1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* binfmt_elf_fdpic.c: FDPIC ELF binary format 3 * 4 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 * Derived from binfmt_elf.c 7 */ 8 9 #include <linux/module.h> 10 11 #include <linux/fs.h> 12 #include <linux/stat.h> 13 #include <linux/sched.h> 14 #include <linux/sched/coredump.h> 15 #include <linux/sched/task_stack.h> 16 #include <linux/sched/cputime.h> 17 #include <linux/mm.h> 18 #include <linux/mman.h> 19 #include <linux/errno.h> 20 #include <linux/signal.h> 21 #include <linux/binfmts.h> 22 #include <linux/string.h> 23 #include <linux/file.h> 24 #include <linux/fcntl.h> 25 #include <linux/slab.h> 26 #include <linux/pagemap.h> 27 #include <linux/security.h> 28 #include <linux/highmem.h> 29 #include <linux/highuid.h> 30 #include <linux/personality.h> 31 #include <linux/ptrace.h> 32 #include <linux/init.h> 33 #include <linux/elf.h> 34 #include <linux/elf-fdpic.h> 35 #include <linux/elfcore.h> 36 #include <linux/coredump.h> 37 #include <linux/dax.h> 38 #include <linux/regset.h> 39 40 #include <linux/uaccess.h> 41 #include <asm/param.h> 42 43 typedef char *elf_caddr_t; 44 45 #if 0 46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 47 #else 48 #define kdebug(fmt, ...) do {} while(0) 49 #endif 50 51 #if 0 52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 53 #else 54 #define kdcore(fmt, ...) do {} while(0) 55 #endif 56 57 MODULE_LICENSE("GPL"); 58 59 static int load_elf_fdpic_binary(struct linux_binprm *); 60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 62 struct mm_struct *, const char *); 63 64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 65 struct elf_fdpic_params *, 66 struct elf_fdpic_params *); 67 68 #ifndef CONFIG_MMU 69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 70 struct file *, 71 struct mm_struct *); 72 #endif 73 74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 75 struct file *, struct mm_struct *); 76 77 #ifdef CONFIG_ELF_CORE 78 static int elf_fdpic_core_dump(struct coredump_params *cprm); 79 #endif 80 81 static struct linux_binfmt elf_fdpic_format = { 82 .module = THIS_MODULE, 83 .load_binary = load_elf_fdpic_binary, 84 #ifdef CONFIG_ELF_CORE 85 .core_dump = elf_fdpic_core_dump, 86 .min_coredump = ELF_EXEC_PAGESIZE, 87 #endif 88 }; 89 90 static int __init init_elf_fdpic_binfmt(void) 91 { 92 register_binfmt(&elf_fdpic_format); 93 return 0; 94 } 95 96 static void __exit exit_elf_fdpic_binfmt(void) 97 { 98 unregister_binfmt(&elf_fdpic_format); 99 } 100 101 core_initcall(init_elf_fdpic_binfmt); 102 module_exit(exit_elf_fdpic_binfmt); 103 104 static int is_elf(struct elfhdr *hdr, struct file *file) 105 { 106 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 107 return 0; 108 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 109 return 0; 110 if (!elf_check_arch(hdr)) 111 return 0; 112 if (!file->f_op->mmap) 113 return 0; 114 return 1; 115 } 116 117 #ifndef elf_check_fdpic 118 #define elf_check_fdpic(x) 0 119 #endif 120 121 #ifndef elf_check_const_displacement 122 #define elf_check_const_displacement(x) 0 123 #endif 124 125 static int is_constdisp(struct elfhdr *hdr) 126 { 127 if (!elf_check_fdpic(hdr)) 128 return 1; 129 if (elf_check_const_displacement(hdr)) 130 return 1; 131 return 0; 132 } 133 134 /*****************************************************************************/ 135 /* 136 * read the program headers table into memory 137 */ 138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 139 struct file *file) 140 { 141 struct elf_phdr *phdr; 142 unsigned long size; 143 int retval, loop; 144 loff_t pos = params->hdr.e_phoff; 145 146 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 147 return -ENOMEM; 148 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 149 return -ENOMEM; 150 151 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 152 params->phdrs = kmalloc(size, GFP_KERNEL); 153 if (!params->phdrs) 154 return -ENOMEM; 155 156 retval = kernel_read(file, params->phdrs, size, &pos); 157 if (unlikely(retval != size)) 158 return retval < 0 ? retval : -ENOEXEC; 159 160 /* determine stack size for this binary */ 161 phdr = params->phdrs; 162 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 163 if (phdr->p_type != PT_GNU_STACK) 164 continue; 165 166 if (phdr->p_flags & PF_X) 167 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 168 else 169 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 170 171 params->stack_size = phdr->p_memsz; 172 break; 173 } 174 175 return 0; 176 } 177 178 /*****************************************************************************/ 179 /* 180 * load an fdpic binary into various bits of memory 181 */ 182 static int load_elf_fdpic_binary(struct linux_binprm *bprm) 183 { 184 struct elf_fdpic_params exec_params, interp_params; 185 struct pt_regs *regs = current_pt_regs(); 186 struct elf_phdr *phdr; 187 unsigned long stack_size, entryaddr; 188 #ifdef ELF_FDPIC_PLAT_INIT 189 unsigned long dynaddr; 190 #endif 191 #ifndef CONFIG_MMU 192 unsigned long stack_prot; 193 #endif 194 struct file *interpreter = NULL; /* to shut gcc up */ 195 char *interpreter_name = NULL; 196 int executable_stack; 197 int retval, i; 198 loff_t pos; 199 200 kdebug("____ LOAD %d ____", current->pid); 201 202 memset(&exec_params, 0, sizeof(exec_params)); 203 memset(&interp_params, 0, sizeof(interp_params)); 204 205 exec_params.hdr = *(struct elfhdr *) bprm->buf; 206 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 207 208 /* check that this is a binary we know how to deal with */ 209 retval = -ENOEXEC; 210 if (!is_elf(&exec_params.hdr, bprm->file)) 211 goto error; 212 if (!elf_check_fdpic(&exec_params.hdr)) { 213 #ifdef CONFIG_MMU 214 /* binfmt_elf handles non-fdpic elf except on nommu */ 215 goto error; 216 #else 217 /* nommu can only load ET_DYN (PIE) ELF */ 218 if (exec_params.hdr.e_type != ET_DYN) 219 goto error; 220 #endif 221 } 222 223 /* read the program header table */ 224 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 225 if (retval < 0) 226 goto error; 227 228 /* scan