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/security.h> 29 #include <linux/highmem.h> 30 #include <linux/highuid.h> 31 #include <linux/personality.h> 32 #include <linux/ptrace.h> 33 #include <linux/init.h> 34 #include <linux/elf.h> 35 #include <linux/elf-fdpic.h> 36 #include <linux/elfcore.h> 37 #include <linux/coredump.h> 38 39 #include <asm/uaccess.h> 40 #include <asm/param.h> 41 #include <asm/pgalloc.h> 42 #include <asm/exec.h> 43 44 typedef char *elf_caddr_t; 45 46 #if 0 47 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 48 #else 49 #define kdebug(fmt, ...) do {} while(0) 50 #endif 51 52 #if 0 53 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 54 #else 55 #define kdcore(fmt, ...) do {} while(0) 56 #endif 57 58 MODULE_LICENSE("GPL"); 59 60 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *); 61 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 62 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 63 struct mm_struct *, const char *); 64 65 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 66 struct elf_fdpic_params *, 67 struct elf_fdpic_params *); 68 69 #ifndef CONFIG_MMU 70 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, 71 unsigned long *); 72 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 73 struct file *, 74 struct mm_struct *); 75 #endif 76 77 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 78 struct file *, struct mm_struct *); 79 80 #ifdef CONFIG_ELF_CORE 81 static int elf_fdpic_core_dump(struct coredump_params *cprm); 82 #endif 83 84 static struct linux_binfmt elf_fdpic_format = { 85 .module = THIS_MODULE, 86 .load_binary = load_elf_fdpic_binary, 87 #ifdef CONFIG_ELF_CORE 88 .core_dump = elf_fdpic_core_dump, 89 #endif 90 .min_coredump = ELF_EXEC_PAGESIZE, 91 }; 92 93 static int __init init_elf_fdpic_binfmt(void) 94 { 95 register_binfmt(&elf_fdpic_format); 96 return 0; 97 } 98 99 static void __exit exit_elf_fdpic_binfmt(void) 100 { 101 unregister_binfmt(&elf_fdpic_format); 102 } 103 104 core_initcall(init_elf_fdpic_binfmt); 105 module_exit(exit_elf_fdpic_binfmt); 106 107 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) 108 { 109 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 110 return 0; 111 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 112 return 0; 113 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) 114 return 0; 115 if (!file->f_op || !file->f_op->mmap) 116 return 0; 117 return 1; 118 } 119 120 /*****************************************************************************/ 121 /* 122 * read the program headers table into memory 123 */ 124 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 125 struct file *file) 126 { 127 struct elf32_phdr *phdr; 128 unsigned long size; 129 int retval, loop; 130 131 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 132 return -ENOMEM; 133 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 134 return -ENOMEM; 135 136 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 137 params->phdrs = kmalloc(size, GFP_KERNEL); 138 if (!params->phdrs) 139 return -ENOMEM; 140 141 retval = kernel_read(file, params->hdr.e_phoff, 142 (char *) params->phdrs, size); 143 if (unlikely(retval != size)) 144 return retval < 0 ? retval : -ENOEXEC; 145 146 /* determine stack size for this binary */ 147 phdr = params->phdrs; 148 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 149 if (phdr->p_type != PT_GNU_STACK) 150 continue; 151 152 if (phdr->p_flags & PF_X) 153 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 154 else 155 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 156 157 params->stack_size = phdr->p_memsz; 158 break; 159 } 160 161 return 0; 162 } 163 164 /*****************************************************************************/ 165 /* 166 * load an fdpic binary into various bits of memory 167 */ 168 static int load_elf_fdpic_binary(struct linux_binprm *bprm, 169 struct pt_regs *regs) 170 { 171 struct elf_fdpic_params exec_params, interp_params; 172 struct elf_phdr *phdr; 173 unsigned long stack_size, entryaddr; 174 #ifdef ELF_FDPIC_PLAT_INIT 175 unsigned long dynaddr; 176 #endif 177 #ifndef CONFIG_MMU 178 unsigned long stack_prot; 179 #endif 180 struct file *interpreter = NULL; /* to shut gcc up */ 181 char *interpreter_name = NULL; 182 int executable_stack; 183 int retval, i; 184 185 kdebug("____ LOAD %d ____", current->pid); 186 187 memset(&exec_params, 0, sizeof(exec_params)); 188 memset(&interp_params, 0, sizeof(interp_params)); 189 190 exec_params.hdr = *(struct elfhdr *) bprm->buf; 191 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 192 193 /* check that this is a binary we know how to deal with */ 194 retval = -ENOEXEC; 195 if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) 196 goto error; 197 198 /* read the program header table */ 199 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 200 if (retval < 0) 201 goto error; 202 203 /* scan for a program header that specifies an interpreter */ 204 phdr = exec_params.phdrs; 205 206 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 207 switch (phdr->p_type) { 208 case PT_INTERP: 209 retval = -ENOMEM; 210 if (phdr->p_filesz > PATH_MAX) 211 goto error; 212 retval = -ENOENT; 213 if (phdr->p_filesz < 2) 214 goto error; 215 216 /* read the name of the interpreter into memory */ 217 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 218 if (!interpreter_name) 219 goto error; 220 221 retval = kernel_read(bprm->file, 222 phdr->p_offset, 223 interpreter_name, 224 phdr->p_filesz); 225 if (unlikely(retval != phdr->p_filesz)) { 226 if (retval >= 0) 227 retval = -ENOEXEC; 228 goto error; 229 } 230 231 retval = -ENOENT; 232 if (interpreter_name[phdr->p_filesz - 1] != '\0') 233 goto error; 234 235 kdebug("Using ELF interpreter %s", interpreter_name); 236 237 /* replace the program with the interpreter */ 238 interpreter = open_exec(interpreter_name); 239 retval = PTR_ERR(interpreter); 240 if (IS_ERR(interpreter)) { 241 interpreter = NULL; 242 goto error; 243 } 244 245 /* 246 * If the binary is not readable then enforce 247 * mm->dumpable = 0 regardless of the interpreter's 248 * permissions. 