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 finalize_exec(bprm); 467 /* everything is now ready... get the userspace context ready to roll */ 468 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 469 start_thread(regs, entryaddr, current->mm->start_stack); 470 471 retval = 0; 472 473 error: 474 if (interpreter) { 475 allow_write_access(interpreter); 476 fput(interpreter); 477 } 478 kfree(interpreter_name); 479 kfree(exec_params.phdrs); 480 kfree(exec_params.loadmap); 481 kfree(interp_params.phdrs); 482 kfree(interp_params.loadmap); 483 return retval; 484 } 485 486 /*****************************************************************************/ 487 488 #ifndef ELF_BASE_PLATFORM 489 /* 490 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 491 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 492 * will be copied to the user stack in the same manner as AT_PLATFORM. 493 */ 494 #define ELF_BASE_PLATFORM NULL 495 #endif 496 497 /* 498 * present useful information to the program by shovelling it onto the new 499 * process's stack 500 */ 501 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 502 struct mm_struct *mm, 503 struct elf_fdpic_params *exec_params, 504 struct elf_fdpic_params *interp_params) 505 { 506 const struct cred *cred = current_cred(); 507 unsigned long sp, csp, nitems; 508 elf_caddr_t __user *argv, *envp; 509 size_t platform_len = 0, len; 510 char *k_platform, *k_base_platform; 511 char __user *u_platform, *u_base_platform, *p; 512 int loop; 513 int nr; /* reset for each csp adjustment */ 514 515 #ifdef CONFIG_MMU 516 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 517 * by the processes running on the same package. One thing we can do is 518 * to shuffle the initial stack for them, so we give the architecture 519 * an opportunity to do so here. 520 */ 521 sp = arch_align_stack(bprm->p); 522 #else 523 sp = mm->start_stack; 524 525 /* stack the program arguments and environment */ 526 if (transfer_args_to_stack(bprm, &sp) < 0) 527 return -EFAULT; 528 sp &= ~15; 529 #endif 530 531 /* 532 * If this architecture has a platform capability string, copy it 533 * to userspace. In some cases (Sparc), this info is impossible 534 * for userspace to get any other way, in others (i386) it is 535 * merely difficult. 536 */ 537 k_platform = ELF_PLATFORM; 538 u_platform = NULL; 539 540 if (k_platform) { 541 platform_len = strlen(k_platform) + 1; 542 sp -= platform_len; 543 u_platform = (char __user *) sp; 544 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 545 return -EFAULT; 546 } 547 548 /* 549 * If this architecture has a "base" platform capability 550 * string, copy it to userspace. 551 */ 552 k_base_platform = ELF_BASE_PLATFORM; 553 u_base_platform = NULL; 554 555 if (k_base_platform) { 556 platform_len = strlen(k_base_platform) + 1; 557 sp -= platform_len; 558 u_base_platform = (char __user *) sp; 559 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 560 return -EFAULT; 561 } 562 563 sp &= ~7UL; 564 565 /* stack the load map(s) */ 566 len = sizeof(struct elf32_fdpic_loadmap); 567 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 568 sp = (sp - len) & ~7UL; 569 exec_params->map_addr = sp; 570 571 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 572 return -EFAULT; 573 574 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 575 576 if (interp_params->loadmap) { 577 len = sizeof(struct elf32_fdpic_loadmap); 578 len += sizeof(struct elf32_fdpic_loadseg) * 579 interp_params->loadmap->nsegs; 580 sp = (sp - len) & ~7UL; 581 interp_params->map_addr = sp; 582 583 if (copy_to_user((void __user *) sp, interp_params->loadmap, 584 len) != 0) 585 return -EFAULT; 586 587 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 588 } 589 590 /* force 16 byte _final_ alignment here for generality */ 591 #define DLINFO_ITEMS 15 592 593 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 594 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 595 596 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 597 nitems++; 598 599 csp = sp; 600 sp -= nitems * 2 * sizeof(unsigned long); 601 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 602 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 603 sp -= 1 * sizeof(unsigned long); /* argc */ 604 605 csp -= sp & 15UL; 606 sp -= sp & 15UL; 607 608 /* put the ELF interpreter info on the stack */ 609 #define NEW_AUX_ENT(id, val) \ 610 do { \ 611 struct { unsigned long _id, _val; } __user *ent; \ 612 \ 613 ent = (void __user *) csp; \ 614 __put_user((id), &ent[nr]._id); \ 615 __put_user((val), &ent[nr]._val); \ 616 nr++; \ 617 } while (0) 618 619 nr = 0; 620 csp -= 2 * sizeof(unsigned long); 621 NEW_AUX_ENT(AT_NULL, 0); 622 if (k_platform) { 623 nr = 0; 624 csp -= 2 * sizeof(unsigned long); 625 NEW_AUX_ENT(AT_PLATFORM, 626 (elf_addr_t) (unsigned long) u_platform); 627 } 628 629 if (k_base_platform) { 630 nr = 0; 631 csp -= 2 * sizeof(unsigned long); 632 NEW_AUX_ENT(AT_BASE_PLATFORM, 