fs/binfmt_elf_fdpic.c

   1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
   2  *
   3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  * Derived from binfmt_elf.c
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14
  15 #include <linux/fs.h>
  16 #include <linux/stat.h>
  17 #include <linux/sched.h>
  18 #include <linux/mm.h>
  19 #include <linux/mman.h>
  20 #include <linux/errno.h>
  21 #include <linux/signal.h>
  22 #include <linux/binfmts.h>
  23 #include <linux/string.h>
  24 #include <linux/file.h>
  25 #include <linux/fcntl.h>
  26 #include <linux/slab.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/security.h>
  29 #include <linux/highmem.h>
  30 #include <linux/highuid.h>
  31 #include <linux/personality.h>
  32 #include <linux/ptrace.h>
  33 #include <linux/init.h>
  34 #include <linux/elf.h>
  35 #include <linux/elf-fdpic.h>
  36 #include <linux/elfcore.h>
  37 #include <linux/coredump.h>
  38 #include <linux/dax.h>
  39
  40 #include <asm/uaccess.h>
  41 #include <asm/param.h>
  42 #include <asm/pgalloc.h>
  43
  44 typedef char *elf_caddr_t;
  45
  46 #if 0
  47 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  48 #else
  49 #define kdebug(fmt, ...) do {} while(0)
  50 #endif
  51
  52 #if 0
  53 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  54 #else
  55 #define kdcore(fmt, ...) do {} while(0)
  56 #endif
  57
  58 MODULE_LICENSE("GPL");
  59
  60 static int load_elf_fdpic_binary(struct linux_binprm *);
  61 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  62 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  63                               struct mm_struct *, const char *);
  64
  65 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  66                                    struct elf_fdpic_params *,
  67                                    struct elf_fdpic_params *);
  68
  69 #ifndef CONFIG_MMU
  70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  71                                                    struct file *,
  72                                                    struct mm_struct *);
  73 #endif
  74
  75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  76                                              struct file *, struct mm_struct *);
  77
  78 #ifdef CONFIG_ELF_CORE
  79 static int elf_fdpic_core_dump(struct coredump_params *cprm);
  80 #endif
  81
  82 static struct linux_binfmt elf_fdpic_format = {
  83         .module         = THIS_MODULE,
  84         .load_binary    = load_elf_fdpic_binary,
  85 #ifdef CONFIG_ELF_CORE
  86         .core_dump      = elf_fdpic_core_dump,
  87 #endif
  88         .min_coredump   = ELF_EXEC_PAGESIZE,
  89 };
  90
  91 static int __init init_elf_fdpic_binfmt(void)
  92 {
  93         register_binfmt(&elf_fdpic_format);
  94         return 0;
  95 }
  96
  97 static void __exit exit_elf_fdpic_binfmt(void)
  98 {
  99         unregister_binfmt(&elf_fdpic_format);
 100 }
 101
 102 core_initcall(init_elf_fdpic_binfmt);
 103 module_exit(exit_elf_fdpic_binfmt);
 104
 105 static int is_elf(struct elfhdr *hdr, struct file *file)
 106 {
 107         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 108                 return 0;
 109         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 110                 return 0;
 111         if (!elf_check_arch(hdr))
 112                 return 0;
 113         if (!file->f_op->mmap)
 114                 return 0;
 115         return 1;
 116 }
 117
 118 #ifndef elf_check_fdpic
 119 #define elf_check_fdpic(x) 0
 120 #endif
 121
 122 #ifndef elf_check_const_displacement
 123 #define elf_check_const_displacement(x) 0
 124 #endif
 125
 126 static int is_constdisp(struct elfhdr *hdr)
 127 {
 128         if (!elf_check_fdpic(hdr))
 129                 return 1;
 130         if (elf_check_const_displacement(hdr))
 131                 return 1;
 132         return 0;
 133 }
 134
 135 /*****************************************************************************/
 136 /*
 137  * read the program headers table into memory
 138  */
 139 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 140                                  struct file *file)
 141 {
 142         struct elf32_phdr *phdr;
 143         unsigned long size;
 144         int retval, loop;
 145
 146         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 147                 return -ENOMEM;
 148         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 149                 return -ENOMEM;
 150
 151         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 152         params->phdrs = kmalloc(size, GFP_KERNEL);
 153         if (!params->phdrs)
 154                 return -ENOMEM;
 155
 156         retval = kernel_read(file, params->hdr.e_phoff,
 157                              (char *) params->phdrs, size);
 158         if (unlikely(retval != size))
 159                 return retval < 0 ? retval : -ENOEXEC;
 160
 161         /* determine stack size for this binary */
 162         phdr = params->phdrs;
 163         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 164                 if (phdr->p_type != PT_GNU_STACK)
 165                         continue;
 166
 167                 if (phdr->p_flags & PF_X)
 168                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 169                 else
 170                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 171
 172                 params->stack_size = phdr->p_memsz;
 173                 break;
 174         }
 175
 176         return 0;
 177 }
 178
 179 /*****************************************************************************/
 180 /*
 181  * load an fdpic binary into various bits of memory
 182  */
 183 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 184 {
 185         struct elf_fdpic_params exec_params, interp_params;
 186         struct pt_regs *regs = current_pt_regs();
 187         struct elf_phdr *phdr;
 188         unsigned long stack_size, entryaddr;
 189 #ifdef ELF_FDPIC_PLAT_INIT
 190         unsigned long dynaddr;
 191 #endif
 192 #ifndef CONFIG_MMU
 193         unsigned long stack_prot;
 194 #endif
 195         struct file *interpreter = NULL; /* to shut gcc up */
 196         char *interpreter_name = NULL;
 197         int executable_stack;
 198         int retval, i;
 199
 200         kdebug("____ LOAD %d ____", current->pid);
 201
 202         memset(&exec_params, 0, sizeof(exec_params));
 203         memset(&interp_params, 0, sizeof(interp_params));
 204
 205         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 206         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 207
 208         /* check that this is a binary we know how to deal with */
 209         retval = -ENOEXEC;
 210         if (!is_elf(&exec_params.hdr, bprm->file))
 211                 goto error;
 212         if (!elf_check_fdpic(&exec_params.hdr)) {
 213 #ifdef CONFIG_MMU
 214                 /* binfmt_elf handles non-fdpic elf except on nommu */
 215                 goto error;
 216 #else
 217                 /* nommu can only load ET_DYN (PIE) ELF */
 218                 if (exec_params.hdr.e_type != ET_DYN)
 219                         goto error;
 220 #endif
 221         }
 222
 223         /* read the program header table */
 224         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 225         if (retval < 0)
 226                 goto error;
 227
 228         /* scan for a program header that specifies an interpreter */
 229         phdr = exec_params.phdrs;
 230
 231         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 232                 switch (phdr->p_type) {
 233                 case PT_INTERP:
 234                         retval = -ENOMEM;
 235                         if (phdr->p_filesz > PATH_MAX)
 236                                 goto error;
 237                         retval = -ENOENT;
 238                         if (phdr->p_filesz < 2)
 239                                 goto error;
 240
 241                         /* read the name of the interpreter into memory */
 242                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 243                         if (!interpreter_name)
 244                                 goto error;
 245
 246                         retval = kernel_read(bprm->file,
 247                                              phdr->p_offset,
 248                                              interpreter_name,
 249                                              phdr->p_filesz);
 250                         if (unlikely(retval != phdr->p_filesz)) {
 251                                 if (retval >= 0)
 252                                         retval = -ENOEXEC;
 253                                 goto error;
 254                         }
 255
 256                         retval = -ENOENT;
 257                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 258                                 goto error;
 259
 260                         kdebug("Using ELF interpreter %s", interpreter_name);
 261
 262                         /* replace the program with the interpreter */
 263                         interpreter = open_exec(interpreter_name);
 264                         retval = PTR_ERR(interpreter);
 265                         if (IS_ERR(interpreter)) {
 266                                 interpreter = NULL;
 267                                 goto error;
 268                         }
 269
 270                         /*
 271                          * If the binary is not readable then enforce
 272                          * mm->dumpable = 0 regardless of the interpreter's
 273                          * permissions.
