fs/binfmt_elf.c

   1 /*
   2  * linux/fs/binfmt_elf.c
   3  *
   4  * These are the functions used to load ELF format executables as used
   5  * on SVr4 machines.  Information on the format may be found in the book
   6  * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
   7  * Tools".
   8  *
   9  * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/fs.h>
  15 #include <linux/mm.h>
  16 #include <linux/mman.h>
  17 #include <linux/errno.h>
  18 #include <linux/signal.h>
  19 #include <linux/binfmts.h>
  20 #include <linux/string.h>
  21 #include <linux/file.h>
  22 #include <linux/slab.h>
  23 #include <linux/personality.h>
  24 #include <linux/elfcore.h>
  25 #include <linux/init.h>
  26 #include <linux/highuid.h>
  27 #include <linux/compiler.h>
  28 #include <linux/highmem.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/vmalloc.h>
  31 #include <linux/security.h>
  32 #include <linux/random.h>
  33 #include <linux/elf.h>
  34 #include <linux/utsname.h>
  35 #include <linux/coredump.h>
  36 #include <linux/sched.h>
  37 #include <asm/uaccess.h>
  38 #include <asm/param.h>
  39 #include <asm/page.h>
  40
  41 #ifndef user_long_t
  42 #define user_long_t long
  43 #endif
  44 #ifndef user_siginfo_t
  45 #define user_siginfo_t siginfo_t
  46 #endif
  47
  48 static int load_elf_binary(struct linux_binprm *bprm);
  49 static int load_elf_library(struct file *);
  50 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
  51                                 int, int, unsigned long);
  52
  53 /*
  54  * If we don't support core dumping, then supply a NULL so we
  55  * don't even try.
  56  */
  57 #ifdef CONFIG_ELF_CORE
  58 static int elf_core_dump(struct coredump_params *cprm);
  59 #else
  60 #define elf_core_dump   NULL
  61 #endif
  62
  63 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
  64 #define ELF_MIN_ALIGN   ELF_EXEC_PAGESIZE
  65 #else
  66 #define ELF_MIN_ALIGN   PAGE_SIZE
  67 #endif
  68
  69 #ifndef ELF_CORE_EFLAGS
  70 #define ELF_CORE_EFLAGS 0
  71 #endif
  72
  73 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
  74 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
  75 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
  76
  77 static struct linux_binfmt elf_format = {
  78         .module         = THIS_MODULE,
  79         .load_binary    = load_elf_binary,
  80         .load_shlib     = load_elf_library,
  81         .core_dump      = elf_core_dump,
  82         .min_coredump   = ELF_EXEC_PAGESIZE,
  83 };
  84
  85 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
  86
  87 static int set_brk(unsigned long start, unsigned long end)
  88 {
  89         start = ELF_PAGEALIGN(start);
  90         end = ELF_PAGEALIGN(end);
  91         if (end > start) {
  92                 unsigned long addr;
  93                 addr = vm_brk(start, end - start);
  94                 if (BAD_ADDR(addr))
  95                         return addr;
  96         }
  97         current->mm->start_brk = current->mm->brk = end;
  98         return 0;
  99 }
 100
 101 /* We need to explicitly zero any fractional pages
 102    after the data section (i.e. bss).  This would
 103    contain the junk from the file that should not
 104    be in memory
 105  */
 106 static int padzero(unsigned long elf_bss)
 107 {
 108         unsigned long nbyte;
 109
 110         nbyte = ELF_PAGEOFFSET(elf_bss);
 111         if (nbyte) {
 112                 nbyte = ELF_MIN_ALIGN - nbyte;
 113                 if (clear_user((void __user *) elf_bss, nbyte))
 114                         return -EFAULT;
 115         }
 116         return 0;
 117 }
 118
 119 /* Let's use some macros to make this stack manipulation a little clearer */
 120 #ifdef CONFIG_STACK_GROWSUP
 121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
 122 #define STACK_ROUND(sp, items) \
 123         ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
 124 #define STACK_ALLOC(sp, len) ({ \
 125         elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
 126         old_sp; })
 127 #else
 128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
 129 #define STACK_ROUND(sp, items) \
 130         (((unsigned long) (sp - items)) &~ 15UL)
 131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
 132 #endif
 133
 134 #ifndef ELF_BASE_PLATFORM
 135 /*
 136  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 137  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 138  * will be copied to the user stack in the same manner as AT_PLATFORM.
 139  */
 140 #define ELF_BASE_PLATFORM NULL
 141 #endif
 142
 143 static int
 144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
 145                 unsigned long load_addr, unsigned long interp_load_addr)
 146 {
 147         unsigned long p = bprm->p;
 148         int argc = bprm->argc;
 149         int envc = bprm->envc;
 150         elf_addr_t __user *argv;
 151         elf_addr_t __user *envp;
 152         elf_addr_t __user *sp;
 153         elf_addr_t __user *u_platform;
 154         elf_addr_t __user *u_base_platform;
 155         elf_addr_t __user *u_rand_bytes;
 156         const char *k_platform = ELF_PLATFORM;
 157         const char *k_base_platform = ELF_BASE_PLATFORM;
 158         unsigned char k_rand_bytes[16];
 159         int items;
 160         elf_addr_t *elf_info;
 161         int ei_index = 0;
 162         const struct cred *cred = current_cred();
 163         struct vm_area_struct *vma;
 164
 165         /*
 166          * In some cases (e.g. Hyper-Threading), we want to avoid L1
 167          * evictions by the processes running on the same package. One
 168          * thing we can do is to shuffle the initial stack for them.
 169          */
 170
 171         p = arch_align_stack(p);
 172
 173         /*
 174          * If this architecture has a platform capability string, copy it
 175          * to userspace.  In some cases (Sparc), this info is impossible
 176          * for userspace to get any other way, in others (i386) it is
 177          * merely difficult.
 178          */
 179         u_platform = NULL;
 180         if (k_platform) {
 181                 size_t len = strlen(k_platform) + 1;
 182
 183                 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
 184                 if (__copy_to_user(u_platform, k_platform, len))
 185                         return -EFAULT;
 186         }
 187
 188         /*
 189          * If this architecture has a "base" platform capability
 190          * string, copy it to userspace.
 191          */
 192         u_base_platform = NULL;
 193         if (k_base_platform) {
 194                 size_t len = strlen(k_base_platform) + 1;
 195
 196                 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
 197                 if (__copy_to_user(u_base_platform, k_base_platform, len))
 198                         return -EFAULT;
 199         }
 200
 201         /*
 202          * Generate 16 random bytes for userspace PRNG seeding.
 203          */
 204         get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
 205         u_rand_bytes = (elf_addr_t __user *)
 206                        STACK_ALLOC(p, sizeof(k_rand_bytes));
 207         if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
 208                 return -EFAULT;
 209
 210         /* Create the ELF interpreter info */
 211         elf_info = (elf_addr_t *)current->mm->saved_auxv;
 212         /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
 213 #define NEW_AUX_ENT(id, val) \
 214         do { \
 215                 elf_info[ei_index++] = id; \
 216                 elf_info[ei_index++] = val; \
 217         } while (0)
 218
 219 #ifdef ARCH_DLINFO
 220         /*
 221          * ARCH_DLINFO must come first so PPC can do its special alignment of
 222          * AUXV.
 223          * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
 224          * ARCH_DLINFO changes
 225          */
 226         ARCH_DLINFO;
 227 #endif
 228         NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
 229         NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
 230         NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
 231         NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
 232         NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
 233         NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
 234         NEW_AUX_ENT(AT_BASE, interp_load_addr);
 235         NEW_AUX_ENT(AT_FLAGS, 0);
 236         NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
 237         NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
 238         NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
 239         NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
 240         NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
 241         NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
 242         NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
 243 #ifdef ELF_HWCAP2
 244         NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
 245 #endif
 246         NEW_AUX_ENT(AT_EXECFN, bprm->exec);
 247         if (k_platform) {
 248                 NEW_AUX_ENT(AT_PLATFORM,
 249                             (elf_addr_t)(unsigned long)u_platform);
 250         }
 251         if (k_base_platform) {
 252                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 253                             (elf_addr_t)(unsigned long)u_base_platform);
 254         }
 255         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 256                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 257         }
 258 #undef NEW_AUX_ENT
 259         /* AT_NULL is zero; clear the rest too */
 260         memset(&elf_info[ei_index], 0,
 261                sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
 262
 263         /* And advance past the AT_NULL entry.  */
 264         ei_index += 2;
 265
 266         sp = STACK_ADD(p, ei_index);
 267
 268         items = (argc + 1) + (envc + 1) + 1;
 269         bprm->p = STACK_ROUND(sp, items);
 270
 271         /* Point sp at the lowest address on the stack */
 272 #ifdef CONFIG_STACK_GROWSUP
 273         sp = (elf_addr_t __user *)bprm->p - items - ei_index;
 274         bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
 275 #else
 276         sp = (elf_addr_t __user *)bprm->p;
 277 #endif
 278
 279
 280         /*
 281          * Grow the stack manually; some architectures have a limit on how
 282          * far ahead a user-space access may be in order to grow the stack.
