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 #include <linux/regset.h> 39 40 #include <linux/uaccess.h> 41 #include <asm/param.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 .min_coredump = ELF_EXEC_PAGESIZE, 87 #endif 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 (!can_mmap_file(file)) 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 elf_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 /* elf ABI allows only one interpreter */ 235 if (interpreter_name) 236 continue; 237 238 retval = -ENOMEM; 239 if (phdr->p_filesz > PATH_MAX) 240 goto error; 241 retval = -ENOENT; 242 if (phdr->p_filesz < 2) 243 goto error; 244 245 /* read the name of the interpreter into memory */ 246 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 247 if (!interpreter_name) 248 goto error; 249 250 pos = phdr->p_offset; 251 retval = kernel_read(bprm->file, interpreter_name, 252 phdr->p_filesz, &pos); 253 if (unlikely(retval != phdr->p_filesz)) { 254 if (retval >= 0) 255 retval = -ENOEXEC; 256 goto error; 257 } 258 259 retval = -ENOENT; 260 if (interpreter_name[phdr->p_filesz - 1] != '\0') 261 goto error; 262 263 kdebug("Using ELF interpreter %s", interpreter_name); 264 265 /* replace the program with the interpreter */ 266 interpreter = bprm_open_interpreter(bprm, 267 interpreter_name); 268 retval = PTR_ERR(interpreter); 269 if (IS_ERR(interpreter)) { 270 interpreter = NULL; 271 goto error; 272 } 273 274 /* 275 * If the binary is not readable then enforce 276 * mm->dumpable = 0 regardless of the interpreter's 277 * permissions. 278 */ 279 would_dump(bprm, interpreter); 280 281 pos = 0; 282 retval = kernel_read(interpreter, bprm->buf, 283 BINPRM_BUF_SIZE, &pos); 284 if (unlikely(retval != BINPRM_BUF_SIZE)) { 285 if (retval >= 0) 286 retval = -ENOEXEC; 287 goto error; 288 } 289 290 interp_params.hdr = *((struct elfhdr *) bprm->buf); 291 break; 292 293 case PT_LOAD: 294 #ifdef CONFIG_MMU 295 if (exec_params.load_addr == 0) 296 exec_params.load_addr = phdr->p_vaddr; 297 #endif 298 break; 299 } 300 301 } 302 303 /* No PT_INTERP to substitute for: the override does not apply. */ 304 bprm_drop_loader(bprm); 305 306 if (is_constdisp(&exec_params.hdr)) 307 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 308 309 /* perform insanity checks on the interpreter */ 310 if (interpreter_name) { 311 retval = -ELIBBAD; 312 if (!is_elf(&interp_params.hdr, interpreter)) 313 goto error; 314 315 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 316 317 /* read the interpreter's program header table */ 318 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 319 if (retval < 0) 320 goto error; 321 } 322 323 stack_size = exec_params.stack_size; 324 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 325 executable_stack = EXSTACK_ENABLE_X; 326 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 327 executable_stack = EXSTACK_DISABLE_X; 328 else 329 executable_stack = EXSTACK_DEFAULT; 330 331 if (stack_size == 0 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) { 332 stack_size = interp_params.stack_size; 333 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 334 executable_stack = EXSTACK_ENABLE_X; 335 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 336 executable_stack = EXSTACK_DISABLE_X; 337 else 338 executable_stack = EXSTACK_DEFAULT; 339 } 340 341 retval = -ENOEXEC; 342 if (stack_size == 0) 343 stack_size = 131072UL; /* same as exec.c's default commit */ 344 345 if (is_constdisp(&interp_params.hdr)) 346 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 347 348 /* flush all traces of the currently running executable */ 349 retval = begin_new_exec(bprm); 350 if (retval) 351 goto error; 352 353 /* there's now no turning back... the old userspace image is dead, 354 * defunct, deceased, etc. 355 */ 356 SET_PERSONALITY(exec_params.hdr); 357 if (elf_check_fdpic(&exec_params.hdr)) 358 current->personality |= PER_LINUX_FDPIC; 359 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 360 current->personality |= READ_IMPLIES_EXEC; 361 362 setup_new_exec(bprm); 363 364 set_binfmt(&elf_fdpic_format); 365 366 current->mm->start_code = 0; 367 current->mm->end_code = 0; 368 current->mm->start_stack = 0; 369 current->mm->start_data = 0; 370 current->mm->end_data = 0; 371 current->mm->context.exec_fdpic_loadmap = 0; 372 current->mm->context.interp_fdpic_loadmap = 0; 373 374 #ifdef CONFIG_MMU 375 elf_fdpic_arch_lay_out_mm(&exec_params, 376 &interp_params, 377 ¤t->mm->start_stack, 378 ¤t->mm->start_brk); 379 380 retval = setup_arg_pages(bprm, current->mm->start_stack, 381 executable_stack); 382 if (retval < 0) 383 goto error; 384 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 385 retval = arch_setup_additional_pages(bprm, !!interpreter_name); 386 if (retval < 0) 387 goto error; 388 #endif 389 #endif 390 391 /* load the executable and interpreter into memory */ 392 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 393 "executable"); 394 if (retval < 0) 395 goto error; 396 397 if (interpreter_name) { 398 retval = elf_fdpic_map_file(&interp_params, interpreter, 399 current->mm, "interpreter"); 400 if (retval < 0) { 401 printk(KERN_ERR "Unable to load interpreter\n"); 402 goto error; 403 } 404 405 exe_file_allow_write_access(interpreter); 406 fput(interpreter); 407 interpreter = NULL; 408 } 409 410 #ifdef CONFIG_MMU 411 if (!current->mm->start_brk) 