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 = ksize((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 if (unlikely(current->ptrace & PT_PTRACED)) { 437 if (current->ptrace & PT_TRACE_EXEC) 438 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP); 439 else 440 send_sig(SIGTRAP, current, 0); 441 } 442 443 retval = 0; 444 445 error: 446 if (interpreter) { 447 allow_write_access(interpreter); 448 fput(interpreter); 449 } 450 kfree(interpreter_name); 451 kfree(exec_params.phdrs); 452 kfree(exec_params.loadmap); 453 kfree(interp_params.phdrs); 454 kfree(interp_params.loadmap); 455 return retval; 456 457 /* unrecoverable error - kill the process */ 458 error_kill: 459 send_sig(SIGSEGV, current, 0); 460 goto error; 461 462 } 463 464 /*****************************************************************************/ 465 /* 466 * present useful information to the program 467 */ 468 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 469 struct mm_struct *mm, 470 struct elf_fdpic_params *exec_params, 471 struct elf_fdpic_params *interp_params) 472 { 473 unsigned long sp, csp, nitems; 474 elf_caddr_t __user *argv, *envp; 475 size_t platform_len = 0, len; 476 char *k_platform; 477 char __user *u_platform, *p; 478 long hwcap; 479 int loop; 480 481 /* we're going to shovel a whole load of stuff onto the stack */ 482 #ifdef CONFIG_MMU 483 sp = bprm->p; 484 #else 485 sp = mm->start_stack; 486 487 /* stack the program arguments and environment */ 488 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 489 return -EFAULT; 490 #endif 491 492 /* get hold of platform and hardware capabilities masks for the machine 493 * we are running on. In some cases (Sparc), this info is impossible 494 * to get, in others (i386) it is merely difficult. 495 */ 496 hwcap = ELF_HWCAP; 497 k_platform = ELF_PLATFORM; 498 u_platform = NULL; 499 500 if (k_platform) { 501 platform_len = strlen(k_platform) + 1; 502 sp -= platform_len; 503 u_platform = (char __user *) sp; 504 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 505 return -EFAULT; 506 } 507 508 #if defined(__i386__) && defined(CONFIG_SMP) 509 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 510 * by the processes running on the same package. One thing we can do is 511 * to shuffle the initial stack for them. 512 * 513 * the conditionals here are unneeded, but kept in to make the code 514 * behaviour the same as pre change unless we have hyperthreaded 515 * processors. This keeps Mr Marcelo Person happier but should be 516 * removed for 2.5 517 */ 518 if (smp_num_siblings > 1) 519 sp = sp - ((current->pid % 64) << 7); 520 #endif 521 522 sp &= ~7UL; 523 524 /* stack the load map(s) */ 525 len = sizeof(struct elf32_fdpic_loadmap); 526 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 527 sp = (sp - len) & ~7UL; 528 exec_params->map_addr = sp; 529 530 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 531 return -EFAULT; 532 533 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 534 535 if (interp_params->loadmap) { 536 len = sizeof(struct elf32_fdpic_loadmap); 537 len += sizeof(struct elf32_fdpic_loadseg) * 538 interp_params->loadmap->nsegs; 539 sp = (sp - len) & ~7UL; 540 interp_params->map_addr = sp; 541 542 if (copy_to_user((void __user *) sp, interp_params->loadmap, 543 len) != 0) 544 return -EFAULT; 545 546 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 547 } 548 549 /* force 16 byte _final_ alignment here for generality */ 550 #define DLINFO_ITEMS 13 551 552 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0); 553 #ifdef DLINFO_ARCH_ITEMS 554 nitems += DLINFO_ARCH_ITEMS; 555 #endif 556 557 csp = sp; 558 sp -= nitems * 2 * sizeof(unsigned long); 559 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 560 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 561 sp -= 1 * sizeof(unsigned long); /* argc */ 562 563 csp -= sp & 15UL; 564 sp -= sp & 15UL; 565 566 /* put the ELF interpreter info on the stack */ 567 #define NEW_AUX_ENT(nr, id, val) \ 568 do { \ 569 struct { unsigned long _id, _val; } __user *ent; \ 570 \ 571 ent = (void __user *) csp; \ 572 __put_user((id), &ent[nr]._id); \ 573 __put_user((val), &ent[nr]._val); \ 574 } while (0) 575 576 csp -= 2 * sizeof(unsigned long); 577 NEW_AUX_ENT(0, AT_NULL, 0); 578 if (k_platform) { 579 csp -= 2 * sizeof(unsigned long); 580 NEW_AUX_ENT(0, AT_PLATFORM, 581 (elf_addr_t) (unsigned long) u_platform); 582 } 583 584 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 585 NEW_AUX_ENT( 0, AT_HWCAP, hwcap); 586 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE); 587 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC); 588 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr); 589 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr)); 590 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum); 591 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr); 592 NEW_AUX_ENT( 7, AT_FLAGS, 0); 593 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr); 594 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid); 595 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid); 596 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid); 597 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid); 598 599 #ifdef ARCH_DLINFO 600 /* ARCH_DLINFO must come last so platform specific code can enforce 601 * special alignment requirements on the AUXV if necessary (eg. PPC). 