviour the same as pre change unless we have hyperthreaded 509 * processors. This keeps Mr Marcelo Person happier but should be 510 * removed for 2.5 511 */ 512 if (smp_num_siblings > 1) 513 sp = sp - ((current->pid % 64) << 7); 514 #endif 515 516 sp &= ~7UL; 517 518 /* stack the load map(s) */ 519 len = sizeof(struct elf32_fdpic_loadmap); 520 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 521 sp = (sp - len) & ~7UL; 522 exec_params->map_addr = sp; 523 524 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 525 return -EFAULT; 526 527 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 528 529 if (interp_params->loadmap) { 530 len = sizeof(struct elf32_fdpic_loadmap); 531 len += sizeof(struct elf32_fdpic_loadseg) * 532 interp_params->loadmap->nsegs; 533 sp = (sp - len) & ~7UL; 534 interp_params->map_addr = sp; 535 536 if (copy_to_user((void __user *) sp, interp_params->loadmap, 537 len) != 0) 538 return -EFAULT; 539 540 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 541 } 542 543 /* force 16 byte _final_ alignment here for generality */ 544 #define DLINFO_ITEMS 13 545 546 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 547 548 csp = sp; 549 sp -= nitems * 2 * sizeof(unsigned long); 550 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 551 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 552 sp -= 1 * sizeof(unsigned long); /* argc */ 553 554 csp -= sp & 15UL; 555 sp -= sp & 15UL; 556 557 /* put the ELF interpreter info on the stack */ 558 #define NEW_AUX_ENT(id, val) \ 559 do { \ 560 struct { unsigned long _id, _val; } __user *ent; \ 561 \ 562 ent = (void __user *) csp; \ 563 __put_user((id), &ent[nr]._id); \ 564 __put_user((val), &ent[nr]._val); \ 565 nr++; \ 566 } while (0) 567 568 nr = 0; 569 csp -= 2 * sizeof(unsigned long); 570 NEW_AUX_ENT(AT_NULL, 0); 571 if (k_platform) { 572 nr = 0; 573 csp -= 2 * sizeof(unsigned long); 574 NEW_AUX_ENT(AT_PLATFORM, 575 (elf_addr_t) (unsigned long) u_platform); 576 } 577 578 nr = 0; 579 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 580 NEW_AUX_ENT(AT_HWCAP, hwcap); 581 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 582 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 583 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 584 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 585 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 586 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 587 NEW_AUX_ENT(AT_FLAGS, 0); 588 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 589 NEW_AUX_ENT(AT_UID, (elf_addr_t) current->uid); 590 NEW_AUX_ENT(AT_EUID, (elf_addr_t) current->euid); 591 NEW_AUX_ENT(AT_GID, (elf_addr_t) current->gid); 592 NEW_AUX_ENT(AT_EGID, (elf_addr_t) current->egid); 593 594 #ifdef ARCH_DLINFO 595 nr = 0; 596 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 597 598 /* ARCH_DLINFO must come last so platform specific code can enforce 599 * special alignment requirements on the AUXV if necessary (eg. PPC). 600 */ 601 ARCH_DLINFO; 602 #endif 603 #undef NEW_AUX_ENT 604 605 /* allocate room for argv[] and envv[] */ 606 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 607 envp = (elf_caddr_t __user *) csp; 608 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 609 argv = (elf_caddr_t __user *) csp; 610 611 /* stack argc */ 612 csp -= sizeof(unsigned long); 613 __put_user(bprm->argc, (unsigned long __user *) csp); 614 615 BUG_ON(csp != sp); 616 617 /* fill in the argv[] array */ 618 #ifdef CONFIG_MMU 619 current->mm->arg_start = bprm->p; 620 #else 621 current->mm->arg_start = current->mm->start_stack - 622 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 623 #endif 624 625 p = (char __user *) current->mm->arg_start; 626 for (loop = bprm->argc; loop > 0; loop--) { 627 __put_user((elf_caddr_t) p, argv++); 628 len = strnlen_user(p, MAX_ARG_STRLEN); 629 if (!len || len > MAX_ARG_STRLEN) 630 return -EINVAL; 631 p += len; 632 } 633 __put_user(NULL, argv); 634 current->mm->arg_end = (unsigned long) p; 635 636 /* fill in the envv[] array */ 637 current->mm->env_start = (unsigned long) p; 638 for (loop = bprm->envc; loop > 0; loop--) { 639 __put_user((elf_caddr_t)(unsigned long) p, envp++); 640 len = strnlen_user(p, MAX_ARG_STRLEN); 641 if (!len || len > MAX_ARG_STRLEN) 642 return -EINVAL; 643 p += len; 644 } 645 __put_user(NULL, envp); 646 current->mm->env_end = (unsigned long) p; 647 648 mm->start_stack = (unsigned long) sp; 649 return 0; 650 } 651 652 /*****************************************************************************/ 653 /* 654 * transfer the program arguments and environment from the holding pages onto 655 * the stack 656 */ 657 #ifndef CONFIG_MMU 658 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 