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 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 79 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit); 80 #endif 81 82 static struct linux_binfmt elf_fdpic_format = { 83 .module = THIS_MODULE, 84 .load_binary = load_elf_fdpic_binary, 85 #if defined(USE_ELF_CORE_DUMP) && defined(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 (stack_size < interp_params.stack_size) 287 stack_size = interp_params.stack_size; 288 289 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 290 executable_stack = EXSTACK_ENABLE_X; 291 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 292 executable_stack = EXSTACK_DISABLE_X; 293 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 294 executable_stack = EXSTACK_ENABLE_X; 295 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 296 executable_stack = EXSTACK_DISABLE_X; 297 else 298 executable_stack = EXSTACK_DEFAULT; 299 300 retval = -ENOEXEC; 301 if (stack_size == 0) 302 goto error; 303 304 if (elf_check_const_displacement(&interp_params.hdr)) 305 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 306 307 /* flush all traces of the currently running executable */ 308 retval = flush_old_exec(bprm); 309 if (retval) 310 goto error; 311 312 /* there's now no turning back... the old userspace image is dead, 313 * defunct, deceased, etc. after this point we have to exit via 314 * error_kill */ 315 set_personality(PER_LINUX_FDPIC); 316 set_binfmt(&elf_fdpic_format); 317 318 current->mm->start_code = 0; 319 current->mm->end_code = 0; 320 current->mm->start_stack = 0; 321 current->mm->start_data = 0; 322 current->mm->end_data = 0; 323 current->mm->context.exec_fdpic_loadmap = 0; 324 current->mm->context.interp_fdpic_loadmap = 0; 325 326 current->flags &= ~PF_FORKNOEXEC; 327 328 #ifdef CONFIG_MMU 329 elf_fdpic_arch_lay_out_mm(&exec_params, 330 &interp_params, 331 ¤t->mm->start_stack, 332 ¤t->mm->start_brk); 333 334 retval = setup_arg_pages(bprm, current->mm->start_stack, 335 executable_stack); 336 if (retval < 0) { 337 send_sig(SIGKILL, current, 0); 338 goto error_kill; 339 } 340 #endif 341 342 /* load the executable and interpreter into memory */ 343 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 344 "executable"); 345 if (retval < 0) 346 goto error_kill; 347 348 if (interpreter_name) { 349 retval = elf_fdpic_map_file(&interp_params, interpreter, 350 current->mm, "interpreter"); 351 if (retval < 0) { 352 printk(KERN_ERR "Unable to load interpreter\n"); 353 goto error_kill; 354 } 355 356 allow_write_access(interpreter); 357 fput(interpreter); 358 interpreter = NULL; 359 } 360 361 #ifdef CONFIG_MMU 362 if (!current->mm->start_brk) 363 current->mm->start_brk = current->mm->end_data; 364 365 current->mm->brk = current->mm->start_brk = 366 PAGE_ALIGN(current->mm->start_brk); 367 368 #else 369 /* create a stack and brk area big enough for everyone 370 * - the brk heap starts at the bottom and works up 371 * - the stack starts at the top and works down 372 */ 373 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 374 if (stack_size < PAGE_SIZE * 2) 375 stack_size = PAGE_SIZE * 2; 376 377 down_write(¤t->mm->mmap_sem); 378 current->mm->start_brk = do_mmap(NULL, 0, stack_size, 379 PROT_READ | PROT_WRITE | PROT_EXEC, 380 MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN, 381 0); 382 383 if (IS_ERR_VALUE(current->mm->start_brk)) { 384 up_write(¤t->mm->mmap_sem); 385 retval = current->mm->start_brk; 386 current->mm->start_brk = 0; 387 goto error_kill; 388 } 389 390 up_write(¤t->mm->mmap_sem); 391 392 current->mm->brk = current->mm->start_brk; 393 current->mm->context.end_brk = current->mm->start_brk; 394 current->mm->context.end_brk += 395 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; 396 current->mm->start_stack = current->mm->start_brk + stack_size; 397 #endif 398 399 install_exec_creds(bprm); 400 current->flags &= ~PF_FORKNOEXEC; 401 if (create_elf_fdpic_tables(bprm, current->mm, 402 &exec_params, &interp_params) < 0) 403 goto error_kill; 404 405 kdebug("- start_code %lx", current->mm->start_code); 406 kdebug("- end_code %lx", current->mm->end_code); 407 kdebug("- start_data %lx", current->mm->start_data); 408 kdebug("- end_data %lx", current->mm->end_data); 409 kdebug("- start_brk %lx", current->mm->start_brk); 410 kdebug("- brk %lx", current->mm->brk); 411 kdebug("- start_stack %lx", current->mm->start_stack); 412 413 #ifdef ELF_FDPIC_PLAT_INIT 414 /* 415 * The ABI may specify that certain registers be set up in special 416 * ways (on i386 %edx is the address of a DT_FINI function, for 417 * example. This macro performs whatever initialization to 418 * the regs structure is required. 419 */ 420 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 421 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 422 dynaddr); 423 #endif 424 425 /* everything is now ready... get the userspace context ready to roll */ 426 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 427 start_thread(regs, entryaddr, current->mm->start_stack); 428 429 retval = 0; 430 431 error: 432 if (interpreter) { 433 allow_write_access(interpreter); 434 fput(interpreter); 435 } 436 kfree(interpreter_name); 437 kfree(exec_params.phdrs); 438 kfree(exec_params.loadmap); 439 kfree(interp_params.phdrs); 440 kfree(interp_params.loadmap); 441 return retval; 442 443 /* unrecoverable error - kill the process */ 444 error_kill: 445 send_sig(SIGSEGV, current, 0); 446 goto error; 447 448 } 449 450 /*****************************************************************************/ 451 452 #ifndef ELF_BASE_PLATFORM 453 /* 454 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 455 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 456 * will be copied to the user stack in the same manner as AT_PLATFORM. 