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/elf.h> 34 #include <linux/elf-fdpic.h> 35 #include <linux/elfcore.h> 36 37 #include <asm/uaccess.h> 38 #include <asm/param.h> 39 #include <asm/pgalloc.h> 40 41 typedef char *elf_caddr_t; 42 43 #if 0 44 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 45 #else 46 #define kdebug(fmt, ...) do {} while(0) 47 #endif 48 49 #if 0 50 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 51 #else 52 #define kdcore(fmt, ...) do {} while(0) 53 #endif 54 55 MODULE_LICENSE("GPL"); 56 57 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *); 58 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 59 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 60 struct mm_struct *, const char *); 61 62 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 63 struct elf_fdpic_params *, 64 struct elf_fdpic_params *); 65 66 #ifndef CONFIG_MMU 67 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, 68 unsigned long *); 69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 70 struct file *, 71 struct mm_struct *); 72 #endif 73 74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 75 struct file *, struct mm_struct *); 76 77 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 78 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *); 79 #endif 80 81 static struct linux_binfmt elf_fdpic_format = { 82 .module = THIS_MODULE, 83 .load_binary = load_elf_fdpic_binary, 84 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 85 .core_dump = elf_fdpic_core_dump, 86 #endif 87 .min_coredump = ELF_EXEC_PAGESIZE, 88 }; 89 90 static int __init init_elf_fdpic_binfmt(void) 91 { 92 return register_binfmt(&elf_fdpic_format); 93 } 94 95 static void __exit exit_elf_fdpic_binfmt(void) 96 { 97 unregister_binfmt(&elf_fdpic_format); 98 } 99 100 core_initcall(init_elf_fdpic_binfmt); 101 module_exit(exit_elf_fdpic_binfmt); 102 103 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) 104 { 105 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 106 return 0; 107 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 108 return 0; 109 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) 110 return 0; 111 if (!file->f_op || !file->f_op->mmap) 112 return 0; 113 return 1; 114 } 115 116 /*****************************************************************************/ 117 /* 118 * read the program headers table into memory 119 */ 120 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 121 struct file *file) 122 { 123 struct elf32_phdr *phdr; 124 unsigned long size; 125 int retval, loop; 126 127 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 128 return -ENOMEM; 129 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 130 return -ENOMEM; 131 132 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 133 params->phdrs = kmalloc(size, GFP_KERNEL); 134 if (!params->phdrs) 135 return -ENOMEM; 136 137 retval = kernel_read(file, params->hdr.e_phoff, 138 (char *) params->phdrs, size); 139 if (retval < 0) 140 return retval; 141 142 /* determine stack size for this binary */ 143 phdr = params->phdrs; 144 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 145 if (phdr->p_type != PT_GNU_STACK) 146 continue; 147 148 if (phdr->p_flags & PF_X) 149 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 150 else 151 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 152 153 params->stack_size = phdr->p_memsz; 154 break; 155 } 156 157 return 0; 158 } 159 160 /*****************************************************************************/ 161 /* 162 * load an fdpic binary into various bits of memory 163 */ 164 static int load_elf_fdpic_binary(struct linux_binprm *bprm, 165 struct pt_regs *regs) 166 { 167 struct elf_fdpic_params exec_params, interp_params; 168 struct elf_phdr *phdr; 169 unsigned long stack_size, entryaddr; 170 #ifndef CONFIG_MMU 171 unsigned long fullsize; 172 #endif 173 #ifdef ELF_FDPIC_PLAT_INIT 174 unsigned long dynaddr; 175 #endif 176 struct file *interpreter = NULL; /* to shut gcc up */ 177 char *interpreter_name = NULL; 178 int executable_stack; 179 int retval, i; 180 181 kdebug("____ LOAD %d ____", current->pid); 182 183 memset(&exec_params, 0, sizeof(exec_params)); 184 memset(&interp_params, 0, sizeof(interp_params)); 185 186 exec_params.hdr = *(struct elfhdr *) bprm->buf; 187 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 188 189 /* check that this is a binary we know how to deal with */ 190 retval = -ENOEXEC; 191 if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) 192 goto error; 193 194 /* read the program header table */ 195 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 196 if (retval < 0) 197 goto error; 198 199 /* scan for a program header that specifies an interpreter */ 200 phdr = exec_params.phdrs; 201 202 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 203 switch (phdr->p_type) { 204 case PT_INTERP: 205 retval = -ENOMEM; 206 if (phdr->p_filesz > PATH_MAX) 207 goto error; 208 retval = -ENOENT; 209 if (phdr->p_filesz < 2) 210 goto error; 211 212 /* read the name of the interpreter into memory */ 213 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 214 if (!interpreter_name) 215 goto error; 216 217 retval = kernel_read(bprm->file, 218 phdr->p_offset, 219 interpreter_name, 220 phdr->p_filesz); 221 if (retval < 0) 222 goto error; 223 224 retval = -ENOENT; 225 if (interpreter_name[phdr->p_filesz - 1] != '\0') 226 goto error; 227 228 kdebug("Using ELF interpreter %s", interpreter_name); 229 230 /* replace the program with the interpreter */ 231 interpreter = open_exec(interpreter_name); 232 retval = PTR_ERR(interpreter); 233 if (IS_ERR(interpreter)) { 234 interpreter = NULL; 235 goto error; 236 } 237 238 /* 239 * If the binary is not readable then enforce 240 * mm->dumpable = 0 regardless of the interpreter's 241 * permissions. 