249 */ 250 would_dump(bprm, interpreter); 251 252 retval = kernel_read(interpreter, 0, bprm->buf, 253 BINPRM_BUF_SIZE); 254 if (unlikely(retval != BINPRM_BUF_SIZE)) { 255 if (retval >= 0) 256 retval = -ENOEXEC; 257 goto error; 258 } 259 260 interp_params.hdr = *((struct elfhdr *) bprm->buf); 261 break; 262 263 case PT_LOAD: 264 #ifdef CONFIG_MMU 265 if (exec_params.load_addr == 0) 266 exec_params.load_addr = phdr->p_vaddr; 267 #endif 268 break; 269 } 270 271 } 272 273 if (elf_check_const_displacement(&exec_params.hdr)) 274 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 275 276 /* perform insanity checks on the interpreter */ 277 if (interpreter_name) { 278 retval = -ELIBBAD; 279 if (!is_elf_fdpic(&interp_params.hdr, interpreter)) 280 goto error; 281 282 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 283 284 /* read the interpreter's program header table */ 285 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 286 if (retval < 0) 287 goto error; 288 } 289 290 stack_size = exec_params.stack_size; 291 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 292 executable_stack = EXSTACK_ENABLE_X; 293 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 294 executable_stack = EXSTACK_DISABLE_X; 295 else 296 executable_stack = EXSTACK_DEFAULT; 297 298 if (stack_size == 0) { 299 stack_size = interp_params.stack_size; 300 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 301 executable_stack = EXSTACK_ENABLE_X; 302 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 303 executable_stack = EXSTACK_DISABLE_X; 304 else 305 executable_stack = EXSTACK_DEFAULT; 306 } 307 308 retval = -ENOEXEC; 309 if (stack_size == 0) 310 goto error; 311 312 if (elf_check_const_displacement(&interp_params.hdr)) 313 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 314 315 /* flush all traces of the currently running executable */ 316 retval = flush_old_exec(bprm); 317 if (retval) 318 goto error; 319 320 /* there's now no turning back... the old userspace image is dead, 321 * defunct, deceased, etc. after this point we have to exit via 322 * error_kill */ 323 set_personality(PER_LINUX_FDPIC); 324 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 325 current->personality |= READ_IMPLIES_EXEC; 326 327 setup_new_exec(bprm); 328 329 set_binfmt(&elf_fdpic_format); 330 331 current->mm->start_code = 0; 332 current->mm->end_code = 0; 333 current->mm->start_stack = 0; 334 current->mm->start_data = 0; 335 current->mm->end_data = 0; 336 current->mm->context.exec_fdpic_loadmap = 0; 337 current->mm->context.interp_fdpic_loadmap = 0; 338 339 #ifdef CONFIG_MMU 340 elf_fdpic_arch_lay_out_mm(&exec_params, 341 &interp_params, 342 ¤t->mm->start_stack, 343 ¤t->mm->start_brk); 344 345 retval = setup_arg_pages(bprm, current->mm->start_stack, 346 executable_stack); 347 if (retval < 0) { 348 send_sig(SIGKILL, current, 0); 349 goto error_kill; 350 } 351 #endif 352 353 /* load the executable and interpreter into memory */ 354 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 355 "executable"); 356 if (retval < 0) 357 goto error_kill; 358 359 if (interpreter_name) { 360 retval = elf_fdpic_map_file(&interp_params, interpreter, 361 current->mm, "interpreter"); 362 if (retval < 0) { 363 printk(KERN_ERR "Unable to load interpreter\n"); 364 goto error_kill; 365 } 366 367 allow_write_access(interpreter); 368 fput(interpreter); 369 interpreter = NULL; 370 } 371 372 #ifdef CONFIG_MMU 373 if (!current->mm->start_brk) 374 current->mm->start_brk = current->mm->end_data; 375 376 current->mm->brk = current->mm->start_brk = 377 PAGE_ALIGN(current->mm->start_brk); 378 379 #else 380 /* create a stack and brk area big enough for everyone 381 * - the brk heap starts at the bottom and works up 382 * - the stack starts at the top and works down 383 */ 384 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 385 if (stack_size < PAGE_SIZE * 2) 386 stack_size = PAGE_SIZE * 2; 387 388 stack_prot = PROT_READ | PROT_WRITE; 389 if (executable_stack == EXSTACK_ENABLE_X || 390 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 391 stack_prot |= PROT_EXEC; 392 393 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 394 MAP_PRIVATE | MAP_ANONYMOUS | 395 MAP_UNINITIALIZED | MAP_GROWSDOWN, 396 0); 397 398 if (IS_ERR_VALUE(current->mm->start_brk)) { 399 retval = current->mm->start_brk; 400 current->mm->start_brk = 0; 401 goto error_kill; 402 } 403 404 current->mm->brk = current->mm->start_brk; 405 current->mm->context.end_brk = current->mm->start_brk; 406 current->mm->context.end_brk += 407 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; 408 current->mm->start_stack = current->mm->start_brk + stack_size; 409 #endif 410 411 install_exec_creds(bprm); 412 if (create_elf_fdpic_tables(bprm, current->mm, 413 &exec_params, &interp_params) < 0) 414 goto error_kill; 415 416 kdebug("- start_code %lx", current->mm->start_code); 417 kdebug("- end_code %lx", current->mm->end_code); 418 kdebug("- start_data %lx", current->mm->start_data); 419 kdebug("- end_data %lx", current->mm->end_data); 420 kdebug("- start_brk %lx", current->mm->start_brk); 421 kdebug("- brk %lx", current->mm->brk); 422 kdebug("- start_stack %lx", current->mm->start_stack); 423 424 #ifdef ELF_FDPIC_PLAT_INIT 425 /* 426 * The ABI may specify that certain registers be set up in special 427 * ways (on i386 %edx is the address of a DT_FINI function, for 428 * example. This macro performs whatever initialization to 429 * the regs structure is required. 430 */ 431 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 432 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 433 dynaddr); 434 #endif 435 436 /* everything is now ready... get the userspace context ready to roll */ 437 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 438 start_thread(regs, entryaddr, current->mm->start_stack); 439 440 retval = 0; 441 442 error: 443 if (interpreter) { 444 allow_write_access(interpreter); 445 fput(interpreter); 446 } 447 kfree(interpreter_name); 448 kfree(exec_params.phdrs); 449 kfree(exec_params.loadmap); 450 kfree(interp_params.phdrs); 451 kfree(interp_params.loadmap); 452 return retval; 453 454 /* unrecoverable error - kill the process */ 455 error_kill: 456 send_sig(SIGSEGV, current, 0); 457 goto error; 458 459 } 460 461 /*****************************************************************************/ 462 463 #ifndef ELF_BASE_PLATFORM 464 /* 465 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 466 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 467 * will be copied to the user stack in the same manner as AT_PLATFORM. 