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 (!file->f_op->mmap) 113 return 0; 114 return 1; 115 } 116 117 #ifndef elf_check_fdpic 118 #define elf_check_fdpic(x) 0 119 #endif 120 121 #ifndef elf_check_const_displacement 122 #define elf_check_const_displacement(x) 0 123 #endif 124 125 static int is_constdisp(struct elfhdr *hdr) 126 { 127 if (!elf_check_fdpic(hdr)) 128 return 1; 129 if (elf_check_const_displacement(hdr)) 130 return 1; 131 return 0; 132 } 133 134 /*****************************************************************************/ 135 /* 136 * read the program headers table into memory 137 */ 138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 139 struct file *file) 140 { 141 struct 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 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 allow_write_access(interpreter); 471 fput(interpreter); 472 } 473 kfree(interpreter_name); 474 kfree(exec_params.phdrs); 475 kfree(exec_params.loadmap); 476 kfree(interp_params.phdrs); 477 kfree(interp_params.loadmap); 478 return retval; 479 } 480 481 /*****************************************************************************/ 482 483 #ifndef ELF_BASE_PLATFORM 484 /* 485 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 486 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 487 * will be copied to the user stack in the same manner as AT_PLATFORM. 488 */ 489 #define ELF_BASE_PLATFORM NULL 490 #endif 491 492 /* 493 * present useful information to the program by shovelling it onto the new 494 * process's stack 495 */ 496 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 497 struct mm_struct *mm, 498 struct elf_fdpic_params *exec_params, 499 struct elf_fdpic_params *interp_params) 500 { 501 const struct cred *cred = current_cred(); 502 unsigned long sp, csp, nitems; 503 elf_caddr_t __user *argv, *envp; 504 size_t platform_len = 0, len; 505 char *k_platform, *k_base_platform; 506 char __user *u_platform, *u_base_platform, *p; 507 int loop; 508 int nr; /* reset for each csp adjustment */ 509 unsigned long flags = 0; 510 511 #ifdef CONFIG_MMU 512 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 513 * by the processes running on the same package. One thing we can do is 514 * to shuffle the initial stack for them, so we give the architecture 515 * an opportunity to do so here. 516 */ 517 sp = arch_align_stack(bprm->p); 518 #else 519 sp = mm->start_stack; 520 521 /* stack the program arguments and environment */ 522 if (transfer_args_to_stack(bprm, &sp) < 0) 523 return -EFAULT; 524 sp &= ~15; 525 #endif 526 527 /* 528 * If this architecture has a platform capability string, copy it 529 * to userspace. In some cases (Sparc), this info is impossible 530 * for userspace to get any other way, in others (i386) it is 531 * merely difficult. 532 */ 533 k_platform = ELF_PLATFORM; 534 u_platform = NULL; 535 536 if (k_platform) { 537 platform_len = strlen(k_platform) + 1; 538 sp -= platform_len; 539 u_platform = (char __user *) sp; 540 if (copy_to_user(u_platform, k_platform, platform_len) != 0) 541 return -EFAULT; 542 } 543 544 /* 545 * If this architecture has a "base" platform capability 546 * string, copy it to userspace. 547 */ 548 k_base_platform = ELF_BASE_PLATFORM; 549 u_base_platform = NULL; 550 551 if (k_base_platform) { 552 platform_len = strlen(k_base_platform) + 1; 553 sp -= platform_len; 554 u_base_platform = (char __user *) sp; 555 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 556 return -EFAULT; 557 } 558 559 sp &= ~7UL; 560 561 /* stack the load map(s) */ 562 len = sizeof(struct elf_fdpic_loadmap); 563 len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs; 564 sp = (sp - len) & ~7UL; 565 exec_params->map_addr = sp; 566 567 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 568 return -EFAULT; 569 570 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 571 572 if (interp_params->loadmap) { 573 len = sizeof(struct elf_fdpic_loadmap); 574 len += sizeof(struct elf_fdpic_loadseg) * 575 interp_params->loadmap->nsegs; 576 sp = (sp - len) & ~7UL; 577 interp_params->map_addr = sp; 578 579 if (copy_to_user((void __user *) sp, interp_params->loadmap, 580 len) != 0) 581 return -EFAULT; 582 583 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 584 } 585 586 /* force 16 byte _final_ alignment here for generality */ 587 #define DLINFO_ITEMS 15 588 589 