242 */ 243 if (file_permission(interpreter, MAY_READ) < 0) 244 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; 245 246 retval = kernel_read(interpreter, 0, bprm->buf, 247 BINPRM_BUF_SIZE); 248 if (retval < 0) 249 goto error; 250 251 interp_params.hdr = *((struct elfhdr *) bprm->buf); 252 break; 253 254 case PT_LOAD: 255 #ifdef CONFIG_MMU 256 if (exec_params.load_addr == 0) 257 exec_params.load_addr = phdr->p_vaddr; 258 #endif 259 break; 260 } 261 262 } 263 264 if (elf_check_const_displacement(&exec_params.hdr)) 265 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 266 267 /* perform insanity checks on the interpreter */ 268 if (interpreter_name) { 269 retval = -ELIBBAD; 270 if (!is_elf_fdpic(&interp_params.hdr, interpreter)) 271 goto error; 272 273 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 274 275 /* read the interpreter's program header table */ 276 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 277 if (retval < 0) 278 goto error; 279 } 280 281 stack_size = exec_params.stack_size; 282 if (stack_size < interp_params.stack_size) 283 stack_size = interp_params.stack_size; 284 285 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 286 executable_stack = EXSTACK_ENABLE_X; 287 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 288 executable_stack = EXSTACK_DISABLE_X; 289 else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 290 executable_stack = EXSTACK_ENABLE_X; 291 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 292 executable_stack = EXSTACK_DISABLE_X; 293 else 294 executable_stack = EXSTACK_DEFAULT; 295 296 retval = -ENOEXEC; 297 if (stack_size == 0) 298 goto error; 299 300 if (elf_check_const_displacement(&interp_params.hdr)) 301 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 302 303 /* flush all traces of the currently running executable */ 304 retval = flush_old_exec(bprm); 305 if (retval) 306 goto error; 307 308 /* there's now no turning back... the old userspace image is dead, 309 * defunct, deceased, etc. after this point we have to exit via 310 * error_kill */ 311 set_personality(PER_LINUX_FDPIC); 312 set_binfmt(&elf_fdpic_format); 313 314 current->mm->start_code = 0; 315 current->mm->end_code = 0; 316 current->mm->start_stack = 0; 317 current->mm->start_data = 0; 318 current->mm->end_data = 0; 319 current->mm->context.exec_fdpic_loadmap = 0; 320 current->mm->context.interp_fdpic_loadmap = 0; 321 322 current->flags &= ~PF_FORKNOEXEC; 323 324 #ifdef CONFIG_MMU 325 elf_fdpic_arch_lay_out_mm(&exec_params, 326 &interp_params, 327 ¤t->mm->start_stack, 328 ¤t->mm->start_brk); 329 330 retval = setup_arg_pages(bprm, current->mm->start_stack, 331 executable_stack); 332 if (retval < 0) { 333 send_sig(SIGKILL, current, 0); 334 goto error_kill; 335 } 336 #endif 337 338 /* load the executable and interpreter into memory */ 339 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 340 "executable"); 341 if (retval < 0) 342 goto error_kill; 343 344 if (interpreter_name) { 345 retval = elf_fdpic_map_file(&interp_params, interpreter, 346 current->mm, "interpreter"); 347 if (retval < 0) { 348 printk(KERN_ERR "Unable to load interpreter\n"); 349 goto error_kill; 350 } 351 352 allow_write_access(interpreter); 353 fput(interpreter); 354 interpreter = NULL; 355 } 356 357 #ifdef CONFIG_MMU 358 if (!current->mm->start_brk) 359 current->mm->start_brk = current->mm->end_data; 360 361 current->mm->brk = current->mm->start_brk = 362 PAGE_ALIGN(current->mm->start_brk); 363 364 #else 365 /* create a stack and brk area big enough for everyone 366 * - the brk heap starts at the bottom and works up 367 * - the stack starts at the top and works down 368 */ 369 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 370 if (stack_size < PAGE_SIZE * 2) 371 stack_size = PAGE_SIZE * 2; 372 373 down_write(¤t->mm->mmap_sem); 374 current->mm->start_brk = do_mmap(NULL, 0, stack_size, 375 PROT_READ | PROT_WRITE | PROT_EXEC, 376 MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN, 377 0); 378 379 if (IS_ERR_VALUE(current->mm->start_brk)) { 380 up_write(¤t->mm->mmap_sem); 381 retval = current->mm->start_brk; 382 current->mm->start_brk = 0; 383 goto error_kill; 384 } 385 386 /* expand the stack mapping to use up the entire allocation granule */ 387 fullsize = ksize((char *) current->mm->start_brk); 388 if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size, 389 fullsize, 0, 0))) 390 stack_size = fullsize; 391 up_write(¤t->mm->mmap_sem); 392 393 current->mm->brk = current->mm->start_brk; 394 current->mm->context.end_brk = current->mm->start_brk; 395 current->mm->context.end_brk += 396 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; 397 current->mm->start_stack = current->mm->start_brk + stack_size; 398 #endif 399 400 compute_creds(bprm); 401 current->flags &= ~PF_FORKNOEXEC; 402 if (create_elf_fdpic_tables(bprm, current->mm, 403 &exec_params, &interp_params) < 0) 404 goto error_kill; 405 406 kdebug("- start_code %lx", current->mm->start_code); 407 kdebug("- end_code %lx", current->mm->end_code); 408 kdebug("- start_data %lx", current->mm->start_data); 409 kdebug("- end_data %lx", current->mm->end_data); 410 kdebug("- start_brk %lx", current->mm->start_brk); 411 kdebug("- brk %lx", current->mm->brk); 412 kdebug("- start_stack %lx", current->mm->start_stack); 413 414 #ifdef ELF_FDPIC_PLAT_INIT 415 /* 416 * The ABI may specify that certain registers be set up in special 417 * ways (on i386 %edx is the address of a DT_FINI function, for 418 * example. This macro performs whatever initialization to 419 * the regs structure is required. 420 */ 421 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 422 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 423 dynaddr); 424 #endif 425 426 /* everything is now ready... get the userspace context ready to roll */ 427 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 428 start_thread(regs, entryaddr, current->mm->start_stack); 429 430 if (unlikely(current->ptrace & PT_PTRACED)) { 431 if (current->ptrace & PT_TRACE_EXEC) 432 ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP); 433 else 434 send_sig(SIGTRAP, current, 0); 435 } 436 437 retval = 0; 438 439 error: 440 if (interpreter) { 441 allow_write_access(interpreter); 442 fput(interpreter); 443 } 444 kfree(interpreter_name); 445 kfree(exec_params.phdrs); 446 kfree(exec_params.loadmap); 447 kfree(interp_params.phdrs); 448 kfree(interp_params.loadmap); 449 return retval; 450 451 /* unrecoverable error - kill the process */ 452 error_kill: 453 send_sig(SIGSEGV, current, 0); 454 goto error; 455 456 } 457 458 /*****************************************************************************/ 459 /* 460 * present useful information to the program 461 */ 462 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 463 struct mm_struct *mm, 464 struct elf_fdpic_params *exec_params, 465 struct elf_fdpic_params *interp_params) 466 { 467 unsigned long sp, csp, nitems; 468 elf_caddr_t __user *argv, *envp; 469 size_t platform_len = 0, len; 470 char *k_platform; 471 char __user *u_platform, *p; 472 long hwcap; 473 int loop; 474 475 /* we're going to shovel a whole load of stuff onto the stack */ 476 #ifdef CONFIG_MMU 477 sp = bprm->p; 478 #else 479 sp = mm->start_stack; 480 481 /* stack the program arguments and environment */ 482 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 483 return -EFAULT; 484 #endif 485 486 /* get hold of platform and hardware capabilities masks for the machine 487 * we are running on. In some cases (Sparc), this info is impossible 488 * to get, in others (i386) it is merely difficult. 