468 */ 469 #define ELF_BASE_PLATFORM NULL 470 #endif 471 472 /* 473 * present useful information to the program by shovelling it onto the new 474 * process's stack 475 */ 476 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 477 struct mm_struct *mm, 478 struct elf_fdpic_params *exec_params, 479 struct elf_fdpic_params *interp_params) 480 { 481 const struct cred *cred = current_cred(); 482 unsigned long sp, csp, nitems; 483 elf_caddr_t __user *argv, *envp; 484 size_t platform_len = 0, len; 485 char *k_platform, *k_base_platform; 486 char __user *u_platform, *u_base_platform, *p; 487 long hwcap; 488 int loop; 489 int nr; /* reset for each csp adjustment */ 490 491 #ifdef CONFIG_MMU 492 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 493 * by the processes running on the same package. One thing we can do is 494 * to shuffle the initial stack for them, so we give the architecture 495 * an opportunity to do so here. 496 */ 497 sp = arch_align_stack(bprm->p); 498 #else 499 sp = mm->start_stack; 500 501 /* stack the program arguments and environment */ 502 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 503 return -EFAULT; 504 #endif 505 506 hwcap = ELF_HWCAP; 507 508 /* 509 * If this architecture has a platform capability string, copy it 510 * to userspace. In some cases (Sparc), this info is impossible 511 * for userspace to get any other way, in others (i386) it is 512 * merely difficult. 513 */ 514 k_platform = ELF_PLATFORM; 515 u_platform = NULL; 516 517 if (k_platform) { 518 platform_len = strlen(k_platform) + 1; 519 sp -= platform_len; 520 u_platform = (char __user *) sp; 521 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 522 return -EFAULT; 523 } 524 525 /* 526 * If this architecture has a "base" platform capability 527 * string, copy it to userspace. 528 */ 529 k_base_platform = ELF_BASE_PLATFORM; 530 u_base_platform = NULL; 531 532 if (k_base_platform) { 533 platform_len = strlen(k_base_platform) + 1; 534 sp -= platform_len; 535 u_base_platform = (char __user *) sp; 536 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 537 return -EFAULT; 538 } 539 540 sp &= ~7UL; 541 542 /* stack the load map(s) */ 543 len = sizeof(struct elf32_fdpic_loadmap); 544 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 545 sp = (sp - len) & ~7UL; 546 exec_params->map_addr = sp; 547 548 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 549 return -EFAULT; 550 551 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 552 553 if (interp_params->loadmap) { 554 len = sizeof(struct elf32_fdpic_loadmap); 555 len += sizeof(struct elf32_fdpic_loadseg) * 556 interp_params->loadmap->nsegs; 557 sp = (sp - len) & ~7UL; 558 interp_params->map_addr = sp; 559 560 if (copy_to_user((void __user *) sp, interp_params->loadmap, 561 len) != 0) 562 return -EFAULT; 563 564 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 565 } 566 567 /* force 16 byte _final_ alignment here for generality */ 568 #define DLINFO_ITEMS 15 569 570 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 571 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 572 573 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 574 nitems++; 575 576 csp = sp; 577 sp -= nitems * 2 * sizeof(unsigned long); 578 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 579 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 580 sp -= 1 * sizeof(unsigned long); /* argc */ 581 582 csp -= sp & 15UL; 583 sp -= sp & 15UL; 584 585 /* put the ELF interpreter info on the stack */ 586 #define NEW_AUX_ENT(id, val) \ 587 do { \ 588 struct { unsigned long _id, _val; } __user *ent; \ 589 \ 590 ent = (void __user *) csp; \ 591 __put_user((id), &ent[nr]._id); \ 592 __put_user((val), &ent[nr]._val); \ 593 nr++; \ 594 } while (0) 595 596 nr = 0; 597 csp -= 2 * sizeof(unsigned long); 598 NEW_AUX_ENT(AT_NULL, 0); 599 if (k_platform) { 600 nr = 0; 601 csp -= 2 * sizeof(unsigned long); 602 NEW_AUX_ENT(AT_PLATFORM, 603 (elf_addr_t) (unsigned long) u_platform); 604 } 605 606 if (k_base_platform) { 607 nr = 0; 608 csp -= 2 * sizeof(unsigned long); 609 NEW_AUX_ENT(AT_BASE_PLATFORM, 610 (elf_addr_t) (unsigned long) u_base_platform); 611 } 612 613 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 614 nr = 0; 615 csp -= 2 * sizeof(unsigned long); 616 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 617 } 618 619 nr = 0; 620 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 621 NEW_AUX_ENT(AT_HWCAP, hwcap); 622 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 623 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 624 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 625 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 626 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 627 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 628 NEW_AUX_ENT(AT_FLAGS, 0); 629 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 630 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 631 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 632 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 633 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 634 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 635 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 636 637 #ifdef ARCH_DLINFO 638 nr = 0; 639 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 640 641 /* ARCH_DLINFO must come last so platform specific code can enforce 642 * special alignment requirements on the AUXV if necessary (eg. PPC). 643 */ 644 ARCH_DLINFO; 645 #endif 646 #undef NEW_AUX_ENT 647 648 /* allocate room for argv[] and envv[] */ 649 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 650 envp = (elf_caddr_t __user *) csp; 651 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 652 argv = (elf_caddr_t __user *) csp; 653 654 /* stack argc */ 655 csp -= sizeof(unsigned long); 656 __put_user(bprm->argc, (unsigned long __user *) csp); 657 658 BUG_ON(csp != sp); 659 660 /* fill in the argv[] array */ 661 #ifdef CONFIG_MMU 662 current->mm->arg_start = bprm->p; 663 #else 664 current->mm->arg_start = current->mm->start_stack - 665 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 666 #endif 667 668 p = (char __user *) current->mm->arg_start; 669 for (loop = bprm->argc; loop > 0; loop--) { 670 __put_user((elf_caddr_t) p, argv++); 671 len = strnlen_user(p, MAX_ARG_STRLEN); 672 if (!len || len > MAX_ARG_STRLEN) 673 return -EINVAL; 674 p += len; 675 } 676 __put_user(NULL, argv); 677 current->mm->arg_end = (unsigned long) p; 678 679 /* fill in the envv[] array */ 680 current->mm->env_start = (unsigned long) p; 681 for (loop = bprm->envc; loop > 0; loop--) { 682 __put_user((elf_caddr_t)(unsigned long) p, envp++); 683 len = strnlen_user(p, MAX_ARG_STRLEN); 684 if (!len || len > MAX_ARG_STRLEN) 685 return -EINVAL; 686 p += len; 687 } 688 __put_user(NULL, envp); 689 current->mm->env_end = (unsigned long) p; 690 691 mm->start_stack = (unsigned long) sp; 692 return 0; 693 } 694 695 /*****************************************************************************/ 696 /* 697 * transfer the program arguments and environment from the holding pages onto 698 * the stack 699 */ 700 #ifndef CONFIG_MMU 701 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 