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/stat.h> 16 #include <linux/time.h> 17 #include <linux/mm.h> 18 #include <linux/mman.h> 19 #include <linux/a.out.h> 20 #include <linux/errno.h> 21 #include <linux/signal.h> 22 #include <linux/binfmts.h> 23 #include <linux/string.h> 24 #include <linux/file.h> 25 #include <linux/fcntl.h> 26 #include <linux/ptrace.h> 27 #include <linux/slab.h> 28 #include <linux/shm.h> 29 #include <linux/personality.h> 30 #include <linux/elfcore.h> 31 #include <linux/init.h> 32 #include <linux/highuid.h> 33 #include <linux/smp.h> 34 #include <linux/smp_lock.h> 35 #include <linux/compiler.h> 36 #include <linux/highmem.h> 37 #include <linux/pagemap.h> 38 #include <linux/security.h> 39 #include <linux/syscalls.h> 40 #include <linux/random.h> 41 42 #include <asm/uaccess.h> 43 #include <asm/param.h> 44 #include <asm/page.h> 45 46 #include <linux/elf.h> 47 48 static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs); 49 static int load_elf_library(struct file*); 50 static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int); 51 extern int dump_fpu (struct pt_regs *, elf_fpregset_t *); 52 53 #ifndef elf_addr_t 54 #define elf_addr_t unsigned long 55 #endif 56 57 /* 58 * If we don't support core dumping, then supply a NULL so we 59 * don't even try. 60 */ 61 #ifdef USE_ELF_CORE_DUMP 62 static int elf_core_dump(long signr, struct pt_regs * regs, struct file * file); 63 #else 64 #define elf_core_dump NULL 65 #endif 66 67 #if ELF_EXEC_PAGESIZE > PAGE_SIZE 68 # define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE 69 #else 70 # define ELF_MIN_ALIGN PAGE_SIZE 71 #endif 72 73 #ifndef ELF_CORE_EFLAGS 74 #define ELF_CORE_EFLAGS 0 75 #endif 76 77 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) 78 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) 79 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) 80 81 static struct linux_binfmt elf_format = { 82 .module = THIS_MODULE, 83 .load_binary = load_elf_binary, 84 .load_shlib = load_elf_library, 85 .core_dump = elf_core_dump, 86 .min_coredump = ELF_EXEC_PAGESIZE 87 }; 88 89 #define BAD_ADDR(x) ((unsigned long)(x) > TASK_SIZE) 90 91 static int set_brk(unsigned long start, unsigned long end) 92 { 93 start = ELF_PAGEALIGN(start); 94 end = ELF_PAGEALIGN(end); 95 if (end > start) { 96 unsigned long addr; 97 down_write(¤t->mm->mmap_sem); 98 addr = do_brk(start, end - start); 99 up_write(¤t->mm->mmap_sem); 100 if (BAD_ADDR(addr)) 101 return addr; 102 } 103 current->mm->start_brk = current->mm->brk = end; 104 return 0; 105 } 106 107 108 /* We need to explicitly zero any fractional pages 109 after the data section (i.e. bss). This would 110 contain the junk from the file that should not 111 be in memory */ 112 113 114 static int padzero(unsigned long elf_bss) 115 { 116 unsigned long nbyte; 117 118 nbyte = ELF_PAGEOFFSET(elf_bss); 119 if (nbyte) { 120 nbyte = ELF_MIN_ALIGN - nbyte; 121 if (clear_user((void __user *) elf_bss, nbyte)) 122 return -EFAULT; 123 } 124 return 0; 125 } 126 127 /* Let's use some macros to make this stack manipulation a litle clearer */ 128 #ifdef CONFIG_STACK_GROWSUP 129 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) 130 #define STACK_ROUND(sp, items) \ 131 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) 132 #define STACK_ALLOC(sp, len) ({ elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; old_sp; }) 133 #else 134 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) 135 #define STACK_ROUND(sp, items) \ 136 (((unsigned long) (sp - items)) &~ 15UL) 137 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) 138 #endif 139 140 static int 141 create_elf_tables(struct linux_binprm *bprm, struct elfhdr * exec, 142 int interp_aout, unsigned long load_addr, 143 unsigned long interp_load_addr) 144 { 145 unsigned long p = bprm->p; 146 int argc = bprm->argc; 147 int envc = bprm->envc; 148 elf_addr_t __user *argv; 149 elf_addr_t __user *envp; 150 elf_addr_t __user *sp; 151 elf_addr_t __user *u_platform; 152 const char *k_platform = ELF_PLATFORM; 153 int items; 154 elf_addr_t *elf_info; 155 int ei_index = 0; 156 struct task_struct *tsk = current; 157 158 /* 159 * If this architecture has a platform capability string, copy it 160 * to userspace. In some cases (Sparc), this info is impossible 161 * for userspace to get any other way, in others (i386) it is 162 * merely difficult. 163 */ 164 165 u_platform = NULL; 166 if (k_platform) { 167 size_t len = strlen(k_platform) + 1; 168 169 /* 170 * In some cases (e.g. Hyper-Threading), we want to avoid L1 171 * evictions by the processes running on the same package. One 172 * thing we can do is to shuffle the initial stack for them. 173 */ 174 175 p = arch_align_stack(p); 176 177 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 178 if (__copy_to_user(u_platform, k_platform, len)) 179 return -EFAULT; 180 } 181 182 /* Create the ELF interpreter info */ 183 elf_info = (elf_addr_t *) current->mm->saved_auxv; 184 #define NEW_AUX_ENT(id, val) \ 185 do { elf_info[ei_index++] = id; elf_info[ei_index++] = val; } while (0) 186 187 #ifdef ARCH_DLINFO 188 /* 189 * ARCH_DLINFO must come first so PPC can do its special alignment of 190 * AUXV. 191 */ 192 ARCH_DLINFO; 193 #endif 194 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 195 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); 196 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 197 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); 198 NEW_AUX_ENT(AT_PHENT, sizeof (struct elf_phdr)); 199 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); 200 NEW_AUX_ENT(AT_BASE, interp_load_addr); 201 NEW_AUX_ENT(AT_FLAGS, 0); 202 NEW_AUX_ENT(AT_ENTRY, exec->e_entry); 203 NEW_AUX_ENT(AT_UID, (elf_addr_t) tsk->uid); 204 NEW_AUX_ENT(AT_EUID, (elf_addr_t) tsk->euid); 205 NEW_AUX_ENT(AT_GID, (elf_addr_t) tsk->gid); 206 NEW_AUX_ENT(AT_EGID, (elf_addr_t) tsk->egid); 207 NEW_AUX_ENT(AT_SECURE, (elf_addr_t) security_bprm_secureexec(bprm)); 208 if (k_platform) { 209 NEW_AUX_ENT(AT_PLATFORM, (elf_addr_t)(unsigned long)u_platform); 210 } 211 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 212 NEW_AUX_ENT(AT_EXECFD, (elf_addr_t) bprm->interp_data); 213 } 214 #undef