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 43 typedef char *elf_caddr_t; 44 45 #if 0 46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 47 #else 48 #define kdebug(fmt, ...) do {} while(0) 49 #endif 50 51 #if 0 52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 53 #else 54 #define kdcore(fmt, ...) do {} while(0) 55 #endif 56 57 MODULE_LICENSE("GPL"); 58 59 static int load_elf_fdpic_binary(struct linux_binprm *); 60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 62 struct mm_struct *, const char *); 63 64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 65 struct elf_fdpic_params *, 66 struct elf_fdpic_params *); 67 68 #ifndef CONFIG_MMU 69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, 70 unsigned long *); 71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 72 struct file *, 73 struct mm_struct *); 74 #endif 75 76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 77 struct file *, struct mm_struct *); 78 79 #ifdef CONFIG_ELF_CORE 80 static int elf_fdpic_core_dump(struct coredump_params *cprm); 81 #endif 82 83 static struct linux_binfmt elf_fdpic_format = { 84 .module = THIS_MODULE, 85 .load_binary = load_elf_fdpic_binary, 86 #ifdef CONFIG_ELF_CORE 87 .core_dump = elf_fdpic_core_dump, 88 #endif 89 .min_coredump = ELF_EXEC_PAGESIZE, 90 }; 91 92 static int __init init_elf_fdpic_binfmt(void) 93 { 94 register_binfmt(&elf_fdpic_format); 95 return 0; 96 } 97 98 static void __exit exit_elf_fdpic_binfmt(void) 99 { 100 unregister_binfmt(&elf_fdpic_format); 101 } 102 103 core_initcall(init_elf_fdpic_binfmt); 104 module_exit(exit_elf_fdpic_binfmt); 105 106 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) 107 { 108 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 109 return 0; 110 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 111 return 0; 112 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) 113 return 0; 114 if (!file->f_op || !file->f_op->mmap) 115 return 0; 116 return 1; 117 } 118 119 /*****************************************************************************/ 120 /* 121 * read the program headers table into memory 122 */ 123 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 124 struct file *file) 125 { 126 struct elf32_phdr *phdr; 127 unsigned long size; 128 int retval, loop; 129 130 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 131 return -ENOMEM; 132 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 133 return -ENOMEM; 134 135 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 136 params->phdrs = kmalloc(size, GFP_KERNEL); 137 if (!params->phdrs) 138 return -ENOMEM; 139 140 retval = kernel_read(file, params->hdr.e_phoff, 141 (char *) params->phdrs, size); 142 if (unlikely(retval != size)) 143 return retval < 0 ? retval : -ENOEXEC; 144 145 /* determine stack size for this binary */ 146 phdr = params->phdrs; 147 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 148 if (phdr->p_type != PT_GNU_STACK) 149 continue; 150 151 if (phdr->p_flags & PF_X) 152 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 153 else 154 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 155 156 params->stack_size = phdr->p_memsz; 157 break; 158 } 159 160 return 0; 161 } 162 163 /*****************************************************************************/ 164 /* 165 * load an fdpic binary into various bits of memory 166 */ 167 static int load_elf_fdpic_binary(struct linux_binprm *bprm) 168 { 169 struct elf_fdpic_params exec_params, interp_params; 170 struct pt_regs *regs = current_pt_regs(); 171 struct elf_phdr *phdr; 172 unsigned long stack_size, entryaddr; 173 #ifdef ELF_FDPIC_PLAT_INIT 174 unsigned long dynaddr; 175 #endif 176 #ifndef CONFIG_MMU 177 unsigned long stack_prot; 178 #endif 179 struct file *interpreter = NULL; /* to shut gcc up */ 180 char *interpreter_name = NULL; 181 int executable_stack; 182 int retval, i; 183 184 kdebug("____ LOAD %d ____", current->pid); 185 186 memset(&exec_params, 0, sizeof(exec_params)); 187 memset(&interp_params, 0, sizeof(interp_params)); 188 189 exec_params.hdr = *(struct elfhdr *) bprm->buf; 190 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 191 192 /* check that this is a binary we know how to deal with */ 193 retval = -ENOEXEC; 194 if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) 195 goto error; 196 197 /* read the program header table */ 198 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 199 if (retval < 0) 200 goto error; 201 202 /* scan for a program header that specifies an interpreter */ 203 phdr = exec_params.phdrs; 204 205 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 206 switch (phdr->p_type) { 207 case PT_INTERP: 208 retval = -ENOMEM; 209 if (phdr->p_filesz > PATH_MAX) 210 goto error; 211 retval = -ENOENT; 212 if (phdr->p_filesz < 2) 213 goto error; 214 215 /* read the name of the interpreter into memory */ 216 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 217 if (!interpreter_name) 218 goto error; 219 220 retval = kernel_read(bprm->file, 221 phdr->p_offset, 222 interpreter_name, 223 phdr->p_filesz); 224 if (unlikely(retval != phdr->p_filesz)) { 225 if (retval >= 0) 226 retval = -ENOEXEC; 227 goto error; 228 } 229 230 retval = -ENOENT; 231 if (interpreter_name[phdr->p_filesz - 1] != '\0') 232 goto error; 233 234 kdebug("Using ELF interpreter %s", interpreter_name); 235 236 /* replace the program with the interpreter */ 237 interpreter = open_exec(interpreter_name); 238 retval = PTR_ERR(interpreter); 239 if (IS_ERR(interpreter)) { 240 interpreter = NULL; 241 goto error; 242 } 243 244 /* 245 * If the binary is not readable then enforce 246 * mm->dumpable = 0 regardless of the interpreter's 247 * permissions. 