457 */ 458 #define ELF_BASE_PLATFORM NULL 459 #endif 460 461 /* 462 * present useful information to the program by shovelling it onto the new 463 * process's stack 464 */ 465 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 466 struct mm_struct *mm, 467 struct elf_fdpic_params *exec_params, 468 struct elf_fdpic_params *interp_params) 469 { 470 const struct cred *cred = current_cred(); 471 unsigned long sp, csp, nitems; 472 elf_caddr_t __user *argv, *envp; 473 size_t platform_len = 0, len; 474 char *k_platform, *k_base_platform; 475 char __user *u_platform, *u_base_platform, *p; 476 long hwcap; 477 int loop; 478 int nr; /* reset for each csp adjustment */ 479 480 #ifdef CONFIG_MMU 481 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 482 * by the processes running on the same package. One thing we can do is 483 * to shuffle the initial stack for them, so we give the architecture 484 * an opportunity to do so here. 485 */ 486 sp = arch_align_stack(bprm->p); 487 #else 488 sp = mm->start_stack; 489 490 /* stack the program arguments and environment */ 491 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 492 return -EFAULT; 493 #endif 494 495 hwcap = ELF_HWCAP; 496 497 /* 498 * If this architecture has a platform capability string, copy it 499 * to userspace. In some cases (Sparc), this info is impossible 500 * for userspace to get any other way, in others (i386) it is 501 * merely difficult. 502 */ 503 k_platform = ELF_PLATFORM; 504 u_platform = NULL; 505 506 if (k_platform) { 507 platform_len = strlen(k_platform) + 1; 508 sp -= platform_len; 509 u_platform = (char __user *) sp; 510 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 511 return -EFAULT; 512 } 513 514 /* 515 * If this architecture has a "base" platform capability 516 * string, copy it to userspace. 517 */ 518 k_base_platform = ELF_BASE_PLATFORM; 519 u_base_platform = NULL; 520 521 if (k_base_platform) { 522 platform_len = strlen(k_base_platform) + 1; 523 sp -= platform_len; 524 u_base_platform = (char __user *) sp; 525 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 526 return -EFAULT; 527 } 528 529 sp &= ~7UL; 530 531 /* stack the load map(s) */ 532 len = sizeof(struct elf32_fdpic_loadmap); 533 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 534 sp = (sp - len) & ~7UL; 535 exec_params->map_addr = sp; 536 537 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 538 return -EFAULT; 539 540 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 541 542 if (interp_params->loadmap) { 543 len = sizeof(struct elf32_fdpic_loadmap); 544 len += sizeof(struct elf32_fdpic_loadseg) * 545 interp_params->loadmap->nsegs; 546 sp = (sp - len) & ~7UL; 547 interp_params->map_addr = sp; 548 549 if (copy_to_user((void __user *) sp, interp_params->loadmap, 550 len) != 0) 551 return -EFAULT; 552 553 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 554 } 555 556 /* force 16 byte _final_ alignment here for generality */ 557 #define DLINFO_ITEMS 15 558 559 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 560 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 561 562 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 563 nitems++; 564 565 csp = sp; 566 sp -= nitems * 2 * sizeof(unsigned long); 567 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 568 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 569 sp -= 1 * sizeof(unsigned long); /* argc */ 570 571 csp -= sp & 15UL; 572 sp -= sp & 15UL; 573 574 /* put the ELF interpreter info on the stack */ 575 #define NEW_AUX_ENT(id, val) \ 576 do { \ 577 struct { unsigned long _id, _val; } __user *ent; \ 578 \ 579 ent = (void __user *) csp; \ 580 __put_user((id), &ent[nr]._id); \ 581 __put_user((val), &ent[nr]._val); \ 582 nr++; \ 583 } while (0) 584 585 nr = 0; 586 csp -= 2 * sizeof(unsigned long); 587 NEW_AUX_ENT(AT_NULL, 0); 588 if (k_platform) { 589 nr = 0; 590 csp -= 2 * sizeof(unsigned long); 591 NEW_AUX_ENT(AT_PLATFORM, 592 (elf_addr_t) (unsigned long) u_platform); 593 } 594 595 if (k_base_platform) { 596 nr = 0; 597 csp -= 2 * sizeof(unsigned long); 598 NEW_AUX_ENT(AT_BASE_PLATFORM, 599 (elf_addr_t) (unsigned long) u_base_platform); 600 } 601 602 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 603 nr = 0; 604 csp -= 2 * sizeof(unsigned long); 605 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 606 } 607 608 nr = 0; 609 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 610 NEW_AUX_ENT(AT_HWCAP, hwcap); 611 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 612 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 613 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 614 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 615 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 616 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 617 NEW_AUX_ENT(AT_FLAGS, 0); 618 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 619 NEW_AUX_ENT(AT_UID, (elf_addr_t) cred->uid); 620 NEW_AUX_ENT(AT_EUID, (elf_addr_t) cred->euid); 621 NEW_AUX_ENT(AT_GID, (elf_addr_t) cred->gid); 622 NEW_AUX_ENT(AT_EGID, (elf_addr_t) cred->egid); 623 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 624 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 625 626 #ifdef ARCH_DLINFO 627 nr = 0; 628 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 629 630 /* ARCH_DLINFO must come last so platform specific code can enforce 631 * special alignment requirements on the AUXV if necessary (eg. PPC). 