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/vmalloc.h> 31 #include <linux/security.h> 32 #include <linux/random.h> 33 #include <linux/elf.h> 34 #include <linux/utsname.h> 35 #include <linux/coredump.h> 36 #include <linux/sched.h> 37 #include <asm/uaccess.h> 38 #include <asm/param.h> 39 #include <asm/page.h> 40 41 #ifndef user_long_t 42 #define user_long_t long 43 #endif 44 #ifndef user_siginfo_t 45 #define user_siginfo_t siginfo_t 46 #endif 47 48 static int load_elf_binary(struct linux_binprm *bprm); 49 static int load_elf_library(struct file *); 50 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, 51 int, int, unsigned long); 52 53 /* 54 * If we don't support core dumping, then supply a NULL so we 55 * don't even try. 56 */ 57 #ifdef CONFIG_ELF_CORE 58 static int elf_core_dump(struct coredump_params *cprm); 59 #else 60 #define elf_core_dump NULL 61 #endif 62 63 #if ELF_EXEC_PAGESIZE > PAGE_SIZE 64 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE 65 #else 66 #define ELF_MIN_ALIGN PAGE_SIZE 67 #endif 68 69 #ifndef ELF_CORE_EFLAGS 70 #define ELF_CORE_EFLAGS 0 71 #endif 72 73 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) 74 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) 75 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) 76 77 static struct linux_binfmt elf_format = { 78 .module = THIS_MODULE, 79 .load_binary = load_elf_binary, 80 .load_shlib = load_elf_library, 81 .core_dump = elf_core_dump, 82 .min_coredump = ELF_EXEC_PAGESIZE, 83 }; 84 85 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) 86 87 static int set_brk(unsigned long start, unsigned long end) 88 { 89 start = ELF_PAGEALIGN(start); 90 end = ELF_PAGEALIGN(end); 91 if (end > start) { 92 unsigned long addr; 93 addr = vm_brk(start, end - start); 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, from_kuid_munged(cred->user_ns, cred->uid)); 238 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid)); 239 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid)); 240 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, 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 #ifdef ELF_HWCAP2 244 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 245 #endif 246 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 247 if (k_platform) { 248 NEW_AUX_ENT(AT_PLATFORM, 249 (elf_addr_t)(unsigned long)u_platform); 250 } 251 if (k_base_platform) { 252 NEW_AUX_ENT(AT_BASE_PLATFORM, 253 (elf_addr_t)(unsigned long)u_base_platform); 254 } 255 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 256 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 257 } 258 #undef NEW_AUX_ENT 259 /* AT_NULL is zero; clear the rest too */ 260 memset(&elf_info[ei_index], 0, 261 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); 262 263 /* And advance past the AT_NULL entry. */ 264 ei_index += 2; 265 266 sp = STACK_ADD(p, ei_index); 267 268 items = (argc + 1) + (envc + 1) + 1; 269 bprm->p = STACK_ROUND(sp, items); 270 271 /* Point sp at the lowest address on the stack */ 272 #ifdef CONFIG_STACK_GROWSUP 273 sp = (elf_addr_t __user *)bprm->p - items - ei_index; 274 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ 275 #else 276 sp = (elf_addr_t __user *)bprm->p; 277 #endif 278 279 280 /* 281 * Grow the stack manually; some architectures have a limit on how 282 * far ahead a user-space access may be in order to grow the stack. 283 */ 284 vma = find_extend_vma(current->mm, bprm->p); 285 if (!vma) 286 return -EFAULT; 287 288 /* Now, let's put argc (and argv, envp if appropriate) on the stack */ 289 if (__put_user(argc, sp++)) 290 return -EFAULT; 291 argv = sp; 292 envp = argv + argc + 1; 293 294 /* Populate argv and envp */ 295 p = current->mm->arg_end = current->mm->arg_start; 296 while (argc-- > 0) { 297 size_t len; 298 if (__put_user((elf_addr_t)p, argv++)) 299 return -EFAULT; 300 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 301 if (!len || len > MAX_ARG_STRLEN) 302 return -EINVAL; 303 p += len; 304 } 305 if (__put_user(0, argv)) 306 return -EFAULT; 307 current->mm->arg_end = current->mm->env_start = p; 308 while (envc-- > 0) { 309 size_t len; 310 if (__put_user((elf_addr_t)p, envp++)) 311 return -EFAULT; 312 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 313 if (!len || len > MAX_ARG_STRLEN) 314 return -EINVAL; 315 p += len; 316 } 317 if (__put_user(0, envp)) 318 return -EFAULT; 319 current->mm->env_end = p; 320 321 /* Put the elf_info on the stack in the right place. */ 322 sp = (elf_addr_t __user *)envp + 1; 323 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) 324 return -EFAULT; 325 return 0; 326 } 327 328 #ifndef elf_map 329 330 static unsigned long elf_map(struct file *filep, unsigned long addr, 331 struct elf_phdr *eppnt, int prot, int type, 332 unsigned long total_size) 333 { 334 unsigned long map_addr; 335 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); 336 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); 337 addr = ELF_PAGESTART(addr); 338 size = ELF_PAGEALIGN(size); 339 340 /* mmap() will return -EINVAL if given a zero size, but a 341 * segment with zero filesize is perfectly valid */ 342 if (!size) 343 return addr; 344 345 /* 346 * total_size is the size of the ELF (interpreter) image. 347 * The _first_ mmap needs to know the full size, otherwise 348 * randomization might put this image into an overlapping 349 * position with the ELF binary image. (since size < total_size) 350 * So we first map the 'big' image - and unmap the remainder at 351 * the end. (which unmap is needed for ELF images with holes.) 352 */ 353 if (total_size) { 354 total_size = ELF_PAGEALIGN(total_size); 355 map_addr = vm_mmap(filep, addr, total_size, prot, type, off); 356 if (!BAD_ADDR(map_addr)) 357 vm_munmap(map_addr+size, total_size-size); 358 } else 359 map_addr = vm_mmap(filep, addr, size, prot, type, off); 360 361 return(map_addr); 362 } 363 364 #endif /* !elf_map */ 365 366 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) 367 { 368 int i, first_idx = -1, last_idx = -1; 369 370 for (i = 0; i < nr; i++) { 371 if (cmds[i].p_type == PT_LOAD) { 372 last_idx = i; 373 if (first_idx == -1) 374 first_idx = i; 375 } 376 } 377 if (first_idx == -1) 378 return 0; 379 380 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - 381 ELF_PAGESTART(cmds[first_idx].p_vaddr); 382 } 383 384 385 /* This is much more generalized than the library routine read function, 386 so we keep this separate. Technically the library read function 387 is only provided so that we can read a.out libraries that have 388 an ELF header */ 389 390 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, 391 struct file *interpreter, unsigned long *interp_map_addr, 392 unsigned long no_base) 393 { 394 struct elf_phdr *elf_phdata; 395 struct elf_phdr *eppnt; 396 unsigned long load_addr = 0; 397 int load_addr_set = 0; 398 unsigned long last_bss = 0, elf_bss = 0; 399 unsigned long error = ~0UL; 400 unsigned long total_size; 401 int retval, i, size; 402 403 /* First of all, some simple consistency checks */ 404 if (interp_elf_ex->e_type != ET_EXEC && 405 interp_elf_ex->e_type != ET_DYN) 406 goto out; 407 if (!elf_check_arch(interp_elf_ex)) 408 goto out; 409 if (!interpreter->f_op->mmap) 410 goto out; 411 412 /* 413 * If the size of this structure has changed, then punt, since 414 * we will be doing the wrong thing. 