412 current->mm->start_brk = current->mm->end_data; 413 414 current->mm->brk = current->mm->start_brk = 415 PAGE_ALIGN(current->mm->start_brk); 416 417 #else 418 /* create a stack area and zero-size brk area */ 419 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 420 if (stack_size < PAGE_SIZE * 2) 421 stack_size = PAGE_SIZE * 2; 422 423 stack_prot = PROT_READ | PROT_WRITE; 424 if (executable_stack == EXSTACK_ENABLE_X || 425 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 426 stack_prot |= PROT_EXEC; 427 428 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 429 MAP_PRIVATE | MAP_ANONYMOUS | 430 MAP_UNINITIALIZED | MAP_GROWSDOWN, 431 0); 432 433 if (IS_ERR_VALUE(current->mm->start_brk)) { 434 retval = current->mm->start_brk; 435 current->mm->start_brk = 0; 436 goto error; 437 } 438 439 current->mm->brk = current->mm->start_brk; 440 current->mm->context.end_brk = current->mm->start_brk; 441 current->mm->start_stack = current->mm->start_brk + stack_size; 442 #endif 443 444 retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params, 445 &interp_params); 446 if (retval < 0) 447 goto error; 448 449 kdebug("- start_code %lx", current->mm->start_code); 450 kdebug("- end_code %lx", current->mm->end_code); 451 kdebug("- start_data %lx", current->mm->start_data); 452 kdebug("- end_data %lx", current->mm->end_data); 453 kdebug("- start_brk %lx", current->mm->start_brk); 454 kdebug("- brk %lx", current->mm->brk); 455 kdebug("- start_stack %lx", current->mm->start_stack); 456 457 #ifdef ELF_FDPIC_PLAT_INIT 458 /* 459 * The ABI may specify that certain registers be set up in special 460 * ways (on i386 %edx is the address of a DT_FINI function, for 461 * example. This macro performs whatever initialization to 462 * the regs structure is required. 463 */ 464 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 465 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 466 dynaddr); 467 #endif 468 469 finalize_exec(bprm); 470 /* everything is now ready... get the userspace context ready to roll */ 471 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 472 start_thread(regs, entryaddr, current->mm->start_stack); 473 474 retval = 0; 475 476 error: 477 if (interpreter) { 478 exe_file_allow_write_access(interpreter); 479 fput(interpreter); 480 } 481 kfree(interpreter_name); 482 kfree(exec_params.phdrs); 483 kfree(exec_params.loadmap); 484 kfree(interp_params.phdrs); 485 kfree(interp_params.loadmap); 486 return retval; 487 } 488 489 /*****************************************************************************/ 490 491 #ifndef ELF_BASE_PLATFORM 492 /* 493 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 494 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 495 * will be copied to the user stack in the same manner as AT_PLATFORM. 496 */ 497 #define ELF_BASE_PLATFORM NULL 498 #endif 499 500 /* 501 * present useful information to the program by shovelling it onto the new 502 * process's stack 503 */ 504 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 505 struct mm_struct *mm, 506 struct elf_fdpic_params *exec_params, 507 struct elf_fdpic_params *interp_params) 508 { 509 const struct cred *cred = current_cred(); 510 unsigned long sp, csp, nitems; 511 elf_caddr_t __user *argv, *envp; 512 size_t platform_len = 0, len; 513 char *k_platform, *k_base_platform; 514 char __user *u_platform, *u_base_platform, *p; 515 int loop; 516 int ei_index; 517 elf_addr_t *elf_info; 518 519 #ifdef CONFIG_MMU 520 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 521 * by the processes running on the same package. One thing we can do is 522 * to shuffle the initial stack for them, so we give the architecture 523 * an opportunity to do so here. 524 */ 525 sp = arch_align_stack(bprm->p); 526 #else 527 sp = mm->start_stack; 528 529 /* stack the program arguments and environment */ 530 if (transfer_args_to_stack(bprm, &sp) < 0) 531 return -EFAULT; 532 sp &= ~15; 533 #endif 534 535 /* 536 * If this architecture has a platform capability string, copy it 537 * to userspace. In some cases (Sparc), this info is impossible 538 * for userspace to get any other way, in others (i386) it is 539 * merely difficult. 540 */ 541 k_platform = ELF_PLATFORM; 542 u_platform = NULL; 543 544 if (k_platform) { 545 platform_len = strlen(k_platform) + 1; 546 sp -= platform_len; 547 u_platform = (char __user *) sp; 548 if (copy_to_user(u_platform, k_platform, platform_len) != 0) 549 return -EFAULT; 550 } 551 552 /* 553 * If this architecture has a "base" platform capability 554 * string, copy it to userspace. 