248 */ 249 would_dump(bprm, interpreter); 250 251 retval = kernel_read(interpreter, 0, bprm->buf, 252 BINPRM_BUF_SIZE); 253 if (unlikely(retval != BINPRM_BUF_SIZE)) { 254 if (retval >= 0) 255 retval = -ENOEXEC; 256 goto error; 257 } 258 259 interp_params.hdr = *((struct elfhdr *) bprm->buf); 260 break; 261 262 case PT_LOAD: 263 #ifdef CONFIG_MMU 264 if (exec_params.load_addr == 0) 265 exec_params.load_addr = phdr->p_vaddr; 266 #endif 267 break; 268 } 269 270 } 271 272 if (elf_check_const_displacement(&exec_params.hdr)) 273 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 274 275 /* perform insanity checks on the interpreter */ 276 if (interpreter_name) { 277 retval = -ELIBBAD; 278 if (!is_elf_fdpic(&interp_params.hdr, interpreter)) 279 goto error; 280 281 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 282 283 /* read the interpreter's program header table */ 284 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 285 if (retval < 0) 286 goto error; 287 } 288 289 stack_size = exec_params.stack_size; 290 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 291 executable_stack = EXSTACK_ENABLE_X; 292 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 293 executable_stack = EXSTACK_DISABLE_X; 294 else 295 executable_stack = EXSTACK_DEFAULT; 296 297 if (stack_size == 0) { 298 stack_size = interp_params.stack_size; 299 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 300 executable_stack = EXSTACK_ENABLE_X; 301 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 302 executable_stack = EXSTACK_DISABLE_X; 303 else 304 executable_stack = EXSTACK_DEFAULT; 305 } 306 307 retval = -ENOEXEC; 308 if (stack_size == 0) 309 goto error; 310 311 if (elf_check_const_displacement(&interp_params.hdr)) 312 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 313 314 /* flush all traces of the currently running executable */ 315 retval = flush_old_exec(bprm); 316 if (retval) 317 goto error; 318 319 /* there's now no turning back... the old userspace image is dead, 320 * defunct, deceased, etc. after this point we have to exit via 321 * error_kill */ 322 set_personality(PER_LINUX_FDPIC); 323 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 324 current->personality |= READ_IMPLIES_EXEC; 325 326 setup_new_exec(bprm); 327 328 set_binfmt(&elf_fdpic_format); 329 330 current->mm->start_code = 0; 331 current->mm->end_code = 0; 332 current->mm->start_stack = 0; 333 current->mm->start_data = 0; 334 current->mm->end_data = 0; 335 current->mm->context.exec_fdpic_loadmap = 0; 336 current->mm->context.interp_fdpic_loadmap = 0; 337 338 #ifdef CONFIG_MMU 339 elf_fdpic_arch_lay_out_mm(&exec_params, 340 &interp_params, 341 ¤t->mm->start_stack, 342 ¤t->mm->start_brk); 343 344 retval = setup_arg_pages(bprm, current->mm->start_stack, 345 executable_stack); 346 if (retval < 0) { 347 send_sig(SIGKILL, current, 0); 348 goto error_kill; 349 } 350 #endif 351 352 /* load the executable and interpreter into memory */ 353 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 354 "executable"); 355 if (retval < 0) 356 goto error_kill; 357 358 if (interpreter_name) { 359 retval = elf_fdpic_map_file(&interp_params, interpreter, 360 current->mm, "interpreter"); 361 if (retval < 0) { 362 printk(KERN_ERR "Unable to load interpreter\n"); 363 goto error_kill; 364 } 365 366 allow_write_access(interpreter); 367 fput(interpreter); 368 interpreter = NULL; 369 } 370 371 #ifdef CONFIG_MMU 372 if (!current->mm->start_brk) 373 current->mm->start_brk = current->mm->end_data; 374 375 current->mm->brk = current->mm->start_brk = 376 PAGE_ALIGN(current->mm->start_brk); 377 378 #else 379 /* create a stack and brk area big enough for everyone 380 * - the brk heap starts at the bottom and works up 381 * - the stack starts at the top and works down 382 */ 383 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 384 if (stack_size < PAGE_SIZE * 2) 385 stack_size = PAGE_SIZE * 2; 386 387 stack_prot = PROT_READ | PROT_WRITE; 388 if (executable_stack == EXSTACK_ENABLE_X || 389 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 390 stack_prot |= PROT_EXEC; 391 392 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 393 MAP_PRIVATE | MAP_ANONYMOUS | 394 MAP_UNINITIALIZED | MAP_GROWSDOWN, 395 0); 396 397 if (IS_ERR_VALUE(current->mm->start_brk)) { 398 retval = current->mm->start_brk; 399 current->mm->start_brk = 0; 400 goto error_kill; 401 } 402 403 current->mm->brk = current->mm->start_brk; 404 current->mm->context.end_brk = current->mm->start_brk; 405 current->mm->context.end_brk += 406 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; 407 current->mm->start_stack = current->mm->start_brk + stack_size; 408 #endif 409 410 install_exec_creds(bprm); 411 if (create_elf_fdpic_tables(bprm, current->mm, 412 &exec_params, &interp_params) < 0) 413 goto error_kill; 414 415 kdebug("- start_code %lx", current->mm->start_code); 416 kdebug("- end_code %lx", current->mm->end_code); 417 kdebug("- start_data %lx", current->mm->start_data); 418 kdebug("- end_data %lx", current->mm->end_data); 419 kdebug("- start_brk %lx", current->mm->start_brk); 420 kdebug("- brk %lx", current->mm->brk); 421 kdebug("- start_stack %lx", current->mm->start_stack); 422 423 #ifdef ELF_FDPIC_PLAT_INIT 424 /* 425 * The ABI may specify that certain registers be set up in special 426 * ways (on i386 %edx is the address of a DT_FINI function, for 427 * example. This macro performs whatever initialization to 428 * the regs structure is required. 429 */ 430 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 431 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 432 dynaddr); 433 #endif 434 435 /* everything is now ready... get the userspace context ready to roll */ 436 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 437 start_thread(regs, entryaddr, current->mm->start_stack); 438 439 retval = 0; 440 441 error: 442 if (interpreter) { 443 allow_write_access(interpreter); 444 fput(interpreter); 445 } 446 kfree(interpreter_name); 447 kfree(exec_params.phdrs); 448 kfree(exec_params.loadmap); 449 kfree(interp_params.phdrs); 450 kfree(interp_params.loadmap); 451 return retval; 452 453 /* unrecoverable error - kill the process */ 454 error_kill: 455 send_sig(SIGSEGV, current, 0); 456 goto error; 457 458 } 459 460 /*****************************************************************************/ 461 462 #ifndef ELF_BASE_PLATFORM 463 /* 464 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 465 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 466 * will be copied to the user stack in the same manner as AT_PLATFORM. 467 */ 468 #define ELF_BASE_PLATFORM NULL 469 #endif 470 471 /* 472 * present useful information to the program by shovelling it onto the new 473 * process's stack 474 */ 475 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 476 struct mm_struct *mm, 477 struct elf_fdpic_params *exec_params, 478 struct elf_fdpic_params *interp_params) 479 { 480 const struct cred *cred = current_cred(); 481 unsigned long sp, csp, nitems; 482 elf_caddr_t __user *argv, *envp; 483 size_t platform_len = 0, len; 484 char *k_platform, *k_base_platform; 485 char __user *u_platform, *u_base_platform, *p; 486 int loop; 487 int nr; /* reset for each csp adjustment */ 488 489 #ifdef CONFIG_MMU 490 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 491 * by the processes running on the same package. One thing we can do is 492 * to shuffle the initial stack for them, so we give the architecture 493 * an opportunity to do so here. 494 */ 495 sp = arch_align_stack(bprm->p); 496 #else 497 sp = mm->start_stack; 498 499 /* stack the program arguments and environment */ 500 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 501 return -EFAULT; 502 #endif 503 504 /* 505 * If this architecture has a platform capability string, copy it 506 * to userspace. In some cases (Sparc), this info is impossible 507 * for userspace to get any other way, in others (i386) it is 508 * merely difficult. 