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 loff_t pos = params->hdr.e_phoff; 149 150 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 151 return -ENOMEM; 152 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 153 return -ENOMEM; 154 155 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 156 params->phdrs = kmalloc(size, GFP_KERNEL); 157 if (!params->phdrs) 158 return -ENOMEM; 159 160 retval = kernel_read(file, params->phdrs, size, &pos); 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 loff_t pos; 203 204 kdebug("____ LOAD %d ____", current->pid); 205 206 memset(&exec_params, 0, sizeof(exec_params)); 207 memset(&interp_params, 0, sizeof(interp_params)); 208 209 exec_params.hdr = *(struct elfhdr *) bprm->buf; 210 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 211 212 /* check that this is a binary we know how to deal with */ 213 retval = -ENOEXEC; 214 if (!is_elf(&exec_params.hdr, bprm->file)) 215 goto error; 216 if (!elf_check_fdpic(&exec_params.hdr)) { 217 #ifdef CONFIG_MMU 218 /* binfmt_elf handles non-fdpic elf except on nommu */ 219 goto error; 220 #else 221 /* nommu can only load ET_DYN (PIE) ELF */ 222 if (exec_params.hdr.e_type != ET_DYN) 223 goto error; 224 #endif 225 } 226 227 /* read the program header table */ 228 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 229 if (retval < 0) 230 goto error; 231 232 /* scan for a program header that specifies an interpreter */ 233 phdr = exec_params.phdrs; 234 235 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 236 switch (phdr->p_type) { 237 case PT_INTERP: 238 retval = -ENOMEM; 239 if (phdr->p_filesz > PATH_MAX) 240 goto error; 241 retval = -ENOENT; 242 if (phdr->p_filesz < 2) 243 goto error; 244 245 /* read the name of the interpreter into memory */ 246 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 247 if (!interpreter_name) 248 goto error; 249 250 pos = phdr->p_offset; 251 retval = kernel_read(bprm->file, interpreter_name, 252 phdr->p_filesz, &pos); 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 pos = 0; 281 retval = kernel_read(interpreter, bprm->buf, 282 BINPRM_BUF_SIZE, &pos); 283 if (unlikely(retval != BINPRM_BUF_SIZE)) { 284 if (retval >= 0) 285 retval = -ENOEXEC; 286 goto error; 287 } 288 289 interp_params.hdr = *((struct elfhdr *) bprm->buf); 290 break; 291 292 case PT_LOAD: 293 #ifdef CONFIG_MMU 294 if (exec_params.load_addr == 0) 295 exec_params.load_addr = phdr->p_vaddr; 296 #endif 297 break; 298 } 299 300 } 301 302 if (is_constdisp(&exec_params.hdr)) 303 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 304 305 /* perform insanity checks on the interpreter */ 306 if (interpreter_name) { 307 retval = -ELIBBAD; 308 if (!is_elf(&interp_params.hdr, interpreter)) 309 goto error; 310 311 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 312 313 /* read the interpreter's program header table */ 314 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 315 if (retval < 0) 316 goto error; 317 } 318 319 stack_size = exec_params.stack_size; 320 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 321 executable_stack = EXSTACK_ENABLE_X; 322 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 323 executable_stack = EXSTACK_DISABLE_X; 324 else 325 executable_stack = EXSTACK_DEFAULT; 326 327 if (stack_size == 0) { 328 stack_size = interp_params.stack_size; 329 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 330 executable_stack = EXSTACK_ENABLE_X; 331 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 332 executable_stack = EXSTACK_DISABLE_X; 333 else 334 executable_stack = EXSTACK_DEFAULT; 335 } 336 337 retval = -ENOEXEC; 338 if (stack_size == 0) 339 stack_size = 131072UL; /* same as exec.c's default commit */ 340 341 if (is_constdisp(&interp_params.hdr)) 342 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 343 344 /* flush all traces of the currently running executable */ 345 retval = flush_old_exec(bprm); 346 if (retval) 347 goto error; 348 349 /* there's now no turning back... the old userspace image is dead, 350 * defunct, deceased, etc. 351 */ 352 if (elf_check_fdpic(&exec_params.hdr)) 353 set_personality(PER_LINUX_FDPIC); 354 else 355 set_personality(PER_LINUX); 356 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 357 current->personality |= READ_IMPLIES_EXEC; 358 359 setup_new_exec(bprm); 360 361 set_binfmt(&elf_fdpic_format); 362 363 current->mm->start_code = 0; 364 current->mm->end_code = 0; 365 current->mm->start_stack = 0; 366 current->mm->start_data = 0; 367 current->mm->end_data = 0; 368 current->mm->context.exec_fdpic_loadmap = 0; 369 current->mm->context.interp_fdpic_loadmap = 0; 370 371 #ifdef CONFIG_MMU 372 elf_fdpic_arch_lay_out_mm(&exec_params, 373 &interp_params, 374 ¤t->mm->start_stack, 375 ¤t->mm->start_brk); 376 377 retval = setup_arg_pages(bprm, current->mm->start_stack, 378 executable_stack); 379 if (retval < 0) 380 goto error; 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 install_exec_creds(bprm); 437 if (create_elf_fdpic_tables(bprm, current->mm, 438 &exec_params, &interp_params) < 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 /* everything is now ready... get the userspace context ready to roll */ 462 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 463 start_thread(regs, entryaddr, current->mm->start_stack); 464 465 retval = 0; 466 467 error: 468 if (interpreter) { 469 allow_write_access(interpreter); 470 fput(interpreter); 471 } 472 kfree(interpreter_name); 473 kfree(exec_params.phdrs); 474 kfree(exec_params.loadmap); 475 kfree(interp_params.phdrs); 476 kfree(interp_params.loadmap); 477 return retval; 478 } 479 480 /*****************************************************************************/ 481 482 #ifndef ELF_BASE_PLATFORM 483 /* 484 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 485 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 486 * will be copied to the user stack in the same manner as AT_PLATFORM. 