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 38 #include <asm/uaccess.h> 39 #include <asm/param.h> 40 #include <asm/pgalloc.h> 41 42 typedef char *elf_caddr_t; 43 44 #if 0 45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 46 #else 47 #define kdebug(fmt, ...) do {} while(0) 48 #endif 49 50 #if 0 51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 52 #else 53 #define kdcore(fmt, ...) do {} while(0) 54 #endif 55 56 MODULE_LICENSE("GPL"); 57 58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *); 59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 61 struct mm_struct *, const char *); 62 63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 64 struct elf_fdpic_params *, 65 struct elf_fdpic_params *); 66 67 #ifndef CONFIG_MMU 68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, 69 unsigned long *); 70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 71 struct file *, 72 struct mm_struct *); 73 #endif 74 75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 76 struct file *, struct mm_struct *); 77 78 #ifdef CONFIG_ELF_CORE 79 static int elf_fdpic_core_dump(struct coredump_params *cprm); 80 #endif 81 82 static struct linux_binfmt elf_fdpic_format = { 83 .module = THIS_MODULE, 84 .load_binary = load_elf_fdpic_binary, 85 #ifdef CONFIG_ELF_CORE 86 .core_dump = elf_fdpic_core_dump, 87 #endif 88 .min_coredump = ELF_EXEC_PAGESIZE, 89 }; 90 91 static int __init init_elf_fdpic_binfmt(void) 92 { 93 return register_binfmt(&elf_fdpic_format); 94 } 95 96 static void __exit exit_elf_fdpic_binfmt(void) 97 { 98 unregister_binfmt(&elf_fdpic_format); 99 } 100 101 core_initcall(init_elf_fdpic_binfmt); 102 module_exit(exit_elf_fdpic_binfmt); 103 104 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) 105 { 106 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 107 return 0; 108 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 109 return 0; 110 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) 111 return 0; 112 if (!file->f_op || !file->f_op->mmap) 113 return 0; 114 return 1; 115 } 116 117 /*****************************************************************************/ 118 /* 119 * read the program headers table into memory 120 */ 121 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 122 struct file *file) 123 { 124 struct elf32_phdr *phdr; 125 unsigned long size; 126 int retval, loop; 127 128 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 129 return -ENOMEM; 130 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 131 return -ENOMEM; 132 133 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 134 params->phdrs = kmalloc(size, GFP_KERNEL); 135 if (!params->phdrs) 136 return -ENOMEM; 137 138 retval = kernel_read(file, params->hdr.e_phoff, 139 (char *) params->phdrs, size); 140 if (unlikely(retval != size)) 141 return retval < 0 ? retval : -ENOEXEC; 142 143 /* determine stack size for this binary */ 144 phdr = params->phdrs; 145 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 146 if (phdr->p_type != PT_GNU_STACK) 147 continue; 148 149 if (phdr->p_flags & PF_X) 150 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 151 else 152 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 153 154 params->stack_size = phdr->p_memsz; 155 break; 156 } 157 158 return 0; 159 } 160 161 /*****************************************************************************/ 162 /* 163 * load an fdpic binary into various bits of memory 164 */ 165 static int load_elf_fdpic_binary(struct linux_binprm *bprm, 166 struct pt_regs *regs) 167 { 168 struct elf_fdpic_params exec_params, interp_params; 169 struct elf_phdr *phdr; 170 unsigned long stack_size, entryaddr; 171 #ifdef ELF_FDPIC_PLAT_INIT 172 unsigned long dynaddr; 173 #endif 174 struct file *interpreter = NULL; /* to shut gcc up */ 175 char *interpreter_name = NULL; 176 int executable_stack; 177 int retval, i; 178 179 kdebug("____ LOAD %d ____", current->pid); 180 181 memset(&exec_params, 0, sizeof(exec_params)); 182 memset(&interp_params, 0, sizeof(interp_params)); 183 184 exec_params.hdr = *(struct elfhdr *) bprm->buf; 185 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 186 187 /* check that this is a binary we know how to deal with */ 188 retval = -ENOEXEC; 189 if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) 190 goto error; 191 192 /* read the program header table */ 193 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 194 if (retval < 0) 195 goto error; 196 197 /* scan for a program header that specifies an interpreter */ 198 phdr = exec_params.phdrs; 199 200 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 201 switch (phdr->p_type) { 202 case PT_INTERP: 203 retval = -ENOMEM; 204 if (phdr->p_filesz > PATH_MAX) 205 goto error; 206 retval = -ENOENT; 207 if (phdr->p_filesz < 2) 208 goto error; 209 210 /* read the name of the interpreter into memory */ 211 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 212 if (!interpreter_name) 213 goto error; 214 215 retval = kernel_read(bprm->file, 216 phdr->p_offset, 217 interpreter_name, 218 phdr->p_filesz); 219 if (unlikely(retval != phdr->p_filesz)) { 220 if (retval >= 0) 221 retval = -ENOEXEC; 222 goto error; 223 } 224 225 retval = -ENOENT; 226 if (interpreter_name[phdr->p_filesz - 1] != '\0') 227 goto error; 228 229 kdebug("Using ELF interpreter %s", interpreter_name); 230 231 /* replace the program with the interpreter */ 232 interpreter = open_exec(interpreter_name); 233 retval = PTR_ERR(interpreter); 234 if (IS_ERR(interpreter)) { 235 interpreter = NULL; 236 goto error; 237 } 238 239 /* 240 * If the binary is not readable then enforce 241 * mm->dumpable = 0 regardless of the interpreter's 242 * permissions. 