1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format 2 * 3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * Derived from binfmt_elf.c 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13 #include <linux/module.h> 14 15 #include <linux/fs.h> 16 #include <linux/stat.h> 17 #include <linux/sched.h> 18 #include <linux/mm.h> 19 #include <linux/mman.h> 20 #include <linux/errno.h> 21 #include <linux/signal.h> 22 #include <linux/binfmts.h> 23 #include <linux/string.h> 24 #include <linux/file.h> 25 #include <linux/fcntl.h> 26 #include <linux/slab.h> 27 #include <linux/pagemap.h> 28 #include <linux/security.h> 29 #include <linux/highmem.h> 30 #include <linux/highuid.h> 31 #include <linux/personality.h> 32 #include <linux/ptrace.h> 33 #include <linux/init.h> 34 #include <linux/elf.h> 35 #include <linux/elf-fdpic.h> 36 #include <linux/elfcore.h> 37 #include <linux/coredump.h> 38 #include <linux/dax.h> 39 40 #include <linux/uaccess.h> 41 #include <asm/param.h> 42 #include <asm/pgalloc.h> 43 44 typedef char *elf_caddr_t; 45 46 #if 0 47 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 48 #else 49 #define kdebug(fmt, ...) do {} while(0) 50 #endif 51 52 #if 0 53 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 54 #else 55 #define kdcore(fmt, ...) do {} while(0) 56 #endif 57 58 MODULE_LICENSE("GPL"); 59 60 static int load_elf_fdpic_binary(struct linux_binprm *); 61 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 62 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 63 struct mm_struct *, const char *); 64 65 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 66 struct elf_fdpic_params *, 67 struct elf_fdpic_params *); 68 69 #ifndef CONFIG_MMU 70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 71 struct file *, 72 struct mm_struct *); 73 #endif 74 75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 76 struct file *, struct mm_struct *); 77 78 #ifdef CONFIG_ELF_CORE 79 static int elf_fdpic_core_dump(struct coredump_params *cprm); 80 #endif 81 82 static struct linux_binfmt elf_fdpic_format = { 83 .module = THIS_MODULE, 84 .load_binary = load_elf_fdpic_binary, 85 #ifdef CONFIG_ELF_CORE 86 .core_dump = elf_fdpic_core_dump, 87 #endif 88 .min_coredump = ELF_EXEC_PAGESIZE, 89 }; 90 91 static int __init init_elf_fdpic_binfmt(void) 92 { 93 register_binfmt(&elf_fdpic_format); 94 return 0; 95 } 96 97 static void __exit exit_elf_fdpic_binfmt(void) 98 { 99 unregister_binfmt(&elf_fdpic_format); 100 } 101 102 core_initcall(init_elf_fdpic_binfmt); 103 module_exit(exit_elf_fdpic_binfmt); 104 105 static int is_elf(struct elfhdr *hdr, struct file *file) 106 { 107 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 108 return 0; 109 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 110 return 0; 111 if (!elf_check_arch(hdr)) 112 return 0; 113 if (!file->f_op->mmap) 114 return 0; 115 return 1; 116 } 117 118 #ifndef elf_check_fdpic 119 #define elf_check_fdpic(x) 0 120 #endif 121 122 #ifndef elf_check_const_displacement 123 #define elf_check_const_displacement(x) 0 124 #endif 125 126 static int is_constdisp(struct elfhdr *hdr) 127 { 128 if (!elf_check_fdpic(hdr)) 129 return 1; 130 if (elf_check_const_displacement(hdr)) 131 return 1; 132 return 0; 133 } 134 135 /*****************************************************************************/ 136 /* 137 * read the program headers table into memory 138 */ 139 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 140 struct file *file) 141 { 142 struct elf32_phdr *phdr; 143 unsigned long size; 144 int retval, loop; 145 146 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 147 return -ENOMEM; 148 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 149 return -ENOMEM; 150 151 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 152 params->phdrs = kmalloc(size, GFP_KERNEL); 153 if (!params->phdrs) 154 return -ENOMEM; 155 156 retval = kernel_read(file, params->hdr.e_phoff, 157 (char *) params->phdrs, size); 158 if (unlikely(retval != size)) 159 return retval < 0 ? retval : -ENOEXEC; 160 161 /* determine stack size for this binary */ 162 phdr = params->phdrs; 163 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 164 if (phdr->p_type != PT_GNU_STACK) 165 continue; 166 167 if (phdr->p_flags & PF_X) 168 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 169 else 170 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 171 172 params->stack_size = phdr->p_memsz; 173 break; 174 } 175 176 return 0; 177 } 178 179 /*****************************************************************************/ 180 /* 181 * load an fdpic binary into various bits of memory 182 */ 183 static int load_elf_fdpic_binary(struct linux_binprm *bprm) 184 { 185 struct elf_fdpic_params exec_params, interp_params; 186 struct pt_regs *regs = current_pt_regs(); 187 struct elf_phdr *phdr; 188 unsigned long stack_size, entryaddr; 189 #ifdef ELF_FDPIC_PLAT_INIT 190 unsigned long dynaddr; 191 #endif 192 #ifndef CONFIG_MMU 193 unsigned long stack_prot; 194 #endif 195 struct file *interpreter = NULL; /* to shut gcc up */ 196 char *interpreter_name = NULL; 197 int executable_stack; 198 int retval, i; 199 200 kdebug("____ LOAD %d ____", current->pid); 201 202 memset(&exec_params, 0, sizeof(exec_params)); 203 memset(&interp_params, 0, sizeof(interp_params)); 204 205 exec_params.hdr = *(struct elfhdr *) bprm->buf; 206 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 207 208 /* check that this is a binary we know how to deal with */ 209 retval = -ENOEXEC; 210 if (!is_elf(&exec_params.hdr, bprm->file)) 211 goto error; 212 if (!elf_check_fdpic(&exec_params.hdr)) { 213 #ifdef CONFIG_MMU 214 /* binfmt_elf handles non-fdpic elf except on nommu */ 215 goto error; 216 #else 217 /* nommu can only load ET_DYN (PIE) ELF */ 218 if (exec_params.hdr.e_type != ET_DYN) 219 goto error; 220 #endif 221 } 222 223 /* read the program header table */ 224 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 225 if (retval < 0) 226 goto error; 227 228 /* scan for a program header that specifies an interpreter */ 229 phdr = exec_params.phdrs; 230 231 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 232 switch (phdr->p_type) { 233 case PT_INTERP: 234 retval = -ENOMEM; 235 if (phdr->p_filesz > PATH_MAX) 236 goto error; 237 retval = -ENOENT; 238 if (phdr->p_filesz < 2) 239 goto error; 240 241 /* read the name of the interpreter into memory */ 242 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 243 if (!interpreter_name) 244 goto error; 245 246 retval = kernel_read(bprm->file, 247 phdr->p_offset, 248 interpreter_name, 249 phdr->p_filesz); 250 if (unlikely(retval != phdr->p_filesz)) { 251 if (retval >= 0) 252 retval = -ENOEXEC; 253 goto error; 254 } 255 256 retval = -ENOENT; 257 if (interpreter_name[phdr->p_filesz - 1] != '\0') 258 goto error; 259 260 kdebug("Using ELF interpreter %s", interpreter_name); 261 262 /* replace the program with the interpreter */ 263 interpreter = open_exec(interpreter_name); 264 retval = PTR_ERR(interpreter); 265 if (IS_ERR(interpreter)) { 266 interpreter = NULL; 267 goto error; 268 } 269 270 /* 271 * If the binary is not readable then enforce 272 * mm->dumpable = 0 regardless of the interpreter's 273 * permissions. 