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