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 #define INTERPRETER_NONE 0 547 #define INTERPRETER_ELF 2 548 549 #ifndef STACK_RND_MASK 550 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ 551 #endif 552 553 static unsigned long randomize_stack_top(unsigned long stack_top) 554 { 555 unsigned int random_variable = 0; 556 557 if ((current->flags & PF_RANDOMIZE) && 558 !(current->personality & ADDR_NO_RANDOMIZE)) { 559 random_variable = get_random_int() & STACK_RND_MASK; 560 random_variable <<= PAGE_SHIFT; 561 } 562 #ifdef CONFIG_STACK_GROWSUP 563 return PAGE_ALIGN(stack_top) + random_variable; 564 #else 565 return PAGE_ALIGN(stack_top) - random_variable; 566 #endif 567 } 568 569 static int load_elf_binary(struct linux_binprm *bprm) 570 { 571 struct file *interpreter = NULL; /* to shut gcc up */ 572 unsigned long load_addr = 0, load_bias = 0; 573 int load_addr_set = 0; 574 char * elf_interpreter = NULL; 575 unsigned long error; 576 struct elf_phdr *elf_ppnt, *elf_phdata; 577 unsigned long elf_bss, elf_brk; 578 int retval, i; 579 unsigned int size; 580 unsigned long elf_entry; 581 unsigned long interp_load_addr = 0; 582 unsigned long start_code, end_code, start_data, end_data; 583 unsigned long reloc_func_desc __maybe_unused = 0; 584 int executable_stack = EXSTACK_DEFAULT; 585 unsigned long def_flags = 0; 586 struct pt_regs *regs = current_pt_regs(); 587 struct { 588 struct elfhdr elf_ex; 589 struct elfhdr interp_elf_ex; 590 } *loc; 591 592 loc = kmalloc(sizeof(*loc), GFP_KERNEL); 593 if (!loc) { 594 retval = -ENOMEM; 595 goto out_ret; 596 } 597 598 /* Get the exec-header */ 599 loc->elf_ex = *((struct elfhdr *)bprm->buf); 600 601 retval = -ENOEXEC; 602 /* First of all, some simple consistency checks */ 603 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 604 goto out; 605 606 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) 607 goto out; 608 if (!elf_check_arch(&loc->elf_ex)) 609 goto out; 610 if (!bprm->file->f_op->mmap) 611 goto out; 612 613 /* Now read in all of the header information */ 614 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) 615 goto out; 616 if (loc->elf_ex.e_phnum < 1 || 617 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) 618 goto out; 619 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); 620 retval = -ENOMEM; 621 elf_phdata = kmalloc(size, GFP_KERNEL); 622 if (!elf_phdata) 623 goto out; 624 625 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, 626 (char *)elf_phdata, size); 627 if (retval != size) { 628 if (retval >= 0) 629 retval = -EIO; 630 goto out_free_ph; 631 } 632 633 elf_ppnt = elf_phdata; 634 elf_bss = 0; 635 elf_brk = 0; 636 637 start_code = ~0UL; 638 end_code = 0; 639 start_data = 0; 640 end_data = 0; 641 642 for (i = 0; i < loc->elf_ex.e_phnum; i++) { 643 if (elf_ppnt->p_type == PT_INTERP) { 644 /* This is the program interpreter used for 645 * shared libraries - for now assume that this 646 * is an a.out format binary 647 */ 648 retval = -ENOEXEC; 649 if (elf_ppnt->p_filesz > PATH_MAX || 650 elf_ppnt->p_filesz < 2) 651 goto out_free_ph; 652 653 retval = -ENOMEM; 654 elf_interpreter = kmalloc(elf_ppnt->p_filesz, 655 GFP_KERNEL); 656 if (!elf_interpreter) 657 goto out_free_ph; 658 659 retval = kernel_read(bprm->file, elf_ppnt->p_offset, 660 elf_interpreter, 661 elf_ppnt->p_filesz); 662 if (retval != elf_ppnt->p_filesz) { 663 if (retval >= 0) 664 retval = -EIO; 665 goto out_free_interp; 666 } 667 /* make sure path is NULL terminated */ 668 retval = -ENOEXEC; 669 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') 670 goto out_free_interp; 671 672 interpreter = open_exec(elf_interpreter); 673 retval = PTR_ERR(interpreter); 674 if (IS_ERR(interpreter)) 675 goto out_free_interp; 676 677 /* 678 * If the binary is not readable then enforce 679 * mm->dumpable = 0 regardless of the interpreter's 680 * permissions. 681 */ 682 would_dump(bprm, interpreter); 683 684 retval = kernel_read(interpreter, 0, bprm->buf, 685 BINPRM_BUF_SIZE); 686 if (retval != BINPRM_BUF_SIZE) { 687 if (retval >= 0) 688 retval = -EIO; 689 goto out_free_dentry; 690 } 691 692 /* Get the exec headers */ 693 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); 694 break; 695 } 696 elf_ppnt++; 697 } 698 699 elf_ppnt = elf_phdata; 700 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) 701 if (elf_ppnt->p_type == PT_GNU_STACK) { 702 if (elf_ppnt->p_flags & PF_X) 703 executable_stack = EXSTACK_ENABLE_X; 704 else 705 executable_stack = EXSTACK_DISABLE_X; 706 break; 707 } 708 709 /* Some simple consistency checks for the interpreter */ 710 if (elf_interpreter) { 711 retval = -ELIBBAD; 712 /* Not an ELF interpreter */ 713 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 714 goto out_free_dentry; 715 /* Verify the interpreter has a valid arch */ 716 if (!elf_check_arch(&loc->interp_elf_ex)) 717 goto out_free_dentry; 718 } 719 720 /* Flush all traces of the currently running executable */ 721 retval = flush_old_exec(bprm); 722 if (retval) 723 goto out_free_dentry; 724 725 /* OK, This is the point of no return */ 726 current->mm->def_flags = def_flags; 727 728 /* Do this immediately, since STACK_TOP as used in setup_arg_pages 729 may depend on the personality. */ 730 SET_PERSONALITY(loc->elf_ex); 731 if (elf_read_implies_exec(loc->elf_ex, executable_stack)) 732 current->personality |= READ_IMPLIES_EXEC; 733 734 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 735 current->flags |= PF_RANDOMIZE; 736 737 setup_new_exec(bprm); 738 739 /* Do this so that we can load the interpreter, if need be. We will 740 change some of these later */ 741 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), 742 executable_stack); 743 if (retval < 0) { 744 send_sig(SIGKILL, current, 0); 745 goto out_free_dentry; 746 } 747 748 current->mm->start_stack = bprm->p; 749 750 /* Now we do a little grungy work by mmapping the ELF image into 751 the correct location in memory. */ 752 for(i = 0, elf_ppnt = elf_phdata; 753 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { 754 int