1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* binfmt_elf_fdpic.c: FDPIC ELF binary format 3 * 4 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 * Derived from binfmt_elf.c 7 */ 8 9 #include <linux/module.h> 10 11 #include <linux/fs.h> 12 #include <linux/stat.h> 13 #include <linux/sched.h> 14 #include <linux/sched/coredump.h> 15 #include <linux/sched/task_stack.h> 16 #include <linux/sched/cputime.h> 17 #include <linux/mm.h> 18 #include <linux/mman.h> 19 #include <linux/errno.h> 20 #include <linux/signal.h> 21 #include <linux/binfmts.h> 22 #include <linux/string.h> 23 #include <linux/file.h> 24 #include <linux/fcntl.h> 25 #include <linux/slab.h> 26 #include <linux/pagemap.h> 27 #include <linux/security.h> 28 #include <linux/highmem.h> 29 #include <linux/highuid.h> 30 #include <linux/personality.h> 31 #include <linux/ptrace.h> 32 #include <linux/init.h> 33 #include <linux/elf.h> 34 #include <linux/elf-fdpic.h> 35 #include <linux/elfcore.h> 36 #include <linux/coredump.h> 37 #include <linux/dax.h> 38 39 #include <linux/uaccess.h> 40 #include <asm/param.h> 41 #include <asm/pgalloc.h> 42 43 typedef char *elf_caddr_t; 44 45 #if 0 46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 47 #else 48 #define kdebug(fmt, ...) do {} while(0) 49 #endif 50 51 #if 0 52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 53 #else 54 #define kdcore(fmt, ...) do {} while(0) 55 #endif 56 57 MODULE_LICENSE("GPL"); 58 59 static int load_elf_fdpic_binary(struct linux_binprm *); 60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 62 struct mm_struct *, const char *); 63 64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 65 struct elf_fdpic_params *, 66 struct elf_fdpic_params *); 67 68 #ifndef CONFIG_MMU 69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 70 struct file *, 71 struct mm_struct *); 72 #endif 73 74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 75 struct file *, struct mm_struct *); 76 77 #ifdef CONFIG_ELF_CORE 78 static int elf_fdpic_core_dump(struct coredump_params *cprm); 79 #endif 80 81 static struct linux_binfmt elf_fdpic_format = { 82 .module = THIS_MODULE, 83 .load_binary = load_elf_fdpic_binary, 84 #ifdef CONFIG_ELF_CORE 85 .core_dump = elf_fdpic_core_dump, 86 #endif 87 .min_coredump = ELF_EXEC_PAGESIZE, 88 }; 89 90 static int __init init_elf_fdpic_binfmt(void) 91 { 92 register_binfmt(&elf_fdpic_format); 93 return 0; 94 } 95 96 static void __exit exit_elf_fdpic_binfmt(void) 97 { 98 unregister_binfmt(&elf_fdpic_format); 99 } 100 101 core_initcall(init_elf_fdpic_binfmt); 102 module_exit(exit_elf_fdpic_binfmt); 103 104 static int is_elf(struct elfhdr *hdr, struct file *file) 105 { 106 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 107 return 0; 108 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 109 return 0; 110 if (!elf_check_arch(hdr)) 111 return 0; 112 if (!file->f_op->mmap) 113 return 0; 114 return 1; 115 } 116 117 #ifndef elf_check_fdpic 118 #define elf_check_fdpic(x) 0 119 #endif 120 121 #ifndef elf_check_const_displacement 122 #define elf_check_const_displacement(x) 0 123 #endif 124 125 static int is_constdisp(struct elfhdr *hdr) 126 { 127 if (!elf_check_fdpic(hdr)) 128 return 1; 129 if (elf_check_const_displacement(hdr)) 130 return 1; 131 return 0; 132 } 133 134 /*****************************************************************************/ 135 /* 136 * read the program headers table into memory 137 */ 138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 139 struct file *file) 140 { 141 struct elf32_phdr *phdr; 142 unsigned long size; 143 int retval, loop; 144 loff_t pos = params->hdr.e_phoff; 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->phdrs, size, &pos); 157 if (unlikely(retval != size)) 158 return retval < 0 ? retval : -ENOEXEC; 159 160 /* determine stack size for this binary */ 161 phdr = params->phdrs; 162 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 163 if (phdr->p_type != PT_GNU_STACK) 164 continue; 165 166 if (phdr->p_flags & PF_X) 167 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 168 else 169 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 170 171 params->stack_size = phdr->p_memsz; 172 break; 173 } 174 175 return 0; 176 } 177 178 /*****************************************************************************/ 179 /* 180 * load an fdpic binary into various bits of memory 181 */ 182 static int load_elf_fdpic_binary(struct linux_binprm *bprm) 183 { 184 struct elf_fdpic_params exec_params, interp_params; 185 struct pt_regs *regs = current_pt_regs(); 186 struct elf_phdr *phdr; 187 unsigned long stack_size, entryaddr; 188 #ifdef ELF_FDPIC_PLAT_INIT 189 unsigned long dynaddr; 190 #endif 191 #ifndef CONFIG_MMU 192 unsigned long stack_prot; 193 #endif 194 struct file *interpreter = NULL; /* to shut gcc up */ 195 char *interpreter_name = NULL; 196 int executable_stack; 197 int retval, i; 198 loff_t pos; 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 pos = phdr->p_offset; 247 retval = kernel_read(bprm->file, interpreter_name, 248 phdr->p_filesz, &pos); 249 if (unlikely(retval != phdr->p_filesz)) { 250 if (retval >= 0) 251 retval = -ENOEXEC; 252 goto error; 253 } 254 255 retval = -ENOENT; 256 if (interpreter_name[phdr->p_filesz - 1] != '\0') 257 goto error; 258 259 kdebug("Using ELF interpreter %s", interpreter_name); 260 261 /* replace the program with the interpreter */ 262 interpreter = open_exec(interpreter_name); 263 retval = PTR_ERR(interpreter); 264 if (IS_ERR(interpreter)) { 265 interpreter = NULL; 266 goto error; 267 } 268 269 /* 270 * If the binary is not readable then enforce 271 * mm->dumpable = 0 regardless of the interpreter's 272 * permissions. 