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 unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, 50 int, int, unsigned long); 51 52 #ifdef CONFIG_USELIB 53 static int load_elf_library(struct file *); 54 #else 55 #define load_elf_library NULL 56 #endif 57 58 /* 59 * If we don't support core dumping, then supply a NULL so we 60 * don't even try. 61 */ 62 #ifdef CONFIG_ELF_CORE 63 static int elf_core_dump(struct coredump_params *cprm); 64 #else 65 #define elf_core_dump NULL 66 #endif 67 68 #if ELF_EXEC_PAGESIZE > PAGE_SIZE 69 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE 70 #else 71 #define ELF_MIN_ALIGN PAGE_SIZE 72 #endif 73 74 #ifndef ELF_CORE_EFLAGS 75 #define ELF_CORE_EFLAGS 0 76 #endif 77 78 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) 79 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) 80 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) 81 82 static struct linux_binfmt elf_format = { 83 .module = THIS_MODULE, 84 .load_binary = load_elf_binary, 85 .load_shlib = load_elf_library, 86 .core_dump = elf_core_dump, 87 .min_coredump = ELF_EXEC_PAGESIZE, 88 }; 89 90 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) 91 92 static int set_brk(unsigned long start, unsigned long end) 93 { 94 start = ELF_PAGEALIGN(start); 95 end = ELF_PAGEALIGN(end); 96 if (end > start) { 97 unsigned long addr; 98 addr = vm_brk(start, end - start); 99 if (BAD_ADDR(addr)) 100 return addr; 101 } 102 current->mm->start_brk = current->mm->brk = end; 103 return 0; 104 } 105 106 /* We need to explicitly zero any fractional pages 107 after the data section (i.e. bss). This would 108 contain the junk from the file that should not 109 be in memory 110 */ 111 static int padzero(unsigned long elf_bss) 112 { 113 unsigned long nbyte; 114 115 nbyte = ELF_PAGEOFFSET(elf_bss); 116 if (nbyte) { 117 nbyte = ELF_MIN_ALIGN - nbyte; 118 if (clear_user((void __user *) elf_bss, nbyte)) 119 return -EFAULT; 120 } 121 return 0; 122 } 123 124 /* Let's use some macros to make this stack manipulation a little clearer */ 125 #ifdef CONFIG_STACK_GROWSUP 126 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) 127 #define STACK_ROUND(sp, items) \ 128 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) 129 #define STACK_ALLOC(sp, len) ({ \ 130 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ 131 old_sp; }) 132 #else 133 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) 134 #define STACK_ROUND(sp, items) \ 135 (((unsigned long) (sp - items)) &~ 15UL) 136 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) 137 #endif 138 139 #ifndef ELF_BASE_PLATFORM 140 /* 141 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 142 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 143 * will be copied to the user stack in the same manner as AT_PLATFORM. 144 */ 145 #define ELF_BASE_PLATFORM NULL 146 #endif 147 148 static int 149 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, 150 unsigned long load_addr, unsigned long interp_load_addr) 151 { 152 unsigned long p = bprm->p; 153 int argc = bprm->argc; 154 int envc = bprm->envc; 155 elf_addr_t __user *argv; 156 elf_addr_t __user *envp; 157 elf_addr_t __user *sp; 158 elf_addr_t __user *u_platform; 159 elf_addr_t __user *u_base_platform; 160 elf_addr_t __user *u_rand_bytes; 161 const char *k_platform = ELF_PLATFORM; 162 const char *k_base_platform = ELF_BASE_PLATFORM; 163 unsigned char k_rand_bytes[16]; 164 int items; 165 elf_addr_t *elf_info; 166 int ei_index = 0; 167 const struct cred *cred = current_cred(); 168 struct vm_area_struct *vma; 169 170 /* 171 * In some cases (e.g. Hyper-Threading), we want to avoid L1 172 * evictions by the processes running on the same package. One 173 * thing we can do is to shuffle the initial stack for them. 174 */ 175 176 p = arch_align_stack(p); 177 178 /* 179 * If this architecture has a platform capability string, copy it 180 * to userspace. In some cases (Sparc), this info is impossible 181 * for userspace to get any other way, in others (i386) it is 182 * merely difficult. 183 */ 184 u_platform = NULL; 185 if (k_platform) { 186 size_t len = strlen(k_platform) + 1; 187 188 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 189 if (__copy_to_user(u_platform, k_platform, len)) 190 return -EFAULT; 191 } 192 193 /* 194 * If this architecture has a "base" platform capability 195 * string, copy it to userspace. 196 */ 197 u_base_platform = NULL; 198 if (k_base_platform) { 199 size_t len = strlen(k_base_platform) + 1; 200 201 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 202 if (__copy_to_user(u_base_platform, k_base_platform, len)) 203 return -EFAULT; 204 } 205 206 /* 207 * Generate 16 random bytes for userspace PRNG seeding. 208 */ 209 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); 210 u_rand_bytes = (elf_addr_t __user *) 211 STACK_ALLOC(p, sizeof(k_rand_bytes)); 212 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) 213 return -EFAULT; 214 215 /* Create the ELF interpreter info */ 216 elf_info = (elf_addr_t *)current->mm->saved_auxv; 217 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ 218 #define NEW_AUX_ENT(id, val) \ 219 do { \ 220 elf_info[ei_index++] = id; \ 221 elf_info[ei_index++] = val; \ 222 } while (0) 223 224 #ifdef ARCH_DLINFO 225 /* 226 * ARCH_DLINFO must come first so PPC can do its special alignment of 227 * AUXV. 228 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in 229 * ARCH_DLINFO changes 230 */ 231 ARCH_DLINFO; 232 #endif 233 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 234 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); 235 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 236 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); 237 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 238 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); 239 NEW_AUX_ENT(AT_BASE, interp_load_addr); 240 NEW_AUX_ENT(AT_FLAGS, 0); 241 NEW_AUX_ENT(AT_ENTRY, exec->e_entry); 242 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid)); 243 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid)); 244 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid)); 245 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid)); 246 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 247 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); 248 #ifdef ELF_HWCAP2 249 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 250 #endif 251 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 252 if (k_platform) { 253 NEW_AUX_ENT(AT_PLATFORM, 254 (elf_addr_t)(unsigned long)u_platform); 255 } 256 if (k_base_platform) { 257 NEW_AUX_ENT(AT_BASE_PLATFORM, 258 (elf_addr_t)(unsigned long)u_base_platform); 259 } 260 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 261 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 262 } 263 #undef NEW_AUX_ENT 264 /* AT_NULL is zero; clear the rest too */ 265 memset(&elf_info[ei_index], 0, 266 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); 267 268 /* And advance past the AT_NULL entry. */ 269 ei_index += 2; 270 271 sp = STACK_ADD(p, ei_index); 272 273 items = (argc + 1) + (envc + 1) + 1; 274 bprm->p = STACK_ROUND(sp, items); 275 276 /* Point sp at the lowest address on the stack */ 277 #ifdef CONFIG_STACK_GROWSUP 278 sp = (elf_addr_t __user *)bprm->p - items - ei_index; 279 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ 280 #else 281 sp = (elf_addr_t __user *)bprm->p; 282 #endif 283 284 285 /* 286 * Grow the stack manually; some architectures have a limit on how 287 * far ahead a user-space access may be in order to grow the stack. 