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 send_sig(SIGKILL, current, 0); 743 goto out_free_dentry; 744 } 745 746 current->mm->start_stack = bprm->p; 747 748 /* Now we do a little grungy work by mmapping the ELF image into 749 the correct location in memory. */ 750 for(i = 0, elf_ppnt = elf_phdata; 751 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { 752 int elf_prot = 0, elf_flags; 753 unsigned long k, vaddr; 754 755 if (elf_ppnt->p_type != PT_LOAD) 756 continue; 757 758 if (unlikely (elf_brk > elf_bss)) { 759 unsigned long nbyte; 760 761 /* There was a PT_LOAD segment with p_memsz > p_filesz 762 before this one. Map anonymous pages, if needed, 763 and clear the area. */ 764 retval = set_brk(elf_bss + load_bias, 765 elf_brk + load_bias); 766 if (retval) { 767 send_sig(SIGKILL, current, 0); 768 goto out_free_dentry; 769 } 770 nbyte = ELF_PAGEOFFSET(elf_bss); 771 if (nbyte) { 772 nbyte = ELF_MIN_ALIGN - nbyte; 773 if (nbyte > elf_brk - elf_bss) 774 nbyte = elf_brk - elf_bss; 775 if (clear_user((void __user *)elf_bss + 776 load_bias, nbyte)) { 777 /* 778 * This bss-zeroing can fail if the ELF 779 * file specifies odd protections. So 780 * we don't check the return value 781 */ 782 } 783 } 784 } 785 786 if (elf_ppnt->p_flags & PF_R) 787 elf_prot |= PROT_READ; 788 if (elf_ppnt->p_flags & PF_W) 789 elf_prot |= PROT_WRITE; 790 if (elf_ppnt->p_flags & PF_X) 791 elf_prot |= PROT_EXEC; 792 793 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; 794 795 vaddr = elf_ppnt->p_vaddr; 796 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { 797 elf_flags |= MAP_FIXED; 798 } else if (loc->elf_ex.e_type == ET_DYN) { 799 /* Try and get dynamic programs out of the way of the 800 * default mmap base, as well as whatever program they 801 * might try to exec. This is because the brk will 802 * follow the loader, and is not movable. */ 803 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE 804 /* Memory randomization might have been switched off 805 * in runtime via sysctl or explicit setting of 806 * personality flags. 807 * If that is the case, retain the original non-zero 808 * load_bias value in order to establish proper 809 * non-randomized mappings. 810 */ 811 if (current->flags & PF_RANDOMIZE) 812 load_bias = 0; 813 else 814 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 815 #else 816 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 817 #endif 818 } 819 820 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, 821 elf_prot, elf_flags, 0); 822 if (BAD_ADDR(error)) { 823 send_sig(SIGKILL, current, 0); 824 retval = IS_ERR((void *)error) ? 825 PTR_ERR((void*)error) : -EINVAL; 826 goto out_free_dentry; 827 } 828 829 if (!load_addr_set) { 830 load_addr_set = 1; 831 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); 832 if (loc->elf_ex.e_type == ET_DYN) { 833 load_bias += error - 834 ELF_PAGESTART(load_bias + vaddr); 835 load_addr += load_bias; 836 reloc_func_desc = load_bias; 837 } 838 } 839 k = elf_ppnt->p_vaddr; 840 if (k < start_code) 841 start_code = k; 842 if (start_data < k) 843 start_data = k; 844 845 /* 846 * Check to see if the section's size will overflow the 847 * allowed task size. Note that p_filesz must always be 848 * <= p_memsz so it is only necessary to check p_memsz. 849 */ 850 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || 851 elf_ppnt->p_memsz > TASK_SIZE || 852 TASK_SIZE - elf_ppnt->p_memsz < k) { 853 /* set_brk can never work. Avoid overflows. */ 854 send_sig(SIGKILL, current, 0); 855 retval = -EINVAL; 856 goto out_free_dentry; 857 } 858 859 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; 860 861 if (k > elf_bss) 862 elf_bss = k; 863 if ((elf_ppnt->p_flags & PF_X) && end_code < k) 864 end_code = k; 865 if (end_data < k) 866 end_data = k; 867 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; 868 if (k > elf_brk) 869 elf_brk = k; 870 } 871 872 loc->elf_ex.e_entry += load_bias; 873 elf_bss += load_bias; 874 elf_brk += load_bias; 875 start_code += load_bias; 876 end_code += load_bias; 877 start_data += load_bias; 878 end_data += load_bias; 879 880 /* Calling set_brk effectively mmaps the pages that we need 881 * for the bss and break sections. We must do this before 882 * mapping in the interpreter, to make sure it doesn't wind 883 * up getting placed where the bss needs to go. 884 */ 885 retval = set_brk(elf_bss, elf_brk); 886 if (retval) { 887 send_sig(SIGKILL, current, 0); 888 goto out_free_dentry; 889 } 890 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { 891 send_sig(SIGSEGV, current, 0); 892 retval = -EFAULT; /* Nobody gets to see this, but.. */ 893 goto out_free_dentry; 894 } 895 896 if (elf_interpreter) { 897 unsigned long interp_map_addr = 0; 898 899 elf_entry = load_elf_interp(&loc->interp_elf_ex, 900 interpreter, 901 &interp_map_addr, 902 load_bias); 903 if (!IS_ERR((void *)elf_entry)) { 904 /* 905 * load_elf_interp() returns relocation 906 * adjustment 907 */ 908 interp_load_addr = elf_entry; 909 elf_entry += loc->interp_elf_ex.e_entry; 910 } 911 if (BAD_ADDR(elf_entry)) { 912 force_sig(SIGSEGV, current); 913 retval = IS_ERR((void *)elf_entry) ? 