binfmt_elf.c (63050B)
1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * linux/fs/binfmt_elf.c 4 * 5 * These are the functions used to load ELF format executables as used 6 * on SVr4 machines. Information on the format may be found in the book 7 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support 8 * Tools". 9 * 10 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com). 11 */ 12 13#include <linux/module.h> 14#include <linux/kernel.h> 15#include <linux/fs.h> 16#include <linux/log2.h> 17#include <linux/mm.h> 18#include <linux/mman.h> 19#include <linux/errno.h> 20#include <linux/signal.h> 21#include <linux/binfmts.h> 22#include <linux/string.h> 23#include <linux/file.h> 24#include <linux/slab.h> 25#include <linux/personality.h> 26#include <linux/elfcore.h> 27#include <linux/init.h> 28#include <linux/highuid.h> 29#include <linux/compiler.h> 30#include <linux/highmem.h> 31#include <linux/hugetlb.h> 32#include <linux/pagemap.h> 33#include <linux/vmalloc.h> 34#include <linux/security.h> 35#include <linux/random.h> 36#include <linux/elf.h> 37#include <linux/elf-randomize.h> 38#include <linux/utsname.h> 39#include <linux/coredump.h> 40#include <linux/sched.h> 41#include <linux/sched/coredump.h> 42#include <linux/sched/task_stack.h> 43#include <linux/sched/cputime.h> 44#include <linux/sizes.h> 45#include <linux/types.h> 46#include <linux/cred.h> 47#include <linux/dax.h> 48#include <linux/uaccess.h> 49#include <asm/param.h> 50#include <asm/page.h> 51 52#ifndef ELF_COMPAT 53#define ELF_COMPAT 0 54#endif 55 56#ifndef user_long_t 57#define user_long_t long 58#endif 59#ifndef user_siginfo_t 60#define user_siginfo_t siginfo_t 61#endif 62 63/* That's for binfmt_elf_fdpic to deal with */ 64#ifndef elf_check_fdpic 65#define elf_check_fdpic(ex) false 66#endif 67 68static int load_elf_binary(struct linux_binprm *bprm); 69 70#ifdef CONFIG_USELIB 71static int load_elf_library(struct file *); 72#else 73#define load_elf_library NULL 74#endif 75 76/* 77 * If we don't support core dumping, then supply a NULL so we 78 * don't even try. 79 */ 80#ifdef CONFIG_ELF_CORE 81static int elf_core_dump(struct coredump_params *cprm); 82#else 83#define elf_core_dump NULL 84#endif 85 86#if ELF_EXEC_PAGESIZE > PAGE_SIZE 87#define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE 88#else 89#define ELF_MIN_ALIGN PAGE_SIZE 90#endif 91 92#ifndef ELF_CORE_EFLAGS 93#define ELF_CORE_EFLAGS 0 94#endif 95 96#define ELF_PAGESTART(_v) ((_v) & ~(int)(ELF_MIN_ALIGN-1)) 97#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) 98#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) 99 100static struct linux_binfmt elf_format = { 101 .module = THIS_MODULE, 102 .load_binary = load_elf_binary, 103 .load_shlib = load_elf_library, 104#ifdef CONFIG_COREDUMP 105 .core_dump = elf_core_dump, 106 .min_coredump = ELF_EXEC_PAGESIZE, 107#endif 108}; 109 110#define BAD_ADDR(x) (unlikely((unsigned long)(x) >= TASK_SIZE)) 111 112static int set_brk(unsigned long start, unsigned long end, int prot) 113{ 114 start = ELF_PAGEALIGN(start); 115 end = ELF_PAGEALIGN(end); 116 if (end > start) { 117 /* 118 * Map the last of the bss segment. 119 * If the header is requesting these pages to be 120 * executable, honour that (ppc32 needs this). 121 */ 122 int error = vm_brk_flags(start, end - start, 123 prot & PROT_EXEC ? VM_EXEC : 0); 124 if (error) 125 return error; 126 } 127 current->mm->start_brk = current->mm->brk = end; 128 return 0; 129} 130 131/* We need to explicitly zero any fractional pages 132 after the data section (i.e. bss). This would 133 contain the junk from the file that should not 134 be in memory 135 */ 136static int padzero(unsigned long elf_bss) 137{ 138 unsigned long nbyte; 139 140 nbyte = ELF_PAGEOFFSET(elf_bss); 141 if (nbyte) { 142 nbyte = ELF_MIN_ALIGN - nbyte; 143 if (clear_user((void __user *) elf_bss, nbyte)) 144 return -EFAULT; 145 } 146 return 0; 147} 148 149/* Let's use some macros to make this stack manipulation a little clearer */ 150#ifdef CONFIG_STACK_GROWSUP 151#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) 152#define STACK_ROUND(sp, items) \ 153 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) 154#define STACK_ALLOC(sp, len) ({ \ 155 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ 156 old_sp; }) 157#else 158#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) 159#define STACK_ROUND(sp, items) \ 160 (((unsigned long) (sp - items)) &~ 15UL) 161#define STACK_ALLOC(sp, len) (sp -= len) 162#endif 163 164#ifndef ELF_BASE_PLATFORM 165/* 166 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. 167 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value 168 * will be copied to the user stack in the same manner as AT_PLATFORM. 169 */ 170#define ELF_BASE_PLATFORM NULL 171#endif 172 173static int 174create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec, 175 unsigned long interp_load_addr, 176 unsigned long e_entry, unsigned long phdr_addr) 177{ 178 struct mm_struct *mm = current->mm; 179 unsigned long p = bprm->p; 180 int argc = bprm->argc; 181 int envc = bprm->envc; 182 elf_addr_t __user *sp; 183 elf_addr_t __user *u_platform; 184 elf_addr_t __user *u_base_platform; 185 elf_addr_t __user *u_rand_bytes; 186 const char *k_platform = ELF_PLATFORM; 187 const char *k_base_platform = ELF_BASE_PLATFORM; 188 unsigned char k_rand_bytes[16]; 189 int items; 190 elf_addr_t *elf_info; 191 elf_addr_t flags = 0; 192 int ei_index; 193 const struct cred *cred = current_cred(); 194 struct vm_area_struct *vma; 195 196 /* 197 * In some cases (e.g. Hyper-Threading), we want to avoid L1 198 * evictions by the processes running on the same package. One 199 * thing we can do is to shuffle the initial stack for them. 200 */ 201 202 p = arch_align_stack(p); 203 204 /* 205 * If this architecture has a platform capability string, copy it 206 * to userspace. In some cases (Sparc), this info is impossible 207 * for userspace to get any other way, in others (i386) it is 208 * merely difficult. 209 */ 210 u_platform = NULL; 211 if (k_platform) { 212 size_t len = strlen(k_platform) + 1; 213 214 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 215 if (copy_to_user(u_platform, k_platform, len)) 216 return -EFAULT; 217 } 218 219 /* 220 * If this architecture has a "base" platform capability 221 * string, copy it to userspace. 222 */ 223 u_base_platform = NULL; 224 if (k_base_platform) { 225 size_t len = strlen(k_base_platform) + 1; 226 227 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); 228 if (copy_to_user(u_base_platform, k_base_platform, len)) 229 return -EFAULT; 230 } 231 232 /* 233 * Generate 16 random bytes for userspace PRNG seeding. 234 */ 235 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); 236 u_rand_bytes = (elf_addr_t __user *) 237 STACK_ALLOC(p, sizeof(k_rand_bytes)); 238 if (copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) 239 return -EFAULT; 240 241 /* Create the ELF interpreter info */ 242 elf_info = (elf_addr_t *)mm->saved_auxv; 243 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ 244#define NEW_AUX_ENT(id, val) \ 245 do { \ 246 *elf_info++ = id; \ 247 *elf_info++ = val; \ 248 } while (0) 249 250#ifdef ARCH_DLINFO 251 /* 252 * ARCH_DLINFO must come first so PPC can do its special alignment of 253 * AUXV. 254 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in 255 * ARCH_DLINFO changes 256 */ 257 ARCH_DLINFO; 258#endif 259 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); 260 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); 261 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); 262 NEW_AUX_ENT(AT_PHDR, phdr_addr); 263 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); 264 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); 265 NEW_AUX_ENT(AT_BASE, interp_load_addr); 266 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0) 267 flags |= AT_FLAGS_PRESERVE_ARGV0; 268 NEW_AUX_ENT(AT_FLAGS, flags); 269 NEW_AUX_ENT(AT_ENTRY, e_entry); 270 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid)); 271 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid)); 272 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid)); 273 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid)); 274 NEW_AUX_ENT(AT_SECURE, bprm->secureexec); 275 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); 276#ifdef ELF_HWCAP2 277 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); 278#endif 279 NEW_AUX_ENT(AT_EXECFN, bprm->exec); 280 if (k_platform) { 281 NEW_AUX_ENT(AT_PLATFORM, 282 (elf_addr_t)(unsigned long)u_platform); 283 } 284 if (k_base_platform) { 285 NEW_AUX_ENT(AT_BASE_PLATFORM, 286 (elf_addr_t)(unsigned long)u_base_platform); 287 } 288 if (bprm->have_execfd) { 289 NEW_AUX_ENT(AT_EXECFD, bprm->execfd); 290 } 291#undef NEW_AUX_ENT 292 /* AT_NULL is zero; clear the rest too */ 293 memset(elf_info, 0, (char *)mm->saved_auxv + 294 sizeof(mm->saved_auxv) - (char *)elf_info); 295 296 /* And advance past the AT_NULL entry. */ 297 elf_info += 2; 298 299 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv; 300 sp = STACK_ADD(p, ei_index); 301 302 items = (argc + 1) + (envc + 1) + 1; 303 bprm->p = STACK_ROUND(sp, items); 304 305 /* Point sp at the lowest address on the stack */ 306#ifdef CONFIG_STACK_GROWSUP 307 sp = (elf_addr_t __user *)bprm->p - items - ei_index; 308 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ 309#else 310 sp = (elf_addr_t __user *)bprm->p; 311#endif 312 313 314 /* 315 * Grow the stack manually; some architectures have a limit on how 316 * far ahead a user-space access may be in order to grow the stack. 