702 unsigned long *_sp) 703 { 704 unsigned long index, stop, sp; 705 char *src; 706 int ret = 0; 707 708 stop = bprm->p >> PAGE_SHIFT; 709 sp = *_sp; 710 711 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 712 src = kmap(bprm->page[index]); 713 sp -= PAGE_SIZE; 714 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 715 ret = -EFAULT; 716 kunmap(bprm->page[index]); 717 if (ret < 0) 718 goto out; 719 } 720 721 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 722 723 out: 724 return ret; 725 } 726 #endif 727 728 /*****************************************************************************/ 729 /* 730 * load the appropriate binary image (executable or interpreter) into memory 731 * - we assume no MMU is available 732 * - if no other PIC bits are set in params->hdr->e_flags 733 * - we assume that the LOADable segments in the binary are independently relocatable 734 * - we assume R/O executable segments are shareable 735 * - else 736 * - we assume the loadable parts of the image to require fixed displacement 737 * - the image is not shareable 738 */ 739 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 740 struct file *file, 741 struct mm_struct *mm, 742 const char *what) 743 { 744 struct elf32_fdpic_loadmap *loadmap; 745 #ifdef CONFIG_MMU 746 struct elf32_fdpic_loadseg *mseg; 747 #endif 748 struct elf32_fdpic_loadseg *seg; 749 struct elf32_phdr *phdr; 750 unsigned long load_addr, stop; 751 unsigned nloads, tmp; 752 size_t size; 753 int loop, ret; 754 755 /* allocate a load map table */ 756 nloads = 0; 757 for (loop = 0; loop < params->hdr.e_phnum; loop++) 758 if (params->phdrs[loop].p_type == PT_LOAD) 759 nloads++; 760 761 if (nloads == 0) 762 return -ELIBBAD; 763 764 size = sizeof(*loadmap) + nloads * sizeof(*seg); 765 loadmap = kzalloc(size, GFP_KERNEL); 766 if (!loadmap) 767 return -ENOMEM; 768 769 params->loadmap = loadmap; 770 771 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 772 loadmap->nsegs = nloads; 773 774 load_addr = params->load_addr; 775 seg = loadmap->segs; 776 777 /* map the requested LOADs into the memory space */ 778 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 779 case ELF_FDPIC_FLAG_CONSTDISP: 780 case ELF_FDPIC_FLAG_CONTIGUOUS: 781 #ifndef CONFIG_MMU 782 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 783 if (ret < 0) 784 return ret; 785 break; 786 #endif 787 default: 788 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 789 if (ret < 0) 790 return ret; 791 break; 792 } 793 794 /* map the entry point */ 795 if (params->hdr.e_entry) { 796 seg = loadmap->segs; 797 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 798 if (params->hdr.e_entry >= seg->p_vaddr && 799 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 800 params->entry_addr = 801 (params->hdr.e_entry - seg->p_vaddr) + 802 seg->addr; 803 break; 804 } 805 } 806 } 807 808 /* determine where the program header table has wound up if mapped */ 809 stop = params->hdr.e_phoff; 810 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 811 phdr = params->phdrs; 812 813 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 814 if (phdr->p_type != PT_LOAD) 815 continue; 816 817 if (phdr->p_offset > params->hdr.e_phoff || 818 phdr->p_offset + phdr->p_filesz < stop) 819 continue; 820 821 seg = loadmap->segs; 822 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 823 if (phdr->p_vaddr >= seg->p_vaddr && 824 phdr->p_vaddr + phdr->p_filesz <= 825 seg->p_vaddr + seg->p_memsz) { 826 params->ph_addr = 827 (phdr->p_vaddr - seg->p_vaddr) + 828 seg->addr + 829 params->hdr.e_phoff - phdr->p_offset; 830 break; 831 } 832 } 833 break; 834 } 835 836 /* determine where the dynamic section has wound up if there is one */ 837 phdr = params->phdrs; 838 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 839 if (phdr->p_type != PT_DYNAMIC) 840 continue; 841 842 seg = loadmap->segs; 843 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 844 if (phdr->p_vaddr >= seg->p_vaddr && 845 phdr->p_vaddr + phdr->p_memsz <= 846 seg->p_vaddr + seg->p_memsz) { 847 params->dynamic_addr = 848 (phdr->p_vaddr - seg->p_vaddr) + 849 seg->addr; 850 851 /* check the dynamic section contains at least 852 * one item, and that the last item is a NULL 853 * entry */ 854 if (phdr->p_memsz == 0 || 855 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 856 goto dynamic_error; 857 858 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 859 if (((Elf32_Dyn *) 860 params->dynamic_addr)[tmp - 1].d_tag != 0) 861 goto dynamic_error; 862 break; 863 } 864 } 865 break; 866 } 867 868 /* now elide adjacent segments in the load map on MMU linux 869 * - on uClinux the holes between may actually be filled with system 870 * stuff or stuff from other processes 871 */ 872 #ifdef CONFIG_MMU 873 nloads = loadmap->nsegs; 874 mseg = loadmap->segs; 875 seg = mseg + 1; 876 for (loop = 1; loop < nloads; loop++) { 877 /* see if we have a candidate for merging */ 878 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 879 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 880 if (load_addr == (seg->addr & PAGE_MASK)) { 881 mseg->p_memsz += 882 load_addr - 883 (mseg->addr + mseg->p_memsz); 884 mseg->p_memsz += seg->addr & ~PAGE_MASK; 885 mseg->p_memsz += seg->p_memsz; 886 loadmap->nsegs--; 887 continue; 888 } 889 } 890 891 mseg++; 892 if (mseg != seg) 893 *mseg = *seg; 894 } 895 #endif 896 897 kdebug("Mapped Object [%s]:", what); 898 kdebug("- elfhdr : %lx", params->elfhdr_addr); 899 kdebug("- entry : %lx", params->entry_addr); 900 kdebug("- PHDR[] : %lx", params->ph_addr); 901 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 902 seg = loadmap->segs; 903 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 904 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 905 loop, 906 seg->addr, seg->addr + seg->p_memsz - 1, 907 seg->p_vaddr, seg->p_memsz); 908 909 return 0; 910 911 dynamic_error: 912 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 913 what, file->f_path.dentry->d_inode->i_ino); 914 return -ELIBBAD; 915 } 916 917 /*****************************************************************************/ 918 /* 919 * map a file with constant displacement under uClinux 920 */ 921 #ifndef CONFIG_MMU 922 static int elf_fdpic_map_file_constdisp_on_uclinux( 923 struct elf_fdpic_params *params, 924 struct file *file, 925 struct mm_struct *mm) 926 { 927 struct elf32_fdpic_loadseg *seg; 928 struct elf32_phdr *phdr; 929 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 930 loff_t fpos; 931 int loop, ret; 932 933 load_addr = params->load_addr; 934 seg = params->loadmap->segs; 935 936 /* determine the bounds of the contiguous