632 */ 633 ARCH_DLINFO; 634 #endif 635 #undef NEW_AUX_ENT 636 637 /* allocate room for argv[] and envv[] */ 638 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 639 envp = (elf_caddr_t __user *) csp; 640 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 641 argv = (elf_caddr_t __user *) csp; 642 643 /* stack argc */ 644 csp -= sizeof(unsigned long); 645 __put_user(bprm->argc, (unsigned long __user *) csp); 646 647 BUG_ON(csp != sp); 648 649 /* fill in the argv[] array */ 650 #ifdef CONFIG_MMU 651 current->mm->arg_start = bprm->p; 652 #else 653 current->mm->arg_start = current->mm->start_stack - 654 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 655 #endif 656 657 p = (char __user *) current->mm->arg_start; 658 for (loop = bprm->argc; loop > 0; loop--) { 659 __put_user((elf_caddr_t) p, argv++); 660 len = strnlen_user(p, MAX_ARG_STRLEN); 661 if (!len || len > MAX_ARG_STRLEN) 662 return -EINVAL; 663 p += len; 664 } 665 __put_user(NULL, argv); 666 current->mm->arg_end = (unsigned long) p; 667 668 /* fill in the envv[] array */ 669 current->mm->env_start = (unsigned long) p; 670 for (loop = bprm->envc; loop > 0; loop--) { 671 __put_user((elf_caddr_t)(unsigned long) p, envp++); 672 len = strnlen_user(p, MAX_ARG_STRLEN); 673 if (!len || len > MAX_ARG_STRLEN) 674 return -EINVAL; 675 p += len; 676 } 677 __put_user(NULL, envp); 678 current->mm->env_end = (unsigned long) p; 679 680 mm->start_stack = (unsigned long) sp; 681 return 0; 682 } 683 684 /*****************************************************************************/ 685 /* 686 * transfer the program arguments and environment from the holding pages onto 687 * the stack 688 */ 689 #ifndef CONFIG_MMU 690 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 691 unsigned long *_sp) 692 { 693 unsigned long index, stop, sp; 694 char *src; 695 int ret = 0; 696 697 stop = bprm->p >> PAGE_SHIFT; 698 sp = *_sp; 699 700 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 701 src = kmap(bprm->page[index]); 702 sp -= PAGE_SIZE; 703 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 704 ret = -EFAULT; 705 kunmap(bprm->page[index]); 706 if (ret < 0) 707 goto out; 708 } 709 710 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 711 712 out: 713 return ret; 714 } 715 #endif 716 717 /*****************************************************************************/ 718 /* 719 * load the appropriate binary image (executable or interpreter) into memory 720 * - we assume no MMU is available 721 * - if no other PIC bits are set in params->hdr->e_flags 722 * - we assume that the LOADable segments in the binary are independently relocatable 723 * - we assume R/O executable segments are shareable 724 * - else 725 * - we assume the loadable parts of the image to require fixed displacement 726 * - the image is not shareable 727 */ 728 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 729 struct file *file, 730 struct mm_struct *mm, 731 const char *what) 732 { 733 struct elf32_fdpic_loadmap *loadmap; 734 #ifdef CONFIG_MMU 735 struct elf32_fdpic_loadseg *mseg; 736 #endif 737 struct elf32_fdpic_loadseg *seg; 738 struct elf32_phdr *phdr; 739 unsigned long load_addr, stop; 740 unsigned nloads, tmp; 741 size_t size; 742 int loop, ret; 743 744 /* allocate a load map table */ 745 nloads = 0; 746 for (loop = 0; loop < params->hdr.e_phnum; loop++) 747 if (params->phdrs[loop].p_type == PT_LOAD) 748 nloads++; 749 750 if (nloads == 0) 751 return -ELIBBAD; 752 753 size = sizeof(*loadmap) + nloads * sizeof(*seg); 754 loadmap = kzalloc(size, GFP_KERNEL); 755 if (!loadmap) 756 return -ENOMEM; 757 758 params->loadmap = loadmap; 759 760 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 761 loadmap->nsegs = nloads; 762 763 load_addr = params->load_addr; 764 seg = loadmap->segs; 765 766 /* map the requested LOADs into the memory space */ 767 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 768 case ELF_FDPIC_FLAG_CONSTDISP: 769 case ELF_FDPIC_FLAG_CONTIGUOUS: 770 #ifndef CONFIG_MMU 771 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 772 if (ret < 0) 773 return ret; 774 break; 775 #endif 776 default: 777 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 778 if (ret < 0) 779 return ret; 780 break; 781 } 782 783 /* map the entry point */ 784 if (params->hdr.e_entry) { 785 seg = loadmap->segs; 786 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 787 if (params->hdr.e_entry >= seg->p_vaddr && 788 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 789 params->entry_addr = 790 (params->hdr.e_entry - seg->p_vaddr) + 791 seg->addr; 792 break; 793 } 794 } 795 } 796 797 /* determine where the program header table has wound up if mapped */ 798 stop = params->hdr.e_phoff; 799 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 800 phdr = params->phdrs; 801 802 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 803 if (phdr->p_type != PT_LOAD) 804 continue; 805 806 if (phdr->p_offset > params->hdr.e_phoff || 807 phdr->p_offset + phdr->p_filesz < stop) 808 continue; 809 810 seg = loadmap->segs; 811 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 812 if (phdr->p_vaddr >= seg->p_vaddr && 813 phdr->p_vaddr + phdr->p_filesz <= 814 seg->p_vaddr + seg->p_memsz) { 815 params->ph_addr = 816 (phdr->p_vaddr - seg->p_vaddr) + 817 seg->addr + 818 params->hdr.e_phoff - phdr->p_offset; 819 break; 820 } 821 } 822 break; 823 } 824 825 /* determine where the dynamic section has wound up if there is one */ 826 phdr = params->phdrs; 