288 */ 289 vma = find_extend_vma(current->mm, bprm->p); 290 if (!vma) 291 return -EFAULT; 292 293 /* Now, let's put argc (and argv, envp if appropriate) on the stack */ 294 if (__put_user(argc, sp++)) 295 return -EFAULT; 296 argv = sp; 297 envp = argv + argc + 1; 298 299 /* Populate argv and envp */ 300 p = current->mm->arg_end = current->mm->arg_start; 301 while (argc-- > 0) { 302 size_t len; 303 if (__put_user((elf_addr_t)p, argv++)) 304 return -EFAULT; 305 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 306 if (!len || len > MAX_ARG_STRLEN) 307 return -EINVAL; 308 p += len; 309 } 310 if (__put_user(0, argv)) 311 return -EFAULT; 312 current->mm->arg_end = current->mm->env_start = p; 313 while (envc-- > 0) { 314 size_t len; 315 if (__put_user((elf_addr_t)p, envp++)) 316 return -EFAULT; 317 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 318 if (!len || len > MAX_ARG_STRLEN) 319 return -EINVAL; 320 p += len; 321 } 322 if (__put_user(0, envp)) 323 return -EFAULT; 324 current->mm->env_end = p; 325 326 /* Put the elf_info on the stack in the right place. */ 327 sp = (elf_addr_t __user *)envp + 1; 328 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) 329 return -EFAULT; 330 return 0; 331 } 332 333 #ifndef elf_map 334 335 static unsigned long elf_map(struct file *filep, unsigned long addr, 336 struct elf_phdr *eppnt, int prot, int type, 337 unsigned long total_size) 338 { 339 unsigned long map_addr; 340 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); 341 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); 342 addr = ELF_PAGESTART(addr); 343 size = ELF_PAGEALIGN(size); 344 345 /* mmap() will return -EINVAL if given a zero size, but a 346 * segment with zero filesize is perfectly valid */ 347 if (!size) 348 return addr; 349 350 /* 351 * total_size is the size of the ELF (interpreter) image. 352 * The _first_ mmap needs to know the full size, otherwise 353 * randomization might put this image into an overlapping 354 * position with the ELF binary image. (since size < total_size) 355 * So we first map the 'big' image - and unmap the remainder at 356 * the end. (which unmap is needed for ELF images with holes.) 357 */ 358 if (total_size) { 359 total_size = ELF_PAGEALIGN(total_size); 360 map_addr = vm_mmap(filep, addr, total_size, prot, type, off); 361 if (!BAD_ADDR(map_addr)) 362 vm_munmap(map_addr+size, total_size-size); 363 } else 364 map_addr = vm_mmap(filep, addr, size, prot, type, off); 365 366 return(map_addr); 367 } 368 369 #endif /* !elf_map */ 370 371 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) 372 { 373 int i, first_idx = -1, last_idx = -1; 374 375 for (i = 0; i < nr; i++) { 376 if (cmds[i].p_type == PT_LOAD) { 377 last_idx = i; 378 if (first_idx == -1) 379 first_idx = i; 380 } 381 } 382 if (first_idx == -1) 383 return 0; 384 385 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - 386 ELF_PAGESTART(cmds[first_idx].p_vaddr); 387 } 388 389 390 /* This is much more generalized than the library routine read function, 391 so we keep this separate. Technically the library read function 392 is only provided so that we can read a.out libraries that have 393 an ELF header */ 394 395 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, 396 struct file *interpreter, unsigned long *interp_map_addr, 397 unsigned long no_base) 398 { 399 struct elf_phdr *elf_phdata; 400 struct elf_phdr *eppnt; 401 unsigned long load_addr = 0; 402 int load_addr_set = 0; 403 unsigned long last_bss = 0, elf_bss = 0; 404 unsigned long error = ~0UL; 405 unsigned long total_size; 406 int retval, i, size; 407 408 /* First of all, some simple consistency checks */ 409 if (interp_elf_ex->e_type != ET_EXEC && 410 interp_elf_ex->e_type != ET_DYN) 411 goto out; 412 if (!elf_check_arch(interp_elf_ex)) 413 goto out; 414 if (!interpreter->f_op->mmap) 415 goto out; 416 417 /* 418 * If the size of this structure has changed, then punt, since 419 * we will be doing the wrong thing. 420 */ 421 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) 422 goto out; 423 if (interp_elf_ex->e_phnum < 1 || 424 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) 425 goto out; 426 427 /* Now read in all of the header information */ 428 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; 429 if (size > ELF_MIN_ALIGN) 430 goto out; 431 elf_phdata = kmalloc(size, GFP_KERNEL); 432 if (!elf_phdata) 433 goto out; 434 435 retval = kernel_read(interpreter, interp_elf_ex->e_phoff, 436 (char *)elf_phdata, size); 437 error = -EIO; 438 if (retval != size) { 439 if (retval < 0) 440 error = retval; 441 goto out_close; 442 } 443 444 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); 445 if (!total_size) { 446 error = -EINVAL; 447 goto out_close; 448 } 449 450 eppnt = elf_phdata; 451 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { 452 if (eppnt->p_type == PT_LOAD) { 453 int elf_type = MAP_PRIVATE | MAP_DENYWRITE; 454 int elf_prot = 0; 455 unsigned long vaddr = 0; 456 unsigned long k, map_addr; 457 458 if (eppnt->p_flags & PF_R) 459 elf_prot = PROT_READ; 460 if (eppnt->p_flags & PF_W) 461 elf_prot |= PROT_WRITE; 462 if (eppnt->p_flags & PF_X) 463 elf_prot |= PROT_EXEC; 464 vaddr = eppnt->p_vaddr; 465 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) 466 elf_type |= MAP_FIXED; 467 else if (no_base && interp_elf_ex->e_type == ET_DYN) 468 load_addr = -vaddr; 469 470 map_addr = elf_map(interpreter, load_addr + vaddr, 471 eppnt, elf_prot, elf_type, total_size); 472 total_size = 0; 473 if (!*interp_map_addr) 474 *interp_map_addr = map_addr; 475 error = map_addr; 476 if (BAD_ADDR(map_addr)) 477 goto out_close; 478 479 if (!load_addr_set && 480 interp_elf_ex->e_type == ET_DYN) { 481 load_addr = map_addr - ELF_PAGESTART(vaddr); 482 load_addr_set = 1; 483 } 484 485 /* 486 * Check to see if the section's size will overflow the 487 * allowed task size. Note that p_filesz must always be 488 * <= p_memsize so it's only necessary to check p_memsz. 489 */ 490 k = load_addr + eppnt->p_vaddr; 491 if (BAD_ADDR(k) || 492 eppnt->p_filesz > eppnt->p_memsz || 493 eppnt->p_memsz > TASK_SIZE || 494 TASK_SIZE - eppnt->p_memsz < k) { 495 error = -ENOMEM; 496 goto out_close; 497 } 498 499 /* 500 * Find the end of the file mapping for this phdr, and 501 * keep track of the largest address we see for this. 502 */ 503 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; 504 if (k > elf_bss) 505 elf_bss = k; 506 507 /* 508 * Do the same thing for the memory mapping - between 509 * elf_bss and last_bss is the bss section. 510 */ 511 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; 512 if (k > last_bss) 513 last_bss = k; 514 } 515 } 516 517 if (last_bss > elf_bss) { 518 /* 519 * Now fill out the bss section. First pad the last page up 520 * to the page boundary, and then perform a mmap to make sure 521 * that there are zero-mapped pages up to and including the 522 * last bss page. 523 */ 524 if (padzero(elf_bss)) { 525 error = -EFAULT; 526 goto out_close; 527 } 528 529 /* What we have mapped so far */ 530 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); 531 532 /* Map the last of the bss segment */ 533 error = vm_brk(elf_bss, last_bss - elf_bss); 534 if (BAD_ADDR(error)) 535 goto out_close; 536 } 537 538 error = load_addr; 539 540 out_close: 541 kfree(elf_phdata); 542 out: 543 return error; 544 } 545 546 /* 547 * These are the functions used to load ELF style executables and shared 548 * libraries. There is no binary dependent code anywhere else. 549 */ 550 551 #ifndef STACK_RND_MASK 552 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ 553 #endif 554 555 static unsigned long randomize_stack_top(unsigned long stack_top) 556 { 557 unsigned int random_variable = 0; 558 559 if ((current->flags & PF_RANDOMIZE) && 560 !