602 */ 603 ARCH_DLINFO; 604 #endif 605 #undef NEW_AUX_ENT 606 607 /* allocate room for argv[] and envv[] */ 608 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 609 envp = (elf_caddr_t __user *) csp; 610 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 611 argv = (elf_caddr_t __user *) csp; 612 613 /* stack argc */ 614 csp -= sizeof(unsigned long); 615 __put_user(bprm->argc, (unsigned long __user *) csp); 616 617 BUG_ON(csp != sp); 618 619 /* fill in the argv[] array */ 620 #ifdef CONFIG_MMU 621 current->mm->arg_start = bprm->p; 622 #else 623 current->mm->arg_start = current->mm->start_stack - 624 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 625 #endif 626 627 p = (char __user *) current->mm->arg_start; 628 for (loop = bprm->argc; loop > 0; loop--) { 629 __put_user((elf_caddr_t) p, argv++); 630 len = strnlen_user(p, MAX_ARG_STRLEN); 631 if (!len || len > MAX_ARG_STRLEN) 632 return -EINVAL; 633 p += len; 634 } 635 __put_user(NULL, argv); 636 current->mm->arg_end = (unsigned long) p; 637 638 /* fill in the envv[] array */ 639 current->mm->env_start = (unsigned long) p; 640 for (loop = bprm->envc; loop > 0; loop--) { 641 __put_user((elf_caddr_t)(unsigned long) p, envp++); 642 len = strnlen_user(p, MAX_ARG_STRLEN); 643 if (!len || len > MAX_ARG_STRLEN) 644 return -EINVAL; 645 p += len; 646 } 647 __put_user(NULL, envp); 648 current->mm->env_end = (unsigned long) p; 649 650 mm->start_stack = (unsigned long) sp; 651 return 0; 652 } 653 654 /*****************************************************************************/ 655 /* 656 * transfer the program arguments and environment from the holding pages onto 657 * the stack 658 */ 659 #ifndef CONFIG_MMU 660 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 661 unsigned long *_sp) 662 { 663 unsigned long index, stop, sp; 664 char *src; 665 int ret = 0; 666 667 stop = bprm->p >> PAGE_SHIFT; 668 sp = *_sp; 669 670 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 671 src = kmap(bprm->page[index]); 672 sp -= PAGE_SIZE; 673 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 674 ret = -EFAULT; 675 kunmap(bprm->page[index]); 676 if (ret < 0) 677 goto out; 678 } 679 680 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 681 682 out: 683 return ret; 684 } 685 #endif 686 687 /*****************************************************************************/ 688 /* 689 * load the appropriate binary image (executable or interpreter) into memory 690 * - we assume no MMU is available 691 * - if no other PIC bits are set in params->hdr->e_flags 692 * - we assume that the LOADable segments in the binary are independently relocatable 693 * - we assume R/O executable segments are shareable 694 * - else 695 * - we assume the loadable parts of the image to require fixed displacement 696 * - the image is not shareable 697 */ 698 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 699 struct file *file, 700 struct mm_struct *mm, 701 const char *what) 702 { 703 struct elf32_fdpic_loadmap *loadmap; 704 #ifdef CONFIG_MMU 705 struct elf32_fdpic_loadseg *mseg; 706 #endif 707 struct elf32_fdpic_loadseg *seg; 708 struct elf32_phdr *phdr; 709 unsigned long load_addr, stop; 710 unsigned nloads, tmp; 711 size_t size; 712 int loop, ret; 713 714 /* allocate a load map table */ 715 nloads = 0; 716 for (loop = 0; loop < params->hdr.e_phnum; loop++) 717 if (params->phdrs[loop].p_type == PT_LOAD) 718 nloads++; 719 720 if (nloads == 0) 721 return -ELIBBAD; 722 723 size = sizeof(*loadmap) + nloads * sizeof(*seg); 724 loadmap = kzalloc(size, GFP_KERNEL); 725 if (!loadmap) 726 return -ENOMEM; 727 728 params->loadmap = loadmap; 729 730 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 731 loadmap->nsegs = nloads; 732 733 load_addr = params->load_addr; 734 seg = loadmap->segs; 735 736 /* map the requested LOADs into the memory space */ 737 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 738 case ELF_FDPIC_FLAG_CONSTDISP: 739 case ELF_FDPIC_FLAG_CONTIGUOUS: 740 #ifndef CONFIG_MMU 741 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 742 if (ret < 0) 743 return ret; 744 break; 745 #endif 746 default: 747 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 748 if (ret < 0) 749 return ret; 750 break; 751 } 752 753 /* map the entry point */ 754 if (params->hdr.e_entry) { 755 seg = loadmap->segs; 756 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 757 if (params->hdr.e_entry >= seg->p_vaddr && 758 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 759 params->entry_addr = 760 (params->hdr.e_entry - seg->p_vaddr) + 761 seg->addr; 762 break; 763 } 764 } 765 } 766 767 /* determine where the program header table has wound up if mapped */ 