827 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 828 if (phdr->p_type != PT_DYNAMIC) 829 continue; 830 831 seg = loadmap->segs; 832 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 833 if (phdr->p_vaddr >= seg->p_vaddr && 834 phdr->p_vaddr + phdr->p_memsz <= 835 seg->p_vaddr + seg->p_memsz) { 836 params->dynamic_addr = 837 (phdr->p_vaddr - seg->p_vaddr) + 838 seg->addr; 839 840 /* check the dynamic section contains at least 841 * one item, and that the last item is a NULL 842 * entry */ 843 if (phdr->p_memsz == 0 || 844 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 845 goto dynamic_error; 846 847 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 848 if (((Elf32_Dyn *) 849 params->dynamic_addr)[tmp - 1].d_tag != 0) 850 goto dynamic_error; 851 break; 852 } 853 } 854 break; 855 } 856 857 /* now elide adjacent segments in the load map on MMU linux 858 * - on uClinux the holes between may actually be filled with system 859 * stuff or stuff from other processes 860 */ 861 #ifdef CONFIG_MMU 862 nloads = loadmap->nsegs; 863 mseg = loadmap->segs; 864 seg = mseg + 1; 865 for (loop = 1; loop < nloads; loop++) { 866 /* see if we have a candidate for merging */ 867 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 868 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 869 if (load_addr == (seg->addr & PAGE_MASK)) { 870 mseg->p_memsz += 871 load_addr - 872 (mseg->addr + mseg->p_memsz); 873 mseg->p_memsz += seg->addr & ~PAGE_MASK; 874 mseg->p_memsz += seg->p_memsz; 875 loadmap->nsegs--; 876 continue; 877 } 878 } 879 880 mseg++; 881 if (mseg != seg) 882 *mseg = *seg; 883 } 884 #endif 885 886 kdebug("Mapped Object [%s]:", what); 887 kdebug("- elfhdr : %lx", params->elfhdr_addr); 888 kdebug("- entry : %lx", params->entry_addr); 889 kdebug("- PHDR[] : %lx", params->ph_addr); 890 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 891 seg = loadmap->segs; 892 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 893 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 894 loop, 895 seg->addr, seg->addr + seg->p_memsz - 1, 896 seg->p_vaddr, seg->p_memsz); 897 898 return 0; 899 900 dynamic_error: 901 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 902 what, file->f_path.dentry->d_inode->i_ino); 903 return -ELIBBAD; 904 } 905 906 /*****************************************************************************/ 907 /* 908 * map a file with constant displacement under uClinux 909 */ 910 #ifndef CONFIG_MMU 911 static int elf_fdpic_map_file_constdisp_on_uclinux( 912 struct elf_fdpic_params *params, 913 struct file *file, 914 struct mm_struct *mm) 915 { 916 struct elf32_fdpic_loadseg *seg; 917 struct elf32_phdr *phdr; 918 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 919 loff_t fpos; 920 int loop, ret; 921 922 load_addr = params->load_addr; 923 seg = params->loadmap->segs; 924 925 /* determine the bounds of the contiguous overall allocation we must 926 * make */ 927 phdr = params->phdrs; 928 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 929 if (params->phdrs[loop].p_type != PT_LOAD) 930 continue; 931 932 if (base > phdr->p_vaddr) 933 base = phdr->p_vaddr; 934 if (top < phdr->p_vaddr + phdr->p_memsz) 935 top = phdr->p_vaddr + phdr->p_memsz; 936 } 937 938 /* allocate one big anon block for everything */ 939 mflags = MAP_PRIVATE; 940 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 941 mflags |= MAP_EXECUTABLE; 942 943 down_write(&mm->mmap_sem); 944 maddr = do_mmap(NULL, load_addr, top - base, 945 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 946 up_write(&mm->mmap_sem); 947 if (IS_ERR_VALUE(maddr)) 948 return (int) maddr; 949 950 if (load_addr != 0) 951 load_addr += PAGE_ALIGN(top - base); 952 953 /* and then load the file segments into it */ 954 phdr = params->phdrs; 955 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 956 if (params->phdrs[loop].p_type != PT_LOAD) 957 continue; 958 959 fpos = phdr->p_offset; 960 961 seg->addr = maddr + (phdr->p_vaddr - base); 962 seg->p_vaddr = phdr->p_vaddr; 963 seg->p_memsz = phdr->p_memsz; 964 965 ret = file->f_op->read(file, (void *) seg->addr, 966 phdr->p_filesz, &fpos); 967 if (ret < 0) 968 return ret; 969 970 /* map the ELF header address if in this segment */ 971 if (phdr->p_offset == 0) 972 params->elfhdr_addr = seg->addr; 973 974 /* clear any space allocated but not loaded */ 975 if (phdr->p_filesz < phdr->p_memsz) 976 clear_user((void *) (seg->addr + phdr->p_filesz), 977 phdr->p_memsz - phdr->p_filesz); 978 979 if (mm) { 980 if (phdr->p_flags & PF_X) { 981 if (!mm->start_code) { 982 mm->start_code = seg->addr; 983 mm->end_code = seg->addr + 984 phdr->p_memsz; 985 } 986 } else if (!mm->start_data) { 987 mm->start_data = seg->addr; 988 #ifndef CONFIG_MMU 989 mm->end_data = seg->addr + phdr->p_memsz; 990 #endif 991 } 992 993 #ifdef CONFIG_MMU 994 if (seg->addr + phdr->p_memsz > mm->end_data) 995 mm->end_data = seg->addr + phdr->p_memsz; 996 #endif 997 } 998 999 seg++; 1000 } 1001 1002 return 0; 1003 } 1004 #endif 1005 1006 /*****************************************************************************/ 1007 /* 1008 * map a binary by direct mmap() of the individual PT_LOAD segments 1009 */ 1010 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1011 struct file *file, 1012 struct mm_struct *mm) 1013 { 1014 struct elf32_fdpic_loadseg *seg; 1015 struct elf32_phdr *phdr; 1016 unsigned long load_addr, delta_vaddr; 1017 int loop, dvset; 1018 1019 load_addr = params->load_addr; 1020 delta_vaddr = 0; 1021 dvset = 0; 1022 1023 seg = params->loadmap->segs; 1024 1025 /* deal