914 (int)elf_entry : -EINVAL; 915 goto out_free_dentry; 916 } 917 reloc_func_desc = interp_load_addr; 918 919 allow_write_access(interpreter); 920 fput(interpreter); 921 kfree(elf_interpreter); 922 } else { 923 elf_entry = loc->elf_ex.e_entry; 924 if (BAD_ADDR(elf_entry)) { 925 force_sig(SIGSEGV, current); 926 retval = -EINVAL; 927 goto out_free_dentry; 928 } 929 } 930 931 kfree(elf_phdata); 932 933 set_binfmt(&elf_format); 934 935 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 936 retval = arch_setup_additional_pages(bprm, !!elf_interpreter); 937 if (retval < 0) { 938 send_sig(SIGKILL, current, 0); 939 goto out; 940 } 941 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ 942 943 install_exec_creds(bprm); 944 retval = create_elf_tables(bprm, &loc->elf_ex, 945 load_addr, interp_load_addr); 946 if (retval < 0) { 947 send_sig(SIGKILL, current, 0); 948 goto out; 949 } 950 /* N.B. passed_fileno might not be initialized? */ 951 current->mm->end_code = end_code; 952 current->mm->start_code = start_code; 953 current->mm->start_data = start_data; 954 current->mm->end_data = end_data; 955 current->mm->start_stack = bprm->p; 956 957 #ifdef arch_randomize_brk 958 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { 959 current->mm->brk = current->mm->start_brk = 960 arch_randomize_brk(current->mm); 961 #ifdef CONFIG_COMPAT_BRK 962 current->brk_randomized = 1; 963 #endif 964 } 965 #endif 966 967 if (current->personality & MMAP_PAGE_ZERO) { 968 /* Why this, you ask??? Well SVr4 maps page 0 as read-only, 969 and some applications "depend" upon this behavior. 970 Since we do not have the power to recompile these, we 971 emulate the SVr4 behavior. Sigh. */ 972 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, 973 MAP_FIXED | MAP_PRIVATE, 0); 974 } 975 976 #ifdef ELF_PLAT_INIT 977 /* 978 * The ABI may specify that certain registers be set up in special 979 * ways (on i386 %edx is the address of a DT_FINI function, for 980 * example. In addition, it may also specify (eg, PowerPC64 ELF) 981 * that the e_entry field is the address of the function descriptor 982 * for the startup routine, rather than the address of the startup 983 * routine itself. This macro performs whatever initialization to 984 * the regs structure is required as well as any relocations to the 985 * function descriptor entries when executing dynamically links apps. 986 */ 987 ELF_PLAT_INIT(regs, reloc_func_desc); 988 #endif 989 990 start_thread(regs, elf_entry, bprm->p); 991 retval = 0; 992 out: 993 kfree(loc); 994 out_ret: 995 return retval; 996 997 /* error cleanup */ 998 out_free_dentry: 999 allow_write_access(interpreter); 1000 if (interpreter) 1001 fput(interpreter); 1002 out_free_interp: 1003 kfree(elf_interpreter); 1004 out_free_ph: 1005 kfree(elf_phdata); 1006 goto out; 1007 } 1008 1009 #ifdef CONFIG_USELIB 1010 /* This is really simpleminded and specialized - we are loading an 1011 a.out library that is given an ELF header. */ 1012 static int load_elf_library(struct file *file) 1013 { 1014 struct elf_phdr *elf_phdata; 1015 struct elf_phdr *eppnt; 1016 unsigned long elf_bss, bss, len; 1017 int retval, error, i, j; 1018 struct elfhdr elf_ex; 1019 1020 error = -ENOEXEC; 1021 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex)); 1022 if (retval != sizeof(elf_ex)) 1023 goto out; 1024 1025 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 1026 goto out; 1027 1028 /* First of all, some simple consistency checks */ 1029 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || 1030 !elf_check_arch(&elf_ex) || !file->f_op->mmap) 1031 goto out; 1032 1033 /* Now read in all of the header information */ 1034 1035 j = sizeof(struct elf_phdr) * elf_ex.e_phnum; 1036 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ 1037 1038 error = -ENOMEM; 1039 elf_phdata = kmalloc(j, GFP_KERNEL); 1040 if (!elf_phdata) 1041 goto out; 1042 1043 eppnt = elf_phdata; 1044 error = -ENOEXEC; 1045 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); 1046 if (retval != j) 1047 goto out_free_ph; 1048 1049 for (j = 0, i = 0; i<elf_ex.e_phnum; i++) 1050 if ((eppnt + i)->p_type == PT_LOAD) 1051 j++; 1052 if (j != 1) 1053 goto out_free_ph; 1054 1055 while (eppnt->p_type != PT_LOAD) 1056 eppnt++; 1057 1058 /* Now use mmap to map the library into memory. */ 1059 error = vm_mmap(file, 1060 ELF_PAGESTART(eppnt->p_vaddr), 1061 (eppnt->p_filesz + 1062 ELF_PAGEOFFSET(eppnt->p_vaddr)), 1063 PROT_READ | PROT_WRITE | PROT_EXEC, 1064 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, 1065 (eppnt->p_offset - 1066 ELF_PAGEOFFSET(eppnt->p_vaddr))); 1067 if (error != ELF_PAGESTART(eppnt->p_vaddr)) 1068 goto out_free_ph; 1069 1070 elf_bss = eppnt->p_vaddr + eppnt->p_filesz; 1071 if (padzero(elf_bss)) { 1072 error = -EFAULT; 1073 goto out_free_ph; 1074 } 1075 1076 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + 1077 ELF_MIN_ALIGN - 1); 1078 bss = eppnt->p_memsz + eppnt->p_vaddr; 1079 if (bss > len) 1080 vm_brk(len, bss - len); 1081 error = 0; 1082 1083 out_free_ph: 1084 kfree(elf_phdata); 1085 out: 1086 return error; 1087 } 1088 #endif /* #ifdef CONFIG_USELIB */ 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 /* 1113 * Assume that all vmas with a .name op should always be dumped. 1114 * If this changes, a new vm_ops field can easily be added. 