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/sched/coredump.h>
  19 #include <linux/sched/task_stack.h>
  20 #include <linux/sched/cputime.h>
  21 #include <linux/mm.h>
  22 #include <linux/mman.h>
  23 #include <linux/errno.h>
  24 #include <linux/signal.h>
  25 #include <linux/binfmts.h>
  26 #include <linux/string.h>
  27 #include <linux/file.h>
  28 #include <linux/fcntl.h>
  29 #include <linux/slab.h>
  30 #include <linux/pagemap.h>
  31 #include <linux/security.h>
  32 #include <linux/highmem.h>
  33 #include <linux/highuid.h>
  34 #include <linux/personality.h>
  35 #include <linux/ptrace.h>
  36 #include <linux/init.h>
  37 #include <linux/elf.h>
  38 #include <linux/elf-fdpic.h>
  39 #include <linux/elfcore.h>
  40 #include <linux/coredump.h>
  41 #include <linux/dax.h>
  42
  43 #include <linux/uaccess.h>
  44 #include <asm/param.h>
  45 #include <asm/pgalloc.h>
  46
  47 typedef char *elf_caddr_t;
  48
  49 #if 0
  50 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  51 #else
  52 #define kdebug(fmt, ...) do {} while(0)
  53 #endif
  54
  55 #if 0
  56 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  57 #else
  58 #define kdcore(fmt, ...) do {} while(0)
  59 #endif
  60
  61 MODULE_LICENSE("GPL");
  62
  63 static int load_elf_fdpic_binary(struct linux_binprm *);
  64 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  65 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  66                               struct mm_struct *, const char *);
  67
  68 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  69                                    struct elf_fdpic_params *,
  70                                    struct elf_fdpic_params *);
  71
  72 #ifndef CONFIG_MMU
  73 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  74                                                    struct file *,
  75                                                    struct mm_struct *);
  76 #endif
  77
  78 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  79                                              struct file *, struct mm_struct *);
  80
  81 #ifdef CONFIG_ELF_CORE
  82 static int elf_fdpic_core_dump(struct coredump_params *cprm);
  83 #endif
  84
  85 static struct linux_binfmt elf_fdpic_format = {
  86         .module         = THIS_MODULE,
  87         .load_binary    = load_elf_fdpic_binary,
  88 #ifdef CONFIG_ELF_CORE
  89         .core_dump      = elf_fdpic_core_dump,
  90 #endif
  91         .min_coredump   = ELF_EXEC_PAGESIZE,
  92 };
  93
  94 static int __init init_elf_fdpic_binfmt(void)
  95 {
  96         register_binfmt(&elf_fdpic_format);
  97         return 0;
  98 }
  99
 100 static void __exit exit_elf_fdpic_binfmt(void)
 101 {
 102         unregister_binfmt(&elf_fdpic_format);
 103 }
 104
 105 core_initcall(init_elf_fdpic_binfmt);
 106 module_exit(exit_elf_fdpic_binfmt);
 107
 108 static int is_elf(struct elfhdr *hdr, struct file *file)
 109 {
 110         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 111                 return 0;
 112         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 113                 return 0;
 114         if (!elf_check_arch(hdr))
 115                 return 0;
 116         if (!file->f_op->mmap)
 117                 return 0;
 118         return 1;
 119 }
 120
 121 #ifndef elf_check_fdpic
 122 #define elf_check_fdpic(x) 0
 123 #endif
 124
 125 #ifndef elf_check_const_displacement
 126 #define elf_check_const_displacement(x) 0
 127 #endif
 128
 129 static int is_constdisp(struct elfhdr *hdr)
 130 {
 131         if (!elf_check_fdpic(hdr))
 132                 return 1;
 133         if (elf_check_const_displacement(hdr))
 134                 return 1;
 135         return 0;
 136 }
 137
 138 /*****************************************************************************/
 139 /*
 140  * read the program headers table into memory
 141  */
 142 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 143                                  struct file *file)
 144 {
 145         struct elf32_phdr *phdr;
 146         unsigned long size;
 147         int retval, loop;
 148         loff_t pos = params->hdr.e_phoff;
 149
 150         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 151                 return -ENOMEM;
 152         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 153                 return -ENOMEM;
 154
 155         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 156         params->phdrs = kmalloc(size, GFP_KERNEL);
 157         if (!params->phdrs)
 158                 return -ENOMEM;
 159
 160         retval = kernel_read(file, params->phdrs, size, &pos);
 161         if (unlikely(retval != size))
 162                 return retval < 0 ? retval : -ENOEXEC;
