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/security.h> 29 #include <linux/highmem.h> 30 #include <linux/highuid.h> 31 #include <linux/personality.h> 32 #include <linux/ptrace.h> 33 #include <linux/init.h> 34 #include <linux/elf.h> 35 #include <linux/elf-fdpic.h> 36 #include <linux/elfcore.h> 37 #include <linux/coredump.h> 38 39 #include <asm/uaccess.h> 40 #include <asm/param.h> 41 #include <asm/pgalloc.h> 42 43 typedef char *elf_caddr_t; 44 45 #if 0 46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 47 #else 48 #define kdebug(fmt, ...) do {} while(0) 49 #endif 50 51 #if 0 52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 53 #else 54 #define kdcore(fmt, ...) do {} while(0) 55 #endif 56 57 MODULE_LICENSE("GPL"); 58 59 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *); 60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 62 struct mm_struct *, const char *); 63 64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 65 struct elf_fdpic_params *, 66 struct elf_fdpic_params *); 67 68 #ifndef CONFIG_MMU 69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, 70 unsigned long *); 71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 72 struct file *, 73 struct mm_struct *); 74 #endif 75 76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 77 struct file *, struct mm_struct *); 78 79 #ifdef CONFIG_ELF_CORE 80 static int elf_fdpic_core_dump(struct coredump_params *cprm); 81 #endif 82 83 static struct linux_binfmt elf_fdpic_format = { 84 .module = THIS_MODULE, 85 .load_binary = load_elf_fdpic_binary, 86 #ifdef CONFIG_ELF_CORE 87 .core_dump = elf_fdpic_core_dump, 88 #endif 89 .min_coredump = ELF_EXEC_PAGESIZE, 90 }; 91 92 static int __init init_elf_fdpic_binfmt(void) 93 { 94 return register_binfmt(&elf_fdpic_format); 95 } 96 97 static void __exit exit_elf_fdpic_binfmt(void) 98 { 99 unregister_binfmt(&elf_fdpic_format); 100 } 101 102 core_initcall(init_elf_fdpic_binfmt); 103 module_exit(exit_elf_fdpic_binfmt); 104 105 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) 106 { 107 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 108 return 0; 109 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 110 return 0; 111 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) 112 return 0; 113 if (!file->f_op || !file->f_op->mmap) 114 return 0; 115 return 1; 116 } 117 118 /*****************************************************************************/ 119 /* 120 * read the program headers table into memory 121 */ 122 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 123 struct file *file) 124 { 125 struct elf32_phdr *phdr; 126 unsigned long size; 127 int retval, loop; 128 129 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 130 return -ENOMEM; 131 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 132 return -ENOMEM; 133 134 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 135 params->phdrs = kmalloc(size, GFP_KERNEL); 136 if (!params->phdrs) 137 return -ENOMEM; 138 139 retval = kernel_read(file, params->hdr.e_phoff, 140 (char *) params->phdrs, size); 141 if (unlikely(retval != size)) 142 return retval < 0 ? retval : -ENOEXEC; 143 144 /* determine stack size for this binary */ 145 phdr = params->phdrs; 146 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 147 if (phdr->p_type != PT_GNU_STACK) 148 continue; 149 150 if (phdr->p_flags & PF_X) 151 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 152 else 153 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 154 155 params->stack_size = phdr->p_memsz; 156 break; 157 } 158 159 return 0; 160 } 161 162 /*****************************************************************************/ 163 /* 164 * load an fdpic binary into various bits of memory 165 */ 166 static int load_elf_fdpic_binary(struct linux_binprm *bprm, 167 struct pt_regs *regs) 168 { 169 struct elf_fdpic_params exec_params, interp_params; 170 struct elf_phdr *phdr; 171 unsigned long stack_size, entryaddr; 172 #ifdef ELF_FDPIC_PLAT_INIT 173 unsigned long dynaddr; 174 #endif 175 #ifndef CONFIG_MMU 176 unsigned long stack_prot; 177 #endif 178 struct file *interpreter = NULL; /* to shut gcc up */ 179 char *interpreter_name = NULL; 180 int executable_stack; 181 int retval, i; 182 183 kdebug("____ LOAD %d ____", current->pid); 184 185 memset(&exec_params, 0, sizeof(exec_params)); 186 memset(&interp_params, 0, sizeof(interp_params)); 187 188 exec_params.hdr = *(struct elfhdr *) bprm->buf; 189 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 190 191 /* check that this is a binary we know how to deal with */ 192 retval = -ENOEXEC; 193 if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) 194 goto error; 195 196 /* read the program header table */ 197 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 198 if (retval < 0) 199 goto error; 200 201 /* scan for a program header that specifies an interpreter */ 202 phdr = exec_params.phdrs; 203 204 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 205 switch (phdr->p_type) { 206 case PT_INTERP: 207 retval = -ENOMEM; 208 if (phdr->p_filesz > PATH_MAX) 209 goto error; 210 retval = -ENOENT; 211 if (phdr->p_filesz < 2) 212 goto error; 213 214 /* read the name of the interpreter into memory */ 215 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 216 if (!interpreter_name) 217 goto error; 218 219 retval = kernel_read(bprm->file, 220 phdr->p_offset, 221 interpreter_name, 222 phdr->p_filesz); 223 if (unlikely(retval != phdr->p_filesz)) { 224 if (retval >= 0) 225 retval = -ENOEXEC; 226 goto error; 227 } 228 229 retval = -ENOENT; 230 if (interpreter_name[phdr->p_filesz - 1] != '\0') 231 goto error; 232 233 kdebug("Using ELF interpreter %s", interpreter_name); 234 235 /* replace the program with the interpreter */ 236 interpreter = open_exec(interpreter_name); 237 retval = PTR_ERR(interpreter); 238 if (IS_ERR(interpreter)) { 239 interpreter = NULL; 240 goto error; 241 } 242 243 /* 244 * If the binary is not readable then enforce 245 * mm->dumpable = 0 regardless of the interpreter's 246 * permissions. 