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/mm.h> 16 #include <linux/mman.h> 17 #include <linux/errno.h> 18 #include <linux/signal.h> 19 #include <linux/binfmts.h> 20 #include <linux/string.h> 21 #include <linux/file.h> 22 #include <linux/slab.h> 23 #include <linux/personality.h> 24 #include <linux/elfcore.h> 25 #include <linux/init.h> 26 #include <linux/highuid.h> 27 #include <linux/compiler.h> 28 #include <linux/highmem.h> 29 #include <linux/pagemap.h> 30 #include <linux/security.h> 31 #include <linux/random.h> 32 #include <linux/elf.h> 33 #include <linux/utsname.h> 34 #include <linux/coredump.h> 35 #include <asm/uaccess.h> 36 #include <asm/param.h> 37 #include <asm/page.h> 38 #include <asm/exec.h> 39 40 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs); 41 static int load_elf_library(struct file *); 42 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, 43 int, int, unsigned long); 44 45 /* 46 * If we don't support core dumping, then supply a NULL so we 47 * don't even try. 48 */ 49 #ifdef CONFIG_ELF_CORE 50 static int elf_core_dump(struct coredump_params *cprm); 51 #else 52 #define elf_core_dump NULL 53 #endif 54 55 #if ELF_EXEC_PAGESIZE > PAGE_SIZE 56 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE 57 #else 58 #define ELF_MIN_ALIGN PAGE_SIZE 59 #endif 60 61 #ifndef ELF_CORE_EFLAGS 62 #define ELF_CORE_EFLAGS 0 63 #endif 64 65 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) 66 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) 67 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) 68 69 static struct linux_binfmt elf_format = { 70 .module = THIS_MODULE, 71 .load_binary = load_elf_binary, 72 .load_shlib = load_elf_library, 73 .core_dump = elf_core_dump, 74 .min_coredump = ELF_EXEC_PAGESIZE, 75 }; 76 77 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) 78 79 static int set_brk(unsigned long start, unsigned long end) 80 { 81 start = ELF_PAGEALIGN(start); 82 end = ELF_PAGEALIGN(end); 83 if (end > start) { 84 unsigned long addr; 85 down_write(¤t->mm->mmap_sem); 86 addr = do_brk(start, end - start); 87 up_write(¤t->mm->mmap_sem); 88 if (BAD_ADDR(addr)) 89 return addr; 90 } 91 current->mm->start_brk = current->mm->brk = end; 92 return 0; 93 } 94 95 /* We need to explicitly zero any fractional pages 96 after the data section (i.e. bss). This would 97 contain the junk from the file that should not 98 be in memory 99 */ 100 static int padzero(unsigned long elf_bss) 101 { 102 unsigned long nbyte; 103 104 nbyte = ELF_PAGEOFFSET(elf_bss); 105 if (nbyte) { 106 nbyte = ELF_MIN_ALIGN - nbyte; 107 if (clear_user((void __user *) elf_bss, nbyte)) 108 return -EFAULT; 109 } 110 return 0; 111 } 112 113 /* Let's use some macros to make this stack manipulation a little clearer */ 114 #ifdef CONFIG_STACK_GROWSUP 115 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) 116 #define STACK_ROUND(sp, items) \ 117 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) 118 #define STACK_ALLOC(sp, len) ({ \ 119 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ 120 old_sp; }) 121 #else 122 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) 123 #define STACK_ROUND(sp, items) \ 124 (((unsigned long) (sp - items)) &~ 15UL) 125 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) 126 #endif 127 128 #ifndef ELF_BASE_PLATFORM 129 /* 130 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 131 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 132 * will be copied to the user stack in the same manner as AT_PLATFORM. 133 */ 134 #define ELF_BASE_PLATFORM NULL 135 #endif 136 137 static int 138 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, 139 unsigned long load_addr, unsigned long interp_load_addr) 140 { 141 unsigned long p = bprm->p; 142 int argc = bprm->argc; 143 int envc = bprm->envc; 144 elf_addr_t __user *argv; 145 elf_addr_t __user *envp; 146 elf_addr_t __user *sp; 147 elf_addr_t __user *u_platform; 148 elf_addr_t __user *u_base_platform; 149 elf_addr_t __user *u_rand_bytes; 150 const char *k_platform = ELF_PLATFORM; 151 const char *k_base_platform = ELF_BASE_PLATFORM; 152 unsigned char k_rand_bytes[16]; 153 int items; 154 elf_addr_t *elf_info; 155 int ei_index = 0; 156 const struct cred *cred = current_cred(); 157 struct vm_area_struct *vma; 158 159 /* 160 * In some cases (e.g. Hyper-Threading), we want to avoid L1 161 * evictions by the processes running on the same package. One 162 * thing we can do is to shuffle the initial stack for them. 163 */ 164 165 p = arch_align_stack(p); 166 167 /* 168 * If this architecture has a platform capability string, copy it 169 * to userspace. In some cases (Sparc), this info is impossible 170 * for userspace to get any other way, in others (i386) it is 171 * merely difficult. 172 */ 173 u_platform = NULL; 174 if (k_platform) { 175 size_t len = strlen(k_platform) + 1; 176 177 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 178 if (__copy_to_user(u_platform, k_platform, len)) 179 return -EFAULT; 180 } 181 182 /* 183 * If this architecture has a "base" platform capability 184 * string, copy it to userspace. 185 */ 186 u_base_platform = NULL; 187 if (k_base_platform) { 188 size_t len = strlen(k_base_platform) + 1; 189 190 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 191 if (__copy_to_user(u_base_platform, k_base_platform, len)) 192 return -EFAULT; 193 } 194 195 /* 196 * Generate 16 random bytes for userspace PRNG seeding. 197 */ 198 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); 199 u_rand_bytes = (elf_addr_t __user *) 200 STACK_ALLOC(p, sizeof(k_rand_bytes)); 201 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) 202 return -EFAULT; 203 204 /* Create the ELF interpreter info */ 205 elf_info = (elf_addr_t *)current->mm->saved_auxv; 206 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ 207 #define NEW_AUX_ENT(id, val) \ 208 do { \ 209 elf_info[ei_index++] = id; \ 210 elf_info[ei_index++] = val; \ 211 } while (0) 212 213 #ifdef ARCH_DLINFO 214 /* 215 * ARCH_DLINFO must come first so PPC can do its special alignment of 216 * AUXV. 217 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in 218 * ARCH_DLINFO changes 219 */ 220 ARCH_DLINFO; 221 #endif 222 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 223 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); 224 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 225 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); 226 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 227 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); 228 NEW_AUX_ENT(AT_BASE, interp_load_addr); 229 NEW_AUX_ENT(AT_FLAGS, 0); 230 NEW_AUX_ENT(AT_ENTRY, exec->e_entry); 231 NEW_AUX_ENT(AT_UID, cred->uid); 232 NEW_AUX_ENT(AT_EUID, cred->euid); 233 NEW_AUX_ENT(AT_GID, cred->gid); 234 NEW_AUX_ENT(AT_EGID, cred->egid); 235 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 236 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); 237 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 238 if (k_platform) { 239 NEW_AUX_ENT(AT_PLATFORM, 240 (elf_addr_t)(unsigned long)u_platform); 241 } 242 if (k_base_platform) { 243 NEW_AUX_ENT(AT_BASE_PLATFORM, 244 (elf_addr_t)(unsigned long)u_base_platform); 245 } 246 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 247 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 248 } 249 #undef NEW_AUX_ENT 250 /* AT_NULL is zero; clear the rest too */ 251 memset(&elf_info[ei_index], 0, 252 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); 253 254 /* And advance past the AT_NULL entry. */ 255 ei_index += 2; 256 257 sp = STACK_ADD(p, ei_index); 258 259 items = (argc + 1) + (envc + 1) + 1; 260 bprm->p = STACK_ROUND(sp, items); 261 262 /* Point sp at the lowest address on the stack */ 263 #ifdef CONFIG_STACK_GROWSUP 264 sp = (elf_addr_t __user *)bprm->p - items - ei_index; 265 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ 266 #else 267 sp = (elf_addr_t __user *)bprm->p; 268 #endif 269 270 271 /* 272 * Grow the stack manually; some architectures have a limit on how 273 * far ahead a user-space access may be in order to grow the stack. 