 274                          */
 275                         would_dump(bprm, interpreter);
 276
 277                         retval = kernel_read(interpreter, 0, bprm->buf,
 278                                              BINPRM_BUF_SIZE);
 279                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
 280                                 if (retval >= 0)
 281                                         retval = -ENOEXEC;
 282                                 goto error;
 283                         }
 284
 285                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 286                         break;
 287
 288                 case PT_LOAD:
 289 #ifdef CONFIG_MMU
 290                         if (exec_params.load_addr == 0)
 291                                 exec_params.load_addr = phdr->p_vaddr;
 292 #endif
 293                         break;
 294                 }
 295
 296         }
 297
 298         if (is_constdisp(&exec_params.hdr))
 299                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 300
 301         /* perform insanity checks on the interpreter */
 302         if (interpreter_name) {
 303                 retval = -ELIBBAD;
 304                 if (!is_elf(&interp_params.hdr, interpreter))
 305                         goto error;
 306
 307                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 308
 309                 /* read the interpreter's program header table */
 310                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 311                 if (retval < 0)
 312                         goto error;
 313         }
 314
 315         stack_size = exec_params.stack_size;
 316         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 317                 executable_stack = EXSTACK_ENABLE_X;
 318         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 319                 executable_stack = EXSTACK_DISABLE_X;
 320         else
 321                 executable_stack = EXSTACK_DEFAULT;
 322
 323         if (stack_size == 0) {
 324                 stack_size = interp_params.stack_size;
 325                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 326                         executable_stack = EXSTACK_ENABLE_X;
 327                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 328                         executable_stack = EXSTACK_DISABLE_X;
 329                 else
 330                         executable_stack = EXSTACK_DEFAULT;
 331         }
 332
 333         retval = -ENOEXEC;
 334         if (stack_size == 0)
 335                 stack_size = 131072UL; /* same as exec.c's default commit */
 336
 337         if (is_constdisp(&interp_params.hdr))
 338                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 339
 340         /* flush all traces of the currently running executable */
 341         retval = flush_old_exec(bprm);
 342         if (retval)
 343                 goto error;
 344
 345         /* there's now no turning back... the old userspace image is dead,
 346          * defunct, deceased, etc.
 347          */
 348         if (elf_check_fdpic(&exec_params.hdr))
 349                 set_personality(PER_LINUX_FDPIC);
 350         else
 351                 set_personality(PER_LINUX);
 352         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 353                 current->personality |= READ_IMPLIES_EXEC;
 354
 355         setup_new_exec(bprm);
 356
 357         set_binfmt(&elf_fdpic_format);
 358
 359         current->mm->start_code = 0;
 360         current->mm->end_code = 0;
 361         current->mm->start_stack = 0;
 362         current->mm->start_data = 0;
 363         current->mm->end_data = 0;
 364         current->mm->context.exec_fdpic_loadmap = 0;
 365         current->mm->context.interp_fdpic_loadmap = 0;
 366
 367 #ifdef CONFIG_MMU
 368         elf_fdpic_arch_lay_out_mm(&exec_params,
 369                                   &interp_params,
 370                                   &current->mm->start_stack,
 371                                   &current->mm->start_brk);
 372
 373         retval = setup_arg_pages(bprm, current->mm->start_stack,
 374                                  executable_stack);
 375         if (retval < 0)
 376                 goto error;
 377 #endif
 378
 379         /* load the executable and interpreter into memory */
 380         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 381                                     "executable");
 382         if (retval < 0)
 383                 goto error;
 384
 385         if (interpreter_name) {
 386                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 387                                             current->mm, "interpreter");
 388                 if (retval < 0) {
 389                         printk(KERN_ERR "Unable to load interpreter\n");
 390                         goto error;
 391                 }
 392
 393                 allow_write_access(interpreter);
 394                 fput(interpreter);
 395                 interpreter = NULL;
 396         }
 397
 398 #ifdef CONFIG_MMU
 399         if (!current->mm->start_brk)
 400                 current->mm->start_brk = current->mm->end_data;
 401
 402         current->mm->brk = current->mm->start_brk =
 403                 PAGE_ALIGN(current->mm->start_brk);
 404
 405 #else
 406         /* create a stack area and zero-size brk area */
 407         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 408         if (stack_size < PAGE_SIZE * 2)
 409                 stack_size = PAGE_SIZE * 2;
 410
 411         stack_prot = PROT_READ | PROT_WRITE;
 412         if (executable_stack == EXSTACK_ENABLE_X ||
 413             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 414                 stack_prot |= PROT_EXEC;
 415
 416         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 417                                          MAP_PRIVATE | MAP_ANONYMOUS |
 418                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 419                                          0);
 420
 421         if (IS_ERR_VALUE(current->mm->start_brk)) {
 422                 retval = current->mm->start_brk;
 423                 current->mm->start_brk = 0;
 424                 goto error;
 425         }
 426
 427         current->mm->brk = current->mm->start_brk;
 428         current->mm->context.end_brk = current->mm->start_brk;
 429         current->mm->start_stack = current->mm->start_brk + stack_size;
 430 #endif
 431
 432         install_exec_creds(bprm);
 433         if (create_elf_fdpic_tables(bprm, current->mm,
 434                                     &exec_params, &interp_params) < 0)
 435                 goto error;
 436
 437         kdebug("- start_code  %lx", current->mm->start_code);
 438         kdebug("- end_code    %lx", current->mm->end_code);
 439         kdebug("- start_data  %lx", current->mm->start_data);
 440         kdebug("- end_data    %lx", current->mm->end_data);
 441         kdebug("- start_brk   %lx", current->mm->start_brk);
 442         kdebug("- brk         %lx", current->mm->brk);
 443         kdebug("- start_stack %lx", current->mm->start_stack);
 444
 445 #ifdef ELF_FDPIC_PLAT_INIT
 446         /*
 447          * The ABI may specify that certain registers be set up in special
 448          * ways (on i386 %edx is the address of a DT_FINI function, for
 449          * example.  This macro performs whatever initialization to
 450          * the regs structure is required.
