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/sched/coredump.h> 19 #include <linux/sched/task_stack.h> 20 #include <linux/sched/cputime.h> 21 #include <linux/mm.h> 22 #include <linux/mman.h> 23 #include <linux/errno.h> 24 #include <linux/signal.h> 25 #include <linux/binfmts.h> 26 #include <linux/string.h> 27 #include <linux/file.h> 28 #include <linux/fcntl.h> 29 #include <linux/slab.h> 30 #include <linux/pagemap.h> 31 #include <linux/security.h> 32 #include <linux/highmem.h> 33 #include <linux/highuid.h> 34 #include <linux/personality.h> 35 #include <linux/ptrace.h> 36 #include <linux/init.h> 37 #include <linux/elf.h> 38 #include <linux/elf-fdpic.h> 39 #include <linux/elfcore.h> 40 #include <linux/coredump.h> 41 #include <linux/dax.h> 42 43 #include <linux/uaccess.h> 44 #include <asm/param.h> 45 #include <asm/pgalloc.h> 46 47 typedef char *elf_caddr_t; 48 49 #if 0 50 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 51 #else 52 #define kdebug(fmt, ...) do {} while(0) 53 #endif 54 55 #if 0 56 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 57 #else 58 #define kdcore(fmt, ...) do {} while(0) 59 #endif 60 61 MODULE_LICENSE("GPL"); 62 63 static int load_elf_fdpic_binary(struct linux_binprm *); 64 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 65 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 66 struct mm_struct *, const char *); 67 68 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 69 struct elf_fdpic_params *, 70 struct elf_fdpic_params *); 71 72 #ifndef CONFIG_MMU 73 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 74 struct file *, 75 struct mm_struct *); 76 #endif 77 78 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 79 struct file *, struct mm_struct *); 80 81 #ifdef CONFIG_ELF_CORE 82 static int elf_fdpic_core_dump(struct coredump_params *cprm); 83 #endif 84 85 static struct linux_binfmt elf_fdpic_format = { 86 .module = THIS_MODULE, 87 .load_binary = load_elf_fdpic_binary, 88 #ifdef CONFIG_ELF_CORE 89 .core_dump = elf_fdpic_core_dump, 90 #endif 91 .min_coredump = ELF_EXEC_PAGESIZE, 92 }; 93 94 static int __init init_elf_fdpic_binfmt(void) 95 { 96 register_binfmt(&elf_fdpic_format); 97 return 0; 98 } 99 100 static void __exit exit_elf_fdpic_binfmt(void) 101 { 102 unregister_binfmt(&elf_fdpic_format); 103 } 104 105 core_initcall(init_elf_fdpic_binfmt); 106 module_exit(exit_elf_fdpic_binfmt); 107 108 static int is_elf(struct elfhdr *hdr, struct file *file) 109 { 110 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 111 return 0; 112 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 113 return 0; 114 if (!elf_check_arch(hdr)) 115 return 0; 116 if (!file->f_op->mmap) 117 return 0; 118 return 1; 119 } 120 121 #ifndef elf_check_fdpic 122 #define elf_check_fdpic(x) 0 123 #endif 124 125 #ifndef elf_check_const_displacement 126 #define elf_check_const_displacement(x) 0 127 #endif 128 129 static int is_constdisp(struct elfhdr *hdr) 130 { 131 if (!elf_check_fdpic(hdr)) 132 return 1; 133 if (elf_check_const_displacement(hdr)) 134 return 1; 135 return 0; 136 } 137 138 /*****************************************************************************/ 139 /* 140 * read the program headers table into memory 141 */ 142 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 143 struct file *file) 144 { 145 struct elf32_phdr *phdr; 146 unsigned long size; 147 int retval, loop; 148 loff_t pos = params->hdr.e_phoff; 149 150 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 151 return -ENOMEM; 152 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 153 return -ENOMEM; 154 155 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 156 params->phdrs = kmalloc(size, GFP_KERNEL); 157 if (!params->phdrs) 158 return -ENOMEM; 159 160 retval = kernel_read(file, params->phdrs, size, &pos); 161 if (unlikely(retval != size)) 162 return retval < 0 ? retval : -ENOEXEC; 163 164 /* determine stack size for this binary */ 165 phdr = params->phdrs; 166 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 167 if (phdr->p_type != PT_GNU_STACK) 168 continue; 169 170 if (phdr->p_flags & PF_X) 171 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 172 else 173 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 174 175 params->stack_size = phdr->p_memsz; 176 break; 177 } 178 179 return 0; 180 } 181 182 /*****************************************************************************/ 183 /* 184 * load an fdpic binary into various bits of memory 185 */ 186 static int load_elf_fdpic_binary(struct linux_binprm *bprm) 187 { 188 struct elf_fdpic_params exec_params, interp_params; 189 struct pt_regs *regs = current_pt_regs(); 190 struct elf_phdr *phdr; 191 unsigned long stack_size, entryaddr; 192 #ifdef ELF_FDPIC_PLAT_INIT 193 unsigned long dynaddr; 194 #endif 195 #ifndef CONFIG_MMU 196 unsigned long stack_prot; 197 #endif 198 struct file *interpreter = NULL; /* to shut gcc up */ 199 char *interpreter_name = NULL; 200 int executable_stack; 201 int retval, i; 202 loff_t pos; 203 204 kdebug("____ LOAD %d ____", current->pid); 205 206 memset(&exec_params, 0, sizeof(exec_params)); 207 memset(&interp_params, 0, sizeof(interp_params)); 208 209 exec_params.hdr = *(struct elfhdr *) bprm->buf; 210 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 211 212 /* check that this is a binary we know how to deal with */ 213 retval = -ENOEXEC; 214 if (!is_elf(&exec_params.hdr, bprm->file)) 215 goto error; 216 if (!elf_check_fdpic(&exec_params.hdr)) { 217 #ifdef CONFIG_MMU 218 /* binfmt_elf handles non-fdpic elf except on nommu */ 219 goto error; 220 #else 221 /* nommu can only load ET_DYN (PIE) ELF */ 222 if (exec_params.hdr.e_type != ET_DYN) 223 goto error; 224 #endif 225 } 226 227 /* read the program header table */ 228 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 229 if (retval < 0) 230 goto error; 231 232 /* scan for a program header that specifies an interpreter */ 233 phdr = exec_params.phdrs; 234 235 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 236 switch (phdr->p_type) { 237 case PT_INTERP: 238 retval = -ENOMEM; 239 if (phdr->p_filesz > PATH_MAX) 240 goto error; 241 retval = -ENOENT; 242 if (phdr->p_filesz < 2) 243 goto error; 244 245 /* read the name of the interpreter into memory */ 246 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 247 if (!interpreter_name) 248 goto error; 249 250 pos = phdr->p_offset; 251 retval = kernel_read(bprm->file, interpreter_name, 252 phdr->p_filesz, &pos); 253 if (unlikely(retval != phdr->p_filesz)) { 254 if (retval >= 0) 255 retval = -ENOEXEC; 256 goto error; 257 } 258 259 retval = -ENOENT; 260 if (interpreter_name[phdr->p_filesz - 1] != '\0') 261 goto error; 262 263 kdebug("Using ELF interpreter %s", interpreter_name); 264 265 /* replace the program with the interpreter */ 266 interpreter = open_exec(interpreter_name); 267 retval = PTR_ERR(interpreter); 268 if (IS_ERR(interpreter)) { 269 interpreter = NULL; 270 goto error; 271 } 272 273 /* 274 * If the binary is not readable then enforce 275 * mm->dumpable = 0 regardless of the interpreter's 276 * permissions. 