274 */ 275 would_dump(bprm, interpreter); 276 277 retval = kernel_read(interpreter, 0, bprm->buf, 278 BINPRM_BUF_SIZE); 279 if (unlikely(retval != BINPRM_BUF_SIZE)) { 280 if (retval >= 0) 281 retval = -ENOEXEC; 282 goto error; 283 } 284 285 interp_params.hdr = *((struct elfhdr *) bprm->buf); 286 break; 287 288 case PT_LOAD: 289 #ifdef CONFIG_MMU 290 if (exec_params.load_addr == 0) 291 exec_params.load_addr = phdr->p_vaddr; 292 #endif 293 break; 294 } 295 296 } 297 298 if (is_constdisp(&exec_params.hdr)) 299 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 300 301 /* perform insanity checks on the interpreter */ 302 if (interpreter_name) { 303 retval = -ELIBBAD; 304 if (!is_elf(&interp_params.hdr, interpreter)) 305 goto error; 306 307 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 308 309 /* read the interpreter's program header table */ 310 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 311 if (retval < 0) 312 goto error; 313 } 314 315 stack_size = exec_params.stack_size; 316 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 317 executable_stack = EXSTACK_ENABLE_X; 318 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 319 executable_stack = EXSTACK_DISABLE_X; 320 else 321 executable_stack = EXSTACK_DEFAULT; 322 323 if (stack_size == 0) { 324 stack_size = interp_params.stack_size; 325 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 326 executable_stack = EXSTACK_ENABLE_X; 327 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 328 executable_stack = EXSTACK_DISABLE_X; 329 else 330 executable_stack = EXSTACK_DEFAULT; 331 } 332 333 retval = -ENOEXEC; 334 if (stack_size == 0) 335 stack_size = 131072UL; /* same as exec.c's default commit */ 336 337 if (is_constdisp(&interp_params.hdr)) 338 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 339 340 /* flush all traces of the currently running executable */ 341 retval = flush_old_exec(bprm); 342 if (retval) 343 goto error; 344 345 /* there's now no turning back... the old userspace image is dead, 346 * defunct, deceased, etc. 347 */ 348 if (elf_check_fdpic(&exec_params.hdr)) 349 set_personality(PER_LINUX_FDPIC); 350 else 351 set_personality(PER_LINUX); 352 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 353 current->personality |= READ_IMPLIES_EXEC; 354 355 setup_new_exec(bprm); 356 357 set_binfmt(&elf_fdpic_format); 358 359 current->mm->start_code = 0; 360 current->mm->end_code = 0; 361 current->mm->start_stack = 0; 362 current->mm->start_data = 0; 363 current->mm->end_data = 0; 364 current->mm->context.exec_fdpic_loadmap = 0; 365 current->mm->context.interp_fdpic_loadmap = 0; 366 367 #ifdef CONFIG_MMU 368 elf_fdpic_arch_lay_out_mm(&exec_params, 369 &interp_params, 370 ¤t->mm->start_stack, 371 ¤t->mm->start_brk); 372 373 retval = setup_arg_pages(bprm, current->mm->start_stack, 374 executable_stack); 375 if (retval < 0) 376 goto error; 377 #endif 378 379 /* load the executable and interpreter into memory */ 380 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 381 "executable"); 382 if (retval < 0) 383 goto error; 384 385 if (interpreter_name) { 386 retval = elf_fdpic_map_file(&interp_params, interpreter, 387 current->mm, "interpreter"); 388 if (retval < 0) { 389 printk(KERN_ERR "Unable to load interpreter\n"); 390 goto error; 391 } 392 393 allow_write_access(interpreter); 394 fput(interpreter); 395 interpreter = NULL; 396 } 397 398 #ifdef CONFIG_MMU 399 if (!current->mm->start_brk) 400 current->mm->start_brk = current->mm->end_data; 401 402 current->mm->brk = current->mm->start_brk = 403 PAGE_ALIGN(current->mm->start_brk); 404 405 #else 406 /* create a stack area and zero-size brk area */ 407 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 408 if (stack_size < PAGE_SIZE * 2) 409 stack_size = PAGE_SIZE * 2; 410 411 stack_prot = PROT_READ | PROT_WRITE; 412 if (executable_stack == EXSTACK_ENABLE_X || 413 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 414 stack_prot |= PROT_EXEC; 415 416 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 417 MAP_PRIVATE | MAP_ANONYMOUS | 418 MAP_UNINITIALIZED | MAP_GROWSDOWN, 419 0); 420 421 if (IS_ERR_VALUE(current->mm->start_brk)) { 422 retval = current->mm->start_brk; 423 current->mm->start_brk = 0; 424 goto error; 425 } 426 427 current->mm->brk = current->mm->start_brk; 428 current->mm->context.end_brk = current->mm->start_brk; 429 current->mm->start_stack = current->mm->start_brk + stack_size; 430 #endif 431 432 install_exec_creds(bprm); 433 if (create_elf_fdpic_tables(bprm, current->mm, 434 &exec_params, &interp_params) < 0) 435 goto error; 436 437 kdebug("- start_code %lx", current->mm->start_code); 438 kdebug("- end_code %lx", current->mm->end_code); 439 kdebug("- start_data %lx", current->mm->start_data); 440 kdebug("- end_data %lx", current->mm->end_data); 441 kdebug("- start_brk %lx", current->mm->start_brk); 442 kdebug("- brk %lx", current->mm->brk); 443 kdebug("- start_stack %lx", current->mm->start_stack); 444 445 #ifdef ELF_FDPIC_PLAT_INIT 446 /* 447 * The ABI may specify that certain registers be set up in special 448 * ways (on i386 %edx is the address of a DT_FINI function, for 449 * example. This macro performs whatever initialization to 450 * the regs structure is required. 451 */ 452 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 453 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 454 dynaddr); 455 #endif 456 457 /* everything is now ready... get the userspace context ready to roll */ 458 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 459 start_thread(regs, entryaddr, current->mm->start_stack); 460 461 retval = 0; 462 463 error: 464 if (interpreter) { 465 allow_write_access(interpreter); 466 fput(interpreter); 467 } 468 kfree(interpreter_name); 469 kfree(exec_params.phdrs); 470 kfree(exec_params.loadmap); 471 kfree(interp_params.phdrs); 472 kfree(interp_params.loadmap); 473 return retval; 474 } 475 476 /*****************************************************************************/ 477 478 #ifndef ELF_BASE_PLATFORM 479 /* 480 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 481 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 482 * will be copied to the user stack in the same manner as AT_PLATFORM. 