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 = open_exec(interpreter_name); 267 retval = PTR_ERR(interpreter); 268 if (IS_ERR(interpreter)) { 269 interpreter = NULL; 270 goto error; 271 } 272 273 /* 274 * If the binary is not readable then enforce 275 * mm->dumpable = 0 regardless of the interpreter's 276 * permissions. 277 */ 278 would_dump(bprm, interpreter); 279 280 pos = 0; 281 retval = kernel_read(interpreter, bprm->buf, 282 BINPRM_BUF_SIZE, &pos); 283 if (unlikely(retval != BINPRM_BUF_SIZE)) { 284 if (retval >= 0) 285 retval = -ENOEXEC; 286 goto error; 287 } 288 289 interp_params.hdr = *((struct elfhdr *) bprm->buf); 290 break; 291 292 case PT_LOAD: 293 #ifdef CONFIG_MMU 294 if (exec_params.load_addr == 0) 295 exec_params.load_addr = phdr->p_vaddr; 296 #endif 297 break; 298 } 299 300 } 301 302 if (is_constdisp(&exec_params.hdr)) 303 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 304 305 /* perform insanity checks on the interpreter */ 306 if (interpreter_name) { 307 retval = -ELIBBAD; 308 if (!is_elf(&interp_params.hdr, interpreter)) 309 goto error; 310 311 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 312 313 /* read the interpreter's program header table */ 314 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 315 if (retval < 0) 316 goto error; 317 } 318 319 stack_size = exec_params.stack_size; 320 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 321 executable_stack = EXSTACK_ENABLE_X; 322 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 323 executable_stack = EXSTACK_DISABLE_X; 324 else 325 executable_stack = EXSTACK_DEFAULT; 326 327 if (stack_size == 0 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) { 328 stack_size = interp_params.stack_size; 329 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 330 executable_stack = EXSTACK_ENABLE_X; 331 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 332 executable_stack = EXSTACK_DISABLE_X; 333 else 334 executable_stack = EXSTACK_DEFAULT; 335 } 336 337 retval = -ENOEXEC; 338 if (stack_size == 0) 339 stack_size = 131072UL; /* same as exec.c's default commit */ 340 341 if (is_constdisp(&interp_params.hdr)) 342 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 343 344 /* flush all traces of the currently running executable */ 345 retval = begin_new_exec(bprm); 346 if (retval) 347 goto error; 348 349 /* there's now no turning back... the old userspace image is dead, 350 * defunct, deceased, etc. 351 */ 352 SET_PERSONALITY(exec_params.hdr); 353 if (elf_check_fdpic(&exec_params.hdr)) 354 current->personality |= PER_LINUX_FDPIC; 355 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 356 current->personality |= READ_IMPLIES_EXEC; 357 358 setup_new_exec(bprm); 359 360 set_binfmt(&elf_fdpic_format); 361 362 current->mm->start_code = 0; 363 current->mm->end_code = 0; 364 current->mm->start_stack = 0; 365 current->mm->start_data = 0; 366 current->mm->end_data = 0; 367 current->mm->context.exec_fdpic_loadmap = 0; 368 current->mm->context.interp_fdpic_loadmap = 0; 369 370 #ifdef CONFIG_MMU 371 elf_fdpic_arch_lay_out_mm(&exec_params, 372 &interp_params, 373 ¤t->mm->start_stack, 374 ¤t->mm->start_brk); 375 376 retval = setup_arg_pages(bprm, current->mm->start_stack, 377 executable_stack); 378 if (retval < 0) 379 goto error; 380 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 381 retval = arch_setup_additional_pages(bprm, !!interpreter_name); 382 if (retval < 0) 383 goto error; 384 #endif 385 #endif 386 387 /* load the executable and interpreter into memory */ 388 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 389 "executable"); 390 if (retval < 0) 391 goto error; 392 393 if (interpreter_name) { 394 retval = elf_fdpic_map_file(&interp_params, interpreter, 395 current->mm, "interpreter"); 396 if (retval < 0) { 397 printk(KERN_ERR "Unable to load interpreter\n"); 398 goto error; 399 } 400 401 exe_file_allow_write_access(interpreter); 402 fput(interpreter); 403 interpreter = NULL; 404 } 405 406 #ifdef CONFIG_MMU 407 if (!current->mm->start_brk) 408 current->mm->start_brk = current->mm->end_data; 409 410 current->mm->brk = current->mm->start_brk = 411 PAGE_ALIGN(current->mm->start_brk); 412 413 #else 414 /* create a stack area and zero-size brk area */ 415 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 416 if (stack_size < PAGE_SIZE * 2) 417 stack_size = PAGE_SIZE * 2; 418 419 stack_prot = PROT_READ | PROT_WRITE; 420 if (executable_stack == EXSTACK_ENABLE_X || 421 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 422 stack_prot |= PROT_EXEC; 423 424 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 425 MAP_PRIVATE | MAP_ANONYMOUS | 426 MAP_UNINITIALIZED | MAP_GROWSDOWN, 427 0); 428 429 if (IS_ERR_VALUE(current->mm->start_brk)) { 430 retval = current->mm->start_brk; 431 current->mm->start_brk = 0; 432 goto error; 433 } 434 435 current->mm->brk = current->mm->start_brk; 436 current->mm->context.end_brk = current->mm->start_brk; 437 current->mm->start_stack = current->mm->start_brk + stack_size; 438 #endif 439 440 retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params, 441 &interp_params); 442 if (retval < 0) 443 goto error; 444 445 kdebug("- start_code %lx", current->mm->start_code); 446 kdebug("- end_code %lx", current->mm->end_code); 447 kdebug("- start_data %lx", current->mm->start_data); 448 kdebug("- end_data %lx", current->mm->end_data); 449 kdebug("- start_brk %lx", current->mm->start_brk); 450 kdebug("- brk %lx", current->mm->brk); 451 kdebug("- start_stack %lx", current->mm->start_stack); 452 453 #ifdef ELF_FDPIC_PLAT_INIT 454 /* 455 * The ABI may specify that certain registers be set up in special 456 * ways (on i386 %edx is the address of a DT_FINI function, for 457 * example. This macro performs whatever initialization to 458 * the regs structure is required. 