243 */ 244 if (file_permission(interpreter, MAY_READ) < 0) 245 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; 246 247 retval = kernel_read(interpreter, 0, bprm->buf, 248 BINPRM_BUF_SIZE); 249 if (unlikely(retval != BINPRM_BUF_SIZE)) { 250 if (retval >= 0) 251 retval = -ENOEXEC; 252 goto error; 253 } 254 255 interp_params.hdr = *((struct elfhdr *) bprm->buf); 256 break; 257 258 case PT_LOAD: 259 #ifdef CONFIG_MMU 260 if (exec_params.load_addr == 0) 261 exec_params.load_addr = phdr->p_vaddr; 262 #endif 263 break; 264 } 265 266 } 267 268 if (elf_check_const_displacement(&exec_params.hdr)) 269 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 270 271 /* perform insanity checks on the interpreter */ 272 if (interpreter_name) { 273 retval = -ELIBBAD; 274 if (!is_elf_fdpic(&interp_params.hdr, interpreter)) 275 goto error; 276 277 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 278 279 /* read the interpreter's program header table */ 280 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 281 if (retval < 0) 282 goto error; 283 } 284 285 stack_size = exec_params.stack_size; 286 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 287 executable_stack = EXSTACK_ENABLE_X; 288 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 289 executable_stack = EXSTACK_DISABLE_X; 290 else 291 executable_stack = EXSTACK_DEFAULT; 292 293 if (stack_size == 0) { 294 stack_size = interp_params.stack_size; 295 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 } 302 303 retval = -ENOEXEC; 304 if (stack_size == 0) 305 goto error; 306 307 if (elf_check_const_displacement(&interp_params.hdr)) 308 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 309 310 /* flush all traces of the currently running executable */ 311 retval = flush_old_exec(bprm); 312 if (retval) 313 goto error; 314 315 /* there's now no turning back... the old userspace image is dead, 316 * defunct, deceased, etc. after this point we have to exit via 317 * error_kill */ 318 set_personality(PER_LINUX_FDPIC); 319 set_binfmt(&elf_fdpic_format); 320 321 current->mm->start_code = 0; 322 current->mm->end_code = 0; 323 current->mm->start_stack = 0; 324 current->mm->start_data = 0; 325 current->mm->end_data = 0; 326 current->mm->context.exec_fdpic_loadmap = 0; 327 current->mm->context.interp_fdpic_loadmap = 0; 328 329 current->flags &= ~PF_FORKNOEXEC; 330 331 #ifdef CONFIG_MMU 332 elf_fdpic_arch_lay_out_mm(&exec_params, 333 &interp_params, 334 ¤t->mm->start_stack, 335 ¤t->mm->start_brk); 336 337 retval = setup_arg_pages(bprm, current->mm->start_stack, 338 executable_stack); 339 if (retval < 0) { 340 send_sig(SIGKILL, current, 0); 341 goto error_kill; 342 } 343 #endif 344 345 /* load the executable and interpreter into memory */ 346 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 347 "executable"); 348 if (retval < 0) 349 goto error_kill; 350 351 if (interpreter_name) { 352 retval = elf_fdpic_map_file(&interp_params, interpreter, 353 current->mm, "interpreter"); 354 if (retval < 0) { 355 printk(KERN_ERR "Unable to load interpreter\n"); 356 goto error_kill; 357 } 358 359 allow_write_access(interpreter); 360 fput(interpreter); 361 interpreter = NULL; 362 } 363 364 #ifdef CONFIG_MMU 365 if (!current->mm->start_brk) 366 current->mm->start_brk = current->mm->end_data; 367 368 current->mm->brk = current->mm->start_brk = 369 PAGE_ALIGN(current->mm->start_brk); 370 371 #else 372 /* create a stack and brk area big enough for everyone 373 * - the brk heap starts at the bottom and works up 374 * - the stack starts at the top and works down 375 */ 376 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 377 if (stack_size < PAGE_SIZE * 2) 378 stack_size = PAGE_SIZE * 2; 379 380 down_write(¤t->mm->mmap_sem); 381 current->mm->start_brk = do_mmap(NULL, 0, stack_size, 382 PROT_READ | PROT_WRITE | PROT_EXEC, 383 MAP_PRIVATE | MAP_ANONYMOUS | 384 MAP_UNINITIALIZED | MAP_GROWSDOWN, 385 0); 386 387 if (IS_ERR_VALUE(current->mm->start_brk)) { 388 up_write(¤t->mm->mmap_sem); 389 retval = current->mm->start_brk; 390 current->mm->start_brk = 0; 391 goto error_kill; 392 } 393 394 up_write(¤t->mm->mmap_sem); 395 396 current->mm->brk = current->mm->start_brk; 397 current->mm->context.end_brk = current->mm->start_brk; 398 current->mm->context.end_brk += 399 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; 400 current->mm->start_stack = current->mm->start_brk + stack_size; 401 #endif 402 403 install_exec_creds(bprm); 404 current->flags &= ~PF_FORKNOEXEC; 405 if (create_elf_fdpic_tables(bprm, current->mm, 406 &exec_params, &interp_params) < 0) 407 goto error_kill; 408 409 kdebug("- start_code %lx", current->mm->start_code); 410 kdebug("- end_code %lx", current->mm->end_code); 411 kdebug("- start_data %lx", current->mm->start_data); 412 kdebug("- end_data %lx", current->mm->end_data); 413 kdebug("- start_brk %lx", current->mm->start_brk); 414 kdebug("- brk %lx", current->mm->brk); 415 kdebug("- start_stack %lx", current->mm->start_stack); 416 417 #ifdef ELF_FDPIC_PLAT_INIT 418 /* 419 * The ABI may specify that certain registers be set up in special 420 * ways (on i386 %edx is the address of a DT_FINI function, for 421 * example. This macro performs whatever initialization to 422 * the regs structure is required. 423 */ 424 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 425 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 426 dynaddr); 427 #endif 428 429 /* everything is now ready... get the userspace context ready to roll */ 430 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 431 start_thread(regs, entryaddr, current->mm->start_stack); 432 433 retval = 0; 434 435 error: 436 if (interpreter) { 437 allow_write_access(interpreter); 438 fput(interpreter); 439 } 440 kfree(interpreter_name); 441 kfree(exec_params.phdrs); 442 kfree(exec_params.loadmap); 443 kfree(interp_params.phdrs); 444 kfree(interp_params.loadmap); 445 return retval; 446 447 /* unrecoverable error - kill the process */ 448 error_kill: 449 send_sig(SIGSEGV, current, 0); 450 goto error; 451 452 } 453 454 /*****************************************************************************/ 455 456 #ifndef ELF_BASE_PLATFORM 457 /* 458 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 459 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 460 * will be copied to the user stack in the same manner as AT_PLATFORM. 461 */ 462 #define ELF_BASE_PLATFORM NULL 463 #endif 464 465 /* 466 * present useful information to the program by shovelling it onto the new 467 * process's stack 468 */ 469 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 470 struct mm_struct *mm, 471 struct elf_fdpic_params *exec_params, 472 struct elf_fdpic_params *interp_params) 473 { 474 const struct cred *cred = current_cred(); 475 unsigned long sp, csp, nitems; 476 elf_caddr_t __user *argv, *envp; 477 size_t platform_len = 0, len; 478 char *k_platform, *k_base_platform; 479 char __user *u_platform, *u_base_platform, *p; 480 long hwcap; 481 int loop; 482 int nr; /* reset for each csp adjustment */ 483 484 #ifdef CONFIG_MMU 485 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 486 * by the processes running on the same package. One thing we can do is 487 * to shuffle the initial stack for them, so we give the architecture 488 * an opportunity to do so here. 489 */ 490 sp = arch_align_stack(bprm->p); 491 #else 492 sp = mm->start_stack; 493 494 /* stack the program arguments and environment */ 495 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 496 return -EFAULT; 497 #endif 498 499 hwcap = ELF_HWCAP; 500 501 /* 502 * If this architecture has a platform capability string, copy it 503 * to userspace. In some cases (Sparc), this info is impossible 504 * for userspace to get any other way, in others (i386) it is 505 * merely difficult. 