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/mm.h> 19#include <linux/mman.h> 20#include <linux/errno.h> 21#include <linux/signal.h> 22#include <linux/binfmts.h> 23#include <linux/string.h> 24#include <linux/file.h> 25#include <linux/fcntl.h> 26#include <linux/slab.h> 27#include <linux/pagemap.h> 28#include <linux/security.h> 29#include <linux/highmem.h> 30#include <linux/highuid.h> 31#include <linux/personality.h> 32#include <linux/ptrace.h> 33#include <linux/init.h> 34#include <linux/elf.h> 35#include <linux/elf-fdpic.h> 36#include <linux/elfcore.h> 37#include <linux/coredump.h> 38#include <linux/dax.h> 39 40#include <asm/uaccess.h> 41#include <asm/param.h> 42#include <asm/pgalloc.h> 43 44typedef char *elf_caddr_t; 45 46#if 0 47#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 48#else 49#define kdebug(fmt, ...) do {} while(0) 50#endif 51 52#if 0 53#define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) 54#else 55#define kdcore(fmt, ...) do {} while(0) 56#endif 57 58MODULE_LICENSE("GPL"); 59 60static int load_elf_fdpic_binary(struct linux_binprm *); 61static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *); 62static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *, 63 struct mm_struct *, const char *); 64 65static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 66 struct elf_fdpic_params *, 67 struct elf_fdpic_params *); 68 69#ifndef CONFIG_MMU 70static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *, 71 unsigned long *); 72static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *, 73 struct file *, 74 struct mm_struct *); 75#endif 76 77static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, 78 struct file *, struct mm_struct *); 79 80#ifdef CONFIG_ELF_CORE 81static int elf_fdpic_core_dump(struct coredump_params *cprm); 82#endif 83 84static struct linux_binfmt elf_fdpic_format = { 85 .module = THIS_MODULE, 86 .load_binary = load_elf_fdpic_binary, 87#ifdef CONFIG_ELF_CORE 88 .core_dump = elf_fdpic_core_dump, 89#endif 90 .min_coredump = ELF_EXEC_PAGESIZE, 91}; 92 93static int __init init_elf_fdpic_binfmt(void) 94{ 95 register_binfmt(&elf_fdpic_format); 96 return 0; 97} 98 99static void __exit exit_elf_fdpic_binfmt(void) 100{ 101 unregister_binfmt(&elf_fdpic_format); 102} 103 104core_initcall(init_elf_fdpic_binfmt); 105module_exit(exit_elf_fdpic_binfmt); 106 107static int is_elf(struct elfhdr *hdr, struct file *file) 108{ 109 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) 110 return 0; 111 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) 112 return 0; 113 if (!elf_check_arch(hdr)) 114 return 0; 115 if (!file->f_op->mmap) 116 return 0; 117 return 1; 118} 119 120#ifndef elf_check_fdpic 121#define elf_check_fdpic(x) 0 122#endif 123 124#ifndef elf_check_const_displacement 125#define elf_check_const_displacement(x) 0 126#endif 127 128static int is_constdisp(struct elfhdr *hdr) 129{ 130 if (!elf_check_fdpic(hdr)) 131 return 1; 132 if (elf_check_const_displacement(hdr)) 133 return 1; 134 return 0; 135} 136 137/*****************************************************************************/ 138/* 139 * read the program headers table into memory 140 */ 141static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, 142 struct file *file) 143{ 144 struct elf32_phdr *phdr; 145 unsigned long size; 146 int retval, loop; 147 148 if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) 149 return -ENOMEM; 150 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) 151 return -ENOMEM; 152 153 size = params->hdr.e_phnum * sizeof(struct elf_phdr); 154 params->phdrs = kmalloc(size, GFP_KERNEL); 155 if (!params->phdrs) 156 return -ENOMEM; 157 158 retval = kernel_read(file, params->hdr.e_phoff, 159 (char *) params->phdrs, size); 160 if (unlikely(retval != size)) 161 return retval < 0 ? retval : -ENOEXEC; 162 163 /* determine stack size for this binary */ 164 phdr = params->phdrs; 165 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 166 if (phdr->p_type != PT_GNU_STACK) 167 continue; 168 169 if (phdr->p_flags & PF_X) 170 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; 171 else 172 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; 173 174 params->stack_size = phdr->p_memsz; 175 break; 176 } 177 178 return 0; 179} 180 181/*****************************************************************************/ 182/* 183 * load an fdpic binary into various bits of memory 184 */ 185static int load_elf_fdpic_binary(struct linux_binprm *bprm) 186{ 187 struct elf_fdpic_params exec_params, interp_params; 188 struct pt_regs *regs = current_pt_regs(); 189 struct elf_phdr *phdr; 190 unsigned long stack_size, entryaddr; 191#ifdef ELF_FDPIC_PLAT_INIT 192 unsigned long dynaddr; 193#endif 194#ifndef CONFIG_MMU 195 unsigned long stack_prot; 196#endif 197 struct file *interpreter = NULL; /* to shut gcc up */ 198 char *interpreter_name = NULL; 199 int executable_stack; 200 int retval, i; 201 202 kdebug("____ LOAD %d ____", current->pid); 203 204 memset(&exec_params, 0, sizeof(exec_params)); 205 memset(&interp_params, 0, sizeof(interp_params)); 206 207 exec_params.hdr = *(struct elfhdr *) bprm->buf; 208 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; 209 210 /* check that this is a binary we know how to deal with */ 211 retval = -ENOEXEC; 212 if (!is_elf(&exec_params.hdr, bprm->file)) 213 goto error; 214 if (!elf_check_fdpic(&exec_params.hdr)) { 215#ifdef CONFIG_MMU 216 /* binfmt_elf handles non-fdpic elf except on nommu */ 217 goto error; 218#else 219 /* nommu can only load ET_DYN (PIE) ELF */ 220 if (exec_params.hdr.e_type != ET_DYN) 221 goto error; 222#endif 223 } 224 225 /* read the program header table */ 226 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); 227 if (retval < 0) 228 goto error; 229 230 /* scan for a program header that specifies an interpreter */ 231 phdr = exec_params.phdrs; 232 233 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { 234 switch (phdr->p_type) { 235 case PT_INTERP: 236 retval = -ENOMEM; 237 if (phdr->p_filesz > PATH_MAX) 238 goto error; 239 retval = -ENOENT; 240 if (phdr->p_filesz < 2) 241 goto error; 242 243 /* read the name of the interpreter into memory */ 244 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL); 245 if (!interpreter_name) 246 goto error; 247 248 retval = kernel_read(bprm->file, 249 phdr->p_offset, 250 interpreter_name, 251 phdr->p_filesz); 252 if (unlikely(retval != phdr->p_filesz)) { 253 if (retval >= 0) 254 retval = -ENOEXEC; 255 goto error; 256 } 257 258 retval = -ENOENT; 259 if (interpreter_name[phdr->p_filesz - 1] != '\0') 260 goto error; 261 262 kdebug("Using ELF interpreter %s", interpreter_name); 263 264 /* replace the program with the interpreter */ 265 interpreter = open_exec(interpreter_name); 266 retval = PTR_ERR(interpreter); 267 if (IS_ERR(interpreter)) { 268 interpreter = NULL; 269 goto error; 270 } 271 272 /* 273 * If the binary is not readable then enforce 274 * mm->dumpable = 0 regardless of the interpreter's 275 * permissions. 