1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format 2 * 3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * Derived from binfmt_elf.c 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13 #include <linux/module.h> 14 15 #include <linux/fs.h> 16 #include <linux/stat.h> 17 #include <linux/sched.h> 18 #include <linux/mm.h> 19 #include <linux/mman.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/slab.h> 27 #include <linux/pagemap.h> 28 #include <linux/highmem.h> 29 #include <linux/highuid.h> 30 #include <linux/personality.h> 31 #include <linux/ptrace.h> 32 #include <linux/init.h> 33 #include <linux/smp_lock.h> 34 #include <linux/elf.h> 35 #include <linux/elf-fdpic.h> 36 #include <linux/elfcore.h> 37 38 #include <asm/uaccess.h> 39 #include <asm/param.h> 40 #include <asm/pgalloc.h> 41 42 typedef char *elf_caddr_t; 43 44 #if 0 45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 46 #else 47 #define kdebug(fmt, ...) do {} while(0) 48 #endif 49 50 #if 0 51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 52 #else 53 #define kdcore(fmt, ...) do {} while(0) 54 #endif 55 56 MODULE_LICENSE("GPL"); 57 58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *); 59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 61 struct mm_struct *, const char *); 62 63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 64 struct elf_fdpic_params *, 65 struct elf_fdpic_params *); 66 67 #ifndef CONFIG_MMU 68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, 69 unsigned long *); 70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 71 struct file *, 72 struct mm_struct *); 73 #endif 74 75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 76 struct file *, struct mm_struct *); 77 78 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 79 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *); 80 #endif 81 82 static struct linux_binfmt elf_fdpic_format = { 83 .module = THIS_MODULE, 84 .load_binary = load_elf_fdpic_binary, 85 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 86 .core_dump = elf_fdpic_core_dump, 87 #endif 88 .min_coredump = ELF_EXEC_PAGESIZE, 89 }; 90 91 static int __init init_elf_fdpic_binfmt(void) 92 { 93 return register_binfmt(&elf_fdpic_format); 94 } 95 96 static void __exit exit_elf_fdpic_binfmt(void) 97 { 98 unregister_binfmt(&elf_fdpic_format); 99 } 100 101 core_initcall(init_elf_fdpic_binfmt); 102 module_exit(exit_elf_fdpic_binfmt); 103 104 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) 105 { 106 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 107 return 0; 108 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 109 return 0; 110 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) 111 return 0; 112 if (!file->f_op || !file->f_op->mmap) 113 return 0; 114 return 1; 115 } 116 117 /*****************************************************************************/ 118 /* 119 * read the program headers table into memory 120 */ 121 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 122 struct file *file) 123 { 124 struct elf32_phdr *phdr; 125 unsigned long size; 126 int retval, loop; 127 128 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 129 return -ENOMEM; 130 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 131 return -ENOMEM; 132 133 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 134 params->phdrs = kmalloc(size, GFP_KERNEL); 135 if (!params->phdrs) 136 return -ENOMEM; 137 138 retval = kernel_read(file, params->hdr.e_phoff, 139 (char *) params->phdrs, size); 140 if (retval < 0) 141 return retval; 142 143 /* determine stack size for this binary */ 144 phdr = params->phdrs; 145 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 146 if (phdr->p_type != PT_GNU_STACK) 147 continue; 148 149 if (phdr->p_flags & PF_X) 150 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 151 else 152 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 153 154 params->stack_size = phdr->p_memsz; 155 break; 156 } 157 158 return 0; 159 } 160 161 /*****************************************************************************/ 162 /* 163 * load an fdpic binary into various bits of memory 164 */ 165 static int load_elf_fdpic_binary(struct linux_binprm *bprm, 166 struct pt_regs *regs) 167 { 168 struct elf_fdpic_params exec_params, interp_params; 169 struct elf_phdr *phdr; 170 unsigned long stack_size, entryaddr; 171 #ifndef CONFIG_MMU 172 unsigned long fullsize; 173 #endif 174 #ifdef ELF_FDPIC_PLAT_INIT 175 unsigned long dynaddr; 176 #endif 177 struct file *interpreter = NULL; /* to shut gcc up */ 178 char *interpreter_name = NULL; 179 int executable_stack; 180 int retval, i; 181 182 memset(&exec_params, 0, sizeof(exec_params)); 183 memset(&interp_params, 0, sizeof(interp_params)); 184 185 exec_params.hdr = *(struct elfhdr *) bprm->buf; 186 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 187 188 /* check that this is a binary we know how to deal with */ 189 retval = -ENOEXEC; 190 if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) 191 goto error; 192 193 /* read the program header table */ 194 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 195 if (retval < 0) 196 goto error; 197 198 /* scan for a program header that specifies an interpreter */ 199 phdr = exec_params.phdrs; 200 201 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 202 switch (phdr->p_type) { 203 case PT_INTERP: 204 retval = -ENOMEM; 205 if (phdr->p_filesz > PATH_MAX) 206 goto error; 207 retval = -ENOENT; 208 if (phdr->p_filesz < 2) 209 goto error; 210 211 /* read the name of the interpreter into memory */ 212 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 213 if (!interpreter_name) 214 goto error; 215 216 retval = kernel_read(bprm->file, 217 phdr->p_offset, 218 interpreter_name, 219 phdr->p_filesz); 220 if (retval < 0) 221 goto error; 222 223 retval = -ENOENT; 224 if (interpreter_name[phdr->p_filesz - 1] != '\0') 225 goto error; 226 227 kdebug("Using ELF interpreter %s", interpreter_name); 228 229 /* replace the program with the interpreter */ 230 interpreter = open_exec(interpreter_name); 231 retval = PTR_ERR(interpreter); 232 if (IS_ERR(interpreter)) { 233 interpreter = NULL; 234 goto error; 235 } 236 237 retval = kernel_read(interpreter, 0, bprm->buf, 238 BINPRM_BUF_SIZE); 239 if (retval < 0) 240 goto error; 241 242 interp_params.hdr = *((struct elfhdr *) bprm->buf); 243 break; 244 245 case PT_LOAD: 246 #ifdef CONFIG_MMU 247 if (exec_params.load_addr == 0) 248 exec_params.load_addr = phdr->p_vaddr; 249 #endif 250 break; 251 } 252 253 } 254 255 if (elf_check_const_displacement(&exec_params.hdr)) 256 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 257 258 /* perform insanity checks on the interpreter */ 259 if (interpreter_name) { 260 retval = -ELIBBAD; 261 if (!is_elf_fdpic(&interp_params.hdr, interpreter)) 262 goto error; 263 264 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 265 266 /* read the interpreter's program header table */ 267 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 268 if (retval < 0) 269 goto error; 270 } 271 272 stack_size = exec_params.stack_size; 273 if (stack_size < interp_params.stack_size) 274 stack_size = interp_params.stack_size; 275 276 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 277 executable_stack = EXSTACK_ENABLE_X; 278 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 279 executable_stack = EXSTACK_DISABLE_X; 280 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 281 executable_stack = EXSTACK_ENABLE_X; 282 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 283 executable_stack = EXSTACK_DISABLE_X; 284 else 285 executable_stack = EXSTACK_DEFAULT; 286 287 retval = -ENOEXEC; 288 if (stack_size == 0) 289 goto error; 290 291 if (elf_check_const_displacement(&interp_params.hdr)) 292 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 293 294 /* flush all traces of the currently running executable */ 295 retval = flush_old_exec(bprm); 296 if (retval) 297 goto error; 298 299 /* there's now no turning back... the old userspace image is dead, 300 * defunct, deceased, etc. after this point we have to exit via 301 * error_kill */ 302 set_personality(PER_LINUX_FDPIC); 303 set_binfmt(&elf_fdpic_format); 304 305 current->mm->start_code = 0; 306 current->mm->end_code = 0; 307 current->mm->start_stack = 0; 308 current->mm->start_data = 0; 309 current->mm->end_data = 0; 310 current->mm->context.exec_fdpic_loadmap = 0; 311 current->mm->context.interp_fdpic_loadmap = 0; 312 313 current->flags &= ~PF_FORKNOEXEC; 314 315 #ifdef CONFIG_MMU 316 elf_fdpic_arch_lay_out_mm(&exec_params, 317 &interp_params, 318 ¤t->mm->start_stack, 319 ¤t->mm->start_brk); 320 321 retval = setup_arg_pages(bprm, current->mm->start_stack, 322 executable_stack); 323 if (retval < 0) { 324 send_sig(SIGKILL, current, 0); 325 goto error_kill; 326 } 327 #endif 328 329 /* load the executable and interpreter into memory */ 330 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 331 "executable"); 332 if (retval < 0) 333 goto error_kill; 334 335 if (interpreter_name) { 336 retval = elf_fdpic_map_file(&interp_params, interpreter, 337 current->mm, "interpreter"); 338 if (retval < 0) { 339 printk(KERN_ERR "Unable to load interpreter\n"); 340 goto error_kill; 341 } 342 343 allow_write_access(interpreter); 344 fput(interpreter); 345 interpreter = NULL; 346 } 347 348 #ifdef CONFIG_MMU 349 if (!current->mm->start_brk) 350 current->mm->start_brk = current->mm->end_data; 351 352 current->mm->brk = current->mm->start_brk = 353 PAGE_ALIGN(current->mm->start_brk); 354 355 #else 356 /* create a stack and brk area big enough for everyone 357 * - the brk heap starts at the bottom and works up 358 * - the stack starts at the top and works down 359 */ 360 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 361 if (stack_size < PAGE_SIZE * 2) 362 stack_size = PAGE_SIZE * 2; 363 364 down_write(¤t->mm->mmap_sem); 365 current->mm->start_brk = do_mmap(NULL, 0, stack_size, 366 PROT_READ | PROT_WRITE | PROT_EXEC, 367 MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN, 368 0); 369 370 if (IS_ERR_VALUE(current->mm->start_brk)) { 371 up_write(¤t->mm->mmap_sem); 372 retval = current->mm->start_brk; 373 current->mm->start_brk = 0; 374 goto error_kill; 375 } 376 377 /* expand the stack mapping to use up the entire allocation granule */ 378 fullsize = ksize((char *) current->mm->start_brk); 379 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size, 380 fullsize, 0, 0))) 381 stack_size = fullsize; 382 up_write(¤t->mm->mmap_sem); 383 384 current->mm->brk = current->mm->start_brk; 385 current->mm->context.end_brk = current->mm->start_brk; 386 current->mm->context.end_brk += 387 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; 388 current->mm->start_stack = current->mm->start_brk + stack_size; 389 #endif 390 391 compute_creds(bprm); 392 current->flags &= ~PF_FORKNOEXEC; 393 if (create_elf_fdpic_tables(bprm, current->mm, 394 &exec_params, &interp_params) < 0) 395 goto error_kill; 396 397 kdebug("- start_code %lx", current->mm->start_code); 398 kdebug("- end_code %lx", current->mm->end_code); 399 kdebug("- start_data %lx", current->mm->start_data); 400 kdebug("- end_data %lx", current->mm->end_data); 401 kdebug("- start_brk %lx", current->mm->start_brk); 402 kdebug("- brk %lx", current->mm->brk); 403 kdebug("- start_stack %lx", current->mm->start_stack); 404 405 #ifdef ELF_FDPIC_PLAT_INIT 406 /* 407 * The ABI may specify that certain registers be set up in special 408 * ways (on i386 %edx is the address of a DT_FINI function, for 409 * example. This macro performs whatever initialization to 410 * the regs structure is required. 411 */ 412 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 413 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 414 dynaddr); 415 #endif 416 417 /* everything is now ready... get the userspace context ready to roll */ 418 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 419 start_thread(regs, entryaddr, current->mm->start_stack); 420 421 if (unlikely(current->ptrace & PT_PTRACED)) { 422 if (current->ptrace & PT_TRACE_EXEC) 423 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP); 424 else 425 send_sig(SIGTRAP, current, 0); 426 } 427 428 retval = 0; 429 430 error: 431 if (interpreter) { 432 allow_write_access(interpreter); 433 fput(interpreter); 434 } 435 kfree(interpreter_name); 436 kfree(exec_params.phdrs); 437 kfree(exec_params.loadmap); 438 kfree(interp_params.phdrs); 439 kfree(interp_params.loadmap); 440 return retval; 441 442 /* unrecoverable error - kill the process */ 443 error_kill: 444 send_sig(SIGSEGV, current, 0); 445 goto error; 446 447 } 448 449 /*****************************************************************************/ 450 /* 451 * present useful information to the program 452 */ 453 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 454 struct mm_struct *mm, 455 struct elf_fdpic_params *exec_params, 456 struct elf_fdpic_params *interp_params) 457 { 458 unsigned long sp, csp, nitems; 459 elf_caddr_t __user *argv, *envp; 460 size_t platform_len = 0, len; 461 char *k_platform; 462 char __user *u_platform, *p; 463 long hwcap; 464 int loop; 465 466 /* we're going to shovel a whole load of stuff onto the stack */ 467 #ifdef CONFIG_MMU 468 sp = bprm->p; 469 #else 470 sp = mm->start_stack; 471 472 /* stack the program arguments and environment */ 473 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 474 return -EFAULT; 475 #endif 476 477 /* get hold of platform and hardware capabilities masks for the machine 478 * we are running on. In some cases (Sparc), this info is impossible 479 * to get, in others (i386) it is merely difficult. 