fs/binfmt

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
set_brk
padzero
create_elf_tables
elf_map
total_mapping_size
load_elf_phdrs
arch_elf_pt_proc
arch_check_elf
make_prot
load_elf_interp
load_elf_binary
load_elf_library
always_dump_vma
vma_dump_size
notesize
writenote
fill_elf_header
fill_elf_note_phdr
fill_note
fill_prstatus
fill_psinfo
fill_auxv_note
fill_siginfo_note
fill_files_note
do_thread_regset_writeback
fill_thread_core_info
fill_note_info
get_note_info_size
write_note_info
free_note_info
elf_dump_thread_status
elf_note_info_init
fill_note_info
get_note_info_size
write_note_info
free_note_info
first_vma
next_vma
fill_extnum_info
elf_core_dump
init_elf_binfmt
exit_elf_binfmt
   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/mm.h>
  17 #include <linux/mman.h>
  18 #include <linux/errno.h>
  19 #include <linux/signal.h>
  20 #include <linux/binfmts.h>
  21 #include <linux/string.h>
  22 #include <linux/file.h>
  23 #include <linux/slab.h>
  24 #include <linux/personality.h>
  25 #include <linux/elfcore.h>
  26 #include <linux/init.h>
  27 #include <linux/highuid.h>
  28 #include <linux/compiler.h>
  29 #include <linux/highmem.h>
  30 #include <linux/pagemap.h>
  31 #include <linux/vmalloc.h>
  32 #include <linux/security.h>
  33 #include <linux/random.h>
  34 #include <linux/elf.h>
  35 #include <linux/elf-randomize.h>
  36 #include <linux/utsname.h>
  37 #include <linux/coredump.h>
  38 #include <linux/sched.h>
  39 #include <linux/sched/coredump.h>
  40 #include <linux/sched/task_stack.h>
  41 #include <linux/sched/cputime.h>
  42 #include <linux/cred.h>
  43 #include <linux/dax.h>
  44 #include <linux/uaccess.h>
  45 #include <asm/param.h>
  46 #include <asm/page.h>
  47 
  48 #ifndef user_long_t
  49 #define user_long_t long
  50 #endif
  51 #ifndef user_siginfo_t
  52 #define user_siginfo_t siginfo_t
  53 #endif
  54 
  55 /* That's for binfmt_elf_fdpic to deal with */
  56 #ifndef elf_check_fdpic
  57 #define elf_check_fdpic(ex) false
  58 #endif
  59 
  60 static int load_elf_binary(struct linux_binprm *bprm);
  61 
  62 #ifdef CONFIG_USELIB
  63 static int load_elf_library(struct file *);
  64 #else
  65 #define load_elf_library NULL
  66 #endif
  67 
  68 /*
  69  * If we don't support core dumping, then supply a NULL so we
  70  * don't even try.
  71  */
  72 #ifdef CONFIG_ELF_CORE
  73 static int elf_core_dump(struct coredump_params *cprm);
  74 #else
  75 #define elf_core_dump   NULL
  76 #endif
  77 
  78 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
  79 #define ELF_MIN_ALIGN   ELF_EXEC_PAGESIZE
  80 #else
  81 #define ELF_MIN_ALIGN   PAGE_SIZE
  82 #endif
  83 
  84 #ifndef ELF_CORE_EFLAGS
  85 #define ELF_CORE_EFLAGS 0
  86 #endif
  87 
  88 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
  89 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
  90 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
  91 
  92 static struct linux_binfmt elf_format = {
  93         .module         = THIS_MODULE,
  94         .load_binary    = load_elf_binary,
  95         .load_shlib     = load_elf_library,
  96         .core_dump      = elf_core_dump,
  97         .min_coredump   = ELF_EXEC_PAGESIZE,
  98 };
  99 
 100 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
 101 
 102 static int set_brk(unsigned long start, unsigned long end, int prot)
 103 {
 104         start = ELF_PAGEALIGN(start);
 105         end = ELF_PAGEALIGN(end);
 106         if (end > start) {
 107                 /*
 108                  * Map the last of the bss segment.
 109                  * If the header is requesting these pages to be
 110                  * executable, honour that (ppc32 needs this).
 111                  */
 112                 int error = vm_brk_flags(start, end - start,
 113                                 prot & PROT_EXEC ? VM_EXEC : 0);
 114                 if (error)
 115                         return error;
 116         }
 117         current->mm->start_brk = current->mm->brk = end;
 118         return 0;
 119 }
 120 
 121 /* We need to explicitly zero any fractional pages
 122    after the data section (i.e. bss).  This would
 123    contain the junk from the file that should not
 124    be in memory
 125  */
 126 static int padzero(unsigned long elf_bss)
 127 {
 128         unsigned long nbyte;
 129 
 130         nbyte = ELF_PAGEOFFSET(elf_bss);
 131         if (nbyte) {
 132                 nbyte = ELF_MIN_ALIGN - nbyte;
 133                 if (clear_user((void __user *) elf_bss, nbyte))
 134                         return -EFAULT;
 135         }
 136         return 0;
 137 }
 138 
 139 /* Let's use some macros to make this stack manipulation a little clearer */
 140 #ifdef CONFIG_STACK_GROWSUP
 141 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
 142 #define STACK_ROUND(sp, items) \
 143         ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
 144 #define STACK_ALLOC(sp, len) ({ \
 145         elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
 146         old_sp; })
 147 #else
 148 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
 149 #define STACK_ROUND(sp, items) \
 150         (((unsigned long) (sp - items)) &~ 15UL)
 151 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
 152 #endif
 153 
 154 #ifndef ELF_BASE_PLATFORM
 155 /*
 156  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 157  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 158  * will be copied to the user stack in the same manner as AT_PLATFORM.
 159  */
 160 #define ELF_BASE_PLATFORM NULL
 161 #endif
 162 
 163 static int
 164 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
 165                 unsigned long load_addr, unsigned long interp_load_addr)
 166 {
 167         unsigned long p = bprm->p;
 168         int argc = bprm->argc;
 169         int envc = bprm->envc;
 170         elf_addr_t __user *sp;
 171         elf_addr_t __user *u_platform;
 172         elf_addr_t __user *u_base_platform;
 173         elf_addr_t __user *u_rand_bytes;
 174         const char *k_platform = ELF_PLATFORM;
 175         const char *k_base_platform = ELF_BASE_PLATFORM;
 176         unsigned char k_rand_bytes[16];
 177         int items;
 178         elf_addr_t *elf_info;
 179         int ei_index = 0;
 180         const struct cred *cred = current_cred();
 181         struct vm_area_struct *vma;
 182 
 183         /*
 184          * In some cases (e.g. Hyper-Threading), we want to avoid L1
 185          * evictions by the processes running on the same package. One
 186          * thing we can do is to shuffle the initial stack for them.
 187          */
 188 
 189         p = arch_align_stack(p);
 190 
 191         /*
 192          * If this architecture has a platform capability string, copy it
 193          * to userspace.  In some cases (Sparc), this info is impossible
 194          * for userspace to get any other way, in others (i386) it is
 195          * merely difficult.
 196          */
 197         u_platform = NULL;
 198         if (k_platform) {
 199                 size_t len = strlen(k_platform) + 1;
 200 
 201                 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
 202                 if (__copy_to_user(u_platform, k_platform, len))
 203                         return -EFAULT;
 204         }
 205 
 206         /*
 207          * If this architecture has a "base" platform capability
 208          * string, copy it to userspace.
 209          */
 210         u_base_platform = NULL;
 211         if (k_base_platform) {
 212                 size_t len = strlen(k_base_platform) + 1;
 213 
 214                 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
 215                 if (__copy_to_user(u_base_platform, k_base_platform, len))
 216                         return -EFAULT;
 217         }
 218 
 219         /*
 220          * Generate 16 random bytes for userspace PRNG seeding.
 221          */
 222         get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
 223         u_rand_bytes = (elf_addr_t __user *)
 224                        STACK_ALLOC(p, sizeof(k_rand_bytes));
 225         if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
 226                 return -EFAULT;
 227 
 228         /* Create the ELF interpreter info */
 229         elf_info = (elf_addr_t *)current->mm->saved_auxv;
 230         /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
 231 #define NEW_AUX_ENT(id, val) \
 232         do { \
 233                 elf_info[ei_index++] = id; \
 234                 elf_info[ei_index++] = val; \
 235         } while (0)
 236 
 237 #ifdef ARCH_DLINFO
 238         /* 
 239          * ARCH_DLINFO must come first so PPC can do its special alignment of
 240          * AUXV.
 241          * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
 242          * ARCH_DLINFO changes
 243          */
 244         ARCH_DLINFO;
 245 #endif
 246         NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
 247         NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
 248         NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
 249         NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
 250         NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
 251         NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
 252         NEW_AUX_ENT(AT_BASE, interp_load_addr);
 253         NEW_AUX_ENT(AT_FLAGS, 0);
 254         NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
 255         NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
 256         NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
 257         NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
 258         NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
 259         NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
 260         NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
 261 #ifdef ELF_HWCAP2
 262         NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
 263 #endif
 264         NEW_AUX_ENT(AT_EXECFN, bprm->exec);
 265         if (k_platform) {
 266                 NEW_AUX_ENT(AT_PLATFORM,
 267                             (elf_addr_t)(unsigned long)u_platform);
 268         }
 269         if (k_base_platform) {
 270                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 271                             (elf_addr_t)(unsigned long)u_base_platform);
 272         }
 273         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 274                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 275         }
 276 #undef NEW_AUX_ENT
 277         /* AT_NULL is zero; clear the rest too */
 278         memset(&elf_info[ei_index], 0,
 279                sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
 280 
 281         /* And advance past the AT_NULL entry.  */
 282         ei_index += 2;
 283 
 284         sp = STACK_ADD(p, ei_index);
 285 
 286         items = (argc + 1) + (envc + 1) + 1;
 287         bprm->p = STACK_ROUND(sp, items);
 288 
 289         /* Point sp at the lowest address on the stack */
 290 #ifdef CONFIG_STACK_GROWSUP
 291         sp = (elf_addr_t __user *)bprm->p - items - ei_index;
 292         bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
 293 #else
 294         sp = (elf_addr_t __user *)bprm->p;
 295 #endif
 296 
 297 
 298         /*
 299          * Grow the stack manually; some architectures have a limit on how
 300          * far ahead a user-space access may be in order to grow the stack.