768 stop = params->hdr.e_phoff; 769 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 770 phdr = params->phdrs; 771 772 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 773 if (phdr->p_type != PT_LOAD) 774 continue; 775 776 if (phdr->p_offset > params->hdr.e_phoff || 777 phdr->p_offset + phdr->p_filesz < stop) 778 continue; 779 780 seg = loadmap->segs; 781 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 782 if (phdr->p_vaddr >= seg->p_vaddr && 783 phdr->p_vaddr + phdr->p_filesz <= 784 seg->p_vaddr + seg->p_memsz) { 785 params->ph_addr = 786 (phdr->p_vaddr - seg->p_vaddr) + 787 seg->addr + 788 params->hdr.e_phoff - phdr->p_offset; 789 break; 790 } 791 } 792 break; 793 } 794 795 /* determine where the dynamic section has wound up if there is one */ 796 phdr = params->phdrs; 797 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 798 if (phdr->p_type != PT_DYNAMIC) 799 continue; 800 801 seg = loadmap->segs; 802 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 803 if (phdr->p_vaddr >= seg->p_vaddr && 804 phdr->p_vaddr + phdr->p_memsz <= 805 seg->p_vaddr + seg->p_memsz) { 806 params->dynamic_addr = 807 (phdr->p_vaddr - seg->p_vaddr) + 808 seg->addr; 809 810 /* check the dynamic section contains at least 811 * one item, and that the last item is a NULL 812 * entry */ 813 if (phdr->p_memsz == 0 || 814 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 815 goto dynamic_error; 816 817 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 818 if (((Elf32_Dyn *) 819 params->dynamic_addr)[tmp - 1].d_tag != 0) 820 goto dynamic_error; 821 break; 822 } 823 } 824 break; 825 } 826 827 /* now elide adjacent segments in the load map on MMU linux 828 * - on uClinux the holes between may actually be filled with system 829 * stuff or stuff from other processes 830 */ 831 #ifdef CONFIG_MMU 832 nloads = loadmap->nsegs; 833 mseg = loadmap->segs; 834 seg = mseg + 1; 835 for (loop = 1; loop < nloads; loop++) { 836 /* see if we have a candidate for merging */ 837 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 838 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 839 if (load_addr == (seg->addr & PAGE_MASK)) { 840 mseg->p_memsz += 841 load_addr - 842 (mseg->addr + mseg->p_memsz); 843 mseg->p_memsz += seg->addr & ~PAGE_MASK; 844 mseg->p_memsz += seg->p_memsz; 845 loadmap->nsegs--; 846 continue; 847 } 848 } 849 850 mseg++; 851 if (mseg != seg) 852 *mseg = *seg; 853 } 854 #endif 855 856 kdebug("Mapped Object [%s]:", what); 857 kdebug("- elfhdr : %lx", params->elfhdr_addr); 858 kdebug("- entry : %lx", params->entry_addr); 859 kdebug("- PHDR[] : %lx", params->ph_addr); 860 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 861 seg = loadmap->segs; 862 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 863 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 864 loop, 865 seg->addr, seg->addr + seg->p_memsz - 1, 866 seg->p_vaddr, seg->p_memsz); 867 868 return 0; 869 870 dynamic_error: 871 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 872 what, file->f_path.dentry->d_inode->i_ino); 873 return -ELIBBAD; 874 } 875 876 /*****************************************************************************/ 877 /* 878 * map a file with constant displacement under uClinux 879 */ 880 #ifndef CONFIG_MMU 881 static int elf_fdpic_map_file_constdisp_on_uclinux( 882 struct elf_fdpic_params *params, 883 struct file *file, 884 struct mm_struct *mm) 885 { 886 struct elf32_fdpic_loadseg *seg; 887 struct elf32_phdr *phdr; 888 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 889 loff_t fpos; 890 int loop, ret; 891 892 load_addr = params->load_addr; 893 seg = params->loadmap->segs; 894 895 /* determine the bounds of the contiguous overall allocation we must 896 * make */ 897 phdr = params->phdrs; 898 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 899 if (params->phdrs[loop].p_type != PT_LOAD) 900 continue; 901 902 if (base > phdr->p_vaddr) 903 base = phdr->p_vaddr; 904 if (top < phdr->p_vaddr + phdr->p_memsz) 905 top = phdr->p_vaddr + phdr->p_memsz; 906 } 907 908 /* allocate one big anon block for everything */ 909 mflags = MAP_PRIVATE; 910 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 911 mflags |= MAP_EXECUTABLE; 912 913 down_write(&mm->mmap_sem); 914 maddr = do_mmap(NULL, load_addr, top - base, 915 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 916 up_write(&mm->mmap_sem); 917 if (IS_ERR_VALUE(maddr)) 918 return (int) maddr; 919 920 if (load_addr != 0) 921 load_addr += PAGE_ALIGN(top - base); 922 923 /* and then load the file segments into it */ 924 phdr = params->phdrs; 925 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 926 if (params->phdrs[loop].p_type != PT_LOAD) 927 continue; 928 929 fpos = phdr->p_offset; 930 931 seg->addr = maddr + (phdr->p_vaddr - base); 932 seg->p_vaddr = phdr->p_vaddr; 933 seg->p_memsz = phdr->p_memsz; 934 935 ret = file->f_op->read(file, (void *) seg->addr, 936 phdr->p_filesz, &fpos); 937 if (ret < 0) 938 return ret; 939 940 /* map the ELF header address if in this segment */ 941 