for a program header that specifies an interpreter */ 229 phdr = exec_params.phdrs; 230 231 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 232 switch (phdr->p_type) { 233 case PT_INTERP: 234 retval = -ENOMEM; 235 if (phdr->p_filesz > PATH_MAX) 236 goto error; 237 retval = -ENOENT; 238 if (phdr->p_filesz < 2) 239 goto error; 240 241 /* read the name of the interpreter into memory */ 242 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 243 if (!interpreter_name) 244 goto error; 245 246 pos = phdr->p_offset; 247 retval = kernel_read(bprm->file, interpreter_name, 248 phdr->p_filesz, &pos); 249 if (unlikely(retval != phdr->p_filesz)) { 250 if (retval >= 0) 251 retval = -ENOEXEC; 252 goto error; 253 } 254 255 retval = -ENOENT; 256 if (interpreter_name[phdr->p_filesz - 1] != '\0') 257 goto error; 258 259 kdebug("Using ELF interpreter %s", interpreter_name); 260 261 /* replace the program with the interpreter */ 262 interpreter = open_exec(interpreter_name); 263 retval = PTR_ERR(interpreter); 264 if (IS_ERR(interpreter)) { 265 interpreter = NULL; 266 goto error; 267 } 268 269 /* 270 * If the binary is not readable then enforce 271 * mm->dumpable = 0 regardless of the interpreter's 272 * permissions. 273 */ 274 would_dump(bprm, interpreter); 275 276 pos = 0; 277 retval = kernel_read(interpreter, bprm->buf, 278 BINPRM_BUF_SIZE, &pos); 279 if (unlikely(retval != BINPRM_BUF_SIZE)) { 280 if (retval >= 0) 281 retval = -ENOEXEC; 282 goto error; 283 } 284 285 interp_params.hdr = *((struct elfhdr *) bprm->buf); 286 break; 287 288 case PT_LOAD: 289 #ifdef CONFIG_MMU 290 if (exec_params.load_addr == 0) 291 exec_params.load_addr = phdr->p_vaddr; 292 #endif 293 break; 294 } 295 296 } 297 298 if (is_constdisp(&exec_params.hdr)) 299 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 300 301 /* perform insanity checks on the interpreter */ 302 if (interpreter_name) { 303 retval = -ELIBBAD; 304 if (!is_elf(&interp_params.hdr, interpreter)) 305 goto error; 306 307 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 308 309 /* read the interpreter's program header table */ 310 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 311 if (retval < 0) 312 goto error; 313 } 314 315 stack_size = exec_params.stack_size; 316 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 317 executable_stack = EXSTACK_ENABLE_X; 318 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 319 executable_stack = EXSTACK_DISABLE_X; 320 else 321 executable_stack = EXSTACK_DEFAULT; 322 323 if (stack_size == 0 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) { 324 stack_size = interp_params.stack_size; 325 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 326 executable_stack = EXSTACK_ENABLE_X; 327 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 328 executable_stack = EXSTACK_DISABLE_X; 329 else 330 executable_stack = EXSTACK_DEFAULT; 331 } 332 333 retval = -ENOEXEC; 334 if (stack_size == 0) 335 stack_size = 131072UL; /* same as exec.c's default commit */ 336 337 if (is_constdisp(&interp_params.hdr)) 338 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 339 340 /* flush all traces of the currently running executable */ 341 retval = begin_new_exec(bprm); 342 if (retval) 343 goto error; 344 345 /* there's now no turning back... the old userspace image is dead, 346 * defunct, deceased, etc. 347 */ 348 SET_PERSONALITY(exec_params.hdr); 349 if (elf_check_fdpic(&exec_params.hdr)) 350 current->personality |= PER_LINUX_FDPIC; 351 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 352 current->personality |= READ_IMPLIES_EXEC; 353 354 setup_new_exec(bprm); 355 356 set_binfmt(&elf_fdpic_format); 357 358 current->mm->start_code = 0; 359 current->mm->end_code = 0; 360 current->mm->start_stack = 0; 361 current->mm->start_data = 0; 362 current->mm->end_data = 0; 363 current->mm->context.exec_fdpic_loadmap = 0; 364 current->mm->context.interp_fdpic_loadmap = 0; 365 366 #ifdef CONFIG_MMU 367 elf_fdpic_arch_lay_out_mm(&exec_params, 368 &interp_params, 369 ¤t->mm->start_stack, 370 ¤t->mm->start_brk); 371 372 retval = setup_arg_pages(bprm, current->mm->start_stack, 373 executable_stack); 374 if (retval < 0) 375 goto error; 376 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 377 retval = arch_setup_additional_pages(bprm, !!interpreter_name); 378 if (retval < 0) 379 goto error; 380 #endif 381 #endif 382 383 /* load the executable and interpreter into memory */ 384 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 385 "executable"); 386 if (retval < 0) 387 goto error; 388 389 if (interpreter_name) { 390 retval = elf_fdpic_map_file(&interp_params, interpreter, 391 current->mm, "interpreter"); 392 if (retval < 0) { 393 printk(KERN_ERR "Unable to load interpreter\n"); 394 goto error; 395 } 396 397 allow_write_access(interpreter); 398 fput(interpreter); 399 interpreter = NULL; 400 } 401 402 #ifdef CONFIG_MMU 403 if (!current->mm->start_brk) 404 current->mm->start_brk = current->mm->end_data; 405 406 current->mm->brk = current->mm->start_brk = 407 PAGE_ALIGN(current->mm->start_brk); 408 409 #else 410 /* create a stack area and zero-size brk area */ 411 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 412 if (stack_size < PAGE_SIZE * 2) 413 stack_size = PAGE_SIZE * 2; 414 415 stack_prot = PROT_READ | PROT_WRITE; 416 if (executable_stack == EXSTACK_ENABLE_X || 417 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 418 stack_prot |= PROT_EXEC; 419 420 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 421 MAP_PRIVATE | MAP_ANONYMOUS | 422 MAP_UNINITIALIZED | MAP_GROWSDOWN, 423 0); 424 425 if (IS_ERR_VALUE(current->mm->start_brk)) { 426 retval = current->mm->start_brk; 427 current->mm->start_brk = 0; 428 goto error; 429 } 430 431 current->mm->brk = current->mm->start_brk; 432 current->mm->context.end_brk = current->mm->start_brk; 433 current->mm->start_stack = current->mm->start_brk + stack_size; 434 #endif 435 436 retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params, 437 &interp_params); 438 if (retval < 0) 439 goto error; 440 441 kdebug("- start_code %lx", current->mm->start_code); 442 kdebug("- end_code %lx", current->mm->end_code); 443 kdebug("- start_data %lx", current->mm->start_data); 444 kdebug("- end_data %lx", current->mm->end_data); 445 kdebug("- start_brk %lx", current->mm->start_brk); 446 kdebug("- brk %lx", current->mm->brk); 447 kdebug("- start_stack %lx", current->mm->start_stack); 448 449 #ifdef ELF_FDPIC_PLAT_INIT 450 /* 451 * The ABI may specify that certain registers be set up in special 452 * ways (on i386 %edx is the address of a DT_FINI function, for 453 * example. This macro performs whatever initialization to 454 * the regs structure is required. 