1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format 2 * 3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * Derived from binfmt_elf.c 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13 #include <linux/module.h> 14 15 #include <linux/fs.h> 16 #include <linux/stat.h> 17 #include <linux/sched.h> 18 #include <linux/sched/coredump.h> 19 #include <linux/sched/task_stack.h> 20 #include <linux/sched/cputime.h> 21 #include <linux/mm.h> 22 #include <linux/mman.h> 23 #include <linux/errno.h> 24 #include <linux/signal.h> 25 #include <linux/binfmts.h> 26 #include <linux/string.h> 27 #include <linux/file.h> 28 #include <linux/fcntl.h> 29 #include <linux/slab.h> 30 #include <linux/pagemap.h> 31 #include <linux/security.h> 32 #include <linux/highmem.h> 33 #include <linux/highuid.h> 34 #include <linux/personality.h> 35 #include <linux/ptrace.h> 36 #include <linux/init.h> 37 #include <linux/elf.h> 38 #include <linux/elf-fdpic.h> 39 #include <linux/elfcore.h> 40 #include <linux/coredump.h> 41 #include <linux/dax.h> 42 43 #include <linux/uaccess.h> 44 #include <asm/param.h> 45 #include <asm/pgalloc.h> 46 47 typedef char *elf_caddr_t; 48 49 #if 0 50 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 51 #else 52 #define kdebug(fmt, ...) do {} while(0) 53 #endif 54 55 #if 0 56 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 57 #else 58 #define kdcore(fmt, ...) do {} while(0) 59 #endif 60 61 MODULE_LICENSE("GPL"); 62 63 static int load_elf_fdpic_binary(struct linux_binprm *); 64 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 65 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 66 struct mm_struct *, const char *); 67 68 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 69 struct elf_fdpic_params *, 70 struct elf_fdpic_params *); 71 72 #ifndef CONFIG_MMU 73 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 74 struct file *, 75 struct mm_struct *); 76 #endif 77 78 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 79 struct file *, struct mm_struct *); 80 81 #ifdef CONFIG_ELF_CORE 82 static int elf_fdpic_core_dump(struct coredump_params *cprm); 83 #endif 84 85 static struct linux_binfmt elf_fdpic_format = { 86 .module = THIS_MODULE, 87 .load_binary = load_elf_fdpic_binary, 88 #ifdef CONFIG_ELF_CORE 89 .core_dump = elf_fdpic_core_dump, 90 #endif 91 .min_coredump = ELF_EXEC_PAGESIZE, 92 }; 93 94 static int __init init_elf_fdpic_binfmt(void) 95 { 96 register_binfmt(&elf_fdpic_format); 97 return 0; 98 } 99 100 static void __exit exit_elf_fdpic_binfmt(void) 101 { 102 unregister_binfmt(&elf_fdpic_format); 103 } 104 105 core_initcall(init_elf_fdpic_binfmt); 106 module_exit(exit_elf_fdpic_binfmt); 107 108 static int is_elf(struct elfhdr *hdr, struct file *file) 109 { 110 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 111 return 0; 112 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 113 return 0; 114 if (!elf_check_arch(hdr)) 115 return 0; 116 if (!file->f_op->mmap) 117 return 0; 118 return 1; 119 } 120 121 #ifndef elf_check_fdpic 122 #define elf_check_fdpic(x) 0 123 #endif 124 125 #ifndef elf_check_const_displacement 126 #define elf_check_const_displacement(x) 0 127 #endif 128 129 static int is_constdisp(struct elfhdr *hdr) 130 { 131 if (!elf_check_fdpic(hdr)) 132 return 1; 133 if (elf_check_const_displacement(hdr)) 134 return 1; 135 return 0; 136 } 137 138 /*****************************************************************************/ 139 /* 140 * read the program headers table into memory 141 */ 142 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 143 struct file *file) 144 { 145 struct elf32_phdr *phdr; 146 unsigned long size; 147 int retval, loop; 148 149 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 150 return -ENOMEM; 151 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 152 return -ENOMEM; 153 154 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 155 params->phdrs = kmalloc(size, GFP_KERNEL); 156 if (!params->phdrs) 157 return -ENOMEM; 158 159 retval = kernel_read(file, params->hdr.e_phoff, 160 (char *) params->phdrs, size); 161 if (unlikely(retval != size)) 162 return retval < 0 ? retval : -ENOEXEC; 163 164 /* determine stack size for this binary */ 165 phdr = params->phdrs; 166 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 167 if (phdr->p_type != PT_GNU_STACK) 168 continue; 169 170 if (phdr->p_flags & PF_X) 171 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 172 else 173 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 174 175 params->stack_size = phdr->p_memsz; 176 break; 177 } 178 179 return 0; 180 } 181 182 /*****************************************************************************/ 183 /* 184 * load an fdpic binary into various bits of memory 185 */ 186 static int load_elf_fdpic_binary(struct linux_binprm *bprm) 187 { 188 struct elf_fdpic_params exec_params, interp_params; 189 struct pt_regs *regs = current_pt_regs(); 190 struct elf_phdr *phdr; 191 unsigned long stack_size, entryaddr; 192 #ifdef ELF_FDPIC_PLAT_INIT 193 unsigned long dynaddr; 194 #endif 195 #ifndef CONFIG_MMU 196 unsigned long stack_prot; 197 #endif 198 struct file *interpreter = NULL; /* to shut gcc up */ 199 char *interpreter_name = NULL; 200 int executable_stack; 201 int retval, i; 202 203 kdebug("____ LOAD %d ____", current->pid); 204 205 memset(&exec_params, 0, sizeof(exec_params)); 206 memset(&interp_params, 0, sizeof(interp_params)); 207 208 exec_params.hdr = *(struct elfhdr *) bprm->buf; 209 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 210 211 /* check that this is a binary we know how to deal with */ 212 retval = -ENOEXEC; 213 if (!is_elf(&exec_params.hdr, bprm->file)) 214 goto error; 215 if (!elf_check_fdpic(&exec_params.hdr)) { 216 #ifdef CONFIG_MMU 217 /* binfmt_elf handles non-fdpic elf except on nommu */ 218 goto error; 219 #else 220 /* nommu can only load ET_DYN (PIE) ELF */ 221 if (exec_params.hdr.e_type != ET_DYN) 222 goto error; 223 #endif 224 } 225 226 /* read the program header table */ 227 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 228 if (retval < 0) 229 goto error; 230 231 /* scan for a program header that specifies an interpreter */ 232 phdr = exec_params.phdrs; 233 234 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 235 switch (phdr->p_type) { 236 case