317 */ 318 if (mmap_read_lock_killable(mm)) 319 return -EINTR; 320 vma = find_extend_vma(mm, bprm->p); 321 mmap_read_unlock(mm); 322 if (!vma) 323 return -EFAULT; 324 325 /* Now, let's put argc (and argv, envp if appropriate) on the stack */ 326 if (put_user(argc, sp++)) 327 return -EFAULT; 328 329 /* Populate list of argv pointers back to argv strings. */ 330 p = mm->arg_end = mm->arg_start; 331 while (argc-- > 0) { 332 size_t len; 333 if (put_user((elf_addr_t)p, sp++)) 334 return -EFAULT; 335 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 336 if (!len || len > MAX_ARG_STRLEN) 337 return -EINVAL; 338 p += len; 339 } 340 if (put_user(0, sp++)) 341 return -EFAULT; 342 mm->arg_end = p; 343 344 /* Populate list of envp pointers back to envp strings. */ 345 mm->env_end = mm->env_start = p; 346 while (envc-- > 0) { 347 size_t len; 348 if (put_user((elf_addr_t)p, sp++)) 349 return -EFAULT; 350 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); 351 if (!len || len > MAX_ARG_STRLEN) 352 return -EINVAL; 353 p += len; 354 } 355 if (put_user(0, sp++)) 356 return -EFAULT; 357 mm->env_end = p; 358 359 /* Put the elf_info on the stack in the right place. */ 360 if (copy_to_user(sp, mm->saved_auxv, ei_index * sizeof(elf_addr_t))) 361 return -EFAULT; 362 return 0; 363} 364 365static unsigned long elf_map(struct file *filep, unsigned long addr, 366 const struct elf_phdr *eppnt, int prot, int type, 367 unsigned long total_size) 368{ 369 unsigned long map_addr; 370 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); 371 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); 372 addr = ELF_PAGESTART(addr); 373 size = ELF_PAGEALIGN(size); 374 375 /* mmap() will return -EINVAL if given a zero size, but a 376 * segment with zero filesize is perfectly valid */ 377 if (!size) 378 return addr; 379 380 /* 381 * total_size is the size of the ELF (interpreter) image. 382 * The _first_ mmap needs to know the full size, otherwise 383 * randomization might put this image into an overlapping 384 * position with the ELF binary image. (since size < total_size) 385 * So we first map the 'big' image - and unmap the remainder at 386 * the end. (which unmap is needed for ELF images with holes.) 387 */ 388 if (total_size) { 389 total_size = ELF_PAGEALIGN(total_size); 390 map_addr = vm_mmap(filep, addr, total_size, prot, type, off); 391 if (!BAD_ADDR(map_addr)) 392 vm_munmap(map_addr+size, total_size-size); 393 } else 394 map_addr = vm_mmap(filep, addr, size, prot, type, off); 395 396 if ((type & MAP_FIXED_NOREPLACE) && 397 PTR_ERR((void *)map_addr) == -EEXIST) 398 pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n", 399 task_pid_nr(current), current->comm, (void *)addr); 400 401 return(map_addr); 402} 403 404static unsigned long total_mapping_size(const struct elf_phdr *phdr, int nr) 405{ 406 elf_addr_t min_addr = -1; 407 elf_addr_t max_addr = 0; 408 bool pt_load = false; 409 int i; 410 411 for (i = 0; i < nr; i++) { 412 if (phdr[i].p_type == PT_LOAD) { 413 min_addr = min(min_addr, ELF_PAGESTART(phdr[i].p_vaddr)); 414 max_addr = max(max_addr, phdr[i].p_vaddr + phdr[i].p_memsz); 415 pt_load = true; 416 } 417 } 418 return pt_load ? (max_addr - min_addr) : 0; 419} 420 421static int elf_read(struct file *file, void *buf, size_t len, loff_t pos) 422{ 423 ssize_t rv; 424 425 rv = kernel_read(file, buf, len, &pos); 426 if (unlikely(rv != len)) { 427 return (rv < 0) ? rv : -EIO; 428 } 429 return 0; 430} 431 432static unsigned long maximum_alignment(struct elf_phdr *cmds, int nr) 433{ 434 unsigned long alignment = 0; 435 int i; 436 437 for (i = 0; i < nr; i++) { 438 if (cmds[i].p_type == PT_LOAD) { 439 unsigned long p_align = cmds[i].p_align; 440 441 /* skip non-power of two alignments as invalid */ 442 if (!is_power_of_2(p_align)) 443 continue; 444 alignment = max(alignment, p_align); 445 } 446 } 447 448 /* ensure we align to at least one page */ 449 return ELF_PAGEALIGN(alignment); 450} 451 452/** 453 * load_elf_phdrs() - load ELF program headers 454 * @elf_ex: ELF header of the binary whose program headers should be loaded 455 * @elf_file: the opened ELF binary file 456 * 457 * Loads ELF program headers from the binary file elf_file, which has the ELF 458 * header pointed to by elf_ex, into a newly allocated array. The caller is 459 * responsible for freeing the allocated data. Returns an ERR_PTR upon failure. 460 */ 461static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex, 462 struct file *elf_file) 463{ 464 struct elf_phdr *elf_phdata = NULL; 465 int retval, err = -1; 466 unsigned int size; 467 468 /* 469 * If the size of this structure has changed, then punt, since 470 * we will be doing the wrong thing. 471 */ 472 if (elf_ex->e_phentsize != sizeof(struct elf_phdr)) 473 goto out; 474 475 /* Sanity check the number of program headers... */ 476 /* ...and their total size. */ 477 size = sizeof(struct elf_phdr) * elf_ex->e_phnum; 478 if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN) 479 goto out; 480 481 elf_phdata = kmalloc(size, GFP_KERNEL); 482 if (!elf_phdata) 483 goto out; 484 485 /* Read in the program headers */ 486 retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff); 487 if (retval < 0) { 488 err = retval; 489 goto out; 490 } 491 492 /* Success! */ 493 err = 0; 494out: 495 if (err) { 496 kfree(elf_phdata); 497 elf_phdata = NULL; 498 } 499 return elf_phdata; 500} 501 502#ifndef CONFIG_ARCH_BINFMT_ELF_STATE 503 504/** 505 * struct arch_elf_state - arch-specific ELF loading state 506 * 507 * This structure is used to preserve architecture specific data during 508 * the loading of an ELF file, throughout the checking of architecture 509 * specific ELF headers & through to the point where the ELF load is 510 * known to be proceeding (ie. SET_PERSONALITY). 511 * 512 * This implementation is a dummy for architectures which require no 513 * specific state. 514 */ 515struct arch_elf_state { 516}; 517 518#define INIT_ARCH_ELF_STATE {} 519 520/** 521 * arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header 522 * @ehdr: The main ELF header 523 * @phdr: The program header to check 524 * @elf: The open ELF file 525 * @is_interp: True if the phdr is from the interpreter of the ELF being 526 * loaded, else false. 527 * @state: Architecture-specific state preserved throughout the process 528 * of loading the ELF. 529 * 530 * Inspects the program header phdr to validate its correctness and/or 531 * suitability for the system. Called once per ELF program header in the 532 * range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its 533 * interpreter. 534 * 535 * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load 536 * with that return code. 537 */ 538static inline int arch_elf_pt_proc(struct elfhdr *ehdr, 539 struct elf_phdr *phdr, 540 struct file *elf, bool is_interp, 541 struct arch_elf_state *state) 542{ 543 /* Dummy implementation, always proceed */ 544 return 0; 545} 546 547/** 548 * arch_check_elf() - check an ELF executable 549 * @ehdr: The main ELF header 550 * @has_interp: True if the ELF has an interpreter, else false. 