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 590 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 591 592 if (bprm->have_execfd) 593 nitems++; 594 595 csp = sp; 596 sp -= nitems * 2 * sizeof(unsigned long); 597 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 598 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 599 sp -= 1 * sizeof(unsigned long); /* argc */ 600 601 csp -= sp & 15UL; 602 sp -= sp & 15UL; 603 604 /* put the ELF interpreter info on the stack */ 605 #define NEW_AUX_ENT(id, val) \ 606 do { \ 607 struct { unsigned long _id, _val; } __user *ent, v; \ 608 \ 609 ent = (void __user *) csp; \ 610 v._id = (id); \ 611 v._val = (val); \ 612 if (copy_to_user(ent + nr, &v, sizeof(v))) \ 613 return -EFAULT; \ 614 nr++; \ 615 } while (0) 616 617 nr = 0; 618 csp -= 2 * sizeof(unsigned long); 619 NEW_AUX_ENT(AT_NULL, 0); 620 if (k_platform) { 621 nr = 0; 622 csp -= 2 * sizeof(unsigned long); 623 NEW_AUX_ENT(AT_PLATFORM, 624 (elf_addr_t) (unsigned long) u_platform); 625 } 626 627 if (k_base_platform) { 628 nr = 0; 629 csp -= 2 * sizeof(unsigned long); 630 NEW_AUX_ENT(AT_BASE_PLATFORM, 631 (elf_addr_t) (unsigned long) u_base_platform); 632 } 633 634 if (bprm->have_execfd) { 635 nr = 0; 636 csp -= 2 * sizeof(unsigned long); 637 NEW_AUX_ENT(AT_EXECFD, bprm->execfd); 638 } 639 640 nr = 0; 641 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 642 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 643 #ifdef ELF_HWCAP2 644 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 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); 662 663 #ifdef ARCH_DLINFO 664 nr = 0; 665 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 666 667 /* ARCH_DLINFO must come last so platform specific code can enforce 668 * special alignment requirements on the AUXV if necessary (eg. PPC). 669 */ 670 ARCH_DLINFO; 671 #endif 672 #undef NEW_AUX_ENT 673 674 /* allocate room for argv[] and envv[] */ 675 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 676 envp = (elf_caddr_t __user *) csp; 677 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 678 argv = (elf_caddr_t __user *) csp; 679 680 /* stack argc */ 681 csp -= sizeof(unsigned long); 682 if (put_user(bprm->argc, (unsigned long __user *) csp)) 683 return -EFAULT; 684 685 BUG_ON(csp != sp); 686 687 /* fill in the argv[] array */ 688 #ifdef CONFIG_MMU 689 current->mm->arg_start = bprm->p; 690 #else 691 current->mm->arg_start = current->mm->start_stack - 692 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 693 #endif 694 695 p = (char __user *) current->mm->arg_start; 696 for (loop = bprm->argc; loop > 0; loop--) { 697 if (put_user((elf_caddr_t) p, argv++)) 698 return -EFAULT; 699 len = strnlen_user(p, MAX_ARG_STRLEN); 700 if (!len || len > MAX_ARG_STRLEN) 701 return -EINVAL; 702 p += len; 703 } 704 if (put_user(NULL, argv)) 705 return -EFAULT; 706 current->mm->arg_end = (unsigned long) p; 707 708 /* fill in the envv[] array */ 709 current->mm->env_start = (unsigned long) p; 710 for (loop = bprm->envc; loop > 0; loop--) { 711 if (put_user((elf_caddr_t)(unsigned long) p, envp++)) 712 return -EFAULT; 713 len = strnlen_user(p, MAX_ARG_STRLEN); 714 if (!len || len > MAX_ARG_STRLEN) 715 return -EINVAL; 716 p += len; 717 } 718 if (put_user(NULL, envp)) 719 return -EFAULT; 720 current->mm->env_end = (unsigned long) p; 721 722 mm->start_stack = (unsigned long) sp; 723 return 0; 724 } 725 726 /*****************************************************************************/ 727 /* 728 * load the appropriate binary image (executable or interpreter) into memory 729 * - we assume no MMU is available 730 * - if no other PIC bits are set in params->hdr->e_flags 731 * - we assume that the LOADable segments in the binary are independently relocatable 732 * - we assume R/O executable segments are shareable 733 * - else 734 * - we assume the loadable parts of the image to require fixed displacement 735 * - the image is not shareable 736 */ 737 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 738 struct file *file, 739 struct mm_struct *mm, 740 const char *what) 741 { 742 struct elf_fdpic_loadmap *loadmap; 743 #ifdef CONFIG_MMU 744 struct elf_fdpic_loadseg *mseg; 745 unsigned long load_addr; 746 #endif 747 struct elf_fdpic_loadseg *seg; 748 struct elf_phdr *phdr; 749 unsigned nloads, tmp; 750 unsigned long stop; 751 int loop, ret; 