277 */ 278 would_dump(bprm, interpreter); 279 280 pos = 0; 281 retval = kernel_read(interpreter, bprm->buf, 282 BINPRM_BUF_SIZE, &pos); 283 if (unlikely(retval != BINPRM_BUF_SIZE)) { 284 if (retval >= 0) 285 retval = -ENOEXEC; 286 goto error; 287 } 288 289 interp_params.hdr = *((struct elfhdr *) bprm->buf); 290 break; 291 292 case PT_LOAD: 293 #ifdef CONFIG_MMU 294 if (exec_params.load_addr == 0) 295 exec_params.load_addr = phdr->p_vaddr; 296 #endif 297 break; 298 } 299 300 } 301 302 if (is_constdisp(&exec_params.hdr)) 303 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 304 305 /* perform insanity checks on the interpreter */ 306 if (interpreter_name) { 307 retval = -ELIBBAD; 308 if (!is_elf(&interp_params.hdr, interpreter)) 309 goto error; 310 311 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 312 313 /* read the interpreter's program header table */ 314 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 315 if (retval < 0) 316 goto error; 317 } 318 319 stack_size = exec_params.stack_size; 320 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 321 executable_stack = EXSTACK_ENABLE_X; 322 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 323 executable_stack = EXSTACK_DISABLE_X; 324 else 325 executable_stack = EXSTACK_DEFAULT; 326 327 if (stack_size == 0) { 328 stack_size = interp_params.stack_size; 329 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 330 executable_stack = EXSTACK_ENABLE_X; 331 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 332 executable_stack = EXSTACK_DISABLE_X; 333 else 334 executable_stack = EXSTACK_DEFAULT; 335 } 336 337 retval = -ENOEXEC; 338 if (stack_size == 0) 339 stack_size = 131072UL; /* same as exec.c's default commit */ 340 341 if (is_constdisp(&interp_params.hdr)) 342 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 343 344 /* flush all traces of the currently running executable */ 345 retval = flush_old_exec(bprm); 346 if (retval) 347 goto error; 348 349 /* there's now no turning back... the old userspace image is dead, 350 * defunct, deceased, etc. 351 */ 352 if (elf_check_fdpic(&exec_params.hdr)) 353 set_personality(PER_LINUX_FDPIC); 354 else 355 set_personality(PER_LINUX); 356 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 357 current->personality |= READ_IMPLIES_EXEC; 358 359 setup_new_exec(bprm); 360 361 set_binfmt(&elf_fdpic_format); 362 363 current->mm->start_code = 0; 364 current->mm->end_code = 0; 365 current->mm->start_stack = 0; 366 current->mm->start_data = 0; 367 current->mm->end_data = 0; 368 current->mm->context.exec_fdpic_loadmap = 0; 369 current->mm->context.interp_fdpic_loadmap = 0; 370 371 #ifdef CONFIG_MMU 372 elf_fdpic_arch_lay_out_mm(&exec_params, 373 &interp_params, 374 ¤t->mm->start_stack, 375 ¤t->mm->start_brk); 376 377 retval = setup_arg_pages(bprm, current->mm->start_stack, 378 executable_stack); 379 if (retval < 0) 380 goto error; 381 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 382 retval = arch_setup_additional_pages(bprm, !!interpreter_name); 383 if (retval < 0) 384 goto error; 385 #endif 386 #endif 387 388 /* load the executable and interpreter into memory */ 389 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 390 "executable"); 391 if (retval < 0) 392 goto error; 393 394 if (interpreter_name) { 395 retval = elf_fdpic_map_file(&interp_params, interpreter, 396 current->mm, "interpreter"); 397 if (retval < 0) { 398 printk(KERN_ERR "Unable to load interpreter\n"); 399 goto error; 400 } 401 402 allow_write_access(interpreter); 403 fput(interpreter); 404 interpreter = NULL; 405 } 406 407 #ifdef CONFIG_MMU 408 if (!current->mm->start_brk) 409 current->mm->start_brk = current->mm->end_data; 410 411 current->mm->brk = current->mm->start_brk = 412 PAGE_ALIGN(current->mm->start_brk); 413 414 #else 415 /* create a stack area and zero-size brk area */ 416 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 417 if (stack_size < PAGE_SIZE * 2) 418 stack_size = PAGE_SIZE * 2; 419 420 stack_prot = PROT_READ | PROT_WRITE; 421 if (executable_stack == EXSTACK_ENABLE_X || 422 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 423 stack_prot |= PROT_EXEC; 424 425 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 426 MAP_PRIVATE | MAP_ANONYMOUS | 427 MAP_UNINITIALIZED | MAP_GROWSDOWN, 428 0); 429 430 if (IS_ERR_VALUE(current->mm->start_brk)) { 431 retval = current->mm->start_brk; 432 current->mm->start_brk = 0; 433 goto error; 434 } 435 436 current->mm->brk = current->mm->start_brk; 437 current->mm->context.end_brk = current->mm->start_brk; 438 current->mm->start_stack = current->mm->start_brk + stack_size; 439 #endif 440 441 install_exec_creds(bprm); 442 if (create_elf_fdpic_tables(bprm, current->mm, 443 &exec_params, &interp_params) < 0) 444 goto error; 445 446 kdebug("- start_code %lx", current->mm->start_code); 447 kdebug("- end_code %lx", current->mm->end_code); 448 kdebug("- start_data %lx", current->mm->start_data); 449 kdebug("- end_data %lx", current->mm->end_data); 450 kdebug("- start_brk %lx", current->mm->start_brk); 451 kdebug("- brk %lx", current->mm->brk); 452 kdebug("- start_stack %lx", current->mm->start_stack); 453 454 #ifdef ELF_FDPIC_PLAT_INIT 455 /* 456 * The ABI may specify that certain registers be set up in special 457 * ways (on i386 %edx is the address of a DT_FINI function, for 458 * example. This macro performs whatever initialization to 459 * the regs structure is required. 460 */ 461 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 462 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 463 dynaddr); 464 #endif 465 466 /* everything is now ready... get the userspace context ready to roll */ 467 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 468 start_thread(regs, entryaddr, current->mm->start_stack); 469 470 retval = 0; 471 472 error: 473 if (interpreter) { 474 allow_write_access(interpreter); 475 fput(interpreter); 476 } 477 kfree(interpreter_name); 478 kfree(exec_params.phdrs); 479 kfree(exec_params.loadmap); 480 kfree(interp_params.phdrs); 481 kfree(interp_params.loadmap); 482 return retval; 483 } 484 485 /*****************************************************************************/ 486 487 #ifndef ELF_BASE_PLATFORM 488 /* 489 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 490 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 491 * will be copied to the user stack in the same manner as AT_PLATFORM. 