overall allocation we must 937 * make */ 938 phdr = params->phdrs; 939 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 940 if (params->phdrs[loop].p_type != PT_LOAD) 941 continue; 942 943 if (base > phdr->p_vaddr) 944 base = phdr->p_vaddr; 945 if (top < phdr->p_vaddr + phdr->p_memsz) 946 top = phdr->p_vaddr + phdr->p_memsz; 947 } 948 949 /* allocate one big anon block for everything */ 950 mflags = MAP_PRIVATE; 951 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 952 mflags |= MAP_EXECUTABLE; 953 954 maddr = vm_mmap(NULL, load_addr, top - base, 955 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 956 if (IS_ERR_VALUE(maddr)) 957 return (int) maddr; 958 959 if (load_addr != 0) 960 load_addr += PAGE_ALIGN(top - base); 961 962 /* and then load the file segments into it */ 963 phdr = params->phdrs; 964 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 965 if (params->phdrs[loop].p_type != PT_LOAD) 966 continue; 967 968 fpos = phdr->p_offset; 969 970 seg->addr = maddr + (phdr->p_vaddr - base); 971 seg->p_vaddr = phdr->p_vaddr; 972 seg->p_memsz = phdr->p_memsz; 973 974 ret = file->f_op->read(file, (void *) seg->addr, 975 phdr->p_filesz, &fpos); 976 if (ret < 0) 977 return ret; 978 979 /* map the ELF header address if in this segment */ 980 if (phdr->p_offset == 0) 981 params->elfhdr_addr = seg->addr; 982 983 /* clear any space allocated but not loaded */ 984 if (phdr->p_filesz < phdr->p_memsz) { 985 if (clear_user((void *) (seg->addr + phdr->p_filesz), 986 phdr->p_memsz - phdr->p_filesz)) 987 return -EFAULT; 988 } 989 990 if (mm) { 991 if (phdr->p_flags & PF_X) { 992 if (!mm->start_code) { 993 mm->start_code = seg->addr; 994 mm->end_code = seg->addr + 995 phdr->p_memsz; 996 } 997 } else if (!mm->start_data) { 998 mm->start_data = seg->addr; 999 mm->end_data = seg->addr + phdr->p_memsz; 1000 } 1001 } 1002 1003 seg++; 1004 } 1005 1006 return 0; 1007 } 1008 #endif 1009 1010 /*****************************************************************************/ 1011 /* 1012 * map a binary by direct mmap() of the individual PT_LOAD segments 1013 */ 1014 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1015 struct file *file, 1016 struct mm_struct *mm) 1017 { 1018 struct elf32_fdpic_loadseg *seg; 1019 struct elf32_phdr *phdr; 1020 unsigned long load_addr, delta_vaddr; 1021 int loop, dvset; 1022 1023 load_addr = params->load_addr; 1024 delta_vaddr = 0; 1025 dvset = 0; 1026 1027 seg = params->loadmap->segs; 1028 1029 /* deal with each load segment separately */ 1030 phdr = params->phdrs; 1031 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1032 unsigned long maddr, disp, excess, excess1; 1033 int prot = 0, flags; 1034 1035 if (phdr->p_type != PT_LOAD) 1036 continue; 1037 1038 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1039 (unsigned long) phdr->p_vaddr, 1040 (unsigned long) phdr->p_offset, 1041 (unsigned long) phdr->p_filesz, 1042 (unsigned long) phdr->p_memsz); 1043 1044 /* determine the mapping parameters */ 1045 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1046 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1047 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1048 1049 flags = MAP_PRIVATE | MAP_DENYWRITE; 1050 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1051 flags |= MAP_EXECUTABLE; 1052 1053 maddr = 0; 1054 1055 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1056 case ELF_FDPIC_FLAG_INDEPENDENT: 1057 /* PT_LOADs are independently locatable */ 1058 break; 1059 1060 case ELF_FDPIC_FLAG_HONOURVADDR: 1061 /* the specified virtual address must be honoured */ 1062 maddr = phdr->p_vaddr; 1063 flags |= MAP_FIXED; 1064 break; 1065 1066 case ELF_FDPIC_FLAG_CONSTDISP: 1067 /* constant displacement 1068 * - can be mapped anywhere, but must be mapped as a 1069 * unit 1070 */ 1071 if (!dvset) { 1072 maddr = load_addr; 1073 delta_vaddr = phdr->p_vaddr; 1074 dvset = 1; 1075 } else { 1076 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1077 flags |= MAP_FIXED; 1078 } 1079 break; 1080 1081 case ELF_FDPIC_FLAG_CONTIGUOUS: 1082 /* contiguity handled later */ 1083 break; 1084 1085 default: 1086 BUG(); 1087 } 1088 1089 maddr &= PAGE_MASK; 1090 1091 /* create the mapping */ 1092 disp = phdr->p_vaddr & ~PAGE_MASK; 1093 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1094 phdr->p_offset - disp); 1095 1096 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1097 loop, phdr->p_memsz + disp, prot, flags, 1098 phdr->p_offset - disp, maddr); 1099 1100 if (IS_ERR_VALUE(maddr)) 1101 return (int) maddr; 1102 1103 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1104 ELF_FDPIC_FLAG_CONTIGUOUS) 1105 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1106 1107 seg->addr = maddr + disp; 1108 seg->p_vaddr = phdr->p_vaddr; 1109 seg->p_memsz = phdr->p_memsz; 1110 1111 /* map the ELF header address if in this segment */ 1112 if (phdr->p_offset == 0) 1113 params->elfhdr_addr = seg->addr; 1114 1115 /* clear the bit between beginning of mapping and beginning of 1116 * PT_LOAD */ 1117 if (prot & PROT_WRITE && disp > 0) { 1118 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1119 if (clear_user((void __user *) maddr, disp)) 1120 return -EFAULT; 1121 maddr += disp; 1122 } 1123 1124 /* clear any space allocated but not loaded 1125 * - on uClinux we can just clear the lot 1126 * - on MMU linux we'll get a SIGBUS beyond the last page 1127 * extant in the file 1128 */ 1129 excess = phdr->p_memsz - phdr->p_filesz; 1130 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1131 1132 #ifdef CONFIG_MMU 1133 if (excess > excess1) { 1134 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1135 unsigned long xmaddr; 1136 1137 flags |= MAP_FIXED | MAP_ANONYMOUS; 1138 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1139 prot, flags, 0); 1140 1141 kdebug("mmap[%d] <anon>" 1142 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1143 loop, xaddr, excess - excess1, prot, flags, 1144 xmaddr); 1145 1146 if (xmaddr != xaddr) 1147 return -ENOMEM; 1148 } 1149 1150 if (prot & PROT_WRITE && excess1 > 0) { 1151 kdebug("clear[%d] ad=%lx sz=%lx", 1152 loop, maddr + phdr->p_filesz, excess1); 1153 if (clear_user((void __user *) maddr + phdr->p_filesz, 1154 excess1)) 1155 return -EFAULT; 1156 } 1157 1158 #else 1159 if (excess > 0) { 1160 kdebug("clear[%d] ad=%lx sz=%lx", 1161 loop, maddr + phdr->p_filesz, excess); 1162 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1163 return -EFAULT; 1164 } 1165 #endif 1166 1167 if (mm) { 1168 if (phdr->p_flags & PF_X) { 1169 if (!mm->start_code) { 1170 mm->start_code = maddr; 1171 mm->end_code = maddr + phdr->p_memsz; 1172 } 1173 } else if (!mm->start_data) { 1174 mm->start_data = maddr; 1175 mm->end_data = maddr + phdr->p_memsz; 1176 } 1177 } 1178 1179 seg++; 1180 } 1181 1182 return 0; 1183 } 1184 1185 /*****************************************************************************/ 1186 /* 1187 * ELF-FDPIC core dumper 1188 * 1189 * Modelled on fs/exec.c:aout_core_dump() 1190 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1191 * 1192 * Modelled on fs/binfmt_elf.c core dumper 1193 */ 1194 #ifdef CONFIG_ELF_CORE 1195 1196 /* 1197 * Decide whether a segment is worth dumping; default is yes to be 1198 * sure (missing info is worse than too much; etc). 