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