551 * @interp_ehdr: The interpreter's ELF header 552 * @state: Architecture-specific state preserved throughout the process 553 * of loading the ELF. 554 * 555 * Provides a final opportunity for architecture code to reject the loading 556 * of the ELF & cause an exec syscall to return an error. This is called after 557 * all program headers to be checked by arch_elf_pt_proc have been. 558 * 559 * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load 560 * with that return code. 561 */ 562static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp, 563 struct elfhdr *interp_ehdr, 564 struct arch_elf_state *state) 565{ 566 /* Dummy implementation, always proceed */ 567 return 0; 568} 569 570#endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */ 571 572static inline int make_prot(u32 p_flags, struct arch_elf_state *arch_state, 573 bool has_interp, bool is_interp) 574{ 575 int prot = 0; 576 577 if (p_flags & PF_R) 578 prot |= PROT_READ; 579 if (p_flags & PF_W) 580 prot |= PROT_WRITE; 581 if (p_flags & PF_X) 582 prot |= PROT_EXEC; 583 584 return arch_elf_adjust_prot(prot, arch_state, has_interp, is_interp); 585} 586 587/* This is much more generalized than the library routine read function, 588 so we keep this separate. Technically the library read function 589 is only provided so that we can read a.out libraries that have 590 an ELF header */ 591 592static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, 593 struct file *interpreter, 594 unsigned long no_base, struct elf_phdr *interp_elf_phdata, 595 struct arch_elf_state *arch_state) 596{ 597 struct elf_phdr *eppnt; 598 unsigned long load_addr = 0; 599 int load_addr_set = 0; 600 unsigned long last_bss = 0, elf_bss = 0; 601 int bss_prot = 0; 602 unsigned long error = ~0UL; 603 unsigned long total_size; 604 int i; 605 606 /* First of all, some simple consistency checks */ 607 if (interp_elf_ex->e_type != ET_EXEC && 608 interp_elf_ex->e_type != ET_DYN) 609 goto out; 610 if (!elf_check_arch(interp_elf_ex) || 611 elf_check_fdpic(interp_elf_ex)) 612 goto out; 613 if (!interpreter->f_op->mmap) 614 goto out; 615 616 total_size = total_mapping_size(interp_elf_phdata, 617 interp_elf_ex->e_phnum); 618 if (!total_size) { 619 error = -EINVAL; 620 goto out; 621 } 622 623 eppnt = interp_elf_phdata; 624 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { 625 if (eppnt->p_type == PT_LOAD) { 626 int elf_type = MAP_PRIVATE; 627 int elf_prot = make_prot(eppnt->p_flags, arch_state, 628 true, true); 629 unsigned long vaddr = 0; 630 unsigned long k, map_addr; 631 632 vaddr = eppnt->p_vaddr; 633 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) 634 elf_type |= MAP_FIXED; 635 else if (no_base && interp_elf_ex->e_type == ET_DYN) 636 load_addr = -vaddr; 637 638 map_addr = elf_map(interpreter, load_addr + vaddr, 639 eppnt, elf_prot, elf_type, total_size); 640 total_size = 0; 641 error = map_addr; 642 if (BAD_ADDR(map_addr)) 643 goto out; 644 645 if (!load_addr_set && 646 interp_elf_ex->e_type == ET_DYN) { 647 load_addr = map_addr - ELF_PAGESTART(vaddr); 648 load_addr_set = 1; 649 } 650 651 /* 652 * Check to see if the section's size will overflow the 653 * allowed task size. Note that p_filesz must always be 654 * <= p_memsize so it's only necessary to check p_memsz. 655 */ 656 k = load_addr + eppnt->p_vaddr; 657 if (BAD_ADDR(k) || 658 eppnt->p_filesz > eppnt->p_memsz || 659 eppnt->p_memsz > TASK_SIZE || 660 TASK_SIZE - eppnt->p_memsz < k) { 661 error = -ENOMEM; 662 goto out; 663 } 664 665 /* 666 * Find the end of the file mapping for this phdr, and 667 * keep track of the largest address we see for this. 668 */ 669 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; 670 if (k > elf_bss) 671 elf_bss = k; 672 673 /* 674 * Do the same thing for the memory mapping - between 675 * elf_bss and last_bss is the bss section. 676 */ 677 k = load_addr + eppnt->p_vaddr + eppnt->p_memsz; 678 if (k > last_bss) { 679 last_bss = k; 680 bss_prot = elf_prot; 681 } 682 } 683 } 684 685 /* 686 * Now fill out the bss section: first pad the last page from 687 * the file up to the page boundary, and zero it from elf_bss 688 * up to the end of the page. 689 */ 690 if (padzero(elf_bss)) { 691 error = -EFAULT; 692 goto out; 693 } 694 /* 695 * Next, align both the file and mem bss up to the page size, 696 * since this is where elf_bss was just zeroed up to, and where 697 * last_bss will end after the vm_brk_flags() below. 698 */ 699 elf_bss = ELF_PAGEALIGN(elf_bss); 700 last_bss = ELF_PAGEALIGN(last_bss); 701 /* Finally, if there is still more bss to allocate, do it. */ 702 if (last_bss > elf_bss) { 703 error = vm_brk_flags(elf_bss, last_bss - elf_bss, 704 bss_prot & PROT_EXEC ? VM_EXEC : 0); 705 if (error) 706 goto out; 707 } 708 709 error = load_addr; 710out: 711 return error; 712} 713 714/* 715 * These are the functions used to load ELF style executables and shared 716 * libraries. There is no binary dependent code anywhere else. 717 */ 718 719static int parse_elf_property(const char *data, size_t *off, size_t datasz, 720 struct arch_elf_state *arch, 721 bool have_prev_type, u32 *prev_type) 722{ 723 size_t o, step; 724 const struct gnu_property *pr; 725 int ret; 726 727 if (*off == datasz) 728 return -ENOENT; 729 730 if (WARN_ON_ONCE(*off > datasz || *off % ELF_GNU_PROPERTY_ALIGN)) 731 return -EIO; 732 o = *off; 733 datasz -= *off; 734 735 if (datasz < sizeof(*pr)) 736 return -ENOEXEC; 737 pr = (const struct gnu_property *)(data + o); 738 o += sizeof(*pr); 739 datasz -= sizeof(*pr); 740 741 if (pr->pr_datasz > datasz) 742 return -ENOEXEC; 743 744 WARN_ON_ONCE(o % ELF_GNU_PROPERTY_ALIGN); 745 step = round_up(pr->pr_datasz, ELF_GNU_PROPERTY_ALIGN); 746 if (step > datasz) 747 return -ENOEXEC; 748 749 /* Properties are supposed to be unique and sorted on pr_type: */ 750 if (have_prev_type && pr->pr_type <= *prev_type) 751 return -ENOEXEC; 752 *prev_type = pr->pr_type; 753 754 ret = arch_parse_elf_property(pr->pr_type, data + o, 755 pr->pr_datasz, ELF_COMPAT, arch); 756 if (ret) 757 return ret; 758 759 *off = o + step; 760 return 0; 761} 762 763#define NOTE_DATA_SZ SZ_1K 764#define GNU_PROPERTY_TYPE_0_NAME "GNU" 765#define NOTE_NAME_SZ (sizeof(GNU_PROPERTY_TYPE_0_NAME)) 766 767static int parse_elf_properties(struct file *f, const struct elf_phdr *phdr, 768 struct arch_elf_state *arch) 769{ 770 union { 771 struct elf_note nhdr; 772 char data[NOTE_DATA_SZ]; 773 } note; 774 loff_t pos; 775 ssize_t n; 776 size_t off, datasz; 777 int ret; 778 bool have_prev_type; 779 u32 prev_type; 780 781 if (!IS_ENABLED(CONFIG_ARCH_USE_GNU_PROPERTY) || !phdr) 782 return 0; 783 784 /* load_elf_binary() shouldn't call us unless this is true... */ 785 if (WARN_ON_ONCE(phdr->p_type != PT_GNU_PROPERTY)) 786 return -ENOEXEC; 787 788 /* If the properties are crazy large, that's too bad (for now): */ 789 if (phdr->p_filesz > sizeof(note)) 790 return -ENOEXEC; 791 792 pos = phdr->p_offset; 793 n = kernel_read(f, ¬e, phdr->p_filesz, &pos); 794 795 BUILD_BUG_ON(sizeof(note) < sizeof(note.nhdr) + NOTE_NAME_SZ); 796 if (n < 0 || n < sizeof(note.nhdr) + NOTE_NAME_SZ) 797 return -EIO; 798 799 if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 || 800 note.nhdr.n_namesz != NOTE_NAME_SZ || 801 strncmp(note.data + sizeof(note.nhdr), 802 GNU_PROPERTY_TYPE_0_NAME, n - sizeof(note.nhdr))) 803 return -ENOEXEC; 804 805 off = round_up(sizeof(note.nhdr) + NOTE_NAME_SZ, 806 ELF_GNU_PROPERTY_ALIGN); 807 if (off > n) 808 return -ENOEXEC; 809 810 if (note.nhdr.n_descsz > n - off) 811 return -ENOEXEC; 812 datasz = off + note.nhdr.n_descsz; 813 814 have_prev_type = false; 815 do { 816 ret = parse_elf_property(note.data, &off, datasz, arch, 817 have_prev_type, &prev_type); 818 have_prev_type = true; 819 } while (!ret); 820 821 return ret == -ENOENT ? 0 : ret; 822} 823 824static int load_elf_binary(struct linux_binprm *bprm) 825{ 826 struct file *interpreter = NULL; /* to shut gcc up */ 827 unsigned long load_bias = 0, phdr_addr = 0; 828 int first_pt_load = 1; 829 unsigned long error; 830 struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL; 831 struct elf_phdr *elf_property_phdata = NULL; 832 unsigned long elf_bss, elf_brk; 833 int bss_prot = 0; 834 int retval, i; 835 unsigned long elf_entry; 836 unsigned long e_entry; 837 unsigned long interp_load_addr = 0; 838 unsigned long start_code, end_code, start_data, end_data; 839 unsigned long reloc_func_desc __maybe_unused = 0; 840 int executable_stack = EXSTACK_DEFAULT; 841 struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf; 842 struct elfhdr *interp_elf_ex = NULL; 843 struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE; 844 struct mm_struct *mm; 845 struct pt_regs *regs; 846 847 retval = -ENOEXEC; 848 /* First of all, some simple consistency checks */ 849 if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0) 850 goto out; 851 852 if (elf_ex->e_type != ET_EXEC && elf_ex->e_type != ET_DYN) 853 goto out; 854 if (!elf_check_arch(elf_ex)) 855 goto out; 856 if (elf_check_fdpic(elf_ex)) 857 goto out; 858 if (!bprm->file->f_op->mmap) 859 goto out; 860 861 elf_phdata = load_elf_phdrs(elf_ex, bprm->file); 862 if (!elf_phdata) 863 goto out; 864 865 elf_ppnt = elf_phdata; 866 for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) { 867 char *elf_interpreter; 868 869 if (elf_ppnt->p_type == PT_GNU_PROPERTY) { 870 elf_property_phdata = elf_ppnt; 871 continue; 872 } 873 874 if (elf_ppnt->p_type != PT_INTERP) 875 continue; 876 877 /* 878 * This is the program interpreter used for shared libraries - 879 * for now assume that this is an a.out format binary. 