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 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 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) { 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 SET_PERSONALITY(exec_params.hdr); 349 if (elf_check_fdpic(&exec_params.hdr)) 350 current->personality |= PER_LINUX_FDPIC; 351 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 352 current->personality |= READ_IMPLIES_EXEC; 353 354 setup_new_exec(bprm); 355 356 set_binfmt(&elf_fdpic_format); 357 358 current->mm->start_code = 0; 359 current->mm->end_code = 0; 360 current->mm->start_stack = 0; 361 current->mm->start_data = 0; 362 current->mm->end_data = 0; 363 current->mm->context.exec_fdpic_loadmap = 0; 364 current->mm->context.interp_fdpic_loadmap = 0; 365 366 #ifdef CONFIG_MMU 367 elf_fdpic_arch_lay_out_mm(&exec_params, 368 &interp_params, 369 ¤t->mm->start_stack, 370 ¤t->mm->start_brk); 371 372 retval = setup_arg_pages(bprm, current->mm->start_stack, 373 executable_stack); 374 if (retval < 0) 375 goto error; 376 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 377 retval = arch_setup_additional_pages(bprm, !!interpreter_name); 378 if (retval < 0) 379 goto error; 380 #endif 381 #endif 382 383 /* load the executable and interpreter into memory */ 384 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 385 "executable"); 386 if (retval < 0) 387 goto error; 388 389 if (interpreter_name) { 390 retval = elf_fdpic_map_file(&interp_params, interpreter, 391 current->mm, "interpreter"); 392 if (retval < 0) { 393 printk(KERN_ERR "Unable to load interpreter\n"); 394 goto error; 395 } 396 397 exe_file_allow_write_access(interpreter); 398 fput(interpreter); 399 interpreter = NULL; 400 } 401 402 #ifdef CONFIG_MMU 403 if (!current->mm->start_brk) 404 current->mm->start_brk = current->mm->end_data; 405 406 current->mm->brk = current->mm->start_brk = 407 PAGE_ALIGN(current->mm->start_brk); 408 409 #else 410 /* create a stack area and zero-size brk area */ 411 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 412 if (stack_size < PAGE_SIZE * 2) 413 stack_size = PAGE_SIZE * 2; 414 415 stack_prot = PROT_READ | PROT_WRITE; 416 if (executable_stack == EXSTACK_ENABLE_X || 417 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 418 stack_prot |= PROT_EXEC; 419 420 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 421 MAP_PRIVATE | MAP_ANONYMOUS | 422 MAP_UNINITIALIZED | MAP_GROWSDOWN, 423 0); 424 425 if (IS_ERR_VALUE(current->mm->start_brk)) { 426 retval = current->mm->start_brk; 427 current->mm->start_brk = 0; 428 goto error; 429 } 430 431 current->mm->brk = current->mm->start_brk; 432 current->mm->context.end_brk = current->mm->start_brk; 433 current->mm->start_stack = current->mm->start_brk + stack_size; 434 #endif 435 436 retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params, 437 &interp_params); 438 if (retval < 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 exe_file_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 unsigned long flags = 0; 509 int ei_index; 510 elf_addr_t *elf_info; 511 512 #ifdef CONFIG_MMU 513 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 514 * by the processes running on the same package. One thing we can do is 515 * to shuffle the initial stack for them, so we give the architecture 516 * an opportunity to do so here. 517 */ 518 sp = arch_align_stack(bprm->p); 519 #else 520 sp = mm->start_stack; 521 522 /* stack the program arguments and environment */ 523 if (transfer_args_to_stack(bprm, &sp) < 0) 524 return -EFAULT; 525 sp &= ~15; 526 #endif 527 528 /* 529 * If this architecture has a platform capability string, copy it 530 * to userspace. In some cases (Sparc), this info is impossible 531 * for userspace to get any other way, in others (i386) it is 532 * merely difficult. 533 */ 534 k_platform = ELF_PLATFORM; 535 u_platform = NULL; 536 537 if (k_platform) { 538 platform_len = strlen(k_platform) + 1; 539 sp -= platform_len; 540 u_platform = (char __user *) sp; 541 if (copy_to_user(u_platform, k_platform, platform_len) != 0) 542 return -EFAULT; 543 } 544 545 /* 546 * If this architecture has a "base" platform capability 547 * string, copy it to userspace. 