 301          */
 302         vma = find_extend_vma(current->mm, bprm->p);
 303         if (!vma)
 304                 return -EFAULT;
 305 
 306         /* Now, let's put argc (and argv, envp if appropriate) on the stack */
 307         if (__put_user(argc, sp++))
 308                 return -EFAULT;
 309 
 310         /* Populate list of argv pointers back to argv strings. */
 311         p = current->mm->arg_end = current->mm->arg_start;
 312         while (argc-- > 0) {
 313                 size_t len;
 314                 if (__put_user((elf_addr_t)p, sp++))
 315                         return -EFAULT;
 316                 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
 317                 if (!len || len > MAX_ARG_STRLEN)
 318                         return -EINVAL;
 319                 p += len;
 320         }
 321         if (__put_user(0, sp++))
 322                 return -EFAULT;
 323         current->mm->arg_end = p;
 324 
 325         /* Populate list of envp pointers back to envp strings. */
 326         current->mm->env_end = current->mm->env_start = p;
 327         while (envc-- > 0) {
 328                 size_t len;
 329                 if (__put_user((elf_addr_t)p, sp++))
 330                         return -EFAULT;
 331                 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
 332                 if (!len || len > MAX_ARG_STRLEN)
 333                         return -EINVAL;
 334                 p += len;
 335         }
 336         if (__put_user(0, sp++))
 337                 return -EFAULT;
 338         current->mm->env_end = p;
 339 
 340         /* Put the elf_info on the stack in the right place.  */
 341         if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
 342                 return -EFAULT;
 343         return 0;
 344 }
 345 
 346 #ifndef elf_map
 347 
 348 static unsigned long elf_map(struct file *filep, unsigned long addr,
 349                 const struct elf_phdr *eppnt, int prot, int type,
 350                 unsigned long total_size)
 351 {
 352         unsigned long map_addr;
 353         unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
 354         unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
 355         addr = ELF_PAGESTART(addr);
 356         size = ELF_PAGEALIGN(size);
 357 
 358         /* mmap() will return -EINVAL if given a zero size, but a
 359          * segment with zero filesize is perfectly valid */
 360         if (!size)
 361                 return addr;
 362 
 363         /*
 364         * total_size is the size of the ELF (interpreter) image.
 365         * The _first_ mmap needs to know the full size, otherwise
 366         * randomization might put this image into an overlapping
 367         * position with the ELF binary image. (since size < total_size)
 368         * So we first map the 'big' image - and unmap the remainder at
 369         * the end. (which unmap is needed for ELF images with holes.)
 370         */
 371         if (total_size) {
 372                 total_size = ELF_PAGEALIGN(total_size);
 373                 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
 374                 if (!BAD_ADDR(map_addr))
 375                         vm_munmap(map_addr+size, total_size-size);
 376         } else
 377                 map_addr = vm_mmap(filep, addr, size, prot, type, off);
 378 
 379         if ((type & MAP_FIXED_NOREPLACE) &&
 380             PTR_ERR((void *)map_addr) == -EEXIST)
 381                 pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
 382                         task_pid_nr(current), current->comm, (void *)addr);
 383 
 384         return(map_addr);
 385 }
 386 
 387 #endif /* !elf_map */
 388 
 389 static unsigned long total_mapping_size(const struct elf_phdr *cmds, int nr)
 390 {
 391         int i, first_idx = -1, last_idx = -1;
 392 
 393         for (i = 0; i < nr; i++) {
 394                 if (cmds[i].p_type == PT_LOAD) {
 395                         last_idx = i;
 396                         if (first_idx == -1)
 397                                 first_idx = i;
 398                 }
 399         }
 400         if (first_idx == -1)
 401                 return 0;
 402 
 403         return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
 404                                 ELF_PAGESTART(cmds[first_idx].p_vaddr);
 405 }
 406 
 407 /**
 408  * load_elf_phdrs() - load ELF program headers
 409  * @elf_ex:   ELF header of the binary whose program headers should be loaded
 410  * @elf_file: the opened ELF binary file
 411  *
 412  * Loads ELF program headers from the binary file elf_file, which has the ELF
 413  * header pointed to by elf_ex, into a newly allocated array. The caller is
 414  * responsible for freeing the allocated data. Returns an ERR_PTR upon failure.
 415  */
 416 static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex,
 417                                        struct file *elf_file)
 418 {
 419         struct elf_phdr *elf_phdata = NULL;
 420         int retval, err = -1;
 421         loff_t pos = elf_ex->e_phoff;
 422         unsigned int size;
 423 
 424         /*
 425          * If the size of this structure has changed, then punt, since
 426          * we will be doing the wrong thing.
 427          */
 428         if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
 429                 goto out;
 430 
 431         /* Sanity check the number of program headers... */
 432         /* ...and their total size. */
 433         size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
 434         if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
 435                 goto out;
 436 
 437         elf_phdata = kmalloc(size, GFP_KERNEL);
 438         if (!elf_phdata)
 439                 goto out;
 440 
 441         /* Read in the program headers */
 442         retval = kernel_read(elf_file, elf_phdata, size, &pos);
 443         if (retval != size) {
 444                 err = (retval < 0) ? retval : -EIO;
 445                 goto out;
 446         }
 447 
 448         /* Success! */
 449         err = 0;
 450 out:
 451         if (err) {
 452                 kfree(elf_phdata);
 453                 elf_phdata = NULL;
 454         }
 455         return elf_phdata;
 456 }
 457 
 458 #ifndef CONFIG_ARCH_BINFMT_ELF_STATE
 459 
 460 /**
 461  * struct arch_elf_state - arch-specific ELF loading state
 462  *
 463  * This structure is used to preserve architecture specific data during
 464  * the loading of an ELF file, throughout the checking of architecture
 465  * specific ELF headers & through to the point where the ELF load is
 466  * known to be proceeding (ie. SET_PERSONALITY).
 467  *
 468  * This implementation is a dummy for architectures which require no
 469  * specific state.
 470  */
 471 struct arch_elf_state {
 472 };
 473 
 474 #define INIT_ARCH_ELF_STATE {}
 475 
 476 /**
 477  * arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header
 478  * @ehdr:       The main ELF header
 479  * @phdr:       The program header to check
 480  * @elf:        The open ELF file
 481  * @is_interp:  True if the phdr is from the interpreter of the ELF being
 482  *              loaded, else false.
 483  * @state:      Architecture-specific state preserved throughout the process
 484  *              of loading the ELF.
 485  *
 486  * Inspects the program header phdr to validate its correctness and/or
 487  * suitability for the system. Called once per ELF program header in the
 488  * range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its
 489  * interpreter.
 490  *
 491  * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
 492  *         with that return code.
 493  */
 494 static inline int arch_elf_pt_proc(struct elfhdr *ehdr,
 495                                    struct elf_phdr *phdr,
 496                                    struct file *elf, bool is_interp,
 497                                    struct arch_elf_state *state)
 498 {
 499         /* Dummy implementation, always proceed */
 500         return 0;
 501 }
 502 
 503 /**
 504  * arch_check_elf() - check an ELF executable
 505  * @ehdr:       The main ELF header
 506  * @has_interp: True if the ELF has an interpreter, else false.
 507  * @interp_ehdr: The interpreter's ELF header
 508  * @state:      Architecture-specific state preserved throughout the process
 509  *              of loading the ELF.
 510  *
 511  * Provides a final opportunity for architecture code to reject the loading
 512  * of the ELF & cause an exec syscall to return an error. This is called after
 513  * all program headers to be checked by arch_elf_pt_proc have been.
 514  *
 515  * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
 516  *         with that return code.
 517  */
 518 static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp,
 519                                  struct elfhdr *interp_ehdr,
 520                                  struct arch_elf_state *state)
 521 {
 522         /* Dummy implementation, always proceed */
 523         return 0;
 524 }
 525 
 526 #endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
 527 
 528 static inline int make_prot(u32 p_flags)
 529 {
 530         int prot = 0;
 531 
 532         if (p_flags & PF_R)
 533                 prot |= PROT_READ;
 534         if (p_flags & PF_W)
 535                 prot |= PROT_WRITE;
 536         if (p_flags & PF_X)
 537                 prot |= PROT_EXEC;
 538         return prot;
 539 }
 540 
 541 /* This is much more generalized than the library routine read function,
 542    so we keep this separate.  Technically the library read function
 543    is only provided so that we can read a.out libraries that have
 544    an ELF header */
 545 
 546 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
 547                 struct file *interpreter, unsigned long *interp_map_addr,
 548                 unsigned long no_base, struct elf_phdr *interp_elf_phdata)
 549 {
 550         struct elf_phdr *eppnt;
 551         unsigned long load_addr = 0;
 552         int load_addr_set = 0;
 553         unsigned long last_bss = 0, elf_bss = 0;
 554         int bss_prot = 0;
 555         unsigned long error = ~0UL;
 556         unsigned long total_size;
 557         int i;
 558 
 559         /* First of all, some simple consistency checks */
 560         if (interp_elf_ex->e_type != ET_EXEC &&
 561             interp_elf_ex->e_type != ET_DYN)
 562                 goto out;
 563         if (!elf_check_arch(interp_elf_ex) ||
 564             elf_check_fdpic(interp_elf_ex))
 565                 goto out;
 566         if (!interpreter->f_op->mmap)
 567                 goto out;
 568 
 569         total_size = total_mapping_size(interp_elf_phdata,
 570                                         interp_elf_ex->e_phnum);
 571         if (!total_size) {
 572                 error = -EINVAL;
 573                 goto out;
 574         }
 575 
 576         eppnt = interp_elf_phdata;
 577         for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
 578                 if (eppnt->p_type == PT_LOAD) {
 579                         int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
 580                         int elf_prot = make_prot(eppnt->p_flags);
 581                         unsigned long vaddr = 0;
 582                         unsigned long k, map_addr;
 583 
 584                         vaddr = eppnt->p_vaddr;
 585                         if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
 586                                 elf_type |= MAP_FIXED_NOREPLACE;
 587                         else if (no_base && interp_elf_ex->e_type == ET_DYN)
 588                                 load_addr = -vaddr;
 589 
 590                         map_addr = elf_map(interpreter, load_addr + vaddr,
 591                                         eppnt, elf_prot, elf_type, total_size);
 592                         total_size = 0;
 593                         if (!*interp_map_addr)
 594                                 *interp_map_addr = map_addr;
 595                         error = map_addr;
 596                         if (BAD_ADDR(map_addr))
 597                                 goto out;
 598 
 599                         if (!load_addr_set &&
 600                             interp_elf_ex->e_type == ET_DYN) {
 601                                 load_addr = map_addr - ELF_PAGESTART(vaddr);
 602                                 load_addr_set = 1;
 603                         }
 604 
 605                         /*
 606                          * Check to see if the section's size will overflow the
 607                          * allowed task size. Note that p_filesz must always be
 608                          * <= p_memsize so it's only necessary to check p_memsz.