274 */ 275 vma = find_extend_vma(current->mm, bprm->p); 276 if (!vma) 277 return -EFAULT; 278 279 /* Now, let's put argc (and argv, envp if appropriate) on the stack */ 280 if (__put_user(argc, sp++)) 281 return -EFAULT; 282 argv = sp; 283 envp = argv + argc + 1; 284 285 /* Populate argv and envp */ 286 p = current->mm->arg_end = current->mm->arg_start; 287 while (argc-- > 0) { 288 size_t len; 289 if (__put_user((elf_addr_t)p, argv++)) 290 return -EFAULT; 291 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 292 if (!len || len > MAX_ARG_STRLEN) 293 return -EINVAL; 294 p += len; 295 } 296 if (__put_user(0, argv)) 297 return -EFAULT; 298 current->mm->arg_end = current->mm->env_start = p; 299 while (envc-- > 0) { 300 size_t len; 301 if (__put_user((elf_addr_t)p, envp++)) 302 return -EFAULT; 303 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 304 if (!len || len > MAX_ARG_STRLEN) 305 return -EINVAL; 306 p += len; 307 } 308 if (__put_user(0, envp)) 309 return -EFAULT; 310 current->mm->env_end = p; 311 312 /* Put the elf_info on the stack in the right place. */ 313 sp = (elf_addr_t __user *)envp + 1; 314 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) 315 return -EFAULT; 316 return 0; 317 } 318 319 static unsigned long elf_map(struct file *filep, unsigned long addr, 320 struct elf_phdr *eppnt, int prot, int type, 321 unsigned long total_size) 322 { 323 unsigned long map_addr; 324 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); 325 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); 326 addr = ELF_PAGESTART(addr); 327 size = ELF_PAGEALIGN(size); 328 329 /* mmap() will return -EINVAL if given a zero size, but a 330 * segment with zero filesize is perfectly valid */ 331 if (!size) 332 return addr; 333 334 down_write(¤t->mm->mmap_sem); 335 /* 336 * total_size is the size of the ELF (interpreter) image. 337 * The _first_ mmap needs to know the full size, otherwise 338 * randomization might put this image into an overlapping 339 * position with the ELF binary image. (since size < total_size) 340 * So we first map the 'big' image - and unmap the remainder at 341 * the end. (which unmap is needed for ELF images with holes.) 342 */ 343 if (total_size) { 344 total_size = ELF_PAGEALIGN(total_size); 345 map_addr = do_mmap(filep, addr, total_size, prot, type, off); 346 if (!BAD_ADDR(map_addr)) 347 do_munmap(current->mm, map_addr+size, total_size-size); 348 } else 349 map_addr = do_mmap(filep, addr, size, prot, type, off); 350 351 up_write(¤t->mm->mmap_sem); 352 return(map_addr); 353 } 354 355 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) 356 { 357 int i, first_idx = -1, last_idx = -1; 358 359 for (i = 0; i < nr; i++) { 360 if (cmds[i].p_type == PT_LOAD) { 361 last_idx = i; 362 if (first_idx == -1) 363 first_idx = i; 364 } 365 } 366 if (first_idx == -1) 367 return 0; 368 369 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - 370 ELF_PAGESTART(cmds[first_idx].p_vaddr); 371 } 372 373 374 /* This is much more generalized than the library routine read function, 375 so we keep this separate. Technically the library read function 376 is only provided so that we can read a.out libraries that have 377 an ELF header */ 378 379 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, 380 struct file *interpreter, unsigned long *interp_map_addr, 381 unsigned long no_base) 382 { 383 struct elf_phdr *elf_phdata; 384 struct elf_phdr *eppnt; 385 unsigned long load_addr = 0; 386 int load_addr_set = 0; 387 unsigned long last_bss = 0, elf_bss = 0; 388 unsigned long error = ~0UL; 389 unsigned long total_size; 390 int retval, i, size; 391 392 /* First of all, some simple consistency checks */ 393 if (interp_elf_ex->e_type != ET_EXEC && 394 interp_elf_ex->e_type != ET_DYN) 395 goto out; 396 if (!elf_check_arch(interp_elf_ex)) 397 goto out; 398 if (!interpreter->f_op || !interpreter->f_op->mmap) 399 goto out; 400 401 /* 402 * If the size of this structure has changed, then punt, since 403 * we will be doing the wrong thing. 404 */ 405 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) 406 goto out; 407 if (interp_elf_ex->e_phnum < 1 || 408 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) 409 goto out; 410 411 /* Now read in all of the header information */ 412 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; 413 if (size > ELF_MIN_ALIGN) 414 goto out; 415 elf_phdata = kmalloc(size, GFP_KERNEL); 416 if (!elf_phdata) 417 goto out; 418 419 retval = kernel_read(interpreter, interp_elf_ex->e_phoff, 420 (char *)elf_phdata, size); 421 error = -EIO; 422 if (retval != size) { 423 if (retval < 0) 424 error = retval; 425 goto out_close; 426 } 427 428 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); 429 if (!total_size) { 430 error = -EINVAL; 431 goto out_close; 432 } 433 434 eppnt = elf_phdata; 435 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { 436 if (eppnt->p_type == PT_LOAD) { 437 int elf_type = MAP_PRIVATE | MAP_DENYWRITE; 438 int elf_prot = 0; 439 unsigned long vaddr = 0; 440 unsigned long k, map_addr; 441 442 if (eppnt->p_flags & PF_R) 443 elf_prot = PROT_READ; 444 if (eppnt->p_flags & PF_W) 445 elf_prot |= PROT_WRITE; 446 if (eppnt->p_flags & PF_X) 447 elf_prot |= PROT_EXEC; 448 vaddr = eppnt->p_vaddr; 449 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) 450 elf_type |= MAP_FIXED; 451 else if (no_base && interp_elf_ex->e_type == ET_DYN) 452 load_addr = -vaddr; 453 454 map_addr = elf_map(interpreter, load_addr + vaddr, 455 eppnt, elf_prot, elf_type, total_size); 456 total_size = 0; 457 if (!*interp_map_addr) 458 *interp_map_addr = map_addr; 459 error = map_addr; 460 if (BAD_ADDR(map_addr)) 461 goto out_close; 462 463 if (!load_addr_set && 464 interp_elf_ex->e_type == ET_DYN) { 465 load_addr = map_addr - ELF_PAGESTART(vaddr); 466 load_addr_set = 1; 467 } 468 469 /* 470 * Check to see if the section's size will overflow the 471 * allowed task size. Note that p_filesz must always be 472 * <= p_memsize so it's only necessary to check p_memsz. 473 */ 474 k = load_addr + eppnt->p_vaddr; 475 if (BAD_ADDR(k) || 476 eppnt->p_filesz > eppnt->p_memsz || 477 eppnt->p_memsz > TASK_SIZE || 478 TASK_SIZE - eppnt->p_memsz < k) { 479 error = -ENOMEM; 480 goto out_close; 481 } 482 483 /* 484 * Find the end of the file mapping for this phdr, and 485 * keep track of the largest address we see for this. 486 */ 487 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; 488 if (k > elf_bss) 489 elf_bss = k; 490 491 /* 492 * Do the same thing for the memory mapping - between 493 * elf_bss and last_bss is the bss section. 494 */ 495 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; 496 if (k > last_bss) 497 last_bss = k; 498 } 499 } 500 501 if (last_bss > elf_bss) { 502 /* 503 * Now fill out the bss section. First pad the last page up 504 * to the page boundary, and then perform a mmap to make sure 505 * that there are zero-mapped pages up to and including the 506 * last bss page. 507 */ 508 if (padzero(elf_bss)) { 509 error = -EFAULT; 510 goto out_close; 511 } 512 513 /* What we have mapped so far */ 514 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); 515 516 /* Map the last of the bss segment */ 517 down_write(¤t->mm->mmap_sem); 518 error = do_brk(elf_bss, last_bss - elf_bss); 519 up_write(¤t->mm->mmap_sem); 520 if (BAD_ADDR(error)) 521 goto out_close; 522 } 523 524 error = load_addr; 525 526 out_close: 527 kfree(elf_phdata); 528 out: 529 return error; 530 } 531 532 /* 533 * These are the functions used to load ELF style executables and shared 534 * libraries. There is no binary dependent code anywhere else. 535 */ 536 537 #define INTERPRETER_NONE 0 538 #define INTERPRETER_ELF 2 539 540 #ifndef STACK_RND_MASK 541 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ 542 #endif 543 544 static unsigned long randomize_stack_top(unsigned long stack_top) 545 { 546 unsigned int random_variable = 0; 547 548 if ((current->flags & PF_RANDOMIZE) && 549 !