487 */ 488 #define ELF_BASE_PLATFORM NULL 489 #endif 490 491 /* 492 * present useful information to the program by shovelling it onto the new 493 * process's stack 494 */ 495 static int create_elf_fdpic_tables(struct linux_binprm *bprm, 496 struct mm_struct *mm, 497 struct elf_fdpic_params *exec_params, 498 struct elf_fdpic_params *interp_params) 499 { 500 const struct cred *cred = current_cred(); 501 unsigned long sp, csp, nitems; 502 elf_caddr_t __user *argv, *envp; 503 size_t platform_len = 0, len; 504 char *k_platform, *k_base_platform; 505 char __user *u_platform, *u_base_platform, *p; 506 int loop; 507 int nr; /* reset for each csp adjustment */ 508 509 #ifdef CONFIG_MMU 510 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 511 * by the processes running on the same package. One thing we can do is 512 * to shuffle the initial stack for them, so we give the architecture 513 * an opportunity to do so here. 514 */ 515 sp = arch_align_stack(bprm->p); 516 #else 517 sp = mm->start_stack; 518 519 /* stack the program arguments and environment */ 520 if (transfer_args_to_stack(bprm, &sp) < 0) 521 return -EFAULT; 522 sp &= ~15; 523 #endif 524 525 /* 526 * If this architecture has a platform capability string, copy it 527 * to userspace. In some cases (Sparc), this info is impossible 528 * for userspace to get any other way, in others (i386) it is 529 * merely difficult. 530 */ 531 k_platform = ELF_PLATFORM; 532 u_platform = NULL; 533 534 if (k_platform) { 535 platform_len = strlen(k_platform) + 1; 536 sp -= platform_len; 537 u_platform = (char __user *) sp; 538 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 539 return -EFAULT; 540 } 541 542 /* 543 * If this architecture has a "base" platform capability 544 * string, copy it to userspace. 545 */ 546 k_base_platform = ELF_BASE_PLATFORM; 547 u_base_platform = NULL; 548 549 if (k_base_platform) { 550 platform_len = strlen(k_base_platform) + 1; 551 sp -= platform_len; 552 u_base_platform = (char __user *) sp; 553 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 554 return -EFAULT; 555 } 556 557 sp &= ~7UL; 558 559 /* stack the load map(s) */ 560 len = sizeof(struct elf32_fdpic_loadmap); 561 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 562 sp = (sp - len) & ~7UL; 563 exec_params->map_addr = sp; 564 565 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 566 return -EFAULT; 567 568 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 569 570 if (interp_params->loadmap) { 571 len = sizeof(struct elf32_fdpic_loadmap); 572 len += sizeof(struct elf32_fdpic_loadseg) * 573 interp_params->loadmap->nsegs; 574 sp = (sp - len) & ~7UL; 575 interp_params->map_addr = sp; 576 577 if (copy_to_user((void __user *) sp, interp_params->loadmap, 578 len) != 0) 579 return -EFAULT; 580 581 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 582 } 583 584 /* force 16 byte _final_ alignment here for generality */ 585 #define DLINFO_ITEMS 15 586 587 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 588 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 589 590 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 591 nitems++; 592 593 csp = sp; 594 sp -= nitems * 2 * sizeof(unsigned long); 595 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 596 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 597 sp -= 1 * sizeof(unsigned long); /* argc */ 598 599 csp -= sp & 15UL; 600 sp -= sp & 15UL; 601 602 /* put the ELF interpreter info on the stack */ 603 #define NEW_AUX_ENT(id, val) \ 604 do { \ 605 struct { unsigned long _id, _val; } __user *ent; \ 606 \ 607 ent = (void __user *) csp; \ 608 __put_user((id), &ent[nr]._id); \ 609 __put_user((val), &ent[nr]._val); \ 610 nr++; \ 611 } while (0) 612 613 nr = 0; 614 csp -= 2 * sizeof(unsigned long); 615 NEW_AUX_ENT(AT_NULL, 0); 616 if (k_platform) { 617 nr = 0; 618 csp -= 2 * sizeof(unsigned long); 619 NEW_AUX_ENT(AT_PLATFORM, 620 (elf_addr_t) (unsigned long) u_platform); 621 } 622 623 if (k_base_platform) { 624 nr = 0; 625 csp -= 2 * sizeof(unsigned long); 626 NEW_AUX_ENT(AT_BASE_PLATFORM, 627 (elf_addr_t) (unsigned long) u_base_platform); 628 } 629 630 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 631 nr = 0; 632 csp -= 2 * sizeof(unsigned long); 633 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 634 } 635 636 nr = 0; 637 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 638 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 639 #ifdef ELF_HWCAP2 640 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 641 #endif 642 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 643 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 644 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 645 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 646 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 647 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 648 NEW_AUX_ENT(AT_FLAGS, 0); 649 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 650 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 651 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 652 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 653 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 654 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 655 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 656 657 #ifdef ARCH_DLINFO 658 nr = 0; 659 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 660 661 /* ARCH_DLINFO must come last so platform specific code can enforce 662 * special alignment requirements on the AUXV if necessary (eg. PPC). 