1 /* 2 * linux/fs/binfmt_elf.c 3 * 4 * These are the functions used to load ELF format executables as used 5 * on SVr4 machines. Information on the format may be found in the book 6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support 7 * Tools". 8 * 9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com). 10 */ 11 12 #include <linux/module.h> 13 #include <linux/kernel.h> 14 #include <linux/fs.h> 15 #include <linux/stat.h> 16 #include <linux/time.h> 17 #include <linux/mm.h> 18 #include <linux/mman.h> 19 #include <linux/errno.h> 20 #include <linux/signal.h> 21 #include <linux/binfmts.h> 22 #include <linux/string.h> 23 #include <linux/file.h> 24 #include <linux/fcntl.h> 25 #include <linux/ptrace.h> 26 #include <linux/slab.h> 27 #include <linux/shm.h> 28 #include <linux/personality.h> 29 #include <linux/elfcore.h> 30 #include <linux/init.h> 31 #include <linux/highuid.h> 32 #include <linux/smp.h> 33 #include <linux/compiler.h> 34 #include <linux/highmem.h> 35 #include <linux/pagemap.h> 36 #include <linux/security.h> 37 #include <linux/syscalls.h> 38 #include <linux/random.h> 39 #include <linux/elf.h> 40 #include <linux/utsname.h> 41 #include <asm/uaccess.h> 42 #include <asm/param.h> 43 #include <asm/page.h> 44 45 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs); 46 static int load_elf_library(struct file *); 47 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, 48 int, int, unsigned long); 49 50 /* 51 * If we don't support core dumping, then supply a NULL so we 52 * don't even try. 53 */ 54 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 55 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit); 56 #else 57 #define elf_core_dump NULL 58 #endif 59 60 #if ELF_EXEC_PAGESIZE > PAGE_SIZE 61 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE 62 #else 63 #define ELF_MIN_ALIGN PAGE_SIZE 64 #endif 65 66 #ifndef ELF_CORE_EFLAGS 67 #define ELF_CORE_EFLAGS 0 68 #endif 69 70 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) 71 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) 72 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) 73 74 static struct linux_binfmt elf_format = { 75 .module = THIS_MODULE, 76 .load_binary = load_elf_binary, 77 .load_shlib = load_elf_library, 78 .core_dump = elf_core_dump, 79 .min_coredump = ELF_EXEC_PAGESIZE, 80 .hasvdso = 1 81 }; 82 83 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) 84 85 static int set_brk(unsigned long start, unsigned long end) 86 { 87 start = ELF_PAGEALIGN(start); 88 end = ELF_PAGEALIGN(end); 89 if (end > start) { 90 unsigned long addr; 91 down_write(¤t->mm->mmap_sem); 92 addr = do_brk(start, end - start); 93 up_write(¤t->mm->mmap_sem); 94 if (BAD_ADDR(addr)) 95 return addr; 96 } 97 current->mm->start_brk = current->mm->brk = end; 98 return 0; 99 } 100 101 /* We need to explicitly zero any fractional pages 102 after the data section (i.e. bss). This would 103 contain the junk from the file that should not 104 be in memory 105 */ 106 static int padzero(unsigned long elf_bss) 107 { 108 unsigned long nbyte; 109 110 nbyte = ELF_PAGEOFFSET(elf_bss); 111 if (nbyte) { 112 nbyte = ELF_MIN_ALIGN - nbyte; 113 if (clear_user((void __user *) elf_bss, nbyte)) 114 return -EFAULT; 115 } 116 return 0; 117 } 118 119 /* Let's use some macros to make this stack manipulation a little clearer */ 120 #ifdef CONFIG_STACK_GROWSUP 121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) 122 #define STACK_ROUND(sp, items) \ 123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) 124 #define STACK_ALLOC(sp, len) ({ \ 125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ 126 old_sp; }) 127 #else 128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) 129 #define STACK_ROUND(sp, items) \ 130 (((unsigned long) (sp - items)) &~ 15UL) 131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) 132 #endif 133 134 #ifndef ELF_BASE_PLATFORM 135 /* 136 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 137 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 138 * will be copied to the user stack in the same manner as AT_PLATFORM. 139 */ 140 #define ELF_BASE_PLATFORM NULL 141 #endif 142 143 static int 144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, 145 unsigned long load_addr, unsigned long interp_load_addr) 146 { 147 unsigned long p = bprm->p; 148 int argc = bprm->argc; 149 int envc = bprm->envc; 150 elf_addr_t __user *argv; 151 elf_addr_t __user *envp; 152 elf_addr_t __user *sp; 153 elf_addr_t __user *u_platform; 154 elf_addr_t __user *u_base_platform; 155 elf_addr_t __user *u_rand_bytes; 156 const char *k_platform = ELF_PLATFORM; 157 const char *k_base_platform = ELF_BASE_PLATFORM; 158 unsigned char k_rand_bytes[16]; 159 int items; 160 elf_addr_t *elf_info; 161 int ei_index = 0; 162 const struct cred *cred = current_cred(); 163 struct vm_area_struct *vma; 164 165 /* 166 * In some cases (e.g. Hyper-Threading), we want to avoid L1 167 * evictions by the processes running on the same package. One 168 * thing we can do is to shuffle the initial stack for them. 169 */ 170 171 p = arch_align_stack(p); 172 173 /* 174 * If this architecture has a platform capability string, copy it 175 * to userspace. In some cases (Sparc), this info is impossible 176 * for userspace to get any other way, in others (i386) it is 177 * merely difficult. 178 */ 179 u_platform = NULL; 180 if (k_platform) { 181 size_t len = strlen(k_platform) + 1; 182 183 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 184 if (__copy_to_user(u_platform, k_platform, len)) 185 return -EFAULT; 186 } 187 188 /* 189 * If this architecture has a "base" platform capability 190 * string, copy it to userspace. 191 */ 192 u_base_platform = NULL; 193 if (k_base_platform) { 194 size_t len = strlen(k_base_platform) + 1; 195 196 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 197 if (__copy_to_user(u_base_platform, k_base_platform, len)) 198 return -EFAULT; 199 } 200 201 /* 202 * Generate 16 random bytes for userspace PRNG seeding. 203 */ 204 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); 205 u_rand_bytes = (elf_addr_t __user *) 206 STACK_ALLOC(p, sizeof(k_rand_bytes)); 207 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) 208 return -EFAULT; 209 210 /* Create the ELF interpreter info */ 211 elf_info = (elf_addr_t *)current->mm->saved_auxv; 212 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ 213 #define NEW_AUX_ENT(id, val) \ 214 do { \ 215 elf_info[ei_index++] = id; \ 216 elf_info[ei_index++] = val; \ 217 } while (0) 218 219 #ifdef ARCH_DLINFO 220 /* 221 * ARCH_DLINFO must come first so PPC can do its special alignment of 222 * AUXV. 223 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in 224 * ARCH_DLINFO changes 225 */ 226 ARCH_DLINFO; 227 #endif 228 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 229 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); 230 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 231 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); 232 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 233 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); 234 NEW_AUX_ENT(AT_BASE, interp_load_addr); 235 NEW_AUX_ENT(AT_FLAGS, 0); 236 NEW_AUX_ENT(AT_ENTRY, exec->e_entry); 237 NEW_AUX_ENT(AT_UID, cred->uid); 238 NEW_AUX_ENT(AT_EUID, cred->euid); 239 NEW_AUX_ENT(AT_GID, cred->gid); 240 NEW_AUX_ENT(AT_EGID, cred->egid); 241 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 242 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); 243 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 244 if (k_platform) { 245 NEW_AUX_ENT(AT_PLATFORM, 246 (elf_addr_t)(unsigned long)u_platform); 247 } 248 if (k_base_platform) { 249 NEW_AUX_ENT(AT_BASE_PLATFORM, 250 (elf_addr_t)(unsigned long)u_base_platform); 251 } 252 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 253 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 254 } 255 #undef NEW_AUX_ENT 256 /* AT_NULL is zero; clear the rest too */ 257 memset(&elf_info[ei_index], 0, 258 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); 259 260 /* And advance past the AT_NULL entry. */ 261 ei_index += 2; 262 263 sp = STACK_ADD(p, ei_index); 264 265 items = (argc + 1) + (envc + 1) + 1; 266 bprm->p = STACK_ROUND(sp, items); 267 268 /* Point sp at the lowest address on the stack */ 269 #ifdef CONFIG_STACK_GROWSUP 270 sp = (elf_addr_t __user *)bprm->p - items - ei_index; 271 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ 272 #else 273 sp = (elf_addr_t __user *)bprm->p; 274 #endif 275 276 277 /* 278 * Grow the stack manually; some architectures have a limit on how 279 * far ahead a user-space access may be in order to grow the stack. 