 283          */
 284         vma = find_extend_vma(current->mm, bprm->p);
 285         if (!vma)
 286                 return -EFAULT;
 287
 288         /* Now, let's put argc (and argv, envp if appropriate) on the stack */
 289         if (__put_user(argc, sp++))
 290                 return -EFAULT;
 291         argv = sp;
 292         envp = argv + argc + 1;
 293
 294         /* Populate argv and envp */
 295         p = current->mm->arg_end = current->mm->arg_start;
 296         while (argc-- > 0) {
 297                 size_t len;
 298                 if (__put_user((elf_addr_t)p, argv++))
 299                         return -EFAULT;
 300                 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
 301                 if (!len || len > MAX_ARG_STRLEN)
 302                         return -EINVAL;
 303                 p += len;
 304         }
 305         if (__put_user(0, argv))
 306                 return -EFAULT;
 307         current->mm->arg_end = current->mm->env_start = p;
 308         while (envc-- > 0) {
 309                 size_t len;
 310                 if (__put_user((elf_addr_t)p, envp++))
 311                         return -EFAULT;
 312                 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
 313                 if (!len || len > MAX_ARG_STRLEN)
 314                         return -EINVAL;
 315                 p += len;
 316         }
 317         if (__put_user(0, envp))
 318                 return -EFAULT;
 319         current->mm->env_end = p;
 320
 321         /* Put the elf_info on the stack in the right place.  */
 322         sp = (elf_addr_t __user *)envp + 1;
 323         if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
 324                 return -EFAULT;
 325         return 0;
 326 }
 327
 328 #ifndef elf_map
 329
 330 static unsigned long elf_map(struct file *filep, unsigned long addr,
 331                 struct elf_phdr *eppnt, int prot, int type,
 332                 unsigned long total_size)
 333 {
 334         unsigned long map_addr;
 335         unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
 336         unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
 337         addr = ELF_PAGESTART(addr);
 338         size = ELF_PAGEALIGN(size);
 339
 340         /* mmap() will return -EINVAL if given a zero size, but a
 341          * segment with zero filesize is perfectly valid */
 342         if (!size)
 343                 return addr;
 344
 345         /*
 346         * total_size is the size of the ELF (interpreter) image.
 347         * The _first_ mmap needs to know the full size, otherwise
 348         * randomization might put this image into an overlapping
 349         * position with the ELF binary image. (since size < total_size)
 350         * So we first map the 'big' image - and unmap the remainder at
 351         * the end. (which unmap is needed for ELF images with holes.)
 352         */
 353         if (total_size) {
 354                 total_size = ELF_PAGEALIGN(total_size);
 355                 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
 356                 if (!BAD_ADDR(map_addr))
 357                         vm_munmap(map_addr+size, total_size-size);
 358         } else
 359                 map_addr = vm_mmap(filep, addr, size, prot, type, off);
 360
 361         return(map_addr);
 362 }
 363
 364 #endif /* !elf_map */
 365
 366 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
 367 {
 368         int i, first_idx = -1, last_idx = -1;
 369
 370         for (i = 0; i < nr; i++) {
 371                 if (cmds[i].p_type == PT_LOAD) {
 372                         last_idx = i;
 373                         if (first_idx == -1)
 374                                 first_idx = i;
 375                 }
 376         }
 377         if (first_idx == -1)
 378                 return 0;
 379
 380         return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
 381                                 ELF_PAGESTART(cmds[first_idx].p_vaddr);
 382 }
 383
 384
 385 /* This is much more generalized than the library routine read function,
 386    so we keep this separate.  Technically the library read function
 387    is only provided so that we can read a.out libraries that have
 388    an ELF header */
 389
 390 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
 391                 struct file *interpreter, unsigned long *interp_map_addr,
 392                 unsigned long no_base)
 393 {
 394         struct elf_phdr *elf_phdata;
 395         struct elf_phdr *eppnt;
 396         unsigned long load_addr = 0;
 397         int load_addr_set = 0;
 398         unsigned long last_bss = 0, elf_bss = 0;
 399         unsigned long error = ~0UL;
 400         unsigned long total_size;
 401         int retval, i, size;
 402
 403         /* First of all, some simple consistency checks */
 404         if (interp_elf_ex->e_type != ET_EXEC &&
 405             interp_elf_ex->e_type != ET_DYN)
 406                 goto out;
 407         if (!elf_check_arch(interp_elf_ex))
 408                 goto out;
 409         if (!interpreter->f_op->mmap)
 410                 goto out;
 411
 412         /*
 413          * If the size of this structure has changed, then punt, since
 414          * we will be doing the wrong thing.
 415          */
 416         if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
 417                 goto out;
 418         if (interp_elf_ex->e_phnum < 1 ||
 419                 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
 420                 goto out;
 421
 422         /* Now read in all of the header information */
 423         size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
 424         if (size > ELF_MIN_ALIGN)
 425                 goto out;
 426         elf_phdata = kmalloc(size, GFP_KERNEL);
 427         if (!elf_phdata)
 428                 goto out;
 429
 430         retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
 431                              (char *)elf_phdata, size);
 432         error = -EIO;
 433         if (retval != size) {
 434                 if (retval < 0)
 435                         error = retval;
 436                 goto out_close;
 437         }
 438
 439         total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
 440         if (!total_size) {
 441                 error = -EINVAL;
 442                 goto out_close;
 443         }
 444
 445         eppnt = elf_phdata;
 446         for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
 447                 if (eppnt->p_type == PT_LOAD) {
 448                         int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
 449                         int elf_prot = 0;
 450                         unsigned long vaddr = 0;
 451                         unsigned long k, map_addr;
 452
 453                         if (eppnt->p_flags & PF_R)
 454                                 elf_prot = PROT_READ;
 455                         if (eppnt->p_flags & PF_W)
 456                                 elf_prot |= PROT_WRITE;
 457                         if (eppnt->p_flags & PF_X)
 458                                 elf_prot |= PROT_EXEC;
 459                         vaddr = eppnt->p_vaddr;
 460                         if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
 461                                 elf_type |= MAP_FIXED;
 462                         else if (no_base && interp_elf_ex->e_type == ET_DYN)
 463                                 load_addr = -vaddr;
 464
 465                         map_addr = elf_map(interpreter, load_addr + vaddr,
 466                                         eppnt, elf_prot, elf_type, total_size);
 467                         total_size = 0;
 468                         if (!*interp_map_addr)
 469                                 *interp_map_addr = map_addr;
 470                         error = map_addr;
 471                         if (BAD_ADDR(map_addr))
 472                                 goto out_close;
 473
 474                         if (!load_addr_set &&
 475                             interp_elf_ex->e_type == ET_DYN) {
 476                                 load_addr = map_addr - ELF_PAGESTART(vaddr);
 477                                 load_addr_set = 1;
 478                         }
 479
 480                         /*
 481                          * Check to see if the section's size will overflow the
 482                          * allowed task size. Note that p_filesz must always be
 483                          * <= p_memsize so it's only necessary to check p_memsz.
 484                          */
 485                         k = load_addr + eppnt->p_vaddr;
 486                         if (BAD_ADDR(k) ||
 487                             eppnt->p_filesz > eppnt->p_memsz ||
 488                             eppnt->p_memsz > TASK_SIZE ||
 489                             TASK_SIZE - eppnt->p_memsz < k) {
 490                                 error = -ENOMEM;
 491                                 goto out_close;
 492                         }
 493
 494                         /*
 495                          * Find the end of the file mapping for this phdr, and
 496                          * keep track of the largest address we see for this.
 497                          */
 498                         k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
 499                         if (k > elf_bss)
 500                                 elf_bss = k;
 501
 502                         /*
 503                          * Do the same thing for the memory mapping - between
 504                          * elf_bss and last_bss is the bss section.
 505                          */
 506                         k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
 507                         if (k > last_bss)
 508                                 last_bss = k;
 509                 }
 510         }
 511
 512         if (last_bss > elf_bss) {
 513                 /*
 514                  * Now fill out the bss section.  First pad the last page up
 515                  * to the page boundary, and then perform a mmap to make sure
 516                  * that there are zero-mapped pages up to and including the
 517                  * last bss page.
 518                  */
 519                 if (padzero(elf_bss)) {
 520                         error = -EFAULT;
 521                         goto out_close;
 522                 }
 523
 524                 /* What we have mapped so far */
 525                 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
 526
 527                 /* Map the last of the bss segment */
 528                 error = vm_brk(elf_bss, last_bss - elf_bss);
 529                 if (BAD_ADDR(error))
 530                         goto out_close;
 531         }
 532
 533         error = load_addr;
 534
 535 out_close:
 536         kfree(elf_phdata);
 537 out:
 538         return error;
 539 }
 540
 541 /*
 542  * These are the functions used to load ELF style executables and shared
 543  * libraries.  There is no binary dependent code anywhere else.