 451          */
 452         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 453         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 454                             dynaddr);
 455 #endif
 456
 457         /* everything is now ready... get the userspace context ready to roll */
 458         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 459         start_thread(regs, entryaddr, current->mm->start_stack);
 460
 461         retval = 0;
 462
 463 error:
 464         if (interpreter) {
 465                 allow_write_access(interpreter);
 466                 fput(interpreter);
 467         }
 468         kfree(interpreter_name);
 469         kfree(exec_params.phdrs);
 470         kfree(exec_params.loadmap);
 471         kfree(interp_params.phdrs);
 472         kfree(interp_params.loadmap);
 473         return retval;
 474 }
 475
 476 /*****************************************************************************/
 477
 478 #ifndef ELF_BASE_PLATFORM
 479 /*
 480  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 481  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 482  * will be copied to the user stack in the same manner as AT_PLATFORM.
 483  */
 484 #define ELF_BASE_PLATFORM NULL
 485 #endif
 486
 487 /*
 488  * present useful information to the program by shovelling it onto the new
 489  * process's stack
 490  */
 491 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 492                                    struct mm_struct *mm,
 493                                    struct elf_fdpic_params *exec_params,
 494                                    struct elf_fdpic_params *interp_params)
 495 {
 496         const struct cred *cred = current_cred();
 497         unsigned long sp, csp, nitems;
 498         elf_caddr_t __user *argv, *envp;
 499         size_t platform_len = 0, len;
 500         char *k_platform, *k_base_platform;
 501         char __user *u_platform, *u_base_platform, *p;
 502         int loop;
 503         int nr; /* reset for each csp adjustment */
 504
 505 #ifdef CONFIG_MMU
 506         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 507          * by the processes running on the same package. One thing we can do is
 508          * to shuffle the initial stack for them, so we give the architecture
 509          * an opportunity to do so here.
 510          */
 511         sp = arch_align_stack(bprm->p);
 512 #else
 513         sp = mm->start_stack;
 514
 515         /* stack the program arguments and environment */
 516         if (transfer_args_to_stack(bprm, &sp) < 0)
 517                 return -EFAULT;
 518         sp &= ~15;
 519 #endif
 520
 521         /*
 522          * If this architecture has a platform capability string, copy it
 523          * to userspace.  In some cases (Sparc), this info is impossible
 524          * for userspace to get any other way, in others (i386) it is
 525          * merely difficult.
 526          */
 527         k_platform = ELF_PLATFORM;
 528         u_platform = NULL;
 529
 530         if (k_platform) {
 531                 platform_len = strlen(k_platform) + 1;
 532                 sp -= platform_len;
 533                 u_platform = (char __user *) sp;
 534                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 535                         return -EFAULT;
 536         }
 537
 538         /*
 539          * If this architecture has a "base" platform capability
 540          * string, copy it to userspace.
 541          */
 542         k_base_platform = ELF_BASE_PLATFORM;
 543         u_base_platform = NULL;
 544
 545         if (k_base_platform) {
 546                 platform_len = strlen(k_base_platform) + 1;
 547                 sp -= platform_len;
 548                 u_base_platform = (char __user *) sp;
 549                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 550                         return -EFAULT;
 551         }
 552
 553         sp &= ~7UL;
 554
 555         /* stack the load map(s) */
 556         len = sizeof(struct elf32_fdpic_loadmap);
 557         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 558         sp = (sp - len) & ~7UL;
 559         exec_params->map_addr = sp;
 560
 561         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 562                 return -EFAULT;
 563
 564         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 565
 566         if (interp_params->loadmap) {
 567                 len = sizeof(struct elf32_fdpic_loadmap);
 568                 len += sizeof(struct elf32_fdpic_loadseg) *
 569                         interp_params->loadmap->nsegs;
 570                 sp = (sp - len) & ~7UL;
 571                 interp_params->map_addr = sp;
 572
 573                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 574                                  len) != 0)
 575                         return -EFAULT;
 576
 577                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 578         }
 579
 580         /* force 16 byte _final_ alignment here for generality */
 581 #define DLINFO_ITEMS 15
 582
 583         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 584                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 585
 586         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 587                 nitems++;
 588
 589         csp = sp;
 590         sp -= nitems * 2 * sizeof(unsigned long);
 591         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 592         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 593         sp -= 1 * sizeof(unsigned long);                /* argc */
 594
 595         csp -= sp & 15UL;
 596         sp -= sp & 15UL;
 597
 598         /* put the ELF interpreter info on the stack */
 599 #define NEW_AUX_ENT(id, val)                                            \
 600         do {                                                            \
 601                 struct { unsigned long _id, _val; } __user *ent;        \
 602                                                                         \
 603                 ent = (void __user *) csp;                              \
 604                 __put_user((id), &ent[nr]._id);                         \
 605                 __put_user((val), &ent[nr]._val);                       \
 606                 nr++;                                                   \
 607         } while (0)
 608
 609         nr = 0;
 610         csp -= 2 * sizeof(unsigned long);
 611         NEW_AUX_ENT(AT_NULL, 0);
 612         if (k_platform) {
 613                 nr = 0;
 614                 csp -= 2 * sizeof(unsigned long);
 615                 NEW_AUX_ENT(AT_PLATFORM,
 616                             (elf_addr_t) (unsigned long) u_platform);
 617         }
 618
 619         if (k_base_platform) {
 620                 nr = 0;
 621                 csp -= 2 * sizeof(unsigned long);
 622                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 623                             (elf_addr_t) (unsigned long) u_base_platform);
 624         }
 625
 626         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 627                 nr = 0;
 628                 csp -= 2 * sizeof(unsigned long);
 629                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 630         }
 631
 632         nr = 0;
 633         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 634         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 635 #ifdef ELF_HWCAP2
 636         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 637 #endif
 638         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 639         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 640         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 641         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 642         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 643         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 644         NEW_AUX_ENT(AT_FLAGS,   0);
 645         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 646         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 647         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 648         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 649         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 650         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
 651         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 652
 653 #ifdef ARCH_DLINFO
 654         nr = 0;
 655         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 656
 657         /* ARCH_DLINFO must come last so platform specific code can enforce
 658          * special alignment requirements on the AUXV if necessary (eg. PPC).