elf_prot = 0, elf_flags; 755 unsigned long k, vaddr; 756 757 if (elf_ppnt->p_type != PT_LOAD) 758 continue; 759 760 if (unlikely (elf_brk > elf_bss)) { 761 unsigned long nbyte; 762 763 /* There was a PT_LOAD segment with p_memsz > p_filesz 764 before this one. Map anonymous pages, if needed, 765 and clear the area. */ 766 retval = set_brk(elf_bss + load_bias, 767 elf_brk + load_bias); 768 if (retval) { 769 send_sig(SIGKILL, current, 0); 770 goto out_free_dentry; 771 } 772 nbyte = ELF_PAGEOFFSET(elf_bss); 773 if (nbyte) { 774 nbyte = ELF_MIN_ALIGN - nbyte; 775 if (nbyte > elf_brk - elf_bss) 776 nbyte = elf_brk - elf_bss; 777 if (clear_user((void __user *)elf_bss + 778 load_bias, nbyte)) { 779 /* 780 * This bss-zeroing can fail if the ELF 781 * file specifies odd protections. So 782 * we don't check the return value 783 */ 784 } 785 } 786 } 787 788 if (elf_ppnt->p_flags & PF_R) 789 elf_prot |= PROT_READ; 790 if (elf_ppnt->p_flags & PF_W) 791 elf_prot |= PROT_WRITE; 792 if (elf_ppnt->p_flags & PF_X) 793 elf_prot |= PROT_EXEC; 794 795 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; 796 797 vaddr = elf_ppnt->p_vaddr; 798 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { 799 elf_flags |= MAP_FIXED; 800 } else if (loc->elf_ex.e_type == ET_DYN) { 801 /* Try and get dynamic programs out of the way of the 802 * default mmap base, as well as whatever program they 803 * might try to exec. This is because the brk will 804 * follow the loader, and is not movable. */ 805 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE 806 /* Memory randomization might have been switched off 807 * in runtime via sysctl or explicit setting of 808 * personality flags. 809 * If that is the case, retain the original non-zero 810 * load_bias value in order to establish proper 811 * non-randomized mappings. 812 */ 813 if (current->flags & PF_RANDOMIZE) 814 load_bias = 0; 815 else 816 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 817 #else 818 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 819 #endif 820 } 821 822 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, 823 elf_prot, elf_flags, 0); 824 if (BAD_ADDR(error)) { 825 send_sig(SIGKILL, current, 0); 826 retval = IS_ERR((void *)error) ? 827 PTR_ERR((void*)error) : -EINVAL; 828 goto out_free_dentry; 829 } 830 831 if (!load_addr_set) { 832 load_addr_set = 1; 833 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); 834 if (loc->elf_ex.e_type == ET_DYN) { 835 load_bias += error - 836 ELF_PAGESTART(load_bias + vaddr); 837 load_addr += load_bias; 838 reloc_func_desc = load_bias; 839 } 840 } 841 k = elf_ppnt->p_vaddr; 842 if (k < start_code) 843 start_code = k; 844 if (start_data < k) 845 start_data = k; 846 847 /* 848 * Check to see if the section's size will overflow the 849 * allowed task size. Note that p_filesz must always be 850 * <= p_memsz so it is only necessary to check p_memsz. 851 */ 852 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || 853 elf_ppnt->p_memsz > TASK_SIZE || 854 TASK_SIZE - elf_ppnt->p_memsz < k) { 855 /* set_brk can never work. Avoid overflows. */ 856 send_sig(SIGKILL, current, 0); 857 retval = -EINVAL; 858 goto out_free_dentry; 859 } 860 861 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; 862 863 if (k > elf_bss) 864 elf_bss = k; 865 if ((elf_ppnt->p_flags & PF_X) && end_code < k) 866 end_code = k; 867 if (end_data < k) 868 end_data = k; 869 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; 870 if (k > elf_brk) 871 elf_brk = k; 872 } 873 874 loc->elf_ex.e_entry += load_bias; 875 elf_bss += load_bias; 876 elf_brk += load_bias; 877 start_code += load_bias; 878 end_code += load_bias; 879 start_data += load_bias; 880 end_data += load_bias; 881 882 /* Calling set_brk effectively mmaps the pages that we need 883 * for the bss and break sections. We must do this before 884 * mapping in the interpreter, to make sure it doesn't wind 885 * up getting placed where the bss needs to go. 886 */ 887 retval = set_brk(elf_bss, elf_brk); 888 if (retval) { 889 send_sig(SIGKILL, current, 0); 890 goto out_free_dentry; 891 } 892 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { 893 send_sig(SIGSEGV, current, 0); 894 retval = -EFAULT; /* Nobody gets to see this, but.. */ 895 goto out_free_dentry; 896 } 897 898 if (elf_interpreter) { 899 unsigned long interp_map_addr = 0; 900 901 elf_entry = load_elf_interp(&loc->interp_elf_ex, 902 interpreter, 903 &interp_map_addr, 904 load_bias); 905 if (!IS_ERR((void *)elf_entry)) { 906 /* 907 * load_elf_interp() returns relocation 908 * adjustment 909 */ 910 interp_load_addr = elf_entry; 911 elf_entry += loc->interp_elf_ex.e_entry; 912 } 913 if (BAD_ADDR(elf_entry)) { 914 force_sig(SIGSEGV, current); 915 retval = IS_ERR((void *)elf_entry) ? 916 (int)elf_entry : -EINVAL; 917 goto out_free_dentry; 918 } 919 reloc_func_desc = interp_load_addr; 920 921 allow_write_access(interpreter); 922 fput(interpreter); 923 kfree(elf_interpreter); 924 } else { 925 elf_entry = loc->elf_ex.e_entry; 926 if (BAD_ADDR(elf_entry)) { 927 force_sig(SIGSEGV, current); 928 retval = -EINVAL; 929 goto out_free_dentry; 930 } 931 } 932 933 kfree(elf_phdata); 934 935 set_binfmt(&elf_format); 936 937 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 938 retval = arch_setup_additional_pages(bprm, !!elf_interpreter); 939 if (retval < 0) { 940 send_sig(SIGKILL, current, 0); 941 goto out; 942 } 943 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ 944 945 install_exec_creds(bprm); 946 retval = create_elf_tables(bprm, &loc->elf_ex, 947 load_addr, interp_load_addr); 948 if (retval < 0) { 949 send_sig(SIGKILL, current, 0); 950 goto out; 951 } 952 /* N.B. passed_fileno might not be initialized? */ 953 current->mm->end_code = end_code; 954 current->mm->start_code = start_code; 955 current->mm->start_data = start_data; 956 current->mm->end_data = end_data; 957 current->mm->start_stack = bprm->p; 958 959 #ifdef arch_randomize_brk 960 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { 961 current->mm->brk = current->mm->start_brk = 962 arch_randomize_brk(current->mm); 963 #ifdef CONFIG_COMPAT_BRK 964 current->brk_randomized = 1; 965 #endif 966 } 967 #endif 968 969 if (current->personality & MMAP_PAGE_ZERO) { 970 /* Why this, you ask??? Well SVr4 maps page 0 as read-only, 971 and some applications "depend" upon this behavior. 