NEW_AUX_ENT 215 /* AT_NULL is zero; clear the rest too */ 216 memset(&elf_info[ei_index], 0, 217 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); 218 219 /* And advance past the AT_NULL entry. */ 220 ei_index += 2; 221 222 sp = STACK_ADD(p, ei_index); 223 224 items = (argc + 1) + (envc + 1); 225 if (interp_aout) { 226 items += 3; /* a.out interpreters require argv & envp too */ 227 } else { 228 items += 1; /* ELF interpreters only put argc on the stack */ 229 } 230 bprm->p = STACK_ROUND(sp, items); 231 232 /* Point sp at the lowest address on the stack */ 233 #ifdef CONFIG_STACK_GROWSUP 234 sp = (elf_addr_t __user *)bprm->p - items - ei_index; 235 bprm->exec = (unsigned long) sp; /* XXX: PARISC HACK */ 236 #else 237 sp = (elf_addr_t __user *)bprm->p; 238 #endif 239 240 /* Now, let's put argc (and argv, envp if appropriate) on the stack */ 241 if (__put_user(argc, sp++)) 242 return -EFAULT; 243 if (interp_aout) { 244 argv = sp + 2; 245 envp = argv + argc + 1; 246 __put_user((elf_addr_t)(unsigned long)argv, sp++); 247 __put_user((elf_addr_t)(unsigned long)envp, sp++); 248 } else { 249 argv = sp; 250 envp = argv + argc + 1; 251 } 252 253 /* Populate argv and envp */ 254 p = current->mm->arg_end = current->mm->arg_start; 255 while (argc-- > 0) { 256 size_t len; 257 __put_user((elf_addr_t)p, argv++); 258 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES); 259 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES) 260 return 0; 261 p += len; 262 } 263 if (__put_user(0, argv)) 264 return -EFAULT; 265 current->mm->arg_end = current->mm->env_start = p; 266 while (envc-- > 0) { 267 size_t len; 268 __put_user((elf_addr_t)p, envp++); 269 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES); 270 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES) 271 return 0; 272 p += len; 273 } 274 if (__put_user(0, envp)) 275 return -EFAULT; 276 current->mm->env_end = p; 277 278 /* Put the elf_info on the stack in the right place. */ 279 sp = (elf_addr_t __user *)envp + 1; 280 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) 281 return -EFAULT; 282 return 0; 283 } 284 285 #ifndef elf_map 286 287 static unsigned long elf_map(struct file *filep, unsigned long addr, 288 struct elf_phdr *eppnt, int prot, int type) 289 { 290 unsigned long map_addr; 291 292 down_write(¤t->mm->mmap_sem); 293 map_addr = do_mmap(filep, ELF_PAGESTART(addr), 294 eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr), prot, type, 295 eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr)); 296 up_write(¤t->mm->mmap_sem); 297 return(map_addr); 298 } 299 300 #endif /* !elf_map */ 301 302 /* This is much more generalized than the library routine read function, 303 so we keep this separate. Technically the library read function 304 is only provided so that we can read a.out libraries that have 305 an ELF header */ 306 307 static unsigned long load_elf_interp(struct elfhdr * interp_elf_ex, 308 struct file * interpreter, 309 unsigned long *interp_load_addr) 310 { 311 struct elf_phdr *elf_phdata; 312 struct elf_phdr *eppnt; 313 unsigned long load_addr = 0; 314 int load_addr_set = 0; 315 unsigned long last_bss = 0, elf_bss = 0; 316 unsigned long error = ~0UL; 317 int retval, i, size; 318 319 /* First of all, some simple consistency checks */ 320 if (interp_elf_ex->e_type != ET_EXEC && 321 interp_elf_ex->e_type != ET_DYN) 322 goto out; 323 if (!elf_check_arch(interp_elf_ex)) 324 goto out; 325 if (!interpreter->f_op || !interpreter->f_op->mmap) 326 goto out; 327 328 /* 329 * If the size of this structure has changed, then punt, since 330 * we will be doing the wrong thing. 331 */ 332 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr)) 333 goto out; 334 if (interp_elf_ex->e_phnum < 1 || 335 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) 336 goto out; 337 338 /* Now read in all of the header information */ 339 340 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum; 341 if (size > ELF_MIN_ALIGN) 342 goto out; 343 elf_phdata = (struct elf_phdr *) kmalloc(size, GFP_KERNEL); 344 if (!elf_phdata) 345 goto out; 346 347 retval = kernel_read(interpreter,interp_elf_ex->e_phoff,(char *)elf_phdata,size); 348 error = -EIO; 349 if (retval != size) { 350 if (retval < 0) 351 error = retval; 352 goto out_close; 353 } 354 355 eppnt = elf_phdata; 356 for (i=0; i<interp_elf_ex->e_phnum; i++, eppnt++) { 357 if (eppnt->p_type == PT_LOAD) { 358 int elf_type = MAP_PRIVATE | MAP_DENYWRITE; 359 int elf_prot = 0; 360 unsigned long vaddr = 0; 361 unsigned long k, map_addr; 362 363 if (eppnt->p_flags & PF_R) elf_prot = PROT_READ; 364 if (eppnt->p_flags & PF_W) elf_prot |= PROT_WRITE; 365 if (eppnt->p_flags & PF_X) elf_prot |= PROT_EXEC; 366 vaddr = eppnt->p_vaddr; 367 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) 368 elf_type |= MAP_FIXED; 369 370 map_addr = elf_map(interpreter, load_addr + vaddr, eppnt, elf_prot, elf_type); 371 error = map_addr; 372 if (BAD_ADDR(map_addr)) 373 goto out_close; 374 375 if (!load_addr_set && interp_elf_ex->e_type == ET_DYN) { 376 load_addr = map_addr - ELF_PAGESTART(vaddr); 377 load_addr_set = 1; 378 } 379 380 /* 381 * Check to see if the section's size will overflow the 382 * allowed task size. Note that p_filesz must always be 383 * <= p_memsize so it is only necessary to check p_memsz. 384 */ 385 k = load_addr + eppnt->p_vaddr; 386 if (k > TASK_SIZE || eppnt->p_filesz > eppnt->p_memsz || 387 eppnt->p_memsz > TASK_SIZE || TASK_SIZE - eppnt->p_memsz < k) { 388 error = -ENOMEM; 389 goto out_close; 390 } 391 392 /* 393 * Find the end of the file mapping for this phdr, and keep 394 * track of the largest address we see for this. 395 */ 396 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; 397 if (k > elf_bss) 398 elf_bss = k; 399 400 /* 401 * Do the same thing for the memory mapping - between 402 * elf_bss and last_bss is the bss section. 