276 */ 277 would_dump(bprm, interpreter); 278 279 retval = kernel_read(interpreter, 0, bprm->buf, 280 BINPRM_BUF_SIZE); 281 if (unlikely(retval != BINPRM_BUF_SIZE)) { 282 if (retval >= 0) 283 retval = -ENOEXEC; 284 goto error; 285 } 286 287 interp_params.hdr = *((struct elfhdr *) bprm->buf); 288 break; 289 290 case PT_LOAD: 291#ifdef CONFIG_MMU 292 if (exec_params.load_addr == 0) 293 exec_params.load_addr = phdr->p_vaddr; 294#endif 295 break; 296 } 297 298 } 299 300 if (is_constdisp(&exec_params.hdr)) 301 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 302 303 /* perform insanity checks on the interpreter */ 304 if (interpreter_name) { 305 retval = -ELIBBAD; 306 if (!is_elf(&interp_params.hdr, interpreter)) 307 goto error; 308 309 interp_params.flags = ELF_FDPIC_FLAG_PRESENT; 310 311 /* read the interpreter's program header table */ 312 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); 313 if (retval < 0) 314 goto error; 315 } 316 317 stack_size = exec_params.stack_size; 318 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 319 executable_stack = EXSTACK_ENABLE_X; 320 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 321 executable_stack = EXSTACK_DISABLE_X; 322 else 323 executable_stack = EXSTACK_DEFAULT; 324 325 if (stack_size == 0) { 326 stack_size = interp_params.stack_size; 327 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) 328 executable_stack = EXSTACK_ENABLE_X; 329 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) 330 executable_stack = EXSTACK_DISABLE_X; 331 else 332 executable_stack = EXSTACK_DEFAULT; 333 } 334 335 retval = -ENOEXEC; 336 if (stack_size == 0) 337 stack_size = 131072UL; /* same as exec.c's default commit */ 338 339 if (is_constdisp(&interp_params.hdr)) 340 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; 341 342 /* flush all traces of the currently running executable */ 343 retval = flush_old_exec(bprm); 344 if (retval) 345 goto error; 346 347 /* there's now no turning back... the old userspace image is dead, 348 * defunct, deceased, etc. 349 */ 350 if (elf_check_fdpic(&exec_params.hdr)) 351 set_personality(PER_LINUX_FDPIC); 352 else 353 set_personality(PER_LINUX); 354 if (elf_read_implies_exec(&exec_params.hdr, executable_stack)) 355 current->personality |= READ_IMPLIES_EXEC; 356 357 setup_new_exec(bprm); 358 359 set_binfmt(&elf_fdpic_format); 360 361 current->mm->start_code = 0; 362 current->mm->end_code = 0; 363 current->mm->start_stack = 0; 364 current->mm->start_data = 0; 365 current->mm->end_data = 0; 366 current->mm->context.exec_fdpic_loadmap = 0; 367 current->mm->context.interp_fdpic_loadmap = 0; 368 369#ifdef CONFIG_MMU 370 elf_fdpic_arch_lay_out_mm(&exec_params, 371 &interp_params, 372 ¤t->mm->start_stack, 373 ¤t->mm->start_brk); 374 375 retval = setup_arg_pages(bprm, current->mm->start_stack, 376 executable_stack); 377 if (retval < 0) 378 goto error; 379#endif 380 381 /* load the executable and interpreter into memory */ 382 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, 383 "executable"); 384 if (retval < 0) 385 goto error; 386 387 if (interpreter_name) { 388 retval = elf_fdpic_map_file(&interp_params, interpreter, 389 current->mm, "interpreter"); 390 if (retval < 0) { 391 printk(KERN_ERR "Unable to load interpreter\n"); 392 goto error; 393 } 394 395 allow_write_access(interpreter); 396 fput(interpreter); 397 interpreter = NULL; 398 } 399 400#ifdef CONFIG_MMU 401 if (!current->mm->start_brk) 402 current->mm->start_brk = current->mm->end_data; 403 404 current->mm->brk = current->mm->start_brk = 405 PAGE_ALIGN(current->mm->start_brk); 406 407#else 408 /* create a stack area and zero-size brk area */ 409 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; 410 if (stack_size < PAGE_SIZE * 2) 411 stack_size = PAGE_SIZE * 2; 412 413 stack_prot = PROT_READ | PROT_WRITE; 414 if (executable_stack == EXSTACK_ENABLE_X || 415 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC)) 416 stack_prot |= PROT_EXEC; 417 418 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot, 419 MAP_PRIVATE | MAP_ANONYMOUS | 420 MAP_UNINITIALIZED | MAP_GROWSDOWN, 421 0); 422 423 if (IS_ERR_VALUE(current->mm->start_brk)) { 424 retval = current->mm->start_brk; 425 current->mm->start_brk = 0; 426 goto error; 427 } 428 429 current->mm->brk = current->mm->start_brk; 430 current->mm->context.end_brk = current->mm->start_brk; 431 current->mm->start_stack = current->mm->start_brk + stack_size; 432#endif 433 434 install_exec_creds(bprm); 435 if (create_elf_fdpic_tables(bprm, current->mm, 436 &exec_params, &interp_params) < 0) 437 goto error; 438 439 kdebug("- start_code %lx", current->mm->start_code); 440 kdebug("- end_code %lx", current->mm->end_code); 441 kdebug("- start_data %lx", current->mm->start_data); 442 kdebug("- end_data %lx", current->mm->end_data); 443 kdebug("- start_brk %lx", current->mm->start_brk); 444 kdebug("- brk %lx", current->mm->brk); 445 kdebug("- start_stack %lx", current->mm->start_stack); 446 447#ifdef ELF_FDPIC_PLAT_INIT 448 /* 449 * The ABI may specify that certain registers be set up in special 450 * ways (on i386 %edx is the address of a DT_FINI function, for 451 * example. This macro performs whatever initialization to 452 * the regs structure is required. 453 */ 454 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr; 455 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr, 456 dynaddr); 457#endif 458 459 /* everything is now ready... get the userspace context ready to roll */ 460 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; 461 start_thread(regs, entryaddr, current->mm->start_stack); 462 463 retval = 0; 464 465error: 466 if (interpreter) { 467 allow_write_access(interpreter); 468 fput(interpreter); 469 } 470 kfree(interpreter_name); 471 kfree(exec_params.phdrs); 472 kfree(exec_params.loadmap); 473 kfree(interp_params.phdrs); 474 kfree(interp_params.loadmap); 475 return retval; 476} 477 478/*****************************************************************************/ 479 480#ifndef ELF_BASE_PLATFORM 481/* 482 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 483 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 484 * will be copied to the user stack in the same manner as AT_PLATFORM. 