415 */ 416 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) 417 goto out; 418 if (interp_elf_ex->e_phnum < 1 || 419 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) 420 goto out; 421 422 /* Now read in all of the header information */ 423 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; 424 if (size > ELF_MIN_ALIGN) 425 goto out; 426 elf_phdata = kmalloc(size, GFP_KERNEL); 427 if (!elf_phdata) 428 goto out; 429 430 retval = kernel_read(interpreter, interp_elf_ex->e_phoff, 431 (char *)elf_phdata, size); 432 error = -EIO; 433 if (retval != size) { 434 if (retval < 0) 435 error = retval; 436 goto out_close; 437 } 438 439 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); 440 if (!total_size) { 441 error = -EINVAL; 442 goto out_close; 443 } 444 445 eppnt = elf_phdata; 446 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { 447 if (eppnt->p_type == PT_LOAD) { 448 int elf_type = MAP_PRIVATE | MAP_DENYWRITE; 449 int elf_prot = 0; 450 unsigned long vaddr = 0; 451 unsigned long k, map_addr; 452 453 if (eppnt->p_flags & PF_R) 454 elf_prot = PROT_READ; 455 if (eppnt->p_flags & PF_W) 456 elf_prot |= PROT_WRITE; 457 if (eppnt->p_flags & PF_X) 458 elf_prot |= PROT_EXEC; 459 vaddr = eppnt->p_vaddr; 460 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) 461 elf_type |= MAP_FIXED; 462 else if (no_base && interp_elf_ex->e_type == ET_DYN) 463 load_addr = -vaddr; 464 465 map_addr = elf_map(interpreter, load_addr + vaddr, 466 eppnt, elf_prot, elf_type, total_size); 467 total_size = 0; 468 if (!*interp_map_addr) 469 *interp_map_addr = map_addr; 470 error = map_addr; 471 if (BAD_ADDR(map_addr)) 472 goto out_close; 473 474 if (!load_addr_set && 475 interp_elf_ex->e_type == ET_DYN) { 476 load_addr = map_addr - ELF_PAGESTART(vaddr); 477 load_addr_set = 1; 478 } 479 480 /* 481 * Check to see if the section's size will overflow the 482 * allowed task size. Note that p_filesz must always be 483 * <= p_memsize so it's only necessary to check p_memsz. 484 */ 485 k = load_addr + eppnt->p_vaddr; 486 if (BAD_ADDR(k) || 487 eppnt->p_filesz > eppnt->p_memsz || 488 eppnt->p_memsz > TASK_SIZE || 489 TASK_SIZE - eppnt->p_memsz < k) { 490 error = -ENOMEM; 491 goto out_close; 492 } 493 494 /* 495 * Find the end of the file mapping for this phdr, and 496 * keep track of the largest address we see for this. 497 */ 498 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; 499 if (k > elf_bss) 500 elf_bss = k; 501 502 /* 503 * Do the same thing for the memory mapping - between 504 * elf_bss and last_bss is the bss section. 505 */ 506 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; 507 if (k > last_bss) 508 last_bss = k; 509 } 510 } 511 512 if (last_bss > elf_bss) { 513 /* 514 * Now fill out the bss section. First pad the last page up 515 * to the page boundary, and then perform a mmap to make sure 516 * that there are zero-mapped pages up to and including the 517 * last bss page. 518 */ 519 if (padzero(elf_bss)) { 520 error = -EFAULT; 521 goto out_close; 522 } 523 524 /* What we have mapped so far */ 525 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); 526 527 /* Map the last of the bss segment */ 528 error = vm_brk(elf_bss, last_bss - elf_bss); 529 if (BAD_ADDR(error)) 530 goto out_close; 531 } 532 533 error = load_addr; 534 535 out_close: 536 kfree(elf_phdata); 537 out: 538 return error; 539 } 540 541 /* 542 * These are the functions used to load ELF style executables and shared 543 * libraries. There is no binary dependent code anywhere else. 544 */ 545 546 #ifndef STACK_RND_MASK 547 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ 548 #endif 549 550 static unsigned long randomize_stack_top(unsigned long stack_top) 551 { 552 unsigned int random_variable = 0; 553 554 if ((current->flags & PF_RANDOMIZE) && 555 !(current->personality & ADDR_NO_RANDOMIZE)) { 556 random_variable = get_random_int() & STACK_RND_MASK; 557 random_variable <<= PAGE_SHIFT; 558 } 559 #ifdef CONFIG_STACK_GROWSUP 560 return PAGE_ALIGN(stack_top) + random_variable; 561 #else 562 return PAGE_ALIGN(stack_top) - random_variable; 563 #endif 564 } 565 566 static int load_elf_binary(struct linux_binprm *bprm) 567 { 568 struct file *interpreter = NULL; /* to shut gcc up */ 569 unsigned long load_addr = 0, load_bias = 0; 570 int load_addr_set = 0; 571 char * elf_interpreter = NULL; 572 unsigned long error; 573 struct elf_phdr *elf_ppnt, *elf_phdata; 574 unsigned long elf_bss, elf_brk; 575 int retval, i; 576 unsigned int size; 577 unsigned long elf_entry; 578 unsigned long interp_load_addr = 0; 579 unsigned long start_code, end_code, start_data, end_data; 580 unsigned long reloc_func_desc __maybe_unused = 0; 581 int executable_stack = EXSTACK_DEFAULT; 582 unsigned long def_flags = 0; 583 struct pt_regs *regs = current_pt_regs(); 584 struct { 585 struct elfhdr elf_ex; 586 struct elfhdr interp_elf_ex; 587 } *loc; 588 589 loc = kmalloc(sizeof(*loc), GFP_KERNEL); 590 if (!loc) { 591 retval = -ENOMEM; 592 goto out_ret; 593 } 594 595 /* Get the exec-header */ 596 loc->elf_ex = *((struct elfhdr *)bprm->buf); 597 598 retval = -ENOEXEC; 599 /* First of all, some simple consistency checks */ 600 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 601 goto out; 602 603 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) 604 goto out; 605 if (!elf_check_arch(&loc->elf_ex)) 606 goto out; 607 if (!bprm->file->f_op->mmap) 608 goto out; 609 610 /* Now read in all of the header information */ 611 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) 612 goto out; 613 if (loc->elf_ex.e_phnum < 1 || 614 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) 615 goto out; 616 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); 617 retval = -ENOMEM; 618 elf_phdata = kmalloc(size, GFP_KERNEL); 619 if (!elf_phdata) 620 goto out; 621 622 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, 623 (char *)elf_phdata, size); 624 if (retval != size) { 625 if (retval >= 0) 626 retval = -EIO; 627 goto out_free_ph; 628 } 629 630 elf_ppnt = elf_phdata; 631 elf_bss = 0; 632 elf_brk = 0; 633 634 start_code = ~0UL; 635 end_code = 0; 636 start_data = 0; 637 end_data = 0; 638 639 for (i = 0; i < loc->elf_ex.e_phnum; i++) { 640 if (elf_ppnt->p_type == PT_INTERP) { 641 /* This is the program interpreter used for 642 * shared libraries - for now assume that this 643 * is an a.out format binary 644 */ 645 retval = -ENOEXEC; 646 if (elf_ppnt->p_filesz > PATH_MAX || 647 elf_ppnt->p_filesz < 2) 648 goto out_free_ph; 649 650 retval = -ENOMEM; 651 elf_interpreter = kmalloc(elf_ppnt->p_filesz, 652 GFP_KERNEL); 653 if (!elf_interpreter) 654 goto out_free_ph; 655 656 retval = kernel_read(bprm->file, elf_ppnt->p_offset, 657 elf_interpreter, 658 elf_ppnt->p_filesz); 659 if (retval != elf_ppnt->p_filesz) { 660 if (retval >= 0) 661 retval = -EIO; 662 goto out_free_interp; 663 } 664 /* make sure path is NULL terminated */ 665 retval = -ENOEXEC; 666 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') 667 goto out_free_interp; 668 669 interpreter = open_exec(elf_interpreter); 670 retval = PTR_ERR(interpreter); 671 if (IS_ERR(interpreter)) 672 goto out_free_interp; 673 674 /* 675 * If the binary is not readable then enforce 676 * mm->dumpable = 0 regardless of the interpreter's 677 * permissions. 