659 unsigned long *_sp) 660 { 661 unsigned long index, stop, sp; 662 char *src; 663 int ret = 0; 664 665 stop = bprm->p >> PAGE_SHIFT; 666 sp = *_sp; 667 668 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 669 src = kmap(bprm->page[index]); 670 sp -= PAGE_SIZE; 671 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 672 ret = -EFAULT; 673 kunmap(bprm->page[index]); 674 if (ret < 0) 675 goto out; 676 } 677 678 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 679 680 out: 681 return ret; 682 } 683 #endif 684 685 /*****************************************************************************/ 686 /* 687 * load the appropriate binary image (executable or interpreter) into memory 688 * - we assume no MMU is available 689 * - if no other PIC bits are set in params->hdr->e_flags 690 * - we assume that the LOADable segments in the binary are independently relocatable 691 * - we assume R/O executable segments are shareable 692 * - else 693 * - we assume the loadable parts of the image to require fixed displacement 694 * - the image is not shareable 695 */ 696 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 697 struct file *file, 698 struct mm_struct *mm, 699 const char *what) 700 { 701 struct elf32_fdpic_loadmap *loadmap; 702 #ifdef CONFIG_MMU 703 struct elf32_fdpic_loadseg *mseg; 704 #endif 705 struct elf32_fdpic_loadseg *seg; 706 struct elf32_phdr *phdr; 707 unsigned long load_addr, stop; 708 unsigned nloads, tmp; 709 size_t size; 710 int loop, ret; 711 712 /* allocate a load map table */ 713 nloads = 0; 714 for (loop = 0; loop < params->hdr.e_phnum; loop++) 715 if (params->phdrs[loop].p_type == PT_LOAD) 716 nloads++; 717 718 if (nloads == 0) 719 return -ELIBBAD; 720 721 size = sizeof(*loadmap) + nloads * sizeof(*seg); 722 loadmap = kzalloc(size, GFP_KERNEL); 723 if (!loadmap) 724 return -ENOMEM; 725 726 params->loadmap = loadmap; 727 728 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 729 loadmap->nsegs = nloads; 730 731 load_addr = params->load_addr; 732 seg = loadmap->segs; 733 734 /* map the requested LOADs into the memory space */ 735 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 736 case ELF_FDPIC_FLAG_CONSTDISP: 737 case ELF_FDPIC_FLAG_CONTIGUOUS: 738 #ifndef CONFIG_MMU 739 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 740 if (ret < 0) 741 return ret; 742 break; 743 #endif 744 default: 745 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 746 if (ret < 0) 747 return ret; 748 break; 749 } 750 751 /* map the entry point */ 752 if (params->hdr.e_entry) { 753 seg = loadmap->segs; 754 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 755 if (params->hdr.e_entry >= seg->p_vaddr && 756 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 757 params->entry_addr = 758 (params->hdr.e_entry - seg->p_vaddr) + 759 seg->addr; 760 break; 761 } 762 } 763 } 764 765 /* determine where the program header table has wound up if mapped */ 766 stop = params->hdr.e_phoff; 767 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 768 phdr = params->phdrs; 769 770 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 771 if (phdr->p_type != PT_LOAD) 772 continue; 773 774 if (phdr->p_offset > params->hdr.e_phoff || 775 phdr->p_offset + phdr->p_filesz < stop) 776 continue; 777 778 seg = loadmap->segs; 779 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 780 if (phdr->p_vaddr >= seg->p_vaddr && 781 phdr->p_vaddr + phdr->p_filesz <= 782 seg->p_vaddr + seg->p_memsz) { 783 params->ph_addr = 784 (phdr->p_vaddr - seg->p_vaddr) + 785 seg->addr + 786 params->hdr.e_phoff - phdr->p_offset; 787 break; 788 } 789 } 790 break; 791 } 792 793 /* determine where the dynamic section has wound up if there is one */ 794 phdr = params->phdrs; 795 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 796 if (phdr->p_type != PT_DYNAMIC) 797 continue; 798 799 seg = loadmap->segs; 800 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 801 if (phdr->p_vaddr >= seg->p_vaddr && 802 phdr->p_vaddr + phdr->p_memsz <= 803 seg->p_vaddr + seg->p_memsz) { 804 params->dynamic_addr = 805 (phdr->p_vaddr - seg->p_vaddr) + 806 seg->addr; 807 808 /* check the dynamic section contains at least 809 * one item, and that the last item is a NULL 810 * entry */ 811 if (phdr->p_memsz == 0 || 812 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 813 goto dynamic_error; 814 815 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 816 if (((Elf32_Dyn *) 817 params->dynamic_addr)[tmp - 1].d_tag != 0) 818 goto dynamic_error; 819 break; 820 } 821 } 822 break; 823 } 824 825 /* now elide adjacent segments in the load map on MMU linux 826 * - on uClinux the holes between may actually be filled with system 827 * stuff or stuff from other