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