247 */ 248 if (file_permission(interpreter, MAY_READ) < 0) 249 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; 250 251 retval = kernel_read(interpreter, 0, bprm->buf, 252 BINPRM_BUF_SIZE); 253 if (unlikely(retval != BINPRM_BUF_SIZE)) { 254 if (retval >= 0) 255 retval = -ENOEXEC; 256 goto error; 257 } 258 259 interp_params.hdr = *((struct elfhdr *) bprm->buf); 260 break; 261 262 case PT_LOAD: 263 #ifdef CONFIG_MMU 264 if (exec_params.load_addr == 0) 265 exec_params.load_addr = phdr->p_vaddr; 266 #endif 267 break; 268 } 269 270 } 271 272 if (elf_check_const_displacement(&exec_params.hdr)) 273 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 274 275 /* perform insanity checks on the interpreter */ 276 if (interpreter_name) { 277 retval = -ELIBBAD; 278 if (!is_elf_fdpic(&interp_params.hdr, interpreter)) 279 goto error; 280 281 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 282 283 /* read the interpreter's program header table */ 284 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 285 if (retval < 0) 286 goto error; 287 } 288 289 stack_size = exec_params.stack_size; 290 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 291 executable_stack = EXSTACK_ENABLE_X; 292 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 293 executable_stack = EXSTACK_DISABLE_X; 294 else 295 executable_stack = EXSTACK_DEFAULT; 296 297 if (stack_size == 0) { 298 stack_size = interp_params.stack_size; 299 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 300 executable_stack = EXSTACK_ENABLE_X; 301 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 302 executable_stack = EXSTACK_DISABLE_X; 303 else 304 executable_stack = EXSTACK_DEFAULT; 305 } 306 307 retval = -ENOEXEC; 308 if (stack_size == 0) 309 goto error; 310 311 if (elf_check_const_displacement(&interp_params.hdr)) 312 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 313 314 /* flush all traces of the currently running executable */ 315 retval = flush_old_exec(bprm); 316 if (retval) 317 goto error; 318 319 /* there's now no turning back... the old userspace image is dead, 320 * defunct, deceased, etc. after this point we have to exit via 321 * error_kill */ 322 set_personality(PER_LINUX_FDPIC); 323 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 324 current->personality |= READ_IMPLIES_EXEC; 325 326 setup_new_exec(bprm); 327 328 set_binfmt(&elf_fdpic_format); 329 330 current->mm->start_code = 0; 331 current->mm->end_code = 0; 332 current->mm->start_stack = 0; 333 current->mm->start_data = 0; 334 current->mm->end_data = 0; 335 current->mm->context.exec_fdpic_loadmap = 0; 336 current->mm->context.interp_fdpic_loadmap = 0; 337 338 current->flags &= ~PF_FORKNOEXEC; 339 340 #ifdef CONFIG_MMU 341 elf_fdpic_arch_lay_out_mm(&exec_params, 342 &interp_params, 343 ¤t->mm->start_stack, 344 ¤t->mm->start_brk); 345 346 retval = setup_arg_pages(bprm, current->mm->start_stack, 347 executable_stack); 348 if (retval < 0) { 349 send_sig(SIGKILL, current, 0); 350 goto error_kill; 351 } 352 #endif 353 354 /* load the executable and interpreter into memory */ 355 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 356 "executable"); 357 if (retval < 0) 358 goto error_kill; 359 360 if (interpreter_name) { 361 retval = elf_fdpic_map_file(&interp_params, interpreter, 362 current->mm, "interpreter"); 363 if (retval < 0) { 364 printk(KERN_ERR "Unable to load interpreter\n"); 365 goto error_kill; 366 } 367 368 allow_write_access(interpreter); 369 fput(interpreter); 370 interpreter = NULL; 371 } 372 373 #ifdef CONFIG_MMU 374 if (!current->mm->start_brk) 375 current->mm->start_brk = current->mm->end_data; 376 377 current->mm->brk = current->mm->start_brk = 378 PAGE_ALIGN(current->mm->start_brk); 379 380 #else 381 /* create a stack and brk area big enough for everyone 382 * - the brk heap starts at the bottom and works up 383 * - the stack starts at the top and works down 384 */ 385 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 386 if (stack_size < PAGE_SIZE * 2) 387 stack_size = PAGE_SIZE * 2; 388 389 stack_prot = PROT_READ | PROT_WRITE; 390 if (executable_stack == EXSTACK_ENABLE_X || 391 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 392 stack_prot |= PROT_EXEC; 393 394 down_write(¤t->mm->mmap_sem); 395 current->mm->start_brk = do_mmap(NULL, 0, stack_size, stack_prot, 396 MAP_PRIVATE | MAP_ANONYMOUS | 397 MAP_UNINITIALIZED | MAP_GROWSDOWN, 398 0); 399 400 if (IS_ERR_VALUE(current->mm->start_brk)) { 401 up_write(¤t->mm->mmap_sem); 402 retval = current->mm->start_brk; 403 current->mm->start_brk = 0; 404 goto error_kill; 405 } 406 407 up_write(¤t->mm->mmap_sem); 408 409 current->mm->brk = current->mm->start_brk; 410 current->mm->context.end_brk = current->mm->start_brk; 411 current->mm->context.end_brk += 412 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; 413 current->mm->start_stack = current->mm->start_brk + stack_size; 414 #endif 415 416 install_exec_creds(bprm); 417 current->flags &= ~PF_FORKNOEXEC; 418 if (create_elf_fdpic_tables(bprm, current->mm, 419 &exec_params, &interp_params) < 0) 420 goto error_kill; 421 422 kdebug("- start_code %lx", current->mm->start_code); 423 kdebug("- end_code %lx", current->mm->end_code); 424 kdebug("- start_data %lx", current->mm->start_data); 425 kdebug("- end_data %lx", current->mm->end_data); 426 kdebug("- start_brk %lx", current->mm->start_brk); 427 kdebug("- brk %lx", current->mm->brk); 428 kdebug("- start_stack %lx", current->mm->start_stack); 429 430 #ifdef ELF_FDPIC_PLAT_INIT 431 /* 432 * The ABI may specify that certain registers be set up in special 433 * ways (on i386 %edx is the address of a DT_FINI function, for 434 * example. This macro performs whatever initialization to 435 * the regs structure is required. 436 */ 437 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 438 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 439 dynaddr); 440 #endif 441 442 /* everything is now ready... get the userspace context ready to roll */ 443 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 444 start_thread(regs, entryaddr, current->mm->start_stack); 445 446 retval = 0; 447 448 error: 449 if (interpreter) { 450 allow_write_access(interpreter); 451 fput(interpreter); 452 } 453 kfree(interpreter_name); 454 kfree(exec_params.phdrs); 455 kfree(exec_params.loadmap); 456 kfree(interp_params.phdrs); 457 kfree(interp_params.loadmap); 458 return retval; 459 460 /* unrecoverable error - kill the process */ 461 error_kill: 462 send_sig(SIGSEGV, current, 0); 463 goto error; 464 465 } 466 467 /*****************************************************************************/ 468 469 #ifndef ELF_BASE_PLATFORM 470 /* 471 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 472 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 473 * will be copied to the user stack in the same manner as AT_PLATFORM. 