548 */ 549 k_base_platform = ELF_BASE_PLATFORM; 550 u_base_platform = NULL; 551 552 if (k_base_platform) { 553 platform_len = strlen(k_base_platform) + 1; 554 sp -= platform_len; 555 u_base_platform = (char __user *) sp; 556 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 557 return -EFAULT; 558 } 559 560 sp &= ~7UL; 561 562 /* stack the load map(s) */ 563 len = sizeof(struct elf_fdpic_loadmap); 564 len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs; 565 sp = (sp - len) & ~7UL; 566 exec_params->map_addr = sp; 567 568 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 569 return -EFAULT; 570 571 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 572 573 if (interp_params->loadmap) { 574 len = sizeof(struct elf_fdpic_loadmap); 575 len += sizeof(struct elf_fdpic_loadseg) * 576 interp_params->loadmap->nsegs; 577 sp = (sp - len) & ~7UL; 578 interp_params->map_addr = sp; 579 580 if (copy_to_user((void __user *) sp, interp_params->loadmap, 581 len) != 0) 582 return -EFAULT; 583 584 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 585 } 586 587 /* force 16 byte _final_ alignment here for generality */ 588 #define DLINFO_ITEMS 15 589 590 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 591 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 592 593 if (bprm->have_execfd) 594 nitems++; 595 #ifdef ELF_HWCAP2 596 nitems++; 597 #endif 598 #ifdef ELF_HWCAP3 599 nitems++; 600 #endif 601 #ifdef ELF_HWCAP4 602 nitems++; 603 #endif 604 605 csp = sp; 606 sp -= nitems * 2 * sizeof(unsigned long); 607 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 608 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 609 sp -= 1 * sizeof(unsigned long); /* argc */ 610 611 csp -= sp & 15UL; 612 sp -= sp & 15UL; 613 614 /* Create the ELF interpreter info */ 615 elf_info = (elf_addr_t *)mm->saved_auxv; 616 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ 617 #define NEW_AUX_ENT(id, val) \ 618 do { \ 619 *elf_info++ = id; \ 620 *elf_info++ = val; \ 621 } while (0) 622 623 #ifdef ARCH_DLINFO 624 /* 625 * ARCH_DLINFO must come first so PPC can do its special alignment of 626 * AUXV. 627 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in 628 * ARCH_DLINFO changes 629 */ 630 ARCH_DLINFO; 631 #endif 632 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 633 #ifdef ELF_HWCAP2 634 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 635 #endif 636 #ifdef ELF_HWCAP3 637 NEW_AUX_ENT(AT_HWCAP3, ELF_HWCAP3); 638 #endif 639 #ifdef ELF_HWCAP4 640 NEW_AUX_ENT(AT_HWCAP4, ELF_HWCAP4); 641 #endif 642 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 643 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 644 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 645 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 646 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 647 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 648 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0) 649 flags |= AT_FLAGS_PRESERVE_ARGV0; 650 NEW_AUX_ENT(AT_FLAGS, flags); 651 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 652 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 653 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 654 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 655 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 656 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 657 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 658 if (k_platform) 659 NEW_AUX_ENT(AT_PLATFORM, 660 (elf_addr_t)(unsigned long)u_platform); 661 if (k_base_platform) 662 NEW_AUX_ENT(AT_BASE_PLATFORM, 663 (elf_addr_t)(unsigned long)u_base_platform); 664 if (bprm->have_execfd) 665 NEW_AUX_ENT(AT_EXECFD, bprm->execfd); 666 #undef NEW_AUX_ENT 667 /* AT_NULL is zero; clear the rest too */ 668 memset(elf_info, 0, (char *)mm->saved_auxv + 669 sizeof(mm->saved_auxv) - (char *)elf_info); 670 671 /* And advance past the AT_NULL entry. */ 672 elf_info += 2; 673 674 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv; 675 csp -= ei_index * sizeof(elf_addr_t); 676 677 /* Put the elf_info on the stack in the right place. */ 678 if (copy_to_user((void __user *)csp, mm->saved_auxv, 679 ei_index * sizeof(elf_addr_t))) 680 return -EFAULT; 681 682 /* allocate room for argv[] and envv[] */ 683 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 684 envp = (elf_caddr_t __user *) csp; 685 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 686 argv = (elf_caddr_t __user *) csp; 687 688 /* stack argc */ 689 csp -= sizeof(unsigned long); 690 if (put_user(bprm->argc, (unsigned long __user *) csp)) 691 return -EFAULT; 692 693 BUG_ON(csp != sp); 694 695 /* fill in the argv[] array */ 696 #ifdef CONFIG_MMU 697 current->mm->arg_start = bprm->p; 698 #else 699 current->mm->arg_start = current->mm->start_stack - 700 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 701 #endif 702 703 p = (char __user *) current->mm->arg_start; 704 for (loop = bprm->argc; loop > 0; loop--) { 705 if (put_user((elf_caddr_t) p, argv++)) 706 return -EFAULT; 707 len = strnlen_user(p, MAX_ARG_STRLEN); 708 if (!len || len > MAX_ARG_STRLEN) 709 return -EINVAL; 710 p += len; 711 } 712 if (put_user(NULL, argv)) 713 return -EFAULT; 714 current->mm->arg_end = (unsigned long) p; 715 716 /* fill in the envv[] array */ 717 current->mm->env_start = (unsigned long) p; 718 for (loop = bprm->envc; loop > 0; loop--) { 719 if (put_user((elf_caddr_t)(unsigned long) p, envp++)) 720 return -EFAULT; 721 len = strnlen_user(p, MAX_ARG_STRLEN); 722 if (!len || len > MAX_ARG_STRLEN) 723 return -EINVAL; 724 p += len; 725 } 726 if (put_user(NULL, envp)) 727 return -EFAULT; 728 current->mm->env_end = (unsigned long) p; 729 730 mm->start_stack = (unsigned long) sp; 731 return 0; 732 } 733 734 /*****************************************************************************/ 735 /* 736 * load the appropriate binary image (executable or interpreter) into memory 737 * - we assume no MMU is available 738 * - if no other PIC bits are set in params->hdr->e_flags 739 * - we assume that the LOADable segments in the binary are independently relocatable 740 * - we assume R/O executable segments are shareable 741 * - else 742 * - we assume the loadable parts of the image to require fixed displacement 743 * - the image is not shareable 744 */ 745 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 746 struct file *file, 747 struct mm_struct *mm, 748 const char *what) 749 { 750 struct elf_fdpic_loadmap *loadmap; 751 #ifdef CONFIG_MMU 752 struct elf_fdpic_loadseg *mseg; 753 unsigned long load_addr; 754 #endif 755 struct elf_fdpic_loadseg *seg; 756 struct elf_phdr *phdr; 757 unsigned nloads, tmp; 758 unsigned long stop; 759 int loop, ret; 760 761 /* allocate a load map table */ 762 nloads = 0; 763 for (loop = 0; loop < params->hdr.e_phnum; loop++) 764 if (params->phdrs[loop].p_type == PT_LOAD) 765 nloads++; 766 767 if (nloads == 0) 768 return -ELIBBAD; 769 770 loadmap = kzalloc_flex(*loadmap, segs, nloads); 771 if (!loadmap) 772 return -ENOMEM; 773 774 params->loadmap = loadmap; 775 776 loadmap->version = ELF_FDPIC_LOADMAP_VERSION; 777 loadmap->nsegs = nloads; 778 779 /* map the requested LOADs into the memory space */ 780 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 781 case ELF_FDPIC_FLAG_CONSTDISP: 782 case ELF_FDPIC_FLAG_CONTIGUOUS: 783 #ifndef CONFIG_MMU 784 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 785 if (ret < 0) 786 return ret; 787 break; 788 #endif 789 default: 790 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 791 if (ret < 0) 792 return ret; 793 break; 794 } 795 796 /* map the entry point */ 797 if (params->hdr.e_entry) { 798 seg = loadmap->segs; 799 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 800 if (params->hdr.e_entry >= seg->p_vaddr && 801 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 802 params->entry_addr = 803 (params->hdr.e_entry - seg->p_vaddr) + 804 seg->addr; 805 break; 806 } 807 } 808 } 809 810 /* determine where the program header table has wound up if mapped */ 811 stop = params->hdr.e_phoff; 812 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 813 phdr = params->phdrs; 814 815 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 816 if (phdr->p_type != PT_LOAD) 817 continue; 818 819 if (phdr->p_offset > params->hdr.e_phoff || 820 phdr->p_offset + phdr->p_filesz < stop) 821 continue; 822 823 seg = loadmap->segs; 824 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 825 if (phdr->p_vaddr >= seg->p_vaddr && 826 phdr->p_vaddr + phdr->p_filesz <= 827 seg->p_vaddr + seg->p_memsz) { 828 params->ph_addr = 829 (phdr->p_vaddr - seg->p_vaddr) + 830 seg->addr + 831 params->hdr.e_phoff - phdr->p_offset; 832 break; 833 } 834 } 835 break; 836 } 837 838 /* determine where the dynamic section has wound up if there is one */ 839 phdr = params->phdrs; 840 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 841 if (phdr->p_type != PT_DYNAMIC) 842 continue; 843 844 seg = loadmap->segs; 845 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 846 if (phdr->p_vaddr >= seg->p_vaddr && 847 phdr->p_vaddr + phdr->p_memsz <= 848 seg->p_vaddr + seg->p_memsz) { 849 Elf_Dyn __user *dyn; 850 Elf_Sword d_tag; 851 852 params->dynamic_addr = 853 (phdr->p_vaddr - seg->p_vaddr) + 854 seg->addr; 855 856 /* check the dynamic section contains at least 857 * one item, and that the last item is a NULL 858 * entry */ 859 if (phdr->p_memsz == 0 || 860 phdr->p_memsz % sizeof(Elf_Dyn) != 0) 861 goto dynamic_error; 862 863 tmp = phdr->p_memsz / sizeof(Elf_Dyn); 864 dyn = (Elf_Dyn __user *)params->dynamic_addr; 865 if (get_user(d_tag, &dyn[tmp - 1].d_tag) || 866 d_tag != 0) 867 goto dynamic_error; 868 break; 869 } 870 } 871 break; 872 } 873 874 /* now elide adjacent segments