(current->personality & ADDR_NO_RANDOMIZE)) { 561 random_variable = get_random_int() & STACK_RND_MASK; 562 random_variable <<= PAGE_SHIFT; 563 } 564 #ifdef CONFIG_STACK_GROWSUP 565 return PAGE_ALIGN(stack_top) + random_variable; 566 #else 567 return PAGE_ALIGN(stack_top) - random_variable; 568 #endif 569 } 570 571 static int load_elf_binary(struct linux_binprm *bprm) 572 { 573 struct file *interpreter = NULL; /* to shut gcc up */ 574 unsigned long load_addr = 0, load_bias = 0; 575 int load_addr_set = 0; 576 char * elf_interpreter = NULL; 577 unsigned long error; 578 struct elf_phdr *elf_ppnt, *elf_phdata; 579 unsigned long elf_bss, elf_brk; 580 int retval, i; 581 unsigned int size; 582 unsigned long elf_entry; 583 unsigned long interp_load_addr = 0; 584 unsigned long start_code, end_code, start_data, end_data; 585 unsigned long reloc_func_desc __maybe_unused = 0; 586 int executable_stack = EXSTACK_DEFAULT; 587 struct pt_regs *regs = current_pt_regs(); 588 struct { 589 struct elfhdr elf_ex; 590 struct elfhdr interp_elf_ex; 591 } *loc; 592 593 loc = kmalloc(sizeof(*loc), GFP_KERNEL); 594 if (!loc) { 595 retval = -ENOMEM; 596 goto out_ret; 597 } 598 599 /* Get the exec-header */ 600 loc->elf_ex = *((struct elfhdr *)bprm->buf); 601 602 retval = -ENOEXEC; 603 /* First of all, some simple consistency checks */ 604 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 605 goto out; 606 607 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) 608 goto out; 609 if (!elf_check_arch(&loc->elf_ex)) 610 goto out; 611 if (!bprm->file->f_op->mmap) 612 goto out; 613 614 /* Now read in all of the header information */ 615 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) 616 goto out; 617 if (loc->elf_ex.e_phnum < 1 || 618 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) 619 goto out; 620 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); 621 retval = -ENOMEM; 622 elf_phdata = kmalloc(size, GFP_KERNEL); 623 if (!elf_phdata) 624 goto out; 625 626 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, 627 (char *)elf_phdata, size); 628 if (retval != size) { 629 if (retval >= 0) 630 retval = -EIO; 631 goto out_free_ph; 632 } 633 634 elf_ppnt = elf_phdata; 635 elf_bss = 0; 636 elf_brk = 0; 637 638 start_code = ~0UL; 639 end_code = 0; 640 start_data = 0; 641 end_data = 0; 642 643 for (i = 0; i < loc->elf_ex.e_phnum; i++) { 644 if (elf_ppnt->p_type == PT_INTERP) { 645 /* This is the program interpreter used for 646 * shared libraries - for now assume that this 647 * is an a.out format binary 648 */ 649 retval = -ENOEXEC; 650 if (elf_ppnt->p_filesz > PATH_MAX || 651 elf_ppnt->p_filesz < 2) 652 goto out_free_ph; 653 654 retval = -ENOMEM; 655 elf_interpreter = kmalloc(elf_ppnt->p_filesz, 656 GFP_KERNEL); 657 if (!elf_interpreter) 658 goto out_free_ph; 659 660 retval = kernel_read(bprm->file, elf_ppnt->p_offset, 661 elf_interpreter, 662 elf_ppnt->p_filesz); 663 if (retval != elf_ppnt->p_filesz) { 664 if (retval >= 0) 665 retval = -EIO; 666 goto out_free_interp; 667 } 668 /* make sure path is NULL terminated */ 669 retval = -ENOEXEC; 670 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') 671 goto out_free_interp; 672 673 interpreter = open_exec(elf_interpreter); 674 retval = PTR_ERR(interpreter); 675 if (IS_ERR(interpreter)) 676 goto out_free_interp; 677 678 /* 679 * If the binary is not readable then enforce 680 * mm->dumpable = 0 regardless of the interpreter's 681 * permissions. 682 */ 683 would_dump(bprm, interpreter); 684 685 retval = kernel_read(interpreter, 0, bprm->buf, 686 BINPRM_BUF_SIZE); 687 if (retval != BINPRM_BUF_SIZE) { 688 if (retval >= 0) 689 retval = -EIO; 690 goto out_free_dentry; 691 } 692 693 /* Get the exec headers */ 694 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf); 695 break; 696 } 697 elf_ppnt++; 698 } 699 700 elf_ppnt = elf_phdata; 701 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) 702 if (elf_ppnt->p_type == PT_GNU_STACK) { 703 if (elf_ppnt->p_flags & PF_X) 704 executable_stack = EXSTACK_ENABLE_X; 705 else 706 executable_stack = EXSTACK_DISABLE_X; 707 break; 708 } 709 710 /* Some simple consistency checks for the interpreter */ 711 if (elf_interpreter) { 712 retval = -ELIBBAD; 713 /* Not an ELF interpreter */ 714 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 715 goto out_free_dentry; 716 /* Verify the interpreter has a valid arch */ 717 if (!elf_check_arch(&loc->interp_elf_ex)) 718 goto out_free_dentry; 719 } 720 721 /* Flush all traces of the currently running executable */ 722 retval = flush_old_exec(bprm); 723 if (retval) 724 goto out_free_dentry; 725 726 /* Do this immediately, since STACK_TOP as used in setup_arg_pages 727 may depend on the personality. */ 728 SET_PERSONALITY(loc->elf_ex); 729 if (elf_read_implies_exec(loc->elf_ex, executable_stack)) 730 current->personality |= READ_IMPLIES_EXEC; 731 732 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 733 current->flags |= PF_RANDOMIZE; 734 735 setup_new_exec(bprm); 736 737 /* Do this so that we can load the interpreter, if need be. We will 738 change some of these later */ 739 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), 740 executable_stack); 741 if (retval < 0) 742 goto out_free_dentry; 743 744 current->mm->start_stack = bprm->p; 745 746 /* Now we do a little grungy work by mmapping the ELF image into 747 the correct location in memory. */ 748 for(i = 0, elf_ppnt = elf_phdata; 749 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { 750 int elf_prot = 0, elf_flags; 751 unsigned long k, vaddr; 752 753 if (elf_ppnt->p_type != PT_LOAD) 754 continue; 755 756 if (unlikely (elf_brk > elf_bss)) { 757 unsigned long nbyte; 758 759 /* There was a PT_LOAD segment with p_memsz > p_filesz 760 before this one. Map anonymous pages, if needed, 761 and clear the area. */ 762 retval = set_brk(elf_bss + load_bias, 763 elf_brk + load_bias); 764 if (retval) 765 goto out_free_dentry; 766 nbyte = ELF_PAGEOFFSET(elf_bss); 767 if (nbyte) { 768 nbyte = ELF_MIN_ALIGN - nbyte; 769 if (nbyte > elf_brk - elf_bss) 770 nbyte = elf_brk - elf_bss; 771 if (clear_user((void __user *)elf_bss + 772 load_bias, nbyte)) { 773 /* 774 * This bss-zeroing can fail if the ELF 775 * file specifies odd protections. So 776 * we don't check the return value 777 */ 778 } 779 } 780 } 781 782 if (elf_ppnt->p_flags & PF_R) 783 elf_prot |= PROT_READ; 784 if (elf_ppnt->p_flags & PF_W) 785 elf_prot |= PROT_WRITE; 786 if (elf_ppnt->p_flags & PF_X) 787 elf_prot |= PROT_EXEC; 788 789 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; 790 791 vaddr = elf_ppnt->p_vaddr; 792 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { 793 elf_flags |= MAP_FIXED; 794 } else if (loc->elf_ex.e_type == ET_DYN) { 795 /* Try and get dynamic programs out of the way of the 796 * default mmap base, as well as whatever program they 797 * might try to exec. This is because the brk will 798 * follow the loader, and is not movable. */ 799 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE 800 /* Memory randomization might have been switched off 801 * in runtime via sysctl or explicit setting of 802 * personality flags. 803 * If that is the case, retain the original non-zero 804 * load_bias value in order to establish proper 805 * non-randomized mappings. 806 */ 807 if (current->flags & PF_RANDOMIZE) 808 load_bias = 0; 809 else 810 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 811 #else 812 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 813 #endif 814 } 815 816 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, 817 elf_prot, elf_flags, 0); 818 if (BAD_ADDR(error)) { 819 retval = IS_ERR((void *)error) ? 820 PTR_ERR((void*)error) : -EINVAL; 821 goto out_free_dentry; 822 } 823 824 if (!load_addr_set) { 825 load_addr_set = 1; 826 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); 827 if (loc->elf_ex.e_type == ET_DYN) { 828 load_bias += error - 829 ELF_PAGESTART(load_bias + vaddr); 830 load_addr += load_bias; 831 reloc_func_desc = load_bias; 832 } 833 } 834 k = elf_ppnt->p_vaddr; 835 if (k < start_code) 836 start_code = k; 837 if (start_data < k) 838 start_data = k; 839 840 /* 841 * Check to see if the section's size will overflow the 842 * allowed task size. Note that p_filesz must always be 843 * <= p_memsz so it is only necessary to check p_memsz. 