 544  */
 545
 546 #define INTERPRETER_NONE 0
 547 #define INTERPRETER_ELF 2
 548
 549 #ifndef STACK_RND_MASK
 550 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12))     /* 8MB of VA */
 551 #endif
 552
 553 static unsigned long randomize_stack_top(unsigned long stack_top)
 554 {
 555         unsigned int random_variable = 0;
 556
 557         if ((current->flags & PF_RANDOMIZE) &&
 558                 !(current->personality & ADDR_NO_RANDOMIZE)) {
 559                 random_variable = get_random_int() & STACK_RND_MASK;
 560                 random_variable <<= PAGE_SHIFT;
 561         }
 562 #ifdef CONFIG_STACK_GROWSUP
 563         return PAGE_ALIGN(stack_top) + random_variable;
 564 #else
 565         return PAGE_ALIGN(stack_top) - random_variable;
 566 #endif
 567 }
 568
 569 static int load_elf_binary(struct linux_binprm *bprm)
 570 {
 571         struct file *interpreter = NULL; /* to shut gcc up */
 572         unsigned long load_addr = 0, load_bias = 0;
 573         int load_addr_set = 0;
 574         char * elf_interpreter = NULL;
 575         unsigned long error;
 576         struct elf_phdr *elf_ppnt, *elf_phdata;
 577         unsigned long elf_bss, elf_brk;
 578         int retval, i;
 579         unsigned int size;
 580         unsigned long elf_entry;
 581         unsigned long interp_load_addr = 0;
 582         unsigned long start_code, end_code, start_data, end_data;
 583         unsigned long reloc_func_desc __maybe_unused = 0;
 584         int executable_stack = EXSTACK_DEFAULT;
 585         unsigned long def_flags = 0;
 586         struct pt_regs *regs = current_pt_regs();
 587         struct {
 588                 struct elfhdr elf_ex;
 589                 struct elfhdr interp_elf_ex;
 590         } *loc;
 591
 592         loc = kmalloc(sizeof(*loc), GFP_KERNEL);
 593         if (!loc) {
 594                 retval = -ENOMEM;
 595                 goto out_ret;
 596         }
 597
 598         /* Get the exec-header */
 599         loc->elf_ex = *((struct elfhdr *)bprm->buf);
 600
 601         retval = -ENOEXEC;
 602         /* First of all, some simple consistency checks */
 603         if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
 604                 goto out;
 605
 606         if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
 607                 goto out;
 608         if (!elf_check_arch(&loc->elf_ex))
 609                 goto out;
 610         if (!bprm->file->f_op->mmap)
 611                 goto out;
 612
 613         /* Now read in all of the header information */
 614         if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
 615                 goto out;
 616         if (loc->elf_ex.e_phnum < 1 ||
 617                 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
 618                 goto out;
 619         size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
 620         retval = -ENOMEM;
 621         elf_phdata = kmalloc(size, GFP_KERNEL);
 622         if (!elf_phdata)
 623                 goto out;
 624
 625         retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
 626                              (char *)elf_phdata, size);
 627         if (retval != size) {
 628                 if (retval >= 0)
 629                         retval = -EIO;
 630                 goto out_free_ph;
 631         }
 632
 633         elf_ppnt = elf_phdata;
 634         elf_bss = 0;
 635         elf_brk = 0;
 636
 637         start_code = ~0UL;
 638         end_code = 0;
 639         start_data = 0;
 640         end_data = 0;
 641
 642         for (i = 0; i < loc->elf_ex.e_phnum; i++) {
 643                 if (elf_ppnt->p_type == PT_INTERP) {
 644                         /* This is the program interpreter used for
 645                          * shared libraries - for now assume that this
 646                          * is an a.out format binary
 647                          */
 648                         retval = -ENOEXEC;
 649                         if (elf_ppnt->p_filesz > PATH_MAX ||
 650                             elf_ppnt->p_filesz < 2)
 651                                 goto out_free_ph;
 652
 653                         retval = -ENOMEM;
 654                         elf_interpreter = kmalloc(elf_ppnt->p_filesz,
 655                                                   GFP_KERNEL);
 656                         if (!elf_interpreter)
 657                                 goto out_free_ph;
 658
 659                         retval = kernel_read(bprm->file, elf_ppnt->p_offset,
 660                                              elf_interpreter,
 661                                              elf_ppnt->p_filesz);
 662                         if (retval != elf_ppnt->p_filesz) {
 663                                 if (retval >= 0)
 664                                         retval = -EIO;
 665                                 goto out_free_interp;
 666                         }
 667                         /* make sure path is NULL terminated */
 668                         retval = -ENOEXEC;
 669                         if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
 670                                 goto out_free_interp;
 671
 672                         interpreter = open_exec(elf_interpreter);
 673                         retval = PTR_ERR(interpreter);
 674                         if (IS_ERR(interpreter))
 675                                 goto out_free_interp;
 676
 677                         /*
 678                          * If the binary is not readable then enforce
 679                          * mm->dumpable = 0 regardless of the interpreter's
 680                          * permissions.
 681                          */
 682                         would_dump(bprm, interpreter);
 683
 684                         retval = kernel_read(interpreter, 0, bprm->buf,
 685                                              BINPRM_BUF_SIZE);
 686                         if (retval != BINPRM_BUF_SIZE) {
 687                                 if (retval >= 0)
 688                                         retval = -EIO;
 689                                 goto out_free_dentry;
 690                         }
 691
 692                         /* Get the exec headers */
 693                         loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
 694                         break;
 695                 }
 696                 elf_ppnt++;
 697         }
 698
 699         elf_ppnt = elf_phdata;
 700         for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
 701                 if (elf_ppnt->p_type == PT_GNU_STACK) {
 702                         if (elf_ppnt->p_flags & PF_X)
 703                                 executable_stack = EXSTACK_ENABLE_X;
 704                         else
 705                                 executable_stack = EXSTACK_DISABLE_X;
 706                         break;
 707                 }
 708
 709         /* Some simple consistency checks for the interpreter */
 710         if (elf_interpreter) {
 711                 retval = -ELIBBAD;
 712                 /* Not an ELF interpreter */
 713                 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
 714                         goto out_free_dentry;
 715                 /* Verify the interpreter has a valid arch */
 716                 if (!elf_check_arch(&loc->interp_elf_ex))
 717                         goto out_free_dentry;
 718         }
 719
 720         /* Flush all traces of the currently running executable */
 721         retval = flush_old_exec(bprm);
 722         if (retval)
 723                 goto out_free_dentry;
 724
 725         /* OK, This is the point of no return */
 726         current->mm->def_flags = def_flags;
 727
 728         /* Do this immediately, since STACK_TOP as used in setup_arg_pages
 729            may depend on the personality.  */
 730         SET_PERSONALITY(loc->elf_ex);
 731         if (elf_read_implies_exec(loc->elf_ex, executable_stack))
 732                 current->personality |= READ_IMPLIES_EXEC;
 733
 734         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
 735                 current->flags |= PF_RANDOMIZE;
 736
 737         setup_new_exec(bprm);
 738
 739         /* Do this so that we can load the interpreter, if need be.  We will
 740            change some of these later */
 741         retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
 742                                  executable_stack);
 743         if (retval < 0) {
 744                 send_sig(SIGKILL, current, 0);
 745                 goto out_free_dentry;
 746         }
 747
 748         current->mm->start_stack = bprm->p;
 749
 750         /* Now we do a little grungy work by mmapping the ELF image into
 751            the correct location in memory. */
 752         for(i = 0, elf_ppnt = elf_phdata;
 753             i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
 754                 int elf_prot = 0, elf_flags;
 755                 unsigned long k, vaddr;
 756
 757                 if (elf_ppnt->p_type != PT_LOAD)
 758                         continue;
 759
 760                 if (unlikely (elf_brk > elf_bss)) {
 761                         unsigned long nbyte;
 762
 763                         /* There was a PT_LOAD segment with p_memsz > p_filesz
 764                            before this one. Map anonymous pages, if needed,
 765                            and clear the area.  */
 766                         retval = set_brk(elf_bss + load_bias,
 767                                          elf_brk + load_bias);
 768                         if (retval) {
 769                                 send_sig(SIGKILL, current, 0);
 770                                 goto out_free_dentry;
 771                         }
 772                         nbyte = ELF_PAGEOFFSET(elf_bss);
 773                         if (nbyte) {
 774                                 nbyte = ELF_MIN_ALIGN - nbyte;
 775                                 if (nbyte > elf_brk - elf_bss)
 776                                         nbyte = elf_brk - elf_bss;
 777                                 if (clear_user((void __user *)elf_bss +
 778                                                         load_bias, nbyte)) {
 779                                         /*
 780                                          * This bss-zeroing can fail if the ELF
 781                                          * file specifies odd protections. So
 782                                          * we don't check the return value
 783                                          */
 784                                 }
 785                         }
 786                 }
 787
 788                 if (elf_ppnt->p_flags & PF_R)
 789                         elf_prot |= PROT_READ;
 790                 if (elf_ppnt->p_flags & PF_W)
 791                         elf_prot |= PROT_WRITE;
 792                 if (elf_ppnt->p_flags & PF_X)
 793                         elf_prot |= PROT_EXEC;
 794
 795                 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
 796
 797                 vaddr = elf_ppnt->p_vaddr;
 798                 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
 799                         elf_flags |= MAP_FIXED;
 800                 } else if (loc->elf_ex.e_type == ET_DYN) {
 801                         /* Try and get dynamic programs out of the way of the
 802                          * default mmap base, as well as whatever program they
 803                          * might try to exec.  This is because the brk will
 804                          * follow the loader, and is not movable.  */
 805 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
 806                         /* Memory randomization might have been switched off
 807                          * in runtime via sysctl or explicit setting of
 808                          * personality flags.