489 */ 490 hwcap = ELF_HWCAP; 491 k_platform = ELF_PLATFORM; 492 u_platform = NULL; 493 494 if (k_platform) { 495 platform_len = strlen(k_platform) + 1; 496 sp -= platform_len; 497 u_platform = (char __user *) sp; 498 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 499 return -EFAULT; 500 } 501 502 #if defined(__i386__) && defined(CONFIG_SMP) 503 /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 504 * by the processes running on the same package. One thing we can do is 505 * to shuffle the initial stack for them. 506 * 507 * the conditionals here are unneeded, but kept in to make the code 508 * behaviour the same as pre change unless we have hyperthreaded 509 * processors. This keeps Mr Marcelo Person happier but should be 510 * removed for 2.5 511 */ 512 if (smp_num_siblings > 1) 513 sp = sp - ((current->pid % 64) << 7); 514 #endif 515 516 sp &= ~7UL; 517 518 /* stack the load map(s) */ 519 len = sizeof(struct elf32_fdpic_loadmap); 520 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 521 sp = (sp - len) & ~7UL; 522 exec_params->map_addr = sp; 523 524 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 525 return -EFAULT; 526 527 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 528 529 if (interp_params->loadmap) { 530 len = sizeof(struct elf32_fdpic_loadmap); 531 len += sizeof(struct elf32_fdpic_loadseg) * 532 interp_params->loadmap->nsegs; 533 sp = (sp - len) & ~7UL; 534 interp_params->map_addr = sp; 535 536 if (copy_to_user((void __user *) sp, interp_params->loadmap, 537 len) != 0) 538 return -EFAULT; 539 540 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 541 } 542 543 /* force 16 byte _final_ alignment here for generality */ 544 #define DLINFO_ITEMS 13 545 546 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0); 547 #ifdef DLINFO_ARCH_ITEMS 548 nitems += DLINFO_ARCH_ITEMS; 549 #endif 550 551 csp = sp; 552 sp -= nitems * 2 * sizeof(unsigned long); 553 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 554 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 555 sp -= 1 * sizeof(unsigned long); /* argc */ 556 557 csp -= sp & 15UL; 558 sp -= sp & 15UL; 559 560 /* put the ELF interpreter info on the stack */ 561 #define NEW_AUX_ENT(nr, id, val) \ 562 do { \ 563 struct { unsigned long _id, _val; } __user *ent; \ 564 \ 565 ent = (void __user *) csp; \ 566 __put_user((id), &ent[nr]._id); \ 567 __put_user((val), &ent[nr]._val); \ 568 } while (0) 569 570 csp -= 2 * sizeof(unsigned long); 571 NEW_AUX_ENT(0, AT_NULL, 0); 572 if (k_platform) { 573 csp -= 2 * sizeof(unsigned long); 574 NEW_AUX_ENT(0, AT_PLATFORM, 575 (elf_addr_t) (unsigned long) u_platform); 576 } 577 578 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 579 NEW_AUX_ENT( 0, AT_HWCAP, hwcap); 580 NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE); 581 NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC); 582 NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr); 583 NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr)); 584 NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum); 585 NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr); 586 NEW_AUX_ENT( 7, AT_FLAGS, 0); 587 NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr); 588 NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid); 589 NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid); 590 NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid); 591 NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid); 592 593 #ifdef ARCH_DLINFO 594 /* ARCH_DLINFO must come last so platform specific code can enforce 595 * special alignment requirements on the AUXV if necessary (eg. PPC). 596 */ 597 ARCH_DLINFO; 598 #endif 599 #undef NEW_AUX_ENT 600 601 /* allocate room for argv[] and envv[] */ 602 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 603 envp = (elf_caddr_t __user *) csp; 604 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 605 argv = (elf_caddr_t __user *) csp; 606 607 /* stack argc */ 608 csp -= sizeof(unsigned long); 609 __put_user(bprm->argc, (unsigned long __user *) csp); 610 611 BUG_ON(csp != sp); 612 613 /* fill in the argv[] array */ 614 #ifdef CONFIG_MMU 615 current->mm->arg_start = bprm->p; 616 #else 617 current->mm->arg_start = current->mm->start_stack - 618 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 619 #endif 620 621 p = (char __user *) current->mm->arg_start; 622 for (loop = bprm->argc; loop > 0; loop--) { 623 __put_user((elf_caddr_t) p, argv++); 624 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES); 625 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES) 626 return -EINVAL; 627 p += len; 628 } 629 __put_user(NULL, argv); 630 current->mm->arg_end = (unsigned long) p; 631 632 /* fill in the envv[] array */ 633 current->mm->env_start = (unsigned long) p; 634 for (loop = bprm->envc; loop > 0; loop--) { 635 __put_user((elf_caddr_t)(unsigned long) p, envp++); 636 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES); 637 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES) 638 return -EINVAL; 639 p += len; 640 } 641 __put_user(NULL, envp); 642 current->mm->env_end = (unsigned long) p; 643 644 mm->start_stack = (unsigned long) sp; 645 return 0; 646 } 647 648 /*****************************************************************************/ 649 /* 650 * transfer the program arguments and environment from the holding pages onto 651 * the stack 652 */ 653 #ifndef CONFIG_MMU 654 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 655 unsigned long *_sp) 656 { 657 unsigned long index, stop, sp; 658 char *src; 659 int ret = 0; 660 661 stop = bprm->p >> PAGE_SHIFT; 662 sp = *_sp; 663 664 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 665 src = kmap(bprm->page[index]); 666 sp -= PAGE_SIZE; 667 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 668 ret = -EFAULT; 