844 */ 845 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || 846 elf_ppnt->p_memsz > TASK_SIZE || 847 TASK_SIZE - elf_ppnt->p_memsz < k) { 848 /* set_brk can never work. Avoid overflows. */ 849 retval = -EINVAL; 850 goto out_free_dentry; 851 } 852 853 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; 854 855 if (k > elf_bss) 856 elf_bss = k; 857 if ((elf_ppnt->p_flags & PF_X) && end_code < k) 858 end_code = k; 859 if (end_data < k) 860 end_data = k; 861 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; 862 if (k > elf_brk) 863 elf_brk = k; 864 } 865 866 loc->elf_ex.e_entry += load_bias; 867 elf_bss += load_bias; 868 elf_brk += load_bias; 869 start_code += load_bias; 870 end_code += load_bias; 871 start_data += load_bias; 872 end_data += load_bias; 873 874 /* Calling set_brk effectively mmaps the pages that we need 875 * for the bss and break sections. We must do this before 876 * mapping in the interpreter, to make sure it doesn't wind 877 * up getting placed where the bss needs to go. 878 */ 879 retval = set_brk(elf_bss, elf_brk); 880 if (retval) 881 goto out_free_dentry; 882 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { 883 retval = -EFAULT; /* Nobody gets to see this, but.. */ 884 goto out_free_dentry; 885 } 886 887 if (elf_interpreter) { 888 unsigned long interp_map_addr = 0; 889 890 elf_entry = load_elf_interp(&loc->interp_elf_ex, 891 interpreter, 892 &interp_map_addr, 893 load_bias); 894 if (!IS_ERR((void *)elf_entry)) { 895 /* 896 * load_elf_interp() returns relocation 897 * adjustment 898 */ 899 interp_load_addr = elf_entry; 900 elf_entry += loc->interp_elf_ex.e_entry; 901 } 902 if (BAD_ADDR(elf_entry)) { 903 retval = IS_ERR((void *)elf_entry) ? 904 (int)elf_entry : -EINVAL; 905 goto out_free_dentry; 906 } 907 reloc_func_desc = interp_load_addr; 908 909 allow_write_access(interpreter); 910 fput(interpreter); 911 kfree(elf_interpreter); 912 } else { 913 elf_entry = loc->elf_ex.e_entry; 914 if (BAD_ADDR(elf_entry)) { 915 retval = -EINVAL; 916 goto out_free_dentry; 917 } 918 } 919 920 kfree(elf_phdata); 921 922 set_binfmt(&elf_format); 923 924 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 925 retval = arch_setup_additional_pages(bprm, !!elf_interpreter); 926 if (retval < 0) 927 goto out; 928 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ 929 930 install_exec_creds(bprm); 931 retval = create_elf_tables(bprm, &loc->elf_ex, 932 load_addr, interp_load_addr); 933 if (retval < 0) 934 goto out; 935 /* N.B. passed_fileno might not be initialized? */ 936 current->mm->end_code = end_code; 937 current->mm->start_code = start_code; 938 current->mm->start_data = start_data; 939 current->mm->end_data = end_data; 940 current->mm->start_stack = bprm->p; 941 942 #ifdef arch_randomize_brk 943 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { 944 current->mm->brk = current->mm->start_brk = 945 arch_randomize_brk(current->mm); 946 #ifdef CONFIG_COMPAT_BRK 947 current->brk_randomized = 1; 948 #endif 949 } 950 #endif 951 952 if (current->personality & MMAP_PAGE_ZERO) { 953 /* Why this, you ask??? Well SVr4 maps page 0 as read-only, 954 and some applications "depend" upon this behavior. 955 Since we do not have the power to recompile these, we 956 emulate the SVr4 behavior. Sigh. */ 957 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, 958 MAP_FIXED | MAP_PRIVATE, 0); 959 } 960 961 #ifdef ELF_PLAT_INIT 962 /* 963 * The ABI may specify that certain registers be set up in special 964 * ways (on i386 %edx is the address of a DT_FINI function, for 965 * example. In addition, it may also specify (eg, PowerPC64 ELF) 966 * that the e_entry field is the address of the function descriptor 967 * for the startup routine, rather than the address of the startup 968 * routine itself. This macro performs whatever initialization to 969 * the regs structure is required as well as any relocations to the 970 * function descriptor entries when executing dynamically links apps. 971 */ 972 ELF_PLAT_INIT(regs, reloc_func_desc); 973 #endif 974 975 start_thread(regs, elf_entry, bprm->p); 976 retval = 0; 977 out: 978 kfree(loc); 979 out_ret: 980 return retval; 981 982 /* error cleanup */ 983 out_free_dentry: 984 allow_write_access(interpreter); 985 if (interpreter) 986 fput(interpreter); 987 out_free_interp: 988 kfree(elf_interpreter); 989 out_free_ph: 990 kfree(elf_phdata); 991 goto out; 992 } 993 994 #ifdef CONFIG_USELIB 995 /* This is really simpleminded and specialized - we are loading an 996 a.out library that is given an ELF header. */ 997 static int load_elf_library(struct file *file) 998 { 999 struct elf_phdr *elf_phdata; 1000 struct elf_phdr *eppnt; 1001 unsigned long elf_bss, bss, len; 1002 int retval, error, i, j; 1003 struct elfhdr elf_ex; 1004 1005 error = -ENOEXEC; 1006 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); 1007 if (retval != sizeof(elf_ex)) 1008 goto out; 1009 1010 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 1011 goto out; 1012 1013 /* First of all, some simple consistency checks */ 1014 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || 1015 !elf_check_arch(&elf_ex) || !file->f_op->mmap) 1016 goto out; 1017 1018 /* Now read in all of the header information */ 1019 1020 j = sizeof(struct elf_phdr) * elf_ex.e_phnum; 1021 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ 1022 1023 error = -ENOMEM; 1024 elf_phdata = kmalloc(j, GFP_KERNEL); 1025 if (!elf_phdata) 1026 goto out; 1027 1028 eppnt = elf_phdata; 1029 error = -ENOEXEC; 1030 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); 1031 if (retval != j) 1032 goto out_free_ph; 1033 1034 for (j = 0, i = 0; i<elf_ex.e_phnum; i++) 1035 if ((eppnt + i)->p_type == PT_LOAD) 1036 j++; 1037 if (j != 1) 1038 goto out_free_ph; 1039 1040 while (eppnt->p_type != PT_LOAD) 1041 eppnt++; 1042 1043 /* Now use mmap to map the library into memory. */ 1044 error = vm_mmap(file, 1045 ELF_PAGESTART(eppnt->p_vaddr), 1046 (eppnt->p_filesz + 1047 ELF_PAGEOFFSET(eppnt->p_vaddr)), 1048 PROT_READ | PROT_WRITE | PROT_EXEC, 1049 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, 1050 (eppnt->p_offset - 1051 ELF_PAGEOFFSET(eppnt->p_vaddr))); 1052 if (error != ELF_PAGESTART(eppnt->p_vaddr)) 1053 goto out_free_ph; 1054 1055 elf_bss = eppnt->p_vaddr + eppnt->p_filesz; 1056 if (padzero(elf_bss)) { 1057 error = -EFAULT; 1058 goto out_free_ph; 1059 } 1060 1061 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + 1062 ELF_MIN_ALIGN - 1); 1063 bss = eppnt->p_memsz + eppnt->p_vaddr; 1064 if (bss > len) 1065 vm_brk(len, bss - len); 1066 error = 0; 1067 1068 out_free_ph: 1069 kfree(elf_phdata); 1070 out: 1071 return error; 1072 } 1073 #endif /* #ifdef CONFIG_USELIB */ 1074 1075 #ifdef CONFIG_ELF_CORE 1076 /* 1077 * ELF core dumper 1078 * 1079 * Modelled on fs/exec.c:aout_core_dump() 1080 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1081 */ 1082 1083 /* 1084 * The purpose of always_dump_vma() is to make sure that special kernel mappings 1085 * that are useful for post-mortem analysis are included in every core dump. 1086 * In that way we ensure that the core dump is fully interpretable later 1087 * without matching up the same kernel and hardware config to see what PC values 1088 * meant. These special mappings include - vDSO, vsyscall, and other 1089 * architecture specific mappings 1090 */ 1091 static bool always_dump_vma(struct vm_area_struct *vma) 1092 { 1093 /* Any vsyscall mappings? */ 1094 if (vma == get_gate_vma(vma->vm_mm)) 1095 return true; 1096 1097 /* 1098 * Assume that all vmas with a .name op should always be dumped. 1099 * If this changes, a new vm_ops field can easily be added. 1100 */ 1101 if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma)) 1102 return true; 1103 1104 /* 1105 * arch_vma_name() returns non-NULL for special architecture mappings, 1106 * such as vDSO sections. 