 609                          */
 610                         k = load_addr + eppnt->p_vaddr;
 611                         if (BAD_ADDR(k) ||
 612                             eppnt->p_filesz > eppnt->p_memsz ||
 613                             eppnt->p_memsz > TASK_SIZE ||
 614                             TASK_SIZE - eppnt->p_memsz < k) {
 615                                 error = -ENOMEM;
 616                                 goto out;
 617                         }
 618 
 619                         /*
 620                          * Find the end of the file mapping for this phdr, and
 621                          * keep track of the largest address we see for this.
 622                          */
 623                         k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
 624                         if (k > elf_bss)
 625                                 elf_bss = k;
 626 
 627                         /*
 628                          * Do the same thing for the memory mapping - between
 629                          * elf_bss and last_bss is the bss section.
 630                          */
 631                         k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
 632                         if (k > last_bss) {
 633                                 last_bss = k;
 634                                 bss_prot = elf_prot;
 635                         }
 636                 }
 637         }
 638 
 639         /*
 640          * Now fill out the bss section: first pad the last page from
 641          * the file up to the page boundary, and zero it from elf_bss
 642          * up to the end of the page.
 643          */
 644         if (padzero(elf_bss)) {
 645                 error = -EFAULT;
 646                 goto out;
 647         }
 648         /*
 649          * Next, align both the file and mem bss up to the page size,
 650          * since this is where elf_bss was just zeroed up to, and where
 651          * last_bss will end after the vm_brk_flags() below.
 652          */
 653         elf_bss = ELF_PAGEALIGN(elf_bss);
 654         last_bss = ELF_PAGEALIGN(last_bss);
 655         /* Finally, if there is still more bss to allocate, do it. */
 656         if (last_bss > elf_bss) {
 657                 error = vm_brk_flags(elf_bss, last_bss - elf_bss,
 658                                 bss_prot & PROT_EXEC ? VM_EXEC : 0);
 659                 if (error)
 660                         goto out;
 661         }
 662 
 663         error = load_addr;
 664 out:
 665         return error;
 666 }
 667 
 668 /*
 669  * These are the functions used to load ELF style executables and shared
 670  * libraries.  There is no binary dependent code anywhere else.
 671  */
 672 
 673 static int load_elf_binary(struct linux_binprm *bprm)
 674 {
 675         struct file *interpreter = NULL; /* to shut gcc up */
 676         unsigned long load_addr = 0, load_bias = 0;
 677         int load_addr_set = 0;
 678         unsigned long error;
 679         struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
 680         unsigned long elf_bss, elf_brk;
 681         int bss_prot = 0;
 682         int retval, i;
 683         unsigned long elf_entry;
 684         unsigned long interp_load_addr = 0;
 685         unsigned long start_code, end_code, start_data, end_data;
 686         unsigned long reloc_func_desc __maybe_unused = 0;
 687         int executable_stack = EXSTACK_DEFAULT;
 688         struct {
 689                 struct elfhdr elf_ex;
 690                 struct elfhdr interp_elf_ex;
 691         } *loc;
 692         struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
 693         struct pt_regs *regs;
 694 
 695         loc = kmalloc(sizeof(*loc), GFP_KERNEL);
 696         if (!loc) {
 697                 retval = -ENOMEM;
 698                 goto out_ret;
 699         }
 700         
 701         /* Get the exec-header */
 702         loc->elf_ex = *((struct elfhdr *)bprm->buf);
 703 
 704         retval = -ENOEXEC;
 705         /* First of all, some simple consistency checks */
 706         if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
 707                 goto out;
 708 
 709         if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
 710                 goto out;
 711         if (!elf_check_arch(&loc->elf_ex))
 712                 goto out;
 713         if (elf_check_fdpic(&loc->elf_ex))
 714                 goto out;
 715         if (!bprm->file->f_op->mmap)
 716                 goto out;
 717 
 718         elf_phdata = load_elf_phdrs(&loc->elf_ex, bprm->file);
 719         if (!elf_phdata)
 720                 goto out;
 721 
 722         elf_ppnt = elf_phdata;
 723         for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
 724                 char *elf_interpreter;
 725                 loff_t pos;
 726 
 727                 if (elf_ppnt->p_type != PT_INTERP)
 728                         continue;
 729 
 730                 /*
 731                  * This is the program interpreter used for shared libraries -
 732                  * for now assume that this is an a.out format binary.
 733                  */
 734                 retval = -ENOEXEC;
 735                 if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2)
 736                         goto out_free_ph;
 737 
 738                 retval = -ENOMEM;
 739                 elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL);
 740                 if (!elf_interpreter)
 741                         goto out_free_ph;
 742 
 743                 pos = elf_ppnt->p_offset;
 744                 retval = kernel_read(bprm->file, elf_interpreter,
 745                                      elf_ppnt->p_filesz, &pos);
 746                 if (retval != elf_ppnt->p_filesz) {
 747                         if (retval >= 0)
 748                                 retval = -EIO;
 749                         goto out_free_interp;
 750                 }
 751                 /* make sure path is NULL terminated */
 752                 retval = -ENOEXEC;
 753                 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
 754                         goto out_free_interp;
 755 
 756                 interpreter = open_exec(elf_interpreter);
 757                 kfree(elf_interpreter);
 758                 retval = PTR_ERR(interpreter);
 759                 if (IS_ERR(interpreter))
 760                         goto out_free_ph;
 761 
 762                 /*
 763                  * If the binary is not readable then enforce mm->dumpable = 0
 764                  * regardless of the interpreter's permissions.
 765                  */
 766                 would_dump(bprm, interpreter);
 767 
 768                 /* Get the exec headers */
 769                 pos = 0;
 770                 retval = kernel_read(interpreter, &loc->interp_elf_ex,
 771                                      sizeof(loc->interp_elf_ex), &pos);
 772                 if (retval != sizeof(loc->interp_elf_ex)) {
 773                         if (retval >= 0)
 774                                 retval = -EIO;
 775                         goto out_free_dentry;
 776                 }
 777 
 778                 break;
 779 
 780 out_free_interp:
 781                 kfree(elf_interpreter);
 782                 goto out_free_ph;
 783         }
 784 
 785         elf_ppnt = elf_phdata;
 786         for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
 787                 switch (elf_ppnt->p_type) {
 788                 case PT_GNU_STACK:
 789                         if (elf_ppnt->p_flags & PF_X)
 790                                 executable_stack = EXSTACK_ENABLE_X;
 791                         else
 792                                 executable_stack = EXSTACK_DISABLE_X;
 793                         break;
 794 
 795                 case PT_LOPROC ... PT_HIPROC:
 796                         retval = arch_elf_pt_proc(&loc->elf_ex, elf_ppnt,
 797                                                   bprm->file, false,
 798                                                   &arch_state);
 799                         if (retval)
 800                                 goto out_free_dentry;
 801                         break;
 802                 }
 803 
 804         /* Some simple consistency checks for the interpreter */
 805         if (interpreter) {
 806                 retval = -ELIBBAD;
 807                 /* Not an ELF interpreter */
 808                 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
 809                         goto out_free_dentry;
 810                 /* Verify the interpreter has a valid arch */
 811                 if (!elf_check_arch(&loc->interp_elf_ex) ||
 812                     elf_check_fdpic(&loc->interp_elf_ex))
 813                         goto out_free_dentry;
 814 
 815                 /* Load the interpreter program headers */
 816                 interp_elf_phdata = load_elf_phdrs(&loc->interp_elf_ex,
 817                                                    interpreter);
 818                 if (!interp_elf_phdata)
 819                         goto out_free_dentry;
 820 
 821                 /* Pass PT_LOPROC..PT_HIPROC headers to arch code */
 822                 elf_ppnt = interp_elf_phdata;
 823                 for (i = 0; i < loc->interp_elf_ex.e_phnum; i++, elf_ppnt++)
 824                         switch (elf_ppnt->p_type) {
 825                         case PT_LOPROC ... PT_HIPROC:
 826                                 retval = arch_elf_pt_proc(&loc->interp_elf_ex,
 827                                                           elf_ppnt, interpreter,
 828                                                           true, &arch_state);
 829                                 if (retval)
 830                                         goto out_free_dentry;
 831                                 break;
 832                         }
 833         }
 834 
 835         /*
 836          * Allow arch code to reject the ELF at this point, whilst it's
 837          * still possible to return an error to the code that invoked
 838          * the exec syscall.