455 */ 456 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 457 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 458 dynaddr); 459 #endif 460 461 finalize_exec(bprm); 462 /* everything is now ready... get the userspace context ready to roll */ 463 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 464 start_thread(regs, entryaddr, current->mm->start_stack); 465 466 retval = 0; 467 468 error: 469 if (interpreter) { 470 allow_write_access(interpreter); 471 fput(interpreter); 472 } 473 kfree(interpreter_name); 474 kfree(exec_params.phdrs); 475 kfree(exec_params.loadmap); 476 kfree(interp_params.phdrs); 477 kfree(interp_params.loadmap); 478 return retval; 479 } 480 481 /*****************************************************************************/ 482 483 #ifndef ELF_BASE_PLATFORM 484 /* 485 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 486 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 487 * will be copied to the user stack in the same manner as AT_PLATFORM. 488 */ 489 #define ELF_BASE_PLATFORM NULL 490 #endif 491 492 /* 493 * present useful information to the program by shovelling it onto the new 494 * process's stack 495 */ 496 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 497 struct mm_struct *mm, 498 struct elf_fdpic_params *exec_params, 499 struct elf_fdpic_params *interp_params) 500 { 501 const struct cred *cred = current_cred(); 502 unsigned long sp, csp, nitems; 503 elf_caddr_t __user *argv, *envp; 504 size_t platform_len = 0, len; 505 char *k_platform, *k_base_platform; 506 char __user *u_platform, *u_base_platform, *p; 507 int loop; 508 unsigned long flags = 0; 509 int ei_index; 510 elf_addr_t *elf_info; 511 512 #ifdef CONFIG_MMU 513 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 514 * by the processes running on the same package. One thing we can do is 515 * to shuffle the initial stack for them, so we give the architecture 516 * an opportunity to do so here. 517 */ 518 sp = arch_align_stack(bprm->p); 519 #else 520 sp = mm->start_stack; 521 522 /* stack the program arguments and environment */ 523 if (transfer_args_to_stack(bprm, &sp) < 0) 524 return -EFAULT; 525 sp &= ~15; 526 #endif 527 528 /* 529 * If this architecture has a platform capability string, copy it 530 * to userspace. In some cases (Sparc), this info is impossible 531 * for userspace to get any other way, in others (i386) it is 532 * merely difficult. 533 */ 534 k_platform = ELF_PLATFORM; 535 u_platform = NULL; 536 537 if (k_platform) { 538 platform_len = strlen(k_platform) + 1; 539 sp -= platform_len; 540 u_platform = (char __user *) sp; 541 if (copy_to_user(u_platform, k_platform, platform_len) != 0) 542 return -EFAULT; 543 } 544 545 /* 546 * If this architecture has a "base" platform capability 547 * string, copy it to userspace. 548 */ 549 k_base_platform = ELF_BASE_PLATFORM; 550 u_base_platform = NULL; 551 552 if (k_base_platform) { 553 platform_len = strlen(k_base_platform) + 1; 554 sp -= platform_len; 555 u_base_platform = (char __user *) sp; 556 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 557 return -EFAULT; 558 } 559 560 sp &= ~7UL; 561 562 /* stack the load map(s) */ 563 len = sizeof(struct elf_fdpic_loadmap); 564 len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs; 565 sp = (sp - len) & ~7UL; 566 exec_params->map_addr = sp; 567 568 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 569 return -EFAULT; 570 571 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 572 573 if (interp_params->loadmap) { 574 len = sizeof(struct elf_fdpic_loadmap); 575 len += sizeof(struct elf_fdpic_loadseg) * 576 interp_params->loadmap->nsegs; 577 sp = (sp - len) & ~7UL; 578 interp_params->map_addr = sp; 579 580 if (copy_to_user((void __user *) sp, interp_params->loadmap, 581 len) != 0) 582 return -EFAULT; 583 584 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 585 } 586 587 /* force 16 byte _final_ alignment here for generality */ 588 #define DLINFO_ITEMS 15 589 590 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 591 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 592 593 if (bprm->have_execfd) 594 nitems++; 595 #ifdef ELF_HWCAP2 596 nitems++; 597 #endif 598 599 csp = sp; 600 sp -= nitems * 2 * sizeof(unsigned long); 601 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 602 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 603 sp -= 1 * sizeof(unsigned long); /* argc */ 604 605 csp -= sp & 15UL; 606 sp -= sp & 15UL; 607 608 /* Create the ELF interpreter info */ 609 elf_info = (elf_addr_t *)mm->saved_auxv; 610 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ 611 #define NEW_AUX_ENT(id, val) \ 612 do { \ 613 *elf_info++ = id; \ 614 *elf_info++ = val; \ 615 } while (0) 616 617 #ifdef ARCH_DLINFO 618 /* 619 * ARCH_DLINFO must come first so PPC can do its special alignment of 620 * AUXV. 621 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in 622 * ARCH_DLINFO changes 623 */ 624 ARCH_DLINFO; 625 #endif 626 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 627 #ifdef ELF_HWCAP2 628 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 629 #endif 630 #ifdef ELF_HWCAP3 631 NEW_AUX_ENT(AT_HWCAP3, ELF_HWCAP3); 632 #endif 633 #ifdef ELF_HWCAP4 634 NEW_AUX_ENT(AT_HWCAP4, ELF_HWCAP4); 635 #endif 636 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 637 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 638 