663 */ 664 ARCH_DLINFO; 665 #endif 666 #undef NEW_AUX_ENT 667 668 /* allocate room for argv[] and envv[] */ 669 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 670 envp = (elf_caddr_t __user *) csp; 671 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 672 argv = (elf_caddr_t __user *) csp; 673 674 /* stack argc */ 675 csp -= sizeof(unsigned long); 676 __put_user(bprm->argc, (unsigned long __user *) csp); 677 678 BUG_ON(csp != sp); 679 680 /* fill in the argv[] array */ 681 #ifdef CONFIG_MMU 682 current->mm->arg_start = bprm->p; 683 #else 684 current->mm->arg_start = current->mm->start_stack - 685 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 686 #endif 687 688 p = (char __user *) current->mm->arg_start; 689 for (loop = bprm->argc; loop > 0; loop--) { 690 __put_user((elf_caddr_t) p, argv++); 691 len = strnlen_user(p, MAX_ARG_STRLEN); 692 if (!len || len > MAX_ARG_STRLEN) 693 return -EINVAL; 694 p += len; 695 } 696 __put_user(NULL, argv); 697 current->mm->arg_end = (unsigned long) p; 698 699 /* fill in the envv[] array */ 700 current->mm->env_start = (unsigned long) p; 701 for (loop = bprm->envc; loop > 0; loop--) { 702 __put_user((elf_caddr_t)(unsigned long) p, envp++); 703 len = strnlen_user(p, MAX_ARG_STRLEN); 704 if (!len || len > MAX_ARG_STRLEN) 705 return -EINVAL; 706 p += len; 707 } 708 __put_user(NULL, envp); 709 current->mm->env_end = (unsigned long) p; 710 711 mm->start_stack = (unsigned long) sp; 712 return 0; 713 } 714 715 /*****************************************************************************/ 716 /* 717 * load the appropriate binary image (executable or interpreter) into memory 718 * - we assume no MMU is available 719 * - if no other PIC bits are set in params->hdr->e_flags 720 * - we assume that the LOADable segments in the binary are independently relocatable 721 * - we assume R/O executable segments are shareable 722 * - else 723 * - we assume the loadable parts of the image to require fixed displacement 724 * - the image is not shareable 725 */ 726 static int elf_fdpic_map_file(struct elf_fdpic_params *params, 727 struct file *file, 728 struct mm_struct *mm, 729 const char *what) 730 { 731 struct elf32_fdpic_loadmap *loadmap; 732 #ifdef CONFIG_MMU 733 struct elf32_fdpic_loadseg *mseg; 734 #endif 735 struct elf32_fdpic_loadseg *seg; 736 struct elf32_phdr *phdr; 737 unsigned long load_addr, stop; 738 unsigned nloads, tmp; 739 size_t size; 740 int loop, ret; 741 742 /* allocate a load map table */ 743 nloads = 0; 744 for (loop = 0; loop < params->hdr.e_phnum; loop++) 745 if (params->phdrs[loop].p_type == PT_LOAD) 746 nloads++; 747 748 if (nloads == 0) 749 return -ELIBBAD; 750 751 size = sizeof(*loadmap) + nloads * sizeof(*seg); 752 loadmap = kzalloc(size, GFP_KERNEL); 753 if (!loadmap) 754 return -ENOMEM; 755 756 params->loadmap = loadmap; 757 758 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 759 loadmap->nsegs = nloads; 760 761 load_addr = params->load_addr; 762 seg = loadmap->segs; 763 764 /* map the requested LOADs into the memory space */ 765 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 766 case ELF_FDPIC_FLAG_CONSTDISP: 767 case ELF_FDPIC_FLAG_CONTIGUOUS: 768 #ifndef CONFIG_MMU 769 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 770 if (ret < 0) 771 return ret; 772 break; 773 #endif 774 default: 775 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 776 if (ret < 0) 777 return ret; 778 break; 779 } 780 781 /* map the entry point */ 782 if (params->hdr.e_entry) { 783 seg = loadmap->segs; 784 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 785 if (params->hdr.e_entry >= seg->p_vaddr && 786 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 787 params->entry_addr = 788 (params->hdr.e_entry - seg->p_vaddr) + 789 seg->addr; 790 break; 791 } 792 } 793 } 794 795 /* determine where the program header table has wound up if mapped */ 796 stop = params->hdr.e_phoff; 797 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 798 phdr = params->phdrs; 799 800 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 801 if (phdr->p_type != PT_LOAD) 802 continue; 803 804 if (phdr->p_offset > params->hdr.e_phoff || 805 phdr->p_offset + phdr->p_filesz < stop) 806 continue; 807 808 seg = loadmap->segs; 809 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 810 if (phdr->p_vaddr >= seg->p_vaddr && 811 phdr->p_vaddr + phdr->p_filesz <= 812 seg->p_vaddr + seg->p_memsz) { 813 params->ph_addr = 814 (phdr->p_vaddr - seg->p_vaddr) + 815 seg->addr + 816 params->hdr.e_phoff - phdr->p_offset; 817 break; 818 } 819 } 820 break; 821 } 822 823 /* determine where the dynamic section has wound up if there is one */ 824 phdr = params->phdrs; 825 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 826 if (phdr->p_type != PT_DYNAMIC) 827 continue; 828 829 seg = loadmap->segs; 830 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 831 if (phdr->p_vaddr >= seg->p_vaddr && 832 phdr->p_vaddr + phdr->p_memsz <= 833 seg->p_vaddr + seg->p_memsz) { 834 params->dynamic_addr = 835 (phdr->p_vaddr - seg->p_vaddr) + 836 seg->addr; 837 838 /* check the dynamic section contains at least 839 * one item, and that the last item is a NULL 840 * entry */ 841 if (phdr->p_memsz == 0 || 842 