 163
 164         /* determine stack size for this binary */
 165         phdr = params->phdrs;
 166         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 167                 if (phdr->p_type != PT_GNU_STACK)
 168                         continue;
 169
 170                 if (phdr->p_flags & PF_X)
 171                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 172                 else
 173                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 174
 175                 params->stack_size = phdr->p_memsz;
 176                 break;
 177         }
 178
 179         return 0;
 180 }
 181
 182 /*****************************************************************************/
 183 /*
 184  * load an fdpic binary into various bits of memory
 185  */
 186 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 187 {
 188         struct elf_fdpic_params exec_params, interp_params;
 189         struct pt_regs *regs = current_pt_regs();
 190         struct elf_phdr *phdr;
 191         unsigned long stack_size, entryaddr;
 192 #ifdef ELF_FDPIC_PLAT_INIT
 193         unsigned long dynaddr;
 194 #endif
 195 #ifndef CONFIG_MMU
 196         unsigned long stack_prot;
 197 #endif
 198         struct file *interpreter = NULL; /* to shut gcc up */
 199         char *interpreter_name = NULL;
 200         int executable_stack;
 201         int retval, i;
 202         loff_t pos;
 203
 204         kdebug("____ LOAD %d ____", current->pid);
 205
 206         memset(&exec_params, 0, sizeof(exec_params));
 207         memset(&interp_params, 0, sizeof(interp_params));
 208
 209         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 210         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 211
 212         /* check that this is a binary we know how to deal with */
 213         retval = -ENOEXEC;
 214         if (!is_elf(&exec_params.hdr, bprm->file))
 215                 goto error;
 216         if (!elf_check_fdpic(&exec_params.hdr)) {
 217 #ifdef CONFIG_MMU
 218                 /* binfmt_elf handles non-fdpic elf except on nommu */
 219                 goto error;
 220 #else
 221                 /* nommu can only load ET_DYN (PIE) ELF */
 222                 if (exec_params.hdr.e_type != ET_DYN)
 223                         goto error;
 224 #endif
 225         }
 226
 227         /* read the program header table */
 228         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 229         if (retval < 0)
 230                 goto error;
 231
 232         /* scan for a program header that specifies an interpreter */
 233         phdr = exec_params.phdrs;
 234
 235         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 236                 switch (phdr->p_type) {
 237                 case PT_INTERP:
 238                         retval = -ENOMEM;
 239                         if (phdr->p_filesz > PATH_MAX)
 240                                 goto error;
 241                         retval = -ENOENT;
 242                         if (phdr->p_filesz < 2)
 243                                 goto error;
 244
 245                         /* read the name of the interpreter into memory */
 246                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 247                         if (!interpreter_name)
 248                                 goto error;
 249
 250                         pos = phdr->p_offset;
 251                         retval = kernel_read(bprm->file, interpreter_name,
 252                                              phdr->p_filesz, &pos);
 253                         if (unlikely(retval != phdr->p_filesz)) {
 254                                 if (retval >= 0)
 255                                         retval = -ENOEXEC;
 256                                 goto error;
 257                         }
 258
 259                         retval = -ENOENT;
 260                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 261                                 goto error;
 262
 263                         kdebug("Using ELF interpreter %s", interpreter_name);
 264
 265                         /* replace the program with the interpreter */
 266                         interpreter = open_exec(interpreter_name);
 267                         retval = PTR_ERR(interpreter);
 268                         if (IS_ERR(interpreter)) {
 269                                 interpreter = NULL;
 270                                 goto error;
 271                         }
 272
 273                         /*
 274                          * If the binary is not readable then enforce
 275                          * mm->dumpable = 0 regardless of the interpreter's
 276                          * permissions.