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 639 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 640 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 641 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 642 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0) 643 flags |= AT_FLAGS_PRESERVE_ARGV0; 644 NEW_AUX_ENT(AT_FLAGS, flags); 645 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 646 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 647 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 648 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 649 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 650 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 651 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 652 if (k_platform) 653 NEW_AUX_ENT(AT_PLATFORM, 654 (elf_addr_t)(unsigned long)u_platform); 655 if (k_base_platform) 656 NEW_AUX_ENT(AT_BASE_PLATFORM, 657 (elf_addr_t)(unsigned long)u_base_platform); 658 if (bprm->have_execfd) 659 NEW_AUX_ENT(AT_EXECFD, bprm->execfd); 660 #undef NEW_AUX_ENT 661 /* AT_NULL is zero; clear the rest too */ 662 memset(elf_info, 0, (char *)mm->saved_auxv + 663 sizeof(mm->saved_auxv) - (char *)elf_info); 664 665 /* And advance past the AT_NULL entry. */ 666 elf_info += 2; 667 668 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv; 669 csp -= ei_index * sizeof(elf_addr_t); 670 671 /* Put the elf_info on the stack in the right place. */ 672 if (copy_to_user((void __user *)csp, mm->saved_auxv, 673 ei_index * sizeof(elf_addr_t))) 674 return -EFAULT; 675 676 /* allocate room for argv[] and envv[] */ 677 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 678 envp = (elf_caddr_t __user *) csp; 679 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 680 argv = (elf_caddr_t __user *) csp; 681 682 /* stack argc */ 683 csp -= sizeof(unsigned long); 684 if (put_user(bprm->argc, (unsigned long __user *) csp)) 685 return -EFAULT; 686 687 BUG_ON(csp != sp); 688 689 /* fill in the argv[] array */ 690 #ifdef CONFIG_MMU 691 current->mm->arg_start = bprm->p; 692 #else 693 current->mm->arg_start = current->mm->start_stack - 694 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 695 #endif 696 697 p = (char __user *) current->mm->arg_start; 698 for (loop = bprm->argc; loop > 0; loop--) { 699 if (put_user((elf_caddr_t) p, argv++)) 700 return -EFAULT; 701 len = strnlen_user(p, MAX_ARG_STRLEN); 702 if (!len || len > MAX_ARG_STRLEN) 703 return -EINVAL; 704 p += len; 705 } 706 if (put_user(NULL, argv)) 707 return -EFAULT; 708 current->mm->arg_end = (unsigned long) p; 709 710 /* fill in the envv[] array */ 711 current->mm->env_start = (unsigned long) p; 712 for (loop = bprm->envc; loop > 0; loop--) { 713 if (put_user((elf_caddr_t)(unsigned long) p, envp++)) 714 return -EFAULT; 715 len = strnlen_user(p, MAX_ARG_STRLEN); 716 if (!len || len > MAX_ARG_STRLEN) 717 return -EINVAL; 718 p += len; 719 } 720 if (put_user(NULL, envp)) 721 return -EFAULT; 722 current->mm->env_end = (unsigned long) p; 723 724 mm->start_stack = (unsigned long) sp; 725 return 0; 726 } 727 728 /*****************************************************************************/ 729 /* 730 * load the appropriate binary image (executable or interpreter) into memory 731 * - we assume no MMU is available 732 * - if no other PIC bits are set in params->hdr->e_flags 733 * - we assume that the LOADable segments in the binary are independently relocatable 734 * - we assume R/O executable segments are shareable 735 * - else 736 * - we assume the loadable parts of the image to require fixed displacement 737 * - the image is not shareable 738 */ 739 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 740 struct file *file, 741 struct mm_struct *mm, 742 const char *what) 743 { 744 struct elf_fdpic_loadmap *loadmap; 745 #ifdef CONFIG_MMU 746 struct elf_fdpic_loadseg *mseg; 747 unsigned long load_addr; 748 #endif 749 struct elf_fdpic_loadseg *seg; 750 struct elf_phdr *phdr; 751 unsigned nloads, tmp; 752 unsigned long stop; 753 int loop, ret; 754 755 /* allocate a load map table */ 756 nloads = 0; 757 for (loop = 0; loop < params->hdr.e_phnum; loop++) 758 if (params->phdrs[loop].p_type == PT_LOAD) 759 nloads++; 760 761 if (nloads == 0) 762 return -ELIBBAD; 763 764 loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL); 765 if (!loadmap) 766 return -ENOMEM; 767 768 params->loadmap = loadmap; 769 770 loadmap->version = ELF_FDPIC_LOADMAP_VERSION; 771 loadmap->nsegs = nloads; 772 773 /* map the requested LOADs into the memory space */ 774 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 775 case ELF_FDPIC_FLAG_CONSTDISP: 776 case ELF_FDPIC_FLAG_CONTIGUOUS: 777 #ifndef CONFIG_MMU 778 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 779 if (ret < 0) 780 return ret; 781 break; 782 #endif 783 default: 784 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 785 if (ret < 0) 786 return ret; 787 break; 788 } 789 790 /* map the entry point */ 791 if (params->hdr.e_entry) { 792 seg = loadmap->segs; 793 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 794 if (params->hdr.e_entry >= seg->p_vaddr && 795 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 796 params->entry_addr = 797 (params->hdr.e_entry - seg->p_vaddr) + 798 seg->addr; 799 break; 800 } 801 } 802 } 803 804 /* determine where the program header table has wound up if mapped */ 805 stop = params->hdr.e_phoff; 806 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 807 phdr = params->phdrs; 808 809 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 810 if (phdr->p_type != PT_LOAD) 811 continue; 812 813 if (phdr->p_offset > params->hdr.e_phoff || 814 phdr->p_offset + phdr->p_filesz < stop) 815 continue; 816 817 seg = loadmap->segs; 818 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 819 if (phdr->p_vaddr >= seg->p_vaddr && 820 phdr->p_vaddr + phdr->p_filesz <= 821 seg->p_vaddr + seg->p_memsz) { 822 params->ph_addr = 823 (phdr->p_vaddr - seg->p_vaddr) + 824 seg->addr + 825 params->hdr.e_phoff - phdr->p_offset; 826 break; 827 } 828 } 829 break; 830 } 831 