PT_INTERP: 237 retval = -ENOMEM; 238 if (phdr->p_filesz > PATH_MAX) 239 goto error; 240 retval = -ENOENT; 241 if (phdr->p_filesz < 2) 242 goto error; 243 244 /* read the name of the interpreter into memory */ 245 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 246 if (!interpreter_name) 247 goto error; 248 249 retval = kernel_read(bprm->file, 250 phdr->p_offset, 251 interpreter_name, 252 phdr->p_filesz); 253 if (unlikely(retval != phdr->p_filesz)) { 254 if (retval >= 0) 255 retval = -ENOEXEC; 256 goto error; 257 } 258 259 retval = -ENOENT; 260 if (interpreter_name[phdr->p_filesz - 1] != '\0') 261 goto error; 262 263 kdebug("Using ELF interpreter %s", interpreter_name); 264 265 /* replace the program with the interpreter */ 266 interpreter = open_exec(interpreter_name); 267 retval = PTR_ERR(interpreter); 268 if (IS_ERR(interpreter)) { 269 interpreter = NULL; 270 goto error; 271 } 272 273 /* 274 * If the binary is not readable then enforce 275 * mm->dumpable = 0 regardless of the interpreter's 276 * permissions. 277 */ 278 would_dump(bprm, interpreter); 279 280 retval = kernel_read(interpreter, 0, bprm->buf, 281 BINPRM_BUF_SIZE); 282 if (unlikely(retval != BINPRM_BUF_SIZE)) { 283 if (retval >= 0) 284 retval = -ENOEXEC; 285 goto error; 286 } 287 288 interp_params.hdr = *((struct elfhdr *) bprm->buf); 289 break; 290 291 case PT_LOAD: 292 #ifdef CONFIG_MMU 293 if (exec_params.load_addr == 0) 294 exec_params.load_addr = phdr->p_vaddr; 295 #endif 296 break; 297 } 298 299 } 300 301 if (is_constdisp(&exec_params.hdr)) 302 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 303 304 /* perform insanity checks on the interpreter */ 305 if (interpreter_name) { 306 retval = -ELIBBAD; 307 if (!is_elf(&interp_params.hdr, interpreter)) 308 goto error; 309 310 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 311 312 /* read the interpreter's program header table */ 313 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 314 if (retval < 0) 315 goto error; 316 } 317 318 stack_size = exec_params.stack_size; 319 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 320 executable_stack = EXSTACK_ENABLE_X; 321 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 322 executable_stack = EXSTACK_DISABLE_X; 323 else 324 executable_stack = EXSTACK_DEFAULT; 325 326 if (stack_size == 0) { 327 stack_size = interp_params.stack_size; 328 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 329 executable_stack = EXSTACK_ENABLE_X; 330 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 331 executable_stack = EXSTACK_DISABLE_X; 332 else 333 executable_stack = EXSTACK_DEFAULT; 334 } 335 336 retval = -ENOEXEC; 337 if (stack_size == 0) 338 stack_size = 131072UL; /* same as exec.c's default commit */ 339 340 if (is_constdisp(&interp_params.hdr)) 341 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 342 343 /* flush all traces of the currently running executable */ 344 retval = flush_old_exec(bprm); 345 if (retval) 346 goto error; 347 348 /* there's now no turning back... the old userspace image is dead, 349 * defunct, deceased, etc. 350 */ 351 if (elf_check_fdpic(&exec_params.hdr)) 352 set_personality(PER_LINUX_FDPIC); 353 else 354 set_personality(PER_LINUX); 355 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 356 current->personality |= READ_IMPLIES_EXEC; 357 358 setup_new_exec(bprm); 359 360 set_binfmt(&elf_fdpic_format); 361 362 current->mm->start_code = 0; 363 current->mm->end_code = 0; 364 current->mm->start_stack = 0; 365 current->mm->start_data = 0; 366 current->mm->end_data = 0; 367 current->mm->context.exec_fdpic_loadmap = 0; 368 current->mm->context.interp_fdpic_loadmap = 0; 369 370 #ifdef CONFIG_MMU 371 elf_fdpic_arch_lay_out_mm(&exec_params, 372 &interp_params, 373 ¤t->mm->start_stack, 374 ¤t->mm->start_brk); 375 376 retval = setup_arg_pages(bprm, current->mm->start_stack, 377 executable_stack); 378 if (retval < 0) 379 goto error; 380 #endif 381 382 /* load the executable and interpreter into memory */ 383 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 384 "executable"); 385 if (retval < 0) 386 goto error; 387 388 if (interpreter_name) { 389 retval = elf_fdpic_map_file(&interp_params, interpreter, 390 current->mm, "interpreter"); 391 if (retval < 0) { 392 printk(KERN_ERR "Unable to load interpreter\n"); 393 goto error; 394 } 395 396 allow_write_access(interpreter); 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 install_exec_creds(bprm); 436 if (create_elf_fdpic_tables(bprm, current->mm, 437 &exec_params, &interp_params) < 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 /* everything is now ready... get the userspace context ready to roll */ 461 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 462 start_thread(regs, entryaddr, current->mm->start_stack); 463 464 retval = 0; 465 466 error: 467 if (interpreter) { 468 allow_write_access(interpreter); 469 fput(interpreter); 470 } 471 kfree(interpreter_name); 472 kfree(exec_params.phdrs); 473 kfree(exec_params.loadmap); 474 kfree(interp_params.phdrs); 475 kfree(interp_params.loadmap); 476 return retval; 477 } 478 479 /*****************************************************************************/ 480 481 #ifndef ELF_BASE_PLATFORM 482 /* 483 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 484 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 485 * will be copied to the user stack in the same manner as AT_PLATFORM. 486 */ 487 #define ELF_BASE_PLATFORM NULL 488 #endif 489 490 /* 491 * present useful information to the program by shovelling it onto the new 492 * process's stack 493 */ 494 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 495 struct mm_struct *mm, 496 struct elf_fdpic_params *exec_params, 497 struct elf_fdpic_params *interp_params) 498 { 499 const struct cred *cred = current_cred(); 500 unsigned long sp, csp, nitems; 501 elf_caddr_t __user *argv, *envp; 502 size_t platform_len = 0, len; 503 char *k_platform, *k_base_platform; 504 char __user *u_platform, *u_base_platform, *p; 505 int loop; 506 int nr; /* reset for each csp adjustment */ 507 508 #ifdef CONFIG_MMU 509 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 510 * by the processes running on the same package. One thing we can do is 511 * to shuffle the initial stack for them, so we give the architecture 512 * an opportunity to do so here. 513 */ 514 sp = arch_align_stack(bprm->p); 515 #else 516 sp = mm->start_stack; 517 518 /* stack the program arguments and environment */ 519 if (transfer_args_to_stack(bprm, &sp) < 0) 520 return -EFAULT; 521 sp &= ~15; 522 #endif 523 524 /* 525 * If this architecture has a platform capability string, copy it 526 * to userspace. In some cases (Sparc), this info is impossible 527 * for userspace to get any other way, in others (i386) it is 528 * merely difficult. 