280 */ 281 vma = find_extend_vma(current->mm, bprm->p); 282 if (!vma) 283 return -EFAULT; 284 285 /* Now, let's put argc (and argv, envp if appropriate) on the stack */ 286 if (__put_user(argc, sp++)) 287 return -EFAULT; 288 argv = sp; 289 envp = argv + argc + 1; 290 291 /* Populate argv and envp */ 292 p = current->mm->arg_end = current->mm->arg_start; 293 while (argc-- > 0) { 294 size_t len; 295 if (__put_user((elf_addr_t)p, argv++)) 296 return -EFAULT; 297 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 298 if (!len || len > MAX_ARG_STRLEN) 299 return -EINVAL; 300 p += len; 301 } 302 if (__put_user(0, argv)) 303 return -EFAULT; 304 current->mm->arg_end = current->mm->env_start = p; 305 while (envc-- > 0) { 306 size_t len; 307 if (__put_user((elf_addr_t)p, envp++)) 308 return -EFAULT; 309 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 310 if (!len || len > MAX_ARG_STRLEN) 311 return -EINVAL; 312 p += len; 313 } 314 if (__put_user(0, envp)) 315 return -EFAULT; 316 current->mm->env_end = p; 317 318 /* Put the elf_info on the stack in the right place. */ 319 sp = (elf_addr_t __user *)envp + 1; 320 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) 321 return -EFAULT; 322 return 0; 323 } 324 325 #ifndef elf_map 326 327 static unsigned long elf_map(struct file *filep, unsigned long addr, 328 struct elf_phdr *eppnt, int prot, int type, 329 unsigned long total_size) 330 { 331 unsigned long map_addr; 332 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); 333 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); 334 addr = ELF_PAGESTART(addr); 335 size = ELF_PAGEALIGN(size); 336 337 /* mmap() will return -EINVAL if given a zero size, but a 338 * segment with zero filesize is perfectly valid */ 339 if (!size) 340 return addr; 341 342 down_write(¤t->mm->mmap_sem); 343 /* 344 * total_size is the size of the ELF (interpreter) image. 345 * The _first_ mmap needs to know the full size, otherwise 346 * randomization might put this image into an overlapping 347 * position with the ELF binary image. (since size < total_size) 348 * So we first map the 'big' image - and unmap the remainder at 349 * the end. (which unmap is needed for ELF images with holes.) 350 */ 351 if (total_size) { 352 total_size = ELF_PAGEALIGN(total_size); 353 map_addr = do_mmap(filep, addr, total_size, prot, type, off); 354 if (!BAD_ADDR(map_addr)) 355 do_munmap(current->mm, map_addr+size, total_size-size); 356 } else 357 map_addr = do_mmap(filep, addr, size, prot, type, off); 358 359 up_write(¤t->mm->mmap_sem); 360 return(map_addr); 361 } 362 363 #endif /* !elf_map */ 364 365 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) 366 { 367 int i, first_idx = -1, last_idx = -1; 368 369 for (i = 0; i < nr; i++) { 370 if (cmds[i].p_type == PT_LOAD) { 371 last_idx = i; 372 if (first_idx == -1) 373 first_idx = i; 374 } 375 } 376 if (first_idx == -1) 377 return 0; 378 379 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - 380 ELF_PAGESTART(cmds[first_idx].p_vaddr); 381 } 382 383 384 /* This is much more generalized than the library routine read function, 385 so we keep this separate. Technically the library read function 386 is only provided so that we can read a.out libraries that have 387 an ELF header */ 388 389 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, 390 struct file *interpreter, unsigned long *interp_map_addr, 391 unsigned long no_base) 392 { 393 struct elf_phdr *elf_phdata; 394 struct elf_phdr *eppnt; 395 unsigned long load_addr = 0; 396 int load_addr_set = 0; 397 unsigned long last_bss = 0, elf_bss = 0; 398 unsigned long error = ~0UL; 399 unsigned long total_size; 400 int retval, i, size; 401 402 /* First of all, some simple consistency checks */ 403 if (interp_elf_ex->e_type != ET_EXEC && 404 interp_elf_ex->e_type != ET_DYN) 405 goto out; 406 if (!elf_check_arch(interp_elf_ex)) 407 goto out; 408 if (!interpreter->f_op || !interpreter->f_op->mmap) 409 goto out; 410 411 /* 412 * If the size of this structure has changed, then punt, since 413 * we will be doing the wrong thing. 414 */ 415 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) 416 goto out; 417 if (interp_elf_ex->e_phnum < 1 || 418 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) 419 goto out; 420 421 /* Now read in all of the header information */ 422 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; 423 if (size > ELF_MIN_ALIGN) 424 goto out; 425 elf_phdata = kmalloc(size, GFP_KERNEL); 426 if (!elf_phdata) 427 goto out; 428 429 retval = kernel_read(interpreter, interp_elf_ex->e_phoff, 430 (char *)elf_phdata,size); 431 error = -EIO; 432 if (retval != size) { 433 if (retval < 0) 434 error = retval; 435 goto out_close; 436 } 437 438 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); 439 if (!total_size) { 440 error = -EINVAL; 441 goto out_close; 442 } 443 444 eppnt = elf_phdata; 445 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { 446 if (eppnt->p_type == PT_LOAD) { 447 int elf_type = MAP_PRIVATE | MAP_DENYWRITE; 448 int elf_prot = 0; 449 unsigned long vaddr = 0; 450 unsigned long k, map_addr; 451 452 if (eppnt->p_flags & PF_R) 453 elf_prot = PROT_READ; 454 if (eppnt->p_flags & PF_W) 455 elf_prot |= PROT_WRITE; 456 if (eppnt->p_flags & PF_X) 457 elf_prot |= PROT_EXEC; 458 vaddr = eppnt->p_vaddr; 459 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) 460 elf_type |= MAP_FIXED; 461 else if (no_base && interp_elf_ex->e_type == ET_DYN) 462 load_addr = -vaddr; 463 464 map_addr = elf_map(interpreter, load_addr + vaddr, 465 eppnt, elf_prot, elf_type, total_size); 466 total_size = 0; 467 if (!*interp_map_addr) 468 *interp_map_addr = map_addr; 469 error = map_addr; 470 if (BAD_ADDR(map_addr)) 471 goto out_close; 472 473 if (!load_addr_set && 474 interp_elf_ex->e_type == ET_DYN) { 475 load_addr = map_addr - ELF_PAGESTART(vaddr); 476 load_addr_set = 1; 477 } 478 479 /* 480 * Check to see if the section's size will overflow the 481 * allowed task size. Note that p_filesz must always be 482 * <= p_memsize so it's only necessary to check p_memsz. 483 */ 484 k = load_addr + eppnt->p_vaddr; 485 if (BAD_ADDR(k) || 486 eppnt->p_filesz > eppnt->p_memsz || 487 eppnt->p_memsz > TASK_SIZE || 488 TASK_SIZE - eppnt->p_memsz < k) { 489 error = -ENOMEM; 490 goto out_close; 491 } 492 493 /* 494 * Find the end of the file mapping for this phdr, and 495 * keep track of the largest address we see for this. 496 */ 497 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; 498 if (k > elf_bss) 499 elf_bss = k; 500 501 /* 502 * Do the same thing for the memory mapping - between 503 * elf_bss and last_bss is the bss section. 