506 */ 507 k_platform = ELF_PLATFORM; 508 u_platform = NULL; 509 510 if (k_platform) { 511 platform_len = strlen(k_platform) + 1; 512 sp -= platform_len; 513 u_platform = (char __user *) sp; 514 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 515 return -EFAULT; 516 } 517 518 /* 519 * If this architecture has a "base" platform capability 520 * string, copy it to userspace. 521 */ 522 k_base_platform = ELF_BASE_PLATFORM; 523 u_base_platform = NULL; 524 525 if (k_base_platform) { 526 platform_len = strlen(k_base_platform) + 1; 527 sp -= platform_len; 528 u_base_platform = (char __user *) sp; 529 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 530 return -EFAULT; 531 } 532 533 sp &= ~7UL; 534 535 /* stack the load map(s) */ 536 len = sizeof(struct elf32_fdpic_loadmap); 537 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 538 sp = (sp - len) & ~7UL; 539 exec_params->map_addr = sp; 540 541 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 542 return -EFAULT; 543 544 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 545 546 if (interp_params->loadmap) { 547 len = sizeof(struct elf32_fdpic_loadmap); 548 len += sizeof(struct elf32_fdpic_loadseg) * 549 interp_params->loadmap->nsegs; 550 sp = (sp - len) & ~7UL; 551 interp_params->map_addr = sp; 552 553 if (copy_to_user((void __user *) sp, interp_params->loadmap, 554 len) != 0) 555 return -EFAULT; 556 557 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 558 } 559 560 /* force 16 byte _final_ alignment here for generality */ 561 #define DLINFO_ITEMS 15 562 563 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 564 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 565 566 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 567 nitems++; 568 569 csp = sp; 570 sp -= nitems * 2 * sizeof(unsigned long); 571 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 572 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 573 sp -= 1 * sizeof(unsigned long); /* argc */ 574 575 csp -= sp & 15UL; 576 sp -= sp & 15UL; 577 578 /* put the ELF interpreter info on the stack */ 579 #define NEW_AUX_ENT(id, val) \ 580 do { \ 581 struct { unsigned long _id, _val; } __user *ent; \ 582 \ 583 ent = (void __user *) csp; \ 584 __put_user((id), &ent[nr]._id); \ 585 __put_user((val), &ent[nr]._val); \ 586 nr++; \ 587 } while (0) 588 589 nr = 0; 590 csp -= 2 * sizeof(unsigned long); 591 NEW_AUX_ENT(AT_NULL, 0); 592 if (k_platform) { 593 nr = 0; 594 csp -= 2 * sizeof(unsigned long); 595 NEW_AUX_ENT(AT_PLATFORM, 596 (elf_addr_t) (unsigned long) u_platform); 597 } 598 599 if (k_base_platform) { 600 nr = 0; 601 csp -= 2 * sizeof(unsigned long); 602 NEW_AUX_ENT(AT_BASE_PLATFORM, 603 (elf_addr_t) (unsigned long) u_base_platform); 604 } 605 606 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 607 nr = 0; 608 csp -= 2 * sizeof(unsigned long); 609 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 610 } 611 612 nr = 0; 613 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 614 NEW_AUX_ENT(AT_HWCAP, hwcap); 615 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 616 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 617 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 618 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 619 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 620 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 621 NEW_AUX_ENT(AT_FLAGS, 0); 622 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 623 NEW_AUX_ENT(AT_UID, (elf_addr_t) cred->uid); 624 NEW_AUX_ENT(AT_EUID, (elf_addr_t) cred->euid); 625 NEW_AUX_ENT(AT_GID, (elf_addr_t) cred->gid); 626 NEW_AUX_ENT(AT_EGID, (elf_addr_t) cred->egid); 627 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 628 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 629 630 #ifdef ARCH_DLINFO 631 nr = 0; 632 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 633 634 /* ARCH_DLINFO must come last so platform specific code can enforce 635 * special alignment requirements on the AUXV if necessary (eg. PPC). 636 */ 637 ARCH_DLINFO; 638 #endif 639 #undef NEW_AUX_ENT 640 641 /* allocate room for argv[] and envv[] */ 642 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 643 envp = (elf_caddr_t __user *) csp; 644 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 645 argv = (elf_caddr_t __user *) csp; 646 647 /* stack argc */ 648 csp -= sizeof(unsigned long); 649 __put_user(bprm->argc, (unsigned long __user *) csp); 650 651 BUG_ON(csp != sp); 652 653 /* fill in the argv[] array */ 654 #ifdef CONFIG_MMU 655 current->mm->arg_start = bprm->p; 656 #else 657 current->mm->arg_start = current->mm->start_stack - 658 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 659 #endif 660 661 p = (char __user *) current->mm->arg_start; 662 for (loop = bprm->argc; loop > 0; loop--) { 663 __put_user((elf_caddr_t) p, argv++); 664 len = strnlen_user(p, MAX_ARG_STRLEN); 665 if (!len || len > MAX_ARG_STRLEN) 666 return -EINVAL; 667 p += len; 668 } 669 __put_user(NULL, argv); 670 current->mm->arg_end = (unsigned long) p; 671 672 /* fill in the envv[] array */ 673 current->mm->env_start = (unsigned long) p; 674 for (loop = bprm->envc; loop > 0; loop--) { 675 __put_user((elf_caddr_t)(unsigned long) p, envp++); 676 len = strnlen_user(p, MAX_ARG_STRLEN); 677 if (!len || len > MAX_ARG_STRLEN) 678 return -EINVAL; 679 p += len; 680 } 681 __put_user(NULL, envp); 682 current->mm->env_end = (unsigned long) p; 683 684 mm->start_stack = (unsigned long) sp; 685 return 0; 686 } 687 688 /*****************************************************************************/ 689 /* 690 * transfer the program arguments and environment from the holding pages onto 691 * the stack 692 */ 693 #ifndef CONFIG_MMU 694 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 695 unsigned long *_sp) 696 { 697 unsigned long index, stop, sp; 698 char *src; 699 int ret = 0; 