669 kunmap(bprm->page[index]); 670 if (ret < 0) 671 goto out; 672 } 673 674 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 675 676 out: 677 return ret; 678 } 679 #endif 680 681 /*****************************************************************************/ 682 /* 683 * load the appropriate binary image (executable or interpreter) into memory 684 * - we assume no MMU is available 685 * - if no other PIC bits are set in params->hdr->e_flags 686 * - we assume that the LOADable segments in the binary are independently relocatable 687 * - we assume R/O executable segments are shareable 688 * - else 689 * - we assume the loadable parts of the image to require fixed displacement 690 * - the image is not shareable 691 */ 692 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 693 struct file *file, 694 struct mm_struct *mm, 695 const char *what) 696 { 697 struct elf32_fdpic_loadmap *loadmap; 698 #ifdef CONFIG_MMU 699 struct elf32_fdpic_loadseg *mseg; 700 #endif 701 struct elf32_fdpic_loadseg *seg; 702 struct elf32_phdr *phdr; 703 unsigned long load_addr, stop; 704 unsigned nloads, tmp; 705 size_t size; 706 int loop, ret; 707 708 /* allocate a load map table */ 709 nloads = 0; 710 for (loop = 0; loop < params->hdr.e_phnum; loop++) 711 if (params->phdrs[loop].p_type == PT_LOAD) 712 nloads++; 713 714 if (nloads == 0) 715 return -ELIBBAD; 716 717 size = sizeof(*loadmap) + nloads * sizeof(*seg); 718 loadmap = kzalloc(size, GFP_KERNEL); 719 if (!loadmap) 720 return -ENOMEM; 721 722 params->loadmap = loadmap; 723 724 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 725 loadmap->nsegs = nloads; 726 727 load_addr = params->load_addr; 728 seg = loadmap->segs; 729 730 /* map the requested LOADs into the memory space */ 731 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 732 case ELF_FDPIC_FLAG_CONSTDISP: 733 case ELF_FDPIC_FLAG_CONTIGUOUS: 734 #ifndef CONFIG_MMU 735 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 736 if (ret < 0) 737 return ret; 738 break; 739 #endif 740 default: 741 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 742 if (ret < 0) 743 return ret; 744 break; 745 } 746 747 /* map the entry point */ 748 if (params->hdr.e_entry) { 749 seg = loadmap->segs; 750 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 751 if (params->hdr.e_entry >= seg->p_vaddr && 752 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 753 params->entry_addr = 754 (params->hdr.e_entry - seg->p_vaddr) + 755 seg->addr; 756 break; 757 } 758 } 759 } 760 761 /* determine where the program header table has wound up if mapped */ 762 stop = params->hdr.e_phoff; 763 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 764 phdr = params->phdrs; 765 766 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 767 if (phdr->p_type != PT_LOAD) 768 continue; 769 770 if (phdr->p_offset > params->hdr.e_phoff || 771 phdr->p_offset + phdr->p_filesz < stop) 772 continue; 773 774 seg = loadmap->segs; 775 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 776 if (phdr->p_vaddr >= seg->p_vaddr && 777 phdr->p_vaddr + phdr->p_filesz <= 778 seg->p_vaddr + seg->p_memsz) { 779 params->ph_addr = 780 (phdr->p_vaddr - seg->p_vaddr) + 781 seg->addr + 782 params->hdr.e_phoff - phdr->p_offset; 783 break; 784 } 785 } 786 break; 787 } 788 789 /* determine where the dynamic section has wound up if there is one */ 790 phdr = params->phdrs; 791 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 792 if (phdr->p_type != PT_DYNAMIC) 793 continue; 794 795 seg = loadmap->segs; 796 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 797 if (phdr->p_vaddr >= seg->p_vaddr && 798 phdr->p_vaddr + phdr->p_memsz <= 799 seg->p_vaddr + seg->p_memsz) { 800 params->dynamic_addr = 801 (phdr->p_vaddr - seg->p_vaddr) + 802 seg->addr; 803 804 /* check the dynamic section contains at least 805 * one item, and that the last item is a NULL 806 * entry */ 807 if (phdr->p_memsz == 0 || 808 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 809 goto dynamic_error; 810 811 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 812 if (((Elf32_Dyn *) 813 params->dynamic_addr)[tmp - 1].d_tag != 0) 814 goto dynamic_error; 815 break; 816 } 817 } 818 break; 819 } 820 821 /* now elide adjacent segments in the load map on MMU linux 822 * - on uClinux the holes between may actually be filled with system 823 * stuff or stuff from other processes 824 */ 825 #ifdef CONFIG_MMU 826 nloads = loadmap->nsegs; 827 mseg = loadmap->segs; 828 seg = mseg + 1; 829 for (loop = 1; loop < nloads; loop++) { 830 /* see if we have a candidate for merging */ 831 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 832 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 833 if (load_addr == (seg->addr & PAGE_MASK)) { 834 mseg->p_memsz += 835 load_addr - 836 (mseg->addr + mseg->p_memsz); 837 mseg->p_memsz += seg->addr & ~PAGE_MASK; 838 mseg->p_memsz += seg->p_memsz; 839 loadmap->nsegs--; 840 continue; 841 } 842 } 843 844 mseg++; 845 if (mseg != seg) 846 *mseg = *seg; 847 } 848 #endif 849 850 kdebug("Mapped Object [%s]:", what); 851 kdebug("- elfhdr : %lx", params->elfhdr_addr); 852 kdebug("- entry : %lx", params->entry_addr); 853 kdebug("- PHDR[] : %lx", params->ph_addr); 854 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 855 seg = loadmap->segs; 856 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 857 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 858 loop, 859 seg->addr, seg->addr + seg->p_memsz - 1, 860 seg->p_vaddr, seg->p_memsz); 861 862 return 0; 863 864 dynamic_error: 865 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 866 what, file->f_path.dentry->d_inode->i_ino); 867 return -ELIBBAD; 868 } 869 870 /*****************************************************************************/ 871 /* 872 * map a file with constant displacement under uClinux 873 */ 874 #ifndef CONFIG_MMU 875 static int elf_fdpic_map_file_constdisp_on_uclinux( 876 struct elf_fdpic_params *params, 877 struct file *file, 878 struct mm_struct *mm) 879 { 880 struct elf32_fdpic_loadseg *seg; 881 struct elf32_phdr *phdr; 882 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 883 loff_t fpos; 884 int loop, ret; 885 886 load_addr = params->load_addr; 887 seg = params->loadmap->segs; 888 889 /* determine the bounds of the contiguous overall allocation we must 890 * make */ 891 phdr = params->phdrs; 892 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 893 if (params->phdrs[loop].p_type != PT_LOAD) 894 continue; 895 896 if (base > phdr->p_vaddr) 897 base = phdr->p_vaddr; 898 if (top < phdr->p_vaddr + phdr->p_memsz) 899 top = phdr->p_vaddr + phdr->p_memsz; 900 } 901 902 /* allocate one big anon block for everything */ 903 mflags = MAP_PRIVATE; 904 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 905 mflags |= MAP_EXECUTABLE; 906 907 down_write(&mm->mmap_sem); 908 maddr = do_mmap(NULL, load_addr, top - base, 909 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 910 up_write(&mm->mmap_sem); 911 if (IS_ERR_VALUE(maddr)) 912 return (int) maddr; 913 914 if (load_addr != 0) 915 load_addr += PAGE_ALIGN(top - base); 916 917 /* and then load the file segments into it */ 918 phdr = params->phdrs; 919 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 920 if (params->phdrs[loop].p_type != PT_LOAD) 921 continue; 922 923 fpos = phdr->p_offset; 924 925 seg->addr = maddr + (phdr->p_vaddr - base); 926 seg->p_vaddr = phdr->p_vaddr; 927 seg->p_memsz = phdr->p_memsz; 928 929 ret = file->f_op->read(file, (void *) seg->addr, 930 phdr->p_filesz, &fpos); 931 if (ret < 0) 932 return ret; 933 934 /* map the ELF header address if in this segment */ 935 if (phdr->p_offset == 0) 936 params->elfhdr_addr = seg->addr; 937 938 /* clear any space allocated but not loaded */ 939 if (phdr->p_filesz < phdr->p_memsz) 940 clear_user((void *) (seg->addr + phdr->p_filesz), 941 phdr->p_memsz - phdr->p_filesz); 942 943 if (mm) { 944 if (phdr->p_flags & PF_X) { 945 if (!mm->start_code) { 946 mm->start_code = seg->addr; 947 mm->end_code = seg->addr + 948 phdr->p_memsz; 949 } 950 } else if (!mm->start_data) { 951 mm->start_data = seg->addr; 952 #ifndef CONFIG_MMU 953 mm->end_data = seg->addr + phdr->p_memsz; 954 #endif 955 } 956 957 #ifdef CONFIG_MMU 958 if (seg->addr + phdr->p_memsz > mm->end_data) 959 mm->end_data = seg->addr + phdr->p_memsz; 960 #endif 961 } 962 963 seg++; 964 } 965 966 return 0; 967 } 968 #endif 969 970 /*****************************************************************************/ 971 /* 972 * map a binary by direct mmap() of the individual PT_LOAD segments 973 */ 974 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 975 struct file *file, 976 struct mm_struct *mm) 977 { 978 struct elf32_fdpic_loadseg *seg; 979 struct elf32_phdr *phdr; 980 unsigned long load_addr, delta_vaddr; 981 int loop, dvset; 982 983 load_addr = params->load_addr; 984 delta_vaddr = 0; 985 dvset = 0; 986 987 seg = params->loadmap->segs; 988 989 /* deal with each load segment separately */ 990 phdr = params->phdrs; 991 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 992 unsigned long maddr, disp, excess, excess1; 993 int prot = 0, flags; 994 995 if (phdr->p_type != PT_LOAD) 996 continue; 997 998 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 999 (unsigned long) phdr->p_vaddr, 1000 (unsigned long) phdr->p_offset, 1001 (unsigned long) phdr->p_filesz, 1002 (unsigned long) phdr->p_memsz); 1003 1004 /* determine the mapping parameters */ 1005 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1006 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1007 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1008 1009 flags = MAP_PRIVATE | MAP_DENYWRITE; 1010 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1011 flags |= MAP_EXECUTABLE; 1012 1013 maddr = 0; 1014 1015 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1016 case ELF_FDPIC_FLAG_INDEPENDENT: 1017 /* PT_LOADs are independently locatable */ 1018 break; 1019 1020 case ELF_FDPIC_FLAG_HONOURVADDR: 1021 /* the specified virtual address must be honoured */ 1022 maddr = phdr->p_vaddr; 1023 flags |= MAP_FIXED; 1024 break; 1025 1026 case ELF_FDPIC_FLAG_CONSTDISP: 1027 /* constant displacement 1028 * - can be mapped anywhere, but must be mapped as a 1029 * unit 1030 */ 1031 if (!dvset) { 1032 maddr = load_addr; 1033 delta_vaddr = phdr->p_vaddr; 1034 dvset = 1; 1035 } else { 1036 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1037 flags |= MAP_FIXED; 1038 } 1039 break; 1040 1041 case ELF_FDPIC_FLAG_CONTIGUOUS: 1042 /* contiguity handled later */ 1043 break; 1044 1045 default: 1046 BUG(); 1047 } 1048 1049 maddr &= PAGE_MASK; 1050 1051 /* create the mapping */ 1052 disp = phdr->p_vaddr & ~PAGE_MASK; 1053 down_write(&mm->mmap_sem); 1054 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1055 phdr->p_offset - disp); 1056 up_write(&mm->mmap_sem); 1057 1058 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1059 loop, phdr->p_memsz + disp, prot, flags, 1060 phdr->p_offset - disp, maddr); 1061 1062 if (IS_ERR_VALUE(maddr)) 1063 return (int) maddr; 1064 1065 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1066 ELF_FDPIC_FLAG_CONTIGUOUS) 1067 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1068 1069 seg->addr = maddr + disp; 1070 seg->p_vaddr = phdr->p_vaddr; 1071 seg->p_memsz = phdr->p_memsz; 1072 1073 /* map the ELF header address if in this segment */ 1074 if (phdr->p_offset == 0) 1075 params->elfhdr_addr = seg->addr; 1076 1077 /* clear the bit between beginning of mapping and beginning of 1078 * PT_LOAD */ 1079 if (prot & PROT_WRITE && disp > 0) { 1080 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1081 clear_user((void __user *) maddr, disp); 1082 maddr += disp; 1083 } 1084 1085 /* clear any space allocated but not loaded 1086 * - on uClinux we can just clear the lot 1087 * - on MMU linux we'll get a SIGBUS beyond the last page 1088 * extant in the file 1089 */ 1090 excess = phdr->p_memsz - phdr->p_filesz; 1091 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1092 1093 #ifdef CONFIG_MMU 1094 if (excess > excess1) { 1095 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1096 unsigned long xmaddr; 1097 1098 flags |= MAP_FIXED | MAP_ANONYMOUS; 1099 down_write(&mm->mmap_sem); 1100 xmaddr = do_mmap(NULL, xaddr, excess - excess1, 1101 prot, flags, 0); 1102 up_write(&mm->mmap_sem); 1103 1104 kdebug("mmap[%d] <anon>" 1105 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1106 loop, xaddr, excess - excess1, prot, flags, 1107 xmaddr); 1108 1109 if (xmaddr != xaddr) 1110 return -ENOMEM; 1111 } 1112 1113 if (prot & PROT_WRITE && excess1 > 0) { 1114 kdebug("clear[%d] ad=%lx sz=%lx", 1115 loop, maddr + phdr->p_filesz, excess1); 1116 clear_user((void __user *) maddr + phdr->p_filesz, 1117 excess1); 1118 } 1119 1120 #else 1121 if (excess > 0) { 1122 kdebug("clear[%d] ad=%lx sz=%lx", 