if (phdr->p_offset == 0) 942 params->elfhdr_addr = seg->addr; 943 944 /* clear any space allocated but not loaded */ 945 if (phdr->p_filesz < phdr->p_memsz) 946 clear_user((void *) (seg->addr + phdr->p_filesz), 947 phdr->p_memsz - phdr->p_filesz); 948 949 if (mm) { 950 if (phdr->p_flags & PF_X) { 951 if (!mm->start_code) { 952 mm->start_code = seg->addr; 953 mm->end_code = seg->addr + 954 phdr->p_memsz; 955 } 956 } else if (!mm->start_data) { 957 mm->start_data = seg->addr; 958 #ifndef CONFIG_MMU 959 mm->end_data = seg->addr + phdr->p_memsz; 960 #endif 961 } 962 963 #ifdef CONFIG_MMU 964 if (seg->addr + phdr->p_memsz > mm->end_data) 965 mm->end_data = seg->addr + phdr->p_memsz; 966 #endif 967 } 968 969 seg++; 970 } 971 972 return 0; 973 } 974 #endif 975 976 /*****************************************************************************/ 977 /* 978 * map a binary by direct mmap() of the individual PT_LOAD segments 979 */ 980 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 981 struct file *file, 982 struct mm_struct *mm) 983 { 984 struct elf32_fdpic_loadseg *seg; 985 struct elf32_phdr *phdr; 986 unsigned long load_addr, delta_vaddr; 987 int loop, dvset; 988 989 load_addr = params->load_addr; 990 delta_vaddr = 0; 991 dvset = 0; 992 993 seg = params->loadmap->segs; 994 995 /* deal with each load segment separately */ 996 phdr = params->phdrs; 997 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 998 unsigned long maddr, disp, excess, excess1; 999 int prot = 0, flags; 1000 1001 if (phdr->p_type != PT_LOAD) 1002 continue; 1003 1004 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1005 (unsigned long) phdr->p_vaddr, 1006 (unsigned long) phdr->p_offset, 1007 (unsigned long) phdr->p_filesz, 1008 (unsigned long) phdr->p_memsz); 1009 1010 /* determine the mapping parameters */ 1011 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1012 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1013 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1014 1015 flags = MAP_PRIVATE | MAP_DENYWRITE; 1016 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1017 flags |= MAP_EXECUTABLE; 1018 1019 maddr = 0; 1020 1021 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1022 case ELF_FDPIC_FLAG_INDEPENDENT: 1023 /* PT_LOADs are independently locatable */ 1024 break; 1025 1026 case ELF_FDPIC_FLAG_HONOURVADDR: 1027 /* the specified virtual address must be honoured */ 1028 maddr = phdr->p_vaddr; 1029 flags |= MAP_FIXED; 1030 break; 1031 1032 case ELF_FDPIC_FLAG_CONSTDISP: 1033 /* constant displacement 1034 * - can be mapped anywhere, but must be mapped as a 1035 * unit 1036 */ 1037 if (!dvset) { 1038 maddr = load_addr; 1039 delta_vaddr = phdr->p_vaddr; 1040 dvset = 1; 1041 } else { 1042 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1043 flags |= MAP_FIXED; 1044 } 1045 break; 1046 1047 case ELF_FDPIC_FLAG_CONTIGUOUS: 1048 /* contiguity handled later */ 1049 break; 1050 1051 default: 1052 BUG(); 1053 } 1054 1055 maddr &= PAGE_MASK; 1056 1057 /* create the mapping */ 1058 disp = phdr->p_vaddr & ~PAGE_MASK; 1059 down_write(&mm->mmap_sem); 1060 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1061 phdr->p_offset - disp); 1062 up_write(&mm->mmap_sem); 1063 1064 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1065 loop, phdr->p_memsz + disp, prot, flags, 1066 phdr->p_offset - disp, maddr); 1067 1068 if (IS_ERR_VALUE(maddr)) 1069 return (int) maddr; 1070 1071 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1072 ELF_FDPIC_FLAG_CONTIGUOUS) 1073 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1074 1075 seg->addr = maddr + disp; 1076 seg->p_vaddr = phdr->p_vaddr; 1077 seg->p_memsz = phdr->p_memsz; 1078 1079 /* map the ELF header address if in this segment */ 1080 if (phdr->p_offset == 0) 1081 params->elfhdr_addr = seg->addr; 1082 1083 /* clear the bit between beginning of mapping and beginning of 1084 * PT_LOAD */ 1085 if (prot & PROT_WRITE && disp > 0) { 1086 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1087 clear_user((void __user *) maddr, disp); 1088 maddr += disp; 1089 } 1090 1091 /* clear any space allocated but not loaded 1092 * - on uClinux we can just clear the lot 1093 * - on MMU linux we'll get a SIGBUS beyond the last page 1094 * extant in the file 1095 */ 1096 excess = phdr->p_memsz - phdr->p_filesz; 1097 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1098 1099 #ifdef CONFIG_MMU 1100 if (excess > excess1) { 1101 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1102 unsigned long xmaddr; 1103 1104 flags |= MAP_FIXED | MAP_ANONYMOUS; 1105 down_write(&mm->mmap_sem); 1106 xmaddr = do_mmap(NULL, xaddr, excess - excess1, 1107 prot, flags, 0); 1108 up_write(&mm->mmap_sem); 1109 1110 kdebug("mmap[%d] <anon>" 1111 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1112 loop, xaddr, excess - excess1, prot, flags, 1113 xmaddr); 1114 1115 if (xmaddr != xaddr) 1116 return -ENOMEM; 1117 } 1118 1119 if (prot & PROT_WRITE && excess1 > 0) { 1120 kdebug("clear[%d] ad=%lx sz=%lx", 1121 loop, maddr + phdr->p_filesz, excess1); 