processes 828 */ 829 #ifdef CONFIG_MMU 830 nloads = loadmap->nsegs; 831 mseg = loadmap->segs; 832 seg = mseg + 1; 833 for (loop = 1; loop < nloads; loop++) { 834 /* see if we have a candidate for merging */ 835 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 836 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 837 if (load_addr == (seg->addr & PAGE_MASK)) { 838 mseg->p_memsz += 839 load_addr - 840 (mseg->addr + mseg->p_memsz); 841 mseg->p_memsz += seg->addr & ~PAGE_MASK; 842 mseg->p_memsz += seg->p_memsz; 843 loadmap->nsegs--; 844 continue; 845 } 846 } 847 848 mseg++; 849 if (mseg != seg) 850 *mseg = *seg; 851 } 852 #endif 853 854 kdebug("Mapped Object [%s]:", what); 855 kdebug("- elfhdr : %lx", params->elfhdr_addr); 856 kdebug("- entry : %lx", params->entry_addr); 857 kdebug("- PHDR[] : %lx", params->ph_addr); 858 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 859 seg = loadmap->segs; 860 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 861 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 862 loop, 863 seg->addr, seg->addr + seg->p_memsz - 1, 864 seg->p_vaddr, seg->p_memsz); 865 866 return 0; 867 868 dynamic_error: 869 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 870 what, file->f_path.dentry->d_inode->i_ino); 871 return -ELIBBAD; 872 } 873 874 /*****************************************************************************/ 875 /* 876 * map a file with constant displacement under uClinux 877 */ 878 #ifndef CONFIG_MMU 879 static int elf_fdpic_map_file_constdisp_on_uclinux( 880 struct elf_fdpic_params *params, 881 struct file *file, 882 struct mm_struct *mm) 883 { 884 struct elf32_fdpic_loadseg *seg; 885 struct elf32_phdr *phdr; 886 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 887 loff_t fpos; 888 int loop, ret; 889 890 load_addr = params->load_addr; 891 seg = params->loadmap->segs; 892 893 /* determine the bounds of the contiguous overall allocation we must 894 * make */ 895 phdr = params->phdrs; 896 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 897 if (params->phdrs[loop].p_type != PT_LOAD) 898 continue; 899 900 if (base > phdr->p_vaddr) 901 base = phdr->p_vaddr; 902 if (top < phdr->p_vaddr + phdr->p_memsz) 903 top = phdr->p_vaddr + phdr->p_memsz; 904 } 905 906 /* allocate one big anon block for everything */ 907 mflags = MAP_PRIVATE; 908 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 909 mflags |= MAP_EXECUTABLE; 910 911 down_write(&mm->mmap_sem); 912 maddr = do_mmap(NULL, load_addr, top - base, 913 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 914 up_write(&mm->mmap_sem); 915 if (IS_ERR_VALUE(maddr)) 916 return (int) maddr; 917 918 if (load_addr != 0) 919 load_addr += PAGE_ALIGN(top - base); 920 921 /* and then load the file segments into it */ 922 phdr = params->phdrs; 923 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 924 if (params->phdrs[loop].p_type != PT_LOAD) 925 continue; 926 927 fpos = phdr->p_offset; 928 929 seg->addr = maddr + (phdr->p_vaddr - base); 930 seg->p_vaddr = phdr->p_vaddr; 931 seg->p_memsz = phdr->p_memsz; 932 933 ret = file->f_op->read(file, (void *) seg->addr, 934 phdr->p_filesz, &fpos); 935 if (ret < 0) 936 return ret; 937 938 /* map the ELF header address if in this segment */ 939 if (phdr->p_offset == 0) 940 params->elfhdr_addr = seg->addr; 941 942 /* clear any space allocated but not loaded */ 943 if (phdr->p_filesz < phdr->p_memsz) 944 clear_user((void *) (seg->addr + phdr->p_filesz), 945 phdr->p_memsz - phdr->p_filesz); 946 947 if (mm) { 948 if (phdr->p_flags & PF_X) { 949 if (!mm->start_code) { 950 mm->start_code = seg->addr; 951 mm->end_code = seg->addr + 952 phdr->p_memsz; 953 } 954 } else if (!mm->start_data) { 955 mm->start_data = seg->addr; 956 #ifndef CONFIG_MMU 957 mm->end_data = seg->addr + phdr->p_memsz; 958 #endif 959 } 960 961 #ifdef CONFIG_MMU 962 if (seg->addr + phdr->p_memsz > mm->end_data) 963 mm->end_data = seg->addr + phdr->p_memsz; 964 #endif 965 } 966 967 seg++; 968 } 969 970 return 0; 971 } 972 #endif 973 974 /*****************************************************************************/ 975 /* 976 * map a binary by direct mmap() of the individual PT_LOAD segments 977 */ 978 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 979 struct file *file, 980 struct mm_struct *mm) 981 { 982 struct elf32_fdpic_loadseg *seg; 983 struct elf32_phdr *phdr; 984 unsigned long load_addr, delta_vaddr; 985 int loop, dvset; 986 987 load_addr = params->load_addr; 988 delta_vaddr = 0; 989 dvset = 0; 990 991 seg = params->loadmap->segs; 992 993 /* deal with each load segment separately */ 994 phdr = params->phdrs; 995 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 996 unsigned long maddr, disp, excess, excess1; 