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 843 goto dynamic_error; 844 845 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 846 if (((Elf32_Dyn *) 847 params->dynamic_addr)[tmp - 1].d_tag != 0) 848 goto dynamic_error; 849 break; 850 } 851 } 852 break; 853 } 854 855 /* now elide adjacent segments in the load map on MMU linux 856 * - on uClinux the holes between may actually be filled with system 857 * stuff or stuff from other processes 858 */ 859 #ifdef CONFIG_MMU 860 nloads = loadmap->nsegs; 861 mseg = loadmap->segs; 862 seg = mseg + 1; 863 for (loop = 1; loop < nloads; loop++) { 864 /* see if we have a candidate for merging */ 865 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 866 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 867 if (load_addr == (seg->addr & PAGE_MASK)) { 868 mseg->p_memsz += 869 load_addr - 870 (mseg->addr + mseg->p_memsz); 871 mseg->p_memsz += seg->addr & ~PAGE_MASK; 872 mseg->p_memsz += seg->p_memsz; 873 loadmap->nsegs--; 874 continue; 875 } 876 } 877 878 mseg++; 879 if (mseg != seg) 880 *mseg = *seg; 881 } 882 #endif 883 884 kdebug("Mapped Object [%s]:", what); 885 kdebug("- elfhdr : %lx", params->elfhdr_addr); 886 kdebug("- entry : %lx", params->entry_addr); 887 kdebug("- PHDR[] : %lx", params->ph_addr); 888 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 889 seg = loadmap->segs; 890 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 891 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 892 loop, 893 seg->addr, seg->addr + seg->p_memsz - 1, 894 seg->p_vaddr, seg->p_memsz); 895 896 return 0; 897 898 dynamic_error: 899 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 900 what, file_inode(file)->i_ino); 901 return -ELIBBAD; 902 } 903 904 /*****************************************************************************/ 905 /* 906 * map a file with constant displacement under uClinux 907 */ 908 #ifndef CONFIG_MMU 909 static int elf_fdpic_map_file_constdisp_on_uclinux( 910 struct elf_fdpic_params *params, 911 struct file *file, 912 struct mm_struct *mm) 913 { 914 struct elf32_fdpic_loadseg *seg; 915 struct elf32_phdr *phdr; 916 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 917 int loop, ret; 918 919 load_addr = params->load_addr; 920 seg = params->loadmap->segs; 921 922 /* determine the bounds of the contiguous overall allocation we must 923 * make */ 924 phdr = params->phdrs; 925 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 926 if (params->phdrs[loop].p_type != PT_LOAD) 927 continue; 928 929 if (base > phdr->p_vaddr) 930 base = phdr->p_vaddr; 931 if (top < phdr->p_vaddr + phdr->p_memsz) 932 top = phdr->p_vaddr + phdr->p_memsz; 933 } 934 935 /* allocate one big anon block for everything */ 936 mflags = MAP_PRIVATE; 937 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 938 mflags |= MAP_EXECUTABLE; 939 940 maddr = vm_mmap(NULL, load_addr, top - base, 941 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 942 if (IS_ERR_VALUE(maddr)) 943 return (int) maddr; 944 945 if (load_addr != 0) 946 load_addr += PAGE_ALIGN(top - base); 947 948 /* and then load the file segments into it */ 949 phdr = params->phdrs; 950 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 951 if (params->phdrs[loop].p_type != PT_LOAD) 952 continue; 953 954 seg->addr = maddr + (phdr->p_vaddr - base); 955 seg->p_vaddr = phdr->p_vaddr; 956 seg->p_memsz = phdr->p_memsz; 957 958 ret = read_code(file, seg->addr, phdr->p_offset, 959 phdr->p_filesz); 960 if (ret < 0) 961 return ret; 962 963 /* map the ELF header address if in this segment */ 964 if (phdr->p_offset == 0) 965 params->elfhdr_addr = seg->addr; 966 967 /* clear any space allocated but not loaded */ 968 if (phdr->p_filesz < phdr->p_memsz) { 969 if (clear_user((void *) (seg->addr + phdr->p_filesz), 970 phdr->p_memsz - phdr->p_filesz)) 971 return -EFAULT; 972 } 973 974 if (mm) { 975 if (phdr->p_flags & PF_X) { 976 if (!mm->start_code) { 977 mm->start_code = seg->addr; 978 mm->end_code = seg->addr + 979 phdr->p_memsz; 980 } 981 } else if (!mm->start_data) { 982 mm->start_data = seg->addr; 983 mm->end_data = seg->addr + phdr->p_memsz; 984 } 985 } 986 987 seg++; 988 } 989 990 return 0; 991 } 992 #endif 993 994 /*****************************************************************************/ 995 /* 996 * map a binary by direct mmap() of the individual PT_LOAD segments 997 */ 998 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 999 struct file *file, 1000 struct mm_struct *mm) 1001 { 1002 struct elf32_fdpic_loadseg *seg; 1003 struct elf32_phdr *phdr; 1004 unsigned long load_addr, delta_vaddr; 1005 int loop, dvset; 1006 1007 load_addr = params->load_addr; 1008 delta_vaddr = 0; 1009 dvset = 0; 1010 1011 seg = params->loadmap->segs; 1012 1013 /* deal with each load segment separately */ 1014 phdr = params->phdrs; 1015 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1016 unsigned long maddr, disp, excess, excess1; 1017 int prot = 0, flags; 1018 1019 if (phdr->p_type != PT_LOAD) 1020 continue; 1021 1022 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1023 (unsigned long) phdr->p_vaddr, 1024 (unsigned long) phdr->p_offset, 1025 (unsigned long) phdr->p_filesz, 1026 (unsigned long) phdr->p_memsz); 1027 1028 /* determine the mapping parameters */ 1029 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1030 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1031 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1032 1033 flags = MAP_PRIVATE | MAP_DENYWRITE; 1034 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1035 flags |= MAP_EXECUTABLE; 1036 1037 