474 */ 475 #define ELF_BASE_PLATFORM NULL 476 #endif 477 478 /* 479 * present useful information to the program by shovelling it onto the new 480 * process's stack 481 */ 482 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 483 struct mm_struct *mm, 484 struct elf_fdpic_params *exec_params, 485 struct elf_fdpic_params *interp_params) 486 { 487 const struct cred *cred = current_cred(); 488 unsigned long sp, csp, nitems; 489 elf_caddr_t __user *argv, *envp; 490 size_t platform_len = 0, len; 491 char *k_platform, *k_base_platform; 492 char __user *u_platform, *u_base_platform, *p; 493 long hwcap; 494 int loop; 495 int nr; /* reset for each csp adjustment */ 496 497 #ifdef CONFIG_MMU 498 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 499 * by the processes running on the same package. One thing we can do is 500 * to shuffle the initial stack for them, so we give the architecture 501 * an opportunity to do so here. 502 */ 503 sp = arch_align_stack(bprm->p); 504 #else 505 sp = mm->start_stack; 506 507 /* stack the program arguments and environment */ 508 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 509 return -EFAULT; 510 #endif 511 512 hwcap = ELF_HWCAP; 513 514 /* 515 * If this architecture has a platform capability string, copy it 516 * to userspace. In some cases (Sparc), this info is impossible 517 * for userspace to get any other way, in others (i386) it is 518 * merely difficult. 519 */ 520 k_platform = ELF_PLATFORM; 521 u_platform = NULL; 522 523 if (k_platform) { 524 platform_len = strlen(k_platform) + 1; 525 sp -= platform_len; 526 u_platform = (char __user *) sp; 527 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 528 return -EFAULT; 529 } 530 531 /* 532 * If this architecture has a "base" platform capability 533 * string, copy it to userspace. 534 */ 535 k_base_platform = ELF_BASE_PLATFORM; 536 u_base_platform = NULL; 537 538 if (k_base_platform) { 539 platform_len = strlen(k_base_platform) + 1; 540 sp -= platform_len; 541 u_base_platform = (char __user *) sp; 542 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 543 return -EFAULT; 544 } 545 546 sp &= ~7UL; 547 548 /* stack the load map(s) */ 549 len = sizeof(struct elf32_fdpic_loadmap); 550 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 551 sp = (sp - len) & ~7UL; 552 exec_params->map_addr = sp; 553 554 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 555 return -EFAULT; 556 557 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 558 559 if (interp_params->loadmap) { 560 len = sizeof(struct elf32_fdpic_loadmap); 561 len += sizeof(struct elf32_fdpic_loadseg) * 562 interp_params->loadmap->nsegs; 563 sp = (sp - len) & ~7UL; 564 interp_params->map_addr = sp; 565 566 if (copy_to_user((void __user *) sp, interp_params->loadmap, 567 len) != 0) 568 return -EFAULT; 569 570 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 571 } 572 573 /* force 16 byte _final_ alignment here for generality */ 574 #define DLINFO_ITEMS 15 575 576 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 577 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 578 579 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 580 nitems++; 581 582 csp = sp; 583 sp -= nitems * 2 * sizeof(unsigned long); 584 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 585 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 586 sp -= 1 * sizeof(unsigned long); /* argc */ 587 588 csp -= sp & 15UL; 589 sp -= sp & 15UL; 590 591 /* put the ELF interpreter info on the stack */ 592 #define NEW_AUX_ENT(id, val) \ 593 do { \ 594 struct { unsigned long _id, _val; } __user *ent; \ 595 \ 596 ent = (void __user *) csp; \ 597 __put_user((id), &ent[nr]._id); \ 598 __put_user((val), &ent[nr]._val); \ 599 nr++; \ 600 } while (0) 601 602 nr = 0; 603 csp -= 2 * sizeof(unsigned long); 604 NEW_AUX_ENT(AT_NULL, 0); 605 if (k_platform) { 606 nr = 0; 607 csp -= 2 * sizeof(unsigned long); 608 NEW_AUX_ENT(AT_PLATFORM, 609 (elf_addr_t) (unsigned long) u_platform); 610 } 611 612 if (k_base_platform) { 613 nr = 0; 614 csp -= 2 * sizeof(unsigned long); 615 NEW_AUX_ENT(AT_BASE_PLATFORM, 616 (elf_addr_t) (unsigned long) u_base_platform); 617 } 618 619 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 620 nr = 0; 621 csp -= 2 * sizeof(unsigned long); 622 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 623 } 624 625 nr = 0; 626 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 627 NEW_AUX_ENT(AT_HWCAP, hwcap); 628 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 629 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 630 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 631 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 632 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 633 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 634 NEW_AUX_ENT(AT_FLAGS, 0); 635 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 636 NEW_AUX_ENT(AT_UID, (elf_addr_t) cred->uid); 637 NEW_AUX_ENT(AT_EUID, (elf_addr_t) cred->euid); 638 NEW_AUX_ENT(AT_GID, (elf_addr_t) cred->gid); 639 NEW_AUX_ENT(AT_EGID, (elf_addr_t) cred->egid); 640 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 641 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 642 643 #ifdef ARCH_DLINFO 644 nr = 0; 645 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 646 647 /* ARCH_DLINFO must come last so platform specific code can enforce 648 * special alignment requirements on the AUXV if necessary (eg. PPC). 649 */ 650 ARCH_DLINFO; 651 #endif 652 #undef NEW_AUX_ENT 653 654 /* allocate room for argv[] and envv[] */ 655 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 656 envp = (elf_caddr_t __user *) csp; 657 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 658 argv = (elf_caddr_t __user *) csp; 659 660 /* stack argc */ 661 csp -= sizeof(unsigned long); 662 __put_user(bprm->argc, (unsigned long __user *) csp); 663 664 BUG_ON(csp != sp); 665 666 /* fill in the argv[] array */ 667 #ifdef CONFIG_MMU 668 current->mm->arg_start = bprm->p; 669 #else 670 current->mm->arg_start = current->mm->start_stack - 671 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 672 #endif 673 674 p = (char __user *) current->mm->arg_start; 675 for (loop = bprm->argc; loop > 0; loop--) { 676 __put_user((elf_caddr_t) p, argv++); 677 len = strnlen_user(p, MAX_ARG_STRLEN); 678 if (!len || len > MAX_ARG_STRLEN) 679 return -EINVAL; 680 p += len; 681 } 682 __put_user(NULL, argv); 683 current->mm->arg_end = (unsigned long) p; 684 685 /* fill in the envv[] array */ 686 current->mm->env_start = (unsigned long) p; 687 for (loop = bprm->envc; loop > 0; loop--) { 688 __put_user((elf_caddr_t)(unsigned long) p, envp++); 689 len = strnlen_user(p, MAX_ARG_STRLEN); 690 if (!len || len > MAX_ARG_STRLEN) 691 return -EINVAL; 692 p += len; 693 } 694 __put_user(NULL, envp); 695 current->mm->env_end = (unsigned long) p; 696 697 mm->start_stack = (unsigned long) sp; 698 return 0; 699 } 700 701 /*****************************************************************************/ 702 /* 703 * transfer the program arguments and environment from the holding pages onto 704 * the stack 705 */ 706 #ifndef CONFIG_MMU 707 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 