in the load map on MMU linux 875 * - on uClinux the holes between may actually be filled with system 876 * stuff or stuff from other processes 877 */ 878 #ifdef CONFIG_MMU 879 nloads = loadmap->nsegs; 880 mseg = loadmap->segs; 881 seg = mseg + 1; 882 for (loop = 1; loop < nloads; loop++) { 883 /* see if we have a candidate for merging */ 884 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 885 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 886 if (load_addr == (seg->addr & PAGE_MASK)) { 887 mseg->p_memsz += 888 load_addr - 889 (mseg->addr + mseg->p_memsz); 890 mseg->p_memsz += seg->addr & ~PAGE_MASK; 891 mseg->p_memsz += seg->p_memsz; 892 loadmap->nsegs--; 893 continue; 894 } 895 } 896 897 mseg++; 898 if (mseg != seg) 899 *mseg = *seg; 900 } 901 #endif 902 903 kdebug("Mapped Object [%s]:", what); 904 kdebug("- elfhdr : %lx", params->elfhdr_addr); 905 kdebug("- entry : %lx", params->entry_addr); 906 kdebug("- PHDR[] : %lx", params->ph_addr); 907 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 908 seg = loadmap->segs; 909 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 910 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]", 911 loop, 912 (unsigned long long) seg->addr, 913 (unsigned long long) seg->addr + seg->p_memsz - 1, 914 (unsigned long long) seg->p_vaddr, 915 (unsigned long long) seg->p_memsz); 916 917 return 0; 918 919 dynamic_error: 920 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%llu)\n", 921 what, file_inode(file)->i_ino); 922 return -ELIBBAD; 923 } 924 925 /*****************************************************************************/ 926 /* 927 * map a file with constant displacement under uClinux 928 */ 929 #ifndef CONFIG_MMU 930 static int elf_fdpic_map_file_constdisp_on_uclinux( 931 struct elf_fdpic_params *params, 932 struct file *file, 933 struct mm_struct *mm) 934 { 935 struct elf_fdpic_loadseg *seg; 936 struct elf_phdr *phdr; 937 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0; 938 int loop, ret; 939 940 load_addr = params->load_addr; 941 seg = params->loadmap->segs; 942 943 /* determine the bounds of the contiguous overall allocation we must 944 * make */ 945 phdr = params->phdrs; 946 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 947 if (params->phdrs[loop].p_type != PT_LOAD) 948 continue; 949 950 if (base > phdr->p_vaddr) 951 base = phdr->p_vaddr; 952 if (top < phdr->p_vaddr + phdr->p_memsz) 953 top = phdr->p_vaddr + phdr->p_memsz; 954 } 955 956 /* allocate one big anon block for everything */ 957 maddr = vm_mmap(NULL, load_addr, top - base, 958 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0); 959 if (IS_ERR_VALUE(maddr)) 960 return (int) maddr; 961 962 if (load_addr != 0) 963 load_addr += PAGE_ALIGN(top - base); 964 965 /* and then load the file segments into it */ 966 phdr = params->phdrs; 967 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 968 if (params->phdrs[loop].p_type != PT_LOAD) 969 continue; 970 971 seg->addr = maddr + (phdr->p_vaddr - base); 972 seg->p_vaddr = phdr->p_vaddr; 973 seg->p_memsz = phdr->p_memsz; 974 975 ret = read_code(file, seg->addr, phdr->p_offset, 976 phdr->p_filesz); 977 if (ret < 0) 978 return ret; 979 980 /* map the ELF header address if in this segment */ 981 if (phdr->p_offset == 0) 982 params->elfhdr_addr = seg->addr; 983 984 /* clear any space allocated but not loaded */ 985 if (phdr->p_filesz < phdr->p_memsz) { 986 if (clear_user((void *) (seg->addr + phdr->p_filesz), 987 phdr->p_memsz - phdr->p_filesz)) 988 return -EFAULT; 989 } 990 991 if (mm) { 992 if (phdr->p_flags & PF_X) { 993 if (!mm->start_code) { 994 mm->start_code = seg->addr; 995 mm->end_code = seg->addr + 996 phdr->p_memsz; 997 } 998 } else if (!mm->start_data) { 999 mm->start_data = seg->addr; 1000 mm->end_data = seg->addr + phdr->p_memsz; 1001 } 1002 } 1003 1004 seg++; 1005 } 1006 1007 return 0; 1008 } 1009 #endif 1010 1011 /*****************************************************************************/ 1012 /* 1013 * map a binary by direct mmap() of the individual PT_LOAD segments 1014 */ 1015 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1016 struct file *file, 1017 struct mm_struct *mm) 1018 { 1019 struct elf_fdpic_loadseg *seg; 1020 struct elf_phdr *phdr; 1021 unsigned long load_addr, delta_vaddr; 1022 int loop, dvset; 1023 1024 load_addr = params->load_addr; 1025 delta_vaddr = 0; 1026 dvset = 0; 1027 1028 seg = params->loadmap->segs; 1029 1030 /* deal with each load segment separately */ 1031 phdr = params->phdrs; 1032 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1033 unsigned long maddr, disp, excess; 1034 int prot = 0, flags; 1035 1036 if (phdr->p_type != PT_LOAD) 1037 continue; 1038 1039 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1040 (unsigned long) phdr->p_vaddr, 1041 (unsigned long) phdr->p_offset, 1042 (unsigned long) phdr->p_filesz, 1043 (unsigned long) phdr->p_memsz); 1044 1045 /* determine the mapping parameters */ 1046 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1047 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1048 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1049 1050 flags = MAP_PRIVATE; 1051 maddr = 0; 1052 1053 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1054 case ELF_FDPIC_FLAG_INDEPENDENT: 1055 /* PT_LOADs are independently locatable */ 1056 break; 1057 1058 case ELF_FDPIC_FLAG_HONOURVADDR: 1059 /* the specified virtual address must be honoured */ 1060 maddr = phdr->p_vaddr; 1061 flags |= MAP_FIXED; 1062 break; 1063 1064 case ELF_FDPIC_FLAG_CONSTDISP: 1065 /* constant displacement 1066 * - can be mapped anywhere, but must be mapped as a 1067 * unit 1068 */ 1069 if (!dvset) { 1070 maddr = load_addr; 1071 delta_vaddr = phdr->p_vaddr; 1072 dvset = 1; 1073 } else { 1074 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1075 flags |= MAP_FIXED; 1076 } 1077 break; 1078 1079 case ELF_FDPIC_FLAG_CONTIGUOUS: 1080 /* contiguity handled later */ 1081 break; 1082 1083 default: 1084 BUG(); 1085 } 1086 1087 maddr &= PAGE_MASK; 1088 1089 /* create the mapping */ 1090 disp = phdr->p_vaddr & ~PAGE_MASK; 1091 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1092 phdr->p_offset - disp); 1093 1094 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx", 1095 loop, (unsigned long long) phdr->p_memsz + disp, 1096 prot, flags, (unsigned long long) phdr->p_offset - disp, 1097 maddr); 1098 1099 if (IS_ERR_VALUE(maddr)) 1100 return (int) maddr; 1101 1102 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1103 ELF_FDPIC_FLAG_CONTIGUOUS) 1104 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1105 1106 seg->addr = maddr + disp; 1107 seg->p_vaddr = phdr->p_vaddr; 1108 seg->p_memsz = phdr->p_memsz; 1109 1110 /* map the ELF header address if in this segment */ 1111 if (phdr->p_offset == 0) 1112 params->elfhdr_addr = seg->addr; 1113 1114 /* clear the bit between beginning of mapping and beginning of 1115 * PT_LOAD */ 1116 if (prot & PROT_WRITE && disp > 0) { 1117 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1118 if (clear_user((void __user *) maddr, disp)) 1119 return -EFAULT; 1120 maddr += disp; 1121 } 1122 1123 /* clear any space allocated but not loaded 1124 * - on uClinux we can just clear the lot 1125 * - on MMU linux we'll get a SIGBUS beyond the last page 1126 * extant in the file 1127 */ 1128 excess = phdr->p_memsz - phdr->p_filesz; 1129 1130 #ifdef CONFIG_MMU 1131 unsigned long excess1 1132 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1133 if (excess > excess1) { 1134 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1135 unsigned long xmaddr; 1136 1137 flags |= MAP_FIXED | MAP_ANONYMOUS; 1138 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1139 prot, flags, 0); 1140 1141 kdebug("mmap[%d] <anon>" 1142 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1143 loop, xaddr, excess - excess1, prot, flags, 1144 xmaddr); 1145 1146 if (xmaddr != xaddr) 1147 return -ENOMEM; 1148 } 1149 1150 if (prot & PROT_WRITE && excess1 > 0) { 1151 kdebug("clear[%d] ad=%lx sz=%lx", 1152 loop, maddr + phdr->p_filesz, excess1); 1153 if (clear_user((void __user *) maddr + phdr->p_filesz, 1154 excess1)) 1155 return -EFAULT; 1156 } 1157 1158 #else 1159 if (excess > 0) { 1160 kdebug("clear[%d] ad=%llx sz=%lx", loop, 1161 (unsigned long long) maddr + phdr->p_filesz, 1162 excess); 1163 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1164 return -EFAULT; 1165 } 1166 #endif 1167 1168 if (mm) { 1169 if (phdr->p_flags & PF_X) { 1170 if (!mm->start_code) { 1171 mm->start_code = maddr; 1172 mm->end_code = maddr + phdr->p_memsz; 1173 } 1174 } else if (!mm->start_data) { 1175 mm->start_data = maddr; 1176 mm->end_data = maddr + phdr->p_memsz; 1177 } 1178 } 1179 1180 seg++; 1181 } 1182 1183 return 0; 1184 } 1185 1186 /*****************************************************************************/ 1187 /* 1188 * ELF-FDPIC core dumper 1189 * 1190 * Modelled on fs/exec.c:aout_core_dump() 1191 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1192 * 1193 * Modelled on fs/binfmt_elf.c core dumper 1194 */ 1195 #ifdef CONFIG_ELF_CORE 1196 1197 struct elf_prstatus_fdpic 1198 { 1199 struct elf_prstatus_common common; 1200 elf_gregset_t pr_reg; /* GP registers */ 1201 /* When using FDPIC, the loadmap addresses need to be communicated 1202 * to GDB in order for GDB to do the necessary relocations. The 1203 * fields (below) used to communicate this information are placed 1204 * immediately after ``pr_reg'', so that the loadmap addresses may 1205 * be viewed as part of the register set if so desired. 