maddr = 0; 1038 1039 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1040 case ELF_FDPIC_FLAG_INDEPENDENT: 1041 /* PT_LOADs are independently locatable */ 1042 break; 1043 1044 case ELF_FDPIC_FLAG_HONOURVADDR: 1045 /* the specified virtual address must be honoured */ 1046 maddr = phdr->p_vaddr; 1047 flags |= MAP_FIXED; 1048 break; 1049 1050 case ELF_FDPIC_FLAG_CONSTDISP: 1051 /* constant displacement 1052 * - can be mapped anywhere, but must be mapped as a 1053 * unit 1054 */ 1055 if (!dvset) { 1056 maddr = load_addr; 1057 delta_vaddr = phdr->p_vaddr; 1058 dvset = 1; 1059 } else { 1060 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1061 flags |= MAP_FIXED; 1062 } 1063 break; 1064 1065 case ELF_FDPIC_FLAG_CONTIGUOUS: 1066 /* contiguity handled later */ 1067 break; 1068 1069 default: 1070 BUG(); 1071 } 1072 1073 maddr &= PAGE_MASK; 1074 1075 /* create the mapping */ 1076 disp = phdr->p_vaddr & ~PAGE_MASK; 1077 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1078 phdr->p_offset - disp); 1079 1080 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1081 loop, phdr->p_memsz + disp, prot, flags, 1082 phdr->p_offset - disp, maddr); 1083 1084 if (IS_ERR_VALUE(maddr)) 1085 return (int) maddr; 1086 1087 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1088 ELF_FDPIC_FLAG_CONTIGUOUS) 1089 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1090 1091 seg->addr = maddr + disp; 1092 seg->p_vaddr = phdr->p_vaddr; 1093 seg->p_memsz = phdr->p_memsz; 1094 1095 /* map the ELF header address if in this segment */ 1096 if (phdr->p_offset == 0) 1097 params->elfhdr_addr = seg->addr; 1098 1099 /* clear the bit between beginning of mapping and beginning of 1100 * PT_LOAD */ 1101 if (prot & PROT_WRITE && disp > 0) { 1102 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1103 if (clear_user((void __user *) maddr, disp)) 1104 return -EFAULT; 1105 maddr += disp; 1106 } 1107 1108 /* clear any space allocated but not loaded 1109 * - on uClinux we can just clear the lot 1110 * - on MMU linux we'll get a SIGBUS beyond the last page 1111 * extant in the file 1112 */ 1113 excess = phdr->p_memsz - phdr->p_filesz; 1114 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1115 1116 #ifdef CONFIG_MMU 1117 if (excess > excess1) { 1118 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1119 unsigned long xmaddr; 1120 1121 flags |= MAP_FIXED | MAP_ANONYMOUS; 1122 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1123 prot, flags, 0); 1124 1125 kdebug("mmap[%d] <anon>" 1126 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1127 loop, xaddr, excess - excess1, prot, flags, 1128 xmaddr); 1129 1130 if (xmaddr != xaddr) 1131 return -ENOMEM; 1132 } 1133 1134 if (prot & PROT_WRITE && excess1 > 0) { 1135 kdebug("clear[%d] ad=%lx sz=%lx", 1136 loop, maddr + phdr->p_filesz, excess1); 1137 if (clear_user((void __user *) maddr + phdr->p_filesz, 1138 excess1)) 1139 return -EFAULT; 1140 } 1141 1142 #else 1143 if (excess > 0) { 1144 kdebug("clear[%d] ad=%lx sz=%lx", 1145 loop, maddr + phdr->p_filesz, excess); 1146 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1147 return -EFAULT; 1148 } 1149 #endif 1150 1151 if (mm) { 1152 if (phdr->p_flags & PF_X) { 1153 if (!mm->start_code) { 1154 mm->start_code = maddr; 1155 mm->end_code = maddr + phdr->p_memsz; 1156 } 1157 } else if (!mm->start_data) { 1158 mm->start_data = maddr; 1159 mm->end_data = maddr + phdr->p_memsz; 1160 } 1161 } 1162 1163 seg++; 1164 } 1165 1166 return 0; 1167 } 1168 1169 /*****************************************************************************/ 1170 /* 1171 * ELF-FDPIC core dumper 1172 * 1173 * Modelled on fs/exec.c:aout_core_dump() 1174 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1175 * 1176 * Modelled on fs/binfmt_elf.c core dumper 1177 */ 1178 #ifdef CONFIG_ELF_CORE 1179 1180 /* 1181 * Decide whether a segment is worth dumping; default is yes to be 1182 * sure (missing info is worse than too much; etc). 1183 * Personally I'd include everything, and use the coredump limit... 1184 * 1185 * I think we should skip something. But I am not sure how. H.J. 1186 */ 1187 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1188 { 1189 int dump_ok; 1190 1191 /* Do not dump I/O mapped devices or special mappings */ 1192 if (vma->vm_flags & VM_IO) { 1193 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1194 return 0; 1195 } 1196 1197 /* If we may not read the contents, don't allow us to dump 1198 * them either. "dump_write()" can't handle it anyway. 1199 */ 1200 if (!(vma->vm_flags & VM_READ)) { 1201 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1202 return 0; 1203 } 1204 1205 /* support for DAX */ 1206 if (vma_is_dax(vma)) { 1207 if (vma->vm_flags & VM_SHARED) { 1208 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags); 1209 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start, 1210 vma->vm_flags, dump_ok ? "yes" : "no"); 1211 } else { 1212 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags); 1213 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start, 1214 vma->vm_flags, dump_ok ? "yes" : "no"); 1215 } 1216 return dump_ok; 1217 } 1218 1219 /* By default, dump shared memory if mapped from an anonymous file. */ 1220 if (vma->vm_flags & VM_SHARED) { 1221 if (file_inode(vma->vm_file)->i_nlink == 0) { 1222 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1223 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1224 vma->vm_flags, dump_ok ? "yes" : "no"); 1225 return dump_ok; 1226 } 1227 1228 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1229 