403 */ 404 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr; 405 if (k > last_bss) 406 last_bss = k; 407 } 408 } 409 410 /* 411 * Now fill out the bss section. First pad the last page up 412 * to the page boundary, and then perform a mmap to make sure 413 * that there are zero-mapped pages up to and including the 414 * last bss page. 415 */ 416 if (padzero(elf_bss)) { 417 error = -EFAULT; 418 goto out_close; 419 } 420 421 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1); /* What we have mapped so far */ 422 423 /* Map the last of the bss segment */ 424 if (last_bss > elf_bss) { 425 down_write(¤t->mm->mmap_sem); 426 error = do_brk(elf_bss, last_bss - elf_bss); 427 up_write(¤t->mm->mmap_sem); 428 if (BAD_ADDR(error)) 429 goto out_close; 430 } 431 432 *interp_load_addr = load_addr; 433 error = ((unsigned long) interp_elf_ex->e_entry) + load_addr; 434 435 out_close: 436 kfree(elf_phdata); 437 out: 438 return error; 439 } 440 441 static unsigned long load_aout_interp(struct exec * interp_ex, 442 struct file * interpreter) 443 { 444 unsigned long text_data, elf_entry = ~0UL; 445 char __user * addr; 446 loff_t offset; 447 448 current->mm->end_code = interp_ex->a_text; 449 text_data = interp_ex->a_text + interp_ex->a_data; 450 current->mm->end_data = text_data; 451 current->mm->brk = interp_ex->a_bss + text_data; 452 453 switch (N_MAGIC(*interp_ex)) { 454 case OMAGIC: 455 offset = 32; 456 addr = (char __user *)0; 457 break; 458 case ZMAGIC: 459 case QMAGIC: 460 offset = N_TXTOFF(*interp_ex); 461 addr = (char __user *) N_TXTADDR(*interp_ex); 462 break; 463 default: 464 goto out; 465 } 466 467 down_write(¤t->mm->mmap_sem); 468 do_brk(0, text_data); 469 up_write(¤t->mm->mmap_sem); 470 if (!interpreter->f_op || !interpreter->f_op->read) 471 goto out; 472 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0) 473 goto out; 474 flush_icache_range((unsigned long)addr, 475 (unsigned long)addr + text_data); 476 477 478 down_write(¤t->mm->mmap_sem); 479 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1), 480 interp_ex->a_bss); 481 up_write(¤t->mm->mmap_sem); 482 elf_entry = interp_ex->a_entry; 483 484 out: 485 return elf_entry; 486 } 487 488 /* 489 * These are the functions used to load ELF style executables and shared 490 * libraries. There is no binary dependent code anywhere else. 491 */ 492 493 #define INTERPRETER_NONE 0 494 #define INTERPRETER_AOUT 1 495 #define INTERPRETER_ELF 2 496 497 498 static unsigned long randomize_stack_top(unsigned long stack_top) 499 { 500 unsigned int random_variable = 0; 501 502 if (current->flags & PF_RANDOMIZE) 503 random_variable = get_random_int() % (8*1024*1024); 504 #ifdef CONFIG_STACK_GROWSUP 505 return PAGE_ALIGN(stack_top + random_variable); 506 #else 507 return PAGE_ALIGN(stack_top - random_variable); 508 #endif 509 } 510 511 static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs) 512 { 513 struct file *interpreter = NULL; /* to shut gcc up */ 514 unsigned long load_addr = 0, load_bias = 0; 515 int load_addr_set = 0; 516 char * elf_interpreter = NULL; 517 unsigned int interpreter_type = INTERPRETER_NONE; 518 unsigned char ibcs2_interpreter = 0; 519 unsigned long error; 520 struct elf_phdr * elf_ppnt, *elf_phdata; 521 unsigned long elf_bss, elf_brk; 522 int elf_exec_fileno; 523 int retval, i; 524 unsigned int size; 525 unsigned long elf_entry, interp_load_addr = 0; 526 unsigned long start_code, end_code, start_data, end_data; 527 unsigned long reloc_func_desc = 0; 528 char passed_fileno[6]; 529 struct files_struct *files; 530 int have_pt_gnu_stack, executable_stack = EXSTACK_DEFAULT; 531 unsigned long def_flags = 0; 532 struct { 533 struct elfhdr elf_ex; 534 struct elfhdr interp_elf_ex; 535 struct exec interp_ex; 536 } *loc; 537 538 loc = kmalloc(sizeof(*loc), GFP_KERNEL); 539 if (!loc) { 540 retval = -ENOMEM; 541 goto out_ret; 542 } 543 544 /* Get the exec-header */ 545 loc->elf_ex = *((struct elfhdr *) bprm->buf); 546 547 retval = -ENOEXEC; 548 /* First of all, some simple consistency checks */ 549 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 550 goto out; 551 552 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) 553 goto out; 554 if (!elf_check_arch(&loc->elf_ex)) 555 goto out; 556 if (!bprm->file->f_op||!bprm->file->f_op->mmap) 557 goto out; 558 559 /* Now read in all of the header information */ 560 561 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr)) 562 goto out; 563 if (loc->elf_ex.e_phnum < 1 || 564 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr)) 565 goto out; 566 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr); 567 retval = -ENOMEM; 568 elf_phdata = (struct elf_phdr *) kmalloc(size, GFP_KERNEL); 569 if (!elf_phdata) 570 goto out; 571 572 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff, (char *) elf_phdata, size); 573 if (retval != size) { 574 if (retval >= 0) 575 retval = -EIO; 576 goto out_free_ph; 577 } 578 579 files = current->files; /* Refcounted so ok */ 580 retval = unshare_files(); 581 if (retval < 0) 582 goto out_free_ph; 583 if (files == current->files) { 584 put_files_struct(files); 585 files = NULL; 586 } 587 588 /* exec will make our files private anyway, but for the a.out 589 loader stuff we need to do it earlier */ 590 591 retval = get_unused_fd(); 592 if (retval < 0) 593 goto out_free_fh; 594 get_file(bprm->file); 595 fd_install(elf_exec_fileno = retval, bprm->file); 596 597 elf_ppnt = elf_phdata; 598 elf_bss = 0; 599 elf_brk = 0; 600 601 start_code = ~0UL; 602 end_code = 0; 603 start_data = 0; 604 end_data = 0; 605 606 for (i = 0; i < loc->elf_ex.e_phnum; i++) { 607 if (elf_ppnt->p_type == PT_INTERP) { 608 /* This is the program interpreter used for 609 * shared libraries - for now assume that this 610 * is an a.out format binary 611 */ 612 613 retval = -ENOEXEC; 614 if (elf_ppnt->p_filesz > PATH_MAX || 615 elf_ppnt->p_filesz < 2) 616 goto out_free_file; 617 618 retval = -ENOMEM; 619 elf_interpreter = (char *) kmalloc(elf_ppnt->p_filesz, 620 GFP_KERNEL); 621 if (!elf_interpreter) 622 goto out_free_file; 623 624 retval = kernel_read(bprm->file, elf_ppnt->p_offset, 625 elf_interpreter, 626 elf_ppnt->p_filesz); 627 if (retval != elf_ppnt->p_filesz) { 628 if (retval >= 0) 629 retval = -EIO; 630 goto out_free_interp; 631 } 632 /* make sure path is NULL terminated */ 633 retval = -ENOEXEC; 634 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') 635 goto out_free_interp; 636 637 /* If the program interpreter is one of these two, 638 * then assume an iBCS2 image. Otherwise assume 639 * a native linux image. 