555 */ 556 k_base_platform = ELF_BASE_PLATFORM; 557 u_base_platform = NULL; 558 559 if (k_base_platform) { 560 platform_len = strlen(k_base_platform) + 1; 561 sp -= platform_len; 562 u_base_platform = (char __user *) sp; 563 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 564 return -EFAULT; 565 } 566 567 sp &= ~7UL; 568 569 /* stack the load map(s) */ 570 len = sizeof(struct elf_fdpic_loadmap); 571 len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs; 572 sp = (sp - len) & ~7UL; 573 exec_params->map_addr = sp; 574 575 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 576 return -EFAULT; 577 578 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 579 580 if (interp_params->loadmap) { 581 len = sizeof(struct elf_fdpic_loadmap); 582 len += sizeof(struct elf_fdpic_loadseg) * 583 interp_params->loadmap->nsegs; 584 sp = (sp - len) & ~7UL; 585 interp_params->map_addr = sp; 586 587 if (copy_to_user((void __user *) sp, interp_params->loadmap, 588 len) != 0) 589 return -EFAULT; 590 591 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 592 } 593 594 /* force 16 byte _final_ alignment here for generality */ 595 #define DLINFO_ITEMS 15 596 597 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 598 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 599 600 if (bprm->have_execfd) 601 nitems++; 602 #ifdef ELF_HWCAP2 603 nitems++; 604 #endif 605 #ifdef ELF_HWCAP3 606 nitems++; 607 #endif 608 #ifdef ELF_HWCAP4 609 nitems++; 610 #endif 611 612 csp = sp; 613 sp -= nitems * 2 * sizeof(unsigned long); 614 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 615 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 616 sp -= 1 * sizeof(unsigned long); /* argc */ 617 618 csp -= sp & 15UL; 619 sp -= sp & 15UL; 620 621 /* Create the ELF interpreter info */ 622 elf_info = (elf_addr_t *)mm->saved_auxv; 623 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ 624 #define NEW_AUX_ENT(id, val) \ 625 do { \ 626 *elf_info++ = id; \ 627 *elf_info++ = val; \ 628 } while (0) 629 630 #ifdef ARCH_DLINFO 631 /* 632 * ARCH_DLINFO must come first so PPC can do its special alignment of 633 * AUXV. 634 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in 635 * ARCH_DLINFO changes 636 */ 637 ARCH_DLINFO; 638 #endif 639 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 640 #ifdef ELF_HWCAP2 641 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 642 #endif 643 #ifdef ELF_HWCAP3 644 NEW_AUX_ENT(AT_HWCAP3, ELF_HWCAP3); 645 #endif 646 #ifdef ELF_HWCAP4 647 NEW_AUX_ENT(AT_HWCAP4, ELF_HWCAP4); 648 #endif 649 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 650 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 651 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 652 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 653 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 654 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 655 NEW_AUX_ENT(AT_FLAGS, bprm_at_flags(bprm)); 656 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 657 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 658 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 659 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 660 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 661 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 662 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 663 if (k_platform) 664 NEW_AUX_ENT(AT_PLATFORM, 665 (elf_addr_t)(unsigned long)u_platform); 666 if (k_base_platform) 667 NEW_AUX_ENT(AT_BASE_PLATFORM, 668 (elf_addr_t)(unsigned long)u_base_platform); 669 if (bprm->have_execfd) 670 NEW_AUX_ENT(AT_EXECFD, bprm->execfd); 671 #undef NEW_AUX_ENT 672 /* AT_NULL is zero; clear the rest too */ 673 memset(elf_info, 0, (char *)mm->saved_auxv + 674 sizeof(mm->saved_auxv) - (char *)elf_info); 675 676 /* And advance past the AT_NULL entry. */ 677 elf_info += 2; 678 679 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv; 680 csp -= ei_index * sizeof(elf_addr_t); 681 682 /* Put the elf_info on the stack in the right place. */ 683 if (copy_to_user((void __user *)csp, mm->saved_auxv, 684 ei_index * sizeof(elf_addr_t))) 685 return -EFAULT; 686 687 /* allocate room for argv[] and envv[] */ 688 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 689 envp = (elf_caddr_t __user *) csp; 690 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 691 argv = (elf_caddr_t __user *) csp; 692 693 /* stack argc */ 694 csp -= sizeof(unsigned long); 695 if (put_user(bprm->argc, (unsigned long __user *) csp)) 696 return -EFAULT; 697 698 BUG_ON(csp != sp); 699 700 /* fill in the argv[] array */ 701 #ifdef CONFIG_MMU 702 current->mm->arg_start = bprm->p; 703 #else 704 current->mm->arg_start = current->mm->start_stack - 705 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 706 #endif 707 708 p = (char __user *) current->mm->arg_start; 709 for (loop = bprm->argc; loop > 0; loop--) { 710 if (put_user((elf_caddr_t) p, argv++)) 711 return -EFAULT; 712 len = strnlen_user(p, MAX_ARG_STRLEN); 713 if (!len || len > MAX_ARG_STRLEN) 714 return -EINVAL; 715 p += len; 716 } 717 if (put_user(NULL, argv)) 718 return -EFAULT; 719 current->mm->arg_end = (unsigned long) p; 720 721 /* fill in the envv[] array */ 722 current->mm->env_start = (unsigned long) p; 723 for (loop = bprm->envc; loop > 0; loop--) { 724 if (put_user((elf_caddr_t)(unsigned long) p, envp++)) 725 return -EFAULT; 726 len = strnlen_user(p, MAX_ARG_STRLEN); 727 if (!len || len > MAX_ARG_STRLEN) 728 return -EINVAL; 729 p += len; 730 } 731 if (put_user(NULL, envp)) 732 return -EFAULT; 733 current->mm->env_end = (unsigned long) p; 734 735 mm->start_stack = (unsigned long) sp; 736 return 0; 737 } 738 739 /*****************************************************************************/ 740 /* 741 * load the appropriate binary image (executable or interpreter) into memory 742 * - we assume no MMU is available 743 * - if no other PIC bits are set in params->hdr->e_flags 744 * - we assume that the LOADable segments in the binary are independently relocatable 745 * - we assume R/O executable segments are shareable 746 * - else 747 * - we assume the loadable parts of