 277                          */
 278                         would_dump(bprm, interpreter);
 279
 280                         pos = 0;
 281                         retval = kernel_read(interpreter, bprm->buf,
 282                                         BINPRM_BUF_SIZE, &pos);
 283                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
 284                                 if (retval >= 0)
 285                                         retval = -ENOEXEC;
 286                                 goto error;
 287                         }
 288
 289                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 290                         break;
 291
 292                 case PT_LOAD:
 293 #ifdef CONFIG_MMU
 294                         if (exec_params.load_addr == 0)
 295                                 exec_params.load_addr = phdr->p_vaddr;
 296 #endif
 297                         break;
 298                 }
 299
 300         }
 301
 302         if (is_constdisp(&exec_params.hdr))
 303                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 304
 305         /* perform insanity checks on the interpreter */
 306         if (interpreter_name) {
 307                 retval = -ELIBBAD;
 308                 if (!is_elf(&interp_params.hdr, interpreter))
 309                         goto error;
 310
 311                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 312
 313                 /* read the interpreter's program header table */
 314                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 315                 if (retval < 0)
 316                         goto error;
 317         }
 318
 319         stack_size = exec_params.stack_size;
 320         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 321                 executable_stack = EXSTACK_ENABLE_X;
 322         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 323                 executable_stack = EXSTACK_DISABLE_X;
 324         else
 325                 executable_stack = EXSTACK_DEFAULT;
 326
 327         if (stack_size == 0) {
 328                 stack_size = interp_params.stack_size;
 329                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 330                         executable_stack = EXSTACK_ENABLE_X;
 331                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 332                         executable_stack = EXSTACK_DISABLE_X;
 333                 else
 334                         executable_stack = EXSTACK_DEFAULT;
 335         }
 336
 337         retval = -ENOEXEC;
 338         if (stack_size == 0)
 339                 stack_size = 131072UL; /* same as exec.c's default commit */
 340
 341         if (is_constdisp(&interp_params.hdr))
 342                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 343
 344         /* flush all traces of the currently running executable */
 345         retval = flush_old_exec(bprm);
 346         if (retval)
 347                 goto error;
 348
 349         /* there's now no turning back... the old userspace image is dead,
 350          * defunct, deceased, etc.
 351          */
 352         if (elf_check_fdpic(&exec_params.hdr))
 353                 set_personality(PER_LINUX_FDPIC);
 354         else
 355                 set_personality(PER_LINUX);
 356         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 357                 current->personality |= READ_IMPLIES_EXEC;
 358
 359         setup_new_exec(bprm);
 360
 361         set_binfmt(&elf_fdpic_format);
 362
 363         current->mm->start_code = 0;
 364         current->mm->end_code = 0;
 365         current->mm->start_stack = 0;
 366         current->mm->start_data = 0;
 367         current->mm->end_data = 0;
 368         current->mm->context.exec_fdpic_loadmap = 0;
 369         current->mm->context.interp_fdpic_loadmap = 0;
 370
 371 #ifdef CONFIG_MMU
 372         elf_fdpic_arch_lay_out_mm(&exec_params,
 373                                   &interp_params,
 374                                   &current->mm->start_stack,
 375                                   &current->mm->start_brk);
 376
 377         retval = setup_arg_pages(bprm, current->mm->start_stack,
 378                                  executable_stack);
 379         if (retval < 0)
 380                 goto error;
 381 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
 382         retval = arch_setup_additional_pages(bprm, !!interpreter_name);
 383         if (retval < 0)
 384                 goto error;
 385 #endif
 386 #endif
 387
 388         /* load the executable and interpreter into memory */
 389         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 390                                     "executable");
 391         if (retval < 0)
 392                 goto error;
 393
 394         if (interpreter_name) {
 395                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 396                                             current->mm, "interpreter");
 397                 if (retval < 0) {
 398                         printk(KERN_ERR "Unable to load interpreter\n");
 399                         goto error;
 400                 }
 401
 402                 allow_write_access(interpreter);
 403                 fput(interpreter);
 404                 interpreter = NULL;
 405         }
 406
 407 #ifdef CONFIG_MMU