997 int prot = 0, flags; 998 999 if (phdr->p_type != PT_LOAD) 1000 continue; 1001 1002 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1003 (unsigned long) phdr->p_vaddr, 1004 (unsigned long) phdr->p_offset, 1005 (unsigned long) phdr->p_filesz, 1006 (unsigned long) phdr->p_memsz); 1007 1008 /* determine the mapping parameters */ 1009 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1010 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1011 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1012 1013 flags = MAP_PRIVATE | MAP_DENYWRITE; 1014 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1015 flags |= MAP_EXECUTABLE; 1016 1017 maddr = 0; 1018 1019 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1020 case ELF_FDPIC_FLAG_INDEPENDENT: 1021 /* PT_LOADs are independently locatable */ 1022 break; 1023 1024 case ELF_FDPIC_FLAG_HONOURVADDR: 1025 /* the specified virtual address must be honoured */ 1026 maddr = phdr->p_vaddr; 1027 flags |= MAP_FIXED; 1028 break; 1029 1030 case ELF_FDPIC_FLAG_CONSTDISP: 1031 /* constant displacement 1032 * - can be mapped anywhere, but must be mapped as a 1033 * unit 1034 */ 1035 if (!dvset) { 1036 maddr = load_addr; 1037 delta_vaddr = phdr->p_vaddr; 1038 dvset = 1; 1039 } else { 1040 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1041 flags |= MAP_FIXED; 1042 } 1043 break; 1044 1045 case ELF_FDPIC_FLAG_CONTIGUOUS: 1046 /* contiguity handled later */ 1047 break; 1048 1049 default: 1050 BUG(); 1051 } 1052 1053 maddr &= PAGE_MASK; 1054 1055 /* create the mapping */ 1056 disp = phdr->p_vaddr & ~PAGE_MASK; 1057 down_write(&mm->mmap_sem); 1058 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1059 phdr->p_offset - disp); 1060 up_write(&mm->mmap_sem); 1061 1062 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1063 loop, phdr->p_memsz + disp, prot, flags, 1064 phdr->p_offset - disp, maddr); 1065 1066 if (IS_ERR_VALUE(maddr)) 1067 return (int) maddr; 1068 1069 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1070 ELF_FDPIC_FLAG_CONTIGUOUS) 1071 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1072 1073 seg->addr = maddr + disp; 1074 seg->p_vaddr = phdr->p_vaddr; 1075 seg->p_memsz = phdr->p_memsz; 1076 1077 /* map the ELF header address if in this segment */ 1078 if (phdr->p_offset == 0) 1079 params->elfhdr_addr = seg->addr; 1080 1081 /* clear the bit between beginning of mapping and beginning of 1082 * PT_LOAD */ 1083 if (prot & PROT_WRITE && disp > 0) { 1084 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1085 clear_user((void __user *) maddr, disp); 1086 maddr += disp; 1087 } 1088 1089 /* clear any space allocated but not loaded 1090 * - on uClinux we can just clear the lot 1091 * - on MMU linux we'll get a SIGBUS beyond the last page 1092 * extant in the file 1093 */ 1094 excess = phdr->p_memsz - phdr->p_filesz; 1095 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1096 1097 #ifdef CONFIG_MMU 1098 if (excess > excess1) { 1099 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1100 unsigned long xmaddr; 1101 1102 flags |= MAP_FIXED | MAP_ANONYMOUS; 1103 down_write(&mm->mmap_sem); 1104 xmaddr = do_mmap(NULL, xaddr, excess - excess1, 1105 prot, flags, 0); 1106 up_write(&mm->mmap_sem); 1107 1108 kdebug("mmap[%d] <anon>" 1109 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1110 loop, xaddr, excess - excess1, prot, flags, 1111 xmaddr); 1112 1113 if (xmaddr != xaddr) 1114 return -ENOMEM; 1115 } 1116 1117 if (prot & PROT_WRITE && excess1 > 0) { 1118 kdebug("clear[%d] ad=%lx sz=%lx", 1119 loop, maddr + phdr->p_filesz, excess1); 1120 clear_user((void __user *) maddr + phdr->p_filesz, 1121 excess1); 1122 } 1123 1124 #else 1125 if (excess > 0) { 1126 kdebug("clear[%d] ad=%lx sz=%lx", 1127 loop, maddr + phdr->p_filesz, excess); 1128 clear_user((void *) maddr + phdr->p_filesz, excess); 1129 } 1130 #endif 1131 1132 if (mm) { 1133 if (phdr->p_flags & PF_X) { 1134 if (!mm->start_code) { 1135 mm->start_code = maddr; 1136 mm->end_code = maddr + phdr->p_memsz; 1137 } 1138 } else if (!mm->start_data) { 1139 mm->start_data = maddr; 1140 mm->end_data = maddr + phdr->p_memsz; 1141 } 1142 } 1143 1144 seg++; 1145 } 1146 1147 return 0; 1148 } 1149 1150 /*****************************************************************************/ 1151 /* 1152 * ELF-FDPIC core dumper 1153 * 1154 * Modelled on fs/exec.c:aout_core_dump() 1155 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1156 * 1157 * Modelled on fs/binfmt_elf.c core dumper 1158 */ 1159 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 1160 1161 /* 1162 * These are the only things you should do on a core-file: use only these 1163 * functions to write out all the necessary info. 1164 */ 1165 static int dump_write(struct file *file, const void *addr, int nr) 1166 { 1167 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 1168 } 1169 1170 static int dump_seek(struct file *file, loff_t off) 1171 { 1172 if (file->f_op->llseek) { 1173 if (file->f_op->llseek(file, off, SEEK_SET) != off) 1174 return 0; 1175 } else { 1176 file->f_pos = off; 1177 } 1178 return 1; 1179 } 1180 1181 /* 1182 * Decide whether a segment is worth dumping; default is yes to be 1183 * sure (missing info is worse than too much; etc). 