678 */ 679 would_dump(bprm, interpreter); 680 681 retval = kernel_read(interpreter, 0, bprm->buf, 682 BINPRM_BUF_SIZE); 683 if (retval != BINPRM_BUF_SIZE) { 684 if (retval >= 0) 685 retval = -EIO; 686 goto out_free_dentry; 687 } 688 689 /* Get the exec headers */ 690 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); 691 break; 692 } 693 elf_ppnt++; 694 } 695 696 elf_ppnt = elf_phdata; 697 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) 698 if (elf_ppnt->p_type == PT_GNU_STACK) { 699 if (elf_ppnt->p_flags & PF_X) 700 executable_stack = EXSTACK_ENABLE_X; 701 else 702 executable_stack = EXSTACK_DISABLE_X; 703 break; 704 } 705 706 /* Some simple consistency checks for the interpreter */ 707 if (elf_interpreter) { 708 retval = -ELIBBAD; 709 /* Not an ELF interpreter */ 710 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 711 goto out_free_dentry; 712 /* Verify the interpreter has a valid arch */ 713 if (!elf_check_arch(&loc->interp_elf_ex)) 714 goto out_free_dentry; 715 } 716 717 /* Flush all traces of the currently running executable */ 718 retval = flush_old_exec(bprm); 719 if (retval) 720 goto out_free_dentry; 721 722 /* OK, This is the point of no return */ 723 current->mm->def_flags = def_flags; 724 725 /* Do this immediately, since STACK_TOP as used in setup_arg_pages 726 may depend on the personality. */ 727 SET_PERSONALITY(loc->elf_ex); 728 if (elf_read_implies_exec(loc->elf_ex, executable_stack)) 729 current->personality |= READ_IMPLIES_EXEC; 730 731 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 732 current->flags |= PF_RANDOMIZE; 733 734 setup_new_exec(bprm); 735 736 /* Do this so that we can load the interpreter, if need be. We will 737 change some of these later */ 738 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), 739 executable_stack); 740 if (retval < 0) { 741 send_sig(SIGKILL, current, 0); 742 goto out_free_dentry; 743 } 744 745 current->mm->start_stack = bprm->p; 746 747 /* Now we do a little grungy work by mmapping the ELF image into 748 the correct location in memory. */ 749 for(i = 0, elf_ppnt = elf_phdata; 750 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { 751 int elf_prot = 0, elf_flags; 752 unsigned long k, vaddr; 753 754 if (elf_ppnt->p_type != PT_LOAD) 755 continue; 756 757 if (unlikely (elf_brk > elf_bss)) { 758 unsigned long nbyte; 759 760 /* There was a PT_LOAD segment with p_memsz > p_filesz 761 before this one. Map anonymous pages, if needed, 762 and clear the area. */ 763 retval = set_brk(elf_bss + load_bias, 764 elf_brk + load_bias); 765 if (retval) { 766 send_sig(SIGKILL, current, 0); 767 goto out_free_dentry; 768 } 769 nbyte = ELF_PAGEOFFSET(elf_bss); 770 if (nbyte) { 771 nbyte = ELF_MIN_ALIGN - nbyte; 772 if (nbyte > elf_brk - elf_bss) 773 nbyte = elf_brk - elf_bss; 774 if (clear_user((void __user *)elf_bss + 775 load_bias, nbyte)) { 776 /* 777 * This bss-zeroing can fail if the ELF 778 * file specifies odd protections. So 779 * we don't check the return value 780 */ 781 } 782 } 783 } 784 785 if (elf_ppnt->p_flags & PF_R) 786 elf_prot |= PROT_READ; 787 if (elf_ppnt->p_flags & PF_W) 788 elf_prot |= PROT_WRITE; 789 if (elf_ppnt->p_flags & PF_X) 790 elf_prot |= PROT_EXEC; 791 792 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; 793 794 vaddr = elf_ppnt->p_vaddr; 795 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { 796 elf_flags |= MAP_FIXED; 797 } else if (loc->elf_ex.e_type == ET_DYN) { 798 /* Try and get dynamic programs out of the way of the 799 * default mmap base, as well as whatever program they 800 * might try to exec. This is because the brk will 801 * follow the loader, and is not movable. */ 802 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE 803 /* Memory randomization might have been switched off 804 * in runtime via sysctl or explicit setting of 805 * personality flags. 806 * If that is the case, retain the original non-zero 807 * load_bias value in order to establish proper 808 * non-randomized mappings. 809 */ 810 if (current->flags & PF_RANDOMIZE) 811 load_bias = 0; 812 else 813 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 814 #else 815 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 816 #endif 817 } 818 819 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, 820 elf_prot, elf_flags, 0); 821 if (BAD_ADDR(error)) { 822 send_sig(SIGKILL, current, 0); 823 retval = IS_ERR((void *)error) ? 824 PTR_ERR((void*)error) : -EINVAL; 825 goto out_free_dentry; 826 } 827 828 if (!load_addr_set) { 829 load_addr_set = 1; 830 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); 831 if (loc->elf_ex.e_type == ET_DYN) { 832 load_bias += error - 833 ELF_PAGESTART(load_bias + vaddr); 834 load_addr += load_bias; 835 reloc_func_desc = load_bias; 836 } 837 } 838 k = elf_ppnt->p_vaddr; 839 if (k < start_code) 840 start_code = k; 841 if (start_data < k) 842 start_data = k; 843 844 /* 845 * Check to see if the section's size will overflow the 846 * allowed task size. Note that p_filesz must always be 847 * <= p_memsz so it is only necessary to check p_memsz. 848 */ 849 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || 850 elf_ppnt->p_memsz > TASK_SIZE || 851 TASK_SIZE - elf_ppnt->p_memsz < k) { 852 /* set_brk can never work. Avoid overflows. */ 853 send_sig(SIGKILL, current, 0); 854 retval = -EINVAL; 855 goto out_free_dentry; 856 } 857 858 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; 859 860 if (k > elf_bss) 861 elf_bss = k; 862 if ((elf_ppnt->p_flags & PF_X) && end_code < k) 863 end_code = k; 864 if (end_data < k) 865 end_data = k; 866 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; 867 if (k > elf_brk) 868 elf_brk = k; 869 } 870 871 loc->elf_ex.e_entry += load_bias; 872 elf_bss += load_bias; 873 elf_brk += load_bias; 874 start_code += load_bias; 875 end_code += load_bias; 876 start_data += load_bias; 877 end_data += load_bias; 878 879 /* Calling set_brk effectively mmaps the pages that we need 880 * for the bss and break sections. We must do this before 881 * mapping in the interpreter, to make sure it doesn't wind 882 * up getting placed where the bss needs to go. 883 */ 884 retval = set_brk(elf_bss, elf_brk); 885 if (retval) { 886 send_sig(SIGKILL, current, 0); 887 goto out_free_dentry; 888 } 889 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { 890 send_sig(SIGSEGV, current, 0); 891 retval = -EFAULT; /* Nobody gets to see this, but.. */ 892 goto out_free_dentry; 893 } 894 895 if (elf_interpreter) { 896 unsigned long interp_map_addr = 0; 897 898 elf_entry = load_elf_interp(&loc->interp_elf_ex, 899 interpreter, 900 &interp_map_addr, 901 load_bias); 902 if (!IS_ERR((void *)elf_entry)) { 903 /* 904 * load_elf_interp() returns relocation 905 * adjustment 906 */ 907 interp_load_addr = elf_entry; 908 elf_entry += loc->interp_elf_ex.e_entry; 909 } 910 if (BAD_ADDR(elf_entry)) { 911 force_sig(SIGSEGV, current); 912 retval = IS_ERR((void *)elf_entry) ? 