1115 */ 1116 if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma)) 1117 return true; 1118 1119 /* 1120 * arch_vma_name() returns non-NULL for special architecture mappings, 1121 * such as vDSO sections. 1122 */ 1123 if (arch_vma_name(vma)) 1124 return true; 1125 1126 return false; 1127 } 1128 1129 /* 1130 * Decide what to dump of a segment, part, all or none. 1131 */ 1132 static unsigned long vma_dump_size(struct vm_area_struct *vma, 1133 unsigned long mm_flags) 1134 { 1135 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) 1136 1137 /* always dump the vdso and vsyscall sections */ 1138 if (always_dump_vma(vma)) 1139 goto whole; 1140 1141 if (vma->vm_flags & VM_DONTDUMP) 1142 return 0; 1143 1144 /* Hugetlb memory check */ 1145 if (vma->vm_flags & VM_HUGETLB) { 1146 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) 1147 goto whole; 1148 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) 1149 goto whole; 1150 return 0; 1151 } 1152 1153 /* Do not dump I/O mapped devices or special mappings */ 1154 if (vma->vm_flags & VM_IO) 1155 return 0; 1156 1157 /* By default, dump shared memory if mapped from an anonymous file. */ 1158 if (vma->vm_flags & VM_SHARED) { 1159 if (file_inode(vma->vm_file)->i_nlink == 0 ? 1160 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) 1161 goto whole; 1162 return 0; 1163 } 1164 1165 /* Dump segments that have been written to. */ 1166 if (vma->anon_vma && FILTER(ANON_PRIVATE)) 1167 goto whole; 1168 if (vma->vm_file == NULL) 1169 return 0; 1170 1171 if (FILTER(MAPPED_PRIVATE)) 1172 goto whole; 1173 1174 /* 1175 * If this looks like the beginning of a DSO or executable mapping, 1176 * check for an ELF header. If we find one, dump the first page to 1177 * aid in determining what was mapped here. 1178 */ 1179 if (FILTER(ELF_HEADERS) && 1180 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { 1181 u32 __user *header = (u32 __user *) vma->vm_start; 1182 u32 word; 1183 mm_segment_t fs = get_fs(); 1184 /* 1185 * Doing it this way gets the constant folded by GCC. 1186 */ 1187 union { 1188 u32 cmp; 1189 char elfmag[SELFMAG]; 1190 } magic; 1191 BUILD_BUG_ON(SELFMAG != sizeof word); 1192 magic.elfmag[EI_MAG0] = ELFMAG0; 1193 magic.elfmag[EI_MAG1] = ELFMAG1; 1194 magic.elfmag[EI_MAG2] = ELFMAG2; 1195 magic.elfmag[EI_MAG3] = ELFMAG3; 1196 /* 1197 * Switch to the user "segment" for get_user(), 1198 * then put back what elf_core_dump() had in place. 1199 */ 1200 set_fs(USER_DS); 1201 if (unlikely(get_user(word, header))) 1202 word = 0; 1203 set_fs(fs); 1204 if (word == magic.cmp) 1205 return PAGE_SIZE; 1206 } 1207 1208 #undef FILTER 1209 1210 return 0; 1211 1212 whole: 1213 return vma->vm_end - vma->vm_start; 1214 } 1215 1216 /* An ELF note in memory */ 1217 struct memelfnote 1218 { 1219 const char *name; 1220 int type; 1221 unsigned int datasz; 1222 void *data; 1223 }; 1224 1225 static int notesize(struct memelfnote *en) 1226 { 1227 int sz; 1228 1229 sz = sizeof(struct elf_note); 1230 sz += roundup(strlen(en->name) + 1, 4); 1231 sz += roundup(en->datasz, 4); 1232 1233 return sz; 1234 } 1235 1236 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1237 { 1238 struct elf_note en; 1239 en.n_namesz = strlen(men->name) + 1; 1240 en.n_descsz = men->datasz; 1241 en.n_type = men->type; 1242 1243 return dump_emit(cprm, &en, sizeof(en)) && 1244 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1245 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1246 } 1247 1248 static void fill_elf_header(struct elfhdr *elf, int segs, 1249 u16 machine, u32 flags) 1250 { 1251 memset(elf, 0, sizeof(*elf)); 1252 1253 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1254 elf->e_ident[EI_CLASS] = ELF_CLASS; 1255 elf->e_ident[EI_DATA] = ELF_DATA; 1256 elf->e_ident[EI_VERSION] = EV_CURRENT; 1257 elf->e_ident[EI_OSABI] = ELF_OSABI; 1258 1259 elf->e_type = ET_CORE; 1260 elf->e_machine = machine; 1261 elf->e_version = EV_CURRENT; 1262 elf->e_phoff = sizeof(struct elfhdr); 1263 elf->e_flags = flags; 1264 elf->e_ehsize = sizeof(struct elfhdr); 1265 elf->e_phentsize = sizeof(struct elf_phdr); 1266 elf->e_phnum = segs; 1267 1268 return; 1269 } 1270 1271 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1272 { 1273 phdr->p_type = PT_NOTE; 1274 phdr->p_offset = offset; 1275 phdr->p_vaddr = 0; 1276 phdr->p_paddr = 0; 1277 phdr->p_filesz = sz; 1278 phdr->p_memsz = 0; 1279 phdr->p_flags = 0; 1280 phdr->p_align = 0; 1281 return; 1282 } 1283 1284 static void fill_note(struct memelfnote *note, const char *name, int type, 1285 unsigned int sz, void *data) 1286 { 1287 note->name = name; 1288 note->type = type; 1289 note->datasz = sz; 1290 note->data = data; 1291 return; 1292 } 1293 1294 /* 1295 * fill up all the fields in prstatus from the given task struct, except 1296 * registers which need to be filled up separately. 1297 */ 1298 static void fill_prstatus(struct elf_prstatus *prstatus, 1299 struct task_struct *p, long signr) 1300 { 1301 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1302 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1303 prstatus->pr_sighold = p->blocked.sig[0]; 1304 rcu_read_lock(); 1305 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1306 rcu_read_unlock(); 1307 prstatus->pr_pid = task_pid_vnr(p); 1308 prstatus->pr_pgrp = task_pgrp_vnr(p); 1309 prstatus->pr_sid = task_session_vnr(p); 1310 if (thread_group_leader(p)) { 1311 struct task_cputime cputime; 1312 1313 /* 1314 * This is the record for the group leader. It shows the 1315 * group-wide total, not its individual thread total. 