633 (elf_addr_t) (unsigned long) u_base_platform); 634 } 635 636 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 637 nr = 0; 638 csp -= 2 * sizeof(unsigned long); 639 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 640 } 641 642 nr = 0; 643 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 644 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 645 #ifdef ELF_HWCAP2 646 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 647 #endif 648 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 649 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 650 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 651 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 652 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 653 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 654 NEW_AUX_ENT(AT_FLAGS, 0); 655 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 656 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 657 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 658 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 659 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 660 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 661 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 662 663 #ifdef ARCH_DLINFO 664 nr = 0; 665 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 666 667 /* ARCH_DLINFO must come last so platform specific code can enforce 668 * special alignment requirements on the AUXV if necessary (eg. PPC). 669 */ 670 ARCH_DLINFO; 671 #endif 672 #undef NEW_AUX_ENT 673 674 /* allocate room for argv[] and envv[] */ 675 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 676 envp = (elf_caddr_t __user *) csp; 677 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 678 argv = (elf_caddr_t __user *) csp; 679 680 /* stack argc */ 681 csp -= sizeof(unsigned long); 682 __put_user(bprm->argc, (unsigned long __user *) csp); 683 684 BUG_ON(csp != sp); 685 686 /* fill in the argv[] array */ 687 #ifdef CONFIG_MMU 688 current->mm->arg_start = bprm->p; 689 #else 690 current->mm->arg_start = current->mm->start_stack - 691 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 692 #endif 693 694 p = (char __user *) current->mm->arg_start; 695 for (loop = bprm->argc; loop > 0; loop--) { 696 __put_user((elf_caddr_t) p, argv++); 697 len = strnlen_user(p, MAX_ARG_STRLEN); 698 if (!len || len > MAX_ARG_STRLEN) 699 return -EINVAL; 700 p += len; 701 } 702 __put_user(NULL, argv); 703 current->mm->arg_end = (unsigned long) p; 704 705 /* fill in the envv[] array */ 706 current->mm->env_start = (unsigned long) p; 707 for (loop = bprm->envc; loop > 0; loop--) { 708 __put_user((elf_caddr_t)(unsigned long) p, envp++); 709 len = strnlen_user(p, MAX_ARG_STRLEN); 710 if (!len || len > MAX_ARG_STRLEN) 711 return -EINVAL; 712 p += len; 713 } 714 __put_user(NULL, envp); 715 current->mm->env_end = (unsigned long) p; 716 717 mm->start_stack = (unsigned long) sp; 718 return 0; 719 } 720 721 /*****************************************************************************/ 722 /* 723 * load the appropriate binary image (executable or interpreter) into memory 724 * - we assume no MMU is available 725 * - if no other PIC bits are set in params->hdr->e_flags 726 * - we assume that the LOADable segments in the binary are independently relocatable 727 * - we assume R/O executable segments are shareable 728 * - else 729 * - we assume the loadable parts of the image to require fixed displacement 730 * - the image is not shareable 731 */ 732 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 733 struct file *file, 734 struct mm_struct *mm, 735 const char *what) 736 { 737 struct elf32_fdpic_loadmap *loadmap; 738 #ifdef CONFIG_MMU 739 struct elf32_fdpic_loadseg *mseg; 740 #endif 741 struct elf32_fdpic_loadseg *seg; 742 struct elf32_phdr *phdr; 743 unsigned long load_addr, stop; 744 unsigned nloads, tmp; 745 size_t size; 746 int loop, ret; 747 748 /* allocate a load map table */ 749 nloads = 0; 750 for (loop = 0; loop < params->hdr.e_phnum; loop++) 751 if (params->phdrs[loop].p_type == PT_LOAD) 752 nloads++; 753 754 if (nloads == 0) 755 return -ELIBBAD; 756 757 size = sizeof(*loadmap) + nloads * sizeof(*seg); 758 loadmap = kzalloc(size, GFP_KERNEL); 759 if (!loadmap) 760 return -ENOMEM; 761 762 params->loadmap = loadmap; 763 764 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 765 loadmap->nsegs = nloads; 766 767 load_addr = params->load_addr; 768 seg = loadmap->segs; 769 770 /* map the requested LOADs into the memory space */ 771 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 772 case ELF_FDPIC_FLAG_CONSTDISP: 773 case ELF_FDPIC_FLAG_CONTIGUOUS: 774 #ifndef CONFIG_MMU 775 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 776 if (ret < 0) 777 return ret; 778 break; 779 #endif 780 default: 781 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 782 if (ret < 0) 783 return ret; 784 break; 785 } 786 787 /* map the entry point */ 