492 */ 493 #define ELF_BASE_PLATFORM NULL 494 #endif 495 496 /* 497 * present useful information to the program by shovelling it onto the new 498 * process's stack 499 */ 500 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 501 struct mm_struct *mm, 502 struct elf_fdpic_params *exec_params, 503 struct elf_fdpic_params *interp_params) 504 { 505 const struct cred *cred = current_cred(); 506 unsigned long sp, csp, nitems; 507 elf_caddr_t __user *argv, *envp; 508 size_t platform_len = 0, len; 509 char *k_platform, *k_base_platform; 510 char __user *u_platform, *u_base_platform, *p; 511 int loop; 512 int nr; /* reset for each csp adjustment */ 513 514 #ifdef CONFIG_MMU 515 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 516 * by the processes running on the same package. One thing we can do is 517 * to shuffle the initial stack for them, so we give the architecture 518 * an opportunity to do so here. 519 */ 520 sp = arch_align_stack(bprm->p); 521 #else 522 sp = mm->start_stack; 523 524 /* stack the program arguments and environment */ 525 if (transfer_args_to_stack(bprm, &sp) < 0) 526 return -EFAULT; 527 sp &= ~15; 528 #endif 529 530 /* 531 * If this architecture has a platform capability string, copy it 532 * to userspace. In some cases (Sparc), this info is impossible 533 * for userspace to get any other way, in others (i386) it is 534 * merely difficult. 535 */ 536 k_platform = ELF_PLATFORM; 537 u_platform = NULL; 538 539 if (k_platform) { 540 platform_len = strlen(k_platform) + 1; 541 sp -= platform_len; 542 u_platform = (char __user *) sp; 543 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 544 return -EFAULT; 545 } 546 547 /* 548 * If this architecture has a "base" platform capability 549 * string, copy it to userspace. 550 */ 551 k_base_platform = ELF_BASE_PLATFORM; 552 u_base_platform = NULL; 553 554 if (k_base_platform) { 555 platform_len = strlen(k_base_platform) + 1; 556 sp -= platform_len; 557 u_base_platform = (char __user *) sp; 558 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 559 return -EFAULT; 560 } 561 562 sp &= ~7UL; 563 564 /* stack the load map(s) */ 565 len = sizeof(struct elf32_fdpic_loadmap); 566 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 567 sp = (sp - len) & ~7UL; 568 exec_params->map_addr = sp; 569 570 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 571 return -EFAULT; 572 573 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 574 575 if (interp_params->loadmap) { 576 len = sizeof(struct elf32_fdpic_loadmap); 577 len += sizeof(struct elf32_fdpic_loadseg) * 578 interp_params->loadmap->nsegs; 579 sp = (sp - len) & ~7UL; 580 interp_params->map_addr = sp; 581 582 if (copy_to_user((void __user *) sp, interp_params->loadmap, 583 len) != 0) 584 return -EFAULT; 585 586 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 587 } 588 589 /* force 16 byte _final_ alignment here for generality */ 590 #define DLINFO_ITEMS 15 591 592 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 593 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 594 595 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 596 nitems++; 597 598 csp = sp; 599 sp -= nitems * 2 * sizeof(unsigned long); 600 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 601 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 602 sp -= 1 * sizeof(unsigned long); /* argc */ 603 604 csp -= sp & 15UL; 605 sp -= sp & 15UL; 606 607 /* put the ELF interpreter info on the stack */ 608 #define NEW_AUX_ENT(id, val) \ 609 do { \ 610 struct { unsigned long _id, _val; } __user *ent; \ 611 \ 612 ent = (void __user *) csp; \ 613 __put_user((id), &ent[nr]._id); \ 614 __put_user((val), &ent[nr]._val); \ 615 nr++; \ 616 } while (0) 617 618 nr = 0; 619 csp -= 2 * sizeof(unsigned long); 620 NEW_AUX_ENT(AT_NULL, 0); 621 if (k_platform) { 622 nr = 0; 623 csp -= 2 * sizeof(unsigned long); 624 NEW_AUX_ENT(AT_PLATFORM, 625 (elf_addr_t) (unsigned long) u_platform); 626 } 627 628 if (k_base_platform) { 629 nr = 0; 630 csp -= 2 * sizeof(unsigned long); 631 NEW_AUX_ENT(AT_BASE_PLATFORM, 632 (elf_addr_t) (unsigned long) u_base_platform); 633 } 634 635 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 636 nr = 0; 637 csp -= 2 * sizeof(unsigned long); 638 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 639 } 640 641 nr = 0; 642 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 643 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 644 #ifdef ELF_HWCAP2 645 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 646 #endif 647 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 648 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 649 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 650 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 651 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 652 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 653 NEW_AUX_ENT(AT_FLAGS, 0); 654 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 655 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 656 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 657 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 658 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 659 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 660 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 661 662 #ifdef ARCH_DLINFO 663 nr = 0; 664 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 665 666 /* ARCH_DLINFO must come last so platform specific code can enforce 667 * special alignment requirements on the AUXV if necessary (eg. PPC). 