 408         if (!current->mm->start_brk)
 409                 current->mm->start_brk = current->mm->end_data;
 410
 411         current->mm->brk = current->mm->start_brk =
 412                 PAGE_ALIGN(current->mm->start_brk);
 413
 414 #else
 415         /* create a stack area and zero-size brk area */
 416         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 417         if (stack_size < PAGE_SIZE * 2)
 418                 stack_size = PAGE_SIZE * 2;
 419
 420         stack_prot = PROT_READ | PROT_WRITE;
 421         if (executable_stack == EXSTACK_ENABLE_X ||
 422             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 423                 stack_prot |= PROT_EXEC;
 424
 425         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 426                                          MAP_PRIVATE | MAP_ANONYMOUS |
 427                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 428                                          0);
 429
 430         if (IS_ERR_VALUE(current->mm->start_brk)) {
 431                 retval = current->mm->start_brk;
 432                 current->mm->start_brk = 0;
 433                 goto error;
 434         }
 435
 436         current->mm->brk = current->mm->start_brk;
 437         current->mm->context.end_brk = current->mm->start_brk;
 438         current->mm->start_stack = current->mm->start_brk + stack_size;
 439 #endif
 440
 441         install_exec_creds(bprm);
 442         if (create_elf_fdpic_tables(bprm, current->mm,
 443                                     &exec_params, &interp_params) < 0)
 444                 goto error;
 445
 446         kdebug("- start_code  %lx", current->mm->start_code);
 447         kdebug("- end_code    %lx", current->mm->end_code);
 448         kdebug("- start_data  %lx", current->mm->start_data);
 449         kdebug("- end_data    %lx", current->mm->end_data);
 450         kdebug("- start_brk   %lx", current->mm->start_brk);
 451         kdebug("- brk         %lx", current->mm->brk);
 452         kdebug("- start_stack %lx", current->mm->start_stack);
 453
 454 #ifdef ELF_FDPIC_PLAT_INIT
 455         /*
 456          * The ABI may specify that certain registers be set up in special
 457          * ways (on i386 %edx is the address of a DT_FINI function, for
 458          * example.  This macro performs whatever initialization to
 459          * the regs structure is required.
 460          */
 461         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 462         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 463                             dynaddr);
 464 #endif
 465
 466         /* everything is now ready... get the userspace context ready to roll */
 467         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 468         start_thread(regs, entryaddr, current->mm->start_stack);
 469
 470         retval = 0;
 471
 472 error:
 473         if (interpreter) {
 474                 allow_write_access(interpreter);
 475                 fput(interpreter);
 476         }
 477         kfree(interpreter_name);
 478         kfree(exec_params.phdrs);
 479         kfree(exec_params.loadmap);
 480         kfree(interp_params.phdrs);
 481         kfree(interp_params.loadmap);
 482         return retval;
 483 }
 484
 485 /*****************************************************************************/
 486
 487 #ifndef ELF_BASE_PLATFORM
 488 /*
 489  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 490  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 491  * will be copied to the user stack in the same manner as AT_PLATFORM.
 492  */
 493 #define ELF_BASE_PLATFORM NULL
 494 #endif
 495
 496 /*
 497  * present useful information to the program by shovelling it onto the new
 498  * process's stack
 499  */
 500 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 501                                    struct mm_struct *mm,
 502                                    struct elf_fdpic_params *exec_params,
 503                                    struct elf_fdpic_params *interp_params)
 504 {
 505         const struct cred *cred = current_cred();
 506         unsigned long sp, csp, nitems;
 507         elf_caddr_t __user *argv, *envp;
 508         size_t platform_len = 0, len;
 509         char *k_platform, *k_base_platform;
 510         char __user *u_platform, *u_base_platform, *p;
 511         int loop;
 512         int nr; /* reset for each csp adjustment */
 513
 514 #ifdef CONFIG_MMU
 515         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 516          * by the processes running on the same package. One thing we can do is
 517          * to shuffle the initial stack for them, so we give the architecture
 518          * an opportunity to do so here.
 519          */
 520         sp = arch_align_stack(bprm->p);
 521 #else
 522         sp = mm->start_stack;
 523
 524         /* stack the program arguments and environment */
 525         if (transfer_args_to_stack(bprm, &sp) < 0)
 526                 return -EFAULT;
 527         sp &= ~15;
 528 #endif
 529
 530         /*
 531          * If this architecture has a platform capability string, copy it
 532          * to userspace.  In some cases (Sparc), this info is impossible
 533          * for userspace to get any other way, in others (i386) it is
 534          * merely difficult.