(current->personality & ADDR_NO_RANDOMIZE)) { 550 random_variable = get_random_int() & STACK_RND_MASK; 551 random_variable <<= PAGE_SHIFT; 552 } 553 #ifdef CONFIG_STACK_GROWSUP 554 return PAGE_ALIGN(stack_top) + random_variable; 555 #else 556 return PAGE_ALIGN(stack_top) - random_variable; 557 #endif 558 } 559 560 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) 561 { 562 struct file *interpreter = NULL; /* to shut gcc up */ 563 unsigned long load_addr = 0, load_bias = 0; 564 int load_addr_set = 0; 565 char * elf_interpreter = NULL; 566 unsigned long error; 567 struct elf_phdr *elf_ppnt, *elf_phdata; 568 unsigned long elf_bss, elf_brk; 569 int retval, i; 570 unsigned int size; 571 unsigned long elf_entry; 572 unsigned long interp_load_addr = 0; 573 unsigned long start_code, end_code, start_data, end_data; 574 unsigned long reloc_func_desc __maybe_unused = 0; 575 int executable_stack = EXSTACK_DEFAULT; 576 unsigned long def_flags = 0; 577 struct { 578 struct elfhdr elf_ex; 579 struct elfhdr interp_elf_ex; 580 } *loc; 581 582 loc = kmalloc(sizeof(*loc), GFP_KERNEL); 583 if (!loc) { 584 retval = -ENOMEM; 585 goto out_ret; 586 } 587 588 /* Get the exec-header */ 589 loc->elf_ex = *((struct elfhdr *)bprm->buf); 590 591 retval = -ENOEXEC; 592 /* First of all, some simple consistency checks */ 593 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 594 goto out; 595 596 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) 597 goto out; 598 if (!elf_check_arch(&loc->elf_ex)) 599 goto out; 600 if (!bprm->file->f_op || !bprm->file->f_op->mmap) 601 goto out; 602 603 /* Now read in all of the header information */ 604 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) 605 goto out; 606 if (loc->elf_ex.e_phnum < 1 || 607 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) 608 goto out; 609 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); 610 retval = -ENOMEM; 611 elf_phdata = kmalloc(size, GFP_KERNEL); 612 if (!elf_phdata) 613 goto out; 614 615 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, 616 (char *)elf_phdata, size); 617 if (retval != size) { 618 if (retval >= 0) 619 retval = -EIO; 620 goto out_free_ph; 621 } 622 623 elf_ppnt = elf_phdata; 624 elf_bss = 0; 625 elf_brk = 0; 626 627 start_code = ~0UL; 628 end_code = 0; 629 start_data = 0; 630 end_data = 0; 631 632 for (i = 0; i < loc->elf_ex.e_phnum; i++) { 633 if (elf_ppnt->p_type == PT_INTERP) { 634 /* This is the program interpreter used for 635 * shared libraries - for now assume that this 636 * is an a.out format binary 637 */ 638 retval = -ENOEXEC; 639 if (elf_ppnt->p_filesz > PATH_MAX || 640 elf_ppnt->p_filesz < 2) 641 goto out_free_ph; 642 643 retval = -ENOMEM; 644 elf_interpreter = kmalloc(elf_ppnt->p_filesz, 645 GFP_KERNEL); 646 if (!elf_interpreter) 647 goto out_free_ph; 648 649 retval = kernel_read(bprm->file, elf_ppnt->p_offset, 650 elf_interpreter, 651 elf_ppnt->p_filesz); 652 if (retval != elf_ppnt->p_filesz) { 653 if (retval >= 0) 654 retval = -EIO; 655 goto out_free_interp; 656 } 657 /* make sure path is NULL terminated */ 658 retval = -ENOEXEC; 659 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') 660 goto out_free_interp; 661 662 interpreter = open_exec(elf_interpreter); 663 retval = PTR_ERR(interpreter); 664 if (IS_ERR(interpreter)) 665 goto out_free_interp; 666 667 /* 668 * If the binary is not readable then enforce 669 * mm->dumpable = 0 regardless of the interpreter's 670 * permissions. 671 */ 672 would_dump(bprm, interpreter); 673 674 retval = kernel_read(interpreter, 0, bprm->buf, 675 BINPRM_BUF_SIZE); 676 if (retval != BINPRM_BUF_SIZE) { 677 if (retval >= 0) 678 retval = -EIO; 679 goto out_free_dentry; 680 } 681 682 /* Get the exec headers */ 683 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); 684 break; 685 } 686 elf_ppnt++; 687 } 688 689 elf_ppnt = elf_phdata; 690 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) 691 if (elf_ppnt->p_type == PT_GNU_STACK) { 692 if (elf_ppnt->p_flags & PF_X) 693 executable_stack = EXSTACK_ENABLE_X; 694 else 695 executable_stack = EXSTACK_DISABLE_X; 696 break; 697 } 698 699 /* Some simple consistency checks for the interpreter */ 700 if (elf_interpreter) { 701 retval = -ELIBBAD; 702 /* Not an ELF interpreter */ 703 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 704 goto out_free_dentry; 705 /* Verify the interpreter has a valid arch */ 706 if (!elf_check_arch(&loc->interp_elf_ex)) 707 goto out_free_dentry; 708 } 709 710 /* Flush all traces of the currently running executable */ 711 retval = flush_old_exec(bprm); 712 if (retval) 713 goto out_free_dentry; 714 715 /* OK, This is the point of no return */ 716 current->mm->def_flags = def_flags; 717 718 /* Do this immediately, since STACK_TOP as used in setup_arg_pages 719 may depend on the personality. */ 720 SET_PERSONALITY(loc->elf_ex); 721 if (elf_read_implies_exec(loc->elf_ex, executable_stack)) 722 current->personality |= READ_IMPLIES_EXEC; 723 724 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 725 current->flags |= PF_RANDOMIZE; 726 727 setup_new_exec(bprm); 728 729 /* Do this so that we can load the interpreter, if need be. We will 730 change some of these later */ 731 current->mm->free_area_cache = current->mm->mmap_base; 732 current->mm->cached_hole_size = 0; 733 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), 734 executable_stack); 735 if (retval < 0) { 736 send_sig(SIGKILL, current, 0); 737 goto out_free_dentry; 738 } 739 740 current->mm->start_stack = bprm->p; 741 742 /* Now we do a little grungy work by mmapping the ELF image into 743 the correct location in memory. */ 744 for(i = 0, elf_ppnt = elf_phdata; 745 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { 746 int elf_prot = 0, elf_flags; 747 unsigned long k, vaddr; 748 749 if (elf_ppnt->p_type != PT_LOAD) 750 continue; 751 752 if (unlikely (elf_brk > elf_bss)) { 753 unsigned long nbyte; 754 755 /* There was a PT_LOAD segment with p_memsz > p_filesz 756 before this one. Map anonymous pages, if needed, 757 and clear the area. */ 758 retval = set_brk(elf_bss + load_bias, 759 elf_brk + load_bias); 760 if (retval) { 761 send_sig(SIGKILL, current, 0); 762 goto out_free_dentry; 763 } 764 nbyte = ELF_PAGEOFFSET(elf_bss); 765 if (nbyte) { 766 nbyte = ELF_MIN_ALIGN - nbyte; 767 if (nbyte > elf_brk - elf_bss) 768 nbyte = elf_brk - elf_bss; 769 if (clear_user((void __user *)elf_bss + 770 load_bias, nbyte)) { 771 /* 772 * This bss-zeroing can fail if the ELF 773 * file specifies odd protections. So 774 * we don't check the return value 775 */ 776 } 777 } 778 } 779 780 if (elf_ppnt->p_flags & PF_R) 781 elf_prot |= PROT_READ; 782 if (elf_ppnt->p_flags & PF_W) 783 elf_prot |= PROT_WRITE; 784 if (elf_ppnt->p_flags & PF_X) 785 elf_prot |= PROT_EXEC; 786 787 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; 788 789 vaddr = elf_ppnt->p_vaddr; 790 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { 791 elf_flags |= MAP_FIXED; 792 } else if (loc->elf_ex.e_type == ET_DYN) { 793 /* Try and get dynamic programs out of the way of the 794 * default mmap base, as well as whatever program they 795 * might try to exec. This is because the brk will 796 * follow the loader, and is not movable. */ 797 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE 798 /* Memory randomization might have been switched off 799 * in runtime via sysctl. 