529 */ 530 k_platform = ELF_PLATFORM; 531 u_platform = NULL; 532 533 if (k_platform) { 534 platform_len = strlen(k_platform) + 1; 535 sp -= platform_len; 536 u_platform = (char __user *) sp; 537 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 538 return -EFAULT; 539 } 540 541 /* 542 * If this architecture has a "base" platform capability 543 * string, copy it to userspace. 544 */ 545 k_base_platform = ELF_BASE_PLATFORM; 546 u_base_platform = NULL; 547 548 if (k_base_platform) { 549 platform_len = strlen(k_base_platform) + 1; 550 sp -= platform_len; 551 u_base_platform = (char __user *) sp; 552 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 553 return -EFAULT; 554 } 555 556 sp &= ~7UL; 557 558 /* stack the load map(s) */ 559 len = sizeof(struct elf32_fdpic_loadmap); 560 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 561 sp = (sp - len) & ~7UL; 562 exec_params->map_addr = sp; 563 564 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 565 return -EFAULT; 566 567 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 568 569 if (interp_params->loadmap) { 570 len = sizeof(struct elf32_fdpic_loadmap); 571 len += sizeof(struct elf32_fdpic_loadseg) * 572 interp_params->loadmap->nsegs; 573 sp = (sp - len) & ~7UL; 574 interp_params->map_addr = sp; 575 576 if (copy_to_user((void __user *) sp, interp_params->loadmap, 577 len) != 0) 578 return -EFAULT; 579 580 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 581 } 582 583 /* force 16 byte _final_ alignment here for generality */ 584 #define DLINFO_ITEMS 15 585 586 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 587 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 588 589 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 590 nitems++; 591 592 csp = sp; 593 sp -= nitems * 2 * sizeof(unsigned long); 594 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 595 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 596 sp -= 1 * sizeof(unsigned long); /* argc */ 597 598 csp -= sp & 15UL; 599 sp -= sp & 15UL; 600 601 /* put the ELF interpreter info on the stack */ 602 #define NEW_AUX_ENT(id, val) \ 603 do { \ 604 struct { unsigned long _id, _val; } __user *ent; \ 605 \ 606 ent = (void __user *) csp; \ 607 __put_user((id), &ent[nr]._id); \ 608 __put_user((val), &ent[nr]._val); \ 609 nr++; \ 610 } while (0) 611 612 nr = 0; 613 csp -= 2 * sizeof(unsigned long); 614 NEW_AUX_ENT(AT_NULL, 0); 615 if (k_platform) { 616 nr = 0; 617 csp -= 2 * sizeof(unsigned long); 618 NEW_AUX_ENT(AT_PLATFORM, 619 (elf_addr_t) (unsigned long) u_platform); 620 } 621 622 if (k_base_platform) { 623 nr = 0; 624 csp -= 2 * sizeof(unsigned long); 625 NEW_AUX_ENT(AT_BASE_PLATFORM, 626 (elf_addr_t) (unsigned long) u_base_platform); 627 } 628 629 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 630 nr = 0; 631 csp -= 2 * sizeof(unsigned long); 632 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 633 } 634 635 nr = 0; 636 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 637 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 638 #ifdef ELF_HWCAP2 639 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 640 #endif 641 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 642 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 643 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 644 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 645 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 646 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 647 NEW_AUX_ENT(AT_FLAGS, 0); 648 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 649 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 650 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 651 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 652 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 653 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 654 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 655 656 #ifdef ARCH_DLINFO 657 nr = 0; 658 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 659 660 /* ARCH_DLINFO must come last so platform specific code can enforce 661 * special alignment requirements on the AUXV if necessary (eg. PPC). 662 */ 663 ARCH_DLINFO; 664 #endif 665 #undef NEW_AUX_ENT 666 667 /* allocate room for argv[] and envv[] */ 668 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 669 envp = (elf_caddr_t __user *) csp; 670 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 671 argv = (elf_caddr_t __user *) csp; 672 673 /* stack argc */ 674 csp -= sizeof(unsigned long); 675 __put_user(bprm->argc, (unsigned long __user *) csp); 676 677 BUG_ON(csp != sp); 678 679 /* fill in the argv[] array */ 680 #ifdef CONFIG_MMU 681 current->mm->arg_start = bprm->p; 682 #else 683 current->mm->arg_start = current->mm->start_stack - 684 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 685 #endif 686 687 p = (char __user *) current->mm->arg_start; 688 for (loop = bprm->argc; loop > 0; loop--) { 689 __put_user((elf_caddr_t) p, argv++); 690 len = strnlen_user(p, MAX_ARG_STRLEN); 691 if (!len || len > MAX_ARG_STRLEN) 692 return -EINVAL; 693 p += len; 694 } 695 __put_user(NULL, argv); 696 current->mm->arg_end = (unsigned long) p; 697 698 /* fill in the envv[] array */ 699 current->mm->env_start = (unsigned long) p; 700 for (loop = bprm->envc; loop > 0; loop--) { 701 __put_user((elf_caddr_t)(unsigned long) p, envp++); 702 len = strnlen_user(p, MAX_ARG_STRLEN); 703 if (!len || len > MAX_ARG_STRLEN) 704 return -EINVAL; 705 p += len; 706 } 707 __put_user(NULL, envp); 708 current->mm->env_end = (unsigned long) p; 709 710 mm->start_stack = (unsigned long) sp; 711 return 0; 712 } 713 714 /*****************************************************************************/ 715 /* 716 * load the appropriate binary image (executable