509 */ 510 k_platform = ELF_PLATFORM; 511 u_platform = NULL; 512 513 if (k_platform) { 514 platform_len = strlen(k_platform) + 1; 515 sp -= platform_len; 516 u_platform = (char __user *) sp; 517 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 518 return -EFAULT; 519 } 520 521 /* 522 * If this architecture has a "base" platform capability 523 * string, copy it to userspace. 524 */ 525 k_base_platform = ELF_BASE_PLATFORM; 526 u_base_platform = NULL; 527 528 if (k_base_platform) { 529 platform_len = strlen(k_base_platform) + 1; 530 sp -= platform_len; 531 u_base_platform = (char __user *) sp; 532 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 533 return -EFAULT; 534 } 535 536 sp &= ~7UL; 537 538 /* stack the load map(s) */ 539 len = sizeof(struct elf32_fdpic_loadmap); 540 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 541 sp = (sp - len) & ~7UL; 542 exec_params->map_addr = sp; 543 544 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 545 return -EFAULT; 546 547 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 548 549 if (interp_params->loadmap) { 550 len = sizeof(struct elf32_fdpic_loadmap); 551 len += sizeof(struct elf32_fdpic_loadseg) * 552 interp_params->loadmap->nsegs; 553 sp = (sp - len) & ~7UL; 554 interp_params->map_addr = sp; 555 556 if (copy_to_user((void __user *) sp, interp_params->loadmap, 557 len) != 0) 558 return -EFAULT; 559 560 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 561 } 562 563 /* force 16 byte _final_ alignment here for generality */ 564 #define DLINFO_ITEMS 15 565 566 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 567 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 568 569 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 570 nitems++; 571 572 csp = sp; 573 sp -= nitems * 2 * sizeof(unsigned long); 574 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 575 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 576 sp -= 1 * sizeof(unsigned long); /* argc */ 577 578 csp -= sp & 15UL; 579 sp -= sp & 15UL; 580 581 /* put the ELF interpreter info on the stack */ 582 #define NEW_AUX_ENT(id, val) \ 583 do { \ 584 struct { unsigned long _id, _val; } __user *ent; \ 585 \ 586 ent = (void __user *) csp; \ 587 __put_user((id), &ent[nr]._id); \ 588 __put_user((val), &ent[nr]._val); \ 589 nr++; \ 590 } while (0) 591 592 nr = 0; 593 csp -= 2 * sizeof(unsigned long); 594 NEW_AUX_ENT(AT_NULL, 0); 595 if (k_platform) { 596 nr = 0; 597 csp -= 2 * sizeof(unsigned long); 598 NEW_AUX_ENT(AT_PLATFORM, 599 (elf_addr_t) (unsigned long) u_platform); 600 } 601 602 if (k_base_platform) { 603 nr = 0; 604 csp -= 2 * sizeof(unsigned long); 605 NEW_AUX_ENT(AT_BASE_PLATFORM, 606 (elf_addr_t) (unsigned long) u_base_platform); 607 } 608 609 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 610 nr = 0; 611 csp -= 2 * sizeof(unsigned long); 612 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 613 } 614 615 nr = 0; 616 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 617 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 618 #ifdef ELF_HWCAP2 619 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 620 #endif 621 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 622 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 623 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 624 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 625 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 626 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 627 NEW_AUX_ENT(AT_FLAGS, 0); 628 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 629 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 630 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 631 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 632 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 633 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 634 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 635 636 #ifdef ARCH_DLINFO 637 nr = 0; 638 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 639 640 /* ARCH_DLINFO must come last so platform specific code can enforce 641 * special alignment requirements on the AUXV if necessary (eg. PPC). 642 */ 643 ARCH_DLINFO; 644 #endif 645 #undef NEW_AUX_ENT 646 647 /* allocate room for argv[] and envv[] */ 648 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 649 envp = (elf_caddr_t __user *) csp; 650 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 651 argv = (elf_caddr_t __user *) csp; 652 653 /* stack argc */ 654 csp -= sizeof(unsigned long); 655 __put_user(bprm->argc, (unsigned long __user *) csp); 656 657 BUG_ON(csp != sp); 658 659 /* fill in the argv[] array */ 660 #ifdef CONFIG_MMU 661 current->mm->arg_start = bprm->p; 662 #else 663 current->mm->arg_start = current->mm->start_stack - 664 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 665 #endif 666 667 p = (char __user *) current->mm->arg_start; 668 for (loop = bprm->argc; loop > 0; loop--) { 669 __put_user((elf_caddr_t) p, argv++); 670 len = strnlen_user(p, MAX_ARG_STRLEN); 671 if (!len || len > MAX_ARG_STRLEN) 672 return -EINVAL; 673 p += len; 674 } 675 __put_user(NULL, argv); 676 current->mm->arg_end = (unsigned long) p; 677 678 /* fill in the envv[] array */ 679 current->mm->env_start = (unsigned long) p; 680 for (loop = bprm->envc; loop > 0; loop--) { 681 __put_user((elf_caddr_t)(unsigned long) p, envp++); 682 len = strnlen_user(p, MAX_ARG_STRLEN); 683 if (!len || len > MAX_ARG_STRLEN) 684 return -EINVAL; 685 p += len; 686 } 687 __put_user(NULL, envp); 688 current->mm->env_end = (unsigned long) p; 689 690 mm->start_stack = (unsigned long) sp; 691 return 0; 692 } 693 694 /*****************************************************************************/ 695 /* 696 * transfer the program arguments and environment from the holding pages onto 697 * the stack 698 */ 699 #ifndef CONFIG_MMU 700 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 701 unsigned long *_sp) 702 { 703 unsigned long index, stop, sp; 704 char *src; 705 int ret = 0; 706 707 stop = bprm->p >> PAGE_SHIFT; 708 sp = *_sp; 709 710 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 