1206 */ 1207 unsigned long pr_exec_fdpic_loadmap; 1208 unsigned long pr_interp_fdpic_loadmap; 1209 int pr_fpvalid; /* True if math co-processor being used. */ 1210 }; 1211 1212 /* An ELF note in memory */ 1213 struct memelfnote 1214 { 1215 const char *name; 1216 int type; 1217 unsigned int datasz; 1218 void *data; 1219 }; 1220 1221 static int notesize(struct memelfnote *en) 1222 { 1223 int sz; 1224 1225 sz = sizeof(struct elf_note); 1226 sz += roundup(strlen(en->name) + 1, 4); 1227 sz += roundup(en->datasz, 4); 1228 1229 return sz; 1230 } 1231 1232 /* #define DEBUG */ 1233 1234 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1235 { 1236 struct elf_note en; 1237 en.n_namesz = strlen(men->name) + 1; 1238 en.n_descsz = men->datasz; 1239 en.n_type = men->type; 1240 1241 return dump_emit(cprm, &en, sizeof(en)) && 1242 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1243 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1244 } 1245 1246 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1247 { 1248 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1249 elf->e_ident[EI_CLASS] = ELF_CLASS; 1250 elf->e_ident[EI_DATA] = ELF_DATA; 1251 elf->e_ident[EI_VERSION] = EV_CURRENT; 1252 elf->e_ident[EI_OSABI] = ELF_OSABI; 1253 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1254 1255 elf->e_type = ET_CORE; 1256 elf->e_machine = ELF_ARCH; 1257 elf->e_version = EV_CURRENT; 1258 elf->e_entry = 0; 1259 elf->e_phoff = sizeof(struct elfhdr); 1260 elf->e_shoff = 0; 1261 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1262 elf->e_ehsize = sizeof(struct elfhdr); 1263 elf->e_phentsize = sizeof(struct elf_phdr); 1264 elf->e_phnum = segs; 1265 elf->e_shentsize = 0; 1266 elf->e_shnum = 0; 1267 elf->e_shstrndx = 0; 1268 return; 1269 } 1270 1271 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1272 { 1273 phdr->p_type = PT_NOTE; 1274 phdr->p_offset = offset; 1275 phdr->p_vaddr = 0; 1276 phdr->p_paddr = 0; 1277 phdr->p_filesz = sz; 1278 phdr->p_memsz = 0; 1279 phdr->p_flags = 0; 1280 phdr->p_align = 4; 1281 return; 1282 } 1283 1284 static inline void __fill_note(struct memelfnote *note, const char *name, int type, 1285 unsigned int sz, void *data) 1286 { 1287 note->name = name; 1288 note->type = type; 1289 note->datasz = sz; 1290 note->data = data; 1291 return; 1292 } 1293 1294 #define fill_note(note, type, sz, data) \ 1295 __fill_note(note, NN_ ## type, NT_ ## type, sz, data) 1296 1297 /* 1298 * fill up all the fields in prstatus from the given task struct, except 1299 * registers which need to be filled up separately. 1300 */ 1301 static void fill_prstatus(struct elf_prstatus_common *prstatus, 1302 struct task_struct *p, long signr) 1303 { 1304 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1305 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1306 prstatus->pr_sighold = p->blocked.sig[0]; 1307 rcu_read_lock(); 1308 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1309 rcu_read_unlock(); 1310 prstatus->pr_pid = task_pid_vnr(p); 1311 prstatus->pr_pgrp = task_pgrp_vnr(p); 1312 prstatus->pr_sid = task_session_vnr(p); 1313 if (thread_group_leader(p)) { 1314 struct task_cputime cputime; 1315 1316 /* 1317 * This is the record for the group leader. It shows the 1318 * group-wide total, not its individual thread total. 1319 */ 1320 thread_group_cputime(p, &cputime); 1321 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime); 1322 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime); 1323 } else { 1324 u64 utime, stime; 1325 1326 task_cputime(p, &utime, &stime); 1327 prstatus->pr_utime = ns_to_kernel_old_timeval(utime); 1328 prstatus->pr_stime = ns_to_kernel_old_timeval(stime); 1329 } 1330 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime); 1331 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime); 1332 } 1333 1334 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1335 struct mm_struct *mm) 1336 { 1337 const struct cred *cred; 1338 unsigned int i, len; 1339 unsigned int state; 1340 1341 /* first copy the parameters from user space */ 1342 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1343 1344 len = mm->arg_end - mm->arg_start; 1345 if (len >= ELF_PRARGSZ) 1346 len = ELF_PRARGSZ - 1; 1347 if (copy_from_user(&psinfo->pr_psargs, 1348 (const char __user *) mm->arg_start, len)) 1349 return -EFAULT; 1350 for (i = 0; i < len; i++) 1351 if (psinfo->pr_psargs[i] == 0) 1352 psinfo->pr_psargs[i] = ' '; 1353 