or interpreter) into memory 717 * - we assume no MMU is available 718 * - if no other PIC bits are set in params->hdr->e_flags 719 * - we assume that the LOADable segments in the binary are independently relocatable 720 * - we assume R/O executable segments are shareable 721 * - else 722 * - we assume the loadable parts of the image to require fixed displacement 723 * - the image is not shareable 724 */ 725 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 726 struct file *file, 727 struct mm_struct *mm, 728 const char *what) 729 { 730 struct elf32_fdpic_loadmap *loadmap; 731 #ifdef CONFIG_MMU 732 struct elf32_fdpic_loadseg *mseg; 733 #endif 734 struct elf32_fdpic_loadseg *seg; 735 struct elf32_phdr *phdr; 736 unsigned long load_addr, stop; 737 unsigned nloads, tmp; 738 size_t size; 739 int loop, ret; 740 741 /* allocate a load map table */ 742 nloads = 0; 743 for (loop = 0; loop < params->hdr.e_phnum; loop++) 744 if (params->phdrs[loop].p_type == PT_LOAD) 745 nloads++; 746 747 if (nloads == 0) 748 return -ELIBBAD; 749 750 size = sizeof(*loadmap) + nloads * sizeof(*seg); 751 loadmap = kzalloc(size, GFP_KERNEL); 752 if (!loadmap) 753 return -ENOMEM; 754 755 params->loadmap = loadmap; 756 757 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 758 loadmap->nsegs = nloads; 759 760 load_addr = params->load_addr; 761 seg = loadmap->segs; 762 763 /* map the requested LOADs into the memory space */ 764 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 765 case ELF_FDPIC_FLAG_CONSTDISP: 766 case ELF_FDPIC_FLAG_CONTIGUOUS: 767 #ifndef CONFIG_MMU 768 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 769 if (ret < 0) 770 return ret; 771 break; 772 #endif 773 default: 774 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 775 if (ret < 0) 776 return ret; 777 break; 778 } 779 780 /* map the entry point */ 781 if (params->hdr.e_entry) { 782 seg = loadmap->segs; 783 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 784 if (params->hdr.e_entry >= seg->p_vaddr && 785 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 786 params->entry_addr = 787 (params->hdr.e_entry - seg->p_vaddr) + 788 seg->addr; 789 break; 790 } 791 } 792 } 793 794 /* determine where the program header table has wound up if mapped */ 795 stop = params->hdr.e_phoff; 796 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 797 phdr = params->phdrs; 798 799 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 800 if (phdr->p_type != PT_LOAD) 801 continue; 802 803 if (phdr->p_offset > params->hdr.e_phoff || 804 phdr->p_offset + phdr->p_filesz < stop) 805 continue; 806 807 seg = loadmap->segs; 808 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 809 if (phdr->p_vaddr >= seg->p_vaddr && 810 phdr->p_vaddr + phdr->p_filesz <= 811 seg->p_vaddr + seg->p_memsz) { 812 params->ph_addr = 813 (phdr->p_vaddr - seg->p_vaddr) + 814 seg->addr + 815 params->hdr.e_phoff - phdr->p_offset; 816 break; 817 } 818 } 819 break; 820 } 821 822 /* determine where the dynamic section has wound up if there is one */ 823 phdr = params->phdrs; 824 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 825 if (phdr->p_type != PT_DYNAMIC) 826 continue; 827 828 seg = loadmap->segs; 829 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 830 if (phdr->p_vaddr >= seg->p_vaddr && 831 phdr->p_vaddr + phdr->p_memsz <= 832 seg->p_vaddr + seg->p_memsz) { 833 params->dynamic_addr = 834 (phdr->p_vaddr - seg->p_vaddr) + 835 seg->addr; 836 837 /* check the dynamic section contains at least 838 * one item, and that the last item is a NULL 839 * entry */ 840 if (phdr->p_memsz == 0 || 841 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 842 goto dynamic_error; 843 844 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 845 if (((Elf32_Dyn *) 846 params->dynamic_addr)[tmp - 1].d_tag != 0) 847 goto dynamic_error; 848 break; 849 } 850 } 851 break; 852 } 853 854 /* now elide adjacent segments in the load map on MMU linux 855 * - on uClinux the holes between may actually be filled with system 856 * stuff or stuff from other processes 857 */ 858 #ifdef CONFIG_MMU 859 nloads = loadmap->nsegs; 860 mseg = loadmap->segs; 861 seg = mseg + 1; 862 for (loop = 1; loop < nloads; loop++) { 863 /* see if we have a candidate for merging */ 864 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 865 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 866 if (load_addr == (seg->addr & PAGE_MASK)) { 867 mseg->p_memsz += 868 load_addr - 869 (mseg->addr + mseg->p_memsz); 870 mseg->p_memsz += seg->addr & ~PAGE_MASK; 871 mseg->p_memsz += seg->p_memsz; 872 loadmap->nsegs--; 873 continue; 874 } 875 } 876 877 mseg++; 878 if (mseg != seg) 879 *mseg = *seg; 880 } 881 #endif 882 883 kdebug("Mapped Object [%s]:", what); 884 kdebug("- elfhdr : %lx", params->elfhdr_addr); 885 kdebug("- entry : %lx", params->entry_addr); 886 kdebug("- PHDR[] : %lx", params->ph_addr); 887 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 888 seg = loadmap->segs; 889 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 890 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 891 loop, 892 seg->addr, seg->addr + seg->p_memsz - 1, 893 seg->p_vaddr, seg->p_memsz); 894 895 return 0; 896 897 dynamic_error: 898 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 899 what, file_inode(file)->i_ino); 900 return -ELIBBAD; 901 } 902 903 /*****************************************************************************/ 904 /* 905 * map a file with constant displacement under uClinux 906 */ 907 #ifndef CONFIG_MMU 908 static int elf_fdpic_map_file_constdisp_on_uclinux( 909 struct elf_fdpic_params *params, 910 struct file *file, 911 struct mm_struct *mm) 912 { 913 struct elf32_fdpic_loadseg *seg; 914 struct elf32_phdr *phdr; 915 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 916 int loop, ret; 917 918 load_addr = params->load_addr; 919 seg = params->loadmap->segs; 920 921 /* determine the bounds of the contiguous overall allocation we must 922 * make */ 923 phdr = params->phdrs; 924 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 925 if (params->phdrs[loop].p_type != PT_LOAD) 926 continue; 927 928 if (base > phdr->p_vaddr) 929 base = phdr->p_vaddr; 930 if (top < phdr->p_vaddr + phdr->p_memsz) 931 top = phdr->p_vaddr + phdr->p_memsz; 932 } 933 934 /* allocate