273 */ 274 would_dump(bprm, interpreter); 275 276 pos = 0; 277 retval = kernel_read(interpreter, bprm->buf, 278 BINPRM_BUF_SIZE, &pos); 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 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 378 retval = arch_setup_additional_pages(bprm, !!interpreter_name); 379 if (retval < 0) 380 goto error; 381 #endif 382 #endif 383 384 /* load the executable and interpreter into memory */ 385 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 386 "executable"); 387 if (retval < 0) 388 goto error; 389 390 if (interpreter_name) { 391 retval = elf_fdpic_map_file(&interp_params, interpreter, 392 current->mm, "interpreter"); 393 if (retval < 0) { 394 printk(KERN_ERR "Unable to load interpreter\n"); 395 goto error; 396 } 397 398 allow_write_access(interpreter); 399 fput(interpreter); 400 interpreter = NULL; 401 } 402 403 #ifdef CONFIG_MMU 404 if (!current->mm->start_brk) 405 current->mm->start_brk = current->mm->end_data; 406 407 current->mm->brk = current->mm->start_brk = 408 PAGE_ALIGN(current->mm->start_brk); 409 410 #else 411 /* create a stack area and zero-size brk area */ 412 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 413 if (stack_size < PAGE_SIZE * 2) 414 stack_size = PAGE_SIZE * 2; 415 416 stack_prot = PROT_READ | PROT_WRITE; 417 if (executable_stack == EXSTACK_ENABLE_X || 418 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 419 stack_prot |= PROT_EXEC; 420 421 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 422 MAP_PRIVATE | MAP_ANONYMOUS | 423 MAP_UNINITIALIZED | MAP_GROWSDOWN, 424 0); 425 426 if (IS_ERR_VALUE(current->mm->start_brk)) { 427 retval = current->mm->start_brk; 428 current->mm->start_brk = 0; 429 goto error; 430 } 431 432 current->mm->brk = current->mm->start_brk; 433 current->mm->context.end_brk = current->mm->start_brk; 434 current->mm->start_stack = current->mm->start_brk + stack_size; 435 #endif 436 437 install_exec_creds(bprm); 438 if (create_elf_fdpic_tables(bprm, current->mm, 439 &exec_params, &interp_params) < 0) 440 goto error; 441 442 kdebug("- start_code %lx", current->mm->start_code); 443 kdebug("- end_code %lx", current->mm->end_code); 444 kdebug("- start_data %lx", current->mm->start_data); 445 kdebug("- end_data %lx", current->mm->end_data); 446 kdebug("- start_brk %lx", current->mm->start_brk); 447 kdebug("- brk %lx", current->mm->brk); 448 kdebug("- start_stack %lx", current->mm->start_stack); 449 450 #ifdef ELF_FDPIC_PLAT_INIT 451 /* 452 * The ABI may specify that certain registers be set up in special 453 * ways (on i386 %edx is the address of a DT_FINI function, for 454 * example. This macro performs whatever initialization to 455 * the regs structure is required. 456 */ 457 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 458 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 459 dynaddr); 460 #endif 461 462 finalize_exec(bprm); 463 /* everything is now ready... get the userspace context ready to roll */ 464 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 465 start_thread(regs, entryaddr, current->mm->start_stack); 466 467 retval = 0; 468 469 error: 470 if (interpreter) { 471 allow_write_access(interpreter); 472 fput(interpreter); 473 } 474 kfree(interpreter_name); 475 kfree(exec_params.phdrs); 476 kfree(exec_params.loadmap); 477 kfree(interp_params.phdrs); 478 kfree(interp_params.loadmap); 479 return retval; 480 } 481 482 /*****************************************************************************/ 483 484 #ifndef ELF_BASE_PLATFORM 485 /* 486 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 487 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 488 * will be copied to the user stack in the same manner as AT_PLATFORM. 489 */ 490 #define ELF_BASE_PLATFORM NULL 491 #endif 492 493 /* 494 * present useful information to the program by shovelling it onto the new 495 * process's stack 496 */ 497 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 498 struct mm_struct *mm, 499 struct elf_fdpic_params *exec_params, 500 struct elf_fdpic_params *interp_params) 501 { 502 const struct cred *cred = current_cred(); 503 unsigned long sp, csp, nitems; 504 elf_caddr_t __user *argv, *envp; 505 size_t platform_len = 0, len; 506 char *k_platform, *k_base_platform; 507 char __user *u_platform, *u_base_platform, *p; 508 int loop; 509 int nr; /* reset for each csp adjustment */ 510 511 #ifdef CONFIG_MMU 512 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 513 * by the processes running on the same package. One thing we can do is 514 * to shuffle the initial stack for them, so we give the architecture 515 * an opportunity to do so here. 516 */ 517 sp = arch_align_stack(bprm->p); 518 #else 519 sp = mm->start_stack; 520 521 /* stack the program arguments and environment */ 522 if (transfer_args_to_stack(bprm, &sp) < 0) 523 return -EFAULT; 524 sp &= ~15; 525 #endif 526 527 /* 528 * If this architecture has a platform capability string, copy it 529 * to userspace. In some cases (Sparc), this info is impossible 530 * for userspace to get any other way, in others (i386) it is 531 * merely difficult. 532 */ 533 k_platform = ELF_PLATFORM; 534 u_platform = NULL; 535 536 if (k_platform) { 537 platform_len = strlen(k_platform) + 1; 538 sp -= platform_len; 539 u_platform = (char __user *) sp; 540 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 541 return -EFAULT; 542 } 543 544 /* 545 * If this architecture has a "base" platform capability 546 * string, copy it to userspace. 