480 */ 481 hwcap = ELF_HWCAP; 482 k_platform = ELF_PLATFORM; 483 u_platform = NULL; 484 485 if (k_platform) { 486 platform_len = strlen(k_platform) + 1; 487 sp -= platform_len; 488 u_platform = (char __user *) sp; 489 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 490 return -EFAULT; 491 } 492 493 #if defined(__i386__) && defined(CONFIG_SMP) 494 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 495 * by the processes running on the same package. One thing we can do is 496 * to shuffle the initial stack for them. 497 * 498 * the conditionals here are unneeded, but kept in to make the code 499 * behaviour the same as pre change unless we have hyperthreaded 500 * processors. This keeps Mr Marcelo Person happier but should be 501 * removed for 2.5 502 */ 503 if (smp_num_siblings > 1) 504 sp = sp - ((current->pid % 64) << 7); 505 #endif 506 507 sp &= ~7UL; 508 509 /* stack the load map(s) */ 510 len = sizeof(struct elf32_fdpic_loadmap); 511 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 512 sp = (sp - len) & ~7UL; 513 exec_params->map_addr = sp; 514 515 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 516 return -EFAULT; 517 518 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 519 520 if (interp_params->loadmap) { 521 len = sizeof(struct elf32_fdpic_loadmap); 522 len += sizeof(struct elf32_fdpic_loadseg) * 523 interp_params->loadmap->nsegs; 524 sp = (sp - len) & ~7UL; 525 interp_params->map_addr = sp; 526 527 if (copy_to_user((void __user *) sp, interp_params->loadmap, 528 len) != 0) 529 return -EFAULT; 530 531 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 532 } 533 534 /* force 16 byte _final_ alignment here for generality */ 535 #define DLINFO_ITEMS 13 536 537 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0); 538 #ifdef DLINFO_ARCH_ITEMS 539 nitems += DLINFO_ARCH_ITEMS; 540 #endif 541 542 csp = sp; 543 sp -= nitems * 2 * sizeof(unsigned long); 544 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 545 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 546 sp -= 1 * sizeof(unsigned long); /* argc */ 547 548 csp -= sp & 15UL; 549 sp -= sp & 15UL; 550 551 /* put the ELF interpreter info on the stack */ 552 #define NEW_AUX_ENT(nr, id, val) \ 553 do { \ 554 struct { unsigned long _id, _val; } __user *ent; \ 555 \ 556 ent = (void __user *) csp; \ 557 __put_user((id), &ent[nr]._id); \ 558 __put_user((val), &ent[nr]._val); \ 559 } while (0) 560 561 csp -= 2 * sizeof(unsigned long); 562 NEW_AUX_ENT(0, AT_NULL, 0); 563 if (k_platform) { 564 csp -= 2 * sizeof(unsigned long); 565 NEW_AUX_ENT(0, AT_PLATFORM, 566 (elf_addr_t) (unsigned long) u_platform); 567 } 568 569 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 570 NEW_AUX_ENT( 0, AT_HWCAP, hwcap); 571 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE); 572 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC); 573 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr); 574 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr)); 575 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum); 576 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr); 577 NEW_AUX_ENT( 7, AT_FLAGS, 0); 578 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr); 579 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid); 580 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid); 581 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid); 582 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid); 583 584 #ifdef ARCH_DLINFO 585 /* ARCH_DLINFO must come last so platform specific code can enforce 586 * special alignment requirements on the AUXV if necessary (eg. PPC). 587 */ 588 ARCH_DLINFO; 589 #endif 590 #undef NEW_AUX_ENT 591 592 /* allocate room for argv[] and envv[] */ 593 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 594 envp = (elf_caddr_t __user *) csp; 595 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 596 argv = (elf_caddr_t __user *) csp; 597 598 /* stack argc */ 599 csp -= sizeof(unsigned long); 600 __put_user(bprm->argc, (unsigned long __user *) csp); 601 602 BUG_ON(csp != sp); 603 604 /* fill in the argv[] array */ 605 #ifdef CONFIG_MMU 606 current->mm->arg_start = bprm->p; 607 #else 608 current->mm->arg_start = current->mm->start_stack - 609 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 610 #endif 611 612 p = (char __user *) current->mm->arg_start; 613 for (loop = bprm->argc; loop > 0; loop--) { 614 __put_user((elf_caddr_t) p, argv++); 615 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES); 616 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES) 617 return -EINVAL; 618 p += len; 619 } 620 __put_user(NULL, argv); 621 current->mm->arg_end = (unsigned long) p; 622 623 /* fill in the envv[] array */ 624 current->mm->env_start = (unsigned long) p; 625 for (loop = bprm->envc; loop > 0; loop--) { 626 __put_user((elf_caddr_t)(unsigned long) p, envp++); 627 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES); 628 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES) 629 return -EINVAL; 630 p += len; 631 } 632 __put_user(NULL, envp); 633 current->mm->env_end = (unsigned long) p; 634 635 mm->start_stack = (unsigned long) sp; 636 return 0; 637 } 638 639 /*****************************************************************************/ 640 /* 641 * transfer the program arguments and environment from the holding pages onto 642 * the stack 643 */ 644 #ifndef CONFIG_MMU 645 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 646 unsigned long *_sp) 647 { 648 unsigned long index, stop, sp; 649 char *src; 650 int ret = 0; 651 652 stop = bprm->p >> PAGE_SHIFT; 653 sp = *_sp; 654 655 