1184 * Personally I'd include everything, and use the coredump limit... 1185 * 1186 * I think we should skip something. But I am not sure how. H.J. 1187 */ 1188 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1189 { 1190 int dump_ok; 1191 1192 /* Do not dump I/O mapped devices or special mappings */ 1193 if (vma->vm_flags & (VM_IO | VM_RESERVED)) { 1194 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1195 return 0; 1196 } 1197 1198 /* If we may not read the contents, don't allow us to dump 1199 * them either. "dump_write()" can't handle it anyway. 1200 */ 1201 if (!(vma->vm_flags & VM_READ)) { 1202 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1203 return 0; 1204 } 1205 1206 /* By default, dump shared memory if mapped from an anonymous file. */ 1207 if (vma->vm_flags & VM_SHARED) { 1208 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1209 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1210 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1211 vma->vm_flags, dump_ok ? "yes" : "no"); 1212 return dump_ok; 1213 } 1214 1215 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1216 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1217 vma->vm_flags, dump_ok ? "yes" : "no"); 1218 return dump_ok; 1219 } 1220 1221 #ifdef CONFIG_MMU 1222 /* By default, if it hasn't been written to, don't write it out */ 1223 if (!vma->anon_vma) { 1224 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1225 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1226 vma->vm_flags, dump_ok ? "yes" : "no"); 1227 return dump_ok; 1228 } 1229 #endif 1230 1231 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1232 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1233 dump_ok ? "yes" : "no"); 1234 return dump_ok; 1235 } 1236 1237 /* An ELF note in memory */ 1238 struct memelfnote 1239 { 1240 const char *name; 1241 int type; 1242 unsigned int datasz; 1243 void *data; 1244 }; 1245 1246 static int notesize(struct memelfnote *en) 1247 { 1248 int sz; 1249 1250 sz = sizeof(struct elf_note); 1251 sz += roundup(strlen(en->name) + 1, 4); 1252 sz += roundup(en->datasz, 4); 1253 1254 return sz; 1255 } 1256 1257 /* #define DEBUG */ 1258 1259 #define DUMP_WRITE(addr, nr) \ 1260 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0) 1261 #define DUMP_SEEK(off) \ 1262 do { if (!dump_seek(file, (off))) return 0; } while(0) 1263 1264 static int writenote(struct memelfnote *men, struct file *file) 1265 { 1266 struct elf_note en; 1267 1268 en.n_namesz = strlen(men->name) + 1; 1269 en.n_descsz = men->datasz; 1270 en.n_type = men->type; 1271 1272 DUMP_WRITE(&en, sizeof(en)); 1273 DUMP_WRITE(men->name, en.n_namesz); 1274 /* XXX - cast from long long to long to avoid need for libgcc.a */ 1275 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1276 DUMP_WRITE(men->data, men->datasz); 1277 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1278 1279 return 1; 1280 } 1281 #undef DUMP_WRITE 1282 #undef DUMP_SEEK 1283 1284 #define DUMP_WRITE(addr, nr) \ 1285 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ 1286 goto end_coredump; 1287 #define DUMP_SEEK(off) \ 1288 if (!dump_seek(file, (off))) \ 1289 goto end_coredump; 1290 1291 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1292 { 1293 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1294 elf->e_ident[EI_CLASS] = ELF_CLASS; 1295 elf->e_ident[EI_DATA] = ELF_DATA; 1296 elf->e_ident[EI_VERSION] = EV_CURRENT; 1297 elf->e_ident[EI_OSABI] = ELF_OSABI; 1298 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1299 1300 elf->e_type = ET_CORE; 1301 elf->e_machine = ELF_ARCH; 1302 elf->e_version = EV_CURRENT; 1303 elf->e_entry = 0; 1304 elf->e_phoff = sizeof(struct elfhdr); 1305 elf->e_shoff = 0; 1306 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1307 elf->e_ehsize = sizeof(struct elfhdr); 1308 elf->e_phentsize = sizeof(struct elf_phdr); 1309 elf->e_phnum = segs; 1310 elf->e_shentsize = 0; 1311 elf->e_shnum = 0; 1312 elf->e_shstrndx = 0; 1313 return; 1314 } 1315 1316 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1317 { 1318 phdr->p_type = PT_NOTE; 1319 phdr->p_offset = offset; 1320 phdr->p_vaddr = 0; 1321 phdr->p_paddr = 0; 1322 phdr->p_filesz = sz; 1323 phdr->p_memsz = 0; 1324 phdr->p_flags = 0; 1325 phdr->p_align = 0; 1326 return; 1327 } 1328 1329 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1330 unsigned int sz, void *data) 1331 { 1332 note->name = name; 1333 note->type = type; 1334 note->datasz = sz; 1335 note->data = data; 1336 return; 1337 } 1338 1339 /* 1340 * fill up all the fields in prstatus from the given task struct, except 1341 * registers which need to be filled up seperately. 