one big anon block for everything */ 935 mflags = MAP_PRIVATE; 936 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 937 mflags |= MAP_EXECUTABLE; 938 939 maddr = vm_mmap(NULL, load_addr, top - base, 940 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 941 if (IS_ERR_VALUE(maddr)) 942 return (int) maddr; 943 944 if (load_addr != 0) 945 load_addr += PAGE_ALIGN(top - base); 946 947 /* and then load the file segments into it */ 948 phdr = params->phdrs; 949 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 950 if (params->phdrs[loop].p_type != PT_LOAD) 951 continue; 952 953 seg->addr = maddr + (phdr->p_vaddr - base); 954 seg->p_vaddr = phdr->p_vaddr; 955 seg->p_memsz = phdr->p_memsz; 956 957 ret = read_code(file, seg->addr, phdr->p_offset, 958 phdr->p_filesz); 959 if (ret < 0) 960 return ret; 961 962 /* map the ELF header address if in this segment */ 963 if (phdr->p_offset == 0) 964 params->elfhdr_addr = seg->addr; 965 966 /* clear any space allocated but not loaded */ 967 if (phdr->p_filesz < phdr->p_memsz) { 968 if (clear_user((void *) (seg->addr + phdr->p_filesz), 969 phdr->p_memsz - phdr->p_filesz)) 970 return -EFAULT; 971 } 972 973 if (mm) { 974 if (phdr->p_flags & PF_X) { 975 if (!mm->start_code) { 976 mm->start_code = seg->addr; 977 mm->end_code = seg->addr + 978 phdr->p_memsz; 979 } 980 } else if (!mm->start_data) { 981 mm->start_data = seg->addr; 982 mm->end_data = seg->addr + phdr->p_memsz; 983 } 984 } 985 986 seg++; 987 } 988 989 return 0; 990 } 991 #endif 992 993 /*****************************************************************************/ 994 /* 995 * map a binary by direct mmap() of the individual PT_LOAD segments 996 */ 997 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 998 struct file *file, 999 struct mm_struct *mm) 1000 { 1001 struct elf32_fdpic_loadseg *seg; 1002 struct elf32_phdr *phdr; 1003 unsigned long load_addr, delta_vaddr; 1004 int loop, dvset; 1005 1006 load_addr = params->load_addr; 1007 delta_vaddr = 0; 1008 dvset = 0; 1009 1010 seg = params->loadmap->segs; 1011 1012 /* deal with each load segment separately */ 1013 phdr = params->phdrs; 1014 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1015 unsigned long maddr, disp, excess, excess1; 1016 int prot = 0, flags; 1017 1018 if (phdr->p_type != PT_LOAD) 1019 continue; 1020 1021 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1022 (unsigned long) phdr->p_vaddr, 1023 (unsigned long) phdr->p_offset, 1024 (unsigned long) phdr->p_filesz, 1025 (unsigned long) phdr->p_memsz); 1026 1027 /* determine the mapping parameters */ 1028 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1029 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1030 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1031 1032 flags = MAP_PRIVATE | MAP_DENYWRITE; 1033 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1034 flags |= MAP_EXECUTABLE; 1035 1036 maddr = 0; 1037 1038 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1039 case ELF_FDPIC_FLAG_INDEPENDENT: 1040 /* PT_LOADs are independently locatable */ 1041 break; 1042 1043 case ELF_FDPIC_FLAG_HONOURVADDR: 1044 /* the specified virtual address must be honoured */ 1045 maddr = phdr->p_vaddr; 1046 flags |= MAP_FIXED; 1047 break; 1048 1049 case ELF_FDPIC_FLAG_CONSTDISP: 1050 /* constant displacement 1051 * - can be mapped anywhere, but must be mapped as a 1052 * unit 1053 */ 1054 if (!dvset) { 1055 maddr = load_addr; 1056 delta_vaddr = phdr->p_vaddr; 1057 dvset = 1; 1058 } else { 1059 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1060 flags |= MAP_FIXED; 1061 } 1062 break; 1063 1064 case ELF_FDPIC_FLAG_CONTIGUOUS: 1065 /* contiguity handled later */ 1066 break; 1067 1068 default: 1069 BUG(); 1070 } 1071 1072 maddr &= PAGE_MASK; 1073 1074 /* create the mapping */ 1075 disp = phdr->p_vaddr & ~PAGE_MASK; 1076 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1077 phdr->p_offset - disp); 1078 1079 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1080 loop, phdr->p_memsz + disp, prot, flags, 1081 phdr->p_offset - disp, maddr); 1082 1083 if (IS_ERR_VALUE(maddr)) 1084 return (int) maddr; 1085 1086 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1087 ELF_FDPIC_FLAG_CONTIGUOUS) 1088 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1089 1090 seg->addr = maddr + disp; 1091 seg->p_vaddr = phdr->p_vaddr; 1092 seg->p_memsz = phdr->p_memsz; 1093 1094 /* map the ELF header address if in this segment */ 1095 if (phdr->p_offset == 0) 1096 params->elfhdr_addr = seg->addr; 1097 1098 /* clear the bit between beginning of mapping and beginning of 1099 * PT_LOAD */ 1100 if (prot & PROT_WRITE && disp > 0) { 1101 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1102 if (clear_user((void __user *) maddr, disp)) 1103 return -EFAULT; 1104 maddr += disp; 1105 } 1106 1107 /* clear any space allocated but not loaded 1108 * - on uClinux we can just clear the lot 1109 * - on MMU linux we'll get a SIGBUS beyond the last page 1110 * extant in the file 1111 */ 1112 excess = phdr->p_memsz - phdr->p_filesz; 1113 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1114 1115 #ifdef CONFIG_MMU 1116 if (excess > excess1) { 1117 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1118 unsigned long xmaddr; 1119 1120 flags |= MAP_FIXED | MAP_ANONYMOUS; 1121 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1122 prot, flags, 0); 1123 1124 kdebug("mmap[%d] <anon>" 1125 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1126 loop, xaddr, excess - excess1, prot, flags, 1127 xmaddr); 1128 1129 if (xmaddr != xaddr) 1130 return -ENOMEM; 1131 } 1132 1133 if (prot & PROT_WRITE && excess1 > 0) { 1134 kdebug("clear[%d] ad=%lx sz=%lx", 1135 loop, maddr + phdr->p_filesz, excess1); 1136 if (clear_user((void __user *) maddr + phdr->p_filesz, 1137 excess1)) 1138 return -EFAULT; 1139 } 1140 1141 #else 1142 if (excess > 0) { 1143 kdebug("clear[%d] ad=%lx sz=%lx", 1144 loop, maddr + phdr->p_filesz, excess); 1145 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1146 return -EFAULT; 1147 } 1148 #endif 1149 1150 if (mm) { 1151 if (phdr->p_flags & PF_X) { 1152 if (!mm->start_code) { 1153 mm->start_code = maddr; 1154 mm->end_code = maddr + phdr->p_memsz; 1155 } 1156 } else if (!mm->start_data) { 1157 mm->start_data = maddr; 1158 mm->end_data = maddr + phdr->p_memsz; 1159 } 1160 } 1161 1162 seg++; 1163 } 1164 1165 return 0; 1166 } 1167 1168 /*****************************************************************************/ 1169 /* 1170 * ELF-FDPIC core dumper 1171 * 1172 * Modelled on fs/exec.c:aout_core_dump() 1173 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1174 * 1175 * Modelled on fs/binfmt_elf.c core dumper 1176 */ 1177 #ifdef CONFIG_ELF_CORE 1178 1179 /* 1180 * Decide whether a segment is worth dumping; default is yes to be 1181 * sure (missing info is worse than too much; etc). 