788 if (params->hdr.e_entry) { 789 seg = loadmap->segs; 790 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 791 if (params->hdr.e_entry >= seg->p_vaddr && 792 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 793 params->entry_addr = 794 (params->hdr.e_entry - seg->p_vaddr) + 795 seg->addr; 796 break; 797 } 798 } 799 } 800 801 /* determine where the program header table has wound up if mapped */ 802 stop = params->hdr.e_phoff; 803 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 804 phdr = params->phdrs; 805 806 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 807 if (phdr->p_type != PT_LOAD) 808 continue; 809 810 if (phdr->p_offset > params->hdr.e_phoff || 811 phdr->p_offset + phdr->p_filesz < stop) 812 continue; 813 814 seg = loadmap->segs; 815 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 816 if (phdr->p_vaddr >= seg->p_vaddr && 817 phdr->p_vaddr + phdr->p_filesz <= 818 seg->p_vaddr + seg->p_memsz) { 819 params->ph_addr = 820 (phdr->p_vaddr - seg->p_vaddr) + 821 seg->addr + 822 params->hdr.e_phoff - phdr->p_offset; 823 break; 824 } 825 } 826 break; 827 } 828 829 /* determine where the dynamic section has wound up if there is one */ 830 phdr = params->phdrs; 831 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 832 if (phdr->p_type != PT_DYNAMIC) 833 continue; 834 835 seg = loadmap->segs; 836 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 837 if (phdr->p_vaddr >= seg->p_vaddr && 838 phdr->p_vaddr + phdr->p_memsz <= 839 seg->p_vaddr + seg->p_memsz) { 840 Elf32_Dyn __user *dyn; 841 Elf32_Sword d_tag; 842 843 params->dynamic_addr = 844 (phdr->p_vaddr - seg->p_vaddr) + 845 seg->addr; 846 847 /* check the dynamic section contains at least 848 * one item, and that the last item is a NULL 849 * entry */ 850 if (phdr->p_memsz == 0 || 851 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 852 goto dynamic_error; 853 854 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 855 dyn = (Elf32_Dyn __user *)params->dynamic_addr; 856 __get_user(d_tag, &dyn[tmp - 1].d_tag); 857 if (d_tag != 0) 858 goto dynamic_error; 859 break; 860 } 861 } 862 break; 863 } 864 865 /* now elide adjacent segments in the load map on MMU linux 866 * - on uClinux the holes between may actually be filled with system 867 * stuff or stuff from other processes 868 */ 869 #ifdef CONFIG_MMU 870 nloads = loadmap->nsegs; 871 mseg = loadmap->segs; 872 seg = mseg + 1; 873 for (loop = 1; loop < nloads; loop++) { 874 /* see if we have a candidate for merging */ 875 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 876 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 877 if (load_addr == (seg->addr & PAGE_MASK)) { 878 mseg->p_memsz += 879 load_addr - 880 (mseg->addr + mseg->p_memsz); 881 mseg->p_memsz += seg->addr & ~PAGE_MASK; 882 mseg->p_memsz += seg->p_memsz; 883 loadmap->nsegs--; 884 continue; 885 } 886 } 887 888 mseg++; 889 if (mseg != seg) 890 *mseg = *seg; 891 } 892 #endif 893 894 kdebug("Mapped Object [%s]:", what); 895 kdebug("- elfhdr : %lx", params->elfhdr_addr); 896 kdebug("- entry : %lx", params->entry_addr); 897 kdebug("- PHDR[] : %lx", params->ph_addr); 898 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 899 seg = loadmap->segs; 900 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 901 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 902 loop, 903 seg->addr, seg->addr + seg->p_memsz - 1, 904 seg->p_vaddr, seg->p_memsz); 905 906 return 0; 907 908 dynamic_error: 909 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 910 what, file_inode(file)->i_ino); 911 return -ELIBBAD; 912 } 913 914 /*****************************************************************************/ 915 /* 916 * map a file with constant displacement under uClinux 917 */ 918 #ifndef CONFIG_MMU 919 static int elf_fdpic_map_file_constdisp_on_uclinux( 920 struct elf_fdpic_params *params, 921 struct file *file, 922 struct mm_struct *mm) 923 { 924 struct elf32_fdpic_loadseg *seg; 925 struct elf32_phdr *phdr; 926 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 927 int loop, ret; 928 929 load_addr = params->load_addr; 930 seg = params->loadmap->segs; 931 932 /* determine the bounds of the contiguous overall allocation we must 933 * make */ 934 phdr = params->phdrs; 935 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 936 if (params->phdrs[loop].p_type != PT_LOAD) 937 continue; 938 939 if (base > phdr->p_vaddr) 940 base = phdr->p_vaddr; 941 if (top < phdr->p_vaddr + phdr->p_memsz) 942 top = phdr->p_vaddr + phdr->p_memsz; 943 } 944 945 /* allocate one big anon block for everything */ 946 mflags = MAP_PRIVATE; 947 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 948 mflags |= MAP_EXECUTABLE; 949 950 maddr = vm_mmap(NULL, load_addr, top - base, 951 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 952 if (IS_ERR_VALUE(maddr)) 953 return (int) maddr; 954 955 if (load_addr != 0) 956 load_addr += PAGE_ALIGN(top - base); 957 958 /* and then load the file