800 * If that is the case, retain the original non-zero 801 * load_bias value in order to establish proper 802 * non-randomized mappings. 803 */ 804 if (current->flags & PF_RANDOMIZE) 805 load_bias = 0; 806 else 807 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 808 #else 809 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 810 #endif 811 } 812 813 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, 814 elf_prot, elf_flags, 0); 815 if (BAD_ADDR(error)) { 816 send_sig(SIGKILL, current, 0); 817 retval = IS_ERR((void *)error) ? 818 PTR_ERR((void*)error) : -EINVAL; 819 goto out_free_dentry; 820 } 821 822 if (!load_addr_set) { 823 load_addr_set = 1; 824 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); 825 if (loc->elf_ex.e_type == ET_DYN) { 826 load_bias += error - 827 ELF_PAGESTART(load_bias + vaddr); 828 load_addr += load_bias; 829 reloc_func_desc = load_bias; 830 } 831 } 832 k = elf_ppnt->p_vaddr; 833 if (k < start_code) 834 start_code = k; 835 if (start_data < k) 836 start_data = k; 837 838 /* 839 * Check to see if the section's size will overflow the 840 * allowed task size. Note that p_filesz must always be 841 * <= p_memsz so it is only necessary to check p_memsz. 842 */ 843 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || 844 elf_ppnt->p_memsz > TASK_SIZE || 845 TASK_SIZE - elf_ppnt->p_memsz < k) { 846 /* set_brk can never work. Avoid overflows. */ 847 send_sig(SIGKILL, current, 0); 848 retval = -EINVAL; 849 goto out_free_dentry; 850 } 851 852 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; 853 854 if (k > elf_bss) 855 elf_bss = k; 856 if ((elf_ppnt->p_flags & PF_X) && end_code < k) 857 end_code = k; 858 if (end_data < k) 859 end_data = k; 860 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; 861 if (k > elf_brk) 862 elf_brk = k; 863 } 864 865 loc->elf_ex.e_entry += load_bias; 866 elf_bss += load_bias; 867 elf_brk += load_bias; 868 start_code += load_bias; 869 end_code += load_bias; 870 start_data += load_bias; 871 end_data += load_bias; 872 873 /* Calling set_brk effectively mmaps the pages that we need 874 * for the bss and break sections. We must do this before 875 * mapping in the interpreter, to make sure it doesn't wind 876 * up getting placed where the bss needs to go. 877 */ 878 retval = set_brk(elf_bss, elf_brk); 879 if (retval) { 880 send_sig(SIGKILL, current, 0); 881 goto out_free_dentry; 882 } 883 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { 884 send_sig(SIGSEGV, current, 0); 885 retval = -EFAULT; /* Nobody gets to see this, but.. */ 886 goto out_free_dentry; 887 } 888 889 if (elf_interpreter) { 890 unsigned long uninitialized_var(interp_map_addr); 891 892 elf_entry = load_elf_interp(&loc->interp_elf_ex, 893 interpreter, 894 &interp_map_addr, 895 load_bias); 896 if (!IS_ERR((void *)elf_entry)) { 897 /* 898 * load_elf_interp() returns relocation 899 * adjustment 900 */ 901 interp_load_addr = elf_entry; 902 elf_entry += loc->interp_elf_ex.e_entry; 903 } 904 if (BAD_ADDR(elf_entry)) { 905 force_sig(SIGSEGV, current); 906 retval = IS_ERR((void *)elf_entry) ? 907 (int)elf_entry : -EINVAL; 908 goto out_free_dentry; 909 } 910 reloc_func_desc = interp_load_addr; 911 912 allow_write_access(interpreter); 913 fput(interpreter); 914 kfree(elf_interpreter); 915 } else { 916 elf_entry = loc->elf_ex.e_entry; 917 if (BAD_ADDR(elf_entry)) { 918 force_sig(SIGSEGV, current); 919 retval = -EINVAL; 920 goto out_free_dentry; 921 } 922 } 923 924 kfree(elf_phdata); 925 926 set_binfmt(&elf_format); 927 928 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 929 retval = arch_setup_additional_pages(bprm, !!elf_interpreter); 930 if (retval < 0) { 931 send_sig(SIGKILL, current, 0); 932 goto out; 933 } 934 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ 935 936 install_exec_creds(bprm); 937 retval = create_elf_tables(bprm, &loc->elf_ex, 938 load_addr, interp_load_addr); 939 if (retval < 0) { 940 send_sig(SIGKILL, current, 0); 941 goto out; 942 } 943 /* N.B. passed_fileno might not be initialized? */ 944 current->mm->end_code = end_code; 945 current->mm->start_code = start_code; 946 current->mm->start_data = start_data; 947 current->mm->end_data = end_data; 948 current->mm->start_stack = bprm->p; 949 950 #ifdef arch_randomize_brk 951 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { 952 current->mm->brk = current->mm->start_brk = 953 arch_randomize_brk(current->mm); 954 #ifdef CONFIG_COMPAT_BRK 955 current->brk_randomized = 1; 956 #endif 957 } 958 #endif 959 960 if (current->personality & MMAP_PAGE_ZERO) { 961 /* Why this, you ask??? Well SVr4 maps page 0 as read-only, 962 and some applications "depend" upon this behavior. 963 Since we do not have the power to recompile these, we 964 emulate the SVr4 behavior. Sigh. */ 965 down_write(¤t->mm->mmap_sem); 966 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, 967 MAP_FIXED | MAP_PRIVATE, 0); 968 up_write(¤t->mm->mmap_sem); 969 } 970 971 #ifdef ELF_PLAT_INIT 972 /* 973 * The ABI may specify that certain registers be set up in special 974 * ways (on i386 %edx is the address of a DT_FINI function, for 975 * example. In addition, it may also specify (eg, PowerPC64 ELF) 976 * that the e_entry field is the address of the function descriptor 977 * for the startup routine, rather than the address of the startup 978 * routine itself. This macro performs whatever initialization to 979 * the regs structure is required as well as any relocations to the 980 * function descriptor entries when executing dynamically links apps. 981 */ 982 ELF_PLAT_INIT(regs, reloc_func_desc); 983 #endif 984 985 start_thread(regs, elf_entry, bprm->p); 986 retval = 0; 987 out: 988 kfree(loc); 989 out_ret: 990 return retval; 991 992 /* error cleanup */ 993 out_free_dentry: 994 allow_write_access(interpreter); 995 if (interpreter) 996 fput(interpreter); 997 out_free_interp: 998 kfree(elf_interpreter); 999 out_free_ph: 1000 kfree(elf_phdata); 1001 goto out; 1002 } 1003 1004 /* This is really simpleminded and specialized - we are loading an 1005 a.out library that is given an ELF header. */ 1006 static int load_elf_library(struct file *file) 1007 { 1008 struct elf_phdr *elf_phdata; 1009 struct elf_phdr *eppnt; 1010 unsigned long elf_bss, bss, len; 1011 int retval, error, i, j; 1012 struct elfhdr elf_ex; 1013 1014 error = -ENOEXEC; 1015 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); 1016 if (retval != sizeof(elf_ex)) 1017 goto out; 1018 1019 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 1020 goto out; 1021 1022 /* First of all, some simple consistency checks */ 1023 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || 1024 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap) 1025 goto out; 1026 1027 /* Now read in all of the header information */ 1028 1029 j = sizeof(struct elf_phdr) * elf_ex.e_phnum; 1030 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ 1031 1032 error = -ENOMEM; 1033 elf_phdata = kmalloc(j, GFP_KERNEL); 1034 if (!elf_phdata) 1035 goto out; 1036 1037 eppnt = elf_phdata; 1038 error = -ENOEXEC; 1039 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); 1040 if (retval != j) 1041 goto out_free_ph; 1042 1043 for (j = 0, i = 0; i<elf_ex.e_phnum; i++) 1044 if ((eppnt + i)->p_type == PT_LOAD) 1045 j++; 1046 if (j != 1) 1047 goto out_free_ph; 1048 1049 while (eppnt->p_type != PT_LOAD) 1050 eppnt++; 1051 1052 /* Now