with each load segment separately */ 1026 phdr = params->phdrs; 1027 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1028 unsigned long maddr, disp, excess, excess1; 1029 int prot = 0, flags; 1030 1031 if (phdr->p_type != PT_LOAD) 1032 continue; 1033 1034 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1035 (unsigned long) phdr->p_vaddr, 1036 (unsigned long) phdr->p_offset, 1037 (unsigned long) phdr->p_filesz, 1038 (unsigned long) phdr->p_memsz); 1039 1040 /* determine the mapping parameters */ 1041 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1042 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1043 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1044 1045 flags = MAP_PRIVATE | MAP_DENYWRITE; 1046 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1047 flags |= MAP_EXECUTABLE; 1048 1049 maddr = 0; 1050 1051 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1052 case ELF_FDPIC_FLAG_INDEPENDENT: 1053 /* PT_LOADs are independently locatable */ 1054 break; 1055 1056 case ELF_FDPIC_FLAG_HONOURVADDR: 1057 /* the specified virtual address must be honoured */ 1058 maddr = phdr->p_vaddr; 1059 flags |= MAP_FIXED; 1060 break; 1061 1062 case ELF_FDPIC_FLAG_CONSTDISP: 1063 /* constant displacement 1064 * - can be mapped anywhere, but must be mapped as a 1065 * unit 1066 */ 1067 if (!dvset) { 1068 maddr = load_addr; 1069 delta_vaddr = phdr->p_vaddr; 1070 dvset = 1; 1071 } else { 1072 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1073 flags |= MAP_FIXED; 1074 } 1075 break; 1076 1077 case ELF_FDPIC_FLAG_CONTIGUOUS: 1078 /* contiguity handled later */ 1079 break; 1080 1081 default: 1082 BUG(); 1083 } 1084 1085 maddr &= PAGE_MASK; 1086 1087 /* create the mapping */ 1088 disp = phdr->p_vaddr & ~PAGE_MASK; 1089 down_write(&mm->mmap_sem); 1090 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1091 phdr->p_offset - disp); 1092 up_write(&mm->mmap_sem); 1093 1094 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1095 loop, phdr->p_memsz + disp, prot, flags, 1096 phdr->p_offset - disp, maddr); 1097 1098 if (IS_ERR_VALUE(maddr)) 1099 return (int) maddr; 1100 1101 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1102 ELF_FDPIC_FLAG_CONTIGUOUS) 1103 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1104 1105 seg->addr = maddr + disp; 1106 seg->p_vaddr = phdr->p_vaddr; 1107 seg->p_memsz = phdr->p_memsz; 1108 1109 /* map the ELF header address if in this segment */ 1110 if (phdr->p_offset == 0) 1111 params->elfhdr_addr = seg->addr; 1112 1113 /* clear the bit between beginning of mapping and beginning of 1114 * PT_LOAD */ 1115 if (prot & PROT_WRITE && disp > 0) { 1116 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1117 clear_user((void __user *) maddr, disp); 1118 maddr += disp; 1119 } 1120 1121 /* clear any space allocated but not loaded 1122 * - on uClinux we can just clear the lot 1123 * - on MMU linux we'll get a SIGBUS beyond the last page 1124 * extant in the file 1125 */ 1126 excess = phdr->p_memsz - phdr->p_filesz; 1127 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1128 1129 #ifdef CONFIG_MMU 1130 if (excess > excess1) { 1131 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1132 unsigned long xmaddr; 1133 1134 flags |= MAP_FIXED | MAP_ANONYMOUS; 1135 down_write(&mm->mmap_sem); 1136 xmaddr = do_mmap(NULL, xaddr, excess - excess1, 1137 prot, flags, 0); 1138 up_write(&mm->mmap_sem); 1139 1140 kdebug("mmap[%d] <anon>" 1141 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1142 loop, xaddr, excess - excess1, prot, flags, 1143 xmaddr); 1144 1145 if (xmaddr != xaddr) 1146 return -ENOMEM; 1147 } 1148 1149 if (prot & PROT_WRITE && excess1 > 0) { 1150 kdebug("clear[%d] ad=%lx sz=%lx", 1151 loop, maddr + phdr->p_filesz, excess1); 1152 clear_user((void __user *) maddr + phdr->p_filesz, 1153 excess1); 1154 } 1155 1156 #else 1157 if (excess > 0) { 1158 kdebug("clear[%d] ad=%lx sz=%lx", 1159 loop, maddr + phdr->p_filesz, excess); 1160 clear_user((void *) maddr + phdr->p_filesz, excess); 1161 } 1162 #endif 1163 1164 if (mm) { 1165 if (phdr->p_flags & PF_X) { 1166 if (!mm->start_code) { 1167 mm->start_code = maddr; 1168 mm->end_code = maddr + phdr->p_memsz; 1169 } 1170 } else if (!mm->start_data) { 1171 mm->start_data = maddr; 1172 mm->end_data = maddr + phdr->p_memsz; 1173 } 1174 } 1175 1176 seg++; 1177 } 1178 1179 return 0; 1180 } 1181 1182 /*****************************************************************************/ 1183 /* 1184 * ELF-FDPIC core dumper 1185 * 1186 * Modelled on fs/exec.c:aout_core_dump() 1187 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1188 * 1189 * Modelled on fs/binfmt_elf.c core dumper 1190 */ 1191 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 1192 1193 /* 1194 * These are the only things you should do on a core-file: use only these 1195 * functions to write out all the necessary info. 1196 */ 1197 static int dump_write(struct file *file, const void *addr, int nr) 1198 { 1199 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 1200 } 1201 1202 static int dump_seek(struct file *file, loff_t off) 1203 { 1204 if (file->f_op->llseek) { 1205 if (file->f_op->llseek(file, off, SEEK_SET) != off) 1206 return 0; 1207 } else { 1208 file->f_pos = off; 1209 } 1210 return 1; 1211 } 1212 1213 /* 1214 * Decide whether a segment is worth dumping; default is yes to be 1215 * sure (missing info is worse than too much; etc). 1216 * Personally I'd include everything, and use the coredump limit... 