 659          */
 660         ARCH_DLINFO;
 661 #endif
 662 #undef NEW_AUX_ENT
 663
 664         /* allocate room for argv[] and envv[] */
 665         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 666         envp = (elf_caddr_t __user *) csp;
 667         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 668         argv = (elf_caddr_t __user *) csp;
 669
 670         /* stack argc */
 671         csp -= sizeof(unsigned long);
 672         __put_user(bprm->argc, (unsigned long __user *) csp);
 673
 674         BUG_ON(csp != sp);
 675
 676         /* fill in the argv[] array */
 677 #ifdef CONFIG_MMU
 678         current->mm->arg_start = bprm->p;
 679 #else
 680         current->mm->arg_start = current->mm->start_stack -
 681                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 682 #endif
 683
 684         p = (char __user *) current->mm->arg_start;
 685         for (loop = bprm->argc; loop > 0; loop--) {
 686                 __put_user((elf_caddr_t) p, argv++);
 687                 len = strnlen_user(p, MAX_ARG_STRLEN);
 688                 if (!len || len > MAX_ARG_STRLEN)
 689                         return -EINVAL;
 690                 p += len;
 691         }
 692         __put_user(NULL, argv);
 693         current->mm->arg_end = (unsigned long) p;
 694
 695         /* fill in the envv[] array */
 696         current->mm->env_start = (unsigned long) p;
 697         for (loop = bprm->envc; loop > 0; loop--) {
 698                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 699                 len = strnlen_user(p, MAX_ARG_STRLEN);
 700                 if (!len || len > MAX_ARG_STRLEN)
 701                         return -EINVAL;
 702                 p += len;
 703         }
 704         __put_user(NULL, envp);
 705         current->mm->env_end = (unsigned long) p;
 706
 707         mm->start_stack = (unsigned long) sp;
 708         return 0;
 709 }
 710
 711 /*****************************************************************************/
 712 /*
 713  * load the appropriate binary image (executable or interpreter) into memory
 714  * - we assume no MMU is available
 715  * - if no other PIC bits are set in params->hdr->e_flags
 716  *   - we assume that the LOADable segments in the binary are independently relocatable
 717  *   - we assume R/O executable segments are shareable
 718  * - else
 719  *   - we assume the loadable parts of the image to require fixed displacement
 720  *   - the image is not shareable
 721  */
 722 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 723                               struct file *file,
 724                               struct mm_struct *mm,
 725                               const char *what)
 726 {
 727         struct elf32_fdpic_loadmap *loadmap;
 728 #ifdef CONFIG_MMU
 729         struct elf32_fdpic_loadseg *mseg;
 730 #endif
 731         struct elf32_fdpic_loadseg *seg;
 732         struct elf32_phdr *phdr;
 733         unsigned long load_addr, stop;
 734         unsigned nloads, tmp;
 735         size_t size;
 736         int loop, ret;
 737
 738         /* allocate a load map table */
 739         nloads = 0;
 740         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 741                 if (params->phdrs[loop].p_type == PT_LOAD)
 742                         nloads++;
 743
 744         if (nloads == 0)
 745                 return -ELIBBAD;
 746
 747         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 748         loadmap = kzalloc(size, GFP_KERNEL);
 749         if (!loadmap)
 750                 return -ENOMEM;
 751
 752         params->loadmap = loadmap;
 753
 754         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 755         loadmap->nsegs = nloads;
 756
 757         load_addr = params->load_addr;
 758         seg = loadmap->segs;
 759
 760         /* map the requested LOADs into the memory space */
 761         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 762         case ELF_FDPIC_FLAG_CONSTDISP:
 763         case ELF_FDPIC_FLAG_CONTIGUOUS:
 764 #ifndef CONFIG_MMU
 765                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 766                 if (ret < 0)
 767                         return ret;
 768                 break;
 769 #endif
 770         default:
 771                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 772                 if (ret < 0)
 773                         return ret;
 774                 break;
 775         }
 776
 777         /* map the entry point */
 778         if (params->hdr.e_entry) {
 779                 seg = loadmap->segs;
 780                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 781                         if (params->hdr.e_entry >= seg->p_vaddr &&
 782                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 783                                 params->entry_addr =
 784                                         (params->hdr.e_entry - seg->p_vaddr) +
 785                                         seg->addr;
 786                                 break;
 787                         }
 788                 }
 789         }
 790
 791         /* determine where the program header table has wound up if mapped */
 792         stop = params->hdr.e_phoff;
 793         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 794         phdr = params->phdrs;
 795
 796         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 797                 if (phdr->p_type != PT_LOAD)
 798                         continue;
 799
 800                 if (phdr->p_offset > params->hdr.e_phoff ||
 801                     phdr->p_offset + phdr->p_filesz < stop)
 802                         continue;
 803
 804                 seg = loadmap->segs;
 805                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 806                         if (phdr->p_vaddr >= seg->p_vaddr &&
 807                             phdr->p_vaddr + phdr->p_filesz <=
 808                             seg->p_vaddr + seg->p_memsz) {
 809                                 params->ph_addr =
 810                                         (phdr->p_vaddr - seg->p_vaddr) +
 811                                         seg->addr +
 812                                         params->hdr.e_phoff - phdr->p_offset;
 813                                 break;
 814                         }
 815                 }
 816                 break;
 817         }
 818
 819         /* determine where the dynamic section has wound up if there is one */
 820         phdr = params->phdrs;
 821         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 822                 if (phdr->p_type != PT_DYNAMIC)
 823                         continue;
 824
 825                 seg = loadmap->segs;
 826                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 827                         if (phdr->p_vaddr >= seg->p_vaddr &&
 828                             phdr->p_vaddr + phdr->p_memsz <=
 829                             seg->p_vaddr + seg->p_memsz) {
 830                                 params->dynamic_addr =
 831                                         (phdr->p_vaddr - seg->p_vaddr) +
 832                                         seg->addr;
 833
 834                                 /* check the dynamic section contains at least
 835                                  * one item, and that the last item is a NULL
 836                                  * entry */
 837                                 if (phdr->p_memsz == 0 ||
 838                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 839                                         goto dynamic_error;
 840
 841                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 842                                 if (((Elf32_Dyn *)
 843                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 844                                         goto dynamic_error;
 845                                 break;
 846                         }
 847                 }
 848                 break;
 849         }
 850
 851         /* now elide adjacent segments in the load map on MMU linux
 852          * - on uClinux the holes between may actually be filled with system
 853          *   stuff or stuff from other processes
 854          */
 855 #ifdef CONFIG_MMU
 856         nloads = loadmap->nsegs;
 857         mseg = loadmap->segs;
 858         seg = mseg + 1;
 859         for (loop = 1; loop < nloads; loop++) {
 860                 /* see if we have a candidate for merging */
 861                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 862                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 863                         if (load_addr == (seg->addr & PAGE_MASK)) {
 864                                 mseg->p_memsz +=
 865                                         load_addr -
 866                                         (mseg->addr + mseg->p_memsz);
 867                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 868                                 mseg->p_memsz += seg->p_memsz;
 869                                 loadmap->nsegs--;
 870                                 continue;
 871                         }