1122 clear_user((void __user *) maddr + phdr->p_filesz, 1123 excess1); 1124 } 1125 1126 #else 1127 if (excess > 0) { 1128 kdebug("clear[%d] ad=%lx sz=%lx", 1129 loop, maddr + phdr->p_filesz, excess); 1130 clear_user((void *) maddr + phdr->p_filesz, excess); 1131 } 1132 #endif 1133 1134 if (mm) { 1135 if (phdr->p_flags & PF_X) { 1136 if (!mm->start_code) { 1137 mm->start_code = maddr; 1138 mm->end_code = maddr + phdr->p_memsz; 1139 } 1140 } else if (!mm->start_data) { 1141 mm->start_data = maddr; 1142 mm->end_data = maddr + phdr->p_memsz; 1143 } 1144 } 1145 1146 seg++; 1147 } 1148 1149 return 0; 1150 } 1151 1152 /*****************************************************************************/ 1153 /* 1154 * ELF-FDPIC core dumper 1155 * 1156 * Modelled on fs/exec.c:aout_core_dump() 1157 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1158 * 1159 * Modelled on fs/binfmt_elf.c core dumper 1160 */ 1161 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 1162 1163 /* 1164 * These are the only things you should do on a core-file: use only these 1165 * functions to write out all the necessary info. 1166 */ 1167 static int dump_write(struct file *file, const void *addr, int nr) 1168 { 1169 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 1170 } 1171 1172 static int dump_seek(struct file *file, loff_t off) 1173 { 1174 if (file->f_op->llseek) { 1175 if (file->f_op->llseek(file, off, SEEK_SET) != off) 1176 return 0; 1177 } else { 1178 file->f_pos = off; 1179 } 1180 return 1; 1181 } 1182 1183 /* 1184 * Decide whether a segment is worth dumping; default is yes to be 1185 * sure (missing info is worse than too much; etc). 1186 * Personally I'd include everything, and use the coredump limit... 1187 * 1188 * I think we should skip something. But I am not sure how. H.J. 1189 */ 1190 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1191 { 1192 int dump_ok; 1193 1194 /* Do not dump I/O mapped devices or special mappings */ 1195 if (vma->vm_flags & (VM_IO | VM_RESERVED)) { 1196 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1197 return 0; 1198 } 1199 1200 /* If we may not read the contents, don't allow us to dump 1201 * them either. "dump_write()" can't handle it anyway. 1202 */ 1203 if (!(vma->vm_flags & VM_READ)) { 1204 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1205 return 0; 1206 } 1207 1208 /* By default, dump shared memory if mapped from an anonymous file. */ 1209 if (vma->vm_flags & VM_SHARED) { 1210 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1211 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1212 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1213 vma->vm_flags, dump_ok ? "yes" : "no"); 1214 return dump_ok; 1215 } 1216 1217 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1218 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1219 vma->vm_flags, dump_ok ? "yes" : "no"); 1220 return dump_ok; 1221 } 1222 1223 #ifdef CONFIG_MMU 1224 /* By default, if it hasn't been written to, don't write it out */ 1225 if (!vma->anon_vma) { 1226 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1227 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1228 vma->vm_flags, dump_ok ? "yes" : "no"); 1229 return dump_ok; 1230 } 1231 #endif 1232 1233 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1234 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1235 dump_ok ? "yes" : "no"); 1236 return dump_ok; 1237 } 1238 1239 /* An ELF note in memory */ 1240 struct memelfnote 1241 { 1242 const char *name; 1243 int type; 1244 unsigned int datasz; 1245 void *data; 1246 }; 1247 1248 static int notesize(struct memelfnote *en) 1249 { 1250 int sz; 1251 1252 sz = sizeof(struct elf_note); 1253 sz += roundup(strlen(en->name) + 1, 4); 1254 sz += roundup(en->datasz, 4); 1255 1256 return sz; 1257 } 1258 1259 /* #define DEBUG */ 1260 1261 #define DUMP_WRITE(addr, nr) \ 1262 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0) 1263 #define DUMP_SEEK(off) \ 1264 do { if (!dump_seek(file, (off))) return 0; } while(0) 1265 1266 static int writenote(struct memelfnote *men, struct file *file) 1267 { 1268 struct elf_note en; 1269 1270 en.n_namesz = strlen(men->name) + 1; 1271 en.n_descsz = men->datasz; 1272 en.n_type = men->type; 1273 1274 DUMP_WRITE(&en, sizeof(en)); 1275 DUMP_WRITE(men->name, en.n_namesz); 1276 /* XXX - cast from long long to long to avoid need for libgcc.a */ 1277 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1278 DUMP_WRITE(men->data, men->datasz); 1279 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1280 1281 return 1; 1282 } 1283 #undef DUMP_WRITE 1284 #undef DUMP_SEEK 1285 1286 #define DUMP_WRITE(addr, nr) \ 1287 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ 1288 goto end_coredump; 1289 #define DUMP_SEEK(off) \ 1290 if (!dump_seek(file, (off))) \ 1291 goto end_coredump; 1292 1293 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1294 { 1295 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1296 elf->e_ident[EI_CLASS] = ELF_CLASS; 1297 elf->e_ident[EI_DATA] = ELF_DATA; 