913 (int)elf_entry : -EINVAL; 914 goto out_free_dentry; 915 } 916 reloc_func_desc = interp_load_addr; 917 918 allow_write_access(interpreter); 919 fput(interpreter); 920 kfree(elf_interpreter); 921 } else { 922 elf_entry = loc->elf_ex.e_entry; 923 if (BAD_ADDR(elf_entry)) { 924 force_sig(SIGSEGV, current); 925 retval = -EINVAL; 926 goto out_free_dentry; 927 } 928 } 929 930 kfree(elf_phdata); 931 932 set_binfmt(&elf_format); 933 934 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 935 retval = arch_setup_additional_pages(bprm, !!elf_interpreter); 936 if (retval < 0) { 937 send_sig(SIGKILL, current, 0); 938 goto out; 939 } 940 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ 941 942 install_exec_creds(bprm); 943 retval = create_elf_tables(bprm, &loc->elf_ex, 944 load_addr, interp_load_addr); 945 if (retval < 0) { 946 send_sig(SIGKILL, current, 0); 947 goto out; 948 } 949 /* N.B. passed_fileno might not be initialized? */ 950 current->mm->end_code = end_code; 951 current->mm->start_code = start_code; 952 current->mm->start_data = start_data; 953 current->mm->end_data = end_data; 954 current->mm->start_stack = bprm->p; 955 956 #ifdef arch_randomize_brk 957 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { 958 current->mm->brk = current->mm->start_brk = 959 arch_randomize_brk(current->mm); 960 #ifdef CONFIG_COMPAT_BRK 961 current->brk_randomized = 1; 962 #endif 963 } 964 #endif 965 966 if (current->personality & MMAP_PAGE_ZERO) { 967 /* Why this, you ask??? Well SVr4 maps page 0 as read-only, 968 and some applications "depend" upon this behavior. 969 Since we do not have the power to recompile these, we 970 emulate the SVr4 behavior. Sigh. */ 971 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, 972 MAP_FIXED | MAP_PRIVATE, 0); 973 } 974 975 #ifdef ELF_PLAT_INIT 976 /* 977 * The ABI may specify that certain registers be set up in special 978 * ways (on i386 %edx is the address of a DT_FINI function, for 979 * example. In addition, it may also specify (eg, PowerPC64 ELF) 980 * that the e_entry field is the address of the function descriptor 981 * for the startup routine, rather than the address of the startup 982 * routine itself. This macro performs whatever initialization to 983 * the regs structure is required as well as any relocations to the 984 * function descriptor entries when executing dynamically links apps. 985 */ 986 ELF_PLAT_INIT(regs, reloc_func_desc); 987 #endif 988 989 start_thread(regs, elf_entry, bprm->p); 990 retval = 0; 991 out: 992 kfree(loc); 993 out_ret: 994 return retval; 995 996 /* error cleanup */ 997 out_free_dentry: 998 allow_write_access(interpreter); 999 if (interpreter) 1000 fput(interpreter); 1001 out_free_interp: 1002 kfree(elf_interpreter); 1003 out_free_ph: 1004 kfree(elf_phdata); 1005 goto out; 1006 } 1007 1008 /* This is really simpleminded and specialized - we are loading an 1009 a.out library that is given an ELF header. */ 1010 static int load_elf_library(struct file *file) 1011 { 1012 struct elf_phdr *elf_phdata; 1013 struct elf_phdr *eppnt; 1014 unsigned long elf_bss, bss, len; 1015 int retval, error, i, j; 1016 struct elfhdr elf_ex; 1017 1018 error = -ENOEXEC; 1019 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); 1020 if (retval != sizeof(elf_ex)) 1021 goto out; 1022 1023 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 1024 goto out; 1025 1026 /* First of all, some simple consistency checks */ 1027 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || 1028 !elf_check_arch(&elf_ex) || !file->f_op->mmap) 1029 goto out; 1030 1031 /* Now read in all of the header information */ 1032 1033 j = sizeof(struct elf_phdr) * elf_ex.e_phnum; 1034 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ 1035 1036 error = -ENOMEM; 1037 elf_phdata = kmalloc(j, GFP_KERNEL); 1038 if (!elf_phdata) 1039 goto out; 1040 1041 eppnt = elf_phdata; 1042 error = -ENOEXEC; 1043 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); 1044 if (retval != j) 1045 goto out_free_ph; 1046 1047 for (j = 0, i = 0; i<elf_ex.e_phnum; i++) 1048 if ((eppnt + i)->p_type == PT_LOAD) 1049 j++; 1050 if (j != 1) 1051 goto out_free_ph; 1052 1053 while (eppnt->p_type != PT_LOAD) 1054 eppnt++; 1055 1056 /* Now use mmap to map the library into memory. */ 1057 error = vm_mmap(file, 1058 ELF_PAGESTART(eppnt->p_vaddr), 1059 (eppnt->p_filesz + 1060 ELF_PAGEOFFSET(eppnt->p_vaddr)), 1061 PROT_READ | PROT_WRITE | PROT_EXEC, 1062 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, 1063 (eppnt->p_offset - 1064 ELF_PAGEOFFSET(eppnt->p_vaddr))); 1065 if (error != ELF_PAGESTART(eppnt->p_vaddr)) 1066 goto out_free_ph; 1067 1068 elf_bss = eppnt->p_vaddr + eppnt->p_filesz; 1069 if (padzero(elf_bss)) { 1070 error = -EFAULT; 1071 goto out_free_ph; 1072 } 1073 1074 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + 1075 ELF_MIN_ALIGN - 1); 1076 bss = eppnt->p_memsz + eppnt->p_vaddr; 1077 if (bss > len) 1078 vm_brk(len, bss - len); 1079 error = 0; 1080 1081 out_free_ph: 1082 kfree(elf_phdata); 1083 out: 1084 return error; 1085 } 1086 1087 #ifdef CONFIG_ELF_CORE 1088 /* 1089 * ELF core dumper 1090 * 1091 * Modelled on fs/exec.c:aout_core_dump() 1092 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1093 */ 1094 1095 /* 1096 * The purpose of always_dump_vma() is to make sure that special kernel mappings 1097 * that are useful for post-mortem analysis are included in every core dump. 1098 * In that way we ensure that the core dump is fully interpretable later 1099 * without matching up the same kernel and hardware config to see what PC values 1100 * meant. These special mappings include - vDSO, vsyscall, and other 1101 * architecture specific mappings 1102 */ 1103 static bool always_dump_vma(struct vm_area_struct *vma) 1104 { 1105 /* Any vsyscall mappings? */ 1106 if (vma == get_gate_vma(vma->vm_mm)) 1107 return true; 1108 /* 1109 * arch_vma_name() returns non-NULL for special architecture mappings, 1110 * such as vDSO sections. 