483 */ 484 #define ELF_BASE_PLATFORM NULL 485 #endif 486 487 /* 488 * present useful information to the program by shovelling it onto the new 489 * process's stack 490 */ 491 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 492 struct mm_struct *mm, 493 struct elf_fdpic_params *exec_params, 494 struct elf_fdpic_params *interp_params) 495 { 496 const struct cred *cred = current_cred(); 497 unsigned long sp, csp, nitems; 498 elf_caddr_t __user *argv, *envp; 499 size_t platform_len = 0, len; 500 char *k_platform, *k_base_platform; 501 char __user *u_platform, *u_base_platform, *p; 502 int loop; 503 int nr; /* reset for each csp adjustment */ 504 505 #ifdef CONFIG_MMU 506 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 507 * by the processes running on the same package. One thing we can do is 508 * to shuffle the initial stack for them, so we give the architecture 509 * an opportunity to do so here. 510 */ 511 sp = arch_align_stack(bprm->p); 512 #else 513 sp = mm->start_stack; 514 515 /* stack the program arguments and environment */ 516 if (transfer_args_to_stack(bprm, &sp) < 0) 517 return -EFAULT; 518 sp &= ~15; 519 #endif 520 521 /* 522 * If this architecture has a platform capability string, copy it 523 * to userspace. In some cases (Sparc), this info is impossible 524 * for userspace to get any other way, in others (i386) it is 525 * merely difficult. 526 */ 527 k_platform = ELF_PLATFORM; 528 u_platform = NULL; 529 530 if (k_platform) { 531 platform_len = strlen(k_platform) + 1; 532 sp -= platform_len; 533 u_platform = (char __user *) sp; 534 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 535 return -EFAULT; 536 } 537 538 /* 539 * If this architecture has a "base" platform capability 540 * string, copy it to userspace. 541 */ 542 k_base_platform = ELF_BASE_PLATFORM; 543 u_base_platform = NULL; 544 545 if (k_base_platform) { 546 platform_len = strlen(k_base_platform) + 1; 547 sp -= platform_len; 548 u_base_platform = (char __user *) sp; 549 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 550 return -EFAULT; 551 } 552 553 sp &= ~7UL; 554 555 /* stack the load map(s) */ 556 len = sizeof(struct elf32_fdpic_loadmap); 557 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 558 sp = (sp - len) & ~7UL; 559 exec_params->map_addr = sp; 560 561 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 562 return -EFAULT; 563 564 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 565 566 if (interp_params->loadmap) { 567 len = sizeof(struct elf32_fdpic_loadmap); 568 len += sizeof(struct elf32_fdpic_loadseg) * 569 interp_params->loadmap->nsegs; 570 sp = (sp - len) & ~7UL; 571 interp_params->map_addr = sp; 572 573 if (copy_to_user((void __user *) sp, interp_params->loadmap, 574 len) != 0) 575 return -EFAULT; 576 577 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 578 } 579 580 /* force 16 byte _final_ alignment here for generality */ 581 #define DLINFO_ITEMS 15 582 583 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 584 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 585 586 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 587 nitems++; 588 589 csp = sp; 590 sp -= nitems * 2 * sizeof(unsigned long); 591 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 592 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 593 sp -= 1 * sizeof(unsigned long); /* argc */ 594 595 csp -= sp & 15UL; 596 sp -= sp & 15UL; 597 598 /* put the ELF interpreter info on the stack */ 599 #define NEW_AUX_ENT(id, val) \ 600 do { \ 601 struct { unsigned long _id, _val; } __user *ent; \ 602 \ 603 ent = (void __user *) csp; \ 604 __put_user((id), &ent[nr]._id); \ 605 __put_user((val), &ent[nr]._val); \ 606 nr++; \ 607 } while (0) 608 609 nr = 0; 610 csp -= 2 * sizeof(unsigned long); 611 NEW_AUX_ENT(AT_NULL, 0); 612 if (k_platform) { 613 nr = 0; 614 csp -= 2 * sizeof(unsigned long); 615 NEW_AUX_ENT(AT_PLATFORM, 616 (elf_addr_t) (unsigned long) u_platform); 617 } 618 619 if (k_base_platform) { 620 nr = 0; 621 csp -= 2 * sizeof(unsigned long); 622 NEW_AUX_ENT(AT_BASE_PLATFORM, 623 (elf_addr_t) (unsigned long) u_base_platform); 624 } 625 626 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 627 nr = 0; 628 csp -= 2 * sizeof(unsigned long); 629 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 630 } 631 632 nr = 0; 633 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 634 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 635 #ifdef ELF_HWCAP2 636 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 637 #endif 638 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 639 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 640 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 641 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 642 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 643 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 644 NEW_AUX_ENT(AT_FLAGS, 0); 645 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 646 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 647 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 648 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 649 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 650 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 651 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 652 653 #ifdef ARCH_DLINFO 654 nr = 0; 655 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 656 657 /* ARCH_DLINFO must come last so platform specific code can enforce 658 * special alignment requirements on the AUXV if necessary (eg. PPC). 