972 Since we do not have the power to recompile these, we 973 emulate the SVr4 behavior. Sigh. */ 974 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, 975 MAP_FIXED | MAP_PRIVATE, 0); 976 } 977 978 #ifdef ELF_PLAT_INIT 979 /* 980 * The ABI may specify that certain registers be set up in special 981 * ways (on i386 %edx is the address of a DT_FINI function, for 982 * example. In addition, it may also specify (eg, PowerPC64 ELF) 983 * that the e_entry field is the address of the function descriptor 984 * for the startup routine, rather than the address of the startup 985 * routine itself. This macro performs whatever initialization to 986 * the regs structure is required as well as any relocations to the 987 * function descriptor entries when executing dynamically links apps. 988 */ 989 ELF_PLAT_INIT(regs, reloc_func_desc); 990 #endif 991 992 start_thread(regs, elf_entry, bprm->p); 993 retval = 0; 994 out: 995 kfree(loc); 996 out_ret: 997 return retval; 998 999 /* error cleanup */ 1000 out_free_dentry: 1001 allow_write_access(interpreter); 1002 if (interpreter) 1003 fput(interpreter); 1004 out_free_interp: 1005 kfree(elf_interpreter); 1006 out_free_ph: 1007 kfree(elf_phdata); 1008 goto out; 1009 } 1010 1011 /* This is really simpleminded and specialized - we are loading an 1012 a.out library that is given an ELF header. */ 1013 static int load_elf_library(struct file *file) 1014 { 1015 struct elf_phdr *elf_phdata; 1016 struct elf_phdr *eppnt; 1017 unsigned long elf_bss, bss, len; 1018 int retval, error, i, j; 1019 struct elfhdr elf_ex; 1020 1021 error = -ENOEXEC; 1022 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); 1023 if (retval != sizeof(elf_ex)) 1024 goto out; 1025 1026 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 1027 goto out; 1028 1029 /* First of all, some simple consistency checks */ 1030 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || 1031 !elf_check_arch(&elf_ex) || !file->f_op->mmap) 1032 goto out; 1033 1034 /* Now read in all of the header information */ 1035 1036 j = sizeof(struct elf_phdr) * elf_ex.e_phnum; 1037 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ 1038 1039 error = -ENOMEM; 1040 elf_phdata = kmalloc(j, GFP_KERNEL); 1041 if (!elf_phdata) 1042 goto out; 1043 1044 eppnt = elf_phdata; 1045 error = -ENOEXEC; 1046 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); 1047 if (retval != j) 1048 goto out_free_ph; 1049 1050 for (j = 0, i = 0; i<elf_ex.e_phnum; i++) 1051 if ((eppnt + i)->p_type == PT_LOAD) 1052 j++; 1053 if (j != 1) 1054 goto out_free_ph; 1055 1056 while (eppnt->p_type != PT_LOAD) 1057 eppnt++; 1058 1059 /* Now use mmap to map the library into memory. */ 1060 error = vm_mmap(file, 1061 ELF_PAGESTART(eppnt->p_vaddr), 1062 (eppnt->p_filesz + 1063 ELF_PAGEOFFSET(eppnt->p_vaddr)), 1064 PROT_READ | PROT_WRITE | PROT_EXEC, 1065 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, 1066 (eppnt->p_offset - 1067 ELF_PAGEOFFSET(eppnt->p_vaddr))); 1068 if (error != ELF_PAGESTART(eppnt->p_vaddr)) 1069 goto out_free_ph; 1070 1071 elf_bss = eppnt->p_vaddr + eppnt->p_filesz; 1072 if (padzero(elf_bss)) { 1073 error = -EFAULT; 1074 goto out_free_ph; 1075 } 1076 1077 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + 1078 ELF_MIN_ALIGN - 1); 1079 bss = eppnt->p_memsz + eppnt->p_vaddr; 1080 if (bss > len) 1081 vm_brk(len, bss - len); 1082 error = 0; 1083 1084 out_free_ph: 1085 kfree(elf_phdata); 1086 out: 1087 return error; 1088 } 1089 1090 #ifdef CONFIG_ELF_CORE 1091 /* 1092 * ELF core dumper 1093 * 1094 * Modelled on fs/exec.c:aout_core_dump() 1095 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1096 */ 1097 1098 /* 1099 * The purpose of always_dump_vma() is to make sure that special kernel mappings 1100 * that are useful for post-mortem analysis are included in every core dump. 1101 * In that way we ensure that the core dump is fully interpretable later 1102 * without matching up the same kernel and hardware config to see what PC values 1103 * meant. These special mappings include - vDSO, vsyscall, and other 1104 * architecture specific mappings 1105 */ 1106 static bool always_dump_vma(struct vm_area_struct *vma) 1107 { 1108 /* Any vsyscall mappings? */ 1109 if (vma == get_gate_vma(vma->vm_mm)) 1110 return true; 1111 /* 1112 * arch_vma_name() returns non-NULL for special architecture mappings, 1113 * such as vDSO sections. 1114 */ 1115 if (arch_vma_name(vma)) 1116 return true; 1117 1118 return false; 1119 } 1120 1121 /* 1122 * Decide what to dump of a segment, part, all or none. 1123 */ 1124 static unsigned long vma_dump_size(struct vm_area_struct *vma, 1125 unsigned long mm_flags) 1126 { 1127 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) 1128 1129 /* always dump the vdso and vsyscall sections */ 1130 if (always_dump_vma(vma)) 1131 goto whole; 1132 1133 if (vma->vm_flags & VM_DONTDUMP) 1134 return 0; 1135 1136 /* Hugetlb memory check */ 1137 if (vma->vm_flags & VM_HUGETLB) { 1138 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) 1139 goto whole; 1140 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) 1141 goto whole; 1142 return 0; 1143 } 1144 1145 /* Do not dump I/O mapped devices or special mappings */ 1146 if (vma->vm_flags & VM_IO) 1147 return 0; 1148 1149 /* By default, dump shared memory if mapped from an anonymous file. */ 1150 if (vma->vm_flags & VM_SHARED) { 1151 if (file_inode(vma->vm_file)->i_nlink == 0 ? 