the image to require fixed displacement 748 * - the image is not shareable 749 */ 750 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 751 struct file *file, 752 struct mm_struct *mm, 753 const char *what) 754 { 755 struct elf_fdpic_loadmap *loadmap; 756 #ifdef CONFIG_MMU 757 struct elf_fdpic_loadseg *mseg; 758 unsigned long load_addr; 759 #endif 760 struct elf_fdpic_loadseg *seg; 761 struct elf_phdr *phdr; 762 unsigned nloads, tmp; 763 unsigned long stop; 764 int loop, ret; 765 766 /* allocate a load map table */ 767 nloads = 0; 768 for (loop = 0; loop < params->hdr.e_phnum; loop++) 769 if (params->phdrs[loop].p_type == PT_LOAD) 770 nloads++; 771 772 if (nloads == 0) 773 return -ELIBBAD; 774 775 loadmap = kzalloc_flex(*loadmap, segs, nloads); 776 if (!loadmap) 777 return -ENOMEM; 778 779 params->loadmap = loadmap; 780 781 loadmap->version = ELF_FDPIC_LOADMAP_VERSION; 782 loadmap->nsegs = nloads; 783 784 /* map the requested LOADs into the memory space */ 785 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 786 case ELF_FDPIC_FLAG_CONSTDISP: 787 case ELF_FDPIC_FLAG_CONTIGUOUS: 788 #ifndef CONFIG_MMU 789 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 790 if (ret < 0) 791 return ret; 792 break; 793 #endif 794 default: 795 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 796 if (ret < 0) 797 return ret; 798 break; 799 } 800 801 /* map the entry point */ 802 if (params->hdr.e_entry) { 803 seg = loadmap->segs; 804 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 805 if (params->hdr.e_entry >= seg->p_vaddr && 806 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 807 params->entry_addr = 808 (params->hdr.e_entry - seg->p_vaddr) + 809 seg->addr; 810 break; 811 } 812 } 813 } 814 815 /* determine where the program header table has wound up if mapped */ 816 stop = params->hdr.e_phoff; 817 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 818 phdr = params->phdrs; 819 820 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 821 if (phdr->p_type != PT_LOAD) 822 continue; 823 824 if (phdr->p_offset > params->hdr.e_phoff || 825 phdr->p_offset + phdr->p_filesz < stop) 826 continue; 827 828 seg = loadmap->segs; 829 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 830 if (phdr->p_vaddr >= seg->p_vaddr && 831 phdr->p_vaddr + phdr->p_filesz <= 832 seg->p_vaddr + seg->p_memsz) { 833 params->ph_addr = 834 (phdr->p_vaddr - seg->p_vaddr) + 835 seg->addr + 836 params->hdr.e_phoff - phdr->p_offset; 837 break; 838 } 839 } 840 break; 841 } 842 843 /* determine where the dynamic section has wound up if there is one */ 844 phdr = params->phdrs; 845 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 846 if (phdr->p_type != PT_DYNAMIC) 847 continue; 848 849 seg = loadmap->segs; 850 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 851 if (phdr->p_vaddr >= seg->p_vaddr && 852 phdr->p_vaddr + phdr->p_memsz <= 853 seg->p_vaddr + seg->p_memsz) { 854 Elf_Dyn __user *dyn; 855 Elf_Sword d_tag; 856 857 params->dynamic_addr = 858 (phdr->p_vaddr - seg->p_vaddr) + 859 seg->addr; 860 861 /* check the dynamic section contains at least 862 * one item, and that the last item is a NULL 863 * entry */ 864 if (phdr->p_memsz == 0 || 865 phdr->p_memsz % sizeof(Elf_Dyn) != 0) 866 goto dynamic_error; 867 868 tmp = phdr->p_memsz / sizeof(Elf_Dyn); 869 dyn = (Elf_Dyn __user *)params->dynamic_addr; 870 if (get_user(d_tag, &dyn[tmp - 1].d_tag) || 871 d_tag != 0) 872 goto dynamic_error; 873 break; 874 } 875 } 876 break; 877 } 878 879 /* now elide adjacent segments in the load map on MMU linux 880 * - on uClinux the holes between may actually be filled with system 881 * stuff or stuff from other processes 882 */ 883 #ifdef CONFIG_MMU 884 nloads = loadmap->nsegs; 885 mseg = loadmap->segs; 886 seg = mseg + 1; 887 for (loop = 1; loop < nloads; loop++) { 888 /* see if we have a candidate for merging */ 889 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 890 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 891 if (load_addr == (seg->addr & PAGE_MASK)) { 892 mseg->p_memsz += 893 load_addr - 894 (mseg->addr + mseg->p_memsz); 895 mseg->p_memsz += seg->addr & ~PAGE_MASK; 896 mseg->p_memsz += seg->p_memsz; 897 loadmap->nsegs--; 898 continue; 899 } 900 } 901 902 mseg++; 903 if (mseg != seg) 904 *mseg = *seg; 905 } 906 #endif 907 908 kdebug("Mapped Object [%s]:", what); 909 kdebug("- elfhdr : %lx", params->elfhdr_addr); 910 kdebug("- entry : %lx", params->entry_addr); 911 kdebug("- PHDR[] : %lx", params->ph_addr); 912 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 913 seg = loadmap->segs; 914 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 915 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]", 916 loop, 917 (unsigned long long) seg->addr, 918 (unsigned long long) seg->addr + seg->p_memsz - 1, 919 (unsigned long long) seg->p_vaddr, 920 (unsigned long long) seg->p_memsz); 921 922 return 0; 923 924 dynamic_error: 925 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%llu)\n", 926 what, file_inode(file)->i_ino); 927 return -ELIBBAD; 928 } 929 930 /*****************************************************************************/ 931 /* 932 * map a file with constant displacement under uClinux 933 */ 934 #ifndef CONFIG_MMU 935 static int elf_fdpic_map_file_constdisp_on_uclinux( 936 struct elf_fdpic_params *params, 937 struct file *file, 938 struct