use mmap to map the library into memory. */ 1053 down_write(¤t->mm->mmap_sem); 1054 error = do_mmap(file, 1055 ELF_PAGESTART(eppnt->p_vaddr), 1056 (eppnt->p_filesz + 1057 ELF_PAGEOFFSET(eppnt->p_vaddr)), 1058 PROT_READ | PROT_WRITE | PROT_EXEC, 1059 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, 1060 (eppnt->p_offset - 1061 ELF_PAGEOFFSET(eppnt->p_vaddr))); 1062 up_write(¤t->mm->mmap_sem); 1063 if (error != ELF_PAGESTART(eppnt->p_vaddr)) 1064 goto out_free_ph; 1065 1066 elf_bss = eppnt->p_vaddr + eppnt->p_filesz; 1067 if (padzero(elf_bss)) { 1068 error = -EFAULT; 1069 goto out_free_ph; 1070 } 1071 1072 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + 1073 ELF_MIN_ALIGN - 1); 1074 bss = eppnt->p_memsz + eppnt->p_vaddr; 1075 if (bss > len) { 1076 down_write(¤t->mm->mmap_sem); 1077 do_brk(len, bss - len); 1078 up_write(¤t->mm->mmap_sem); 1079 } 1080 error = 0; 1081 1082 out_free_ph: 1083 kfree(elf_phdata); 1084 out: 1085 return error; 1086 } 1087 1088 #ifdef CONFIG_ELF_CORE 1089 /* 1090 * ELF core dumper 1091 * 1092 * Modelled on fs/exec.c:aout_core_dump() 1093 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1094 */ 1095 1096 /* 1097 * The purpose of always_dump_vma() is to make sure that special kernel mappings 1098 * that are useful for post-mortem analysis are included in every core dump. 1099 * In that way we ensure that the core dump is fully interpretable later 1100 * without matching up the same kernel and hardware config to see what PC values 1101 * meant. These special mappings include - vDSO, vsyscall, and other 1102 * architecture specific mappings 1103 */ 1104 static bool always_dump_vma(struct vm_area_struct *vma) 1105 { 1106 /* Any vsyscall mappings? */ 1107 if (vma == get_gate_vma(vma->vm_mm)) 1108 return true; 1109 /* 1110 * arch_vma_name() returns non-NULL for special architecture mappings, 1111 * such as vDSO sections. 1112 */ 1113 if (arch_vma_name(vma)) 1114 return true; 1115 1116 return false; 1117 } 1118 1119 /* 1120 * Decide what to dump of a segment, part, all or none. 1121 */ 1122 static unsigned long vma_dump_size(struct vm_area_struct *vma, 1123 unsigned long mm_flags) 1124 { 1125 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) 1126 1127 /* always dump the vdso and vsyscall sections */ 1128 if (always_dump_vma(vma)) 1129 goto whole; 1130 1131 if (vma->vm_flags & VM_NODUMP) 1132 return 0; 1133 1134 /* Hugetlb memory check */ 1135 if (vma->vm_flags & VM_HUGETLB) { 1136 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) 1137 goto whole; 1138 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) 1139 goto whole; 1140 } 1141 1142 /* Do not dump I/O mapped devices or special mappings */ 1143 if (vma->vm_flags & (VM_IO | VM_RESERVED)) 1144 return 0; 1145 1146 /* By default, dump shared memory if mapped from an anonymous file. */ 1147 if (vma->vm_flags & VM_SHARED) { 1148 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ? 1149 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) 1150 goto whole; 1151 return 0; 1152 } 1153 1154 /* Dump segments that have been written to. */ 1155 if (vma->anon_vma && FILTER(ANON_PRIVATE)) 1156 goto whole; 1157 if (vma->vm_file == NULL) 1158 return 0; 1159 1160 if (FILTER(MAPPED_PRIVATE)) 1161 goto whole; 1162 1163 /* 1164 * If this looks like the beginning of a DSO or executable mapping, 1165 * check for an ELF header. If we find one, dump the first page to 1166 * aid in determining what was mapped here. 1167 */ 1168 if (FILTER(ELF_HEADERS) && 1169 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { 1170 u32 __user *header = (u32 __user *) vma->vm_start; 1171 u32 word; 1172 mm_segment_t fs = get_fs(); 1173 /* 1174 * Doing it this way gets the constant folded by GCC. 1175 */ 1176 union { 1177 u32 cmp; 1178 char elfmag[SELFMAG]; 1179 } magic; 1180 BUILD_BUG_ON(SELFMAG != sizeof word); 1181 magic.elfmag[EI_MAG0] = ELFMAG0; 1182 magic.elfmag[EI_MAG1] = ELFMAG1; 1183 magic.elfmag[EI_MAG2] = ELFMAG2; 1184 magic.elfmag[EI_MAG3] = ELFMAG3; 1185 /* 1186 * Switch to the user "segment" for get_user(), 1187 * then put back what elf_core_dump() had in place. 1188 */ 1189 set_fs(USER_DS); 1190 if (unlikely(get_user(word, header))) 1191 word = 0; 1192 set_fs(fs); 1193 if (word == magic.cmp) 1194 return PAGE_SIZE; 1195 } 1196 1197 #undef FILTER 1198 1199 return 0; 1200 1201 whole: 1202 return vma->vm_end - vma->vm_start; 1203 } 1204 1205 /* An ELF note in memory */ 1206 struct memelfnote 1207 { 1208 const char *name; 1209 int type; 1210 unsigned int datasz; 1211 void *data; 1212 }; 1213 1214 static int notesize(struct memelfnote *en) 1215 { 1216 int sz; 1217 1218 sz = sizeof(struct elf_note); 1219 sz += roundup(strlen(en->name) + 1, 4); 1220 sz += roundup(en->datasz, 4); 1221 1222 return sz; 1223 } 1224 1225 #define DUMP_WRITE(addr, nr, foffset) \ 1226 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) 1227 1228 static int alignfile(struct file *file, loff_t *foffset) 1229 { 1230 static const char buf[4] = { 0, }; 1231 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); 1232 return 1; 1233 } 1234 1235 static int writenote(struct memelfnote *men, struct file *file, 1236 loff_t *foffset) 1237 { 1238 struct elf_note en; 1239 en.n_namesz = strlen(men->name) + 1; 1240 en.n_descsz = men->datasz; 1241 en.n_type = men->type; 1242 1243 DUMP_WRITE(&en, sizeof(en), foffset); 1244 DUMP_WRITE(men->name, en.n_namesz, foffset); 1245 if (!alignfile(file, foffset)) 1246 return 0; 1247 DUMP_WRITE(men->data, men->datasz, foffset); 1248 if (!alignfile(file, foffset)) 1249 return 0; 1250 1251 return 1; 1252 } 1253 #undef DUMP_WRITE 1254 1255 static void fill_elf_header(struct elfhdr *elf, int segs, 1256 u16 machine, u32 flags, u8 osabi) 1257 { 1258 memset(elf, 0, sizeof(*elf)); 1259 1260 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1261 elf->e_ident[EI_CLASS] = ELF_CLASS; 1262 elf->e_ident[EI_DATA] = ELF_DATA; 1263 elf->e_ident[EI_VERSION] = EV_CURRENT; 1264 elf->e_ident[EI_OSABI] = ELF_OSABI; 1265 1266 elf->e_type = ET_CORE; 1267 elf->e_machine = machine; 1268 elf->e_version = EV_CURRENT; 1269 elf->e_phoff = sizeof(struct elfhdr); 1270 elf->e_flags = flags; 1271 elf->e_ehsize = sizeof(struct elfhdr); 1272 elf->e_phentsize = sizeof(struct elf_phdr); 1273 elf->e_phnum = segs; 1274 1275 return; 1276 } 1277 1278 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1279 { 1280 phdr->p_type = PT_NOTE; 1281 phdr->p_offset = offset; 1282 phdr->p_vaddr = 0; 1283 phdr->p_paddr = 0; 1284 phdr->p_filesz = sz; 1285 phdr->p_memsz = 0; 1286 phdr->p_flags = 0; 1287 phdr->p_align = 0; 1288 return; 1289 } 1290 1291 static void fill_note(struct memelfnote *note, const char *name, int type, 1292 unsigned int sz, void *data) 1293 { 1294 note->name = name; 1295 note->type = type; 1296 note->datasz = sz; 1297 note->data = data; 1298 return; 1299 } 1300 1301 /* 1302 * fill up all the fields in prstatus from the given task struct, except 1303 * registers which need to be filled up separately. 1304 */ 1305 static void fill_prstatus(struct elf_prstatus *prstatus, 1306 struct task_struct *p, long signr) 1307 { 1308 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1309 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1310 prstatus->pr_sighold = p->blocked.sig[0]; 1311 rcu_read_lock(); 1312 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1313 rcu_read_unlock(); 1314 prstatus->pr_pid = task_pid_vnr(p); 1315 prstatus->pr_pgrp = task_pgrp_vnr(p); 1316 prstatus->pr_sid = task_session_vnr(p); 1317 if (thread_group_leader(p)) { 1318 struct task_cputime cputime; 1319 1320 /* 1321 * This is the record for the group leader. It shows the 1322 * group-wide total, not its individual thread total. 