459 */ 460 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 461 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 462 dynaddr); 463 #endif 464 465 finalize_exec(bprm); 466 /* everything is now ready... get the userspace context ready to roll */ 467 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 468 start_thread(regs, entryaddr, current->mm->start_stack); 469 470 retval = 0; 471 472 error: 473 if (interpreter) { 474 exe_file_allow_write_access(interpreter); 475 fput(interpreter); 476 } 477 kfree(interpreter_name); 478 kfree(exec_params.phdrs); 479 kfree(exec_params.loadmap); 480 kfree(interp_params.phdrs); 481 kfree(interp_params.loadmap); 482 return retval; 483 } 484 485 /*****************************************************************************/ 486 487 #ifndef ELF_BASE_PLATFORM 488 /* 489 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 490 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 491 * will be copied to the user stack in the same manner as AT_PLATFORM. 492 */ 493 #define ELF_BASE_PLATFORM NULL 494 #endif 495 496 /* 497 * present useful information to the program by shovelling it onto the new 498 * process's stack 499 */ 500 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 501 struct mm_struct *mm, 502 struct elf_fdpic_params *exec_params, 503 struct elf_fdpic_params *interp_params) 504 { 505 const struct cred *cred = current_cred(); 506 unsigned long sp, csp, nitems; 507 elf_caddr_t __user *argv, *envp; 508 size_t platform_len = 0, len; 509 char *k_platform, *k_base_platform; 510 char __user *u_platform, *u_base_platform, *p; 511 int loop; 512 unsigned long flags = 0; 513 int ei_index; 514 elf_addr_t *elf_info; 515 516 #ifdef CONFIG_MMU 517 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 518 * by the processes running on the same package. One thing we can do is 519 * to shuffle the initial stack for them, so we give the architecture 520 * an opportunity to do so here. 521 */ 522 sp = arch_align_stack(bprm->p); 523 #else 524 sp = mm->start_stack; 525 526 /* stack the program arguments and environment */ 527 if (transfer_args_to_stack(bprm, &sp) < 0) 528 return -EFAULT; 529 sp &= ~15; 530 #endif 531 532 /* 533 * If this architecture has a platform capability string, copy it 534 * to userspace. In some cases (Sparc), this info is impossible 535 * for userspace to get any other way, in others (i386) it is 536 * merely difficult. 537 */ 538 k_platform = ELF_PLATFORM; 539 u_platform = NULL; 540 541 if (k_platform) { 542 platform_len = strlen(k_platform) + 1; 543 sp -= platform_len; 544 u_platform = (char __user *) sp; 545 if (copy_to_user(u_platform, k_platform, platform_len) != 0) 546 return -EFAULT; 547 } 548 549 /* 550 * If this architecture has a "base" platform capability 551 * string, copy it to userspace. 552 */ 553 k_base_platform = ELF_BASE_PLATFORM; 554 u_base_platform = NULL; 555 556 if (k_base_platform) { 557 platform_len = strlen(k_base_platform) + 1; 558 sp -= platform_len; 559 u_base_platform = (char __user *) sp; 560 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 561 return -EFAULT; 562 } 563 564 sp &= ~7UL; 565 566 /* stack the load map(s) */ 567 len = sizeof(struct elf_fdpic_loadmap); 568 len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs; 569 sp = (sp - len) & ~7UL; 570 exec_params->map_addr = sp; 571 572 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 573 return -EFAULT; 574 575 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 576 577 if (interp_params->loadmap) { 578 len = sizeof(struct elf_fdpic_loadmap); 579 len += sizeof(struct elf_fdpic_loadseg) * 580 interp_params->loadmap->nsegs; 581 sp = (sp - len) & ~7UL; 582 interp_params->map_addr = sp; 583 584 if (copy_to_user((void __user *) sp, interp_params->loadmap, 585 len) != 0) 586 return -EFAULT; 587 588 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 589 } 590 591 /* force 16 byte _final_ alignment here for generality */ 592 #define DLINFO_ITEMS 15 593 594 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 595 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 596 597 if (bprm->have_execfd) 598 nitems++; 599 #ifdef ELF_HWCAP2 600 nitems++; 601 #endif 602 #ifdef ELF_HWCAP3 603 nitems++; 604 #endif 605 #ifdef ELF_HWCAP4 606 nitems++; 607 #endif 608 609 csp = sp; 610 sp -= nitems * 2 * sizeof(unsigned long); 611 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 612 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 613 sp -= 1 * sizeof(unsigned long); /* argc */ 614 615 csp -= sp & 15UL; 616 sp -= sp & 15UL; 617 618 /* Create the ELF