700 701 stop = bprm->p >> PAGE_SHIFT; 702 sp = *_sp; 703 704 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 705 src = kmap(bprm->page[index]); 706 sp -= PAGE_SIZE; 707 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 708 ret = -EFAULT; 709 kunmap(bprm->page[index]); 710 if (ret < 0) 711 goto out; 712 } 713 714 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 715 716 out: 717 return ret; 718 } 719 #endif 720 721 /*****************************************************************************/ 722 /* 723 * load the appropriate binary image (executable or interpreter) into memory 724 * - we assume no MMU is available 725 * - if no other PIC bits are set in params->hdr->e_flags 726 * - we assume that the LOADable segments in the binary are independently relocatable 727 * - we assume R/O executable segments are shareable 728 * - else 729 * - we assume the loadable parts of the image to require fixed displacement 730 * - the image is not shareable 731 */ 732 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 733 struct file *file, 734 struct mm_struct *mm, 735 const char *what) 736 { 737 struct elf32_fdpic_loadmap *loadmap; 738 #ifdef CONFIG_MMU 739 struct elf32_fdpic_loadseg *mseg; 740 #endif 741 struct elf32_fdpic_loadseg *seg; 742 struct elf32_phdr *phdr; 743 unsigned long load_addr, stop; 744 unsigned nloads, tmp; 745 size_t size; 746 int loop, ret; 747 748 /* allocate a load map table */ 749 nloads = 0; 750 for (loop = 0; loop < params->hdr.e_phnum; loop++) 751 if (params->phdrs[loop].p_type == PT_LOAD) 752 nloads++; 753 754 if (nloads == 0) 755 return -ELIBBAD; 756 757 size = sizeof(*loadmap) + nloads * sizeof(*seg); 758 loadmap = kzalloc(size, GFP_KERNEL); 759 if (!loadmap) 760 return -ENOMEM; 761 762 params->loadmap = loadmap; 763 764 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 765 loadmap->nsegs = nloads; 766 767 load_addr = params->load_addr; 768 seg = loadmap->segs; 769 770 /* map the requested LOADs into the memory space */ 771 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 772 case ELF_FDPIC_FLAG_CONSTDISP: 773 case ELF_FDPIC_FLAG_CONTIGUOUS: 774 #ifndef CONFIG_MMU 775 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 776 if (ret < 0) 777 return ret; 778 break; 779 #endif 780 default: 781 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 782 if (ret < 0) 783 return ret; 784 break; 785 } 786 787 /* map the entry point */ 788 if (params->hdr.e_entry) { 789 seg = loadmap->segs; 790 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 791 if (params->hdr.e_entry >= seg->p_vaddr && 792 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 793 params->entry_addr = 794 (params->hdr.e_entry - seg->p_vaddr) + 795 seg->addr; 796 break; 797 } 798 } 799 } 800 801 /* determine where the program header table has wound up if mapped */ 802 stop = params->hdr.e_phoff; 803 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 804 phdr = params->phdrs; 805 806 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 807 if (phdr->p_type != PT_LOAD) 808 continue; 809 810 if (phdr->p_offset > params->hdr.e_phoff || 811 phdr->p_offset + phdr->p_filesz < stop) 812 continue; 813 814 seg = loadmap->segs; 815 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 816 if (phdr->p_vaddr >= seg->p_vaddr && 817 phdr->p_vaddr + phdr->p_filesz <= 818 seg->p_vaddr + seg->p_memsz) { 819 params->ph_addr = 820 (phdr->p_vaddr - seg->p_vaddr) + 821 seg->addr + 822 params->hdr.e_phoff - phdr->p_offset; 823 break; 824 } 825 } 826 break; 827 } 828 829 /* determine where the dynamic section has wound up if there is one */ 830 phdr = params->phdrs; 831 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 832 if (phdr->p_type != PT_DYNAMIC) 833 continue; 834 835 seg = loadmap->segs; 836 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 837 if (phdr->p_vaddr >= seg->p_vaddr && 838 phdr->p_vaddr + phdr->p_memsz <= 839 seg->p_vaddr + seg->p_memsz) { 840 params->dynamic_addr = 841 (phdr->p_vaddr - seg->p_vaddr) + 842 seg->addr; 843 844 /* check the dynamic section contains at least 845 * one item, and that the last item is a NULL 846 * entry */ 847 if (phdr->p_memsz == 0 || 848 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 849 goto dynamic_error; 850 851 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 852 if (((Elf32_Dyn *) 853 params->dynamic_addr)[tmp - 1].d_tag != 0) 854 goto dynamic_error; 855 break; 856 } 857 } 858 break; 859 } 860 861 /* now elide adjacent segments in the load map on MMU linux 862 * - on uClinux the holes between may actually be filled with system 863 * stuff or stuff from other processes 864 */ 865 #ifdef CONFIG_MMU 866 nloads = loadmap->nsegs; 867 mseg = loadmap->segs; 868 seg = mseg + 1; 869 for (loop = 1; loop < nloads; loop++) { 870 /* see if we have a candidate for merging */ 871 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 872 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 873 if (load_addr == (seg->addr & PAGE_MASK)) { 874 mseg->p_memsz += 875 load_addr - 876 (mseg->addr + mseg->p_memsz); 877 mseg->p_memsz += seg->addr & ~PAGE_MASK; 878 mseg->p_memsz += seg->p_memsz; 879 loadmap->nsegs--; 880 continue; 881 } 882 } 883 884 mseg++; 885 if (mseg != seg) 886 *mseg = *seg; 887 } 888 #endif 889 890 kdebug("Mapped Object [%s]:", what); 891 kdebug("- elfhdr : %lx", params->elfhdr_addr); 892 kdebug("- entry : %lx", params->entry_addr); 893 kdebug("- PHDR[] : %lx", params->ph_addr); 894 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 895 seg = loadmap->segs; 896 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 897 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 898 loop, 899 seg->addr, seg->addr + seg->p_memsz - 1, 900 seg->p_vaddr, seg->p_memsz); 901 902 return 0; 903 904 dynamic_error: 905 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 906 what, file->f_path.dentry->d_inode->i_ino); 907 return -ELIBBAD; 908 } 909 910 /*****************************************************************************/ 911 /* 912 * map a file with constant displacement under uClinux 913 */ 914 #ifndef CONFIG_MMU 915 static int elf_fdpic_map_file_constdisp_on_uclinux( 916 struct elf_fdpic_params *params, 917 struct file *file, 918 struct mm_struct *mm) 919 { 920 struct elf32_fdpic_loadseg *seg; 921 struct elf32_phdr *phdr; 922 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 923 loff_t fpos; 924 int loop, ret; 925 926 load_addr = params->load_addr; 