1323 */ 1324 thread_group_cputime(p, &cputime); 1325 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1326 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1327 } else { 1328 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1329 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1330 } 1331 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1332 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1333 } 1334 1335 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1336 struct mm_struct *mm) 1337 { 1338 const struct cred *cred; 1339 unsigned int i, len; 1340 1341 /* first copy the parameters from user space */ 1342 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1343 1344 len = mm->arg_end - mm->arg_start; 1345 if (len >= ELF_PRARGSZ) 1346 len = ELF_PRARGSZ-1; 1347 if (copy_from_user(&psinfo->pr_psargs, 1348 (const char __user *)mm->arg_start, len)) 1349 return -EFAULT; 1350 for(i = 0; i < len; i++) 1351 if (psinfo->pr_psargs[i] == 0) 1352 psinfo->pr_psargs[i] = ' '; 1353 psinfo->pr_psargs[len] = 0; 1354 1355 rcu_read_lock(); 1356 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1357 rcu_read_unlock(); 1358 psinfo->pr_pid = task_pid_vnr(p); 1359 psinfo->pr_pgrp = task_pgrp_vnr(p); 1360 psinfo->pr_sid = task_session_vnr(p); 1361 1362 i = p->state ? ffz(~p->state) + 1 : 0; 1363 psinfo->pr_state = i; 1364 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1365 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1366 psinfo->pr_nice = task_nice(p); 1367 psinfo->pr_flag = p->flags; 1368 rcu_read_lock(); 1369 cred = __task_cred(p); 1370 SET_UID(psinfo->pr_uid, cred->uid); 1371 SET_GID(psinfo->pr_gid, cred->gid); 1372 rcu_read_unlock(); 1373 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1374 1375 return 0; 1376 } 1377 1378 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) 1379 { 1380 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; 1381 int i = 0; 1382 do 1383 i += 2; 1384 while (auxv[i - 2] != AT_NULL); 1385 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1386 } 1387 1388 #ifdef CORE_DUMP_USE_REGSET 1389 #include <linux/regset.h> 1390 1391 struct elf_thread_core_info { 1392 struct elf_thread_core_info *next; 1393 struct task_struct *task; 1394 struct elf_prstatus prstatus; 1395 struct memelfnote notes[0]; 1396 }; 1397 1398 struct elf_note_info { 1399 struct elf_thread_core_info *thread; 1400 struct memelfnote psinfo; 1401 struct memelfnote auxv; 1402 size_t size; 1403 int thread_notes; 1404 }; 1405 1406 /* 1407 * When a regset has a writeback hook, we call it on each thread before 1408 * dumping user memory. On register window machines, this makes sure the 1409 * user memory backing the register data is up to date before we read it. 1410 */ 1411 static void do_thread_regset_writeback(struct task_struct *task, 1412 const struct user_regset *regset) 1413 { 1414 if (regset->writeback) 1415 regset->writeback(task, regset, 1); 1416 } 1417 1418 #ifndef PR_REG_SIZE 1419 #define PR_REG_SIZE(S) sizeof(S) 1420 #endif 1421 1422 #ifndef PRSTATUS_SIZE 1423 #define PRSTATUS_SIZE(S) sizeof(S) 1424 #endif 1425 1426 #ifndef PR_REG_PTR 1427 #define PR_REG_PTR(S) (&((S)->pr_reg)) 1428 #endif 1429 1430 #ifndef SET_PR_FPVALID 1431 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V)) 1432 #endif 1433 1434 static int fill_thread_core_info(struct elf_thread_core_info *t, 1435 const struct user_regset_view *view, 1436 long signr, size_t *total) 1437 { 1438 unsigned int i; 1439 1440 /* 1441 * NT_PRSTATUS is the one special case, because the regset data 1442 * goes into the pr_reg field inside the note contents, rather 1443 * than being the whole note contents. We fill the reset in here. 1444 * We assume that regset 0 is NT_PRSTATUS. 1445 */ 1446 fill_prstatus(&t->prstatus, t->task, signr); 1447 (void) view->regsets[0].get(t->task, &view->regsets[0], 1448 0, PR_REG_SIZE(t->prstatus.pr_reg), 1449 PR_REG_PTR(&t->prstatus), NULL); 1450 1451 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, 1452 PRSTATUS_SIZE(t->prstatus), &t->prstatus); 1453 *total += notesize(&t->notes[0]); 1454 1455 do_thread_regset_writeback(t->task, &view->regsets[0]); 1456 1457 /* 1458 * Each other regset might generate a note too. For each regset 1459 * that has no core_note_type or is inactive, we leave t->notes[i] 1460 * all zero and we'll know to skip writing it later. 1461 */ 1462 for (i = 1; i < view->n; ++i) { 1463 const struct user_regset *regset = &view->regsets[i]; 1464 do_thread_regset_writeback(t->task, regset); 1465 if (regset->core_note_type && regset->get && 1466 (!regset->active || regset->active(t->task, regset))) { 1467 int ret; 1468 size_t size = regset->n * regset->size; 1469 void *data = kmalloc(size, GFP_KERNEL); 1470 if (unlikely(!data)) 1471 return 0; 1472 ret = regset->get(t->task, regset, 1473 0, size, data, NULL); 1474 if (unlikely(ret)) 1475 kfree(data); 1476 else { 1477 if (regset->core_note_type != NT_PRFPREG) 1478 fill_note(&t->notes[i], "LINUX", 1479 regset->core_note_type, 1480 size, data); 1481 else { 1482 SET_PR_FPVALID(&t->prstatus, 1); 1483 fill_note(&t->notes[i], "CORE", 1484 NT_PRFPREG, size, data); 1485 } 1486 *total += notesize(&t->notes[i]); 1487 } 1488 } 1489 } 1490 1491 return 1; 1492 } 1493 1494 static int fill_note_info(struct elfhdr *elf, int phdrs, 1495 struct elf_note_info *info, 1496 long signr, struct pt_regs *regs) 1497 { 1498 struct task_struct *dump_task = current; 1499 const struct user_regset_view *view = task_user_regset_view(dump_task); 1500 struct elf_thread_core_info *t; 1501 struct elf_prpsinfo *psinfo; 1502 struct core_thread *ct; 1503 unsigned int i; 1504 1505 info->size = 0; 1506 info->thread = NULL; 1507 1508 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1509 if (psinfo == NULL) 1510 return 0; 1511 1512 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1513 1514 /* 1515 * Figure out how many notes we're going to need for each thread. 1516 */ 1517 info->thread_notes = 0; 1518 for (i = 0; i < view->n; ++i) 1519 if (view->regsets[i].core_note_type != 0) 1520 ++info->thread_notes; 1521 1522 /* 1523 * Sanity check. We rely on regset 0 being in NT_PRSTATUS, 1524 * since it is our one special case. 1525 */ 1526 if (unlikely(info->thread_notes == 0) || 1527 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { 1528 WARN_ON(1); 1529 return 0; 1530 } 1531 1532 /* 1533 * Initialize the ELF file header. 1534 */ 1535 fill_elf_header(elf, phdrs, 1536 view->e_machine, view->e_flags, view->ei_osabi); 1537 1538 /* 1539 * Allocate a structure for each thread. 1540 */ 1541 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { 1542 t = kzalloc(offsetof(struct elf_thread_core_info, 1543 notes[info->thread_notes]), 1544 GFP_KERNEL); 1545 if (unlikely(!t)) 1546 return 0; 1547 1548 t->task = ct->task; 1549 if (ct->task == dump_task || !info->thread) { 1550 t->next = info->thread; 1551 info->thread = t; 1552 } else { 1553 /* 1554 * Make sure to keep the original task at 1555 * the head of the list. 1556 */ 1557 t->next = info->thread->next; 1558 info->thread->next = t; 1559 } 1560 } 1561 1562 /* 1563 * Now fill in each thread's information. 1564 */ 1565 for (t = info->thread; t != NULL; t = t->next) 1566 if (!fill_thread_core_info(t, view, signr, &info->size)) 1567 return 0; 1568 1569 /* 1570 * Fill in the two process-wide notes. 