711 src = kmap(bprm->page[index]); 712 sp -= PAGE_SIZE; 713 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 714 ret = -EFAULT; 715 kunmap(bprm->page[index]); 716 if (ret < 0) 717 goto out; 718 } 719 720 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 721 722 out: 723 return ret; 724 } 725 #endif 726 727 /*****************************************************************************/ 728 /* 729 * load the appropriate binary image (executable or interpreter) into memory 730 * - we assume no MMU is available 731 * - if no other PIC bits are set in params->hdr->e_flags 732 * - we assume that the LOADable segments in the binary are independently relocatable 733 * - we assume R/O executable segments are shareable 734 * - else 735 * - we assume the loadable parts of the image to require fixed displacement 736 * - the image is not shareable 737 */ 738 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 739 struct file *file, 740 struct mm_struct *mm, 741 const char *what) 742 { 743 struct elf32_fdpic_loadmap *loadmap; 744 #ifdef CONFIG_MMU 745 struct elf32_fdpic_loadseg *mseg; 746 #endif 747 struct elf32_fdpic_loadseg *seg; 748 struct elf32_phdr *phdr; 749 unsigned long load_addr, stop; 750 unsigned nloads, tmp; 751 size_t size; 752 int loop, ret; 753 754 /* allocate a load map table */ 755 nloads = 0; 756 for (loop = 0; loop < params->hdr.e_phnum; loop++) 757 if (params->phdrs[loop].p_type == PT_LOAD) 758 nloads++; 759 760 if (nloads == 0) 761 return -ELIBBAD; 762 763 size = sizeof(*loadmap) + nloads * sizeof(*seg); 764 loadmap = kzalloc(size, GFP_KERNEL); 765 if (!loadmap) 766 return -ENOMEM; 767 768 params->loadmap = loadmap; 769 770 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 771 loadmap->nsegs = nloads; 772 773 load_addr = params->load_addr; 774 seg = loadmap->segs; 775 776 /* map the requested LOADs into the memory space */ 777 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 778 case ELF_FDPIC_FLAG_CONSTDISP: 779 case ELF_FDPIC_FLAG_CONTIGUOUS: 780 #ifndef CONFIG_MMU 781 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 782 if (ret < 0) 783 return ret; 784 break; 785 #endif 786 default: 787 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 788 if (ret < 0) 789 return ret; 790 break; 791 } 792 793 /* map the entry point */ 794 if (params->hdr.e_entry) { 795 seg = loadmap->segs; 796 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 797 if (params->hdr.e_entry >= seg->p_vaddr && 798 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 799 params->entry_addr = 800 (params->hdr.e_entry - seg->p_vaddr) + 801 seg->addr; 802 break; 803 } 804 } 805 } 806 807 /* determine where the program header table has wound up if mapped */ 808 stop = params->hdr.e_phoff; 809 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 810 phdr = params->phdrs; 811 812 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 813 if (phdr->p_type != PT_LOAD) 814 continue; 815 816 if (phdr->p_offset > params->hdr.e_phoff || 817 phdr->p_offset + phdr->p_filesz < stop) 818 continue; 819 820 seg = loadmap->segs; 821 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 822 if (phdr->p_vaddr >= seg->p_vaddr && 823 phdr->p_vaddr + phdr->p_filesz <= 824 seg->p_vaddr + seg->p_memsz) { 825 params->ph_addr = 826 (phdr->p_vaddr - seg->p_vaddr) + 827 seg->addr + 828 params->hdr.e_phoff - phdr->p_offset; 829 break; 830 } 831 } 832 break; 833 } 834 835 /* determine where the dynamic section has wound up if there is one */ 836 phdr = params->phdrs; 837 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 838 if (phdr->p_type != PT_DYNAMIC) 839 continue; 840 841 seg = loadmap->segs; 842 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 843 if (phdr->p_vaddr >= seg->p_vaddr && 844 phdr->p_vaddr + phdr->p_memsz <= 845 seg->p_vaddr + seg->p_memsz) { 846 params->dynamic_addr = 847 (phdr->p_vaddr - seg->p_vaddr) + 848 seg->addr; 849 850 /* check the dynamic section contains at least 851 * one item, and that the last item is a NULL 852 * entry */ 853 if (phdr->p_memsz == 0 || 854 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 855 goto dynamic_error; 856 857 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 858 if (((Elf32_Dyn *) 859 params->dynamic_addr)[tmp - 1].d_tag != 0) 860 goto dynamic_error; 861 break; 862 } 863 } 864 break; 865 } 866 867 /* now elide adjacent segments in the load map on MMU linux 868 * - on uClinux the holes between may actually be filled with system 869 * stuff or stuff from other processes 870 */ 871 #ifdef CONFIG_MMU 872 nloads = loadmap->nsegs; 873 mseg = loadmap->segs; 874 seg = mseg + 1; 875 for (loop = 1; loop < nloads; loop++) { 876 /* see if we have a candidate for merging */ 877 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 878 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 879 if (load_addr == (seg->addr & PAGE_MASK)) { 880 mseg->p_memsz += 881 load_addr - 882 (mseg->addr + mseg->p_memsz); 883 mseg->p_memsz += seg->addr & ~PAGE_MASK; 884 mseg->p_memsz += seg->p_memsz; 885 loadmap->nsegs--; 886 continue; 887 } 888 } 889 890 mseg++; 891 if (mseg != seg) 892 *mseg = *seg; 893 } 894 #endif 895 896 kdebug("Mapped Object [%s]:", what); 897 kdebug("- elfhdr : %lx", params->elfhdr_addr); 898 kdebug("- entry : %lx", params->entry_addr); 899 kdebug("- PHDR[] : %lx", params->ph_addr); 900 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 901 seg = loadmap->segs; 902 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 903 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 904 loop, 905 seg->addr, seg->addr + seg->p_memsz - 1, 906 seg->p_vaddr, seg->p_memsz); 907 908 return 0; 909 910 dynamic_error: 911 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 912 what, file_inode(file)->i_ino); 913 return -ELIBBAD; 914 } 915 916 /*****************************************************************************/ 917 /* 918 * map a file with constant displacement under uClinux 919 */ 920 #ifndef CONFIG_MMU 921 static int elf_fdpic_map_file_constdisp_on_uclinux( 922 struct elf_fdpic_params *params, 923 struct file *file, 924 struct mm_struct *mm) 925 { 926 struct elf32_fdpic_loadseg *seg; 927 struct elf32_phdr *phdr; 928 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 929 int loop, ret; 930 931 load_addr = params->load_addr; 932 seg = params->loadmap->segs; 933 934 /* determine the bounds of the contiguous overall allocation we must 935 * make */ 936 phdr = params->phdrs; 937 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 938 if (params->phdrs[loop].p_type != PT_LOAD) 939 continue; 940 941 if (base > phdr->p_vaddr) 942 base = phdr->p_vaddr; 943 if (top < phdr->p_vaddr + phdr->p_memsz) 944 top = phdr->p_vaddr + phdr->p_memsz; 945 } 946 947 /* allocate one big anon block for everything */ 948 mflags = MAP_PRIVATE; 949 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 950 mflags |= MAP_EXECUTABLE; 951 952 maddr = vm_mmap(NULL, load_addr, top - base, 953 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 954 if (IS_ERR_VALUE(maddr)) 955 return (int) maddr; 956 957 if (load_addr != 0) 958 load_addr += PAGE_ALIGN(top - base); 959 960 /* and then load the file segments into it */ 961 phdr = params->phdrs; 962 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 963 if (params->phdrs[loop].p_type != PT_LOAD) 964 continue; 965 966 seg->addr = maddr + (phdr->p_vaddr - base); 967 seg->p_vaddr = phdr->p_vaddr; 968 seg->p_memsz = phdr->p_memsz; 969 970 ret = read_code(file, seg->addr, phdr->p_offset, 971 phdr->p_filesz); 972 if (ret < 0) 973 return ret; 974 975 /* map the ELF header address if in this segment */ 976 if (phdr->p_offset == 0) 977 params->elfhdr_addr = seg->addr; 978 979 /* clear any space allocated but not loaded */ 980 if (phdr->p_filesz < phdr->p_memsz) { 981 if (clear_user((void *) (seg->addr + phdr->p_filesz), 982 phdr->p_memsz - phdr->p_filesz)) 983 return -EFAULT; 984 } 985 986 if (mm) { 987 if (phdr->p_flags & PF_X) { 988 if (!mm->start_code) { 989 mm->start_code = seg->addr; 990 mm->end_code = seg->addr + 991 phdr->p_memsz; 992 } 993 } else if (!mm->start_data) { 994 mm->start_data = seg->addr; 995 mm->end_data = seg->addr + phdr->p_memsz; 996 } 997 } 998 999 seg++; 1000 } 1001 1002 return 0; 1003 } 1004 #endif 1005 1006 /*****************************************************************************/ 1007 /* 1008 * map a binary by direct mmap() of the individual PT_LOAD segments 1009 */ 1010 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1011 struct file *file, 1012 struct mm_struct *mm) 1013 { 1014 struct elf32_fdpic_loadseg *seg; 1015 struct elf32_phdr *phdr; 1016 unsigned long load_addr, delta_vaddr; 1017 int loop, dvset; 1018 1019 load_addr = params->load_addr; 1020 delta_vaddr = 0; 1021 dvset = 0; 1022 1023 seg = params->loadmap->segs; 1024 1025 /* deal with each load segment separately */ 1026 phdr = params->phdrs; 1027 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1028 unsigned long maddr, disp, excess, excess1; 1029 int prot = 0, flags; 1030 1031 if (phdr->p_type != PT_LOAD) 1032 continue; 1033 1034 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1035 (unsigned long) phdr->p_vaddr, 1036 (unsigned long) phdr->p_offset, 1037 (unsigned long) phdr->p_filesz, 1038 (unsigned long) phdr->p_memsz); 1039 1040 /* determine the mapping parameters */ 1041 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1042 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1043 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1044 1045 flags = MAP_PRIVATE | MAP_DENYWRITE; 1046 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1047 flags |= MAP_EXECUTABLE; 1048 1049 maddr = 0; 1050 1051 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1052 case ELF_FDPIC_FLAG_INDEPENDENT: 1053 /* PT_LOADs are independently locatable */ 1054 break; 1055 1056 case ELF_FDPIC_FLAG_HONOURVADDR: 1057 /* the specified virtual address must be honoured */ 1058 maddr = phdr->p_vaddr; 1059 flags |= MAP_FIXED; 1060 break; 1061 1062 case ELF_FDPIC_FLAG_CONSTDISP: 1063 /* constant displacement 1064 * - can be mapped anywhere, but must be mapped as a 1065 * unit 1066 */ 1067 if (!dvset) { 1068 maddr = load_addr; 1069 delta_vaddr = phdr->p_vaddr; 1070 dvset = 1; 1071 } else { 1072 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1073 flags |= MAP_FIXED; 1074 } 1075 break; 1076 1077 case ELF_FDPIC_FLAG_CONTIGUOUS: 1078 /* contiguity handled later */ 1079 break; 1080 1081 default: 1082 BUG(); 1083 } 1084 1085 maddr &= PAGE_MASK; 1086 1087 /* create the mapping */ 1088 disp = phdr->p_vaddr & ~PAGE_MASK; 1089 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1090 phdr->p_offset - disp); 1091 1092 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1093 loop, phdr->p_memsz + disp, prot, flags, 1094 phdr->p_offset - disp, maddr); 1095 1096 if (IS_ERR_VALUE(maddr)) 1097 return (int) maddr; 1098 1099 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1100 ELF_FDPIC_FLAG_CONTIGUOUS) 1101 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1102 1103 seg->addr = maddr + disp; 1104 seg->p_vaddr = phdr->p_vaddr; 1105 seg->p_memsz = phdr->p_memsz; 1106 1107 /* map the ELF header address if in this segment */ 1108 if (phdr->p_offset == 0) 1109 params->elfhdr_addr = seg->addr; 1110 1111 /* clear the bit between beginning of mapping and beginning of 1112 * PT_LOAD */ 1113 if (prot & PROT_WRITE && disp > 0) { 1114 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1115 if (clear_user((void __user *) maddr, disp)) 1116 return -EFAULT; 1117 maddr += disp; 1118 } 1119 1120 /* clear any space allocated but not loaded 1121 * - on uClinux we can just clear the lot 1122 * - on MMU linux we'll get a SIGBUS beyond the last page 1123 * extant in the file 1124 */ 1125 excess = phdr->p_memsz - phdr->p_filesz; 1126 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1127 1128 #ifdef CONFIG_MMU 1129 if (excess > excess1) { 1130 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1131 unsigned long xmaddr; 1132 1133 flags |= MAP_FIXED | MAP_ANONYMOUS; 1134 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1135 prot, flags, 0); 1136 1137 kdebug("mmap[%d] <anon>" 1138 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1139 loop, xaddr, excess - excess1, prot, flags, 1140 xmaddr); 1141 1142 if (xmaddr != xaddr) 1143 return -ENOMEM; 1144 } 1145 1146 if (prot & PROT_WRITE && excess1 > 0) { 1147 kdebug("clear[%d] ad=%lx sz=%lx", 1148 loop, maddr + phdr->p_filesz, excess1); 1149 if (clear_user((void __user *) maddr + phdr->p_filesz, 1150 excess1)) 1151 return -EFAULT; 1152 } 1153 1154 #else 1155 if (excess > 0) { 1156 kdebug("clear[%d] ad=%lx sz=%lx", 1157 loop, maddr + phdr->p_filesz, excess); 1158 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1159 return -EFAULT; 1160 } 1161 #endif 1162 1163 if (mm) { 1164 if (phdr->p_flags & PF_X) { 1165 if (!mm->start_code) { 1166 mm->start_code = maddr; 1167 mm->end_code = maddr + phdr->p_memsz; 1168 } 1169 } else if (!mm->start_data) { 1170 mm->start_data = maddr; 1171 mm->end_data = maddr + phdr->p_memsz; 1172 } 1173 } 1174 1175 seg++; 1176 } 1177 1178 return 0; 1179 } 1180 1181 /*****************************************************************************/ 1182 /* 1183 * ELF-FDPIC core dumper 1184 * 1185 * Modelled on fs/exec.c:aout_core_dump() 1186 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1187 * 1188 * Modelled on fs/binfmt_elf.c core dumper 1189 */ 1190 #ifdef CONFIG_ELF_CORE 1191 1192 /* 1193 * Decide whether a segment is worth dumping; default is yes to be 1194 * sure (missing info is worse than too much; etc). 