1111 */ 1112 if (arch_vma_name(vma)) 1113 return true; 1114 1115 return false; 1116 } 1117 1118 /* 1119 * Decide what to dump of a segment, part, all or none. 1120 */ 1121 static unsigned long vma_dump_size(struct vm_area_struct *vma, 1122 unsigned long mm_flags) 1123 { 1124 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) 1125 1126 /* always dump the vdso and vsyscall sections */ 1127 if (always_dump_vma(vma)) 1128 goto whole; 1129 1130 if (vma->vm_flags & VM_DONTDUMP) 1131 return 0; 1132 1133 /* Hugetlb memory check */ 1134 if (vma->vm_flags & VM_HUGETLB) { 1135 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) 1136 goto whole; 1137 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) 1138 goto whole; 1139 return 0; 1140 } 1141 1142 /* Do not dump I/O mapped devices or special mappings */ 1143 if (vma->vm_flags & VM_IO) 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 (file_inode(vma->vm_file)->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 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1226 { 1227 struct elf_note en; 1228 en.n_namesz = strlen(men->name) + 1; 1229 en.n_descsz = men->datasz; 1230 en.n_type = men->type; 1231 1232 return dump_emit(cprm, &en, sizeof(en)) && 1233 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1234 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1235 } 1236 1237 static void fill_elf_header(struct elfhdr *elf, int segs, 1238 u16 machine, u32 flags) 1239 { 1240 memset(elf, 0, sizeof(*elf)); 1241 1242 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1243 elf->e_ident[EI_CLASS] = ELF_CLASS; 1244 elf->e_ident[EI_DATA] = ELF_DATA; 1245 elf->e_ident[EI_VERSION] = EV_CURRENT; 1246 elf->e_ident[EI_OSABI] = ELF_OSABI; 1247 1248 elf->e_type = ET_CORE; 1249 elf->e_machine = machine; 1250 elf->e_version = EV_CURRENT; 1251 elf->e_phoff = sizeof(struct elfhdr); 1252 elf->e_flags = flags; 1253 elf->e_ehsize = sizeof(struct elfhdr); 1254 elf->e_phentsize = sizeof(struct elf_phdr); 1255 elf->e_phnum = segs; 1256 1257 return; 1258 } 1259 1260 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1261 { 1262 phdr->p_type = PT_NOTE; 1263 phdr->p_offset = offset; 1264 phdr->p_vaddr = 0; 1265 phdr->p_paddr = 0; 1266 phdr->p_filesz = sz; 1267 phdr->p_memsz = 0; 1268 phdr->p_flags = 0; 1269 phdr->p_align = 0; 1270 return; 1271 } 1272 1273 static void fill_note(struct memelfnote *note, const char *name, int type, 1274 unsigned int sz, void *data) 1275 { 1276 note->name = name; 1277 note->type = type; 1278 note->datasz = sz; 1279 note->data = data; 1280 return; 1281 } 1282 1283 /* 1284 * fill up all the fields in prstatus from the given task struct, except 1285 * registers which need to be filled up separately. 1286 */ 1287 static void fill_prstatus(struct elf_prstatus *prstatus, 1288 struct task_struct *p, long signr) 1289 { 1290 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1291 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1292 prstatus->pr_sighold = p->blocked.sig[0]; 1293 rcu_read_lock(); 1294 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1295 rcu_read_unlock(); 1296 prstatus->pr_pid = task_pid_vnr(p); 1297 prstatus->pr_pgrp = task_pgrp_vnr(p); 1298 prstatus->pr_sid = task_session_vnr(p); 1299 if (thread_group_leader(p)) { 1300 struct task_cputime cputime; 1301 1302 /* 1303 * This is the record for the group leader. It shows the 1304 * group-wide total, not its individual thread total. 1305 */ 1306 thread_group_cputime(p, &cputime); 1307 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1308 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1309 } else { 1310 cputime_t utime, stime; 1311 1312 task_cputime(p, &utime, &stime); 1313 cputime_to_timeval(utime, &prstatus->pr_utime); 1314 cputime_to_timeval(stime, &prstatus->pr_stime); 1315 } 1316 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1317 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1318 } 1319 1320 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1321 struct mm_struct *mm) 1322 { 1323 const struct cred *cred; 1324 unsigned int i, len; 1325 1326 /* first copy the parameters from user space */ 1327 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1328 1329 len = mm->arg_end - mm->arg_start; 1330 if (len >= ELF_PRARGSZ) 1331 len = ELF_PRARGSZ-1; 1332 if (copy_from_user(&psinfo->pr_psargs, 1333 (const char __user *)mm->arg_start, len)) 1334 return -EFAULT; 1335 for(i = 0; i < len; i++) 1336 if (psinfo->pr_psargs[i] == 0) 1337 psinfo->pr_psargs[i] = ' '; 1338 psinfo->pr_psargs[len] = 0; 1339 1340 rcu_read_lock(); 1341 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1342 rcu_read_unlock(); 1343 psinfo->pr_pid = task_pid_vnr(p); 1344 psinfo->pr_pgrp = task_pgrp_vnr(p); 1345 psinfo->pr_sid = task_session_vnr(p); 1346 1347 i = p->state ? ffz(~p->state) + 1 : 0; 1348 psinfo->pr_state = i; 1349 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1350 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1351 psinfo->pr_nice = task_nice(p); 1352 psinfo->pr_flag = p->flags; 1353 rcu_read_lock(); 1354 cred = __task_cred(p); 1355 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1356 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1357 rcu_read_unlock(); 1358 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1359 1360 return 0; 1361 } 1362 1363 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) 1364 { 1365 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; 1366 int i = 0; 1367 do 1368 i += 2; 1369 while (auxv[i - 2] != AT_NULL); 1370 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1371 } 1372 1373 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, 1374 const siginfo_t *siginfo) 1375 { 1376 mm_segment_t old_fs = get_fs(); 1377 set_fs(KERNEL_DS); 1378 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo); 1379 set_fs(old_fs); 1380 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); 1381 } 1382 1383 #define MAX_FILE_NOTE_SIZE (4*1024*1024) 1384 /* 1385 * Format of NT_FILE note: 1386 * 1387 * long count -- how many files are mapped 1388 * long page_size -- units for file_ofs 1389 * array of [COUNT] elements of 1390 * long start 1391 * long end 1392 * long file_ofs 1393 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL... 1394 */ 1395 static int fill_files_note(struct memelfnote *note) 1396 { 1397 struct vm_area_struct *vma; 1398 unsigned count, size, names_ofs, remaining, n; 1399 user_long_t *data; 1400 user_long_t *start_end_ofs; 1401 char *name_base, *name_curpos; 1402 1403 /* *Estimated* file count and total data size needed */ 1404 count = current->mm->map_count; 1405 size = count * 64; 1406 1407 names_ofs = (2 + 3 * count) * sizeof(data[0]); 1408 alloc: 1409 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */ 1410 return -EINVAL; 1411 size = round_up(size, PAGE_SIZE); 1412 data = vmalloc(size); 1413 if (!data) 1414 return -ENOMEM; 1415 1416 start_end_ofs = data + 2; 1417 name_base = name_curpos = ((char *)data) + names_ofs; 1418 remaining = size - names_ofs; 1419 count = 0; 1420 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) { 1421 struct file *file; 1422 const char *filename; 1423 1424 file = vma->vm_file; 1425 if (!file) 1426 continue; 1427 filename = d_path(&file->f_path, name_curpos, remaining); 1428 if (IS_ERR(filename)) { 1429 if (PTR_ERR(filename) == -ENAMETOOLONG) { 1430 vfree(data); 1431 size = size * 5 / 4; 1432 goto alloc; 1433 } 1434 continue; 1435 } 1436 1437 /* d_path() fills at the end, move name down */ 1438 /* n = strlen(filename) + 1: */ 1439 n = (name_curpos + remaining) - filename; 1440 remaining = filename - name_curpos; 1441 memmove(name_curpos, filename, n); 1442 name_curpos += n; 1443 1444 *start_end_ofs++ = vma->vm_start; 1445 *start_end_ofs++ = vma->vm_end; 1446 *start_end_ofs++ = vma->vm_pgoff; 1447 count++; 1448 } 1449 1450 /* Now we know exact count of files, can store it */ 1451 data[0] = count; 1452 data[1] = PAGE_SIZE; 1453 /* 1454 * Count usually is less than current->mm->map_count, 1455 * we need to move filenames down. 1456 */ 1457 n = current->mm->map_count - count; 1458 if (n != 0) { 1459 unsigned shift_bytes = n * 3 * sizeof(data[0]); 1460 memmove(name_base - shift_bytes, name_base, 