485 */ 486#define ELF_BASE_PLATFORM NULL 487#endif 488 489/* 490 * present useful information to the program by shovelling it onto the new 491 * process's stack 492 */ 493static int create_elf_fdpic_tables(struct linux_binprm *bprm, 494 struct mm_struct *mm, 495 struct elf_fdpic_params *exec_params, 496 struct elf_fdpic_params *interp_params) 497{ 498 const struct cred *cred = current_cred(); 499 unsigned long sp, csp, nitems; 500 elf_caddr_t __user *argv, *envp; 501 size_t platform_len = 0, len; 502 char *k_platform, *k_base_platform; 503 char __user *u_platform, *u_base_platform, *p; 504 int loop; 505 int nr; /* reset for each csp adjustment */ 506 507#ifdef CONFIG_MMU 508 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions 509 * by the processes running on the same package. One thing we can do is 510 * to shuffle the initial stack for them, so we give the architecture 511 * an opportunity to do so here. 512 */ 513 sp = arch_align_stack(bprm->p); 514#else 515 sp = mm->start_stack; 516 517 /* stack the program arguments and environment */ 518 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) 519 return -EFAULT; 520#endif 521 522 /* 523 * If this architecture has a platform capability string, copy it 524 * to userspace. In some cases (Sparc), this info is impossible 525 * for userspace to get any other way, in others (i386) it is 526 * merely difficult. 527 */ 528 k_platform = ELF_PLATFORM; 529 u_platform = NULL; 530 531 if (k_platform) { 532 platform_len = strlen(k_platform) + 1; 533 sp -= platform_len; 534 u_platform = (char __user *) sp; 535 if (__copy_to_user(u_platform, k_platform, platform_len) != 0) 536 return -EFAULT; 537 } 538 539 /* 540 * If this architecture has a "base" platform capability 541 * string, copy it to userspace. 542 */ 543 k_base_platform = ELF_BASE_PLATFORM; 544 u_base_platform = NULL; 545 546 if (k_base_platform) { 547 platform_len = strlen(k_base_platform) + 1; 548 sp -= platform_len; 549 u_base_platform = (char __user *) sp; 550 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0) 551 return -EFAULT; 552 } 553 554 sp &= ~7UL; 555 556 /* stack the load map(s) */ 557 len = sizeof(struct elf32_fdpic_loadmap); 558 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; 559 sp = (sp - len) & ~7UL; 560 exec_params->map_addr = sp; 561 562 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0) 563 return -EFAULT; 564 565 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; 566 567 if (interp_params->loadmap) { 568 len = sizeof(struct elf32_fdpic_loadmap); 569 len += sizeof(struct elf32_fdpic_loadseg) * 570 interp_params->loadmap->nsegs; 571 sp = (sp - len) & ~7UL; 572 interp_params->map_addr = sp; 573 574 if (copy_to_user((void __user *) sp, interp_params->loadmap, 575 len) != 0) 576 return -EFAULT; 577 578 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; 579 } 580 581 /* force 16 byte _final_ alignment here for generality */ 582#define DLINFO_ITEMS 15 583 584 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + 585 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH; 586 587 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) 588 nitems++; 589 590 csp = sp; 591 sp -= nitems * 2 * sizeof(unsigned long); 592 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ 593 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ 594 sp -= 1 * sizeof(unsigned long); /* argc */ 595 596 csp -= sp & 15UL; 597 sp -= sp & 15UL; 598 599 /* put the ELF interpreter info on the stack */ 600#define NEW_AUX_ENT(id, val) \ 601 do { \ 602 struct { unsigned long _id, _val; } __user *ent; \ 603 \ 604 ent = (void __user *) csp; \ 605 __put_user((id), &ent[nr]._id); \ 606 __put_user((val), &ent[nr]._val); \ 607 nr++; \ 608 } while (0) 609 610 nr = 0; 611 csp -= 2 * sizeof(unsigned long); 612 NEW_AUX_ENT(AT_NULL, 0); 613 if (k_platform) { 614 nr = 0; 615 csp -= 2 * sizeof(unsigned long); 616 NEW_AUX_ENT(AT_PLATFORM, 617 (elf_addr_t) (unsigned long) u_platform); 618 } 619 620 if (k_base_platform) { 621 nr = 0; 622 csp -= 2 * sizeof(unsigned long); 623 NEW_AUX_ENT(AT_BASE_PLATFORM, 624 (elf_addr_t) (unsigned long) u_base_platform); 625 } 626 627 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { 628 nr = 0; 629 csp -= 2 * sizeof(unsigned long); 630 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); 631 } 632 633 nr = 0; 634 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); 635 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 636#ifdef ELF_HWCAP2 637 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 638#endif 639 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE); 640 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 641 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr); 642 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 643 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); 644 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); 645 NEW_AUX_ENT(AT_FLAGS, 0); 646 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); 647 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); 648 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); 649 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid)); 650 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid)); 651 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm)); 652 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 653 654#ifdef ARCH_DLINFO 655 nr = 0; 656 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long); 657 658 /* ARCH_DLINFO must come last so platform specific code can enforce 659 * special alignment requirements on the AUXV if necessary (eg. PPC). 