interpreter info */ 619 elf_info = (elf_addr_t *)mm->saved_auxv; 620 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ 621 #define NEW_AUX_ENT(id, val) \ 622 do { \ 623 *elf_info++ = id; \ 624 *elf_info++ = val; \ 625 } while (0) 626 627 #ifdef ARCH_DLINFO 628 /* 629 * ARCH_DLINFO must come first so PPC can do its special alignment of 630 * AUXV. 631 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in 632 * ARCH_DLINFO changes 633 */ 634 ARCH_DLINFO; 635 #endif 636 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 637 #ifdef ELF_HWCAP2 638 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 639 #endif 640 #ifdef ELF_HWCAP3 641 NEW_AUX_ENT(AT_HWCAP3, ELF_HWCAP3); 642 #endif 643 #ifdef ELF_HWCAP4 644 NEW_AUX_ENT(AT_HWCAP4, ELF_HWCAP4); 645 #endif 646 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 647 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 648 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 649 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 650 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 651 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 652 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0) 653 flags |= AT_FLAGS_PRESERVE_ARGV0; 654 NEW_AUX_ENT(AT_FLAGS, flags); 655 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 656 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 657 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 658 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 659 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 660 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 661 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 662 if (k_platform) 663 NEW_AUX_ENT(AT_PLATFORM, 664 (elf_addr_t)(unsigned long)u_platform); 665 if (k_base_platform) 666 NEW_AUX_ENT(AT_BASE_PLATFORM, 667 (elf_addr_t)(unsigned long)u_base_platform); 668 if (bprm->have_execfd) 669 NEW_AUX_ENT(AT_EXECFD, bprm->execfd); 670 #undef NEW_AUX_ENT 671 /* AT_NULL is zero; clear the rest too */ 672 memset(elf_info, 0, (char *)mm->saved_auxv + 673 sizeof(mm->saved_auxv) - (char *)elf_info); 674 675 /* And advance past the AT_NULL entry. */ 676 elf_info += 2; 677 678 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv; 679 csp -= ei_index * sizeof(elf_addr_t); 680 681 /* Put the elf_info on the stack in the right place. */ 682 if (copy_to_user((void __user *)csp, mm->saved_auxv, 683 ei_index * sizeof(elf_addr_t))) 684 return -EFAULT; 685 686 /* allocate room for argv[] and envv[] */ 687 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 688 envp = (elf_caddr_t __user *) csp; 689 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 690 argv = (elf_caddr_t __user *) csp; 691 692 /* stack argc */ 693 csp -= sizeof(unsigned long); 694 if (put_user(bprm->argc, (unsigned long __user *) csp)) 695 return -EFAULT; 696 697 BUG_ON(csp != sp); 698 699 /* fill in the argv[] array */ 700 #ifdef CONFIG_MMU 701 current->mm->arg_start = bprm->p; 702 #else 703 current->mm->arg_start = current->mm->start_stack - 704 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 705 #endif 706 707 p = (char __user *) current->mm->arg_start; 708 for (loop = bprm->argc; loop > 0; loop--) { 709 if (put_user((elf_caddr_t) p, argv++)) 710 return -EFAULT; 711 len = strnlen_user(p, MAX_ARG_STRLEN); 712 if (!len || len > MAX_ARG_STRLEN) 713 return -EINVAL; 714 p += len; 715 } 716 if (put_user(NULL, argv)) 717 return -EFAULT; 718 current->mm->arg_end = (unsigned long) p; 719 720 /* fill in the envv[] array */ 721 current->mm->env_start = (unsigned long) p; 722 for (loop = bprm->envc; loop > 0; loop--) { 723 if (put_user((elf_caddr_t)(unsigned long) p, envp++)) 724 return -EFAULT; 725 len = strnlen_user(p, MAX_ARG_STRLEN); 726 if (!len || len > MAX_ARG_STRLEN) 727 return -EINVAL; 728 p += len; 729 } 730 if (put_user(NULL, envp)) 731 return -EFAULT; 732 current->mm->env_end = (unsigned long) p; 733 734 mm->start_stack = (unsigned long) sp; 735 return 0; 736 } 737 738 /*****************************************************************************/ 739 /* 740 * load the appropriate binary image (executable or interpreter) into memory 741 * - we assume no MMU is available 742 * - if no other PIC bits are set in params->hdr->e_flags 743 * - we assume that the LOADable segments in the binary are independently relocatable 744 * - we assume R/O executable segments are shareable 745 * - else 746 * - we assume the loadable parts of the image to require fixed displacement 747 * - the image is not shareable 748 */ 749 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 750 struct file *file, 751 struct mm_struct *mm, 752 const char *what) 753 { 754 struct elf_fdpic_loadmap *loadmap; 755 #ifdef CONFIG_MMU 756 struct elf_fdpic_loadseg *mseg; 757 unsigned long load_addr; 758 #endif 759 struct elf_fdpic_loadseg *seg; 760 struct elf_phdr *phdr; 761 unsigned nloads, tmp; 762 unsigned long stop; 763 int loop, ret; 764 765 /* allocate a load map table */ 766 nloads = 0; 767 for (loop = 0; loop < params->hdr.e_phnum; loop++) 768 if (params->phdrs[loop].p_type == PT_LOAD) 769 nloads++; 770 771 if (nloads == 0) 772 return -ELIBBAD; 773 774 loadmap = kzalloc_flex(*loadmap, segs, nloads); 775 