1461 name_curpos - name_base); 1462 name_curpos -= shift_bytes; 1463 } 1464 1465 size = name_curpos - (char *)data; 1466 fill_note(note, "CORE", NT_FILE, size, data); 1467 return 0; 1468 } 1469 1470 #ifdef CORE_DUMP_USE_REGSET 1471 #include <linux/regset.h> 1472 1473 struct elf_thread_core_info { 1474 struct elf_thread_core_info *next; 1475 struct task_struct *task; 1476 struct elf_prstatus prstatus; 1477 struct memelfnote notes[0]; 1478 }; 1479 1480 struct elf_note_info { 1481 struct elf_thread_core_info *thread; 1482 struct memelfnote psinfo; 1483 struct memelfnote signote; 1484 struct memelfnote auxv; 1485 struct memelfnote files; 1486 user_siginfo_t csigdata; 1487 size_t size; 1488 int thread_notes; 1489 }; 1490 1491 /* 1492 * When a regset has a writeback hook, we call it on each thread before 1493 * dumping user memory. On register window machines, this makes sure the 1494 * user memory backing the register data is up to date before we read it. 1495 */ 1496 static void do_thread_regset_writeback(struct task_struct *task, 1497 const struct user_regset *regset) 1498 { 1499 if (regset->writeback) 1500 regset->writeback(task, regset, 1); 1501 } 1502 1503 #ifndef PR_REG_SIZE 1504 #define PR_REG_SIZE(S) sizeof(S) 1505 #endif 1506 1507 #ifndef PRSTATUS_SIZE 1508 #define PRSTATUS_SIZE(S) sizeof(S) 1509 #endif 1510 1511 #ifndef PR_REG_PTR 1512 #define PR_REG_PTR(S) (&((S)->pr_reg)) 1513 #endif 1514 1515 #ifndef SET_PR_FPVALID 1516 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V)) 1517 #endif 1518 1519 static int fill_thread_core_info(struct elf_thread_core_info *t, 1520 const struct user_regset_view *view, 1521 long signr, size_t *total) 1522 { 1523 unsigned int i; 1524 1525 /* 1526 * NT_PRSTATUS is the one special case, because the regset data 1527 * goes into the pr_reg field inside the note contents, rather 1528 * than being the whole note contents. We fill the reset in here. 1529 * We assume that regset 0 is NT_PRSTATUS. 1530 */ 1531 fill_prstatus(&t->prstatus, t->task, signr); 1532 (void) view->regsets[0].get(t->task, &view->regsets[0], 1533 0, PR_REG_SIZE(t->prstatus.pr_reg), 1534 PR_REG_PTR(&t->prstatus), NULL); 1535 1536 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, 1537 PRSTATUS_SIZE(t->prstatus), &t->prstatus); 1538 *total += notesize(&t->notes[0]); 1539 1540 do_thread_regset_writeback(t->task, &view->regsets[0]); 1541 1542 /* 1543 * Each other regset might generate a note too. For each regset 1544 * that has no core_note_type or is inactive, we leave t->notes[i] 1545 * all zero and we'll know to skip writing it later. 1546 */ 1547 for (i = 1; i < view->n; ++i) { 1548 const struct user_regset *regset = &view->regsets[i]; 1549 do_thread_regset_writeback(t->task, regset); 1550 if (regset->core_note_type && regset->get && 1551 (!regset->active || regset->active(t->task, regset))) { 1552 int ret; 1553 size_t size = regset->n * regset->size; 1554 void *data = kmalloc(size, GFP_KERNEL); 1555 if (unlikely(!data)) 1556 return 0; 1557 ret = regset->get(t->task, regset, 1558 0, size, data, NULL); 1559 if (unlikely(ret)) 1560 kfree(data); 1561 else { 1562 if (regset->core_note_type != NT_PRFPREG) 1563 fill_note(&t->notes[i], "LINUX", 1564 regset->core_note_type, 1565 size, data); 1566 else { 1567 SET_PR_FPVALID(&t->prstatus, 1); 1568 fill_note(&t->notes[i], "CORE", 1569 NT_PRFPREG, size, data); 1570 } 1571 *total += notesize(&t->notes[i]); 1572 } 1573 } 1574 } 1575 1576 return 1; 1577 } 1578 1579 static int fill_note_info(struct elfhdr *elf, int phdrs, 1580 struct elf_note_info *info, 1581 const siginfo_t *siginfo, struct pt_regs *regs) 1582 { 1583 struct task_struct *dump_task = current; 1584 const struct user_regset_view *view = task_user_regset_view(dump_task); 1585 struct elf_thread_core_info *t; 1586 struct elf_prpsinfo *psinfo; 1587 struct core_thread *ct; 1588 unsigned int i; 1589 1590 info->size = 0; 1591 info->thread = NULL; 1592 1593 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1594 if (psinfo == NULL) { 1595 info->psinfo.data = NULL; /* So we don't free this wrongly */ 1596 return 0; 1597 } 1598 1599 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1600 1601 /* 1602 * Figure out how many notes we're going to need for each thread. 1603 */ 1604 info->thread_notes = 0; 1605 for (i = 0; i < view->n; ++i) 1606 if (view->regsets[i].core_note_type != 0) 1607 ++info->thread_notes; 1608 1609 /* 1610 * Sanity check. We rely on regset 0 being in NT_PRSTATUS, 1611 * since it is our one special case. 1612 */ 1613 if (unlikely(info->thread_notes == 0) || 1614 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { 1615 WARN_ON(1); 1616 return 0; 1617 } 1618 1619 /* 1620 * Initialize the ELF file header. 1621 */ 1622 fill_elf_header(elf, phdrs, 1623 view->e_machine, view->e_flags); 1624 1625 /* 1626 * Allocate a structure for each thread. 1627 */ 1628 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { 1629 t = kzalloc(offsetof(struct elf_thread_core_info, 1630 notes[info->thread_notes]), 1631 GFP_KERNEL); 1632 if (unlikely(!t)) 1633 return 0; 1634 1635 t->task = ct->task; 1636 if (ct->task == dump_task || !info->thread) { 1637 t->next = info->thread; 1638 info->thread = t; 1639 } else { 1640 /* 1641 * Make sure to keep the original task at 1642 * the head of the list. 1643 */ 1644 t->next = info->thread->next; 1645 info->thread->next = t; 1646 } 1647 } 1648 1649 /* 1650 * Now fill in each thread's information. 1651 */ 1652 for (t = info->thread; t != NULL; t = t->next) 1653 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size)) 1654 return 0; 1655 1656 /* 1657 * Fill in the two process-wide notes. 1658 */ 1659 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); 1660 info->size += notesize(&info->psinfo); 1661 1662 fill_siginfo_note(&info->signote, &info->csigdata, siginfo); 1663 info->size += notesize(&info->signote); 1664 1665 fill_auxv_note(&info->auxv, current->mm); 1666 info->size += notesize(&info->auxv); 1667 1668 if (fill_files_note(&info->files) == 0) 1669 info->size += notesize(&info->files); 1670 1671 return 1; 1672 } 1673 1674 static size_t get_note_info_size(struct elf_note_info *info) 1675 { 1676 return info->size; 1677 } 1678 1679 /* 1680 * Write all the notes for each thread. When writing the first thread, the 1681 * process-wide notes are interleaved after the first thread-specific note. 1682 */ 1683 static int write_note_info(struct elf_note_info *info, 1684 struct coredump_params *cprm) 1685 { 1686 bool first = 1; 1687 struct elf_thread_core_info *t = info->thread; 1688 1689 do { 1690 int i; 1691 1692 if (!writenote(&t->notes[0], cprm)) 1693 return 0; 1694 1695 if (first && !writenote(&info->psinfo, cprm)) 1696 return 0; 1697 if (first && !writenote(&info->signote, cprm)) 1698 return 0; 1699 if (first && !writenote(&info->auxv, cprm)) 1700 return 0; 1701 if (first && info->files.data && 1702 !writenote(&info->files, cprm)) 1703 return 0; 1704 1705 for (i = 1; i < info->thread_notes; ++i) 1706 if (t->notes[i].data && 1707 !writenote(&t->notes[i], cprm)) 1708 return 0; 1709 1710 first = 0; 1711 t = t->next; 1712 } while (t); 