 872                 }
 873
 874                 mseg++;
 875                 if (mseg != seg)
 876                         *mseg = *seg;
 877         }
 878 #endif
 879
 880         kdebug("Mapped Object [%s]:", what);
 881         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 882         kdebug("- entry    : %lx", params->entry_addr);
 883         kdebug("- PHDR[]   : %lx", params->ph_addr);
 884         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 885         seg = loadmap->segs;
 886         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 887                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 888                        loop,
 889                        seg->addr, seg->addr + seg->p_memsz - 1,
 890                        seg->p_vaddr, seg->p_memsz);
 891
 892         return 0;
 893
 894 dynamic_error:
 895         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 896                what, file_inode(file)->i_ino);
 897         return -ELIBBAD;
 898 }
 899
 900 /*****************************************************************************/
 901 /*
 902  * map a file with constant displacement under uClinux
 903  */
 904 #ifndef CONFIG_MMU
 905 static int elf_fdpic_map_file_constdisp_on_uclinux(
 906         struct elf_fdpic_params *params,
 907         struct file *file,
 908         struct mm_struct *mm)
 909 {
 910         struct elf32_fdpic_loadseg *seg;
 911         struct elf32_phdr *phdr;
 912         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 913         int loop, ret;
 914
 915         load_addr = params->load_addr;
 916         seg = params->loadmap->segs;
 917
 918         /* determine the bounds of the contiguous overall allocation we must
 919          * make */
 920         phdr = params->phdrs;
 921         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 922                 if (params->phdrs[loop].p_type != PT_LOAD)
 923                         continue;
 924
 925                 if (base > phdr->p_vaddr)
 926                         base = phdr->p_vaddr;
 927                 if (top < phdr->p_vaddr + phdr->p_memsz)
 928                         top = phdr->p_vaddr + phdr->p_memsz;
 929         }
 930
 931         /* allocate one big anon block for everything */
 932         mflags = MAP_PRIVATE;
 933         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 934                 mflags |= MAP_EXECUTABLE;
 935
 936         maddr = vm_mmap(NULL, load_addr, top - base,
 937                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 938         if (IS_ERR_VALUE(maddr))
 939                 return (int) maddr;
 940
 941         if (load_addr != 0)
 942                 load_addr += PAGE_ALIGN(top - base);
 943
 944         /* and then load the file segments into it */
 945         phdr = params->phdrs;
 946         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 947                 if (params->phdrs[loop].p_type != PT_LOAD)
 948                         continue;
 949
 950                 seg->addr = maddr + (phdr->p_vaddr - base);
 951                 seg->p_vaddr = phdr->p_vaddr;
 952                 seg->p_memsz = phdr->p_memsz;
 953
 954                 ret = read_code(file, seg->addr, phdr->p_offset,
 955                                        phdr->p_filesz);
 956                 if (ret < 0)
 957                         return ret;
 958
 959                 /* map the ELF header address if in this segment */
 960                 if (phdr->p_offset == 0)
 961                         params->elfhdr_addr = seg->addr;
 962
 963                 /* clear any space allocated but not loaded */
 964                 if (phdr->p_filesz < phdr->p_memsz) {
 965                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
 966                                        phdr->p_memsz - phdr->p_filesz))
 967                                 return -EFAULT;
 968                 }
 969
 970                 if (mm) {
 971                         if (phdr->p_flags & PF_X) {
 972                                 if (!mm->start_code) {
 973                                         mm->start_code = seg->addr;
 974                                         mm->end_code = seg->addr +
 975                                                 phdr->p_memsz;
 976                                 }
 977                         } else if (!mm->start_data) {
 978                                 mm->start_data = seg->addr;
 979                                 mm->end_data = seg->addr + phdr->p_memsz;
 980                         }
 981                 }
 982
 983                 seg++;
 984         }
 985
 986         return 0;
 987 }
 988 #endif
 989
 990 /*****************************************************************************/
 991 /*
 992  * map a binary by direct mmap() of the individual PT_LOAD segments
 993  */
 994 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 995                                              struct file *file,
 996                                              struct mm_struct *mm)
 997 {
 998         struct elf32_fdpic_loadseg *seg;
 999         struct elf32_phdr *phdr;
1000         unsigned long load_addr, delta_vaddr;
1001         int loop, dvset;
1002
1003         load_addr = params->load_addr;
1004         delta_vaddr = 0;
1005         dvset = 0;
1006
1007         seg = params->loadmap->segs;
1008
1009         /* deal with each load segment separately */
1010         phdr = params->phdrs;
1011         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1012                 unsigned long maddr, disp, excess, excess1;
1013                 int prot = 0, flags;
1014
1015                 if (phdr->p_type != PT_LOAD)
1016                         continue;
1017
1018                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1019                        (unsigned long) phdr->p_vaddr,
1020                        (unsigned long) phdr->p_offset,
1021                        (unsigned long) phdr->p_filesz,
1022                        (unsigned long) phdr->p_memsz);
1023
1024                 /* determine the mapping parameters */
1025                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1026                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1027                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1028
1029                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1030                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1031                         flags |= MAP_EXECUTABLE;
1032
1033                 maddr = 0;
1034
1035                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1036                 case ELF_FDPIC_FLAG_INDEPENDENT:
1037                         /* PT_LOADs are independently locatable */
1038                         break;
1039
1040                 case ELF_FDPIC_FLAG_HONOURVADDR:
1041                         /* the specified virtual address must be honoured */
1042                         maddr = phdr->p_vaddr;
1043                         flags |= MAP_FIXED;
1044                         break;
1045
1046                 case ELF_FDPIC_FLAG_CONSTDISP:
1047                         /* constant displacement
1048                          * - can be mapped anywhere, but must be mapped as a
1049                          *   unit
1050                          */
1051                         if (!dvset) {
1052                                 maddr = load_addr;
1053                                 delta_vaddr = phdr->p_vaddr;
1054                                 dvset = 1;
1055                         } else {
1056                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1057                                 flags |= MAP_FIXED;
1058                         }
1059                         break;
1060
1061                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1062                         /* contiguity handled later */
1063                         break;
1064
1065                 default:
1066                         BUG();
1067                 }
1068
1069                 maddr &= PAGE_MASK;
1070
1071                 /* create the mapping */
1072                 disp = phdr->p_vaddr & ~PAGE_MASK;
1073                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1074                                 phdr->p_offset - disp);
1075
1076                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1077                        loop, phdr->p_memsz + disp, prot, flags,
1078                        phdr->p_offset - disp, maddr);
1079
1080                 if (IS_ERR_VALUE(maddr))
1081                         return (int) maddr;
1082
1083                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1084                     ELF_FDPIC_FLAG_CONTIGUOUS)
1085                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1086
1087                 seg->addr = maddr + disp;
1088                 seg->p_vaddr = phdr->p_vaddr;
1089                 seg->p_memsz = phdr->p_memsz;
1090
1091                 /* map the ELF header address if in this segment */
1092                 if (phdr->p_offset == 0)
1093                         params->elfhdr_addr = seg->addr;