668 */ 669 ARCH_DLINFO; 670 #endif 671 #undef NEW_AUX_ENT 672 673 /* allocate room for argv[] and envv[] */ 674 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 675 envp = (elf_caddr_t __user *) csp; 676 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 677 argv = (elf_caddr_t __user *) csp; 678 679 /* stack argc */ 680 csp -= sizeof(unsigned long); 681 __put_user(bprm->argc, (unsigned long __user *) csp); 682 683 BUG_ON(csp != sp); 684 685 /* fill in the argv[] array */ 686 #ifdef CONFIG_MMU 687 current->mm->arg_start = bprm->p; 688 #else 689 current->mm->arg_start = current->mm->start_stack - 690 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 691 #endif 692 693 p = (char __user *) current->mm->arg_start; 694 for (loop = bprm->argc; loop > 0; loop--) { 695 __put_user((elf_caddr_t) p, argv++); 696 len = strnlen_user(p, MAX_ARG_STRLEN); 697 if (!len || len > MAX_ARG_STRLEN) 698 return -EINVAL; 699 p += len; 700 } 701 __put_user(NULL, argv); 702 current->mm->arg_end = (unsigned long) p; 703 704 /* fill in the envv[] array */ 705 current->mm->env_start = (unsigned long) p; 706 for (loop = bprm->envc; loop > 0; loop--) { 707 __put_user((elf_caddr_t)(unsigned long) p, envp++); 708 len = strnlen_user(p, MAX_ARG_STRLEN); 709 if (!len || len > MAX_ARG_STRLEN) 710 return -EINVAL; 711 p += len; 712 } 713 __put_user(NULL, envp); 714 current->mm->env_end = (unsigned long) p; 715 716 mm->start_stack = (unsigned long) sp; 717 return 0; 718 } 719 720 /*****************************************************************************/ 721 /* 722 * load the appropriate binary image (executable or interpreter) into memory 723 * - we assume no MMU is available 724 * - if no other PIC bits are set in params->hdr->e_flags 725 * - we assume that the LOADable segments in the binary are independently relocatable 726 * - we assume R/O executable segments are shareable 727 * - else 728 * - we assume the loadable parts of the image to require fixed displacement 729 * - the image is not shareable 730 */ 731 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 732 struct file *file, 733 struct mm_struct *mm, 734 const char *what) 735 { 736 struct elf32_fdpic_loadmap *loadmap; 737 #ifdef CONFIG_MMU 738 struct elf32_fdpic_loadseg *mseg; 739 #endif 740 struct elf32_fdpic_loadseg *seg; 741 struct elf32_phdr *phdr; 742 unsigned long load_addr, stop; 743 unsigned nloads, tmp; 744 size_t size; 745 int loop, ret; 746 747 /* allocate a load map table */ 748 nloads = 0; 749 for (loop = 0; loop < params->hdr.e_phnum; loop++) 750 if (params->phdrs[loop].p_type == PT_LOAD) 751 nloads++; 752 753 if (nloads == 0) 754 return -ELIBBAD; 755 756 size = sizeof(*loadmap) + nloads * sizeof(*seg); 757 loadmap = kzalloc(size, GFP_KERNEL); 758 if (!loadmap) 759 return -ENOMEM; 760 761 params->loadmap = loadmap; 762 763 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 764 loadmap->nsegs = nloads; 765 766 load_addr = params->load_addr; 767 seg = loadmap->segs; 768 769 /* map the requested LOADs into the memory space */ 770 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 771 case ELF_FDPIC_FLAG_CONSTDISP: 772 case ELF_FDPIC_FLAG_CONTIGUOUS: 773 #ifndef CONFIG_MMU 774 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 775 if (ret < 0) 776 return ret; 777 break; 778 #endif 779 default: 780 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 781 if (ret < 0) 782 return ret; 783 break; 784 } 785 786 /* map the entry point */ 787 if (params->hdr.e_entry) { 788 seg = loadmap->segs; 789 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 790 if (params->hdr.e_entry >= seg->p_vaddr && 791 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 792 params->entry_addr = 793 (params->hdr.e_entry - seg->p_vaddr) + 794 seg->addr; 795 break; 796 } 797 } 798 } 799 800 /* determine where the program header table has wound up if mapped */ 801 stop = params->hdr.e_phoff; 802 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 803 phdr = params->phdrs; 804 805 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 806 if (phdr->p_type != PT_LOAD) 807 continue; 808 809 if (phdr->p_offset > params->hdr.e_phoff || 810 phdr->p_offset + phdr->p_filesz < stop) 811 continue; 812 813 seg = loadmap->segs; 814 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 815 if (phdr->p_vaddr >= seg->p_vaddr && 816 phdr->p_vaddr + phdr->p_filesz <= 817 seg->p_vaddr + seg->p_memsz) { 818 params->ph_addr = 819 (phdr->p_vaddr - seg->p_vaddr) + 820 seg->addr + 821 params->hdr.e_phoff - phdr->p_offset; 822 break; 823 } 824 } 825 break; 826 } 827 828 /* determine where the dynamic section has wound up if there is one */ 829 phdr = params->phdrs; 830 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 831 if (phdr->p_type != PT_DYNAMIC) 832 continue; 833 834 seg = loadmap->segs; 835 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 836 if (phdr->p_vaddr >= seg->p_vaddr && 837 phdr->p_vaddr + phdr->p_memsz <= 838 seg->p_vaddr + seg->p_memsz) { 839 Elf32_Dyn __user *dyn; 840 Elf32_Sword d_tag; 841 842 params->dynamic_addr = 843 (phdr->p_vaddr - seg->p_vaddr) + 844 seg->addr; 845 846 /* check the dynamic section contains at least 847 * one item, and that the last item is a NULL 848 * entry */ 849 if (phdr->p_memsz == 0 || 850 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 851 goto dynamic_error; 852 853 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 854 dyn = (Elf32_Dyn __user *)params->dynamic_addr; 855 __get_user(d_tag, &dyn[tmp - 1].d_tag); 856 if (d_tag != 0) 857 goto dynamic_error; 858 break; 859 } 860 } 861 break; 862 } 863 864 /* now elide adjacent segments in the load map on MMU linux 865 * - on uClinux the holes between may actually be filled with system 866 * stuff or stuff from other processes 867 */ 868 #ifdef CONFIG_MMU 869 nloads = loadmap->nsegs; 870 mseg = loadmap->segs; 871 seg = mseg + 1; 872 for (loop = 1; loop < nloads; loop++) { 873 /* see if we have a candidate for merging */ 874 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 875 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 876 if (load_addr == (seg->addr & PAGE_MASK)) { 877 mseg->p_memsz += 878 load_addr - 879 (mseg->addr + mseg->p_memsz); 880 mseg->p_memsz += seg->addr & ~PAGE_MASK; 881 mseg->p_memsz += seg->p_memsz; 882 loadmap->nsegs--; 883 continue; 884 } 885 } 886 887 mseg++; 888 if (mseg != seg) 889 *mseg = *seg; 890 } 891 #endif 892 893 kdebug("Mapped Object [%s]:", what); 894 kdebug("- elfhdr : %lx", params->elfhdr_addr); 895 kdebug("- entry : %lx", params->entry_addr); 896 kdebug("- PHDR[] : %lx", params->ph_addr); 897 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 898 seg = loadmap->segs; 899 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 900 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 901 loop, 902 seg->addr, seg->addr + seg->p_memsz - 1, 903 seg->p_vaddr, seg->p_memsz); 904 905 return 0; 906 907 dynamic_error: 908 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 909 what, file_inode(file)->i_ino); 910 return -ELIBBAD; 911 } 912 913 /*****************************************************************************/ 914 /* 915 * map a file with constant displacement under uClinux 916 */ 917 #ifndef CONFIG_MMU 918 static int elf_fdpic_map_file_constdisp_on_uclinux( 919 struct elf_fdpic_params *params, 920 struct file *file, 921 struct mm_struct *mm) 922 { 923 struct elf32_fdpic_loadseg *seg; 924 struct elf32_phdr *phdr; 925 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 926 int loop, ret; 927 928 load_addr = params->load_addr; 929 seg = params->loadmap->segs; 930 931 /* determine the bounds of the contiguous overall allocation we must 932 * make */ 933 phdr = params->phdrs; 934 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 935 if (params->phdrs[loop].p_type != PT_LOAD) 936 continue; 937 938 if (base > phdr->p_vaddr) 939 base = phdr->p_vaddr; 940 if (top < phdr->p_vaddr + phdr->p_memsz) 941 top = phdr->p_vaddr + phdr->p_memsz; 942 } 943 944 /* allocate one big anon block for everything */ 945 mflags = MAP_PRIVATE; 946 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 947 mflags |= MAP_EXECUTABLE; 948 949 maddr = vm_mmap(NULL, load_addr, top - base, 950 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 951 if (IS_ERR_VALUE(maddr)) 952 return (int) maddr; 953 954 if (load_addr != 0) 955 load_addr += PAGE_ALIGN(top - base); 956 957 /* and then load the file segments into it */ 958 phdr = params->phdrs; 959 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 960 if (params->phdrs[loop].p_type != PT_LOAD) 961 continue; 962 963 seg->addr = maddr + (phdr->p_vaddr - base); 964 seg->p_vaddr = phdr->p_vaddr; 965 seg->p_memsz = phdr->p_memsz; 966 967 ret = read_code(file, seg->addr, phdr->p_offset, 968 phdr->p_filesz); 969 if (ret < 0) 970 return ret; 971 972 /* map the ELF header address if in this segment */ 973 if (phdr->p_offset == 0) 974 params->elfhdr_addr = seg->addr; 975 976 /* clear any space allocated but not loaded */ 977 if (phdr->p_filesz < phdr->p_memsz) { 978 if (clear_user((void *) (seg->addr + phdr->p_filesz), 979 phdr->p_memsz - phdr->p_filesz)) 980 return -EFAULT; 981 } 982 983 if (mm) { 984 if (phdr->p_flags & PF_X) { 985 if (!mm->start_code) { 986 mm->start_code = seg->addr; 987 mm->end_code = seg->addr + 988 phdr->p_memsz; 989 } 990 } else if (!mm->start_data) { 991 mm->start_data = seg->addr; 992 mm->end_data = seg->addr + phdr->p_memsz; 993 } 994 } 995 996 seg++; 997 } 998 999 return 0; 1000 } 1001 #endif 1002 1003 /*****************************************************************************/ 1004 /* 1005 * map a binary by direct mmap() of the individual PT_LOAD segments 1006 */ 1007 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1008 struct file *file, 1009 struct mm_struct *mm) 1010 { 1011 struct elf32_fdpic_loadseg *seg; 1012 struct elf32_phdr *phdr; 1013 unsigned long load_addr, delta_vaddr; 1014 int loop, dvset; 1015 1016 load_addr = params->load_addr; 1017 delta_vaddr = 0; 1018 dvset = 0; 1019 1020 seg = params->loadmap->segs; 1021 1022 /* deal with each load segment separately */ 1023 phdr = params->phdrs; 1024 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1025 unsigned long maddr, disp, excess, excess1; 1026 int prot = 0, flags; 1027 1028 if (phdr->p_type != PT_LOAD) 1029 continue; 1030 1031 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1032 (unsigned long) phdr->p_vaddr, 1033 (unsigned long) phdr->p_offset, 1034 (unsigned long) phdr->p_filesz, 1035 (unsigned long) phdr->p_memsz); 1036 1037 /* determine the mapping parameters */ 1038 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1039 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1040 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1041 1042 flags = MAP_PRIVATE | MAP_DENYWRITE; 1043 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1044 flags |= MAP_EXECUTABLE; 1045 1046 maddr = 0; 1047 1048 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1049 case ELF_FDPIC_FLAG_INDEPENDENT: 1050 /* PT_LOADs are independently locatable */ 1051 break; 1052 1053 case ELF_FDPIC_FLAG_HONOURVADDR: 1054 /* the specified virtual address must be honoured */ 1055 maddr = phdr->p_vaddr; 1056 flags |= MAP_FIXED; 1057 break; 1058 1059 case ELF_FDPIC_FLAG_CONSTDISP: 1060 /* constant displacement 1061 * - can be mapped anywhere, but must be mapped as a 1062 * unit 1063 */ 1064 if (!dvset) { 1065 maddr = load_addr; 1066 delta_vaddr = phdr->p_vaddr; 1067 dvset = 1; 1068 } else { 1069 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1070 flags |= MAP_FIXED; 1071 } 1072 break; 1073 1074 case ELF_FDPIC_FLAG_CONTIGUOUS: 1075 /* contiguity handled later */ 1076 break; 1077 1078 default: 1079 BUG(); 1080 } 1081 1082 maddr &= PAGE_MASK; 1083 1084 /* create the mapping */ 1085 disp = phdr->p_vaddr & ~PAGE_MASK; 1086 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1087 phdr->p_offset - disp); 1088 1089 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1090 loop, phdr->p_memsz + disp, prot, flags, 1091 phdr->p_offset - disp, maddr); 1092 1093 if (IS_ERR_VALUE(maddr)) 1094 return (int) maddr; 1095 1096 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1097 ELF_FDPIC_FLAG_CONTIGUOUS) 1098 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1099 1100 seg->addr = maddr + disp; 1101 seg->p_vaddr = phdr->p_vaddr; 1102 seg->p_memsz = phdr->p_memsz; 1103 1104 /* map the ELF header address if in this segment */ 1105 if (phdr->p_offset == 0) 1106 params->elfhdr_addr = seg->addr; 1107 1108 /* clear the bit between beginning of mapping and beginning of 1109 * PT_LOAD */ 1110 if (prot & PROT_WRITE && disp > 0) { 1111 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1112 if (clear_user((void __user *) maddr, disp)) 1113 return -EFAULT; 1114 maddr += disp; 1115 } 1116 1117 /* clear any space allocated but not loaded 1118 * - on uClinux we can just clear the lot 1119 * - on MMU linux we'll get a SIGBUS beyond the last page 1120 * extant in the file 1121 */ 1122 excess = phdr->p_memsz - phdr->p_filesz; 1123 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1124 1125 #ifdef CONFIG_MMU 1126 if (excess > excess1) { 1127 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1128 unsigned long xmaddr; 1129 1130 flags |= MAP_FIXED | MAP_ANONYMOUS; 1131 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1132 prot, flags, 0); 1133 1134 kdebug("mmap[%d] <anon>" 1135 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1136 loop, xaddr, excess - excess1, prot, flags, 1137 xmaddr); 1138 1139 if (xmaddr != xaddr) 1140 return -ENOMEM; 1141 } 1142 1143 if (prot & PROT_WRITE && excess1 > 0) { 1144 kdebug("clear[%d] ad=%lx sz=%lx", 1145 loop, maddr + phdr->p_filesz, excess1); 1146 if (clear_user((void __user *) maddr + phdr->p_filesz, 1147 excess1)) 1148 return -EFAULT; 1149 } 1150 1151 #else 1152 if (excess > 0) { 1153 kdebug("clear[%d] ad=%lx sz=%lx", 1154 loop, maddr + phdr->p_filesz, excess); 1155 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1156 return -EFAULT; 1157 } 1158 #endif 1159 1160 if (mm) { 1161 if (phdr->p_flags & PF_X) { 1162 if (!mm->start_code) { 1163 mm->start_code = maddr; 1164 mm->end_code = maddr + phdr->p_memsz; 1165 } 1166 } else if (!mm->start_data) { 1167 mm->start_data = maddr; 1168 mm->end_data = maddr + phdr->p_memsz; 1169 } 1170 } 1171 1172 seg++; 1173 } 1174 1175 return 0; 1176 } 1177 1178 /*****************************************************************************/ 1179 /* 1180 * ELF-FDPIC core dumper 1181 * 1182 * Modelled on fs/exec.c:aout_core_dump() 1183 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1184 * 1185 * Modelled on fs/binfmt_elf.c core dumper 1186 */ 1187 #ifdef CONFIG_ELF_CORE 1188 1189 /* 1190 * Decide whether a segment is worth dumping; default is yes to be 1191 * sure (missing info is worse than too much; etc). 1192 * Personally I'd include everything, and use the coredump limit... 1193 * 1194 * I think we should skip something. But I am not sure how. H.J. 1195 */ 1196 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1197 { 1198 int dump_ok; 1199 1200 /* Do not dump I/O mapped devices or special mappings */ 1201 if (vma->vm_flags & VM_IO) { 1202 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1203 return 0; 1204 } 1205 1206 /* If we may not read the contents, don't allow us to dump 1207 * them either. "dump_write()" can't handle it anyway. 1208 */ 1209 if (!(vma->vm_flags & VM_READ)) { 1210 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1211 return 0; 1212 } 1213 1214 /* support for DAX */ 1215 if (vma_is_dax(vma)) { 1216 if (vma->vm_flags & VM_SHARED) { 1217 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags); 1218 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start, 1219 vma->vm_flags, dump_ok ? "yes" : "no"); 1220 } else { 1221 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags); 1222 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start, 1223 vma->vm_flags, dump_ok ? "yes" : "no"); 1224 } 1225 return dump_ok; 1226 } 1227 1228 /* By default, dump shared memory if mapped from an anonymous file. */ 1229 if (vma->vm_flags & VM_SHARED) { 1230 if (file_inode(vma->vm_file)->i_nlink == 0) { 1231 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1232 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1233 vma->vm_flags, dump_ok ? "yes" : "no"); 1234 return dump_ok; 1235 } 1236 1237 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1238 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1239 vma->vm_flags, dump_ok ? "yes" : "no"); 1240 return dump_ok; 1241 } 1242 1243 #ifdef CONFIG_MMU 1244 /* By default, if it hasn't been written to, don't write it out */ 1245 if (!vma->anon_vma) { 1246 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1247 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1248 vma->vm_flags, dump_ok ? "yes" : "no"); 1249 return dump_ok; 1250 } 1251 #endif 1252 1253 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1254 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1255 dump_ok ? "yes" : "no"); 1256 return dump_ok; 1257 } 1258 1259 /* An ELF note in memory */ 1260 struct memelfnote 1261 { 1262 const char *name; 1263 int type; 1264 unsigned int datasz; 1265 void *data; 1266 }; 1267 1268 static int notesize(struct memelfnote *en) 1269 { 1270 int sz; 1271 1272 sz = sizeof(struct elf_note); 1273 sz += roundup(strlen(en->name) + 1, 4); 1274 sz += roundup(en->datasz, 4); 1275 1276 return sz; 1277 } 1278 1279 /* #define DEBUG */ 1280 1281 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1282 { 1283 struct elf_note en; 1284 en.n_namesz = strlen(men->name) + 1; 1285 en.n_descsz = men->datasz; 1286 en.n_type = men->type; 1287 1288 return dump_emit(cprm, &en, sizeof(en)) && 1289 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1290 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1291 } 1292 1293 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1294 { 1295 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1296 elf->e_ident[EI_CLASS] = ELF_CLASS; 1297 elf->e_ident[EI_DATA] = ELF_DATA; 1298 elf->e_ident[EI_VERSION] = EV_CURRENT; 1299 elf->e_ident[EI_OSABI] = ELF_OSABI; 1300 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1301 1302 elf->e_type = ET_CORE; 1303 elf->e_machine = ELF_ARCH; 1304 elf->e_version = EV_CURRENT; 1305 elf->e_entry = 0; 1306 elf->e_phoff = sizeof(struct elfhdr); 1307 elf->e_shoff = 0; 1308 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1309 elf->e_ehsize = sizeof(struct elfhdr); 1310 elf->e_phentsize = sizeof(struct elf_phdr); 1311 elf->e_phnum = segs; 1312 elf->e_shentsize = 0; 1313 elf->e_shnum = 0; 1314 elf->e_shstrndx = 0; 1315 return; 1316 } 1317 1318 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1319 { 1320 phdr->p_type = PT_NOTE; 1321 phdr->p_offset = offset; 1322 phdr->p_vaddr = 0; 1323 phdr->p_paddr = 0; 1324 phdr->p_filesz = sz; 1325 phdr->p_memsz = 0; 1326 phdr->p_flags = 0; 1327 phdr->p_align = 0; 1328 return; 1329 } 1330 1331 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1332 unsigned int sz, void *data) 1333 { 1334 note->name = name; 1335 note->type = type; 1336 note->datasz = sz; 1337 note->data = data; 1338 return; 1339 } 1340 1341 /* 1342 * fill up all the fields in prstatus from the given task struct, except 1343 * registers which need to be filled up separately. 1344 */ 1345 static void fill_prstatus(struct elf_prstatus *prstatus, 1346 struct task_struct *p, long signr) 1347 { 1348 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1349 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1350 prstatus->pr_sighold = p->blocked.sig[0]; 1351 rcu_read_lock(); 1352 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1353 rcu_read_unlock(); 1354 prstatus->pr_pid = task_pid_vnr(p); 1355 prstatus->pr_pgrp = task_pgrp_vnr(p); 1356 prstatus->pr_sid = task_session_vnr(p); 1357 if (thread_group_leader(p)) { 1358 struct task_cputime cputime; 1359 1360 /* 1361 * This is the record for the group leader. It shows the 1362 * group-wide total, not its individual thread total. 