832 /* determine where the dynamic section has wound up if there is one */ 833 phdr = params->phdrs; 834 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 835 if (phdr->p_type != PT_DYNAMIC) 836 continue; 837 838 seg = loadmap->segs; 839 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 840 if (phdr->p_vaddr >= seg->p_vaddr && 841 phdr->p_vaddr + phdr->p_memsz <= 842 seg->p_vaddr + seg->p_memsz) { 843 Elf_Dyn __user *dyn; 844 Elf_Sword d_tag; 845 846 params->dynamic_addr = 847 (phdr->p_vaddr - seg->p_vaddr) + 848 seg->addr; 849 850 /* check the dynamic section contains at least 851 * one item, and that the last item is a NULL 852 * entry */ 853 if (phdr->p_memsz == 0 || 854 phdr->p_memsz % sizeof(Elf_Dyn) != 0) 855 goto dynamic_error; 856 857 tmp = phdr->p_memsz / sizeof(Elf_Dyn); 858 dyn = (Elf_Dyn __user *)params->dynamic_addr; 859 if (get_user(d_tag, &dyn[tmp - 1].d_tag) || 860 d_tag != 0) 861 goto dynamic_error; 862 break; 863 } 864 } 865 break; 866 } 867 868 /* now elide adjacent segments in the load map on MMU linux 869 * - on uClinux the holes between may actually be filled with system 870 * stuff or stuff from other processes 871 */ 872 #ifdef CONFIG_MMU 873 nloads = loadmap->nsegs; 874 mseg = loadmap->segs; 875 seg = mseg + 1; 876 for (loop = 1; loop < nloads; loop++) { 877 /* see if we have a candidate for merging */ 878 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 879 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 880 if (load_addr == (seg->addr & PAGE_MASK)) { 881 mseg->p_memsz += 882 load_addr - 883 (mseg->addr + mseg->p_memsz); 884 mseg->p_memsz += seg->addr & ~PAGE_MASK; 885 mseg->p_memsz += seg->p_memsz; 886 loadmap->nsegs--; 887 continue; 888 } 889 } 890 891 mseg++; 892 if (mseg != seg) 893 *mseg = *seg; 894 } 895 #endif 896 897 kdebug("Mapped Object [%s]:", what); 898 kdebug("- elfhdr : %lx", params->elfhdr_addr); 899 kdebug("- entry : %lx", params->entry_addr); 900 kdebug("- PHDR[] : %lx", params->ph_addr); 901 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 902 seg = loadmap->segs; 903 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 904 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]", 905 loop, 906 (unsigned long long) seg->addr, 907 (unsigned long long) seg->addr + seg->p_memsz - 1, 908 (unsigned long long) seg->p_vaddr, 909 (unsigned long long) seg->p_memsz); 910 911 return 0; 912 913 dynamic_error: 914 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 915 what, file_inode(file)->i_ino); 916 return -ELIBBAD; 917 } 918 919 /*****************************************************************************/ 920 /* 921 * map a file with constant displacement under uClinux 922 */ 923 #ifndef CONFIG_MMU 924 static int elf_fdpic_map_file_constdisp_on_uclinux( 925 struct elf_fdpic_params *params, 926 struct file *file, 927 struct mm_struct *mm) 928 { 929 struct elf_fdpic_loadseg *seg; 930 struct elf_phdr *phdr; 931 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0; 932 int loop, ret; 933 934 load_addr = params->load_addr; 935 seg = params->loadmap->segs; 936 937 /* determine the bounds of the contiguous overall allocation we must 938 * make */ 939 phdr = params->phdrs; 940 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 941 if (params->phdrs[loop].p_type != PT_LOAD) 942 continue; 943 944 if (base > phdr->p_vaddr) 945 base = phdr->p_vaddr; 946 if (top < phdr->p_vaddr + phdr->p_memsz) 947 top = phdr->p_vaddr + phdr->p_memsz; 948 } 949 950 /* allocate one big anon block for everything */ 951 maddr = vm_mmap(NULL, load_addr, top - base, 952 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0); 953 if (IS_ERR_VALUE(maddr)) 954 return (int) maddr; 955 956 if (load_addr != 0) 957 load_addr += PAGE_ALIGN(top - base); 958 959 /* and then load the file segments into it */ 960 phdr = params->phdrs; 961 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 962 if (params->phdrs[loop].p_type != PT_LOAD) 963 continue; 964 965 seg->addr = maddr + (phdr->p_vaddr - base); 966 seg->p_vaddr = phdr->p_vaddr; 967 seg->p_memsz = phdr->p_memsz; 968 969 ret = read_code(file, seg->addr, phdr->p_offset, 970 phdr->p_filesz); 971 if (ret < 0) 972 return ret; 973 974 /* map the ELF header address if in this segment */ 975 if (phdr->p_offset == 0) 976 params->elfhdr_addr = seg->addr; 977 978 /* clear any space allocated but not loaded */ 979 if (phdr->p_filesz < phdr->p_memsz) { 980 if (clear_user((void *) (seg->addr + phdr->p_filesz), 981 phdr->p_memsz - phdr->p_filesz)) 982 return -EFAULT; 983 } 984 985 if (mm) { 986 if (phdr->p_flags & PF_X) { 987 if (!mm->start_code) { 988 mm->start_code = seg->addr; 989 mm->end_code = seg->addr + 990 phdr->p_memsz; 991 } 992 } else if (!mm->start_data) { 993 mm->start_data = seg->addr; 994 mm->end_data = seg->addr + phdr->p_memsz; 995 } 996 } 997 998 seg++; 999 } 1000 1001 return 0; 1002 } 1003 #endif 1004 1005 /*****************************************************************************/ 1006 /* 1007 * map a binary by direct mmap() of the individual PT_LOAD segments 1008 */ 1009 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1010 struct file *file, 1011 struct mm_struct *mm) 1012 { 1013 struct elf_fdpic_loadseg *seg; 1014 struct elf_phdr *phdr; 1015 unsigned long load_addr, delta_vaddr; 1016 int loop, dvset; 1017 1018 load_addr = params->load_addr; 1019 delta_vaddr = 0; 1020 dvset = 0; 1021 1022 seg = params->loadmap->segs; 1023 1024 /* deal with each load segment separately */ 1025 phdr = params->phdrs; 1026 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1027 unsigned long maddr, disp, excess, excess1; 1028 int prot = 0, flags; 1029 1030 if (phdr->p_type != PT_LOAD) 1031 continue; 1032 1033 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1034 (unsigned long) phdr->p_vaddr, 1035 (unsigned long) phdr->p_offset, 1036 (unsigned long) phdr->p_filesz, 1037 (unsigned long) phdr->p_memsz); 1038 1039 /* determine the mapping parameters */ 1040 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1041 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1042 