547 */ 548 k_base_platform = ELF_BASE_PLATFORM; 549 u_base_platform = NULL; 550 551 if (k_base_platform) { 552 platform_len = strlen(k_base_platform) + 1; 553 sp -= platform_len; 554 u_base_platform = (char __user *) sp; 555 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 556 return -EFAULT; 557 } 558 559 sp &= ~7UL; 560 561 /* stack the load map(s) */ 562 len = sizeof(struct elf32_fdpic_loadmap); 563 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 564 sp = (sp - len) & ~7UL; 565 exec_params->map_addr = sp; 566 567 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 568 return -EFAULT; 569 570 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 571 572 if (interp_params->loadmap) { 573 len = sizeof(struct elf32_fdpic_loadmap); 574 len += sizeof(struct elf32_fdpic_loadseg) * 575 interp_params->loadmap->nsegs; 576 sp = (sp - len) & ~7UL; 577 interp_params->map_addr = sp; 578 579 if (copy_to_user((void __user *) sp, interp_params->loadmap, 580 len) != 0) 581 return -EFAULT; 582 583 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 584 } 585 586 /* force 16 byte _final_ alignment here for generality */ 587 #define DLINFO_ITEMS 15 588 589 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 590 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 591 592 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 593 nitems++; 594 595 csp = sp; 596 sp -= nitems * 2 * sizeof(unsigned long); 597 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 598 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 599 sp -= 1 * sizeof(unsigned long); /* argc */ 600 601 csp -= sp & 15UL; 602 sp -= sp & 15UL; 603 604 /* put the ELF interpreter info on the stack */ 605 #define NEW_AUX_ENT(id, val) \ 606 do { \ 607 struct { unsigned long _id, _val; } __user *ent; \ 608 \ 609 ent = (void __user *) csp; \ 610 __put_user((id), &ent[nr]._id); \ 611 __put_user((val), &ent[nr]._val); \ 612 nr++; \ 613 } while (0) 614 615 nr = 0; 616 csp -= 2 * sizeof(unsigned long); 617 NEW_AUX_ENT(AT_NULL, 0); 618 if (k_platform) { 619 nr = 0; 620 csp -= 2 * sizeof(unsigned long); 621 NEW_AUX_ENT(AT_PLATFORM, 622 (elf_addr_t) (unsigned long) u_platform); 623 } 624 625 if (k_base_platform) { 626 nr = 0; 627 csp -= 2 * sizeof(unsigned long); 628 NEW_AUX_ENT(AT_BASE_PLATFORM, 629 (elf_addr_t) (unsigned long) u_base_platform); 630 } 631 632 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 633 nr = 0; 634 csp -= 2 * sizeof(unsigned long); 635 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 636 } 637 638 nr = 0; 639 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 640 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 641 #ifdef ELF_HWCAP2 642 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 643 #endif 644 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 645 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 646 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 647 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 648 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 649 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 650 NEW_AUX_ENT(AT_FLAGS, 0); 651 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 652 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 653 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 654 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 655 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 656 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 657 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 658 659 #ifdef ARCH_DLINFO 660 nr = 0; 661 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 662 663 /* ARCH_DLINFO must come last so platform specific code can enforce 664 * special alignment requirements on the AUXV if necessary (eg. PPC). 665 */ 666 ARCH_DLINFO; 667 #endif 668 #undef NEW_AUX_ENT 669 670 /* allocate room for argv[] and envv[] */ 671 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 672 envp = (elf_caddr_t __user *) csp; 673 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 674 argv = (elf_caddr_t __user *) csp; 675 676 /* stack argc */ 677 csp -= sizeof(unsigned long); 678 __put_user(bprm->argc, (unsigned long __user *) csp); 679 680 BUG_ON(csp != sp); 681 682 /* fill in the argv[] array */ 683 #ifdef CONFIG_MMU 684 current->mm->arg_start = bprm->p; 685 #else 686 current->mm->arg_start = current->mm->start_stack - 687 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 688 #endif 689 690 p = (char __user *) current->mm->arg_start; 691 for (loop = bprm->argc; loop > 0; loop--) { 692 __put_user((elf_caddr_t) p, argv++); 693 len = strnlen_user(p, MAX_ARG_STRLEN); 694 if (!len || len > MAX_ARG_STRLEN) 695 return -EINVAL; 696 p += len; 697 } 698 __put_user(NULL, argv); 699 current->mm->arg_end = (unsigned long) p; 700 701 /* fill in the envv[] array */ 702 current->mm->env_start = (unsigned long) p; 703 for (loop = bprm->envc; loop > 0; loop--) { 704 __put_user((elf_caddr_t)(unsigned long) p, envp++); 705 len = strnlen_user(p, MAX_ARG_STRLEN); 706 if (!len || len > MAX_ARG_STRLEN) 707 return -EINVAL; 708 p += len; 709 } 710 __put_user(NULL, envp); 711 current->mm->env_end = (unsigned long) p; 712 713 mm->start_stack = (unsigned long) sp; 714 return 0; 715 } 716 717 /*****************************************************************************/ 718 /* 719 * load the appropriate binary image (executable or interpreter) into memory 720 * - we assume no MMU is available 721 * - if no other PIC bits are set in params->hdr->e_flags 722 * - we assume that the LOADable segments in the binary are independently relocatable 723 * - we assume R/O executable segments are shareable 724 * - else 725 * - we assume the loadable parts of the image to require fixed displacement 726 * - the image is not shareable 727 */ 728 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 729 struct file *file, 730 struct mm_struct *mm, 731 const char *what) 732 { 733 struct elf32_fdpic_loadmap *loadmap; 734 #ifdef CONFIG_MMU 735 struct elf32_fdpic_loadseg *mseg; 736 #endif 737 struct elf32_fdpic_loadseg *seg; 738 struct elf32_phdr *phdr; 739 unsigned long load_addr, stop; 740 unsigned nloads, tmp; 741 size_t size; 742 int loop, ret; 743 744 /* allocate a load map table */ 745 nloads = 0; 746 for (loop = 0; loop < params->hdr.e_phnum; loop++) 747 if (params->phdrs[loop].p_type == PT_LOAD) 748 nloads++; 749 750 if (nloads == 0) 751 return -ELIBBAD; 752 753 size = sizeof(*loadmap) + nloads * sizeof(*seg); 754 loadmap = kzalloc(size, GFP_KERNEL); 755 if (!loadmap) 756 return -ENOMEM; 757 758 params->loadmap = loadmap; 759 760 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 761 loadmap->nsegs = nloads; 762 763 load_addr = params->load_addr; 764 seg = loadmap->segs; 765 766 /* map the requested LOADs into the memory space */ 767 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 768 case