1316 */ 1317 thread_group_cputime(p, &cputime); 1318 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1319 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1320 } else { 1321 cputime_t utime, stime; 1322 1323 task_cputime(p, &utime, &stime); 1324 cputime_to_timeval(utime, &prstatus->pr_utime); 1325 cputime_to_timeval(stime, &prstatus->pr_stime); 1326 } 1327 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1328 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1329 } 1330 1331 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1332 struct mm_struct *mm) 1333 { 1334 const struct cred *cred; 1335 unsigned int i, len; 1336 1337 /* first copy the parameters from user space */ 1338 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1339 1340 len = mm->arg_end - mm->arg_start; 1341 if (len >= ELF_PRARGSZ) 1342 len = ELF_PRARGSZ-1; 1343 if (copy_from_user(&psinfo->pr_psargs, 1344 (const char __user *)mm->arg_start, len)) 1345 return -EFAULT; 1346 for(i = 0; i < len; i++) 1347 if (psinfo->pr_psargs[i] == 0) 1348 psinfo->pr_psargs[i] = ' '; 1349 psinfo->pr_psargs[len] = 0; 1350 1351 rcu_read_lock(); 1352 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1353 rcu_read_unlock(); 1354 psinfo->pr_pid = task_pid_vnr(p); 1355 psinfo->pr_pgrp = task_pgrp_vnr(p); 1356 psinfo->pr_sid = task_session_vnr(p); 1357 1358 i = p->state ? ffz(~p->state) + 1 : 0; 1359 psinfo->pr_state = i; 1360 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1361 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1362 psinfo->pr_nice = task_nice(p); 1363 psinfo->pr_flag = p->flags; 1364 rcu_read_lock(); 1365 cred = __task_cred(p); 1366 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1367 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1368 rcu_read_unlock(); 1369 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1370 1371 return 0; 1372 } 1373 1374 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) 1375 { 1376 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; 1377 int i = 0; 1378 do 1379 i += 2; 1380 while (auxv[i - 2] != AT_NULL); 1381 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1382 } 1383 1384 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, 1385 const siginfo_t *siginfo) 1386 { 1387 mm_segment_t old_fs = get_fs(); 1388 set_fs(KERNEL_DS); 1389 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo); 1390 set_fs(old_fs); 1391 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); 1392 } 1393 1394 #define MAX_FILE_NOTE_SIZE (4*1024*1024) 1395 /* 1396 * Format of NT_FILE note: 1397 * 1398 * long count -- how many files are mapped 1399 * long page_size -- units for file_ofs 1400 * array of [COUNT] elements of 1401 * long start 1402 * long end 1403 * long file_ofs 1404 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL... 1405 */ 1406 static int fill_files_note(struct memelfnote *note) 1407 { 1408 struct vm_area_struct *vma; 1409 unsigned count, size, names_ofs, remaining, n; 1410 user_long_t *data; 1411 user_long_t *start_end_ofs; 1412 char *name_base, *name_curpos; 1413 1414 /* *Estimated* file count and total data size needed */ 1415 count = current->mm->map_count; 1416 size = count * 64; 1417 1418 names_ofs = (2 + 3 * count) * sizeof(data[0]); 1419 alloc: 1420 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */ 1421 return -EINVAL; 1422 size = round_up(size, PAGE_SIZE); 1423 data = vmalloc(size); 1424 if (!data) 1425 return -ENOMEM; 1426 1427 start_end_ofs = data + 2; 1428 name_base = name_curpos = ((char *)data) + names_ofs; 1429 remaining = size - names_ofs; 1430 count = 0; 1431 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) { 1432 struct file *file; 1433 const char *filename; 1434 1435 file = vma->vm_file; 1436 if (!file) 1437 continue; 1438 filename = d_path(&file->f_path, name_curpos, remaining); 1439 if (IS_ERR(filename)) { 1440 if (PTR_ERR(filename) == -ENAMETOOLONG) { 1441 vfree(data); 1442 size = size * 5 / 4; 1443 goto alloc; 1444 } 1445 continue; 1446 } 1447 1448 /* d_path() fills at the end, move name down */ 1449 /* n = strlen(filename) + 1: */ 1450 n = (name_curpos + remaining) - filename; 1451 remaining = filename - name_curpos; 1452 memmove(name_curpos, filename, n); 1453 name_curpos += n; 1454 1455 *start_end_ofs++ = vma->vm_start; 1456 *start_end_ofs++ = vma->vm_end; 1457 *start_end_ofs++ = vma->vm_pgoff; 1458 count++; 1459 } 1460 1461 /* Now we know exact count of files, can store it */ 1462 data[0] = count; 1463 data[1] = PAGE_SIZE; 1464 /* 1465 * Count usually is less than current->mm->map_count, 1466 * we need to move filenames down. 1467 */ 1468 n = current->mm->map_count - count; 1469 if (n != 0) { 1470 unsigned shift_bytes = n * 3 * sizeof(data[0]); 1471 memmove(name_base - shift_bytes, name_base, 1472 name_curpos - name_base); 1473 name_curpos -= shift_bytes; 1474 } 1475 1476 size = name_curpos - (char *)data; 1477 fill_note(note, "CORE", NT_FILE, size, data); 1478 return 0; 1479 } 1480 1481 #ifdef CORE_DUMP_USE_REGSET 1482 #include <linux/regset.h> 1483 1484 struct elf_thread_core_info { 1485 struct elf_thread_core_info *next; 