 535          */
 536         k_platform = ELF_PLATFORM;
 537         u_platform = NULL;
 538
 539         if (k_platform) {
 540                 platform_len = strlen(k_platform) + 1;
 541                 sp -= platform_len;
 542                 u_platform = (char __user *) sp;
 543                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 544                         return -EFAULT;
 545         }
 546
 547         /*
 548          * If this architecture has a "base" platform capability
 549          * string, copy it to userspace.
 550          */
 551         k_base_platform = ELF_BASE_PLATFORM;
 552         u_base_platform = NULL;
 553
 554         if (k_base_platform) {
 555                 platform_len = strlen(k_base_platform) + 1;
 556                 sp -= platform_len;
 557                 u_base_platform = (char __user *) sp;
 558                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 559                         return -EFAULT;
 560         }
 561
 562         sp &= ~7UL;
 563
 564         /* stack the load map(s) */
 565         len = sizeof(struct elf32_fdpic_loadmap);
 566         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 567         sp = (sp - len) & ~7UL;
 568         exec_params->map_addr = sp;
 569
 570         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 571                 return -EFAULT;
 572
 573         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 574
 575         if (interp_params->loadmap) {
 576                 len = sizeof(struct elf32_fdpic_loadmap);
 577                 len += sizeof(struct elf32_fdpic_loadseg) *
 578                         interp_params->loadmap->nsegs;
 579                 sp = (sp - len) & ~7UL;
 580                 interp_params->map_addr = sp;
 581
 582                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 583                                  len) != 0)
 584                         return -EFAULT;
 585
 586                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 587         }
 588
 589         /* force 16 byte _final_ alignment here for generality */
 590 #define DLINFO_ITEMS 15
 591
 592         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 593                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 594
 595         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 596                 nitems++;
 597
 598         csp = sp;
 599         sp -= nitems * 2 * sizeof(unsigned long);
 600         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 601         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 602         sp -= 1 * sizeof(unsigned long);                /* argc */
 603
 604         csp -= sp & 15UL;
 605         sp -= sp & 15UL;
 606
 607         /* put the ELF interpreter info on the stack */
 608 #define NEW_AUX_ENT(id, val)                                            \
 609         do {                                                            \
 610                 struct { unsigned long _id, _val; } __user *ent;        \
 611                                                                         \
 612                 ent = (void __user *) csp;                              \
 613                 __put_user((id), &ent[nr]._id);                         \
 614                 __put_user((val), &ent[nr]._val);                       \
 615                 nr++;                                                   \
 616         } while (0)
 617
 618         nr = 0;
 619         csp -= 2 * sizeof(unsigned long);
 620         NEW_AUX_ENT(AT_NULL, 0);
 621         if (k_platform) {
 622                 nr = 0;
 623                 csp -= 2 * sizeof(unsigned long);
 624                 NEW_AUX_ENT(AT_PLATFORM,
 625                             (elf_addr_t) (unsigned long) u_platform);
 626         }
 627
 628         if (k_base_platform) {
 629                 nr = 0;
 630                 csp -= 2 * sizeof(unsigned long);
 631                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 632                             (elf_addr_t) (unsigned long) u_base_platform);
 633         }
 634
 635         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 636                 nr = 0;
 637                 csp -= 2 * sizeof(unsigned long);
 638                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 639         }
 640
 641         nr = 0;
 642         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 643         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 644 #ifdef ELF_HWCAP2
 645         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 646 #endif
 647         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 648         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 649         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 650         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 651         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 652         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 653         NEW_AUX_ENT(AT_FLAGS,   0);
 654         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 655         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 656         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 657         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 658         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 659         NEW_AUX_ENT(AT_SECURE,  bprm->secureexec);
 660         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 661
 662 #ifdef ARCH_DLINFO
 663         nr = 0;
 664         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 665
 666         /* ARCH_DLINFO must come last so platform specific code can enforce
 667          * special alignment requirements on the AUXV if necessary (eg. PPC).