1107 */ 1108 if (arch_vma_name(vma)) 1109 return true; 1110 1111 return false; 1112 } 1113 1114 /* 1115 * Decide what to dump of a segment, part, all or none. 1116 */ 1117 static unsigned long vma_dump_size(struct vm_area_struct *vma, 1118 unsigned long mm_flags) 1119 { 1120 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) 1121 1122 /* always dump the vdso and vsyscall sections */ 1123 if (always_dump_vma(vma)) 1124 goto whole; 1125 1126 if (vma->vm_flags & VM_DONTDUMP) 1127 return 0; 1128 1129 /* Hugetlb memory check */ 1130 if (vma->vm_flags & VM_HUGETLB) { 1131 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) 1132 goto whole; 1133 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) 1134 goto whole; 1135 return 0; 1136 } 1137 1138 /* Do not dump I/O mapped devices or special mappings */ 1139 if (vma->vm_flags & VM_IO) 1140 return 0; 1141 1142 /* By default, dump shared memory if mapped from an anonymous file. */ 1143 if (vma->vm_flags & VM_SHARED) { 1144 if (file_inode(vma->vm_file)->i_nlink == 0 ? 1145 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) 1146 goto whole; 1147 return 0; 1148 } 1149 1150 /* Dump segments that have been written to. */ 1151 if (vma->anon_vma && FILTER(ANON_PRIVATE)) 1152 goto whole; 1153 if (vma->vm_file == NULL) 1154 return 0; 1155 1156 if (FILTER(MAPPED_PRIVATE)) 1157 goto whole; 1158 1159 /* 1160 * If this looks like the beginning of a DSO or executable mapping, 1161 * check for an ELF header. If we find one, dump the first page to 1162 * aid in determining what was mapped here. 1163 */ 1164 if (FILTER(ELF_HEADERS) && 1165 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { 1166 u32 __user *header = (u32 __user *) vma->vm_start; 1167 u32 word; 1168 mm_segment_t fs = get_fs(); 1169 /* 1170 * Doing it this way gets the constant folded by GCC. 1171 */ 1172 union { 1173 u32 cmp; 1174 char elfmag[SELFMAG]; 1175 } magic; 1176 BUILD_BUG_ON(SELFMAG != sizeof word); 1177 magic.elfmag[EI_MAG0] = ELFMAG0; 1178 magic.elfmag[EI_MAG1] = ELFMAG1; 1179 magic.elfmag[EI_MAG2] = ELFMAG2; 1180 magic.elfmag[EI_MAG3] = ELFMAG3; 1181 /* 1182 * Switch to the user "segment" for get_user(), 1183 * then put back what elf_core_dump() had in place. 1184 */ 1185 set_fs(USER_DS); 1186 if (unlikely(get_user(word, header))) 1187 word = 0; 1188 set_fs(fs); 1189 if (word == magic.cmp) 1190 return PAGE_SIZE; 1191 } 1192 1193 #undef FILTER 1194 1195 return 0; 1196 1197 whole: 1198 return vma->vm_end - vma->vm_start; 1199 } 1200 1201 /* An ELF note in memory */ 1202 struct memelfnote 1203 { 1204 const char *name; 1205 int type; 1206 unsigned int datasz; 1207 void *data; 1208 }; 1209 1210 static int notesize(struct memelfnote *en) 1211 { 1212 int sz; 1213 1214 sz = sizeof(struct elf_note); 1215 sz += roundup(strlen(en->name) + 1, 4); 1216 sz += roundup(en->datasz, 4); 1217 1218 return sz; 1219 } 1220 1221 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1222 { 1223 struct elf_note en; 1224 en.n_namesz = strlen(men->name) + 1; 1225 en.n_descsz = men->datasz; 1226 en.n_type = men->type; 1227 1228 return dump_emit(cprm, &en, sizeof(en)) && 1229 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1230 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1231 } 1232 1233 static void fill_elf_header(struct elfhdr *elf, int segs, 1234 u16 machine, u32 flags) 1235 { 1236 memset(elf, 0, sizeof(*elf)); 1237 1238 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1239 elf->e_ident[EI_CLASS] = ELF_CLASS; 1240 elf->e_ident[EI_DATA] = ELF_DATA; 1241 elf->e_ident[EI_VERSION] = EV_CURRENT; 1242 elf->e_ident[EI_OSABI] = ELF_OSABI; 1243 1244 elf->e_type = ET_CORE; 1245 elf->e_machine = machine; 1246 elf->e_version = EV_CURRENT; 1247 elf->e_phoff = sizeof(struct elfhdr); 1248 elf->e_flags = flags; 1249 elf->e_ehsize = sizeof(struct elfhdr); 1250 elf->e_phentsize = sizeof(struct elf_phdr); 1251 elf->e_phnum = segs; 1252 1253 return; 1254 } 1255 1256 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1257 { 1258 phdr->p_type = PT_NOTE; 1259 phdr->p_offset = offset; 1260 phdr->p_vaddr = 0; 1261 phdr->p_paddr = 0; 1262 phdr->p_filesz = sz; 1263 phdr->p_memsz = 0; 1264 phdr->p_flags = 0; 1265 phdr->p_align = 0; 1266 return; 1267 } 1268 1269 static void fill_note(struct memelfnote *note, const char *name, int type, 1270 unsigned int sz, void *data) 1271 { 1272 note->name = name; 1273 note->type = type; 1274 note->datasz = sz; 1275 note->data = data; 1276 return; 1277 } 1278 1279 /* 1280 * fill up all the fields in prstatus from the given task struct, except 1281 * registers which need to be filled up separately. 1282 */ 1283 static void fill_prstatus(struct elf_prstatus *prstatus, 1284 struct task_struct *p, long signr) 1285 { 1286 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1287 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1288 prstatus->pr_sighold = p->blocked.sig[0]; 1289 rcu_read_lock(); 1290 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1291 rcu_read_unlock(); 1292 prstatus->pr_pid = task_pid_vnr(p); 1293 prstatus->pr_pgrp = task_pgrp_vnr(p); 1294 prstatus->pr_sid = task_session_vnr(p); 1295 if (thread_group_leader(p)) { 1296 struct task_cputime cputime; 1297 1298 /* 1299 * This is the record for the group leader. It shows the 1300 * group-wide total, not its individual thread total. 1301 */ 1302 thread_group_cputime(p, &cputime); 1303 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1304 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1305 } else { 1306 cputime_t utime, stime; 1307 1308 task_cputime(p, &utime, &stime); 1309 cputime_to_timeval(utime, &prstatus->pr_utime); 1310 cputime_to_timeval(stime, &prstatus->pr_stime); 1311 } 1312 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1313 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1314 } 1315 1316 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1317 struct mm_struct *mm) 1318 { 1319 const struct cred *cred; 1320 unsigned int i, len; 1321 1322 /* first copy the parameters from user space */ 1323 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1324 1325 len = mm->arg_end - mm->arg_start; 1326 if (len >= ELF_PRARGSZ) 1327 len = ELF_PRARGSZ-1; 1328 if (copy_from_user(&psinfo->pr_psargs, 1329 (const char __user *)mm->arg_start, len)) 1330 return -EFAULT; 1331 for(i = 0; i < len; i++) 1332 if (psinfo->pr_psargs[i] == 0) 1333 psinfo->pr_psargs[i] = ' '; 1334 psinfo->pr_psargs[len] = 0; 1335 1336 rcu_read_lock(); 1337 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1338 rcu_read_unlock(); 1339 psinfo->pr_pid = task_pid_vnr(p); 1340 psinfo->pr_pgrp = task_pgrp_vnr(p); 1341 psinfo->pr_sid = task_session_vnr(p); 1342 1343 i = p->state ? ffz(~p->state) + 1 : 0; 1344 psinfo->pr_state = i; 1345 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1346 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1347 psinfo->pr_nice = task_nice(p); 1348 psinfo->pr_flag = p->flags; 1349 rcu_read_lock(); 1350 cred = __task_cred(p); 1351 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1352 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1353 rcu_read_unlock(); 1354 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1355 1356 return 0; 1357 } 1358 1359 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) 1360 { 1361 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; 1362 int i = 0; 1363 do 1364 i += 2; 1365 while (auxv[i - 2] != AT_NULL); 1366 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1367 } 1368 1369 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, 1370 const siginfo_t *siginfo) 1371 { 1372 mm_segment_t old_fs = get_fs(); 1373 set_fs(KERNEL_DS); 1374 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo); 1375 set_fs(old_fs); 1376 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); 1377 } 1378 1379 #define MAX_FILE_NOTE_SIZE (4*1024*1024) 1380 /* 1381 * Format of NT_FILE note: 