 809                          * If that is the case, retain the original non-zero
 810                          * load_bias value in order to establish proper
 811                          * non-randomized mappings.
 812                          */
 813                         if (current->flags & PF_RANDOMIZE)
 814                                 load_bias = 0;
 815                         else
 816                                 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
 817 #else
 818                         load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
 819 #endif
 820                 }
 821
 822                 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
 823                                 elf_prot, elf_flags, 0);
 824                 if (BAD_ADDR(error)) {
 825                         send_sig(SIGKILL, current, 0);
 826                         retval = IS_ERR((void *)error) ?
 827                                 PTR_ERR((void*)error) : -EINVAL;
 828                         goto out_free_dentry;
 829                 }
 830
 831                 if (!load_addr_set) {
 832                         load_addr_set = 1;
 833                         load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
 834                         if (loc->elf_ex.e_type == ET_DYN) {
 835                                 load_bias += error -
 836                                              ELF_PAGESTART(load_bias + vaddr);
 837                                 load_addr += load_bias;
 838                                 reloc_func_desc = load_bias;
 839                         }
 840                 }
 841                 k = elf_ppnt->p_vaddr;
 842                 if (k < start_code)
 843                         start_code = k;
 844                 if (start_data < k)
 845                         start_data = k;
 846
 847                 /*
 848                  * Check to see if the section's size will overflow the
 849                  * allowed task size. Note that p_filesz must always be
 850                  * <= p_memsz so it is only necessary to check p_memsz.
 851                  */
 852                 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
 853                     elf_ppnt->p_memsz > TASK_SIZE ||
 854                     TASK_SIZE - elf_ppnt->p_memsz < k) {
 855                         /* set_brk can never work. Avoid overflows. */
 856                         send_sig(SIGKILL, current, 0);
 857                         retval = -EINVAL;
 858                         goto out_free_dentry;
 859                 }
 860
 861                 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
 862
 863                 if (k > elf_bss)
 864                         elf_bss = k;
 865                 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
 866                         end_code = k;
 867                 if (end_data < k)
 868                         end_data = k;
 869                 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
 870                 if (k > elf_brk)
 871                         elf_brk = k;
 872         }
 873
 874         loc->elf_ex.e_entry += load_bias;
 875         elf_bss += load_bias;
 876         elf_brk += load_bias;
 877         start_code += load_bias;
 878         end_code += load_bias;
 879         start_data += load_bias;
 880         end_data += load_bias;
 881
 882         /* Calling set_brk effectively mmaps the pages that we need
 883          * for the bss and break sections.  We must do this before
 884          * mapping in the interpreter, to make sure it doesn't wind
 885          * up getting placed where the bss needs to go.
 886          */
 887         retval = set_brk(elf_bss, elf_brk);
 888         if (retval) {
 889                 send_sig(SIGKILL, current, 0);
 890                 goto out_free_dentry;
 891         }
 892         if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
 893                 send_sig(SIGSEGV, current, 0);
 894                 retval = -EFAULT; /* Nobody gets to see this, but.. */
 895                 goto out_free_dentry;
 896         }
 897
 898         if (elf_interpreter) {
 899                 unsigned long interp_map_addr = 0;
 900
 901                 elf_entry = load_elf_interp(&loc->interp_elf_ex,
 902                                             interpreter,
 903                                             &interp_map_addr,
 904                                             load_bias);
 905                 if (!IS_ERR((void *)elf_entry)) {
 906                         /*
 907                          * load_elf_interp() returns relocation
 908                          * adjustment
 909                          */
 910                         interp_load_addr = elf_entry;
 911                         elf_entry += loc->interp_elf_ex.e_entry;
 912                 }
 913                 if (BAD_ADDR(elf_entry)) {
 914                         force_sig(SIGSEGV, current);
 915                         retval = IS_ERR((void *)elf_entry) ?
 916                                         (int)elf_entry : -EINVAL;
 917                         goto out_free_dentry;
 918                 }
 919                 reloc_func_desc = interp_load_addr;
 920
 921                 allow_write_access(interpreter);
 922                 fput(interpreter);
 923                 kfree(elf_interpreter);
 924         } else {
 925                 elf_entry = loc->elf_ex.e_entry;
 926                 if (BAD_ADDR(elf_entry)) {
 927                         force_sig(SIGSEGV, current);
 928                         retval = -EINVAL;
 929                         goto out_free_dentry;
 930                 }
 931         }
 932
 933         kfree(elf_phdata);
 934
 935         set_binfmt(&elf_format);
 936
 937 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
 938         retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
 939         if (retval < 0) {
 940                 send_sig(SIGKILL, current, 0);
 941                 goto out;
 942         }
 943 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
 944
 945         install_exec_creds(bprm);
 946         retval = create_elf_tables(bprm, &loc->elf_ex,
 947                           load_addr, interp_load_addr);
 948         if (retval < 0) {
 949                 send_sig(SIGKILL, current, 0);
 950                 goto out;
 951         }
 952         /* N.B. passed_fileno might not be initialized? */
 953         current->mm->end_code = end_code;
 954         current->mm->start_code = start_code;
 955         current->mm->start_data = start_data;
 956         current->mm->end_data = end_data;
 957         current->mm->start_stack = bprm->p;
 958
 959 #ifdef arch_randomize_brk
 960         if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
 961                 current->mm->brk = current->mm->start_brk =
 962                         arch_randomize_brk(current->mm);
 963 #ifdef CONFIG_COMPAT_BRK
 964                 current->brk_randomized = 1;
 965 #endif
 966         }
 967 #endif
 968
 969         if (current->personality & MMAP_PAGE_ZERO) {
 970                 /* Why this, you ask???  Well SVr4 maps page 0 as read-only,
 971                    and some applications "depend" upon this behavior.
 972                    Since we do not have the power to recompile these, we
 973                    emulate the SVr4 behavior. Sigh. */
 974                 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
 975                                 MAP_FIXED | MAP_PRIVATE, 0);
 976         }
 977
 978 #ifdef ELF_PLAT_INIT
 979         /*
 980          * The ABI may specify that certain registers be set up in special
 981          * ways (on i386 %edx is the address of a DT_FINI function, for
 982          * example.  In addition, it may also specify (eg, PowerPC64 ELF)
 983          * that the e_entry field is the address of the function descriptor
 984          * for the startup routine, rather than the address of the startup
 985          * routine itself.  This macro performs whatever initialization to
 986          * the regs structure is required as well as any relocations to the
 987          * function descriptor entries when executing dynamically links apps.
 988          */
 989         ELF_PLAT_INIT(regs, reloc_func_desc);
 990 #endif
 991
 992         start_thread(regs, elf_entry, bprm->p);
 993         retval = 0;
 994 out:
 995         kfree(loc);
 996 out_ret:
 997         return retval;
 998
 999         /* error cleanup */
1000 out_free_dentry:
1001         allow_write_access(interpreter);
1002         if (interpreter)
1003                 fput(interpreter);
1004 out_free_interp:
1005         kfree(elf_interpreter);
1006 out_free_ph:
1007         kfree(elf_phdata);
1008         goto out;
1009 }
1010
1011 /* This is really simpleminded and specialized - we are loading an
1012    a.out library that is given an ELF header. */
1013 static int load_elf_library(struct file *file)
1014 {
1015         struct elf_phdr *elf_phdata;
1016         struct elf_phdr *eppnt;
1017         unsigned long elf_bss, bss, len;
1018         int retval, error, i, j;
1019         struct elfhdr elf_ex;
1020
1021         error = -ENOEXEC;
1022         retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1023         if (retval != sizeof(elf_ex))
1024                 goto out;
1025
1026         if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1027                 goto out;
1028
1029         /* First of all, some simple consistency checks */
1030         if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1031             !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1032                 goto out;
1033
1034         /* Now read in all of the header information */
1035
1036         j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1037         /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1038
1039         error = -ENOMEM;
1040         elf_phdata = kmalloc(j, GFP_KERNEL);
1041         if (!elf_phdata)
1042                 goto out;
1043
1044         eppnt = elf_phdata;
1045         error = -ENOEXEC;
1046         retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1047         if (retval != j)
1048                 goto out_free_ph;
1049
1050         for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1051                 if ((eppnt + i)->p_type == PT_LOAD)
1052                         j++;
1053         if (j != 1)
1054                 goto out_free_ph;
1055
1056         while (eppnt->p_type != PT_LOAD)
1057                 eppnt++;
1058
1059         /* Now use mmap to map the library into memory. */
1060         error = vm_mmap(file,
1061                         ELF_PAGESTART(eppnt->p_vaddr),
1062                         (eppnt->p_filesz +
1063                          ELF_PAGEOFFSET(eppnt->p_vaddr)),
1064                         PROT_READ | PROT_WRITE | PROT_EXEC,
1065                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1066                         (eppnt->p_offset -
1067                          ELF_PAGEOFFSET(eppnt->p_vaddr)));
1068         if (error != ELF_PAGESTART(eppnt->p_vaddr))
1069                 goto out_free_ph;
1070
1071         elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1072         if (padzero(elf_bss)) {
1073                 error = -EFAULT;
1074                 goto out_free_ph;
1075         }
1076
1077         len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1078                             ELF_MIN_ALIGN - 1);
1079         bss = eppnt->p_memsz + eppnt->p_vaddr;
1080         if (bss > len)
1081                 vm_brk(len, bss - len);
1082         error = 0;
1083
1084 out_free_ph:
1085         kfree(elf_phdata);
1086 out:
1087         return error;
1088 }
1089
1090 #ifdef CONFIG_ELF_CORE
1091 /*
1092  * ELF core dumper
1093  *
1094  * Modelled on fs/exec.c:aout_core_dump()
1095  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1096  */
1097
1098 /*
1099  * The purpose of always_dump_vma() is to make sure that special kernel mappings
1100  * that are useful for post-mortem analysis are included in every core dump.