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1230 vma->vm_flags, dump_ok ? "yes" : "no"); 1231 return dump_ok; 1232 } 1233 1234 #ifdef CONFIG_MMU 1235 /* By default, if it hasn't been written to, don't write it out */ 1236 if (!vma->anon_vma) { 1237 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1238 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1239 vma->vm_flags, dump_ok ? "yes" : "no"); 1240 return dump_ok; 1241 } 1242 #endif 1243 1244 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1245 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1246 dump_ok ? "yes" : "no"); 1247 return dump_ok; 1248 } 1249 1250 /* An ELF note in memory */ 1251 struct memelfnote 1252 { 1253 const char *name; 1254 int type; 1255 unsigned int datasz; 1256 void *data; 1257 }; 1258 1259 static int notesize(struct memelfnote *en) 1260 { 1261 int sz; 1262 1263 sz = sizeof(struct elf_note); 1264 sz += roundup(strlen(en->name) + 1, 4); 1265 sz += roundup(en->datasz, 4); 1266 1267 return sz; 1268 } 1269 1270 /* #define DEBUG */ 1271 1272 static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1273 { 1274 struct elf_note en; 1275 en.n_namesz = strlen(men->name) + 1; 1276 en.n_descsz = men->datasz; 1277 en.n_type = men->type; 1278 1279 return dump_emit(cprm, &en, sizeof(en)) && 1280 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1281 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1282 } 1283 1284 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1285 { 1286 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1287 elf->e_ident[EI_CLASS] = ELF_CLASS; 1288 elf->e_ident[EI_DATA] = ELF_DATA; 1289 elf->e_ident[EI_VERSION] = EV_CURRENT; 1290 elf->e_ident[EI_OSABI] = ELF_OSABI; 1291 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1292 1293 elf->e_type = ET_CORE; 1294 elf->e_machine = ELF_ARCH; 1295 elf->e_version = EV_CURRENT; 1296 elf->e_entry = 0; 1297 elf->e_phoff = sizeof(struct elfhdr); 1298 elf->e_shoff = 0; 1299 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1300 elf->e_ehsize = sizeof(struct elfhdr); 1301 elf->e_phentsize = sizeof(struct elf_phdr); 1302 elf->e_phnum = segs; 1303 elf->e_shentsize = 0; 1304 elf->e_shnum = 0; 1305 elf->e_shstrndx = 0; 1306 return; 1307 } 1308 1309 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1310 { 1311 phdr->p_type = PT_NOTE; 1312 phdr->p_offset = offset; 1313 phdr->p_vaddr = 0; 1314 phdr->p_paddr = 0; 1315 phdr->p_filesz = sz; 1316 phdr->p_memsz = 0; 1317 phdr->p_flags = 0; 1318 phdr->p_align = 0; 1319 return; 1320 } 1321 1322 static inline void fill_note(struct memelfnote *note, const char *name, int type, 1323 unsigned int sz, void *data) 1324 { 1325 note->name = name; 1326 note->type = type; 1327 note->datasz = sz; 1328 note->data = data; 1329 return; 1330 } 1331 1332 /* 1333 * fill up all the fields in prstatus from the given task struct, except 1334 * registers which need to be filled up separately. 1335 */ 1336 static void fill_prstatus(struct elf_prstatus *prstatus, 1337 struct task_struct *p, long signr) 1338 { 1339 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1340 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1341 prstatus->pr_sighold = p->blocked.sig[0]; 1342 rcu_read_lock(); 1343 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1344 rcu_read_unlock(); 1345 prstatus->pr_pid = task_pid_vnr(p); 1346 prstatus->pr_pgrp = task_pgrp_vnr(p); 1347 prstatus->pr_sid = task_session_vnr(p); 1348 if (thread_group_leader(p)) { 1349 struct task_cputime cputime; 1350 1351 /* 1352 * This is the record for the group leader. It shows the 1353 * group-wide total, not its individual thread total. 1354 */ 1355 thread_group_cputime(p, &cputime); 1356 prstatus->pr_utime = ns_to_timeval(cputime.utime); 1357 prstatus->pr_stime = ns_to_timeval(cputime.stime); 1358 } else { 1359 u64 utime, stime; 1360 1361 task_cputime(p, &utime, &stime); 1362 prstatus->pr_utime = ns_to_timeval(utime); 1363 prstatus->pr_stime = ns_to_timeval(stime); 1364 } 1365 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime); 1366 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime); 1367 1368 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1369 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1370 } 1371 1372 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1373 struct mm_struct *mm) 1374 { 1375 const struct cred *cred; 1376 unsigned int i, len; 1377 1378 /* first copy the parameters from user space */ 1379 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1380 1381 len = mm->arg_end - mm->arg_start; 1382 if (len >= ELF_PRARGSZ) 1383 len = ELF_PRARGSZ - 1; 1384 if (copy_from_user(&psinfo->pr_psargs, 1385 (const char __user *) mm->arg_start, len)) 1386 return -EFAULT; 1387 for (i = 0; i < len; i++) 1388 if (psinfo->pr_psargs[i] == 0) 1389 psinfo->pr_psargs[i] = ' '; 1390 psinfo->pr_psargs[len] = 0; 1391 1392 rcu_read_lock(); 1393 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1394 rcu_read_unlock(); 1395 psinfo->pr_pid = task_pid_vnr(p); 1396 psinfo->pr_pgrp = task_pgrp_vnr(p); 1397 psinfo->pr_sid = task_session_vnr(p); 1398 1399 i = p->state ? ffz(~p->state) + 1 : 0; 1400 psinfo->pr_state = i; 1401 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1402 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1403 psinfo->pr_nice = task_nice(p); 1404 psinfo->pr_flag = p->flags; 1405 rcu_read_lock(); 1406 cred = __task_cred(p); 1407 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1408 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1409 rcu_read_unlock(); 1410 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1411 