880 */ 881 retval = -ENOEXEC; 882 if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2) 883 goto out_free_ph; 884 885 retval = -ENOMEM; 886 elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL); 887 if (!elf_interpreter) 888 goto out_free_ph; 889 890 retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz, 891 elf_ppnt->p_offset); 892 if (retval < 0) 893 goto out_free_interp; 894 /* make sure path is NULL terminated */ 895 retval = -ENOEXEC; 896 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') 897 goto out_free_interp; 898 899 interpreter = open_exec(elf_interpreter); 900 kfree(elf_interpreter); 901 retval = PTR_ERR(interpreter); 902 if (IS_ERR(interpreter)) 903 goto out_free_ph; 904 905 /* 906 * If the binary is not readable then enforce mm->dumpable = 0 907 * regardless of the interpreter's permissions. 908 */ 909 would_dump(bprm, interpreter); 910 911 interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL); 912 if (!interp_elf_ex) { 913 retval = -ENOMEM; 914 goto out_free_ph; 915 } 916 917 /* Get the exec headers */ 918 retval = elf_read(interpreter, interp_elf_ex, 919 sizeof(*interp_elf_ex), 0); 920 if (retval < 0) 921 goto out_free_dentry; 922 923 break; 924 925out_free_interp: 926 kfree(elf_interpreter); 927 goto out_free_ph; 928 } 929 930 elf_ppnt = elf_phdata; 931 for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) 932 switch (elf_ppnt->p_type) { 933 case PT_GNU_STACK: 934 if (elf_ppnt->p_flags & PF_X) 935 executable_stack = EXSTACK_ENABLE_X; 936 else 937 executable_stack = EXSTACK_DISABLE_X; 938 break; 939 940 case PT_LOPROC ... PT_HIPROC: 941 retval = arch_elf_pt_proc(elf_ex, elf_ppnt, 942 bprm->file, false, 943 &arch_state); 944 if (retval) 945 goto out_free_dentry; 946 break; 947 } 948 949 /* Some simple consistency checks for the interpreter */ 950 if (interpreter) { 951 retval = -ELIBBAD; 952 /* Not an ELF interpreter */ 953 if (memcmp(interp_elf_ex->e_ident, ELFMAG, SELFMAG) != 0) 954 goto out_free_dentry; 955 /* Verify the interpreter has a valid arch */ 956 if (!elf_check_arch(interp_elf_ex) || 957 elf_check_fdpic(interp_elf_ex)) 958 goto out_free_dentry; 959 960 /* Load the interpreter program headers */ 961 interp_elf_phdata = load_elf_phdrs(interp_elf_ex, 962 interpreter); 963 if (!interp_elf_phdata) 964 goto out_free_dentry; 965 966 /* Pass PT_LOPROC..PT_HIPROC headers to arch code */ 967 elf_property_phdata = NULL; 968 elf_ppnt = interp_elf_phdata; 969 for (i = 0; i < interp_elf_ex->e_phnum; i++, elf_ppnt++) 970 switch (elf_ppnt->p_type) { 971 case PT_GNU_PROPERTY: 972 elf_property_phdata = elf_ppnt; 973 break; 974 975 case PT_LOPROC ... PT_HIPROC: 976 retval = arch_elf_pt_proc(interp_elf_ex, 977 elf_ppnt, interpreter, 978 true, &arch_state); 979 if (retval) 980 goto out_free_dentry; 981 break; 982 } 983 } 984 985 retval = parse_elf_properties(interpreter ?: bprm->file, 986 elf_property_phdata, &arch_state); 987 if (retval) 988 goto out_free_dentry; 989 990 /* 991 * Allow arch code to reject the ELF at this point, whilst it's 992 * still possible to return an error to the code that invoked 993 * the exec syscall. 994 */ 995 retval = arch_check_elf(elf_ex, 996 !!interpreter, interp_elf_ex, 997 &arch_state); 998 if (retval) 999 goto out_free_dentry; 1000 1001 /* Flush all traces of the currently running executable */ 1002 retval = begin_new_exec(bprm); 1003 if (retval) 1004 goto out_free_dentry; 1005 1006 /* Do this immediately, since STACK_TOP as used in setup_arg_pages 1007 may depend on the personality. */ 1008 SET_PERSONALITY2(*elf_ex, &arch_state); 1009 if (elf_read_implies_exec(*elf_ex, executable_stack)) 1010 current->personality |= READ_IMPLIES_EXEC; 1011 1012 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 1013 current->flags |= PF_RANDOMIZE; 1014 1015 setup_new_exec(bprm); 1016 1017 /* Do this so that we can load the interpreter, if need be. We will 1018 change some of these later */ 1019 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), 1020 executable_stack); 1021 if (retval < 0) 1022 goto out_free_dentry; 1023 1024 elf_bss = 0; 1025 elf_brk = 0; 1026 1027 start_code = ~0UL; 1028 end_code = 0; 1029 start_data = 0; 1030 end_data = 0; 1031 1032 /* Now we do a little grungy work by mmapping the ELF image into 1033 the correct location in memory. */ 1034 for(i = 0, elf_ppnt = elf_phdata; 1035 i < elf_ex->e_phnum; i++, elf_ppnt++) { 1036 int elf_prot, elf_flags; 1037 unsigned long k, vaddr; 1038 unsigned long total_size = 0; 1039 unsigned long alignment; 1040 1041 if (elf_ppnt->p_type != PT_LOAD) 1042 continue; 1043 1044 if (unlikely (elf_brk > elf_bss)) { 1045 unsigned long nbyte; 1046 1047 /* There was a PT_LOAD segment with p_memsz > p_filesz 1048 before this one. Map anonymous pages, if needed, 1049 and clear the area. */ 1050 retval = set_brk(elf_bss + load_bias, 1051 elf_brk + load_bias, 1052 bss_prot); 1053 if (retval) 1054 goto out_free_dentry; 1055 nbyte = ELF_PAGEOFFSET(elf_bss); 1056 if (nbyte) { 1057 nbyte = ELF_MIN_ALIGN - nbyte; 1058 if (nbyte > elf_brk - elf_bss) 1059 nbyte = elf_brk - elf_bss; 1060 if (clear_user((void __user *)elf_bss + 1061 load_bias, nbyte)) { 1062 /* 1063 * This bss-zeroing can fail if the ELF 1064 * file specifies odd protections. So 1065 * we don't check the return value 1066 */ 1067 } 1068 } 1069 } 1070 1071 elf_prot = make_prot(elf_ppnt->p_flags, &arch_state, 1072 !!interpreter, false); 1073 1074 elf_flags = MAP_PRIVATE; 1075 1076 vaddr = elf_ppnt->p_vaddr; 1077 /* 1078 * The first time through the loop, first_pt_load is true: 1079 * layout will be calculated. Once set, use MAP_FIXED since 1080 * we know we've already safely mapped the entire region with 1081 * MAP_FIXED_NOREPLACE in the once-per-binary logic following. 1082 */ 1083 if (!first_pt_load) { 1084 elf_flags |= MAP_FIXED; 1085 } else if (elf_ex->e_type == ET_EXEC) { 1086 /* 1087 * This logic is run once for the first LOAD Program 1088 * Header for ET_EXEC binaries. No special handling 1089 * is needed. 1090 */ 1091 elf_flags |= MAP_FIXED_NOREPLACE; 1092 } else if (elf_ex->e_type == ET_DYN) { 1093 /* 1094 * This logic is run once for the first LOAD Program 1095 * Header for ET_DYN binaries to calculate the 1096 * randomization (load_bias) for all the LOAD 1097 * Program Headers. 1098 * 1099 * There are effectively two types of ET_DYN 1100 * binaries: programs (i.e. PIE: ET_DYN with INTERP) 1101 * and loaders (ET_DYN without INTERP, since they 1102 * _are_ the ELF interpreter). The loaders must 1103 * be loaded away from programs since the program 1104 * may otherwise collide with the loader (especially 1105 * for ET_EXEC which does not have a randomized 1106 * position). For example to handle invocations of 1107 * "./ld.so someprog" to test out a new version of 1108 * the loader, the subsequent program that the 1109 * loader loads must avoid the loader itself, so 1110 * they cannot share the same load range. Sufficient 1111 * room for the brk must be allocated with the 1112 * loader as well, since brk must be available with 1113 * the loader. 1114 * 1115 * Therefore, programs are loaded offset from 1116 * ELF_ET_DYN_BASE and loaders are loaded into the 1117 * independently randomized mmap region (0 load_bias 1118 * without MAP_FIXED nor MAP_FIXED_NOREPLACE). 1119 */ 1120 if (interpreter) { 1121 load_bias = ELF_ET_DYN_BASE; 1122 if (current->flags & PF_RANDOMIZE) 1123 load_bias += arch_mmap_rnd(); 1124 alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum); 1125 if (alignment) 1126 load_bias &= ~(alignment - 1); 1127 elf_flags |= MAP_FIXED_NOREPLACE; 1128 } else 1129 load_bias = 0; 1130 1131 /* 1132 * Since load_bias is used for all subsequent loading 1133 * calculations, we must lower it by the first vaddr 1134 * so that the remaining calculations based on the 1135 * ELF vaddrs will be correctly offset. The result 1136 * is then page aligned. 1137 */ 1138 load_bias = ELF_PAGESTART(load_bias - vaddr); 1139 1140 /* 1141 * Calculate the entire size of the ELF mapping 1142 * (total_size), used for the initial mapping, 1143 * due to load_addr_set which is set to true later 1144 * once the initial mapping is performed. 1145 * 1146 * Note that this is only sensible when the LOAD 1147 * segments are contiguous (or overlapping). If 1148 * used for LOADs that are far apart, this would 1149 * cause the holes between LOADs to be mapped, 1150 * running the risk of having the mapping fail, 1151 * as it would be larger than the ELF file itself. 