1195 * Personally I'd include everything, and use the coredump limit... 1196 * 1197 * I think we should skip something. But I am not sure how. H.J. 1198 */ 1199 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1200 { 1201 int dump_ok; 1202 1203 /* Do not dump I/O mapped devices or special mappings */ 1204 if (vma->vm_flags & VM_IO) { 1205 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1206 return 0; 1207 } 1208 1209 /* If we may not read the contents, don't allow us to dump 1210 * them either. "dump_write()" can't handle it anyway. 1211 */ 1212 if (!(vma->vm_flags & VM_READ)) { 1213 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1214 return 0; 1215 } 1216 1217 /* By default, dump shared memory if mapped from an anonymous file. */ 1218 if (vma->vm_flags & VM_SHARED) { 1219 if (file_inode(vma->vm_file)->i_nlink == 0) { 1220 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1221 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1222 vma->vm_flags, dump_ok ? "yes" : "no"); 1223 return dump_ok; 1224 } 1225 1226 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1227 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1228 vma->vm_flags, dump_ok ? "yes" : "no"); 1229 return dump_ok; 1230 } 1231 1232 #ifdef CONFIG_MMU 1233 /* By default, if it hasn't been written to, don't write it out */ 1234 if (!vma->anon_vma) { 1235 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1236 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1237 vma->vm_flags, dump_ok ? "yes" : "no"); 1238 return dump_ok; 1239 } 1240 #endif 1241 1242 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1243 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1244 dump_ok ? "yes" : "no"); 1245 return dump_ok; 1246 } 1247 1248 /* An ELF note in memory */ 1249 struct memelfnote 1250 { 1251 const char *name; 1252 int type; 1253 unsigned int datasz; 1254 void *data; 1255 }; 1256 1257 static int notesize(struct memelfnote *en) 1258 { 1259 int sz; 1260 1261 sz = sizeof(struct elf_note); 1262 sz += roundup(strlen(en->name) + 1, 4); 1263 sz += roundup(en->datasz, 4); 1264 1265 return sz; 1266 } 1267 1268 /* #define DEBUG */ 1269 1270 #define DUMP_WRITE(addr, nr, foffset) \ 1271 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) 1272 1273 static int alignfile(struct file *file, loff_t *foffset) 1274 { 1275 static const char buf[4] = { 0, }; 1276 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); 1277 return 1; 1278 } 1279 1280 static int writenote(struct memelfnote *men, struct file *file, 1281 loff_t *foffset) 1282 { 1283 struct elf_note en; 1284 en.n_namesz = strlen(men->name) + 1; 1285 en.n_descsz = men->datasz; 1286 en.n_type = men->type; 1287 1288 DUMP_WRITE(&en, sizeof(en), foffset); 1289 DUMP_WRITE(men->name, en.n_namesz, foffset); 1290 if (!alignfile(file, foffset)) 1291 return 0; 1292 DUMP_WRITE(men->data, men->datasz, foffset); 1293 if (!alignfile(file, foffset)) 1294 return 0; 1295 1296 return 1; 1297 } 1298 #undef DUMP_WRITE 1299 1300 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1301 { 1302 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1303 elf->e_ident[EI_CLASS] = ELF_CLASS; 1304 elf->e_ident[EI_DATA] = ELF_DATA; 1305 elf->e_ident[EI_VERSION] = EV_CURRENT; 1306 elf->e_ident[EI_OSABI] = ELF_OSABI; 1307 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1308 1309 elf->e_type = ET_CORE; 1310 elf->e_machine = ELF_ARCH; 1311 elf->e_version = EV_CURRENT; 1312 elf->e_entry = 0; 1313 elf->e_phoff = sizeof(struct elfhdr); 1314 elf->e_shoff = 0; 1315 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1316 elf->e_ehsize = sizeof(struct elfhdr); 1317 elf->e_phentsize = sizeof(struct elf_phdr); 1318 elf->e_phnum = segs; 1319 elf->e_shentsize = 0; 1320 elf->e_shnum = 0; 1321 elf->e_shstrndx = 0; 1322 return; 1323 } 1324 1325 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1326 { 1327 phdr->p_type = PT_NOTE; 1328 phdr->p_offset = offset; 1329 phdr->p_vaddr = 0; 1330 phdr->p_paddr = 0; 1331 phdr->p_filesz = sz; 1332 phdr->p_memsz = 0; 1333 phdr->p_flags = 0; 1334 phdr->p_align = 0; 1335 return; 1336 } 1337 1338 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1339 unsigned int sz, void *data) 1340 { 1341 note->name = name; 1342 note->type = type; 1343 note->datasz = sz; 1344 note->data = data; 1345 return; 1346 } 1347 1348 /* 1349 * fill up all the fields in prstatus from the given task struct, except 1350 * registers which need to be filled up separately. 1351 */ 1352 static void fill_prstatus(struct elf_prstatus *prstatus, 1353 struct task_struct *p, long signr) 1354 { 1355 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1356 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1357 prstatus->pr_sighold = p->blocked.sig[0]; 1358 rcu_read_lock(); 1359 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1360 rcu_read_unlock(); 1361 prstatus->pr_pid = task_pid_vnr(p); 1362 prstatus->pr_pgrp = task_pgrp_vnr(p); 1363 prstatus->pr_sid = task_session_vnr(p); 1364 if (thread_group_leader(p)) { 1365 struct task_cputime cputime; 1366 1367 /* 1368 * This is the record for the group leader. It shows the 1369 * group-wide total, not its individual thread total. 