708 unsigned long *_sp) 709 { 710 unsigned long index, stop, sp; 711 char *src; 712 int ret = 0; 713 714 stop = bprm->p >> PAGE_SHIFT; 715 sp = *_sp; 716 717 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 718 src = kmap(bprm->page[index]); 719 sp -= PAGE_SIZE; 720 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 721 ret = -EFAULT; 722 kunmap(bprm->page[index]); 723 if (ret < 0) 724 goto out; 725 } 726 727 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 728 729 out: 730 return ret; 731 } 732 #endif 733 734 /*****************************************************************************/ 735 /* 736 * load the appropriate binary image (executable or interpreter) into memory 737 * - we assume no MMU is available 738 * - if no other PIC bits are set in params->hdr->e_flags 739 * - we assume that the LOADable segments in the binary are independently relocatable 740 * - we assume R/O executable segments are shareable 741 * - else 742 * - we assume the loadable parts of the image to require fixed displacement 743 * - the image is not shareable 744 */ 745 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 746 struct file *file, 747 struct mm_struct *mm, 748 const char *what) 749 { 750 struct elf32_fdpic_loadmap *loadmap; 751 #ifdef CONFIG_MMU 752 struct elf32_fdpic_loadseg *mseg; 753 #endif 754 struct elf32_fdpic_loadseg *seg; 755 struct elf32_phdr *phdr; 756 unsigned long load_addr, stop; 757 unsigned nloads, tmp; 758 size_t size; 759 int loop, ret; 760 761 /* allocate a load map table */ 762 nloads = 0; 763 for (loop = 0; loop < params->hdr.e_phnum; loop++) 764 if (params->phdrs[loop].p_type == PT_LOAD) 765 nloads++; 766 767 if (nloads == 0) 768 return -ELIBBAD; 769 770 size = sizeof(*loadmap) + nloads * sizeof(*seg); 771 loadmap = kzalloc(size, GFP_KERNEL); 772 if (!loadmap) 773 return -ENOMEM; 774 775 params->loadmap = loadmap; 776 777 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 778 loadmap->nsegs = nloads; 779 780 load_addr = params->load_addr; 781 seg = loadmap->segs; 782 783 /* map the requested LOADs into the memory space */ 784 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 785 case ELF_FDPIC_FLAG_CONSTDISP: 786 case ELF_FDPIC_FLAG_CONTIGUOUS: 787 #ifndef CONFIG_MMU 788 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 789 if (ret < 0) 790 return ret; 791 break; 792 #endif 793 default: 794 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 795 if (ret < 0) 796 return ret; 797 break; 798 } 799 800 /* map the entry point */ 801 if (params->hdr.e_entry) { 802 seg = loadmap->segs; 803 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 804 if (params->hdr.e_entry >= seg->p_vaddr && 805 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 806 params->entry_addr = 807 (params->hdr.e_entry - seg->p_vaddr) + 808 seg->addr; 809 break; 810 } 811 } 812 } 813 814 /* determine where the program header table has wound up if mapped */ 815 stop = params->hdr.e_phoff; 816 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 817 phdr = params->phdrs; 818 819 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 820 if (phdr->p_type != PT_LOAD) 821 continue; 822 823 if (phdr->p_offset > params->hdr.e_phoff || 824 phdr->p_offset + phdr->p_filesz < stop) 825 continue; 826 827 seg = loadmap->segs; 828 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 829 if (phdr->p_vaddr >= seg->p_vaddr && 830 phdr->p_vaddr + phdr->p_filesz <= 831 seg->p_vaddr + seg->p_memsz) { 832 params->ph_addr = 833 (phdr->p_vaddr - seg->p_vaddr) + 834 seg->addr + 835 params->hdr.e_phoff - phdr->p_offset; 836 break; 837 } 838 } 839 break; 840 } 841 842 /* determine where the dynamic section has wound up if there is one */ 843 phdr = params->phdrs; 844 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 845 if (phdr->p_type != PT_DYNAMIC) 846 continue; 847 848 seg = loadmap->segs; 849 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 850 if (phdr->p_vaddr >= seg->p_vaddr && 851 phdr->p_vaddr + phdr->p_memsz <= 852 seg->p_vaddr + seg->p_memsz) { 853 params->dynamic_addr = 854 (phdr->p_vaddr - seg->p_vaddr) + 855 seg->addr; 856 857 /* check the dynamic section contains at least 858 * one item, and that the last item is a NULL 859 * entry */ 860 if (phdr->p_memsz == 0 || 861 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 862 goto dynamic_error; 863 864 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 865 if (((Elf32_Dyn *) 866 params->dynamic_addr)[tmp - 1].d_tag != 0) 867 goto dynamic_error; 868 break; 869 } 870 } 871 break; 872 } 873 874 /* now elide adjacent segments in the load map on MMU linux 875 * - on uClinux the holes between may actually be filled with system 876 * stuff or stuff from other processes 877 */ 878 #ifdef CONFIG_MMU 879 nloads = loadmap->nsegs; 880 mseg = loadmap->segs; 881 seg = mseg + 1; 882 for (loop = 1; loop < nloads; loop++) { 883 /* see if we have a candidate for merging */ 884 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 885 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 886 if (load_addr == (seg->addr & PAGE_MASK)) { 887 mseg->p_memsz += 888 load_addr - 889 (mseg->addr + mseg->p_memsz); 890 mseg->p_memsz += seg->addr & ~PAGE_MASK; 891 mseg->p_memsz += seg->p_memsz; 892 loadmap->nsegs--; 893 continue; 894 } 895 } 896 897 mseg++; 898 if (mseg != seg) 899 *mseg = *seg; 900 } 901 #endif 902 903 kdebug("Mapped Object [%s]:", what); 904 kdebug("- elfhdr : %lx", params->elfhdr_addr); 905 kdebug("- entry : %lx", params->entry_addr); 906 kdebug("- PHDR[] : %lx", params->ph_addr); 907 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 908 seg = loadmap->segs; 909 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 910 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 911 loop, 912 seg->addr, seg->addr + seg->p_memsz - 1, 913 seg->p_vaddr, seg->p_memsz); 914 915 return 0; 916 917 dynamic_error: 918 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 919 what, file->f_path.dentry->d_inode->i_ino); 920 return -ELIBBAD; 921 } 922 923 /*****************************************************************************/ 924 /* 925 * map a file with constant displacement under uClinux 926 */ 927 #ifndef CONFIG_MMU 928 static int elf_fdpic_map_file_constdisp_on_uclinux( 929 struct elf_fdpic_params *params, 930 struct file *file, 931 struct mm_struct *mm) 932 { 933 struct elf32_fdpic_loadseg *seg; 934 struct elf32_phdr *phdr; 935 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 936 loff_t fpos; 937 int loop, ret; 938 939 load_addr = params->load_addr; 940 seg = params->loadmap->segs; 941 942 /* determine the bounds of the contiguous overall allocation we must 943 * make */ 944 phdr = params->phdrs; 