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 656 src = kmap(bprm->page[index]); 657 sp -= PAGE_SIZE; 658 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 659 ret = -EFAULT; 660 kunmap(bprm->page[index]); 661 if (ret < 0) 662 goto out; 663 } 664 665 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 666 667 out: 668 return ret; 669 } 670 #endif 671 672 /*****************************************************************************/ 673 /* 674 * load the appropriate binary image (executable or interpreter) into memory 675 * - we assume no MMU is available 676 * - if no other PIC bits are set in params->hdr->e_flags 677 * - we assume that the LOADable segments in the binary are independently relocatable 678 * - we assume R/O executable segments are shareable 679 * - else 680 * - we assume the loadable parts of the image to require fixed displacement 681 * - the image is not shareable 682 */ 683 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 684 struct file *file, 685 struct mm_struct *mm, 686 const char *what) 687 { 688 struct elf32_fdpic_loadmap *loadmap; 689 #ifdef CONFIG_MMU 690 struct elf32_fdpic_loadseg *mseg; 691 #endif 692 struct elf32_fdpic_loadseg *seg; 693 struct elf32_phdr *phdr; 694 unsigned long load_addr, stop; 695 unsigned nloads, tmp; 696 size_t size; 697 int loop, ret; 698 699 /* allocate a load map table */ 700 nloads = 0; 701 for (loop = 0; loop < params->hdr.e_phnum; loop++) 702 if (params->phdrs[loop].p_type == PT_LOAD) 703 nloads++; 704 705 if (nloads == 0) 706 return -ELIBBAD; 707 708 size = sizeof(*loadmap) + nloads * sizeof(*seg); 709 loadmap = kmalloc(size, GFP_KERNEL); 710 if (!loadmap) 711 return -ENOMEM; 712 713 params->loadmap = loadmap; 714 memset(loadmap, 0, size); 715 716 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 717 loadmap->nsegs = nloads; 718 719 load_addr = params->load_addr; 720 seg = loadmap->segs; 721 722 /* map the requested LOADs into the memory space */ 723 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 724 case ELF_FDPIC_FLAG_CONSTDISP: 725 case ELF_FDPIC_FLAG_CONTIGUOUS: 726 #ifndef CONFIG_MMU 727 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 728 if (ret < 0) 729 return ret; 730 break; 731 #endif 732 default: 733 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 734 if (ret < 0) 735 return ret; 736 break; 737 } 738 739 /* map the entry point */ 740 if (params->hdr.e_entry) { 741 seg = loadmap->segs; 742 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 743 if (params->hdr.e_entry >= seg->p_vaddr && 744 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 745 params->entry_addr = 746 (params->hdr.e_entry - seg->p_vaddr) + 747 seg->addr; 748 break; 749 } 750 } 751 } 752 753 /* determine where the program header table has wound up if mapped */ 754 stop = params->hdr.e_phoff; 755 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 756 phdr = params->phdrs; 757 758 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 759 if (phdr->p_type != PT_LOAD) 760 continue; 761 762 if (phdr->p_offset > params->hdr.e_phoff || 763 phdr->p_offset + phdr->p_filesz < stop) 764 continue; 765 766 seg = loadmap->segs; 767 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 768 if (phdr->p_vaddr >= seg->p_vaddr && 769 phdr->p_vaddr + phdr->p_filesz <= 770 seg->p_vaddr + seg->p_memsz) { 771 params->ph_addr = 772 (phdr->p_vaddr - seg->p_vaddr) + 773 seg->addr + 774 params->hdr.e_phoff - phdr->p_offset; 775 break; 776 } 777 } 778 break; 779 } 780 781 /* determine where the dynamic section has wound up if there is one */ 782 phdr = params->phdrs; 783 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 784 if (phdr->p_type != PT_DYNAMIC) 785 continue; 786 787 seg = loadmap->segs; 788 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 789 if (phdr->p_vaddr >= seg->p_vaddr && 790 phdr->p_vaddr + phdr->p_memsz <= 791 seg->p_vaddr + seg->p_memsz) { 792 params->dynamic_addr = 793 (phdr->p_vaddr - seg->p_vaddr) + 794 seg->addr; 795 796 /* check the dynamic section contains at least 797 * one item, and that the last item is a NULL 798 * entry */ 799 if (phdr->p_memsz == 0 || 800 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 801 goto dynamic_error; 802 803 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 804 if (((Elf32_Dyn *) 805 params->dynamic_addr)[tmp - 1].d_tag != 0) 806 goto dynamic_error; 807 break; 808 } 809 } 810 break; 811 } 812 813 /* now elide adjacent segments in the load map on MMU linux 814 * - on uClinux the holes between may actually be filled with system 815 * stuff or stuff from other processes 816 */ 817 #ifdef CONFIG_MMU 818 nloads = loadmap->nsegs; 819 mseg = loadmap->segs; 820 seg = mseg + 1; 821 for (loop = 1; loop < nloads; loop++) { 822 /* see if we have a candidate for merging */ 823 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 824 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 825 if (load_addr == (seg->addr & PAGE_MASK)) { 826 mseg->p_memsz += 827 load_addr - 828 (mseg->addr + mseg->p_memsz); 829 mseg->p_memsz += seg->addr & ~PAGE_MASK; 830 mseg->p_memsz += seg->p_memsz; 831 loadmap->nsegs--; 832 continue; 833 } 834 } 835 836 mseg++; 837 if (mseg != seg) 838 *mseg = *seg; 839 } 840 #endif 841 842 kdebug("Mapped Object [%s]:", what); 843 kdebug("- elfhdr : %lx", params->elfhdr_addr); 844 kdebug("- entry : %lx", params->entry_addr); 845 kdebug("- PHDR[] : %lx", params->ph_addr); 846 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 847 seg = loadmap->segs; 848 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 849 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 850 loop, 851 seg->addr, seg->addr + seg->p_memsz - 1, 852 seg->p_vaddr, seg->p_memsz); 853 854 return 0; 855 856 dynamic_error: 857 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 858 what, file->f_path.dentry->d_inode->i_ino); 859 return -ELIBBAD; 860 } 861 862 /*****************************************************************************/ 863 /* 864 * map a file with constant displacement under uClinux 865 */ 866 #ifndef CONFIG_MMU 867 static int elf_fdpic_map_file_constdisp_on_uclinux( 868 struct elf_fdpic_params *params, 869 struct file *file, 870 struct mm_struct *mm) 871 { 872 struct elf32_fdpic_loadseg *seg; 873 struct elf32_phdr *phdr; 874 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 875 loff_t fpos; 876 int loop, ret; 877 878 load_addr = params->load_addr; 879 seg = params->loadmap->segs; 