1094
1095                 /* clear the bit between beginning of mapping and beginning of
1096                  * PT_LOAD */
1097                 if (prot & PROT_WRITE && disp > 0) {
1098                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1099                         if (clear_user((void __user *) maddr, disp))
1100                                 return -EFAULT;
1101                         maddr += disp;
1102                 }
1103
1104                 /* clear any space allocated but not loaded
1105                  * - on uClinux we can just clear the lot
1106                  * - on MMU linux we'll get a SIGBUS beyond the last page
1107                  *   extant in the file
1108                  */
1109                 excess = phdr->p_memsz - phdr->p_filesz;
1110                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1111
1112 #ifdef CONFIG_MMU
1113                 if (excess > excess1) {
1114                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1115                         unsigned long xmaddr;
1116
1117                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1118                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1119                                          prot, flags, 0);
1120
1121                         kdebug("mmap[%d] <anon>"
1122                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1123                                loop, xaddr, excess - excess1, prot, flags,
1124                                xmaddr);
1125
1126                         if (xmaddr != xaddr)
1127                                 return -ENOMEM;
1128                 }
1129
1130                 if (prot & PROT_WRITE && excess1 > 0) {
1131                         kdebug("clear[%d] ad=%lx sz=%lx",
1132                                loop, maddr + phdr->p_filesz, excess1);
1133                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1134                                        excess1))
1135                                 return -EFAULT;
1136                 }
1137
1138 #else
1139                 if (excess > 0) {
1140                         kdebug("clear[%d] ad=%lx sz=%lx",
1141                                loop, maddr + phdr->p_filesz, excess);
1142                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1143                                 return -EFAULT;
1144                 }
1145 #endif
1146
1147                 if (mm) {
1148                         if (phdr->p_flags & PF_X) {
1149                                 if (!mm->start_code) {
1150                                         mm->start_code = maddr;
1151                                         mm->end_code = maddr + phdr->p_memsz;
1152                                 }
1153                         } else if (!mm->start_data) {
1154                                 mm->start_data = maddr;
1155                                 mm->end_data = maddr + phdr->p_memsz;
1156                         }
1157                 }
1158
1159                 seg++;
1160         }
1161
1162         return 0;
1163 }
1164
1165 /*****************************************************************************/
1166 /*
1167  * ELF-FDPIC core dumper
1168  *
1169  * Modelled on fs/exec.c:aout_core_dump()
1170  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1171  *
1172  * Modelled on fs/binfmt_elf.c core dumper
1173  */
1174 #ifdef CONFIG_ELF_CORE
1175
1176 /*
1177  * Decide whether a segment is worth dumping; default is yes to be
1178  * sure (missing info is worse than too much; etc).
1179  * Personally I'd include everything, and use the coredump limit...
1180  *
1181  * I think we should skip something. But I am not sure how. H.J.
1182  */
1183 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1184 {
1185         int dump_ok;
1186
1187         /* Do not dump I/O mapped devices or special mappings */
1188         if (vma->vm_flags & VM_IO) {
1189                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1190                 return 0;
1191         }
1192
1193         /* If we may not read the contents, don't allow us to dump
1194          * them either. "dump_write()" can't handle it anyway.
1195          */
1196         if (!(vma->vm_flags & VM_READ)) {
1197                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1198                 return 0;
1199         }
1200
1201         /* support for DAX */
1202         if (vma_is_dax(vma)) {
1203                 if (vma->vm_flags & VM_SHARED) {
1204                         dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
1205                         kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
1206                                vma->vm_flags, dump_ok ? "yes" : "no");
1207                 } else {
1208                         dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
1209                         kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
1210                                vma->vm_flags, dump_ok ? "yes" : "no");
1211                 }
1212                 return dump_ok;
1213         }
1214
1215         /* By default, dump shared memory if mapped from an anonymous file. */
1216         if (vma->vm_flags & VM_SHARED) {
1217                 if (file_inode(vma->vm_file)->i_nlink == 0) {
1218                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1219                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1220                                vma->vm_flags, dump_ok ? "yes" : "no");
1221                         return dump_ok;
1222                 }
1223
1224                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1225                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1226                        vma->vm_flags, dump_ok ? "yes" : "no");
1227                 return dump_ok;
1228         }
1229
1230 #ifdef CONFIG_MMU
1231         /* By default, if it hasn't been written to, don't write it out */
1232         if (!vma->anon_vma) {
1233                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1234                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1235                        vma->vm_flags, dump_ok ? "yes" : "no");
1236                 return dump_ok;
1237         }
1238 #endif
1239
1240         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1241         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1242                dump_ok ? "yes" : "no");
1243         return dump_ok;
1244 }
1245
1246 /* An ELF note in memory */
1247 struct memelfnote
1248 {
1249         const char *name;
1250         int type;
1251         unsigned int datasz;
1252         void *data;
1253 };
1254
1255 static int notesize(struct memelfnote *en)
1256 {
1257         int sz;
1258
1259         sz = sizeof(struct elf_note);
1260         sz += roundup(strlen(en->name) + 1, 4);
1261         sz += roundup(en->datasz, 4);
1262
1263         return sz;
1264 }
1265
1266 /* #define DEBUG */
1267
1268 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1269 {
1270         struct elf_note en;
1271         en.n_namesz = strlen(men->name) + 1;
1272         en.n_descsz = men->datasz;
1273         en.n_type = men->type;
1274
1275         return dump_emit(cprm, &en, sizeof(en)) &&
1276                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1277                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1278 }
1279
1280 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1281 {
1282         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1283         elf->e_ident[EI_CLASS] = ELF_CLASS;
1284         elf->e_ident[EI_DATA] = ELF_DATA;
1285         elf->e_ident[EI_VERSION] = EV_CURRENT;
1286         elf->e_ident[EI_OSABI] = ELF_OSABI;
1287         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1288
1289         elf->e_type = ET_CORE;
1290         elf->e_machine = ELF_ARCH;
1291         elf->e_version = EV_CURRENT;
1292         elf->e_entry = 0;
1293         elf->e_phoff = sizeof(struct elfhdr);
1294         elf->e_shoff = 0;
1295         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1296         elf->e_ehsize = sizeof(struct elfhdr);
1297         elf->e_phentsize = sizeof(struct elf_phdr);
1298         elf->e_phnum = segs;
1299         elf->e_shentsize = 0;
1300         elf->e_shnum = 0;
1301         elf->e_shstrndx = 0;
1302         return;
1303 }
1304
1305 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1306 {
1307         phdr->p_type = PT_NOTE;
1308         phdr->p_offset = offset;
1309         phdr->p_vaddr = 0;
1310         phdr->p_paddr = 0;
1311         phdr->p_filesz = sz;
1312         phdr->p_memsz = 0;
1313         phdr->p_flags = 0;
1314         phdr->p_align = 0;
1315         return;
1316 }
1317
1318 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1319                 unsigned int sz, void *data)
1320 {
1321         note->name = name;
1322         note->type = type;
1323         note->datasz = sz;
1324         note->data = data;
1325         return;
1326 }
1327
1328 /*
1329  * fill up all the fields in prstatus from the given task struct, except
1330  * registers which need to be filled up separately.
