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FreeBSD/Linux Kernel Cross Reference
sys/fs/binfmt_elf_fdpic.c
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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 long hwcap; 487 int loop; 488 int nr; /* reset for each csp adjustment */ 489 490 #ifdef CONFIG_MMU 491 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 492 * by the processes running on the same package. One thing we can do is 493 * to shuffle the initial stack for them, so we give the architecture 494 * an opportunity to do so here. 495 */ 496 sp = arch_align_stack(bprm->p); 497 #else 498 sp = mm->start_stack; 499 500 /* stack the program arguments and environment */ 501 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 502 return -EFAULT; 503 #endif 504 505 hwcap = ELF_HWCAP; 506 507 /* 508 * If this architecture has a platform capability string, copy it 509 * to userspace. In some cases (Sparc), this info is impossible 510 * for userspace to get any other way, in others (i386) it is 511 * merely difficult. 512 */ 513 k_platform = ELF_PLATFORM; 514 u_platform = NULL; 515 516 if (k_platform) { 517 platform_len = strlen(k_platform) + 1; 518 sp -= platform_len; 519 u_platform = (char __user *) sp; 520 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 521 return -EFAULT; 522 } 523 524 /* 525 * If this architecture has a "base" platform capability 526 * string, copy it to userspace. 527 */ 528 k_base_platform = ELF_BASE_PLATFORM; 529 u_base_platform = NULL; 530 531 if (k_base_platform) { 532 platform_len = strlen(k_base_platform) + 1; 533 sp -= platform_len; 534 u_base_platform = (char __user *) sp; 535 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 536 return -EFAULT; 537 } 538 539 sp &= ~7UL; 540 541 /* stack the load map(s) */ 542 len = sizeof(struct elf32_fdpic_loadmap); 543 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 544 sp = (sp - len) & ~7UL; 545 exec_params->map_addr = sp; 546 547 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 548 return -EFAULT; 549 550 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 551 552 if (interp_params->loadmap) { 553 len = sizeof(struct elf32_fdpic_loadmap); 554 len += sizeof(struct elf32_fdpic_loadseg) * 555 interp_params->loadmap->nsegs; 556 sp = (sp - len) & ~7UL; 557 interp_params->map_addr = sp; 558 559 if (copy_to_user((void __user *) sp, interp_params->loadmap, 560 len) != 0) 561 return -EFAULT; 562 563 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 564 } 565 566 /* force 16 byte _final_ alignment here for generality */ 567 #define DLINFO_ITEMS 15 568 569 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 570 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 571 572 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 573 nitems++; 574 575 csp = sp; 576 sp -= nitems * 2 * sizeof(unsigned long); 577 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 578 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 579 sp -= 1 * sizeof(unsigned long); /* argc */ 580 581 csp -= sp & 15UL; 582 sp -= sp & 15UL; 583 584 /* put the ELF interpreter info on the stack */ 585 #define NEW_AUX_ENT(id, val) \ 586 do { \ 587 struct { unsigned long _id, _val; } __user *ent; \ 588 \ 589 ent = (void __user *) csp; \ 590 __put_user((id), &ent[nr]._id); \ 591 __put_user((val), &ent[nr]._val); \ 592 nr++; \ 593 } while (0) 594 595 nr = 0; 596 csp -= 2 * sizeof(unsigned long); 597 NEW_AUX_ENT(AT_NULL, 0); 598 if (k_platform) { 599 nr = 0; 600 csp -= 2 * sizeof(unsigned long); 601 NEW_AUX_ENT(AT_PLATFORM, 602 (elf_addr_t) (unsigned long) u_platform); 603 } 604 605 if (k_base_platform) { 606 nr = 0; 607 csp -= 2 * sizeof(unsigned long); 608 NEW_AUX_ENT(AT_BASE_PLATFORM, 609 (elf_addr_t) (unsigned long) u_base_platform); 610 } 611 612 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 613 nr = 0; 614 csp -= 2 * sizeof(unsigned long); 615 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 616 } 617 618 nr = 0; 619 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 620 NEW_AUX_ENT(AT_HWCAP, hwcap); 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->f_path.dentry->d_inode->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 loff_t fpos; 930 int loop, ret; 931 932 load_addr = params->load_addr; 933 seg = params->loadmap->segs; 934 935 /* determine the bounds of the contiguous overall allocation we must 936 * make */ 937 phdr = params->phdrs; 938 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 939 if (params->phdrs[loop].p_type != PT_LOAD) 940 continue; 941 942 if (base > phdr->p_vaddr) 943 base = phdr->p_vaddr; 944 if (top < phdr->p_vaddr + phdr->p_memsz) 945 top = phdr->p_vaddr + phdr->p_memsz; 946 } 947 948 /* allocate one big anon block for everything */ 949 mflags = MAP_PRIVATE; 950 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 951 mflags |= MAP_EXECUTABLE; 952 953 maddr = vm_mmap(NULL, load_addr, top - base, 954 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 955 if (IS_ERR_VALUE(maddr)) 956 return (int) maddr; 957 958 if (load_addr != 0) 959 load_addr += PAGE_ALIGN(top - base); 960 961 /* and then load the file segments into it */ 962 phdr = params->phdrs; 963 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 964 if (params->phdrs[loop].p_type != PT_LOAD) 965 continue; 966 967 fpos = phdr->p_offset; 968 969 seg->addr = maddr + (phdr->p_vaddr - base); 970 seg->p_vaddr = phdr->p_vaddr; 971 seg->p_memsz = phdr->p_memsz; 972 973 ret = file->f_op->read(file, (void *) seg->addr, 974 phdr->p_filesz, &fpos); 975 if (ret < 0) 976 return ret; 977 978 /* map the ELF header address if in this segment */ 979 if (phdr->p_offset == 0) 980 params->elfhdr_addr = seg->addr; 981 982 /* clear any space allocated but not loaded */ 983 if (phdr->p_filesz < phdr->p_memsz) { 984 if (clear_user((void *) (seg->addr + phdr->p_filesz), 985 phdr->p_memsz - phdr->p_filesz)) 986 return -EFAULT; 987 } 988 989 if (mm) { 990 if (phdr->p_flags & PF_X) { 991 if (!mm->start_code) { 992 mm->start_code = seg->addr; 993 mm->end_code = seg->addr + 994 phdr->p_memsz; 995 } 996 } else if (!mm->start_data) { 997 mm->start_data = seg->addr; 998 mm->end_data = seg->addr + phdr->p_memsz; 999 } 1000 } 1001 1002 seg++; 1003 } 1004 1005 return 0; 1006 } 1007 #endif 1008 1009 /*****************************************************************************/ 1010 /* 1011 * map a binary by direct mmap() of the individual PT_LOAD segments 1012 */ 1013 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1014 struct file *file, 1015 struct mm_struct *mm) 1016 { 1017 struct elf32_fdpic_loadseg *seg; 1018 struct elf32_phdr *phdr; 1019 unsigned long load_addr, delta_vaddr; 1020 int loop, dvset; 1021 1022 load_addr = params->load_addr; 1023 delta_vaddr = 0; 1024 dvset = 0; 1025 1026 seg = params->loadmap->segs; 1027 1028 /* deal with each load segment separately */ 1029 phdr = params->phdrs; 1030 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1031 unsigned long maddr, disp, excess, excess1; 1032 int prot = 0, flags; 1033 1034 if (phdr->p_type != PT_LOAD) 1035 continue; 1036 1037 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1038 (unsigned long) phdr->p_vaddr, 1039 (unsigned long) phdr->p_offset, 1040 (unsigned long) phdr->p_filesz, 1041 (unsigned long) phdr->p_memsz); 1042 1043 /* determine the mapping parameters */ 1044 