1152 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) 1153 goto whole; 1154 return 0; 1155 } 1156 1157 /* Dump segments that have been written to. */ 1158 if (vma->anon_vma && FILTER(ANON_PRIVATE)) 1159 goto whole; 1160 if (vma->vm_file == NULL) 1161 return 0; 1162 1163 if (FILTER(MAPPED_PRIVATE)) 1164 goto whole; 1165 1166 /* 1167 * If this looks like the beginning of a DSO or executable mapping, 1168 * check for an ELF header. If we find one, dump the first page to 1169 * aid in determining what was mapped here. 1170 */ 1171 if (FILTER(ELF_HEADERS) && 1172 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { 1173 u32 __user *header = (u32 __user *) vma->vm_start; 1174 u32 word; 1175 mm_segment_t fs = get_fs(); 1176 /* 1177 * Doing it this way gets the constant folded by GCC. 1178 */ 1179 union { 1180 u32 cmp; 1181 char elfmag[SELFMAG]; 1182 } magic; 1183 BUILD_BUG_ON(SELFMAG != sizeof word); 1184 magic.elfmag[EI_MAG0] = ELFMAG0; 1185 magic.elfmag[EI_MAG1] = ELFMAG1; 1186 magic.elfmag[EI_MAG2] = ELFMAG2; 1187 magic.elfmag[EI_MAG3] = ELFMAG3; 1188 /* 1189 * Switch to the user "segment" for get_user(), 1190 * then put back what elf_core_dump() had in place. 1191 */ 1192 set_fs(USER_DS); 1193 if (unlikely(get_user(word, header))) 1194 word = 0; 1195 set_fs(fs); 1196 if (word == magic.cmp) 1197 return PAGE_SIZE; 1198 } 1199 1200 #undef FILTER 1201 1202 return 0; 1203 1204 whole: 1205 return vma->vm_end - vma->vm_start; 1206 } 1207 1208 /* An ELF note in memory */ 1209 struct memelfnote 1210 { 1211 const char *name; 1212 int type; 1213 unsigned int datasz; 1214 void *data; 1215 }; 1216 1217 static int notesize(struct memelfnote *en) 1218 { 1219 int sz; 1220 1221 sz = sizeof(struct elf_note); 1222 sz += roundup(strlen(en->name) + 1, 4); 1223 sz += roundup(en->datasz, 4); 1224 1225 return sz; 1226 } 1227 1228 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1229 { 1230 struct elf_note en; 1231 en.n_namesz = strlen(men->name) + 1; 1232 en.n_descsz = men->datasz; 1233 en.n_type = men->type; 1234 1235 return dump_emit(cprm, &en, sizeof(en)) && 1236 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1237 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1238 } 1239 1240 static void fill_elf_header(struct elfhdr *elf, int segs, 1241 u16 machine, u32 flags) 1242 { 1243 memset(elf, 0, sizeof(*elf)); 1244 1245 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1246 elf->e_ident[EI_CLASS] = ELF_CLASS; 1247 elf->e_ident[EI_DATA] = ELF_DATA; 1248 elf->e_ident[EI_VERSION] = EV_CURRENT; 1249 elf->e_ident[EI_OSABI] = ELF_OSABI; 1250 1251 elf->e_type = ET_CORE; 1252 elf->e_machine = machine; 1253 elf->e_version = EV_CURRENT; 1254 elf->e_phoff = sizeof(struct elfhdr); 1255 elf->e_flags = flags; 1256 elf->e_ehsize = sizeof(struct elfhdr); 1257 elf->e_phentsize = sizeof(struct elf_phdr); 1258 elf->e_phnum = segs; 1259 1260 return; 1261 } 1262 1263 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1264 { 1265 phdr->p_type = PT_NOTE; 1266 phdr->p_offset = offset; 1267 phdr->p_vaddr = 0; 1268 phdr->p_paddr = 0; 1269 phdr->p_filesz = sz; 1270 phdr->p_memsz = 0; 1271 phdr->p_flags = 0; 1272 phdr->p_align = 0; 1273 return; 1274 } 1275 1276 static void fill_note(struct memelfnote *note, const char *name, int type, 1277 unsigned int sz, void *data) 1278 { 1279 note->name = name; 1280 note->type = type; 1281 note->datasz = sz; 1282 note->data = data; 1283 return; 1284 } 1285 1286 /* 1287 * fill up all the fields in prstatus from the given task struct, except 1288 * registers which need to be filled up separately. 1289 */ 1290 static void fill_prstatus(struct elf_prstatus *prstatus, 1291 struct task_struct *p, long signr) 1292 { 1293 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1294 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1295 prstatus->pr_sighold = p->blocked.sig[0]; 1296 rcu_read_lock(); 1297 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1298 rcu_read_unlock(); 1299 prstatus->pr_pid = task_pid_vnr(p); 1300 prstatus->pr_pgrp = task_pgrp_vnr(p); 1301 prstatus->pr_sid = task_session_vnr(p); 1302 if (thread_group_leader(p)) { 1303 struct task_cputime cputime; 1304 1305 /* 1306 * This is the record for the group leader. It shows the 1307 * group-wide total, not its individual thread total. 1308 */ 1309 thread_group_cputime(p, &cputime); 1310 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1311 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1312 } else { 1313 cputime_t utime, stime; 1314 1315 task_cputime(p, &utime, &stime); 1316 cputime_to_timeval(utime, &prstatus->pr_utime); 1317 cputime_to_timeval(stime, &prstatus->pr_stime); 1318 } 1319 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1320 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1321 } 1322 1323 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1324 struct mm_struct *mm) 1325 { 1326 const struct cred *cred; 1327 unsigned int i, len; 1328 1329 /* first copy the parameters from user space */ 1330 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1331 1332 len = mm->arg_end - mm->arg_start; 1333 if (len >= ELF_PRARGSZ) 1334 len = ELF_PRARGSZ-1; 1335 if (copy_from_user(&psinfo->pr_psargs, 1336 (const char __user *)mm->arg_start, len)) 1337 return -EFAULT; 1338 for(i = 0; i < len; i++) 1339 if (psinfo->pr_psargs[i] == 0) 1340 psinfo->pr_psargs[i] = ' '; 1341 psinfo->pr_psargs[len] = 0; 1342 1343 rcu_read_lock(); 1344 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1345 rcu_read_unlock(); 1346 psinfo->pr_pid = task_pid_vnr(p); 1347 psinfo->pr_pgrp = task_pgrp_vnr(p); 1348 psinfo->pr_sid = task_session_vnr(p); 1349 1350 i = p->state ? ffz(~p->state) + 1 : 0; 1351 psinfo->pr_state = i; 1352 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1353 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1354 psinfo->pr_nice = task_nice(p); 1355 psinfo->pr_flag = p->flags; 1356 rcu_read_lock(); 1357 cred = __task_cred(p); 1358 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1359 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1360 rcu_read_unlock(); 1361 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1362 1363 return 0; 1364 } 1365 1366 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) 1367 { 1368 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; 1369 int i = 0; 1370 do 1371 i += 2; 