1123 loop, maddr + phdr->p_filesz, excess); 1124 clear_user((void *) maddr + phdr->p_filesz, excess); 1125 } 1126 #endif 1127 1128 if (mm) { 1129 if (phdr->p_flags & PF_X) { 1130 if (!mm->start_code) { 1131 mm->start_code = maddr; 1132 mm->end_code = maddr + phdr->p_memsz; 1133 } 1134 } else if (!mm->start_data) { 1135 mm->start_data = maddr; 1136 mm->end_data = maddr + phdr->p_memsz; 1137 } 1138 } 1139 1140 seg++; 1141 } 1142 1143 return 0; 1144 } 1145 1146 /*****************************************************************************/ 1147 /* 1148 * ELF-FDPIC core dumper 1149 * 1150 * Modelled on fs/exec.c:aout_core_dump() 1151 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1152 * 1153 * Modelled on fs/binfmt_elf.c core dumper 1154 */ 1155 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE) 1156 1157 /* 1158 * These are the only things you should do on a core-file: use only these 1159 * functions to write out all the necessary info. 1160 */ 1161 static int dump_write(struct file *file, const void *addr, int nr) 1162 { 1163 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 1164 } 1165 1166 static int dump_seek(struct file *file, loff_t off) 1167 { 1168 if (file->f_op->llseek) { 1169 if (file->f_op->llseek(file, off, SEEK_SET) != off) 1170 return 0; 1171 } else { 1172 file->f_pos = off; 1173 } 1174 return 1; 1175 } 1176 1177 /* 1178 * Decide whether a segment is worth dumping; default is yes to be 1179 * sure (missing info is worse than too much; etc). 1180 * Personally I'd include everything, and use the coredump limit... 1181 * 1182 * I think we should skip something. But I am not sure how. H.J. 1183 */ 1184 static int maydump(struct vm_area_struct *vma) 1185 { 1186 /* Do not dump I/O mapped devices or special mappings */ 1187 if (vma->vm_flags & (VM_IO | VM_RESERVED)) { 1188 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1189 return 0; 1190 } 1191 1192 /* If we may not read the contents, don't allow us to dump 1193 * them either. "dump_write()" can't handle it anyway. 1194 */ 1195 if (!(vma->vm_flags & VM_READ)) { 1196 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1197 return 0; 1198 } 1199 1200 /* Dump shared memory only if mapped from an anonymous file. */ 1201 if (vma->vm_flags & VM_SHARED) { 1202 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1203 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags); 1204 return 1; 1205 } 1206 1207 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags); 1208 return 0; 1209 } 1210 1211 #ifdef CONFIG_MMU 1212 /* If it hasn't been written to, don't write it out */ 1213 if (!vma->anon_vma) { 1214 kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags); 1215 return 0; 1216 } 1217 #endif 1218 1219 kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags); 1220 return 1; 1221 } 1222 1223 /* An ELF note in memory */ 1224 struct memelfnote 1225 { 1226 const char *name; 1227 int type; 1228 unsigned int datasz; 1229 void *data; 1230 }; 1231 1232 static int notesize(struct memelfnote *en) 1233 { 1234 int sz; 1235 1236 sz = sizeof(struct elf_note); 1237 sz += roundup(strlen(en->name) + 1, 4); 1238 sz += roundup(en->datasz, 4); 1239 1240 return sz; 1241 } 1242 1243 /* #define DEBUG */ 1244 1245 #define DUMP_WRITE(addr, nr) \ 1246 do { if (!dump_write(file, (addr), (nr))) return 0; } while(0) 1247 #define DUMP_SEEK(off) \ 1248 do { if (!dump_seek(file, (off))) return 0; } while(0) 1249 1250 static int writenote(struct memelfnote *men, struct file *file) 1251 { 1252 struct elf_note en; 1253 1254 en.n_namesz = strlen(men->name) + 1; 1255 en.n_descsz = men->datasz; 1256 en.n_type = men->type; 1257 1258 DUMP_WRITE(&en, sizeof(en)); 1259 DUMP_WRITE(men->name, en.n_namesz); 1260 /* XXX - cast from long long to long to avoid need for libgcc.a */ 1261 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1262 DUMP_WRITE(men->data, men->datasz); 1263 DUMP_SEEK(roundup((unsigned long)file->f_pos, 4)); /* XXX */ 1264 1265 return 1; 1266 } 1267 #undef DUMP_WRITE 1268 #undef DUMP_SEEK 1269 1270 #define DUMP_WRITE(addr, nr) \ 1271 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \ 1272 goto end_coredump; 1273 #define DUMP_SEEK(off) \ 1274 if (!dump_seek(file, (off))) \ 1275 goto end_coredump; 1276 1277 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1278 { 1279 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1280 elf->e_ident[EI_CLASS] = ELF_CLASS; 1281 elf->e_ident[EI_DATA] = ELF_DATA; 1282 elf->e_ident[EI_VERSION] = EV_CURRENT; 1283 elf->e_ident[EI_OSABI] = ELF_OSABI; 1284 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1285 1286 elf->e_type = ET_CORE; 1287 elf->e_machine = ELF_ARCH; 1288 elf->e_version = EV_CURRENT; 1289 elf->e_entry = 0; 1290 elf->e_phoff = sizeof(struct elfhdr); 1291 elf->e_shoff = 0; 1292 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1293 elf->e_ehsize = sizeof(struct elfhdr); 1294 elf->e_phentsize = sizeof(struct elf_phdr); 1295 elf->e_phnum = segs; 1296 elf->e_shentsize = 0; 1297 elf->e_shnum = 0; 1298 elf->e_shstrndx = 0; 1299 return; 1300 } 1301 1302 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1303 { 1304 phdr->p_type = PT_NOTE; 1305 phdr->p_offset = offset; 1306 phdr->p_vaddr = 0; 1307 phdr->p_paddr = 0; 1308 phdr->p_filesz = sz; 1309 phdr->p_memsz = 0; 1310 phdr->p_flags = 0; 1311 phdr->p_align = 0; 1312 return; 1313 } 1314 1315 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1316 unsigned int sz, void *data) 1317 { 1318 note->name = name; 1319 note->type = type; 1320 note->datasz = sz; 1321 note->data = data; 1322 return; 1323 } 1324 1325 /* 1326 * fill up all the fields in prstatus from the given task struct, except 1327 * registers which need to be filled up seperately. 1328 */ 1329 static void fill_prstatus(struct elf_prstatus *prstatus, 1330 struct task_struct *p, long signr) 1331 { 1332 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1333 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1334 prstatus->pr_sighold = p->blocked.sig[0]; 1335 prstatus->pr_pid = p->pid; 1336 prstatus->pr_ppid = p->parent->pid; 1337 prstatus->pr_pgrp = process_group(p); 1338 prstatus->pr_sid = process_session(p); 1339 if (thread_group_leader(p)) { 1340 /* 1341 * This is the record for the group leader. Add in the 1342 * cumulative times of previous dead threads. This total 1343 * won't include the time of each live thread whose state 1344 * is included in the core dump. The final total reported 1345 * to our parent process when it calls wait4 will include 1346 * those sums as well as the little bit more time it takes 1347 * this and each other thread to finish dying after the 1348 * core dump synchronization phase. 