psinfo->pr_psargs[len] = 0; 1354 1355 rcu_read_lock(); 1356 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1357 rcu_read_unlock(); 1358 psinfo->pr_pid = task_pid_vnr(p); 1359 psinfo->pr_pgrp = task_pgrp_vnr(p); 1360 psinfo->pr_sid = task_session_vnr(p); 1361 1362 state = READ_ONCE(p->__state); 1363 i = state ? ffz(~state) + 1 : 0; 1364 psinfo->pr_state = i; 1365 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1366 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1367 psinfo->pr_nice = task_nice(p); 1368 psinfo->pr_flag = p->flags; 1369 rcu_read_lock(); 1370 cred = __task_cred(p); 1371 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1372 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1373 rcu_read_unlock(); 1374 get_task_comm(psinfo->pr_fname, p); 1375 1376 return 0; 1377 } 1378 1379 /* Here is the structure in which status of each thread is captured. */ 1380 struct elf_thread_status 1381 { 1382 struct elf_thread_status *next; 1383 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */ 1384 elf_fpregset_t fpu; /* NT_PRFPREG */ 1385 struct memelfnote notes[2]; 1386 int num_notes; 1387 }; 1388 1389 /* 1390 * In order to add the specific thread information for the elf file format, 1391 * we need to keep a linked list of every thread's pr_status and then create 1392 * a single section for them in the final core file. 1393 */ 1394 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz) 1395 { 1396 const struct user_regset_view *view = task_user_regset_view(p); 1397 struct elf_thread_status *t; 1398 int i, ret; 1399 1400 t = kzalloc_obj(struct elf_thread_status); 1401 if (!t) 1402 return t; 1403 1404 fill_prstatus(&t->prstatus.common, p, signr); 1405 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1406 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1407 regset_get(p, &view->regsets[0], 1408 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg); 1409 1410 fill_note(&t->notes[0], PRSTATUS, sizeof(t->prstatus), &t->prstatus); 1411 t->num_notes++; 1412 *sz += notesize(&t->notes[0]); 1413 1414 for (i = 1; i < view->n; ++i) { 1415 const struct user_regset *regset = &view->regsets[i]; 1416 if (regset->core_note_type != NT_PRFPREG) 1417 continue; 1418 if (regset->active && regset->active(p, regset) <= 0) 1419 continue; 1420 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu); 1421 if (ret >= 0) 1422 t->prstatus.pr_fpvalid = 1; 1423 break; 1424 } 1425 1426 if (t->prstatus.pr_fpvalid) { 1427 fill_note(&t->notes[1], PRFPREG, sizeof(t->fpu), &t->fpu); 1428 t->num_notes++; 1429 *sz += notesize(&t->notes[1]); 1430 } 1431 return t; 1432 } 1433 1434 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1435 elf_addr_t e_shoff, int segs) 1436 { 1437 elf->e_shoff = e_shoff; 1438 elf->e_shentsize = sizeof(*shdr4extnum); 1439 elf->e_shnum = 1; 1440 elf->e_shstrndx = SHN_UNDEF; 1441 1442 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1443 1444 shdr4extnum->sh_type = SHT_NULL; 1445 shdr4extnum->sh_size = elf->e_shnum; 1446 shdr4extnum->sh_link = elf->e_shstrndx; 1447 shdr4extnum->sh_info = segs; 1448 } 1449 1450 /* 1451 * dump the segments for an MMU process 1452 */ 1453 static bool elf_fdpic_dump_segments(struct coredump_params *cprm, 1454 struct core_vma_metadata *vma_meta, 1455 int vma_count) 1456 { 1457 int i; 1458 1459 for (i = 0; i < vma_count; i++) { 1460 struct core_vma_metadata *meta = vma_meta + i; 1461 1462 if (!dump_user_range(cprm, meta->start, meta->dump_size)) 1463 return false; 1464 } 1465 return true; 1466 } 1467 1468 /* 1469 * Actual dumper 1470 * 1471 * This is a two-pass process; first we find the offsets of the bits, 1472 * and then they are actually written out. If we run out of core limit 1473 * we just truncate. 1474 */ 1475 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1476 { 1477 int has_dumped = 0; 1478 int segs; 1479 int i; 1480 struct elfhdr *elf = NULL; 1481 loff_t offset = 0, dataoff; 1482 struct memelfnote psinfo_note, auxv_note; 1483 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1484 struct elf_thread_status *thread_list = NULL; 1485 int thread_status_size = 0; 1486 elf_addr_t *auxv; 1487 struct elf_phdr *phdr4note = NULL; 1488 struct elf_shdr *shdr4extnum = NULL; 1489 Elf_Half e_phnum; 1490 elf_addr_t e_shoff; 1491 struct core_thread *ct; 1492 struct elf_thread_status *tmp; 1493 1494 /* alloc memory for large data structures: too large to be on stack */ 1495 elf = kmalloc_obj(*elf); 1496 if (!elf) 1497 goto end_coredump; 1498 psinfo = kmalloc_obj(*psinfo); 1499 if (!psinfo) 1500 goto end_coredump; 1501 1502 for (ct = current->signal->core_state->dumper.next; 1503 ct; ct = ct->next) { 