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1043 1044 flags = MAP_PRIVATE; 1045 maddr = 0; 1046 1047 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1048 case ELF_FDPIC_FLAG_INDEPENDENT: 1049 /* PT_LOADs are independently locatable */ 1050 break; 1051 1052 case ELF_FDPIC_FLAG_HONOURVADDR: 1053 /* the specified virtual address must be honoured */ 1054 maddr = phdr->p_vaddr; 1055 flags |= MAP_FIXED; 1056 break; 1057 1058 case ELF_FDPIC_FLAG_CONSTDISP: 1059 /* constant displacement 1060 * - can be mapped anywhere, but must be mapped as a 1061 * unit 1062 */ 1063 if (!dvset) { 1064 maddr = load_addr; 1065 delta_vaddr = phdr->p_vaddr; 1066 dvset = 1; 1067 } else { 1068 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1069 flags |= MAP_FIXED; 1070 } 1071 break; 1072 1073 case ELF_FDPIC_FLAG_CONTIGUOUS: 1074 /* contiguity handled later */ 1075 break; 1076 1077 default: 1078 BUG(); 1079 } 1080 1081 maddr &= PAGE_MASK; 1082 1083 /* create the mapping */ 1084 disp = phdr->p_vaddr & ~PAGE_MASK; 1085 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1086 phdr->p_offset - disp); 1087 1088 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx", 1089 loop, (unsigned long long) phdr->p_memsz + disp, 1090 prot, flags, (unsigned long long) phdr->p_offset - disp, 1091 maddr); 1092 1093 if (IS_ERR_VALUE(maddr)) 1094 return (int) maddr; 1095 1096 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1097 ELF_FDPIC_FLAG_CONTIGUOUS) 1098 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1099 1100 seg->addr = maddr + disp; 1101 seg->p_vaddr = phdr->p_vaddr; 1102 seg->p_memsz = phdr->p_memsz; 1103 1104 /* map the ELF header address if in this segment */ 1105 if (phdr->p_offset == 0) 1106 params->elfhdr_addr = seg->addr; 1107 1108 /* clear the bit between beginning of mapping and beginning of 1109 * PT_LOAD */ 1110 if (prot & PROT_WRITE && disp > 0) { 1111 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1112 if (clear_user((void __user *) maddr, disp)) 1113 return -EFAULT; 1114 maddr += disp; 1115 } 1116 1117 /* clear any space allocated but not loaded 1118 * - on uClinux we can just clear the lot 1119 * - on MMU linux we'll get a SIGBUS beyond the last page 1120 * extant in the file 1121 */ 1122 excess = phdr->p_memsz - phdr->p_filesz; 1123 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1124 1125 #ifdef CONFIG_MMU 1126 if (excess > excess1) { 1127 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1128 unsigned long xmaddr; 1129 1130 flags |= MAP_FIXED | MAP_ANONYMOUS; 1131 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1132 prot, flags, 0); 1133 1134 kdebug("mmap[%d] <anon>" 1135 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1136 loop, xaddr, excess - excess1, prot, flags, 1137 xmaddr); 1138 1139 if (xmaddr != xaddr) 1140 return -ENOMEM; 1141 } 1142 1143 if (prot & PROT_WRITE && excess1 > 0) { 1144 kdebug("clear[%d] ad=%lx sz=%lx", 1145 loop, maddr + phdr->p_filesz, excess1); 1146 if (clear_user((void __user *) maddr + phdr->p_filesz, 1147 excess1)) 1148 return -EFAULT; 1149 } 1150 1151 #else 1152 if (excess > 0) { 1153 kdebug("clear[%d] ad=%llx sz=%lx", loop, 1154 (unsigned long long) maddr + phdr->p_filesz, 1155 excess); 1156 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1157 return -EFAULT; 1158 } 1159 #endif 1160 1161 if (mm) { 1162 if (phdr->p_flags & PF_X) { 1163 if (!mm->start_code) { 1164 mm->start_code = maddr; 1165 mm->end_code = maddr + phdr->p_memsz; 1166 } 1167 } else if (!mm->start_data) { 1168 mm->start_data = maddr; 1169 mm->end_data = maddr + phdr->p_memsz; 1170 } 1171 } 1172 1173 seg++; 1174 } 1175 1176 return 0; 1177 } 1178 1179 /*****************************************************************************/ 1180 /* 1181 * ELF-FDPIC core dumper 1182 * 1183 * Modelled on fs/exec.c:aout_core_dump() 1184 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1185 * 1186 * Modelled on fs/binfmt_elf.c core dumper 1187 */ 1188 #ifdef CONFIG_ELF_CORE 1189 1190 struct elf_prstatus_fdpic 1191 { 1192 struct elf_prstatus_common common; 1193 elf_gregset_t pr_reg; /* GP registers */ 1194 /* When using FDPIC, the loadmap addresses need to be communicated 1195 * to GDB in order for GDB to do the necessary relocations. The 1196 * fields (below) used to communicate this information are placed 1197 * immediately after ``pr_reg'', so that the loadmap addresses may 1198 * be viewed as part of the register set if so desired. 1199 */ 1200 unsigned long pr_exec_fdpic_loadmap; 1201 unsigned long pr_interp_fdpic_loadmap; 1202 int pr_fpvalid; /* True if math co-processor being used. */ 1203 }; 1204 1205 /* An ELF note in memory */ 1206 struct memelfnote 1207 { 1208 const char *name; 1209 int type; 1210 unsigned int datasz; 1211 void *data; 1212 }; 1213 1214 static int notesize(struct memelfnote *en) 1215 { 1216 int sz; 1217 1218 sz = sizeof(struct elf_note); 1219 sz += roundup(strlen(en->name) + 1, 4); 1220 sz += roundup(en->datasz, 4); 1221 1222 return sz; 1223 } 1224 1225 /* #define DEBUG */ 1226 1227 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1228 { 1229 struct elf_note en; 1230 en.n_namesz = strlen(men->name) + 1; 1231 en.n_descsz = men->datasz; 1232 en.n_type = men->type; 1233 1234 return dump_emit(cprm, &en, sizeof(en)) && 1235 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1236 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1237 } 1238 1239 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1240 { 1241 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1242 elf->e_ident[EI_CLASS] = ELF_CLASS; 1243 elf->e_ident[EI_DATA] = ELF_DATA; 1244 elf->e_ident[EI_VERSION] = EV_CURRENT; 1245 elf->e_ident[EI_OSABI] = ELF_OSABI; 1246 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1247 1248 elf->e_type = ET_CORE; 1249 elf->e_machine = ELF_ARCH; 1250 elf->e_version = EV_CURRENT; 1251 elf->e_entry = 0; 1252 elf->e_phoff = sizeof(struct elfhdr); 1253 elf->e_shoff = 0; 1254 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1255 elf->e_ehsize = sizeof(struct elfhdr); 1256 elf->e_phentsize = sizeof(struct elf_phdr); 1257 elf->e_phnum = segs; 1258 elf->e_shentsize = 0; 1259 elf->e_shnum = 0; 1260 elf->e_shstrndx = 0; 1261 return; 1262 } 1263 1264 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1265 { 1266 phdr->p_type = PT_NOTE; 1267 phdr->p_offset = offset; 1268 phdr->p_vaddr = 0; 1269 phdr->p_paddr = 0; 1270 phdr->p_filesz = sz; 1271 phdr->p_memsz = 0; 1272 phdr->p_flags = 0; 1273 phdr->p_align = 4; 1274 return; 1275 } 1276 1277 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1278 unsigned int sz, void *data) 1279 { 1280 note->name = name; 1281 note->type = type; 1282 note->datasz = sz; 1283 note->data = data; 1284 return; 1285 } 1286 1287 /* 1288 * fill up all the fields in prstatus from the given task struct, except 1289 * registers which need to be filled up separately. 