1486 struct task_struct *task; 1487 struct elf_prstatus prstatus; 1488 struct memelfnote notes[0]; 1489 }; 1490 1491 struct elf_note_info { 1492 struct elf_thread_core_info *thread; 1493 struct memelfnote psinfo; 1494 struct memelfnote signote; 1495 struct memelfnote auxv; 1496 struct memelfnote files; 1497 user_siginfo_t csigdata; 1498 size_t size; 1499 int thread_notes; 1500 }; 1501 1502 /* 1503 * When a regset has a writeback hook, we call it on each thread before 1504 * dumping user memory. On register window machines, this makes sure the 1505 * user memory backing the register data is up to date before we read it. 1506 */ 1507 static void do_thread_regset_writeback(struct task_struct *task, 1508 const struct user_regset *regset) 1509 { 1510 if (regset->writeback) 1511 regset->writeback(task, regset, 1); 1512 } 1513 1514 #ifndef PR_REG_SIZE 1515 #define PR_REG_SIZE(S) sizeof(S) 1516 #endif 1517 1518 #ifndef PRSTATUS_SIZE 1519 #define PRSTATUS_SIZE(S) sizeof(S) 1520 #endif 1521 1522 #ifndef PR_REG_PTR 1523 #define PR_REG_PTR(S) (&((S)->pr_reg)) 1524 #endif 1525 1526 #ifndef SET_PR_FPVALID 1527 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V)) 1528 #endif 1529 1530 static int fill_thread_core_info(struct elf_thread_core_info *t, 1531 const struct user_regset_view *view, 1532 long signr, size_t *total) 1533 { 1534 unsigned int i; 1535 1536 /* 1537 * NT_PRSTATUS is the one special case, because the regset data 1538 * goes into the pr_reg field inside the note contents, rather 1539 * than being the whole note contents. We fill the reset in here. 1540 * We assume that regset 0 is NT_PRSTATUS. 1541 */ 1542 fill_prstatus(&t->prstatus, t->task, signr); 1543 (void) view->regsets[0].get(t->task, &view->regsets[0], 1544 0, PR_REG_SIZE(t->prstatus.pr_reg), 1545 PR_REG_PTR(&t->prstatus), NULL); 1546 1547 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, 1548 PRSTATUS_SIZE(t->prstatus), &t->prstatus); 1549 *total += notesize(&t->notes[0]); 1550 1551 do_thread_regset_writeback(t->task, &view->regsets[0]); 1552 1553 /* 1554 * Each other regset might generate a note too. For each regset 1555 * that has no core_note_type or is inactive, we leave t->notes[i] 1556 * all zero and we'll know to skip writing it later. 1557 */ 1558 for (i = 1; i < view->n; ++i) { 1559 const struct user_regset *regset = &view->regsets[i]; 1560 do_thread_regset_writeback(t->task, regset); 1561 if (regset->core_note_type && regset->get && 1562 (!regset->active || regset->active(t->task, regset))) { 1563 int ret; 1564 size_t size = regset->n * regset->size; 1565 void *data = kmalloc(size, GFP_KERNEL); 1566 if (unlikely(!data)) 1567 return 0; 1568 ret = regset->get(t->task, regset, 1569 0, size, data, NULL); 1570 if (unlikely(ret)) 1571 kfree(data); 1572 else { 1573 if (regset->core_note_type != NT_PRFPREG) 1574 fill_note(&t->notes[i], "LINUX", 1575 regset->core_note_type, 1576 size, data); 1577 else { 1578 SET_PR_FPVALID(&t->prstatus, 1); 1579 fill_note(&t->notes[i], "CORE", 1580 NT_PRFPREG, size, data); 1581 } 1582 *total += notesize(&t->notes[i]); 1583 } 1584 } 1585 } 1586 1587 return 1; 1588 } 1589 1590 static int fill_note_info(struct elfhdr *elf, int phdrs, 1591 struct elf_note_info *info, 1592 const siginfo_t *siginfo, struct pt_regs *regs) 1593 { 1594 struct task_struct *dump_task = current; 1595 const struct user_regset_view *view = task_user_regset_view(dump_task); 1596 struct elf_thread_core_info *t; 1597 struct elf_prpsinfo *psinfo; 1598 struct core_thread *ct; 1599 unsigned int i; 1600 1601 info->size = 0; 1602 info->thread = NULL; 1603 1604 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1605 if (psinfo == NULL) { 1606 info->psinfo.data = NULL; /* So we don't free this wrongly */ 1607 return 0; 1608 } 1609 1610 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1611 1612 /* 1613 * Figure out how many notes we're going to need for each thread. 1614 */ 1615 info->thread_notes = 0; 1616 for (i = 0; i < view->n; ++i) 1617 if (view->regsets[i].core_note_type != 0) 1618 ++info->thread_notes; 1619 1620 /* 1621 * Sanity check. We rely on regset 0 being in NT_PRSTATUS, 1622 * since it is our one special case. 1623 */ 1624 if (unlikely(info->thread_notes == 0) || 1625 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { 1626 WARN_ON(1); 1627 return 0; 1628 } 1629 1630 /* 1631 * Initialize the ELF file header. 1632 */ 1633 fill_elf_header(elf, phdrs, 1634 view->e_machine, view->e_flags); 1635 1636 /* 1637 * Allocate a structure for each thread. 1638 */ 1639 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { 1640 t = kzalloc(offsetof(struct elf_thread_core_info, 1641 notes[info->thread_notes]), 1642 GFP_KERNEL); 1643 if (unlikely(!t)) 1644 return 0; 1645 1646 t->task = ct->task; 1647 if (ct->task == dump_task || !info->thread) { 1648 t->next = info->thread; 1649 info->thread = t; 1650 } else { 1651 /* 1652 * Make sure to keep the original task at 1653 * the head of the list. 1654 */ 1655 t->next = info->thread->next; 1656 info->thread->next = t; 1657 } 1658 } 1659 1660 /* 1661 * Now fill in each thread's information. 1662 */ 1663 for (t = info->thread; t != NULL; t = t->next) 1664 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size)) 1665 return 0; 1666 1667 /* 1668 * Fill in the two process-wide notes. 