ELF_FDPIC_FLAG_CONSTDISP: 769 case ELF_FDPIC_FLAG_CONTIGUOUS: 770 #ifndef CONFIG_MMU 771 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 772 if (ret < 0) 773 return ret; 774 break; 775 #endif 776 default: 777 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 778 if (ret < 0) 779 return ret; 780 break; 781 } 782 783 /* map the entry point */ 784 if (params->hdr.e_entry) { 785 seg = loadmap->segs; 786 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 787 if (params->hdr.e_entry >= seg->p_vaddr && 788 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 789 params->entry_addr = 790 (params->hdr.e_entry - seg->p_vaddr) + 791 seg->addr; 792 break; 793 } 794 } 795 } 796 797 /* determine where the program header table has wound up if mapped */ 798 stop = params->hdr.e_phoff; 799 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 800 phdr = params->phdrs; 801 802 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 803 if (phdr->p_type != PT_LOAD) 804 continue; 805 806 if (phdr->p_offset > params->hdr.e_phoff || 807 phdr->p_offset + phdr->p_filesz < stop) 808 continue; 809 810 seg = loadmap->segs; 811 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 812 if (phdr->p_vaddr >= seg->p_vaddr && 813 phdr->p_vaddr + phdr->p_filesz <= 814 seg->p_vaddr + seg->p_memsz) { 815 params->ph_addr = 816 (phdr->p_vaddr - seg->p_vaddr) + 817 seg->addr + 818 params->hdr.e_phoff - phdr->p_offset; 819 break; 820 } 821 } 822 break; 823 } 824 825 /* determine where the dynamic section has wound up if there is one */ 826 phdr = params->phdrs; 827 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 828 if (phdr->p_type != PT_DYNAMIC) 829 continue; 830 831 seg = loadmap->segs; 832 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 833 if (phdr->p_vaddr >= seg->p_vaddr && 834 phdr->p_vaddr + phdr->p_memsz <= 835 seg->p_vaddr + seg->p_memsz) { 836 Elf32_Dyn __user *dyn; 837 Elf32_Sword d_tag; 838 839 params->dynamic_addr = 840 (phdr->p_vaddr - seg->p_vaddr) + 841 seg->addr; 842 843 /* check the dynamic section contains at least 844 * one item, and that the last item is a NULL 845 * entry */ 846 if (phdr->p_memsz == 0 || 847 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 848 goto dynamic_error; 849 850 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 851 dyn = (Elf32_Dyn __user *)params->dynamic_addr; 852 __get_user(d_tag, &dyn[tmp - 1].d_tag); 853 if (d_tag != 0) 854 goto dynamic_error; 855 break; 856 } 857 } 858 break; 859 } 860 861 /* now elide adjacent segments in the load map on MMU linux 862 * - on uClinux the holes between may actually be filled with system 863 * stuff or stuff from other processes 864 */ 865 #ifdef CONFIG_MMU 866 nloads = loadmap->nsegs; 867 mseg = loadmap->segs; 868 seg = mseg + 1; 869 for (loop = 1; loop < nloads; loop++) { 870 /* see if we have a candidate for merging */ 871 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 872 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 873 if (load_addr == (seg->addr & PAGE_MASK)) { 874 mseg->p_memsz += 875 load_addr - 876 (mseg->addr + mseg->p_memsz); 877 mseg->p_memsz += seg->addr & ~PAGE_MASK; 878 mseg->p_memsz += seg->p_memsz; 879 loadmap->nsegs--; 880 continue; 881 } 882 } 883 884 mseg++; 885 if (mseg != seg) 886 *mseg = *seg; 887 } 888 #endif 889 890 kdebug("Mapped Object [%s]:", what); 891 kdebug("- elfhdr : %lx", params->elfhdr_addr); 892 kdebug("- entry : %lx", params->entry_addr); 893 kdebug("- PHDR[] : %lx", params->ph_addr); 894 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 895 seg = loadmap->segs; 896 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 897 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 898 loop, 899 seg->addr, seg->addr + seg->p_memsz - 1, 900 seg->p_vaddr, seg->p_memsz); 901 902 return 0; 903 904 dynamic_error: 905 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 906 what, file_inode(file)->i_ino); 907 return -ELIBBAD; 908 } 909 910 /*****************************************************************************/ 911 /* 912 * map a file with constant displacement under uClinux 913 */ 914 #ifndef CONFIG_MMU 915 static int elf_fdpic_map_file_constdisp_on_uclinux( 916 struct elf_fdpic_params *params, 917 struct file *file, 918 struct mm_struct *mm) 919 { 920 struct elf32_fdpic_loadseg *seg; 921 struct elf32_phdr *phdr; 922 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 923 int loop, ret; 924 925 load_addr = params->load_addr; 926 seg = params->loadmap->segs; 927 928 /* determine the bounds of the contiguous overall allocation we must 929 * make */ 930 phdr = params->phdrs; 931 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 932 if (params->phdrs[loop].p_type != PT_LOAD) 933 continue; 934 935 if (base > phdr->p_vaddr) 936 base = phdr->p_vaddr; 937 if (top < phdr->p_vaddr + phdr->p_memsz) 938 top = phdr->p_vaddr + phdr->p_memsz; 939 } 940 941 /* allocate one big anon block for everything */ 942 mflags = MAP_PRIVATE; 943 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 944 mflags |= MAP_EXECUTABLE; 945 946 maddr = vm_mmap(NULL, load_addr, top - base, 947 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 948 if (IS_ERR_VALUE(maddr)) 949 return (int) maddr; 950 951 if (load_addr != 0) 952 load_addr += PAGE_ALIGN(top - base); 953 954 /* and then load the file segments into it */ 955 phdr = params->phdrs; 956 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 957 if (params->phdrs[loop].p_type != PT_LOAD) 958 continue; 959 960 seg->addr = maddr + (phdr->p_vaddr - base); 961 seg->p_vaddr = phdr->p_vaddr; 962 seg->p_memsz = phdr->p_memsz; 963 964 ret = read_code(file, seg->addr, phdr->p_offset, 965 phdr->p_filesz); 966 if (ret < 0) 967 return ret; 968 969 /* map the ELF header address if in this segment */ 970 if (phdr->p_offset == 0) 971 params->elfhdr_addr = seg->addr; 972 973 /* clear any space allocated but not loaded */ 974 if (phdr->p_filesz < phdr->p_memsz) { 975 if (clear_user((void *) (seg->addr + phdr->p_filesz), 976 phdr->p_memsz - phdr->p_filesz)) 