1382 * 1383 * long count -- how many files are mapped 1384 * long page_size -- units for file_ofs 1385 * array of [COUNT] elements of 1386 * long start 1387 * long end 1388 * long file_ofs 1389 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL... 1390 */ 1391 static int fill_files_note(struct memelfnote *note) 1392 { 1393 struct vm_area_struct *vma; 1394 unsigned count, size, names_ofs, remaining, n; 1395 user_long_t *data; 1396 user_long_t *start_end_ofs; 1397 char *name_base, *name_curpos; 1398 1399 /* *Estimated* file count and total data size needed */ 1400 count = current->mm->map_count; 1401 size = count * 64; 1402 1403 names_ofs = (2 + 3 * count) * sizeof(data[0]); 1404 alloc: 1405 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */ 1406 return -EINVAL; 1407 size = round_up(size, PAGE_SIZE); 1408 data = vmalloc(size); 1409 if (!data) 1410 return -ENOMEM; 1411 1412 start_end_ofs = data + 2; 1413 name_base = name_curpos = ((char *)data) + names_ofs; 1414 remaining = size - names_ofs; 1415 count = 0; 1416 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) { 1417 struct file *file; 1418 const char *filename; 1419 1420 file = vma->vm_file; 1421 if (!file) 1422 continue; 1423 filename = d_path(&file->f_path, name_curpos, remaining); 1424 if (IS_ERR(filename)) { 1425 if (PTR_ERR(filename) == -ENAMETOOLONG) { 1426 vfree(data); 1427 size = size * 5 / 4; 1428 goto alloc; 1429 } 1430 continue; 1431 } 1432 1433 /* d_path() fills at the end, move name down */ 1434 /* n = strlen(filename) + 1: */ 1435 n = (name_curpos + remaining) - filename; 1436 remaining = filename - name_curpos; 1437 memmove(name_curpos, filename, n); 1438 name_curpos += n; 1439 1440 *start_end_ofs++ = vma->vm_start; 1441 *start_end_ofs++ = vma->vm_end; 1442 *start_end_ofs++ = vma->vm_pgoff; 1443 count++; 1444 } 1445 1446 /* Now we know exact count of files, can store it */ 1447 data[0] = count; 1448 data[1] = PAGE_SIZE; 1449 /* 1450 * Count usually is less than current->mm->map_count, 1451 * we need to move filenames down. 1452 */ 1453 n = current->mm->map_count - count; 1454 if (n != 0) { 1455 unsigned shift_bytes = n * 3 * sizeof(data[0]); 1456 memmove(name_base - shift_bytes, name_base, 1457 name_curpos - name_base); 1458 name_curpos -= shift_bytes; 1459 } 1460 1461 size = name_curpos - (char *)data; 1462 fill_note(note, "CORE", NT_FILE, size, data); 1463 return 0; 1464 } 1465 1466 #ifdef CORE_DUMP_USE_REGSET 1467 #include <linux/regset.h> 1468 1469 struct elf_thread_core_info { 1470 struct elf_thread_core_info *next; 1471 struct task_struct *task; 1472 struct elf_prstatus prstatus; 1473 struct memelfnote notes[0]; 1474 }; 1475 1476 struct elf_note_info { 1477 struct elf_thread_core_info *thread; 1478 struct memelfnote psinfo; 1479 struct memelfnote signote; 1480 struct memelfnote auxv; 1481 struct memelfnote files; 1482 user_siginfo_t csigdata; 1483 size_t size; 1484 int thread_notes; 1485 }; 1486 1487 /* 1488 * When a regset has a writeback hook, we call it on each thread before 1489 * dumping user memory. On register window machines, this makes sure the 1490 * user memory backing the register data is up to date before we read it. 1491 */ 1492 static void do_thread_regset_writeback(struct task_struct *task, 1493 const struct user_regset *regset) 1494 { 1495 if (regset->writeback) 1496 regset->writeback(task, regset, 1); 1497 } 1498 1499 #ifndef PR_REG_SIZE 1500 #define PR_REG_SIZE(S) sizeof(S) 1501 #endif 1502 1503 #ifndef PRSTATUS_SIZE 1504 #define PRSTATUS_SIZE(S) sizeof(S) 1505 #endif 1506 1507 #ifndef PR_REG_PTR 1508 #define PR_REG_PTR(S) (&((S)->pr_reg)) 1509 #endif 1510 1511 #ifndef SET_PR_FPVALID 1512 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V)) 1513 #endif 1514 1515 static int fill_thread_core_info(struct elf_thread_core_info *t, 1516 const struct user_regset_view *view, 1517 long signr, size_t *total) 1518 { 1519 unsigned int i; 1520 1521 /* 1522 * NT_PRSTATUS is the one special case, because the regset data 1523 * goes into the pr_reg field inside the note contents, rather 1524 * than being the whole note contents. We fill the reset in here. 1525 * We assume that regset 0 is NT_PRSTATUS. 1526 */ 1527 fill_prstatus(&t->prstatus, t->task, signr); 1528 (void) view->regsets[0].get(t->task, &view->regsets[0], 1529 0, PR_REG_SIZE(t->prstatus.pr_reg), 1530 PR_REG_PTR(&t->prstatus), NULL); 1531 1532 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, 1533 PRSTATUS_SIZE(t->prstatus), &t->prstatus); 1534 *total += notesize(&t->notes[0]); 1535 1536 do_thread_regset_writeback(t->task, &view->regsets[0]); 1537 1538 /* 1539 * Each other regset might generate a note too. For each regset 1540 * that has no core_note_type or is inactive, we leave t->notes[i] 1541 * all zero and we'll know to skip writing it later. 1542 */ 1543 for (i = 1; i < view->n; ++i) { 1544 const struct user_regset *regset = &view->regsets[i]; 1545 do_thread_regset_writeback(t->task, regset); 1546 if (regset->core_note_type && regset->get && 1547 (!regset->active || regset->active(t->task, regset))) { 1548 int ret; 1549 size_t size = regset->n * regset->size; 1550 void *data = kmalloc(size, GFP_KERNEL); 1551 if (unlikely(!data)) 1552 return 0; 1553 ret = regset->get(t->task, regset, 1554 0, size, data, NULL); 1555 if (unlikely(ret)) 1556 kfree(data); 1557 else { 1558 if (regset->core_note_type != NT_PRFPREG) 1559 fill_note(&t->notes[i], "LINUX", 1560 regset->core_note_type, 1561 size, data); 1562 else { 1563 SET_PR_FPVALID(&t->prstatus, 1); 1564 fill_note(&t->notes[i], "CORE", 1565 NT_PRFPREG, size, data); 1566 } 1567 *total += notesize(&t->notes[i]); 1568 } 1569 } 1570 } 1571 1572 return 1; 1573 } 1574 1575 static int fill_note_info(struct elfhdr *elf, int phdrs, 1576 struct elf_note_info *info, 1577 const siginfo_t *siginfo, struct pt_regs *regs) 1578 { 1579 struct task_struct *dump_task = current; 1580 const struct user_regset_view *view = task_user_regset_view(dump_task); 1581 struct elf_thread_core_info *t; 1582 struct elf_prpsinfo *psinfo; 1583 struct core_thread *ct; 1584 unsigned int i; 1585 1586 info->size = 0; 1587 info->thread = NULL; 1588 1589 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1590 if (psinfo == NULL) { 1591 info->psinfo.data = NULL; /* So we don't free this wrongly */ 1592 return 0; 1593 } 1594 1595 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1596 1597 /* 1598 * Figure out how many notes we're going to need for each thread. 1599 */ 1600 info->thread_notes = 0; 1601 for (i = 0; i < view->n; ++i) 1602 if (view->regsets[i].core_note_type != 0) 1603 ++info->thread_notes; 1604 1605 /* 1606 * Sanity check. We rely on regset 0 being in NT_PRSTATUS, 1607 * since it is our one special case. 1608 */ 1609 if (unlikely(info->thread_notes == 0) || 1610 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { 1611 WARN_ON(1); 1612 return 0; 1613 } 1614 1615 /* 1616 * Initialize the ELF file header. 1617 */ 1618 fill_elf_header(elf, phdrs, 1619 view->e_machine, view->e_flags); 1620 1621 /* 1622 * Allocate a structure for each thread. 1623 */ 1624 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { 1625 t = kzalloc(offsetof(struct elf_thread_core_info, 1626 notes[info->thread_notes]), 1627 GFP_KERNEL); 1628 if (unlikely(!t)) 1629 return 0; 1630 1631 t->task = ct->task; 1632 if (ct->task == dump_task || !info->thread) { 1633 t->next = info->thread; 1634 info->thread = t; 1635 } else { 1636 /* 1637 * Make sure to keep the original task at 1638 * the head of the list. 1639 */ 1640 t->next = info->thread->next; 1641 info->thread->next = t; 1642 } 1643 } 1644 1645 /* 1646 * Now fill in each thread's information. 1647 */ 1648 for (t = info->thread; t != NULL; t = t->next) 1649 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size)) 1650 return 0; 1651 1652 /* 1653 * Fill in the two process-wide notes. 