1370 */ 1371 thread_group_cputime(p, &cputime); 1372 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1373 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1374 } else { 1375 cputime_t utime, stime; 1376 1377 task_cputime(p, &utime, &stime); 1378 cputime_to_timeval(utime, &prstatus->pr_utime); 1379 cputime_to_timeval(stime, &prstatus->pr_stime); 1380 } 1381 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1382 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1383 1384 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1385 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1386 } 1387 1388 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1389 struct mm_struct *mm) 1390 { 1391 const struct cred *cred; 1392 unsigned int i, len; 1393 1394 /* first copy the parameters from user space */ 1395 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1396 1397 len = mm->arg_end - mm->arg_start; 1398 if (len >= ELF_PRARGSZ) 1399 len = ELF_PRARGSZ - 1; 1400 if (copy_from_user(&psinfo->pr_psargs, 1401 (const char __user *) mm->arg_start, len)) 1402 return -EFAULT; 1403 for (i = 0; i < len; i++) 1404 if (psinfo->pr_psargs[i] == 0) 1405 psinfo->pr_psargs[i] = ' '; 1406 psinfo->pr_psargs[len] = 0; 1407 1408 rcu_read_lock(); 1409 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1410 rcu_read_unlock(); 1411 psinfo->pr_pid = task_pid_vnr(p); 1412 psinfo->pr_pgrp = task_pgrp_vnr(p); 1413 psinfo->pr_sid = task_session_vnr(p); 1414 1415 i = p->state ? ffz(~p->state) + 1 : 0; 1416 psinfo->pr_state = i; 1417 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1418 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1419 psinfo->pr_nice = task_nice(p); 1420 psinfo->pr_flag = p->flags; 1421 rcu_read_lock(); 1422 cred = __task_cred(p); 1423 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1424 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1425 rcu_read_unlock(); 1426 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1427 1428 return 0; 1429 } 1430 1431 /* Here is the structure in which status of each thread is captured. */ 1432 struct elf_thread_status 1433 { 1434 struct list_head list; 1435 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1436 elf_fpregset_t fpu; /* NT_PRFPREG */ 1437 struct task_struct *thread; 1438 #ifdef ELF_CORE_COPY_XFPREGS 1439 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1440 #endif 1441 struct memelfnote notes[3]; 1442 int num_notes; 1443 }; 1444 1445 /* 1446 * In order to add the specific thread information for the elf file format, 1447 * we need to keep a linked list of every thread's pr_status and then create 1448 * a single section for them in the final core file. 1449 */ 1450 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1451 { 1452 struct task_struct *p = t->thread; 1453 int sz = 0; 1454 1455 t->num_notes = 0; 1456 1457 fill_prstatus(&t->prstatus, p, signr); 1458 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1459 1460 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1461 &t->prstatus); 1462 t->num_notes++; 1463 sz += notesize(&t->notes[0]); 1464 1465 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1466 if (t->prstatus.pr_fpvalid) { 1467 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1468 &t->fpu); 1469 t->num_notes++; 1470 sz += notesize(&t->notes[1]); 1471 } 1472 1473 #ifdef ELF_CORE_COPY_XFPREGS 1474 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1475 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1476 sizeof(t->xfpu), &t->xfpu); 1477 t->num_notes++; 1478 sz += notesize(&t->notes[2]); 1479 } 1480 #endif 1481 return sz; 1482 } 1483 1484 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1485 elf_addr_t e_shoff, int segs) 1486 { 1487 elf->e_shoff = e_shoff; 1488 elf->e_shentsize = sizeof(*shdr4extnum); 1489 elf->e_shnum = 1; 1490 elf->e_shstrndx = SHN_UNDEF; 1491 1492 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1493 1494 shdr4extnum->sh_type = SHT_NULL; 1495 shdr4extnum->sh_size = elf->e_shnum; 1496 shdr4extnum->sh_link = elf->e_shstrndx; 1497 shdr4extnum->sh_info = segs; 1498 } 1499 1500 /* 1501 * dump the segments for an MMU process 1502 */ 1503 #ifdef CONFIG_MMU 1504 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1505 unsigned long *limit, unsigned long mm_flags) 1506 { 1507 struct vm_area_struct *vma; 1508 int err = 0; 1509 1510 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1511 unsigned long addr; 1512 1513 if (!maydump(vma, mm_flags)) 1514 continue; 1515 1516 for (addr = vma->vm_start; addr < vma->vm_end; 1517 addr += PAGE_SIZE) { 1518 struct page *page = get_dump_page(addr); 1519 if (page) { 1520 void *kaddr = kmap(page); 1521 *size += PAGE_SIZE; 1522 if (*size > *limit) 1523 err = -EFBIG; 1524 else if (!dump_write(file, kaddr, PAGE_SIZE)) 1525 err = -EIO; 1526 kunmap(page); 1527 page_cache_release(page); 1528 } else if (!dump_seek(file, PAGE_SIZE)) 1529 err = -EFBIG; 1530 if (err) 1531 goto out; 1532 } 1533 } 1534 out: 1535 return err; 1536 } 1537 #endif 1538 1539 /* 1540 * dump the segments for a NOMMU process 1541 */ 1542 #ifndef CONFIG_MMU 1543 static int elf_fdpic_dump_segments(struct file *file, size_t *size, 1544 unsigned long *limit, unsigned long mm_flags) 1545 { 1546 struct vm_area_struct *vma; 1547 1548 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1549 if (!maydump(vma, mm_flags)) 1550 continue; 1551 1552 if ((*size += PAGE_SIZE) > *limit) 1553 return -EFBIG; 1554 1555 if (!dump_write(file, (void *) vma->vm_start, 1556 vma->vm_end - vma->vm_start)) 1557 return -EIO; 1558 } 1559 1560 return 0; 1561 } 1562 #endif 1563 1564 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1565 { 1566 struct vm_area_struct *vma; 1567 size_t size = 0; 1568 1569 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1570 if (maydump(vma, mm_flags)) 1571 size += vma->vm_end - vma->vm_start; 1572 return size; 1573 } 1574 1575 /* 1576 * Actual dumper 1577 * 1578 * This is a two-pass process; first we find the offsets of the bits, 1579 * and then they are actually written out. If we run out of core limit 1580 * we just truncate. 1581 */ 1582 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1583 { 1584 #define NUM_NOTES 6 1585 int has_dumped = 0; 1586 mm_segment_t fs; 1587 int segs; 1588 size_t size = 0; 1589 int i; 1590 struct vm_area_struct *vma; 1591 struct elfhdr *elf = NULL; 1592 loff_t offset = 0, dataoff, foffset; 1593 int numnote; 1594 struct memelfnote *notes = NULL; 1595 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1596 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1597 LIST_HEAD(thread_list); 1598 struct list_head *t; 1599 elf_fpregset_t *fpu = NULL; 1600 #ifdef ELF_CORE_COPY_XFPREGS 1601 elf_fpxregset_t *xfpu = NULL; 1602 #endif 1603 int thread_status_size = 0; 1604 elf_addr_t *auxv; 1605 struct elf_phdr *phdr4note = NULL; 1606 struct elf_shdr *shdr4extnum = NULL; 1607 Elf_Half e_phnum; 1608 elf_addr_t e_shoff; 1609 1610 /* 1611 * We no longer stop all VM operations. 