977 return -EFAULT; 978 } 979 980 if (mm) { 981 if (phdr->p_flags & PF_X) { 982 if (!mm->start_code) { 983 mm->start_code = seg->addr; 984 mm->end_code = seg->addr + 985 phdr->p_memsz; 986 } 987 } else if (!mm->start_data) { 988 mm->start_data = seg->addr; 989 mm->end_data = seg->addr + phdr->p_memsz; 990 } 991 } 992 993 seg++; 994 } 995 996 return 0; 997 } 998 #endif 999 1000 /*****************************************************************************/ 1001 /* 1002 * map a binary by direct mmap() of the individual PT_LOAD segments 1003 */ 1004 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1005 struct file *file, 1006 struct mm_struct *mm) 1007 { 1008 struct elf32_fdpic_loadseg *seg; 1009 struct elf32_phdr *phdr; 1010 unsigned long load_addr, delta_vaddr; 1011 int loop, dvset; 1012 1013 load_addr = params->load_addr; 1014 delta_vaddr = 0; 1015 dvset = 0; 1016 1017 seg = params->loadmap->segs; 1018 1019 /* deal with each load segment separately */ 1020 phdr = params->phdrs; 1021 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1022 unsigned long maddr, disp, excess, excess1; 1023 int prot = 0, flags; 1024 1025 if (phdr->p_type != PT_LOAD) 1026 continue; 1027 1028 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1029 (unsigned long) phdr->p_vaddr, 1030 (unsigned long) phdr->p_offset, 1031 (unsigned long) phdr->p_filesz, 1032 (unsigned long) phdr->p_memsz); 1033 1034 /* determine the mapping parameters */ 1035 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1036 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1037 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1038 1039 flags = MAP_PRIVATE | MAP_DENYWRITE; 1040 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1041 flags |= MAP_EXECUTABLE; 1042 1043 maddr = 0; 1044 1045 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1046 case ELF_FDPIC_FLAG_INDEPENDENT: 1047 /* PT_LOADs are independently locatable */ 1048 break; 1049 1050 case ELF_FDPIC_FLAG_HONOURVADDR: 1051 /* the specified virtual address must be honoured */ 1052 maddr = phdr->p_vaddr; 1053 flags |= MAP_FIXED; 1054 break; 1055 1056 case ELF_FDPIC_FLAG_CONSTDISP: 1057 /* constant displacement 1058 * - can be mapped anywhere, but must be mapped as a 1059 * unit 1060 */ 1061 if (!dvset) { 1062 maddr = load_addr; 1063 delta_vaddr = phdr->p_vaddr; 1064 dvset = 1; 1065 } else { 1066 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1067 flags |= MAP_FIXED; 1068 } 1069 break; 1070 1071 case ELF_FDPIC_FLAG_CONTIGUOUS: 1072 /* contiguity handled later */ 1073 break; 1074 1075 default: 1076 BUG(); 1077 } 1078 1079 maddr &= PAGE_MASK; 1080 1081 /* create the mapping */ 1082 disp = phdr->p_vaddr & ~PAGE_MASK; 1083 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1084 phdr->p_offset - disp); 1085 1086 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1087 loop, phdr->p_memsz + disp, prot, flags, 1088 phdr->p_offset - disp, maddr); 1089 1090 if (IS_ERR_VALUE(maddr)) 1091 return (int) maddr; 1092 1093 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1094 ELF_FDPIC_FLAG_CONTIGUOUS) 1095 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1096 1097 seg->addr = maddr + disp; 1098 seg->p_vaddr = phdr->p_vaddr; 1099 seg->p_memsz = phdr->p_memsz; 1100 1101 /* map the ELF header address if in this segment */ 1102 if (phdr->p_offset == 0) 1103 params->elfhdr_addr = seg->addr; 1104 1105 /* clear the bit between beginning of mapping and beginning of 1106 * PT_LOAD */ 1107 if (prot & PROT_WRITE && disp > 0) { 1108 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1109 if (clear_user((void __user *) maddr, disp)) 1110 return -EFAULT; 1111 maddr += disp; 1112 } 1113 1114 /* clear any space allocated but not loaded 1115 * - on uClinux we can just clear the lot 1116 * - on MMU linux we'll get a SIGBUS beyond the last page 1117 * extant in the file 1118 */ 1119 excess = phdr->p_memsz - phdr->p_filesz; 1120 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1121 1122 #ifdef CONFIG_MMU 1123 if (excess > excess1) { 1124 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1125 unsigned long xmaddr; 1126 1127 flags |= MAP_FIXED | MAP_ANONYMOUS; 1128 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1129 prot, flags, 0); 1130 1131 kdebug("mmap[%d] <anon>" 1132 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1133 loop, xaddr, excess - excess1, prot, flags, 1134 xmaddr); 1135 1136 if (xmaddr != xaddr) 1137 return -ENOMEM; 1138 } 1139 1140 if (prot & PROT_WRITE && excess1 > 0) { 1141 kdebug("clear[%d] ad=%lx sz=%lx", 1142 loop, maddr + phdr->p_filesz, excess1); 1143 if (clear_user((void __user *) maddr + phdr->p_filesz, 1144 excess1)) 1145 return -EFAULT; 1146 } 1147 1148 #else 1149 if (excess > 0) { 1150 kdebug("clear[%d] ad=%lx sz=%lx", 1151 loop, maddr + phdr->p_filesz, excess); 1152 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1153 return -EFAULT; 1154 } 1155 #endif 1156 1157 if (mm) { 1158 if (phdr->p_flags & PF_X) { 1159 if (!mm->start_code) { 1160 mm->start_code = maddr; 1161 mm->end_code = maddr + phdr->p_memsz; 1162 } 1163 } else if (!mm->start_data) { 1164 mm->start_data = maddr; 1165 mm->end_data = maddr + phdr->p_memsz; 1166 } 1167 } 1168 1169 seg++; 1170 } 1171 1172 return 0; 1173 } 1174 1175 /*****************************************************************************/ 1176 /* 1177 * ELF-FDPIC core dumper 1178 * 1179 * Modelled on fs/exec.c:aout_core_dump() 1180 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1181 * 1182 * Modelled on fs/binfmt_elf.c core dumper 1183 */ 1184 #ifdef CONFIG_ELF_CORE 1185 1186 /* 1187 * Decide whether a segment is worth dumping; default is yes to be 1188 * sure (missing info is worse than too much; etc). 1189 * Personally I'd include everything, and use the coredump limit... 