1654 */ 1655 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); 1656 info->size += notesize(&info->psinfo); 1657 1658 fill_siginfo_note(&info->signote, &info->csigdata, siginfo); 1659 info->size += notesize(&info->signote); 1660 1661 fill_auxv_note(&info->auxv, current->mm); 1662 info->size += notesize(&info->auxv); 1663 1664 if (fill_files_note(&info->files) == 0) 1665 info->size += notesize(&info->files); 1666 1667 return 1; 1668 } 1669 1670 static size_t get_note_info_size(struct elf_note_info *info) 1671 { 1672 return info->size; 1673 } 1674 1675 /* 1676 * Write all the notes for each thread. When writing the first thread, the 1677 * process-wide notes are interleaved after the first thread-specific note. 1678 */ 1679 static int write_note_info(struct elf_note_info *info, 1680 struct coredump_params *cprm) 1681 { 1682 bool first = true; 1683 struct elf_thread_core_info *t = info->thread; 1684 1685 do { 1686 int i; 1687 1688 if (!writenote(&t->notes[0], cprm)) 1689 return 0; 1690 1691 if (first && !writenote(&info->psinfo, cprm)) 1692 return 0; 1693 if (first && !writenote(&info->signote, cprm)) 1694 return 0; 1695 if (first && !writenote(&info->auxv, cprm)) 1696 return 0; 1697 if (first && info->files.data && 1698 !writenote(&info->files, cprm)) 1699 return 0; 1700 1701 for (i = 1; i < info->thread_notes; ++i) 1702 if (t->notes[i].data && 1703 !writenote(&t->notes[i], cprm)) 1704 return 0; 1705 1706 first = false; 1707 t = t->next; 1708 } while (t); 1709 1710 return 1; 1711 } 1712 1713 static void free_note_info(struct elf_note_info *info) 1714 { 1715 struct elf_thread_core_info *threads = info->thread; 1716 while (threads) { 1717 unsigned int i; 1718 struct elf_thread_core_info *t = threads; 1719 threads = t->next; 1720 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); 1721 for (i = 1; i < info->thread_notes; ++i) 1722 kfree(t->notes[i].data); 1723 kfree(t); 1724 } 1725 kfree(info->psinfo.data); 1726 vfree(info->files.data); 1727 } 1728 1729 #else 1730 1731 /* Here is the structure in which status of each thread is captured. */ 1732 struct elf_thread_status 1733 { 1734 struct list_head list; 1735 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1736 elf_fpregset_t fpu; /* NT_PRFPREG */ 1737 struct task_struct *thread; 1738 #ifdef ELF_CORE_COPY_XFPREGS 1739 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1740 #endif 1741 struct memelfnote notes[3]; 1742 int num_notes; 1743 }; 1744 1745 /* 1746 * In order to add the specific thread information for the elf file format, 1747 * we need to keep a linked list of every threads pr_status and then create 1748 * a single section for them in the final core file. 1749 */ 1750 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1751 { 1752 int sz = 0; 1753 struct task_struct *p = t->thread; 1754 t->num_notes = 0; 1755 1756 fill_prstatus(&t->prstatus, p, signr); 1757 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1758 1759 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1760 &(t->prstatus)); 1761 t->num_notes++; 1762 sz += notesize(&t->notes[0]); 1763 1764 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, 1765 &t->fpu))) { 1766 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1767 &(t->fpu)); 1768 t->num_notes++; 1769 sz += notesize(&t->notes[1]); 1770 } 1771 1772 #ifdef ELF_CORE_COPY_XFPREGS 1773 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1774 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1775 sizeof(t->xfpu), &t->xfpu); 1776 t->num_notes++; 1777 sz += notesize(&t->notes[2]); 1778 } 1779 #endif 1780 return sz; 1781 } 1782 1783 struct elf_note_info { 1784 struct memelfnote *notes; 1785 struct memelfnote *notes_files; 1786 struct elf_prstatus *prstatus; /* NT_PRSTATUS */ 1787 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ 1788 struct list_head thread_list; 1789 elf_fpregset_t *fpu; 1790 #ifdef ELF_CORE_COPY_XFPREGS 1791 elf_fpxregset_t *xfpu; 1792 #endif 1793 user_siginfo_t csigdata; 1794 int thread_status_size; 1795 int numnote; 1796 }; 1797 1798 static int elf_note_info_init(struct elf_note_info *info) 1799 { 1800 memset(info, 0, sizeof(*info)); 1801 INIT_LIST_HEAD(&info->thread_list); 1802 1803 /* Allocate space for ELF notes */ 1804 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL); 1805 if (!info->notes) 1806 return 0; 1807 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); 1808 if (!info->psinfo) 1809 return 0; 1810 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); 1811 if (!info->prstatus) 1812 return 0; 1813 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); 1814 if (!info->fpu) 1815 return 0; 1816 #ifdef ELF_CORE_COPY_XFPREGS 1817 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); 1818 if (!info->xfpu) 1819 return 0; 1820 #endif 1821 return 1; 1822 } 1823 1824 static int fill_note_info(struct elfhdr *elf, int phdrs, 1825 struct elf_note_info *info, 1826 const siginfo_t *siginfo, struct pt_regs *regs) 1827 { 1828 struct list_head *t; 1829 struct core_thread *ct; 1830 struct elf_thread_status *ets; 1831 1832 if (!elf_note_info_init(info)) 1833 return 0; 1834 1835 for (ct = current->mm->core_state->dumper.next; 1836 ct; ct = ct->next) { 1837 ets = kzalloc(sizeof(*ets), GFP_KERNEL); 1838 if (!ets) 1839 return 0; 1840 1841 ets->thread = ct->task; 1842 list_add(&ets->list, &info->thread_list); 1843 } 1844 1845 list_for_each(t, &info->thread_list) { 1846 int sz; 1847 1848 ets = list_entry(t, struct elf_thread_status, list); 1849 sz = elf_dump_thread_status(siginfo->si_signo, ets); 1850 info->thread_status_size += sz; 1851 } 1852 /* now collect the dump for the current */ 1853 memset(info->prstatus, 0, sizeof(*info->prstatus)); 1854 fill_prstatus(info->prstatus, current, siginfo->si_signo); 1855 elf_core_copy_regs(&info->prstatus->pr_reg, regs); 1856 1857 /* Set up header */ 1858 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS); 1859 1860 /* 1861 * Set up the notes in similar form to SVR4 core dumps made 1862 * with info from their /proc. 1863 */ 1864 1865 fill_note(info->notes + 0, "CORE", NT_PRSTATUS, 1866 sizeof(*info->prstatus), info->prstatus); 1867 fill_psinfo(info->psinfo, current->group_leader, current->mm); 1868 fill_note(info->notes + 1, "CORE", NT_PRPSINFO, 1869 sizeof(*info->psinfo), info->psinfo); 1870 1871 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo); 1872 fill_auxv_note(info->notes + 3, current->mm); 1873 info->numnote = 4; 1874 1875 if (fill_files_note(info->notes + info->numnote) == 0) { 1876 info->notes_files = info->notes + info->numnote; 1877 info->numnote++; 1878 } 1879 1880 /* Try to dump the FPU. */ 1881 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, 1882 info->fpu); 1883 if (info->prstatus->pr_fpvalid) 1884 fill_note(info->notes + info->numnote++, 1885 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); 1886 #ifdef ELF_CORE_COPY_XFPREGS 1887 if (elf_core_copy_task_xfpregs(current, info->xfpu)) 1888 fill_note(info->notes + info->numnote++, 1889 "LINUX", ELF_CORE_XFPREG_TYPE, 1890 sizeof(*info->xfpu), info->xfpu); 1891 #endif 1892 1893 return 1; 1894 } 1895 1896 static size_t get_note_info_size(struct elf_note_info *info) 1897 { 1898 int sz = 0; 1899 int i; 1900 1901 for (i = 0; i < info->numnote; i++) 1902 sz += notesize(info->notes + i); 1903 1904 sz += info->thread_status_size; 1905 1906 return sz; 1907 } 1908 1909 static int write_note_info(struct elf_note_info *info, 1910 struct coredump_params *cprm) 1911 { 1912 int i; 1913 struct list_head *t; 1914 1915 for (i = 0; i < info->numnote; i++) 1916 if (!writenote(info->notes + i, cprm)) 1917 return 0; 1918 1919 /* write out the thread status notes section */ 1920 list_for_each(t, &info->thread_list) { 1921 struct elf_thread_status *tmp = 1922 list_entry(t, struct elf_thread_status, list); 1923 1924 for (i = 0; i < tmp->num_notes; i++) 1925 if (!writenote(&tmp->notes[i], cprm)) 1926 return 0; 1927 } 1928 1929 return 1; 1930 } 1931 1932 static void free_note_info(struct elf_note_info *info) 1933 { 1934 while (!list_empty(&info->thread_list)) { 1935 struct list_head *tmp = info->thread_list.next; 1936 list_del(tmp); 1937 kfree(list_entry(tmp, struct elf_thread_status, list)); 1938 } 1939 1940 /* Free data possibly allocated by fill_files_note(): */ 1941 if (info->notes_files) 1942 vfree(info->notes_files->data); 1943 1944 kfree(info->prstatus); 1945 kfree(info->psinfo); 1946 kfree(info->notes); 1947 kfree(info->fpu); 1948 #ifdef ELF_CORE_COPY_XFPREGS 1949 kfree(info->xfpu); 1950 #endif 1951 } 1952 1953 #endif 1954 1955 static struct vm_area_struct *first_vma(struct task_struct *tsk, 1956 struct vm_area_struct *gate_vma) 1957 { 1958 struct vm_area_struct *ret = tsk->mm->mmap; 1959 1960 if (ret) 1961 return ret; 1962 return gate_vma; 1963 } 1964 /* 1965 * Helper function for iterating across a vma list. It ensures that the caller 1966 * will visit `gate_vma' prior to terminating the search. 