640 */ 641 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 || 642 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0) 643 ibcs2_interpreter = 1; 644 645 /* 646 * The early SET_PERSONALITY here is so that the lookup 647 * for the interpreter happens in the namespace of the 648 * to-be-execed image. SET_PERSONALITY can select an 649 * alternate root. 650 * 651 * However, SET_PERSONALITY is NOT allowed to switch 652 * this task into the new images's memory mapping 653 * policy - that is, TASK_SIZE must still evaluate to 654 * that which is appropriate to the execing application. 655 * This is because exit_mmap() needs to have TASK_SIZE 656 * evaluate to the size of the old image. 657 * 658 * So if (say) a 64-bit application is execing a 32-bit 659 * application it is the architecture's responsibility 660 * to defer changing the value of TASK_SIZE until the 661 * switch really is going to happen - do this in 662 * flush_thread(). - akpm 663 */ 664 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter); 665 666 interpreter = open_exec(elf_interpreter); 667 retval = PTR_ERR(interpreter); 668 if (IS_ERR(interpreter)) 669 goto out_free_interp; 670 retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE); 671 if (retval != BINPRM_BUF_SIZE) { 672 if (retval >= 0) 673 retval = -EIO; 674 goto out_free_dentry; 675 } 676 677 /* Get the exec headers */ 678 loc->interp_ex = *((struct exec *) bprm->buf); 679 loc->interp_elf_ex = *((struct elfhdr *) bprm->buf); 680 break; 681 } 682 elf_ppnt++; 683 } 684 685 elf_ppnt = elf_phdata; 686 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) 687 if (elf_ppnt->p_type == PT_GNU_STACK) { 688 if (elf_ppnt->p_flags & PF_X) 689 executable_stack = EXSTACK_ENABLE_X; 690 else 691 executable_stack = EXSTACK_DISABLE_X; 692 break; 693 } 694 have_pt_gnu_stack = (i < loc->elf_ex.e_phnum); 695 696 /* Some simple consistency checks for the interpreter */ 697 if (elf_interpreter) { 698 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT; 699 700 /* Now figure out which format our binary is */ 701 if ((N_MAGIC(loc->interp_ex) != OMAGIC) && 702 (N_MAGIC(loc->interp_ex) != ZMAGIC) && 703 (N_MAGIC(loc->interp_ex) != QMAGIC)) 704 interpreter_type = INTERPRETER_ELF; 705 706 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 707 interpreter_type &= ~INTERPRETER_ELF; 708 709 retval = -ELIBBAD; 710 if (!interpreter_type) 711 goto out_free_dentry; 712 713 /* Make sure only one type was selected */ 714 if ((interpreter_type & INTERPRETER_ELF) && 715 interpreter_type != INTERPRETER_ELF) { 716 // FIXME - ratelimit this before re-enabling 717 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n"); 718 interpreter_type = INTERPRETER_ELF; 719 } 720 /* Verify the interpreter has a valid arch */ 721 if ((interpreter_type == INTERPRETER_ELF) && 722 !elf_check_arch(&loc->interp_elf_ex)) 723 goto out_free_dentry; 724 } else { 725 /* Executables without an interpreter also need a personality */ 726 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter); 727 } 728 729 /* OK, we are done with that, now set up the arg stuff, 730 and then start this sucker up */ 731 732 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) { 733 char *passed_p = passed_fileno; 734 sprintf(passed_fileno, "%d", elf_exec_fileno); 735 736 if (elf_interpreter) { 737 retval = copy_strings_kernel(1, &passed_p, bprm); 738 if (retval) 739 goto out_free_dentry; 740 bprm->argc++; 741 } 742 } 743 744 /* Flush all traces of the currently running executable */ 745 retval = flush_old_exec(bprm); 746 if (retval) 747 goto out_free_dentry; 748 749 /* Discard our unneeded old files struct */ 750 if (files) { 751 steal_locks(files); 752 put_files_struct(files); 753 files = NULL; 754 } 755 756 /* OK, This is the point of no return */ 757 current->mm->start_data = 0; 758 current->mm->end_data = 0; 759 current->mm->end_code = 0; 760 current->mm->mmap = NULL; 761 current->flags &= ~PF_FORKNOEXEC; 762 current->mm->def_flags = def_flags; 763 764 /* Do this immediately, since STACK_TOP as used in setup_arg_pages 765 may depend on the personality. */ 766 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter); 767 if (elf_read_implies_exec(loc->elf_ex, executable_stack)) 768 current->personality |= READ_IMPLIES_EXEC; 769 770 if ( !(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 771 current->flags |= PF_RANDOMIZE; 772 arch_pick_mmap_layout(current->mm); 773 774 /* Do this so that we can load the interpreter, if need be. We will 775 change some of these later */ 776 current->mm->free_area_cache = current->mm->mmap_base; 777 current->mm->cached_hole_size = 0; 778 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), 779 executable_stack); 780 if (retval < 0) { 781 send_sig(SIGKILL, current, 0); 782 goto out_free_dentry; 783 } 784 785 current->mm->start_stack = bprm->p; 786 787 /* Now we do a little grungy work by mmaping the ELF image into 788 the correct location in memory. At this point, we assume that 789 the image should be loaded at fixed address, not at a variable 790 address. */ 791 792 for(i = 0, elf_ppnt = elf_phdata; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { 793 int elf_prot = 0, elf_flags; 794 unsigned long k, vaddr; 795 796 if (elf_ppnt->p_type != PT_LOAD) 797 continue; 798 799 if (unlikely (elf_brk > elf_bss)) { 800 unsigned long nbyte; 801 802 /* There was a PT_LOAD segment with p_memsz > p_filesz 803 before this one. Map anonymous pages, if needed, 804 and clear the area. */ 805 retval = set_brk (elf_bss + load_bias, 806 elf_brk + load_bias); 807 if (retval) { 808 send_sig(SIGKILL, current, 0); 809 goto out_free_dentry; 810 } 811 nbyte = ELF_PAGEOFFSET(elf_bss); 812 if (nbyte) { 813 nbyte = ELF_MIN_ALIGN - nbyte; 814 if (nbyte > elf_brk - elf_bss) 815 nbyte = elf_brk - elf_bss; 816 if (clear_user((void __user *)elf_bss + 817 load_bias, nbyte)) { 818 /* 819 * This bss-zeroing can fail if the ELF 820 * file specifies odd protections. So 821 * we don't check the return value 822 */ 823 } 824 } 825 } 826 827 if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ; 828 if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE; 829 if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC; 