504 */ 505 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; 506 if (k > last_bss) 507 last_bss = k; 508 } 509 } 510 511 /* 512 * Now fill out the bss section. First pad the last page up 513 * to the page boundary, and then perform a mmap to make sure 514 * that there are zero-mapped pages up to and including the 515 * last bss page. 516 */ 517 if (padzero(elf_bss)) { 518 error = -EFAULT; 519 goto out_close; 520 } 521 522 /* What we have mapped so far */ 523 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); 524 525 /* Map the last of the bss segment */ 526 if (last_bss > elf_bss) { 527 down_write(¤t->mm->mmap_sem); 528 error = do_brk(elf_bss, last_bss - elf_bss); 529 up_write(¤t->mm->mmap_sem); 530 if (BAD_ADDR(error)) 531 goto out_close; 532 } 533 534 error = load_addr; 535 536 out_close: 537 kfree(elf_phdata); 538 out: 539 return error; 540 } 541 542 /* 543 * These are the functions used to load ELF style executables and shared 544 * libraries. There is no binary dependent code anywhere else. 545 */ 546 547 #define INTERPRETER_NONE 0 548 #define INTERPRETER_ELF 2 549 550 #ifndef STACK_RND_MASK 551 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ 552 #endif 553 554 static unsigned long randomize_stack_top(unsigned long stack_top) 555 { 556 unsigned int random_variable = 0; 557 558 if ((current->flags & PF_RANDOMIZE) && 559 !(current->personality & ADDR_NO_RANDOMIZE)) { 560 random_variable = get_random_int() & STACK_RND_MASK; 561 random_variable <<= PAGE_SHIFT; 562 } 563 #ifdef CONFIG_STACK_GROWSUP 564 return PAGE_ALIGN(stack_top) + random_variable; 565 #else 566 return PAGE_ALIGN(stack_top) - random_variable; 567 #endif 568 } 569 570 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) 571 { 572 struct file *interpreter = NULL; /* to shut gcc up */ 573 unsigned long load_addr = 0, load_bias = 0; 574 int load_addr_set = 0; 575 char * elf_interpreter = NULL; 576 unsigned long error; 577 struct elf_phdr *elf_ppnt, *elf_phdata; 578 unsigned long elf_bss, elf_brk; 579 int elf_exec_fileno; 580 int retval, i; 581 unsigned int size; 582 unsigned long elf_entry; 583 unsigned long interp_load_addr = 0; 584 unsigned long start_code, end_code, start_data, end_data; 585 unsigned long reloc_func_desc = 0; 586 int executable_stack = EXSTACK_DEFAULT; 587 unsigned long def_flags = 0; 588 struct { 589 struct elfhdr elf_ex; 590 struct elfhdr interp_elf_ex; 591 } *loc; 592 593 loc = kmalloc(sizeof(*loc), GFP_KERNEL); 594 if (!loc) { 595 retval = -ENOMEM; 596 goto out_ret; 597 } 598 599 /* Get the exec-header */ 600 loc->elf_ex = *((struct elfhdr *)bprm->buf); 601 602 retval = -ENOEXEC; 603 /* First of all, some simple consistency checks */ 604 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 605 goto out; 606 607 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) 608 goto out; 609 if (!elf_check_arch(&loc->elf_ex)) 610 goto out; 611 if (!bprm->file->f_op||!bprm->file->f_op->mmap) 612 goto out; 613 614 /* Now read in all of the header information */ 615 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) 616 goto out; 617 if (loc->elf_ex.e_phnum < 1 || 618 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) 619 goto out; 620 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); 621 retval = -ENOMEM; 622 elf_phdata = kmalloc(size, GFP_KERNEL); 623 if (!elf_phdata) 624 goto out; 625 626 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, 627 (char *)elf_phdata, size); 628 if (retval != size) { 629 if (retval >= 0) 630 retval = -EIO; 631 goto out_free_ph; 632 } 633 634 retval = get_unused_fd(); 635 if (retval < 0) 636 goto out_free_ph; 637 get_file(bprm->file); 638 fd_install(elf_exec_fileno = retval, bprm->file); 639 640 elf_ppnt = elf_phdata; 641 elf_bss = 0; 642 elf_brk = 0; 643 644 start_code = ~0UL; 645 end_code = 0; 646 start_data = 0; 647 end_data = 0; 648 649 for (i = 0; i < loc->elf_ex.e_phnum; i++) { 650 if (elf_ppnt->p_type == PT_INTERP) { 651 /* This is the program interpreter used for 652 * shared libraries - for now assume that this 653 * is an a.out format binary 654 */ 655 retval = -ENOEXEC; 656 if (elf_ppnt->p_filesz > PATH_MAX || 657 elf_ppnt->p_filesz < 2) 658 goto out_free_file; 659 660 retval = -ENOMEM; 661 elf_interpreter = kmalloc(elf_ppnt->p_filesz, 662 GFP_KERNEL); 663 if (!elf_interpreter) 664 goto out_free_file; 665 666 retval = kernel_read(bprm->file, elf_ppnt->p_offset, 667 elf_interpreter, 668 elf_ppnt->p_filesz); 669 if (retval != elf_ppnt->p_filesz) { 670 if (retval >= 0) 671 retval = -EIO; 672 goto out_free_interp; 673 } 674 /* make sure path is NULL terminated */ 675 retval = -ENOEXEC; 676 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') 677 goto out_free_interp; 678 679 /* 680 * The early SET_PERSONALITY here is so that the lookup 681 * for the interpreter happens in the namespace of the 682 * to-be-execed image. SET_PERSONALITY can select an 683 * alternate root. 684 * 685 * However, SET_PERSONALITY is NOT allowed to switch 686 * this task into the new images's memory mapping 687 * policy - that is, TASK_SIZE must still evaluate to 688 * that which is appropriate to the execing application. 689 * This is because exit_mmap() needs to have TASK_SIZE 690 * evaluate to the size of the old image. 691 * 692 * So if (say) a 64-bit application is execing a 32-bit 693 * application it is the architecture's responsibility 694 * to defer changing the value of TASK_SIZE until the 695 * switch really is going to happen - do this in 696 * flush_thread(). - akpm 697 */ 698 SET_PERSONALITY(loc->elf_ex); 699 700 interpreter = open_exec(elf_interpreter); 701 retval = PTR_ERR(interpreter); 702 if (IS_ERR(interpreter)) 703 goto out_free_interp; 704 705 /* 706 * If the binary is not readable then enforce 707 * mm->dumpable = 0 regardless of the interpreter's 708 * permissions. 709 */ 710 if (file_permission(interpreter, MAY_READ) < 0) 711 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; 712 713 retval = kernel_read(interpreter, 0, bprm->buf, 714 BINPRM_BUF_SIZE); 715 if (retval != BINPRM_BUF_SIZE) { 716 if (retval >= 0) 717 retval = -EIO; 718 goto out_free_dentry; 719 } 720 721 /* Get the exec headers */ 722 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); 723 break; 724 } 725 elf_ppnt++; 726 } 727 728 elf_ppnt = elf_phdata; 729 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) 730 if (elf_ppnt->p_type == PT_GNU_STACK) { 731 if (elf_ppnt->p_flags & PF_X) 732 executable_stack = EXSTACK_ENABLE_X; 733 else 734 executable_stack = EXSTACK_DISABLE_X; 735 break; 736 } 737 738 /* Some simple consistency checks for the interpreter */ 739 if (elf_interpreter) { 740 retval = -ELIBBAD; 741 /* Not an ELF interpreter */ 742 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 743 goto out_free_dentry; 744 /* Verify the interpreter has a valid arch */ 745 if (!elf_check_arch(&loc->interp_elf_ex)) 746 goto out_free_dentry; 747 } else { 748 /* Executables without an interpreter also need a personality */ 749 SET_PERSONALITY(loc->elf_ex); 750 } 751 752 /* Flush all traces of the currently running executable */ 753 retval = flush_old_exec(bprm); 754 if (retval) 755 goto out_free_dentry; 756 757 /* OK, This is the point of no return */ 758 current->flags &= ~PF_FORKNOEXEC; 759 current->mm->def_flags = def_flags; 760 761 /* Do this immediately, since STACK_TOP as used in setup_arg_pages 762 may depend on the personality. */ 763 SET_PERSONALITY(loc->elf_ex); 764 if (elf_read_implies_exec(loc->elf_ex, executable_stack)) 765 current->personality |= READ_IMPLIES_EXEC; 766 767 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 