1182 * Personally I'd include everything, and use the coredump limit... 1183 * 1184 * I think we should skip something. But I am not sure how. H.J. 1185 */ 1186 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1187 { 1188 int dump_ok; 1189 1190 /* Do not dump I/O mapped devices or special mappings */ 1191 if (vma->vm_flags & VM_IO) { 1192 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1193 return 0; 1194 } 1195 1196 /* If we may not read the contents, don't allow us to dump 1197 * them either. "dump_write()" can't handle it anyway. 1198 */ 1199 if (!(vma->vm_flags & VM_READ)) { 1200 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1201 return 0; 1202 } 1203 1204 /* support for DAX */ 1205 if (vma_is_dax(vma)) { 1206 if (vma->vm_flags & VM_SHARED) { 1207 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags); 1208 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start, 1209 vma->vm_flags, dump_ok ? "yes" : "no"); 1210 } else { 1211 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags); 1212 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start, 1213 vma->vm_flags, dump_ok ? "yes" : "no"); 1214 } 1215 return dump_ok; 1216 } 1217 1218 /* By default, dump shared memory if mapped from an anonymous file. */ 1219 if (vma->vm_flags & VM_SHARED) { 1220 if (file_inode(vma->vm_file)->i_nlink == 0) { 1221 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1222 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1223 vma->vm_flags, dump_ok ? "yes" : "no"); 1224 return dump_ok; 1225 } 1226 1227 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1228 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1229 vma->vm_flags, dump_ok ? "yes" : "no"); 1230 return dump_ok; 1231 } 1232 1233 #ifdef CONFIG_MMU 1234 /* By default, if it hasn't been written to, don't write it out */ 1235 if (!vma->anon_vma) { 1236 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1237 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1238 vma->vm_flags, dump_ok ? "yes" : "no"); 1239 return dump_ok; 1240 } 1241 #endif 1242 1243 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1244 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1245 dump_ok ? "yes" : "no"); 1246 return dump_ok; 1247 } 1248 1249 /* An ELF note in memory */ 1250 struct memelfnote 1251 { 1252 const char *name; 1253 int type; 1254 unsigned int datasz; 1255 void *data; 1256 }; 1257 1258 static int notesize(struct memelfnote *en) 1259 { 1260 int sz; 1261 1262 sz = sizeof(struct elf_note); 1263 sz += roundup(strlen(en->name) + 1, 4); 1264 sz += roundup(en->datasz, 4); 1265 1266 return sz; 1267 } 1268 1269 /* #define DEBUG */ 1270 1271 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1272 { 1273 struct elf_note en; 1274 en.n_namesz = strlen(men->name) + 1; 1275 en.n_descsz = men->datasz; 1276 en.n_type = men->type; 1277 1278 return dump_emit(cprm, &en, sizeof(en)) && 1279 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1280 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1281 } 1282 1283 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1284 { 1285 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1286 elf->e_ident[EI_CLASS] = ELF_CLASS; 1287 elf->e_ident[EI_DATA] = ELF_DATA; 1288 elf->e_ident[EI_VERSION] = EV_CURRENT; 1289 elf->e_ident[EI_OSABI] = ELF_OSABI; 1290 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1291 1292 elf->e_type = ET_CORE; 1293 elf->e_machine = ELF_ARCH; 1294 elf->e_version = EV_CURRENT; 1295 elf->e_entry = 0; 1296 elf->e_phoff = sizeof(struct elfhdr); 1297 elf->e_shoff = 0; 1298 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1299 elf->e_ehsize = sizeof(struct elfhdr); 1300 elf->e_phentsize = sizeof(struct elf_phdr); 1301 elf->e_phnum = segs; 1302 elf->e_shentsize = 0; 1303 elf->e_shnum = 0; 1304 elf->e_shstrndx = 0; 1305 return; 1306 } 1307 1308 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1309 { 1310 phdr->p_type = PT_NOTE; 1311 phdr->p_offset = offset; 1312 phdr->p_vaddr = 0; 1313 phdr->p_paddr = 0; 1314 phdr->p_filesz = sz; 1315 phdr->p_memsz = 0; 1316 phdr->p_flags = 0; 1317 phdr->p_align = 0; 1318 return; 1319 } 1320 1321 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1322 unsigned int sz, void *data) 1323 { 1324 note->name = name; 1325 note->type = type; 1326 note->datasz = sz; 1327 note->data = data; 1328 return; 1329 } 1330 1331 /* 1332 * fill up all the fields in prstatus from the given task struct, except 1333 * registers which need to be filled up separately. 1334 */ 1335 static void fill_prstatus(struct elf_prstatus *prstatus, 1336 struct task_struct *p, long signr) 1337 { 1338 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1339 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1340 prstatus->pr_sighold = p->blocked.sig[0]; 1341 rcu_read_lock(); 1342 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1343 rcu_read_unlock(); 1344 prstatus->pr_pid = task_pid_vnr(p); 1345 prstatus->pr_pgrp = task_pgrp_vnr(p); 1346 prstatus->pr_sid = task_session_vnr(p); 1347 if (thread_group_leader(p)) { 1348 struct task_cputime cputime; 1349 1350 /* 1351 * This is the record for the group leader. It shows the 1352 * group-wide total, not its individual thread total. 