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