752 753 /* allocate a load map table */ 754 nloads = 0; 755 for (loop = 0; loop < params->hdr.e_phnum; loop++) 756 if (params->phdrs[loop].p_type == PT_LOAD) 757 nloads++; 758 759 if (nloads == 0) 760 return -ELIBBAD; 761 762 loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL); 763 if (!loadmap) 764 return -ENOMEM; 765 766 params->loadmap = loadmap; 767 768 loadmap->version = ELF_FDPIC_LOADMAP_VERSION; 769 loadmap->nsegs = nloads; 770 771 /* map the requested LOADs into the memory space */ 772 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 773 case ELF_FDPIC_FLAG_CONSTDISP: 774 case ELF_FDPIC_FLAG_CONTIGUOUS: 775 #ifndef CONFIG_MMU 776 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 777 if (ret < 0) 778 return ret; 779 break; 780 #endif 781 default: 782 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 783 if (ret < 0) 784 return ret; 785 break; 786 } 787 788 /* map the entry point */ 789 if (params->hdr.e_entry) { 790 seg = loadmap->segs; 791 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 792 if (params->hdr.e_entry >= seg->p_vaddr && 793 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 794 params->entry_addr = 795 (params->hdr.e_entry - seg->p_vaddr) + 796 seg->addr; 797 break; 798 } 799 } 800 } 801 802 /* determine where the program header table has wound up if mapped */ 803 stop = params->hdr.e_phoff; 804 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 805 phdr = params->phdrs; 806 807 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 808 if (phdr->p_type != PT_LOAD) 809 continue; 810 811 if (phdr->p_offset > params->hdr.e_phoff || 812 phdr->p_offset + phdr->p_filesz < stop) 813 continue; 814 815 seg = loadmap->segs; 816 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 817 if (phdr->p_vaddr >= seg->p_vaddr && 818 phdr->p_vaddr + phdr->p_filesz <= 819 seg->p_vaddr + seg->p_memsz) { 820 params->ph_addr = 821 (phdr->p_vaddr - seg->p_vaddr) + 822 seg->addr + 823 params->hdr.e_phoff - phdr->p_offset; 824 break; 825 } 826 } 827 break; 828 } 829 830 /* determine where the dynamic section has wound up if there is one */ 831 phdr = params->phdrs; 832 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 833 if (phdr->p_type != PT_DYNAMIC) 834 continue; 835 836 seg = loadmap->segs; 837 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 838 if (phdr->p_vaddr >= seg->p_vaddr && 839 phdr->p_vaddr + phdr->p_memsz <= 840 seg->p_vaddr + seg->p_memsz) { 841 Elf_Dyn __user *dyn; 842 Elf_Sword d_tag; 843 844 params->dynamic_addr = 845 (phdr->p_vaddr - seg->p_vaddr) + 846 seg->addr; 847 848 /* check the dynamic section contains at least 849 * one item, and that the last item is a NULL 850 * entry */ 851 if (phdr->p_memsz == 0 || 852 phdr->p_memsz % sizeof(Elf_Dyn) != 0) 853 goto dynamic_error; 854 855 tmp = phdr->p_memsz / sizeof(Elf_Dyn); 856 dyn = (Elf_Dyn __user *)params->dynamic_addr; 857 if (get_user(d_tag, &dyn[tmp - 1].d_tag) || 858 d_tag != 0) 859 goto dynamic_error; 860 break; 861 } 862 } 863 break; 864 } 865 866 /* now elide adjacent segments in the load map on MMU linux 867 * - on uClinux the holes between may actually be filled with system 868 * stuff or stuff from other processes 869 */ 870 #ifdef CONFIG_MMU 871 nloads = loadmap->nsegs; 872 mseg = loadmap->segs; 873 seg = mseg + 1; 874 for (loop = 1; loop < nloads; loop++) { 875 /* see if we have a candidate for merging */ 876 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 877 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 878 if (load_addr == (seg->addr & PAGE_MASK)) { 879 mseg->p_memsz += 880 load_addr - 881 (mseg->addr + mseg->p_memsz); 882 mseg->p_memsz += seg->addr & ~PAGE_MASK; 883 mseg->p_memsz += seg->p_memsz; 884 loadmap->nsegs--; 885 continue; 886 } 887 } 888 889 mseg++; 890 if (mseg != seg) 891 *mseg = *seg; 892 } 893 #endif 894 895 kdebug("Mapped Object [%s]:", what); 896 kdebug("- elfhdr : %lx", params->elfhdr_addr); 897 kdebug("- entry : %lx", params->entry_addr); 898 kdebug("- PHDR[] : %lx", params->ph_addr); 899 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 900 seg = loadmap->segs; 901 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 902 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]", 903 loop, 904 (unsigned long long) seg->addr, 905 (unsigned long long) seg->addr + seg->p_memsz - 1, 906 (unsigned long long) seg->p_vaddr, 907 (unsigned