927 seg = params->loadmap->segs; 928 929 /* determine the bounds of the contiguous overall allocation we must 930 * make */ 931 phdr = params->phdrs; 932 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 933 if (params->phdrs[loop].p_type != PT_LOAD) 934 continue; 935 936 if (base > phdr->p_vaddr) 937 base = phdr->p_vaddr; 938 if (top < phdr->p_vaddr + phdr->p_memsz) 939 top = phdr->p_vaddr + phdr->p_memsz; 940 } 941 942 /* allocate one big anon block for everything */ 943 mflags = MAP_PRIVATE; 944 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 945 mflags |= MAP_EXECUTABLE; 946 947 down_write(&mm->mmap_sem); 948 maddr = do_mmap(NULL, load_addr, top - base, 949 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 950 up_write(&mm->mmap_sem); 951 if (IS_ERR_VALUE(maddr)) 952 return (int) maddr; 953 954 if (load_addr != 0) 955 load_addr += PAGE_ALIGN(top - base); 956 957 /* and then load the file segments into it */ 958 phdr = params->phdrs; 959 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 960 if (params->phdrs[loop].p_type != PT_LOAD) 961 continue; 962 963 fpos = phdr->p_offset; 964 965 seg->addr = maddr + (phdr->p_vaddr - base); 966 seg->p_vaddr = phdr->p_vaddr; 967 seg->p_memsz = phdr->p_memsz; 968 969 ret = file->f_op->read(file, (void *) seg->addr, 970 phdr->p_filesz, &fpos); 971 if (ret < 0) 972 return ret; 973 974 /* map the ELF header address if in this segment */ 975 if (phdr->p_offset == 0) 976 params->elfhdr_addr = seg->addr; 977 978 /* clear any space allocated but not loaded */ 979 if (phdr->p_filesz < phdr->p_memsz) { 980 ret = clear_user((void *) (seg->addr + phdr->p_filesz), 981 phdr->p_memsz - phdr->p_filesz); 982 if (ret) 983 return ret; 984 } 985 986 if (mm) { 987 if (phdr->p_flags & PF_X) { 988 if (!mm->start_code) { 989 mm->start_code = seg->addr; 990 mm->end_code = seg->addr + 991 phdr->p_memsz; 992 } 993 } else if (!mm->start_data) { 994 mm->start_data = seg->addr; 995 #ifndef CONFIG_MMU 996 mm->end_data = seg->addr + phdr->p_memsz; 997 #endif 998 } 999 1000 #ifdef CONFIG_MMU 1001 if (seg->addr + phdr->p_memsz > mm->end_data) 1002 mm->end_data = seg->addr + phdr->p_memsz; 1003 #endif 1004 } 1005 1006 seg++; 1007 } 1008 1009 return 0; 1010 } 1011 #endif 1012 1013 /*****************************************************************************/ 1014 /* 1015 * map a binary by direct mmap() of the individual PT_LOAD segments 1016 */ 1017 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1018 struct file *file, 1019 struct mm_struct *mm) 1020 { 1021 struct elf32_fdpic_loadseg *seg; 1022 struct elf32_phdr *phdr; 1023 unsigned long load_addr, delta_vaddr; 1024 int loop, dvset, ret; 1025 1026 load_addr = params->load_addr; 1027 delta_vaddr = 0; 1028 dvset = 0; 1029 1030 seg = params->loadmap->segs; 1031 1032 /* deal with each load segment separately */ 1033 phdr = params->phdrs; 1034 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1035 unsigned long maddr, disp, excess, excess1; 1036 int prot = 0, flags; 1037 1038 if (phdr->p_type != PT_LOAD) 1039 continue; 1040 1041 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1042 (unsigned long) phdr->p_vaddr, 1043 (unsigned long) phdr->p_offset, 1044 (unsigned long) phdr->p_filesz, 1045 (unsigned long) phdr->p_memsz); 1046 1047 /* determine the mapping parameters */ 1048 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1049 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1050 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1051 1052 flags = MAP_PRIVATE | MAP_DENYWRITE; 1053 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1054 flags |= MAP_EXECUTABLE; 1055 1056 maddr = 0; 1057 1058 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1059 case ELF_FDPIC_FLAG_INDEPENDENT: 1060 /* PT_LOADs are independently locatable */ 1061 break; 1062 1063 case ELF_FDPIC_FLAG_HONOURVADDR: 1064 /* the specified virtual address must be honoured */ 1065 maddr = phdr->p_vaddr; 1066 flags |= MAP_FIXED; 1067 break; 1068 1069 case ELF_FDPIC_FLAG_CONSTDISP: 1070 /* constant displacement 1071 * - can be mapped anywhere, but must be mapped as a 1072 * unit 1073 */ 1074 if (!dvset) { 1075 maddr = load_addr; 1076 delta_vaddr = phdr->p_vaddr; 1077 dvset = 1; 1078 } else { 1079 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1080 flags |= MAP_FIXED; 1081 } 1082 break; 1083 1084 case ELF_FDPIC_FLAG_CONTIGUOUS: 1085 /* contiguity handled later */ 1086 break; 1087 1088 default: 1089 BUG(); 1090 } 1091 1092 maddr &= PAGE_MASK; 1093 1094 /* create the mapping */ 1095 disp = phdr->p_vaddr & ~PAGE_MASK; 1096 down_write(&mm->mmap_sem); 1097 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1098 phdr->p_offset - disp); 1099 up_write(&mm->mmap_sem); 1100 1101 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1102 loop, phdr->p_memsz + disp, prot, flags, 1103 phdr->p_offset - disp, maddr); 1104 1105 if (IS_ERR_VALUE(maddr)) 1106 return (int) maddr; 1107 1108 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1109 ELF_FDPIC_FLAG_CONTIGUOUS) 1110 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1111 1112 seg->addr = maddr + disp; 1113 seg->p_vaddr = phdr->p_vaddr; 1114 seg->p_memsz = phdr->p_memsz; 1115 1116 /* map the ELF header address if in this segment */ 1117 if (phdr->p_offset == 0) 1118 params->elfhdr_addr = seg->addr; 1119 1120 /* clear the bit between beginning of mapping and beginning of 1121 * PT_LOAD */ 1122 if (prot & PROT_WRITE && disp > 0) { 1123 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1124 ret = clear_user((void __user *) maddr, disp); 1125 if (ret) 1126 return ret; 1127 maddr += disp; 1128 } 1129 1130 /* clear any space allocated but not loaded 1131 * - on uClinux we can just clear the lot 1132 * - on MMU linux we'll get a SIGBUS beyond the last page 1133 * extant in the file 1134 */ 1135 excess = phdr->p_memsz - phdr->p_filesz; 1136 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1137 1138 #ifdef CONFIG_MMU 1139 if (excess > excess1) { 1140 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1141 unsigned long xmaddr; 1142 1143 flags |= MAP_FIXED | MAP_ANONYMOUS; 1144 down_write(&mm->mmap_sem); 1145 xmaddr = do_mmap(NULL, xaddr, excess - excess1, 1146 prot, flags, 0); 1147 up_write(&mm->mmap_sem); 1148 1149 kdebug("mmap[%d] <anon>" 1150 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1151 loop, xaddr, excess - excess1, prot, flags, 1152 xmaddr); 1153 1154 if (xmaddr != xaddr) 1155 return -ENOMEM; 