1190 * 1191 * I think we should skip something. But I am not sure how. H.J. 1192 */ 1193 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1194 { 1195 int dump_ok; 1196 1197 /* Do not dump I/O mapped devices or special mappings */ 1198 if (vma->vm_flags & VM_IO) { 1199 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1200 return 0; 1201 } 1202 1203 /* If we may not read the contents, don't allow us to dump 1204 * them either. "dump_write()" can't handle it anyway. 1205 */ 1206 if (!(vma->vm_flags & VM_READ)) { 1207 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1208 return 0; 1209 } 1210 1211 /* support for DAX */ 1212 if (vma_is_dax(vma)) { 1213 if (vma->vm_flags & VM_SHARED) { 1214 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags); 1215 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start, 1216 vma->vm_flags, dump_ok ? "yes" : "no"); 1217 } else { 1218 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags); 1219 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start, 1220 vma->vm_flags, dump_ok ? "yes" : "no"); 1221 } 1222 return dump_ok; 1223 } 1224 1225 /* By default, dump shared memory if mapped from an anonymous file. */ 1226 if (vma->vm_flags & VM_SHARED) { 1227 if (file_inode(vma->vm_file)->i_nlink == 0) { 1228 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1229 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1230 vma->vm_flags, dump_ok ? "yes" : "no"); 1231 return dump_ok; 1232 } 1233 1234 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1235 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1236 vma->vm_flags, dump_ok ? "yes" : "no"); 1237 return dump_ok; 1238 } 1239 1240 #ifdef CONFIG_MMU 1241 /* By default, if it hasn't been written to, don't write it out */ 1242 if (!vma->anon_vma) { 1243 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1244 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1245 vma->vm_flags, dump_ok ? "yes" : "no"); 1246 return dump_ok; 1247 } 1248 #endif 1249 1250 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1251 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1252 dump_ok ? "yes" : "no"); 1253 return dump_ok; 1254 } 1255 1256 /* An ELF note in memory */ 1257 struct memelfnote 1258 { 1259 const char *name; 1260 int type; 1261 unsigned int datasz; 1262 void *data; 1263 }; 1264 1265 static int notesize(struct memelfnote *en) 1266 { 1267 int sz; 1268 1269 sz = sizeof(struct elf_note); 1270 sz += roundup(strlen(en->name) + 1, 4); 1271 sz += roundup(en->datasz, 4); 1272 1273 return sz; 1274 } 1275 1276 /* #define DEBUG */ 1277 1278 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1279 { 1280 struct elf_note en; 1281 en.n_namesz = strlen(men->name) + 1; 1282 en.n_descsz = men->datasz; 1283 en.n_type = men->type; 1284 1285 return dump_emit(cprm, &en, sizeof(en)) && 1286 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1287 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1288 } 1289 1290 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1291 { 1292 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1293 elf->e_ident[EI_CLASS] = ELF_CLASS; 1294 elf->e_ident[EI_DATA] = ELF_DATA; 1295 elf->e_ident[EI_VERSION] = EV_CURRENT; 1296 elf->e_ident[EI_OSABI] = ELF_OSABI; 1297 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1298 1299 elf->e_type = ET_CORE; 1300 elf->e_machine = ELF_ARCH; 1301 elf->e_version = EV_CURRENT; 1302 elf->e_entry = 0; 1303 elf->e_phoff = sizeof(struct elfhdr); 1304 elf->e_shoff = 0; 1305 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1306 elf->e_ehsize = sizeof(struct elfhdr); 1307 elf->e_phentsize = sizeof(struct elf_phdr); 1308 elf->e_phnum = segs; 1309 elf->e_shentsize = 0; 1310 elf->e_shnum = 0; 1311 elf->e_shstrndx = 0; 1312 return; 1313 } 1314 1315 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1316 { 1317 phdr->p_type = PT_NOTE; 1318 phdr->p_offset = offset; 1319 phdr->p_vaddr = 0; 1320 phdr->p_paddr = 0; 1321 phdr->p_filesz = sz; 1322 phdr->p_memsz = 0; 1323 phdr->p_flags = 0; 1324 phdr->p_align = 0; 1325 return; 1326 } 1327 1328 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1329 unsigned int sz, void *data) 1330 { 1331 note->name = name; 1332 note->type = type; 1333 note->datasz = sz; 1334 note->data = data; 1335 return; 1336 } 1337 1338 /* 1339 * fill up all the fields in prstatus from the given task struct, except 1340 * registers which need to be filled up separately. 1341 */ 1342 static void fill_prstatus(struct elf_prstatus *prstatus, 1343 struct task_struct *p, long signr) 1344 { 1345 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1346 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1347 prstatus->pr_sighold = p->blocked.sig[0]; 1348 rcu_read_lock(); 1349 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1350 rcu_read_unlock(); 1351 prstatus->pr_pid = task_pid_vnr(p); 1352 prstatus->pr_pgrp = task_pgrp_vnr(p); 1353 prstatus->pr_sid = task_session_vnr(p); 1354 if (thread_group_leader(p)) { 1355 struct task_cputime cputime; 1356 1357 /* 1358 * This is the record for the group leader. It shows the 1359 * group-wide total, not its individual thread total. 1360 */ 1361 thread_group_cputime(p, &cputime); 1362 prstatus->pr_utime = ns_to_timeval(cputime.utime); 1363 prstatus->pr_stime = ns_to_timeval(cputime.stime); 1364 } else { 1365 u64 utime, stime; 1366 1367 task_cputime(p, &utime, &stime); 1368 prstatus->pr_utime = ns_to_timeval(utime); 1369 prstatus->pr_stime = ns_to_timeval(stime); 1370 } 1371 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime); 1372 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime); 1373 1374 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1375 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1376 } 1377 1378 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1379 struct mm_struct *mm) 1380 { 1381 const struct cred *cred; 1382 unsigned int i, len; 1383 1384 /* first copy the parameters from user space */ 1385 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1386 1387 len = mm->arg_end - mm->arg_start; 1388 if (len >= ELF_PRARGSZ) 1389 len = ELF_PRARGSZ - 1; 1390 if (copy_from_user(&psinfo->pr_psargs, 1391 (const char __user *) mm->arg_start, len)) 1392 return -EFAULT; 1393 for (i = 0; i < len; i++) 