880 881 /* determine the bounds of the contiguous overall allocation we must 882 * make */ 883 phdr = params->phdrs; 884 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 885 if (params->phdrs[loop].p_type != PT_LOAD) 886 continue; 887 888 if (base > phdr->p_vaddr) 889 base = phdr->p_vaddr; 890 if (top < phdr->p_vaddr + phdr->p_memsz) 891 top = phdr->p_vaddr + phdr->p_memsz; 892 } 893 894 /* allocate one big anon block for everything */ 895 mflags = MAP_PRIVATE; 896 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 897 mflags |= MAP_EXECUTABLE; 898 899 down_write(&mm->mmap_sem); 900 maddr = do_mmap(NULL, load_addr, top - base, 901 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 902 up_write(&mm->mmap_sem); 903 if (IS_ERR_VALUE(maddr)) 904 return (int) maddr; 905 906 if (load_addr != 0) 907 load_addr += PAGE_ALIGN(top - base); 908 909 /* and then load the file segments into it */ 910 phdr = params->phdrs; 911 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 912 if (params->phdrs[loop].p_type != PT_LOAD) 913 continue; 914 915 fpos = phdr->p_offset; 916 917 seg->addr = maddr + (phdr->p_vaddr - base); 918 seg->p_vaddr = phdr->p_vaddr; 919 seg->p_memsz = phdr->p_memsz; 920 921 ret = file->f_op->read(file, (void *) seg->addr, 922 phdr->p_filesz, &fpos); 923 if (ret < 0) 924 return ret; 925 926 /* map the ELF header address if in this segment */ 927 if (phdr->p_offset == 0) 928 params->elfhdr_addr = seg->addr; 929 930 /* clear any space allocated but not loaded */ 931 if (phdr->p_filesz < phdr->p_memsz) 932 clear_user((void *) (seg->addr + phdr->p_filesz), 933 phdr->p_memsz - phdr->p_filesz); 934 935 if (mm) { 936 if (phdr->p_flags & PF_X) { 937 mm->start_code = seg->addr; 938 mm->end_code = seg->addr + phdr->p_memsz; 939 } else if (!mm->start_data) { 940 mm->start_data = seg->addr; 941 #ifndef CONFIG_MMU 942 mm->end_data = seg->addr + phdr->p_memsz; 943 #endif 944 } 945 946 #ifdef CONFIG_MMU 947 if (seg->addr + phdr->p_memsz > mm->end_data) 948 mm->end_data = seg->addr + phdr->p_memsz; 949 #endif 950 } 951 952 seg++; 953 } 954 955 return 0; 956 } 957 #endif 958 959 /*****************************************************************************/ 960 /* 961 * map a binary by direct mmap() of the individual PT_LOAD segments 962 */ 963 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 964 struct file *file, 965 struct mm_struct *mm) 966 { 967 struct elf32_fdpic_loadseg *seg; 968 struct elf32_phdr *phdr; 969 unsigned long load_addr, delta_vaddr; 970 int loop, dvset; 971 972 load_addr = params->load_addr; 973 delta_vaddr = 0; 974 dvset = 0; 975 976 seg = params->loadmap->segs; 977 978 /* deal with each load segment separately */ 979 phdr = params->phdrs; 980 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 981 unsigned long maddr, disp, excess, excess1; 982 int prot = 0, flags; 983 984 if (phdr->p_type != PT_LOAD) 985 continue; 986 987 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 988 (unsigned long) phdr->p_vaddr, 989 (unsigned long) phdr->p_offset, 990 (unsigned long) phdr->p_filesz, 991 (unsigned long) phdr->p_memsz); 992 993 /* determine the mapping parameters */ 994 if (phdr->p_flags & PF_R) prot |= PROT_READ; 995 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 996 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 997 998 flags = MAP_PRIVATE | MAP_DENYWRITE; 999 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1000 flags |= MAP_EXECUTABLE; 1001 1002 maddr = 0; 1003 1004 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1005 case ELF_FDPIC_FLAG_INDEPENDENT: 1006 /* PT_LOADs are independently locatable */ 1007 break; 1008 1009 case ELF_FDPIC_FLAG_HONOURVADDR: 1010 /* the specified virtual address must be honoured */ 1011 maddr = phdr->p_vaddr; 1012 flags |= MAP_FIXED; 1013 break; 1014 1015 case ELF_FDPIC_FLAG_CONSTDISP: 1016 /* constant displacement 1017 * - can be mapped anywhere, but must be mapped as a 1018 * unit 1019 */ 1020 if (!dvset) { 1021 maddr = load_addr; 1022 delta_vaddr = phdr->p_vaddr; 1023 dvset = 1; 1024 } else { 1025 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1026 flags |= MAP_FIXED; 1027 } 1028 break; 1029 1030 case ELF_FDPIC_FLAG_CONTIGUOUS: 1031 /* contiguity handled later */ 1032 break; 1033 1034 default: 1035 BUG(); 1036 } 1037 1038 maddr &= PAGE_MASK; 1039 1040 /* create the mapping */ 1041 disp = phdr->p_vaddr & ~PAGE_MASK; 1042 down_write(&mm->mmap_sem); 1043 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1044 phdr->p_offset - disp); 1045 up_write(&mm->mmap_sem); 1046 1047 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1048 loop, phdr->p_memsz + disp, prot, flags, 1049 phdr->p_offset - disp, maddr); 1050 1051 if (IS_ERR_VALUE(maddr)) 1052 return (int) maddr; 1053 1054 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1055 ELF_FDPIC_FLAG_CONTIGUOUS) 1056 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1057 1058 seg->addr = maddr + disp; 1059 seg->p_vaddr = phdr->p_vaddr; 1060 seg->p_memsz = phdr->p_memsz; 1061 1062 /* map the ELF header address if in this segment */ 1063 if (phdr->p_offset == 0) 1064 params->elfhdr_addr = seg->addr; 1065 1066 /* clear the bit between beginning of mapping and beginning of 1067 * PT_LOAD */ 1068 if (prot & PROT_WRITE && disp > 0) { 1069 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1070 clear_user((void __user *) maddr, disp); 1071 maddr += disp; 1072 } 1073 1074 /* clear any space allocated but not loaded 1075 * - on uClinux we can just clear the lot 1076 * - on MMU linux we'll get a SIGBUS beyond the last page 1077 * extant in the file 1078 */ 1079 excess = phdr->p_memsz - phdr->p_filesz; 1080 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1081 1082 #ifdef CONFIG_MMU 1083 if (excess > excess1) { 1084 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1085 unsigned long xmaddr; 1086 1087 flags |= MAP_FIXED | MAP_ANONYMOUS; 1088 down_write(&mm->mmap_sem); 1089 xmaddr = do_mmap(NULL, xaddr, excess - excess1, 1090 prot, flags, 0); 1091 up_write(&mm->mmap_sem); 1092 1093 kdebug("mmap[%d] <anon>" 1094 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1095 loop, xaddr, excess - excess1, prot, flags, 1096 xmaddr); 1097 1098 if (xmaddr != xaddr) 1099 return -ENOMEM; 1100 } 1101 1102 if (prot & PROT_WRITE && excess1 > 0) { 1103 kdebug("clear[%d] ad=%lx sz=%lx", 1104 loop, maddr + phdr->p_filesz, excess1); 1105 clear_user((void __user *) maddr + phdr->p_filesz, 