830 831 elf_flags = MAP_PRIVATE|MAP_DENYWRITE|MAP_EXECUTABLE; 832 833 vaddr = elf_ppnt->p_vaddr; 834 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { 835 elf_flags |= MAP_FIXED; 836 } else if (loc->elf_ex.e_type == ET_DYN) { 837 /* Try and get dynamic programs out of the way of the default mmap 838 base, as well as whatever program they might try to exec. This 839 is because the brk will follow the loader, and is not movable. */ 840 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); 841 } 842 843 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, elf_prot, elf_flags); 844 if (BAD_ADDR(error)) { 845 send_sig(SIGKILL, current, 0); 846 goto out_free_dentry; 847 } 848 849 if (!load_addr_set) { 850 load_addr_set = 1; 851 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); 852 if (loc->elf_ex.e_type == ET_DYN) { 853 load_bias += error - 854 ELF_PAGESTART(load_bias + vaddr); 855 load_addr += load_bias; 856 reloc_func_desc = load_bias; 857 } 858 } 859 k = elf_ppnt->p_vaddr; 860 if (k < start_code) start_code = k; 861 if (start_data < k) start_data = k; 862 863 /* 864 * Check to see if the section's size will overflow the 865 * allowed task size. Note that p_filesz must always be 866 * <= p_memsz so it is only necessary to check p_memsz. 867 */ 868 if (k > TASK_SIZE || elf_ppnt->p_filesz > elf_ppnt->p_memsz || 869 elf_ppnt->p_memsz > TASK_SIZE || 870 TASK_SIZE - elf_ppnt->p_memsz < k) { 871 /* set_brk can never work. Avoid overflows. */ 872 send_sig(SIGKILL, current, 0); 873 goto out_free_dentry; 874 } 875 876 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; 877 878 if (k > elf_bss) 879 elf_bss = k; 880 if ((elf_ppnt->p_flags & PF_X) && end_code < k) 881 end_code = k; 882 if (end_data < k) 883 end_data = k; 884 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; 885 if (k > elf_brk) 886 elf_brk = k; 887 } 888 889 loc->elf_ex.e_entry += load_bias; 890 elf_bss += load_bias; 891 elf_brk += load_bias; 892 start_code += load_bias; 893 end_code += load_bias; 894 start_data += load_bias; 895 end_data += load_bias; 896 897 /* Calling set_brk effectively mmaps the pages that we need 898 * for the bss and break sections. We must do this before 899 * mapping in the interpreter, to make sure it doesn't wind 900 * up getting placed where the bss needs to go. 901 */ 902 retval = set_brk(elf_bss, elf_brk); 903 if (retval) { 904 send_sig(SIGKILL, current, 0); 905 goto out_free_dentry; 906 } 907 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { 908 send_sig(SIGSEGV, current, 0); 909 retval = -EFAULT; /* Nobody gets to see this, but.. */ 910 goto out_free_dentry; 911 } 912 913 if (elf_interpreter) { 914 if (interpreter_type == INTERPRETER_AOUT) 915 elf_entry = load_aout_interp(&loc->interp_ex, 916 interpreter); 917 else 918 elf_entry = load_elf_interp(&loc->interp_elf_ex, 919 interpreter, 920 &interp_load_addr); 921 if (BAD_ADDR(elf_entry)) { 922 printk(KERN_ERR "Unable to load interpreter %.128s\n", 923 elf_interpreter); 924 force_sig(SIGSEGV, current); 925 retval = -ENOEXEC; /* Nobody gets to see this, but.. */ 926 goto out_free_dentry; 927 } 928 reloc_func_desc = interp_load_addr; 929 930 allow_write_access(interpreter); 931 fput(interpreter); 932 kfree(elf_interpreter); 933 } else { 934 elf_entry = loc->elf_ex.e_entry; 935 } 936 937 kfree(elf_phdata); 938 939 if (interpreter_type != INTERPRETER_AOUT) 940 sys_close(elf_exec_fileno); 941 942 set_binfmt(&elf_format); 943 944 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 945 retval = arch_setup_additional_pages(bprm, executable_stack); 946 if (retval < 0) { 947 send_sig(SIGKILL, current, 0); 948 goto out; 949 } 950 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ 951 952 compute_creds(bprm); 953 current->flags &= ~PF_FORKNOEXEC; 954 create_elf_tables(bprm, &loc->elf_ex, (interpreter_type == INTERPRETER_AOUT), 955 load_addr, interp_load_addr); 956 /* N.B. passed_fileno might not be initialized? */ 957 if (interpreter_type == INTERPRETER_AOUT) 958 current->mm->arg_start += strlen(passed_fileno) + 1; 959 current->mm->end_code = end_code; 960 current->mm->start_code = start_code; 961 current->mm->start_data = start_data; 962 current->mm->end_data = end_data; 963 current->mm->start_stack = bprm->p; 964 965 if (current->personality & MMAP_PAGE_ZERO) { 966 /* Why this, you ask??? Well SVr4 maps page 0 as read-only, 967 and some applications "depend" upon this behavior. 968 Since we do not have the power to recompile these, we 969 emulate the SVr4 behavior. Sigh. */ 970 down_write(¤t->mm->mmap_sem); 971 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, 972 MAP_FIXED | MAP_PRIVATE, 0); 973 up_write(¤t->mm->mmap_sem); 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 if (unlikely(current->ptrace & PT_PTRACED)) { 992 if (current->ptrace & PT_TRACE_EXEC) 993 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP); 994 else 995 send_sig(SIGTRAP, current, 0); 996 } 997 retval = 0; 998 out: 999 kfree(loc); 1000 out_ret: 1001 return retval; 1002 1003 /* error cleanup */ 1004 out_free_dentry: 1005 allow_write_access(interpreter); 1006 if (interpreter) 1007 fput(interpreter); 1008 out_free_interp: 1009 kfree(elf_interpreter); 1010 out_free_file: 1011 sys_close(elf_exec_fileno); 1012 out_free_fh: 1013 if (files) { 1014 put_files_struct(current->files); 1015 current->files = files; 1016 } 1017 out_free_ph: 1018 kfree(elf_phdata); 1019 goto out; 1020 } 1021 1022 /* This is really simpleminded and specialized - we are loading an 1023 a.out library that is given an ELF header. */ 1024 1025 static int load_elf_library(struct file *file) 1026 { 1027 struct elf_phdr *elf_phdata; 1028 struct elf_phdr *eppnt; 1029 unsigned long elf_bss, bss, len; 1030 int retval, error, i, j; 1031 struct elfhdr elf_ex; 1032 1033 error = -ENOEXEC; 1034 retval = kernel_read(file, 0, (char *) &elf_ex, sizeof(elf_ex)); 1035 if (retval != sizeof(elf_ex)) 1036 goto out; 1037 1038 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 1039 goto out; 1040 1041 /* First of all, some simple consistency checks */ 1042 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || 1043 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap) 