1353 */ 1354 thread_group_cputime(p, &cputime); 1355 prstatus->pr_utime = ns_to_timeval(cputime.utime); 1356 prstatus->pr_stime = ns_to_timeval(cputime.stime); 1357 } else { 1358 u64 utime, stime; 1359 1360 task_cputime(p, &utime, &stime); 1361 prstatus->pr_utime = ns_to_timeval(utime); 1362 prstatus->pr_stime = ns_to_timeval(stime); 1363 } 1364 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime); 1365 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime); 1366 1367 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1368 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1369 } 1370 1371 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1372 struct mm_struct *mm) 1373 { 1374 const struct cred *cred; 1375 unsigned int i, len; 1376 1377 /* first copy the parameters from user space */ 1378 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1379 1380 len = mm->arg_end - mm->arg_start; 1381 if (len >= ELF_PRARGSZ) 1382 len = ELF_PRARGSZ - 1; 1383 if (copy_from_user(&psinfo->pr_psargs, 1384 (const char __user *) mm->arg_start, len)) 1385 return -EFAULT; 1386 for (i = 0; i < len; i++) 1387 if (psinfo->pr_psargs[i] == 0) 1388 psinfo->pr_psargs[i] = ' '; 1389 psinfo->pr_psargs[len] = 0; 1390 1391 rcu_read_lock(); 1392 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1393 rcu_read_unlock(); 1394 psinfo->pr_pid = task_pid_vnr(p); 1395 psinfo->pr_pgrp = task_pgrp_vnr(p); 1396 psinfo->pr_sid = task_session_vnr(p); 1397 1398 i = p->state ? ffz(~p->state) + 1 : 0; 1399 psinfo->pr_state = i; 1400 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1401 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1402 psinfo->pr_nice = task_nice(p); 1403 psinfo->pr_flag = p->flags; 1404 rcu_read_lock(); 1405 cred = __task_cred(p); 1406 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1407 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1408 rcu_read_unlock(); 1409 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1410 1411 return 0; 1412 } 1413 1414 /* Here is the structure in which status of each thread is captured. */ 1415 struct elf_thread_status 1416 { 1417 struct list_head list; 1418 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1419 elf_fpregset_t fpu; /* NT_PRFPREG */ 1420 struct task_struct *thread; 1421 #ifdef ELF_CORE_COPY_XFPREGS 1422 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1423 #endif 1424 struct memelfnote notes[3]; 1425 int num_notes; 1426 }; 1427 1428 /* 1429 * In order to add the specific thread information for the elf file format, 1430 * we need to keep a linked list of every thread's pr_status and then create 1431 * a single section for them in the final core file. 1432 */ 1433 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1434 { 1435 struct task_struct *p = t->thread; 1436 int sz = 0; 1437 1438 t->num_notes = 0; 1439 1440 fill_prstatus(&t->prstatus, p, signr); 1441 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1442 1443 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1444 &t->prstatus); 1445 t->num_notes++; 1446 sz += notesize(&t->notes[0]); 1447 1448 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1449 if (t->prstatus.pr_fpvalid) { 1450 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1451 &t->fpu); 1452 t->num_notes++; 1453 sz += notesize(&t->notes[1]); 1454 } 1455 1456 #ifdef ELF_CORE_COPY_XFPREGS 1457 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1458 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1459 sizeof(t->xfpu), &t->xfpu); 1460 t->num_notes++; 1461 sz += notesize(&t->notes[2]); 1462 } 1463 #endif 1464 return sz; 1465 } 1466 1467 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1468 elf_addr_t e_shoff, int segs) 1469 { 1470 elf->e_shoff = e_shoff; 1471 elf->e_shentsize = sizeof(*shdr4extnum); 1472 elf->e_shnum = 1; 1473 elf->e_shstrndx = SHN_UNDEF; 1474 1475 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1476 1477 shdr4extnum->sh_type = SHT_NULL; 1478 shdr4extnum->sh_size = elf->e_shnum; 1479 shdr4extnum->sh_link = elf->e_shstrndx; 1480 shdr4extnum->sh_info = segs; 1481 } 1482 1483 /* 1484 * dump the segments for an MMU process 1485 */ 1486 static bool elf_fdpic_dump_segments(struct coredump_params *cprm) 1487 { 1488 struct vm_area_struct *vma; 1489 1490 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1491 unsigned long addr; 1492 1493 if (!maydump(vma, cprm->mm_flags)) 1494 continue; 1495 1496 #ifdef CONFIG_MMU 1497 for (addr = vma->vm_start; addr < vma->vm_end; 1498 addr += PAGE_SIZE) { 1499 bool res; 1500 struct page *page = get_dump_page(addr); 1501 if (page) { 1502 void *kaddr = kmap(page); 1503 res = dump_emit(cprm, kaddr, PAGE_SIZE); 1504 kunmap(page); 1505 put_page(page); 1506 } else { 1507 res = dump_skip(cprm, PAGE_SIZE); 1508 } 1509 if (!res) 1510 return false; 1511 } 1512 #else 1513 if (!dump_emit(cprm, (void *) vma->vm_start, 1514 vma->vm_end - vma->vm_start)) 1515 return false; 1516 #endif 1517 } 1518 return true; 1519 } 1520 1521 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1522 { 1523 struct vm_area_struct *vma; 1524 size_t size = 0; 1525 1526 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1527 if (maydump(vma, mm_flags)) 1528 size += vma->vm_end - vma->vm_start; 1529 return size; 1530 } 1531 1532 /* 1533 * Actual dumper 1534 * 1535 * This is a two-pass process; first we find the offsets of the bits, 1536 * and then they are actually written out. If we run out of core limit 1537 * we just truncate. 1538 */ 1539 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1540 { 1541 #define NUM_NOTES 6 1542 int has_dumped = 0; 1543 mm_segment_t fs; 1544 int segs; 1545 int i; 1546 struct vm_area_struct *vma; 1547 struct elfhdr *elf = NULL; 1548 loff_t offset = 0, dataoff; 1549 int numnote; 1550 struct memelfnote *notes = NULL; 1551 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1552 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1553 LIST_HEAD(thread_list); 1554 struct list_head *t; 1555 elf_fpregset_t *fpu = NULL; 1556 #ifdef ELF_CORE_COPY_XFPREGS 1557 elf_fpxregset_t *xfpu = NULL; 1558 #endif 1559 int thread_status_size = 0; 1560 elf_addr_t *auxv; 1561 struct elf_phdr *phdr4note = NULL; 1562 struct elf_shdr *shdr4extnum = NULL; 1563 Elf_Half e_phnum; 1564 elf_addr_t e_shoff; 1565 struct core_thread *ct; 1566 struct elf_thread_status *tmp; 1567 1568 /* 1569 * We no longer stop all VM operations. 