660 */ 661 ARCH_DLINFO; 662#endif 663#undef NEW_AUX_ENT 664 665 /* allocate room for argv[] and envv[] */ 666 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); 667 envp = (elf_caddr_t __user *) csp; 668 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); 669 argv = (elf_caddr_t __user *) csp; 670 671 /* stack argc */ 672 csp -= sizeof(unsigned long); 673 __put_user(bprm->argc, (unsigned long __user *) csp); 674 675 BUG_ON(csp != sp); 676 677 /* fill in the argv[] array */ 678#ifdef CONFIG_MMU 679 current->mm->arg_start = bprm->p; 680#else 681 current->mm->arg_start = current->mm->start_stack - 682 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); 683#endif 684 685 p = (char __user *) current->mm->arg_start; 686 for (loop = bprm->argc; loop > 0; loop--) { 687 __put_user((elf_caddr_t) p, argv++); 688 len = strnlen_user(p, MAX_ARG_STRLEN); 689 if (!len || len > MAX_ARG_STRLEN) 690 return -EINVAL; 691 p += len; 692 } 693 __put_user(NULL, argv); 694 current->mm->arg_end = (unsigned long) p; 695 696 /* fill in the envv[] array */ 697 current->mm->env_start = (unsigned long) p; 698 for (loop = bprm->envc; loop > 0; loop--) { 699 __put_user((elf_caddr_t)(unsigned long) p, envp++); 700 len = strnlen_user(p, MAX_ARG_STRLEN); 701 if (!len || len > MAX_ARG_STRLEN) 702 return -EINVAL; 703 p += len; 704 } 705 __put_user(NULL, envp); 706 current->mm->env_end = (unsigned long) p; 707 708 mm->start_stack = (unsigned long) sp; 709 return 0; 710} 711 712/*****************************************************************************/ 713/* 714 * transfer the program arguments and environment from the holding pages onto 715 * the stack 716 */ 717#ifndef CONFIG_MMU 718static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, 719 unsigned long *_sp) 720{ 721 unsigned long index, stop, sp; 722 char *src; 723 int ret = 0; 724 725 stop = bprm->p >> PAGE_SHIFT; 726 sp = *_sp; 727 728 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { 729 src = kmap(bprm->page[index]); 730 sp -= PAGE_SIZE; 731 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) 732 ret = -EFAULT; 733 kunmap(bprm->page[index]); 734 if (ret < 0) 735 goto out; 736 } 737 738 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; 739 740out: 741 return ret; 742} 743#endif 744 745/*****************************************************************************/ 746/* 747 * load the appropriate binary image (executable or interpreter) into memory 748 * - we assume no MMU is available 749 * - if no other PIC bits are set in params->hdr->e_flags 750 * - we assume that the LOADable segments in the binary are independently relocatable 751 * - we assume R/O executable segments are shareable 752 * - else 753 * - we assume the loadable parts of the image to require fixed displacement 754 * - the image is not shareable 755 */ 756static int elf_fdpic_map_file(struct elf_fdpic_params *params, 757 struct file *file, 758 struct mm_struct *mm, 759 const char *what) 760{ 761 struct elf32_fdpic_loadmap *loadmap; 762#ifdef CONFIG_MMU 763 struct elf32_fdpic_loadseg *mseg; 764#endif 765 struct elf32_fdpic_loadseg *seg; 766 struct elf32_phdr *phdr; 767 unsigned long load_addr, stop; 768 unsigned nloads, tmp; 769 size_t size; 770 int loop, ret; 771 772 /* allocate a load map table */ 773 nloads = 0; 774 for (loop = 0; loop < params->hdr.e_phnum; loop++) 775 if (params->phdrs[loop].p_type == PT_LOAD) 776 nloads++; 777 778 if (nloads == 0) 779 return -ELIBBAD; 780 781 size = sizeof(*loadmap) + nloads * sizeof(*seg); 782 loadmap = kzalloc(size, GFP_KERNEL); 783 if (!loadmap) 784 return -ENOMEM; 785 786 params->loadmap = loadmap; 787 788 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; 789 loadmap->nsegs = nloads; 790 791 load_addr = params->load_addr; 792 seg = loadmap->segs; 793 794 /* map the requested LOADs into the memory space */ 795 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 796 case ELF_FDPIC_FLAG_CONSTDISP: 797 case ELF_FDPIC_FLAG_CONTIGUOUS: 798#ifndef CONFIG_MMU 799 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); 800 if (ret < 0) 801 return ret; 802 break; 803#endif 804 default: 805 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); 806 if (ret < 0) 807 return ret; 808 break; 809 } 810 811 /* map the entry point */ 812 if (params->hdr.e_entry) { 813 seg = loadmap->segs; 814 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 815 if (params->hdr.e_entry >= seg->p_vaddr && 816 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) { 817 params->entry_addr = 818 (params->hdr.e_entry - seg->p_vaddr) + 819 seg->addr; 820 break; 821 } 822 } 823 } 824 825 /* determine where the program header table has wound up if mapped */ 826 stop = params->hdr.e_phoff; 827 stop += params->hdr.e_phnum * sizeof (struct elf_phdr); 828 phdr = params->phdrs; 829 830 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 831 if (phdr->p_type != PT_LOAD) 832 continue; 833 834 if (phdr->p_offset > params->hdr.e_phoff || 835 phdr->p_offset + phdr->p_filesz < stop) 836 continue; 837 838 seg = loadmap->segs; 839 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 840 if (phdr->p_vaddr >= seg->p_vaddr && 841 phdr->p_vaddr + phdr->p_filesz <= 842 seg->p_vaddr + seg->p_memsz) { 843 params->ph_addr = 844 (phdr->p_vaddr - seg->p_vaddr) + 845 seg->addr + 846 params->hdr.e_phoff - phdr->p_offset; 847 break; 848 } 849 } 850 break; 851 } 852 853 /* determine where the dynamic section has wound up if there is one */ 854 phdr = params->phdrs; 855 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 856 if (phdr->p_type != PT_DYNAMIC) 857 continue; 858 859 seg = loadmap->segs; 860 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { 861 if (phdr->p_vaddr >= seg->p_vaddr && 862 phdr->p_vaddr + phdr->p_memsz <= 863 seg->p_vaddr + seg->p_memsz) { 864 params->dynamic_addr = 865 (phdr->p_vaddr - seg->p_vaddr) + 866 seg->addr; 867 868 /* check the dynamic section contains at least 869 * one item, and that the last item is a NULL 870 * entry */ 871 if (phdr->p_memsz == 0 || 872 phdr->p_memsz % sizeof(Elf32_Dyn) != 0) 873 goto dynamic_error; 874 875 tmp = phdr->p_memsz / sizeof(Elf32_Dyn); 876 if (((Elf32_Dyn *) 877 params->dynamic_addr)[tmp - 1].d_tag != 0) 878 goto dynamic_error; 879 break; 880 } 881 } 882 break; 883 } 884 885 /* now elide adjacent segments in the load map on MMU linux 886 * - on uClinux the holes between may actually be filled with system 887 * stuff or stuff from other processes 888 */ 889#ifdef CONFIG_MMU 890 nloads = loadmap->nsegs; 891 mseg = loadmap->segs; 892 seg = mseg + 1; 893 for (loop = 1; loop < nloads; loop++) { 894 /* see if we have a candidate for merging */ 895 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { 896 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); 897 if (load_addr == (seg->addr & PAGE_MASK)) { 898 mseg->p_memsz += 899 load_addr - 900 (mseg->addr + mseg->p_memsz); 901 mseg->p_memsz += seg->addr & ~PAGE_MASK; 902 mseg->p_memsz += seg->p_memsz; 903 loadmap->nsegs--; 904 continue; 905 } 906 } 907 908 mseg++; 909 if (mseg != seg) 910 *mseg = *seg; 911 } 912#endif 913 914 kdebug("Mapped Object [%s]:", what); 915 kdebug("- elfhdr : %lx", params->elfhdr_addr); 916 kdebug("- entry : %lx", params->entry_addr); 917 kdebug("- PHDR[] : %lx", params->ph_addr); 918 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); 919 seg = loadmap->segs; 920 for (loop = 0; loop < loadmap->nsegs; loop++, seg++) 921 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", 922 loop, 923 seg->addr, seg->addr + seg->p_memsz - 1, 924 seg->p_vaddr, seg->p_memsz); 925 926 return 