1363 */ 1364 thread_group_cputime(p, &cputime); 1365 prstatus->pr_utime = ns_to_timeval(cputime.utime); 1366 prstatus->pr_stime = ns_to_timeval(cputime.stime); 1367 } else { 1368 u64 utime, stime; 1369 1370 task_cputime(p, &utime, &stime); 1371 prstatus->pr_utime = ns_to_timeval(utime); 1372 prstatus->pr_stime = ns_to_timeval(stime); 1373 } 1374 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime); 1375 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime); 1376 1377 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1378 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1379 } 1380 1381 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1382 struct mm_struct *mm) 1383 { 1384 const struct cred *cred; 1385 unsigned int i, len; 1386 1387 /* first copy the parameters from user space */ 1388 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1389 1390 len = mm->arg_end - mm->arg_start; 1391 if (len >= ELF_PRARGSZ) 1392 len = ELF_PRARGSZ - 1; 1393 if (copy_from_user(&psinfo->pr_psargs, 1394 (const char __user *) mm->arg_start, len)) 1395 return -EFAULT; 1396 for (i = 0; i < len; i++) 1397 if (psinfo->pr_psargs[i] == 0) 1398 psinfo->pr_psargs[i] = ' '; 1399 psinfo->pr_psargs[len] = 0; 1400 1401 rcu_read_lock(); 1402 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1403 rcu_read_unlock(); 1404 psinfo->pr_pid = task_pid_vnr(p); 1405 psinfo->pr_pgrp = task_pgrp_vnr(p); 1406 psinfo->pr_sid = task_session_vnr(p); 1407 1408 i = p->state ? ffz(~p->state) + 1 : 0; 1409 psinfo->pr_state = i; 1410 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1411 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1412 psinfo->pr_nice = task_nice(p); 1413 psinfo->pr_flag = p->flags; 1414 rcu_read_lock(); 1415 cred = __task_cred(p); 1416 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1417 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1418 rcu_read_unlock(); 1419 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1420 1421 return 0; 1422 } 1423 1424 /* Here is the structure in which status of each thread is captured. */ 1425 struct elf_thread_status 1426 { 1427 struct list_head list; 1428 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1429 elf_fpregset_t fpu; /* NT_PRFPREG */ 1430 struct task_struct *thread; 1431 #ifdef ELF_CORE_COPY_XFPREGS 1432 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1433 #endif 1434 struct memelfnote notes[3]; 1435 int num_notes; 1436 }; 1437 1438 /* 1439 * In order to add the specific thread information for the elf file format, 1440 * we need to keep a linked list of every thread's pr_status and then create 1441 * a single section for them in the final core file. 1442 */ 1443 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1444 { 1445 struct task_struct *p = t->thread; 1446 int sz = 0; 1447 1448 t->num_notes = 0; 1449 1450 fill_prstatus(&t->prstatus, p, signr); 1451 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1452 1453 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1454 &t->prstatus); 1455 t->num_notes++; 1456 sz += notesize(&t->notes[0]); 1457 1458 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1459 if (t->prstatus.pr_fpvalid) { 1460 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1461 &t->fpu); 1462 t->num_notes++; 1463 sz += notesize(&t->notes[1]); 1464 } 1465 1466 #ifdef ELF_CORE_COPY_XFPREGS 1467 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1468 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1469 sizeof(t->xfpu), &t->xfpu); 1470 t->num_notes++; 1471 sz += notesize(&t->notes[2]); 1472 } 1473 #endif 1474 return sz; 1475 } 1476 1477 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1478 elf_addr_t e_shoff, int segs) 1479 { 1480 elf->e_shoff = e_shoff; 1481 elf->e_shentsize = sizeof(*shdr4extnum); 1482 elf->e_shnum = 1; 1483 elf->e_shstrndx = SHN_UNDEF; 1484 1485 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1486 1487 shdr4extnum->sh_type = SHT_NULL; 1488 shdr4extnum->sh_size = elf->e_shnum; 1489 shdr4extnum->sh_link = elf->e_shstrndx; 1490 shdr4extnum->sh_info = segs; 1491 } 1492 1493 /* 1494 * dump the segments for an MMU process 1495 */ 1496 static bool elf_fdpic_dump_segments(struct coredump_params *cprm) 1497 { 1498 struct vm_area_struct *vma; 1499 1500 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1501 #ifdef CONFIG_MMU 1502 unsigned long addr; 1503 #endif 1504 1505 if (!maydump(vma, cprm->mm_flags)) 1506 continue; 1507 1508 #ifdef CONFIG_MMU 1509 for (addr = vma->vm_start; addr < vma->vm_end; 1510 addr += PAGE_SIZE) { 1511 bool res; 1512 struct page *page = get_dump_page(addr); 1513 if (page) { 1514 void *kaddr = kmap(page); 1515 res = dump_emit(cprm, kaddr, PAGE_SIZE); 1516 kunmap(page); 1517 put_page(page); 1518 } else { 1519 res = dump_skip(cprm, PAGE_SIZE); 1520 } 1521 if (!res) 1522 return false; 1523 } 1524 #else 1525 if (!dump_emit(cprm, (void *) vma->vm_start, 1526 vma->vm_end - vma->vm_start)) 1527 return false; 1528 #endif 1529 } 1530 return true; 1531 } 1532 1533 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1534 { 1535 struct vm_area_struct *vma; 1536 size_t size = 0; 1537 1538 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1539 if (maydump(vma, mm_flags)) 1540 size += vma->vm_end - vma->vm_start; 1541 return size; 1542 } 1543 1544 /* 1545 * Actual dumper 1546 * 1547 * This is a two-pass process; first we find the offsets of the bits, 1548 * and then they are actually written out. If we run out of core limit 1549 * we just truncate. 1550 */ 1551 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1552 { 1553 #define NUM_NOTES 6 1554 int has_dumped = 0; 1555 mm_segment_t fs; 1556 int segs; 1557 int i; 1558 struct vm_area_struct *vma; 1559 struct elfhdr *elf = NULL; 1560 loff_t offset = 0, dataoff; 1561 int numnote; 1562 struct memelfnote *notes = NULL; 1563 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1564 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1565 LIST_HEAD(thread_list); 1566 struct list_head *t; 1567 elf_fpregset_t *fpu = NULL; 1568 #ifdef ELF_CORE_COPY_XFPREGS 1569 elf_fpxregset_t *xfpu = NULL; 1570 #endif 1571 int thread_status_size = 0; 1572 elf_addr_t *auxv; 1573 struct elf_phdr *phdr4note = NULL; 1574 struct elf_shdr *shdr4extnum = NULL; 1575 Elf_Half e_phnum; 1576 elf_addr_t e_shoff; 1577 struct core_thread *ct; 1578 struct elf_thread_status *tmp; 1579 1580 /* 1581 * We no longer stop all VM operations. 