if (!loadmap) 776 return -ENOMEM; 777 778 params->loadmap = loadmap; 779 780 loadmap->version = ELF_FDPIC_LOADMAP_VERSION; 781 loadmap->nsegs = nloads; 782 783 /* map the requested LOADs into the memory space */ 784 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 785 case ELF_FDPIC_FLAG_CONSTDISP: 786 case ELF_FDPIC_FLAG_CONTIGUOUS: 787 #ifndef CONFIG_MMU 788 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 789 if (ret < 0) 790 return ret; 791 break; 792 #endif 793 default: 794 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 795 if (ret < 0) 796 return ret; 797 break; 798 } 799 800 /* map the entry point */ 801 if (params->hdr.e_entry) { 802 seg = loadmap->segs; 803 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 804 if (params->hdr.e_entry >= seg->p_vaddr && 805 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 806 params->entry_addr = 807 (params->hdr.e_entry - seg->p_vaddr) + 808 seg->addr; 809 break; 810 } 811 } 812 } 813 814 /* determine where the program header table has wound up if mapped */ 815 stop = params->hdr.e_phoff; 816 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 817 phdr = params->phdrs; 818 819 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 820 if (phdr->p_type != PT_LOAD) 821 continue; 822 823 if (phdr->p_offset > params->hdr.e_phoff || 824 phdr->p_offset + phdr->p_filesz < stop) 825 continue; 826 827 seg = loadmap->segs; 828 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 829 if (phdr->p_vaddr >= seg->p_vaddr && 830 phdr->p_vaddr + phdr->p_filesz <= 831 seg->p_vaddr + seg->p_memsz) { 832 params->ph_addr = 833 (phdr->p_vaddr - seg->p_vaddr) + 834 seg->addr + 835 params->hdr.e_phoff - phdr->p_offset; 836 break; 837 } 838 } 839 break; 840 } 841 842 /* determine where the dynamic section has wound up if there is one */ 843 phdr = params->phdrs; 844 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 845 if (phdr->p_type != PT_DYNAMIC) 846 continue; 847 848 seg = loadmap->segs; 849 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 850 if (phdr->p_vaddr >= seg->p_vaddr && 851 phdr->p_vaddr + phdr->p_memsz <= 852 seg->p_vaddr + seg->p_memsz) { 853 Elf_Dyn __user *dyn; 854 Elf_Sword d_tag; 855 856 params->dynamic_addr = 857 (phdr->p_vaddr - seg->p_vaddr) + 858 seg->addr; 859 860 /* check the dynamic section contains at least 861 * one item, and that the last item is a NULL 862 * entry */ 863 if (phdr->p_memsz == 0 || 864 phdr->p_memsz % sizeof(Elf_Dyn) != 0) 865 goto dynamic_error; 866 867 tmp = phdr->p_memsz / sizeof(Elf_Dyn); 868 dyn = (Elf_Dyn __user *)params->dynamic_addr; 869 if (get_user(d_tag, &dyn[tmp - 1].d_tag) || 870 d_tag != 0) 871 goto dynamic_error; 872 break; 873 } 874 } 875 break; 876 } 877 878 /* now elide adjacent segments in the load map on MMU linux 879 * - on uClinux the holes between may actually be filled with system 880 * stuff or stuff from other processes 881 */ 882 #ifdef CONFIG_MMU 883 nloads = loadmap->nsegs; 884 mseg = loadmap->segs; 885 seg = mseg + 1; 886 for (loop = 1; loop < nloads; loop++) { 887 /* see if we have a candidate for merging */ 888 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 889 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 890 if (load_addr == (seg->addr & PAGE_MASK)) { 891 mseg->p_memsz += 892 load_addr - 893 (mseg->addr + mseg->p_memsz); 894 mseg->p_memsz += seg->addr & ~PAGE_MASK; 895 mseg->p_memsz += seg->p_memsz; 896 loadmap->nsegs--; 897 continue; 898 } 899 } 900 901 mseg++; 902 if (mseg != seg) 903 *mseg = *seg; 904 } 905 #endif 906 907 kdebug("Mapped Object [%s]:", what); 908 kdebug("- elfhdr : %lx", params->elfhdr_addr); 909 kdebug("- entry : %lx", params->entry_addr); 910 kdebug("- PHDR[] : %lx", params->ph_addr); 911 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 912 seg = loadmap->segs; 913 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 914 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]", 915 loop, 916 (unsigned long long) seg->addr, 917 (unsigned long long) seg->addr + seg->p_memsz - 1, 918 (unsigned long long) seg->p_vaddr, 919 (unsigned long long) seg->p_memsz); 920 921 return 0; 922 923 dynamic_error: 924 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%llu)\n", 925 what, file_inode(file)->i_ino); 926 return -ELIBBAD; 927 } 928 929 /*****************************************************************************/ 930 /* 931 * map a file with constant displacement under uClinux 932 */ 933 #ifndef CONFIG_MMU 934 static int elf_fdpic_map_file_constdisp_on_uclinux( 935 struct elf_fdpic_params *params, 936 struct file *file, 937 struct mm_struct *mm) 938 { 939 struct elf_fdpic_loadseg *seg; 940 struct elf_phdr *phdr; 941 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0; 942 int loop, ret; 943 944 load_addr = params->load_addr; 945 seg = params->loadmap->segs; 946 947 /* determine the bounds of the contiguous overall allocation we must 948 * make */ 949 phdr = params->phdrs; 950 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 951 if (params->phdrs[loop].p_type != PT_LOAD) 952 continue; 953 954 if (base > phdr->p_vaddr) 955 base = phdr->p_vaddr; 956 if (top < phdr->p_vaddr + phdr->p_memsz) 957 top = phdr->p_vaddr + phdr->p_memsz; 