segments into it */ 959 phdr = params->phdrs; 960 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 961 if (params->phdrs[loop].p_type != PT_LOAD) 962 continue; 963 964 seg->addr = maddr + (phdr->p_vaddr - base); 965 seg->p_vaddr = phdr->p_vaddr; 966 seg->p_memsz = phdr->p_memsz; 967 968 ret = read_code(file, seg->addr, phdr->p_offset, 969 phdr->p_filesz); 970 if (ret < 0) 971 return ret; 972 973 /* map the ELF header address if in this segment */ 974 if (phdr->p_offset == 0) 975 params->elfhdr_addr = seg->addr; 976 977 /* clear any space allocated but not loaded */ 978 if (phdr->p_filesz < phdr->p_memsz) { 979 if (clear_user((void *) (seg->addr + phdr->p_filesz), 980 phdr->p_memsz - phdr->p_filesz)) 981 return -EFAULT; 982 } 983 984 if (mm) { 985 if (phdr->p_flags & PF_X) { 986 if (!mm->start_code) { 987 mm->start_code = seg->addr; 988 mm->end_code = seg->addr + 989 phdr->p_memsz; 990 } 991 } else if (!mm->start_data) { 992 mm->start_data = seg->addr; 993 mm->end_data = seg->addr + phdr->p_memsz; 994 } 995 } 996 997 seg++; 998 } 999 1000 return 0; 1001 } 1002 #endif 1003 1004 /*****************************************************************************/ 1005 /* 1006 * map a binary by direct mmap() of the individual PT_LOAD segments 1007 */ 1008 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1009 struct file *file, 1010 struct mm_struct *mm) 1011 { 1012 struct elf32_fdpic_loadseg *seg; 1013 struct elf32_phdr *phdr; 1014 unsigned long load_addr, delta_vaddr; 1015 int loop, dvset; 1016 1017 load_addr = params->load_addr; 1018 delta_vaddr = 0; 1019 dvset = 0; 1020 1021 seg = params->loadmap->segs; 1022 1023 /* deal with each load segment separately */ 1024 phdr = params->phdrs; 1025 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1026 unsigned long maddr, disp, excess, excess1; 1027 int prot = 0, flags; 1028 1029 if (phdr->p_type != PT_LOAD) 1030 continue; 1031 1032 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1033 (unsigned long) phdr->p_vaddr, 1034 (unsigned long) phdr->p_offset, 1035 (unsigned long) phdr->p_filesz, 1036 (unsigned long) phdr->p_memsz); 1037 1038 /* determine the mapping parameters */ 1039 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1040 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1041 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1042 1043 flags = MAP_PRIVATE | MAP_DENYWRITE; 1044 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1045 flags |= MAP_EXECUTABLE; 1046 1047 maddr = 0; 1048 1049 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1050 case ELF_FDPIC_FLAG_INDEPENDENT: 1051 /* PT_LOADs are independently locatable */ 1052 break; 1053 1054 case ELF_FDPIC_FLAG_HONOURVADDR: 1055 /* the specified virtual address must be honoured */ 1056 maddr = phdr->p_vaddr; 1057 flags |= MAP_FIXED; 1058 break; 1059 1060 case ELF_FDPIC_FLAG_CONSTDISP: 1061 /* constant displacement 1062 * - can be mapped anywhere, but must be mapped as a 1063 * unit 1064 */ 1065 if (!dvset) { 1066 maddr = load_addr; 1067 delta_vaddr = phdr->p_vaddr; 1068 dvset = 1; 1069 } else { 1070 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1071 flags |= MAP_FIXED; 1072 } 1073 break; 1074 1075 case ELF_FDPIC_FLAG_CONTIGUOUS: 1076 /* contiguity handled later */ 1077 break; 1078 1079 default: 1080 BUG(); 1081 } 1082 1083 maddr &= PAGE_MASK; 1084 1085 /* create the mapping */ 1086 disp = phdr->p_vaddr & ~PAGE_MASK; 1087 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1088 phdr->p_offset - disp); 1089 1090 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1091 loop, phdr->p_memsz + disp, prot, flags, 1092 phdr->p_offset - disp, maddr); 1093 1094 if (IS_ERR_VALUE(maddr)) 1095 return (int) maddr; 1096 1097 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1098 ELF_FDPIC_FLAG_CONTIGUOUS) 1099 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1100 1101 seg->addr = maddr + disp; 1102 seg->p_vaddr = phdr->p_vaddr; 1103 seg->p_memsz = phdr->p_memsz; 1104 1105 /* map the ELF header address if in this segment */ 1106 if (phdr->p_offset == 0) 1107 params->elfhdr_addr = seg->addr; 1108 1109 /* clear the bit between beginning of mapping and beginning of 1110 * PT_LOAD */ 1111 if (prot & PROT_WRITE && disp > 0) { 1112 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1113 if (clear_user((void __user *) maddr, disp)) 1114 return -EFAULT; 1115 maddr += disp; 1116 } 1117 1118 /* clear any space allocated but not loaded 1119 * - on uClinux we can just clear the lot 1120 * - on MMU linux we'll get a SIGBUS beyond the last page 1121 * extant in the file 1122 */ 1123 excess = phdr->p_memsz - phdr->p_filesz; 1124 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1125 1126 #ifdef CONFIG_MMU 1127 if (excess > excess1) { 1128 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1129 unsigned long xmaddr; 1130 1131 flags |= MAP_FIXED | MAP_ANONYMOUS; 1132 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1133 prot, flags, 0); 