1669 */ 1670 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); 1671 info->size += notesize(&info->psinfo); 1672 1673 fill_siginfo_note(&info->signote, &info->csigdata, siginfo); 1674 info->size += notesize(&info->signote); 1675 1676 fill_auxv_note(&info->auxv, current->mm); 1677 info->size += notesize(&info->auxv); 1678 1679 if (fill_files_note(&info->files) == 0) 1680 info->size += notesize(&info->files); 1681 1682 return 1; 1683 } 1684 1685 static size_t get_note_info_size(struct elf_note_info *info) 1686 { 1687 return info->size; 1688 } 1689 1690 /* 1691 * Write all the notes for each thread. When writing the first thread, the 1692 * process-wide notes are interleaved after the first thread-specific note. 1693 */ 1694 static int write_note_info(struct elf_note_info *info, 1695 struct coredump_params *cprm) 1696 { 1697 bool first = true; 1698 struct elf_thread_core_info *t = info->thread; 1699 1700 do { 1701 int i; 1702 1703 if (!writenote(&t->notes[0], cprm)) 1704 return 0; 1705 1706 if (first && !writenote(&info->psinfo, cprm)) 1707 return 0; 1708 if (first && !writenote(&info->signote, cprm)) 1709 return 0; 1710 if (first && !writenote(&info->auxv, cprm)) 1711 return 0; 1712 if (first && info->files.data && 1713 !writenote(&info->files, cprm)) 1714 return 0; 1715 1716 for (i = 1; i < info->thread_notes; ++i) 1717 if (t->notes[i].data && 1718 !writenote(&t->notes[i], cprm)) 1719 return 0; 1720 1721 first = false; 1722 t = t->next; 1723 } while (t); 1724 1725 return 1; 1726 } 1727 1728 static void free_note_info(struct elf_note_info *info) 1729 { 1730 struct elf_thread_core_info *threads = info->thread; 1731 while (threads) { 1732 unsigned int i; 1733 struct elf_thread_core_info *t = threads; 1734 threads = t->next; 1735 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); 1736 for (i = 1; i < info->thread_notes; ++i) 1737 kfree(t->notes[i].data); 1738 kfree(t); 1739 } 1740 kfree(info->psinfo.data); 1741 vfree(info->files.data); 1742 } 1743 1744 #else 1745 1746 /* Here is the structure in which status of each thread is captured. */ 1747 struct elf_thread_status 1748 { 1749 struct list_head list; 1750 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1751 elf_fpregset_t fpu; /* NT_PRFPREG */ 1752 struct task_struct *thread; 1753 #ifdef ELF_CORE_COPY_XFPREGS 1754 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1755 #endif 1756 struct memelfnote notes[3]; 1757 int num_notes; 1758 }; 1759 1760 /* 1761 * In order to add the specific thread information for the elf file format, 1762 * we need to keep a linked list of every threads pr_status and then create 1763 * a single section for them in the final core file. 1764 */ 1765 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1766 { 1767 int sz = 0; 1768 struct task_struct *p = t->thread; 1769 t->num_notes = 0; 1770 1771 fill_prstatus(&t->prstatus, p, signr); 1772 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1773 1774 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1775 &(t->prstatus)); 1776 t->num_notes++; 1777 sz += notesize(&t->notes[0]); 1778 1779 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, 1780 &t->fpu))) { 1781 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1782 &(t->fpu)); 1783 t->num_notes++; 1784 sz += notesize(&t->notes[1]); 1785 } 1786 1787 #ifdef ELF_CORE_COPY_XFPREGS 1788 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1789 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1790 sizeof(t->xfpu), &t->xfpu); 1791 t->num_notes++; 1792 sz += notesize(&t->notes[2]); 1793 } 1794 #endif 1795 return sz; 1796 } 1797 1798 struct elf_note_info { 1799 struct memelfnote *notes; 1800 struct memelfnote *notes_files; 1801 struct elf_prstatus *prstatus; /* NT_PRSTATUS */ 1802 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ 1803 struct list_head thread_list; 1804 elf_fpregset_t *fpu; 1805 #ifdef ELF_CORE_COPY_XFPREGS 1806 elf_fpxregset_t *xfpu; 1807 #endif 1808 user_siginfo_t csigdata; 1809 int thread_status_size; 1810 int numnote; 1811 }; 1812 1813 static int elf_note_info_init(struct elf_note_info *info) 1814 { 1815 memset(info, 0, sizeof(*info)); 1816 INIT_LIST_HEAD(&info->thread_list); 1817 1818 /* Allocate space for ELF notes */ 1819 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL); 1820 if (!info->notes) 1821 return 0; 1822 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); 1823 if (!info->psinfo) 1824 return 0; 1825 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); 1826 if (!info->prstatus) 1827 return 0; 1828 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); 1829 if (!info->fpu) 1830 return 0; 1831 #ifdef ELF_CORE_COPY_XFPREGS 1832 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); 1833 if (!info->xfpu) 1834 return 0; 1835 #endif 1836 return 1; 1837 } 1838 1839 static int fill_note_info(struct elfhdr *elf, int phdrs, 1840 struct elf_note_info *info, 1841 const siginfo_t *siginfo, struct pt_regs *regs) 1842 { 1843 struct list_head *t; 1844 struct core_thread *ct; 1845 struct elf_thread_status *ets; 1846 1847 if (!elf_note_info_init(info)) 1848 return 0; 1849 1850 for (ct = current->mm->core_state->dumper.next; 1851 ct; ct = ct->next) { 1852 ets = kzalloc(sizeof(*ets), GFP_KERNEL); 