1290 */ 1291 static void fill_prstatus(struct elf_prstatus_common *prstatus, 1292 struct task_struct *p, long signr) 1293 { 1294 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1295 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1296 prstatus->pr_sighold = p->blocked.sig[0]; 1297 rcu_read_lock(); 1298 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1299 rcu_read_unlock(); 1300 prstatus->pr_pid = task_pid_vnr(p); 1301 prstatus->pr_pgrp = task_pgrp_vnr(p); 1302 prstatus->pr_sid = task_session_vnr(p); 1303 if (thread_group_leader(p)) { 1304 struct task_cputime cputime; 1305 1306 /* 1307 * This is the record for the group leader. It shows the 1308 * group-wide total, not its individual thread total. 1309 */ 1310 thread_group_cputime(p, &cputime); 1311 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime); 1312 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime); 1313 } else { 1314 u64 utime, stime; 1315 1316 task_cputime(p, &utime, &stime); 1317 prstatus->pr_utime = ns_to_kernel_old_timeval(utime); 1318 prstatus->pr_stime = ns_to_kernel_old_timeval(stime); 1319 } 1320 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime); 1321 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime); 1322 } 1323 1324 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1325 struct mm_struct *mm) 1326 { 1327 const struct cred *cred; 1328 unsigned int i, len; 1329 unsigned int state; 1330 1331 /* first copy the parameters from user space */ 1332 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1333 1334 len = mm->arg_end - mm->arg_start; 1335 if (len >= ELF_PRARGSZ) 1336 len = ELF_PRARGSZ - 1; 1337 if (copy_from_user(&psinfo->pr_psargs, 1338 (const char __user *) mm->arg_start, len)) 1339 return -EFAULT; 1340 for (i = 0; i < len; i++) 1341 if (psinfo->pr_psargs[i] == 0) 1342 psinfo->pr_psargs[i] = ' '; 1343 psinfo->pr_psargs[len] = 0; 1344 1345 rcu_read_lock(); 1346 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1347 rcu_read_unlock(); 1348 psinfo->pr_pid = task_pid_vnr(p); 1349 psinfo->pr_pgrp = task_pgrp_vnr(p); 1350 psinfo->pr_sid = task_session_vnr(p); 1351 1352 state = READ_ONCE(p->__state); 1353 i = state ? ffz(~state) + 1 : 0; 1354 psinfo->pr_state = i; 1355 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1356 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1357 psinfo->pr_nice = task_nice(p); 1358 psinfo->pr_flag = p->flags; 1359 rcu_read_lock(); 1360 cred = __task_cred(p); 1361 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1362 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1363 rcu_read_unlock(); 1364 get_task_comm(psinfo->pr_fname, p); 1365 1366 return 0; 1367 } 1368 1369 /* Here is the structure in which status of each thread is captured. */ 1370 struct elf_thread_status 1371 { 1372 struct elf_thread_status *next; 1373 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */ 1374 elf_fpregset_t fpu; /* NT_PRFPREG */ 1375 struct memelfnote notes[2]; 1376 int num_notes; 1377 }; 1378 1379 /* 1380 * In order to add the specific thread information for the elf file format, 1381 * we need to keep a linked list of every thread's pr_status and then create 1382 * a single section for them in the final core file. 1383 */ 1384 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz) 1385 { 1386 const struct user_regset_view *view = task_user_regset_view(p); 1387 struct elf_thread_status *t; 1388 int i, ret; 1389 1390 t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL); 1391 if (!t) 1392 return t; 1393 1394 fill_prstatus(&t->prstatus.common, p, signr); 1395 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1396 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1397 regset_get(p, &view->regsets[0], 1398 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg); 1399 1400 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1401 &t->prstatus); 1402 t->num_notes++; 1403 *sz += notesize(&t->notes[0]); 1404 1405 for (i = 1; i < view->n; ++i) { 1406 const struct user_regset *regset = &view->regsets[i]; 1407 if (regset->core_note_type != NT_PRFPREG) 1408 continue; 1409 if (regset->active && regset->active(p, regset) <= 0) 1410 continue; 1411 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu); 1412 if (ret >= 0) 1413 t->prstatus.pr_fpvalid = 1; 1414 break; 1415 } 1416 1417 if (t->prstatus.pr_fpvalid) { 1418 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1419 &t->fpu); 1420 t->num_notes++; 1421 *sz += notesize(&t->notes[1]); 1422 } 1423 return t; 1424 } 1425 1426 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1427 elf_addr_t e_shoff, int segs) 1428 { 1429 elf->e_shoff = e_shoff; 1430 elf->e_shentsize = sizeof(*shdr4extnum); 1431 elf->e_shnum = 1; 1432 elf->e_shstrndx = SHN_UNDEF; 1433 1434 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1435 1436 shdr4extnum->sh_type = SHT_NULL; 1437 shdr4extnum->sh_size = elf->e_shnum; 1438 shdr4extnum->sh_link = elf->e_shstrndx; 1439 shdr4extnum->sh_info = segs; 1440 } 1441 1442 /* 1443 * dump the segments for an MMU process 1444 */ 1445 static bool elf_fdpic_dump_segments(struct coredump_params *cprm, 1446 struct core_vma_metadata *vma_meta, 1447 int vma_count) 1448 { 1449 int i; 1450 1451 for (i = 0; i < vma_count; i++) { 1452 struct core_vma_metadata *meta = vma_meta + i; 1453 1454 if (!dump_user_range(cprm, meta->start, meta->dump_size)) 1455 return false; 1456 } 1457 return true; 1458 } 1459 1460 /* 1461 * Actual dumper 1462 * 1463 * This is a two-pass process; first we find the offsets of the bits, 1464 * and then they are actually written out. If we run out of core limit 1465 * we just truncate. 