1372 while (auxv[i - 2] != AT_NULL); 1373 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1374 } 1375 1376 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, 1377 const siginfo_t *siginfo) 1378 { 1379 mm_segment_t old_fs = get_fs(); 1380 set_fs(KERNEL_DS); 1381 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo); 1382 set_fs(old_fs); 1383 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); 1384 } 1385 1386 #define MAX_FILE_NOTE_SIZE (4*1024*1024) 1387 /* 1388 * Format of NT_FILE note: 1389 * 1390 * long count -- how many files are mapped 1391 * long page_size -- units for file_ofs 1392 * array of [COUNT] elements of 1393 * long start 1394 * long end 1395 * long file_ofs 1396 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL... 1397 */ 1398 static int fill_files_note(struct memelfnote *note) 1399 { 1400 struct vm_area_struct *vma; 1401 unsigned count, size, names_ofs, remaining, n; 1402 user_long_t *data; 1403 user_long_t *start_end_ofs; 1404 char *name_base, *name_curpos; 1405 1406 /* *Estimated* file count and total data size needed */ 1407 count = current->mm->map_count; 1408 size = count * 64; 1409 1410 names_ofs = (2 + 3 * count) * sizeof(data[0]); 1411 alloc: 1412 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */ 1413 return -EINVAL; 1414 size = round_up(size, PAGE_SIZE); 1415 data = vmalloc(size); 1416 if (!data) 1417 return -ENOMEM; 1418 1419 start_end_ofs = data + 2; 1420 name_base = name_curpos = ((char *)data) + names_ofs; 1421 remaining = size - names_ofs; 1422 count = 0; 1423 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) { 1424 struct file *file; 1425 const char *filename; 1426 1427 file = vma->vm_file; 1428 if (!file) 1429 continue; 1430 filename = d_path(&file->f_path, name_curpos, remaining); 1431 if (IS_ERR(filename)) { 1432 if (PTR_ERR(filename) == -ENAMETOOLONG) { 1433 vfree(data); 1434 size = size * 5 / 4; 1435 goto alloc; 1436 } 1437 continue; 1438 } 1439 1440 /* d_path() fills at the end, move name down */ 1441 /* n = strlen(filename) + 1: */ 1442 n = (name_curpos + remaining) - filename; 1443 remaining = filename - name_curpos; 1444 memmove(name_curpos, filename, n); 1445 name_curpos += n; 1446 1447 *start_end_ofs++ = vma->vm_start; 1448 *start_end_ofs++ = vma->vm_end; 1449 *start_end_ofs++ = vma->vm_pgoff; 1450 count++; 1451 } 1452 1453 /* Now we know exact count of files, can store it */ 1454 data[0] = count; 1455 data[1] = PAGE_SIZE; 1456 /* 1457 * Count usually is less than current->mm->map_count, 1458 * we need to move filenames down. 1459 */ 1460 n = current->mm->map_count - count; 1461 if (n != 0) { 1462 unsigned shift_bytes = n * 3 * sizeof(data[0]); 1463 memmove(name_base - shift_bytes, name_base, 1464 name_curpos - name_base); 1465 name_curpos -= shift_bytes; 1466 } 1467 1468 size = name_curpos - (char *)data; 1469 fill_note(note, "CORE", NT_FILE, size, data); 1470 return 0; 1471 } 1472 1473 #ifdef CORE_DUMP_USE_REGSET 1474 #include <linux/regset.h> 1475 1476 struct elf_thread_core_info { 1477 struct elf_thread_core_info *next; 1478 struct task_struct *task; 1479 struct elf_prstatus prstatus; 1480 struct memelfnote notes[0]; 1481 }; 1482 1483 struct elf_note_info { 1484 struct elf_thread_core_info *thread; 1485 struct memelfnote psinfo; 1486 struct memelfnote signote; 1487 struct memelfnote auxv; 1488 struct memelfnote files; 1489 user_siginfo_t csigdata; 1490 size_t size; 1491 int thread_notes; 1492 }; 1493 1494 /* 1495 * When a regset has a writeback hook, we call it on each thread before 1496 * dumping user memory. On register window machines, this makes sure the 1497 * user memory backing the register data is up to date before we read it. 1498 */ 1499 static void do_thread_regset_writeback(struct task_struct *task, 1500 const struct user_regset *regset) 1501 { 1502 if (regset->writeback) 1503 regset->writeback(task, regset, 1); 1504 } 1505 1506 #ifndef PR_REG_SIZE 1507 #define PR_REG_SIZE(S) sizeof(S) 1508 #endif 1509 1510 #ifndef PRSTATUS_SIZE 1511 #define PRSTATUS_SIZE(S) sizeof(S) 1512 #endif 1513 1514 #ifndef PR_REG_PTR 1515 #define PR_REG_PTR(S) (&((S)->pr_reg)) 1516 #endif 1517 1518 #ifndef SET_PR_FPVALID 1519 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V)) 1520 #endif 1521 1522 static int fill_thread_core_info(struct elf_thread_core_info *t, 1523 const struct user_regset_view *view, 1524 long signr, size_t *total) 1525 { 1526 unsigned int i; 1527 1528 /* 1529 * NT_PRSTATUS is the one special case, because the regset data 1530 * goes into the pr_reg field inside the note contents, rather 1531 * than being the whole note contents. We fill the reset in here. 1532 * We assume that regset 0 is NT_PRSTATUS. 1533 */ 1534 fill_prstatus(&t->prstatus, t->task, signr); 1535 (void) view->regsets[0].get(t->task, &view->regsets[0], 1536 0, PR_REG_SIZE(t->prstatus.pr_reg), 1537 PR_REG_PTR(&t->prstatus), NULL); 1538 1539 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, 1540 PRSTATUS_SIZE(t->prstatus), &t->prstatus); 1541 *total += notesize(&t->notes[0]); 1542 1543 do_thread_regset_writeback(t->task, &view->regsets[0]); 1544 1545 /* 1546 * Each other regset might generate a note too. For each regset 1547 * that has no core_note_type or is inactive, we leave t->notes[i] 1548 * all zero and we'll know to skip writing it later. 