1349 */ 1350 cputime_to_timeval(cputime_add(p->utime, p->signal->utime), 1351 &prstatus->pr_utime); 1352 cputime_to_timeval(cputime_add(p->stime, p->signal->stime), 1353 &prstatus->pr_stime); 1354 } else { 1355 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1356 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1357 } 1358 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1359 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1360 1361 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1362 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1363 } 1364 1365 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1366 struct mm_struct *mm) 1367 { 1368 unsigned int i, len; 1369 1370 /* first copy the parameters from user space */ 1371 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1372 1373 len = mm->arg_end - mm->arg_start; 1374 if (len >= ELF_PRARGSZ) 1375 len = ELF_PRARGSZ - 1; 1376 if (copy_from_user(&psinfo->pr_psargs, 1377 (const char __user *) mm->arg_start, len)) 1378 return -EFAULT; 1379 for (i = 0; i < len; i++) 1380 if (psinfo->pr_psargs[i] == 0) 1381 psinfo->pr_psargs[i] = ' '; 1382 psinfo->pr_psargs[len] = 0; 1383 1384 psinfo->pr_pid = p->pid; 1385 psinfo->pr_ppid = p->parent->pid; 1386 psinfo->pr_pgrp = process_group(p); 1387 psinfo->pr_sid = process_session(p); 1388 1389 i = p->state ? ffz(~p->state) + 1 : 0; 1390 psinfo->pr_state = i; 1391 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1392 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1393 psinfo->pr_nice = task_nice(p); 1394 psinfo->pr_flag = p->flags; 1395 SET_UID(psinfo->pr_uid, p->uid); 1396 SET_GID(psinfo->pr_gid, p->gid); 1397 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1398 1399 return 0; 1400 } 1401 1402 /* Here is the structure in which status of each thread is captured. */ 1403 struct elf_thread_status 1404 { 1405 struct list_head list; 1406 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1407 elf_fpregset_t fpu; /* NT_PRFPREG */ 1408 struct task_struct *thread; 1409 #ifdef ELF_CORE_COPY_XFPREGS 1410 elf_fpxregset_t xfpu; /* NT_PRXFPREG */ 1411 #endif 1412 struct memelfnote notes[3]; 1413 int num_notes; 1414 }; 1415 1416 /* 1417 * In order to add the specific thread information for the elf file format, 1418 * we need to keep a linked list of every thread's pr_status and then create 1419 * a single section for them in the final core file. 1420 */ 1421 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1422 { 1423 struct task_struct *p = t->thread; 1424 int sz = 0; 1425 1426 t->num_notes = 0; 1427 1428 fill_prstatus(&t->prstatus, p, signr); 1429 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1430 1431 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1432 &t->prstatus); 1433 t->num_notes++; 1434 sz += notesize(&t->notes[0]); 1435 1436 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1437 if (t->prstatus.pr_fpvalid) { 1438 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1439 &t->fpu); 1440 t->num_notes++; 1441 sz += notesize(&t->notes[1]); 1442 } 1443 1444 #ifdef ELF_CORE_COPY_XFPREGS 1445 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1446 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu), 1447 &t->xfpu); 1448 t->num_notes++; 1449 sz += notesize(&t->notes[2]); 1450 } 1451 #endif 1452 return sz; 1453 } 1454 1455 /* 1456 * dump the segments for an MMU process 1457 */ 1458 #ifdef CONFIG_MMU 1459 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm, 1460 size_t *size, unsigned long *limit) 1461 { 1462 struct vm_area_struct *vma; 1463 1464 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1465 unsigned long addr; 1466 1467 if (!maydump(vma)) 1468 continue; 1469 1470 for (addr = vma->vm_start; 1471 addr < vma->vm_end; 1472 addr += PAGE_SIZE 1473 ) { 1474 struct vm_area_struct *vma; 1475 struct page *page; 1476 1477 if (get_user_pages(current, current->mm, addr, 1, 0, 1, 1478 &page, &vma) <= 0) { 1479 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1480 } 1481 else if (page == ZERO_PAGE(addr)) { 1482 page_cache_release(page); 1483 DUMP_SEEK(file->f_pos + PAGE_SIZE); 1484 } 1485 else { 1486 void *kaddr; 1487 1488 flush_cache_page(vma, addr, page_to_pfn(page)); 1489 kaddr = kmap(page); 1490 if ((*size += PAGE_SIZE) > *limit || 1491 !dump_write(file, kaddr, PAGE_SIZE) 1492 ) { 1493 kunmap(page); 1494 page_cache_release(page); 1495 return -EIO; 1496 } 1497 kunmap(page); 1498 page_cache_release(page); 1499 } 1500 } 1501 } 1502 1503 return 0; 1504 1505 end_coredump: 1506 return -EFBIG; 1507 } 1508 #endif 1509 1510 /* 1511 * dump the segments for a NOMMU process 1512 */ 1513 #ifndef CONFIG_MMU 1514 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm, 1515 size_t *size, unsigned long *limit) 1516 { 1517 struct vm_list_struct *vml; 1518 1519 for (vml = current->mm->context.vmlist; vml; vml = vml->next) { 1520 struct vm_area_struct *vma = vml->vma; 1521 1522 if (!maydump(vma)) 1523 continue; 1524 1525 if ((*size += PAGE_SIZE) > *limit) 1526 return -EFBIG; 1527 1528 if (!dump_write(file, (void *) vma->vm_start, 1529 vma->vm_end - vma->vm_start)) 1530 return -EIO; 1531 } 1532 1533 return 0; 1534 } 1535 #endif 1536 1537 /* 1538 * Actual dumper 1539 * 1540 * This is a two-pass process; first we find the offsets of the bits, 1541 * and then they are actually written out. If we run out of core limit 1542 * we just truncate. 1543 */ 1544 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, 1545 struct file *file) 1546 { 1547 #define NUM_NOTES 6 1548 int has_dumped = 0; 1549 mm_segment_t fs; 1550 int segs; 1551 size_t size = 0; 1552 int i; 1553 struct vm_area_struct *vma; 1554 struct elfhdr *elf = NULL; 1555 loff_t offset = 0, dataoff; 1556 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur; 1557 int numnote; 1558 struct memelfnote *notes = NULL; 1559 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1560 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1561 struct task_struct *g, *p; 1562 LIST_HEAD(thread_list); 1563 struct list_head *t; 1564 elf_fpregset_t *fpu = NULL; 1565 #ifdef ELF_CORE_COPY_XFPREGS 1566 elf_fpxregset_t *xfpu = NULL; 1567 #endif 1568 int thread_status_size = 0; 1569 #ifndef CONFIG_MMU 1570 struct vm_list_struct *vml; 1571 #endif 1572 elf_addr_t *auxv; 1573 1574 /* 1575 * We no longer stop all VM operations. 