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