1134 1135 kdebug("mmap[%d] <anon>" 1136 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1137 loop, xaddr, excess - excess1, prot, flags, 1138 xmaddr); 1139 1140 if (xmaddr != xaddr) 1141 return -ENOMEM; 1142 } 1143 1144 if (prot & PROT_WRITE && excess1 > 0) { 1145 kdebug("clear[%d] ad=%lx sz=%lx", 1146 loop, maddr + phdr->p_filesz, excess1); 1147 if (clear_user((void __user *) maddr + phdr->p_filesz, 1148 excess1)) 1149 return -EFAULT; 1150 } 1151 1152 #else 1153 if (excess > 0) { 1154 kdebug("clear[%d] ad=%lx sz=%lx", 1155 loop, maddr + phdr->p_filesz, excess); 1156 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1157 return -EFAULT; 1158 } 1159 #endif 1160 1161 if (mm) { 1162 if (phdr->p_flags & PF_X) { 1163 if (!mm->start_code) { 1164 mm->start_code = maddr; 1165 mm->end_code = maddr + phdr->p_memsz; 1166 } 1167 } else if (!mm->start_data) { 1168 mm->start_data = maddr; 1169 mm->end_data = maddr + phdr->p_memsz; 1170 } 1171 } 1172 1173 seg++; 1174 } 1175 1176 return 0; 1177 } 1178 1179 /*****************************************************************************/ 1180 /* 1181 * ELF-FDPIC core dumper 1182 * 1183 * Modelled on fs/exec.c:aout_core_dump() 1184 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1185 * 1186 * Modelled on fs/binfmt_elf.c core dumper 1187 */ 1188 #ifdef CONFIG_ELF_CORE 1189 1190 /* 1191 * Decide whether a segment is worth dumping; default is yes to be 1192 * sure (missing info is worse than too much; etc). 1193 * Personally I'd include everything, and use the coredump limit... 1194 * 1195 * I think we should skip something. But I am not sure how. H.J. 1196 */ 1197 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1198 { 1199 int dump_ok; 1200 1201 /* Do not dump I/O mapped devices or special mappings */ 1202 if (vma->vm_flags & VM_IO) { 1203 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1204 return 0; 1205 } 1206 1207 /* If we may not read the contents, don't allow us to dump 1208 * them either. "dump_write()" can't handle it anyway. 1209 */ 1210 if (!(vma->vm_flags & VM_READ)) { 1211 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1212 return 0; 1213 } 1214 1215 /* support for DAX */ 1216 if (vma_is_dax(vma)) { 1217 if (vma->vm_flags & VM_SHARED) { 1218 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags); 1219 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start, 1220 vma->vm_flags, dump_ok ? "yes" : "no"); 1221 } else { 1222 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags); 1223 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start, 1224 vma->vm_flags, dump_ok ? "yes" : "no"); 1225 } 1226 return dump_ok; 1227 } 1228 1229 /* By default, dump shared memory if mapped from an anonymous file. */ 1230 if (vma->vm_flags & VM_SHARED) { 1231 if (file_inode(vma->vm_file)->i_nlink == 0) { 1232 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1233 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1234 vma->vm_flags, dump_ok ? "yes" : "no"); 1235 return dump_ok; 1236 } 1237 1238 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1239 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1240 vma->vm_flags, dump_ok ? "yes" : "no"); 1241 return dump_ok; 1242 } 1243 1244 #ifdef CONFIG_MMU 1245 /* By default, if it hasn't been written to, don't write it out */ 1246 if (!vma->anon_vma) { 1247 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1248 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1249 vma->vm_flags, dump_ok ? "yes" : "no"); 1250 return dump_ok; 1251 } 1252 #endif 1253 1254 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1255 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1256 dump_ok ? "yes" : "no"); 1257 return dump_ok; 1258 } 1259 1260 /* An ELF note in memory */ 1261 struct memelfnote 1262 { 1263 const char *name; 1264 int type; 1265 unsigned int datasz; 1266 void *data; 1267 }; 1268 1269 static int notesize(struct memelfnote *en) 1270 { 1271 int sz; 1272 1273 sz = sizeof(struct elf_note); 1274 sz += roundup(strlen(en->name) + 1, 4); 1275 sz += roundup(en->datasz, 4); 1276 1277 return sz; 1278 } 1279 1280 /* #define DEBUG */ 1281 1282 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1283 { 1284 struct elf_note en; 1285 en.n_namesz = strlen(men->name) + 1; 1286 en.n_descsz = men->datasz; 1287 en.n_type = men->type; 1288 1289 return dump_emit(cprm, &en, sizeof(en)) && 1290 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1291 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1292 } 1293 1294 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1295 { 1296 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1297 elf->e_ident[EI_CLASS] = ELF_CLASS; 1298 elf->e_ident[EI_DATA] = ELF_DATA; 1299 elf->e_ident[EI_VERSION] = EV_CURRENT; 1300 elf->e_ident[EI_OSABI] = ELF_OSABI; 1301 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1302 1303 elf->e_type = ET_CORE; 1304 elf->e_machine = ELF_ARCH; 1305 elf->e_version = EV_CURRENT; 1306 elf->e_entry = 0; 1307 elf->e_phoff = sizeof(struct elfhdr); 1308 elf->e_shoff = 0; 1309 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1310 elf->e_ehsize = sizeof(struct elfhdr); 1311 elf->e_phentsize = sizeof(struct elf_phdr); 1312 elf->e_phnum = segs; 1313 elf->e_shentsize = 0; 1314 elf->e_shnum = 0; 1315 elf->e_shstrndx = 0; 1316 return; 1317 } 1318 1319 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1320 { 1321 phdr->p_type = PT_NOTE; 1322 phdr->p_offset = offset; 1323 phdr->p_vaddr = 0; 1324 phdr->p_paddr = 0; 1325 phdr->p_filesz = sz; 1326 phdr->p_memsz = 0; 1327 phdr->p_flags = 0; 1328 phdr->p_align = 0; 1329 return; 1330 } 1331 1332 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1333 unsigned int sz, void *data) 1334 { 1335 note->name = name; 1336 note->type = type; 1337 note->datasz = sz; 1338 note->data = data; 1339 return; 1340 } 1341 1342 /* 1343 * fill up all the fields in prstatus from the given task struct, except 1344 * registers which need to be filled up separately. 1345 */ 1346 static void fill_prstatus(struct elf_prstatus *prstatus, 1347 struct task_struct *p, long signr) 1348 { 1349 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1350 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1351 prstatus->pr_sighold = p->blocked.sig[0]; 1352 rcu_read_lock(); 1353 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1354 rcu_read_unlock(); 1355 prstatus->pr_pid = task_pid_vnr(p); 1356 prstatus->pr_pgrp = task_pgrp_vnr(p); 1357 prstatus->pr_sid = task_session_vnr(p); 1358 if (thread_group_leader(p)) { 1359 struct task_cputime cputime; 1360 1361 /* 1362 * This is the record for the group leader. It shows the 1363 * group-wide total, not its individual thread total. 1364 */ 1365 thread_group_cputime(p, &cputime); 1366 prstatus->pr_utime = ns_to_timeval(cputime.utime); 1367 prstatus->pr_stime = ns_to_timeval(cputime.stime); 1368 } else { 1369 u64 utime, stime; 1370 1371 task_cputime(p, &utime, &stime); 1372 prstatus->pr_utime = ns_to_timeval(utime); 1373 prstatus->pr_stime = ns_to_timeval(stime); 1374 } 1375 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime); 1376 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime); 1377 1378 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1379 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1380 } 1381 1382 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1383 struct mm_struct *mm) 1384 { 1385 const struct cred *cred; 1386 unsigned int i, len; 1387 1388 /* first copy the parameters from user space */ 1389 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1390 1391 len = mm->arg_end - mm->arg_start; 1392 if (len >= ELF_PRARGSZ) 1393 len = ELF_PRARGSZ - 1; 1394 if (copy_from_user(&psinfo->pr_psargs, 1395 (const char __user *) mm->arg_start, len)) 1396 return -EFAULT; 1397 for (i = 0; i < len; i++) 1398 if (psinfo->pr_psargs[i] == 0) 1399 psinfo->pr_psargs[i] = ' '; 1400 psinfo->pr_psargs[len] = 0; 1401 1402 rcu_read_lock(); 1403 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1404 rcu_read_unlock(); 1405 psinfo->pr_pid = task_pid_vnr(p); 1406 psinfo->pr_pgrp = task_pgrp_vnr(p); 1407 psinfo->pr_sid = task_session_vnr(p); 1408 1409 i = p->state ? ffz(~p->state) + 1 : 0; 1410 psinfo->pr_state = i; 1411 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1412 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1413 psinfo->pr_nice = task_nice(p); 1414 psinfo->pr_flag = p->flags; 1415 rcu_read_lock(); 1416 cred = __task_cred(p); 1417 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1418 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1419 rcu_read_unlock(); 1420 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1421 1422 return 0; 1423 } 1424 1425 /* Here is the structure in which status of each thread is captured. */ 1426 struct elf_thread_status 1427 { 1428 struct list_head list; 1429 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1430 elf_fpregset_t fpu; /* NT_PRFPREG */ 1431 struct task_struct *thread; 1432 #ifdef ELF_CORE_COPY_XFPREGS 1433 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1434 #endif 1435 struct memelfnote notes[3]; 1436 int num_notes; 1437 }; 1438 1439 /* 1440 * In order to add the specific thread information for the elf file format, 1441 * we need to keep a linked list of every thread's pr_status and then create 1442 * a single section for them in the final core file. 1443 */ 1444 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1445 { 1446 struct task_struct *p = t->thread; 1447 int sz = 0; 1448 1449 t->num_notes = 0; 1450 1451 fill_prstatus(&t->prstatus, p, signr); 1452 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1453 1454 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1455 &t->prstatus); 1456 t->num_notes++; 1457 sz += notesize(&t->notes[0]); 1458 1459 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1460 if (t->prstatus.pr_fpvalid) { 1461 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1462 &t->fpu); 1463 t->num_notes++; 1464 sz += notesize(&t->notes[1]); 1465 } 1466 1467 #ifdef ELF_CORE_COPY_XFPREGS 1468 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1469 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1470 sizeof(t->xfpu), &t->xfpu); 1471 t->num_notes++; 1472 sz += notesize(&t->notes[2]); 1473 } 1474 #endif 1475 return sz; 1476 } 1477 1478 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1479 elf_addr_t e_shoff, int segs) 1480 { 1481 elf->e_shoff = e_shoff; 1482 elf->e_shentsize = sizeof(*shdr4extnum); 1483 elf->e_shnum = 1; 1484 elf->e_shstrndx = SHN_UNDEF; 1485 1486 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1487 1488 shdr4extnum->sh_type = SHT_NULL; 1489 shdr4extnum->sh_size = elf->e_shnum; 1490 shdr4extnum->sh_link = elf->e_shstrndx; 1491 shdr4extnum->sh_info = segs; 1492 } 1493 1494 /* 1495 * dump the segments for an MMU process 1496 */ 1497 static bool elf_fdpic_dump_segments(struct coredump_params *cprm) 1498 { 1499 struct vm_area_struct *vma; 1500 1501 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1502 #ifdef CONFIG_MMU 1503 unsigned long addr; 1504 #endif 1505 1506 if (!maydump(vma, cprm->mm_flags)) 1507 continue; 1508 1509 #ifdef CONFIG_MMU 1510 for (addr = vma->vm_start; addr < vma->vm_end; 1511 addr += PAGE_SIZE) { 1512 bool res; 1513 struct page *page = get_dump_page(addr); 1514 if (page) { 1515 void *kaddr = kmap(page); 1516 res = dump_emit(cprm, kaddr, PAGE_SIZE); 1517 kunmap(page); 1518 put_page(page); 1519 } else { 1520 res = dump_skip(cprm, PAGE_SIZE); 1521 } 1522 if (!res) 1523 return false; 1524 } 1525 #else 1526 if (!dump_emit(cprm, (void *) vma->vm_start, 1527 vma->vm_end - vma->vm_start)) 1528 return false; 1529 #endif 1530 } 1531 return true; 1532 } 1533 1534 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1535 { 1536 struct vm_area_struct *vma; 1537 size_t size = 0; 1538 1539 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1540 if (maydump(vma, mm_flags)) 1541 size += vma->vm_end - vma->vm_start; 1542 return size; 1543 } 1544 1545 /* 1546 * Actual dumper 1547 * 1548 * This is a two-pass process; first we find the offsets of the bits, 1549 * and then they are actually written out. If we run out of core limit 1550 * we just truncate. 1551 */ 1552 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1553 { 1554 #define NUM_NOTES 6 1555 int has_dumped = 0; 1556 mm_segment_t fs; 1557 int segs; 1558 int i; 1559 struct vm_area_struct *vma; 1560 struct elfhdr *elf = NULL; 1561 loff_t offset = 0, dataoff; 1562 int numnote; 1563 struct memelfnote *notes = NULL; 1564 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1565 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1566 LIST_HEAD(thread_list); 1567 struct list_head *t; 1568 elf_fpregset_t *fpu = NULL; 1569 #ifdef ELF_CORE_COPY_XFPREGS 1570 elf_fpxregset_t *xfpu = NULL; 1571 #endif 1572 int thread_status_size = 0; 1573 elf_addr_t *auxv; 1574 struct elf_phdr *phdr4note = NULL; 1575 struct elf_shdr *shdr4extnum = NULL; 1576 Elf_Half e_phnum; 1577 elf_addr_t e_shoff; 1578 struct core_thread *ct; 1579 struct elf_thread_status *tmp; 1580 1581 /* 1582 * We no longer stop all VM operations. 1583 * 1584 * This is because those proceses that could possibly change map_count 1585 * or the mmap / vma pages are now blocked in do_exit on current 1586 * finishing this core dump. 1587 * 1588 * Only ptrace can touch these memory addresses, but it doesn't change 1589 * the map_count or the pages allocated. So no possibility of crashing 1590 * exists while dumping the mm->vm_next areas to the core file. 1591 */ 1592 1593 /* alloc memory for large data structures: too large to be on stack */ 1594 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1595 if (!elf) 1596 goto cleanup; 1597 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1598 if (!prstatus) 1599 goto cleanup; 1600 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1601 if (!psinfo) 1602 goto cleanup; 1603 notes = kmalloc_array(NUM_NOTES, sizeof(struct memelfnote), 1604 GFP_KERNEL); 1605 if (!notes) 1606 goto cleanup; 1607 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1608 if (!fpu) 1609 goto cleanup; 1610 #ifdef ELF_CORE_COPY_XFPREGS 1611 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1612 if (!xfpu) 1613 goto cleanup; 1614 #endif 1615 1616 for (ct = current->mm->core_state->dumper.next; 1617 ct; ct = ct->next) { 1618 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1619 if (!tmp) 1620 goto cleanup; 1621 1622 tmp->thread = ct->task; 1623 list_add(&tmp->list, &thread_list); 1624 } 1625 1626 list_for_each(t, &thread_list) { 1627 struct elf_thread_status *tmp; 1628 int sz; 1629 1630 tmp = list_entry(t, struct elf_thread_status, list); 1631 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp); 1632 thread_status_size += sz; 1633 } 1634 1635 /* now collect the dump for the current */ 1636 fill_prstatus(prstatus, current, cprm->siginfo->si_signo); 1637 