768 current->flags |= PF_RANDOMIZE; 769 arch_pick_mmap_layout(current->mm); 770 771 /* Do this so that we can load the interpreter, if need be. We will 772 change some of these later */ 773 current->mm->free_area_cache = current->mm->mmap_base; 774 current->mm->cached_hole_size = 0; 775 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), 776 executable_stack); 777 if (retval < 0) { 778 send_sig(SIGKILL, current, 0); 779 goto out_free_dentry; 780 } 781 782 current->mm->start_stack = bprm->p; 783 784 /* Now we do a little grungy work by mmaping the ELF image into 785 the correct location in memory. */ 786 for(i = 0, elf_ppnt = elf_phdata; 787 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { 788 int elf_prot = 0, elf_flags; 789 unsigned long k, vaddr; 790 791 if (elf_ppnt->p_type != PT_LOAD) 792 continue; 793 794 if (unlikely (elf_brk > elf_bss)) { 795 unsigned long nbyte; 796 797 /* There was a PT_LOAD segment with p_memsz > p_filesz 798 before this one. Map anonymous pages, if needed, 799 and clear the area. */ 800 retval = set_brk (elf_bss + load_bias, 801 elf_brk + load_bias); 802 if (retval) { 803 send_sig(SIGKILL, current, 0); 804 goto out_free_dentry; 805 } 806 nbyte = ELF_PAGEOFFSET(elf_bss); 807 if (nbyte) { 808 nbyte = ELF_MIN_ALIGN - nbyte; 809 if (nbyte > elf_brk - elf_bss) 810 nbyte = elf_brk - elf_bss; 811 if (clear_user((void __user *)elf_bss + 812 load_bias, nbyte)) { 813 /* 814 * This bss-zeroing can fail if the ELF 815 * file specifies odd protections. So 816 * we don't check the return value 817 */ 818 } 819 } 820 } 821 822 if (elf_ppnt->p_flags & PF_R) 823 elf_prot |= PROT_READ; 824 if (elf_ppnt->p_flags & PF_W) 825 elf_prot |= PROT_WRITE; 826 if (elf_ppnt->p_flags & PF_X) 827 elf_prot |= PROT_EXEC; 828 829 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; 830 831 vaddr = elf_ppnt->p_vaddr; 832 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { 833 elf_flags |= MAP_FIXED; 834 } else if (loc->elf_ex.e_type == ET_DYN) { 835 /* Try and get dynamic programs out of the way of the 836 * default mmap base, as well as whatever program they 837 * might try to exec. This is because the brk will 838 * follow the loader, and is not movable. */ 839 #ifdef CONFIG_X86 840 load_bias = 0; 841 #else 842 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 843 #endif 844 } 845 846 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, 847 elf_prot, elf_flags, 0); 848 if (BAD_ADDR(error)) { 849 send_sig(SIGKILL, current, 0); 850 retval = IS_ERR((void *)error) ? 851 PTR_ERR((void*)error) : -EINVAL; 852 goto out_free_dentry; 853 } 854 855 if (!load_addr_set) { 856 load_addr_set = 1; 857 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); 858 if (loc->elf_ex.e_type == ET_DYN) { 859 load_bias += error - 860 ELF_PAGESTART(load_bias + vaddr); 861 load_addr += load_bias; 862 reloc_func_desc = load_bias; 863 } 864 } 865 k = elf_ppnt->p_vaddr; 866 if (k < start_code) 867 start_code = k; 868 if (start_data < k) 869 start_data = k; 870 871 /* 872 * Check to see if the section's size will overflow the 873 * allowed task size. Note that p_filesz must always be 874 * <= p_memsz so it is only necessary to check p_memsz. 875 */ 876 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || 877 elf_ppnt->p_memsz > TASK_SIZE || 878 TASK_SIZE - elf_ppnt->p_memsz < k) { 879 /* set_brk can never work. Avoid overflows. */ 880 send_sig(SIGKILL, current, 0); 881 retval = -EINVAL; 882 goto out_free_dentry; 883 } 884 885 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; 886 887 if (k > elf_bss) 888 elf_bss = k; 889 if ((elf_ppnt->p_flags & PF_X) && end_code < k) 890 end_code = k; 891 if (end_data < k) 892 end_data = k; 893 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; 894 if (k > elf_brk) 895 elf_brk = k; 896 } 897 898 loc->elf_ex.e_entry += load_bias; 899 elf_bss += load_bias; 900 elf_brk += load_bias; 901 start_code += load_bias; 902 end_code += load_bias; 903 start_data += load_bias; 904 end_data += load_bias; 905 906 /* Calling set_brk effectively mmaps the pages that we need 907 * for the bss and break sections. We must do this before 908 * mapping in the interpreter, to make sure it doesn't wind 909 * up getting placed where the bss needs to go. 910 */ 911 retval = set_brk(elf_bss, elf_brk); 912 if (retval) { 913 send_sig(SIGKILL, current, 0); 914 goto out_free_dentry; 915 } 916 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { 917 send_sig(SIGSEGV, current, 0); 918 retval = -EFAULT; /* Nobody gets to see this, but.. */ 919 goto out_free_dentry; 920 } 921 922 if (elf_interpreter) { 923 unsigned long uninitialized_var(interp_map_addr); 924 925 elf_entry = load_elf_interp(&loc->interp_elf_ex, 926 interpreter, 927 &interp_map_addr, 928 load_bias); 929 if (!IS_ERR((void *)elf_entry)) { 930 /* 931 * load_elf_interp() returns relocation 932 * adjustment 933 */ 934 interp_load_addr = elf_entry; 935 elf_entry += loc->interp_elf_ex.e_entry; 936 } 937 if (BAD_ADDR(elf_entry)) { 938 force_sig(SIGSEGV, current); 939 retval = IS_ERR((void *)elf_entry) ? 940 (int)elf_entry : -EINVAL; 941 goto out_free_dentry; 942 } 943 reloc_func_desc = interp_load_addr; 944 945 allow_write_access(interpreter); 946 fput(interpreter); 947 kfree(elf_interpreter); 948 } else { 949 elf_entry = loc->elf_ex.e_entry; 950 if (BAD_ADDR(elf_entry)) { 951 force_sig(SIGSEGV, current); 952 retval = -EINVAL; 953 goto out_free_dentry; 954 } 955 } 956 957 kfree(elf_phdata); 958 959 sys_close(elf_exec_fileno); 960 961 set_binfmt(&elf_format); 962 963 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 964 retval = arch_setup_additional_pages(bprm, !!elf_interpreter); 965 if (retval < 0) { 966 send_sig(SIGKILL, current, 0); 967 goto out; 968 } 969 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ 970 971 install_exec_creds(bprm); 972 current->flags &= ~PF_FORKNOEXEC; 973 retval = create_elf_tables(bprm, &loc->elf_ex, 974 load_addr, interp_load_addr); 975 if (retval < 0) { 976 send_sig(SIGKILL, current, 0); 977 goto out; 978 } 979 /* N.B. passed_fileno might not be initialized? */ 980 current->mm->end_code = end_code; 981 current->mm->start_code = start_code; 982 current->mm->start_data = start_data; 983 current->mm->end_data = end_data; 984 current->mm->start_stack = bprm->p; 985 986 #ifdef arch_randomize_brk 987 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) 988 current->mm->brk = current->mm->start_brk = 989 arch_randomize_brk(current->mm); 990 #endif 991 992 if (current->personality & MMAP_PAGE_ZERO) { 993 /* Why this, you ask??? Well SVr4 maps page 0 as read-only, 994 and some applications "depend" upon this behavior. 