1044 goto out; 1045 1046 /* Now read in all of the header information */ 1047 1048 j = sizeof(struct elf_phdr) * elf_ex.e_phnum; 1049 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ 1050 1051 error = -ENOMEM; 1052 elf_phdata = kmalloc(j, GFP_KERNEL); 1053 if (!elf_phdata) 1054 goto out; 1055 1056 eppnt = elf_phdata; 1057 error = -ENOEXEC; 1058 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j); 1059 if (retval != j) 1060 goto out_free_ph; 1061 1062 for (j = 0, i = 0; i<elf_ex.e_phnum; i++) 1063 if ((eppnt + i)->p_type == PT_LOAD) 1064 j++; 1065 if (j != 1) 1066 goto out_free_ph; 1067 1068 while (eppnt->p_type != PT_LOAD) 1069 eppnt++; 1070 1071 /* Now use mmap to map the library into memory. */ 1072 down_write(¤t->mm->mmap_sem); 1073 error = do_mmap(file, 1074 ELF_PAGESTART(eppnt->p_vaddr), 1075 (eppnt->p_filesz + 1076 ELF_PAGEOFFSET(eppnt->p_vaddr)), 1077 PROT_READ | PROT_WRITE | PROT_EXEC, 1078 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE, 1079 (eppnt->p_offset - 1080 ELF_PAGEOFFSET(eppnt->p_vaddr))); 1081 up_write(¤t->mm->mmap_sem); 1082 if (error != ELF_PAGESTART(eppnt->p_vaddr)) 1083 goto out_free_ph; 1084 1085 elf_bss = eppnt->p_vaddr + eppnt->p_filesz; 1086 if (padzero(elf_bss)) { 1087 error = -EFAULT; 1088 goto out_free_ph; 1089 } 1090 1091 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + ELF_MIN_ALIGN - 1); 1092 bss = eppnt->p_memsz + eppnt->p_vaddr; 1093 if (bss > len) { 1094 down_write(¤t->mm->mmap_sem); 1095 do_brk(len, bss - len); 1096 up_write(¤t->mm->mmap_sem); 1097 } 1098 error = 0; 1099 1100 out_free_ph: 1101 kfree(elf_phdata); 1102 out: 1103 return error; 1104 } 1105 1106 /* 1107 * Note that some platforms still use traditional core dumps and not 1108 * the ELF core dump. Each platform can select it as appropriate. 1109 */ 1110 #ifdef USE_ELF_CORE_DUMP 1111 1112 /* 1113 * ELF core dumper 1114 * 1115 * Modelled on fs/exec.c:aout_core_dump() 1116 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1117 */ 1118 /* 1119 * These are the only things you should do on a core-file: use only these 1120 * functions to write out all the necessary info. 1121 */ 1122 static int dump_write(struct file *file, const void *addr, int nr) 1123 { 1124 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 1125 } 1126 1127 static int dump_seek(struct file *file, loff_t off) 1128 { 1129 if (file->f_op->llseek) { 1130 if (file->f_op->llseek(file, off, 0) != off) 1131 return 0; 1132 } else 1133 file->f_pos = off; 1134 return 1; 1135 } 1136 1137 /* 1138 * Decide whether a segment is worth dumping; default is yes to be 1139 * sure (missing info is worse than too much; etc). 1140 * Personally I'd include everything, and use the coredump limit... 1141 * 1142 * I think we should skip something. But I am not sure how. H.J. 1143 */ 1144 static int maydump(struct vm_area_struct *vma) 1145 { 1146 /* Do not dump I/O mapped devices or special mappings */ 1147 if (vma->vm_flags & (VM_IO | VM_RESERVED)) 1148 return 0; 1149 1150 /* Dump shared memory only if mapped from an anonymous file. */ 1151 if (vma->vm_flags & VM_SHARED) 1152 return vma->vm_file->f_dentry->d_inode->i_nlink == 0; 1153 1154 /* If it hasn't been written to, don't write it out */ 1155 if (!vma->anon_vma) 1156 return 0; 1157 1158 return 1; 1159 } 1160 1161 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) 1162 1163 /* An ELF note in memory */ 1164 struct memelfnote 1165 { 1166 const char *name; 1167 int type; 1168 unsigned int datasz; 1169 void *data; 1170 }; 1171 1172 static int notesize(struct memelfnote *en) 1173 { 1174 int sz; 1175 1176 sz = sizeof(struct elf_note); 1177 sz += roundup(strlen(en->name) + 1, 4); 1178 sz += roundup(en->datasz, 4); 1179 1180 return sz; 1181 } 1182 1183 #define DUMP_WRITE(addr, nr) \ 1184 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0) 1185 #define DUMP_SEEK(off) \ 1186 do { if (!dump_seek(file, (off))) return 0; } while(0) 1187 1188 static int writenote(struct memelfnote *men, struct file *file) 1189 { 1190 struct elf_note en; 1191 1192 en.n_namesz = strlen(men->name) + 1; 1193 en.n_descsz = men->datasz; 1194 en.n_type = men->type; 1195 1196 DUMP_WRITE(&en, sizeof(en)); 1197 DUMP_WRITE(men->name, en.n_namesz); 1198 /* XXX - cast from long long to long to avoid need for libgcc.a */ 1199 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1200 DUMP_WRITE(men->data, men->datasz); 1201 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1202 1203 return 1; 1204 } 1205 #undef DUMP_WRITE 1206 #undef DUMP_SEEK 1207 1208 #define DUMP_WRITE(addr, nr) \ 1209 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ 1210 goto end_coredump; 1211 #define DUMP_SEEK(off) \ 1212 if (!dump_seek(file, (off))) \ 1213 goto end_coredump; 1214 1215 static inline void fill_elf_header(struct elfhdr *elf, int segs) 1216 { 1217 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1218 elf->e_ident[EI_CLASS] = ELF_CLASS; 1219 elf->e_ident[EI_DATA] = ELF_DATA; 1220 elf->e_ident[EI_VERSION] = EV_CURRENT; 1221 elf->e_ident[EI_OSABI] = ELF_OSABI; 1222 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1223 1224 elf->e_type = ET_CORE; 1225 elf->e_machine = ELF_ARCH; 1226 elf->e_version = EV_CURRENT; 1227 elf->e_entry = 0; 1228 elf->e_phoff = sizeof(struct elfhdr); 1229 elf->e_shoff = 0; 1230 elf->e_flags = ELF_CORE_EFLAGS; 1231 elf->e_ehsize = sizeof(struct elfhdr); 1232 elf->e_phentsize = sizeof(struct elf_phdr); 1233 elf->e_phnum = segs; 1234 elf->e_shentsize = 0; 1235 elf->e_shnum = 0; 1236 elf->e_shstrndx = 0; 1237 return; 1238 } 1239 1240 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, off_t offset) 1241 { 1242 phdr->p_type = PT_NOTE; 1243 phdr->p_offset = offset; 1244 phdr->p_vaddr = 0; 1245 phdr->p_paddr = 0; 1246 phdr->p_filesz = sz; 1247 phdr->p_memsz = 0; 1248 phdr->p_flags = 0; 1249 phdr->p_align = 0; 1250 return; 1251 } 1252 1253 static void fill_note(struct memelfnote *note, const char *name, int type, 1254 unsigned int sz, void *data) 1255 { 1256 note->name = name; 1257 note->type = type; 1258 note->datasz = sz; 1259 note->data = data; 1260 return; 1261 } 1262 1263 /* 1264 * fill up all the fields in prstatus from the given task struct, except registers 1265 * which need to be filled up separately. 