mm_struct *mm) 939 { 940 struct elf_fdpic_loadseg *seg; 941 struct elf_phdr *phdr; 942 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0; 943 int loop, ret; 944 945 load_addr = params->load_addr; 946 seg = params->loadmap->segs; 947 948 /* determine the bounds of the contiguous overall allocation we must 949 * make */ 950 phdr = params->phdrs; 951 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 952 if (params->phdrs[loop].p_type != PT_LOAD) 953 continue; 954 955 if (base > phdr->p_vaddr) 956 base = phdr->p_vaddr; 957 if (top < phdr->p_vaddr + phdr->p_memsz) 958 top = phdr->p_vaddr + phdr->p_memsz; 959 } 960 961 /* allocate one big anon block for everything */ 962 maddr = vm_mmap(NULL, load_addr, top - base, 963 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0); 964 if (IS_ERR_VALUE(maddr)) 965 return (int) maddr; 966 967 if (load_addr != 0) 968 load_addr += PAGE_ALIGN(top - base); 969 970 /* and then load the file segments into it */ 971 phdr = params->phdrs; 972 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 973 if (params->phdrs[loop].p_type != PT_LOAD) 974 continue; 975 976 seg->addr = maddr + (phdr->p_vaddr - base); 977 seg->p_vaddr = phdr->p_vaddr; 978 seg->p_memsz = phdr->p_memsz; 979 980 ret = read_code(file, seg->addr, phdr->p_offset, 981 phdr->p_filesz); 982 if (ret < 0) 983 return ret; 984 985 /* map the ELF header address if in this segment */ 986 if (phdr->p_offset == 0) 987 params->elfhdr_addr = seg->addr; 988 989 /* clear any space allocated but not loaded */ 990 if (phdr->p_filesz < phdr->p_memsz) { 991 if (clear_user((void *) (seg->addr + phdr->p_filesz), 992 phdr->p_memsz - phdr->p_filesz)) 993 return -EFAULT; 994 } 995 996 if (mm) { 997 if (phdr->p_flags & PF_X) { 998 if (!mm->start_code) { 999 mm->start_code = seg->addr; 1000 mm->end_code = seg->addr + 1001 phdr->p_memsz; 1002 } 1003 } else if (!mm->start_data) { 1004 mm->start_data = seg->addr; 1005 mm->end_data = seg->addr + phdr->p_memsz; 1006 } 1007 } 1008 1009 seg++; 1010 } 1011 1012 return 0; 1013 } 1014 #endif 1015 1016 /*****************************************************************************/ 1017 /* 1018 * map a binary by direct mmap() of the individual PT_LOAD segments 1019 */ 1020 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1021 struct file *file, 1022 struct mm_struct *mm) 1023 { 1024 struct elf_fdpic_loadseg *seg; 1025 struct elf_phdr *phdr; 1026 unsigned long load_addr, delta_vaddr; 1027 int loop, dvset; 1028 1029 load_addr = params->load_addr; 1030 delta_vaddr = 0; 1031 dvset = 0; 1032 1033 seg = params->loadmap->segs; 1034 1035 /* deal with each load segment separately */ 1036 phdr = params->phdrs; 1037 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1038 unsigned long maddr, disp, excess; 1039 int prot = 0, flags; 1040 1041 if (phdr->p_type != PT_LOAD) 1042 continue; 1043 1044 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1045 (unsigned long) phdr->p_vaddr, 1046 (unsigned long) phdr->p_offset, 1047 (unsigned long) phdr->p_filesz, 1048 (unsigned long) phdr->p_memsz); 1049 1050 /* determine the mapping parameters */ 1051 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1052 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1053 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1054 1055 flags = MAP_PRIVATE; 1056 maddr = 0; 1057 1058 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1059 case ELF_FDPIC_FLAG_INDEPENDENT: 1060 /* PT_LOADs are independently locatable */ 1061 break; 1062 1063 case ELF_FDPIC_FLAG_HONOURVADDR: 1064 /* the specified virtual address must be honoured */ 1065 maddr = phdr->p_vaddr; 1066 flags |= MAP_FIXED; 1067 break; 1068 1069 case ELF_FDPIC_FLAG_CONSTDISP: 1070 /* constant displacement 1071 * - can be mapped anywhere, but must be mapped as a 1072 * unit 1073 */ 1074 if (!dvset) { 1075 maddr = load_addr; 1076 delta_vaddr = phdr->p_vaddr; 1077 dvset = 1; 1078 } else { 1079 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1080 flags |= MAP_FIXED; 1081 } 1082 break; 1083 1084 case ELF_FDPIC_FLAG_CONTIGUOUS: 1085 /* contiguity handled later */ 1086 break; 1087 1088 default: 1089 BUG(); 1090 } 1091 1092 maddr &= PAGE_MASK; 1093 1094 /* create the mapping */ 1095 disp = phdr->p_vaddr & ~PAGE_MASK; 1096 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1097 phdr->p_offset - disp); 1098 1099 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx", 1100 loop, (unsigned long long) phdr->p_memsz + disp, 1101 prot, flags, (unsigned long long) phdr->p_offset - disp, 1102 maddr); 1103 1104 if (IS_ERR_VALUE(maddr)) 1105 return (int) maddr; 1106 1107 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1108 ELF_FDPIC_FLAG_CONTIGUOUS) 1109 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1110 1111 seg->addr = maddr + disp; 1112 seg->p_vaddr = phdr->p_vaddr; 1113 seg->p_memsz = phdr->p_memsz; 1114 1115 /* map the ELF header address if in this segment */ 1116 if (phdr->p_offset == 0) 1117 params->elfhdr_addr = seg->addr; 1118 1119 /* clear the bit between beginning of mapping and beginning of 1120 * PT_LOAD */ 1121 if (prot & PROT_WRITE && disp > 0) { 1122 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1123 if (clear_user((void __user *) maddr, disp)) 1124 return -EFAULT; 1125 maddr += disp; 1126 } 1127 1128 /* clear any space allocated but not loaded 1129 * - on uClinux we can