1853 if (!ets) 1854 return 0; 1855 1856 ets->thread = ct->task; 1857 list_add(&ets->list, &info->thread_list); 1858 } 1859 1860 list_for_each(t, &info->thread_list) { 1861 int sz; 1862 1863 ets = list_entry(t, struct elf_thread_status, list); 1864 sz = elf_dump_thread_status(siginfo->si_signo, ets); 1865 info->thread_status_size += sz; 1866 } 1867 /* now collect the dump for the current */ 1868 memset(info->prstatus, 0, sizeof(*info->prstatus)); 1869 fill_prstatus(info->prstatus, current, siginfo->si_signo); 1870 elf_core_copy_regs(&info->prstatus->pr_reg, regs); 1871 1872 /* Set up header */ 1873 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS); 1874 1875 /* 1876 * Set up the notes in similar form to SVR4 core dumps made 1877 * with info from their /proc. 1878 */ 1879 1880 fill_note(info->notes + 0, "CORE", NT_PRSTATUS, 1881 sizeof(*info->prstatus), info->prstatus); 1882 fill_psinfo(info->psinfo, current->group_leader, current->mm); 1883 fill_note(info->notes + 1, "CORE", NT_PRPSINFO, 1884 sizeof(*info->psinfo), info->psinfo); 1885 1886 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo); 1887 fill_auxv_note(info->notes + 3, current->mm); 1888 info->numnote = 4; 1889 1890 if (fill_files_note(info->notes + info->numnote) == 0) { 1891 info->notes_files = info->notes + info->numnote; 1892 info->numnote++; 1893 } 1894 1895 /* Try to dump the FPU. */ 1896 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, 1897 info->fpu); 1898 if (info->prstatus->pr_fpvalid) 1899 fill_note(info->notes + info->numnote++, 1900 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); 1901 #ifdef ELF_CORE_COPY_XFPREGS 1902 if (elf_core_copy_task_xfpregs(current, info->xfpu)) 1903 fill_note(info->notes + info->numnote++, 1904 "LINUX", ELF_CORE_XFPREG_TYPE, 1905 sizeof(*info->xfpu), info->xfpu); 1906 #endif 1907 1908 return 1; 1909 } 1910 1911 static size_t get_note_info_size(struct elf_note_info *info) 1912 { 1913 int sz = 0; 1914 int i; 1915 1916 for (i = 0; i < info->numnote; i++) 1917 sz += notesize(info->notes + i); 1918 1919 sz += info->thread_status_size; 1920 1921 return sz; 1922 } 1923 1924 static int write_note_info(struct elf_note_info *info, 1925 struct coredump_params *cprm) 1926 { 1927 int i; 1928 struct list_head *t; 1929 1930 for (i = 0; i < info->numnote; i++) 1931 if (!writenote(info->notes + i, cprm)) 1932 return 0; 1933 1934 /* write out the thread status notes section */ 1935 list_for_each(t, &info->thread_list) { 1936 struct elf_thread_status *tmp = 1937 list_entry(t, struct elf_thread_status, list); 1938 1939 for (i = 0; i < tmp->num_notes; i++) 1940 if (!writenote(&tmp->notes[i], cprm)) 1941 return 0; 1942 } 1943 1944 return 1; 1945 } 1946 1947 static void free_note_info(struct elf_note_info *info) 1948 { 1949 while (!list_empty(&info->thread_list)) { 1950 struct list_head *tmp = info->thread_list.next; 1951 list_del(tmp); 1952 kfree(list_entry(tmp, struct elf_thread_status, list)); 1953 } 1954 1955 /* Free data possibly allocated by fill_files_note(): */ 1956 if (info->notes_files) 1957 vfree(info->notes_files->data); 1958 1959 kfree(info->prstatus); 1960 kfree(info->psinfo); 1961 kfree(info->notes); 1962 kfree(info->fpu); 1963 #ifdef ELF_CORE_COPY_XFPREGS 1964 kfree(info->xfpu); 1965 #endif 1966 } 1967 1968 #endif 1969 1970 static struct vm_area_struct *first_vma(struct task_struct *tsk, 1971 struct vm_area_struct *gate_vma) 1972 { 1973 struct vm_area_struct *ret = tsk->mm->mmap; 1974 1975 if (ret) 1976 return ret; 1977 return gate_vma; 1978 } 1979 /* 1980 * Helper function for iterating across a vma list. It ensures that the caller 1981 * will visit `gate_vma' prior to terminating the search. 1982 */ 1983 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, 1984 struct vm_area_struct *gate_vma) 1985 { 1986 struct vm_area_struct *ret; 1987 1988 ret = this_vma->vm_next; 1989 if (ret) 1990 return ret; 1991 if (this_vma == gate_vma) 1992 return NULL; 1993 return gate_vma; 1994 } 1995 1996 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1997 elf_addr_t e_shoff, int segs) 1998 { 1999 elf->e_shoff = e_shoff; 2000 elf->e_shentsize = sizeof(*shdr4extnum); 2001 elf->e_shnum = 1; 2002 elf->e_shstrndx = SHN_UNDEF; 2003 2004 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 2005 2006 shdr4extnum->sh_type = SHT_NULL; 2007 shdr4extnum->sh_size = elf->e_shnum; 2008 shdr4extnum->sh_link = elf->e_shstrndx; 2009 shdr4extnum->sh_info = segs; 2010 } 2011 2012 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma, 2013 unsigned long mm_flags) 2014 { 2015 struct vm_area_struct *vma; 2016 size_t size = 0; 2017 2018 for (vma = first_vma(current, gate_vma); vma != NULL; 2019 vma = next_vma(vma, gate_vma)) 2020 size += vma_dump_size(vma, mm_flags); 2021 return size; 2022 } 2023 2024 /* 2025 * Actual dumper 2026 * 2027 * This is a two-pass process; first we find the offsets of the bits, 2028 * and then they are actually written out. If we run out of core limit 2029 * we just truncate. 2030 */ 2031 static int elf_core_dump(struct coredump_params *cprm) 2032 { 2033 int has_dumped = 0; 2034 mm_segment_t fs; 2035 int segs; 2036 struct vm_area_struct *vma, *gate_vma; 2037 struct elfhdr *elf = NULL; 2038 loff_t offset = 0, dataoff; 2039 struct elf_note_info info = { }; 2040 struct elf_phdr *phdr4note = NULL; 2041 struct elf_shdr *shdr4extnum = NULL; 2042 Elf_Half e_phnum; 2043 elf_addr_t e_shoff; 2044 2045 /* 2046 * We no longer stop all VM operations. 