long long) seg->p_memsz); 908 909 return 0; 910 911 dynamic_error: 912 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 913 what, file_inode(file)->i_ino); 914 return -ELIBBAD; 915 } 916 917 /*****************************************************************************/ 918 /* 919 * map a file with constant displacement under uClinux 920 */ 921 #ifndef CONFIG_MMU 922 static int elf_fdpic_map_file_constdisp_on_uclinux( 923 struct elf_fdpic_params *params, 924 struct file *file, 925 struct mm_struct *mm) 926 { 927 struct elf_fdpic_loadseg *seg; 928 struct elf_phdr *phdr; 929 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0; 930 int loop, ret; 931 932 load_addr = params->load_addr; 933 seg = params->loadmap->segs; 934 935 /* determine the bounds of the contiguous overall allocation we must 936 * make */ 937 phdr = params->phdrs; 938 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 939 if (params->phdrs[loop].p_type != PT_LOAD) 940 continue; 941 942 if (base > phdr->p_vaddr) 943 base = phdr->p_vaddr; 944 if (top < phdr->p_vaddr + phdr->p_memsz) 945 top = phdr->p_vaddr + phdr->p_memsz; 946 } 947 948 /* allocate one big anon block for everything */ 949 maddr = vm_mmap(NULL, load_addr, top - base, 950 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0); 951 if (IS_ERR_VALUE(maddr)) 952 return (int) maddr; 953 954 if (load_addr != 0) 955 load_addr += PAGE_ALIGN(top - base); 956 957 /* and then load the file segments into it */ 958 phdr = params->phdrs; 959 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 960 if (params->phdrs[loop].p_type != PT_LOAD) 961 continue; 962 963 seg->addr = maddr + (phdr->p_vaddr - base); 964 seg->p_vaddr = phdr->p_vaddr; 965 seg->p_memsz = phdr->p_memsz; 966 967 ret = read_code(file, seg->addr, phdr->p_offset, 968 phdr->p_filesz); 969 if (ret < 0) 970 return ret; 971 972 /* map the ELF header address if in this segment */ 973 if (phdr->p_offset == 0) 974 params->elfhdr_addr = seg->addr; 975 976 /* clear any space allocated but not loaded */ 977 if (phdr->p_filesz < phdr->p_memsz) { 978 if (clear_user((void *) (seg->addr + phdr->p_filesz), 979 phdr->p_memsz - phdr->p_filesz)) 980 return -EFAULT; 981 } 982 983 if (mm) { 984 if (phdr->p_flags & PF_X) { 985 if (!mm->start_code) { 986 mm->start_code = seg->addr; 987 mm->end_code = seg->addr + 988 phdr->p_memsz; 989 } 990 } else if (!mm->start_data) { 991 mm->start_data = seg->addr; 992 mm->end_data = seg->addr + phdr->p_memsz; 993 } 994 } 995 996 seg++; 997 } 998 999 return 0; 1000 } 1001 #endif 1002 1003 /*****************************************************************************/ 1004 /* 1005 * map a binary by direct mmap() of the individual PT_LOAD segments 1006 */ 1007 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1008 struct file *file, 1009 struct mm_struct *mm) 1010 { 1011 struct elf_fdpic_loadseg *seg; 1012 struct elf_phdr *phdr; 1013 unsigned long load_addr, delta_vaddr; 1014 int loop, dvset; 1015 1016 load_addr = params->load_addr; 1017 delta_vaddr = 0; 1018 dvset = 0; 1019 1020 seg = params->loadmap->segs; 1021 1022 /* deal with each load segment separately */ 1023 phdr = params->phdrs; 1024 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1025 unsigned long maddr, disp, excess, excess1; 1026 int prot = 0, flags; 1027 1028 if (phdr->p_type != PT_LOAD) 1029 continue; 1030 1031 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1032 (unsigned long) phdr->p_vaddr, 1033 (unsigned long) phdr->p_offset, 1034 (unsigned long) phdr->p_filesz, 1035 (unsigned long) phdr->p_memsz); 1036 1037 /* determine the mapping parameters */ 1038 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1039 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1040 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1041 1042 flags = MAP_PRIVATE; 1043 maddr = 0; 1044 1045 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1046 case ELF_FDPIC_FLAG_INDEPENDENT: 1047 /* PT_LOADs are independently locatable */ 1048 break; 1049 1050 case ELF_FDPIC_FLAG_HONOURVADDR: 1051 /* the specified virtual address must be honoured */ 1052 maddr = phdr->p_vaddr; 1053 flags |= MAP_FIXED; 1054 break; 1055 1056 case ELF_FDPIC_FLAG_CONSTDISP: 1057 /* constant displacement 1058 * - can be mapped anywhere, but must be mapped as a 1059 * unit 1060 */ 1061 if (!dvset) { 1062 maddr = load_addr; 1063 delta_vaddr = phdr->p_vaddr; 1064 dvset = 1; 1065 } else { 1066 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1067 flags |= MAP_FIXED; 1068 } 1069 break; 1070 1071 case ELF_FDPIC_FLAG_CONTIGUOUS: 1072 /* contiguity handled later */ 1073 break; 1074 1075 default: 1076 BUG(); 1077 } 1078 1079 maddr &= PAGE_MASK; 1080 1081 /* create the mapping */ 1082 disp = phdr->p_vaddr & ~PAGE_MASK; 1083 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1084 phdr->p_offset - disp); 1085 1086 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx", 1087 loop, (unsigned long long) phdr->p_memsz + disp, 1088 prot, flags, (unsigned long long) phdr->p_offset - disp, 1089 maddr); 1090 1091 if (IS_ERR_VALUE(maddr)) 1092 return (int) maddr; 1093 1094 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1095 ELF_FDPIC_FLAG_CONTIGUOUS) 1096 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1097 1098 seg->addr = maddr + disp; 1099 seg->p_vaddr = phdr->p_vaddr; 1100 seg->p_memsz = phdr->p_memsz; 1101 1102 /* map the ELF header address if in this segment */ 1103 if (phdr->p_offset == 0) 1104 params->elfhdr_addr = seg->addr; 1105 1106 /* clear the bit between beginning of mapping and beginning of 1107 * PT_LOAD */ 1108 if (prot & PROT_WRITE && disp > 0) { 1109 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1110 if (clear_user((void __user *) maddr, disp)) 1111 return -EFAULT; 1112 maddr += disp; 1113 } 1114 1115 /* clear any space allocated but not loaded 1116 * - on uClinux we can just clear the lot 1117 * - on MMU linux we'll get a SIGBUS beyond the last page 1118 * extant in the file 1119 */ 1120 excess = phdr->p_memsz - phdr->p_filesz; 1121 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1122 1123 #ifdef CONFIG_MMU 1124 if (excess > excess1) { 1125 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1126 unsigned long xmaddr; 1127 1128 flags |= MAP_FIXED | MAP_ANONYMOUS; 1129 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1130 prot, flags, 0); 1131 1132 kdebug("mmap[%d] <anon>" 1133 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1134 loop, xaddr, excess - excess1, prot, flags, 1135 xmaddr); 1136 1137 if (xmaddr != xaddr) 1138 return -ENOMEM; 1139 } 1140 1141 if (prot & PROT_WRITE && excess1 > 0) { 1142 kdebug("clear[%d] ad=%lx sz=%lx", 1143 loop, maddr + phdr->p_filesz, excess1); 1144 if (clear_user((void __user *) maddr + phdr->p_filesz, 1145 excess1)) 1146 return -EFAULT; 1147 } 1148 1149 #else 1150 if (excess > 0) { 1151 kdebug("clear[%d] ad=%llx sz=%lx", loop, 1152 (unsigned long long) maddr + phdr->p_filesz, 1153 excess); 1154 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1155 return -EFAULT; 1156 } 1157 #endif 1158 1159 if (mm) { 1160 if (phdr->p_flags & PF_X) { 1161 if (!mm->start_code) { 1162 mm->start_code = maddr; 1163 mm->end_code = maddr + phdr->p_memsz; 1164 } 1165 } else if (!mm->start_data) { 1166 mm->start_data = maddr; 1167 mm->end_data = maddr + phdr->p_memsz; 1168 } 1169 } 1170 1171 seg++; 1172 } 1173 1174 return 0; 1175 } 1176 1177 /*****************************************************************************/ 1178 /* 1179 * ELF-FDPIC core dumper 1180 * 1181 * Modelled on fs/exec.c:aout_core_dump() 1182 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1183 * 1184 * Modelled on fs/binfmt_elf.c core dumper 1185 */ 1186 #ifdef CONFIG_ELF_CORE 1187 1188 struct elf_prstatus_fdpic 1189 { 1190 struct elf_prstatus_common common; 1191 elf_gregset_t pr_reg; /* GP registers */ 1192 /* When using FDPIC, the loadmap addresses need to be communicated 1193 * to GDB in order for GDB to do the necessary relocations. The 1194 * fields (below) used to communicate this information are placed 1195 * immediately after ``pr_reg'', so that the loadmap addresses may 1196 * be viewed as part of the register set if so desired. 