659 */ 660 ARCH_DLINFO; 661 #endif 662 #undef NEW_AUX_ENT 663 664 /* allocate room for argv[] and envv[] */ 665 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 666 envp = (elf_caddr_t __user *) csp; 667 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 668 argv = (elf_caddr_t __user *) csp; 669 670 /* stack argc */ 671 csp -= sizeof(unsigned long); 672 __put_user(bprm->argc, (unsigned long __user *) csp); 673 674 BUG_ON(csp != sp); 675 676 /* fill in the argv[] array */ 677 #ifdef CONFIG_MMU 678 current->mm->arg_start = bprm->p; 679 #else 680 current->mm->arg_start = current->mm->start_stack - 681 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 682 #endif 683 684 p = (char __user *) current->mm->arg_start; 685 for (loop = bprm->argc; loop > 0; loop--) { 686 __put_user((elf_caddr_t) p, argv++); 687 len = strnlen_user(p, MAX_ARG_STRLEN); 688 if (!len || len > MAX_ARG_STRLEN) 689 return -EINVAL; 690 p += len; 691 } 692 __put_user(NULL, argv); 693 current->mm->arg_end = (unsigned long) p; 694 695 /* fill in the envv[] array */ 696 current->mm->env_start = (unsigned long) p; 697 for (loop = bprm->envc; loop > 0; loop--) { 698 __put_user((elf_caddr_t)(unsigned long) p, envp++); 699 len = strnlen_user(p, MAX_ARG_STRLEN); 700 if (!len || len > MAX_ARG_STRLEN) 701 return -EINVAL; 702 p += len; 703 } 704 __put_user(NULL, envp); 705 current->mm->env_end = (unsigned long) p; 706 707 mm->start_stack = (unsigned long) sp; 708 return 0; 709 } 710 711 /*****************************************************************************/ 712 /* 713 * load the appropriate binary image (executable or interpreter) into memory 714 * - we assume no MMU is available 715 * - if no other PIC bits are set in params->hdr->e_flags 716 * - we assume that the LOADable segments in the binary are independently relocatable 717 * - we assume R/O executable segments are shareable 718 * - else 719 * - we assume the loadable parts of the image to require fixed displacement 720 * - the image is not shareable 721 */ 722 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 723 struct file *file, 724 struct mm_struct *mm, 725 const char *what) 726 { 727 struct elf32_fdpic_loadmap *loadmap; 728 #ifdef CONFIG_MMU 729 struct elf32_fdpic_loadseg *mseg; 730 #endif 731 struct elf32_fdpic_loadseg *seg; 732 struct elf32_phdr *phdr; 733 unsigned long load_addr, stop; 734 unsigned nloads, tmp; 735 size_t size; 736 int loop, ret; 737 738 /* allocate a load map table */ 739 nloads = 0; 740 for (loop = 0; loop < params->hdr.e_phnum; loop++) 741 if (params->phdrs[loop].p_type == PT_LOAD) 742 nloads++; 743 744 if (nloads == 0) 745 return -ELIBBAD; 746 747 size = sizeof(*loadmap) + nloads * sizeof(*seg); 748 loadmap = kzalloc(size, GFP_KERNEL); 749 if (!loadmap) 750 return -ENOMEM; 751 752 params->loadmap = loadmap; 753 754 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 755 loadmap->nsegs = nloads; 756 757 load_addr = params->load_addr; 758 seg = loadmap->segs; 759 760 /* map the requested LOADs into the memory space */ 761 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 762 case ELF_FDPIC_FLAG_CONSTDISP: 763 case ELF_FDPIC_FLAG_CONTIGUOUS: 764 #ifndef CONFIG_MMU 765 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 766 if (ret < 0) 767 return ret; 768 break; 769 #endif 770 default: 771 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 772 if (ret < 0) 773 return ret; 774 break; 775 } 776 777 /* map the entry point */ 778 if (params->hdr.e_entry) { 779 seg = loadmap->segs; 780 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 781 if (params->hdr.e_entry >= seg->p_vaddr && 782 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 783 params->entry_addr = 784 (params->hdr.e_entry - seg->p_vaddr) + 785 seg->addr; 786 break; 787 } 788 } 789 } 790 791 /* determine where the program header table has wound up if mapped */ 792 stop = params->hdr.e_phoff; 793 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 794 phdr = params->phdrs; 795 796 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 797 if (phdr->p_type != PT_LOAD) 798 continue; 799 800 if (phdr->p_offset > params->hdr.e_phoff || 801 phdr->p_offset + phdr->p_filesz < stop) 802 continue; 803 804 seg = loadmap->segs; 805 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 806 if (phdr->p_vaddr >= seg->p_vaddr && 807 phdr->p_vaddr + phdr->p_filesz <= 808 seg->p_vaddr + seg->p_memsz) { 809 params->ph_addr = 810 (phdr->p_vaddr - seg->p_vaddr) + 811 seg->addr + 812 params->hdr.e_phoff - phdr->p_offset; 813 break; 814 } 815 } 816 break; 817 } 818 819 /* determine where the dynamic section has wound up if there is one */ 820 phdr = params->phdrs; 821 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 822 if (phdr->p_type != PT_DYNAMIC) 823 continue; 824 825 seg = loadmap->segs; 826 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 827 if (phdr->p_vaddr >= seg->p_vaddr && 828 phdr->p_vaddr + phdr->p_memsz <= 829 seg->p_vaddr + seg->p_memsz) { 830 params->dynamic_addr = 831 (phdr->p_vaddr - seg->p_vaddr) + 832 seg->addr; 833 834 /* check the dynamic section contains at least 835 * one item, and that the last item is a NULL 836 * entry */ 837 if (phdr->p_memsz == 0 || 838 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 839 goto dynamic_error; 840 841 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 842 if (((Elf32_Dyn *) 843 params->dynamic_addr)[tmp - 1].d_tag != 0) 844 goto dynamic_error; 845 break; 846 } 847 } 848 break; 849 } 850 851 /* now elide adjacent segments in the load map on MMU linux 852 * - on uClinux the holes between may actually be filled with system 853 * stuff or stuff from other processes 854 */ 855 #ifdef CONFIG_MMU 856 nloads = loadmap->nsegs; 857 mseg = loadmap->segs; 858 seg = mseg + 1; 859 for (loop = 1; loop < nloads; loop++) { 860 /* see if we have a candidate for merging */ 861 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 862 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 863 if (load_addr == (seg->addr & PAGE_MASK)) { 864 mseg->p_memsz += 865 load_addr - 866 (mseg->addr + mseg->p_memsz); 867 mseg->p_memsz += seg->addr & ~PAGE_MASK; 868 mseg->p_memsz += seg->p_memsz; 869 loadmap->nsegs--; 870 continue; 871 } 872 } 873 874 mseg++; 875 if (mseg != seg) 876 *mseg = *seg; 877 } 878 #endif 879 880 kdebug("Mapped Object [%s]:", what); 881 kdebug("- elfhdr : %lx", params->elfhdr_addr); 882 kdebug("- entry : %lx", params->entry_addr); 883 kdebug("- PHDR[] : %lx", params->ph_addr); 884 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 885 seg = loadmap->segs; 886 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 887 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 888 loop, 889 seg->addr, seg->addr + seg->p_memsz - 1, 890 seg->p_vaddr, seg->p_memsz); 891 892 return 0; 893 894 dynamic_error: 895 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 896 what, file_inode(file)->i_ino); 897 return -ELIBBAD; 898 } 899 900 /*****************************************************************************/ 901 /* 902 * map a file with constant displacement under uClinux 903 */ 904 #ifndef CONFIG_MMU 905 static int elf_fdpic_map_file_constdisp_on_uclinux( 906 struct elf_fdpic_params *params, 907 struct file *file, 908 struct mm_struct *mm) 909 { 910 struct elf32_fdpic_loadseg *seg; 911 struct elf32_phdr *phdr; 912 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 913 int loop, ret; 914 915 load_addr = params->load_addr; 916 seg = params->loadmap->segs; 917 918 /* determine the bounds of the contiguous overall allocation we must 919 * make */ 920 phdr = params->phdrs; 921 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 922 if (params->phdrs[loop].p_type != PT_LOAD) 923 continue; 924 925 if (base > phdr->p_vaddr) 926 base = phdr->p_vaddr; 927 if (top < phdr->p_vaddr + phdr->p_memsz) 928 top = phdr->p_vaddr + phdr->p_memsz; 929 } 930 931 /* allocate one big anon block for everything */ 932 mflags = MAP_PRIVATE; 933 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 934 mflags |= MAP_EXECUTABLE; 935 936 maddr = vm_mmap(NULL, load_addr, top - base, 937 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 938 if (IS_ERR_VALUE(maddr)) 939 return (int) maddr; 940 941 if (load_addr != 0) 942 load_addr += PAGE_ALIGN(top - base); 943 944 /* and then load the file segments into it */ 945 phdr = params->phdrs; 946 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 947 if (params->phdrs[loop].p_type != PT_LOAD) 948 continue; 949 950 seg->addr = maddr + (phdr->p_vaddr - base); 951 seg->p_vaddr = phdr->p_vaddr; 952 seg->p_memsz = phdr->p_memsz; 953 954 ret = read_code(file, seg->addr, phdr->p_offset, 955 phdr->p_filesz); 956 if (ret < 0) 957 return ret; 958 959 /* map the ELF header address if in this segment */ 960 if (phdr->p_offset == 0) 961 params->elfhdr_addr = seg->addr; 962 963 /* clear any space allocated but not loaded */ 964 if (phdr->p_filesz < phdr->p_memsz) { 965 if (clear_user((void *) (seg->addr + phdr->p_filesz), 966 phdr->p_memsz - phdr->p_filesz)) 967 return -EFAULT; 968 } 969 970 if (mm) { 971 if (phdr->p_flags & PF_X) { 972 if (!mm->start_code) { 973 mm->start_code = seg->addr; 974 mm->end_code = seg->addr + 975 phdr->p_memsz; 976 } 977 } else if (!mm->start_data) { 978 mm->start_data = seg->addr; 979 mm->end_data = seg->addr + phdr->p_memsz; 980 } 981 } 982 983 seg++; 984 } 985 986 return 0; 987 } 988 #endif 989 990 /*****************************************************************************/ 991 /* 992 * map a binary by direct mmap() of the individual PT_LOAD segments 993 */ 994 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 995 struct file *file, 996 struct mm_struct *mm) 997 { 998 struct elf32_fdpic_loadseg *seg; 999 struct elf32_phdr *phdr; 1000 unsigned long load_addr, delta_vaddr; 1001 int loop, dvset; 1002 1003 load_addr = params->load_addr; 1004 delta_vaddr = 0; 1005 dvset = 0; 1006 1007 seg = params->loadmap->segs; 1008 1009 /* deal with each load segment separately */ 1010 phdr = params->phdrs; 1011 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1012 unsigned long maddr, disp, excess, excess1; 1013 int prot = 0, flags; 1014 1015 if (phdr->p_type != PT_LOAD) 1016 continue; 1017 1018 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1019 (unsigned long) phdr->p_vaddr, 1020 (unsigned long) phdr->p_offset, 1021 (unsigned long) phdr->p_filesz, 1022 (unsigned long) phdr->p_memsz); 1023 1024 /* determine the mapping parameters */ 1025 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1026 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1027 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1028 1029 flags = MAP_PRIVATE | MAP_DENYWRITE; 1030 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1031 flags |= MAP_EXECUTABLE; 1032 1033 maddr = 0; 1034 1035 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1036 case ELF_FDPIC_FLAG_INDEPENDENT: 1037 /* PT_LOADs are independently locatable */ 1038 break; 1039 1040 case ELF_FDPIC_FLAG_HONOURVADDR: 1041 /* the specified virtual address must be honoured */ 1042 maddr = phdr->p_vaddr; 1043 flags |= MAP_FIXED; 1044 break; 1045 1046 case ELF_FDPIC_FLAG_CONSTDISP: 1047 /* constant displacement 1048 * - can be mapped anywhere, but must be mapped as a 1049 * unit 1050 */ 1051 if (!dvset) { 1052 maddr = load_addr; 1053 delta_vaddr = phdr->p_vaddr; 1054 dvset = 1; 1055 } else { 1056 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1057 flags |= MAP_FIXED; 1058 } 1059 break; 1060 1061 case ELF_FDPIC_FLAG_CONTIGUOUS: 1062 /* contiguity handled later */ 1063 break; 1064 1065 default: 1066 BUG(); 1067 } 1068 1069 maddr &= PAGE_MASK; 1070 1071 /* create the mapping */ 1072 disp = phdr->p_vaddr & ~PAGE_MASK; 1073 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1074 phdr->p_offset - disp); 1075 1076 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1077 loop, phdr->p_memsz + disp, prot, flags, 1078 phdr->p_offset - disp, maddr); 1079 1080 if (IS_ERR_VALUE(maddr)) 1081 return (int) maddr; 1082 1083 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1084 ELF_FDPIC_FLAG_CONTIGUOUS) 1085 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1086 1087 seg->addr = maddr + disp; 1088 seg->p_vaddr = phdr->p_vaddr; 1089 seg->p_memsz = phdr->p_memsz; 1090 1091 /* map the ELF header address if in this segment */ 1092 if (phdr->p_offset == 0) 1093 params->elfhdr_addr = seg->addr; 1094 1095 /* clear the bit between beginning of mapping and beginning of 1096 * PT_LOAD */ 1097 if (prot & PROT_WRITE && disp > 0) { 1098 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1099 if (clear_user((void __user *) maddr, disp)) 1100 return -EFAULT; 1101 maddr += disp; 1102 } 1103 1104 /* clear any space allocated but not loaded 1105 * - on uClinux we can just clear the lot 1106 * - on MMU linux we'll get a SIGBUS beyond the last page 1107 * extant in the file 1108 */ 1109 excess = phdr->p_memsz - phdr->p_filesz; 1110 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1111 1112 #ifdef CONFIG_MMU 1113 if (excess > excess1) { 1114 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1115 unsigned long xmaddr; 1116 1117 flags |= MAP_FIXED | MAP_ANONYMOUS; 1118 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1119 prot, flags, 0); 1120 1121 kdebug("mmap[%d] <anon>" 1122 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1123 loop, xaddr, excess - excess1, prot, flags, 1124 xmaddr); 1125 1126 if (xmaddr != xaddr) 1127 return -ENOMEM; 1128 } 1129 1130 if (prot & PROT_WRITE && excess1 > 0) { 1131 