1101  * In that way we ensure that the core dump is fully interpretable later
1102  * without matching up the same kernel and hardware config to see what PC values
1103  * meant. These special mappings include - vDSO, vsyscall, and other
1104  * architecture specific mappings
1105  */
1106 static bool always_dump_vma(struct vm_area_struct *vma)
1107 {
1108         /* Any vsyscall mappings? */
1109         if (vma == get_gate_vma(vma->vm_mm))
1110                 return true;
1111         /*
1112          * arch_vma_name() returns non-NULL for special architecture mappings,
1113          * such as vDSO sections.
1114          */
1115         if (arch_vma_name(vma))
1116                 return true;
1117
1118         return false;
1119 }
1120
1121 /*
1122  * Decide what to dump of a segment, part, all or none.
1123  */
1124 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1125                                    unsigned long mm_flags)
1126 {
1127 #define FILTER(type)    (mm_flags & (1UL << MMF_DUMP_##type))
1128
1129         /* always dump the vdso and vsyscall sections */
1130         if (always_dump_vma(vma))
1131                 goto whole;
1132
1133         if (vma->vm_flags & VM_DONTDUMP)
1134                 return 0;
1135
1136         /* Hugetlb memory check */
1137         if (vma->vm_flags & VM_HUGETLB) {
1138                 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1139                         goto whole;
1140                 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1141                         goto whole;
1142                 return 0;
1143         }
1144
1145         /* Do not dump I/O mapped devices or special mappings */
1146         if (vma->vm_flags & VM_IO)
1147                 return 0;
1148
1149         /* By default, dump shared memory if mapped from an anonymous file. */
1150         if (vma->vm_flags & VM_SHARED) {
1151                 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1152                     FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1153                         goto whole;
1154                 return 0;
1155         }
1156
1157         /* Dump segments that have been written to.  */
1158         if (vma->anon_vma && FILTER(ANON_PRIVATE))
1159                 goto whole;
1160         if (vma->vm_file == NULL)
1161                 return 0;
1162
1163         if (FILTER(MAPPED_PRIVATE))
1164                 goto whole;
1165
1166         /*
1167          * If this looks like the beginning of a DSO or executable mapping,
1168          * check for an ELF header.  If we find one, dump the first page to
1169          * aid in determining what was mapped here.
1170          */
1171         if (FILTER(ELF_HEADERS) &&
1172             vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1173                 u32 __user *header = (u32 __user *) vma->vm_start;
1174                 u32 word;
1175                 mm_segment_t fs = get_fs();
1176                 /*
1177                  * Doing it this way gets the constant folded by GCC.
1178                  */
1179                 union {
1180                         u32 cmp;
1181                         char elfmag[SELFMAG];
1182                 } magic;
1183                 BUILD_BUG_ON(SELFMAG != sizeof word);
1184                 magic.elfmag[EI_MAG0] = ELFMAG0;
1185                 magic.elfmag[EI_MAG1] = ELFMAG1;
1186                 magic.elfmag[EI_MAG2] = ELFMAG2;
1187                 magic.elfmag[EI_MAG3] = ELFMAG3;
1188                 /*
1189                  * Switch to the user "segment" for get_user(),
1190                  * then put back what elf_core_dump() had in place.
1191                  */
1192                 set_fs(USER_DS);
1193                 if (unlikely(get_user(word, header)))
1194                         word = 0;
1195                 set_fs(fs);
1196                 if (word == magic.cmp)
1197                         return PAGE_SIZE;
1198         }
1199
1200 #undef  FILTER
1201
1202         return 0;
1203
1204 whole:
1205         return vma->vm_end - vma->vm_start;
1206 }
1207
1208 /* An ELF note in memory */
1209 struct memelfnote
1210 {
1211         const char *name;
1212         int type;
1213         unsigned int datasz;
1214         void *data;
1215 };
1216
1217 static int notesize(struct memelfnote *en)
1218 {
1219         int sz;
1220
1221         sz = sizeof(struct elf_note);
1222         sz += roundup(strlen(en->name) + 1, 4);
1223         sz += roundup(en->datasz, 4);
1224
1225         return sz;
1226 }
1227
1228 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1229 {
1230         struct elf_note en;
1231         en.n_namesz = strlen(men->name) + 1;
1232         en.n_descsz = men->datasz;
1233         en.n_type = men->type;
1234
1235         return dump_emit(cprm, &en, sizeof(en)) &&
1236             dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1237             dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1238 }
1239
1240 static void fill_elf_header(struct elfhdr *elf, int segs,
1241                             u16 machine, u32 flags)
1242 {
1243         memset(elf, 0, sizeof(*elf));
1244
1245         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1246         elf->e_ident[EI_CLASS] = ELF_CLASS;
1247         elf->e_ident[EI_DATA] = ELF_DATA;
1248         elf->e_ident[EI_VERSION] = EV_CURRENT;
1249         elf->e_ident[EI_OSABI] = ELF_OSABI;
1250
1251         elf->e_type = ET_CORE;
1252         elf->e_machine = machine;
1253         elf->e_version = EV_CURRENT;
1254         elf->e_phoff = sizeof(struct elfhdr);
1255         elf->e_flags = flags;
1256         elf->e_ehsize = sizeof(struct elfhdr);
1257         elf->e_phentsize = sizeof(struct elf_phdr);
1258         elf->e_phnum = segs;
1259
1260         return;
1261 }
1262
1263 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1264 {
1265         phdr->p_type = PT_NOTE;
1266         phdr->p_offset = offset;
1267         phdr->p_vaddr = 0;
1268         phdr->p_paddr = 0;
1269         phdr->p_filesz = sz;
1270         phdr->p_memsz = 0;
1271         phdr->p_flags = 0;
1272         phdr->p_align = 0;
1273         return;
1274 }
1275
1276 static void fill_note(struct memelfnote *note, const char *name, int type,
1277                 unsigned int sz, void *data)
1278 {
1279         note->name = name;
1280         note->type = type;
1281         note->datasz = sz;
1282         note->data = data;
1283         return;
1284 }
1285
1286 /*
1287  * fill up all the fields in prstatus from the given task struct, except
1288  * registers which need to be filled up separately.
1289  */
1290 static void fill_prstatus(struct elf_prstatus *prstatus,
1291                 struct task_struct *p, long signr)
1292 {
1293         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1294         prstatus->pr_sigpend = p->pending.signal.sig[0];
1295         prstatus->pr_sighold = p->blocked.sig[0];
1296         rcu_read_lock();
1297         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1298         rcu_read_unlock();
1299         prstatus->pr_pid = task_pid_vnr(p);
1300         prstatus->pr_pgrp = task_pgrp_vnr(p);
1301         prstatus->pr_sid = task_session_vnr(p);
1302         if (thread_group_leader(p)) {
1303                 struct task_cputime cputime;
1304
1305                 /*
1306                  * This is the record for the group leader.  It shows the
1307                  * group-wide total, not its individual thread total.