1342 */ 1343 static void fill_prstatus(struct elf_prstatus *prstatus, 1344 struct task_struct *p, long signr) 1345 { 1346 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1347 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1348 prstatus->pr_sighold = p->blocked.sig[0]; 1349 prstatus->pr_pid = task_pid_vnr(p); 1350 prstatus->pr_ppid = task_pid_vnr(p->parent); 1351 prstatus->pr_pgrp = task_pgrp_vnr(p); 1352 prstatus->pr_sid = task_session_vnr(p); 1353 if (thread_group_leader(p)) { 1354 /* 1355 * This is the record for the group leader. Add in the 1356 * cumulative times of previous dead threads. This total 1357 * won't include the time of each live thread whose state 1358 * is included in the core dump. The final total reported 1359 * to our parent process when it calls wait4 will include 1360 * those sums as well as the little bit more time it takes 1361 * this and each other thread to finish dying after the 1362 * core dump synchronization phase. 1363 */ 1364 cputime_to_timeval(cputime_add(p->utime, p->signal->utime), 1365 &prstatus->pr_utime); 1366 cputime_to_timeval(cputime_add(p->stime, p->signal->stime), 1367 &prstatus->pr_stime); 1368 } else { 1369 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1370 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1371 } 1372 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1373 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1374 1375 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1376 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1377 } 1378 1379 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1380 struct mm_struct *mm) 1381 { 1382 unsigned int i, len; 1383 1384 /* first copy the parameters from user space */ 1385 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1386 1387 len = mm->arg_end - mm->arg_start; 1388 if (len >= ELF_PRARGSZ) 1389 len = ELF_PRARGSZ - 1; 1390 if (copy_from_user(&psinfo->pr_psargs, 1391 (const char __user *) mm->arg_start, len)) 1392 return -EFAULT; 1393 for (i = 0; i < len; i++) 1394 if (psinfo->pr_psargs[i] == 0) 1395 psinfo->pr_psargs[i] = ' '; 1396 psinfo->pr_psargs[len] = 0; 1397 1398 psinfo->pr_pid = task_pid_vnr(p); 1399 psinfo->pr_ppid = task_pid_vnr(p->parent); 1400 psinfo->pr_pgrp = task_pgrp_vnr(p); 1401 psinfo->pr_sid = task_session_vnr(p); 1402 1403 i = p->state ? ffz(~p->state) + 1 : 0; 1404 psinfo->pr_state = i; 1405 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1406 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1407 psinfo->pr_nice = task_nice(p); 1408 psinfo->pr_flag = p->flags; 1409 SET_UID(psinfo->pr_uid, p->uid); 1410 SET_GID(psinfo->pr_gid, p->gid); 1411 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1412 1413 return 0; 1414 } 1415 1416 /* Here is the structure in which status of each thread is captured. */ 1417 struct elf_thread_status 1418 { 1419 struct list_head list; 1420 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1421 elf_fpregset_t fpu; /* NT_PRFPREG */ 1422 struct task_struct *thread; 1423 #ifdef ELF_CORE_COPY_XFPREGS 1424 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1425 #endif 1426 struct memelfnote notes[3]; 1427 int num_notes; 1428 }; 1429 1430 /* 1431 * In order to add the specific thread information for the elf file format, 1432 * we need to keep a linked list of every thread's pr_status and then create 1433 * a single section for them in the final core file. 1434 */ 1435 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1436 { 1437 struct task_struct *p = t->thread; 1438 int sz = 0; 1439 1440 t->num_notes = 0; 1441 1442 fill_prstatus(&t->prstatus, p, signr); 1443 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1444 1445 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1446 &t->prstatus); 1447 t->num_notes++; 1448 sz += notesize(&t->notes[0]); 1449 1450 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1451 if (t->prstatus.pr_fpvalid) { 1452 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1453 &t->fpu); 1454 t->num_notes++; 1455 sz += notesize(&t->notes[1]); 1456 } 1457 1458 #ifdef ELF_CORE_COPY_XFPREGS 1459 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1460 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1461 sizeof(t->xfpu), &t->xfpu); 1462 t->num_notes++; 1463 sz += notesize(&t->notes[2]); 1464 } 