just clear the lot 1130 * - on MMU linux we'll get a SIGBUS beyond the last page 1131 * extant in the file 1132 */ 1133 excess = phdr->p_memsz - phdr->p_filesz; 1134 1135 #ifdef CONFIG_MMU 1136 unsigned long excess1 1137 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1138 if (excess > excess1) { 1139 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1140 unsigned long xmaddr; 1141 1142 flags |= MAP_FIXED | MAP_ANONYMOUS; 1143 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1144 prot, flags, 0); 1145 1146 kdebug("mmap[%d] <anon>" 1147 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1148 loop, xaddr, excess - excess1, prot, flags, 1149 xmaddr); 1150 1151 if (xmaddr != xaddr) 1152 return -ENOMEM; 1153 } 1154 1155 if (prot & PROT_WRITE && excess1 > 0) { 1156 kdebug("clear[%d] ad=%lx sz=%lx", 1157 loop, maddr + phdr->p_filesz, excess1); 1158 if (clear_user((void __user *) maddr + phdr->p_filesz, 1159 excess1)) 1160 return -EFAULT; 1161 } 1162 1163 #else 1164 if (excess > 0) { 1165 kdebug("clear[%d] ad=%llx sz=%lx", loop, 1166 (unsigned long long) maddr + phdr->p_filesz, 1167 excess); 1168 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1169 return -EFAULT; 1170 } 1171 #endif 1172 1173 if (mm) { 1174 if (phdr->p_flags & PF_X) { 1175 if (!mm->start_code) { 1176 mm->start_code = maddr; 1177 mm->end_code = maddr + phdr->p_memsz; 1178 } 1179 } else if (!mm->start_data) { 1180 mm->start_data = maddr; 1181 mm->end_data = maddr + phdr->p_memsz; 1182 } 1183 } 1184 1185 seg++; 1186 } 1187 1188 return 0; 1189 } 1190 1191 /*****************************************************************************/ 1192 /* 1193 * ELF-FDPIC core dumper 1194 * 1195 * Modelled on fs/exec.c:aout_core_dump() 1196 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1197 * 1198 * Modelled on fs/binfmt_elf.c core dumper 1199 */ 1200 #ifdef CONFIG_ELF_CORE 1201 1202 struct elf_prstatus_fdpic 1203 { 1204 struct elf_prstatus_common common; 1205 elf_gregset_t pr_reg; /* GP registers */ 1206 /* When using FDPIC, the loadmap addresses need to be communicated 1207 * to GDB in order for GDB to do the necessary relocations. The 1208 * fields (below) used to communicate this information are placed 1209 * immediately after ``pr_reg'', so that the loadmap addresses may 1210 * be viewed as part of the register set if so desired. 1211 */ 1212 unsigned long pr_exec_fdpic_loadmap; 1213 unsigned long pr_interp_fdpic_loadmap; 1214 int pr_fpvalid; /* True if math co-processor being used. */ 1215 }; 1216 1217 /* An ELF note in memory */ 1218 struct memelfnote 1219 { 1220 const char *name; 1221 int type; 1222 unsigned int datasz; 1223 void *data; 1224 }; 1225 1226 static int notesize(struct memelfnote *en) 1227 { 1228 int sz; 1229 1230 sz = sizeof(struct elf_note); 1231 sz += roundup(strlen(en->name) + 1, 4); 1232 sz += roundup(en->datasz, 4); 1233 1234 return sz; 1235 } 1236 1237 /* #define DEBUG */ 1238 1239 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1240 { 1241 struct elf_note en; 1242 en.n_namesz = strlen(men->name) + 1; 1243 en.n_descsz = men->datasz; 1244 en.n_type = men->type; 1245 1246 return dump_emit(cprm, &en, sizeof(en)) && 1247 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1248 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1249 } 1250 1251 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1252 { 1253 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1254 elf->e_ident[EI_CLASS] = ELF_CLASS; 1255 elf->e_ident[EI_DATA] = ELF_DATA; 1256 elf->e_ident[EI_VERSION] = EV_CURRENT; 1257 elf->e_ident[EI_OSABI] = ELF_OSABI; 1258 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1259 1260 elf->e_type = ET_CORE; 1261 elf->e_machine = ELF_ARCH; 1262 elf->e_version = EV_CURRENT; 1263 elf->e_entry = 0; 1264 elf->e_phoff = sizeof(struct elfhdr); 1265 elf->e_shoff = 0; 1266 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1267 elf->e_ehsize = sizeof(struct elfhdr); 1268 elf->e_phentsize = sizeof(struct elf_phdr); 1269 elf->e_phnum = segs; 1270 elf->e_shentsize = 0; 1271 elf->e_shnum = 0; 1272 elf->e_shstrndx = 0; 1273 return; 1274 } 1275 1276 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1277 { 1278 phdr->p_type = PT_NOTE; 1279 phdr->p_offset = offset; 1280 phdr->p_vaddr = 0; 1281 phdr->p_paddr = 0; 1282 phdr->p_filesz = sz; 1283 phdr->p_memsz = 0; 1284 phdr->p_flags = 0; 1285 phdr->p_align = 4; 1286 return; 1287 } 1288 1289 static inline void __fill_note(struct memelfnote *note, const char *name, int type, 1290 unsigned int sz, void *data) 1291 { 1292 note->name = name; 1293 note->type = type; 1294 note->datasz = sz; 1295 note->data = data; 1296 return; 1297 } 1298 1299 #define fill_note(note, type, sz, data) \ 1300 __fill_note(note, NN_ ## type, NT_ ## type, sz, data) 1301 1302 /* 1303 * fill up all the fields in prstatus from the given task struct, except 1304 * registers which need to be filled up separately. 1305 */ 1306 static void fill_prstatus(struct elf_prstatus_common *prstatus, 1307 struct task_struct *p, long signr) 1308 { 1309 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1310 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1311 prstatus->pr_sighold = p->blocked.sig[0]; 1312 rcu_read_lock(); 1313 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1314 rcu_read_unlock(); 1315 prstatus->pr_pid = task_pid_vnr(p); 1316 prstatus->pr_pgrp = task_pgrp_vnr(p); 1317 prstatus->pr_sid = task_session_vnr(p); 1318 if (thread_group_leader(p)) { 1319 struct task_cputime cputime; 1320 1321 /* 1322 * This is the record for the group leader. It shows the 1323 * group-wide total, not its individual thread total. 