1570 * 1571 * This is because those proceses that could possibly change map_count 1572 * or the mmap / vma pages are now blocked in do_exit on current 1573 * finishing this core dump. 1574 * 1575 * Only ptrace can touch these memory addresses, but it doesn't change 1576 * the map_count or the pages allocated. So no possibility of crashing 1577 * exists while dumping the mm->vm_next areas to the core file. 1578 */ 1579 1580 /* alloc memory for large data structures: too large to be on stack */ 1581 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1582 if (!elf) 1583 goto cleanup; 1584 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1585 if (!prstatus) 1586 goto cleanup; 1587 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1588 if (!psinfo) 1589 goto cleanup; 1590 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1591 if (!notes) 1592 goto cleanup; 1593 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1594 if (!fpu) 1595 goto cleanup; 1596 #ifdef ELF_CORE_COPY_XFPREGS 1597 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1598 if (!xfpu) 1599 goto cleanup; 1600 #endif 1601 1602 for (ct = current->mm->core_state->dumper.next; 1603 ct; ct = ct->next) { 1604 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1605 if (!tmp) 1606 goto cleanup; 1607 1608 tmp->thread = ct->task; 1609 list_add(&tmp->list, &thread_list); 1610 } 1611 1612 list_for_each(t, &thread_list) { 1613 struct elf_thread_status *tmp; 1614 int sz; 1615 1616 tmp = list_entry(t, struct elf_thread_status, list); 1617 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp); 1618 thread_status_size += sz; 1619 } 1620 1621 /* now collect the dump for the current */ 1622 fill_prstatus(prstatus, current, cprm->siginfo->si_signo); 1623 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1624 1625 segs = current->mm->map_count; 1626 segs += elf_core_extra_phdrs(); 1627 1628 /* for notes section */ 1629 segs++; 1630 1631 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1632 * this, kernel supports extended numbering. Have a look at 1633 * include/linux/elf.h for further information. */ 1634 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1635 1636 /* Set up header */ 1637 fill_elf_fdpic_header(elf, e_phnum); 1638 1639 has_dumped = 1; 1640 /* 1641 * Set up the notes in similar form to SVR4 core dumps made 1642 * with info from their /proc. 1643 */ 1644 1645 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1646 fill_psinfo(psinfo, current->group_leader, current->mm); 1647 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1648 1649 numnote = 2; 1650 1651 auxv = (elf_addr_t *) current->mm->saved_auxv; 1652 1653 i = 0; 1654 do 1655 i += 2; 1656 while (auxv[i - 2] != AT_NULL); 1657 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1658 i * sizeof(elf_addr_t), auxv); 1659 1660 /* Try to dump the FPU. */ 1661 if ((prstatus->pr_fpvalid = 1662 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1663 fill_note(notes + numnote++, 1664 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1665 #ifdef ELF_CORE_COPY_XFPREGS 1666 if (elf_core_copy_task_xfpregs(current, xfpu)) 1667 fill_note(notes + numnote++, 1668 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1669 #endif 1670 1671 fs = get_fs(); 1672 set_fs(KERNEL_DS); 1673 1674 offset += sizeof(*elf); /* Elf header */ 1675 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1676 1677 /* Write notes phdr entry */ 1678 { 1679 int sz = 0; 1680 1681 for (i = 0; i < numnote; i++) 1682 sz += notesize(notes + i); 1683 1684 sz += thread_status_size; 1685 1686 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1687 if (!phdr4note) 1688 goto end_coredump; 1689 1690 fill_elf_note_phdr(phdr4note, sz, offset); 1691 offset += sz; 1692 } 1693 1694 /* Page-align dumped data */ 1695 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1696 1697 offset += elf_core_vma_data_size(cprm->mm_flags); 1698 offset += elf_core_extra_data_size(); 1699 e_shoff = offset; 1700 1701 if (e_phnum == PN_XNUM) { 1702 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1703 if (!shdr4extnum) 1704 goto end_coredump; 1705 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1706 } 1707 1708 offset = dataoff; 1709 1710 if (!dump_emit(cprm, elf, sizeof(*elf))) 1711 goto end_coredump; 1712 1713 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1714 goto end_coredump; 1715 1716 /* write program headers for segments dump */ 1717 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1718 struct elf_phdr phdr; 1719 size_t sz; 1720 1721 sz = vma->vm_end - vma->vm_start; 1722 1723 phdr.p_type = PT_LOAD; 1724 phdr.p_offset = offset; 1725 phdr.p_vaddr = vma->vm_start; 1726 phdr.p_paddr = 0; 1727 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1728 phdr.p_memsz = sz; 1729 offset += phdr.p_filesz; 1730 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1731 if (vma->vm_flags & VM_WRITE) 1732 phdr.p_flags |= PF_W; 1733 if (vma->vm_flags & VM_EXEC) 1734 phdr.p_flags |= PF_X; 1735 phdr.p_align = ELF_EXEC_PAGESIZE; 1736 1737 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1738 goto end_coredump; 1739 } 1740 1741 if (!elf_core_write_extra_phdrs(cprm, offset)) 1742 goto end_coredump; 1743 1744 /* write out the notes section */ 1745 for (i = 0; i < numnote; i++) 1746 if (!writenote(notes + i, cprm)) 1747 goto end_coredump; 1748 1749 /* write out the thread status notes section */ 1750 list_for_each(t, &thread_list) { 1751 struct elf_thread_status *tmp = 1752 list_entry(t, struct elf_thread_status, list); 1753 1754 for (i = 0; i < tmp->num_notes; i++) 1755 if (!writenote(&tmp->notes[i], cprm)) 1756 goto end_coredump; 1757 } 1758 1759 if (!dump_skip(cprm, dataoff - cprm->pos)) 1760 goto end_coredump; 1761 1762 if (!elf_fdpic_dump_segments(cprm)) 1763 goto end_coredump; 1764 1765 if (!elf_core_write_extra_data(cprm)) 1766 goto end_coredump; 1767 1768 if (e_phnum == PN_XNUM) { 1769 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1770 goto end_coredump; 1771 } 1772 1773 if (cprm->file->f_pos != offset) { 1774 /* Sanity check */ 1775 printk(KERN_WARNING 1776 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1777 cprm->file->f_pos, offset); 1778 } 1779 1780 end_coredump: 1781 set_fs(fs); 1782 1783 cleanup: 1784 while (!list_empty(&thread_list)) { 1785 struct list_head *tmp = thread_list.next; 1786 list_del(tmp); 1787 kfree(list_entry(tmp, struct elf_thread_status, list)); 1788 } 1789 kfree(phdr4note); 1790 kfree(elf); 1791 kfree(prstatus); 1792 kfree(psinfo); 1793 kfree(notes); 1794 kfree(fpu); 1795 kfree(shdr4extnum); 1796 #ifdef ELF_CORE_COPY_XFPREGS 1797 kfree(xfpu); 1798 #endif 1799 return has_dumped; 1800 #undef NUM_NOTES 1801 } 1802 1803 #endif /* CONFIG_ELF_CORE */ 1804