1465 #endif 1466 return sz; 1467 } 1468 1469 /* 1470 * dump the segments for an MMU process 1471 */ 1472 #ifdef CONFIG_MMU 1473 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1474 unsigned long *limit, unsigned long mm_flags) 1475 { 1476 struct vm_area_struct *vma; 1477 1478 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1479 unsigned long addr; 1480 1481 if (!maydump(vma, mm_flags)) 1482 continue; 1483 1484 for (addr = vma->vm_start; 1485 addr < vma->vm_end; 1486 addr += PAGE_SIZE 1487 ) { 1488 struct vm_area_struct *vma; 1489 struct page *page; 1490 1491 if (get_user_pages(current, current->mm, addr, 1, 0, 1, 1492 &page, &vma) <= 0) { 1493 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1494 } 1495 else if (page == ZERO_PAGE(0)) { 1496 page_cache_release(page); 1497 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1498 } 1499 else { 1500 void *kaddr; 1501 1502 flush_cache_page(vma, addr, page_to_pfn(page)); 1503 kaddr = kmap(page); 1504 if ((*size += PAGE_SIZE) > *limit || 1505 !dump_write(file, kaddr, PAGE_SIZE) 1506 ) { 1507 kunmap(page); 1508 page_cache_release(page); 1509 return -EIO; 1510 } 1511 kunmap(page); 1512 page_cache_release(page); 1513 } 1514 } 1515 } 1516 1517 return 0; 1518 1519 end_coredump: 1520 return -EFBIG; 1521 } 1522 #endif 1523 1524 /* 1525 * dump the segments for a NOMMU process 1526 */ 1527 #ifndef CONFIG_MMU 1528 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1529 unsigned long *limit, unsigned long mm_flags) 1530 { 1531 struct vm_list_struct *vml; 1532 1533 for (vml = current->mm->context.vmlist; vml; vml = vml->next) { 1534 struct vm_area_struct *vma = vml->vma; 1535 1536 if (!maydump(vma, mm_flags)) 1537 continue; 1538 1539 if ((*size += PAGE_SIZE) > *limit) 1540 return -EFBIG; 1541 1542 if (!dump_write(file, (void *) vma->vm_start, 1543 vma->vm_end - vma->vm_start)) 1544 return -EIO; 1545 } 1546 1547 return 0; 1548 } 1549 #endif 1550 1551 /* 1552 * Actual dumper 1553 * 1554 * This is a two-pass process; first we find the offsets of the bits, 1555 * and then they are actually written out. If we run out of core limit 1556 * we just truncate. 1557 */ 1558 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 1559 struct file *file, unsigned long limit) 1560 { 1561 #define NUM_NOTES 6 1562 int has_dumped = 0; 1563 mm_segment_t fs; 1564 int segs; 1565 size_t size = 0; 1566 int i; 1567 struct vm_area_struct *vma; 1568 struct elfhdr *elf = NULL; 1569 loff_t offset = 0, dataoff; 1570 int numnote; 1571 struct memelfnote *notes = NULL; 1572 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1573 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1574 LIST_HEAD(thread_list); 1575 struct list_head *t; 1576 elf_fpregset_t *fpu = NULL; 1577 #ifdef ELF_CORE_COPY_XFPREGS 1578 elf_fpxregset_t *xfpu = NULL; 1579 #endif 1580 int thread_status_size = 0; 1581 #ifndef CONFIG_MMU 1582 struct vm_list_struct *vml; 1583 #endif 1584 elf_addr_t *auxv; 1585 unsigned long mm_flags; 1586 1587 /* 1588 * We no longer stop all VM operations. 1589 * 1590 * This is because those proceses that could possibly change map_count 1591 * or the mmap / vma pages are now blocked in do_exit on current 1592 * finishing this core dump. 1593 * 1594 * Only ptrace can touch these memory addresses, but it doesn't change 1595 * the map_count or the pages allocated. So no possibility of crashing 1596 * exists while dumping the mm->vm_next areas to the core file. 1597 */ 1598 1599 /* alloc memory for large data structures: too large to be on stack */ 1600 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1601 if (!elf) 1602 goto cleanup; 1603 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1604 if (!prstatus) 1605 goto cleanup; 1606 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1607 if (!psinfo) 1608 goto cleanup; 1609 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1610 if (!notes) 1611 goto cleanup; 1612 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1613 if (!fpu) 1614 goto cleanup; 1615 #ifdef ELF_CORE_COPY_XFPREGS 1616 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1617 if (!xfpu) 1618 goto cleanup; 1619 #endif 1620 1621 if (signr) { 1622 struct core_thread *ct; 1623 struct elf_thread_status *tmp; 1624 1625 for (ct = current->mm->core_state->dumper.next; 1626 ct; ct = ct->next) { 1627 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1628 if (!tmp) 1629 goto cleanup; 1630 1631 tmp->thread = ct->task; 1632 list_add(&tmp->list, &thread_list); 1633 } 1634 1635 list_for_each(t, &thread_list) { 1636 struct elf_thread_status *tmp; 1637 int sz; 1638 1639 tmp = list_entry(t, struct elf_thread_status, list); 1640 sz = elf_dump_thread_status(signr, tmp); 1641 thread_status_size += sz; 