1199 * Personally I'd include everything, and use the coredump limit... 1200 * 1201 * I think we should skip something. But I am not sure how. H.J. 1202 */ 1203 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1204 { 1205 int dump_ok; 1206 1207 /* Do not dump I/O mapped devices or special mappings */ 1208 if (vma->vm_flags & (VM_IO | VM_RESERVED)) { 1209 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1210 return 0; 1211 } 1212 1213 /* If we may not read the contents, don't allow us to dump 1214 * them either. "dump_write()" can't handle it anyway. 1215 */ 1216 if (!(vma->vm_flags & VM_READ)) { 1217 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1218 return 0; 1219 } 1220 1221 /* By default, dump shared memory if mapped from an anonymous file. */ 1222 if (vma->vm_flags & VM_SHARED) { 1223 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1224 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1225 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1226 vma->vm_flags, dump_ok ? "yes" : "no"); 1227 return dump_ok; 1228 } 1229 1230 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1231 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1232 vma->vm_flags, dump_ok ? "yes" : "no"); 1233 return dump_ok; 1234 } 1235 1236 #ifdef CONFIG_MMU 1237 /* By default, if it hasn't been written to, don't write it out */ 1238 if (!vma->anon_vma) { 1239 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1240 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1241 vma->vm_flags, dump_ok ? "yes" : "no"); 1242 return dump_ok; 1243 } 1244 #endif 1245 1246 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1247 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1248 dump_ok ? "yes" : "no"); 1249 return dump_ok; 1250 } 1251 1252 /* An ELF note in memory */ 1253 struct memelfnote 1254 { 1255 const char *name; 1256 int type; 1257 unsigned int datasz; 1258 void *data; 1259 }; 1260 1261 static int notesize(struct memelfnote *en) 1262 { 1263 int sz; 1264 1265 sz = sizeof(struct elf_note); 1266 sz += roundup(strlen(en->name) + 1, 4); 1267 sz += roundup(en->datasz, 4); 1268 1269 return sz; 1270 } 1271 1272 /* #define DEBUG */ 1273 1274 #define DUMP_WRITE(addr, nr, foffset) \ 1275 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) 1276 1277 static int alignfile(struct file *file, loff_t *foffset) 1278 { 1279 static const char buf[4] = { 0, }; 1280 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); 1281 return 1; 1282 } 1283 1284 static int writenote(struct memelfnote *men, struct file *file, 1285 loff_t *foffset) 1286 { 1287 struct elf_note en; 1288 en.n_namesz = strlen(men->name) + 1; 1289 en.n_descsz = men->datasz; 1290 en.n_type = men->type; 1291 1292 DUMP_WRITE(&en, sizeof(en), foffset); 1293 DUMP_WRITE(men->name, en.n_namesz, foffset); 1294 if (!alignfile(file, foffset)) 1295 return 0; 1296 DUMP_WRITE(men->data, men->datasz, foffset); 1297 if (!alignfile(file, foffset)) 1298 return 0; 1299 1300 return 1; 1301 } 1302 #undef DUMP_WRITE 1303 1304 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1305 { 1306 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1307 elf->e_ident[EI_CLASS] = ELF_CLASS; 1308 elf->e_ident[EI_DATA] = ELF_DATA; 1309 elf->e_ident[EI_VERSION] = EV_CURRENT; 1310 elf->e_ident[EI_OSABI] = ELF_OSABI; 1311 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1312 1313 elf->e_type = ET_CORE; 1314 elf->e_machine = ELF_ARCH; 1315 elf->e_version = EV_CURRENT; 1316 elf->e_entry = 0; 1317 elf->e_phoff = sizeof(struct elfhdr); 1318 elf->e_shoff = 0; 1319 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1320 elf->e_ehsize = sizeof(struct elfhdr); 1321 elf->e_phentsize = sizeof(struct elf_phdr); 1322 elf->e_phnum = segs; 1323 elf->e_shentsize = 0; 1324 elf->e_shnum = 0; 1325 elf->e_shstrndx = 0; 1326 return; 1327 } 1328 1329 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1330 { 1331 phdr->p_type = PT_NOTE; 1332 phdr->p_offset = offset; 1333 phdr->p_vaddr = 0; 1334 phdr->p_paddr = 0; 1335 phdr->p_filesz = sz; 1336 phdr->p_memsz = 0; 1337 phdr->p_flags = 0; 1338 phdr->p_align = 0; 1339 return; 1340 } 1341 1342 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1343 unsigned int sz, void *data) 1344 { 1345 note->name = name; 1346 note->type = type; 1347 note->datasz = sz; 1348 note->data = data; 1349 return; 1350 } 1351 1352 /* 1353 * fill up all the fields in prstatus from the given task struct, except 1354 * registers which need to be filled up separately. 1355 */ 1356 static void fill_prstatus(struct elf_prstatus *prstatus, 1357 struct task_struct *p, long signr) 1358 { 1359 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1360 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1361 prstatus->pr_sighold = p->blocked.sig[0]; 1362 rcu_read_lock(); 1363 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1364 rcu_read_unlock(); 1365 prstatus->pr_pid = task_pid_vnr(p); 1366 prstatus->pr_pgrp = task_pgrp_vnr(p); 1367 prstatus->pr_sid = task_session_vnr(p); 1368 if (thread_group_leader(p)) { 1369 struct task_cputime cputime; 1370 1371 /* 1372 * This is the record for the group leader. It shows the 1373 * group-wide total, not its individual thread total. 