1582 * 1583 * This is because those proceses that could possibly change map_count 1584 * or the mmap / vma pages are now blocked in do_exit on current 1585 * finishing this core dump. 1586 * 1587 * Only ptrace can touch these memory addresses, but it doesn't change 1588 * the map_count or the pages allocated. So no possibility of crashing 1589 * exists while dumping the mm->vm_next areas to the core file. 1590 */ 1591 1592 /* alloc memory for large data structures: too large to be on stack */ 1593 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1594 if (!elf) 1595 goto cleanup; 1596 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1597 if (!prstatus) 1598 goto cleanup; 1599 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1600 if (!psinfo) 1601 goto cleanup; 1602 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1603 if (!notes) 1604 goto cleanup; 1605 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1606 if (!fpu) 1607 goto cleanup; 1608 #ifdef ELF_CORE_COPY_XFPREGS 1609 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1610 if (!xfpu) 1611 goto cleanup; 1612 #endif 1613 1614 for (ct = current->mm->core_state->dumper.next; 1615 ct; ct = ct->next) { 1616 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1617 if (!tmp) 1618 goto cleanup; 1619 1620 tmp->thread = ct->task; 1621 list_add(&tmp->list, &thread_list); 1622 } 1623 1624 list_for_each(t, &thread_list) { 1625 struct elf_thread_status *tmp; 1626 int sz; 1627 1628 tmp = list_entry(t, struct elf_thread_status, list); 1629 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp); 1630 thread_status_size += sz; 1631 } 1632 1633 /* now collect the dump for the current */ 1634 fill_prstatus(prstatus, current, cprm->siginfo->si_signo); 1635 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1636 1637 segs = current->mm->map_count; 1638 segs += elf_core_extra_phdrs(); 1639 1640 /* for notes section */ 1641 segs++; 1642 1643 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1644 * this, kernel supports extended numbering. Have a look at 1645 * include/linux/elf.h for further information. */ 1646 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1647 1648 /* Set up header */ 1649 fill_elf_fdpic_header(elf, e_phnum); 1650 1651 has_dumped = 1; 1652 /* 1653 * Set up the notes in similar form to SVR4 core dumps made 1654 * with info from their /proc. 1655 */ 1656 1657 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1658 fill_psinfo(psinfo, current->group_leader, current->mm); 1659 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1660 1661 numnote = 2; 1662 1663 auxv = (elf_addr_t *) current->mm->saved_auxv; 1664 1665 i = 0; 1666 do 1667 i += 2; 1668 while (auxv[i - 2] != AT_NULL); 1669 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1670 i * sizeof(elf_addr_t), auxv); 1671 1672 /* Try to dump the FPU. */ 1673 if ((prstatus->pr_fpvalid = 1674 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1675 fill_note(notes + numnote++, 1676 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1677 #ifdef ELF_CORE_COPY_XFPREGS 1678 if (elf_core_copy_task_xfpregs(current, xfpu)) 1679 fill_note(notes + numnote++, 1680 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1681 #endif 1682 1683 fs = get_fs(); 1684 set_fs(KERNEL_DS); 1685 1686 offset += sizeof(*elf); /* Elf header */ 1687 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1688 1689 /* Write notes phdr entry */ 1690 { 1691 int sz = 0; 1692 1693 for (i = 0; i < numnote; i++) 1694 sz += notesize(notes + i); 1695 1696 sz += thread_status_size; 1697 1698 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1699 if (!phdr4note) 1700 goto end_coredump; 1701 1702 fill_elf_note_phdr(phdr4note, sz, offset); 1703 offset += sz; 1704 } 1705 1706 /* Page-align dumped data */ 1707 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1708 1709 offset += elf_core_vma_data_size(cprm->mm_flags); 1710 offset += elf_core_extra_data_size(); 1711 e_shoff = offset; 1712 1713 if (e_phnum == PN_XNUM) { 1714 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1715 if (!shdr4extnum) 1716 goto end_coredump; 1717 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1718 } 1719 1720 offset = dataoff; 1721 1722 if (!dump_emit(cprm, elf, sizeof(*elf))) 1723 goto end_coredump; 1724 1725 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1726 goto end_coredump; 1727 1728 /* write program headers for segments dump */ 1729 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1730 struct elf_phdr phdr; 1731 size_t sz; 1732 1733 sz = vma->vm_end - vma->vm_start; 1734 1735 phdr.p_type = PT_LOAD; 1736 phdr.p_offset = offset; 1737 phdr.p_vaddr = vma->vm_start; 1738 phdr.p_paddr = 0; 1739 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1740 phdr.p_memsz = sz; 1741 offset += phdr.p_filesz; 1742 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1743 if (vma->vm_flags & VM_WRITE) 1744 phdr.p_flags |= PF_W; 1745 if (vma->vm_flags & VM_EXEC) 1746 phdr.p_flags |= PF_X; 1747 phdr.p_align = ELF_EXEC_PAGESIZE; 1748 1749 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1750 goto end_coredump; 1751 } 1752 1753 if (!elf_core_write_extra_phdrs(cprm, offset)) 1754 goto end_coredump; 1755 1756 /* write out the notes section */ 1757 for (i = 0; i < numnote; i++) 1758 if (!writenote(notes + i, cprm)) 1759 goto end_coredump; 1760 1761 /* write out the thread status notes section */ 1762 list_for_each(t, &thread_list) { 1763 struct elf_thread_status *tmp = 1764 list_entry(t, struct elf_thread_status, list); 1765 1766 for (i = 0; i < tmp->num_notes; i++) 1767 if (!writenote(&tmp->notes[i], cprm)) 1768 goto end_coredump; 1769 } 1770 1771 if (!dump_skip(cprm, dataoff - cprm->pos)) 1772 goto end_coredump; 1773 1774 if (!elf_fdpic_dump_segments(cprm)) 1775 goto end_coredump; 1776 1777 if (!elf_core_write_extra_data(cprm)) 1778 goto end_coredump; 1779 1780 if (e_phnum == PN_XNUM) { 1781 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1782 goto end_coredump; 1783 } 1784 1785 if (cprm->file->f_pos != offset) { 1786 /* Sanity check */ 1787 printk(KERN_WARNING 1788 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1789 cprm->file->f_pos, offset); 1790 } 1791 1792 end_coredump: 1793 set_fs(fs); 1794 1795 cleanup: 1796 while (!list_empty(&thread_list)) { 1797 struct list_head *tmp = thread_list.next; 1798 list_del(tmp); 1799 kfree(list_entry(tmp, struct elf_thread_status, list)); 1800 } 1801 kfree(phdr4note); 1802 kfree(elf); 1803 kfree(prstatus); 1804 kfree(psinfo); 1805 kfree(notes); 1806 kfree(fpu); 1807 kfree(shdr4extnum); 1808 #ifdef ELF_CORE_COPY_XFPREGS 1809 kfree(xfpu); 1810 #endif 1811 return has_dumped; 1812 #undef NUM_NOTES 1813 } 1814 1815 #endif /* CONFIG_ELF_CORE */ 1816