kdebug("clear[%d] ad=%lx sz=%lx", 1132 loop, maddr + phdr->p_filesz, excess1); 1133 if (clear_user((void __user *) maddr + phdr->p_filesz, 1134 excess1)) 1135 return -EFAULT; 1136 } 1137 1138 #else 1139 if (excess > 0) { 1140 kdebug("clear[%d] ad=%lx sz=%lx", 1141 loop, maddr + phdr->p_filesz, excess); 1142 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1143 return -EFAULT; 1144 } 1145 #endif 1146 1147 if (mm) { 1148 if (phdr->p_flags & PF_X) { 1149 if (!mm->start_code) { 1150 mm->start_code = maddr; 1151 mm->end_code = maddr + phdr->p_memsz; 1152 } 1153 } else if (!mm->start_data) { 1154 mm->start_data = maddr; 1155 mm->end_data = maddr + phdr->p_memsz; 1156 } 1157 } 1158 1159 seg++; 1160 } 1161 1162 return 0; 1163 } 1164 1165 /*****************************************************************************/ 1166 /* 1167 * ELF-FDPIC core dumper 1168 * 1169 * Modelled on fs/exec.c:aout_core_dump() 1170 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1171 * 1172 * Modelled on fs/binfmt_elf.c core dumper 1173 */ 1174 #ifdef CONFIG_ELF_CORE 1175 1176 /* 1177 * Decide whether a segment is worth dumping; default is yes to be 1178 * sure (missing info is worse than too much; etc). 1179 * Personally I'd include everything, and use the coredump limit... 1180 * 1181 * I think we should skip something. But I am not sure how. H.J. 1182 */ 1183 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1184 { 1185 int dump_ok; 1186 1187 /* Do not dump I/O mapped devices or special mappings */ 1188 if (vma->vm_flags & VM_IO) { 1189 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1190 return 0; 1191 } 1192 1193 /* If we may not read the contents, don't allow us to dump 1194 * them either. "dump_write()" can't handle it anyway. 1195 */ 1196 if (!(vma->vm_flags & VM_READ)) { 1197 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1198 return 0; 1199 } 1200 1201 /* support for DAX */ 1202 if (vma_is_dax(vma)) { 1203 if (vma->vm_flags & VM_SHARED) { 1204 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags); 1205 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start, 1206 vma->vm_flags, dump_ok ? "yes" : "no"); 1207 } else { 1208 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags); 1209 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start, 1210 vma->vm_flags, dump_ok ? "yes" : "no"); 1211 } 1212 return dump_ok; 1213 } 1214 1215 /* By default, dump shared memory if mapped from an anonymous file. */ 1216 if (vma->vm_flags & VM_SHARED) { 1217 if (file_inode(vma->vm_file)->i_nlink == 0) { 1218 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1219 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1220 vma->vm_flags, dump_ok ? "yes" : "no"); 1221 return dump_ok; 1222 } 1223 1224 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1225 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1226 vma->vm_flags, dump_ok ? "yes" : "no"); 1227 return dump_ok; 1228 } 1229 1230 #ifdef CONFIG_MMU 1231 /* By default, if it hasn't been written to, don't write it out */ 1232 if (!vma->anon_vma) { 1233 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1234 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1235 vma->vm_flags, dump_ok ? "yes" : "no"); 1236 return dump_ok; 1237 } 1238 #endif 1239 1240 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1241 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1242 dump_ok ? "yes" : "no"); 1243 return dump_ok; 1244 } 1245 1246 /* An ELF note in memory */ 1247 struct memelfnote 1248 { 1249 const char *name; 1250 int type; 1251 unsigned int datasz; 1252 void *data; 1253 }; 1254 1255 static int notesize(struct memelfnote *en) 1256 { 1257 int sz; 1258 1259 sz = sizeof(struct elf_note); 1260 sz += roundup(strlen(en->name) + 1, 4); 1261 sz += roundup(en->datasz, 4); 1262 1263 return sz; 1264 } 1265 1266 /* #define DEBUG */ 1267 1268 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1269 { 1270 struct elf_note en; 1271 en.n_namesz = strlen(men->name) + 1; 1272 en.n_descsz = men->datasz; 1273 en.n_type = men->type; 1274 1275 return dump_emit(cprm, &en, sizeof(en)) && 1276 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1277 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1278 } 1279 1280 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1281 { 1282 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1283 elf->e_ident[EI_CLASS] = ELF_CLASS; 1284 elf->e_ident[EI_DATA] = ELF_DATA; 1285 elf->e_ident[EI_VERSION] = EV_CURRENT; 1286 elf->e_ident[EI_OSABI] = ELF_OSABI; 1287 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1288 1289 elf->e_type = ET_CORE; 1290 elf->e_machine = ELF_ARCH; 1291 elf->e_version = EV_CURRENT; 1292 elf->e_entry = 0; 1293 elf->e_phoff = sizeof(struct elfhdr); 1294 elf->e_shoff = 0; 1295 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1296 elf->e_ehsize = sizeof(struct elfhdr); 1297 elf->e_phentsize = sizeof(struct elf_phdr); 1298 elf->e_phnum = segs; 1299 elf->e_shentsize = 0; 1300 elf->e_shnum = 0; 1301 elf->e_shstrndx = 0; 1302 return; 1303 } 1304 1305 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1306 { 1307 phdr->p_type = PT_NOTE; 1308 phdr->p_offset = offset; 1309 phdr->p_vaddr = 0; 1310 phdr->p_paddr = 0; 1311 phdr->p_filesz = sz; 1312 phdr->p_memsz = 0; 1313 phdr->p_flags = 0; 1314 phdr->p_align = 0; 1315 return; 1316 } 1317 1318 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1319 unsigned int sz, void *data) 1320 { 1321 note->name = name; 1322 note->type = type; 1323 note->datasz = sz; 1324 note->data = data; 1325 return; 1326 } 1327 1328 /* 1329 * fill up all the fields in prstatus from the given task struct, except 1330 * registers which need to be filled up separately. 1331 */ 1332 static void fill_prstatus(struct elf_prstatus *prstatus, 1333 struct task_struct *p, long signr) 1334 { 1335 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1336 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1337 prstatus->pr_sighold = p->blocked.sig[0]; 1338 rcu_read_lock(); 1339 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1340 rcu_read_unlock(); 1341 prstatus->pr_pid = task_pid_vnr(p); 1342 prstatus->pr_pgrp = task_pgrp_vnr(p); 1343 prstatus->pr_sid = task_session_vnr(p); 1344 if (thread_group_leader(p)) { 1345 struct task_cputime cputime; 1346 1347 /* 1348 * This is the record for the group leader. It shows the 1349 * group-wide total, not its individual thread total. 