1504 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1505 ct->task, &thread_status_size); 1506 if (!tmp) 1507 goto end_coredump; 1508 1509 tmp->next = thread_list; 1510 thread_list = tmp; 1511 } 1512 1513 /* now collect the dump for the current */ 1514 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1515 current, &thread_status_size); 1516 if (!tmp) 1517 goto end_coredump; 1518 tmp->next = thread_list; 1519 thread_list = tmp; 1520 1521 segs = cprm->vma_count + elf_core_extra_phdrs(cprm); 1522 1523 /* for notes section */ 1524 segs++; 1525 1526 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1527 * this, kernel supports extended numbering. Have a look at 1528 * include/linux/elf.h for further information. */ 1529 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1530 1531 /* Set up header */ 1532 fill_elf_fdpic_header(elf, e_phnum); 1533 1534 has_dumped = 1; 1535 /* 1536 * Set up the notes in similar form to SVR4 core dumps made 1537 * with info from their /proc. 1538 */ 1539 1540 fill_psinfo(psinfo, current->group_leader, current->mm); 1541 fill_note(&psinfo_note, PRPSINFO, sizeof(*psinfo), psinfo); 1542 thread_status_size += notesize(&psinfo_note); 1543 1544 auxv = (elf_addr_t *) current->mm->saved_auxv; 1545 i = 0; 1546 do 1547 i += 2; 1548 while (auxv[i - 2] != AT_NULL); 1549 fill_note(&auxv_note, AUXV, i * sizeof(elf_addr_t), auxv); 1550 thread_status_size += notesize(&auxv_note); 1551 1552 offset = sizeof(*elf); /* ELF header */ 1553 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1554 1555 /* Write notes phdr entry */ 1556 phdr4note = kmalloc_obj(*phdr4note); 1557 if (!phdr4note) 1558 goto end_coredump; 1559 1560 fill_elf_note_phdr(phdr4note, thread_status_size, offset); 1561 offset += thread_status_size; 1562 1563 /* Page-align dumped data */ 1564 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1565 1566 offset += cprm->vma_data_size; 1567 offset += elf_core_extra_data_size(cprm); 1568 e_shoff = offset; 1569 1570 if (e_phnum == PN_XNUM) { 1571 shdr4extnum = kmalloc_obj(*shdr4extnum); 1572 if (!shdr4extnum) 1573 goto end_coredump; 1574 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1575 } 1576 1577 offset = dataoff; 1578 1579 if (!dump_emit(cprm, elf, sizeof(*elf))) 1580 goto end_coredump; 1581 1582 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1583 goto end_coredump; 1584 1585 /* write program headers for segments dump */ 1586 for (i = 0; i < cprm->vma_count; i++) { 1587 struct core_vma_metadata *meta = cprm->vma_meta + i; 1588 struct elf_phdr phdr; 1589 size_t sz; 1590 1591 sz = meta->end - meta->start; 1592 1593 phdr.p_type = PT_LOAD; 1594 phdr.p_offset = offset; 1595 phdr.p_vaddr = meta->start; 1596 phdr.p_paddr = 0; 1597 phdr.p_filesz = meta->dump_size; 1598 phdr.p_memsz = sz; 1599 offset += phdr.p_filesz; 1600 phdr.p_flags = 0; 1601 if (meta->flags & VM_READ) 1602 phdr.p_flags |= PF_R; 1603 if (meta->flags & VM_WRITE) 1604 phdr.p_flags |= PF_W; 1605 if (meta->flags & VM_EXEC) 1606 phdr.p_flags |= PF_X; 1607 phdr.p_align = ELF_EXEC_PAGESIZE; 1608 1609 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1610 goto end_coredump; 1611 } 1612 1613 if (!elf_core_write_extra_phdrs(cprm, offset)) 1614 goto end_coredump; 1615 1616 /* write out the notes section */ 1617 if (!writenote(thread_list->notes, cprm)) 1618 goto end_coredump; 1619 if (!writenote(&psinfo_note, cprm)) 1620 goto end_coredump; 1621 if (!writenote(&auxv_note, cprm)) 1622 goto end_coredump; 1623 for (i = 1; i < thread_list->num_notes; i++) 1624 if (!writenote(thread_list->notes + i, cprm)) 1625 goto end_coredump; 1626 1627 /* write out the thread status notes section */ 1628 for (tmp = thread_list->next; tmp; tmp = tmp->next) { 1629 for (i = 0; i < tmp->num_notes; i++) 1630 if (!writenote(&tmp->notes[i], cprm)) 1631 goto end_coredump; 1632 } 1633 1634 dump_skip_to(cprm, dataoff); 1635 1636 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count)) 1637 goto end_coredump; 1638 1639 if (!elf_core_write_extra_data(cprm)) 1640 goto end_coredump; 1641 1642 if (e_phnum == PN_XNUM) { 1643 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1644 goto end_coredump; 1645 } 1646 1647 if (cprm->file->f_pos != offset) { 1648 /* Sanity check */ 1649 printk(KERN_WARNING 1650 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1651 cprm->file->f_pos, offset); 1652 } 1653 1654 end_coredump: 1655 while (thread_list) { 1656 tmp = thread_list; 1657 thread_list = thread_list->next; 1658 kfree(tmp); 1659 } 1660 kfree(phdr4note); 1661 kfree(elf); 1662 kfree(psinfo); 1663 kfree(shdr4extnum); 1664 return has_dumped; 1665 } 1666 1667 #endif /* CONFIG_ELF_CORE */ 1668