1549 */ 1550 for (i = 1; i < view->n; ++i) { 1551 const struct user_regset *regset = &view->regsets[i]; 1552 do_thread_regset_writeback(t->task, regset); 1553 if (regset->core_note_type && regset->get && 1554 (!regset->active || regset->active(t->task, regset))) { 1555 int ret; 1556 size_t size = regset->n * regset->size; 1557 void *data = kmalloc(size, GFP_KERNEL); 1558 if (unlikely(!data)) 1559 return 0; 1560 ret = regset->get(t->task, regset, 1561 0, size, data, NULL); 1562 if (unlikely(ret)) 1563 kfree(data); 1564 else { 1565 if (regset->core_note_type != NT_PRFPREG) 1566 fill_note(&t->notes[i], "LINUX", 1567 regset->core_note_type, 1568 size, data); 1569 else { 1570 SET_PR_FPVALID(&t->prstatus, 1); 1571 fill_note(&t->notes[i], "CORE", 1572 NT_PRFPREG, size, data); 1573 } 1574 *total += notesize(&t->notes[i]); 1575 } 1576 } 1577 } 1578 1579 return 1; 1580 } 1581 1582 static int fill_note_info(struct elfhdr *elf, int phdrs, 1583 struct elf_note_info *info, 1584 const siginfo_t *siginfo, struct pt_regs *regs) 1585 { 1586 struct task_struct *dump_task = current; 1587 const struct user_regset_view *view = task_user_regset_view(dump_task); 1588 struct elf_thread_core_info *t; 1589 struct elf_prpsinfo *psinfo; 1590 struct core_thread *ct; 1591 unsigned int i; 1592 1593 info->size = 0; 1594 info->thread = NULL; 1595 1596 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1597 if (psinfo == NULL) { 1598 info->psinfo.data = NULL; /* So we don't free this wrongly */ 1599 return 0; 1600 } 1601 1602 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1603 1604 /* 1605 * Figure out how many notes we're going to need for each thread. 1606 */ 1607 info->thread_notes = 0; 1608 for (i = 0; i < view->n; ++i) 1609 if (view->regsets[i].core_note_type != 0) 1610 ++info->thread_notes; 1611 1612 /* 1613 * Sanity check. We rely on regset 0 being in NT_PRSTATUS, 1614 * since it is our one special case. 1615 */ 1616 if (unlikely(info->thread_notes == 0) || 1617 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { 1618 WARN_ON(1); 1619 return 0; 1620 } 1621 1622 /* 1623 * Initialize the ELF file header. 1624 */ 1625 fill_elf_header(elf, phdrs, 1626 view->e_machine, view->e_flags); 1627 1628 /* 1629 * Allocate a structure for each thread. 1630 */ 1631 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { 1632 t = kzalloc(offsetof(struct elf_thread_core_info, 1633 notes[info->thread_notes]), 1634 GFP_KERNEL); 1635 if (unlikely(!t)) 1636 return 0; 1637 1638 t->task = ct->task; 1639 if (ct->task == dump_task || !info->thread) { 1640 t->next = info->thread; 1641 info->thread = t; 1642 } else { 1643 /* 1644 * Make sure to keep the original task at 1645 * the head of the list. 1646 */ 1647 t->next = info->thread->next; 1648 info->thread->next = t; 1649 } 1650 } 1651 1652 /* 1653 * Now fill in each thread's information. 1654 */ 1655 for (t = info->thread; t != NULL; t = t->next) 1656 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size)) 1657 return 0; 1658 1659 /* 1660 * Fill in the two process-wide notes. 1661 */ 1662 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); 1663 info->size += notesize(&info->psinfo); 1664 1665 fill_siginfo_note(&info->signote, &info->csigdata, siginfo); 1666 info->size += notesize(&info->signote); 1667 1668 fill_auxv_note(&info->auxv, current->mm); 1669 info->size += notesize(&info->auxv); 1670 1671 if (fill_files_note(&info->files) == 0) 1672 info->size += notesize(&info->files); 1673 1674 return 1; 1675 } 1676 1677 static size_t get_note_info_size(struct elf_note_info *info) 1678 { 1679 return info->size; 1680 } 1681 1682 /* 1683 * Write all the notes for each thread. When writing the first thread, the 1684 * process-wide notes are interleaved after the first thread-specific note. 1685 */ 1686 static int write_note_info(struct elf_note_info *info, 1687 struct coredump_params *cprm) 1688 { 1689 bool first = 1; 1690 struct elf_thread_core_info *t = info->thread; 1691 1692 do { 1693 int i; 1694 1695 if (!writenote(&t->notes[0], cprm)) 1696 return 0; 1697 1698 if (first && !writenote(&info->psinfo, cprm)) 1699 return 0; 1700 if (first && !writenote(&info->signote, cprm)) 1701 return 0; 1702 if (first && !writenote(&info->auxv, cprm)) 1703 return 0; 1704 if (first && info->files.data && 1705 !writenote(&info->files, cprm)) 1706 return 0; 1707 1708 for (i = 1; i < info->thread_notes; ++i) 1709 if (t->notes[i].data && 1710 !writenote(&t->notes[i], cprm)) 1711 return 0; 1712 1713 first = 0; 1714 t = t->next; 1715 } while (t); 1716 1717 return 1; 1718 } 1719 1720 static void free_note_info(struct elf_note_info *info) 1721 { 1722 struct elf_thread_core_info *threads = info->thread; 1723 while (threads) { 1724 unsigned int i; 1725 struct elf_thread_core_info *t = threads; 1726 threads = t->next; 1727 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); 1728 for (i = 1; i < info->thread_notes; ++i) 1729 kfree(t->notes[i].data); 1730 kfree(t); 1731 } 1732 kfree(info->psinfo.data); 1733 vfree(info->files.data); 1734 } 1735 1736 #else 1737 1738 /* Here is the structure in which status of each thread is captured. */ 1739 struct elf_thread_status 1740 { 1741 struct list_head list; 1742 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1743 elf_fpregset_t fpu; /* NT_PRFPREG */ 1744 struct task_struct *thread; 1745 #ifdef ELF_CORE_COPY_XFPREGS 1746 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1747 #endif 1748 struct memelfnote notes[3]; 1749 int num_notes; 1750 }; 1751 1752 /* 1753 * In order to add the specific thread information for the elf file format, 1754 * we need to keep a linked list of every threads pr_status and then create 1755 * a single section for them in the final core file. 1756 */ 1757 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1758 { 1759 int sz = 0; 1760 struct task_struct *p = t->thread; 1761 t->num_notes = 0; 1762 1763 fill_prstatus(&t->prstatus, p, signr); 1764 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1765 1766 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1767 &(t->prstatus)); 1768 t->num_notes++; 1769 sz += notesize(&t->notes[0]); 1770 1771 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, 1772 &t->fpu))) { 1773 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1774 &(t->fpu)); 1775 t->num_notes++; 1776 sz += notesize(&t->notes[1]); 1777 } 1778 1779 #ifdef ELF_CORE_COPY_XFPREGS 1780 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1781 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1782 sizeof(t->xfpu), &t->xfpu); 1783 t->num_notes++; 1784 sz += notesize(&t->notes[2]); 1785 } 1786 #endif 1787 return sz; 1788 } 1789 1790 struct elf_note_info { 1791 struct memelfnote *notes; 1792 struct memelfnote *notes_files; 1793 struct