1156 } 1157 1158 if (prot & PROT_WRITE && excess1 > 0) { 1159 kdebug("clear[%d] ad=%lx sz=%lx", 1160 loop, maddr + phdr->p_filesz, excess1); 1161 ret = clear_user((void __user *) maddr + phdr->p_filesz, 1162 excess1); 1163 if (ret) 1164 return ret; 1165 } 1166 1167 #else 1168 if (excess > 0) { 1169 kdebug("clear[%d] ad=%lx sz=%lx", 1170 loop, maddr + phdr->p_filesz, excess); 1171 ret = clear_user((void *) maddr + phdr->p_filesz, excess); 1172 if (ret) 1173 return ret; 1174 } 1175 #endif 1176 1177 if (mm) { 1178 if (phdr->p_flags & PF_X) { 1179 if (!mm->start_code) { 1180 mm->start_code = maddr; 1181 mm->end_code = maddr + phdr->p_memsz; 1182 } 1183 } else if (!mm->start_data) { 1184 mm->start_data = maddr; 1185 mm->end_data = maddr + phdr->p_memsz; 1186 } 1187 } 1188 1189 seg++; 1190 } 1191 1192 return 0; 1193 } 1194 1195 /*****************************************************************************/ 1196 /* 1197 * ELF-FDPIC core dumper 1198 * 1199 * Modelled on fs/exec.c:aout_core_dump() 1200 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1201 * 1202 * Modelled on fs/binfmt_elf.c core dumper 1203 */ 1204 #ifdef CONFIG_ELF_CORE 1205 1206 /* 1207 * These are the only things you should do on a core-file: use only these 1208 * functions to write out all the necessary info. 1209 */ 1210 static int dump_write(struct file *file, const void *addr, int nr) 1211 { 1212 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 1213 } 1214 1215 static int dump_seek(struct file *file, loff_t off) 1216 { 1217 if (file->f_op->llseek) { 1218 if (file->f_op->llseek(file, off, SEEK_SET) != off) 1219 return 0; 1220 } else { 1221 file->f_pos = off; 1222 } 1223 return 1; 1224 } 1225 1226 /* 1227 * Decide whether a segment is worth dumping; default is yes to be 1228 * sure (missing info is worse than too much; etc). 1229 * Personally I'd include everything, and use the coredump limit... 1230 * 1231 * I think we should skip something. But I am not sure how. H.J. 1232 */ 1233 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1234 { 1235 int dump_ok; 1236 1237 /* Do not dump I/O mapped devices or special mappings */ 1238 if (vma->vm_flags & (VM_IO | VM_RESERVED)) { 1239 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1240 return 0; 1241 } 1242 1243 /* If we may not read the contents, don't allow us to dump 1244 * them either. "dump_write()" can't handle it anyway. 1245 */ 1246 if (!(vma->vm_flags & VM_READ)) { 1247 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1248 return 0; 1249 } 1250 1251 /* By default, dump shared memory if mapped from an anonymous file. */ 1252 if (vma->vm_flags & VM_SHARED) { 1253 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1254 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1255 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1256 vma->vm_flags, dump_ok ? "yes" : "no"); 1257 return dump_ok; 1258 } 1259 1260 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1261 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1262 vma->vm_flags, dump_ok ? "yes" : "no"); 1263 return dump_ok; 1264 } 1265 1266 #ifdef CONFIG_MMU 1267 /* By default, if it hasn't been written to, don't write it out */ 1268 if (!vma->anon_vma) { 1269 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1270 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1271 vma->vm_flags, dump_ok ? "yes" : "no"); 1272 return dump_ok; 1273 } 1274 #endif 1275 1276 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1277 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1278 dump_ok ? "yes" : "no"); 1279 return dump_ok; 1280 } 1281 1282 /* An ELF note in memory */ 1283 struct memelfnote 1284 { 1285 const char *name; 1286 int type; 1287 unsigned int datasz; 1288 void *data; 1289 }; 1290 1291 static int notesize(struct memelfnote *en) 1292 { 1293 int sz; 1294 1295 sz = sizeof(struct elf_note); 1296 sz += roundup(strlen(en->name) + 1, 4); 1297 sz += roundup(en->datasz, 4); 1298 1299 return sz; 1300 } 1301 1302 /* #define DEBUG */ 1303 1304 #define DUMP_WRITE(addr, nr) \ 1305 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0) 1306 #define DUMP_SEEK(off) \ 1307 do { if (!dump_seek(file, (off))) return 0; } while(0) 1308 1309 static int writenote(struct memelfnote *men, struct file *file) 1310 { 1311 struct elf_note en; 1312 1313 en.n_namesz = strlen(men->name) + 1; 1314 en.n_descsz = men->datasz; 1315 en.n_type = men->type; 1316 1317 DUMP_WRITE(&en, sizeof(en)); 1318 DUMP_WRITE(men->name, en.n_namesz); 1319 /* XXX - cast from long long to long to avoid need for libgcc.a */ 1320 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1321 DUMP_WRITE(men->data, men->datasz); 1322 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1323 1324 return 1; 1325 } 1326 #undef DUMP_WRITE 1327 #undef DUMP_SEEK 1328 1329 #define DUMP_WRITE(addr, nr) \ 1330 if ((size += (nr)) > cprm->limit || \ 1331 !dump_write(cprm->file, (addr), (nr))) \ 1332 goto end_coredump; 1333 1334 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1335 { 1336 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1337 elf->e_ident[EI_CLASS] = ELF_CLASS; 1338 elf->e_ident[EI_DATA] = ELF_DATA; 1339 elf->e_ident[EI_VERSION] = EV_CURRENT; 1340 elf->e_ident[EI_OSABI] = ELF_OSABI; 1341 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1342 1343 elf->e_type = ET_CORE; 1344 elf->e_machine = ELF_ARCH; 1345 elf->e_version = EV_CURRENT; 1346 elf->e_entry = 0; 1347 elf->e_phoff = sizeof(struct elfhdr); 1348 elf->e_shoff = 0; 1349 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1350 elf->e_ehsize = sizeof(struct elfhdr); 1351 elf->e_phentsize = sizeof(struct elf_phdr); 1352 elf->e_phnum = segs; 1353 elf->e_shentsize = 0; 1354 elf->e_shnum = 0; 1355 elf->e_shstrndx = 0; 1356 return; 1357 } 1358 1359 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1360 { 1361 phdr->p_type = PT_NOTE; 1362 phdr->p_offset = offset; 1363 phdr->p_vaddr = 0; 1364 phdr->p_paddr = 0; 1365 phdr->p_filesz = sz; 1366 phdr->p_memsz = 0; 1367 phdr->p_flags = 0; 1368 phdr->p_align = 0; 1369 return; 1370 } 1371 1372 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1373 unsigned int sz, void *data) 1374 { 1375 note->name = name; 1376 note->type = type; 1377 note->datasz = sz; 1378 note->data = data; 1379 return; 1380 } 1381 1382 /* 1383 * fill up all the fields in prstatus from the given task struct, except 1384 * registers which need to be filled up seperately. 