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1045 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1046 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1047 1048 flags = MAP_PRIVATE | MAP_DENYWRITE; 1049 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1050 flags |= MAP_EXECUTABLE; 1051 1052 maddr = 0; 1053 1054 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1055 case ELF_FDPIC_FLAG_INDEPENDENT: 1056 /* PT_LOADs are independently locatable */ 1057 break; 1058 1059 case ELF_FDPIC_FLAG_HONOURVADDR: 1060 /* the specified virtual address must be honoured */ 1061 maddr = phdr->p_vaddr; 1062 flags |= MAP_FIXED; 1063 break; 1064 1065 case ELF_FDPIC_FLAG_CONSTDISP: 1066 /* constant displacement 1067 * - can be mapped anywhere, but must be mapped as a 1068 * unit 1069 */ 1070 if (!dvset) { 1071 maddr = load_addr; 1072 delta_vaddr = phdr->p_vaddr; 1073 dvset = 1; 1074 } else { 1075 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1076 flags |= MAP_FIXED; 1077 } 1078 break; 1079 1080 case ELF_FDPIC_FLAG_CONTIGUOUS: 1081 /* contiguity handled later */ 1082 break; 1083 1084 default: 1085 BUG(); 1086 } 1087 1088 maddr &= PAGE_MASK; 1089 1090 /* create the mapping */ 1091 disp = phdr->p_vaddr & ~PAGE_MASK; 1092 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1093 phdr->p_offset - disp); 1094 1095 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1096 loop, phdr->p_memsz + disp, prot, flags, 1097 phdr->p_offset - disp, maddr); 1098 1099 if (IS_ERR_VALUE(maddr)) 1100 return (int) maddr; 1101 1102 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1103 ELF_FDPIC_FLAG_CONTIGUOUS) 1104 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1105 1106 seg->addr = maddr + disp; 1107 seg->p_vaddr = phdr->p_vaddr; 1108 seg->p_memsz = phdr->p_memsz; 1109 1110 /* map the ELF header address if in this segment */ 1111 if (phdr->p_offset == 0) 1112 params->elfhdr_addr = seg->addr; 1113 1114 /* clear the bit between beginning of mapping and beginning of 1115 * PT_LOAD */ 1116 if (prot & PROT_WRITE && disp > 0) { 1117 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1118 if (clear_user((void __user *) maddr, disp)) 1119 return -EFAULT; 1120 maddr += disp; 1121 } 1122 1123 /* clear any space allocated but not loaded 1124 * - on uClinux we can just clear the lot 1125 * - on MMU linux we'll get a SIGBUS beyond the last page 1126 * extant in the file 1127 */ 1128 excess = phdr->p_memsz - phdr->p_filesz; 1129 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1130 1131 #ifdef CONFIG_MMU 1132 if (excess > excess1) { 1133 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1134 unsigned long xmaddr; 1135 1136 flags |= MAP_FIXED | MAP_ANONYMOUS; 1137 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1138 prot, flags, 0); 1139 1140 kdebug("mmap[%d] <anon>" 1141 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1142 loop, xaddr, excess - excess1, prot, flags, 1143 xmaddr); 1144 1145 if (xmaddr != xaddr) 1146 return -ENOMEM; 1147 } 1148 1149 if (prot & PROT_WRITE && excess1 > 0) { 1150 kdebug("clear[%d] ad=%lx sz=%lx", 1151 loop, maddr + phdr->p_filesz, excess1); 1152 if (clear_user((void __user *) maddr + phdr->p_filesz, 1153 excess1)) 1154 return -EFAULT; 1155 } 1156 1157 #else 1158 if (excess > 0) { 1159 kdebug("clear[%d] ad=%lx sz=%lx", 1160 loop, maddr + phdr->p_filesz, excess); 1161 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1162 return -EFAULT; 1163 } 1164 #endif 1165 1166 if (mm) { 1167 if (phdr->p_flags & PF_X) { 1168 if (!mm->start_code) { 1169 mm->start_code = maddr; 1170 mm->end_code = maddr + phdr->p_memsz; 1171 } 1172 } else if (!mm->start_data) { 1173 mm->start_data = maddr; 1174 