elf_prstatus *prstatus; /* NT_PRSTATUS */ 1794 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ 1795 struct list_head thread_list; 1796 elf_fpregset_t *fpu; 1797 #ifdef ELF_CORE_COPY_XFPREGS 1798 elf_fpxregset_t *xfpu; 1799 #endif 1800 user_siginfo_t csigdata; 1801 int thread_status_size; 1802 int numnote; 1803 }; 1804 1805 static int elf_note_info_init(struct elf_note_info *info) 1806 { 1807 memset(info, 0, sizeof(*info)); 1808 INIT_LIST_HEAD(&info->thread_list); 1809 1810 /* Allocate space for ELF notes */ 1811 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL); 1812 if (!info->notes) 1813 return 0; 1814 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); 1815 if (!info->psinfo) 1816 return 0; 1817 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); 1818 if (!info->prstatus) 1819 return 0; 1820 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); 1821 if (!info->fpu) 1822 return 0; 1823 #ifdef ELF_CORE_COPY_XFPREGS 1824 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); 1825 if (!info->xfpu) 1826 return 0; 1827 #endif 1828 return 1; 1829 } 1830 1831 static int fill_note_info(struct elfhdr *elf, int phdrs, 1832 struct elf_note_info *info, 1833 const siginfo_t *siginfo, struct pt_regs *regs) 1834 { 1835 struct list_head *t; 1836 struct core_thread *ct; 1837 struct elf_thread_status *ets; 1838 1839 if (!elf_note_info_init(info)) 1840 return 0; 1841 1842 for (ct = current->mm->core_state->dumper.next; 1843 ct; ct = ct->next) { 1844 ets = kzalloc(sizeof(*ets), GFP_KERNEL); 1845 if (!ets) 1846 return 0; 1847 1848 ets->thread = ct->task; 1849 list_add(&ets->list, &info->thread_list); 1850 } 1851 1852 list_for_each(t, &info->thread_list) { 1853 int sz; 1854 1855 ets = list_entry(t, struct elf_thread_status, list); 1856 sz = elf_dump_thread_status(siginfo->si_signo, ets); 1857 info->thread_status_size += sz; 1858 } 1859 /* now collect the dump for the current */ 1860 memset(info->prstatus, 0, sizeof(*info->prstatus)); 1861 fill_prstatus(info->prstatus, current, siginfo->si_signo); 1862 elf_core_copy_regs(&info->prstatus->pr_reg, regs); 1863 1864 /* Set up header */ 1865 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS); 1866 1867 /* 1868 * Set up the notes in similar form to SVR4 core dumps made 1869 * with info from their /proc. 1870 */ 1871 1872 fill_note(info->notes + 0, "CORE", NT_PRSTATUS, 1873 sizeof(*info->prstatus), info->prstatus); 1874 fill_psinfo(info->psinfo, current->group_leader, current->mm); 1875 fill_note(info->notes + 1, "CORE", NT_PRPSINFO, 1876 sizeof(*info->psinfo), info->psinfo); 1877 1878 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo); 1879 fill_auxv_note(info->notes + 3, current->mm); 1880 info->numnote = 4; 1881 1882 if (fill_files_note(info->notes + info->numnote) == 0) { 1883 info->notes_files = info->notes + info->numnote; 1884 info->numnote++; 1885 } 1886 1887 /* Try to dump the FPU. */ 1888 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, 1889 info->fpu); 1890 if (info->prstatus->pr_fpvalid) 1891 fill_note(info->notes + info->numnote++, 1892 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); 1893 #ifdef ELF_CORE_COPY_XFPREGS 1894 if (elf_core_copy_task_xfpregs(current, info->xfpu)) 1895 fill_note(info->notes + info->numnote++, 1896 "LINUX", ELF_CORE_XFPREG_TYPE, 1897 sizeof(*info->xfpu), info->xfpu); 1898 #endif 1899 1900 return 1; 1901 } 1902 1903 static size_t get_note_info_size(struct elf_note_info *info) 1904 { 1905 int sz = 0; 1906 int i; 1907 1908 for (i = 0; i < info->numnote; i++) 1909 sz += notesize(info->notes + i); 1910 1911 sz += info->thread_status_size; 1912 1913 return sz; 1914 } 1915 1916 static int write_note_info(struct elf_note_info *info, 1917 struct coredump_params *cprm) 1918 { 1919 int i; 1920 struct list_head *t; 1921 1922 for (i = 0; i < info->numnote; i++) 1923 if (!writenote(info->notes + i, cprm)) 1924 return 0; 1925 1926 /* write out the thread status notes section */ 1927 list_for_each(t, &info->thread_list) { 1928 struct elf_thread_status *tmp = 1929 list_entry(t, struct elf_thread_status, list); 1930 1931 for (i = 0; i < tmp->num_notes; i++) 1932 if (!writenote(&tmp->notes[i], cprm)) 1933 return 0; 1934 } 1935 1936 return 1; 1937 } 1938 1939 static void free_note_info(struct elf_note_info *info) 1940 { 1941 while (!list_empty(&info->thread_list)) { 1942 struct list_head *tmp = info->thread_list.next; 1943 list_del(tmp); 1944 kfree(list_entry(tmp, struct elf_thread_status, list)); 1945 } 1946 1947 /* Free data possibly allocated by fill_files_note(): */ 1948 if (info->notes_files) 1949 vfree(info->notes_files->data); 1950 1951 kfree(info->prstatus); 1952 kfree(info->psinfo); 1953 kfree(info->notes); 1954 kfree(info->fpu); 1955 #ifdef ELF_CORE_COPY_XFPREGS 1956 kfree(info->xfpu); 1957 #endif 1958 } 1959 1960 #endif 1961 1962 static struct vm_area_struct *first_vma(struct task_struct *tsk, 1963 struct vm_area_struct *gate_vma) 1964 { 1965 struct vm_area_struct *ret = tsk->mm->mmap; 1966 1967 if (ret) 1968 return ret; 1969 return gate_vma; 1970 } 1971 /* 1972 * Helper function for iterating across a vma list. It ensures that the caller 1973 * will visit `gate_vma' prior to terminating the search. 1974 */ 1975 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, 1976 struct vm_area_struct *gate_vma) 1977 { 1978 struct vm_area_struct *ret; 1979 1980 ret = this_vma->vm_next; 1981 if (ret) 1982 return ret; 1983 if (this_vma == gate_vma) 1984 return NULL; 1985 return gate_vma; 1986 } 1987 1988 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1989 elf_addr_t e_shoff, int segs) 1990 { 1991 elf->e_shoff = e_shoff; 1992 elf->e_shentsize = sizeof(*shdr4extnum); 1993 elf->e_shnum = 1; 1994 elf->e_shstrndx = SHN_UNDEF; 1995 1996 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1997 1998 shdr4extnum->sh_type = SHT_NULL; 1999 shdr4extnum->sh_size = elf->e_shnum; 2000 shdr4extnum->sh_link = elf->e_shstrndx; 2001 shdr4extnum->sh_info = segs; 2002 } 2003 2004 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, 2005 unsigned long mm_flags) 2006 { 2007 struct vm_area_struct *vma; 2008 size_t size = 0; 2009 2010 for (vma = first_vma(current, gate_vma); vma != NULL; 2011 vma = next_vma(vma, gate_vma)) 2012 size += vma_dump_size(vma, mm_flags); 2013 return size; 2014 } 2015 2016 /* 2017 * Actual dumper 2018 * 2019 * This is a two-pass process; first we find the offsets of the bits, 2020 * and then they are actually written out. If we run out of core limit 2021 * we just truncate. 