2047 * 2048 * This is because those proceses that could possibly change map_count 2049 * or the mmap / vma pages are now blocked in do_exit on current 2050 * finishing this core dump. 2051 * 2052 * Only ptrace can touch these memory addresses, but it doesn't change 2053 * the map_count or the pages allocated. So no possibility of crashing 2054 * exists while dumping the mm->vm_next areas to the core file. 2055 */ 2056 2057 /* alloc memory for large data structures: too large to be on stack */ 2058 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 2059 if (!elf) 2060 goto out; 2061 /* 2062 * The number of segs are recored into ELF header as 16bit value. 2063 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. 2064 */ 2065 segs = current->mm->map_count; 2066 segs += elf_core_extra_phdrs(); 2067 2068 gate_vma = get_gate_vma(current->mm); 2069 if (gate_vma != NULL) 2070 segs++; 2071 2072 /* for notes section */ 2073 segs++; 2074 2075 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 2076 * this, kernel supports extended numbering. Have a look at 2077 * include/linux/elf.h for further information. */ 2078 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 2079 2080 /* 2081 * Collect all the non-memory information about the process for the 2082 * notes. This also sets up the file header. 2083 */ 2084 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs)) 2085 goto cleanup; 2086 2087 has_dumped = 1; 2088 2089 fs = get_fs(); 2090 set_fs(KERNEL_DS); 2091 2092 offset += sizeof(*elf); /* Elf header */ 2093 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 2094 2095 /* Write notes phdr entry */ 2096 { 2097 size_t sz = get_note_info_size(&info); 2098 2099 sz += elf_coredump_extra_notes_size(); 2100 2101 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 2102 if (!phdr4note) 2103 goto end_coredump; 2104 2105 fill_elf_note_phdr(phdr4note, sz, offset); 2106 offset += sz; 2107 } 2108 2109 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 2110 2111 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags); 2112 offset += elf_core_extra_data_size(); 2113 e_shoff = offset; 2114 2115 if (e_phnum == PN_XNUM) { 2116 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 2117 if (!shdr4extnum) 2118 goto end_coredump; 2119 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 2120 } 2121 2122 offset = dataoff; 2123 2124 if (!dump_emit(cprm, elf, sizeof(*elf))) 2125 goto end_coredump; 2126 2127 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 2128 goto end_coredump; 2129 2130 /* Write program headers for segments dump */ 2131 for (vma = first_vma(current, gate_vma); vma != NULL; 2132 vma = next_vma(vma, gate_vma)) { 2133 struct elf_phdr phdr; 2134 2135 phdr.p_type = PT_LOAD; 2136 phdr.p_offset = offset; 2137 phdr.p_vaddr = vma->vm_start; 2138 phdr.p_paddr = 0; 2139 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags); 2140 phdr.p_memsz = vma->vm_end - vma->vm_start; 2141 offset += phdr.p_filesz; 2142 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 2143 if (vma->vm_flags & VM_WRITE) 2144 phdr.p_flags |= PF_W; 2145 if (vma->vm_flags & VM_EXEC) 2146 phdr.p_flags |= PF_X; 2147 phdr.p_align = ELF_EXEC_PAGESIZE; 2148 2149 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 2150 goto end_coredump; 2151 } 2152 2153 if (!elf_core_write_extra_phdrs(cprm, offset)) 2154 goto end_coredump; 2155 2156 /* write out the notes section */ 2157 if (!write_note_info(&info, cprm)) 2158 goto end_coredump; 2159 2160 if (elf_coredump_extra_notes_write(cprm)) 2161 goto end_coredump; 2162 2163 /* Align to page */ 2164 if (!dump_skip(cprm, dataoff - cprm->written)) 2165 goto end_coredump; 2166 2167 for (vma = first_vma(current, gate_vma); vma != NULL; 2168 vma = next_vma(vma, gate_vma)) { 2169 unsigned long addr; 2170 unsigned long end; 2171 2172 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags); 2173 2174 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { 2175 struct page *page; 2176 int stop; 2177 2178 page = get_dump_page(addr); 2179 if (page) { 2180 void *kaddr = kmap(page); 2181 stop = !dump_emit(cprm, kaddr, PAGE_SIZE); 2182 kunmap(page); 2183 page_cache_release(page); 2184 } else 2185 stop = !dump_skip(cprm, PAGE_SIZE); 2186 if (stop) 2187 goto end_coredump; 2188 } 2189 } 2190 2191 if (!elf_core_write_extra_data(cprm)) 2192 goto end_coredump; 2193 2194 if (e_phnum == PN_XNUM) { 2195 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 2196 goto end_coredump; 2197 } 2198 2199 end_coredump: 2200 set_fs(fs); 2201 2202 cleanup: 2203 free_note_info(&info); 2204 kfree(shdr4extnum); 2205 kfree(phdr4note); 2206 kfree(elf); 2207 out: 2208 return has_dumped; 2209 } 2210 2211 #endif /* CONFIG_ELF_CORE */ 2212 2213 static int __init init_elf_binfmt(void) 2214 { 2215 register_binfmt(&elf_format); 2216 return 0; 2217 } 2218 2219 static void __exit exit_elf_binfmt(void) 2220 { 2221 /* Remove the COFF and ELF loaders. */ 2222 unregister_binfmt(&elf_format); 2223 } 2224 2225 core_initcall(init_elf_binfmt); 2226 module_exit(exit_elf_binfmt); 2227 MODULE_LICENSE("GPL"); 2228