0; 927 928dynamic_error: 929 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", 930 what, file_inode(file)->i_ino); 931 return -ELIBBAD; 932} 933 934/*****************************************************************************/ 935/* 936 * map a file with constant displacement under uClinux 937 */ 938#ifndef CONFIG_MMU 939static int elf_fdpic_map_file_constdisp_on_uclinux( 940 struct elf_fdpic_params *params, 941 struct file *file, 942 struct mm_struct *mm) 943{ 944 struct elf32_fdpic_loadseg *seg; 945 struct elf32_phdr *phdr; 946 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; 947 int loop, ret; 948 949 load_addr = params->load_addr; 950 seg = params->loadmap->segs; 951 952 /* determine the bounds of the contiguous overall allocation we must 953 * make */ 954 phdr = params->phdrs; 955 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 956 if (params->phdrs[loop].p_type != PT_LOAD) 957 continue; 958 959 if (base > phdr->p_vaddr) 960 base = phdr->p_vaddr; 961 if (top < phdr->p_vaddr + phdr->p_memsz) 962 top = phdr->p_vaddr + phdr->p_memsz; 963 } 964 965 /* allocate one big anon block for everything */ 966 mflags = MAP_PRIVATE; 967 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 968 mflags |= MAP_EXECUTABLE; 969 970 maddr = vm_mmap(NULL, load_addr, top - base, 971 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); 972 if (IS_ERR_VALUE(maddr)) 973 return (int) maddr; 974 975 if (load_addr != 0) 976 load_addr += PAGE_ALIGN(top - base); 977 978 /* and then load the file segments into it */ 979 phdr = params->phdrs; 980 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 981 if (params->phdrs[loop].p_type != PT_LOAD) 982 continue; 983 984 seg->addr = maddr + (phdr->p_vaddr - base); 985 seg->p_vaddr = phdr->p_vaddr; 986 seg->p_memsz = phdr->p_memsz; 987 988 ret = read_code(file, seg->addr, phdr->p_offset, 989 phdr->p_filesz); 990 if (ret < 0) 991 return ret; 992 993 /* map the ELF header address if in this segment */ 994 if (phdr->p_offset == 0) 995 params->elfhdr_addr = seg->addr; 996 997 /* clear any space allocated but not loaded */ 998 if (phdr->p_filesz < phdr->p_memsz) { 999 if (clear_user((void *) (seg->addr + phdr->p_filesz), 1000 phdr->p_memsz - phdr->p_filesz)) 1001 return -EFAULT; 1002 } 1003 1004 if (mm) { 1005 if (phdr->p_flags & PF_X) { 1006 if (!mm->start_code) { 1007 mm->start_code = seg->addr; 1008 mm->end_code = seg->addr + 1009 phdr->p_memsz; 1010 } 1011 } else if (!mm->start_data) { 1012 mm->start_data = seg->addr; 1013 mm->end_data = seg->addr + phdr->p_memsz; 1014 } 1015 } 1016 1017 seg++; 1018 } 1019 1020 return 0; 1021} 1022#endif 1023 1024/*****************************************************************************/ 1025/* 1026 * map a binary by direct mmap() of the individual PT_LOAD segments 1027 */ 1028static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 1029 struct file *file, 1030 struct mm_struct *mm) 1031{ 1032 struct elf32_fdpic_loadseg *seg; 1033 struct elf32_phdr *phdr; 1034 unsigned long load_addr, delta_vaddr; 1035 int loop, dvset; 1036 1037 load_addr = params->load_addr; 1038 delta_vaddr = 0; 1039 dvset = 0; 1040 1041 seg = params->loadmap->segs; 1042 1043 /* deal with each load segment separately */ 1044 phdr = params->phdrs; 1045 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { 1046 unsigned long maddr, disp, excess, excess1; 1047 int prot = 0, flags; 1048 1049 if (phdr->p_type != PT_LOAD) 1050 continue; 1051 1052 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", 1053 (unsigned long) phdr->p_vaddr, 1054 (unsigned long) phdr->p_offset, 1055 (unsigned long) phdr->p_filesz, 1056 (unsigned long) phdr->p_memsz); 1057 1058 /* determine the mapping parameters */ 1059 if (phdr->p_flags & PF_R) prot |= PROT_READ; 1060 if (phdr->p_flags & PF_W) prot |= PROT_WRITE; 1061 if (phdr->p_flags & PF_X) prot |= PROT_EXEC; 1062 1063 flags = MAP_PRIVATE | MAP_DENYWRITE; 1064 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) 1065 flags |= MAP_EXECUTABLE; 1066 1067 maddr = 0; 1068 1069 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { 1070 case ELF_FDPIC_FLAG_INDEPENDENT: 1071 /* PT_LOADs are independently locatable */ 1072 break; 1073 1074 case ELF_FDPIC_FLAG_HONOURVADDR: 1075 /* the specified virtual address must be honoured */ 1076 maddr = phdr->p_vaddr; 1077 flags |= MAP_FIXED; 1078 break; 1079 1080 case ELF_FDPIC_FLAG_CONSTDISP: 1081 /* constant displacement 1082 * - can be mapped anywhere, but must be mapped as a 1083 * unit 1084 */ 1085 if (!dvset) { 1086 maddr = load_addr; 1087 delta_vaddr = phdr->p_vaddr; 1088 dvset = 1; 1089 } else { 1090 maddr = load_addr + phdr->p_vaddr - delta_vaddr; 1091 flags |= MAP_FIXED; 1092 } 1093 break; 1094 1095 case ELF_FDPIC_FLAG_CONTIGUOUS: 1096 /* contiguity handled later */ 1097 break; 1098 1099 default: 1100 BUG(); 1101 } 1102 1103 maddr &= PAGE_MASK; 1104 1105 /* create the mapping */ 1106 disp = phdr->p_vaddr & ~PAGE_MASK; 1107 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, 1108 phdr->p_offset - disp); 1109 1110 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", 1111 loop, phdr->p_memsz + disp, prot, flags, 1112 phdr->p_offset - disp, maddr); 1113 1114 if (IS_ERR_VALUE(maddr)) 1115 return (int) maddr; 1116 1117 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == 1118 ELF_FDPIC_FLAG_CONTIGUOUS) 1119 load_addr += PAGE_ALIGN(phdr->p_memsz + disp); 1120 1121 seg->addr = maddr + disp; 1122 seg->p_vaddr = phdr->p_vaddr; 1123 seg->p_memsz = phdr->p_memsz; 1124 1125 /* map the ELF header address if in this segment */ 1126 if (phdr->p_offset == 0) 1127 params->elfhdr_addr = seg->addr; 1128 1129 /* clear the bit between beginning of mapping and beginning of 1130 * PT_LOAD */ 1131 if (prot & PROT_WRITE && disp > 0) { 1132 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); 1133 if (clear_user((void __user *) maddr, disp)) 1134 return -EFAULT; 1135 maddr += disp; 1136 } 1137 1138 /* clear any space allocated but not loaded 1139 * - on uClinux we can just clear the lot 1140 * - on MMU linux we'll get a SIGBUS beyond the last page 1141 * extant in the file 1142 */ 1143 excess = phdr->p_memsz - phdr->p_filesz; 1144 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); 1145 1146#ifdef CONFIG_MMU 1147 if (excess > excess1) { 1148 unsigned long xaddr = maddr + phdr->p_filesz + excess1; 1149 unsigned long xmaddr; 1150 1151 flags |= MAP_FIXED | MAP_ANONYMOUS; 1152 xmaddr = vm_mmap(NULL, xaddr, excess - excess1, 1153 prot, flags, 0); 1154 1155 kdebug("mmap[%d] <anon>" 1156 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", 1157 loop, xaddr, excess - excess1, prot, flags, 1158 xmaddr); 1159 1160 if (xmaddr != xaddr) 1161 return -ENOMEM; 1162 } 1163 1164 if (prot & PROT_WRITE && excess1 > 0) { 1165 kdebug("clear[%d] ad=%lx sz=%lx", 1166 loop, maddr + phdr->p_filesz, excess1); 1167 if (clear_user((void __user *) maddr + phdr->p_filesz, 1168 excess1)) 1169 return -EFAULT; 1170 } 1171 1172#else 1173 if (excess > 0) { 1174 kdebug("clear[%d] ad=%lx sz=%lx", 1175 loop, maddr + phdr->p_filesz, excess); 1176 if (clear_user((void *) maddr + phdr->p_filesz, excess)) 1177 return -EFAULT; 1178 } 1179#endif 1180 1181 if (mm) { 1182 if (phdr->p_flags & PF_X) { 1183 if (!mm->start_code) { 1184 mm->start_code = maddr; 1185 mm->end_code = maddr + phdr->p_memsz; 1186 } 1187 } else if (!mm->start_data) { 1188 mm->start_data = maddr; 1189 mm->end_data = maddr + phdr->p_memsz; 1190 } 1191 } 1192 1193 seg++; 1194 } 1195 1196 return 0; 1197} 1198 1199/*****************************************************************************/ 1200/* 1201 * ELF-FDPIC core dumper 1202 * 1203 * Modelled on fs/exec.c:aout_core_dump() 1204 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1205 * 1206 * Modelled on fs/binfmt_elf.c core dumper 1207 */ 1208#ifdef CONFIG_ELF_CORE 1209 1210/* 1211 * Decide whether a segment is worth dumping; default is yes to be 1212 * sure (missing info is worse than too much; etc). 1213 * Personally I'd include everything, and use the coredump limit... 1214 * 1215 * I think we should skip something. But I am not sure how. H.J. 1216 */ 1217static int maydump(struct vm_area_struct *vma, unsigned long mm_flags) 1218{ 1219 int dump_ok; 1220 1221 /* Do not dump I/O mapped devices or special mappings */ 1222 if (vma->vm_flags & VM_IO) { 1223 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags); 1224 return 0; 1225 } 1226 1227 /* If we may not read the contents, don't allow us to dump 1228 * them either. "dump_write()" can't handle it anyway. 1229 */ 1230 if (!(vma->vm_flags & VM_READ)) { 1231 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags); 1232 return 0; 1233 } 1234 1235 /* support for DAX */ 1236 if (vma_is_dax(vma)) { 1237 if (vma->vm_flags & VM_SHARED) { 1238 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags); 1239 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start, 1240 vma->vm_flags, dump_ok ? "yes" : "no"); 1241 } else { 1242 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags); 1243 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start, 1244 vma->vm_flags, dump_ok ? "yes" : "no"); 1245 } 1246 return dump_ok; 1247 } 1248 1249 /* By default, dump shared memory if mapped from an anonymous file. */ 1250 if (vma->vm_flags & VM_SHARED) { 1251 if (file_inode(vma->vm_file)->i_nlink == 0) { 1252 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags); 1253 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1254 vma->vm_flags, dump_ok ? "yes" : "no"); 1255 return dump_ok; 1256 } 1257 1258 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags); 1259 kdcore("%08lx: %08lx: %s (share)", vma->vm_start, 1260 vma->vm_flags, dump_ok ? "yes" : "no"); 1261 return dump_ok; 1262 } 1263 1264#ifdef CONFIG_MMU 1265 /* By default, if it hasn't been written to, don't write it out */ 1266 if (!vma->anon_vma) { 1267 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags); 1268 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start, 1269 vma->vm_flags, dump_ok ? "yes" : "no"); 1270 return dump_ok; 1271 } 1272#endif 1273 1274 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags); 1275 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags, 1276 dump_ok ? "yes" : "no"); 1277 return dump_ok; 1278} 1279 1280/* An ELF note in memory */ 1281struct memelfnote 1282{ 1283 const char *name; 1284 int type; 1285 unsigned int datasz; 1286 void *data; 1287}; 1288 1289static int notesize(struct memelfnote *en) 1290{ 1291 int sz; 1292 1293 sz = sizeof(struct elf_note); 1294 sz += roundup(strlen(en->name) + 1, 4); 1295 sz += roundup(en->datasz, 4); 1296 1297 return sz; 1298} 1299 1300/* #define DEBUG */ 1301 1302static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1303{ 1304 struct elf_note en; 1305 en.n_namesz = strlen(men->name) + 1; 1306 en.n_descsz = men->datasz; 1307 en.n_type = men->type; 1308 1309 return dump_emit(cprm, &en, sizeof(en)) && 1310 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1311 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1312} 1313 1314static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs) 1315{ 1316 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1317 elf->e_ident[EI_CLASS] = ELF_CLASS; 1318 elf->e_ident[EI_DATA] = ELF_DATA; 1319 elf->e_ident[EI_VERSION] = EV_CURRENT; 1320 elf->e_ident[EI_OSABI] = ELF_OSABI; 1321 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1322 1323 elf->e_type = ET_CORE; 1324 elf->e_machine = ELF_ARCH; 1325 elf->e_version = EV_CURRENT; 1326 elf->e_entry = 0; 1327 elf->e_phoff = sizeof(struct elfhdr); 1328 elf->e_shoff = 0; 1329 elf->e_flags = ELF_FDPIC_CORE_EFLAGS; 1330 elf->e_ehsize = sizeof(struct elfhdr); 1331 elf->e_phentsize = sizeof(struct elf_phdr); 1332 elf->e_phnum = segs; 1333 elf->e_shentsize = 0; 1334 elf->e_shnum = 0; 1335 elf->e_shstrndx = 0; 1336 return; 1337} 1338 1339static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1340{ 1341 phdr->p_type = PT_NOTE; 1342 phdr->p_offset = offset; 1343 phdr->p_vaddr = 0; 1344 phdr->p_paddr = 0; 1345 phdr->p_filesz = sz; 1346 phdr->p_memsz = 0; 1347 phdr->p_flags = 0; 1348 phdr->p_align = 0; 1349 return; 1350} 1351 1352static inline void fill_note(struct memelfnote *note, const char *name, int type, 1353 unsigned int sz, void *data) 1354{ 1355 note->name = name; 1356 note->type = type; 1357 note->datasz = sz; 1358 note->data = data; 1359 return; 1360} 1361 1362/* 1363 * fill up all the fields in prstatus from the given task struct, except 1364 * registers which need to be filled up separately. 1365 */ 1366static void fill_prstatus(struct elf_prstatus *prstatus, 1367 struct task_struct *p, long signr) 1368{ 1369 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1370 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1371 prstatus->pr_sighold = p->blocked.sig[0]; 1372 rcu_read_lock(); 1373 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1374 rcu_read_unlock(); 1375 prstatus->pr_pid = task_pid_vnr(p); 1376 prstatus->pr_pgrp = task_pgrp_vnr(p); 1377 prstatus->pr_sid = task_session_vnr(p); 1378 if (thread_group_leader(p)) { 1379 struct task_cputime cputime; 1380 1381 /* 1382 * This is the record for the group leader. It shows the 1383 * group-wide total, not its individual thread total. 