mm->end_data = maddr + phdr->p_memsz; 1175 } 1176 } 1177 1178 seg++; 1179 } 1180 1181 return 0; 1182 } 1183 1184 /*****************************************************************************/ 1185 /* 1186 * ELF-FDPIC core dumper 1187 * 1188 * Modelled on fs/exec.c:aout_core_dump() 1189 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1190 * 1191 * Modelled on fs/binfmt_elf.c core dumper 1192 */ 1193 #ifdef CONFIG_ELF_CORE 1194 1195 /* 1196 * Decide whether a segment is worth dumping; default is yes to be 1197 * sure (missing info is worse than too much; etc). 1198 * Personally I'd include everything, and use the coredump limit... 1199 * 1200 * I think we should skip something. But I am not sure how. H.J. 1201 */ 1202 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1203 { 1204 int dump_ok; 1205 1206 /* Do not dump I/O mapped devices or special mappings */ 1207 if (vma->vm_flags & VM_IO) { 1208 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1209 return 0; 1210 } 1211 1212 /* If we may not read the contents, don't allow us to dump 1213 * them either. "dump_write()" can't handle it anyway. 1214 */ 1215 if (!(vma->vm_flags & VM_READ)) { 1216 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1217 return 0; 1218 } 1219 1220 /* By default, dump shared memory if mapped from an anonymous file. */ 1221 if (vma->vm_flags & VM_SHARED) { 1222 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) { 1223 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1224 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1225 vma->vm_flags, dump_ok ? "yes" : "no"); 1226 return dump_ok; 1227 } 1228 1229 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1230 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1231 vma->vm_flags, dump_ok ? "yes" : "no"); 1232 return dump_ok; 1233 } 1234 1235 #ifdef CONFIG_MMU 1236 /* By default, if it hasn't been written to, don't write it out */ 1237 if (!vma->anon_vma) { 1238 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1239 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1240 vma->vm_flags, dump_ok ? "yes" : "no"); 1241 return dump_ok; 1242 } 1243 #endif 1244 1245 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1246 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1247 dump_ok ? "yes" : "no"); 1248 return dump_ok; 1249 } 1250 1251 /* An ELF note in memory */ 1252 struct memelfnote 1253 { 1254 const char *name; 1255 int type; 1256 unsigned int datasz; 1257 void *data; 1258 }; 1259 1260 static int notesize(struct memelfnote *en) 1261 { 1262 int sz; 1263 1264 sz = sizeof(struct elf_note); 1265 sz += roundup(strlen(en->name) + 1, 4); 1266 sz += roundup(en->datasz, 4); 1267 1268 return sz; 1269 } 1270 1271 /* #define DEBUG */ 1272 1273 #define DUMP_WRITE(addr, nr, foffset) \ 1274 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0) 1275 1276 static int alignfile(struct file *file, loff_t *foffset) 1277 { 1278 static const char buf[4] = { 0, }; 1279 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset); 1280 return 1; 1281 } 1282 1283 static int writenote(struct memelfnote *men, struct file *file, 1284 loff_t *foffset) 1285 { 1286 struct elf_note en; 1287 en.n_namesz = strlen(men->name) + 1; 1288 en.n_descsz = men->datasz; 1289 en.n_type = men->type; 1290 1291 DUMP_WRITE(&en, sizeof(en), foffset); 1292 DUMP_WRITE(men->name, en.n_namesz, foffset); 1293 if (!alignfile(file, foffset)) 1294 return 0; 1295 DUMP_WRITE(men->data, men->datasz, foffset); 1296 if (!alignfile(file, foffset)) 1297 return 0; 1298 1299 return 1; 1300 } 1301 #undef DUMP_WRITE 1302 1303 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1304 { 1305 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1306 