1576 * 1577 * This is because those proceses that could possibly change map_count 1578 * or the mmap / vma pages are now blocked in do_exit on current 1579 * finishing this core dump. 1580 * 1581 * Only ptrace can touch these memory addresses, but it doesn't change 1582 * the map_count or the pages allocated. So no possibility of crashing 1583 * exists while dumping the mm->vm_next areas to the core file. 1584 */ 1585 1586 /* alloc memory for large data structures: too large to be on stack */ 1587 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1588 if (!elf) 1589 goto cleanup; 1590 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1591 if (!prstatus) 1592 goto cleanup; 1593 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1594 if (!psinfo) 1595 goto cleanup; 1596 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1597 if (!notes) 1598 goto cleanup; 1599 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1600 if (!fpu) 1601 goto cleanup; 1602 #ifdef ELF_CORE_COPY_XFPREGS 1603 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1604 if (!xfpu) 1605 goto cleanup; 1606 #endif 1607 1608 if (signr) { 1609 struct elf_thread_status *tmp; 1610 rcu_read_lock(); 1611 do_each_thread(g,p) 1612 if (current->mm == p->mm && current != p) { 1613 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC); 1614 if (!tmp) { 1615 rcu_read_unlock(); 1616 goto cleanup; 1617 } 1618 tmp->thread = p; 1619 list_add(&tmp->list, &thread_list); 1620 } 1621 while_each_thread(g,p); 1622 rcu_read_unlock(); 1623 list_for_each(t, &thread_list) { 1624 struct elf_thread_status *tmp; 1625 int sz; 1626 1627 tmp = list_entry(t, struct elf_thread_status, list); 1628 sz = elf_dump_thread_status(signr, tmp); 1629 thread_status_size += sz; 1630 } 1631 } 1632 1633 /* now collect the dump for the current */ 1634 fill_prstatus(prstatus, current, signr); 1635 elf_core_copy_regs(&prstatus->pr_reg, regs); 1636 1637 #ifdef CONFIG_MMU 1638 segs = current->mm->map_count; 1639 #else 1640 segs = 0; 1641 for (vml = current->mm->context.vmlist; vml; vml = vml->next) 1642 segs++; 1643 #endif 1644 #ifdef ELF_CORE_EXTRA_PHDRS 1645 segs += ELF_CORE_EXTRA_PHDRS; 1646 #endif 1647 1648 /* Set up header */ 1649 fill_elf_fdpic_header(elf, segs + 1); /* including notes section */ 1650 1651 has_dumped = 1; 1652 current->flags |= PF_DUMPCORE; 1653 1654 /* 1655 * Set up the notes in similar form to SVR4 core dumps made 1656 * with info from their /proc. 1657 */ 1658 1659 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1660 fill_psinfo(psinfo, current->group_leader, current->mm); 1661 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1662 1663 numnote = 2; 1664 1665 auxv = (elf_addr_t *) current->mm->saved_auxv; 1666 1667 i = 0; 1668 do 1669 i += 2; 1670 while (auxv[i - 2] != AT_NULL); 1671 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1672 i * sizeof(elf_addr_t), auxv); 1673 1674 /* Try to dump the FPU. */ 1675 if ((prstatus->pr_fpvalid = 1676 elf_core_copy_task_fpregs(current, regs, fpu))) 1677 fill_note(notes + numnote++, 1678 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1679 #ifdef ELF_CORE_COPY_XFPREGS 1680 if (elf_core_copy_task_xfpregs(current, xfpu)) 1681 fill_note(notes + numnote++, 1682 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu); 1683 #endif 1684 1685 fs = get_fs(); 1686 set_fs(KERNEL_DS); 1687 1688 DUMP_WRITE(elf, sizeof(*elf)); 1689 offset += sizeof(*elf); /* Elf header */ 1690 offset += (segs+1) * sizeof(struct elf_phdr); /* Program headers */ 1691 1692 /* Write notes phdr entry */ 1693 { 1694 struct elf_phdr phdr; 1695 int sz = 0; 1696 1697 for (i = 0; i < numnote; i++) 1698 sz += notesize(notes + i); 1699 1700 sz += thread_status_size; 1701 1702 fill_elf_note_phdr(&phdr, sz, offset); 1703 offset += sz; 1704 DUMP_WRITE(&phdr, sizeof(phdr)); 1705 } 1706 1707 /* Page-align dumped data */ 1708 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1709 1710 /* write program headers for segments dump */ 1711 for ( 1712 #ifdef CONFIG_MMU 1713 vma = current->mm->mmap; vma; vma = vma->vm_next 1714 #else 1715 vml = current->mm->context.vmlist; vml; vml = vml->next 1716 #endif 1717 ) { 1718 struct elf_phdr phdr; 1719 size_t sz; 1720 1721 #ifndef CONFIG_MMU 1722 vma = vml->vma; 1723 #endif 1724 1725 sz = vma->vm_end - vma->vm_start; 1726 1727 phdr.p_type = PT_LOAD; 1728 phdr.p_offset = offset; 1729 phdr.p_vaddr = vma->vm_start; 1730 phdr.p_paddr = 0; 1731 phdr.p_filesz = maydump(vma) ? sz : 0; 1732 phdr.p_memsz = sz; 1733 offset += phdr.p_filesz; 1734 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1735 if (vma->vm_flags & VM_WRITE) 1736 phdr.p_flags |= PF_W; 1737 if (vma->vm_flags & VM_EXEC) 1738 phdr.p_flags |= PF_X; 1739 phdr.p_align = ELF_EXEC_PAGESIZE; 1740 1741 DUMP_WRITE(&phdr, sizeof(phdr)); 1742 } 1743 1744 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS 1745 ELF_CORE_WRITE_EXTRA_PHDRS; 1746 #endif 1747 1748 /* write out the notes section */ 1749 for (i = 0; i < numnote; i++) 1750 if (!writenote(notes + i, file)) 1751 goto end_coredump; 1752 1753 /* write out the thread status notes section */ 1754 list_for_each(t, &thread_list) { 1755 struct elf_thread_status *tmp = 1756 list_entry(t, struct elf_thread_status, list); 1757 1758 for (i = 0; i < tmp->num_notes; i++) 1759 if (!writenote(&tmp->notes[i], file)) 1760 goto end_coredump; 1761 } 1762 1763 DUMP_SEEK(dataoff); 1764 1765 if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0) 1766 goto end_coredump; 1767 1768 #ifdef ELF_CORE_WRITE_EXTRA_DATA 1769 ELF_CORE_WRITE_EXTRA_DATA; 1770 #endif 1771 1772 if (file->f_pos != offset) { 1773 /* Sanity check */ 1774 printk(KERN_WARNING 1775 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1776 file->f_pos, offset); 1777 } 1778 1779 end_coredump: 1780 set_fs(fs); 1781 1782 cleanup: 1783 while (!list_empty(&thread_list)) { 1784 struct list_head *tmp = thread_list.next; 1785 list_del(tmp); 1786 kfree(list_entry(tmp, struct elf_thread_status, list)); 1787 } 1788 1789 kfree(elf); 1790 kfree(prstatus); 1791 kfree(psinfo); 1792 kfree(notes); 1793 kfree(fpu); 1794 #ifdef ELF_CORE_COPY_XFPREGS 1795 kfree(xfpu); 1796 #endif 1797 return has_dumped; 1798 #undef NUM_NOTES 1799 } 1800 1801 #endif /* USE_ELF_CORE_DUMP */ 1802