1106 excess1); 1107 } 1108 1109 #else 1110 if (excess > 0) { 1111 kdebug("clear[%d] ad=%lx sz=%lx", 1112 loop, maddr + phdr->p_filesz, excess); 1113 clear_user((void *) maddr + phdr->p_filesz, excess); 1114 } 1115 #endif 1116 1117 if (mm) { 1118 if (phdr->p_flags & PF_X) { 1119 mm->start_code = maddr; 1120 mm->end_code = maddr + phdr->p_memsz; 1121 } else if (!mm->start_data) { 1122 mm->start_data = maddr; 1123 mm->end_data = maddr + phdr->p_memsz; 1124 } 1125 } 1126 1127 seg++; 1128 } 1129 1130 return 0; 1131 } 1132 1133 /*****************************************************************************/ 1134 /* 1135 * ELF-FDPIC core dumper 1136 * 1137 * Modelled on fs/exec.c:aout_core_dump() 1138 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1139 * 1140 * Modelled on fs/binfmt_elf.c core dumper 1141 */ 1142 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 1143 1144 /* 1145 * These are the only things you should do on a core-file: use only these 1146 * functions to write out all the necessary info. 1147 */ 1148 static int dump_write(struct file *file, const void *addr, int nr) 1149 { 1150 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 1151 } 1152 1153 static int dump_seek(struct file *file, loff_t off) 1154 { 1155 if (file->f_op->llseek) { 1156 if (file->f_op->llseek(file, off, SEEK_SET) != off) 1157 return 0; 1158 } else { 1159 file->f_pos = off; 1160 } 1161 return 1; 1162 } 1163 1164 /* 1165 * Decide whether a segment is worth dumping; default is yes to be 1166 * sure (missing info is worse than too much; etc). 1167 * Personally I'd include everything, and use the coredump limit... 1168 * 1169 * I think we should skip something. But I am not sure how. H.J. 1170 */ 1171 static int maydump(struct vm_area_struct *vma) 1172 { 1173 /* Do not dump I/O mapped devices or special mappings */ 1174 if (vma->vm_flags & (VM_IO | VM_RESERVED)) { 1175 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1176 return 0; 1177 } 1178 1179 /* If we may not read the contents, don't allow us to dump 1180 * them either. "dump_write()" can't handle it anyway. 1181 */ 1182 if (!(vma->vm_flags & VM_READ)) { 1183 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1184 return 0; 1185 } 1186 1187 /* Dump shared memory only if mapped from an anonymous file. */ 1188 if (vma->vm_flags & VM_SHARED) { 1189 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1190 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags); 1191 return 1; 1192 } 1193 1194 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags); 1195 return 0; 1196 } 1197 1198 #ifdef CONFIG_MMU 1199 /* If it hasn't been written to, don't write it out */ 1200 if (!vma->anon_vma) { 1201 kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags); 1202 return 0; 1203 } 1204 #endif 1205 1206 kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags); 1207 return 1; 1208 } 1209 1210 /* An ELF note in memory */ 1211 struct memelfnote 1212 { 1213 const char *name; 1214 int type; 1215 unsigned int datasz; 1216 void *data; 1217 }; 1218 1219 static int notesize(struct memelfnote *en) 1220 { 1221 int sz; 1222 1223 sz = sizeof(struct elf_note); 1224 sz += roundup(strlen(en->name) + 1, 4); 1225 sz += roundup(en->datasz, 4); 1226 1227 return sz; 1228 } 1229 1230 /* #define DEBUG */ 1231 1232 #define DUMP_WRITE(addr, nr) \ 1233 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0) 1234 #define DUMP_SEEK(off) \ 1235 do { if (!dump_seek(file, (off))) return 0; } while(0) 1236 1237 static int writenote(struct memelfnote *men, struct file *file) 1238 { 1239 struct elf_note en; 1240 1241 en.n_namesz = strlen(men->name) + 1; 1242 en.n_descsz = men->datasz; 1243 en.n_type = men->type; 1244 1245 DUMP_WRITE(&en, sizeof(en)); 1246 DUMP_WRITE(men->name, en.n_namesz); 1247 /* XXX - cast from long long to long to avoid need for libgcc.a */ 1248 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1249 DUMP_WRITE(men->data, men->datasz); 1250 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1251 1252 return 1; 1253 } 1254 #undef DUMP_WRITE 1255 #undef DUMP_SEEK 1256 1257 #define DUMP_WRITE(addr, nr) \ 1258 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ 1259 goto end_coredump; 1260 #define DUMP_SEEK(off) \ 1261 if (!dump_seek(file, (off))) \ 1262 goto end_coredump; 1263 1264 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1265 { 1266 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1267 elf->e_ident[EI_CLASS] = ELF_CLASS; 1268 elf->e_ident[EI_DATA] = ELF_DATA; 1269 elf->e_ident[EI_VERSION] = EV_CURRENT; 1270 elf->e_ident[EI_OSABI] = ELF_OSABI; 1271 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1272 1273 elf->e_type = ET_CORE; 1274 elf->e_machine = ELF_ARCH; 1275 elf->e_version = EV_CURRENT; 1276 elf->e_entry = 0; 1277 elf->e_phoff = sizeof(struct elfhdr); 1278 elf->e_shoff = 0; 1279 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1280 elf->e_ehsize = sizeof(struct elfhdr); 1281 elf->e_phentsize = sizeof(struct elf_phdr); 1282 elf->e_phnum = segs; 1283 elf->e_shentsize = 0; 1284 elf->e_shnum = 0; 1285 elf->e_shstrndx = 0; 1286 return; 1287 } 1288 1289 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1290 { 1291 phdr->p_type = PT_NOTE; 1292 phdr->p_offset = offset; 1293 phdr->p_vaddr = 0; 1294 phdr->p_paddr = 0; 1295 phdr->p_filesz = sz; 1296 phdr->p_memsz = 0; 1297 phdr->p_flags = 0; 1298 phdr->p_align = 0; 1299 return; 1300 } 1301 1302 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1303 unsigned int sz, void *data) 1304 { 1305 note->name = name; 1306 note->type = type; 1307 note->datasz = sz; 1308 note->data = data; 1309 return; 1310 } 1311 1312 /* 1313 * fill up all the fields in prstatus from the given task struct, except 1314 * registers which need to be filled up seperately. 1315 */ 1316 static void fill_prstatus(struct elf_prstatus *prstatus, 1317 struct task_struct *p, long signr) 1318 { 1319 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1320 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1321 prstatus->pr_sighold = p->blocked.sig[0]; 1322 prstatus->pr_pid = p->pid; 1323 prstatus->pr_ppid = p->parent->pid; 1324 prstatus->pr_pgrp = process_group(p); 1325 prstatus->pr_sid = process_session(p); 1326 if (thread_group_leader(p)) { 1327 /* 1328 * This is the record for the group leader. Add in the 1329 * cumulative times of previous dead threads. This total 1330 * won't include the time of each live thread whose state 1331 * is included in the core dump. The final total reported 1332 * to our parent process when it calls wait4 will include 1333 * those sums as well as the little bit more time it takes 1334 * this and each other thread to finish dying after the 1335 * core dump synchronization phase. 