1308                  */
1309                 thread_group_cputime(p, &cputime);
1310                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1311                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1312         } else {
1313                 cputime_t utime, stime;
1314
1315                 task_cputime(p, &utime, &stime);
1316                 cputime_to_timeval(utime, &prstatus->pr_utime);
1317                 cputime_to_timeval(stime, &prstatus->pr_stime);
1318         }
1319         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1320         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1321 }
1322
1323 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1324                        struct mm_struct *mm)
1325 {
1326         const struct cred *cred;
1327         unsigned int i, len;
1328
1329         /* first copy the parameters from user space */
1330         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1331
1332         len = mm->arg_end - mm->arg_start;
1333         if (len >= ELF_PRARGSZ)
1334                 len = ELF_PRARGSZ-1;
1335         if (copy_from_user(&psinfo->pr_psargs,
1336                            (const char __user *)mm->arg_start, len))
1337                 return -EFAULT;
1338         for(i = 0; i < len; i++)
1339                 if (psinfo->pr_psargs[i] == 0)
1340                         psinfo->pr_psargs[i] = ' ';
1341         psinfo->pr_psargs[len] = 0;
1342
1343         rcu_read_lock();
1344         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1345         rcu_read_unlock();
1346         psinfo->pr_pid = task_pid_vnr(p);
1347         psinfo->pr_pgrp = task_pgrp_vnr(p);
1348         psinfo->pr_sid = task_session_vnr(p);
1349
1350         i = p->state ? ffz(~p->state) + 1 : 0;
1351         psinfo->pr_state = i;
1352         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1353         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1354         psinfo->pr_nice = task_nice(p);
1355         psinfo->pr_flag = p->flags;
1356         rcu_read_lock();
1357         cred = __task_cred(p);
1358         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1359         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1360         rcu_read_unlock();
1361         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1362
1363         return 0;
1364 }
1365
1366 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1367 {
1368         elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1369         int i = 0;
1370         do
1371                 i += 2;
1372         while (auxv[i - 2] != AT_NULL);
1373         fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1374 }
1375
1376 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1377                 const siginfo_t *siginfo)
1378 {
1379         mm_segment_t old_fs = get_fs();
1380         set_fs(KERNEL_DS);
1381         copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1382         set_fs(old_fs);
1383         fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1384 }
1385
1386 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1387 /*
1388  * Format of NT_FILE note:
1389  *
1390  * long count     -- how many files are mapped
1391  * long page_size -- units for file_ofs
1392  * array of [COUNT] elements of
1393  *   long start
1394  *   long end
1395  *   long file_ofs
1396  * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1397  */
1398 static int fill_files_note(struct memelfnote *note)
1399 {
1400         struct vm_area_struct *vma;
1401         unsigned count, size, names_ofs, remaining, n;
1402         user_long_t *data;
1403         user_long_t *start_end_ofs;
1404         char *name_base, *name_curpos;
1405
1406         /* *Estimated* file count and total data size needed */
1407         count = current->mm->map_count;
1408         size = count * 64;
1409
1410         names_ofs = (2 + 3 * count) * sizeof(data[0]);
1411  alloc:
1412         if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1413                 return -EINVAL;
1414         size = round_up(size, PAGE_SIZE);
1415         data = vmalloc(size);
1416         if (!data)
1417                 return -ENOMEM;
1418
1419         start_end_ofs = data + 2;
1420         name_base = name_curpos = ((char *)data) + names_ofs;
1421         remaining = size - names_ofs;
1422         count = 0;
1423         for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1424                 struct file *file;
1425                 const char *filename;
1426
1427                 file = vma->vm_file;
1428                 if (!file)
1429                         continue;
1430                 filename = d_path(&file->f_path, name_curpos, remaining);
1431                 if (IS_ERR(filename)) {
1432                         if (PTR_ERR(filename) == -ENAMETOOLONG) {
1433                                 vfree(data);
1434                                 size = size * 5 / 4;
1435                                 goto alloc;
1436                         }
1437                         continue;
1438                 }
1439
1440                 /* d_path() fills at the end, move name down */
1441                 /* n = strlen(filename) + 1: */
1442                 n = (name_curpos + remaining) - filename;
1443                 remaining = filename - name_curpos;
1444                 memmove(name_curpos, filename, n);
1445                 name_curpos += n;
1446
1447                 *start_end_ofs++ = vma->vm_start;
1448                 *start_end_ofs++ = vma->vm_end;
1449                 *start_end_ofs++ = vma->vm_pgoff;
1450                 count++;
1451         }
1452
1453         /* Now we know exact count of files, can store it */
1454         data[0] = count;
1455         data[1] = PAGE_SIZE;
1456         /*
1457          * Count usually is less than current->mm->map_count,
1458          * we need to move filenames down.
1459          */
1460         n = current->mm->map_count - count;
1461         if (n != 0) {
1462                 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1463                 memmove(name_base - shift_bytes, name_base,
1464                         name_curpos - name_base);
1465                 name_curpos -= shift_bytes;
1466         }
1467
1468         size = name_curpos - (char *)data;
1469         fill_note(note, "CORE", NT_FILE, size, data);
1470         return 0;
1471 }
1472
1473 #ifdef CORE_DUMP_USE_REGSET
1474 #include <linux/regset.h>
1475
1476 struct elf_thread_core_info {
1477         struct elf_thread_core_info *next;
1478         struct task_struct *task;
1479         struct elf_prstatus prstatus;
1480         struct memelfnote notes[0];
1481 };
1482
1483 struct elf_note_info {
1484         struct elf_thread_core_info *thread;
1485         struct memelfnote psinfo;
1486         struct memelfnote signote;
1487         struct memelfnote auxv;
1488         struct memelfnote files;
1489         user_siginfo_t csigdata;
1490         size_t size;
1491         int thread_notes;
1492 };
1493
1494 /*
1495  * When a regset has a writeback hook, we call it on each thread before
1496  * dumping user memory.  On register window machines, this makes sure the
1497  * user memory backing the register data is up to date before we read it.
1498  */
1499 static void do_thread_regset_writeback(struct task_struct *task,
1500                                        const struct user_regset *regset)
1501 {
1502         if (regset->writeback)
1503                 regset->writeback(task, regset, 1);
1504 }
1505
1506 #ifndef PR_REG_SIZE
1507 #define PR_REG_SIZE(S) sizeof(S)
1508 #endif
1509
1510 #ifndef PRSTATUS_SIZE
1511 #define PRSTATUS_SIZE(S) sizeof(S)
1512 #endif
1513
1514 #ifndef PR_REG_PTR
1515 #define PR_REG_PTR(S) (&((S)->pr_reg))
1516 #endif
1517
1518 #ifndef SET_PR_FPVALID
1519 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1520 #endif
1521
1522 static int fill_thread_core_info(struct elf_thread_core_info *t,
1523                                  const struct user_regset_view *view,
1524                                  long signr, size_t *total)
1525 {
1526         unsigned int i;
1527
1528         /*
1529          * NT_PRSTATUS is the one special case, because the regset data
1530          * goes into the pr_reg field inside the note contents, rather
1531          * than being the whole note contents.  We fill the reset in here.
1532          * We assume that regset 0 is NT_PRSTATUS.
1533          */
1534         fill_prstatus(&t->prstatus, t->task, signr);
1535         (void) view->regsets[0].get(t->task, &view->regsets[0],
1536                                     0, PR_REG_SIZE(t->prstatus.pr_reg),
1537                                     PR_REG_PTR(&t->prstatus), NULL);
1538
1539         fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1540                   PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1541         *total += notesize(&t->notes[0]);
1542
1543         do_thread_regset_writeback(t->task, &view->regsets[0]);
1544
1545         /*
1546          * Each other regset might generate a note too.  For each regset
1547          * that has no core_note_type or is inactive, we leave t->notes[i]
1548          * all zero and we'll know to skip writing it later.
1549          */
1550         for (i = 1; i < view->n; ++i) {
1551                 const struct user_regset *regset = &view->regsets[i];
1552                 do_thread_regset_writeback(t->task, regset);
1553                 if (regset->core_note_type && regset->get &&
1554                     (!regset->active || regset->active(t->task, regset))) {
1555                         int ret;
1556                         size_t size = regset->n * regset->size;
1557                         void *data = kmalloc(size, GFP_KERNEL);
1558                         if (unlikely(!data))
1559                                 return 0;
1560                         ret = regset->get(t->task, regset,
1561                                           0, size, data, NULL);
1562                         if (unlikely(ret))
1563                                 kfree(data);
1564                         else {
1565                                 if (regset->core_note_type != NT_PRFPREG)
1566                                         fill_note(&t->notes[i], "LINUX",
1567                                                   regset->core_note_type,
1568                                                   size, data);
1569                                 else {
1570                                         SET_PR_FPVALID(&t->prstatus, 1);
1571                                         fill_note(&t->notes[i], "CORE",
1572                                                   NT_PRFPREG, size, data);
1573                                 }
1574                                 *total += notesize(&t->notes[i]);
1575                         }
1576                 }
1577         }
1578
1579         return 1;
1580 }
1581
1582 static int fill_note_info(struct elfhdr *elf, int phdrs,
1583                           struct elf_note_info *info,
1584                           const siginfo_t *siginfo, struct pt_regs *regs)
1585 {
1586         struct task_struct *dump_task = current;
1587         const struct user_regset_view *view = task_user_regset_view(dump_task);
1588         struct elf_thread_core_info *t;
1589         struct elf_prpsinfo *psinfo;
1590         struct core_thread *ct;
1591         unsigned int i;
1592
1593         info->size = 0;
1594         info->thread = NULL;
1595
1596         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1597         if (psinfo == NULL) {
1598                 info->psinfo.data = NULL; /* So we don't free this wrongly */
1599                 return 0;
1600         }
1601
1602         fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1603
1604         /*
1605          * Figure out how many notes we're going to need for each thread.
1606          */
1607         info->thread_notes = 0;
1608         for (i = 0; i < view->n; ++i)
1609                 if (view->regsets[i].core_note_type != 0)
1610                         ++info->thread_notes;
1611
1612         /*
1613          * Sanity check.  We rely on regset 0 being in NT_PRSTATUS,
1614          * since it is our one special case.