1384 */ 1385 thread_group_cputime(p, &cputime); 1386 cputime_to_timeval(cputime.utime, &prstatus->pr_utime); 1387 cputime_to_timeval(cputime.stime, &prstatus->pr_stime); 1388 } else { 1389 cputime_t utime, stime; 1390 1391 task_cputime(p, &utime, &stime); 1392 cputime_to_timeval(utime, &prstatus->pr_utime); 1393 cputime_to_timeval(stime, &prstatus->pr_stime); 1394 } 1395 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime); 1396 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime); 1397 1398 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap; 1399 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap; 1400} 1401 1402static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1403 struct mm_struct *mm) 1404{ 1405 const struct cred *cred; 1406 unsigned int i, len; 1407 1408 /* first copy the parameters from user space */ 1409 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1410 1411 len = mm->arg_end - mm->arg_start; 1412 if (len >= ELF_PRARGSZ) 1413 len = ELF_PRARGSZ - 1; 1414 if (copy_from_user(&psinfo->pr_psargs, 1415 (const char __user *) mm->arg_start, len)) 1416 return -EFAULT; 1417 for (i = 0; i < len; i++) 1418 if (psinfo->pr_psargs[i] == 0) 1419 psinfo->pr_psargs[i] = ' '; 1420 psinfo->pr_psargs[len] = 0; 1421 1422 rcu_read_lock(); 1423 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1424 rcu_read_unlock(); 1425 psinfo->pr_pid = task_pid_vnr(p); 1426 psinfo->pr_pgrp = task_pgrp_vnr(p); 1427 psinfo->pr_sid = task_session_vnr(p); 1428 1429 i = p->state ? ffz(~p->state) + 1 : 0; 1430 psinfo->pr_state = i; 1431 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1432 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1433 psinfo->pr_nice = task_nice(p); 1434 psinfo->pr_flag = p->flags; 1435 rcu_read_lock(); 1436 cred = __task_cred(p); 1437 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1438 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1439 rcu_read_unlock(); 1440 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); 1441 1442 return 0; 1443} 1444 1445/* Here is the structure in which status of each thread is captured. */ 1446struct elf_thread_status 1447{ 1448 struct list_head list; 1449 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1450 elf_fpregset_t fpu; /* NT_PRFPREG */ 1451 struct task_struct *thread; 1452#ifdef ELF_CORE_COPY_XFPREGS 1453 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ 1454#endif 1455 struct memelfnote notes[3]; 1456 int num_notes; 1457}; 1458 1459/* 1460 * In order to add the specific thread information for the elf file format, 1461 * we need to keep a linked list of every thread's pr_status and then create 1462 * a single section for them in the final core file. 1463 */ 1464static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 1465{ 1466 struct task_struct *p = t->thread; 1467 int sz = 0; 1468 1469 t->num_notes = 0; 1470 1471 fill_prstatus(&t->prstatus, p, signr); 1472 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 1473 1474 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 1475 &t->prstatus); 1476 t->num_notes++; 1477 sz += notesize(&t->notes[0]); 1478 1479 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu); 1480 if (t->prstatus.pr_fpvalid) { 1481 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 1482 &t->fpu); 1483 t->num_notes++; 1484 sz += notesize(&t->notes[1]); 1485 } 1486 1487#ifdef ELF_CORE_COPY_XFPREGS 1488 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { 1489 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, 1490 sizeof(t->xfpu), &t->xfpu); 1491 t->num_notes++; 1492 sz += notesize(&t->notes[2]); 1493 } 1494#endif 1495 return sz; 1496} 1497 1498static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 1499 elf_addr_t e_shoff, int segs) 1500{ 1501 elf->e_shoff = e_shoff; 1502 elf->e_shentsize = sizeof(*shdr4extnum); 1503 elf->e_shnum = 1; 1504 elf->e_shstrndx = SHN_UNDEF; 1505 1506 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 1507 1508 shdr4extnum->sh_type = SHT_NULL; 1509 shdr4extnum->sh_size = elf->e_shnum; 1510 shdr4extnum->sh_link = elf->e_shstrndx; 1511 shdr4extnum->sh_info = segs; 1512} 1513 1514/* 1515 * dump the segments for an MMU process 1516 */ 1517static bool elf_fdpic_dump_segments(struct coredump_params *cprm) 1518{ 1519 struct vm_area_struct *vma; 1520 1521 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1522 unsigned long addr; 1523 1524 if (!maydump(vma, cprm->mm_flags)) 1525 continue; 1526 1527#ifdef CONFIG_MMU 1528 for (addr = vma->vm_start; addr < vma->vm_end; 1529 addr += PAGE_SIZE) { 1530 bool res; 1531 struct page *page = get_dump_page(addr); 1532 if (page) { 1533 void *kaddr = kmap(page); 1534 res = dump_emit(cprm, kaddr, PAGE_SIZE); 1535 kunmap(page); 1536 page_cache_release(page); 1537 } else { 1538 res = dump_skip(cprm, PAGE_SIZE); 1539 } 1540 if (!res) 1541 return false; 1542 } 1543#else 1544 if (!dump_emit(cprm, (void *) vma->vm_start, 1545 vma->vm_end - vma->vm_start)) 1546 return false; 1547#endif 1548 } 1549 return true; 1550} 1551 1552static size_t elf_core_vma_data_size(unsigned long mm_flags) 1553{ 1554 struct vm_area_struct *vma; 1555 size_t size = 0; 1556 1557 for (vma = current->mm->mmap; vma; vma = vma->vm_next) 1558 if (maydump(vma, mm_flags)) 1559 size += vma->vm_end - vma->vm_start; 1560 return size; 1561} 1562 1563/* 1564 * Actual dumper 1565 * 1566 * This is a two-pass process; first we find the offsets of the bits, 1567 * and then they are actually written out. If we run out of core limit 1568 * we just truncate. 1569 */ 1570static int elf_fdpic_core_dump(struct coredump_params *cprm) 1571{ 1572#define NUM_NOTES 6 1573 int has_dumped = 0; 1574 mm_segment_t fs; 1575 int segs; 1576 int i; 1577 struct vm_area_struct *vma; 1578 struct elfhdr *elf = NULL; 1579 loff_t offset = 0, dataoff; 1580 int numnote; 1581 struct memelfnote *notes = NULL; 1582 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */ 1583 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */ 1584 LIST_HEAD(thread_list); 1585 struct list_head *t; 1586 elf_fpregset_t *fpu = NULL; 1587#ifdef ELF_CORE_COPY_XFPREGS 1588 elf_fpxregset_t *xfpu = NULL; 1589#endif 1590 int thread_status_size = 0; 1591 elf_addr_t *auxv; 1592 struct elf_phdr *phdr4note = NULL; 1593 struct elf_shdr *shdr4extnum = NULL; 1594 Elf_Half e_phnum; 1595 elf_addr_t e_shoff; 1596 struct core_thread *ct; 1597 struct elf_thread_status *tmp; 1598 1599 /* 1600 * We no longer stop all VM operations. 