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1638 1639 segs = current->mm->map_count; 1640 segs += elf_core_extra_phdrs(); 1641 1642 /* for notes section */ 1643 segs++; 1644 1645 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1646 * this, kernel supports extended numbering. Have a look at 1647 * include/linux/elf.h for further information. */ 1648 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1649 1650 /* Set up header */ 1651 fill_elf_fdpic_header(elf, e_phnum); 1652 1653 has_dumped = 1; 1654 /* 1655 * Set up the notes in similar form to SVR4 core dumps made 1656 * with info from their /proc. 1657 */ 1658 1659 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1660 fill_psinfo(psinfo, current->group_leader, current->mm); 1661 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1662 1663 numnote = 2; 1664 1665 auxv = (elf_addr_t *) current->mm->saved_auxv; 1666 1667 i = 0; 1668 do 1669 i += 2; 1670 while (auxv[i - 2] != AT_NULL); 1671 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1672 i * sizeof(elf_addr_t), auxv); 1673 1674 /* Try to dump the FPU. */ 1675 if ((prstatus->pr_fpvalid = 1676 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1677 fill_note(notes + numnote++, 1678 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1679 #ifdef ELF_CORE_COPY_XFPREGS 1680 if (elf_core_copy_task_xfpregs(current, xfpu)) 1681 fill_note(notes + numnote++, 1682 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1683 #endif 1684 1685 fs = get_fs(); 1686 set_fs(KERNEL_DS); 1687 1688 offset += sizeof(*elf); /* Elf header */ 1689 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1690 1691 /* Write notes phdr entry */ 1692 { 1693 int sz = 0; 1694 1695 for (i = 0; i < numnote; i++) 1696 sz += notesize(notes + i); 1697 1698 sz += thread_status_size; 1699 1700 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1701 if (!phdr4note) 1702 goto end_coredump; 1703 1704 fill_elf_note_phdr(phdr4note, sz, offset); 1705 offset += sz; 1706 } 1707 1708 /* Page-align dumped data */ 1709 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1710 1711 offset += elf_core_vma_data_size(cprm->mm_flags); 1712 offset += elf_core_extra_data_size(); 1713 e_shoff = offset; 1714 1715 if (e_phnum == PN_XNUM) { 1716 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1717 if (!shdr4extnum) 1718 goto end_coredump; 1719 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1720 } 1721 1722 offset = dataoff; 1723 1724 if (!dump_emit(cprm, elf, sizeof(*elf))) 1725 goto end_coredump; 1726 1727 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1728 goto end_coredump; 1729 1730 /* write program headers for segments dump */ 1731 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1732 struct elf_phdr phdr; 1733 size_t sz; 1734 1735 sz = vma->vm_end - vma->vm_start; 1736 1737 phdr.p_type = PT_LOAD; 1738 phdr.p_offset = offset; 1739 phdr.p_vaddr = vma->vm_start; 1740 phdr.p_paddr = 0; 1741 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1742 phdr.p_memsz = sz; 1743 offset += phdr.p_filesz; 1744 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1745 if (vma->vm_flags & VM_WRITE) 1746 phdr.p_flags |= PF_W; 1747 if (vma->vm_flags & VM_EXEC) 1748 phdr.p_flags |= PF_X; 1749 phdr.p_align = ELF_EXEC_PAGESIZE; 1750 1751 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1752 goto end_coredump; 1753 } 1754 1755 if (!elf_core_write_extra_phdrs(cprm, offset)) 1756 goto end_coredump; 1757 1758 /* write out the notes section */ 1759 for (i = 0; i < numnote; i++) 1760 if (!writenote(notes + i, cprm)) 1761 goto end_coredump; 1762 1763 /* write out the thread status notes section */ 1764 list_for_each(t, &thread_list) { 1765 struct elf_thread_status *tmp = 1766 list_entry(t, struct elf_thread_status, list); 1767 1768 for (i = 0; i < tmp->num_notes; i++) 1769 if (!writenote(&tmp->notes[i], cprm)) 1770 goto end_coredump; 1771 } 1772 1773 if (!dump_skip(cprm, dataoff - cprm->pos)) 1774 goto end_coredump; 1775 1776 if (!elf_fdpic_dump_segments(cprm)) 1777 goto end_coredump; 1778 1779 if (!elf_core_write_extra_data(cprm)) 1780 goto end_coredump; 1781 1782 if (e_phnum == PN_XNUM) { 1783 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1784 goto end_coredump; 1785 } 1786 1787 if (cprm->file->f_pos != offset) { 1788 /* Sanity check */ 1789 printk(KERN_WARNING 1790 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1791 cprm->file->f_pos, offset); 1792 } 1793 1794 end_coredump: 1795 set_fs(fs); 1796 1797 cleanup: 1798 while (!list_empty(&thread_list)) { 1799 struct list_head *tmp = thread_list.next; 1800 list_del(tmp); 1801 kfree(list_entry(tmp, struct elf_thread_status, list)); 1802 } 1803 kfree(phdr4note); 1804 kfree(elf); 1805 kfree(prstatus); 1806 kfree(psinfo); 1807 kfree(notes); 1808 kfree(fpu); 1809 kfree(shdr4extnum); 1810 #ifdef ELF_CORE_COPY_XFPREGS 1811 kfree(xfpu); 1812 #endif 1813 return has_dumped; 1814 #undef NUM_NOTES 1815 } 1816 1817 #endif /* CONFIG_ELF_CORE */ 1818