1967 */ 1968 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, 1969 struct vm_area_struct *gate_vma) 1970 { 1971 struct vm_area_struct *ret; 1972 1973 ret = this_vma->vm_next; 1974 if (ret) 1975 return ret; 1976 if (this_vma == gate_vma) 1977 return NULL; 1978 return gate_vma; 1979 } 1980 1981 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1982 elf_addr_t e_shoff, int segs) 1983 { 1984 elf->e_shoff = e_shoff; 1985 elf->e_shentsize = sizeof(*shdr4extnum); 1986 elf->e_shnum = 1; 1987 elf->e_shstrndx = SHN_UNDEF; 1988 1989 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1990 1991 shdr4extnum->sh_type = SHT_NULL; 1992 shdr4extnum->sh_size = elf->e_shnum; 1993 shdr4extnum->sh_link = elf->e_shstrndx; 1994 shdr4extnum->sh_info = segs; 1995 } 1996 1997 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, 1998 unsigned long mm_flags) 1999 { 2000 struct vm_area_struct *vma; 2001 size_t size = 0; 2002 2003 for (vma = first_vma(current, gate_vma); vma != NULL; 2004 vma = next_vma(vma, gate_vma)) 2005 size += vma_dump_size(vma, mm_flags); 2006 return size; 2007 } 2008 2009 /* 2010 * Actual dumper 2011 * 2012 * This is a two-pass process; first we find the offsets of the bits, 2013 * and then they are actually written out. If we run out of core limit 2014 * we just truncate. 2015 */ 2016 static int elf_core_dump(struct coredump_params *cprm) 2017 { 2018 int has_dumped = 0; 2019 mm_segment_t fs; 2020 int segs; 2021 struct vm_area_struct *vma, *gate_vma; 2022 struct elfhdr *elf = NULL; 2023 loff_t offset = 0, dataoff; 2024 struct elf_note_info info = { }; 2025 struct elf_phdr *phdr4note = NULL; 2026 struct elf_shdr *shdr4extnum = NULL; 2027 Elf_Half e_phnum; 2028 elf_addr_t e_shoff; 2029 2030 /* 2031 * We no longer stop all VM operations. 2032 * 2033 * This is because those proceses that could possibly change map_count 2034 * or the mmap / vma pages are now blocked in do_exit on current 2035 * finishing this core dump. 2036 * 2037 * Only ptrace can touch these memory addresses, but it doesn't change 2038 * the map_count or the pages allocated. So no possibility of crashing 2039 * exists while dumping the mm->vm_next areas to the core file. 2040 */ 2041 2042 /* alloc memory for large data structures: too large to be on stack */ 2043 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 2044 if (!elf) 2045 goto out; 2046 /* 2047 * The number of segs are recored into ELF header as 16bit value. 2048 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. 2049 */ 2050 segs = current->mm->map_count; 2051 segs += elf_core_extra_phdrs(); 2052 2053 gate_vma = get_gate_vma(current->mm); 2054 if (gate_vma != NULL) 2055 segs++; 2056 2057 /* for notes section */ 2058 segs++; 2059 2060 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 2061 * this, kernel supports extended numbering. Have a look at 2062 * include/linux/elf.h for further information. */ 2063 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 2064 2065 /* 2066 * Collect all the non-memory information about the process for the 2067 * notes. This also sets up the file header. 2068 */ 2069 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs)) 2070 goto cleanup; 2071 2072 has_dumped = 1; 2073 2074 fs = get_fs(); 2075 set_fs(KERNEL_DS); 2076 2077 offset += sizeof(*elf); /* Elf header */ 2078 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 2079 2080 /* Write notes phdr entry */ 2081 { 2082 size_t sz = get_note_info_size(&info); 2083 2084 sz += elf_coredump_extra_notes_size(); 2085 2086 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 2087 if (!phdr4note) 2088 goto end_coredump; 2089 2090 fill_elf_note_phdr(phdr4note, sz, offset); 2091 offset += sz; 2092 } 2093 2094 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 2095 2096 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags); 2097 offset += elf_core_extra_data_size(); 2098 e_shoff = offset; 2099 2100 if (e_phnum == PN_XNUM) { 2101 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 2102 if (!shdr4extnum) 2103 goto end_coredump; 2104 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 2105 } 2106 2107 offset = dataoff; 2108 2109 if (!dump_emit(cprm, elf, sizeof(*elf))) 2110 goto end_coredump; 2111 2112 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 2113 goto end_coredump; 2114 2115 /* Write program headers for segments dump */ 2116 for (vma = first_vma(current, gate_vma); vma != NULL; 2117 vma = next_vma(vma, gate_vma)) { 2118 struct elf_phdr phdr; 2119 2120 phdr.p_type = PT_LOAD; 2121 phdr.p_offset = offset; 2122 phdr.p_vaddr = vma->vm_start; 2123 phdr.p_paddr = 0; 2124 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags); 2125 phdr.p_memsz = vma->vm_end - vma->vm_start; 2126 offset += phdr.p_filesz; 2127 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 2128 if (vma->vm_flags & VM_WRITE) 2129 phdr.p_flags |= PF_W; 2130 if (vma->vm_flags & VM_EXEC) 2131 phdr.p_flags |= PF_X; 2132 phdr.p_align = ELF_EXEC_PAGESIZE; 2133 2134 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 2135 goto end_coredump; 2136 } 2137 2138 if (!elf_core_write_extra_phdrs(cprm, offset)) 2139 goto end_coredump; 2140 2141 /* write out the notes section */ 2142 if (!write_note_info(&info, cprm)) 2143 goto end_coredump; 2144 2145 if (elf_coredump_extra_notes_write(cprm)) 2146 goto end_coredump; 2147 2148 /* Align to page */ 2149 if (!dump_skip(cprm, dataoff - cprm->written)) 2150 goto end_coredump; 2151 2152 for (vma = first_vma(current, gate_vma); vma != NULL; 2153 vma = next_vma(vma, gate_vma)) { 2154 unsigned long addr; 2155 unsigned long end; 2156 2157 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags); 2158 2159 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { 2160 struct page *page; 2161 int stop; 2162 2163 page = get_dump_page(addr); 2164 if (page) { 2165 void *kaddr = kmap(page); 2166 stop = !dump_emit(cprm, kaddr, PAGE_SIZE); 2167 kunmap(page); 2168 page_cache_release(page); 2169 } else 2170 stop = !dump_skip(cprm, PAGE_SIZE); 2171 if (stop) 2172 goto end_coredump; 2173 } 2174 } 2175 2176 if (!elf_core_write_extra_data(cprm)) 2177 goto end_coredump; 2178 2179 if (e_phnum == PN_XNUM) { 2180 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 2181 goto end_coredump; 2182 } 2183 2184 end_coredump: 2185 set_fs(fs); 2186 2187 cleanup: 2188 free_note_info(&info); 2189 kfree(shdr4extnum); 2190 kfree(phdr4note); 2191 kfree(elf); 2192 out: 2193 return has_dumped; 2194 } 2195 2196 #endif /* CONFIG_ELF_CORE */ 2197 2198 static int __init init_elf_binfmt(void) 2199 { 2200 register_binfmt(&elf_format); 2201 return 0; 2202 } 2203 2204 static void __exit exit_elf_binfmt(void) 2205 { 2206 /* Remove the COFF and ELF loaders. */ 2207 unregister_binfmt(&elf_format); 2208 } 2209 2210 core_initcall(init_elf_binfmt); 2211 module_exit(exit_elf_binfmt); 2212 MODULE_LICENSE("GPL"); 2213