1612 * 1613 * This is because those proceses that could possibly change map_count 1614 * or the mmap / vma pages are now blocked in do_exit on current 1615 * finishing this core dump. 1616 * 1617 * Only ptrace can touch these memory addresses, but it doesn't change 1618 * the map_count or the pages allocated. So no possibility of crashing 1619 * exists while dumping the mm->vm_next areas to the core file. 1620 */ 1621 1622 /* alloc memory for large data structures: too large to be on stack */ 1623 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1624 if (!elf) 1625 goto cleanup; 1626 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1627 if (!prstatus) 1628 goto cleanup; 1629 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1630 if (!psinfo) 1631 goto cleanup; 1632 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1633 if (!notes) 1634 goto cleanup; 1635 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1636 if (!fpu) 1637 goto cleanup; 1638 #ifdef ELF_CORE_COPY_XFPREGS 1639 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1640 if (!xfpu) 1641 goto cleanup; 1642 #endif 1643 1644 if (cprm->siginfo->si_signo) { 1645 struct core_thread *ct; 1646 struct elf_thread_status *tmp; 1647 1648 for (ct = current->mm->core_state->dumper.next; 1649 ct; ct = ct->next) { 1650 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1651 if (!tmp) 1652 goto cleanup; 1653 1654 tmp->thread = ct->task; 1655 list_add(&tmp->list, &thread_list); 1656 } 1657 1658 list_for_each(t, &thread_list) { 1659 struct elf_thread_status *tmp; 1660 int sz; 1661 1662 tmp = list_entry(t, struct elf_thread_status, list); 1663 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp); 1664 thread_status_size += sz; 1665 } 1666 } 1667 1668 /* now collect the dump for the current */ 1669 fill_prstatus(prstatus, current, cprm->siginfo->si_signo); 1670 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1671 1672 segs = current->mm->map_count; 1673 segs += elf_core_extra_phdrs(); 1674 1675 /* for notes section */ 1676 segs++; 1677 1678 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1679 * this, kernel supports extended numbering. Have a look at 1680 * include/linux/elf.h for further information. */ 1681 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1682 1683 /* Set up header */ 1684 fill_elf_fdpic_header(elf, e_phnum); 1685 1686 has_dumped = 1; 1687 /* 1688 * Set up the notes in similar form to SVR4 core dumps made 1689 * with info from their /proc. 1690 */ 1691 1692 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1693 fill_psinfo(psinfo, current->group_leader, current->mm); 1694 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1695 1696 numnote = 2; 1697 1698 auxv = (elf_addr_t *) current->mm->saved_auxv; 1699 1700 i = 0; 1701 do 1702 i += 2; 1703 while (auxv[i - 2] != AT_NULL); 1704 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1705 i * sizeof(elf_addr_t), auxv); 1706 1707 /* Try to dump the FPU. */ 1708 if ((prstatus->pr_fpvalid = 1709 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1710 fill_note(notes + numnote++, 1711 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1712 #ifdef ELF_CORE_COPY_XFPREGS 1713 if (elf_core_copy_task_xfpregs(current, xfpu)) 1714 fill_note(notes + numnote++, 1715 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1716 #endif 1717 1718 fs = get_fs(); 1719 set_fs(KERNEL_DS); 1720 1721 offset += sizeof(*elf); /* Elf header */ 1722 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1723 foffset = offset; 1724 1725 /* Write notes phdr entry */ 1726 { 1727 int sz = 0; 1728 1729 for (i = 0; i < numnote; i++) 1730 sz += notesize(notes + i); 1731 1732 sz += thread_status_size; 1733 1734 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1735 if (!phdr4note) 1736 goto end_coredump; 1737 1738 fill_elf_note_phdr(phdr4note, sz, offset); 1739 offset += sz; 1740 } 1741 1742 /* Page-align dumped data */ 1743 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1744 1745 offset += elf_core_vma_data_size(cprm->mm_flags); 1746 offset += elf_core_extra_data_size(); 1747 e_shoff = offset; 1748 1749 if (e_phnum == PN_XNUM) { 1750 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1751 if (!shdr4extnum) 1752 goto end_coredump; 1753 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1754 } 1755 1756 offset = dataoff; 1757 1758 size += sizeof(*elf); 1759 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) 1760 goto end_coredump; 1761 1762 size += sizeof(*phdr4note); 1763 if (size > cprm->limit 1764 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) 1765 goto end_coredump; 1766 1767 /* write program headers for segments dump */ 1768 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1769 struct elf_phdr phdr; 1770 size_t sz; 1771 1772 sz = vma->vm_end - vma->vm_start; 1773 1774 phdr.p_type = PT_LOAD; 1775 phdr.p_offset = offset; 1776 phdr.p_vaddr = vma->vm_start; 1777 phdr.p_paddr = 0; 1778 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1779 phdr.p_memsz = sz; 1780 offset += phdr.p_filesz; 1781 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1782 if (vma->vm_flags & VM_WRITE) 1783 phdr.p_flags |= PF_W; 1784 if (vma->vm_flags & VM_EXEC) 1785 phdr.p_flags |= PF_X; 1786 phdr.p_align = ELF_EXEC_PAGESIZE; 1787 1788 size += sizeof(phdr); 1789 if (size > cprm->limit 1790 || !dump_write(cprm->file, &phdr, sizeof(phdr))) 1791 goto end_coredump; 1792 } 1793 1794 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) 1795 goto end_coredump; 1796 1797 /* write out the notes section */ 1798 for (i = 0; i < numnote; i++) 1799 if (!writenote(notes + i, cprm->file, &foffset)) 1800 goto end_coredump; 1801 1802 /* write out the thread status notes section */ 1803 list_for_each(t, &thread_list) { 1804 struct elf_thread_status *tmp = 1805 list_entry(t, struct elf_thread_status, list); 1806 1807 for (i = 0; i < tmp->num_notes; i++) 1808 if (!writenote(&tmp->notes[i], cprm->file, &foffset)) 1809 goto end_coredump; 1810 } 1811 1812 if (!dump_seek(cprm->file, dataoff - foffset)) 1813 goto end_coredump; 1814 1815 if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit, 1816 cprm->mm_flags) < 0) 1817 goto end_coredump; 1818 1819 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) 1820 goto end_coredump; 1821 1822 if (e_phnum == PN_XNUM) { 1823 size += sizeof(*shdr4extnum); 1824 if (size > cprm->limit 1825 || !dump_write(cprm->file, shdr4extnum, 1826 sizeof(*shdr4extnum))) 1827 goto end_coredump; 1828 } 1829 1830 if (cprm->file->f_pos != offset) { 1831 /* Sanity check */ 1832 printk(KERN_WARNING 1833 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1834 cprm->file->f_pos, offset); 1835 } 1836 1837 end_coredump: 1838 set_fs(fs); 1839 1840 cleanup: 1841 while (!list_empty(&thread_list)) { 1842 struct list_head *tmp = thread_list.next; 1843 list_del(tmp); 1844 kfree(list_entry(tmp, struct elf_thread_status, list)); 1845 } 1846 kfree(phdr4note); 1847 kfree(elf); 1848 kfree(prstatus); 1849 kfree(psinfo); 1850 kfree(notes); 1851 kfree(fpu); 1852 kfree(shdr4extnum); 1853 #ifdef ELF_CORE_COPY_XFPREGS 1854 kfree(xfpu); 1855 #endif 1856 return has_dumped; 1857 #undef NUM_NOTES 1858 } 1859 1860 #endif /* CONFIG_ELF_CORE */ 1861