945 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 946 if (params->phdrs[loop].p_type != PT_LOAD) 947 continue; 948 949 if (base > phdr->p_vaddr) 950 base = phdr->p_vaddr; 951 if (top < phdr->p_vaddr + phdr->p_memsz) 952 top = phdr->p_vaddr + phdr->p_memsz; 953 } 954 955 /* allocate one big anon block for everything */ 956 mflags = MAP_PRIVATE; 957 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 958 mflags |= MAP_EXECUTABLE; 959 960 down_write(&mm->mmap_sem); 961 maddr = do_mmap(NULL, load_addr, top - base, 962 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 963 up_write(&mm->mmap_sem); 964 if (IS_ERR_VALUE(maddr)) 965 return (int) maddr; 966 967 if (load_addr != 0) 968 load_addr += PAGE_ALIGN(top - base); 969 970 /* and then load the file segments into it */ 971 phdr = params->phdrs; 972 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 973 if (params->phdrs[loop].p_type != PT_LOAD) 974 continue; 975 976 fpos = phdr->p_offset; 977 978 seg->addr = maddr + (phdr->p_vaddr - base); 979 seg->p_vaddr = phdr->p_vaddr; 980 seg->p_memsz = phdr->p_memsz; 981 982 ret = file->f_op->read(file, (void *) seg->addr, 983 phdr->p_filesz, &fpos); 984 if (ret < 0) 985 return ret; 986 987 /* map the ELF header address if in this segment */ 988 if (phdr->p_offset == 0) 989 params->elfhdr_addr = seg->addr; 990 991 /* clear any space allocated but not loaded */ 992 if (phdr->p_filesz < phdr->p_memsz) { 993 ret = clear_user((void *) (seg->addr + phdr->p_filesz), 994 phdr->p_memsz - phdr->p_filesz); 995 if (ret) 996 return ret; 997 } 998 999 if (mm) { 1000 if (phdr->p_flags & PF_X) { 1001 if (!mm->start_code) { 1002 mm->start_code = seg->addr; 1003 mm->end_code = seg->addr + 1004 phdr->p_memsz; 1005 } 1006 } else if (!mm->start_data) { 1007 mm->start_data = seg->addr; 1008 #ifndef CONFIG_MMU 1009 mm->end_data = seg->addr + phdr->p_memsz; 1010 #endif 1011 } 1012 1013 #ifdef CONFIG_MMU 1014 if (seg->addr + phdr->p_memsz > mm->end_data) 1015 mm->end_data = seg->addr + phdr->p_memsz; 1016 #endif 1017 } 1018 1019 seg++; 1020 } 1021 1022 return 0; 1023 } 1024 #endif 1025 1026 /*****************************************************************************/ 1027 /* 1028 * map a binary by direct mmap() of the individual PT_LOAD segments 1029 */ 1030 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1031 struct file *file, 1032 struct mm_struct *mm) 1033 { 1034 struct elf32_fdpic_loadseg *seg; 1035 struct elf32_phdr *phdr; 1036 unsigned long load_addr, delta_vaddr; 1037 int loop, dvset, ret; 1038 1039 load_addr = params->load_addr; 1040 delta_vaddr = 0; 1041 dvset = 0; 1042 1043 seg = params->loadmap->segs; 1044 1045 /* deal with each load segment separately */ 1046 phdr = params->phdrs; 1047 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1048 unsigned long maddr, disp, excess, excess1; 1049 int prot = 0, flags; 1050 1051 if (phdr->p_type != PT_LOAD) 1052 continue; 1053 1054 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1055 (unsigned long) phdr->p_vaddr, 1056 (unsigned long) phdr->p_offset, 1057 (unsigned long) phdr->p_filesz, 1058 (unsigned long) phdr->p_memsz); 1059 1060 /* determine the mapping parameters */ 1061 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1062 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1063 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1064 1065 flags = MAP_PRIVATE | MAP_DENYWRITE; 1066 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1067 flags |= MAP_EXECUTABLE; 1068 1069 maddr = 0; 1070 1071 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1072 case ELF_FDPIC_FLAG_INDEPENDENT: 1073 /* PT_LOADs are independently locatable */ 1074 break; 1075 1076 case ELF_FDPIC_FLAG_HONOURVADDR: 1077 /* the specified virtual address must be honoured */ 1078 maddr = phdr->p_vaddr; 1079 flags |= MAP_FIXED; 1080 break; 1081 1082 case ELF_FDPIC_FLAG_CONSTDISP: 1083 /* constant displacement 1084 * - can be mapped anywhere, but must be mapped as a 1085 * unit 1086 */ 1087 if (!dvset) { 1088 maddr = load_addr; 1089 delta_vaddr = phdr->p_vaddr; 1090 dvset = 1; 1091 } else { 1092 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1093 flags |= MAP_FIXED; 1094 } 1095 break; 1096 1097 case ELF_FDPIC_FLAG_CONTIGUOUS: 1098 /* contiguity handled later */ 1099 break; 1100 1101 default: 1102 BUG(); 1103 } 1104 1105 maddr &= PAGE_MASK; 1106 1107 /* create the mapping */ 1108 disp = phdr->p_vaddr & ~PAGE_MASK; 1109 down_write(&mm->mmap_sem); 1110 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1111 phdr->p_offset - disp); 1112 up_write(&mm->mmap_sem); 1113 1114 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1115 loop, phdr->p_memsz + disp, prot, flags, 1116 phdr->p_offset - disp, maddr); 1117 1118 if (IS_ERR_VALUE(maddr)) 1119 return (int) maddr; 1120 1121 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1122 ELF_FDPIC_FLAG_CONTIGUOUS) 1123 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1124 1125 seg->addr = maddr + disp; 1126 seg->p_vaddr = phdr->p_vaddr; 1127 seg->p_memsz = phdr->p_memsz; 1128 1129 /* map the ELF header address if in this segment */ 1130 if (phdr->p_offset == 0) 1131 params->elfhdr_addr = seg->addr; 1132 1133 /* clear the bit between beginning of mapping and beginning of 1134 * PT_LOAD */ 1135 if (prot & PROT_WRITE && disp > 0) { 1136 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1137 ret = clear_user((void __user *) maddr, disp); 1138 if (ret) 1139 return ret; 1140 maddr += disp; 1141 } 1142 1143 /* clear any space allocated but not loaded 1144 * - on uClinux we can just clear the lot 1145 * - on MMU linux we'll get a SIGBUS beyond the last page 1146 * extant in the file 1147 */ 1148 excess = phdr->p_memsz - phdr->p_filesz; 1149 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1150 1151 #ifdef CONFIG_MMU 1152 if (excess > excess1) { 1153 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1154 unsigned long xmaddr; 1155 1156 flags |= MAP_FIXED | MAP_ANONYMOUS; 1157 down_write(&mm->mmap_sem); 1158 xmaddr = do_mmap(NULL, xaddr, excess - excess1, 1159 prot, flags, 0); 1160 up_write(&mm->mmap_sem); 1161 1162 kdebug("mmap[%d] <anon>" 1163 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1164 loop, xaddr, excess - excess1, prot, flags, 1165 xmaddr); 1166 1167 if (xmaddr != xaddr) 1168 return -ENOMEM; 1169 } 1170 1171 if (prot & PROT_WRITE && excess1 > 0) { 1172 kdebug("clear[%d] ad=%lx sz=%lx", 1173 loop, maddr + phdr->p_filesz, excess1); 1174 ret = clear_user((void __user *) maddr + phdr->p_filesz, 1175 excess1); 1176 if (ret) 1177 return ret; 1178 } 1179 1180 #else 1181 if (excess > 0) { 1182 kdebug("clear[%d] ad=%lx sz=%lx", 1183 loop, maddr + phdr->p_filesz, excess); 1184 ret = clear_user((void *) maddr + phdr->p_filesz, excess); 1185 if (ret) 1186 return ret; 1187 } 1188 #endif 1189 1190 if (mm) { 1191 if (phdr->p_flags & PF_X) { 1192 if (!mm->start_code) { 1193 mm->start_code = maddr; 1194 mm->end_code = maddr + phdr->p_memsz; 1195 } 1196 } else if (!mm->start_data) { 1197 mm->start_data = maddr; 1198 mm->end_data = maddr + phdr->p_memsz; 1199 } 1200 } 1201 1202 seg++; 1203 } 1204 1205 return 0; 1206 } 1207 1208 /*****************************************************************************/ 1209 /* 1210 * ELF-FDPIC core dumper 1211 * 1212 * Modelled on fs/exec.c:aout_core_dump() 1213 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1214 * 1215 * Modelled on fs/binfmt_elf.c core dumper 1216 */ 1217 #ifdef CONFIG_ELF_CORE 1218 1219 /* 1220 * Decide whether a segment is worth dumping; default is yes to be 1221 * sure (missing info is worse than too much; etc). 