 668          */
 669         ARCH_DLINFO;
 670 #endif
 671 #undef NEW_AUX_ENT
 672
 673         /* allocate room for argv[] and envv[] */
 674         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 675         envp = (elf_caddr_t __user *) csp;
 676         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 677         argv = (elf_caddr_t __user *) csp;
 678
 679         /* stack argc */
 680         csp -= sizeof(unsigned long);
 681         __put_user(bprm->argc, (unsigned long __user *) csp);
 682
 683         BUG_ON(csp != sp);
 684
 685         /* fill in the argv[] array */
 686 #ifdef CONFIG_MMU
 687         current->mm->arg_start = bprm->p;
 688 #else
 689         current->mm->arg_start = current->mm->start_stack -
 690                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 691 #endif
 692
 693         p = (char __user *) current->mm->arg_start;
 694         for (loop = bprm->argc; loop > 0; loop--) {
 695                 __put_user((elf_caddr_t) p, argv++);
 696                 len = strnlen_user(p, MAX_ARG_STRLEN);
 697                 if (!len || len > MAX_ARG_STRLEN)
 698                         return -EINVAL;
 699                 p += len;
 700         }
 701         __put_user(NULL, argv);
 702         current->mm->arg_end = (unsigned long) p;
 703
 704         /* fill in the envv[] array */
 705         current->mm->env_start = (unsigned long) p;
 706         for (loop = bprm->envc; loop > 0; loop--) {
 707                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 708                 len = strnlen_user(p, MAX_ARG_STRLEN);
 709                 if (!len || len > MAX_ARG_STRLEN)
 710                         return -EINVAL;
 711                 p += len;
 712         }
 713         __put_user(NULL, envp);
 714         current->mm->env_end = (unsigned long) p;
 715
 716         mm->start_stack = (unsigned long) sp;
 717         return 0;
 718 }
 719
 720 /*****************************************************************************/
 721 /*
 722  * load the appropriate binary image (executable or interpreter) into memory
 723  * - we assume no MMU is available
 724  * - if no other PIC bits are set in params->hdr->e_flags
 725  *   - we assume that the LOADable segments in the binary are independently relocatable
 726  *   - we assume R/O executable segments are shareable
 727  * - else
 728  *   - we assume the loadable parts of the image to require fixed displacement
 729  *   - the image is not shareable
 730  */
 731 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 732                               struct file *file,
 733                               struct mm_struct *mm,
 734                               const char *what)
 735 {
 736         struct elf32_fdpic_loadmap *loadmap;
 737 #ifdef CONFIG_MMU
 738         struct elf32_fdpic_loadseg *mseg;
 739 #endif
 740         struct elf32_fdpic_loadseg *seg;
 741         struct elf32_phdr *phdr;
 742         unsigned long load_addr, stop;
 743         unsigned nloads, tmp;
 744         size_t size;
 745         int loop, ret;
 746
 747         /* allocate a load map table */
 748         nloads = 0;
 749         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 750                 if (params->phdrs[loop].p_type == PT_LOAD)
 751                         nloads++;
 752
 753         if (nloads == 0)
 754                 return -ELIBBAD;
 755
 756         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 757         loadmap = kzalloc(size, GFP_KERNEL);
 758         if (!loadmap)
 759                 return -ENOMEM;
 760
 761         params->loadmap = loadmap;
 762
 763         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 764         loadmap->nsegs = nloads;
 765
 766         load_addr = params->load_addr;
 767         seg = loadmap->segs;
 768
 769         /* map the requested LOADs into the memory space */
 770         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 771         case ELF_FDPIC_FLAG_CONSTDISP:
 772         case ELF_FDPIC_FLAG_CONTIGUOUS:
 773 #ifndef CONFIG_MMU
 774                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 775                 if (ret < 0)
 776                         return ret;
 777                 break;
 778 #endif
 779         default:
 780                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 781                 if (ret < 0)
 782                         return ret;
 783                 break;
 784         }
 785
 786         /* map the entry point */
 787         if (params->hdr.e_entry) {
 788                 seg = loadmap->segs;
 789                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 790                         if (params->hdr.e_entry >= seg->p_vaddr &&
 791                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 792                                 params->entry_addr =
 793                                         (params->hdr.e_entry - seg->p_vaddr) +
 794                                         seg->addr;
 795                                 break;
 796                         }
 797                 }
 798         }
 799
 800         /* determine where the program header table has wound up if mapped */
 801         stop = params->hdr.e_phoff;
 802         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 803         phdr = params->phdrs;
 804
 805         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 806                 if (phdr->p_type != PT_LOAD)
 807                         continue;
 808
 809                 if (phdr->p_offset > params->hdr.e_phoff ||