1197 */ 1198 unsigned long pr_exec_fdpic_loadmap; 1199 unsigned long pr_interp_fdpic_loadmap; 1200 int pr_fpvalid; /* True if math co-processor being used. */ 1201 }; 1202 1203 /* An ELF note in memory */ 1204 struct memelfnote 1205 { 1206 const char *name; 1207 int type; 1208 unsigned int datasz; 1209 void *data; 1210 }; 1211 1212 static int notesize(struct memelfnote *en) 1213 { 1214 int sz; 1215 1216 sz = sizeof(struct elf_note); 1217 sz += roundup(strlen(en->name) + 1, 4); 1218 sz += roundup(en->datasz, 4); 1219 1220 return sz; 1221 } 1222 1223 /* #define DEBUG */ 1224 1225 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1226 { 1227 struct elf_note en; 1228 en.n_namesz = strlen(men->name) + 1; 1229 en.n_descsz = men->datasz; 1230 en.n_type = men->type; 1231 1232 return dump_emit(cprm, &en, sizeof(en)) && 1233 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1234 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1235 } 1236 1237 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1238 { 1239 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1240 elf->e_ident[EI_CLASS] = ELF_CLASS; 1241 elf->e_ident[EI_DATA] = ELF_DATA; 1242 elf->e_ident[EI_VERSION] = EV_CURRENT; 1243 elf->e_ident[EI_OSABI] = ELF_OSABI; 1244 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1245 1246 elf->e_type = ET_CORE; 1247 elf->e_machine = ELF_ARCH; 1248 elf->e_version = EV_CURRENT; 1249 elf->e_entry = 0; 1250 elf->e_phoff = sizeof(struct elfhdr); 1251 elf->e_shoff = 0; 1252 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1253 elf->e_ehsize = sizeof(struct elfhdr); 1254 elf->e_phentsize = sizeof(struct elf_phdr); 1255 elf->e_phnum = segs; 1256 elf->e_shentsize = 0; 1257 elf->e_shnum = 0; 1258 elf->e_shstrndx = 0; 1259 return; 1260 } 1261 1262 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1263 { 1264 phdr->p_type = PT_NOTE; 1265 phdr->p_offset = offset; 1266 phdr->p_vaddr = 0; 1267 phdr->p_paddr = 0; 1268 phdr->p_filesz = sz; 1269 phdr->p_memsz = 0; 1270 phdr->p_flags = 0; 1271 phdr->p_align = 4; 1272 return; 1273 } 1274 1275 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1276 unsigned int sz, void *data) 1277 { 1278 note->name = name; 1279 note->type = type; 1280 note->datasz = sz; 1281 note->data = data; 1282 return; 1283 } 1284 1285 /* 1286 * fill up all the fields in prstatus from the given task struct, except 1287 * registers which need to be filled up separately. 1288 */ 1289 static void fill_prstatus(struct elf_prstatus_common *prstatus, 1290 struct task_struct *p, long signr) 1291 { 1292 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1293 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1294 prstatus->pr_sighold = p->blocked.sig[0]; 1295 rcu_read_lock(); 1296 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1297 rcu_read_unlock(); 1298 prstatus->pr_pid = task_pid_vnr(p); 1299 prstatus->pr_pgrp = task_pgrp_vnr(p); 1300 prstatus->pr_sid = task_session_vnr(p); 1301 if (thread_group_leader(p)) { 1302 struct task_cputime cputime; 1303 1304 /* 1305 * This is the record for the group leader. It shows the 1306 * group-wide total, not its individual thread total. 1307 */ 1308 thread_group_cputime(p, &cputime); 1309 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime); 1310 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime); 1311 } else { 1312 u64 utime, stime; 1313 1314 task_cputime(p, &utime, &stime); 1315 prstatus->pr_utime = ns_to_kernel_old_timeval(utime); 1316 prstatus->pr_stime = ns_to_kernel_old_timeval(stime); 1317 } 1318 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime); 1319 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime); 1320 } 1321 1322 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1323 struct mm_struct *mm) 1324 { 1325 const struct cred *cred; 1326 unsigned int i, len; 1327 unsigned int state; 1328 1329 /* first copy the parameters from user space */ 1330 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1331 1332 len = mm->arg_end - mm->arg_start; 1333 if (len >= ELF_PRARGSZ) 1334 len = ELF_PRARGSZ - 1; 1335 if (copy_from_user(&psinfo->pr_psargs, 1336 (const char __user *) mm->arg_start, len)) 1337 return -EFAULT; 1338 for (i = 0; i < len; i++) 1339 if (psinfo->pr_psargs[i] == 0) 1340 psinfo->pr_psargs[i] = ' '; 1341 psinfo->pr_psargs[len] = 0; 1342 1343 rcu_read_lock(); 1344 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1345 rcu_read_unlock(); 1346 psinfo->pr_pid = task_pid_vnr(p); 1347 psinfo->pr_pgrp = task_pgrp_vnr(p); 1348 psinfo->pr_sid = task_session_vnr(p); 1349 1350 state = READ_ONCE(p->__state); 1351 i = state ? ffz(~state) + 1 : 0; 1352 psinfo->pr_state = i; 1353 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1354 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1355 psinfo->pr_nice = task_nice(p); 1356 psinfo->pr_flag = p->flags; 1357 rcu_read_lock(); 1358 cred = __task_cred(p); 1359 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1360 