995 Since we do not have the power to recompile these, we 996 emulate the SVr4 behavior. Sigh. */ 997 down_write(¤t->mm->mmap_sem); 998 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, 999 MAP_FIXED | MAP_PRIVATE, 0); 1000 up_write(¤t->mm->mmap_sem); 1001 } 1002 1003 #ifdef ELF_PLAT_INIT 1004 /* 1005 * The ABI may specify that certain registers be set up in special 1006 * ways (on i386 %edx is the address of a DT_FINI function, for 1007 * example. In addition, it may also specify (eg, PowerPC64 ELF) 1008 * that the e_entry field is the address of the function descriptor 1009 * for the startup routine, rather than the address of the startup 1010 * routine itself. This macro performs whatever initialization to 1011 * the regs structure is required as well as any relocations to the 1012 * function descriptor entries when executing dynamically links apps. 1013 */ 1014 ELF_PLAT_INIT(regs, reloc_func_desc); 1015 #endif 1016 1017 start_thread(regs, elf_entry, bprm->p); 1018 retval = 0; 1019 out: 1020 kfree(loc); 1021 out_ret: 1022 return retval; 1023 1024 /* error cleanup */ 1025 out_free_dentry: 1026 allow_write_access(interpreter); 1027 if (interpreter) 1028 fput(interpreter); 1029 out_free_interp: 1030 kfree(elf_interpreter); 1031 out_free_file: 1032 sys_close(elf_exec_fileno); 1033 out_free_ph: 1034 kfree(elf_phdata); 1035 goto out; 1036 } 1037 1038 /* This is really simpleminded and specialized - we are loading an 1039 a.out library that is given an ELF header. */ 1040 static int load_elf_library(struct file *file) 1041 { 1042 struct elf_phdr *elf_phdata; 1043 struct elf_phdr *eppnt; 1044 unsigned long elf_bss, bss, len; 1045 int retval, error, i, j; 1046 struct elfhdr elf_ex; 1047 1048 error = -ENOEXEC; 1049 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); 1050 if (retval != sizeof(elf_ex)) 1051 goto out; 1052 1053 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 1054 goto out; 1055 1056 /* First of all, some simple consistency checks */ 1057 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || 1058 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap) 1059 goto out; 1060 1061 /* Now read in all of the header information */ 1062 1063 j = sizeof(struct elf_phdr) * elf_ex.e_phnum; 1064 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ 1065 1066 error = -ENOMEM; 1067 elf_phdata = kmalloc(j, GFP_KERNEL); 1068 if (!elf_phdata) 1069 goto out; 1070 1071 eppnt = elf_phdata; 1072 error = -ENOEXEC; 1073 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); 1074 if (retval != j) 1075 goto out_free_ph; 1076 1077 for (j = 0, i = 0; i<elf_ex.e_phnum; i++) 1078 if ((eppnt + i)->p_type == PT_LOAD) 1079 j++; 1080 if (j != 1) 1081 goto out_free_ph; 1082 1083 while (eppnt->p_type != PT_LOAD) 1084 eppnt++; 1085 1086 /* Now use mmap to map the library into memory. */ 1087 down_write(¤t->mm->mmap_sem); 1088 error = do_mmap(file, 1089 ELF_PAGESTART(eppnt->p_vaddr), 1090 (eppnt->p_filesz + 1091 ELF_PAGEOFFSET(eppnt->p_vaddr)), 1092 PROT_READ | PROT_WRITE | PROT_EXEC, 1093 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, 1094 (eppnt->p_offset - 1095 ELF_PAGEOFFSET(eppnt->p_vaddr))); 1096 up_write(¤t->mm->mmap_sem); 1097 if (error != ELF_PAGESTART(eppnt->p_vaddr)) 1098 goto out_free_ph; 1099 1100 elf_bss = eppnt->p_vaddr + eppnt->p_filesz; 1101 if (padzero(elf_bss)) { 1102 error = -EFAULT; 1103 goto out_free_ph; 1104 } 1105 1106 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + 1107 ELF_MIN_ALIGN - 1); 1108 bss = eppnt->p_memsz + eppnt->p_vaddr; 1109 if (bss > len) { 1110 down_write(¤t->mm->mmap_sem); 1111 do_brk(len, bss - len); 1112 up_write(¤t->mm->mmap_sem); 1113 } 1114 error = 0; 1115 1116 out_free_ph: 1117 kfree(elf_phdata); 1118 out: 1119 return error; 1120 } 1121 1122 /* 1123 * Note that some platforms still use traditional core dumps and not 1124 * the ELF core dump. Each platform can select it as appropriate. 1125 */ 1126 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 1127 1128 /* 1129 * ELF core dumper 1130 * 1131 * Modelled on fs/exec.c:aout_core_dump() 1132 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1133 */ 1134 /* 1135 * These are the only things you should do on a core-file: use only these 1136 * functions to write out all the necessary info. 1137 */ 1138 static int dump_write(struct file *file, const void *addr, int nr) 1139 { 1140 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 1141 } 1142 1143 static int dump_seek(struct file *file, loff_t off) 1144 { 1145 if (file->f_op->llseek && file->f_op->llseek != no_llseek) { 1146 if (file->f_op->llseek(file, off, SEEK_CUR) < 0) 1147 return 0; 1148 } else { 1149 char *buf = (char *)get_zeroed_page(GFP_KERNEL); 1150 if (!buf) 1151 return 0; 1152 while (off > 0) { 1153 unsigned long n = off; 1154 if (n > PAGE_SIZE) 1155 n = PAGE_SIZE; 1156 if (!dump_write(file, buf, n)) 1157 return 0; 1158 off -= n; 1159 } 1160 free_page((unsigned long)buf); 1161 } 1162 return 1; 1163 } 1164 1165 /* 1166 * Decide what to dump of a segment, part, all or none. 1167 */ 1168 static unsigned long vma_dump_size(struct vm_area_struct *vma, 1169 unsigned long mm_flags) 1170 { 1171 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) 1172 1173 /* The vma can be set up to tell us the answer directly. */ 1174 if (vma->vm_flags & VM_ALWAYSDUMP) 1175 goto whole; 1176 1177 /* Hugetlb memory check */ 1178 if (vma->vm_flags & VM_HUGETLB) { 1179 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) 1180 goto whole; 1181 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) 1182 goto whole; 1183 } 1184 1185 /* Do not dump I/O mapped devices or special mappings */ 1186 if (vma->vm_flags & (VM_IO | VM_RESERVED)) 1187 return 0; 1188 1189 /* By default, dump shared memory if mapped from an anonymous file. */ 1190 if (vma->vm_flags & VM_SHARED) { 1191 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ? 1192 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) 1193 goto whole; 1194 return 0; 1195 } 1196 1197 /* Dump segments that have been written to. */ 1198 if (vma->anon_vma && FILTER(ANON_PRIVATE)) 1199 goto whole; 1200 if (vma->vm_file == NULL) 1201 return 0; 1202 1203 if (FILTER(MAPPED_PRIVATE)) 1204 goto whole; 1205 1206 /* 1207 * If this looks like the beginning of a DSO or executable mapping, 1208 * check for an ELF header. If we find one, dump the first page to 1209 * aid in determining what was mapped here. 1210 */ 1211 if (FILTER(ELF_HEADERS) && 1212 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { 1213 u32 __user *header = (u32 __user *) vma->vm_start; 1214 u32 word; 1215 mm_segment_t fs = get_fs(); 1216 /* 1217 * Doing it this way gets the constant folded by GCC. 1218 */ 1219 union { 1220 u32 cmp; 1221 char elfmag[SELFMAG]; 1222 } magic; 1223 BUILD_BUG_ON(SELFMAG != sizeof word); 1224 magic.elfmag[EI_MAG0] = ELFMAG0; 1225 magic.elfmag[EI_MAG1] = ELFMAG1; 1226 magic.elfmag[EI_MAG2] = ELFMAG2; 1227 magic.elfmag[EI_MAG3] = ELFMAG3; 1228 /* 1229 * Switch to the user "segment" for get_user(), 1230 * then put back what elf_core_dump() had in place. 1231 */ 1232 set_fs(USER_DS); 1233 if (unlikely(get_user(word, header))) 1234 word = 0; 1235 set_fs(fs); 1236 if (word == magic.cmp) 1237 return PAGE_SIZE; 1238 } 1239 1240 #undef FILTER 1241 1242 return 0; 1243 1244 whole: 1245 return vma->vm_end - vma->vm_start; 1246 } 1247 1248 /* An ELF note in memory */ 1249 struct memelfnote 1250 { 1251 const char *name; 1252 int type; 1253 unsigned int datasz; 1254 void *data; 1255 }; 1256 1257 static int notesize(struct memelfnote *en) 1258 { 1259 int sz; 1260 1261 sz = sizeof(struct elf_note); 1262 sz += roundup(strlen(en->name) + 1, 4); 1263 sz += roundup(en->datasz, 4); 1264 1265 return sz; 1266 } 1267 1268 #define DUMP_WRITE(addr, nr, foffset) \ 1269 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) 1270 1271 static int alignfile(struct file *file, loff_t *foffset) 1272 { 1273 static const char buf[4] = { 0, }; 1274 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); 1275 return 1; 1276 } 1277 1278 static int writenote(struct memelfnote *men, struct file *file, 1279 loff_t *foffset) 1280 { 1281 struct elf_note en; 1282 en.n_namesz = strlen(men->name) + 1; 1283 en.n_descsz = men->datasz; 1284 en.n_type = men->type; 1285 1286 DUMP_WRITE(&en, sizeof(en), foffset); 1287 DUMP_WRITE(men->name, en.n_namesz, foffset); 1288 if (!alignfile(file, foffset)) 1289 return 0; 1290 DUMP_WRITE(men->data, men->datasz, foffset); 1291 if (!alignfile(file, foffset)) 1292 return 0; 1293 1294 return 1; 1295 } 1296 #undef DUMP_WRITE 1297 1298 #define