1642 } 1643 } 1644 1645 /* now collect the dump for the current */ 1646 fill_prstatus(prstatus, current, signr); 1647 elf_core_copy_regs(&prstatus->pr_reg, regs); 1648 1649 #ifdef CONFIG_MMU 1650 segs = current->mm->map_count; 1651 #else 1652 segs = 0; 1653 for (vml = current->mm->context.vmlist; vml; vml = vml->next) 1654 segs++; 1655 #endif 1656 #ifdef ELF_CORE_EXTRA_PHDRS 1657 segs += ELF_CORE_EXTRA_PHDRS; 1658 #endif 1659 1660 /* Set up header */ 1661 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */ 1662 1663 has_dumped = 1; 1664 current->flags |= PF_DUMPCORE; 1665 1666 /* 1667 * Set up the notes in similar form to SVR4 core dumps made 1668 * with info from their /proc. 1669 */ 1670 1671 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1672 fill_psinfo(psinfo, current->group_leader, current->mm); 1673 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1674 1675 numnote = 2; 1676 1677 auxv = (elf_addr_t *) current->mm->saved_auxv; 1678 1679 i = 0; 1680 do 1681 i += 2; 1682 while (auxv[i - 2] != AT_NULL); 1683 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1684 i * sizeof(elf_addr_t), auxv); 1685 1686 /* Try to dump the FPU. */ 1687 if ((prstatus->pr_fpvalid = 1688 elf_core_copy_task_fpregs(current, regs, fpu))) 1689 fill_note(notes + numnote++, 1690 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1691 #ifdef ELF_CORE_COPY_XFPREGS 1692 if (elf_core_copy_task_xfpregs(current, xfpu)) 1693 fill_note(notes + numnote++, 1694 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1695 #endif 1696 1697 fs = get_fs(); 1698 set_fs(KERNEL_DS); 1699 1700 DUMP_WRITE(elf, sizeof(*elf)); 1701 offset += sizeof(*elf); /* Elf header */ 1702 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */ 1703 1704 /* Write notes phdr entry */ 1705 { 1706 struct elf_phdr phdr; 1707 int sz = 0; 1708 1709 for (i = 0; i < numnote; i++) 1710 sz += notesize(notes + i); 1711 1712 sz += thread_status_size; 1713 1714 fill_elf_note_phdr(&phdr, sz, offset); 1715 offset += sz; 1716 DUMP_WRITE(&phdr, sizeof(phdr)); 1717 } 1718 1719 /* Page-align dumped data */ 1720 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1721 1722 /* 1723 * We must use the same mm->flags while dumping core to avoid 1724 * inconsistency between the program headers and bodies, otherwise an 1725 * unusable core file can be generated. 1726 */ 1727 mm_flags = current->mm->flags; 1728 1729 /* write program headers for segments dump */ 1730 for ( 1731 #ifdef CONFIG_MMU 1732 vma = current->mm->mmap; vma; vma = vma->vm_next 1733 #else 1734 vml = current->mm->context.vmlist; vml; vml = vml->next 1735 #endif 1736 ) { 1737 struct elf_phdr phdr; 1738 size_t sz; 1739 1740 #ifndef CONFIG_MMU 1741 vma = vml->vma; 1742 #endif 1743 1744 sz = vma->vm_end - vma->vm_start; 1745 1746 phdr.p_type = PT_LOAD; 1747 phdr.p_offset = offset; 1748 phdr.p_vaddr = vma->vm_start; 1749 phdr.p_paddr = 0; 1750 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0; 1751 phdr.p_memsz = sz; 1752 offset += phdr.p_filesz; 1753 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1754 if (vma->vm_flags & VM_WRITE) 1755 phdr.p_flags |= PF_W; 1756 if (vma->vm_flags & VM_EXEC) 1757 phdr.p_flags |= PF_X; 1758 phdr.p_align = ELF_EXEC_PAGESIZE; 1759 1760 DUMP_WRITE(&phdr, sizeof(phdr)); 1761 } 1762 1763 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS 1764 ELF_CORE_WRITE_EXTRA_PHDRS; 1765 #endif 1766 1767 /* write out the notes section */ 1768 for (i = 0; i < numnote; i++) 1769 if (!writenote(notes + i, file)) 1770 goto end_coredump; 1771 1772 /* write out the thread status notes section */ 1773 list_for_each(t, &thread_list) { 1774 struct elf_thread_status *tmp = 1775 list_entry(t, struct elf_thread_status, list); 1776 1777 for (i = 0; i < tmp->num_notes; i++) 1778 if (!writenote(&tmp->notes[i], file)) 1779 goto end_coredump; 1780 } 1781 1782 DUMP_SEEK(dataoff); 1783 1784 if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0) 1785 goto end_coredump; 1786 1787 #ifdef ELF_CORE_WRITE_EXTRA_DATA 1788 ELF_CORE_WRITE_EXTRA_DATA; 1789 #endif 1790 1791 if (file->f_pos != offset) { 1792 /* Sanity check */ 1793 printk(KERN_WARNING 1794 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1795 file->f_pos, offset); 1796 } 1797 1798 end_coredump: 1799 set_fs(fs); 1800 1801 cleanup: 1802 while (!list_empty(&thread_list)) { 1803 struct list_head *tmp = thread_list.next; 1804 list_del(tmp); 1805 kfree(list_entry(tmp, struct elf_thread_status, list)); 1806 } 1807 1808 kfree(elf); 1809 kfree(prstatus); 1810 kfree(psinfo); 1811 kfree(notes); 1812 kfree(fpu); 1813 #ifdef ELF_CORE_COPY_XFPREGS 1814 kfree(xfpu); 1815 #endif 1816 return has_dumped; 1817 #undef NUM_NOTES 1818 } 1819 1820 #endif /* USE_ELF_CORE_DUMP */ 1821