 839          */
 840         retval = arch_check_elf(&loc->elf_ex,
 841                                 !!interpreter, &loc->interp_elf_ex,
 842                                 &arch_state);
 843         if (retval)
 844                 goto out_free_dentry;
 845 
 846         /* Flush all traces of the currently running executable */
 847         retval = flush_old_exec(bprm);
 848         if (retval)
 849                 goto out_free_dentry;
 850 
 851         /* Do this immediately, since STACK_TOP as used in setup_arg_pages
 852            may depend on the personality.  */
 853         SET_PERSONALITY2(loc->elf_ex, &arch_state);
 854         if (elf_read_implies_exec(loc->elf_ex, executable_stack))
 855                 current->personality |= READ_IMPLIES_EXEC;
 856 
 857         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
 858                 current->flags |= PF_RANDOMIZE;
 859 
 860         setup_new_exec(bprm);
 861         install_exec_creds(bprm);
 862 
 863         /* Do this so that we can load the interpreter, if need be.  We will
 864            change some of these later */
 865         retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
 866                                  executable_stack);
 867         if (retval < 0)
 868                 goto out_free_dentry;
 869         
 870         elf_bss = 0;
 871         elf_brk = 0;
 872 
 873         start_code = ~0UL;
 874         end_code = 0;
 875         start_data = 0;
 876         end_data = 0;
 877 
 878         /* Now we do a little grungy work by mmapping the ELF image into
 879            the correct location in memory. */
 880         for(i = 0, elf_ppnt = elf_phdata;
 881             i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
 882                 int elf_prot, elf_flags;
 883                 unsigned long k, vaddr;
 884                 unsigned long total_size = 0;
 885 
 886                 if (elf_ppnt->p_type != PT_LOAD)
 887                         continue;
 888 
 889                 if (unlikely (elf_brk > elf_bss)) {
 890                         unsigned long nbyte;
 891                     
 892                         /* There was a PT_LOAD segment with p_memsz > p_filesz
 893                            before this one. Map anonymous pages, if needed,
 894                            and clear the area.  */
 895                         retval = set_brk(elf_bss + load_bias,
 896                                          elf_brk + load_bias,
 897                                          bss_prot);
 898                         if (retval)
 899                                 goto out_free_dentry;
 900                         nbyte = ELF_PAGEOFFSET(elf_bss);
 901                         if (nbyte) {
 902                                 nbyte = ELF_MIN_ALIGN - nbyte;
 903                                 if (nbyte > elf_brk - elf_bss)
 904                                         nbyte = elf_brk - elf_bss;
 905                                 if (clear_user((void __user *)elf_bss +
 906                                                         load_bias, nbyte)) {
 907                                         /*
 908                                          * This bss-zeroing can fail if the ELF
 909                                          * file specifies odd protections. So
 910                                          * we don't check the return value
 911                                          */
 912                                 }
 913                         }
 914                 }
 915 
 916                 elf_prot = make_prot(elf_ppnt->p_flags);
 917 
 918                 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
 919 
 920                 vaddr = elf_ppnt->p_vaddr;
 921                 /*
 922                  * If we are loading ET_EXEC or we have already performed
 923                  * the ET_DYN load_addr calculations, proceed normally.
 924                  */
 925                 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
 926                         elf_flags |= MAP_FIXED;
 927                 } else if (loc->elf_ex.e_type == ET_DYN) {
 928                         /*
 929                          * This logic is run once for the first LOAD Program
 930                          * Header for ET_DYN binaries to calculate the
 931                          * randomization (load_bias) for all the LOAD
 932                          * Program Headers, and to calculate the entire
 933                          * size of the ELF mapping (total_size). (Note that
 934                          * load_addr_set is set to true later once the
 935                          * initial mapping is performed.)
 936                          *
 937                          * There are effectively two types of ET_DYN
 938                          * binaries: programs (i.e. PIE: ET_DYN with INTERP)
 939                          * and loaders (ET_DYN without INTERP, since they
 940                          * _are_ the ELF interpreter). The loaders must
 941                          * be loaded away from programs since the program
 942                          * may otherwise collide with the loader (especially
 943                          * for ET_EXEC which does not have a randomized
 944                          * position). For example to handle invocations of
 945                          * "./ld.so someprog" to test out a new version of
 946                          * the loader, the subsequent program that the
 947                          * loader loads must avoid the loader itself, so
 948                          * they cannot share the same load range. Sufficient
 949                          * room for the brk must be allocated with the
 950                          * loader as well, since brk must be available with
 951                          * the loader.
 952                          *
 953                          * Therefore, programs are loaded offset from
 954                          * ELF_ET_DYN_BASE and loaders are loaded into the
 955                          * independently randomized mmap region (0 load_bias
 956                          * without MAP_FIXED).
 957                          */
 958                         if (interpreter) {
 959                                 load_bias = ELF_ET_DYN_BASE;
 960                                 if (current->flags & PF_RANDOMIZE)
 961                                         load_bias += arch_mmap_rnd();
 962                                 elf_flags |= MAP_FIXED;
 963                         } else
 964                                 load_bias = 0;
 965 
 966                         /*
 967                          * Since load_bias is used for all subsequent loading
 968                          * calculations, we must lower it by the first vaddr
 969                          * so that the remaining calculations based on the
 970                          * ELF vaddrs will be correctly offset. The result
 971                          * is then page aligned.
 972                          */
 973                         load_bias = ELF_PAGESTART(load_bias - vaddr);
 974 
 975                         total_size = total_mapping_size(elf_phdata,
 976                                                         loc->elf_ex.e_phnum);
 977                         if (!total_size) {
 978                                 retval = -EINVAL;
 979                                 goto out_free_dentry;
 980                         }
 981                 }
 982 
 983                 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
 984                                 elf_prot, elf_flags, total_size);
 985                 if (BAD_ADDR(error)) {
 986                         retval = IS_ERR((void *)error) ?
 987                                 PTR_ERR((void*)error) : -EINVAL;
 988                         goto out_free_dentry;
 989                 }
 990 
 991                 if (!load_addr_set) {
 992                         load_addr_set = 1;
 993                         load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
 994                         if (loc->elf_ex.e_type == ET_DYN) {
 995                                 load_bias += error -
 996                                              ELF_PAGESTART(load_bias + vaddr);
 997                                 load_addr += load_bias;
 998                                 reloc_func_desc = load_bias;
 999                         }
1000                 }
1001                 k = elf_ppnt->p_vaddr;
1002                 if (k < start_code)
1003                         start_code = k;
1004                 if (start_data < k)
1005                         start_data = k;
1006 
1007                 /*
1008                  * Check to see if the section's size will overflow the
1009                  * allowed task size. Note that p_filesz must always be
1010                  * <= p_memsz so it is only necessary to check p_memsz.
1011                  */
1012                 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
1013                     elf_ppnt->p_memsz > TASK_SIZE ||
1014                     TASK_SIZE - elf_ppnt->p_memsz < k) {
1015                         /* set_brk can never work. Avoid overflows. */
1016                         retval = -EINVAL;
1017                         goto out_free_dentry;
1018                 }
1019 
1020                 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
1021 
1022                 if (k > elf_bss)
1023                         elf_bss = k;
1024                 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
1025                         end_code = k;
1026                 if (end_data < k)
1027                         end_data = k;
1028                 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
1029                 if (k > elf_brk) {
1030                         bss_prot = elf_prot;
1031                         elf_brk = k;
1032                 }
1033         }
1034 
1035         loc->elf_ex.e_entry += load_bias;
1036         elf_bss += load_bias;
1037         elf_brk += load_bias;
1038         start_code += load_bias;
1039         end_code += load_bias;
1040         start_data += load_bias;
1041         end_data += load_bias;
1042 
1043         /* Calling set_brk effectively mmaps the pages that we need
1044          * for the bss and break sections.  We must do this before
1045          * mapping in the interpreter, to make sure it doesn't wind
1046          * up getting placed where the bss needs to go.
1047          */
1048         retval = set_brk(elf_bss, elf_brk, bss_prot);
1049         if (retval)
1050                 goto out_free_dentry;
1051         if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
1052                 retval = -EFAULT; /* Nobody gets to see this, but.. */
1053                 goto out_free_dentry;
1054         }
1055 
1056         if (interpreter) {
1057                 unsigned long interp_map_addr = 0;
1058 
1059                 elf_entry = load_elf_interp(&loc->interp_elf_ex,
1060                                             interpreter,
1061                                             &interp_map_addr,
1062                                             load_bias, interp_elf_phdata);
1063                 if (!IS_ERR((void *)elf_entry)) {
1064                         /*
1065                          * load_elf_interp() returns relocation
1066                          * adjustment
1067                          */
1068                         interp_load_addr = elf_entry;
1069                         elf_entry += loc->interp_elf_ex.e_entry;
1070                 }
1071                 if (BAD_ADDR(elf_entry)) {
1072                         retval = IS_ERR((void *)elf_entry) ?
1073                                         (int)elf_entry : -EINVAL;
1074                         goto out_free_dentry;
1075                 }
1076                 reloc_func_desc = interp_load_addr;
1077 
1078                 allow_write_access(interpreter);
1079                 fput(interpreter);
1080         } else {
1081                 elf_entry = loc->elf_ex.e_entry;
1082                 if (BAD_ADDR(elf_entry)) {
1083                         retval = -EINVAL;
1084                         goto out_free_dentry;
1085                 }
1086         }
1087 
1088         kfree(interp_elf_phdata);
1089         kfree(elf_phdata);
1090 
1091         set_binfmt(&elf_format);
1092 
1093 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1094         retval = arch_setup_additional_pages(bprm, !!interpreter);
1095         if (retval < 0)
1096                 goto out;
1097 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1098 
1099         retval = create_elf_tables(bprm, &loc->elf_ex,
1100                           load_addr, interp_load_addr);
1101         if (retval < 0)
1102                 goto out;
1103         current->mm->end_code = end_code;
1104         current->mm->start_code = start_code;
1105         current->mm->start_data = start_data;
1106         current->mm->end_data = end_data;
1107         current->mm->start_stack = bprm->p;
1108 
1109         if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
1110                 /*
1111                  * For architectures with ELF randomization, when executing
1112                  * a loader directly (i.e. no interpreter listed in ELF
1113                  * headers), move the brk area out of the mmap region
1114                  * (since it grows up, and may collide early with the stack
1115                  * growing down), and into the unused ELF_ET_DYN_BASE region.
1116                  */
1117                 if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
1118                     loc->elf_ex.e_type == ET_DYN && !interpreter)
1119                         current->mm->brk = current->mm->start_brk =
1120                                 ELF_ET_DYN_BASE;
1121 
1122                 current->mm->brk = current->mm->start_brk =
1123                         arch_randomize_brk(current->mm);
1124 #ifdef compat_brk_randomized
1125                 current->brk_randomized = 1;
1126 #endif
1127         }
1128 
1129         if (current->personality & MMAP_PAGE_ZERO) {
1130                 /* Why this, you ask???  Well SVr4 maps page 0 as read-only,
1131                    and some applications "depend" upon this behavior.