1571 */ 1572 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); 1573 info->size += notesize(&info->psinfo); 1574 1575 fill_auxv_note(&info->auxv, current->mm); 1576 info->size += notesize(&info->auxv); 1577 1578 return 1; 1579 } 1580 1581 static size_t get_note_info_size(struct elf_note_info *info) 1582 { 1583 return info->size; 1584 } 1585 1586 /* 1587 * Write all the notes for each thread. When writing the first thread, the 1588 * process-wide notes are interleaved after the first thread-specific note. 1589 */ 1590 static int write_note_info(struct elf_note_info *info, 1591 struct file *file, loff_t *foffset) 1592 { 1593 bool first = 1; 1594 struct elf_thread_core_info *t = info->thread; 1595 1596 do { 1597 int i; 1598 1599 if (!writenote(&t->notes[0], file, foffset)) 1600 return 0; 1601 1602 if (first && !writenote(&info->psinfo, file, foffset)) 1603 return 0; 1604 if (first && !writenote(&info->auxv, file, foffset)) 1605 return 0; 1606 1607 for (i = 1; i < info->thread_notes; ++i) 1608 if (t->notes[i].data && 1609 !writenote(&t->notes[i], file, foffset)) 1610 return 0; 1611 1612 first = 0; 1613 t = t->next; 1614 } while (t); 1615 1616 return 1; 1617 } 1618 1619 static void free_note_info(struct elf_note_info *info) 1620 { 1621 struct elf_thread_core_info *threads = info->thread; 1622 while (threads) { 1623 unsigned int i; 1624 struct elf_thread_core_info *t = threads; 1625 threads = t->next; 1626 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); 1627 for (i = 1; i < info->thread_notes; ++i) 1628 kfree(t->notes[i].data); 1629 kfree(t); 1630 } 1631 kfree(info->psinfo.data); 1632 } 1633 1634 #else 1635 1636 /* Here is the structure in which status of each thread is captured. */ 1637 struct elf_thread_status 1638 { 1639 struct list_head list; 1640 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1641 elf_fpregset_t fpu; /* NT_PRFPREG */ 1642 struct task_struct *thread; 1643 #ifdef ELF_CORE_COPY_XFPREGS 1644 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1645 #endif 1646 struct memelfnote notes[3]; 1647 int num_notes; 1648 }; 1649 1650 /* 1651 * In order to add the specific thread information for the elf file format, 1652 * we need to keep a linked list of every threads pr_status and then create 1653 * a single section for them in the final core file. 1654 */ 1655 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1656 { 1657 int sz = 0; 1658 struct task_struct *p = t->thread; 1659 t->num_notes = 0; 1660 1661 fill_prstatus(&t->prstatus, p, signr); 1662 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1663 1664 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1665 &(t->prstatus)); 1666 t->num_notes++; 1667 sz += notesize(&t->notes[0]); 1668 1669 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, 1670 &t->fpu))) { 1671 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1672 &(t->fpu)); 1673 t->num_notes++; 1674 sz += notesize(&t->notes[1]); 1675 } 1676 1677 #ifdef ELF_CORE_COPY_XFPREGS 1678 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1679 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1680 sizeof(t->xfpu), &t->xfpu); 1681 t->num_notes++; 1682 sz += notesize(&t->notes[2]); 1683 } 1684 #endif 1685 return sz; 1686 } 1687 1688 struct elf_note_info { 1689 struct memelfnote *notes; 1690 struct elf_prstatus *prstatus; /* NT_PRSTATUS */ 1691 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ 1692 struct list_head thread_list; 1693 elf_fpregset_t *fpu; 1694 #ifdef ELF_CORE_COPY_XFPREGS 1695 elf_fpxregset_t *xfpu; 1696 #endif 1697 int thread_status_size; 1698 int numnote; 1699 }; 1700 1701 static int elf_note_info_init(struct elf_note_info *info) 1702 { 1703 memset(info, 0, sizeof(*info)); 1704 INIT_LIST_HEAD(&info->thread_list); 1705 1706 /* Allocate space for six ELF notes */ 1707 info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL); 1708 if (!info->notes) 1709 return 0; 1710 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); 1711 if (!info->psinfo) 1712 goto notes_free; 1713 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); 1714 if (!info->prstatus) 1715 goto psinfo_free; 1716 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); 1717 if (!info->fpu) 1718 goto prstatus_free; 1719 #ifdef ELF_CORE_COPY_XFPREGS 1720 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); 1721 if (!info->xfpu) 1722 goto fpu_free; 1723 #endif 1724 return 1; 1725 #ifdef ELF_CORE_COPY_XFPREGS 1726 fpu_free: 1727 kfree(info->fpu); 1728 #endif 1729 prstatus_free: 1730 kfree(info->prstatus); 1731 psinfo_free: 1732 kfree(info->psinfo); 1733 notes_free: 1734 kfree(info->notes); 1735 return 0; 1736 } 1737 1738 static int fill_note_info(struct elfhdr *elf, int phdrs, 1739 struct elf_note_info *info, 1740 long signr, struct pt_regs *regs) 1741 { 1742 struct list_head *t; 1743 1744 if (!elf_note_info_init(info)) 1745 return 0; 1746 1747 if (signr) { 1748 struct core_thread *ct; 1749 struct elf_thread_status *ets; 1750 1751 for (ct = current->mm->core_state->dumper.next; 1752 ct; ct = ct->next) { 1753 ets = kzalloc(sizeof(*ets), GFP_KERNEL); 1754 if (!ets) 1755 return 0; 1756 1757 ets->thread = ct->task; 1758 list_add(&ets->list, &info->thread_list); 1759 } 1760 1761 list_for_each(t, &info->thread_list) { 1762 int sz; 1763 1764 ets = list_entry(t, struct elf_thread_status, list); 1765 sz = elf_dump_thread_status(signr, ets); 1766 info->thread_status_size += sz; 1767 } 1768 } 1769 /* now collect the dump for the current */ 1770 memset(info->prstatus, 0, sizeof(*info->prstatus)); 1771 fill_prstatus(info->prstatus, current, signr); 1772 elf_core_copy_regs(&info->prstatus->pr_reg, regs); 1773 1774 /* Set up header */ 1775 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI); 1776 1777 /* 1778 * Set up the notes in similar form to SVR4 core dumps made 1779 * with info from their /proc. 1780 */ 1781 1782 fill_note(info->notes + 0, "CORE", NT_PRSTATUS, 1783 sizeof(*info->prstatus), info->prstatus); 1784 fill_psinfo(info->psinfo, current->group_leader, current->mm); 1785 fill_note(info->notes + 1, "CORE", NT_PRPSINFO, 1786 sizeof(*info->psinfo), info->psinfo); 1787 1788 info->numnote = 2; 1789 1790 fill_auxv_note(&info->notes[info->numnote++], current->mm); 1791 1792 /* Try to dump the FPU. */ 1793 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, 1794 info->fpu); 1795 if (info->prstatus->pr_fpvalid) 1796 fill_note(info->notes + info->numnote++, 1797 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); 1798 #ifdef ELF_CORE_COPY_XFPREGS 1799 if (elf_core_copy_task_xfpregs(current, info->xfpu)) 1800 fill_note(info->notes + info->numnote++, 1801 "LINUX", ELF_CORE_XFPREG_TYPE, 1802 sizeof(*info->xfpu), info->xfpu); 1803 #endif 1804 1805 return 1; 1806 } 1807 1808 static size_t get_note_info_size(struct elf_note_info *info) 1809 { 1810 int sz = 0; 1811 int i; 1812 1813 for (i = 0; i < info->numnote; i++) 1814 sz += notesize(info->notes + i); 1815 1816 sz += info->thread_status_size; 1817 1818 return sz; 1819 } 1820 1821 static int write_note_info(struct elf_note_info *info, 1822 struct file *file, loff_t *foffset) 1823 { 1824 int i; 1825 struct list_head *t; 1826 1827 for (i = 0; i < info->numnote; i++) 1828 if (!writenote(info->notes + i, file, foffset)) 1829 return 0; 1830 1831 /* write out the thread status notes section */ 1832 list_for_each(t, &info->thread_list) { 1833 struct elf_thread_status *tmp = 1834 list_entry(t, struct elf_thread_status, list); 1835 1836 for (i = 0; i < tmp->num_notes; i++) 1837 if (!writenote(&tmp->notes[i], file, foffset)) 1838 return 0; 1839 } 1840 1841 return 1; 1842 } 1843 1844 static void free_note_info(struct elf_note_info *info) 1845 { 1846 while (!list_empty(&info->thread_list)) { 1847 struct list_head *tmp = info->thread_list.next; 1848 list_del(tmp); 1849 kfree(list_entry(tmp, struct elf_thread_status, list)); 1850 } 1851 1852 kfree(info->prstatus); 1853 kfree(info->psinfo); 1854 kfree(info->notes); 1855 kfree(info->fpu); 1856 #ifdef ELF_CORE_COPY_XFPREGS 1857 kfree(info->xfpu); 1858 #endif 1859 } 1860 1861 #endif 1862 1863 static struct vm_area_struct *first_vma(struct task_struct *tsk, 1864 struct vm_area_struct *gate_vma) 1865 { 1866 struct vm_area_struct *ret = tsk->mm->mmap; 1867 1868 if (ret) 1869 return ret; 1870 return gate_vma; 1871 } 1872 /* 1873 * Helper function for iterating across a vma list. It ensures that the caller 1874 * will visit `gate_vma' prior to terminating the search. 