1385 */ 1386 static void fill_prstatus(struct elf_prstatus *prstatus, 1387 struct task_struct *p, long signr) 1388 { 1389 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1390 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1391 prstatus->pr_sighold = p->blocked.sig[0]; 1392 rcu_read_lock(); 1393 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1394 rcu_read_unlock(); 1395 prstatus->pr_pid = task_pid_vnr(p); 1396 prstatus->pr_pgrp = task_pgrp_vnr(p); 1397 prstatus->pr_sid = task_session_vnr(p); 1398 if (thread_group_leader(p)) { 1399 struct task_cputime cputime; 1400 1401 /* 1402 * This is the record for the group leader. It shows the 1403 * group-wide total, not its individual thread total. 1404 */ 1405 thread_group_cputime(p, &cputime); 1406 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1407 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1408 } else { 1409 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1410 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1411 } 1412 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1413 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1414 1415 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1416 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1417 } 1418 1419 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1420 struct mm_struct *mm) 1421 { 1422 const struct cred *cred; 1423 unsigned int i, len; 1424 1425 /* first copy the parameters from user space */ 1426 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1427 1428 len = mm->arg_end - mm->arg_start; 1429 if (len >= ELF_PRARGSZ) 1430 len = ELF_PRARGSZ - 1; 1431 if (copy_from_user(&psinfo->pr_psargs, 1432 (const char __user *) mm->arg_start, len)) 1433 return -EFAULT; 1434 for (i = 0; i < len; i++) 1435 if (psinfo->pr_psargs[i] == 0) 1436 psinfo->pr_psargs[i] = ' '; 1437 psinfo->pr_psargs[len] = 0; 1438 1439 rcu_read_lock(); 1440 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1441 rcu_read_unlock(); 1442 psinfo->pr_pid = task_pid_vnr(p); 1443 psinfo->pr_pgrp = task_pgrp_vnr(p); 1444 psinfo->pr_sid = task_session_vnr(p); 1445 1446 i = p->state ? ffz(~p->state) + 1 : 0; 1447 psinfo->pr_state = i; 1448 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1449 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1450 psinfo->pr_nice = task_nice(p); 1451 psinfo->pr_flag = p->flags; 1452 rcu_read_lock(); 1453 cred = __task_cred(p); 1454 SET_UID(psinfo->pr_uid, cred->uid); 1455 SET_GID(psinfo->pr_gid, cred->gid); 1456 rcu_read_unlock(); 1457 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1458 1459 return 0; 1460 } 1461 1462 /* Here is the structure in which status of each thread is captured. */ 1463 struct elf_thread_status 1464 { 1465 struct list_head list; 1466 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1467 elf_fpregset_t fpu; /* NT_PRFPREG */ 1468 struct task_struct *thread; 1469 #ifdef ELF_CORE_COPY_XFPREGS 1470 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1471 #endif 1472 struct memelfnote notes[3]; 1473 int num_notes; 1474 }; 1475 1476 /* 1477 * In order to add the specific thread information for the elf file format, 1478 * we need to keep a linked list of every thread's pr_status and then create 1479 * a single section for them in the final core file. 1480 */ 1481 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1482 { 1483 struct task_struct *p = t->thread; 1484 int sz = 0; 1485 1486 t->num_notes = 0; 1487 1488 fill_prstatus(&t->prstatus, p, signr); 1489 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1490 1491 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1492 &t->prstatus); 1493 t->num_notes++; 1494 sz += notesize(&t->notes[0]); 1495 1496 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1497 if (t->prstatus.pr_fpvalid) { 1498 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1499 &t->fpu); 1500 t->num_notes++; 1501 sz += notesize(&t->notes[1]); 1502 } 1503 1504 #ifdef ELF_CORE_COPY_XFPREGS 1505 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1506 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1507 sizeof(t->xfpu), &t->xfpu); 1508 t->num_notes++; 1509 sz += notesize(&t->notes[2]); 1510 } 1511 #endif 1512 return sz; 1513 } 1514 1515 /* 1516 * dump the segments for an MMU process 1517 */ 1518 #ifdef CONFIG_MMU 1519 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1520 unsigned long *limit, unsigned long mm_flags) 1521 { 1522 struct vm_area_struct *vma; 1523 int err = 0; 1524 1525 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1526 unsigned long addr; 1527 1528 if (!maydump(vma, mm_flags)) 1529 continue; 1530 1531 for (addr = vma->vm_start; addr < vma->vm_end; 1532 addr += PAGE_SIZE) { 1533 struct page *page = get_dump_page(addr); 1534 if (page) { 1535 void *kaddr = kmap(page); 1536 *size += PAGE_SIZE; 1537 if (*size > *limit) 1538 err = -EFBIG; 1539 else if (!dump_write(file, kaddr, PAGE_SIZE)) 1540 err = -EIO; 1541 kunmap(page); 1542 page_cache_release(page); 1543 } else if (!dump_seek(file, file->f_pos + PAGE_SIZE)) 1544 err = -EFBIG; 1545 if (err) 1546 goto out; 1547 } 1548 } 1549 out: 1550 return err; 1551 } 1552 #endif 1553 1554 /* 1555 * dump the segments for a NOMMU process 1556 */ 1557 #ifndef CONFIG_MMU 1558 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1559 unsigned long *limit, unsigned long mm_flags) 1560 { 1561 struct vm_area_struct *vma; 1562 1563 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1564 if (!maydump(vma, mm_flags)) 1565 continue; 1566 1567 if ((*size += PAGE_SIZE) > *limit) 1568 return -EFBIG; 1569 1570 if (!dump_write(file, (void *) vma->vm_start, 1571 vma->vm_end - vma->vm_start)) 1572 return -EIO; 1573 } 1574 1575 return 0; 1576 } 1577 #endif 1578 1579 /* 1580 * Actual dumper 1581 * 1582 * This is a two-pass process; first we find the offsets of the bits, 1583 * and then they are actually written out. If we run out of core limit 1584 * we just truncate. 1585 */ 1586 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1587 { 1588 #define NUM_NOTES 6 1589 int has_dumped = 0; 1590 mm_segment_t fs; 1591 int segs; 1592 size_t size = 0; 1593 int i; 1594 struct vm_area_struct *vma; 1595 struct elfhdr *elf = NULL; 1596 loff_t offset = 0, dataoff; 1597 int numnote; 1598 struct memelfnote *notes = NULL; 1599 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1600 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1601 LIST_HEAD(thread_list); 1602 struct list_head *t; 1603 elf_fpregset_t *fpu = NULL; 1604 #ifdef ELF_CORE_COPY_XFPREGS 1605 elf_fpxregset_t *xfpu = NULL; 1606 #endif 1607 int thread_status_size = 0; 1608 elf_addr_t *auxv; 1609 unsigned long mm_flags; 1610 1611 /* 1612 * We no longer stop all VM operations. 