958 } 959 960 /* allocate one big anon block for everything */ 961 maddr = vm_mmap(NULL, load_addr, top - base, 962 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0); 963 if (IS_ERR_VALUE(maddr)) 964 return (int) maddr; 965 966 if (load_addr != 0) 967 load_addr += PAGE_ALIGN(top - base); 968 969 /* and then load the file segments into it */ 970 phdr = params->phdrs; 971 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 972 if (params->phdrs[loop].p_type != PT_LOAD) 973 continue; 974 975 seg->addr = maddr + (phdr->p_vaddr - base); 976 seg->p_vaddr = phdr->p_vaddr; 977 seg->p_memsz = phdr->p_memsz; 978 979 ret = read_code(file, seg->addr, phdr->p_offset, 980 phdr->p_filesz); 981 if (ret < 0) 982 return ret; 983 984 /* map the ELF header address if in this segment */ 985 if (phdr->p_offset == 0) 986 params->elfhdr_addr = seg->addr; 987 988 /* clear any space allocated but not loaded */ 989 if (phdr->p_filesz < phdr->p_memsz) { 990 if (clear_user((void *) (seg->addr + phdr->p_filesz), 991 phdr->p_memsz - phdr->p_filesz)) 992 return -EFAULT; 993 } 994 995 if (mm) { 996 if (phdr->p_flags & PF_X) { 997 if (!mm->start_code) { 998 mm->start_code = seg->addr; 999 mm->end_code = seg->addr + 1000 phdr->p_memsz; 1001 } 1002 } else if (!mm->start_data) { 1003 mm->start_data = seg->addr; 1004 mm->end_data = seg->addr + phdr->p_memsz; 1005 } 1006 } 1007 1008 seg++; 1009 } 1010 1011 return 0; 1012 } 1013 #endif 1014 1015 /*****************************************************************************/ 1016 /* 1017 * map a binary by direct mmap() of the individual PT_LOAD segments 1018 */ 1019 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1020 struct file *file, 1021 struct mm_struct *mm) 1022 { 1023 struct elf_fdpic_loadseg *seg; 1024 struct elf_phdr *phdr; 1025 unsigned long load_addr, delta_vaddr; 1026 int loop, dvset; 1027 1028 load_addr = params->load_addr; 1029 delta_vaddr = 0; 1030 dvset = 0; 1031 1032 seg = params->loadmap->segs; 1033 1034 /* deal with each load segment separately */ 1035 phdr = params->phdrs; 1036 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1037 unsigned long maddr, disp, excess; 1038 int prot = 0, flags; 1039 1040 if (phdr->p_type != PT_LOAD) 1041 continue; 1042 1043 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1044 (unsigned long) phdr->p_vaddr, 1045 (unsigned long) phdr->p_offset, 1046 (unsigned long) phdr->p_filesz, 1047 (unsigned long) phdr->p_memsz); 1048 1049 /* determine the mapping parameters */ 1050 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1051 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1052 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1053 1054 flags = MAP_PRIVATE; 1055 maddr = 0; 1056 1057 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1058 case ELF_FDPIC_FLAG_INDEPENDENT: 1059 /* PT_LOADs are independently locatable */ 1060 break; 1061 1062 case ELF_FDPIC_FLAG_HONOURVADDR: 1063 /* the specified virtual address must be honoured */ 1064 maddr = phdr->p_vaddr; 1065 flags |= MAP_FIXED; 1066 break; 1067 1068 case ELF_FDPIC_FLAG_CONSTDISP: 1069 /* constant displacement 1070 * - can be mapped anywhere, but must be mapped as a 1071 * unit 1072 */ 1073 if (!dvset) { 1074 maddr = load_addr; 1075 delta_vaddr = phdr->p_vaddr; 1076 dvset = 1; 1077 } else { 1078 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1079 flags |= MAP_FIXED; 1080 } 1081 break; 1082 1083 case ELF_FDPIC_FLAG_CONTIGUOUS: 1084 /* contiguity handled later */ 1085 break; 1086 1087 default: 1088 BUG(); 1089 } 1090 1091 maddr &= PAGE_MASK; 1092 1093 /* create the mapping */ 1094 disp = phdr->p_vaddr & ~PAGE_MASK; 1095 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1096 phdr->p_offset - disp); 1097 1098 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx", 1099 loop, (unsigned long long) phdr->p_memsz + disp, 1100 prot, flags, (unsigned long long) phdr->p_offset - disp, 1101 maddr); 1102 1103 if (IS_ERR_VALUE(maddr)) 1104 return (int) maddr; 1105 1106 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1107 ELF_FDPIC_FLAG_CONTIGUOUS) 1108 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1109 1110 seg->addr = maddr + disp; 1111 seg->p_vaddr = phdr->p_vaddr; 1112 seg->p_memsz = phdr->p_memsz; 1113 1114 /* map the ELF header address if in this segment */ 1115 if (phdr->p_offset == 0) 1116 params->elfhdr_addr = seg->addr; 1117 1118 /* clear the bit between beginning of mapping and beginning of 1119 * PT_LOAD */ 1120 if (prot & PROT_WRITE && disp > 0) { 1121 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1122 if (clear_user((void __user *) maddr, disp)) 1123 return -EFAULT; 1124 maddr += disp; 1125 } 1126 1127 /* clear any space allocated but not loaded 1128 * - on uClinux we can just clear the lot 1129 * - on MMU linux we'll get a SIGBUS beyond the last page 1130 * extant in the file 1131 */ 1132 excess = phdr->p_memsz - phdr->p_filesz; 1133 1134 #ifdef CONFIG_MMU 1135 unsigned long excess1 1136 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1137 if (excess > excess1) { 1138 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1139 unsigned long xmaddr; 1140 1141 flags |= MAP_FIXED | MAP_ANONYMOUS; 1142 