1875 */ 1876 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, 1877 struct vm_area_struct *gate_vma) 1878 { 1879 struct vm_area_struct *ret; 1880 1881 ret = this_vma->vm_next; 1882 if (ret) 1883 return ret; 1884 if (this_vma == gate_vma) 1885 return NULL; 1886 return gate_vma; 1887 } 1888 1889 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1890 elf_addr_t e_shoff, int segs) 1891 { 1892 elf->e_shoff = e_shoff; 1893 elf->e_shentsize = sizeof(*shdr4extnum); 1894 elf->e_shnum = 1; 1895 elf->e_shstrndx = SHN_UNDEF; 1896 1897 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1898 1899 shdr4extnum->sh_type = SHT_NULL; 1900 shdr4extnum->sh_size = elf->e_shnum; 1901 shdr4extnum->sh_link = elf->e_shstrndx; 1902 shdr4extnum->sh_info = segs; 1903 } 1904 1905 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, 1906 unsigned long mm_flags) 1907 { 1908 struct vm_area_struct *vma; 1909 size_t size = 0; 1910 1911 for (vma = first_vma(current, gate_vma); vma != NULL; 1912 vma = next_vma(vma, gate_vma)) 1913 size += vma_dump_size(vma, mm_flags); 1914 return size; 1915 } 1916 1917 /* 1918 * Actual dumper 1919 * 1920 * This is a two-pass process; first we find the offsets of the bits, 1921 * and then they are actually written out. If we run out of core limit 1922 * we just truncate. 1923 */ 1924 static int elf_core_dump(struct coredump_params *cprm) 1925 { 1926 int has_dumped = 0; 1927 mm_segment_t fs; 1928 int segs; 1929 size_t size = 0; 1930 struct vm_area_struct *vma, *gate_vma; 1931 struct elfhdr *elf = NULL; 1932 loff_t offset = 0, dataoff, foffset; 1933 struct elf_note_info info; 1934 struct elf_phdr *phdr4note = NULL; 1935 struct elf_shdr *shdr4extnum = NULL; 1936 Elf_Half e_phnum; 1937 elf_addr_t e_shoff; 1938 1939 /* 1940 * We no longer stop all VM operations. 1941 * 1942 * This is because those proceses that could possibly change map_count 1943 * or the mmap / vma pages are now blocked in do_exit on current 1944 * finishing this core dump. 1945 * 1946 * Only ptrace can touch these memory addresses, but it doesn't change 1947 * the map_count or the pages allocated. So no possibility of crashing 1948 * exists while dumping the mm->vm_next areas to the core file. 1949 */ 1950 1951 /* alloc memory for large data structures: too large to be on stack */ 1952 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1953 if (!elf) 1954 goto out; 1955 /* 1956 * The number of segs are recored into ELF header as 16bit value. 1957 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. 1958 */ 1959 segs = current->mm->map_count; 1960 segs += elf_core_extra_phdrs(); 1961 1962 gate_vma = get_gate_vma(current->mm); 1963 if (gate_vma != NULL) 1964 segs++; 1965 1966 /* for notes section */ 1967 segs++; 1968 1969 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1970 * this, kernel supports extended numbering. Have a look at 1971 * include/linux/elf.h for further information. */ 1972 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1973 1974 /* 1975 * Collect all the non-memory information about the process for the 1976 * notes. This also sets up the file header. 1977 */ 1978 if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs)) 1979 goto cleanup; 1980 1981 has_dumped = 1; 1982 current->flags |= PF_DUMPCORE; 1983 1984 fs = get_fs(); 1985 set_fs(KERNEL_DS); 1986 1987 offset += sizeof(*elf); /* Elf header */ 1988 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1989 foffset = offset; 1990 1991 /* Write notes phdr entry */ 1992 { 1993 size_t sz = get_note_info_size(&info); 1994 1995 sz += elf_coredump_extra_notes_size(); 1996 1997 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1998 if (!phdr4note) 1999 goto end_coredump; 2000 2001 fill_elf_note_phdr(phdr4note, sz, offset); 2002 offset += sz; 2003 } 2004 2005 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 2006 2007 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags); 2008 offset += elf_core_extra_data_size(); 2009 e_shoff = offset; 2010 2011 if (e_phnum == PN_XNUM) { 2012 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 2013 if (!shdr4extnum) 2014 goto end_coredump; 2015 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 2016 } 2017 2018 offset = dataoff; 2019 2020 size += sizeof(*elf); 2021 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) 2022 goto end_coredump; 2023 2024 size += sizeof(*phdr4note); 2025 if (size > cprm->limit 2026 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) 2027 goto end_coredump; 2028 2029 /* Write program headers for segments dump */ 2030 for (vma = first_vma(current, gate_vma); vma != NULL; 2031 vma = next_vma(vma, gate_vma)) { 2032 struct elf_phdr phdr; 2033 2034 phdr.p_type = PT_LOAD; 2035 phdr.p_offset = offset; 2036 phdr.p_vaddr = vma->vm_start; 2037 phdr.p_paddr = 0; 2038 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags); 2039 phdr.p_memsz = vma->vm_end - vma->vm_start; 2040 offset += phdr.p_filesz; 2041 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 2042 if (vma->vm_flags & VM_WRITE) 2043 phdr.p_flags |= PF_W; 2044 if (vma->vm_flags & VM_EXEC) 2045 phdr.p_flags |= PF_X; 2046 phdr.p_align = ELF_EXEC_PAGESIZE; 2047 2048 size += sizeof(phdr); 2049 if (size > cprm->limit 2050 || !dump_write(cprm->file, &phdr, sizeof(phdr))) 2051 goto end_coredump; 2052 } 2053 2054 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) 2055 goto end_coredump; 2056 2057 /* write out the notes section */ 2058 if (!write_note_info(&info, cprm->file, &foffset)) 2059 goto end_coredump; 2060 2061 if (elf_coredump_extra_notes_write(cprm->file, &foffset)) 2062 goto end_coredump; 2063 2064 /* Align to page */ 2065 if (!dump_seek(cprm->file, dataoff - foffset)) 2066 goto end_coredump; 2067 2068 for (vma = first_vma(current, gate_vma); vma != NULL; 2069 vma = next_vma(vma, gate_vma)) { 2070 unsigned long addr; 2071 unsigned long end; 2072 2073 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags); 2074 2075 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { 2076 struct page *page; 2077 int stop; 2078 2079 page = get_dump_page(addr); 2080 if (page) { 2081 void *kaddr = kmap(page); 2082 stop = ((size += PAGE_SIZE) > cprm->limit) || 2083 !dump_write(cprm->file, kaddr, 2084 PAGE_SIZE); 2085 kunmap(page); 2086 page_cache_release(page); 2087 } else 2088 stop = !dump_seek(cprm->file, PAGE_SIZE); 2089 if (stop) 2090 goto end_coredump; 2091 } 2092 } 2093 2094 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) 2095 goto end_coredump; 2096 2097 if (e_phnum == PN_XNUM) { 2098 size += sizeof(*shdr4extnum); 2099 if (size > cprm->limit 2100 || !dump_write(cprm->file, shdr4extnum, 2101 sizeof(*shdr4extnum))) 2102 goto end_coredump; 2103 } 2104 2105 end_coredump: 2106 set_fs(fs); 2107 2108 cleanup: 2109 free_note_info(&info); 2110 kfree(shdr4extnum); 2111 kfree(phdr4note); 2112 kfree(elf); 2113 out: 2114 return has_dumped; 2115 } 2116 2117 #endif /* CONFIG_ELF_CORE */ 2118 2119 static int __init init_elf_binfmt(void) 2120 { 2121 register_binfmt(&elf_format); 2122 return 0; 2123 } 2124 2125 static void __exit exit_elf_binfmt(void) 2126 { 2127 /* Remove the COFF and ELF loaders. */ 2128 unregister_binfmt(&elf_format); 2129 } 2130 2131 core_initcall(init_elf_binfmt); 2132 module_exit(exit_elf_binfmt); 2133 MODULE_LICENSE("GPL"); 2134