1374 */ 1375 thread_group_cputime(p, &cputime); 1376 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1377 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1378 } else { 1379 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1380 cputime_to_timeval(p->stime, &prstatus->pr_stime); 1381 } 1382 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1383 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1384 1385 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1386 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1387 } 1388 1389 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1390 struct mm_struct *mm) 1391 { 1392 const struct cred *cred; 1393 unsigned int i, len; 1394 1395 /* first copy the parameters from user space */ 1396 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1397 1398 len = mm->arg_end - mm->arg_start; 1399 if (len >= ELF_PRARGSZ) 1400 len = ELF_PRARGSZ - 1; 1401 if (copy_from_user(&psinfo->pr_psargs, 1402 (const char __user *) mm->arg_start, len)) 1403 return -EFAULT; 1404 for (i = 0; i < len; i++) 1405 if (psinfo->pr_psargs[i] == 0) 1406 psinfo->pr_psargs[i] = ' '; 1407 psinfo->pr_psargs[len] = 0; 1408 1409 rcu_read_lock(); 1410 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1411 rcu_read_unlock(); 1412 psinfo->pr_pid = task_pid_vnr(p); 1413 psinfo->pr_pgrp = task_pgrp_vnr(p); 1414 psinfo->pr_sid = task_session_vnr(p); 1415 1416 i = p->state ? ffz(~p->state) + 1 : 0; 1417 psinfo->pr_state = i; 1418 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1419 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1420 psinfo->pr_nice = task_nice(p); 1421 psinfo->pr_flag = p->flags; 1422 rcu_read_lock(); 1423 cred = __task_cred(p); 1424 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1425 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1426 rcu_read_unlock(); 1427 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1428 1429 return 0; 1430 } 1431 1432 /* Here is the structure in which status of each thread is captured. */ 1433 struct elf_thread_status 1434 { 1435 struct list_head list; 1436 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1437 elf_fpregset_t fpu; /* NT_PRFPREG */ 1438 struct task_struct *thread; 1439 #ifdef ELF_CORE_COPY_XFPREGS 1440 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1441 #endif 1442 struct memelfnote notes[3]; 1443 int num_notes; 1444 }; 1445 1446 /* 1447 * In order to add the specific thread information for the elf file format, 1448 * we need to keep a linked list of every thread's pr_status and then create 1449 * a single section for them in the final core file. 1450 */ 1451 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1452 { 1453 struct task_struct *p = t->thread; 1454 int sz = 0; 1455 1456 t->num_notes = 0; 1457 1458 fill_prstatus(&t->prstatus, p, signr); 1459 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1460 1461 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1462 &t->prstatus); 1463 t->num_notes++; 1464 sz += notesize(&t->notes[0]); 1465 1466 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1467 if (t->prstatus.pr_fpvalid) { 1468 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1469 &t->fpu); 1470 t->num_notes++; 1471 sz += notesize(&t->notes[1]); 1472 } 1473 1474 #ifdef ELF_CORE_COPY_XFPREGS 1475 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1476 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1477 sizeof(t->xfpu), &t->xfpu); 1478 t->num_notes++; 1479 sz += notesize(&t->notes[2]); 1480 } 1481 #endif 1482 return sz; 1483 } 1484 1485 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1486 elf_addr_t e_shoff, int segs) 1487 { 1488 elf->e_shoff = e_shoff; 1489 elf->e_shentsize = sizeof(*shdr4extnum); 1490 elf->e_shnum = 1; 1491 elf->e_shstrndx = SHN_UNDEF; 1492 1493 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1494 1495 shdr4extnum->sh_type = SHT_NULL; 1496 shdr4extnum->sh_size = elf->e_shnum; 1497 shdr4extnum->sh_link = elf->e_shstrndx; 1498 shdr4extnum->sh_info = segs; 1499 } 1500 1501 /* 1502 * dump the segments for an MMU process 1503 */ 1504 #ifdef CONFIG_MMU 1505 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1506 unsigned long *limit, unsigned long mm_flags) 1507 { 1508 struct vm_area_struct *vma; 1509 int err = 0; 1510 1511 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1512 unsigned long addr; 1513 1514 if (!maydump(vma, mm_flags)) 1515 continue; 1516 1517 for (addr = vma->vm_start; addr < vma->vm_end; 1518 addr += PAGE_SIZE) { 1519 struct page *page = get_dump_page(addr); 1520 if (page) { 1521 void *kaddr = kmap(page); 1522 *size += PAGE_SIZE; 1523 if (*size > *limit) 1524 err = -EFBIG; 1525 else if (!dump_write(file, kaddr, PAGE_SIZE)) 1526 err = -EIO; 1527 kunmap(page); 1528 page_cache_release(page); 1529 } else if (!dump_seek(file, PAGE_SIZE)) 1530 err = -EFBIG; 1531 if (err) 1532 goto out; 1533 } 1534 } 1535 out: 1536 return err; 1537 } 1538 #endif 1539 1540 /* 1541 * dump the segments for a NOMMU process 1542 */ 1543 #ifndef CONFIG_MMU 1544 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1545 unsigned long *limit, unsigned long mm_flags) 1546 { 1547 struct vm_area_struct *vma; 1548 1549 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1550 if (!maydump(vma, mm_flags)) 1551 continue; 1552 1553 if ((*size += PAGE_SIZE) > *limit) 1554 return -EFBIG; 1555 1556 if (!dump_write(file, (void *) vma->vm_start, 1557 vma->vm_end - vma->vm_start)) 1558 return -EIO; 1559 } 1560 1561 return 0; 1562 } 1563 #endif 1564 1565 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1566 { 1567 struct vm_area_struct *vma; 1568 size_t size = 0; 1569 1570 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1571 if (maydump(vma, mm_flags)) 1572 size += vma->vm_end - vma->vm_start; 1573 return size; 1574 } 1575 1576 /* 1577 * Actual dumper 1578 * 1579 * This is a two-pass process; first we find the offsets of the bits, 1580 * and then they are actually written out. If we run out of core limit 1581 * we just truncate. 1582 */ 1583 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1584 { 1585 #define NUM_NOTES 6 1586 int has_dumped = 0; 1587 mm_segment_t fs; 1588 int segs; 1589 size_t size = 0; 1590 int i; 1591 struct vm_area_struct *vma; 1592 struct elfhdr *elf = NULL; 1593 loff_t offset = 0, dataoff, foffset; 1594 int numnote; 1595 struct memelfnote *notes = NULL; 1596 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1597 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1598 LIST_HEAD(thread_list); 1599 struct list_head *t; 1600 elf_fpregset_t *fpu = NULL; 1601 #ifdef ELF_CORE_COPY_XFPREGS 1602 elf_fpxregset_t *xfpu = NULL; 1603 #endif 1604 int thread_status_size = 0; 1605 elf_addr_t *auxv; 1606 struct elf_phdr *phdr4note = NULL; 1607 struct elf_shdr *shdr4extnum = NULL; 1608 Elf_Half e_phnum; 1609 elf_addr_t e_shoff; 1610 1611 /* 1612 * We no longer stop all VM operations. 