1152 * 1153 * As a result, only ET_DYN does this, since 1154 * some ET_EXEC (e.g. ia64) may have large virtual 1155 * memory holes between LOADs. 1156 * 1157 */ 1158 total_size = total_mapping_size(elf_phdata, 1159 elf_ex->e_phnum); 1160 if (!total_size) { 1161 retval = -EINVAL; 1162 goto out_free_dentry; 1163 } 1164 } 1165 1166 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, 1167 elf_prot, elf_flags, total_size); 1168 if (BAD_ADDR(error)) { 1169 retval = IS_ERR((void *)error) ? 1170 PTR_ERR((void*)error) : -EINVAL; 1171 goto out_free_dentry; 1172 } 1173 1174 if (first_pt_load) { 1175 first_pt_load = 0; 1176 if (elf_ex->e_type == ET_DYN) { 1177 load_bias += error - 1178 ELF_PAGESTART(load_bias + vaddr); 1179 reloc_func_desc = load_bias; 1180 } 1181 } 1182 1183 /* 1184 * Figure out which segment in the file contains the Program 1185 * Header table, and map to the associated memory address. 1186 */ 1187 if (elf_ppnt->p_offset <= elf_ex->e_phoff && 1188 elf_ex->e_phoff < elf_ppnt->p_offset + elf_ppnt->p_filesz) { 1189 phdr_addr = elf_ex->e_phoff - elf_ppnt->p_offset + 1190 elf_ppnt->p_vaddr; 1191 } 1192 1193 k = elf_ppnt->p_vaddr; 1194 if ((elf_ppnt->p_flags & PF_X) && k < start_code) 1195 start_code = k; 1196 if (start_data < k) 1197 start_data = k; 1198 1199 /* 1200 * Check to see if the section's size will overflow the 1201 * allowed task size. Note that p_filesz must always be 1202 * <= p_memsz so it is only necessary to check p_memsz. 1203 */ 1204 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || 1205 elf_ppnt->p_memsz > TASK_SIZE || 1206 TASK_SIZE - elf_ppnt->p_memsz < k) { 1207 /* set_brk can never work. Avoid overflows. */ 1208 retval = -EINVAL; 1209 goto out_free_dentry; 1210 } 1211 1212 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; 1213 1214 if (k > elf_bss) 1215 elf_bss = k; 1216 if ((elf_ppnt->p_flags & PF_X) && end_code < k) 1217 end_code = k; 1218 if (end_data < k) 1219 end_data = k; 1220 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; 1221 if (k > elf_brk) { 1222 bss_prot = elf_prot; 1223 elf_brk = k; 1224 } 1225 } 1226 1227 e_entry = elf_ex->e_entry + load_bias; 1228 phdr_addr += load_bias; 1229 elf_bss += load_bias; 1230 elf_brk += load_bias; 1231 start_code += load_bias; 1232 end_code += load_bias; 1233 start_data += load_bias; 1234 end_data += load_bias; 1235 1236 /* Calling set_brk effectively mmaps the pages that we need 1237 * for the bss and break sections. We must do this before 1238 * mapping in the interpreter, to make sure it doesn't wind 1239 * up getting placed where the bss needs to go. 1240 */ 1241 retval = set_brk(elf_bss, elf_brk, bss_prot); 1242 if (retval) 1243 goto out_free_dentry; 1244 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { 1245 retval = -EFAULT; /* Nobody gets to see this, but.. */ 1246 goto out_free_dentry; 1247 } 1248 1249 if (interpreter) { 1250 elf_entry = load_elf_interp(interp_elf_ex, 1251 interpreter, 1252 load_bias, interp_elf_phdata, 1253 &arch_state); 1254 if (!IS_ERR((void *)elf_entry)) { 1255 /* 1256 * load_elf_interp() returns relocation 1257 * adjustment 1258 */ 1259 interp_load_addr = elf_entry; 1260 elf_entry += interp_elf_ex->e_entry; 1261 } 1262 if (BAD_ADDR(elf_entry)) { 1263 retval = IS_ERR((void *)elf_entry) ? 1264 (int)elf_entry : -EINVAL; 1265 goto out_free_dentry; 1266 } 1267 reloc_func_desc = interp_load_addr; 1268 1269 allow_write_access(interpreter); 1270 fput(interpreter); 1271 1272 kfree(interp_elf_ex); 1273 kfree(interp_elf_phdata); 1274 } else { 1275 elf_entry = e_entry; 1276 if (BAD_ADDR(elf_entry)) { 1277 retval = -EINVAL; 1278 goto out_free_dentry; 1279 } 1280 } 1281 1282 kfree(elf_phdata); 1283 1284 set_binfmt(&elf_format); 1285 1286#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES 1287 retval = ARCH_SETUP_ADDITIONAL_PAGES(bprm, elf_ex, !!interpreter); 1288 if (retval < 0) 1289 goto out; 1290#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ 1291 1292 retval = create_elf_tables(bprm, elf_ex, interp_load_addr, 1293 e_entry, phdr_addr); 1294 if (retval < 0) 1295 goto out; 1296 1297 mm = current->mm; 1298 mm->end_code = end_code; 1299 mm->start_code = start_code; 1300 mm->start_data = start_data; 1301 mm->end_data = end_data; 1302 mm->start_stack = bprm->p; 1303 1304 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { 1305 /* 1306 * For architectures with ELF randomization, when executing 1307 * a loader directly (i.e. no interpreter listed in ELF 1308 * headers), move the brk area out of the mmap region 1309 * (since it grows up, and may collide early with the stack 1310 * growing down), and into the unused ELF_ET_DYN_BASE region. 1311 */ 1312 if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) && 1313 elf_ex->e_type == ET_DYN && !interpreter) { 1314 mm->brk = mm->start_brk = ELF_ET_DYN_BASE; 1315 } 1316 1317 mm->brk = mm->start_brk = arch_randomize_brk(mm); 1318#ifdef compat_brk_randomized 1319 current->brk_randomized = 1; 1320#endif 1321 } 1322 1323 if (current->personality & MMAP_PAGE_ZERO) { 1324 /* Why this, you ask??? Well SVr4 maps page 0 as read-only, 1325 and some applications "depend" upon this behavior. 1326 Since we do not have the power to recompile these, we 1327 emulate the SVr4 behavior. Sigh. */ 1328 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, 1329 MAP_FIXED | MAP_PRIVATE, 0); 1330 } 1331 1332 regs = current_pt_regs(); 1333#ifdef ELF_PLAT_INIT 1334 /* 1335 * The ABI may specify that certain registers be set up in special 1336 * ways (on i386 %edx is the address of a DT_FINI function, for 1337 * example. In addition, it may also specify (eg, PowerPC64 ELF) 1338 * that the e_entry field is the address of the function descriptor 1339 * for the startup routine, rather than the address of the startup 1340 * routine itself. This macro performs whatever initialization to 1341 * the regs structure is required as well as any relocations to the 1342 * function descriptor entries when executing dynamically links apps. 1343 */ 1344 ELF_PLAT_INIT(regs, reloc_func_desc); 1345#endif 1346 1347 finalize_exec(bprm); 1348 START_THREAD(elf_ex, regs, elf_entry, bprm->p); 1349 retval = 0; 1350out: 1351 return retval; 1352 1353 /* error cleanup */ 1354out_free_dentry: 1355 kfree(interp_elf_ex); 1356 kfree(interp_elf_phdata); 1357 allow_write_access(interpreter); 1358 if (interpreter) 1359 fput(interpreter); 1360out_free_ph: 1361 kfree(elf_phdata); 1362 goto out; 1363} 1364 1365#ifdef CONFIG_USELIB 1366/* This is really simpleminded and specialized - we are loading an 1367 a.out library that is given an ELF header. */ 1368static int load_elf_library(struct file *file) 1369{ 1370 struct elf_phdr *elf_phdata; 1371 struct elf_phdr *eppnt; 1372 unsigned long elf_bss, bss, len; 1373 int retval, error, i, j; 1374 struct elfhdr elf_ex; 1375 1376 error = -ENOEXEC; 1377 retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0); 1378 if (retval < 0) 1379 goto out; 1380 1381 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) 1382 goto out; 1383 1384 /* First of all, some simple consistency checks */ 1385 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || 1386 !elf_check_arch(&elf_ex) || !file->f_op->mmap) 1387 goto out; 1388 if (elf_check_fdpic(&elf_ex)) 1389 goto out; 1390 1391 /* Now read in all of the header information */ 1392 1393 j = sizeof(struct elf_phdr) * elf_ex.e_phnum; 1394 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ 1395 1396 error = -ENOMEM; 1397 elf_phdata = kmalloc(j, GFP_KERNEL); 1398 if (!elf_phdata) 1399 goto out; 1400 1401 eppnt = elf_phdata; 1402 error = -ENOEXEC; 1403 retval = elf_read(file, eppnt, j, elf_ex.e_phoff); 1404 if (retval < 0) 1405 goto out_free_ph; 1406 1407 for (j = 0, i = 0; i<elf_ex.e_phnum; i++) 1408 if ((eppnt + i)->p_type == PT_LOAD) 1409 j++; 1410 if (j != 1) 1411 goto out_free_ph; 1412 1413 while (eppnt->p_type != PT_LOAD) 1414 eppnt++; 1415 1416 /* Now use mmap to map the library into memory. */ 1417 error = vm_mmap(file, 1418 ELF_PAGESTART(eppnt->p_vaddr), 1419 (eppnt->p_filesz + 1420 ELF_PAGEOFFSET(eppnt->p_vaddr)), 1421 PROT_READ | PROT_WRITE | PROT_EXEC, 1422 MAP_FIXED_NOREPLACE | MAP_PRIVATE, 1423 (eppnt->p_offset - 1424 ELF_PAGEOFFSET(eppnt->p_vaddr))); 1425 if (error != ELF_PAGESTART(eppnt->p_vaddr)) 1426 goto out_free_ph; 1427 1428 elf_bss = eppnt->p_vaddr + eppnt->p_filesz; 1429 if (padzero(elf_bss)) { 1430 error = -EFAULT; 1431 goto out_free_ph; 1432 } 1433 1434 len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr); 1435 bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr); 1436 if (bss > len) { 1437 error = vm_brk(len, bss - len); 1438 if (error) 1439 