1132                    Since we do not have the power to recompile these, we
1133                    emulate the SVr4 behavior. Sigh. */
1134                 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1135                                 MAP_FIXED | MAP_PRIVATE, 0);
1136         }
1137 
1138         regs = current_pt_regs();
1139 #ifdef ELF_PLAT_INIT
1140         /*
1141          * The ABI may specify that certain registers be set up in special
1142          * ways (on i386 %edx is the address of a DT_FINI function, for
1143          * example.  In addition, it may also specify (eg, PowerPC64 ELF)
1144          * that the e_entry field is the address of the function descriptor
1145          * for the startup routine, rather than the address of the startup
1146          * routine itself.  This macro performs whatever initialization to
1147          * the regs structure is required as well as any relocations to the
1148          * function descriptor entries when executing dynamically links apps.
1149          */
1150         ELF_PLAT_INIT(regs, reloc_func_desc);
1151 #endif
1152 
1153         finalize_exec(bprm);
1154         start_thread(regs, elf_entry, bprm->p);
1155         retval = 0;
1156 out:
1157         kfree(loc);
1158 out_ret:
1159         return retval;
1160 
1161         /* error cleanup */
1162 out_free_dentry:
1163         kfree(interp_elf_phdata);
1164         allow_write_access(interpreter);
1165         if (interpreter)
1166                 fput(interpreter);
1167 out_free_ph:
1168         kfree(elf_phdata);
1169         goto out;
1170 }
1171 
1172 #ifdef CONFIG_USELIB
1173 /* This is really simpleminded and specialized - we are loading an
1174    a.out library that is given an ELF header. */
1175 static int load_elf_library(struct file *file)
1176 {
1177         struct elf_phdr *elf_phdata;
1178         struct elf_phdr *eppnt;
1179         unsigned long elf_bss, bss, len;
1180         int retval, error, i, j;
1181         struct elfhdr elf_ex;
1182         loff_t pos = 0;
1183 
1184         error = -ENOEXEC;
1185         retval = kernel_read(file, &elf_ex, sizeof(elf_ex), &pos);
1186         if (retval != sizeof(elf_ex))
1187                 goto out;
1188 
1189         if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1190                 goto out;
1191 
1192         /* First of all, some simple consistency checks */
1193         if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1194             !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1195                 goto out;
1196         if (elf_check_fdpic(&elf_ex))
1197                 goto out;
1198 
1199         /* Now read in all of the header information */
1200 
1201         j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1202         /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1203 
1204         error = -ENOMEM;
1205         elf_phdata = kmalloc(j, GFP_KERNEL);
1206         if (!elf_phdata)
1207                 goto out;
1208 
1209         eppnt = elf_phdata;
1210         error = -ENOEXEC;
1211         pos =  elf_ex.e_phoff;
1212         retval = kernel_read(file, eppnt, j, &pos);
1213         if (retval != j)
1214                 goto out_free_ph;
1215 
1216         for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1217                 if ((eppnt + i)->p_type == PT_LOAD)
1218                         j++;
1219         if (j != 1)
1220                 goto out_free_ph;
1221 
1222         while (eppnt->p_type != PT_LOAD)
1223                 eppnt++;
1224 
1225         /* Now use mmap to map the library into memory. */
1226         error = vm_mmap(file,
1227                         ELF_PAGESTART(eppnt->p_vaddr),
1228                         (eppnt->p_filesz +
1229                          ELF_PAGEOFFSET(eppnt->p_vaddr)),
1230                         PROT_READ | PROT_WRITE | PROT_EXEC,
1231                         MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_DENYWRITE,
1232                         (eppnt->p_offset -
1233                          ELF_PAGEOFFSET(eppnt->p_vaddr)));
1234         if (error != ELF_PAGESTART(eppnt->p_vaddr))
1235                 goto out_free_ph;
1236 
1237         elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1238         if (padzero(elf_bss)) {
1239                 error = -EFAULT;
1240                 goto out_free_ph;
1241         }
1242 
1243         len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr);
1244         bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr);
1245         if (bss > len) {
1246                 error = vm_brk(len, bss - len);
1247                 if (error)
1248                         goto out_free_ph;
1249         }
1250         error = 0;
1251 
1252 out_free_ph:
1253         kfree(elf_phdata);
1254 out:
1255         return error;
1256 }
1257 #endif /* #ifdef CONFIG_USELIB */
1258 
1259 #ifdef CONFIG_ELF_CORE
1260 /*
1261  * ELF core dumper
1262  *
1263  * Modelled on fs/exec.c:aout_core_dump()
1264  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1265  */
1266 
1267 /*
1268  * The purpose of always_dump_vma() is to make sure that special kernel mappings
1269  * that are useful for post-mortem analysis are included in every core dump.
1270  * In that way we ensure that the core dump is fully interpretable later
1271  * without matching up the same kernel and hardware config to see what PC values
1272  * meant. These special mappings include - vDSO, vsyscall, and other
1273  * architecture specific mappings
1274  */
1275 static bool always_dump_vma(struct vm_area_struct *vma)
1276 {
1277         /* Any vsyscall mappings? */
1278         if (vma == get_gate_vma(vma->vm_mm))
1279                 return true;
1280 
1281         /*
1282          * Assume that all vmas with a .name op should always be dumped.
1283          * If this changes, a new vm_ops field can easily be added.
1284          */
1285         if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma))
1286                 return true;
1287 
1288         /*
1289          * arch_vma_name() returns non-NULL for special architecture mappings,
1290          * such as vDSO sections.
1291          */
1292         if (arch_vma_name(vma))
1293                 return true;
1294 
1295         return false;
1296 }
1297 
1298 /*
1299  * Decide what to dump of a segment, part, all or none.
1300  */
1301 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1302                                    unsigned long mm_flags)
1303 {
1304 #define FILTER(type)    (mm_flags & (1UL << MMF_DUMP_##type))
1305 
1306         /* always dump the vdso and vsyscall sections */
1307         if (always_dump_vma(vma))
1308                 goto whole;
1309 
1310         if (vma->vm_flags & VM_DONTDUMP)
1311                 return 0;
1312 
1313         /* support for DAX */
1314         if (vma_is_dax(vma)) {
1315                 if ((vma->vm_flags & VM_SHARED) && FILTER(DAX_SHARED))
1316                         goto whole;
1317                 if (!(vma->vm_flags & VM_SHARED) && FILTER(DAX_PRIVATE))
1318                         goto whole;
1319                 return 0;
1320         }
1321 
1322         /* Hugetlb memory check */
1323         if (vma->vm_flags & VM_HUGETLB) {
1324                 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1325                         goto whole;
1326                 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1327                         goto whole;
1328                 return 0;
1329         }
1330 
1331         /* Do not dump I/O mapped devices or special mappings */
1332         if (vma->vm_flags & VM_IO)
1333                 return 0;
1334 
1335         /* By default, dump shared memory if mapped from an anonymous file. */
1336         if (vma->vm_flags & VM_SHARED) {
1337                 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1338                     FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1339                         goto whole;
1340                 return 0;
1341         }
1342 
1343         /* Dump segments that have been written to.  */
1344         if (vma->anon_vma && FILTER(ANON_PRIVATE))
1345                 goto whole;
1346         if (vma->vm_file == NULL)
1347                 return 0;
1348 
1349         if (FILTER(MAPPED_PRIVATE))
1350                 goto whole;
1351 
1352         /*
1353          * If this looks like the beginning of a DSO or executable mapping,
1354          * check for an ELF header.  If we find one, dump the first page to
1355          * aid in determining what was mapped here.
1356          */
1357         if (FILTER(ELF_HEADERS) &&
1358             vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1359                 u32 __user *header = (u32 __user *) vma->vm_start;
1360                 u32 word;
1361                 mm_segment_t fs = get_fs();
1362                 /*
1363                  * Doing it this way gets the constant folded by GCC.
1364                  */
1365                 union {
1366                         u32 cmp;
1367                         char elfmag[SELFMAG];
1368                 } magic;
1369                 BUILD_BUG_ON(SELFMAG != sizeof word);
1370                 magic.elfmag[EI_MAG0] = ELFMAG0;
1371                 magic.elfmag[EI_MAG1] = ELFMAG1;
1372                 magic.elfmag[EI_MAG2] = ELFMAG2;
1373                 magic.elfmag[EI_MAG3] = ELFMAG3;
1374                 /*
1375                  * Switch to the user "segment" for get_user(),
1376                  * then put back what elf_core_dump() had in place.
1377                  */
1378                 set_fs(USER_DS);
1379                 if (unlikely(get_user(word, header)))
1380                         word = 0;
1381                 set_fs(fs);
1382                 if (word == magic.cmp)
1383                         return PAGE_SIZE;
1384         }
1385 
1386 #undef  FILTER
1387 
1388         return 0;
1389 
1390 whole:
1391         return vma->vm_end - vma->vm_start;
1392 }
1393 
1394 /* An ELF note in memory */
1395 struct memelfnote
1396 {
1397         const char *name;
1398         int type;
1399         unsigned int datasz;
1400         void *data;
1401 };
1402 
1403 static int notesize(struct memelfnote *en)
1404 {
1405         int sz;
1406 
1407         sz = sizeof(struct elf_note);
1408         sz += roundup(strlen(en->name) + 1, 4);
1409         sz += roundup(en->datasz, 4);
1410 
1411         return sz;
1412 }
1413 
1414 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1415 {
1416         struct elf_note en;
1417         en.n_namesz = strlen(men->name) + 1;
1418         en.n_descsz = men->datasz;
1419         en.n_type = men->type;
1420 
1421         return dump_emit(cprm, &en, sizeof(en)) &&
1422             dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1423             dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1424 }
1425 
1426 static void fill_elf_header(struct elfhdr *elf, int segs,
1427                             u16 machine, u32 flags)
1428 {
1429         memset(elf, 0, sizeof(*elf));
1430 
1431         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1432         elf->e_ident[EI_CLASS] = ELF_CLASS;
1433         elf->e_ident[EI_DATA] = ELF_DATA;
1434         elf->e_ident[EI_VERSION] = EV_CURRENT;
1435         elf->e_ident[EI_OSABI] = ELF_OSABI;
1436 
1437         elf->e_type = ET_CORE;
1438         elf->e_machine = machine;
1439         elf->e_version = EV_CURRENT;
1440         elf->e_phoff = sizeof(struct elfhdr);
1441         elf->e_flags = flags;
1442         elf->e_ehsize = sizeof(struct elfhdr);
1443         elf->e_phentsize = sizeof(struct elf_phdr);
1444         elf->e_phnum = segs;
1445 }
1446 
1447 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1448 {
1449         phdr->p_type = PT_NOTE;
1450         phdr->p_offset = offset;
1451         phdr->p_vaddr = 0;
1452         phdr->p_paddr = 0;
1453         phdr->p_filesz = sz;
1454         phdr->p_memsz = 0;
1455         phdr->p_flags = 0;
1456         phdr->p_align = 0;
1457 }
1458 
1459 static void fill_note(struct memelfnote *note, const char *name, int type, 
1460                 unsigned int sz, void *data)
1461 {
1462         note->name = name;
1463         note->type = type;
1464         note->datasz = sz;
1465         note->data = data;
1466 }
1467 
1468 /*
1469  * fill up all the fields in prstatus from the given task struct, except
1470  * registers which need to be filled up separately.