1217 * 1218 * I think we should skip something. But I am not sure how. H.J. 1219 */ 1220 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1221 { 1222 int dump_ok; 1223 1224 /* Do not dump I/O mapped devices or special mappings */ 1225 if (vma->vm_flags & (VM_IO | VM_RESERVED)) { 1226 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1227 return 0; 1228 } 1229 1230 /* If we may not read the contents, don't allow us to dump 1231 * them either. "dump_write()" can't handle it anyway. 1232 */ 1233 if (!(vma->vm_flags & VM_READ)) { 1234 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1235 return 0; 1236 } 1237 1238 /* By default, dump shared memory if mapped from an anonymous file. */ 1239 if (vma->vm_flags & VM_SHARED) { 1240 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1241 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1242 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1243 vma->vm_flags, dump_ok ? "yes" : "no"); 1244 return dump_ok; 1245 } 1246 1247 dump_ok = test_bit(MMF_DUMP_MAPPED_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 #ifdef CONFIG_MMU 1254 /* By default, if it hasn't been written to, don't write it out */ 1255 if (!vma->anon_vma) { 1256 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1257 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1258 vma->vm_flags, dump_ok ? "yes" : "no"); 1259 return dump_ok; 1260 } 1261 #endif 1262 1263 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1264 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1265 dump_ok ? "yes" : "no"); 1266 return dump_ok; 1267 } 1268 1269 /* An ELF note in memory */ 1270 struct memelfnote 1271 { 1272 const char *name; 1273 int type; 1274 unsigned int datasz; 1275 void *data; 1276 }; 1277 1278 static int notesize(struct memelfnote *en) 1279 { 1280 int sz; 1281 1282 sz = sizeof(struct elf_note); 1283 sz += roundup(strlen(en->name) + 1, 4); 1284 sz += roundup(en->datasz, 4); 1285 1286 return sz; 1287 } 1288 1289 /* #define DEBUG */ 1290 1291 #define DUMP_WRITE(addr, nr) \ 1292 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0) 1293 #define DUMP_SEEK(off) \ 1294 do { if (!dump_seek(file, (off))) return 0; } while(0) 1295 1296 static int writenote(struct memelfnote *men, struct file *file) 1297 { 1298 struct elf_note en; 1299 1300 en.n_namesz = strlen(men->name) + 1; 1301 en.n_descsz = men->datasz; 1302 en.n_type = men->type; 1303 1304 DUMP_WRITE(&en, sizeof(en)); 1305 DUMP_WRITE(men->name, en.n_namesz); 1306 /* XXX - cast from long long to long to avoid need for libgcc.a */ 1307 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1308 DUMP_WRITE(men->data, men->datasz); 1309 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1310 1311 return 1; 1312 } 1313 #undef DUMP_WRITE 1314 #undef DUMP_SEEK 1315 1316 #define DUMP_WRITE(addr, nr) \ 1317 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ 1318 goto end_coredump; 1319 #define DUMP_SEEK(off) \ 1320 if (!dump_seek(file, (off))) \ 1321 goto end_coredump; 1322 1323 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1324 { 1325 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1326 elf->e_ident[EI_CLASS] = ELF_CLASS; 1327 elf->e_ident[EI_DATA] = ELF_DATA; 1328 elf->e_ident[EI_VERSION] = EV_CURRENT; 1329 elf->e_ident[EI_OSABI] = ELF_OSABI; 1330 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1331 1332 elf->e_type = ET_CORE; 1333 elf->e_machine = ELF_ARCH; 1334 elf->e_version = EV_CURRENT; 1335 elf->e_entry = 0; 1336 elf->e_phoff = sizeof(struct elfhdr); 1337 elf->e_shoff = 0; 1338 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1339 elf->e_ehsize = sizeof(struct elfhdr); 1340 elf->e_phentsize = sizeof(struct elf_phdr); 1341 elf->e_phnum = segs; 1342 elf->e_shentsize = 0; 1343 elf->e_shnum = 0; 1344 elf->e_shstrndx = 0; 1345 return; 1346 } 1347 1348 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1349 { 1350 phdr->p_type = PT_NOTE; 1351 phdr->p_offset = offset; 1352 phdr->p_vaddr = 0; 1353 phdr->p_paddr = 0; 1354 phdr->p_filesz = sz; 1355 phdr->p_memsz = 0; 1356 phdr->p_flags = 0; 1357 phdr->p_align = 0; 1358 return; 1359 } 1360 1361 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1362 unsigned int sz, void *data) 1363 { 1364 note->name = name; 1365 note->type = type; 1366 note->datasz = sz; 1367 note->data = data; 1368 return; 1369 } 1370 1371 /* 1372 * fill up all the fields in prstatus from the given task struct, except 1373 * registers which need to be filled up seperately. 1374 */ 1375 static void fill_prstatus(struct elf_prstatus *prstatus, 1376 struct task_struct *p, long signr) 1377 { 1378 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1379 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1380 prstatus->pr_sighold = p->blocked.sig[0]; 1381 prstatus->pr_pid = task_pid_vnr(p); 1382 prstatus->pr_ppid = task_pid_vnr(p->parent); 1383 prstatus->pr_pgrp = task_pgrp_vnr(p); 1384 prstatus->pr_sid = task_session_vnr(p); 1385 if (thread_group_leader(p)) { 1386 struct task_cputime cputime; 1387 1388 /* 1389 * This is the record for the group leader. It shows the 1390 * group-wide total, not its individual thread total. 