goto out_free_ph; 1440 } 1441 error = 0; 1442 1443out_free_ph: 1444 kfree(elf_phdata); 1445out: 1446 return error; 1447} 1448#endif /* #ifdef CONFIG_USELIB */ 1449 1450#ifdef CONFIG_ELF_CORE 1451/* 1452 * ELF core dumper 1453 * 1454 * Modelled on fs/exec.c:aout_core_dump() 1455 * Jeremy Fitzhardinge <jeremy@sw.oz.au> 1456 */ 1457 1458/* An ELF note in memory */ 1459struct memelfnote 1460{ 1461 const char *name; 1462 int type; 1463 unsigned int datasz; 1464 void *data; 1465}; 1466 1467static int notesize(struct memelfnote *en) 1468{ 1469 int sz; 1470 1471 sz = sizeof(struct elf_note); 1472 sz += roundup(strlen(en->name) + 1, 4); 1473 sz += roundup(en->datasz, 4); 1474 1475 return sz; 1476} 1477 1478static int writenote(struct memelfnote *men, struct coredump_params *cprm) 1479{ 1480 struct elf_note en; 1481 en.n_namesz = strlen(men->name) + 1; 1482 en.n_descsz = men->datasz; 1483 en.n_type = men->type; 1484 1485 return dump_emit(cprm, &en, sizeof(en)) && 1486 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && 1487 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); 1488} 1489 1490static void fill_elf_header(struct elfhdr *elf, int segs, 1491 u16 machine, u32 flags) 1492{ 1493 memset(elf, 0, sizeof(*elf)); 1494 1495 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1496 elf->e_ident[EI_CLASS] = ELF_CLASS; 1497 elf->e_ident[EI_DATA] = ELF_DATA; 1498 elf->e_ident[EI_VERSION] = EV_CURRENT; 1499 elf->e_ident[EI_OSABI] = ELF_OSABI; 1500 1501 elf->e_type = ET_CORE; 1502 elf->e_machine = machine; 1503 elf->e_version = EV_CURRENT; 1504 elf->e_phoff = sizeof(struct elfhdr); 1505 elf->e_flags = flags; 1506 elf->e_ehsize = sizeof(struct elfhdr); 1507 elf->e_phentsize = sizeof(struct elf_phdr); 1508 elf->e_phnum = segs; 1509} 1510 1511static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) 1512{ 1513 phdr->p_type = PT_NOTE; 1514 phdr->p_offset = offset; 1515 phdr->p_vaddr = 0; 1516 phdr->p_paddr = 0; 1517 phdr->p_filesz = sz; 1518 phdr->p_memsz = 0; 1519 phdr->p_flags = 0; 1520 phdr->p_align = 0; 1521} 1522 1523static void fill_note(struct memelfnote *note, const char *name, int type, 1524 unsigned int sz, void *data) 1525{ 1526 note->name = name; 1527 note->type = type; 1528 note->datasz = sz; 1529 note->data = data; 1530} 1531 1532/* 1533 * fill up all the fields in prstatus from the given task struct, except 1534 * registers which need to be filled up separately. 1535 */ 1536static void fill_prstatus(struct elf_prstatus_common *prstatus, 1537 struct task_struct *p, long signr) 1538{ 1539 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; 1540 prstatus->pr_sigpend = p->pending.signal.sig[0]; 1541 prstatus->pr_sighold = p->blocked.sig[0]; 1542 rcu_read_lock(); 1543 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1544 rcu_read_unlock(); 1545 prstatus->pr_pid = task_pid_vnr(p); 1546 prstatus->pr_pgrp = task_pgrp_vnr(p); 1547 prstatus->pr_sid = task_session_vnr(p); 1548 if (thread_group_leader(p)) { 1549 struct task_cputime cputime; 1550 1551 /* 1552 * This is the record for the group leader. It shows the 1553 * group-wide total, not its individual thread total. 1554 */ 1555 thread_group_cputime(p, &cputime); 1556 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime); 1557 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime); 1558 } else { 1559 u64 utime, stime; 1560 1561 task_cputime(p, &utime, &stime); 1562 prstatus->pr_utime = ns_to_kernel_old_timeval(utime); 1563 prstatus->pr_stime = ns_to_kernel_old_timeval(stime); 1564 } 1565 1566 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime); 1567 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime); 1568} 1569 1570static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, 1571 struct mm_struct *mm) 1572{ 1573 const struct cred *cred; 1574 unsigned int i, len; 1575 unsigned int state; 1576 1577 /* first copy the parameters from user space */ 1578 memset(psinfo, 0, sizeof(struct elf_prpsinfo)); 1579 1580 len = mm->arg_end - mm->arg_start; 1581 if (len >= ELF_PRARGSZ) 1582 len = ELF_PRARGSZ-1; 1583 if (copy_from_user(&psinfo->pr_psargs, 1584 (const char __user *)mm->arg_start, len)) 1585 return -EFAULT; 1586 for(i = 0; i < len; i++) 1587 if (psinfo->pr_psargs[i] == 0) 1588 psinfo->pr_psargs[i] = ' '; 1589 psinfo->pr_psargs[len] = 0; 1590 1591 rcu_read_lock(); 1592 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); 1593 rcu_read_unlock(); 1594 psinfo->pr_pid = task_pid_vnr(p); 1595 psinfo->pr_pgrp = task_pgrp_vnr(p); 1596 psinfo->pr_sid = task_session_vnr(p); 1597 1598 state = READ_ONCE(p->__state); 1599 i = state ? ffz(~state) + 1 : 0; 1600 psinfo->pr_state = i; 1601 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; 1602 psinfo->pr_zomb = psinfo->pr_sname == 'Z'; 1603 psinfo->pr_nice = task_nice(p); 1604 psinfo->pr_flag = p->flags; 1605 rcu_read_lock(); 1606 cred = __task_cred(p); 1607 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); 1608 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); 1609 rcu_read_unlock(); 1610 get_task_comm(psinfo->pr_fname, p); 1611 1612 return 0; 1613} 1614 1615static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) 1616{ 1617 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; 1618 int i = 0; 1619 do 1620 i += 2; 1621 while (auxv[i - 2] != AT_NULL); 1622 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); 1623} 1624 1625static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, 1626 const kernel_siginfo_t *siginfo) 1627{ 1628 copy_siginfo_to_external(csigdata, siginfo); 1629 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); 1630} 1631 1632#define MAX_FILE_NOTE_SIZE (4*1024*1024) 1633/* 1634 * Format of NT_FILE note: 1635 * 1636 * long count -- how many files are mapped 1637 * long page_size -- units for file_ofs 1638 * array of [COUNT] elements of 1639 * long start 1640 * long end 1641 * long file_ofs 1642 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL... 1643 */ 1644static int fill_files_note(struct memelfnote *note, struct coredump_params *cprm) 1645{ 1646 unsigned count, size, names_ofs, remaining, n; 1647 user_long_t *data; 1648 user_long_t *start_end_ofs; 1649 char *name_base, *name_curpos; 1650 int i; 1651 1652 /* *Estimated* file count and total data size needed */ 1653 count = cprm->vma_count; 1654 if (count > UINT_MAX / 64) 1655 return -EINVAL; 1656 size = count * 64; 1657 1658 names_ofs = (2 + 3 * count) * sizeof(data[0]); 1659 alloc: 1660 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */ 1661 return -EINVAL; 1662 size = round_up(size, PAGE_SIZE); 1663 /* 1664 * "size" can be 0 here legitimately. 1665 * Let it ENOMEM and omit NT_FILE section which will be empty anyway. 1666 */ 1667 data = kvmalloc(size, GFP_KERNEL); 1668 if (ZERO_OR_NULL_PTR(data)) 1669 return -ENOMEM; 1670 1671 start_end_ofs = data + 2; 1672 name_base = name_curpos = ((char *)data) + names_ofs; 1673 remaining = size - names_ofs; 1674 count = 0; 1675 for (i = 0; i < cprm->vma_count; i++) { 1676 struct core_vma_metadata *m = &cprm->vma_meta[i]; 1677 struct file *file; 1678 const char *filename; 1679 1680 file = m->file; 1681 if (!file) 1682 continue; 1683 filename = file_path(file, name_curpos, remaining); 1684 if (IS_ERR(filename)) { 1685 if (PTR_ERR(filename) == -ENAMETOOLONG) { 1686 kvfree(data); 1687 size = size * 5 / 4; 1688 goto alloc; 1689 } 1690 continue; 1691 } 1692 1693 /* file_path() fills at the end, move name down */ 1694 /* n = strlen(filename) + 1: */ 1695 n = (name_curpos + remaining) - filename; 1696 remaining = filename - name_curpos; 1697 memmove(name_curpos, filename, n); 1698 name_curpos += n; 1699 1700 *start_end_ofs++ = m->start; 1701 *start_end_ofs++ = m->end; 1702 *start_end_ofs++ = m->pgoff; 1703 count++; 1704 } 1705 1706 /* Now we know exact count of files, can store it */ 1707 data[0] = count; 1708 data[1] = PAGE_SIZE; 1709 /* 1710 * Count usually is less than mm->map_count, 1711 * we need to move filenames down. 1712 */ 1713 n = cprm->vma_count - count; 1714 if (n != 0) { 1715 unsigned shift_bytes = n * 3 * sizeof(data[0]); 1716 memmove(name_base - shift_bytes, name_base, 1717 name_curpos - name_base); 1718 name_curpos -= shift_bytes; 1719 } 1720 1721 size = name_curpos - (char *)data; 1722 fill_note(note, "CORE", NT_FILE, size, data); 1723 return 0; 1724} 1725 1726#ifdef CORE_DUMP_USE_REGSET 1727#include <linux/regset.h> 1728 1729struct elf_thread_core_info { 1730 struct elf_thread_core_info *next; 1731 struct task_struct *task; 1732 struct elf_prstatus prstatus; 1733 struct memelfnote notes[]; 1734}; 1735 1736struct elf_note_info { 1737 struct elf_thread_core_info *thread; 1738 struct memelfnote psinfo; 1739 struct memelfnote signote; 1740 struct memelfnote auxv; 1741 struct memelfnote files; 1742 user_siginfo_t csigdata; 1743 size_t size; 1744 int thread_notes; 1745}; 1746 1747/* 1748 * When a regset has a writeback hook, we call it on each thread before 1749 * dumping user memory. On register window machines, this makes sure the 1750 * user memory backing the register data is up to date before we read it. 1751 */ 1752static void do_thread_regset_writeback(struct task_struct *task, 1753 const struct user_regset *regset) 1754{ 1755 if (regset->writeback) 1756 regset->writeback(task, regset, 1); 1757} 1758 1759#ifndef PRSTATUS_SIZE 1760#define PRSTATUS_SIZE sizeof(struct elf_prstatus) 1761#endif 1762 1763#ifndef SET_PR_FPVALID 1764#define SET_PR_FPVALID(S) ((S)->pr_fpvalid = 1) 1765#endif 1766 1767static int fill_thread_core_info(struct elf_thread_core_info *t, 1768 const struct user_regset_view *view, 1769 long signr, struct elf_note_info *info) 1770{ 1771 unsigned int note_iter, view_iter; 1772 1773 /* 1774 * NT_PRSTATUS is the one special case, because the regset data 1775 * goes into the pr_reg field inside the note contents, rather 1776 * than being the whole note contents. We fill the reset in here. 1777 * We assume that regset 0 is NT_PRSTATUS. 