DUMP_WRITE(addr, nr) \ 1299 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ 1300 goto end_coredump; 1301 #define DUMP_SEEK(off) \ 1302 if (!dump_seek(file, (off))) \ 1303 goto end_coredump; 1304 1305 static void fill_elf_header(struct elfhdr *elf, int segs, 1306 u16 machine, u32 flags, u8 osabi) 1307 { 1308 memset(elf, 0, sizeof(*elf)); 1309 1310 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1311 elf->e_ident[EI_CLASS] = ELF_CLASS; 1312 elf->e_ident[EI_DATA] = ELF_DATA; 1313 elf->e_ident[EI_VERSION] = EV_CURRENT; 1314 elf->e_ident[EI_OSABI] = ELF_OSABI; 1315 1316 elf->e_type = ET_CORE; 1317 elf->e_machine = machine; 1318 elf->e_version = EV_CURRENT; 1319 elf->e_phoff = sizeof(struct elfhdr); 1320 elf->e_flags = flags; 1321 elf->e_ehsize = sizeof(struct elfhdr); 1322 elf->e_phentsize = sizeof(struct elf_phdr); 1323 elf->e_phnum = segs; 1324 1325 return; 1326 } 1327 1328 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1329 { 1330 phdr->p_type = PT_NOTE; 1331 phdr->p_offset = offset; 1332 phdr->p_vaddr = 0; 1333 phdr->p_paddr = 0; 1334 phdr->p_filesz = sz; 1335 phdr->p_memsz = 0; 1336 phdr->p_flags = 0; 1337 phdr->p_align = 0; 1338 return; 1339 } 1340 1341 static void fill_note(struct memelfnote *note, const char *name, int type, 1342 unsigned int sz, void *data) 1343 { 1344 note->name = name; 1345 note->type = type; 1346 note->datasz = sz; 1347 note->data = data; 1348 return; 1349 } 1350 1351 /* 1352 * fill up all the fields in prstatus from the given task struct, except 1353 * registers which need to be filled up separately. 1354 */ 1355 static void fill_prstatus(struct elf_prstatus *prstatus, 1356 struct task_struct *p, long signr) 1357 { 1358 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1359 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1360 prstatus->pr_sighold = p->blocked.sig[0]; 1361 prstatus->pr_pid = task_pid_vnr(p); 1362 prstatus->pr_ppid = task_pid_vnr(p->real_parent); 1363 prstatus->pr_pgrp = task_pgrp_vnr(p); 1364 prstatus->pr_sid = task_session_vnr(p); 1365 if (thread_group_leader(p)) { 1366 struct task_cputime cputime; 1367 1368 /* 1369 * This is the record for the group leader. It shows the 1370 * group-wide total, not its individual thread total. 1371 */ 1372 thread_group_cputime(p, &cputime); 1373 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1374 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1375 } else { 1376 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1377 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1378 } 1379 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1380 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1381 } 1382 1383 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1384 struct mm_struct *mm) 1385 { 1386 const struct cred *cred; 1387 unsigned int i, len; 1388 1389 /* first copy the parameters from user space */ 1390 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1391 1392 len = mm->arg_end - mm->arg_start; 1393 if (len >= ELF_PRARGSZ) 1394 len = ELF_PRARGSZ-1; 1395 if (copy_from_user(&psinfo->pr_psargs, 1396 (const char __user *)mm->arg_start, len)) 1397 return -EFAULT; 1398 for(i = 0; i < len; i++) 1399 if (psinfo->pr_psargs[i] == 0) 1400 psinfo->pr_psargs[i] = ' '; 1401 psinfo->pr_psargs[len] = 0; 1402 1403 psinfo->pr_pid = task_pid_vnr(p); 1404 psinfo->pr_ppid = task_pid_vnr(p->real_parent); 1405 psinfo->pr_pgrp = task_pgrp_vnr(p); 1406 psinfo->pr_sid = task_session_vnr(p); 1407 1408 i = p->state ? ffz(~p->state) + 1 : 0; 1409 psinfo->pr_state = i; 1410 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1411 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1412 psinfo->pr_nice = task_nice(p); 1413 psinfo->pr_flag = p->flags; 1414 rcu_read_lock(); 1415 cred = __task_cred(p); 1416 SET_UID(psinfo->pr_uid, cred->uid); 1417 SET_GID(psinfo->pr_gid, cred->gid); 1418 rcu_read_unlock(); 1419 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1420 1421 return 0; 1422 } 1423 1424 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) 1425 { 1426 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; 1427 int i = 0; 1428 do 1429 i += 2; 1430 while (auxv[i - 2] != AT_NULL); 1431 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1432 } 1433 1434 #ifdef CORE_DUMP_USE_REGSET 1435 #include <linux/regset.h> 1436 1437 struct elf_thread_core_info { 1438 struct elf_thread_core_info *next; 1439 struct task_struct *task; 1440 struct elf_prstatus prstatus; 1441 struct memelfnote notes[0]; 1442 }; 1443 1444 struct elf_note_info { 1445 struct elf_thread_core_info *thread; 1446 struct memelfnote psinfo; 1447 struct memelfnote auxv; 1448 size_t size; 1449 int thread_notes; 1450 }; 1451 1452 /* 1453 * When a regset has a writeback hook, we call it on each thread before 1454 * dumping user memory. On register window machines, this makes sure the 1455 * user memory backing the register data is up to date before we read it. 1456 */ 1457 static void do_thread_regset_writeback(struct task_struct *task, 1458 const struct user_regset *regset) 1459 { 1460 if (regset->writeback) 1461 regset->writeback(task, regset, 1); 1462 } 1463 1464 static int fill_thread_core_info(struct elf_thread_core_info *t, 1465 const struct user_regset_view *view, 1466 long signr, size_t *total) 1467 { 1468 unsigned int i; 1469 1470 /* 1471 * NT_PRSTATUS is the one special case, because the regset data 1472 * goes into the pr_reg field inside the note contents, rather 1473 * than being the whole note contents. We fill the reset in here. 1474 * We assume that regset 0 is NT_PRSTATUS. 1475 */ 1476 fill_prstatus(&t->prstatus, t->task, signr); 1477 (void) view->regsets[0].get(t->task, &view->regsets[0], 1478 0, sizeof(t->prstatus.pr_reg), 1479 &t->prstatus.pr_reg, NULL); 1480 1481 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, 1482 sizeof(t->prstatus), &t->prstatus); 1483 *total += notesize(&t->notes[0]); 1484 1485 do_thread_regset_writeback(t->task, &view->regsets[0]); 1486 1487 /* 1488 * Each other regset might generate a note too. For each regset 1489 * that has no core_note_type or is inactive, we leave t->notes[i] 1490 * all zero and we'll know to skip writing it later. 1491 */ 1492 for (i = 1; i < view->n; ++i) { 1493 const struct user_regset *regset = &view->regsets[i]; 1494 do_thread_regset_writeback(t->task, regset); 1495 if (regset->core_note_type && 1496 (!regset->active || regset->active(t->task, regset))) { 1497 int ret; 1498 size_t size = regset->n * regset->size; 1499 void *data = kmalloc(size, GFP_KERNEL); 1500 if (unlikely(!data)) 1501 return 0; 1502 ret = regset->get(t->task, regset, 1503 0, size, data, NULL); 1504 if (unlikely(ret)) 1505 kfree(data); 1506 else { 1507 if (regset->core_note_type != NT_PRFPREG) 1508 fill_note(&t->notes[i], "LINUX", 1509 regset->core_note_type, 1510 size, data); 1511 else { 1512 t->prstatus.pr_fpvalid = 1; 1513 fill_note(&t->notes[i], "CORE", 1514 NT_PRFPREG, size, data); 1515 } 1516 *total += notesize(&t->notes[i]); 1517 } 1518 } 1519 } 1520 1521 return 1; 1522 } 1523 1524 static int fill_note_info(struct elfhdr *elf, int phdrs, 1525 struct elf_note_info *info, 1526 long signr, struct pt_regs *regs) 1527 { 1528 struct task_struct *dump_task = current; 1529 const struct user_regset_view *view = task_user_regset_view(dump_task); 1530 struct elf_thread_core_info *t; 1531 struct elf_prpsinfo *psinfo; 1532 struct core_thread *ct; 1533 unsigned int i; 1534 1535 info->size = 0; 1536 info->thread = NULL; 1537 1538 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1539 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1540 1541 if (psinfo == NULL) 1542 return 0; 1543 1544 /* 1545 * Figure out how many notes we're going to need for each thread. 