1394 if (psinfo->pr_psargs[i] == 0) 1395 psinfo->pr_psargs[i] = ' '; 1396 psinfo->pr_psargs[len] = 0; 1397 1398 rcu_read_lock(); 1399 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1400 rcu_read_unlock(); 1401 psinfo->pr_pid = task_pid_vnr(p); 1402 psinfo->pr_pgrp = task_pgrp_vnr(p); 1403 psinfo->pr_sid = task_session_vnr(p); 1404 1405 i = p->state ? ffz(~p->state) + 1 : 0; 1406 psinfo->pr_state = i; 1407 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1408 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1409 psinfo->pr_nice = task_nice(p); 1410 psinfo->pr_flag = p->flags; 1411 rcu_read_lock(); 1412 cred = __task_cred(p); 1413 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1414 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1415 rcu_read_unlock(); 1416 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1417 1418 return 0; 1419 } 1420 1421 /* Here is the structure in which status of each thread is captured. */ 1422 struct elf_thread_status 1423 { 1424 struct list_head list; 1425 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1426 elf_fpregset_t fpu; /* NT_PRFPREG */ 1427 struct task_struct *thread; 1428 #ifdef ELF_CORE_COPY_XFPREGS 1429 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1430 #endif 1431 struct memelfnote notes[3]; 1432 int num_notes; 1433 }; 1434 1435 /* 1436 * In order to add the specific thread information for the elf file format, 1437 * we need to keep a linked list of every thread's pr_status and then create 1438 * a single section for them in the final core file. 1439 */ 1440 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1441 { 1442 struct task_struct *p = t->thread; 1443 int sz = 0; 1444 1445 t->num_notes = 0; 1446 1447 fill_prstatus(&t->prstatus, p, signr); 1448 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1449 1450 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1451 &t->prstatus); 1452 t->num_notes++; 1453 sz += notesize(&t->notes[0]); 1454 1455 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1456 if (t->prstatus.pr_fpvalid) { 1457 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1458 &t->fpu); 1459 t->num_notes++; 1460 sz += notesize(&t->notes[1]); 1461 } 1462 1463 #ifdef ELF_CORE_COPY_XFPREGS 1464 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1465 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1466 sizeof(t->xfpu), &t->xfpu); 1467 t->num_notes++; 1468 sz += notesize(&t->notes[2]); 1469 } 1470 #endif 1471 return sz; 1472 } 1473 1474 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1475 elf_addr_t e_shoff, int segs) 1476 { 1477 elf->e_shoff = e_shoff; 1478 elf->e_shentsize = sizeof(*shdr4extnum); 1479 elf->e_shnum = 1; 1480 elf->e_shstrndx = SHN_UNDEF; 1481 1482 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1483 1484 shdr4extnum->sh_type = SHT_NULL; 1485 shdr4extnum->sh_size = elf->e_shnum; 1486 shdr4extnum->sh_link = elf->e_shstrndx; 1487 shdr4extnum->sh_info = segs; 1488 } 1489 1490 /* 1491 * dump the segments for an MMU process 1492 */ 1493 static bool elf_fdpic_dump_segments(struct coredump_params *cprm) 1494 { 1495 struct vm_area_struct *vma; 1496 1497 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1498 #ifdef CONFIG_MMU 1499 unsigned long addr; 1500 #endif 1501 1502 if (!maydump(vma, cprm->mm_flags)) 1503 continue; 1504 1505 #ifdef CONFIG_MMU 1506 for (addr = vma->vm_start; addr < vma->vm_end; 1507 addr += PAGE_SIZE) { 1508 bool res; 1509 struct page *page = get_dump_page(addr); 1510 if (page) { 1511 void *kaddr = kmap(page); 1512 res = dump_emit(cprm, kaddr, PAGE_SIZE); 1513 kunmap(page); 1514 put_page(page); 1515 } else { 1516 res = dump_skip(cprm, PAGE_SIZE); 1517 } 1518 if (!res) 1519 return false; 1520 } 1521 #else 1522 if (!dump_emit(cprm, (void *) vma->vm_start, 1523 vma->vm_end - vma->vm_start)) 1524 return false; 1525 #endif 1526 } 1527 return true; 1528 } 1529 1530 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1531 { 1532 struct vm_area_struct *vma; 1533 size_t size = 0; 1534 1535 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1536 if (maydump(vma, mm_flags)) 1537 size += vma->vm_end - vma->vm_start; 1538 return size; 1539 } 1540 1541 /* 1542 * Actual dumper 1543 * 1544 * This is a two-pass process; first we find the offsets of the bits, 1545 * and then they are actually written out. If we run out of core limit 1546 * we just truncate. 1547 */ 1548 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1549 { 1550 #define NUM_NOTES 6 1551 int has_dumped = 0; 1552 mm_segment_t fs; 1553 int segs; 1554 int i; 1555 struct vm_area_struct *vma; 1556 struct elfhdr *elf = NULL; 1557 loff_t offset = 0, dataoff; 1558 int numnote; 1559 struct memelfnote *notes = NULL; 1560 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1561 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1562 LIST_HEAD(thread_list); 1563 struct list_head *t; 1564 elf_fpregset_t *fpu = NULL; 1565 #ifdef ELF_CORE_COPY_XFPREGS 1566 elf_fpxregset_t *xfpu = NULL; 1567 #endif 1568 int thread_status_size = 0; 1569 elf_addr_t *auxv; 1570 struct elf_phdr *phdr4note = NULL; 1571 struct elf_shdr *shdr4extnum = NULL; 1572 Elf_Half e_phnum; 1573 elf_addr_t e_shoff; 1574 struct core_thread *ct; 1575 struct elf_thread_status *tmp; 1576 1577 /* 1578 * We no longer stop all VM operations. 