1222 * Personally I'd include everything, and use the coredump limit... 1223 * 1224 * I think we should skip something. But I am not sure how. H.J. 1225 */ 1226 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1227 { 1228 int dump_ok; 1229 1230 /* Do not dump I/O mapped devices or special mappings */ 1231 if (vma->vm_flags & (VM_IO | VM_RESERVED)) { 1232 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1233 return 0; 1234 } 1235 1236 /* If we may not read the contents, don't allow us to dump 1237 * them either. "dump_write()" can't handle it anyway. 1238 */ 1239 if (!(vma->vm_flags & VM_READ)) { 1240 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1241 return 0; 1242 } 1243 1244 /* By default, dump shared memory if mapped from an anonymous file. */ 1245 if (vma->vm_flags & VM_SHARED) { 1246 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1247 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1248 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1249 vma->vm_flags, dump_ok ? "yes" : "no"); 1250 return dump_ok; 1251 } 1252 1253 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1254 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1255 vma->vm_flags, dump_ok ? "yes" : "no"); 1256 return dump_ok; 1257 } 1258 1259 #ifdef CONFIG_MMU 1260 /* By default, if it hasn't been written to, don't write it out */ 1261 if (!vma->anon_vma) { 1262 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1263 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1264 vma->vm_flags, dump_ok ? "yes" : "no"); 1265 return dump_ok; 1266 } 1267 #endif 1268 1269 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1270 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1271 dump_ok ? "yes" : "no"); 1272 return dump_ok; 1273 } 1274 1275 /* An ELF note in memory */ 1276 struct memelfnote 1277 { 1278 const char *name; 1279 int type; 1280 unsigned int datasz; 1281 void *data; 1282 }; 1283 1284 static int notesize(struct memelfnote *en) 1285 { 1286 int sz; 1287 1288 sz = sizeof(struct elf_note); 1289 sz += roundup(strlen(en->name) + 1, 4); 1290 sz += roundup(en->datasz, 4); 1291 1292 return sz; 1293 } 1294 1295 /* #define DEBUG */ 1296 1297 #define DUMP_WRITE(addr, nr, foffset) \ 1298 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) 1299 1300 static int alignfile(struct file *file, loff_t *foffset) 1301 { 1302 static const char buf[4] = { 0, }; 1303 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); 1304 return 1; 1305 } 1306 1307 static int writenote(struct memelfnote *men, struct file *file, 1308 loff_t *foffset) 1309 { 1310 struct elf_note en; 1311 en.n_namesz = strlen(men->name) + 1; 1312 en.n_descsz = men->datasz; 1313 en.n_type = men->type; 1314 1315 DUMP_WRITE(&en, sizeof(en), foffset); 1316 DUMP_WRITE(men->name, en.n_namesz, foffset); 1317 if (!alignfile(file, foffset)) 1318 return 0; 1319 DUMP_WRITE(men->data, men->datasz, foffset); 1320 if (!alignfile(file, foffset)) 1321 return 0; 1322 1323 return 1; 1324 } 1325 #undef DUMP_WRITE 1326 1327 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1328 { 1329 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1330 elf->e_ident[EI_CLASS] = ELF_CLASS; 1331 elf->e_ident[EI_DATA] = ELF_DATA; 1332 elf->e_ident[EI_VERSION] = EV_CURRENT; 1333 elf->e_ident[EI_OSABI] = ELF_OSABI; 1334 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1335 1336 elf->e_type = ET_CORE; 1337 elf->e_machine = ELF_ARCH; 1338 elf->e_version = EV_CURRENT; 1339 elf->e_entry = 0; 1340 elf->e_phoff = sizeof(struct elfhdr); 1341 elf->e_shoff = 0; 1342 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1343 elf->e_ehsize = sizeof(struct elfhdr); 1344 elf->e_phentsize = sizeof(struct elf_phdr); 1345 elf->e_phnum = segs; 1346 elf->e_shentsize = 0; 1347 elf->e_shnum = 0; 1348 elf->e_shstrndx = 0; 1349 return; 1350 } 1351 1352 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1353 { 1354 phdr->p_type = PT_NOTE; 1355 phdr->p_offset = offset; 1356 phdr->p_vaddr = 0; 1357 phdr->p_paddr = 0; 1358 phdr->p_filesz = sz; 1359 phdr->p_memsz = 0; 1360 phdr->p_flags = 0; 1361 phdr->p_align = 0; 1362 return; 1363 } 1364 1365 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1366 unsigned int sz, void *data) 1367 { 1368 note->name = name; 1369 note->type = type; 1370 note->datasz = sz; 1371 note->data = data; 1372 return; 1373 } 1374 1375 /* 1376 * fill up all the fields in prstatus from the given task struct, except 1377 * registers which need to be filled up separately. 1378 */ 1379 static void fill_prstatus(struct elf_prstatus *prstatus, 1380 struct task_struct *p, long signr) 1381 { 1382 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1383 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1384 prstatus->pr_sighold = p->blocked.sig[0]; 1385 rcu_read_lock(); 1386 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1387 rcu_read_unlock(); 1388 prstatus->pr_pid = task_pid_vnr(p); 1389 prstatus->pr_pgrp = task_pgrp_vnr(p); 1390 prstatus->pr_sid = task_session_vnr(p); 1391 if (thread_group_leader(p)) { 1392 struct task_cputime cputime; 1393 1394 /* 1395 * This is the record for the group leader. It shows the 1396 * group-wide total, not its individual thread total. 