1546 */ 1547 info->thread_notes = 0; 1548 for (i = 0; i < view->n; ++i) 1549 if (view->regsets[i].core_note_type != 0) 1550 ++info->thread_notes; 1551 1552 /* 1553 * Sanity check. We rely on regset 0 being in NT_PRSTATUS, 1554 * since it is our one special case. 1555 */ 1556 if (unlikely(info->thread_notes == 0) || 1557 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { 1558 WARN_ON(1); 1559 return 0; 1560 } 1561 1562 /* 1563 * Initialize the ELF file header. 1564 */ 1565 fill_elf_header(elf, phdrs, 1566 view->e_machine, view->e_flags, view->ei_osabi); 1567 1568 /* 1569 * Allocate a structure for each thread. 1570 */ 1571 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { 1572 t = kzalloc(offsetof(struct elf_thread_core_info, 1573 notes[info->thread_notes]), 1574 GFP_KERNEL); 1575 if (unlikely(!t)) 1576 return 0; 1577 1578 t->task = ct->task; 1579 if (ct->task == dump_task || !info->thread) { 1580 t->next = info->thread; 1581 info->thread = t; 1582 } else { 1583 /* 1584 * Make sure to keep the original task at 1585 * the head of the list. 1586 */ 1587 t->next = info->thread->next; 1588 info->thread->next = t; 1589 } 1590 } 1591 1592 /* 1593 * Now fill in each thread's information. 1594 */ 1595 for (t = info->thread; t != NULL; t = t->next) 1596 if (!fill_thread_core_info(t, view, signr, &info->size)) 1597 return 0; 1598 1599 /* 1600 * Fill in the two process-wide notes. 1601 */ 1602 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); 1603 info->size += notesize(&info->psinfo); 1604 1605 fill_auxv_note(&info->auxv, current->mm); 1606 info->size += notesize(&info->auxv); 1607 1608 return 1; 1609 } 1610 1611 static size_t get_note_info_size(struct elf_note_info *info) 1612 { 1613 return info->size; 1614 } 1615 1616 /* 1617 * Write all the notes for each thread. When writing the first thread, the 1618 * process-wide notes are interleaved after the first thread-specific note. 1619 */ 1620 static int write_note_info(struct elf_note_info *info, 1621 struct file *file, loff_t *foffset) 1622 { 1623 bool first = 1; 1624 struct elf_thread_core_info *t = info->thread; 1625 1626 do { 1627 int i; 1628 1629 if (!writenote(&t->notes[0], file, foffset)) 1630 return 0; 1631 1632 if (first && !writenote(&info->psinfo, file, foffset)) 1633 return 0; 1634 if (first && !writenote(&info->auxv, file, foffset)) 1635 return 0; 1636 1637 for (i = 1; i < info->thread_notes; ++i) 1638 if (t->notes[i].data && 1639 !writenote(&t->notes[i], file, foffset)) 1640 return 0; 1641 1642 first = 0; 1643 t = t->next; 1644 } while (t); 1645 1646 return 1; 1647 } 1648 1649 static void free_note_info(struct elf_note_info *info) 1650 { 1651 struct elf_thread_core_info *threads = info->thread; 1652 while (threads) { 1653 unsigned int i; 1654 struct elf_thread_core_info *t = threads; 1655 threads = t->next; 1656 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); 1657 for (i = 1; i < info->thread_notes; ++i) 1658 kfree(t->notes[i].data); 1659 kfree(t); 1660 } 1661 kfree(info->psinfo.data); 1662 } 1663 1664 #else 1665 1666 /* Here is the structure in which status of each thread is captured. */ 1667 struct elf_thread_status 1668 { 1669 struct list_head list; 1670 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1671 elf_fpregset_t fpu; /* NT_PRFPREG */ 1672 struct task_struct *thread; 1673 #ifdef ELF_CORE_COPY_XFPREGS 1674 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1675 #endif 1676 struct memelfnote notes[3]; 1677 int num_notes; 1678 }; 1679 1680 /* 1681 * In order to add the specific thread information for the elf file format, 1682 * we need to keep a linked list of every threads pr_status and then create 1683 * a single section for them in the final core file. 1684 */ 1685 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1686 { 1687 int sz = 0; 1688 struct task_struct *p = t->thread; 1689 t->num_notes = 0; 1690 1691 fill_prstatus(&t->prstatus, p, signr); 1692 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1693 1694 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1695 &(t->prstatus)); 1696 t->num_notes++; 1697 sz += notesize(&t->notes[0]); 1698 1699 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, 1700 &t->fpu))) { 1701 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1702 &(t->fpu)); 1703 t->num_notes++; 1704 sz += notesize(&t->notes[1]); 1705 } 1706 1707 #ifdef ELF_CORE_COPY_XFPREGS 1708 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1709 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1710 sizeof(t->xfpu), &t->xfpu); 1711 t->num_notes++; 1712 sz += notesize(&t->notes[2]); 1713 } 1714 #endif 1715 return sz; 1716 } 1717 1718 struct elf_note_info { 1719 struct memelfnote *notes; 1720 struct elf_prstatus *prstatus; /* NT_PRSTATUS */ 1721 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ 1722 struct list_head thread_list; 1723 elf_fpregset_t *fpu; 1724 #ifdef ELF_CORE_COPY_XFPREGS 1725 elf_fpxregset_t *xfpu; 1726 #endif 1727 int thread_status_size; 1728 int numnote; 1729 }; 1730 1731 static int fill_note_info(struct elfhdr *elf, int phdrs, 1732 struct elf_note_info *info, 1733 long signr, struct pt_regs *regs) 1734 { 1735 #define NUM_NOTES 6 1736 struct list_head *t; 1737 1738 info->notes = NULL; 1739 info->prstatus = NULL; 1740 info->psinfo = NULL; 1741 info->fpu = NULL; 1742 #ifdef ELF_CORE_COPY_XFPREGS 1743 info->xfpu = NULL; 1744 #endif 1745 INIT_LIST_HEAD(&info->thread_list); 1746 1747 info->notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), 1748 GFP_KERNEL); 1749 if (!info->notes) 1750 return 0; 1751 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); 1752 if (!info->psinfo) 1753 return 0; 1754 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); 1755 if (!info->prstatus) 1756 return 0; 1757 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); 1758 if (!info->fpu) 1759 return 0; 1760 #ifdef ELF_CORE_COPY_XFPREGS 1761 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); 1762 if (!info->xfpu) 1763 return 0; 1764 #endif 1765 1766 info->thread_status_size = 0; 1767 if (signr) { 1768 struct core_thread *ct; 1769 struct elf_thread_status *ets; 1770 1771 for (ct = current->mm->core_state->dumper.next; 1772 ct; ct = ct->next) { 1773 ets = kzalloc(sizeof(*ets), GFP_KERNEL); 1774 if (!ets) 1775 return 0; 1776 1777 ets->thread = ct->task; 1778 list_add(&ets->list, &info->thread_list); 1779 } 1780 1781 list_for_each(t, &info->thread_list) { 1782 int sz; 1783 1784 ets = list_entry(t, struct elf_thread_status, list); 1785 sz = elf_dump_thread_status(signr, ets); 1786 info->thread_status_size += sz; 1787 } 1788 } 1789 /* now collect the dump for the current */ 1790 memset(info->prstatus, 0, sizeof(*info->prstatus)); 1791 fill_prstatus(info->prstatus, current, signr); 1792 elf_core_copy_regs(&info->prstatus->pr_reg, regs); 1793 1794 /* Set up header */ 1795 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI); 1796 1797 /* 1798 * Set up the notes in similar form to SVR4 core dumps made 1799 * with info from their /proc. 1800 */ 1801 1802 fill_note(info->notes + 0, "CORE", NT_PRSTATUS, 1803 sizeof(*info->prstatus), info->prstatus); 1804 fill_psinfo(info->psinfo, current->group_leader, current->mm); 1805 fill_note(info->notes + 1, "CORE", NT_PRPSINFO, 1806 sizeof(*info->psinfo), info->psinfo); 1807 1808 info->numnote = 2; 1809 1810 fill_auxv_note(&info->notes[info->numnote++], current->mm); 1811 1812 /* Try to dump the FPU. */ 1813 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, 1814 info->fpu); 1815 if (info->prstatus->pr_fpvalid) 