1331  */
1332 static void fill_prstatus(struct elf_prstatus *prstatus,
1333                           struct task_struct *p, long signr)
1334 {
1335         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1336         prstatus->pr_sigpend = p->pending.signal.sig[0];
1337         prstatus->pr_sighold = p->blocked.sig[0];
1338         rcu_read_lock();
1339         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1340         rcu_read_unlock();
1341         prstatus->pr_pid = task_pid_vnr(p);
1342         prstatus->pr_pgrp = task_pgrp_vnr(p);
1343         prstatus->pr_sid = task_session_vnr(p);
1344         if (thread_group_leader(p)) {
1345                 struct task_cputime cputime;
1346
1347                 /*
1348                  * This is the record for the group leader.  It shows the
1349                  * group-wide total, not its individual thread total.
1350                  */
1351                 thread_group_cputime(p, &cputime);
1352                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1353                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1354         } else {
1355                 cputime_t utime, stime;
1356
1357                 task_cputime(p, &utime, &stime);
1358                 cputime_to_timeval(utime, &prstatus->pr_utime);
1359                 cputime_to_timeval(stime, &prstatus->pr_stime);
1360         }
1361         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1362         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1363
1364         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1365         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1366 }
1367
1368 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1369                        struct mm_struct *mm)
1370 {
1371         const struct cred *cred;
1372         unsigned int i, len;
1373
1374         /* first copy the parameters from user space */
1375         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1376
1377         len = mm->arg_end - mm->arg_start;
1378         if (len >= ELF_PRARGSZ)
1379                 len = ELF_PRARGSZ - 1;
1380         if (copy_from_user(&psinfo->pr_psargs,
1381                            (const char __user *) mm->arg_start, len))
1382                 return -EFAULT;
1383         for (i = 0; i < len; i++)
1384                 if (psinfo->pr_psargs[i] == 0)
1385                         psinfo->pr_psargs[i] = ' ';
1386         psinfo->pr_psargs[len] = 0;
1387
1388         rcu_read_lock();
1389         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1390         rcu_read_unlock();
1391         psinfo->pr_pid = task_pid_vnr(p);
1392         psinfo->pr_pgrp = task_pgrp_vnr(p);
1393         psinfo->pr_sid = task_session_vnr(p);
1394
1395         i = p->state ? ffz(~p->state) + 1 : 0;
1396         psinfo->pr_state = i;
1397         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1398         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1399         psinfo->pr_nice = task_nice(p);
1400         psinfo->pr_flag = p->flags;
1401         rcu_read_lock();
1402         cred = __task_cred(p);
1403         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1404         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1405         rcu_read_unlock();
1406         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1407
1408         return 0;
1409 }
1410
1411 /* Here is the structure in which status of each thread is captured. */
1412 struct elf_thread_status
1413 {
1414         struct list_head list;
1415         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1416         elf_fpregset_t fpu;             /* NT_PRFPREG */
1417         struct task_struct *thread;
1418 #ifdef ELF_CORE_COPY_XFPREGS
1419         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1420 #endif
1421         struct memelfnote notes[3];
1422         int num_notes;
1423 };
1424
1425 /*
1426  * In order to add the specific thread information for the elf file format,
1427  * we need to keep a linked list of every thread's pr_status and then create
1428  * a single section for them in the final core file.
1429  */
1430 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1431 {
1432         struct task_struct *p = t->thread;
1433         int sz = 0;
1434
1435         t->num_notes = 0;
1436
1437         fill_prstatus(&t->prstatus, p, signr);
1438         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1439
1440         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1441                   &t->prstatus);
1442         t->num_notes++;
1443         sz += notesize(&t->notes[0]);
1444
1445         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1446         if (t->prstatus.pr_fpvalid) {
1447                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1448                           &t->fpu);
1449                 t->num_notes++;
1450                 sz += notesize(&t->notes[1]);
1451         }
1452
1453 #ifdef ELF_CORE_COPY_XFPREGS
1454         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1455                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1456                           sizeof(t->xfpu), &t->xfpu);
1457                 t->num_notes++;
1458                 sz += notesize(&t->notes[2]);
1459         }
1460 #endif
1461         return sz;
1462 }
1463
1464 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1465                              elf_addr_t e_shoff, int segs)
1466 {
1467         elf->e_shoff = e_shoff;
1468         elf->e_shentsize = sizeof(*shdr4extnum);
1469         elf->e_shnum = 1;
1470         elf->e_shstrndx = SHN_UNDEF;
1471
1472         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1473
1474         shdr4extnum->sh_type = SHT_NULL;
1475         shdr4extnum->sh_size = elf->e_shnum;
1476         shdr4extnum->sh_link = elf->e_shstrndx;
1477         shdr4extnum->sh_info = segs;
1478 }
1479
1480 /*
1481  * dump the segments for an MMU process
1482  */
1483 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1484 {
1485         struct vm_area_struct *vma;
1486
1487         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1488                 unsigned long addr;
1489
1490                 if (!maydump(vma, cprm->mm_flags))
1491                         continue;
1492
1493 #ifdef CONFIG_MMU
1494                 for (addr = vma->vm_start; addr < vma->vm_end;
1495                                                         addr += PAGE_SIZE) {
1496                         bool res;
1497                         struct page *page = get_dump_page(addr);
1498                         if (page) {
1499                                 void *kaddr = kmap(page);
1500                                 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1501                                 kunmap(page);
1502                                 put_page(page);
1503                         } else {
1504                                 res = dump_skip(cprm, PAGE_SIZE);
1505                         }
1506                         if (!res)
1507                                 return false;
1508                 }
1509 #else
1510                 if (!dump_emit(cprm, (void *) vma->vm_start,
1511                                 vma->vm_end - vma->vm_start))
1512                         return false;
1513 #endif
1514         }
1515         return true;
1516 }
1517
1518 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1519 {
1520         struct vm_area_struct *vma;
1521         size_t size = 0;
1522
1523         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1524                 if (maydump(vma, mm_flags))
1525                         size += vma->vm_end - vma->vm_start;
1526         return size;
1527 }
1528
1529 /*
1530  * Actual dumper
1531  *
1532  * This is a two-pass process; first we find the offsets of the bits,
1533  * and then they are actually written out.  If we run out of core limit
1534  * we just truncate.
1535  */
1536 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1537 {
1538 #define NUM_NOTES       6
1539         int has_dumped = 0;
1540         mm_segment_t fs;
1541         int segs;
1542         int i;
1543         struct vm_area_struct *vma;
1544         struct elfhdr *elf = NULL;
1545         loff_t offset = 0, dataoff;
1546         int numnote;
1547         struct memelfnote *notes = NULL;
1548         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1549         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1550         LIST_HEAD(thread_list);
1551         struct list_head *t;
1552         elf_fpregset_t *fpu = NULL;
1553 #ifdef ELF_CORE_COPY_XFPREGS
1554         elf_fpxregset_t *xfpu = NULL;
1555 #endif
1556         int thread_status_size = 0;
1557         elf_addr_t *auxv;
1558         struct elf_phdr *phdr4note = NULL;
1559         struct elf_shdr *shdr4extnum = NULL;
1560         Elf_Half e_phnum;
1561         elf_addr_t e_shoff;
1562         struct core_thread *ct;
1563         struct elf_thread_status *tmp;
1564
1565         /*
1566          * We no longer stop all VM operations.