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1361 rcu_read_unlock(); 1362 get_task_comm(psinfo->pr_fname, p); 1363 1364 return 0; 1365 } 1366 1367 /* Here is the structure in which status of each thread is captured. */ 1368 struct elf_thread_status 1369 { 1370 struct elf_thread_status *next; 1371 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */ 1372 elf_fpregset_t fpu; /* NT_PRFPREG */ 1373 struct memelfnote notes[2]; 1374 int num_notes; 1375 }; 1376 1377 /* 1378 * In order to add the specific thread information for the elf file format, 1379 * we need to keep a linked list of every thread's pr_status and then create 1380 * a single section for them in the final core file. 1381 */ 1382 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz) 1383 { 1384 const struct user_regset_view *view = task_user_regset_view(p); 1385 struct elf_thread_status *t; 1386 int i, ret; 1387 1388 t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL); 1389 if (!t) 1390 return t; 1391 1392 fill_prstatus(&t->prstatus.common, p, signr); 1393 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1394 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1395 regset_get(p, &view->regsets[0], 1396 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg); 1397 1398 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1399 &t->prstatus); 1400 t->num_notes++; 1401 *sz += notesize(&t->notes[0]); 1402 1403 for (i = 1; i < view->n; ++i) { 1404 const struct user_regset *regset = &view->regsets[i]; 1405 if (regset->core_note_type != NT_PRFPREG) 1406 continue; 1407 if (regset->active && regset->active(p, regset) <= 0) 1408 continue; 1409 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu); 1410 if (ret >= 0) 1411 t->prstatus.pr_fpvalid = 1; 1412 break; 1413 } 1414 1415 if (t->prstatus.pr_fpvalid) { 1416 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1417 &t->fpu); 1418 t->num_notes++; 1419 *sz += notesize(&t->notes[1]); 1420 } 1421 return t; 1422 } 1423 1424 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1425 elf_addr_t e_shoff, int segs) 1426 { 1427 elf->e_shoff = e_shoff; 1428 elf->e_shentsize = sizeof(*shdr4extnum); 1429 elf->e_shnum = 1; 1430 elf->e_shstrndx = SHN_UNDEF; 1431 1432 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1433 1434 shdr4extnum->sh_type = SHT_NULL; 1435 shdr4extnum->sh_size = elf->e_shnum; 1436 shdr4extnum->sh_link = elf->e_shstrndx; 1437 shdr4extnum->sh_info = segs; 1438 } 1439 1440 /* 1441 * dump the segments for an MMU process 1442 */ 1443 static bool elf_fdpic_dump_segments(struct coredump_params *cprm, 1444 struct core_vma_metadata *vma_meta, 1445 int vma_count) 1446 { 1447 int i; 1448 1449 for (i = 0; i < vma_count; i++) { 1450 struct core_vma_metadata *meta = vma_meta + i; 1451 1452 if (!dump_user_range(cprm, meta->start, meta->dump_size)) 1453 return false; 1454 } 1455 return true; 1456 } 1457 1458 /* 1459 * Actual dumper 1460 * 1461 * This is a two-pass process; first we find the offsets of the bits, 1462 * and then they are actually written out. If we run out of core limit 1463 * we just truncate. 1464 */ 1465 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1466 { 1467 int has_dumped = 0; 1468 int segs; 1469 int i; 1470 struct elfhdr *elf = NULL; 1471 loff_t offset = 0, dataoff; 1472 struct memelfnote psinfo_note, auxv_note; 1473 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1474 struct elf_thread_status *thread_list = NULL; 1475 int thread_status_size = 0; 1476 elf_addr_t *auxv; 1477 struct elf_phdr *phdr4note = NULL; 1478 struct elf_shdr *shdr4extnum = NULL; 1479 Elf_Half e_phnum; 1480 elf_addr_t e_shoff; 1481 struct core_thread *ct; 1482 struct elf_thread_status *tmp; 1483 1484 /* alloc memory for large data structures: too large to be on stack */ 1485 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1486 if (!elf) 1487 goto end_coredump; 1488 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1489 if (!psinfo) 1490 goto end_coredump; 1491 1492 for (ct = current->signal->core_state->dumper.next; 1493 ct; ct = ct->next) { 1494 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1495 ct->task, &thread_status_size); 1496 if (!tmp) 1497 goto end_coredump; 1498 1499 tmp->next = thread_list; 1500 thread_list = tmp; 1501 } 1502 1503 /* now collect the dump for the current */ 1504 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1505 