1713 1714 return 1; 1715 } 1716 1717 static void free_note_info(struct elf_note_info *info) 1718 { 1719 struct elf_thread_core_info *threads = info->thread; 1720 while (threads) { 1721 unsigned int i; 1722 struct elf_thread_core_info *t = threads; 1723 threads = t->next; 1724 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); 1725 for (i = 1; i < info->thread_notes; ++i) 1726 kfree(t->notes[i].data); 1727 kfree(t); 1728 } 1729 kfree(info->psinfo.data); 1730 vfree(info->files.data); 1731 } 1732 1733 #else 1734 1735 /* Here is the structure in which status of each thread is captured. */ 1736 struct elf_thread_status 1737 { 1738 struct list_head list; 1739 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1740 elf_fpregset_t fpu; /* NT_PRFPREG */ 1741 struct task_struct *thread; 1742 #ifdef ELF_CORE_COPY_XFPREGS 1743 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1744 #endif 1745 struct memelfnote notes[3]; 1746 int num_notes; 1747 }; 1748 1749 /* 1750 * In order to add the specific thread information for the elf file format, 1751 * we need to keep a linked list of every threads pr_status and then create 1752 * a single section for them in the final core file. 1753 */ 1754 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1755 { 1756 int sz = 0; 1757 struct task_struct *p = t->thread; 1758 t->num_notes = 0; 1759 1760 fill_prstatus(&t->prstatus, p, signr); 1761 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1762 1763 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1764 &(t->prstatus)); 1765 t->num_notes++; 1766 sz += notesize(&t->notes[0]); 1767 1768 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, 1769 &t->fpu))) { 1770 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1771 &(t->fpu)); 1772 t->num_notes++; 1773 sz += notesize(&t->notes[1]); 1774 } 1775 1776 #ifdef ELF_CORE_COPY_XFPREGS 1777 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1778 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1779 sizeof(t->xfpu), &t->xfpu); 1780 t->num_notes++; 1781 sz += notesize(&t->notes[2]); 1782 } 1783 #endif 1784 return sz; 1785 } 1786 1787 struct elf_note_info { 1788 struct memelfnote *notes; 1789 struct memelfnote *notes_files; 1790 struct elf_prstatus *prstatus; /* NT_PRSTATUS */ 1791 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ 1792 struct list_head thread_list; 1793 elf_fpregset_t *fpu; 1794 #ifdef ELF_CORE_COPY_XFPREGS 1795 elf_fpxregset_t *xfpu; 1796 #endif 1797 user_siginfo_t csigdata; 1798 int thread_status_size; 1799 int numnote; 1800 }; 1801 1802 static int elf_note_info_init(struct elf_note_info *info) 1803 { 1804 memset(info, 0, sizeof(*info)); 1805 INIT_LIST_HEAD(&info->thread_list); 1806 1807 /* Allocate space for ELF notes */ 1808 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL); 1809 if (!info->notes) 1810 return 0; 1811 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); 1812 if (!info->psinfo) 1813 return 0; 1814 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); 1815 if (!info->prstatus) 1816 return 0; 1817 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); 1818 if (!info->fpu) 1819 return 0; 1820 #ifdef ELF_CORE_COPY_XFPREGS 1821 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); 1822 if (!info->xfpu) 1823 return 0; 1824 #endif 1825 return 1; 1826 } 1827 1828 static int fill_note_info(struct elfhdr *elf, int phdrs, 1829 struct elf_note_info *info, 1830 const siginfo_t *siginfo, struct pt_regs *regs) 1831 { 1832 struct list_head *t; 1833 struct core_thread *ct; 1834 struct elf_thread_status *ets; 1835 1836 if (!elf_note_info_init(info)) 1837 return 0; 1838 1839 for (ct = current->mm->core_state->dumper.next; 1840 ct; ct = ct->next) { 1841 ets = kzalloc(sizeof(*ets), GFP_KERNEL); 1842 if (!ets) 1843 return 0; 1844 1845 ets->thread = ct->task; 1846 list_add(&ets->list, &info->thread_list); 1847 } 1848 1849 list_for_each(t, &info->thread_list) { 1850 int sz; 1851 1852 ets = list_entry(t, struct elf_thread_status, list); 1853 sz = elf_dump_thread_status(siginfo->si_signo, ets); 1854 info->thread_status_size += sz; 1855 } 1856 /* now collect the dump for the current */ 1857 memset(info->prstatus, 0, sizeof(*info->prstatus)); 1858 fill_prstatus(info->prstatus, current, siginfo->si_signo); 1859 elf_core_copy_regs(&info->prstatus->pr_reg, regs); 1860 1861 /* Set up header */ 1862 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS); 1863 1864 /* 1865 * Set up the notes in similar form to SVR4 core dumps made 1866 * with info from their /proc. 1867 */ 1868 1869 fill_note(info->notes + 0, "CORE", NT_PRSTATUS, 1870 sizeof(*info->prstatus), info->prstatus); 1871 fill_psinfo(info->psinfo, current->group_leader, current->mm); 1872 fill_note(info->notes + 1, "CORE", NT_PRPSINFO, 1873 sizeof(*info->psinfo), info->psinfo); 1874 1875 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo); 1876 fill_auxv_note(info->notes + 3, current->mm); 1877 info->numnote = 4; 1878 1879 if (fill_files_note(info->notes + info->numnote) == 0) { 1880 info->notes_files = info->notes + info->numnote; 1881 info->numnote++; 1882 } 1883 1884 /* Try to dump the FPU. */ 1885 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, 1886 info->fpu); 1887 if (info->prstatus->pr_fpvalid) 1888 fill_note(info->notes + info->numnote++, 1889 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); 1890 #ifdef ELF_CORE_COPY_XFPREGS 1891 if (elf_core_copy_task_xfpregs(current, info->xfpu)) 1892 fill_note(info->notes + info->numnote++, 1893 "LINUX", ELF_CORE_XFPREG_TYPE, 1894 sizeof(*info->xfpu), info->xfpu); 1895 #endif 1896 1897 return 1; 1898 } 1899 1900 static size_t get_note_info_size(struct elf_note_info *info) 1901 { 1902 int sz = 0; 1903 int i; 1904 1905 for (i = 0; i < info->numnote; i++) 1906 sz += notesize(info->notes + i); 1907 1908 sz += info->thread_status_size; 1909 1910 return sz; 1911 } 1912 1913 static int write_note_info(struct elf_note_info *info, 1914 struct coredump_params *cprm) 1915 { 1916 int i; 1917 struct list_head *t; 1918 1919 for (i = 0; i < info->numnote; i++) 1920 if (!writenote(info->notes + i, cprm)) 1921 return 0; 1922 1923 /* write out the thread status notes section */ 1924 list_for_each(t, &info->thread_list) { 1925 struct elf_thread_status *tmp = 1926 list_entry(t, struct elf_thread_status, list); 1927 1928 for (i = 0; i < tmp->num_notes; i++) 1929 if (!writenote(&tmp->notes[i], cprm)) 1930 return 0; 1931 } 1932 1933 return 1; 1934 } 1935 1936 static void free_note_info(struct elf_note_info *info) 1937 { 1938 while (!list_empty(&info->thread_list)) { 1939 struct list_head *tmp = info->thread_list.next; 1940 list_del(tmp); 1941 kfree(list_entry(tmp, struct elf_thread_status, list)); 1942 } 1943 1944 /* Free data possibly allocated by fill_files_note(): */ 1945 if (info->notes_files) 1946 vfree(info->notes_files->data); 1947 1948 kfree(info->prstatus); 1949 kfree(info->psinfo); 1950 kfree(info->notes); 1951 kfree(info->fpu); 1952 #ifdef ELF_CORE_COPY_XFPREGS 1953 kfree(info->xfpu); 1954 #endif 1955 } 1956 1957 #endif 1958 1959 static struct vm_area_struct *first_vma(struct task_struct *tsk, 1960 struct vm_area_struct *gate_vma) 1961 { 1962 struct vm_area_struct *ret = tsk->mm->mmap; 1963 1964 if (ret) 1965 return ret; 1966 return gate_vma; 1967 } 1968 /* 1969 * Helper function for iterating across a vma list. It ensures that the caller 1970 * will visit `gate_vma' prior to terminating the search. 