1266 */ 1267 static void fill_prstatus(struct elf_prstatus *prstatus, 1268 struct task_struct *p, long signr) 1269 { 1270 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1271 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1272 prstatus->pr_sighold = p->blocked.sig[0]; 1273 prstatus->pr_pid = p->pid; 1274 prstatus->pr_ppid = p->parent->pid; 1275 prstatus->pr_pgrp = process_group(p); 1276 prstatus->pr_sid = p->signal->session; 1277 if (thread_group_leader(p)) { 1278 /* 1279 * This is the record for the group leader. Add in the 1280 * cumulative times of previous dead threads. This total 1281 * won't include the time of each live thread whose state 1282 * is included in the core dump. The final total reported 1283 * to our parent process when it calls wait4 will include 1284 * those sums as well as the little bit more time it takes 1285 * this and each other thread to finish dying after the 1286 * core dump synchronization phase. 1287 */ 1288 cputime_to_timeval(cputime_add(p->utime, p->signal->utime), 1289 &prstatus->pr_utime); 1290 cputime_to_timeval(cputime_add(p->stime, p->signal->stime), 1291 &prstatus->pr_stime); 1292 } else { 1293 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1294 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1295 } 1296 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1297 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1298 } 1299 1300 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1301 struct mm_struct *mm) 1302 { 1303 unsigned int i, len; 1304 1305 /* first copy the parameters from user space */ 1306 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1307 1308 len = mm->arg_end - mm->arg_start; 1309 if (len >= ELF_PRARGSZ) 1310 len = ELF_PRARGSZ-1; 1311 if (copy_from_user(&psinfo->pr_psargs, 1312 (const char __user *)mm->arg_start, len)) 1313 return -EFAULT; 1314 for(i = 0; i < len; i++) 1315 if (psinfo->pr_psargs[i] == 0) 1316 psinfo->pr_psargs[i] = ' '; 1317 psinfo->pr_psargs[len] = 0; 1318 1319 psinfo->pr_pid = p->pid; 1320 psinfo->pr_ppid = p->parent->pid; 1321 psinfo->pr_pgrp = process_group(p); 1322 psinfo->pr_sid = p->signal->session; 1323 1324 i = p->state ? ffz(~p->state) + 1 : 0; 1325 psinfo->pr_state = i; 1326 psinfo->pr_sname = (i < 0 || i > 5) ? '.' : "RSDTZW"[i]; 1327 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1328 psinfo->pr_nice = task_nice(p); 1329 psinfo->pr_flag = p->flags; 1330 SET_UID(psinfo->pr_uid, p->uid); 1331 SET_GID(psinfo->pr_gid, p->gid); 1332 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1333 1334 return 0; 1335 } 1336 1337 /* Here is the structure in which status of each thread is captured. */ 1338 struct elf_thread_status 1339 { 1340 struct list_head list; 1341 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1342 elf_fpregset_t fpu; /* NT_PRFPREG */ 1343 struct task_struct *thread; 1344 #ifdef ELF_CORE_COPY_XFPREGS 1345 elf_fpxregset_t xfpu; /* NT_PRXFPREG */ 1346 #endif 1347 struct memelfnote notes[3]; 1348 int num_notes; 1349 }; 1350 1351 /* 1352 * In order to add the specific thread information for the elf file format, 1353 * we need to keep a linked list of every threads pr_status and then 1354 * create a single section for them in the final core file. 1355 */ 1356 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1357 { 1358 int sz = 0; 1359 struct task_struct *p = t->thread; 1360 t->num_notes = 0; 1361 1362 fill_prstatus(&t->prstatus, p, signr); 1363 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1364 1365 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), &(t->prstatus)); 1366 t->num_notes++; 1367 sz += notesize(&t->notes[0]); 1368 1369 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu))) { 1370 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), &(t->fpu)); 1371 t->num_notes++; 1372 sz += notesize(&t->notes[1]); 1373 } 1374 1375 #ifdef ELF_CORE_COPY_XFPREGS 1376 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1377 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu), &t->xfpu); 1378 t->num_notes++; 1379 sz += notesize(&t->notes[2]); 1380 } 1381 #endif 1382 return sz; 1383 } 1384 1385 /* 1386 * Actual dumper 1387 * 1388 * This is a two-pass process; first we find the offsets of the bits, 1389 * and then they are actually written out. If we run out of core limit 1390 * we just truncate. 1391 */ 1392 static int elf_core_dump(long signr, struct pt_regs * regs, struct file * file) 1393 { 1394 #define NUM_NOTES 6 1395 int has_dumped = 0; 1396 mm_segment_t fs; 1397 int segs; 1398 size_t size = 0; 1399 int i; 1400 struct vm_area_struct *vma; 1401 struct elfhdr *elf = NULL; 1402 off_t offset = 0, dataoff; 1403 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur; 1404 int numnote; 1405 struct memelfnote *notes = NULL; 1406 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1407 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1408 struct task_struct *g, *p; 1409 LIST_HEAD(thread_list); 1410 struct list_head *t; 1411 elf_fpregset_t *fpu = NULL; 1412 #ifdef ELF_CORE_COPY_XFPREGS 1413 elf_fpxregset_t *xfpu = NULL; 1414 #endif 1415 int thread_status_size = 0; 1416 elf_addr_t *auxv; 1417 1418 /* 1419 * We no longer stop all VM operations. 1420 * 1421 * This is because those proceses that could possibly change map_count or 1422 * the mmap / vma pages are now blocked in do_exit on current finishing 1423 * this core dump. 1424 * 1425 * Only ptrace can touch these memory addresses, but it doesn't change 1426 * the map_count or the pages allocated. So no possibility of crashing 1427 * exists while dumping the mm->vm_next areas to the core file. 1428 */ 1429 1430 /* alloc memory for large data structures: too large to be on stack */ 1431 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1432 if (!elf) 1433 goto cleanup; 1434 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL); 1435 if (!prstatus) 1436 goto cleanup; 1437 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1438 if (!psinfo) 1439 goto cleanup; 1440 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1441 if (!notes) 1442 goto cleanup; 1443 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1444 if (!fpu) 1445 