1615          */
1616         if (unlikely(info->thread_notes == 0) ||
1617             unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1618                 WARN_ON(1);
1619                 return 0;
1620         }
1621
1622         /*
1623          * Initialize the ELF file header.
1624          */
1625         fill_elf_header(elf, phdrs,
1626                         view->e_machine, view->e_flags);
1627
1628         /*
1629          * Allocate a structure for each thread.
1630          */
1631         for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1632                 t = kzalloc(offsetof(struct elf_thread_core_info,
1633                                      notes[info->thread_notes]),
1634                             GFP_KERNEL);
1635                 if (unlikely(!t))
1636                         return 0;
1637
1638                 t->task = ct->task;
1639                 if (ct->task == dump_task || !info->thread) {
1640                         t->next = info->thread;
1641                         info->thread = t;
1642                 } else {
1643                         /*
1644                          * Make sure to keep the original task at
1645                          * the head of the list.
1646                          */
1647                         t->next = info->thread->next;
1648                         info->thread->next = t;
1649                 }
1650         }
1651
1652         /*
1653          * Now fill in each thread's information.
1654          */
1655         for (t = info->thread; t != NULL; t = t->next)
1656                 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1657                         return 0;
1658
1659         /*
1660          * Fill in the two process-wide notes.
1661          */
1662         fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1663         info->size += notesize(&info->psinfo);
1664
1665         fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1666         info->size += notesize(&info->signote);
1667
1668         fill_auxv_note(&info->auxv, current->mm);
1669         info->size += notesize(&info->auxv);
1670
1671         if (fill_files_note(&info->files) == 0)
1672                 info->size += notesize(&info->files);
1673
1674         return 1;
1675 }
1676
1677 static size_t get_note_info_size(struct elf_note_info *info)
1678 {
1679         return info->size;
1680 }
1681
1682 /*
1683  * Write all the notes for each thread.  When writing the first thread, the
1684  * process-wide notes are interleaved after the first thread-specific note.
1685  */
1686 static int write_note_info(struct elf_note_info *info,
1687                            struct coredump_params *cprm)
1688 {
1689         bool first = 1;
1690         struct elf_thread_core_info *t = info->thread;
1691
1692         do {
1693                 int i;
1694
1695                 if (!writenote(&t->notes[0], cprm))
1696                         return 0;
1697
1698                 if (first && !writenote(&info->psinfo, cprm))
1699                         return 0;
1700                 if (first && !writenote(&info->signote, cprm))
1701                         return 0;
1702                 if (first && !writenote(&info->auxv, cprm))
1703                         return 0;
1704                 if (first && info->files.data &&
1705                                 !writenote(&info->files, cprm))
1706                         return 0;
1707
1708                 for (i = 1; i < info->thread_notes; ++i)
1709                         if (t->notes[i].data &&
1710                             !writenote(&t->notes[i], cprm))
1711                                 return 0;
1712
1713                 first = 0;
1714                 t = t->next;
1715         } while (t);
1716
1717         return 1;
1718 }
1719
1720 static void free_note_info(struct elf_note_info *info)
1721 {
1722         struct elf_thread_core_info *threads = info->thread;
1723         while (threads) {
1724                 unsigned int i;
1725                 struct elf_thread_core_info *t = threads;
1726                 threads = t->next;
1727                 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1728                 for (i = 1; i < info->thread_notes; ++i)
1729                         kfree(t->notes[i].data);
1730                 kfree(t);
1731         }
1732         kfree(info->psinfo.data);
1733         vfree(info->files.data);
1734 }
1735
1736 #else
1737
1738 /* Here is the structure in which status of each thread is captured. */
1739 struct elf_thread_status
1740 {
1741         struct list_head list;
1742         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1743         elf_fpregset_t fpu;             /* NT_PRFPREG */
1744         struct task_struct *thread;
1745 #ifdef ELF_CORE_COPY_XFPREGS
1746         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1747 #endif
1748         struct memelfnote notes[3];
1749         int num_notes;
1750 };
1751
1752 /*
1753  * In order to add the specific thread information for the elf file format,
1754  * we need to keep a linked list of every threads pr_status and then create
1755  * a single section for them in the final core file.
1756  */
1757 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1758 {
1759         int sz = 0;
1760         struct task_struct *p = t->thread;
1761         t->num_notes = 0;
1762
1763         fill_prstatus(&t->prstatus, p, signr);
1764         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1765
1766         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1767                   &(t->prstatus));
1768         t->num_notes++;
1769         sz += notesize(&t->notes[0]);
1770
1771         if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1772                                                                 &t->fpu))) {
1773                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1774                           &(t->fpu));
1775                 t->num_notes++;
1776                 sz += notesize(&t->notes[1]);
1777         }
1778
1779 #ifdef ELF_CORE_COPY_XFPREGS
1780         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1781                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1782                           sizeof(t->xfpu), &t->xfpu);
1783                 t->num_notes++;
1784                 sz += notesize(&t->notes[2]);
1785         }
1786 #endif
1787         return sz;
1788 }
1789
1790 struct elf_note_info {
1791         struct memelfnote *notes;
1792         struct memelfnote *notes_files;
1793         struct elf_prstatus *prstatus;  /* NT_PRSTATUS */
1794         struct elf_prpsinfo *psinfo;    /* NT_PRPSINFO */
1795         struct list_head thread_list;
1796         elf_fpregset_t *fpu;
1797 #ifdef ELF_CORE_COPY_XFPREGS
1798         elf_fpxregset_t *xfpu;
1799 #endif
1800         user_siginfo_t csigdata;
1801         int thread_status_size;
1802         int numnote;
1803 };
1804
1805 static int elf_note_info_init(struct elf_note_info *info)
1806 {
1807         memset(info, 0, sizeof(*info));
1808         INIT_LIST_HEAD(&info->thread_list);
1809
1810         /* Allocate space for ELF notes */
1811         info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1812         if (!info->notes)
1813                 return 0;
1814         info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1815         if (!info->psinfo)
1816                 return 0;
1817         info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1818         if (!info->prstatus)
1819                 return 0;
1820         info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1821         if (!info->fpu)
1822                 return 0;
1823 #ifdef ELF_CORE_COPY_XFPREGS
1824         info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1825         if (!info->xfpu)
1826                 return 0;
1827 #endif
1828         return 1;
1829 }
1830
1831 static int fill_note_info(struct elfhdr *elf, int phdrs,
1832                           struct elf_note_info *info,
1833                           const siginfo_t *siginfo, struct pt_regs *regs)
1834 {
1835         struct list_head *t;
1836         struct core_thread *ct;
1837         struct elf_thread_status *ets;
1838
1839         if (!elf_note_info_init(info))
1840                 return 0;
1841
1842         for (ct = current->mm->core_state->dumper.next;
1843                                         ct; ct = ct->next) {
1844                 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1845                 if (!ets)
1846                         return 0;
1847
1848                 ets->thread = ct->task;
1849                 list_add(&ets->list, &info->thread_list);
1850         }
1851
1852         list_for_each(t, &info->thread_list) {
1853                 int sz;
1854
1855                 ets = list_entry(t, struct elf_thread_status, list);
1856                 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1857                 info->thread_status_size += sz;
1858         }
1859         /* now collect the dump for the current */
1860         memset(info->prstatus, 0, sizeof(*info->prstatus));
1861         fill_prstatus(info->prstatus, current, siginfo->si_signo);
1862         elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1863
1864         /* Set up header */
1865         fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1866
1867         /*
1868          * Set up the notes in similar form to SVR4 core dumps made
1869          * with info from their /proc.
1870          */
1871
1872         fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1873                   sizeof(*info->prstatus), info->prstatus);
1874         fill_psinfo(info->psinfo, current->group_leader, current->mm);
1875         fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1876                   sizeof(*info->psinfo), info->psinfo);
1877
1878         fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1879         fill_auxv_note(info->notes + 3, current->mm);
1880         info->numnote = 4;
1881
1882         if (fill_files_note(info->notes + info->numnote) == 0) {
1883                 info->notes_files = info->notes + info->numnote;
1884                 info->numnote++;
1885         }
1886
1887         /* Try to dump the FPU. */
1888         info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1889                                                                info->fpu);
1890         if (info->prstatus->pr_fpvalid)
1891                 fill_note(info->notes + info->numnote++,
1892                           "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1893 #ifdef ELF_CORE_COPY_XFPREGS
1894         if (elf_core_copy_task_xfpregs(current, info->xfpu))
1895                 fill_note(info->notes + info->numnote++,
1896                           "LINUX", ELF_CORE_XFPREG_TYPE,
1897                           sizeof(*info->xfpu), info->xfpu);
1898 #endif
1899
1900         return 1;
1901 }
1902
1903 static size_t get_note_info_size(struct elf_note_info *info)
1904 {
1905         int sz = 0;
1906         int i;
1907
1908         for (i = 0; i < info->numnote; i++)
1909                 sz += notesize(info->notes + i);
1910
1911         sz += info->thread_status_size;
1912
1913         return sz;
1914 }
1915
1916 static int write_note_info(struct elf_note_info *info,
1917                            struct coredump_params *cprm)
1918 {
1919         int i;
1920         struct list_head *t;
1921
1922         for (i = 0; i < info->numnote; i++)
1923                 if (!writenote(info->notes + i, cprm))
1924                         return 0;
1925
1926         /* write out the thread status notes section */
1927         list_for_each(t, &info->thread_list) {
1928                 struct elf_thread_status *tmp =
1929                                 list_entry(t, struct elf_thread_status, list);
1930
1931                 for (i = 0; i < tmp->num_notes; i++)
1932                         if (!writenote(&tmp->notes[i], cprm))
1933                                 return 0;
1934         }
1935
1936         return 1;
1937 }
1938
1939 static void free_note_info(struct elf_note_info *info)
1940 {
1941         while (!list_empty(&info->thread_list)) {
1942                 struct list_head *tmp = info->thread_list.next;
1943                 list_del(tmp);
1944                 kfree(list_entry(tmp, struct elf_thread_status, list));
1945         }
1946
1947         /* Free data possibly allocated by fill_files_note(): */
1948         if (info->notes_files)
1949                 vfree(info->notes_files->data);
1950
1951         kfree(info->prstatus);
1952         kfree(info->psinfo);
1953         kfree(info->notes);
1954         kfree(info->fpu);
1955 #ifdef ELF_CORE_COPY_XFPREGS
1956         kfree(info->xfpu);
1957 #endif
1958 }
1959
1960 #endif
1961
1962 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1963                                         struct vm_area_struct *gate_vma)
1964 {
1965         struct vm_area_struct *ret = tsk->mm->mmap;
1966
1967         if (ret)
1968                 return ret;
1969         return gate_vma;
1970 }
1971 /*
1972  * Helper function for iterating across a vma list.  It ensures that the caller
1973  * will visit `gate_vma' prior to terminating the search.