1971 */ 1972 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, 1973 struct vm_area_struct *gate_vma) 1974 { 1975 struct vm_area_struct *ret; 1976 1977 ret = this_vma->vm_next; 1978 if (ret) 1979 return ret; 1980 if (this_vma == gate_vma) 1981 return NULL; 1982 return gate_vma; 1983 } 1984 1985 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1986 elf_addr_t e_shoff, int segs) 1987 { 1988 elf->e_shoff = e_shoff; 1989 elf->e_shentsize = sizeof(*shdr4extnum); 1990 elf->e_shnum = 1; 1991 elf->e_shstrndx = SHN_UNDEF; 1992 1993 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1994 1995 shdr4extnum->sh_type = SHT_NULL; 1996 shdr4extnum->sh_size = elf->e_shnum; 1997 shdr4extnum->sh_link = elf->e_shstrndx; 1998 shdr4extnum->sh_info = segs; 1999 } 2000 2001 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, 2002 unsigned long mm_flags) 2003 { 2004 struct vm_area_struct *vma; 2005 size_t size = 0; 2006 2007 for (vma = first_vma(current, gate_vma); vma != NULL; 2008 vma = next_vma(vma, gate_vma)) 2009 size += vma_dump_size(vma, mm_flags); 2010 return size; 2011 } 2012 2013 /* 2014 * Actual dumper 2015 * 2016 * This is a two-pass process; first we find the offsets of the bits, 2017 * and then they are actually written out. If we run out of core limit 2018 * we just truncate. 2019 */ 2020 static int elf_core_dump(struct coredump_params *cprm) 2021 { 2022 int has_dumped = 0; 2023 mm_segment_t fs; 2024 int segs; 2025 struct vm_area_struct *vma, *gate_vma; 2026 struct elfhdr *elf = NULL; 2027 loff_t offset = 0, dataoff; 2028 struct elf_note_info info = { }; 2029 struct elf_phdr *phdr4note = NULL; 2030 struct elf_shdr *shdr4extnum = NULL; 2031 Elf_Half e_phnum; 2032 elf_addr_t e_shoff; 2033 2034 /* 2035 * We no longer stop all VM operations. 2036 * 2037 * This is because those proceses that could possibly change map_count 2038 * or the mmap / vma pages are now blocked in do_exit on current 2039 * finishing this core dump. 2040 * 2041 * Only ptrace can touch these memory addresses, but it doesn't change 2042 * the map_count or the pages allocated. So no possibility of crashing 2043 * exists while dumping the mm->vm_next areas to the core file. 2044 */ 2045 2046 /* alloc memory for large data structures: too large to be on stack */ 2047 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 2048 if (!elf) 2049 goto out; 2050 /* 2051 * The number of segs are recored into ELF header as 16bit value. 2052 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. 2053 */ 2054 segs = current->mm->map_count; 2055 segs += elf_core_extra_phdrs(); 2056 2057 gate_vma = get_gate_vma(current->mm); 2058 if (gate_vma != NULL) 2059 segs++; 2060 2061 /* for notes section */ 2062 segs++; 2063 2064 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 2065 * this, kernel supports extended numbering. Have a look at 2066 * include/linux/elf.h for further information. */ 2067 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 2068 2069 /* 2070 * Collect all the non-memory information about the process for the 2071 * notes. This also sets up the file header. 2072 */ 2073 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs)) 2074 goto cleanup; 2075 2076 has_dumped = 1; 2077 2078 fs = get_fs(); 2079 set_fs(KERNEL_DS); 2080 2081 offset += sizeof(*elf); /* Elf header */ 2082 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 2083 2084 /* Write notes phdr entry */ 2085 { 2086 size_t sz = get_note_info_size(&info); 2087 2088 sz += elf_coredump_extra_notes_size(); 2089 2090 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 2091 if (!phdr4note) 2092 goto end_coredump; 2093 2094 fill_elf_note_phdr(phdr4note, sz, offset); 2095 offset += sz; 2096 } 2097 2098 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 2099 2100 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags); 2101 offset += elf_core_extra_data_size(); 2102 e_shoff = offset; 2103 2104 if (e_phnum == PN_XNUM) { 2105 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 2106 if (!shdr4extnum) 2107 goto end_coredump; 2108 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 2109 } 2110 2111 offset = dataoff; 2112 2113 if (!dump_emit(cprm, elf, sizeof(*elf))) 2114 goto end_coredump; 2115 2116 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 2117 goto end_coredump; 2118 2119 /* Write program headers for segments dump */ 2120 for (vma = first_vma(current, gate_vma); vma != NULL; 2121 vma = next_vma(vma, gate_vma)) { 2122 struct elf_phdr phdr; 2123 2124 phdr.p_type = PT_LOAD; 2125 phdr.p_offset = offset; 2126 phdr.p_vaddr = vma->vm_start; 2127 phdr.p_paddr = 0; 2128 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags); 2129 phdr.p_memsz = vma->vm_end - vma->vm_start; 2130 offset += phdr.p_filesz; 2131 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 2132 if (vma->vm_flags & VM_WRITE) 2133 phdr.p_flags |= PF_W; 2134 if (vma->vm_flags & VM_EXEC) 2135 phdr.p_flags |= PF_X; 2136 phdr.p_align = ELF_EXEC_PAGESIZE; 2137 2138 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 2139 goto end_coredump; 2140 } 2141 2142 if (!elf_core_write_extra_phdrs(cprm, offset)) 2143 goto end_coredump; 2144 2145 /* write out the notes section */ 2146 if (!write_note_info(&info, cprm)) 2147 goto end_coredump; 2148 2149 if (elf_coredump_extra_notes_write(cprm)) 2150 goto end_coredump; 2151 2152 /* Align to page */ 2153 if (!dump_skip(cprm, dataoff - cprm->written)) 2154 goto end_coredump; 2155 2156 for (vma = first_vma(current, gate_vma); vma != NULL; 2157 vma = next_vma(vma, gate_vma)) { 2158 unsigned long addr; 2159 unsigned long end; 2160 2161 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags); 2162 2163 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { 2164 struct page *page; 2165 int stop; 2166 2167 page = get_dump_page(addr); 2168 if (page) { 2169 void *kaddr = kmap(page); 2170 stop = !dump_emit(cprm, kaddr, PAGE_SIZE); 2171 kunmap(page); 2172 page_cache_release(page); 2173 } else 2174 stop = !dump_skip(cprm, PAGE_SIZE); 2175 if (stop) 2176 goto end_coredump; 2177 } 2178 } 2179 2180 if (!elf_core_write_extra_data(cprm)) 2181 goto end_coredump; 2182 2183 if (e_phnum == PN_XNUM) { 2184 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 2185 goto end_coredump; 2186 } 2187 2188 end_coredump: 2189 set_fs(fs); 2190 2191 cleanup: 2192 free_note_info(&info); 2193 kfree(shdr4extnum); 2194 kfree(phdr4note); 2195 kfree(elf); 2196 out: 2197 return has_dumped; 2198 } 2199 2200 #endif /* CONFIG_ELF_CORE */ 2201 2202 static int __init init_elf_binfmt(void) 2203 { 2204 register_binfmt(&elf_format); 2205 return 0; 2206 } 2207 2208 static void __exit exit_elf_binfmt(void) 2209 { 2210 /* Remove the COFF and ELF loaders. */ 2211 unregister_binfmt(&elf_format); 2212 } 2213 2214 core_initcall(init_elf_binfmt); 2215 module_exit(exit_elf_binfmt); 2216 MODULE_LICENSE("GPL"); 2217