1816 fill_note(info->notes + info->numnote++, 1817 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); 1818 #ifdef ELF_CORE_COPY_XFPREGS 1819 if (elf_core_copy_task_xfpregs(current, info->xfpu)) 1820 fill_note(info->notes + info->numnote++, 1821 "LINUX", ELF_CORE_XFPREG_TYPE, 1822 sizeof(*info->xfpu), info->xfpu); 1823 #endif 1824 1825 return 1; 1826 1827 #undef NUM_NOTES 1828 } 1829 1830 static size_t get_note_info_size(struct elf_note_info *info) 1831 { 1832 int sz = 0; 1833 int i; 1834 1835 for (i = 0; i < info->numnote; i++) 1836 sz += notesize(info->notes + i); 1837 1838 sz += info->thread_status_size; 1839 1840 return sz; 1841 } 1842 1843 static int write_note_info(struct elf_note_info *info, 1844 struct file *file, loff_t *foffset) 1845 { 1846 int i; 1847 struct list_head *t; 1848 1849 for (i = 0; i < info->numnote; i++) 1850 if (!writenote(info->notes + i, file, foffset)) 1851 return 0; 1852 1853 /* write out the thread status notes section */ 1854 list_for_each(t, &info->thread_list) { 1855 struct elf_thread_status *tmp = 1856 list_entry(t, struct elf_thread_status, list); 1857 1858 for (i = 0; i < tmp->num_notes; i++) 1859 if (!writenote(&tmp->notes[i], file, foffset)) 1860 return 0; 1861 } 1862 1863 return 1; 1864 } 1865 1866 static void free_note_info(struct elf_note_info *info) 1867 { 1868 while (!list_empty(&info->thread_list)) { 1869 struct list_head *tmp = info->thread_list.next; 1870 list_del(tmp); 1871 kfree(list_entry(tmp, struct elf_thread_status, list)); 1872 } 1873 1874 kfree(info->prstatus); 1875 kfree(info->psinfo); 1876 kfree(info->notes); 1877 kfree(info->fpu); 1878 #ifdef ELF_CORE_COPY_XFPREGS 1879 kfree(info->xfpu); 1880 #endif 1881 } 1882 1883 #endif 1884 1885 static struct vm_area_struct *first_vma(struct task_struct *tsk, 1886 struct vm_area_struct *gate_vma) 1887 { 1888 struct vm_area_struct *ret = tsk->mm->mmap; 1889 1890 if (ret) 1891 return ret; 1892 return gate_vma; 1893 } 1894 /* 1895 * Helper function for iterating across a vma list. It ensures that the caller 1896 * will visit `gate_vma' prior to terminating the search. 1897 */ 1898 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, 1899 struct vm_area_struct *gate_vma) 1900 { 1901 struct vm_area_struct *ret; 1902 1903 ret = this_vma->vm_next; 1904 if (ret) 1905 return ret; 1906 if (this_vma == gate_vma) 1907 return NULL; 1908 return gate_vma; 1909 } 1910 1911 /* 1912 * Actual dumper 1913 * 1914 * This is a two-pass process; first we find the offsets of the bits, 1915 * and then they are actually written out. If we run out of core limit 1916 * we just truncate. 1917 */ 1918 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit) 1919 { 1920 int has_dumped = 0; 1921 mm_segment_t fs; 1922 int segs; 1923 size_t size = 0; 1924 struct vm_area_struct *vma, *gate_vma; 1925 struct elfhdr *elf = NULL; 1926 loff_t offset = 0, dataoff, foffset; 1927 unsigned long mm_flags; 1928 struct elf_note_info info; 1929 1930 /* 1931 * We no longer stop all VM operations. 1932 * 1933 * This is because those proceses that could possibly change map_count 1934 * or the mmap / vma pages are now blocked in do_exit on current 1935 * finishing this core dump. 1936 * 1937 * Only ptrace can touch these memory addresses, but it doesn't change 1938 * the map_count or the pages allocated. So no possibility of crashing 1939 * exists while dumping the mm->vm_next areas to the core file. 1940 */ 1941 1942 /* alloc memory for large data structures: too large to be on stack */ 1943 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1944 if (!elf) 1945 goto out; 1946 1947 segs = current->mm->map_count; 1948 #ifdef ELF_CORE_EXTRA_PHDRS 1949 segs += ELF_CORE_EXTRA_PHDRS; 1950 #endif 1951 1952 gate_vma = get_gate_vma(current); 1953 if (gate_vma != NULL) 1954 segs++; 1955 1956 /* 1957 * Collect all the non-memory information about the process for the 1958 * notes. This also sets up the file header. 1959 */ 1960 if (!fill_note_info(elf, segs + 1, /* including notes section */ 1961 &info, signr, regs)) 1962 goto cleanup; 1963 1964 has_dumped = 1; 1965 current->flags |= PF_DUMPCORE; 1966 1967 fs = get_fs(); 1968 set_fs(KERNEL_DS); 1969 1970 DUMP_WRITE(elf, sizeof(*elf)); 1971 offset += sizeof(*elf); /* Elf header */ 1972 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */ 1973 foffset = offset; 1974 1975 /* Write notes phdr entry */ 1976 { 1977 struct elf_phdr phdr; 1978 size_t sz = get_note_info_size(&info); 1979 1980 sz += elf_coredump_extra_notes_size(); 1981 1982 fill_elf_note_phdr(&phdr, sz, offset); 1983 offset += sz; 1984 DUMP_WRITE(&phdr, sizeof(phdr)); 1985 } 1986 1987 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1988 1989 /* 1990 * We must use the same mm->flags while dumping core to avoid 1991 * inconsistency between the program headers and bodies, otherwise an 1992 * unusable core file can be generated. 1993 */ 1994 mm_flags = current->mm->flags; 1995 1996 /* Write program headers for segments dump */ 1997 for (vma = first_vma(current, gate_vma); vma != NULL; 1998 vma = next_vma(vma, gate_vma)) { 1999 struct elf_phdr phdr; 2000 2001 phdr.p_type = PT_LOAD; 2002 phdr.p_offset = offset; 2003 phdr.p_vaddr = vma->vm_start; 2004 phdr.p_paddr = 0; 2005 phdr.p_filesz = vma_dump_size(vma, mm_flags); 2006 phdr.p_memsz = vma->vm_end - vma->vm_start; 2007 offset += phdr.p_filesz; 2008 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 2009 if (vma->vm_flags & VM_WRITE) 2010 phdr.p_flags |= PF_W; 2011 if (vma->vm_flags & VM_EXEC) 2012 phdr.p_flags |= PF_X; 2013 phdr.p_align = ELF_EXEC_PAGESIZE; 2014 2015 DUMP_WRITE(&phdr, sizeof(phdr)); 2016 } 2017 2018 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS 2019 ELF_CORE_WRITE_EXTRA_PHDRS; 2020 #endif 2021 2022 /* write out the notes section */ 2023 if (!write_note_info(&info, file, &foffset)) 2024 goto end_coredump; 2025 2026 if (elf_coredump_extra_notes_write(file, &foffset)) 2027 goto end_coredump; 2028 2029 /* Align to page */ 2030 DUMP_SEEK(dataoff - foffset); 2031 2032 for (vma = first_vma(current, gate_vma); vma != NULL; 2033 vma = next_vma(vma, gate_vma)) { 2034 unsigned long addr; 2035 unsigned long end; 2036 2037 end = vma->vm_start + vma_dump_size(vma, mm_flags); 2038 2039 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { 2040 struct page *page; 2041 struct vm_area_struct *tmp_vma; 2042 2043 if (get_user_pages(current, current->mm, addr, 1, 0, 1, 2044 &page, &tmp_vma) <= 0) { 2045 DUMP_SEEK(PAGE_SIZE); 2046 } else { 2047 if (page == ZERO_PAGE(0)) { 2048 if (!dump_seek(file, PAGE_SIZE)) { 2049 page_cache_release(page); 2050 goto end_coredump; 2051 } 2052 } else { 2053 void *kaddr; 2054 flush_cache_page(tmp_vma, addr, 2055 page_to_pfn(page)); 2056 kaddr = kmap(page); 2057 if ((size += PAGE_SIZE) > limit || 2058 !dump_write(file, kaddr, 2059 PAGE_SIZE)) { 2060 kunmap(page); 2061 page_cache_release(page); 2062 goto end_coredump; 2063 } 2064 kunmap(page); 2065 } 2066 page_cache_release(page); 2067 } 2068 } 2069 } 2070 2071 #ifdef ELF_CORE_WRITE_EXTRA_DATA 2072 ELF_CORE_WRITE_EXTRA_DATA; 2073 #endif 2074 2075 end_coredump: 2076 set_fs(fs); 2077 2078 cleanup: 2079 free_note_info(&info); 2080 kfree(elf); 2081 out: 2082 return has_dumped; 2083 } 2084 2085 #endif /* USE_ELF_CORE_DUMP */ 2086 2087 static int __init init_elf_binfmt(void) 2088 { 2089 return register_binfmt(&elf_format); 2090 } 2091 2092 static void __exit exit_elf_binfmt(void) 2093 { 2094 /* Remove the COFF and ELF loaders. */ 2095 unregister_binfmt(&elf_format); 2096 } 2097 2098 core_initcall(init_elf_binfmt); 2099 module_exit(exit_elf_binfmt); 2100 MODULE_LICENSE("GPL"); 2101