1613 * 1614 * This is because those proceses that could possibly change map_count 1615 * or the mmap / vma pages are now blocked in do_exit on current 1616 * finishing this core dump. 1617 * 1618 * Only ptrace can touch these memory addresses, but it doesn't change 1619 * the map_count or the pages allocated. So no possibility of crashing 1620 * exists while dumping the mm->vm_next areas to the core file. 1621 */ 1622 1623 /* alloc memory for large data structures: too large to be on stack */ 1624 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1625 if (!elf) 1626 goto cleanup; 1627 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1628 if (!prstatus) 1629 goto cleanup; 1630 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1631 if (!psinfo) 1632 goto cleanup; 1633 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1634 if (!notes) 1635 goto cleanup; 1636 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1637 if (!fpu) 1638 goto cleanup; 1639 #ifdef ELF_CORE_COPY_XFPREGS 1640 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1641 if (!xfpu) 1642 goto cleanup; 1643 #endif 1644 1645 if (cprm->signr) { 1646 struct core_thread *ct; 1647 struct elf_thread_status *tmp; 1648 1649 for (ct = current->mm->core_state->dumper.next; 1650 ct; ct = ct->next) { 1651 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1652 if (!tmp) 1653 goto cleanup; 1654 1655 tmp->thread = ct->task; 1656 list_add(&tmp->list, &thread_list); 1657 } 1658 1659 list_for_each(t, &thread_list) { 1660 struct elf_thread_status *tmp; 1661 int sz; 1662 1663 tmp = list_entry(t, struct elf_thread_status, list); 1664 sz = elf_dump_thread_status(cprm->signr, tmp); 1665 thread_status_size += sz; 1666 } 1667 } 1668 1669 /* now collect the dump for the current */ 1670 fill_prstatus(prstatus, current, cprm->signr); 1671 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1672 1673 segs = current->mm->map_count; 1674 #ifdef ELF_CORE_EXTRA_PHDRS 1675 segs += ELF_CORE_EXTRA_PHDRS; 1676 #endif 1677 1678 /* Set up header */ 1679 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */ 1680 1681 has_dumped = 1; 1682 current->flags |= PF_DUMPCORE; 1683 1684 /* 1685 * Set up the notes in similar form to SVR4 core dumps made 1686 * with info from their /proc. 1687 */ 1688 1689 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1690 fill_psinfo(psinfo, current->group_leader, current->mm); 1691 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1692 1693 numnote = 2; 1694 1695 auxv = (elf_addr_t *) current->mm->saved_auxv; 1696 1697 i = 0; 1698 do 1699 i += 2; 1700 while (auxv[i - 2] != AT_NULL); 1701 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1702 i * sizeof(elf_addr_t), auxv); 1703 1704 /* Try to dump the FPU. */ 1705 if ((prstatus->pr_fpvalid = 1706 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1707 fill_note(notes + numnote++, 1708 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1709 #ifdef ELF_CORE_COPY_XFPREGS 1710 if (elf_core_copy_task_xfpregs(current, xfpu)) 1711 fill_note(notes + numnote++, 1712 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1713 #endif 1714 1715 fs = get_fs(); 1716 set_fs(KERNEL_DS); 1717 1718 DUMP_WRITE(elf, sizeof(*elf)); 1719 offset += sizeof(*elf); /* Elf header */ 1720 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */ 1721 1722 /* Write notes phdr entry */ 1723 { 1724 struct elf_phdr phdr; 1725 int sz = 0; 1726 1727 for (i = 0; i < numnote; i++) 1728 sz += notesize(notes + i); 1729 1730 sz += thread_status_size; 1731 1732 fill_elf_note_phdr(&phdr, sz, offset); 1733 offset += sz; 1734 DUMP_WRITE(&phdr, sizeof(phdr)); 1735 } 1736 1737 /* Page-align dumped data */ 1738 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1739 1740 /* 1741 * We must use the same mm->flags while dumping core to avoid 1742 * inconsistency between the program headers and bodies, otherwise an 1743 * unusable core file can be generated. 1744 */ 1745 mm_flags = current->mm->flags; 1746 1747 /* write program headers for segments dump */ 1748 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1749 struct elf_phdr phdr; 1750 size_t sz; 1751 1752 sz = vma->vm_end - vma->vm_start; 1753 1754 phdr.p_type = PT_LOAD; 1755 phdr.p_offset = offset; 1756 phdr.p_vaddr = vma->vm_start; 1757 phdr.p_paddr = 0; 1758 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0; 1759 phdr.p_memsz = sz; 1760 offset += phdr.p_filesz; 1761 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1762 if (vma->vm_flags & VM_WRITE) 1763 phdr.p_flags |= PF_W; 1764 if (vma->vm_flags & VM_EXEC) 1765 phdr.p_flags |= PF_X; 1766 phdr.p_align = ELF_EXEC_PAGESIZE; 1767 1768 DUMP_WRITE(&phdr, sizeof(phdr)); 1769 } 1770 1771 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS 1772 ELF_CORE_WRITE_EXTRA_PHDRS; 1773 #endif 1774 1775 /* write out the notes section */ 1776 for (i = 0; i < numnote; i++) 1777 if (!writenote(notes + i, cprm->file)) 1778 goto end_coredump; 1779 1780 /* write out the thread status notes section */ 1781 list_for_each(t, &thread_list) { 1782 struct elf_thread_status *tmp = 1783 list_entry(t, struct elf_thread_status, list); 1784 1785 for (i = 0; i < tmp->num_notes; i++) 1786 if (!writenote(&tmp->notes[i], cprm->file)) 1787 goto end_coredump; 1788 } 1789 1790 if (!dump_seek(cprm->file, dataoff)) 1791 goto end_coredump; 1792 1793 if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit, 1794 mm_flags) < 0) 1795 goto end_coredump; 1796 1797 #ifdef ELF_CORE_WRITE_EXTRA_DATA 1798 ELF_CORE_WRITE_EXTRA_DATA; 1799 #endif 1800 1801 if (file->f_pos != offset) { 1802 /* Sanity check */ 1803 printk(KERN_WARNING 1804 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1805 file->f_pos, offset); 1806 } 1807 1808 end_coredump: 1809 set_fs(fs); 1810 1811 cleanup: 1812 while (!list_empty(&thread_list)) { 1813 struct list_head *tmp = thread_list.next; 1814 list_del(tmp); 1815 kfree(list_entry(tmp, struct elf_thread_status, list)); 1816 } 1817 1818 kfree(elf); 1819 kfree(prstatus); 1820 kfree(psinfo); 1821 kfree(notes); 1822 kfree(fpu); 1823 #ifdef ELF_CORE_COPY_XFPREGS 1824 kfree(xfpu); 1825 #endif 1826 return has_dumped; 1827 #undef NUM_NOTES 1828 } 1829 1830 #endif /* CONFIG_ELF_CORE */ 1831