1471  */
1472 static void fill_prstatus(struct elf_prstatus *prstatus,
1473                 struct task_struct *p, long signr)
1474 {
1475         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1476         prstatus->pr_sigpend = p->pending.signal.sig[0];
1477         prstatus->pr_sighold = p->blocked.sig[0];
1478         rcu_read_lock();
1479         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1480         rcu_read_unlock();
1481         prstatus->pr_pid = task_pid_vnr(p);
1482         prstatus->pr_pgrp = task_pgrp_vnr(p);
1483         prstatus->pr_sid = task_session_vnr(p);
1484         if (thread_group_leader(p)) {
1485                 struct task_cputime cputime;
1486 
1487                 /*
1488                  * This is the record for the group leader.  It shows the
1489                  * group-wide total, not its individual thread total.
1490                  */
1491                 thread_group_cputime(p, &cputime);
1492                 prstatus->pr_utime = ns_to_timeval(cputime.utime);
1493                 prstatus->pr_stime = ns_to_timeval(cputime.stime);
1494         } else {
1495                 u64 utime, stime;
1496 
1497                 task_cputime(p, &utime, &stime);
1498                 prstatus->pr_utime = ns_to_timeval(utime);
1499                 prstatus->pr_stime = ns_to_timeval(stime);
1500         }
1501 
1502         prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
1503         prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
1504 }
1505 
1506 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1507                        struct mm_struct *mm)
1508 {
1509         const struct cred *cred;
1510         unsigned int i, len;
1511         
1512         /* first copy the parameters from user space */
1513         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1514 
1515         len = mm->arg_end - mm->arg_start;
1516         if (len >= ELF_PRARGSZ)
1517                 len = ELF_PRARGSZ-1;
1518         if (copy_from_user(&psinfo->pr_psargs,
1519                            (const char __user *)mm->arg_start, len))
1520                 return -EFAULT;
1521         for(i = 0; i < len; i++)
1522                 if (psinfo->pr_psargs[i] == 0)
1523                         psinfo->pr_psargs[i] = ' ';
1524         psinfo->pr_psargs[len] = 0;
1525 
1526         rcu_read_lock();
1527         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1528         rcu_read_unlock();
1529         psinfo->pr_pid = task_pid_vnr(p);
1530         psinfo->pr_pgrp = task_pgrp_vnr(p);
1531         psinfo->pr_sid = task_session_vnr(p);
1532 
1533         i = p->state ? ffz(~p->state) + 1 : 0;
1534         psinfo->pr_state = i;
1535         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1536         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1537         psinfo->pr_nice = task_nice(p);
1538         psinfo->pr_flag = p->flags;
1539         rcu_read_lock();
1540         cred = __task_cred(p);
1541         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1542         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1543         rcu_read_unlock();
1544         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1545         
1546         return 0;
1547 }
1548 
1549 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1550 {
1551         elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1552         int i = 0;
1553         do
1554                 i += 2;
1555         while (auxv[i - 2] != AT_NULL);
1556         fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1557 }
1558 
1559 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1560                 const kernel_siginfo_t *siginfo)
1561 {
1562         mm_segment_t old_fs = get_fs();
1563         set_fs(KERNEL_DS);
1564         copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1565         set_fs(old_fs);
1566         fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1567 }
1568 
1569 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1570 /*
1571  * Format of NT_FILE note:
1572  *
1573  * long count     -- how many files are mapped
1574  * long page_size -- units for file_ofs
1575  * array of [COUNT] elements of
1576  *   long start
1577  *   long end
1578  *   long file_ofs
1579  * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1580  */
1581 static int fill_files_note(struct memelfnote *note)
1582 {
1583         struct vm_area_struct *vma;
1584         unsigned count, size, names_ofs, remaining, n;
1585         user_long_t *data;
1586         user_long_t *start_end_ofs;
1587         char *name_base, *name_curpos;
1588 
1589         /* *Estimated* file count and total data size needed */
1590         count = current->mm->map_count;
1591         if (count > UINT_MAX / 64)
1592                 return -EINVAL;
1593         size = count * 64;
1594 
1595         names_ofs = (2 + 3 * count) * sizeof(data[0]);
1596  alloc:
1597         if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1598                 return -EINVAL;
1599         size = round_up(size, PAGE_SIZE);
1600         data = kvmalloc(size, GFP_KERNEL);
1601         if (ZERO_OR_NULL_PTR(data))
1602                 return -ENOMEM;
1603 
1604         start_end_ofs = data + 2;
1605         name_base = name_curpos = ((char *)data) + names_ofs;
1606         remaining = size - names_ofs;
1607         count = 0;
1608         for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1609                 struct file *file;
1610                 const char *filename;
1611 
1612                 file = vma->vm_file;
1613                 if (!file)
1614                         continue;
1615                 filename = file_path(file, name_curpos, remaining);
1616                 if (IS_ERR(filename)) {
1617                         if (PTR_ERR(filename) == -ENAMETOOLONG) {
1618                                 kvfree(data);
1619                                 size = size * 5 / 4;
1620                                 goto alloc;
1621                         }
1622                         continue;
1623                 }
1624 
1625                 /* file_path() fills at the end, move name down */
1626                 /* n = strlen(filename) + 1: */
1627                 n = (name_curpos + remaining) - filename;
1628                 remaining = filename - name_curpos;
1629                 memmove(name_curpos, filename, n);
1630                 name_curpos += n;
1631 
1632                 *start_end_ofs++ = vma->vm_start;
1633                 *start_end_ofs++ = vma->vm_end;
1634                 *start_end_ofs++ = vma->vm_pgoff;
1635                 count++;
1636         }
1637 
1638         /* Now we know exact count of files, can store it */
1639         data[0] = count;
1640         data[1] = PAGE_SIZE;
1641         /*
1642          * Count usually is less than current->mm->map_count,
1643          * we need to move filenames down.
1644          */
1645         n = current->mm->map_count - count;
1646         if (n != 0) {
1647                 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1648                 memmove(name_base - shift_bytes, name_base,
1649                         name_curpos - name_base);
1650                 name_curpos -= shift_bytes;
1651         }
1652 
1653         size = name_curpos - (char *)data;
1654         fill_note(note, "CORE", NT_FILE, size, data);
1655         return 0;
1656 }
1657 
1658 #ifdef CORE_DUMP_USE_REGSET
1659 #include <linux/regset.h>
1660 
1661 struct elf_thread_core_info {
1662         struct elf_thread_core_info *next;
1663         struct task_struct *task;
1664         struct elf_prstatus prstatus;
1665         struct memelfnote notes[0];
1666 };
1667 
1668 struct elf_note_info {
1669         struct elf_thread_core_info *thread;
1670         struct memelfnote psinfo;
1671         struct memelfnote signote;
1672         struct memelfnote auxv;
1673         struct memelfnote files;
1674         user_siginfo_t csigdata;
1675         size_t size;
1676         int thread_notes;
1677 };
1678 
1679 /*
1680  * When a regset has a writeback hook, we call it on each thread before
1681  * dumping user memory.  On register window machines, this makes sure the
1682  * user memory backing the register data is up to date before we read it.
1683  */
1684 static void do_thread_regset_writeback(struct task_struct *task,
1685                                        const struct user_regset *regset)
1686 {
1687         if (regset->writeback)
1688                 regset->writeback(task, regset, 1);
1689 }
1690 
1691 #ifndef PRSTATUS_SIZE
1692 #define PRSTATUS_SIZE(S, R) sizeof(S)
1693 #endif
1694 
1695 #ifndef SET_PR_FPVALID
1696 #define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V))
1697 #endif
1698 
1699 static int fill_thread_core_info(struct elf_thread_core_info *t,
1700                                  const struct user_regset_view *view,
1701                                  long signr, size_t *total)
1702 {
1703         unsigned int i;
1704         unsigned int regset0_size = regset_size(t->task, &view->regsets[0]);
1705 
1706         /*
1707          * NT_PRSTATUS is the one special case, because the regset data
1708          * goes into the pr_reg field inside the note contents, rather
1709          * than being the whole note contents.  We fill the reset in here.
1710          * We assume that regset 0 is NT_PRSTATUS.
1711          */
1712         fill_prstatus(&t->prstatus, t->task, signr);
1713         (void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset0_size,
1714                                     &t->prstatus.pr_reg, NULL);
1715 
1716         fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1717                   PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus);
1718         *total += notesize(&t->notes[0]);
1719 
1720         do_thread_regset_writeback(t->task, &view->regsets[0]);
1721 
1722         /*
1723          * Each other regset might generate a note too.  For each regset
1724          * that has no core_note_type or is inactive, we leave t->notes[i]
1725          * all zero and we'll know to skip writing it later.