1412 return 0; 1413 } 1414 1415 /* Here is the structure in which status of each thread is captured. */ 1416 struct elf_thread_status 1417 { 1418 struct list_head list; 1419 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1420 elf_fpregset_t fpu; /* NT_PRFPREG */ 1421 struct task_struct *thread; 1422 #ifdef ELF_CORE_COPY_XFPREGS 1423 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1424 #endif 1425 struct memelfnote notes[3]; 1426 int num_notes; 1427 }; 1428 1429 /* 1430 * In order to add the specific thread information for the elf file format, 1431 * we need to keep a linked list of every thread's pr_status and then create 1432 * a single section for them in the final core file. 1433 */ 1434 static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1435 { 1436 struct task_struct *p = t->thread; 1437 int sz = 0; 1438 1439 t->num_notes = 0; 1440 1441 fill_prstatus(&t->prstatus, p, signr); 1442 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1443 1444 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1445 &t->prstatus); 1446 t->num_notes++; 1447 sz += notesize(&t->notes[0]); 1448 1449 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1450 if (t->prstatus.pr_fpvalid) { 1451 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1452 &t->fpu); 1453 t->num_notes++; 1454 sz += notesize(&t->notes[1]); 1455 } 1456 1457 #ifdef ELF_CORE_COPY_XFPREGS 1458 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1459 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1460 sizeof(t->xfpu), &t->xfpu); 1461 t->num_notes++; 1462 sz += notesize(&t->notes[2]); 1463 } 1464 #endif 1465 return sz; 1466 } 1467 1468 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1469 elf_addr_t e_shoff, int segs) 1470 { 1471 elf->e_shoff = e_shoff; 1472 elf->e_shentsize = sizeof(*shdr4extnum); 1473 elf->e_shnum = 1; 1474 elf->e_shstrndx = SHN_UNDEF; 1475 1476 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1477 1478 shdr4extnum->sh_type = SHT_NULL; 1479 shdr4extnum->sh_size = elf->e_shnum; 1480 shdr4extnum->sh_link = elf->e_shstrndx; 1481 shdr4extnum->sh_info = segs; 1482 } 1483 1484 /* 1485 * dump the segments for an MMU process 1486 */ 1487 static bool elf_fdpic_dump_segments(struct coredump_params *cprm) 1488 { 1489 struct vm_area_struct *vma; 1490 1491 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1492 unsigned long addr; 1493 1494 if (!maydump(vma, cprm->mm_flags)) 1495 continue; 1496 1497 #ifdef CONFIG_MMU 1498 for (addr = vma->vm_start; addr < vma->vm_end; 1499 addr += PAGE_SIZE) { 1500 bool res; 1501 struct page *page = get_dump_page(addr); 1502 if (page) { 1503 void *kaddr = kmap(page); 1504 res = dump_emit(cprm, kaddr, PAGE_SIZE); 1505 kunmap(page); 1506 put_page(page); 1507 } else { 1508 res = dump_skip(cprm, PAGE_SIZE); 1509 } 1510 if (!res) 1511 return false; 1512 } 1513 #else 1514 if (!dump_emit(cprm, (void *) vma->vm_start, 1515 vma->vm_end - vma->vm_start)) 1516 return false; 1517 #endif 1518 } 1519 return true; 1520 } 1521 1522 static size_t elf_core_vma_data_size(unsigned long mm_flags) 1523 { 1524 struct vm_area_struct *vma; 1525 size_t size = 0; 1526 1527 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1528 if (maydump(vma, mm_flags)) 1529 size += vma->vm_end - vma->vm_start; 1530 return size; 1531 } 1532 1533 /* 1534 * Actual dumper 1535 * 1536 * This is a two-pass process; first we find the offsets of the bits, 1537 * and then they are actually written out. If we run out of core limit 1538 * we just truncate. 1539 */ 1540 static int elf_fdpic_core_dump(struct coredump_params *cprm) 1541 { 1542 #define NUM_NOTES 6 1543 int has_dumped = 0; 1544 mm_segment_t fs; 1545 int segs; 1546 int i; 1547 struct vm_area_struct *vma; 1548 struct elfhdr *elf = NULL; 1549 loff_t offset = 0, dataoff; 1550 int numnote; 1551 struct memelfnote *notes = NULL; 1552 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1553 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1554 LIST_HEAD(thread_list); 1555 struct list_head *t; 1556 elf_fpregset_t *fpu = NULL; 1557 #ifdef ELF_CORE_COPY_XFPREGS 1558 elf_fpxregset_t *xfpu = NULL; 1559 #endif 1560 int thread_status_size = 0; 1561 elf_addr_t *auxv; 1562 struct elf_phdr *phdr4note = NULL; 1563 struct elf_shdr *shdr4extnum = NULL; 1564 Elf_Half e_phnum; 1565 elf_addr_t e_shoff; 1566 struct core_thread *ct; 1567 struct elf_thread_status *tmp; 1568 1569 /* 1570 * We no longer stop all VM operations. 1571 * 1572 * This is because those proceses that could possibly change map_count 1573 * or the mmap / vma pages are now blocked in do_exit on current 1574 * finishing this core dump. 1575 * 1576 * Only ptrace can touch these memory addresses, but it doesn't change 1577 * the map_count or the pages allocated. So no possibility of crashing 1578 * exists while dumping the mm->vm_next areas to the core file. 1579 */ 1580 1581 /* alloc memory for large data structures: too large to be on stack */ 1582 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1583 if (!elf) 1584 goto cleanup; 1585 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1586 if (!prstatus) 1587 goto cleanup; 1588 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1589 if (!psinfo) 1590 goto cleanup; 1591 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1592 if (!notes) 1593 goto cleanup; 1594 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1595 if (!fpu) 1596 goto cleanup; 1597 #ifdef ELF_CORE_COPY_XFPREGS 1598 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1599 if (!xfpu) 1600 goto cleanup; 1601 #endif 1602 1603 for (ct = current->mm->core_state->dumper.next; 1604 ct; ct = ct->next) { 1605 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1606 if (!tmp) 1607 goto cleanup; 1608 1609 tmp->thread = ct->task; 1610 list_add(&tmp->list, &thread_list); 1611 } 1612 1613 list_for_each(t, &thread_list) { 1614 struct elf_thread_status *tmp; 1615 int sz; 1616 1617 tmp = list_entry(t, struct elf_thread_status, list); 1618 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp); 1619 thread_status_size += sz; 1620 } 1621 1622 /* now collect the dump for the current */ 1623 fill_prstatus(prstatus, current, cprm->siginfo->si_signo); 1624 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1625 1626 segs = current->mm->map_count; 1627 segs += elf_core_extra_phdrs(); 1628 1629 /* for notes section */ 1630 segs++; 1631 1632 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1633 * this, kernel supports extended numbering. Have a look at 1634 * include/linux/elf.h for further information. */ 1635 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1636 1637 /* Set up header */ 1638 fill_elf_fdpic_header(elf, e_phnum); 1639 1640 has_dumped = 1; 1641 /* 1642 * Set up the notes in similar form to SVR4 core dumps made 1643 * with info from their /proc. 1644 */ 1645 1646 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1647 fill_psinfo(psinfo, current->group_leader, current->mm); 1648 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1649 1650 numnote = 2; 1651 1652 auxv = (elf_addr_t *) current->mm->saved_auxv; 1653 1654 i = 0; 1655 do 1656 i += 2; 1657 while (auxv[i - 2] != AT_NULL); 1658 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1659 i * sizeof(elf_addr_t), auxv); 1660 1661 /* Try to dump the FPU. */ 1662 if ((prstatus->pr_fpvalid = 1663 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1664 fill_note(notes + numnote++, 1665 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1666 #ifdef ELF_CORE_COPY_XFPREGS 1667 if (elf_core_copy_task_xfpregs(current, xfpu)) 1668 fill_note(notes + numnote++, 1669 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1670 #endif 1671 1672 fs = get_fs(); 1673 set_fs(KERNEL_DS); 1674 1675 offset += sizeof(*elf); /* Elf header */ 1676 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1677 1678 /* Write notes phdr entry */ 1679 { 1680 int sz = 0; 1681 1682 for (i = 0; i < numnote; i++) 1683 sz += notesize(notes + i); 1684 1685 sz += thread_status_size; 1686 1687 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1688 if (!phdr4note) 1689 goto end_coredump; 1690 1691 fill_elf_note_phdr(phdr4note, sz, offset); 1692 offset += sz; 1693 } 1694 1695 /* Page-align dumped data */ 1696 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1697 1698 offset += elf_core_vma_data_size(cprm->mm_flags); 1699 offset += elf_core_extra_data_size(); 1700 e_shoff = offset; 1701 1702 if (e_phnum == PN_XNUM) { 1703 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1704 if (!shdr4extnum) 1705 goto end_coredump; 1706 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1707 } 1708 1709 offset = dataoff; 1710 1711 if (!dump_emit(cprm, elf, sizeof(*elf))) 1712 goto end_coredump; 1713 1714 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1715 goto end_coredump; 1716 1717 /* write program headers for segments dump */ 1718 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1719 struct elf_phdr phdr; 1720 size_t sz; 1721 1722 sz = vma->vm_end - vma->vm_start; 1723 1724 phdr.p_type = PT_LOAD; 1725 phdr.p_offset = offset; 1726 phdr.p_vaddr = vma->vm_start; 1727 phdr.p_paddr = 0; 1728 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1729 phdr.p_memsz = sz; 1730 offset += phdr.p_filesz; 1731 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1732 if (vma->vm_flags & VM_WRITE) 1733 phdr.p_flags |= PF_W; 1734 if (vma->vm_flags & VM_EXEC) 1735 phdr.p_flags |= PF_X; 1736 phdr.p_align = ELF_EXEC_PAGESIZE; 1737 1738 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1739 goto end_coredump; 1740 } 1741 1742 if (!elf_core_write_extra_phdrs(cprm, offset)) 1743 goto end_coredump; 1744 1745 /* write out the notes section */ 1746 for (i = 0; i < numnote; i++) 1747 if (!writenote(notes + i, cprm)) 1748 goto end_coredump; 1749 1750 /* write out the thread status notes section */ 1751 list_for_each(t, &thread_list) { 1752 struct elf_thread_status *tmp = 1753 list_entry(t, struct elf_thread_status, list); 1754 1755 for (i = 0; i < tmp->num_notes; i++) 1756 if (!writenote(&tmp->notes[i], cprm)) 1757 goto end_coredump; 1758 } 1759 1760 if (!dump_skip(cprm, dataoff - cprm->pos)) 1761 goto end_coredump; 1762 1763 if (!elf_fdpic_dump_segments(cprm)) 1764 goto end_coredump; 1765 1766 if (!elf_core_write_extra_data(cprm)) 1767 goto end_coredump; 1768 1769 if (e_phnum == PN_XNUM) { 1770 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1771 goto end_coredump; 1772 } 1773 1774 if (cprm->file->f_pos != offset) { 1775 /* Sanity check */ 1776 printk(KERN_WARNING 1777 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1778 cprm->file->f_pos, offset); 1779 } 1780 1781 end_coredump: 1782 set_fs(fs); 1783 1784 cleanup: 1785 while (!list_empty(&thread_list)) { 1786 struct list_head *tmp = thread_list.next; 1787 list_del(tmp); 1788 kfree(list_entry(tmp, struct elf_thread_status, list)); 1789 } 1790 kfree(phdr4note); 1791 kfree(elf); 1792 kfree(prstatus); 1793 kfree(psinfo); 1794 kfree(notes); 1795 kfree(fpu); 1796 kfree(shdr4extnum); 1797 #ifdef ELF_CORE_COPY_XFPREGS 1798 kfree(xfpu); 1799 #endif 1800 return has_dumped; 1801 #undef NUM_NOTES 1802 } 1803 1804 #endif /* CONFIG_ELF_CORE */ 1805