1778 */ 1779 fill_prstatus(&t->prstatus.common, t->task, signr); 1780 regset_get(t->task, &view->regsets[0], 1781 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg); 1782 1783 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, 1784 PRSTATUS_SIZE, &t->prstatus); 1785 info->size += notesize(&t->notes[0]); 1786 1787 do_thread_regset_writeback(t->task, &view->regsets[0]); 1788 1789 /* 1790 * Each other regset might generate a note too. For each regset 1791 * that has no core_note_type or is inactive, skip it. 1792 */ 1793 note_iter = 1; 1794 for (view_iter = 1; view_iter < view->n; ++view_iter) { 1795 const struct user_regset *regset = &view->regsets[view_iter]; 1796 int note_type = regset->core_note_type; 1797 bool is_fpreg = note_type == NT_PRFPREG; 1798 void *data; 1799 int ret; 1800 1801 do_thread_regset_writeback(t->task, regset); 1802 if (!note_type) // not for coredumps 1803 continue; 1804 if (regset->active && regset->active(t->task, regset) <= 0) 1805 continue; 1806 1807 ret = regset_get_alloc(t->task, regset, ~0U, &data); 1808 if (ret < 0) 1809 continue; 1810 1811 if (WARN_ON_ONCE(note_iter >= info->thread_notes)) 1812 break; 1813 1814 if (is_fpreg) 1815 SET_PR_FPVALID(&t->prstatus); 1816 1817 fill_note(&t->notes[note_iter], is_fpreg ? "CORE" : "LINUX", 1818 note_type, ret, data); 1819 1820 info->size += notesize(&t->notes[note_iter]); 1821 note_iter++; 1822 } 1823 1824 return 1; 1825} 1826 1827static int fill_note_info(struct elfhdr *elf, int phdrs, 1828 struct elf_note_info *info, 1829 struct coredump_params *cprm) 1830{ 1831 struct task_struct *dump_task = current; 1832 const struct user_regset_view *view = task_user_regset_view(dump_task); 1833 struct elf_thread_core_info *t; 1834 struct elf_prpsinfo *psinfo; 1835 struct core_thread *ct; 1836 unsigned int i; 1837 1838 info->size = 0; 1839 info->thread = NULL; 1840 1841 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); 1842 if (psinfo == NULL) { 1843 info->psinfo.data = NULL; /* So we don't free this wrongly */ 1844 return 0; 1845 } 1846 1847 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); 1848 1849 /* 1850 * Figure out how many notes we're going to need for each thread. 1851 */ 1852 info->thread_notes = 0; 1853 for (i = 0; i < view->n; ++i) 1854 if (view->regsets[i].core_note_type != 0) 1855 ++info->thread_notes; 1856 1857 /* 1858 * Sanity check. We rely on regset 0 being in NT_PRSTATUS, 1859 * since it is our one special case. 1860 */ 1861 if (unlikely(info->thread_notes == 0) || 1862 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { 1863 WARN_ON(1); 1864 return 0; 1865 } 1866 1867 /* 1868 * Initialize the ELF file header. 1869 */ 1870 fill_elf_header(elf, phdrs, 1871 view->e_machine, view->e_flags); 1872 1873 /* 1874 * Allocate a structure for each thread. 1875 */ 1876 for (ct = &dump_task->signal->core_state->dumper; ct; ct = ct->next) { 1877 t = kzalloc(offsetof(struct elf_thread_core_info, 1878 notes[info->thread_notes]), 1879 GFP_KERNEL); 1880 if (unlikely(!t)) 1881 return 0; 1882 1883 t->task = ct->task; 1884 if (ct->task == dump_task || !info->thread) { 1885 t->next = info->thread; 1886 info->thread = t; 1887 } else { 1888 /* 1889 * Make sure to keep the original task at 1890 * the head of the list. 1891 */ 1892 t->next = info->thread->next; 1893 info->thread->next = t; 1894 } 1895 } 1896 1897 /* 1898 * Now fill in each thread's information. 1899 */ 1900 for (t = info->thread; t != NULL; t = t->next) 1901 if (!fill_thread_core_info(t, view, cprm->siginfo->si_signo, info)) 1902 return 0; 1903 1904 /* 1905 * Fill in the two process-wide notes. 1906 */ 1907 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); 1908 info->size += notesize(&info->psinfo); 1909 1910 fill_siginfo_note(&info->signote, &info->csigdata, cprm->siginfo); 1911 info->size += notesize(&info->signote); 1912 1913 fill_auxv_note(&info->auxv, current->mm); 1914 info->size += notesize(&info->auxv); 1915 1916 if (fill_files_note(&info->files, cprm) == 0) 1917 info->size += notesize(&info->files); 1918 1919 return 1; 1920} 1921 1922static size_t get_note_info_size(struct elf_note_info *info) 1923{ 1924 return info->size; 1925} 1926 1927/* 1928 * Write all the notes for each thread. When writing the first thread, the 1929 * process-wide notes are interleaved after the first thread-specific note. 1930 */ 1931static int write_note_info(struct elf_note_info *info, 1932 struct coredump_params *cprm) 1933{ 1934 bool first = true; 1935 struct elf_thread_core_info *t = info->thread; 1936 1937 do { 1938 int i; 1939 1940 if (!writenote(&t->notes[0], cprm)) 1941 return 0; 1942 1943 if (first && !writenote(&info->psinfo, cprm)) 1944 return 0; 1945 if (first && !writenote(&info->signote, cprm)) 1946 return 0; 1947 if (first && !writenote(&info->auxv, cprm)) 1948 return 0; 1949 if (first && info->files.data && 1950 !writenote(&info->files, cprm)) 1951 return 0; 1952 1953 for (i = 1; i < info->thread_notes; ++i) 1954 if (t->notes[i].data && 1955 !writenote(&t->notes[i], cprm)) 1956 return 0; 1957 1958 first = false; 1959 t = t->next; 1960 } while (t); 1961 1962 return 1; 1963} 1964 1965static void free_note_info(struct elf_note_info *info) 1966{ 1967 struct elf_thread_core_info *threads = info->thread; 1968 while (threads) { 1969 unsigned int i; 1970 struct elf_thread_core_info *t = threads; 1971 threads = t->next; 1972 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); 1973 for (i = 1; i < info->thread_notes; ++i) 1974 kfree(t->notes[i].data); 1975 kfree(t); 1976 } 1977 kfree(info->psinfo.data); 1978 kvfree(info->files.data); 1979} 1980 1981#else 1982 1983/* Here is the structure in which status of each thread is captured. */ 1984struct elf_thread_status 1985{ 1986 struct list_head list; 1987 struct elf_prstatus prstatus; /* NT_PRSTATUS */ 1988 elf_fpregset_t fpu; /* NT_PRFPREG */ 1989 struct task_struct *thread; 1990 struct memelfnote notes[3]; 1991 int num_notes; 1992}; 1993 1994/* 1995 * In order to add the specific thread information for the elf file format, 1996 * we need to keep a linked list of every threads pr_status and then create 1997 * a single section for them in the final core file. 1998 */ 1999static int elf_dump_thread_status(long signr, struct elf_thread_status *t) 2000{ 2001 int sz = 0; 2002 struct task_struct *p = t->thread; 2003 t->num_notes = 0; 2004 2005 fill_prstatus(&t->prstatus.common, p, signr); 2006 elf_core_copy_task_regs(p, &t->prstatus.pr_reg); 2007 2008 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), 2009 &(t->prstatus)); 2010 t->num_notes++; 2011 sz += notesize(&t->notes[0]); 2012 2013 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, 2014 &t->fpu))) { 2015 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), 2016 &(t->fpu)); 2017 t->num_notes++; 2018 sz += notesize(&t->notes[1]); 2019 } 2020 return sz; 2021} 2022 2023struct elf_note_info { 2024 struct memelfnote *notes; 2025 struct memelfnote *notes_files; 2026 struct elf_prstatus *prstatus; /* NT_PRSTATUS */ 2027 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ 2028 struct list_head thread_list; 2029 elf_fpregset_t *fpu; 2030 user_siginfo_t csigdata; 2031 int thread_status_size; 2032 int numnote; 2033}; 2034 2035static int elf_note_info_init(struct elf_note_info *info) 2036{ 2037 memset(info, 0, sizeof(*info)); 2038 INIT_LIST_HEAD(&info->thread_list); 2039 2040 /* Allocate space for ELF notes */ 2041 