 810                     phdr->p_offset + phdr->p_filesz < stop)
 811                         continue;
 812
 813                 seg = loadmap->segs;
 814                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 815                         if (phdr->p_vaddr >= seg->p_vaddr &&
 816                             phdr->p_vaddr + phdr->p_filesz <=
 817                             seg->p_vaddr + seg->p_memsz) {
 818                                 params->ph_addr =
 819                                         (phdr->p_vaddr - seg->p_vaddr) +
 820                                         seg->addr +
 821                                         params->hdr.e_phoff - phdr->p_offset;
 822                                 break;
 823                         }
 824                 }
 825                 break;
 826         }
 827
 828         /* determine where the dynamic section has wound up if there is one */
 829         phdr = params->phdrs;
 830         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 831                 if (phdr->p_type != PT_DYNAMIC)
 832                         continue;
 833
 834                 seg = loadmap->segs;
 835                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 836                         if (phdr->p_vaddr >= seg->p_vaddr &&
 837                             phdr->p_vaddr + phdr->p_memsz <=
 838                             seg->p_vaddr + seg->p_memsz) {
 839                                 Elf32_Dyn __user *dyn;
 840                                 Elf32_Sword d_tag;
 841
 842                                 params->dynamic_addr =
 843                                         (phdr->p_vaddr - seg->p_vaddr) +
 844                                         seg->addr;
 845
 846                                 /* check the dynamic section contains at least
 847                                  * one item, and that the last item is a NULL
 848                                  * entry */
 849                                 if (phdr->p_memsz == 0 ||
 850                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 851                                         goto dynamic_error;
 852
 853                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 854                                 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
 855                                 __get_user(d_tag, &dyn[tmp - 1].d_tag);
 856                                 if (d_tag != 0)
 857                                         goto dynamic_error;
 858                                 break;
 859                         }
 860                 }
 861                 break;
 862         }
 863
 864         /* now elide adjacent segments in the load map on MMU linux
 865          * - on uClinux the holes between may actually be filled with system
 866          *   stuff or stuff from other processes
 867          */
 868 #ifdef CONFIG_MMU
 869         nloads = loadmap->nsegs;
 870         mseg = loadmap->segs;
 871         seg = mseg + 1;
 872         for (loop = 1; loop < nloads; loop++) {
 873                 /* see if we have a candidate for merging */
 874                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 875                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 876                         if (load_addr == (seg->addr & PAGE_MASK)) {
 877                                 mseg->p_memsz +=
 878                                         load_addr -
 879                                         (mseg->addr + mseg->p_memsz);
 880                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 881                                 mseg->p_memsz += seg->p_memsz;
 882                                 loadmap->nsegs--;
 883                                 continue;
 884                         }
 885                 }
 886
 887                 mseg++;
 888                 if (mseg != seg)
 889                         *mseg = *seg;
 890         }
 891 #endif
 892
 893         kdebug("Mapped Object [%s]:", what);
 894         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 895         kdebug("- entry    : %lx", params->entry_addr);
 896         kdebug("- PHDR[]   : %lx", params->ph_addr);
 897         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 898         seg = loadmap->segs;
 899         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 900                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 901                        loop,
 902                        seg->addr, seg->addr + seg->p_memsz - 1,
 903                        seg->p_vaddr, seg->p_memsz);
 904
 905         return 0;
 906
 907 dynamic_error:
 908         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 909                what, file_inode(file)->i_ino);
 910         return -ELIBBAD;
 911 }
 912
 913 /*****************************************************************************/
 914 /*
 915  * map a file with constant displacement under uClinux
 916  */
 917 #ifndef CONFIG_MMU
 918 static int elf_fdpic_map_file_constdisp_on_uclinux(
 919         struct elf_fdpic_params *params,
 920         struct file *file,
 921         struct mm_struct *mm)
 922 {
 923         struct elf32_fdpic_loadseg *seg;
 924         struct elf32_phdr *phdr;
 925         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 926         int loop, ret;
 927
 928         load_addr = params->load_addr;
 929         seg = params->loadmap->segs;
 930
 931         /* determine the bounds of the contiguous overall allocation we must
 932          * make */