2022 */ 2023 static int elf_core_dump(struct coredump_params *cprm) 2024 { 2025 int has_dumped = 0; 2026 mm_segment_t fs; 2027 int segs; 2028 struct vm_area_struct *vma, *gate_vma; 2029 struct elfhdr *elf = NULL; 2030 loff_t offset = 0, dataoff; 2031 struct elf_note_info info = { }; 2032 struct elf_phdr *phdr4note = NULL; 2033 struct elf_shdr *shdr4extnum = NULL; 2034 Elf_Half e_phnum; 2035 elf_addr_t e_shoff; 2036 2037 /* 2038 * We no longer stop all VM operations. 2039 * 2040 * This is because those proceses that could possibly change map_count 2041 * or the mmap / vma pages are now blocked in do_exit on current 2042 * finishing this core dump. 2043 * 2044 * Only ptrace can touch these memory addresses, but it doesn't change 2045 * the map_count or the pages allocated. So no possibility of crashing 2046 * exists while dumping the mm->vm_next areas to the core file. 2047 */ 2048 2049 /* alloc memory for large data structures: too large to be on stack */ 2050 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 2051 if (!elf) 2052 goto out; 2053 /* 2054 * The number of segs are recored into ELF header as 16bit value. 2055 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. 2056 */ 2057 segs = current->mm->map_count; 2058 segs += elf_core_extra_phdrs(); 2059 2060 gate_vma = get_gate_vma(current->mm); 2061 if (gate_vma != NULL) 2062 segs++; 2063 2064 /* for notes section */ 2065 segs++; 2066 2067 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 2068 * this, kernel supports extended numbering. Have a look at 2069 * include/linux/elf.h for further information. */ 2070 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 2071 2072 /* 2073 * Collect all the non-memory information about the process for the 2074 * notes. This also sets up the file header. 2075 */ 2076 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs)) 2077 goto cleanup; 2078 2079 has_dumped = 1; 2080 2081 fs = get_fs(); 2082 set_fs(KERNEL_DS); 2083 2084 offset += sizeof(*elf); /* Elf header */ 2085 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 2086 2087 /* Write notes phdr entry */ 2088 { 2089 size_t sz = get_note_info_size(&info); 2090 2091 sz += elf_coredump_extra_notes_size(); 2092 2093 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 2094 if (!phdr4note) 2095 goto end_coredump; 2096 2097 fill_elf_note_phdr(phdr4note, sz, offset); 2098 offset += sz; 2099 } 2100 2101 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 2102 2103 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags); 2104 offset += elf_core_extra_data_size(); 2105 e_shoff = offset; 2106 2107 if (e_phnum == PN_XNUM) { 2108 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 2109 if (!shdr4extnum) 2110 goto end_coredump; 2111 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 2112 } 2113 2114 offset = dataoff; 2115 2116 if (!dump_emit(cprm, elf, sizeof(*elf))) 2117 goto end_coredump; 2118 2119 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 2120 goto end_coredump; 2121 2122 /* Write program headers for segments dump */ 2123 for (vma = first_vma(current, gate_vma); vma != NULL; 2124 vma = next_vma(vma, gate_vma)) { 2125 struct elf_phdr phdr; 2126 2127 phdr.p_type = PT_LOAD; 2128 phdr.p_offset = offset; 2129 phdr.p_vaddr = vma->vm_start; 2130 phdr.p_paddr = 0; 2131 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags); 2132 phdr.p_memsz = vma->vm_end - vma->vm_start; 2133 offset += phdr.p_filesz; 2134 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 2135 if (vma->vm_flags & VM_WRITE) 2136 phdr.p_flags |= PF_W; 2137 if (vma->vm_flags & VM_EXEC) 2138 phdr.p_flags |= PF_X; 2139 phdr.p_align = ELF_EXEC_PAGESIZE; 2140 2141 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 2142 goto end_coredump; 2143 } 2144 2145 if (!elf_core_write_extra_phdrs(cprm, offset)) 2146 goto end_coredump; 2147 2148 /* write out the notes section */ 2149 if (!write_note_info(&info, cprm)) 2150 goto end_coredump; 2151 2152 if (elf_coredump_extra_notes_write(cprm)) 2153 goto end_coredump; 2154 2155 /* Align to page */ 2156 if (!dump_skip(cprm, dataoff - cprm->written)) 2157 goto end_coredump; 2158 2159 for (vma = first_vma(current, gate_vma); vma != NULL; 2160 vma = next_vma(vma, gate_vma)) { 2161 unsigned long addr; 2162 unsigned long end; 2163 2164 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags); 2165 2166 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { 2167 struct page *page; 2168 int stop; 2169 2170 page = get_dump_page(addr); 2171 if (page) { 2172 void *kaddr = kmap(page); 2173 stop = !dump_emit(cprm, kaddr, PAGE_SIZE); 2174 kunmap(page); 2175 page_cache_release(page); 2176 } else 2177 stop = !dump_skip(cprm, PAGE_SIZE); 2178 if (stop) 2179 goto end_coredump; 2180 } 2181 } 2182 2183 if (!elf_core_write_extra_data(cprm)) 2184 goto end_coredump; 2185 2186 if (e_phnum == PN_XNUM) { 2187 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 2188 goto end_coredump; 2189 } 2190 2191 end_coredump: 2192 set_fs(fs); 2193 2194 cleanup: 2195 free_note_info(&info); 2196 kfree(shdr4extnum); 2197 kfree(phdr4note); 2198 kfree(elf); 2199 out: 2200 return has_dumped; 2201 } 2202 2203 #endif /* CONFIG_ELF_CORE */ 2204 2205 static int __init init_elf_binfmt(void) 2206 { 2207 register_binfmt(&elf_format); 2208 return 0; 2209 } 2210 2211 static void __exit exit_elf_binfmt(void) 2212 { 2213 /* Remove the COFF and ELF loaders. */ 2214 unregister_binfmt(&elf_format); 2215 } 2216 2217 core_initcall(init_elf_binfmt); 2218 module_exit(exit_elf_binfmt); 2219 MODULE_LICENSE("GPL"); 2220