1391 */ 1392 thread_group_cputime(p, &cputime); 1393 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1394 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1395 } else { 1396 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1397 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1398 } 1399 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1400 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1401 1402 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1403 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1404 } 1405 1406 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1407 struct mm_struct *mm) 1408 { 1409 const struct cred *cred; 1410 unsigned int i, len; 1411 1412 /* first copy the parameters from user space */ 1413 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1414 1415 len = mm->arg_end - mm->arg_start; 1416 if (len >= ELF_PRARGSZ) 1417 len = ELF_PRARGSZ - 1; 1418 if (copy_from_user(&psinfo->pr_psargs, 1419 (const char __user *) mm->arg_start, len)) 1420 return -EFAULT; 1421 for (i = 0; i < len; i++) 1422 if (psinfo->pr_psargs[i] == 0) 1423 psinfo->pr_psargs[i] = ' '; 1424 psinfo->pr_psargs[len] = 0; 1425 1426 psinfo->pr_pid = task_pid_vnr(p); 1427 psinfo->pr_ppid = task_pid_vnr(p->parent); 1428 psinfo->pr_pgrp = task_pgrp_vnr(p); 1429 psinfo->pr_sid = task_session_vnr(p); 1430 1431 i = p->state ? ffz(~p->state) + 1 : 0; 1432 psinfo->pr_state = i; 1433 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1434 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1435 psinfo->pr_nice = task_nice(p); 1436 psinfo->pr_flag = p->flags; 1437 rcu_read_lock(); 1438 cred = __task_cred(p); 1439 SET_UID(psinfo->pr_uid, cred->uid); 1440 SET_GID(psinfo->pr_gid, cred->gid); 1441 rcu_read_unlock(); 1442 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1443 1444 return 0; 1445 } 1446 1447 /* Here is the structure in which status of each thread is captured. */ 1448 struct elf_thread_status 1449 { 1450 struct list_head list; 1451 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1452 elf_fpregset_t fpu; /* NT_PRFPREG */ 1453 struct task_struct *thread; 1454 #ifdef ELF_CORE_COPY_XFPREGS 1455 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1456 #endif 1457 struct memelfnote notes[3]; 1458 int num_notes; 1459 }; 1460 1461 /* 1462 * In order to add the specific thread information for the elf file format, 1463 * we need to keep a linked list of every thread's pr_status and then create 1464 * a single section for them in the final core file. 1465 */ 1466 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1467 { 1468 struct task_struct *p = t->thread; 1469 int sz = 0; 1470 1471 t->num_notes = 0; 1472 1473 fill_prstatus(&t->prstatus, p, signr); 1474 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1475 1476 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1477 &t->prstatus); 1478 t->num_notes++; 1479 sz += notesize(&t->notes[0]); 1480 1481 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1482 if (t->prstatus.pr_fpvalid) { 1483 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1484 &t->fpu); 1485 t->num_notes++; 1486 sz += notesize(&t->notes[1]); 1487 } 1488 1489 #ifdef ELF_CORE_COPY_XFPREGS 1490 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1491 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1492 sizeof(t->xfpu), &t->xfpu); 1493 t->num_notes++; 1494 sz += notesize(&t->notes[2]); 1495 } 1496 #endif 1497 return sz; 1498 } 1499 1500 /* 1501 * dump the segments for an MMU process 1502 */ 1503 #ifdef CONFIG_MMU 1504 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1505 unsigned long *limit, unsigned long mm_flags) 1506 { 1507 struct vm_area_struct *vma; 1508 1509 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1510 unsigned long addr; 1511 1512 if (!maydump(vma, mm_flags)) 1513 continue; 1514 1515 for (addr = vma->vm_start; 1516 addr < vma->vm_end; 1517 addr += PAGE_SIZE 1518 ) { 1519 struct vm_area_struct *vma; 1520 struct page *page; 1521 1522 if (get_user_pages(current, current->mm, addr, 1, 0, 1, 1523 &page, &vma) <= 0) { 1524 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1525 } 1526 else if (page == ZERO_PAGE(0)) { 1527 page_cache_release(page); 1528 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1529 } 1530 else { 1531 void *kaddr; 1532 1533 flush_cache_page(vma, addr, page_to_pfn(page)); 1534 kaddr = kmap(page); 1535 if ((*size += PAGE_SIZE) > *limit || 1536 !dump_write(file, kaddr, PAGE_SIZE) 1537 ) { 1538 kunmap(page); 1539 page_cache_release(page); 1540 return -EIO; 1541 } 1542 kunmap(page); 1543 page_cache_release(page); 1544 } 1545 } 1546 } 1547 1548 return 0; 1549 1550 end_coredump: 1551 return -EFBIG; 1552 } 1553 #endif 1554 1555 /* 1556 * dump the segments for a NOMMU process 1557 */ 1558 #ifndef CONFIG_MMU 1559 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1560 unsigned long *limit, unsigned long mm_flags) 1561 { 1562 struct vm_area_struct *vma; 1563 1564 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1565 if (!maydump(vma, mm_flags)) 1566 continue; 1567 1568 if ((*size += PAGE_SIZE) > *limit) 1569 return -EFBIG; 1570 1571 if (!dump_write(file, (void *) vma->vm_start, 1572 vma->vm_end - vma->vm_start)) 1573 return -EIO; 1574 } 1575 1576 return 0; 1577 } 1578 #endif 1579 1580 /* 1581 * Actual dumper 1582 * 1583 * This is a two-pass process; first we find the offsets of the bits, 1584 * and then they are actually written out. If we run out of core limit 1585 * we just truncate. 1586 */ 1587 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 1588 struct file *file, unsigned long limit) 1589 { 1590 #define NUM_NOTES 6 1591 int has_dumped = 0; 1592 mm_segment_t fs; 1593 int segs; 1594 size_t size = 0; 1595 int i; 1596 struct vm_area_struct *vma; 1597 struct elfhdr *elf = NULL; 1598 loff_t offset = 0, dataoff; 1599 int numnote; 1600 struct memelfnote *notes = NULL; 1601 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1602 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1603 LIST_HEAD(thread_list); 1604 struct list_head *t; 1605 elf_fpregset_t *fpu = NULL; 1606 #ifdef ELF_CORE_COPY_XFPREGS 1607 elf_fpxregset_t *xfpu = NULL; 1608 #endif 1609 int thread_status_size = 0; 1610 elf_addr_t *auxv; 1611 unsigned long mm_flags; 1612 1613 /* 1614 * We no longer stop all VM operations. 