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1143 prot, flags, 0); 1144 1145 kdebug("mmap[%d] <anon>" 1146 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1147 loop, xaddr, excess - excess1, prot, flags, 1148 xmaddr); 1149 1150 if (xmaddr != xaddr) 1151 return -ENOMEM; 1152 } 1153 1154 if (prot & PROT_WRITE && excess1 > 0) { 1155 kdebug("clear[%d] ad=%lx sz=%lx", 1156 loop, maddr + phdr->p_filesz, excess1); 1157 if (clear_user((void __user *) maddr + phdr->p_filesz, 1158 excess1)) 1159 return -EFAULT; 1160 } 1161 1162 #else 1163 if (excess > 0) { 1164 kdebug("clear[%d] ad=%llx sz=%lx", loop, 1165 (unsigned long long) maddr + phdr->p_filesz, 1166 excess); 1167 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1168 return -EFAULT; 1169 } 1170 #endif 1171 1172 if (mm) { 1173 if (phdr->p_flags & PF_X) { 1174 if (!mm->start_code) { 1175 mm->start_code = maddr; 1176 mm->end_code = maddr + phdr->p_memsz; 1177 } 1178 } else if (!mm->start_data) { 1179 mm->start_data = maddr; 1180 mm->end_data = maddr + phdr->p_memsz; 1181 } 1182 } 1183 1184 seg++; 1185 } 1186 1187 return 0; 1188 } 1189 1190 /*****************************************************************************/ 1191 /* 1192 * ELF-FDPIC core dumper 1193 * 1194 * Modelled on fs/exec.c:aout_core_dump() 1195 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1196 * 1197 * Modelled on fs/binfmt_elf.c core dumper 1198 */ 1199 #ifdef CONFIG_ELF_CORE 1200 1201 struct elf_prstatus_fdpic 1202 { 1203 struct elf_prstatus_common common; 1204 elf_gregset_t pr_reg; /* GP registers */ 1205 /* When using FDPIC, the loadmap addresses need to be communicated 1206 * to GDB in order for GDB to do the necessary relocations. The 1207 * fields (below) used to communicate this information are placed 1208 * immediately after ``pr_reg'', so that the loadmap addresses may 1209 * be viewed as part of the register set if so desired. 1210 */ 1211 unsigned long pr_exec_fdpic_loadmap; 1212 unsigned long pr_interp_fdpic_loadmap; 1213 int pr_fpvalid; /* True if math co-processor being used. */ 1214 }; 1215 1216 /* An ELF note in memory */ 1217 struct memelfnote 1218 { 1219 const char *name; 1220 int type; 1221 unsigned int datasz; 1222 void *data; 1223 }; 1224 1225 static int notesize(struct memelfnote *en) 1226 { 1227 int sz; 1228 1229 sz = sizeof(struct elf_note); 1230 sz += roundup(strlen(en->name) + 1, 4); 1231 sz += roundup(en->datasz, 4); 1232 1233 return sz; 1234 } 1235 1236 /* #define DEBUG */ 1237 1238 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1239 { 1240 struct elf_note en; 1241 en.n_namesz = strlen(men->name) + 1; 1242 en.n_descsz = men->datasz; 1243 en.n_type = men->type; 1244 1245 return dump_emit(cprm, &en, sizeof(en)) && 1246 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1247 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1248 } 1249 1250 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1251 { 1252 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1253 elf->e_ident[EI_CLASS] = ELF_CLASS; 1254 elf->e_ident[EI_DATA] = ELF_DATA; 1255 elf->e_ident[EI_VERSION] = EV_CURRENT; 1256 elf->e_ident[EI_OSABI] = ELF_OSABI; 1257 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1258 1259 elf->e_type = ET_CORE; 1260 elf->e_machine = ELF_ARCH; 1261 elf->e_version = EV_CURRENT; 1262 elf->e_entry = 0; 1263 elf->e_phoff = sizeof(struct elfhdr); 1264 elf->e_shoff = 0; 1265 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1266 elf->e_ehsize = sizeof(struct elfhdr); 1267 elf->e_phentsize = sizeof(struct elf_phdr); 1268 elf->e_phnum = segs; 1269 elf->e_shentsize = 0; 1270 elf->e_shnum = 0; 1271 elf->e_shstrndx = 0; 1272 return; 1273 } 1274 1275 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1276 { 1277 phdr->p_type = PT_NOTE; 1278 phdr->p_offset = offset; 1279 phdr->p_vaddr = 0; 1280 phdr->p_paddr = 0; 1281 phdr->p_filesz = sz; 1282 phdr->p_memsz = 0; 1283 phdr->p_flags = 0; 1284 phdr->p_align = 4; 1285 return; 1286 } 1287 1288 static inline void __fill_note(struct memelfnote *note, const char *name, int type, 1289 unsigned int sz, void *data) 1290 { 1291 note->name = name; 1292 note->type = type; 1293 note->datasz = sz; 1294 note->data = data; 1295 return; 1296 } 1297 1298 #define fill_note(note, type, sz, data) \ 1299 __fill_note(note, NN_ ## type, NT_ ## type, sz, data) 1300 1301 /* 1302 * fill up all the fields in prstatus from the given task struct, except 1303 * registers which need to be filled up separately. 1304 */ 1305 static void fill_prstatus(struct elf_prstatus_common *prstatus, 1306 struct task_struct *p, long signr) 1307 { 1308 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1309 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1310 prstatus->pr_sighold = p->blocked.sig[0]; 1311 rcu_read_lock(); 1312 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1313 rcu_read_unlock(); 1314 prstatus->pr_pid = task_pid_vnr(p); 1315 prstatus->pr_pgrp = task_pgrp_vnr(p); 1316 prstatus->pr_sid = task_session_vnr(p); 1317 if (thread_group_leader(p)) { 1318 struct task_cputime cputime; 1319 1320 /* 1321 * This is the record for the group leader. It shows the 1322 * group-wide total, not its individual thread total. 