1397 */ 1398 thread_group_cputime(p, &cputime); 1399 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1400 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1401 } else { 1402 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1403 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1404 } 1405 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1406 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1407 1408 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1409 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1410 } 1411 1412 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1413 struct mm_struct *mm) 1414 { 1415 const struct cred *cred; 1416 unsigned int i, len; 1417 1418 /* first copy the parameters from user space */ 1419 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1420 1421 len = mm->arg_end - mm->arg_start; 1422 if (len >= ELF_PRARGSZ) 1423 len = ELF_PRARGSZ - 1; 1424 if (copy_from_user(&psinfo->pr_psargs, 1425 (const char __user *) mm->arg_start, len)) 1426 return -EFAULT; 1427 for (i = 0; i < len; i++) 1428 if (psinfo->pr_psargs[i] == 0) 1429 psinfo->pr_psargs[i] = ' '; 1430 psinfo->pr_psargs[len] = 0; 1431 1432 rcu_read_lock(); 1433 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1434 rcu_read_unlock(); 1435 psinfo->pr_pid = task_pid_vnr(p); 1436 psinfo->pr_pgrp = task_pgrp_vnr(p); 1437 psinfo->pr_sid = task_session_vnr(p); 1438 1439 i = p->state ? ffz(~p->state) + 1 : 0; 1440 psinfo->pr_state = i; 1441 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1442 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1443 psinfo->pr_nice = task_nice(p); 1444 psinfo->pr_flag = p->flags; 1445 rcu_read_lock(); 1446 cred = __task_cred(p); 1447 SET_UID(psinfo->pr_uid, cred->uid); 1448 SET_GID(psinfo->pr_gid, cred->gid); 1449 rcu_read_unlock(); 1450 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1451 1452 return 0; 1453 } 1454 1455 /* Here is the structure in which status of each thread is captured. */ 1456 struct elf_thread_status 1457 { 1458 struct list_head list; 1459 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1460 elf_fpregset_t fpu; /* NT_PRFPREG */ 1461 struct task_struct *thread; 1462 #ifdef ELF_CORE_COPY_XFPREGS 1463 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1464 #endif 1465 struct memelfnote notes[3]; 1466 int num_notes; 1467 }; 1468 1469 /* 1470 * In order to add the specific thread information for the elf file format, 1471 * we need to keep a linked list of every thread's pr_status and then create 1472 * a single section for them in the final core file. 1473 */ 1474 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1475 { 1476 struct task_struct *p = t->thread; 1477 int sz = 0; 1478 1479 t->num_notes = 0; 1480 1481 fill_prstatus(&t->prstatus, p, signr); 1482 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1483 1484 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1485 &t->prstatus); 1486 t->num_notes++; 1487 sz += notesize(&t->notes[0]); 1488 1489 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1490 if (t->prstatus.pr_fpvalid) { 1491 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1492 &t->fpu); 1493 t->num_notes++; 1494 sz += notesize(&t->notes[1]); 1495 } 1496 1497 #ifdef ELF_CORE_COPY_XFPREGS 1498 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1499 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1500 sizeof(t->xfpu), &t->xfpu); 1501 t->num_notes++; 1502 sz += notesize(&t->notes[2]); 1503 } 1504 #endif 1505 return sz; 1506 } 1507 1508 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1509 elf_addr_t e_shoff, int segs) 1510 { 1511 elf->e_shoff = e_shoff; 1512 elf->e_shentsize = sizeof(*shdr4extnum); 1513 elf->e_shnum = 1; 1514 elf->e_shstrndx = SHN_UNDEF; 1515 1516 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1517 1518 shdr4extnum->sh_type = SHT_NULL; 1519 shdr4extnum->sh_size = elf->e_shnum; 1520 shdr4extnum->sh_link = elf->e_shstrndx; 1521 shdr4extnum->sh_info = segs; 1522 } 1523 1524 /* 1525 * dump the segments for an MMU process 1526 */ 1527 #ifdef 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_area_struct *vma; 1532 int err = 0; 1533 1534 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1535 unsigned long addr; 1536 1537 if (!maydump(vma, mm_flags)) 1538 continue; 1539 1540 for (addr = vma->vm_start; addr < vma->vm_end; 1541 addr += PAGE_SIZE) { 1542 struct page *page = get_dump_page(addr); 1543 if (page) { 1544 void *kaddr = kmap(page); 1545 *size += PAGE_SIZE; 1546 if (*size > *limit) 1547 err = -EFBIG; 1548 else if (!dump_write(file, kaddr, PAGE_SIZE)) 1549 err = -EIO; 1550 kunmap(page); 1551 page_cache_release(page); 1552 } else if (!dump_seek(file, PAGE_SIZE)) 1553 err = -EFBIG; 1554 if (err) 1555 goto out; 1556 } 1557 } 1558 out: 1559 return err; 1560 } 1561 #endif 1562 1563 /* 1564 * dump the segments for a NOMMU process 1565 */ 1566 #ifndef CONFIG_MMU 1567 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1568 unsigned long *limit, unsigned long mm_flags) 1569 { 1570 struct vm_area_struct *vma; 1571 1572 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1573 if (!maydump(vma, mm_flags)) 1574 continue; 1575 1576 if ((*size += PAGE_SIZE) > *limit) 1577 return -EFBIG; 1578 1579 if (!dump_write(file, (void *) vma->vm_start, 1580 vma->vm_end - vma->vm_start)) 1581 return -EIO; 1582 } 1583 1584 return 0; 1585 } 1586 #endif 1587 1588 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1589 { 1590 struct vm_area_struct *vma; 1591 size_t size = 0; 1592 1593 for (vma = current->mm->mmap; vma; vma->vm_next) 1594 if (maydump(vma, mm_flags)) 1595 size += vma->vm_end - vma->vm_start; 1596 return size; 1597 } 1598 1599 /* 1600 * Actual dumper 1601 * 1602 * This is a two-pass process; first we find the offsets of the bits, 1603 * and then they are actually written out. If we run out of core limit 1604 * we just truncate. 1605 */ 1606 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1607 { 1608 #define NUM_NOTES 6 1609 int has_dumped = 0; 1610 mm_segment_t fs; 1611 int segs; 1612 size_t size = 0; 1613 int i; 1614 struct vm_area_struct *vma; 1615 struct elfhdr *elf = NULL; 1616 loff_t offset = 0, dataoff, foffset; 1617 int numnote; 1618 struct memelfnote *notes = NULL; 1619 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1620 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1621 LIST_HEAD(thread_list); 1622 struct list_head *t; 1623 elf_fpregset_t *fpu = NULL; 1624 #ifdef ELF_CORE_COPY_XFPREGS 1625 elf_fpxregset_t *xfpu = NULL; 1626 #endif 1627 int thread_status_size = 0; 1628 elf_addr_t *auxv; 1629 struct elf_phdr *phdr4note = NULL; 1630 struct elf_shdr *shdr4extnum = NULL; 1631 Elf_Half e_phnum; 1632 elf_addr_t e_shoff; 1633 1634 /* 1635 * We no longer stop all VM operations. 