1615 * 1616 * This is because those proceses that could possibly change map_count 1617 * or the mmap / vma pages are now blocked in do_exit on current 1618 * finishing this core dump. 1619 * 1620 * Only ptrace can touch these memory addresses, but it doesn't change 1621 * the map_count or the pages allocated. So no possibility of crashing 1622 * exists while dumping the mm->vm_next areas to the core file. 1623 */ 1624 1625 /* alloc memory for large data structures: too large to be on stack */ 1626 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1627 if (!elf) 1628 goto cleanup; 1629 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1630 if (!prstatus) 1631 goto cleanup; 1632 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1633 if (!psinfo) 1634 goto cleanup; 1635 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1636 if (!notes) 1637 goto cleanup; 1638 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1639 if (!fpu) 1640 goto cleanup; 1641 #ifdef ELF_CORE_COPY_XFPREGS 1642 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1643 if (!xfpu) 1644 goto cleanup; 1645 #endif 1646 1647 if (signr) { 1648 struct core_thread *ct; 1649 struct elf_thread_status *tmp; 1650 1651 for (ct = current->mm->core_state->dumper.next; 1652 ct; ct = ct->next) { 1653 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1654 if (!tmp) 1655 goto cleanup; 1656 1657 tmp->thread = ct->task; 1658 list_add(&tmp->list, &thread_list); 1659 } 1660 1661 list_for_each(t, &thread_list) { 1662 struct elf_thread_status *tmp; 1663 int sz; 1664 1665 tmp = list_entry(t, struct elf_thread_status, list); 1666 sz = elf_dump_thread_status(signr, tmp); 1667 thread_status_size += sz; 1668 } 1669 } 1670 1671 /* now collect the dump for the current */ 1672 fill_prstatus(prstatus, current, signr); 1673 elf_core_copy_regs(&prstatus->pr_reg, regs); 1674 1675 segs = current->mm->map_count; 1676 #ifdef ELF_CORE_EXTRA_PHDRS 1677 segs += ELF_CORE_EXTRA_PHDRS; 1678 #endif 1679 1680 /* Set up header */ 1681 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */ 1682 1683 has_dumped = 1; 1684 current->flags |= PF_DUMPCORE; 1685 1686 /* 1687 * Set up the notes in similar form to SVR4 core dumps made 1688 * with info from their /proc. 1689 */ 1690 1691 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1692 fill_psinfo(psinfo, current->group_leader, current->mm); 1693 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1694 1695 numnote = 2; 1696 1697 auxv = (elf_addr_t *) current->mm->saved_auxv; 1698 1699 i = 0; 1700 do 1701 i += 2; 1702 while (auxv[i - 2] != AT_NULL); 1703 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1704 i * sizeof(elf_addr_t), auxv); 1705 1706 /* Try to dump the FPU. */ 1707 if ((prstatus->pr_fpvalid = 1708 elf_core_copy_task_fpregs(current, regs, fpu))) 1709 fill_note(notes + numnote++, 1710 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1711 #ifdef ELF_CORE_COPY_XFPREGS 1712 if (elf_core_copy_task_xfpregs(current, xfpu)) 1713 fill_note(notes + numnote++, 1714 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1715 #endif 1716 1717 fs = get_fs(); 1718 set_fs(KERNEL_DS); 1719 1720 DUMP_WRITE(elf, sizeof(*elf)); 1721 offset += sizeof(*elf); /* Elf header */ 1722 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */ 1723 1724 /* Write notes phdr entry */ 1725 { 1726 struct elf_phdr phdr; 1727 int sz = 0; 1728 1729 for (i = 0; i < numnote; i++) 1730 sz += notesize(notes + i); 1731 1732 sz += thread_status_size; 1733 1734 fill_elf_note_phdr(&phdr, sz, offset); 1735 offset += sz; 1736 DUMP_WRITE(&phdr, sizeof(phdr)); 1737 } 1738 1739 /* Page-align dumped data */ 1740 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1741 1742 /* 1743 * We must use the same mm->flags while dumping core to avoid 1744 * inconsistency between the program headers and bodies, otherwise an 1745 * unusable core file can be generated. 1746 */ 1747 mm_flags = current->mm->flags; 1748 1749 /* write program headers for segments dump */ 1750 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1751 struct elf_phdr phdr; 1752 size_t sz; 1753 1754 sz = vma->vm_end - vma->vm_start; 1755 1756 phdr.p_type = PT_LOAD; 1757 phdr.p_offset = offset; 1758 phdr.p_vaddr = vma->vm_start; 1759 phdr.p_paddr = 0; 1760 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0; 1761 phdr.p_memsz = sz; 1762 offset += phdr.p_filesz; 1763 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1764 if (vma->vm_flags & VM_WRITE) 1765 phdr.p_flags |= PF_W; 1766 if (vma->vm_flags & VM_EXEC) 1767 phdr.p_flags |= PF_X; 1768 phdr.p_align = ELF_EXEC_PAGESIZE; 1769 1770 DUMP_WRITE(&phdr, sizeof(phdr)); 1771 } 1772 1773 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS 1774 ELF_CORE_WRITE_EXTRA_PHDRS; 1775 #endif 1776 1777 /* write out the notes section */ 1778 for (i = 0; i < numnote; i++) 1779 if (!writenote(notes + i, file)) 1780 goto end_coredump; 1781 1782 /* write out the thread status notes section */ 1783 list_for_each(t, &thread_list) { 1784 struct elf_thread_status *tmp = 1785 list_entry(t, struct elf_thread_status, list); 1786 1787 for (i = 0; i < tmp->num_notes; i++) 1788 if (!writenote(&tmp->notes[i], file)) 1789 goto end_coredump; 1790 } 1791 1792 DUMP_SEEK(dataoff); 1793 1794 if (elf_fdpic_dump_segments(file, &size, &limit, 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 /* USE_ELF_CORE_DUMP */ 1831