1323 */ 1324 thread_group_cputime(p, &cputime); 1325 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime); 1326 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime); 1327 } else { 1328 u64 utime, stime; 1329 1330 task_cputime(p, &utime, &stime); 1331 prstatus->pr_utime = ns_to_kernel_old_timeval(utime); 1332 prstatus->pr_stime = ns_to_kernel_old_timeval(stime); 1333 } 1334 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime); 1335 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime); 1336 } 1337 1338 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1339 struct mm_struct *mm) 1340 { 1341 const struct cred *cred; 1342 unsigned int i, len; 1343 unsigned int state; 1344 1345 /* first copy the parameters from user space */ 1346 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1347 1348 len = mm->arg_end - mm->arg_start; 1349 if (len >= ELF_PRARGSZ) 1350 len = ELF_PRARGSZ - 1; 1351 if (copy_from_user(&psinfo->pr_psargs, 1352 (const char __user *) mm->arg_start, len)) 1353 return -EFAULT; 1354 for (i = 0; i < len; i++) 1355 if (psinfo->pr_psargs[i] == 0) 1356 psinfo->pr_psargs[i] = ' '; 1357 psinfo->pr_psargs[len] = 0; 1358 1359 rcu_read_lock(); 1360 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1361 rcu_read_unlock(); 1362 psinfo->pr_pid = task_pid_vnr(p); 1363 psinfo->pr_pgrp = task_pgrp_vnr(p); 1364 psinfo->pr_sid = task_session_vnr(p); 1365 1366 state = READ_ONCE(p->__state); 1367 i = state ? ffz(~state) + 1 : 0; 1368 psinfo->pr_state = i; 1369 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1370 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1371 psinfo->pr_nice = task_nice(p); 1372 psinfo->pr_flag = p->flags; 1373 rcu_read_lock(); 1374 cred = __task_cred(p); 1375 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1376 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1377 rcu_read_unlock(); 1378 get_task_comm(psinfo->pr_fname, p); 1379 1380 return 0; 1381 } 1382 1383 /* Here is the structure in which status of each thread is captured. */ 1384 struct elf_thread_status 1385 { 1386 struct elf_thread_status *next; 1387 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */ 1388 elf_fpregset_t fpu; /* NT_PRFPREG */ 1389 struct memelfnote notes[2]; 1390 int num_notes; 1391 }; 1392 1393 /* 1394 * In order to add the specific thread information for the elf file format, 1395 * we need to keep a linked list of every thread's pr_status and then create 1396 * a single section for them in the final core file. 1397 */ 1398 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz) 1399 { 1400 const struct user_regset_view *view = task_user_regset_view(p); 1401 struct elf_thread_status *t; 1402 int i, ret; 1403 1404 t = kzalloc_obj(struct elf_thread_status); 1405 if (!t) 1406 return t; 1407 1408 fill_prstatus(&t->prstatus.common, p, signr); 1409 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1410 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1411 regset_get(p, &view->regsets[0], 1412 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg); 1413 1414 fill_note(&t->notes[0], PRSTATUS, sizeof(t->prstatus), &t->prstatus); 1415 t->num_notes++; 1416 *sz += notesize(&t->notes[0]); 1417 1418 for (i = 1; i < view->n; ++i) { 1419 const struct user_regset *regset = &view->regsets[i]; 1420 if (regset->core_note_type != NT_PRFPREG) 1421 continue; 1422 if (regset->active && regset->active(p, regset) <= 0) 1423 continue; 1424 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu); 1425 if (ret >= 0) 1426 t->prstatus.pr_fpvalid = 1; 1427 break; 1428 } 1429 1430 if (t->prstatus.pr_fpvalid) { 1431 fill_note(&t->notes[1], PRFPREG, sizeof(t->fpu), &t->fpu); 1432 t->num_notes++; 1433 *sz += notesize(&t->notes[1]); 1434 } 1435 return t; 1436 } 1437 1438 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1439 elf_addr_t e_shoff, int segs) 1440 { 1441 elf->e_shoff = e_shoff; 1442 elf->e_shentsize = sizeof(*shdr4extnum); 1443 elf->e_shnum = 1; 1444 elf->e_shstrndx = SHN_UNDEF; 1445 1446 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1447 1448 shdr4extnum->sh_type = SHT_NULL; 1449 shdr4extnum->sh_size = elf->e_shnum; 1450 shdr4extnum->sh_link = elf->e_shstrndx; 1451 shdr4extnum->sh_info = segs; 1452 } 1453 1454 /* 1455 * dump the segments for an MMU process 1456 */ 1457 static bool elf_fdpic_dump_segments(struct coredump_params *cprm, 1458 struct core_vma_metadata *vma_meta, 1459 int vma_count) 1460 { 1461 int i; 1462 1463 for (i = 0; i < vma_count; i++) { 1464 struct core_vma_metadata *meta = vma_meta + i; 1465 1466 if (!dump_user_range(cprm, meta->start, meta->dump_size)) 1467 return false; 1468 } 1469 return true; 1470 } 1471 1472 /* 1473 * Actual dumper 1474 * 1475 * This is a two-pass process; first we find the offsets of the bits, 1476 * and then they are actually written out. If we run out of core limit 1477 * we just truncate. 