1324 */ 1325 thread_group_cputime(p, &cputime); 1326 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime); 1327 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime); 1328 } else { 1329 u64 utime, stime; 1330 1331 task_cputime(p, &utime, &stime); 1332 prstatus->pr_utime = ns_to_kernel_old_timeval(utime); 1333 prstatus->pr_stime = ns_to_kernel_old_timeval(stime); 1334 } 1335 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime); 1336 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime); 1337 } 1338 1339 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1340 struct mm_struct *mm) 1341 { 1342 const struct cred *cred; 1343 unsigned int i, len; 1344 unsigned int state; 1345 1346 /* first copy the parameters from user space */ 1347 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1348 1349 len = mm->arg_end - mm->arg_start; 1350 if (len >= ELF_PRARGSZ) 1351 len = ELF_PRARGSZ - 1; 1352 if (copy_from_user(&psinfo->pr_psargs, 1353 (const char __user *) mm->arg_start, len)) 1354 return -EFAULT; 1355 for (i = 0; i < len; i++) 1356 if (psinfo->pr_psargs[i] == 0) 1357 psinfo->pr_psargs[i] = ' '; 1358 psinfo->pr_psargs[len] = 0; 1359 1360 rcu_read_lock(); 1361 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1362 rcu_read_unlock(); 1363 psinfo->pr_pid = task_pid_vnr(p); 1364 psinfo->pr_pgrp = task_pgrp_vnr(p); 1365 psinfo->pr_sid = task_session_vnr(p); 1366 1367 state = READ_ONCE(p->__state); 1368 i = state ? ffz(~state) + 1 : 0; 1369 psinfo->pr_state = i; 1370 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1371 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1372 psinfo->pr_nice = task_nice(p); 1373 psinfo->pr_flag = p->flags; 1374 rcu_read_lock(); 1375 cred = __task_cred(p); 1376 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1377 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1378 rcu_read_unlock(); 1379 get_task_comm(psinfo->pr_fname, p); 1380 1381 return 0; 1382 } 1383 1384 /* Here is the structure in which status of each thread is captured. */ 1385 struct elf_thread_status 1386 { 1387 struct elf_thread_status *next; 1388 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */ 1389 elf_fpregset_t fpu; /* NT_PRFPREG */ 1390 struct memelfnote notes[2]; 1391 int num_notes; 1392 }; 1393 1394 /* 1395 * In order to add the specific thread information for the elf file format, 1396 * we need to keep a linked list of every thread's pr_status and then create 1397 * a single section for them in the final core file. 1398 */ 1399 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz) 1400 { 1401 const struct user_regset_view *view = task_user_regset_view(p); 1402 struct elf_thread_status *t; 1403 int i, ret; 1404 1405 t = kzalloc_obj(struct elf_thread_status); 1406 if (!t) 1407 return t; 1408 1409 fill_prstatus(&t->prstatus.common, p, signr); 1410 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1411 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1412 regset_get(p, &view->regsets[0], 1413 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg); 1414 1415 fill_note(&t->notes[0], PRSTATUS, sizeof(t->prstatus), &t->prstatus); 1416 t->num_notes++; 1417 *sz += notesize(&t->notes[0]); 1418 1419 for (i = 1; i < view->n; ++i) { 1420 const struct user_regset *regset = &view->regsets[i]; 1421 if (regset->core_note_type != NT_PRFPREG) 1422 continue; 1423 if (regset->active && regset->active(p, regset) <= 0) 1424 continue; 1425 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu); 1426 if (ret >= 0) 1427 t->prstatus.pr_fpvalid = 1; 1428 break; 1429 } 1430 1431 if (t->prstatus.pr_fpvalid) { 1432 fill_note(&t->notes[1], PRFPREG, sizeof(t->fpu), &t->fpu); 1433 t->num_notes++; 1434 *sz += notesize(&t->notes[1]); 1435 } 1436 return t; 1437 } 1438 1439 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1440 elf_addr_t e_shoff, int segs) 1441 { 1442 elf->e_shoff = e_shoff; 1443 elf->e_shentsize = sizeof(*shdr4extnum); 1444 elf->e_shnum = 1; 1445 elf->e_shstrndx = SHN_UNDEF; 1446 1447 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1448 1449 shdr4extnum->sh_type = SHT_NULL; 1450 shdr4extnum->sh_size = elf->e_shnum; 1451 shdr4extnum->sh_link = elf->e_shstrndx; 1452 shdr4extnum->sh_info = segs; 1453 } 1454 1455 /* 1456 * dump the segments for an MMU process 1457 */ 1458 static bool elf_fdpic_dump_segments(struct coredump_params *cprm, 1459 struct core_vma_metadata *vma_meta, 1460 int vma_count) 1461 { 1462 int i; 1463 1464 for (i = 0; i < vma_count; i++) { 1465 struct core_vma_metadata *meta = vma_meta + i; 1466 1467 if (!dump_user_range(cprm, meta->start, meta->dump_size)) 1468 return false; 1469 } 1470 return true; 1471 } 1472 1473 /* 1474 * Actual dumper 1475 * 1476 * This is a two-pass process; first we find the offsets of the bits, 1477 * and then they are actually written out. If we run out of core limit 1478 * we just truncate. 