1298 elf->e_ident[EI_VERSION] = EV_CURRENT; 1299 elf->e_ident[EI_OSABI] = ELF_OSABI; 1300 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1301 1302 elf->e_type = ET_CORE; 1303 elf->e_machine = ELF_ARCH; 1304 elf->e_version = EV_CURRENT; 1305 elf->e_entry = 0; 1306 elf->e_phoff = sizeof(struct elfhdr); 1307 elf->e_shoff = 0; 1308 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1309 elf->e_ehsize = sizeof(struct elfhdr); 1310 elf->e_phentsize = sizeof(struct elf_phdr); 1311 elf->e_phnum = segs; 1312 elf->e_shentsize = 0; 1313 elf->e_shnum = 0; 1314 elf->e_shstrndx = 0; 1315 return; 1316 } 1317 1318 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1319 { 1320 phdr->p_type = PT_NOTE; 1321 phdr->p_offset = offset; 1322 phdr->p_vaddr = 0; 1323 phdr->p_paddr = 0; 1324 phdr->p_filesz = sz; 1325 phdr->p_memsz = 0; 1326 phdr->p_flags = 0; 1327 phdr->p_align = 0; 1328 return; 1329 } 1330 1331 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1332 unsigned int sz, void *data) 1333 { 1334 note->name = name; 1335 note->type = type; 1336 note->datasz = sz; 1337 note->data = data; 1338 return; 1339 } 1340 1341 /* 1342 * fill up all the fields in prstatus from the given task struct, except 1343 * registers which need to be filled up seperately. 1344 */ 1345 static void fill_prstatus(struct elf_prstatus *prstatus, 1346 struct task_struct *p, long signr) 1347 { 1348 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1349 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1350 prstatus->pr_sighold = p->blocked.sig[0]; 1351 prstatus->pr_pid = task_pid_vnr(p); 1352 prstatus->pr_ppid = task_pid_vnr(p->parent); 1353 prstatus->pr_pgrp = task_pgrp_vnr(p); 1354 prstatus->pr_sid = task_session_vnr(p); 1355 if (thread_group_leader(p)) { 1356 /* 1357 * This is the record for the group leader. Add in the 1358 * cumulative times of previous dead threads. This total 1359 * won't include the time of each live thread whose state 1360 * is included in the core dump. The final total reported 1361 * to our parent process when it calls wait4 will include 1362 * those sums as well as the little bit more time it takes 1363 * this and each other thread to finish dying after the 1364 * core dump synchronization phase. 1365 */ 1366 cputime_to_timeval(cputime_add(p->utime, p->signal->utime), 1367 &prstatus->pr_utime); 1368 cputime_to_timeval(cputime_add(p->stime, p->signal->stime), 1369 &prstatus->pr_stime); 1370 } else { 1371 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1372 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1373 } 1374 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1375 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1376 1377 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1378 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1379 } 1380 1381 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1382 struct mm_struct *mm) 1383 { 1384 unsigned int i, len; 1385 1386 /* first copy the parameters from user space */ 1387 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1388 1389 len = mm->arg_end - mm->arg_start; 1390 if (len >= ELF_PRARGSZ) 1391 len = ELF_PRARGSZ - 1; 1392 if (copy_from_user(&psinfo->pr_psargs, 1393 (const char __user *) mm->arg_start, len)) 1394 return -EFAULT; 1395 for (i = 0; i < len; i++) 1396 if (psinfo->pr_psargs[i] == 0) 1397 psinfo->pr_psargs[i] = ' '; 1398 psinfo->pr_psargs[len] = 0; 1399 1400 psinfo->pr_pid = task_pid_vnr(p); 1401 psinfo->pr_ppid = task_pid_vnr(p->parent); 1402 psinfo->pr_pgrp = task_pgrp_vnr(p); 1403 psinfo->pr_sid = task_session_vnr(p); 1404 1405 i = p->state ? ffz(~p->state) + 1 : 0; 1406 psinfo->pr_state = i; 1407 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1408 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1409 psinfo->pr_nice = task_nice(p); 1410 psinfo->pr_flag = p->flags; 1411 SET_UID(psinfo->pr_uid, p->uid); 1412 SET_GID(psinfo->pr_gid, p->gid); 1413 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1414 1415 return 0; 1416 } 1417 1418 /* Here is the structure in which status of each thread is captured. */ 1419 struct elf_thread_status 1420 { 1421 struct list_head list; 1422 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1423 elf_fpregset_t fpu; /* NT_PRFPREG */ 1424 struct task_struct *thread; 1425 #ifdef ELF_CORE_COPY_XFPREGS 1426 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1427 #endif 1428 struct memelfnote notes[3]; 1429 int num_notes; 1430 }; 1431 1432 /* 1433 * In order to add the specific thread information for the elf file format, 1434 * we need to keep a linked list of every thread's pr_status and then create 1435 * a single section for them in the final core file. 1436 */ 1437 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1438 { 1439 struct task_struct *p = t->thread; 1440 int sz = 0; 1441 1442 t->num_notes = 0; 1443 1444 fill_prstatus(&t->prstatus, p, signr); 1445 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1446 1447 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1448 &t->prstatus); 1449 