1974  */
1975 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1976                                         struct vm_area_struct *gate_vma)
1977 {
1978         struct vm_area_struct *ret;
1979
1980         ret = this_vma->vm_next;
1981         if (ret)
1982                 return ret;
1983         if (this_vma == gate_vma)
1984                 return NULL;
1985         return gate_vma;
1986 }
1987
1988 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1989                              elf_addr_t e_shoff, int segs)
1990 {
1991         elf->e_shoff = e_shoff;
1992         elf->e_shentsize = sizeof(*shdr4extnum);
1993         elf->e_shnum = 1;
1994         elf->e_shstrndx = SHN_UNDEF;
1995
1996         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1997
1998         shdr4extnum->sh_type = SHT_NULL;
1999         shdr4extnum->sh_size = elf->e_shnum;
2000         shdr4extnum->sh_link = elf->e_shstrndx;
2001         shdr4extnum->sh_info = segs;
2002 }
2003
2004 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2005                                      unsigned long mm_flags)
2006 {
2007         struct vm_area_struct *vma;
2008         size_t size = 0;
2009
2010         for (vma = first_vma(current, gate_vma); vma != NULL;
2011              vma = next_vma(vma, gate_vma))
2012                 size += vma_dump_size(vma, mm_flags);
2013         return size;
2014 }
2015
2016 /*
2017  * Actual dumper
2018  *
2019  * This is a two-pass process; first we find the offsets of the bits,
2020  * and then they are actually written out.  If we run out of core limit
2021  * we just truncate.
2022  */
2023 static int elf_core_dump(struct coredump_params *cprm)
2024 {
2025         int has_dumped = 0;
2026         mm_segment_t fs;
2027         int segs;
2028         struct vm_area_struct *vma, *gate_vma;
2029         struct elfhdr *elf = NULL;
2030         loff_t offset = 0, dataoff;
2031         struct elf_note_info info = { };
2032         struct elf_phdr *phdr4note = NULL;
2033         struct elf_shdr *shdr4extnum = NULL;
2034         Elf_Half e_phnum;
2035         elf_addr_t e_shoff;
2036
2037         /*
2038          * We no longer stop all VM operations.
2039          *
2040          * This is because those proceses that could possibly change map_count
2041          * or the mmap / vma pages are now blocked in do_exit on current
2042          * finishing this core dump.
2043          *
2044          * Only ptrace can touch these memory addresses, but it doesn't change
2045          * the map_count or the pages allocated. So no possibility of crashing
2046          * exists while dumping the mm->vm_next areas to the core file.
2047          */
2048
2049         /* alloc memory for large data structures: too large to be on stack */
2050         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2051         if (!elf)
2052                 goto out;
2053         /*
2054          * The number of segs are recored into ELF header as 16bit value.
2055          * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2056          */
2057         segs = current->mm->map_count;
2058         segs += elf_core_extra_phdrs();
2059
2060         gate_vma = get_gate_vma(current->mm);
2061         if (gate_vma != NULL)
2062                 segs++;
2063
2064         /* for notes section */
2065         segs++;
2066
2067         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2068          * this, kernel supports extended numbering. Have a look at
2069          * include/linux/elf.h for further information. */
2070         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2071
2072         /*
2073          * Collect all the non-memory information about the process for the
2074          * notes.  This also sets up the file header.
2075          */
2076         if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2077                 goto cleanup;
2078
2079         has_dumped = 1;
2080
2081         fs = get_fs();
2082         set_fs(KERNEL_DS);
2083
2084         offset += sizeof(*elf);                         /* Elf header */
2085         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
2086
2087         /* Write notes phdr entry */
2088         {
2089                 size_t sz = get_note_info_size(&info);
2090
2091                 sz += elf_coredump_extra_notes_size();
2092
2093                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2094                 if (!phdr4note)
2095                         goto end_coredump;
2096
2097                 fill_elf_note_phdr(phdr4note, sz, offset);
2098                 offset += sz;
2099         }
2100
2101         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2102
2103         offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2104         offset += elf_core_extra_data_size();
2105         e_shoff = offset;
2106
2107         if (e_phnum == PN_XNUM) {
2108                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2109                 if (!shdr4extnum)
2110                         goto end_coredump;
2111                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2112         }
2113
2114         offset = dataoff;
2115
2116         if (!dump_emit(cprm, elf, sizeof(*elf)))
2117                 goto end_coredump;
2118
2119         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2120                 goto end_coredump;
2121
2122         /* Write program headers for segments dump */
2123         for (vma = first_vma(current, gate_vma); vma != NULL;
2124                         vma = next_vma(vma, gate_vma)) {
2125                 struct elf_phdr phdr;
2126
2127                 phdr.p_type = PT_LOAD;
2128                 phdr.p_offset = offset;
2129                 phdr.p_vaddr = vma->vm_start;
2130                 phdr.p_paddr = 0;
2131                 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2132                 phdr.p_memsz = vma->vm_end - vma->vm_start;
2133                 offset += phdr.p_filesz;
2134                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2135                 if (vma->vm_flags & VM_WRITE)
2136                         phdr.p_flags |= PF_W;
2137                 if (vma->vm_flags & VM_EXEC)
2138                         phdr.p_flags |= PF_X;
2139                 phdr.p_align = ELF_EXEC_PAGESIZE;
2140
2141                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2142                         goto end_coredump;
2143         }
2144
2145         if (!elf_core_write_extra_phdrs(cprm, offset))
2146                 goto end_coredump;
2147
2148         /* write out the notes section */
2149         if (!write_note_info(&info, cprm))
2150                 goto end_coredump;
2151
2152         if (elf_coredump_extra_notes_write(cprm))
2153                 goto end_coredump;
2154
2155         /* Align to page */
2156         if (!dump_skip(cprm, dataoff - cprm->written))
2157                 goto end_coredump;
2158
2159         for (vma = first_vma(current, gate_vma); vma != NULL;
2160                         vma = next_vma(vma, gate_vma)) {
2161                 unsigned long addr;
2162                 unsigned long end;
2163
2164                 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2165
2166                 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2167                         struct page *page;
2168                         int stop;
2169
2170                         page = get_dump_page(addr);
2171                         if (page) {
2172                                 void *kaddr = kmap(page);
2173                                 stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
2174                                 kunmap(page);
2175                                 page_cache_release(page);
2176                         } else
2177                                 stop = !dump_skip(cprm, PAGE_SIZE);
2178                         if (stop)
2179                                 goto end_coredump;
2180                 }
2181         }
2182
2183         if (!elf_core_write_extra_data(cprm))
2184                 goto end_coredump;
2185
2186         if (e_phnum == PN_XNUM) {
2187                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2188                         goto end_coredump;
2189         }
2190
2191 end_coredump:
2192         set_fs(fs);
2193
2194 cleanup:
2195         free_note_info(&info);
2196         kfree(shdr4extnum);
2197         kfree(phdr4note);
2198         kfree(elf);
2199 out:
2200         return has_dumped;
2201 }
2202
2203 #endif          /* CONFIG_ELF_CORE */
2204
2205 static int __init init_elf_binfmt(void)
2206 {
2207         register_binfmt(&elf_format);
2208         return 0;
2209 }
2210
2211 static void __exit exit_elf_binfmt(void)
2212 {
2213         /* Remove the COFF and ELF loaders. */
2214         unregister_binfmt(&elf_format);
2215 }
2216
2217 core_initcall(init_elf_binfmt);
2218 module_exit(exit_elf_binfmt);
2219 MODULE_LICENSE("GPL");