elf->e_ident[EI_CLASS] = ELF_CLASS; 1307 elf->e_ident[EI_DATA] = ELF_DATA; 1308 elf->e_ident[EI_VERSION] = EV_CURRENT; 1309 elf->e_ident[EI_OSABI] = ELF_OSABI; 1310 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1311 1312 elf->e_type = ET_CORE; 1313 elf->e_machine = ELF_ARCH; 1314 elf->e_version = EV_CURRENT; 1315 elf->e_entry = 0; 1316 elf->e_phoff = sizeof(struct elfhdr); 1317 elf->e_shoff = 0; 1318 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1319 elf->e_ehsize = sizeof(struct elfhdr); 1320 elf->e_phentsize = sizeof(struct elf_phdr); 1321 elf->e_phnum = segs; 1322 elf->e_shentsize = 0; 1323 elf->e_shnum = 0; 1324 elf->e_shstrndx = 0; 1325 return; 1326 } 1327 1328 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1329 { 1330 phdr->p_type = PT_NOTE; 1331 phdr->p_offset = offset; 1332 phdr->p_vaddr = 0; 1333 phdr->p_paddr = 0; 1334 phdr->p_filesz = sz; 1335 phdr->p_memsz = 0; 1336 phdr->p_flags = 0; 1337 phdr->p_align = 0; 1338 return; 1339 } 1340 1341 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1342 unsigned int sz, void *data) 1343 { 1344 note->name = name; 1345 note->type = type; 1346 note->datasz = sz; 1347 note->data = data; 1348 return; 1349 } 1350 1351 /* 1352 * fill up all the fields in prstatus from the given task struct, except 1353 * registers which need to be filled up separately. 1354 */ 1355 static void fill_prstatus(struct elf_prstatus *prstatus, 1356 struct task_struct *p, long signr) 1357 { 1358 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1359 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1360 prstatus->pr_sighold = p->blocked.sig[0]; 1361 rcu_read_lock(); 1362 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1363 rcu_read_unlock(); 1364 prstatus->pr_pid = task_pid_vnr(p); 1365 prstatus->pr_pgrp = task_pgrp_vnr(p); 1366 prstatus->pr_sid = task_session_vnr(p); 1367 if (thread_group_leader(p)) { 1368 struct task_cputime cputime; 1369 1370 /* 1371 * This is the record for the group leader. It shows the 1372 * group-wide total, not its individual thread total. 1373 */ 1374 thread_group_cputime(p, &cputime); 1375 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1376 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1377 } else { 1378 cputime_to_timeval(p->utime, &prstatus->pr_utime); 1379 cputime_to_timeval(p->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 current->flags |= PF_DUMPCORE; 1688 1689 /* 1690 * Set up the notes in similar form to SVR4 core dumps made 1691 * with info from their /proc. 1692 */ 1693 1694 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1695 fill_psinfo(psinfo, current->group_leader, current->mm); 1696 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1697 1698 numnote = 2; 1699 1700 auxv = (elf_addr_t *) current->mm->saved_auxv; 1701 1702 i = 0; 1703 do 1704 i += 2; 1705 while (auxv[i - 2] != AT_NULL); 1706 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1707 i * sizeof(elf_addr_t), auxv); 1708 1709 /* Try to dump the FPU. */ 1710 if ((prstatus->pr_fpvalid = 1711 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1712 fill_note(notes + numnote++, 1713 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1714 #ifdef ELF_CORE_COPY_XFPREGS 1715 if (elf_core_copy_task_xfpregs(current, xfpu)) 1716 fill_note(notes + numnote++, 1717 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1718 #endif 1719 1720 fs = get_fs(); 1721 set_fs(KERNEL_DS); 1722 1723 offset += sizeof(*elf); /* Elf header */ 1724 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1725 foffset = offset; 1726 1727 /* Write notes phdr entry */ 1728 { 1729 int sz = 0; 1730 1731 for (i = 0; i < numnote; i++) 