goto cleanup; 1446 #ifdef ELF_CORE_COPY_XFPREGS 1447 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1448 if (!xfpu) 1449 goto cleanup; 1450 #endif 1451 1452 if (signr) { 1453 struct elf_thread_status *tmp; 1454 read_lock(&tasklist_lock); 1455 do_each_thread(g,p) 1456 if (current->mm == p->mm && current != p) { 1457 tmp = kmalloc(sizeof(*tmp), GFP_ATOMIC); 1458 if (!tmp) { 1459 read_unlock(&tasklist_lock); 1460 goto cleanup; 1461 } 1462 memset(tmp, 0, sizeof(*tmp)); 1463 INIT_LIST_HEAD(&tmp->list); 1464 tmp->thread = p; 1465 list_add(&tmp->list, &thread_list); 1466 } 1467 while_each_thread(g,p); 1468 read_unlock(&tasklist_lock); 1469 list_for_each(t, &thread_list) { 1470 struct elf_thread_status *tmp; 1471 int sz; 1472 1473 tmp = list_entry(t, struct elf_thread_status, list); 1474 sz = elf_dump_thread_status(signr, tmp); 1475 thread_status_size += sz; 1476 } 1477 } 1478 /* now collect the dump for the current */ 1479 memset(prstatus, 0, sizeof(*prstatus)); 1480 fill_prstatus(prstatus, current, signr); 1481 elf_core_copy_regs(&prstatus->pr_reg, regs); 1482 1483 segs = current->mm->map_count; 1484 #ifdef ELF_CORE_EXTRA_PHDRS 1485 segs += ELF_CORE_EXTRA_PHDRS; 1486 #endif 1487 1488 /* Set up header */ 1489 fill_elf_header(elf, segs+1); /* including notes section */ 1490 1491 has_dumped = 1; 1492 current->flags |= PF_DUMPCORE; 1493 1494 /* 1495 * Set up the notes in similar form to SVR4 core dumps made 1496 * with info from their /proc. 1497 */ 1498 1499 fill_note(notes +0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1500 1501 fill_psinfo(psinfo, current->group_leader, current->mm); 1502 fill_note(notes +1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1503 1504 numnote = 2; 1505 1506 auxv = (elf_addr_t *) current->mm->saved_auxv; 1507 1508 i = 0; 1509 do 1510 i += 2; 1511 while (auxv[i - 2] != AT_NULL); 1512 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1513 i * sizeof (elf_addr_t), auxv); 1514 1515 /* Try to dump the FPU. */ 1516 if ((prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, fpu))) 1517 fill_note(notes + numnote++, 1518 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1519 #ifdef ELF_CORE_COPY_XFPREGS 1520 if (elf_core_copy_task_xfpregs(current, xfpu)) 1521 fill_note(notes + numnote++, 1522 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu); 1523 #endif 1524 1525 fs = get_fs(); 1526 set_fs(KERNEL_DS); 1527 1528 DUMP_WRITE(elf, sizeof(*elf)); 1529 offset += sizeof(*elf); /* Elf header */ 1530 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */ 1531 1532 /* Write notes phdr entry */ 1533 { 1534 struct elf_phdr phdr; 1535 int sz = 0; 1536 1537 for (i = 0; i < numnote; i++) 1538 sz += notesize(notes + i); 1539 1540 sz += thread_status_size; 1541 1542 fill_elf_note_phdr(&phdr, sz, offset); 1543 offset += sz; 1544 DUMP_WRITE(&phdr, sizeof(phdr)); 1545 } 1546 1547 /* Page-align dumped data */ 1548 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1549 1550 /* Write program headers for segments dump */ 1551 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) { 1552 struct elf_phdr phdr; 1553 size_t sz; 1554 1555 sz = vma->vm_end - vma->vm_start; 1556 1557 phdr.p_type = PT_LOAD; 1558 phdr.p_offset = offset; 1559 phdr.p_vaddr = vma->vm_start; 1560 phdr.p_paddr = 0; 1561 phdr.p_filesz = maydump(vma) ? sz : 0; 1562 phdr.p_memsz = sz; 1563 offset += phdr.p_filesz; 1564 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1565 if (vma->vm_flags & VM_WRITE) phdr.p_flags |= PF_W; 1566 if (vma->vm_flags & VM_EXEC) phdr.p_flags |= PF_X; 1567 phdr.p_align = ELF_EXEC_PAGESIZE; 1568 1569 DUMP_WRITE(&phdr, sizeof(phdr)); 1570 } 1571 1572 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS 1573 ELF_CORE_WRITE_EXTRA_PHDRS; 1574 #endif 1575 1576 /* write out the notes section */ 1577 for (i = 0; i < numnote; i++) 1578 if (!writenote(notes + i, file)) 1579 goto end_coredump; 1580 1581 /* write out the thread status notes section */ 1582 list_for_each(t, &thread_list) { 1583 struct elf_thread_status *tmp = list_entry(t, struct elf_thread_status, list); 1584 for (i = 0; i < tmp->num_notes; i++) 1585 if (!writenote(&tmp->notes[i], file)) 1586 goto end_coredump; 1587 } 1588 1589 DUMP_SEEK(dataoff); 1590 1591 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) { 1592 unsigned long addr; 1593 1594 if (!maydump(vma)) 1595 continue; 1596 1597 for (addr = vma->vm_start; 1598 addr < vma->vm_end; 1599 addr += PAGE_SIZE) { 1600 struct page* page; 1601 struct vm_area_struct *vma; 1602 1603 if (get_user_pages(current, current->mm, addr, 1, 0, 1, 1604 &page, &vma) <= 0) { 1605 DUMP_SEEK (file->f_pos + PAGE_SIZE); 1606 } else { 1607 if (page == ZERO_PAGE(addr)) { 1608 DUMP_SEEK (file->f_pos + PAGE_SIZE); 1609 } else { 1610 void *kaddr; 1611 flush_cache_page(vma, addr, page_to_pfn(page)); 1612 kaddr = kmap(page); 1613 if ((size += PAGE_SIZE) > limit || 1614 !dump_write(file, kaddr, 1615 PAGE_SIZE)) { 1616 kunmap(page); 1617 page_cache_release(page); 1618 goto end_coredump; 1619 } 1620 kunmap(page); 1621 } 1622 page_cache_release(page); 1623 } 1624 } 1625 } 1626 1627 #ifdef ELF_CORE_WRITE_EXTRA_DATA 1628 ELF_CORE_WRITE_EXTRA_DATA; 1629 #endif 1630 1631 if ((off_t) file->f_pos != offset) { 1632 /* Sanity check */ 1633 printk("elf_core_dump: file->f_pos (%ld) != offset (%ld)\n", 1634 (off_t) file->f_pos, offset); 1635 } 1636 1637 end_coredump: 1638 set_fs(fs); 1639 1640 cleanup: 1641 while(!list_empty(&thread_list)) { 1642 struct list_head *tmp = thread_list.next; 1643 list_del(tmp); 1644 kfree(list_entry(tmp, struct elf_thread_status, list)); 1645 } 1646 1647 kfree(elf); 1648 kfree(prstatus); 1649 kfree(psinfo); 1650 kfree(notes); 1651 kfree(fpu); 1652 #ifdef ELF_CORE_COPY_XFPREGS 1653 kfree(xfpu); 1654 #endif 1655 return has_dumped; 1656 #undef NUM_NOTES 1657 } 1658 1659 #endif /* USE_ELF_CORE_DUMP */ 1660 1661 static int __init init_elf_binfmt(void) 1662 { 1663 return register_binfmt(&elf_format); 1664 } 1665 1666 static void __exit exit_elf_binfmt(void) 1667 { 1668 /* Remove the COFF and ELF loaders. */ 1669 unregister_binfmt(&elf_format); 1670 } 1671 1672 core_initcall(init_elf_binfmt); 1673 module_exit(exit_elf_binfmt); 1674 MODULE_LICENSE("GPL"); 1675