current, &thread_status_size); 1506 if (!tmp) 1507 goto end_coredump; 1508 tmp->next = thread_list; 1509 thread_list = tmp; 1510 1511 segs = cprm->vma_count + elf_core_extra_phdrs(cprm); 1512 1513 /* for notes section */ 1514 segs++; 1515 1516 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1517 * this, kernel supports extended numbering. Have a look at 1518 * include/linux/elf.h for further information. */ 1519 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1520 1521 /* Set up header */ 1522 fill_elf_fdpic_header(elf, e_phnum); 1523 1524 has_dumped = 1; 1525 /* 1526 * Set up the notes in similar form to SVR4 core dumps made 1527 * with info from their /proc. 1528 */ 1529 1530 fill_psinfo(psinfo, current->group_leader, current->mm); 1531 fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1532 thread_status_size += notesize(&psinfo_note); 1533 1534 auxv = (elf_addr_t *) current->mm->saved_auxv; 1535 i = 0; 1536 do 1537 i += 2; 1538 while (auxv[i - 2] != AT_NULL); 1539 fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1540 thread_status_size += notesize(&auxv_note); 1541 1542 offset = sizeof(*elf); /* ELF header */ 1543 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1544 1545 /* Write notes phdr entry */ 1546 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1547 if (!phdr4note) 1548 goto end_coredump; 1549 1550 fill_elf_note_phdr(phdr4note, thread_status_size, offset); 1551 offset += thread_status_size; 1552 1553 /* Page-align dumped data */ 1554 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1555 1556 offset += cprm->vma_data_size; 1557 offset += elf_core_extra_data_size(cprm); 1558 e_shoff = offset; 1559 1560 if (e_phnum == PN_XNUM) { 1561 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1562 if (!shdr4extnum) 1563 goto end_coredump; 1564 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1565 } 1566 1567 offset = dataoff; 1568 1569 if (!dump_emit(cprm, elf, sizeof(*elf))) 1570 goto end_coredump; 1571 1572 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1573 goto end_coredump; 1574 1575 /* write program headers for segments dump */ 1576 for (i = 0; i < cprm->vma_count; i++) { 1577 struct core_vma_metadata *meta = cprm->vma_meta + i; 1578 struct elf_phdr phdr; 1579 size_t sz; 1580 1581 sz = meta->end - meta->start; 1582 1583 phdr.p_type = PT_LOAD; 1584 phdr.p_offset = offset; 1585 phdr.p_vaddr = meta->start; 1586 phdr.p_paddr = 0; 1587 phdr.p_filesz = meta->dump_size; 1588 phdr.p_memsz = sz; 1589 offset += phdr.p_filesz; 1590 phdr.p_flags = 0; 1591 if (meta->flags & VM_READ) 1592 phdr.p_flags |= PF_R; 1593 if (meta->flags & VM_WRITE) 1594 phdr.p_flags |= PF_W; 1595 if (meta->flags & VM_EXEC) 1596 phdr.p_flags |= PF_X; 1597 phdr.p_align = ELF_EXEC_PAGESIZE; 1598 1599 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1600 goto end_coredump; 1601 } 1602 1603 if (!elf_core_write_extra_phdrs(cprm, offset)) 1604 goto end_coredump; 1605 1606 /* write out the notes section */ 1607 if (!writenote(thread_list->notes, cprm)) 1608 goto end_coredump; 1609 if (!writenote(&psinfo_note, cprm)) 1610 goto end_coredump; 1611 if (!writenote(&auxv_note, cprm)) 1612 goto end_coredump; 1613 for (i = 1; i < thread_list->num_notes; i++) 1614 if (!writenote(thread_list->notes + i, cprm)) 1615 goto end_coredump; 1616 1617 /* write out the thread status notes section */ 1618 for (tmp = thread_list->next; tmp; tmp = tmp->next) { 1619 for (i = 0; i < tmp->num_notes; i++) 1620 if (!writenote(&tmp->notes[i], cprm)) 1621 goto end_coredump; 1622 } 1623 1624 dump_skip_to(cprm, dataoff); 1625 1626 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count)) 1627 goto end_coredump; 1628 1629 if (!elf_core_write_extra_data(cprm)) 1630 goto end_coredump; 1631 1632 if (e_phnum == PN_XNUM) { 1633 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1634 goto end_coredump; 1635 } 1636 1637 if (cprm->file->f_pos != offset) { 1638 /* Sanity check */ 1639 printk(KERN_WARNING 1640 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1641 cprm->file->f_pos, offset); 1642 } 1643 1644 end_coredump: 1645 while (thread_list) { 1646 tmp = thread_list; 1647 thread_list = thread_list->next; 1648 kfree(tmp); 1649 } 1650 kfree(phdr4note); 1651 kfree(elf); 1652 kfree(psinfo); 1653 kfree(shdr4extnum); 1654 return has_dumped; 1655 } 1656 1657 #endif /* CONFIG_ELF_CORE */ 1658