1613 * 1614 * This is because those proceses that could possibly change map_count 1615 * or the mmap / vma pages are now blocked in do_exit on current 1616 * finishing this core dump. 1617 * 1618 * Only ptrace can touch these memory addresses, but it doesn't change 1619 * the map_count or the pages allocated. So no possibility of crashing 1620 * exists while dumping the mm->vm_next areas to the core file. 1621 */ 1622 1623 /* alloc memory for large data structures: too large to be on stack */ 1624 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1625 if (!elf) 1626 goto cleanup; 1627 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1628 if (!prstatus) 1629 goto cleanup; 1630 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1631 if (!psinfo) 1632 goto cleanup; 1633 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1634 if (!notes) 1635 goto cleanup; 1636 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1637 if (!fpu) 1638 goto cleanup; 1639 #ifdef ELF_CORE_COPY_XFPREGS 1640 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1641 if (!xfpu) 1642 goto cleanup; 1643 #endif 1644 1645 if (cprm->signr) { 1646 struct core_thread *ct; 1647 struct elf_thread_status *tmp; 1648 1649 for (ct = current->mm->core_state->dumper.next; 1650 ct; ct = ct->next) { 1651 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1652 if (!tmp) 1653 goto cleanup; 1654 1655 tmp->thread = ct->task; 1656 list_add(&tmp->list, &thread_list); 1657 } 1658 1659 list_for_each(t, &thread_list) { 1660 struct elf_thread_status *tmp; 1661 int sz; 1662 1663 tmp = list_entry(t, struct elf_thread_status, list); 1664 sz = elf_dump_thread_status(cprm->signr, tmp); 1665 thread_status_size += sz; 1666 } 1667 } 1668 1669 /* now collect the dump for the current */ 1670 fill_prstatus(prstatus, current, cprm->signr); 1671 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1672 1673 segs = current->mm->map_count; 1674 segs += elf_core_extra_phdrs(); 1675 1676 /* for notes section */ 1677 segs++; 1678 1679 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1680 * this, kernel supports extended numbering. Have a look at 1681 * include/linux/elf.h for further information. */ 1682 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1683 1684 /* Set up header */ 1685 fill_elf_fdpic_header(elf, e_phnum); 1686 1687 has_dumped = 1; 1688 current->flags |= PF_DUMPCORE; 1689 1690 /* 1691 * Set up the notes in similar form to SVR4 core dumps made 1692 * with info from their /proc. 1693 */ 1694 1695 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1696 fill_psinfo(psinfo, current->group_leader, current->mm); 1697 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1698 1699 numnote = 2; 1700 1701 auxv = (elf_addr_t *) current->mm->saved_auxv; 1702 1703 i = 0; 1704 do 1705 i += 2; 1706 while (auxv[i - 2] != AT_NULL); 1707 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1708 i * sizeof(elf_addr_t), auxv); 1709 1710 /* Try to dump the FPU. */ 1711 if ((prstatus->pr_fpvalid = 1712 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1713 fill_note(notes + numnote++, 1714 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1715 #ifdef ELF_CORE_COPY_XFPREGS 1716 if (elf_core_copy_task_xfpregs(current, xfpu)) 1717 fill_note(notes + numnote++, 1718 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1719 #endif 1720 1721 fs = get_fs(); 1722 set_fs(KERNEL_DS); 1723 1724 offset += sizeof(*elf); /* Elf header */ 1725 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1726 foffset = offset; 1727 1728 /* Write notes phdr entry */ 1729 { 1730 int sz = 0; 1731 1732 for (i = 0; i < numnote; i++) 1733 sz += notesize(notes + i); 1734 1735 sz += thread_status_size; 1736 1737 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1738 if (!phdr4note) 1739 goto end_coredump; 1740 1741 fill_elf_note_phdr(phdr4note, sz, offset); 1742 offset += sz; 1743 } 1744 1745 /* Page-align dumped data */ 1746 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1747 1748 offset += elf_core_vma_data_size(cprm->mm_flags); 1749 offset += elf_core_extra_data_size(); 1750 e_shoff = offset; 1751 1752 if (e_phnum == PN_XNUM) { 1753 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1754 if (!shdr4extnum) 1755 goto end_coredump; 1756 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1757 } 1758 1759 offset = dataoff; 1760 1761 size += sizeof(*elf); 1762 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) 1763 goto end_coredump; 1764 1765 size += sizeof(*phdr4note); 1766 if (size > cprm->limit 1767 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) 1768 goto end_coredump; 1769 1770 /* write program headers for segments dump */ 1771 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1772 struct elf_phdr phdr; 1773 size_t sz; 1774 1775 sz = vma->vm_end - vma->vm_start; 1776 1777 phdr.p_type = PT_LOAD; 1778 phdr.p_offset = offset; 1779 phdr.p_vaddr = vma->vm_start; 1780 phdr.p_paddr = 0; 1781 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1782 phdr.p_memsz = sz; 1783 offset += phdr.p_filesz; 1784 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1785 if (vma->vm_flags & VM_WRITE) 1786 phdr.p_flags |= PF_W; 1787 if (vma->vm_flags & VM_EXEC) 1788 phdr.p_flags |= PF_X; 1789 phdr.p_align = ELF_EXEC_PAGESIZE; 1790 1791 size += sizeof(phdr); 1792 if (size > cprm->limit 1793 || !dump_write(cprm->file, &phdr, sizeof(phdr))) 1794 goto end_coredump; 1795 } 1796 1797 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) 1798 goto end_coredump; 1799 1800 /* write out the notes section */ 1801 for (i = 0; i < numnote; i++) 1802 if (!writenote(notes + i, cprm->file, &foffset)) 1803 goto end_coredump; 1804 1805 /* write out the thread status notes section */ 1806 list_for_each(t, &thread_list) { 1807 struct elf_thread_status *tmp = 1808 list_entry(t, struct elf_thread_status, list); 1809 1810 for (i = 0; i < tmp->num_notes; i++) 1811 if (!writenote(&tmp->notes[i], cprm->file, &foffset)) 1812 goto end_coredump; 1813 } 1814 1815 if (!dump_seek(cprm->file, dataoff - foffset)) 1816 goto end_coredump; 1817 1818 if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit, 1819 cprm->mm_flags) < 0) 1820 goto end_coredump; 1821 1822 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) 1823 goto end_coredump; 1824 1825 if (e_phnum == PN_XNUM) { 1826 size += sizeof(*shdr4extnum); 1827 if (size > cprm->limit 1828 || !dump_write(cprm->file, shdr4extnum, 1829 sizeof(*shdr4extnum))) 1830 goto end_coredump; 1831 } 1832 1833 if (cprm->file->f_pos != offset) { 1834 /* Sanity check */ 1835 printk(KERN_WARNING 1836 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1837 cprm->file->f_pos, offset); 1838 } 1839 1840 end_coredump: 1841 set_fs(fs); 1842 1843 cleanup: 1844 while (!list_empty(&thread_list)) { 1845 struct list_head *tmp = thread_list.next; 1846 list_del(tmp); 1847 kfree(list_entry(tmp, struct elf_thread_status, list)); 1848 } 1849 kfree(phdr4note); 1850 kfree(elf); 1851 kfree(prstatus); 1852 kfree(psinfo); 1853 kfree(notes); 1854 kfree(fpu); 1855 kfree(shdr4extnum); 1856 #ifdef ELF_CORE_COPY_XFPREGS 1857 kfree(xfpu); 1858 #endif 1859 return has_dumped; 1860 #undef NUM_NOTES 1861 } 1862 1863 #endif /* CONFIG_ELF_CORE */ 1864