t->num_notes++; 1450 sz += notesize(&t->notes[0]); 1451 1452 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1453 if (t->prstatus.pr_fpvalid) { 1454 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1455 &t->fpu); 1456 t->num_notes++; 1457 sz += notesize(&t->notes[1]); 1458 } 1459 1460 #ifdef ELF_CORE_COPY_XFPREGS 1461 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1462 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1463 sizeof(t->xfpu), &t->xfpu); 1464 t->num_notes++; 1465 sz += notesize(&t->notes[2]); 1466 } 1467 #endif 1468 return sz; 1469 } 1470 1471 /* 1472 * dump the segments for an MMU process 1473 */ 1474 #ifdef CONFIG_MMU 1475 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1476 unsigned long *limit, unsigned long mm_flags) 1477 { 1478 struct vm_area_struct *vma; 1479 1480 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1481 unsigned long addr; 1482 1483 if (!maydump(vma, mm_flags)) 1484 continue; 1485 1486 for (addr = vma->vm_start; 1487 addr < vma->vm_end; 1488 addr += PAGE_SIZE 1489 ) { 1490 struct vm_area_struct *vma; 1491 struct page *page; 1492 1493 if (get_user_pages(current, current->mm, addr, 1, 0, 1, 1494 &page, &vma) <= 0) { 1495 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1496 } 1497 else if (page == ZERO_PAGE(0)) { 1498 page_cache_release(page); 1499 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1500 } 1501 else { 1502 void *kaddr; 1503 1504 flush_cache_page(vma, addr, page_to_pfn(page)); 1505 kaddr = kmap(page); 1506 if ((*size += PAGE_SIZE) > *limit || 1507 !dump_write(file, kaddr, PAGE_SIZE) 1508 ) { 1509 kunmap(page); 1510 page_cache_release(page); 1511 return -EIO; 1512 } 1513 kunmap(page); 1514 page_cache_release(page); 1515 } 1516 } 1517 } 1518 1519 return 0; 1520 1521 end_coredump: 1522 return -EFBIG; 1523 } 1524 #endif 1525 1526 /* 1527 * dump the segments for a NOMMU process 1528 */ 1529 #ifndef CONFIG_MMU 1530 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1531 unsigned long *limit, unsigned long mm_flags) 1532 { 1533 struct vm_list_struct *vml; 1534 1535 for (vml = current->mm->context.vmlist; vml; vml = vml->next) { 1536 struct vm_area_struct *vma = vml->vma; 1537 1538 if (!maydump(vma, mm_flags)) 1539 continue; 1540 1541 if ((*size += PAGE_SIZE) > *limit) 1542 return -EFBIG; 1543 1544 if (!dump_write(file, (void *) vma->vm_start, 1545 vma->vm_end - vma->vm_start)) 1546 return -EIO; 1547 } 1548 1549 return 0; 1550 } 1551 #endif 1552 1553 /* 1554 * Actual dumper 1555 * 1556 * This is a two-pass process; first we find the offsets of the bits, 1557 * and then they are actually written out. If we run out of core limit 1558 * we just truncate. 1559 */ 1560 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 1561 struct file *file, unsigned long limit) 1562 { 1563 #define NUM_NOTES 6 1564 int has_dumped = 0; 1565 mm_segment_t fs; 1566 int segs; 1567 size_t size = 0; 1568 int i; 1569 struct vm_area_struct *vma; 1570 struct elfhdr *elf = NULL; 1571 loff_t offset = 0, dataoff; 1572 int numnote; 1573 struct memelfnote *notes = NULL; 1574 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1575 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1576 struct task_struct *g, *p; 1577 LIST_HEAD(thread_list); 1578 struct list_head *t; 1579 elf_fpregset_t *fpu = NULL; 1580 #ifdef ELF_CORE_COPY_XFPREGS 1581 elf_fpxregset_t *xfpu = NULL; 1582 #endif 1583 int thread_status_size = 0; 1584 #ifndef CONFIG_MMU 1585 struct vm_list_struct *vml; 1586 #endif 1587 elf_addr_t *auxv; 1588 unsigned long mm_flags; 1589 1590 /* 1591 * We no longer stop all VM operations. 1592 * 1593 * This is because those proceses that could possibly change map_count 1594 * or the mmap / vma pages are now blocked in do_exit on current 1595 * finishing this core dump. 1596 * 1597 * Only ptrace can touch these memory addresses, but it doesn't change 1598 * the map_count or the pages allocated. So no possibility of crashing 1599 * exists while dumping the mm->vm_next areas to the core file. 1600 */ 1601 1602 /* alloc memory for large data structures: too large to be on stack */ 1603 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1604 if (!elf) 1605 goto cleanup; 1606 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1607 if (!prstatus) 1608 goto cleanup; 1609 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1610 if (!psinfo) 1611 goto cleanup; 1612 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1613 if (!notes) 1614 goto cleanup; 1615 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1616 if (!fpu) 1617 goto cleanup; 1618 #ifdef ELF_CORE_COPY_XFPREGS 1619 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1620 if (!xfpu) 1621 goto cleanup; 1622 #endif 1623 1624 if (signr) { 1625 struct elf_thread_status *tmp; 1626 rcu_read_lock(); 1627 do_each_thread(g,p) 1628 if (current->mm == p->mm && current != p) { 1629 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC); 1630 if (!tmp) { 1631 rcu_read_unlock(); 1632 goto cleanup; 1633 } 1634 tmp->thread = p; 1635 