1479 */ 1480 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1481 { 1482 int has_dumped = 0; 1483 int segs; 1484 int i; 1485 struct elfhdr *elf = NULL; 1486 loff_t offset = 0, dataoff; 1487 struct memelfnote psinfo_note, auxv_note; 1488 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1489 struct elf_thread_status *thread_list = NULL; 1490 int thread_status_size = 0; 1491 elf_addr_t *auxv; 1492 struct elf_phdr *phdr4note = NULL; 1493 struct elf_shdr *shdr4extnum = NULL; 1494 Elf_Half e_phnum; 1495 elf_addr_t e_shoff; 1496 struct core_thread *ct; 1497 struct elf_thread_status *tmp; 1498 1499 /* alloc memory for large data structures: too large to be on stack */ 1500 elf = kmalloc_obj(*elf); 1501 if (!elf) 1502 goto end_coredump; 1503 psinfo = kmalloc_obj(*psinfo); 1504 if (!psinfo) 1505 goto end_coredump; 1506 1507 for (ct = current->signal->core_state->dumper.next; 1508 ct; ct = ct->next) { 1509 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1510 ct->task, &thread_status_size); 1511 if (!tmp) 1512 goto end_coredump; 1513 1514 tmp->next = thread_list; 1515 thread_list = tmp; 1516 } 1517 1518 /* now collect the dump for the current */ 1519 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1520 current, &thread_status_size); 1521 if (!tmp) 1522 goto end_coredump; 1523 tmp->next = thread_list; 1524 thread_list = tmp; 1525 1526 segs = cprm->vma_count + elf_core_extra_phdrs(cprm); 1527 1528 /* for notes section */ 1529 segs++; 1530 1531 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1532 * this, kernel supports extended numbering. Have a look at 1533 * include/linux/elf.h for further information. */ 1534 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1535 1536 /* Set up header */ 1537 fill_elf_fdpic_header(elf, e_phnum); 1538 1539 has_dumped = 1; 1540 /* 1541 * Set up the notes in similar form to SVR4 core dumps made 1542 * with info from their /proc. 1543 */ 1544 1545 fill_psinfo(psinfo, current->group_leader, current->mm); 1546 fill_note(&psinfo_note, PRPSINFO, sizeof(*psinfo), psinfo); 1547 thread_status_size += notesize(&psinfo_note); 1548 1549 auxv = (elf_addr_t *) current->mm->saved_auxv; 1550 i = 0; 1551 do 1552 i += 2; 1553 while (auxv[i - 2] != AT_NULL); 1554 fill_note(&auxv_note, AUXV, i * sizeof(elf_addr_t), auxv); 1555 thread_status_size += notesize(&auxv_note); 1556 1557 offset = sizeof(*elf); /* ELF header */ 1558 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1559 1560 /* Write notes phdr entry */ 1561 phdr4note = kmalloc_obj(*phdr4note); 1562 if (!phdr4note) 1563 goto end_coredump; 1564 1565 fill_elf_note_phdr(phdr4note, thread_status_size, offset); 1566 offset += thread_status_size; 1567 1568 /* Page-align dumped data */ 1569 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1570 1571 offset += cprm->vma_data_size; 1572 offset += elf_core_extra_data_size(cprm); 1573 e_shoff = offset; 1574 1575 if (e_phnum == PN_XNUM) { 1576 shdr4extnum = kmalloc_obj(*shdr4extnum); 1577 if (!shdr4extnum) 1578 goto end_coredump; 1579 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1580 } 1581 1582 offset = dataoff; 1583 1584 if (!dump_emit(cprm, elf, sizeof(*elf))) 1585 goto end_coredump; 1586 1587 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1588 goto end_coredump; 1589 1590 /* write program headers for segments dump */ 1591 for (i = 0; i < cprm->vma_count; i++) { 1592 struct core_vma_metadata *meta = cprm->vma_meta + i; 1593 struct elf_phdr phdr; 1594 size_t sz; 1595 1596 sz = meta->end - meta->start; 1597 1598 phdr.p_type = PT_LOAD; 1599 phdr.p_offset = offset; 1600 phdr.p_vaddr = meta->start; 1601 phdr.p_paddr = 0; 1602 phdr.p_filesz = meta->dump_size; 1603 phdr.p_memsz = sz; 1604 offset += phdr.p_filesz; 1605 phdr.p_flags = 0; 1606 if (meta->flags & VM_READ) 1607 phdr.p_flags |= PF_R; 1608 if (meta->flags & VM_WRITE) 1609 phdr.p_flags |= PF_W; 1610 if (meta->flags & VM_EXEC) 1611 phdr.p_flags |= PF_X; 1612 phdr.p_align = ELF_EXEC_PAGESIZE; 1613 1614 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1615 goto end_coredump; 1616 } 1617 1618 if (!elf_core_write_extra_phdrs(cprm, offset)) 1619 goto end_coredump; 1620 1621 /* write out the notes section */ 1622 if (!writenote(thread_list->notes, cprm)) 1623 goto end_coredump; 1624 if (!writenote(&psinfo_note, cprm)) 1625 goto end_coredump; 1626 if (!writenote(&auxv_note, cprm)) 1627 goto end_coredump; 1628 for (i = 1; i < thread_list->num_notes; i++) 1629 if (!writenote(thread_list->notes + i, cprm)) 1630 goto end_coredump; 1631 1632 /* write out the thread status notes section */ 1633 for (tmp = thread_list->next; tmp; tmp = tmp->next) { 1634 for (i = 0; i < tmp->num_notes; i++) 1635 if (!writenote(&tmp->notes[i], cprm)) 1636 goto end_coredump; 1637 } 1638 1639 dump_skip_to(cprm, dataoff); 1640 1641 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count)) 1642 goto end_coredump; 1643 1644 if (!elf_core_write_extra_data(cprm)) 1645 goto end_coredump; 1646 1647 if (e_phnum == PN_XNUM) { 1648 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1649 goto end_coredump; 1650 } 1651 1652 if (cprm->file->f_pos != offset) { 1653 /* Sanity check */ 1654 printk(KERN_WARNING 1655 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1656 cprm->file->f_pos, offset); 1657 } 1658 1659 end_coredump: 1660 while (thread_list) { 1661 tmp = thread_list; 1662 thread_list = thread_list->next; 1663 kfree(tmp); 1664 } 1665 kfree(phdr4note); 1666 kfree(elf); 1667 kfree(psinfo); 1668 kfree(shdr4extnum); 1669 return has_dumped; 1670 } 1671 1672 #endif /* CONFIG_ELF_CORE */ 1673