1601 * 1602 * This is because those proceses that could possibly change map_count 1603 * or the mmap / vma pages are now blocked in do_exit on current 1604 * finishing this core dump. 1605 * 1606 * Only ptrace can touch these memory addresses, but it doesn't change 1607 * the map_count or the pages allocated. So no possibility of crashing 1608 * exists while dumping the mm->vm_next areas to the core file. 1609 */ 1610 1611 /* alloc memory for large data structures: too large to be on stack */ 1612 elf = kmalloc(sizeof(*elf), GFP_KERNEL); 1613 if (!elf) 1614 goto cleanup; 1615 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL); 1616 if (!prstatus) 1617 goto cleanup; 1618 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1619 if (!psinfo) 1620 goto cleanup; 1621 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL); 1622 if (!notes) 1623 goto cleanup; 1624 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL); 1625 if (!fpu) 1626 goto cleanup; 1627#ifdef ELF_CORE_COPY_XFPREGS 1628 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL); 1629 if (!xfpu) 1630 goto cleanup; 1631#endif 1632 1633 for (ct = current->mm->core_state->dumper.next; 1634 ct; ct = ct->next) { 1635 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL); 1636 if (!tmp) 1637 goto cleanup; 1638 1639 tmp->thread = ct->task; 1640 list_add(&tmp->list, &thread_list); 1641 } 1642 1643 list_for_each(t, &thread_list) { 1644 struct elf_thread_status *tmp; 1645 int sz; 1646 1647 tmp = list_entry(t, struct elf_thread_status, list); 1648 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp); 1649 thread_status_size += sz; 1650 } 1651 1652 /* now collect the dump for the current */ 1653 fill_prstatus(prstatus, current, cprm->siginfo->si_signo); 1654 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs); 1655 1656 segs = current->mm->map_count; 1657 segs += elf_core_extra_phdrs(); 1658 1659 /* for notes section */ 1660 segs++; 1661 1662 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 1663 * this, kernel supports extended numbering. Have a look at 1664 * include/linux/elf.h for further information. */ 1665 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 1666 1667 /* Set up header */ 1668 fill_elf_fdpic_header(elf, e_phnum); 1669 1670 has_dumped = 1; 1671 /* 1672 * Set up the notes in similar form to SVR4 core dumps made 1673 * with info from their /proc. 1674 */ 1675 1676 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus); 1677 fill_psinfo(psinfo, current->group_leader, current->mm); 1678 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1679 1680 numnote = 2; 1681 1682 auxv = (elf_addr_t *) current->mm->saved_auxv; 1683 1684 i = 0; 1685 do 1686 i += 2; 1687 while (auxv[i - 2] != AT_NULL); 1688 fill_note(¬es[numnote++], "CORE", NT_AUXV, 1689 i * sizeof(elf_addr_t), auxv); 1690 1691 /* Try to dump the FPU. */ 1692 if ((prstatus->pr_fpvalid = 1693 elf_core_copy_task_fpregs(current, cprm->regs, fpu))) 1694 fill_note(notes + numnote++, 1695 "CORE", NT_PRFPREG, sizeof(*fpu), fpu); 1696#ifdef ELF_CORE_COPY_XFPREGS 1697 if (elf_core_copy_task_xfpregs(current, xfpu)) 1698 fill_note(notes + numnote++, 1699 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu); 1700#endif 1701 1702 fs = get_fs(); 1703 set_fs(KERNEL_DS); 1704 1705 offset += sizeof(*elf); /* Elf header */ 1706 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 1707 1708 /* Write notes phdr entry */ 1709 { 1710 int sz = 0; 1711 1712 for (i = 0; i < numnote; i++) 1713 sz += notesize(notes + i); 1714 1715 sz += thread_status_size; 1716 1717 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 1718 if (!phdr4note) 1719 goto end_coredump; 1720 1721 fill_elf_note_phdr(phdr4note, sz, offset); 1722 offset += sz; 1723 } 1724 1725 /* Page-align dumped data */ 1726 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 1727 1728 offset += elf_core_vma_data_size(cprm->mm_flags); 1729 offset += elf_core_extra_data_size(); 1730 e_shoff = offset; 1731 1732 if (e_phnum == PN_XNUM) { 1733 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 1734 if (!shdr4extnum) 1735 goto end_coredump; 1736 fill_extnum_info(elf, shdr4extnum, e_shoff, segs); 1737 } 1738 1739 offset = dataoff; 1740 1741 if (!dump_emit(cprm, elf, sizeof(*elf))) 1742 goto end_coredump; 1743 1744 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 1745 goto end_coredump; 1746 1747 /* write program headers for segments dump */ 1748 for (vma = current->mm->mmap; vma; vma = vma->vm_next) { 1749 struct elf_phdr phdr; 1750 size_t sz; 1751 1752 sz = vma->vm_end - vma->vm_start; 1753 1754 phdr.p_type = PT_LOAD; 1755 phdr.p_offset = offset; 1756 phdr.p_vaddr = vma->vm_start; 1757 phdr.p_paddr = 0; 1758 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; 1759 phdr.p_memsz = sz; 1760 offset += phdr.p_filesz; 1761 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; 1762 if (vma->vm_flags & VM_WRITE) 1763 phdr.p_flags |= PF_W; 1764 if (vma->vm_flags & VM_EXEC) 1765 phdr.p_flags |= PF_X; 1766 phdr.p_align = ELF_EXEC_PAGESIZE; 1767 1768 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 1769 goto end_coredump; 1770 } 1771 1772 if (!elf_core_write_extra_phdrs(cprm, offset)) 1773 goto end_coredump; 1774 1775 /* write out the notes section */ 1776 for (i = 0; i < numnote; i++) 1777 if (!writenote(notes + i, cprm)) 1778 goto end_coredump; 1779 1780 /* write out the thread status notes section */ 1781 list_for_each(t, &thread_list) { 1782 struct elf_thread_status *tmp = 1783 list_entry(t, struct elf_thread_status, list); 1784 1785 for (i = 0; i < tmp->num_notes; i++) 1786 if (!writenote(&tmp->notes[i], cprm)) 1787 goto end_coredump; 1788 } 1789 1790 if (!dump_skip(cprm, dataoff - cprm->written)) 1791 goto end_coredump; 1792 1793 if (!elf_fdpic_dump_segments(cprm)) 1794 goto end_coredump; 1795 1796 if (!elf_core_write_extra_data(cprm)) 1797 goto end_coredump; 1798 1799 if (e_phnum == PN_XNUM) { 1800 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 1801 goto end_coredump; 1802 } 1803 1804 if (cprm->file->f_pos != offset) { 1805 /* Sanity check */ 1806 printk(KERN_WARNING 1807 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n", 1808 cprm->file->f_pos, offset); 1809 } 1810 1811end_coredump: 1812 set_fs(fs); 1813 1814cleanup: 1815 while (!list_empty(&thread_list)) { 1816 struct list_head *tmp = thread_list.next; 1817 list_del(tmp); 1818 kfree(list_entry(tmp, struct elf_thread_status, list)); 1819 } 1820 kfree(phdr4note); 1821 kfree(elf); 1822 kfree(prstatus); 1823 kfree(psinfo); 1824 kfree(notes); 1825 kfree(fpu); 1826 kfree(shdr4extnum); 1827#ifdef ELF_CORE_COPY_XFPREGS 1828 kfree(xfpu); 1829#endif 1830 return has_dumped; 1831#undef NUM_NOTES 1832} 1833 1834#endif /* CONFIG_ELF_CORE */ 1835