1567          *
1568          * This is because those proceses that could possibly change map_count
1569          * or the mmap / vma pages are now blocked in do_exit on current
1570          * finishing this core dump.
1571          *
1572          * Only ptrace can touch these memory addresses, but it doesn't change
1573          * the map_count or the pages allocated. So no possibility of crashing
1574          * exists while dumping the mm->vm_next areas to the core file.
1575          */
1576
1577         /* alloc memory for large data structures: too large to be on stack */
1578         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1579         if (!elf)
1580                 goto cleanup;
1581         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1582         if (!prstatus)
1583                 goto cleanup;
1584         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1585         if (!psinfo)
1586                 goto cleanup;
1587         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1588         if (!notes)
1589                 goto cleanup;
1590         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1591         if (!fpu)
1592                 goto cleanup;
1593 #ifdef ELF_CORE_COPY_XFPREGS
1594         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1595         if (!xfpu)
1596                 goto cleanup;
1597 #endif
1598
1599         for (ct = current->mm->core_state->dumper.next;
1600                                         ct; ct = ct->next) {
1601                 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1602                 if (!tmp)
1603                         goto cleanup;
1604
1605                 tmp->thread = ct->task;
1606                 list_add(&tmp->list, &thread_list);
1607         }
1608
1609         list_for_each(t, &thread_list) {
1610                 struct elf_thread_status *tmp;
1611                 int sz;
1612
1613                 tmp = list_entry(t, struct elf_thread_status, list);
1614                 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1615                 thread_status_size += sz;
1616         }
1617
1618         /* now collect the dump for the current */
1619         fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1620         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1621
1622         segs = current->mm->map_count;
1623         segs += elf_core_extra_phdrs();
1624
1625         /* for notes section */
1626         segs++;
1627
1628         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1629          * this, kernel supports extended numbering. Have a look at
1630          * include/linux/elf.h for further information. */
1631         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1632
1633         /* Set up header */
1634         fill_elf_fdpic_header(elf, e_phnum);
1635
1636         has_dumped = 1;
1637         /*
1638          * Set up the notes in similar form to SVR4 core dumps made
1639          * with info from their /proc.
1640          */
1641
1642         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1643         fill_psinfo(psinfo, current->group_leader, current->mm);
1644         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1645
1646         numnote = 2;
1647
1648         auxv = (elf_addr_t *) current->mm->saved_auxv;
1649
1650         i = 0;
1651         do
1652                 i += 2;
1653         while (auxv[i - 2] != AT_NULL);
1654         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1655                   i * sizeof(elf_addr_t), auxv);
1656
1657         /* Try to dump the FPU. */
1658         if ((prstatus->pr_fpvalid =
1659              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1660                 fill_note(notes + numnote++,
1661                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1662 #ifdef ELF_CORE_COPY_XFPREGS
1663         if (elf_core_copy_task_xfpregs(current, xfpu))
1664                 fill_note(notes + numnote++,
1665                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1666 #endif
1667
1668         fs = get_fs();
1669         set_fs(KERNEL_DS);
1670
1671         offset += sizeof(*elf);                         /* Elf header */
1672         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1673
1674         /* Write notes phdr entry */
1675         {
1676                 int sz = 0;
1677
1678                 for (i = 0; i < numnote; i++)
1679                         sz += notesize(notes + i);
1680
1681                 sz += thread_status_size;
1682
1683                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1684                 if (!phdr4note)
1685                         goto end_coredump;
1686
1687                 fill_elf_note_phdr(phdr4note, sz, offset);
1688                 offset += sz;
1689         }
1690
1691         /* Page-align dumped data */
1692         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1693
1694         offset += elf_core_vma_data_size(cprm->mm_flags);
1695         offset += elf_core_extra_data_size();
1696         e_shoff = offset;
1697
1698         if (e_phnum == PN_XNUM) {
1699                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1700                 if (!shdr4extnum)
1701                         goto end_coredump;
1702                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1703         }
1704
1705         offset = dataoff;
1706
1707         if (!dump_emit(cprm, elf, sizeof(*elf)))
1708                 goto end_coredump;
1709
1710         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1711                 goto end_coredump;
1712
1713         /* write program headers for segments dump */
1714         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1715                 struct elf_phdr phdr;
1716                 size_t sz;
1717
1718                 sz = vma->vm_end - vma->vm_start;
1719
1720                 phdr.p_type = PT_LOAD;
1721                 phdr.p_offset = offset;
1722                 phdr.p_vaddr = vma->vm_start;
1723                 phdr.p_paddr = 0;
1724                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1725                 phdr.p_memsz = sz;
1726                 offset += phdr.p_filesz;
1727                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1728                 if (vma->vm_flags & VM_WRITE)
1729                         phdr.p_flags |= PF_W;
1730                 if (vma->vm_flags & VM_EXEC)
1731                         phdr.p_flags |= PF_X;
1732                 phdr.p_align = ELF_EXEC_PAGESIZE;
1733
1734                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1735                         goto end_coredump;
1736         }
1737
1738         if (!elf_core_write_extra_phdrs(cprm, offset))
1739                 goto end_coredump;
1740
1741         /* write out the notes section */
1742         for (i = 0; i < numnote; i++)
1743                 if (!writenote(notes + i, cprm))
1744                         goto end_coredump;
1745
1746         /* write out the thread status notes section */
1747         list_for_each(t, &thread_list) {
1748                 struct elf_thread_status *tmp =
1749                                 list_entry(t, struct elf_thread_status, list);
1750
1751                 for (i = 0; i < tmp->num_notes; i++)
1752                         if (!writenote(&tmp->notes[i], cprm))
1753                                 goto end_coredump;
1754         }
1755
1756         if (!dump_skip(cprm, dataoff - cprm->pos))
1757                 goto end_coredump;
1758
1759         if (!elf_fdpic_dump_segments(cprm))
1760                 goto end_coredump;
1761
1762         if (!elf_core_write_extra_data(cprm))
1763                 goto end_coredump;
1764
1765         if (e_phnum == PN_XNUM) {
1766                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1767                         goto end_coredump;
1768         }
1769
1770         if (cprm->file->f_pos != offset) {
1771                 /* Sanity check */
1772                 printk(KERN_WARNING
1773                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1774                        cprm->file->f_pos, offset);
1775         }
1776
1777 end_coredump:
1778         set_fs(fs);
1779
1780 cleanup:
1781         while (!list_empty(&thread_list)) {
1782                 struct list_head *tmp = thread_list.next;
1783                 list_del(tmp);
1784                 kfree(list_entry(tmp, struct elf_thread_status, list));
1785         }
1786         kfree(phdr4note);
1787         kfree(elf);
1788         kfree(prstatus);
1789         kfree(psinfo);
1790         kfree(notes);
1791         kfree(fpu);
1792         kfree(shdr4extnum);
1793 #ifdef ELF_CORE_COPY_XFPREGS
1794         kfree(xfpu);
1795 #endif
1796         return has_dumped;
1797 #undef NUM_NOTES
1798 }
1799
1800 #endif          /* CONFIG_ELF_CORE */