1732 sz += notesize(notes + i); 1733 1734 sz += thread_status_size; 1735 1736 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1737 if (!phdr4note) 1738 goto end_coredump; 1739 1740 fill_elf_note_phdr(phdr4note, sz, offset); 1741 offset += sz; 1742 } 1743 1744 /* Page-align dumped data */ 1745 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1746 1747 offset += elf_core_vma_data_size(cprm->mm_flags); 1748 offset += elf_core_extra_data_size(); 1749 e_shoff = offset; 1750 1751 if (e_phnum == PN_XNUM) { 1752 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1753 if (!shdr4extnum) 1754 goto end_coredump; 1755 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1756 } 1757 1758 offset = dataoff; 1759 1760 size += sizeof(*elf); 1761 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf))) 1762 goto end_coredump; 1763 1764 size += sizeof(*phdr4note); 1765 if (size > cprm->limit 1766 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note))) 1767 goto end_coredump; 1768 1769 /* write program headers for segments dump */ 1770 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1771 struct elf_phdr phdr; 1772 size_t sz; 1773 1774 sz = vma->vm_end - vma->vm_start; 1775 1776 phdr.p_type = PT_LOAD; 1777 phdr.p_offset = offset; 1778 phdr.p_vaddr = vma->vm_start; 1779 phdr.p_paddr = 0; 1780 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1781 phdr.p_memsz = sz; 1782 offset += phdr.p_filesz; 1783 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1784 if (vma->vm_flags & VM_WRITE) 1785 phdr.p_flags |= PF_W; 1786 if (vma->vm_flags & VM_EXEC) 1787 phdr.p_flags |= PF_X; 1788 phdr.p_align = ELF_EXEC_PAGESIZE; 1789 1790 size += sizeof(phdr); 1791 if (size > cprm->limit 1792 || !dump_write(cprm->file, &phdr, sizeof(phdr))) 1793 goto end_coredump; 1794 } 1795 1796 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit)) 1797 goto end_coredump; 1798 1799 /* write out the notes section */ 1800 for (i = 0; i < numnote; i++) 1801 if (!writenote(notes + i, cprm->file, &foffset)) 1802 goto end_coredump; 1803 1804 /* write out the thread status notes section */ 1805 list_for_each(t, &thread_list) { 1806 struct elf_thread_status *tmp = 1807 list_entry(t, struct elf_thread_status, list); 1808 1809 for (i = 0; i < tmp->num_notes; i++) 1810 if (!writenote(&tmp->notes[i], cprm->file, &foffset)) 1811 goto end_coredump; 1812 } 1813 1814 if (!dump_seek(cprm->file, dataoff - foffset)) 1815 goto end_coredump; 1816 1817 if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit, 1818 cprm->mm_flags) < 0) 1819 goto end_coredump; 1820 1821 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) 1822 goto end_coredump; 1823 1824 if (e_phnum == PN_XNUM) { 1825 size += sizeof(*shdr4extnum); 1826 if (size > cprm->limit 1827 || !dump_write(cprm->file, shdr4extnum, 1828 sizeof(*shdr4extnum))) 1829 goto end_coredump; 1830 } 1831 1832 if (cprm->file->f_pos != offset) { 1833 /* Sanity check */ 1834 printk(KERN_WARNING 1835 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1836 cprm->file->f_pos, offset); 1837 } 1838 1839 end_coredump: 1840 set_fs(fs); 1841 1842 cleanup: 1843 while (!list_empty(&thread_list)) { 1844 struct list_head *tmp = thread_list.next; 1845 list_del(tmp); 1846 kfree(list_entry(tmp, struct elf_thread_status, list)); 1847 } 1848 kfree(phdr4note); 1849 kfree(elf); 1850 kfree(prstatus); 1851 kfree(psinfo); 1852 kfree(notes); 1853 kfree(fpu); 1854 kfree(shdr4extnum); 1855 #ifdef ELF_CORE_COPY_XFPREGS 1856 kfree(xfpu); 1857 #endif 1858 return has_dumped; 1859 #undef NUM_NOTES 1860 } 1861 1862 #endif /* CONFIG_ELF_CORE */
Cache object: c3518a3c5619d516f0ab310b72c45123
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