1579 * 1580 * This is because those proceses that could possibly change map_count 1581 * or the mmap / vma pages are now blocked in do_exit on current 1582 * finishing this core dump. 1583 * 1584 * Only ptrace can touch these memory addresses, but it doesn't change 1585 * the map_count or the pages allocated. So no possibility of crashing 1586 * exists while dumping the mm->vm_next areas to the core file. 1587 */ 1588 1589 /* alloc memory for large data structures: too large to be on stack */ 1590 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1591 if (!elf) 1592 goto cleanup; 1593 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1594 if (!prstatus) 1595 goto cleanup; 1596 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1597 if (!psinfo) 1598 goto cleanup; 1599 notes = kmalloc_array(NUM_NOTES, sizeof(struct memelfnote), 1600 GFP_KERNEL); 1601 if (!notes) 1602 goto cleanup; 1603 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1604 if (!fpu) 1605 goto cleanup; 1606 #ifdef ELF_CORE_COPY_XFPREGS 1607 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1608 if (!xfpu) 1609 goto cleanup; 1610 #endif 1611 1612 for (ct = current->mm->core_state->dumper.next; 1613 ct; ct = ct->next) { 1614 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1615 if (!tmp) 1616 goto cleanup; 1617 1618 tmp->thread = ct->task; 1619 list_add(&tmp->list, &thread_list); 1620 } 1621 1622 list_for_each(t, &thread_list) { 1623 struct elf_thread_status *tmp; 1624 int sz; 1625 1626 tmp = list_entry(t, struct elf_thread_status, list); 1627 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp); 1628 thread_status_size += sz; 1629 } 1630 1631 /* now collect the dump for the current */ 1632 fill_prstatus(prstatus, current, cprm->siginfo->si_signo); 1633 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1634 1635 segs = current->mm->map_count; 1636 segs += elf_core_extra_phdrs(); 1637 1638 /* for notes section */ 1639 segs++; 1640 1641 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1642 * this, kernel supports extended numbering. Have a look at 1643 * include/linux/elf.h for further information. */ 1644 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1645 1646 /* Set up header */ 1647 fill_elf_fdpic_header(elf, e_phnum); 1648 1649 has_dumped = 1; 1650 /* 1651 * Set up the notes in similar form to SVR4 core dumps made 1652 * with info from their /proc. 1653 */ 1654 1655 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1656 fill_psinfo(psinfo, current->group_leader, current->mm); 1657 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1658 1659 numnote = 2; 1660 1661 auxv = (elf_addr_t *) current->mm->saved_auxv; 1662 1663 i = 0; 1664 do 1665 i += 2; 1666 while (auxv[i - 2] != AT_NULL); 1667 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1668 i * sizeof(elf_addr_t), auxv); 1669 1670 /* Try to dump the FPU. */ 1671 if ((prstatus->pr_fpvalid = 1672 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1673 fill_note(notes + numnote++, 1674 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1675 #ifdef ELF_CORE_COPY_XFPREGS 1676 if (elf_core_copy_task_xfpregs(current, xfpu)) 1677 fill_note(notes + numnote++, 1678 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1679 #endif 1680 1681 fs = get_fs(); 1682 set_fs(KERNEL_DS); 1683 1684 offset += sizeof(*elf); /* Elf header */ 1685 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1686 1687 /* Write notes phdr entry */ 1688 { 1689 int sz = 0; 1690 1691 for (i = 0; i < numnote; i++) 1692 sz += notesize(notes + i); 1693 1694 sz += thread_status_size; 1695 1696 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1697 if (!phdr4note) 1698 goto end_coredump; 1699 1700 fill_elf_note_phdr(phdr4note, sz, offset); 1701 offset += sz; 1702 } 1703 1704 /* Page-align dumped data */ 1705 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1706 1707 offset += elf_core_vma_data_size(cprm->mm_flags); 1708 offset += elf_core_extra_data_size(); 1709 e_shoff = offset; 1710 1711 if (e_phnum == PN_XNUM) { 1712 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1713 if (!shdr4extnum) 1714 goto end_coredump; 1715 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1716 } 1717 1718 offset = dataoff; 1719 1720 if (!dump_emit(cprm, elf, sizeof(*elf))) 1721 goto end_coredump; 1722 1723 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1724 goto end_coredump; 1725 1726 /* write program headers for segments dump */ 1727 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1728 struct elf_phdr phdr; 1729 size_t sz; 1730 1731 sz = vma->vm_end - vma->vm_start; 1732 1733 phdr.p_type = PT_LOAD; 1734 phdr.p_offset = offset; 1735 phdr.p_vaddr = vma->vm_start; 1736 phdr.p_paddr = 0; 1737 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1738 phdr.p_memsz = sz; 1739 offset += phdr.p_filesz; 1740 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1741 if (vma->vm_flags & VM_WRITE) 1742 phdr.p_flags |= PF_W; 1743 if (vma->vm_flags & VM_EXEC) 1744 phdr.p_flags |= PF_X; 1745 phdr.p_align = ELF_EXEC_PAGESIZE; 1746 1747 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1748 goto end_coredump; 1749 } 1750 1751 if (!elf_core_write_extra_phdrs(cprm, offset)) 1752 goto end_coredump; 1753 1754 /* write out the notes section */ 1755 for (i = 0; i < numnote; i++) 1756 if (!writenote(notes + i, cprm)) 1757 goto end_coredump; 1758 1759 /* write out the thread status notes section */ 1760 list_for_each(t, &thread_list) { 1761 struct elf_thread_status *tmp = 1762 list_entry(t, struct elf_thread_status, list); 1763 1764 for (i = 0; i < tmp->num_notes; i++) 1765 if (!writenote(&tmp->notes[i], cprm)) 1766 goto end_coredump; 1767 } 1768 1769 if (!dump_skip(cprm, dataoff - cprm->pos)) 1770 goto end_coredump; 1771 1772 if (!elf_fdpic_dump_segments(cprm)) 1773 goto end_coredump; 1774 1775 if (!elf_core_write_extra_data(cprm)) 1776 goto end_coredump; 1777 1778 if (e_phnum == PN_XNUM) { 1779 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1780 goto end_coredump; 1781 } 1782 1783 if (cprm->file->f_pos != offset) { 1784 /* Sanity check */ 1785 printk(KERN_WARNING 1786 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1787 cprm->file->f_pos, offset); 1788 } 1789 1790 end_coredump: 1791 set_fs(fs); 1792 1793 cleanup: 1794 while (!list_empty(&thread_list)) { 1795 struct list_head *tmp = thread_list.next; 1796 list_del(tmp); 1797 kfree(list_entry(tmp, struct elf_thread_status, list)); 1798 } 1799 kfree(phdr4note); 1800 kfree(elf); 1801 kfree(prstatus); 1802 kfree(psinfo); 1803 kfree(notes); 1804 kfree(fpu); 1805 kfree(shdr4extnum); 1806 #ifdef ELF_CORE_COPY_XFPREGS 1807 kfree(xfpu); 1808 #endif 1809 return has_dumped; 1810 #undef NUM_NOTES 1811 } 1812 1813 #endif /* CONFIG_ELF_CORE */ 1814