1726          */
1727         for (i = 1; i < view->n; ++i) {
1728                 const struct user_regset *regset = &view->regsets[i];
1729                 do_thread_regset_writeback(t->task, regset);
1730                 if (regset->core_note_type && regset->get &&
1731                     (!regset->active || regset->active(t->task, regset) > 0)) {
1732                         int ret;
1733                         size_t size = regset_size(t->task, regset);
1734                         void *data = kzalloc(size, GFP_KERNEL);
1735                         if (unlikely(!data))
1736                                 return 0;
1737                         ret = regset->get(t->task, regset,
1738                                           0, size, data, NULL);
1739                         if (unlikely(ret))
1740                                 kfree(data);
1741                         else {
1742                                 if (regset->core_note_type != NT_PRFPREG)
1743                                         fill_note(&t->notes[i], "LINUX",
1744                                                   regset->core_note_type,
1745                                                   size, data);
1746                                 else {
1747                                         SET_PR_FPVALID(&t->prstatus,
1748                                                         1, regset0_size);
1749                                         fill_note(&t->notes[i], "CORE",
1750                                                   NT_PRFPREG, size, data);
1751                                 }
1752                                 *total += notesize(&t->notes[i]);
1753                         }
1754                 }
1755         }
1756 
1757         return 1;
1758 }
1759 
1760 static int fill_note_info(struct elfhdr *elf, int phdrs,
1761                           struct elf_note_info *info,
1762                           const kernel_siginfo_t *siginfo, struct pt_regs *regs)
1763 {
1764         struct task_struct *dump_task = current;
1765         const struct user_regset_view *view = task_user_regset_view(dump_task);
1766         struct elf_thread_core_info *t;
1767         struct elf_prpsinfo *psinfo;
1768         struct core_thread *ct;
1769         unsigned int i;
1770 
1771         info->size = 0;
1772         info->thread = NULL;
1773 
1774         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1775         if (psinfo == NULL) {
1776                 info->psinfo.data = NULL; /* So we don't free this wrongly */
1777                 return 0;
1778         }
1779 
1780         fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1781 
1782         /*
1783          * Figure out how many notes we're going to need for each thread.
1784          */
1785         info->thread_notes = 0;
1786         for (i = 0; i < view->n; ++i)
1787                 if (view->regsets[i].core_note_type != 0)
1788                         ++info->thread_notes;
1789 
1790         /*
1791          * Sanity check.  We rely on regset 0 being in NT_PRSTATUS,
1792          * since it is our one special case.
1793          */
1794         if (unlikely(info->thread_notes == 0) ||
1795             unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1796                 WARN_ON(1);
1797                 return 0;
1798         }
1799 
1800         /*
1801          * Initialize the ELF file header.
1802          */
1803         fill_elf_header(elf, phdrs,
1804                         view->e_machine, view->e_flags);
1805 
1806         /*
1807          * Allocate a structure for each thread.
1808          */
1809         for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1810                 t = kzalloc(offsetof(struct elf_thread_core_info,
1811                                      notes[info->thread_notes]),
1812                             GFP_KERNEL);
1813                 if (unlikely(!t))
1814                         return 0;
1815 
1816                 t->task = ct->task;
1817                 if (ct->task == dump_task || !info->thread) {
1818                         t->next = info->thread;
1819                         info->thread = t;
1820                 } else {
1821                         /*
1822                          * Make sure to keep the original task at
1823                          * the head of the list.
1824                          */
1825                         t->next = info->thread->next;
1826                         info->thread->next = t;
1827                 }
1828         }
1829 
1830         /*
1831          * Now fill in each thread's information.
1832          */
1833         for (t = info->thread; t != NULL; t = t->next)
1834                 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1835                         return 0;
1836 
1837         /*
1838          * Fill in the two process-wide notes.
1839          */
1840         fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1841         info->size += notesize(&info->psinfo);
1842 
1843         fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1844         info->size += notesize(&info->signote);
1845 
1846         fill_auxv_note(&info->auxv, current->mm);
1847         info->size += notesize(&info->auxv);
1848 
1849         if (fill_files_note(&info->files) == 0)
1850                 info->size += notesize(&info->files);
1851 
1852         return 1;
1853 }
1854 
1855 static size_t get_note_info_size(struct elf_note_info *info)
1856 {
1857         return info->size;
1858 }
1859 
1860 /*
1861  * Write all the notes for each thread.  When writing the first thread, the
1862  * process-wide notes are interleaved after the first thread-specific note.
1863  */
1864 static int write_note_info(struct elf_note_info *info,
1865                            struct coredump_params *cprm)
1866 {
1867         bool first = true;
1868         struct elf_thread_core_info *t = info->thread;
1869 
1870         do {
1871                 int i;
1872 
1873                 if (!writenote(&t->notes[0], cprm))
1874                         return 0;
1875 
1876                 if (first && !writenote(&info->psinfo, cprm))
1877                         return 0;
1878                 if (first && !writenote(&info->signote, cprm))
1879                         return 0;
1880                 if (first && !writenote(&info->auxv, cprm))
1881                         return 0;
1882                 if (first && info->files.data &&
1883                                 !writenote(&info->files, cprm))
1884                         return 0;
1885 
1886                 for (i = 1; i < info->thread_notes; ++i)
1887                         if (t->notes[i].data &&
1888                             !writenote(&t->notes[i], cprm))
1889                                 return 0;
1890 
1891                 first = false;
1892                 t = t->next;
1893         } while (t);
1894 
1895         return 1;
1896 }
1897 
1898 static void free_note_info(struct elf_note_info *info)
1899 {
1900         struct elf_thread_core_info *threads = info->thread;
1901         while (threads) {
1902                 unsigned int i;
1903                 struct elf_thread_core_info *t = threads;
1904                 threads = t->next;
1905                 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1906                 for (i = 1; i < info->thread_notes; ++i)
1907                         kfree(t->notes[i].data);
1908                 kfree(t);
1909         }
1910         kfree(info->psinfo.data);
1911         kvfree(info->files.data);
1912 }
1913 
1914 #else
1915 
1916 /* Here is the structure in which status of each thread is captured. */
1917 struct elf_thread_status
1918 {
1919         struct list_head list;
1920         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1921         elf_fpregset_t fpu;             /* NT_PRFPREG */
1922         struct task_struct *thread;
1923 #ifdef ELF_CORE_COPY_XFPREGS
1924         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1925 #endif
1926         struct memelfnote notes[3];
1927         int num_notes;
1928 };
1929 
1930 /*
1931  * In order to add the specific thread information for the elf file format,
1932  * we need to keep a linked list of every threads pr_status and then create
1933  * a single section for them in the final core file.
1934  */
1935 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1936 {
1937         int sz = 0;
1938         struct task_struct *p = t->thread;
1939         t->num_notes = 0;
1940 
1941         fill_prstatus(&t->prstatus, p, signr);
1942         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);        
1943         
1944         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1945                   &(t->prstatus));
1946         t->num_notes++;
1947         sz += notesize(&t->notes[0]);
1948 
1949         if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1950                                                                 &t->fpu))) {
1951                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1952                           &(t->fpu));
1953                 t->num_notes++;
1954                 sz += notesize(&t->notes[1]);
1955         }
1956 
1957 #ifdef ELF_CORE_COPY_XFPREGS
1958         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1959                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1960                           sizeof(t->xfpu), &t->xfpu);
1961                 t->num_notes++;
1962                 sz += notesize(&t->notes[2]);
1963         }
1964 #endif  
1965         return sz;
1966 }
1967 
1968 struct elf_note_info {
1969         struct memelfnote *notes;
1970         struct memelfnote *notes_files;
1971         struct elf_prstatus *prstatus;  /* NT_PRSTATUS */
1972         struct elf_prpsinfo *psinfo;    /* NT_PRPSINFO */
1973         struct list_head thread_list;
1974         elf_fpregset_t *fpu;
1975 #ifdef ELF_CORE_COPY_XFPREGS
1976         elf_fpxregset_t *xfpu;
1977 #endif
1978         user_siginfo_t csigdata;
1979         int thread_status_size;
1980         int numnote;
1981 };
1982 
1983 static int elf_note_info_init(struct elf_note_info *info)
1984 {
1985         memset(info, 0, sizeof(*info));
1986         INIT_LIST_HEAD(&info->thread_list);
1987 
1988         /* Allocate space for ELF notes */
1989         info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
1990         if (!info->notes)
1991                 return 0;
1992         info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1993         if (!info->psinfo)
1994                 return 0;
1995         info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1996         if (!info->prstatus)
1997                 return 0;
1998         info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1999         if (!info->fpu)
2000                 return 0;
2001 #ifdef ELF_CORE_COPY_XFPREGS
2002         info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
2003         if (!info->xfpu)
2004                 return 0;
2005 #endif
2006         return 1;
2007 }
2008 
2009 static int fill_note_info(struct elfhdr *elf, int phdrs,
2010                           struct elf_note_info *info,
2011                           const kernel_siginfo_t *siginfo, struct pt_regs *regs)
2012 {
2013         struct core_thread *ct;
2014         struct elf_thread_status *ets;
2015 
2016         if (!elf_note_info_init(info))
2017                 return 0;
2018 
2019         for (ct = current->mm->core_state->dumper.next;
2020                                         ct; ct = ct->next) {
2021                 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
2022                 if (!ets)
2023                         return 0;
2024 
2025                 ets->thread = ct->task;
2026                 list_add(&ets->list, &info->thread_list);
2027         }
2028 
2029         list_for_each_entry(ets, &info->thread_list, list) {
2030                 int sz;
2031 
2032                 sz = elf_dump_thread_status(siginfo->si_signo, ets);
2033                 info->thread_status_size += sz;
2034         }
2035         /* now collect the dump for the current */
2036         memset(info->prstatus, 0, sizeof(*info->prstatus));
2037         fill_prstatus(info->prstatus, current, siginfo->si_signo);
2038         elf_core_copy_regs(&info->prstatus->pr_reg, regs);
2039 
2040         /* Set up header */
2041         fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
2042 
2043         /*
2044          * Set up the notes in similar form to SVR4 core dumps made
2045          * with info from their /proc.