info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL); 2042 if (!info->notes) 2043 return 0; 2044 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); 2045 if (!info->psinfo) 2046 return 0; 2047 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); 2048 if (!info->prstatus) 2049 return 0; 2050 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); 2051 if (!info->fpu) 2052 return 0; 2053 return 1; 2054} 2055 2056static int fill_note_info(struct elfhdr *elf, int phdrs, 2057 struct elf_note_info *info, 2058 struct coredump_params *cprm) 2059{ 2060 struct core_thread *ct; 2061 struct elf_thread_status *ets; 2062 2063 if (!elf_note_info_init(info)) 2064 return 0; 2065 2066 for (ct = current->signal->core_state->dumper.next; 2067 ct; ct = ct->next) { 2068 ets = kzalloc(sizeof(*ets), GFP_KERNEL); 2069 if (!ets) 2070 return 0; 2071 2072 ets->thread = ct->task; 2073 list_add(&ets->list, &info->thread_list); 2074 } 2075 2076 list_for_each_entry(ets, &info->thread_list, list) { 2077 int sz; 2078 2079 sz = elf_dump_thread_status(cprm->siginfo->si_signo, ets); 2080 info->thread_status_size += sz; 2081 } 2082 /* now collect the dump for the current */ 2083 memset(info->prstatus, 0, sizeof(*info->prstatus)); 2084 fill_prstatus(&info->prstatus->common, current, cprm->siginfo->si_signo); 2085 elf_core_copy_regs(&info->prstatus->pr_reg, cprm->regs); 2086 2087 /* Set up header */ 2088 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS); 2089 2090 /* 2091 * Set up the notes in similar form to SVR4 core dumps made 2092 * with info from their /proc. 2093 */ 2094 2095 fill_note(info->notes + 0, "CORE", NT_PRSTATUS, 2096 sizeof(*info->prstatus), info->prstatus); 2097 fill_psinfo(info->psinfo, current->group_leader, current->mm); 2098 fill_note(info->notes + 1, "CORE", NT_PRPSINFO, 2099 sizeof(*info->psinfo), info->psinfo); 2100 2101 fill_siginfo_note(info->notes + 2, &info->csigdata, cprm->siginfo); 2102 fill_auxv_note(info->notes + 3, current->mm); 2103 info->numnote = 4; 2104 2105 if (fill_files_note(info->notes + info->numnote, cprm) == 0) { 2106 info->notes_files = info->notes + info->numnote; 2107 info->numnote++; 2108 } 2109 2110 /* Try to dump the FPU. */ 2111 info->prstatus->pr_fpvalid = 2112 elf_core_copy_task_fpregs(current, cprm->regs, info->fpu); 2113 if (info->prstatus->pr_fpvalid) 2114 fill_note(info->notes + info->numnote++, 2115 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); 2116 return 1; 2117} 2118 2119static size_t get_note_info_size(struct elf_note_info *info) 2120{ 2121 int sz = 0; 2122 int i; 2123 2124 for (i = 0; i < info->numnote; i++) 2125 sz += notesize(info->notes + i); 2126 2127 sz += info->thread_status_size; 2128 2129 return sz; 2130} 2131 2132static int write_note_info(struct elf_note_info *info, 2133 struct coredump_params *cprm) 2134{ 2135 struct elf_thread_status *ets; 2136 int i; 2137 2138 for (i = 0; i < info->numnote; i++) 2139 if (!writenote(info->notes + i, cprm)) 2140 return 0; 2141 2142 /* write out the thread status notes section */ 2143 list_for_each_entry(ets, &info->thread_list, list) { 2144 for (i = 0; i < ets->num_notes; i++) 2145 if (!writenote(&ets->notes[i], cprm)) 2146 return 0; 2147 } 2148 2149 return 1; 2150} 2151 2152static void free_note_info(struct elf_note_info *info) 2153{ 2154 while (!list_empty(&info->thread_list)) { 2155 struct list_head *tmp = info->thread_list.next; 2156 list_del(tmp); 2157 kfree(list_entry(tmp, struct elf_thread_status, list)); 2158 } 2159 2160 /* Free data possibly allocated by fill_files_note(): */ 2161 if (info->notes_files) 2162 kvfree(info->notes_files->data); 2163 2164 kfree(info->prstatus); 2165 kfree(info->psinfo); 2166 kfree(info->notes); 2167 kfree(info->fpu); 2168} 2169 2170#endif 2171 2172static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, 2173 elf_addr_t e_shoff, int segs) 2174{ 2175 elf->e_shoff = e_shoff; 2176 elf->e_shentsize = sizeof(*shdr4extnum); 2177 elf->e_shnum = 1; 2178 elf->e_shstrndx = SHN_UNDEF; 2179 2180 memset(shdr4extnum, 0, sizeof(*shdr4extnum)); 2181 2182 shdr4extnum->sh_type = SHT_NULL; 2183 shdr4extnum->sh_size = elf->e_shnum; 2184 shdr4extnum->sh_link = elf->e_shstrndx; 2185 shdr4extnum->sh_info = segs; 2186} 2187 2188/* 2189 * Actual dumper 2190 * 2191 * This is a two-pass process; first we find the offsets of the bits, 2192 * and then they are actually written out. If we run out of core limit 2193 * we just truncate. 2194 */ 2195static int elf_core_dump(struct coredump_params *cprm) 2196{ 2197 int has_dumped = 0; 2198 int segs, i; 2199 struct elfhdr elf; 2200 loff_t offset = 0, dataoff; 2201 struct elf_note_info info = { }; 2202 struct elf_phdr *phdr4note = NULL; 2203 struct elf_shdr *shdr4extnum = NULL; 2204 Elf_Half e_phnum; 2205 elf_addr_t e_shoff; 2206 2207 /* 2208 * The number of segs are recored into ELF header as 16bit value. 2209 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. 2210 */ 2211 segs = cprm->vma_count + elf_core_extra_phdrs(); 2212 2213 /* for notes section */ 2214 segs++; 2215 2216 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid 2217 * this, kernel supports extended numbering. Have a look at 2218 * include/linux/elf.h for further information. */ 2219 e_phnum = segs > PN_XNUM ? PN_XNUM : segs; 2220 2221 /* 2222 * Collect all the non-memory information about the process for the 2223 * notes. This also sets up the file header. 2224 */ 2225 if (!fill_note_info(&elf, e_phnum, &info, cprm)) 2226 goto end_coredump; 2227 2228 has_dumped = 1; 2229 2230 offset += sizeof(elf); /* Elf header */ 2231 offset += segs * sizeof(struct elf_phdr); /* Program headers */ 2232 2233 /* Write notes phdr entry */ 2234 { 2235 size_t sz = get_note_info_size(&info); 2236 2237 /* For cell spufs */ 2238 sz += elf_coredump_extra_notes_size(); 2239 2240 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); 2241 if (!phdr4note) 2242 goto end_coredump; 2243 2244 fill_elf_note_phdr(phdr4note, sz, offset); 2245 offset += sz; 2246 } 2247 2248 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); 2249 2250 offset += cprm->vma_data_size; 2251 offset += elf_core_extra_data_size(); 2252 e_shoff = offset; 2253 2254 if (e_phnum == PN_XNUM) { 2255 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); 2256 if (!shdr4extnum) 2257 goto end_coredump; 2258 fill_extnum_info(&elf, shdr4extnum, e_shoff, segs); 2259 } 2260 2261 offset = dataoff; 2262 2263 if (!dump_emit(cprm, &elf, sizeof(elf))) 2264 goto end_coredump; 2265 2266 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) 2267 goto end_coredump; 2268 2269 /* Write program headers for segments dump */ 2270 for (i = 0; i < cprm->vma_count; i++) { 2271 struct core_vma_metadata *meta = cprm->vma_meta + i; 2272 struct elf_phdr phdr; 2273 2274 phdr.p_type = PT_LOAD; 2275 phdr.p_offset = offset; 2276 phdr.p_vaddr = meta->start; 2277 phdr.p_paddr = 0; 2278 phdr.p_filesz = meta->dump_size; 2279 phdr.p_memsz = meta->end - meta->start; 2280 offset += phdr.p_filesz; 2281 phdr.p_flags = 0; 2282 if (meta->flags & VM_READ) 2283 phdr.p_flags |= PF_R; 2284 if (meta->flags & VM_WRITE) 2285 phdr.p_flags |= PF_W; 2286 if (meta->flags & VM_EXEC) 2287 phdr.p_flags |= PF_X; 2288 phdr.p_align = ELF_EXEC_PAGESIZE; 2289 2290 if (!dump_emit(cprm, &phdr, sizeof(phdr))) 2291 goto end_coredump; 2292 } 2293 2294 if (!elf_core_write_extra_phdrs(cprm, offset)) 2295 goto end_coredump; 2296 2297 /* write out the notes section */ 2298 if (!write_note_info(&info, cprm)) 2299 goto end_coredump; 2300 2301 /* For cell spufs */ 2302 if (elf_coredump_extra_notes_write(cprm)) 2303 goto end_coredump; 2304 2305 /* Align to page */ 2306 dump_skip_to(cprm, dataoff); 2307 2308 for (i = 0; i < cprm->vma_count; i++) { 2309 struct core_vma_metadata *meta = cprm->vma_meta + i; 2310 2311 if (!dump_user_range(cprm, meta->start, meta->dump_size)) 2312 goto end_coredump; 2313 } 2314 2315 if (!elf_core_write_extra_data(cprm)) 2316 goto end_coredump; 2317 2318 if (e_phnum == PN_XNUM) { 2319 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) 2320 goto end_coredump; 2321 } 2322 2323end_coredump: 2324 free_note_info(&info); 2325 kfree(shdr4extnum); 2326 kfree(phdr4note); 2327 return has_dumped; 2328} 2329 2330#endif /* CONFIG_ELF_CORE */ 2331 2332static int __init init_elf_binfmt(void) 2333{ 2334 register_binfmt(&elf_format); 2335 return 0; 2336} 2337 2338static void __exit exit_elf_binfmt(void) 2339{ 2340 /* Remove the COFF and ELF loaders. */ 2341 unregister_binfmt(&elf_format); 2342} 2343 2344core_initcall(init_elf_binfmt); 2345module_exit(exit_elf_binfmt); 2346MODULE_LICENSE("GPL"); 2347 2348#ifdef CONFIG_BINFMT_ELF_KUNIT_TEST 2349#include "binfmt_elf_test.c" 2350#endif