1636 * 1637 * This is because those proceses that could possibly change map_count 1638 * or the mmap / vma pages are now blocked in do_exit on current 1639 * finishing this core dump. 1640 * 1641 * Only ptrace can touch these memory addresses, but it doesn't change 1642 * the map_count or the pages allocated. So no possibility of crashing 1643 * exists while dumping the mm->vm_next areas to the core file. 1644 */ 1645 1646 /* alloc memory for large data structures: too large to be on stack */ 1647 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1648 if (!elf) 1649 goto cleanup; 1650 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1651 if (!prstatus) 1652 goto cleanup; 1653 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1654 if (!psinfo) 1655 goto cleanup; 1656 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1657 if (!notes) 1658 goto cleanup; 1659 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1660 if (!fpu) 1661 goto cleanup; 1662 #ifdef ELF_CORE_COPY_XFPREGS 1663 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1664 if (!xfpu) 1665 goto cleanup; 1666 #endif 1667 1668 if (cprm->signr) { 1669 struct core_thread *ct; 1670 struct elf_thread_status *tmp; 1671 1672 for (ct = current->mm->core_state->dumper.next; 1673 ct; ct = ct->next) { 1674 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1675 if (!tmp) 1676 goto cleanup; 1677 1678 tmp->thread = ct->task; 1679 list_add(&tmp->list, &thread_list); 1680 } 1681 1682 list_for_each(t, &thread_list) { 1683 struct elf_thread_status *tmp; 1684 int sz; 1685 1686 tmp = list_entry(t, struct elf_thread_status, list); 1687 sz = elf_dump_thread_status(cprm->signr, tmp); 1688 thread_status_size += sz; 1689 } 1690 } 1691 1692 /* now collect the dump for the current */ 1693 fill_prstatus(prstatus, current, cprm->signr); 1694 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1695 1696 segs = current->mm->map_count; 1697 segs += elf_core_extra_phdrs(); 1698 1699 /* for notes section */ 1700 segs++; 1701 1702 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1703 * this, kernel supports extended numbering. Have a look at 1704 * include/linux/elf.h for further information. */ 1705 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1706 1707 /* Set up header */ 1708 fill_elf_fdpic_header(elf, e_phnum); 1709 1710 has_dumped = 1; 1711 current->flags |= PF_DUMPCORE; 1712 1713 /* 1714 * Set up the notes in similar form to SVR4 core dumps made 1715 * with info from their /proc. 1716 */ 1717 1718 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1719 fill_psinfo(psinfo, current->group_leader, current->mm); 1720 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1721 1722 numnote = 2; 1723 1724 auxv = (elf_addr_t *) current->mm->saved_auxv; 1725 1726 i = 0; 1727 do 1728 i += 2; 1729 while (auxv[i - 2] != AT_NULL); 1730 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1731 i * sizeof(elf_addr_t), auxv); 1732 1733 /* Try to dump the FPU. */ 1734 if ((prstatus->pr_fpvalid = 1735 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1736 fill_note(notes + numnote++, 1737 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1738 #ifdef ELF_CORE_COPY_XFPREGS 1739 if (elf_core_copy_task_xfpregs(current, xfpu)) 1740 fill_note(notes + numnote++, 1741 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1742 #endif 1743 1744 fs = get_fs(); 1745 set_fs(KERNEL_DS); 1746 1747 offset += sizeof(*elf); /* Elf header */ 1748 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1749 foffset = offset; 1750 1751 /* Write notes phdr entry */ 1752 { 1753 int sz = 0; 1754 1755 for (i = 0; i < numnote; i++) 1756 sz += notesize(notes + i); 1757 1758 sz += thread_status_size; 1759 1760 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1761 if (!phdr4note) 1762 goto end_coredump; 1763 1764 fill_elf_note_phdr(phdr4note, sz, offset); 1765 offset += sz; 1766 } 1767 1768 /* Page-align dumped data */ 1769 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1770 1771 offset += elf_core_vma_data_size(cprm->mm_flags); 1772 offset += elf_core_extra_data_size(); 1773 e_shoff = offset; 1774 1775 if (e_phnum == PN_XNUM) { 1776 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1777 if (!shdr4extnum) 1778 goto end_coredump; 1779 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1780 } 1781 1782 offset = dataoff; 1783 1784 size += sizeof(*elf); 1785 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) 1786 goto end_coredump; 1787 1788 size += sizeof(*phdr4note); 1789 if (size > cprm->limit 1790 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) 1791 goto end_coredump; 1792 1793 /* write program headers for segments dump */ 1794 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1795 struct elf_phdr phdr; 1796 size_t sz; 1797 1798 sz = vma->vm_end - vma->vm_start; 1799 1800 phdr.p_type = PT_LOAD; 1801 phdr.p_offset = offset; 1802 phdr.p_vaddr = vma->vm_start; 1803 phdr.p_paddr = 0; 1804 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1805 phdr.p_memsz = sz; 1806 offset += phdr.p_filesz; 1807 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1808 if (vma->vm_flags & VM_WRITE) 1809 phdr.p_flags |= PF_W; 1810 if (vma->vm_flags & VM_EXEC) 1811 phdr.p_flags |= PF_X; 1812 phdr.p_align = ELF_EXEC_PAGESIZE; 1813 1814 size += sizeof(phdr); 1815 if (size > cprm->limit 1816 || !dump_write(cprm->file, &phdr, sizeof(phdr))) 1817 goto end_coredump; 1818 } 1819 1820 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) 1821 goto end_coredump; 1822 1823 /* write out the notes section */ 1824 for (i = 0; i < numnote; i++) 1825 if (!writenote(notes + i, cprm->file, &foffset)) 1826 goto end_coredump; 1827 1828 /* write out the thread status notes section */ 1829 list_for_each(t, &thread_list) { 1830 struct elf_thread_status *tmp = 1831 list_entry(t, struct elf_thread_status, list); 1832 1833 for (i = 0; i < tmp->num_notes; i++) 1834 if (!writenote(&tmp->notes[i], cprm->file, &foffset)) 1835 goto end_coredump; 1836 } 1837 1838 if (!dump_seek(cprm->file, dataoff - foffset)) 1839 goto end_coredump; 1840 1841 if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit, 1842 cprm->mm_flags) < 0) 1843 goto end_coredump; 1844 1845 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) 1846 goto end_coredump; 1847 1848 if (e_phnum == PN_XNUM) { 1849 size += sizeof(*shdr4extnum); 1850 if (size > cprm->limit 1851 || !dump_write(cprm->file, shdr4extnum, 1852 sizeof(*shdr4extnum))) 1853 goto end_coredump; 1854 } 1855 1856 if (cprm->file->f_pos != offset) { 1857 /* Sanity check */ 1858 printk(KERN_WARNING 1859 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1860 cprm->file->f_pos, offset); 1861 } 1862 1863 end_coredump: 1864 set_fs(fs); 1865 1866 cleanup: 1867 while (!list_empty(&thread_list)) { 1868 struct list_head *tmp = thread_list.next; 1869 list_del(tmp); 1870 kfree(list_entry(tmp, struct elf_thread_status, list)); 1871 } 1872 kfree(phdr4note); 1873 kfree(elf); 1874 kfree(prstatus); 1875 kfree(psinfo); 1876 kfree(notes); 1877 kfree(fpu); 1878 #ifdef ELF_CORE_COPY_XFPREGS 1879 kfree(xfpu); 1880 #endif 1881 return has_dumped; 1882 #undef NUM_NOTES 1883 } 1884 1885 #endif /* CONFIG_ELF_CORE */ 1886