1478 */ 1479 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1480 { 1481 int has_dumped = 0; 1482 int segs; 1483 int i; 1484 struct elfhdr *elf = NULL; 1485 loff_t offset = 0, dataoff; 1486 struct memelfnote psinfo_note, auxv_note; 1487 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1488 struct elf_thread_status *thread_list = NULL; 1489 int thread_status_size = 0; 1490 elf_addr_t *auxv; 1491 struct elf_phdr *phdr4note = NULL; 1492 struct elf_shdr *shdr4extnum = NULL; 1493 Elf_Half e_phnum; 1494 elf_addr_t e_shoff; 1495 struct core_thread *ct; 1496 struct elf_thread_status *tmp; 1497 1498 /* alloc memory for large data structures: too large to be on stack */ 1499 elf = kmalloc_obj(*elf); 1500 if (!elf) 1501 goto end_coredump; 1502 psinfo = kmalloc_obj(*psinfo); 1503 if (!psinfo) 1504 goto end_coredump; 1505 1506 for (ct = current->signal->core_state->dumper.next; 1507 ct; ct = ct->next) { 1508 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1509 ct->task, &thread_status_size); 1510 if (!tmp) 1511 goto end_coredump; 1512 1513 tmp->next = thread_list; 1514 thread_list = tmp; 1515 } 1516 1517 /* now collect the dump for the current */ 1518 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1519 current, &thread_status_size); 1520 if (!tmp) 1521 goto end_coredump; 1522 tmp->next = thread_list; 1523 thread_list = tmp; 1524 1525 segs = cprm->vma_count + elf_core_extra_phdrs(cprm); 1526 1527 /* for notes section */ 1528 segs++; 1529 1530 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1531 * this, kernel supports extended numbering. Have a look at 1532 * include/linux/elf.h for further information. */ 1533 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1534 1535 /* Set up header */ 1536 fill_elf_fdpic_header(elf, e_phnum); 1537 1538 has_dumped = 1; 1539 /* 1540 * Set up the notes in similar form to SVR4 core dumps made 1541 * with info from their /proc. 1542 */ 1543 1544 fill_psinfo(psinfo, current->group_leader, current->mm); 1545 fill_note(&psinfo_note, PRPSINFO, sizeof(*psinfo), psinfo); 1546 thread_status_size += notesize(&psinfo_note); 1547 1548 auxv = (elf_addr_t *) current->mm->saved_auxv; 1549 i = 0; 1550 do 1551 i += 2; 1552 while (auxv[i - 2] != AT_NULL); 1553 fill_note(&auxv_note, AUXV, i * sizeof(elf_addr_t), auxv); 1554 thread_status_size += notesize(&auxv_note); 1555 1556 offset = sizeof(*elf); /* ELF header */ 1557 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1558 1559 /* Write notes phdr entry */ 1560 phdr4note = kmalloc_obj(*phdr4note); 1561 if (!phdr4note) 1562 goto end_coredump; 1563 1564 fill_elf_note_phdr(phdr4note, thread_status_size, offset); 1565 offset += thread_status_size; 1566 1567 /* Page-align dumped data */ 1568 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1569 1570 offset += cprm->vma_data_size; 1571 offset += elf_core_extra_data_size(cprm); 1572 e_shoff = offset; 1573 1574 if (e_phnum == PN_XNUM) { 1575 shdr4extnum = kmalloc_obj(*shdr4extnum); 1576 if (!shdr4extnum) 1577 goto end_coredump; 1578 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1579 } 1580 1581 offset = dataoff; 1582 1583 if (!dump_emit(cprm, elf, sizeof(*elf))) 1584 goto end_coredump; 1585 1586 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1587 goto end_coredump; 1588 1589 /* write program headers for segments dump */ 1590 for (i = 0; i < cprm->vma_count; i++) { 1591 struct core_vma_metadata *meta = cprm->vma_meta + i; 1592 struct elf_phdr phdr; 1593 size_t sz; 1594 1595 sz = meta->end - meta->start; 1596 1597 phdr.p_type = PT_LOAD; 1598 phdr.p_offset = offset; 1599 phdr.p_vaddr = meta->start; 1600 phdr.p_paddr = 0; 1601 phdr.p_filesz = meta->dump_size; 1602 phdr.p_memsz = sz; 1603 offset += phdr.p_filesz; 1604 phdr.p_flags = 0; 1605 if (meta->flags & VM_READ) 1606 phdr.p_flags |= PF_R; 1607 if (meta->flags & VM_WRITE) 1608 phdr.p_flags |= PF_W; 1609 if (meta->flags & VM_EXEC) 1610 phdr.p_flags |= PF_X; 1611 phdr.p_align = ELF_EXEC_PAGESIZE; 1612 1613 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1614 goto end_coredump; 1615 } 1616 1617 if (!elf_core_write_extra_phdrs(cprm, offset)) 1618 goto end_coredump; 1619 1620 /* write out the notes section */ 1621 if (!writenote(thread_list->notes, cprm)) 1622 goto end_coredump; 1623 if (!writenote(&psinfo_note, cprm)) 1624 goto end_coredump; 1625 if (!writenote(&auxv_note, cprm)) 1626 goto end_coredump; 1627 for (i = 1; i < thread_list->num_notes; i++) 1628 if (!writenote(thread_list->notes + i, cprm)) 1629 goto end_coredump; 1630 1631 /* write out the thread status notes section */ 1632 for (tmp = thread_list->next; tmp; tmp = tmp->next) { 1633 for (i = 0; i < tmp->num_notes; i++) 1634 if (!writenote(&tmp->notes[i], cprm)) 1635 goto end_coredump; 1636 } 1637 1638 dump_skip_to(cprm, dataoff); 1639 1640 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count)) 1641 goto end_coredump; 1642 1643 if (!elf_core_write_extra_data(cprm)) 1644 goto end_coredump; 1645 1646 if (e_phnum == PN_XNUM) { 1647 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1648 goto end_coredump; 1649 } 1650 1651 if (cprm->file->f_pos != offset) { 1652 /* Sanity check */ 1653 printk(KERN_WARNING 1654 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1655 cprm->file->f_pos, offset); 1656 } 1657 1658 end_coredump: 1659 while (thread_list) { 1660 tmp = thread_list; 1661 thread_list = thread_list->next; 1662 kfree(tmp); 1663 } 1664 kfree(phdr4note); 1665 kfree(elf); 1666 kfree(psinfo); 1667 kfree(shdr4extnum); 1668 return has_dumped; 1669 } 1670 1671 #endif /* CONFIG_ELF_CORE */ 1672