1466 */ 1467 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1468 { 1469 int has_dumped = 0; 1470 int segs; 1471 int i; 1472 struct elfhdr *elf = NULL; 1473 loff_t offset = 0, dataoff; 1474 struct memelfnote psinfo_note, auxv_note; 1475 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1476 struct elf_thread_status *thread_list = NULL; 1477 int thread_status_size = 0; 1478 elf_addr_t *auxv; 1479 struct elf_phdr *phdr4note = NULL; 1480 struct elf_shdr *shdr4extnum = NULL; 1481 Elf_Half e_phnum; 1482 elf_addr_t e_shoff; 1483 struct core_thread *ct; 1484 struct elf_thread_status *tmp; 1485 1486 /* alloc memory for large data structures: too large to be on stack */ 1487 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1488 if (!elf) 1489 goto end_coredump; 1490 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1491 if (!psinfo) 1492 goto end_coredump; 1493 1494 for (ct = current->signal->core_state->dumper.next; 1495 ct; ct = ct->next) { 1496 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1497 ct->task, &thread_status_size); 1498 if (!tmp) 1499 goto end_coredump; 1500 1501 tmp->next = thread_list; 1502 thread_list = tmp; 1503 } 1504 1505 /* now collect the dump for the current */ 1506 tmp = elf_dump_thread_status(cprm->siginfo->si_signo, 1507 current, &thread_status_size); 1508 if (!tmp) 1509 goto end_coredump; 1510 tmp->next = thread_list; 1511 thread_list = tmp; 1512 1513 segs = cprm->vma_count + elf_core_extra_phdrs(cprm); 1514 1515 /* for notes section */ 1516 segs++; 1517 1518 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1519 * this, kernel supports extended numbering. Have a look at 1520 * include/linux/elf.h for further information. */ 1521 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1522 1523 /* Set up header */ 1524 fill_elf_fdpic_header(elf, e_phnum); 1525 1526 has_dumped = 1; 1527 /* 1528 * Set up the notes in similar form to SVR4 core dumps made 1529 * with info from their /proc. 1530 */ 1531 1532 fill_psinfo(psinfo, current->group_leader, current->mm); 1533 fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1534 thread_status_size += notesize(&psinfo_note); 1535 1536 auxv = (elf_addr_t *) current->mm->saved_auxv; 1537 i = 0; 1538 do 1539 i += 2; 1540 while (auxv[i - 2] != AT_NULL); 1541 fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1542 thread_status_size += notesize(&auxv_note); 1543 1544 offset = sizeof(*elf); /* ELF header */ 1545 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1546 1547 /* Write notes phdr entry */ 1548 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1549 if (!phdr4note) 1550 goto end_coredump; 1551 1552 fill_elf_note_phdr(phdr4note, thread_status_size, offset); 1553 offset += thread_status_size; 1554 1555 /* Page-align dumped data */ 1556 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1557 1558 offset += cprm->vma_data_size; 1559 offset += elf_core_extra_data_size(cprm); 1560 e_shoff = offset; 1561 1562 if (e_phnum == PN_XNUM) { 1563 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1564 if (!shdr4extnum) 1565 goto end_coredump; 1566 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1567 } 1568 1569 offset = dataoff; 1570 1571 if (!dump_emit(cprm, elf, sizeof(*elf))) 1572 goto end_coredump; 1573 1574 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1575 goto end_coredump; 1576 1577 /* write program headers for segments dump */ 1578 for (i = 0; i < cprm->vma_count; i++) { 1579 struct core_vma_metadata *meta = cprm->vma_meta + i; 1580 struct elf_phdr phdr; 1581 size_t sz; 1582 1583 sz = meta->end - meta->start; 1584 1585 phdr.p_type = PT_LOAD; 1586 phdr.p_offset = offset; 1587 phdr.p_vaddr = meta->start; 1588 phdr.p_paddr = 0; 1589 phdr.p_filesz = meta->dump_size; 1590 phdr.p_memsz = sz; 1591 offset += phdr.p_filesz; 1592 phdr.p_flags = 0; 1593 if (meta->flags & VM_READ) 1594 phdr.p_flags |= PF_R; 1595 if (meta->flags & VM_WRITE) 1596 phdr.p_flags |= PF_W; 1597 if (meta->flags & VM_EXEC) 1598 phdr.p_flags |= PF_X; 1599 phdr.p_align = ELF_EXEC_PAGESIZE; 1600 1601 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1602 goto end_coredump; 1603 } 1604 1605 if (!elf_core_write_extra_phdrs(cprm, offset)) 1606 goto end_coredump; 1607 1608 /* write out the notes section */ 1609 if (!writenote(thread_list->notes, cprm)) 1610 goto end_coredump; 1611 if (!writenote(&psinfo_note, cprm)) 1612 goto end_coredump; 1613 if (!writenote(&auxv_note, cprm)) 1614 goto end_coredump; 1615 for (i = 1; i < thread_list->num_notes; i++) 1616 if (!writenote(thread_list->notes + i, cprm)) 1617 goto end_coredump; 1618 1619 /* write out the thread status notes section */ 1620 for (tmp = thread_list->next; tmp; tmp = tmp->next) { 1621 for (i = 0; i < tmp->num_notes; i++) 1622 if (!writenote(&tmp->notes[i], cprm)) 1623 goto end_coredump; 1624 } 1625 1626 dump_skip_to(cprm, dataoff); 1627 1628 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count)) 1629 goto end_coredump; 1630 1631 if (!elf_core_write_extra_data(cprm)) 1632 goto end_coredump; 1633 1634 if (e_phnum == PN_XNUM) { 1635 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1636 goto end_coredump; 1637 } 1638 1639 if (cprm->file->f_pos != offset) { 1640 /* Sanity check */ 1641 printk(KERN_WARNING 1642 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1643 cprm->file->f_pos, offset); 1644 } 1645 1646 end_coredump: 1647 while (thread_list) { 1648 tmp = thread_list; 1649 thread_list = thread_list->next; 1650 kfree(tmp); 1651 } 1652 kfree(phdr4note); 1653 kfree(elf); 1654 kfree(psinfo); 1655 kfree(shdr4extnum); 1656 return has_dumped; 1657 } 1658 1659 #endif /* CONFIG_ELF_CORE */ 1660