list_add(&tmp->list, &thread_list); 1636 } 1637 while_each_thread(g,p); 1638 rcu_read_unlock(); 1639 list_for_each(t, &thread_list) { 1640 struct elf_thread_status *tmp; 1641 int sz; 1642 1643 tmp = list_entry(t, struct elf_thread_status, list); 1644 sz = elf_dump_thread_status(signr, tmp); 1645 thread_status_size += sz; 1646 } 1647 } 1648 1649 /* now collect the dump for the current */ 1650 fill_prstatus(prstatus, current, signr); 1651 elf_core_copy_regs(&prstatus->pr_reg, regs); 1652 1653 #ifdef CONFIG_MMU 1654 segs = current->mm->map_count; 1655 #else 1656 segs = 0; 1657 for (vml = current->mm->context.vmlist; vml; vml = vml->next) 1658 segs++; 1659 #endif 1660 #ifdef ELF_CORE_EXTRA_PHDRS 1661 segs += ELF_CORE_EXTRA_PHDRS; 1662 #endif 1663 1664 /* Set up header */ 1665 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */ 1666 1667 has_dumped = 1; 1668 current->flags |= PF_DUMPCORE; 1669 1670 /* 1671 * Set up the notes in similar form to SVR4 core dumps made 1672 * with info from their /proc. 1673 */ 1674 1675 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1676 fill_psinfo(psinfo, current->group_leader, current->mm); 1677 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1678 1679 numnote = 2; 1680 1681 auxv = (elf_addr_t *) current->mm->saved_auxv; 1682 1683 i = 0; 1684 do 1685 i += 2; 1686 while (auxv[i - 2] != AT_NULL); 1687 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1688 i * sizeof(elf_addr_t), auxv); 1689 1690 /* Try to dump the FPU. */ 1691 if ((prstatus->pr_fpvalid = 1692 elf_core_copy_task_fpregs(current, regs, fpu))) 1693 fill_note(notes + numnote++, 1694 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1695 #ifdef ELF_CORE_COPY_XFPREGS 1696 if (elf_core_copy_task_xfpregs(current, xfpu)) 1697 fill_note(notes + numnote++, 1698 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1699 #endif 1700 1701 fs = get_fs(); 1702 set_fs(KERNEL_DS); 1703 1704 DUMP_WRITE(elf, sizeof(*elf)); 1705 offset += sizeof(*elf); /* Elf header */ 1706 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */ 1707 1708 /* Write notes phdr entry */ 1709 { 1710 struct elf_phdr phdr; 1711 int sz = 0; 1712 1713 for (i = 0; i < numnote; i++) 1714 sz += notesize(notes + i); 1715 1716 sz += thread_status_size; 1717 1718 fill_elf_note_phdr(&phdr, sz, offset); 1719 offset += sz; 1720 DUMP_WRITE(&phdr, sizeof(phdr)); 1721 } 1722 1723 /* Page-align dumped data */ 1724 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1725 1726 /* 1727 * We must use the same mm->flags while dumping core to avoid 1728 * inconsistency between the program headers and bodies, otherwise an 1729 * unusable core file can be generated. 1730 */ 1731 mm_flags = current->mm->flags; 1732 1733 /* write program headers for segments dump */ 1734 for ( 1735 #ifdef CONFIG_MMU 1736 vma = current->mm->mmap; vma; vma = vma->vm_next 1737 #else 1738 vml = current->mm->context.vmlist; vml; vml = vml->next 1739 #endif 1740 ) { 1741 struct elf_phdr phdr; 1742 size_t sz; 1743 1744 #ifndef CONFIG_MMU 1745 vma = vml->vma; 1746 #endif 1747 1748 sz = vma->vm_end - vma->vm_start; 1749 1750 phdr.p_type = PT_LOAD; 1751 phdr.p_offset = offset; 1752 phdr.p_vaddr = vma->vm_start; 1753 phdr.p_paddr = 0; 1754 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0; 1755 phdr.p_memsz = sz; 1756 offset += phdr.p_filesz; 1757 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1758 if (vma->vm_flags & VM_WRITE) 1759 phdr.p_flags |= PF_W; 1760 if (vma->vm_flags & VM_EXEC) 1761 phdr.p_flags |= PF_X; 1762 phdr.p_align = ELF_EXEC_PAGESIZE; 1763 1764 DUMP_WRITE(&phdr, sizeof(phdr)); 1765 } 1766 1767 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS 1768 ELF_CORE_WRITE_EXTRA_PHDRS; 1769 #endif 1770 1771 /* write out the notes section */ 1772 for (i = 0; i < numnote; i++) 1773 if (!writenote(notes + i, file)) 1774 goto end_coredump; 1775 1776 /* write out the thread status notes section */ 1777 list_for_each(t, &thread_list) { 1778 struct elf_thread_status *tmp = 1779 list_entry(t, struct elf_thread_status, list); 1780 1781 for (i = 0; i < tmp->num_notes; i++) 1782 if (!writenote(&tmp->notes[i], file)) 1783 goto end_coredump; 1784 } 1785 1786 DUMP_SEEK(dataoff); 1787 1788 if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0) 1789 goto end_coredump; 1790 1791 #ifdef ELF_CORE_WRITE_EXTRA_DATA 1792 ELF_CORE_WRITE_EXTRA_DATA; 1793 #endif 1794 1795 if (file->f_pos != offset) { 1796 /* Sanity check */ 1797 printk(KERN_WARNING 1798 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1799 file->f_pos, offset); 1800 } 1801 1802 end_coredump: 1803 set_fs(fs); 1804 1805 cleanup: 1806 while (!list_empty(&thread_list)) { 1807 struct list_head *tmp = thread_list.next; 1808 list_del(tmp); 1809 kfree(list_entry(tmp, struct elf_thread_status, list)); 1810 } 1811 1812 kfree(elf); 1813 kfree(prstatus); 1814 kfree(psinfo); 1815 kfree(notes); 1816 kfree(fpu); 1817 #ifdef ELF_CORE_COPY_XFPREGS 1818 kfree(xfpu); 1819 #endif 1820 return has_dumped; 1821 #undef NUM_NOTES 1822 } 1823 1824 #endif /* USE_ELF_CORE_DUMP */ 1825