1336 */ 1337 cputime_to_timeval(cputime_add(p->utime, p->signal->utime), 1338 &prstatus->pr_utime); 1339 cputime_to_timeval(cputime_add(p->stime, p->signal->stime), 1340 &prstatus->pr_stime); 1341 } else { 1342 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1343 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1344 } 1345 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1346 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1347 1348 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1349 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1350 } 1351 1352 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1353 struct mm_struct *mm) 1354 { 1355 unsigned int i, len; 1356 1357 /* first copy the parameters from user space */ 1358 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1359 1360 len = mm->arg_end - mm->arg_start; 1361 if (len >= ELF_PRARGSZ) 1362 len = ELF_PRARGSZ - 1; 1363 if (copy_from_user(&psinfo->pr_psargs, 1364 (const char __user *) mm->arg_start, len)) 1365 return -EFAULT; 1366 for (i = 0; i < len; i++) 1367 if (psinfo->pr_psargs[i] == 0) 1368 psinfo->pr_psargs[i] = ' '; 1369 psinfo->pr_psargs[len] = 0; 1370 1371 psinfo->pr_pid = p->pid; 1372 psinfo->pr_ppid = p->parent->pid; 1373 psinfo->pr_pgrp = process_group(p); 1374 psinfo->pr_sid = process_session(p); 1375 1376 i = p->state ? ffz(~p->state) + 1 : 0; 1377 psinfo->pr_state = i; 1378 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1379 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1380 psinfo->pr_nice = task_nice(p); 1381 psinfo->pr_flag = p->flags; 1382 SET_UID(psinfo->pr_uid, p->uid); 1383 SET_GID(psinfo->pr_gid, p->gid); 1384 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1385 1386 return 0; 1387 } 1388 1389 /* Here is the structure in which status of each thread is captured. */ 1390 struct elf_thread_status 1391 { 1392 struct list_head list; 1393 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1394 elf_fpregset_t fpu; /* NT_PRFPREG */ 1395 struct task_struct *thread; 1396 #ifdef ELF_CORE_COPY_XFPREGS 1397 elf_fpxregset_t xfpu; /* NT_PRXFPREG */ 1398 #endif 1399 struct memelfnote notes[3]; 1400 int num_notes; 1401 }; 1402 1403 /* 1404 * In order to add the specific thread information for the elf file format, 1405 * we need to keep a linked list of every thread's pr_status and then create 1406 * a single section for them in the final core file. 1407 */ 1408 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1409 { 1410 struct task_struct *p = t->thread; 1411 int sz = 0; 1412 1413 t->num_notes = 0; 1414 1415 fill_prstatus(&t->prstatus, p, signr); 1416 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1417 1418 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1419 &t->prstatus); 1420 t->num_notes++; 1421 sz += notesize(&t->notes[0]); 1422 1423 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1424 if (t->prstatus.pr_fpvalid) { 1425 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1426 &t->fpu); 1427 t->num_notes++; 1428 sz += notesize(&t->notes[1]); 1429 } 1430 1431 #ifdef ELF_CORE_COPY_XFPREGS 1432 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1433 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu), 1434 &t->xfpu); 1435 t->num_notes++; 1436 sz += notesize(&t->notes[2]); 1437 } 1438 #endif 1439 return sz; 1440 } 1441 1442 /* 1443 * dump the segments for an MMU process 1444 */ 1445 #ifdef CONFIG_MMU 1446 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm, 1447 size_t *size, unsigned long *limit) 1448 { 1449 struct vm_area_struct *vma; 1450 1451 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1452 unsigned long addr; 1453 1454 if (!maydump(vma)) 1455 continue; 1456 1457 for (addr = vma->vm_start; 1458 addr < vma->vm_end; 1459 addr += PAGE_SIZE 1460 ) { 1461 struct vm_area_struct *vma; 1462 struct page *page; 1463 1464 if (get_user_pages(current, current->mm, addr, 1, 0, 1, 1465 &page, &vma) <= 0) { 1466 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1467 } 1468 else if (page == ZERO_PAGE(addr)) { 1469 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1470 page_cache_release(page); 1471 } 1472 else { 1473 void *kaddr; 1474 1475 flush_cache_page(vma, addr, page_to_pfn(page)); 1476 kaddr = kmap(page); 1477 if ((*size += PAGE_SIZE) > *limit || 1478 !dump_write(file, kaddr, PAGE_SIZE) 1479 ) { 1480 kunmap(page); 1481 page_cache_release(page); 1482 return -EIO; 1483 } 1484 kunmap(page); 1485 page_cache_release(page); 1486 } 1487 } 1488 } 1489 1490 return 0; 1491 1492 end_coredump: 1493 return -EFBIG; 1494 } 1495 #endif 1496 1497 /* 1498 * dump the segments for a NOMMU process 1499 */ 1500 #ifndef CONFIG_MMU 1501 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm, 1502 size_t *size, unsigned long *limit) 1503 { 1504 struct vm_list_struct *vml; 1505 1506 for (vml = current->mm->context.vmlist; vml; vml = vml->next) { 1507 struct vm_area_struct *vma = vml->vma; 1508 1509 if (!maydump(vma)) 1510 continue; 1511 1512 if ((*size += PAGE_SIZE) > *limit) 1513 return -EFBIG; 1514 1515 if (!dump_write(file, (void *) vma->vm_start, 1516 vma->vm_end - vma->vm_start)) 1517 return -EIO; 1518 } 1519 1520 return 0; 1521 } 1522 #endif 1523 1524 /* 1525 * Actual dumper 1526 * 1527 * This is a two-pass process; first we find the offsets of the bits, 1528 * and then they are actually written out. If we run out of core limit 1529 * we just truncate. 1530 */ 1531 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 1532 struct file *file) 1533 { 1534 #define NUM_NOTES 6 1535 int has_dumped = 0; 1536 mm_segment_t fs; 1537 int segs; 1538 size_t size = 0; 1539 int i; 1540 struct vm_area_struct *vma; 1541 struct elfhdr *elf = NULL; 1542 loff_t offset = 0, dataoff; 1543 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur; 1544 int numnote; 1545 struct memelfnote *notes = NULL; 1546 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1547 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1548 struct task_struct *g, *p; 1549 LIST_HEAD(thread_list); 1550 struct list_head *t; 1551 elf_fpregset_t *fpu = NULL; 1552 #ifdef ELF_CORE_COPY_XFPREGS 1553 elf_fpxregset_t *xfpu = NULL; 1554 #endif 1555 int thread_status_size = 0; 1556 #ifndef CONFIG_MMU 1557 struct vm_list_struct *vml; 1558 #endif 1559 elf_addr_t *auxv; 1560 1561 /* 1562 * We no longer stop all VM operations. 