1350 */ 1351 thread_group_cputime(p, &cputime); 1352 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1353 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1354 } else { 1355 cputime_t utime, stime; 1356 1357 task_cputime(p, &utime, &stime); 1358 cputime_to_timeval(utime, &prstatus->pr_utime); 1359 cputime_to_timeval(stime, &prstatus->pr_stime); 1360 } 1361 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1362 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1363 1364 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1365 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1366 } 1367 1368 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1369 struct mm_struct *mm) 1370 { 1371 const struct cred *cred; 1372 unsigned int i, len; 1373 1374 /* first copy the parameters from user space */ 1375 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1376 1377 len = mm->arg_end - mm->arg_start; 1378 if (len >= ELF_PRARGSZ) 1379 len = ELF_PRARGSZ - 1; 1380 if (copy_from_user(&psinfo->pr_psargs, 1381 (const char __user *) mm->arg_start, len)) 1382 return -EFAULT; 1383 for (i = 0; i < len; i++) 1384 if (psinfo->pr_psargs[i] == 0) 1385 psinfo->pr_psargs[i] = ' '; 1386 psinfo->pr_psargs[len] = 0; 1387 1388 rcu_read_lock(); 1389 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1390 rcu_read_unlock(); 1391 psinfo->pr_pid = task_pid_vnr(p); 1392 psinfo->pr_pgrp = task_pgrp_vnr(p); 1393 psinfo->pr_sid = task_session_vnr(p); 1394 1395 i = p->state ? ffz(~p->state) + 1 : 0; 1396 psinfo->pr_state = i; 1397 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1398 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1399 psinfo->pr_nice = task_nice(p); 1400 psinfo->pr_flag = p->flags; 1401 rcu_read_lock(); 1402 cred = __task_cred(p); 1403 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1404 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1405 rcu_read_unlock(); 1406 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1407 1408 return 0; 1409 } 1410 1411 /* Here is the structure in which status of each thread is captured. */ 1412 struct elf_thread_status 1413 { 1414 struct list_head list; 1415 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1416 elf_fpregset_t fpu; /* NT_PRFPREG */ 1417 struct task_struct *thread; 1418 #ifdef ELF_CORE_COPY_XFPREGS 1419 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1420 #endif 1421 struct memelfnote notes[3]; 1422 int num_notes; 1423 }; 1424 1425 /* 1426 * In order to add the specific thread information for the elf file format, 1427 * we need to keep a linked list of every thread's pr_status and then create 1428 * a single section for them in the final core file. 1429 */ 1430 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1431 { 1432 struct task_struct *p = t->thread; 1433 int sz = 0; 1434 1435 t->num_notes = 0; 1436 1437 fill_prstatus(&t->prstatus, p, signr); 1438 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1439 1440 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1441 &t->prstatus); 1442 t->num_notes++; 1443 sz += notesize(&t->notes[0]); 1444 1445 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1446 if (t->prstatus.pr_fpvalid) { 1447 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1448 &t->fpu); 1449 t->num_notes++; 1450 sz += notesize(&t->notes[1]); 1451 } 1452 1453 #ifdef ELF_CORE_COPY_XFPREGS 1454 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1455 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1456 sizeof(t->xfpu), &t->xfpu); 1457 t->num_notes++; 1458 sz += notesize(&t->notes[2]); 1459 } 1460 #endif 1461 return sz; 1462 } 1463 1464 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1465 elf_addr_t e_shoff, int segs) 1466 { 1467 elf->e_shoff = e_shoff; 1468 elf->e_shentsize = sizeof(*shdr4extnum); 1469 elf->e_shnum = 1; 1470 elf->e_shstrndx = SHN_UNDEF; 1471 1472 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1473 1474 shdr4extnum->sh_type = SHT_NULL; 1475 shdr4extnum->sh_size = elf->e_shnum; 1476 shdr4extnum->sh_link = elf->e_shstrndx; 1477 shdr4extnum->sh_info = segs; 1478 } 1479 1480 /* 1481 * dump the segments for an MMU process 1482 */ 1483 static bool elf_fdpic_dump_segments(struct coredump_params *cprm) 1484 { 1485 struct vm_area_struct *vma; 1486 1487 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1488 unsigned long addr; 1489 1490 if (!maydump(vma, cprm->mm_flags)) 1491 continue; 1492 1493 #ifdef CONFIG_MMU 1494 for (addr = vma->vm_start; addr < vma->vm_end; 1495 addr += PAGE_SIZE) { 1496 bool res; 1497 struct page *page = get_dump_page(addr); 1498 if (page) { 1499 void *kaddr = kmap(page); 1500 res = dump_emit(cprm, kaddr, PAGE_SIZE); 1501 kunmap(page); 1502 put_page(page); 1503 } else { 1504 res = dump_skip(cprm, PAGE_SIZE); 1505 } 1506 if (!res) 1507 return false; 1508 } 1509 #else 1510 if (!dump_emit(cprm, (void *) vma->vm_start, 1511 vma->vm_end - vma->vm_start)) 1512 return false; 1513 #endif 1514 } 1515 return true; 1516 } 1517 1518 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1519 { 1520 struct vm_area_struct *vma; 1521 size_t size = 0; 1522 1523 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1524 if (maydump(vma, mm_flags)) 1525 size += vma->vm_end - vma->vm_start; 1526 return size; 1527 } 1528 1529 /* 1530 * Actual dumper 1531 * 1532 * This is a two-pass process; first we find the offsets of the bits, 1533 * and then they are actually written out. If we run out of core limit 1534 * we just truncate. 1535 */ 1536 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1537 { 1538 #define NUM_NOTES 6 1539 int has_dumped = 0; 1540 mm_segment_t fs; 1541 int segs; 1542 int i; 1543 struct vm_area_struct *vma; 1544 struct elfhdr *elf = NULL; 1545 loff_t offset = 0, dataoff; 1546 int numnote; 1547 struct memelfnote *notes = NULL; 1548 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1549 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1550 LIST_HEAD(thread_list); 1551 struct list_head *t; 1552 elf_fpregset_t *fpu = NULL; 1553 #ifdef ELF_CORE_COPY_XFPREGS 1554 elf_fpxregset_t *xfpu = NULL; 1555 #endif 1556 int thread_status_size = 0; 1557 elf_addr_t *auxv; 1558 struct elf_phdr *phdr4note = NULL; 1559 struct elf_shdr *shdr4extnum = NULL; 1560 Elf_Half e_phnum; 1561 elf_addr_t e_shoff; 1562 struct core_thread *ct; 1563 struct elf_thread_status *tmp; 1564 1565 /* 1566 * We no longer stop all VM operations. 