2046          */
2047 
2048         fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
2049                   sizeof(*info->prstatus), info->prstatus);
2050         fill_psinfo(info->psinfo, current->group_leader, current->mm);
2051         fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
2052                   sizeof(*info->psinfo), info->psinfo);
2053 
2054         fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
2055         fill_auxv_note(info->notes + 3, current->mm);
2056         info->numnote = 4;
2057 
2058         if (fill_files_note(info->notes + info->numnote) == 0) {
2059                 info->notes_files = info->notes + info->numnote;
2060                 info->numnote++;
2061         }
2062 
2063         /* Try to dump the FPU. */
2064         info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
2065                                                                info->fpu);
2066         if (info->prstatus->pr_fpvalid)
2067                 fill_note(info->notes + info->numnote++,
2068                           "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
2069 #ifdef ELF_CORE_COPY_XFPREGS
2070         if (elf_core_copy_task_xfpregs(current, info->xfpu))
2071                 fill_note(info->notes + info->numnote++,
2072                           "LINUX", ELF_CORE_XFPREG_TYPE,
2073                           sizeof(*info->xfpu), info->xfpu);
2074 #endif
2075 
2076         return 1;
2077 }
2078 
2079 static size_t get_note_info_size(struct elf_note_info *info)
2080 {
2081         int sz = 0;
2082         int i;
2083 
2084         for (i = 0; i < info->numnote; i++)
2085                 sz += notesize(info->notes + i);
2086 
2087         sz += info->thread_status_size;
2088 
2089         return sz;
2090 }
2091 
2092 static int write_note_info(struct elf_note_info *info,
2093                            struct coredump_params *cprm)
2094 {
2095         struct elf_thread_status *ets;
2096         int i;
2097 
2098         for (i = 0; i < info->numnote; i++)
2099                 if (!writenote(info->notes + i, cprm))
2100                         return 0;
2101 
2102         /* write out the thread status notes section */
2103         list_for_each_entry(ets, &info->thread_list, list) {
2104                 for (i = 0; i < ets->num_notes; i++)
2105                         if (!writenote(&ets->notes[i], cprm))
2106                                 return 0;
2107         }
2108 
2109         return 1;
2110 }
2111 
2112 static void free_note_info(struct elf_note_info *info)
2113 {
2114         while (!list_empty(&info->thread_list)) {
2115                 struct list_head *tmp = info->thread_list.next;
2116                 list_del(tmp);
2117                 kfree(list_entry(tmp, struct elf_thread_status, list));
2118         }
2119 
2120         /* Free data possibly allocated by fill_files_note(): */
2121         if (info->notes_files)
2122                 kvfree(info->notes_files->data);
2123 
2124         kfree(info->prstatus);
2125         kfree(info->psinfo);
2126         kfree(info->notes);
2127         kfree(info->fpu);
2128 #ifdef ELF_CORE_COPY_XFPREGS
2129         kfree(info->xfpu);
2130 #endif
2131 }
2132 
2133 #endif
2134 
2135 static struct vm_area_struct *first_vma(struct task_struct *tsk,
2136                                         struct vm_area_struct *gate_vma)
2137 {
2138         struct vm_area_struct *ret = tsk->mm->mmap;
2139 
2140         if (ret)
2141                 return ret;
2142         return gate_vma;
2143 }
2144 /*
2145  * Helper function for iterating across a vma list.  It ensures that the caller
2146  * will visit `gate_vma' prior to terminating the search.
2147  */
2148 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
2149                                         struct vm_area_struct *gate_vma)
2150 {
2151         struct vm_area_struct *ret;
2152 
2153         ret = this_vma->vm_next;
2154         if (ret)
2155                 return ret;
2156         if (this_vma == gate_vma)
2157                 return NULL;
2158         return gate_vma;
2159 }
2160 
2161 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2162                              elf_addr_t e_shoff, int segs)
2163 {
2164         elf->e_shoff = e_shoff;
2165         elf->e_shentsize = sizeof(*shdr4extnum);
2166         elf->e_shnum = 1;
2167         elf->e_shstrndx = SHN_UNDEF;
2168 
2169         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2170 
2171         shdr4extnum->sh_type = SHT_NULL;
2172         shdr4extnum->sh_size = elf->e_shnum;
2173         shdr4extnum->sh_link = elf->e_shstrndx;
2174         shdr4extnum->sh_info = segs;
2175 }
2176 
2177 /*
2178  * Actual dumper
2179  *
2180  * This is a two-pass process; first we find the offsets of the bits,
2181  * and then they are actually written out.  If we run out of core limit
2182  * we just truncate.
2183  */
2184 static int elf_core_dump(struct coredump_params *cprm)
2185 {
2186         int has_dumped = 0;
2187         mm_segment_t fs;
2188         int segs, i;
2189         size_t vma_data_size = 0;
2190         struct vm_area_struct *vma, *gate_vma;
2191         struct elfhdr *elf = NULL;
2192         loff_t offset = 0, dataoff;
2193         struct elf_note_info info = { };
2194         struct elf_phdr *phdr4note = NULL;
2195         struct elf_shdr *shdr4extnum = NULL;
2196         Elf_Half e_phnum;
2197         elf_addr_t e_shoff;
2198         elf_addr_t *vma_filesz = NULL;
2199 
2200         /*
2201          * We no longer stop all VM operations.
2202          * 
2203          * This is because those proceses that could possibly change map_count
2204          * or the mmap / vma pages are now blocked in do_exit on current
2205          * finishing this core dump.
2206          *
2207          * Only ptrace can touch these memory addresses, but it doesn't change
2208          * the map_count or the pages allocated. So no possibility of crashing
2209          * exists while dumping the mm->vm_next areas to the core file.
2210          */
2211   
2212         /* alloc memory for large data structures: too large to be on stack */
2213         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2214         if (!elf)
2215                 goto out;
2216         /*
2217          * The number of segs are recored into ELF header as 16bit value.
2218          * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2219          */
2220         segs = current->mm->map_count;
2221         segs += elf_core_extra_phdrs();
2222 
2223         gate_vma = get_gate_vma(current->mm);
2224         if (gate_vma != NULL)
2225                 segs++;
2226 
2227         /* for notes section */
2228         segs++;
2229 
2230         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2231          * this, kernel supports extended numbering. Have a look at
2232          * include/linux/elf.h for further information. */
2233         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2234 
2235         /*
2236          * Collect all the non-memory information about the process for the
2237          * notes.  This also sets up the file header.
2238          */
2239         if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2240                 goto cleanup;
2241 
2242         has_dumped = 1;
2243 
2244         fs = get_fs();
2245         set_fs(KERNEL_DS);
2246 
2247         offset += sizeof(*elf);                         /* Elf header */
2248         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
2249 
2250         /* Write notes phdr entry */
2251         {
2252                 size_t sz = get_note_info_size(&info);
2253 
2254                 sz += elf_coredump_extra_notes_size();
2255 
2256                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2257                 if (!phdr4note)
2258                         goto end_coredump;
2259 
2260                 fill_elf_note_phdr(phdr4note, sz, offset);
2261                 offset += sz;
2262         }
2263 
2264         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2265 
2266         if (segs - 1 > ULONG_MAX / sizeof(*vma_filesz))
2267                 goto end_coredump;
2268         vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)),
2269                               GFP_KERNEL);
2270         if (ZERO_OR_NULL_PTR(vma_filesz))
2271                 goto end_coredump;
2272 
2273         for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2274                         vma = next_vma(vma, gate_vma)) {
2275                 unsigned long dump_size;
2276 
2277                 dump_size = vma_dump_size(vma, cprm->mm_flags);
2278                 vma_filesz[i++] = dump_size;
2279                 vma_data_size += dump_size;
2280         }
2281 
2282         offset += vma_data_size;
2283         offset += elf_core_extra_data_size();
2284         e_shoff = offset;
2285 
2286         if (e_phnum == PN_XNUM) {
2287                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2288                 if (!shdr4extnum)
2289                         goto end_coredump;
2290                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2291         }
2292 
2293         offset = dataoff;
2294 
2295         if (!dump_emit(cprm, elf, sizeof(*elf)))
2296                 goto end_coredump;
2297 
2298         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2299                 goto end_coredump;
2300 
2301         /* Write program headers for segments dump */
2302         for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2303                         vma = next_vma(vma, gate_vma)) {
2304                 struct elf_phdr phdr;
2305 
2306                 phdr.p_type = PT_LOAD;
2307                 phdr.p_offset = offset;
2308                 phdr.p_vaddr = vma->vm_start;
2309                 phdr.p_paddr = 0;
2310                 phdr.p_filesz = vma_filesz[i++];
2311                 phdr.p_memsz = vma->vm_end - vma->vm_start;
2312                 offset += phdr.p_filesz;
2313                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2314                 if (vma->vm_flags & VM_WRITE)
2315                         phdr.p_flags |= PF_W;
2316                 if (vma->vm_flags & VM_EXEC)
2317                         phdr.p_flags |= PF_X;
2318                 phdr.p_align = ELF_EXEC_PAGESIZE;
2319 
2320                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2321                         goto end_coredump;
2322         }
2323 
2324         if (!elf_core_write_extra_phdrs(cprm, offset))
2325                 goto end_coredump;
2326 
2327         /* write out the notes section */
2328         if (!write_note_info(&info, cprm))
2329                 goto end_coredump;
2330 
2331         if (elf_coredump_extra_notes_write(cprm))
2332                 goto end_coredump;
2333 
2334         /* Align to page */
2335         if (!dump_skip(cprm, dataoff - cprm->pos))
2336                 goto end_coredump;
2337 
2338         for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2339                         vma = next_vma(vma, gate_vma)) {
2340                 unsigned long addr;
2341                 unsigned long end;
2342 
2343                 end = vma->vm_start + vma_filesz[i++];
2344 
2345                 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2346                         struct page *page;
2347                         int stop;
2348 
2349                         page = get_dump_page(addr);
2350                         if (page) {
2351                                 void *kaddr = kmap(page);
2352                                 stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
2353                                 kunmap(page);
2354                                 put_page(page);
2355                         } else
2356                                 stop = !dump_skip(cprm, PAGE_SIZE);
2357                         if (stop)
2358                                 goto end_coredump;
2359                 }
2360         }
2361         dump_truncate(cprm);
2362 
2363         if (!elf_core_write_extra_data(cprm))
2364                 goto end_coredump;
2365 
2366         if (e_phnum == PN_XNUM) {
2367                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2368                         goto end_coredump;
2369         }
2370 
2371 end_coredump:
2372         set_fs(fs);
2373 
2374 cleanup:
2375         free_note_info(&info);
2376         kfree(shdr4extnum);
2377         kvfree(vma_filesz);
2378         kfree(phdr4note);
2379         kfree(elf);
2380 out:
2381         return has_dumped;
2382 }
2383 
2384 #endif          /* CONFIG_ELF_CORE */
2385 
2386 static int __init init_elf_binfmt(void)
2387 {
2388         register_binfmt(&elf_format);
2389         return 0;
2390 }
2391 
2392 static void __exit exit_elf_binfmt(void)
2393 {
2394         /* Remove the COFF and ELF loaders. */
2395         unregister_binfmt(&elf_format);
2396 }
2397 
2398 core_initcall(init_elf_binfmt);
2399 module_exit(exit_elf_binfmt);
2400 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/fs/binfmt_elf.c

DEFINITIONS