1563 * 1564 * This is because those proceses that could possibly change map_count 1565 * or the mmap / vma pages are now blocked in do_exit on current 1566 * finishing this core dump. 1567 * 1568 * Only ptrace can touch these memory addresses, but it doesn't change 1569 * the map_count or the pages allocated. So no possibility of crashing 1570 * exists while dumping the mm->vm_next areas to the core file. 1571 */ 1572 1573 /* alloc memory for large data structures: too large to be on stack */ 1574 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1575 if (!elf) 1576 goto cleanup; 1577 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1578 if (!prstatus) 1579 goto cleanup; 1580 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1581 if (!psinfo) 1582 goto cleanup; 1583 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1584 if (!notes) 1585 goto cleanup; 1586 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1587 if (!fpu) 1588 goto cleanup; 1589 #ifdef ELF_CORE_COPY_XFPREGS 1590 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1591 if (!xfpu) 1592 goto cleanup; 1593 #endif 1594 1595 if (signr) { 1596 struct elf_thread_status *tmp; 1597 rcu_read_lock(); 1598 do_each_thread(g,p) 1599 if (current->mm == p->mm && current != p) { 1600 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC); 1601 if (!tmp) { 1602 rcu_read_unlock(); 1603 goto cleanup; 1604 } 1605 tmp->thread = p; 1606 list_add(&tmp->list, &thread_list); 1607 } 1608 while_each_thread(g,p); 1609 rcu_read_unlock(); 1610 list_for_each(t, &thread_list) { 1611 struct elf_thread_status *tmp; 1612 int sz; 1613 1614 tmp = list_entry(t, struct elf_thread_status, list); 1615 sz = elf_dump_thread_status(signr, tmp); 1616 thread_status_size += sz; 1617 } 1618 } 1619 1620 /* now collect the dump for the current */ 1621 fill_prstatus(prstatus, current, signr); 1622 elf_core_copy_regs(&prstatus->pr_reg, regs); 1623 1624 #ifdef CONFIG_MMU 1625 segs = current->mm->map_count; 1626 #else 1627 segs = 0; 1628 for (vml = current->mm->context.vmlist; vml; vml = vml->next) 1629 segs++; 1630 #endif 1631 #ifdef ELF_CORE_EXTRA_PHDRS 1632 segs += ELF_CORE_EXTRA_PHDRS; 1633 #endif 1634 1635 /* Set up header */ 1636 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */ 1637 1638 has_dumped = 1; 1639 current->flags |= PF_DUMPCORE; 1640 1641 /* 1642 * Set up the notes in similar form to SVR4 core dumps made 1643 * with info from their /proc. 1644 */ 1645 1646 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1647 fill_psinfo(psinfo, current->group_leader, current->mm); 1648 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1649 1650 numnote = 2; 1651 1652 auxv = (elf_addr_t *) current->mm->saved_auxv; 1653 1654 i = 0; 1655 do 1656 i += 2; 1657 while (auxv[i - 2] != AT_NULL); 1658 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1659 i * sizeof(elf_addr_t), auxv); 1660 1661 /* Try to dump the FPU. */ 1662 if ((prstatus->pr_fpvalid = 1663 elf_core_copy_task_fpregs(current, regs, fpu))) 1664 fill_note(notes + numnote++, 1665 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1666 #ifdef ELF_CORE_COPY_XFPREGS 1667 if (elf_core_copy_task_xfpregs(current, xfpu)) 1668 fill_note(notes + numnote++, 1669 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu); 1670 #endif 1671 1672 fs = get_fs(); 1673 set_fs(KERNEL_DS); 1674 1675 DUMP_WRITE(elf, sizeof(*elf)); 1676 offset += sizeof(*elf); /* Elf header */ 1677 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */ 1678 1679 /* Write notes phdr entry */ 1680 { 1681 struct elf_phdr phdr; 1682 int sz = 0; 1683 1684 for (i = 0; i < numnote; i++) 1685 sz += notesize(notes + i); 1686 1687 sz += thread_status_size; 1688 1689 fill_elf_note_phdr(&phdr, sz, offset); 1690 offset += sz; 1691 DUMP_WRITE(&phdr, sizeof(phdr)); 1692 } 1693 1694 /* Page-align dumped data */ 1695 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1696 1697 /* write program headers for segments dump */ 1698 for ( 1699 #ifdef CONFIG_MMU 1700 vma = current->mm->mmap; vma; vma = vma->vm_next 1701 #else 1702 vml = current->mm->context.vmlist; vml; vml = vml->next 1703 #endif 1704 ) { 1705 struct elf_phdr phdr; 1706 size_t sz; 1707 1708 #ifndef CONFIG_MMU 1709 vma = vml->vma; 1710 #endif 1711 1712 sz = vma->vm_end - vma->vm_start; 1713 1714 phdr.p_type = PT_LOAD; 1715 phdr.p_offset = offset; 1716 phdr.p_vaddr = vma->vm_start; 1717 phdr.p_paddr = 0; 1718 phdr.p_filesz = maydump(vma) ? sz : 0; 1719 phdr.p_memsz = sz; 1720 offset += phdr.p_filesz; 1721 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1722 if (vma->vm_flags & VM_WRITE) 1723 phdr.p_flags |= PF_W; 1724 if (vma->vm_flags & VM_EXEC) 1725 phdr.p_flags |= PF_X; 1726 phdr.p_align = ELF_EXEC_PAGESIZE; 1727 1728 DUMP_WRITE(&phdr, sizeof(phdr)); 1729 } 1730 1731 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS 1732 ELF_CORE_WRITE_EXTRA_PHDRS; 1733 #endif 1734 1735 /* write out the notes section */ 1736 for (i = 0; i < numnote; i++) 1737 if (!writenote(notes + i, file)) 1738 goto end_coredump; 1739 1740 /* write out the thread status notes section */ 1741 list_for_each(t, &thread_list) { 1742 struct elf_thread_status *tmp = 1743 list_entry(t, struct elf_thread_status, list); 1744 1745 for (i = 0; i < tmp->num_notes; i++) 1746 if (!writenote(&tmp->notes[i], file)) 1747 goto end_coredump; 1748 } 1749 1750 DUMP_SEEK(dataoff); 1751 1752 if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0) 1753 goto end_coredump; 1754 1755 #ifdef ELF_CORE_WRITE_EXTRA_DATA 1756 ELF_CORE_WRITE_EXTRA_DATA; 1757 #endif 1758 1759 if (file->f_pos != offset) { 1760 /* Sanity check */ 1761 printk(KERN_WARNING 1762 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1763 file->f_pos, offset); 1764 } 1765 1766 end_coredump: 1767 set_fs(fs); 1768 1769 cleanup: 1770 while (!list_empty(&thread_list)) { 1771 struct list_head *tmp = thread_list.next; 1772 list_del(tmp); 1773 kfree(list_entry(tmp, struct elf_thread_status, list)); 1774 } 1775 1776 kfree(elf); 1777 kfree(prstatus); 1778 kfree(psinfo); 1779 kfree(notes); 1780 kfree(fpu); 1781 #ifdef ELF_CORE_COPY_XFPREGS 1782 kfree(xfpu); 1783 #endif 1784 return has_dumped; 1785 #undef NUM_NOTES 1786 } 1787 1788 #endif /* USE_ELF_CORE_DUMP */ 1789