1567 * 1568 * This is because those proceses that could possibly change map_count 1569 * or the mmap / vma pages are now blocked in do_exit on current 1570 * finishing this core dump. 1571 * 1572 * Only ptrace can touch these memory addresses, but it doesn't change 1573 * the map_count or the pages allocated. So no possibility of crashing 1574 * exists while dumping the mm->vm_next areas to the core file. 1575 */ 1576 1577 /* alloc memory for large data structures: too large to be on stack */ 1578 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1579 if (!elf) 1580 goto cleanup; 1581 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1582 if (!prstatus) 1583 goto cleanup; 1584 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1585 if (!psinfo) 1586 goto cleanup; 1587 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1588 if (!notes) 1589 goto cleanup; 1590 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1591 if (!fpu) 1592 goto cleanup; 1593 #ifdef ELF_CORE_COPY_XFPREGS 1594 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1595 if (!xfpu) 1596 goto cleanup; 1597 #endif 1598 1599 for (ct = current->mm->core_state->dumper.next; 1600 ct; ct = ct->next) { 1601 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1602 if (!tmp) 1603 goto cleanup; 1604 1605 tmp->thread = ct->task; 1606 list_add(&tmp->list, &thread_list); 1607 } 1608 1609 list_for_each(t, &thread_list) { 1610 struct elf_thread_status *tmp; 1611 int sz; 1612 1613 tmp = list_entry(t, struct elf_thread_status, list); 1614 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp); 1615 thread_status_size += sz; 1616 } 1617 1618 /* now collect the dump for the current */ 1619 fill_prstatus(prstatus, current, cprm->siginfo->si_signo); 1620 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1621 1622 segs = current->mm->map_count; 1623 segs += elf_core_extra_phdrs(); 1624 1625 /* for notes section */ 1626 segs++; 1627 1628 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1629 * this, kernel supports extended numbering. Have a look at 1630 * include/linux/elf.h for further information. */ 1631 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1632 1633 /* Set up header */ 1634 fill_elf_fdpic_header(elf, e_phnum); 1635 1636 has_dumped = 1; 1637 /* 1638 * Set up the notes in similar form to SVR4 core dumps made 1639 * with info from their /proc. 1640 */ 1641 1642 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1643 fill_psinfo(psinfo, current->group_leader, current->mm); 1644 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1645 1646 numnote = 2; 1647 1648 auxv = (elf_addr_t *) current->mm->saved_auxv; 1649 1650 i = 0; 1651 do 1652 i += 2; 1653 while (auxv[i - 2] != AT_NULL); 1654 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1655 i * sizeof(elf_addr_t), auxv); 1656 1657 /* Try to dump the FPU. */ 1658 if ((prstatus->pr_fpvalid = 1659 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1660 fill_note(notes + numnote++, 1661 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1662 #ifdef ELF_CORE_COPY_XFPREGS 1663 if (elf_core_copy_task_xfpregs(current, xfpu)) 1664 fill_note(notes + numnote++, 1665 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1666 #endif 1667 1668 fs = get_fs(); 1669 set_fs(KERNEL_DS); 1670 1671 offset += sizeof(*elf); /* Elf header */ 1672 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1673 1674 /* Write notes phdr entry */ 1675 { 1676 int sz = 0; 1677 1678 for (i = 0; i < numnote; i++) 1679 sz += notesize(notes + i); 1680 1681 sz += thread_status_size; 1682 1683 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1684 if (!phdr4note) 1685 goto end_coredump; 1686 1687 fill_elf_note_phdr(phdr4note, sz, offset); 1688 offset += sz; 1689 } 1690 1691 /* Page-align dumped data */ 1692 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1693 1694 offset += elf_core_vma_data_size(cprm->mm_flags); 1695 offset += elf_core_extra_data_size(); 1696 e_shoff = offset; 1697 1698 if (e_phnum == PN_XNUM) { 1699 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1700 if (!shdr4extnum) 1701 goto end_coredump; 1702 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1703 } 1704 1705 offset = dataoff; 1706 1707 if (!dump_emit(cprm, elf, sizeof(*elf))) 1708 goto end_coredump; 1709 1710 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1711 goto end_coredump; 1712 1713 /* write program headers for segments dump */ 1714 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1715 struct elf_phdr phdr; 1716 size_t sz; 1717 1718 sz = vma->vm_end - vma->vm_start; 1719 1720 phdr.p_type = PT_LOAD; 1721 phdr.p_offset = offset; 1722 phdr.p_vaddr = vma->vm_start; 1723 phdr.p_paddr = 0; 1724 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1725 phdr.p_memsz = sz; 1726 offset += phdr.p_filesz; 1727 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1728 if (vma->vm_flags & VM_WRITE) 1729 phdr.p_flags |= PF_W; 1730 if (vma->vm_flags & VM_EXEC) 1731 phdr.p_flags |= PF_X; 1732 phdr.p_align = ELF_EXEC_PAGESIZE; 1733 1734 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1735 goto end_coredump; 1736 } 1737 1738 if (!elf_core_write_extra_phdrs(cprm, offset)) 1739 goto end_coredump; 1740 1741 /* write out the notes section */ 1742 for (i = 0; i < numnote; i++) 1743 if (!writenote(notes + i, cprm)) 1744 goto end_coredump; 1745 1746 /* write out the thread status notes section */ 1747 list_for_each(t, &thread_list) { 1748 struct elf_thread_status *tmp = 1749 list_entry(t, struct elf_thread_status, list); 1750 1751 for (i = 0; i < tmp->num_notes; i++) 1752 if (!writenote(&tmp->notes[i], cprm)) 1753 goto end_coredump; 1754 } 1755 1756 if (!dump_skip(cprm, dataoff - cprm->pos)) 1757 goto end_coredump; 1758 1759 if (!elf_fdpic_dump_segments(cprm)) 1760 goto end_coredump; 1761 1762 if (!elf_core_write_extra_data(cprm)) 1763 goto end_coredump; 1764 1765 if (e_phnum == PN_XNUM) { 1766 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1767 goto end_coredump; 1768 } 1769 1770 if (cprm->file->f_pos != offset) { 1771 /* Sanity check */ 1772 printk(KERN_WARNING 1773 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1774 cprm->file->f_pos, offset); 1775 } 1776 1777 end_coredump: 1778 set_fs(fs); 1779 1780 cleanup: 1781 while (!list_empty(&thread_list)) { 1782 struct list_head *tmp = thread_list.next; 1783 list_del(tmp); 1784 kfree(list_entry(tmp, struct elf_thread_status, list)); 1785 } 1786 kfree(phdr4note); 1787 kfree(elf); 1788 kfree(prstatus); 1789 kfree(psinfo); 1790 kfree(notes); 1791 kfree(fpu); 1792 kfree(shdr4extnum); 1793 #ifdef ELF_CORE_COPY_XFPREGS 1794 kfree(xfpu); 1795 #endif 1796 return has_dumped; 1797 #undef NUM_NOTES 1798 } 1799 1800 #endif /* CONFIG_ELF_CORE */ 1801