 933         phdr = params->phdrs;
 934         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 935                 if (params->phdrs[loop].p_type != PT_LOAD)
 936                         continue;
 937
 938                 if (base > phdr->p_vaddr)
 939                         base = phdr->p_vaddr;
 940                 if (top < phdr->p_vaddr + phdr->p_memsz)
 941                         top = phdr->p_vaddr + phdr->p_memsz;
 942         }
 943
 944         /* allocate one big anon block for everything */
 945         mflags = MAP_PRIVATE;
 946         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 947                 mflags |= MAP_EXECUTABLE;
 948
 949         maddr = vm_mmap(NULL, load_addr, top - base,
 950                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 951         if (IS_ERR_VALUE(maddr))
 952                 return (int) maddr;
 953
 954         if (load_addr != 0)
 955                 load_addr += PAGE_ALIGN(top - base);
 956
 957         /* and then load the file segments into it */
 958         phdr = params->phdrs;
 959         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 960                 if (params->phdrs[loop].p_type != PT_LOAD)
 961                         continue;
 962
 963                 seg->addr = maddr + (phdr->p_vaddr - base);
 964                 seg->p_vaddr = phdr->p_vaddr;
 965                 seg->p_memsz = phdr->p_memsz;
 966
 967                 ret = read_code(file, seg->addr, phdr->p_offset,
 968                                        phdr->p_filesz);
 969                 if (ret < 0)
 970                         return ret;
 971
 972                 /* map the ELF header address if in this segment */
 973                 if (phdr->p_offset == 0)
 974                         params->elfhdr_addr = seg->addr;
 975
 976                 /* clear any space allocated but not loaded */
 977                 if (phdr->p_filesz < phdr->p_memsz) {
 978                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
 979                                        phdr->p_memsz - phdr->p_filesz))
 980                                 return -EFAULT;
 981                 }
 982
 983                 if (mm) {
 984                         if (phdr->p_flags & PF_X) {
 985                                 if (!mm->start_code) {
 986                                         mm->start_code = seg->addr;
 987                                         mm->end_code = seg->addr +
 988                                                 phdr->p_memsz;
 989                                 }
 990                         } else if (!mm->start_data) {
 991                                 mm->start_data = seg->addr;
 992                                 mm->end_data = seg->addr + phdr->p_memsz;
 993                         }
 994                 }
 995
 996                 seg++;
 997         }
 998
 999         return 0;
1000 }
1001 #endif
1002
1003 /*****************************************************************************/
1004 /*
1005  * map a binary by direct mmap() of the individual PT_LOAD segments
1006  */
1007 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1008                                              struct file *file,
1009                                              struct mm_struct *mm)
1010 {
1011         struct elf32_fdpic_loadseg *seg;
1012         struct elf32_phdr *phdr;
1013         unsigned long load_addr, delta_vaddr;
1014         int loop, dvset;
1015
1016         load_addr = params->load_addr;
1017         delta_vaddr = 0;
1018         dvset = 0;
1019
1020         seg = params->loadmap->segs;
1021
1022         /* deal with each load segment separately */
1023         phdr = params->phdrs;
1024         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1025                 unsigned long maddr, disp, excess, excess1;
1026                 int prot = 0, flags;
1027
1028                 if (phdr->p_type != PT_LOAD)
1029                         continue;
1030
1031                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1032                        (unsigned long) phdr->p_vaddr,
1033                        (unsigned long) phdr->p_offset,
1034                        (unsigned long) phdr->p_filesz,
1035                        (unsigned long) phdr->p_memsz);
1036
1037                 /* determine the mapping parameters */
1038                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1039                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1040                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1041
1042                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1043                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1044                         flags |= MAP_EXECUTABLE;
1045
1046                 maddr = 0;
1047
1048                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1049                 case ELF_FDPIC_FLAG_INDEPENDENT:
1050                         /* PT_LOADs are independently locatable */
1051                         break;
1052
1053                 case ELF_FDPIC_FLAG_HONOURVADDR:
1054                         /* the specified virtual address must be honoured */
1055                         maddr = phdr->p_vaddr;
1056                         flags |= MAP_FIXED;
1057                         break;
1058
1059                 case ELF_FDPIC_FLAG_CONSTDISP:
1060                         /* constant displacement
1061                          * - can be mapped anywhere, but must be mapped as a
1062                          *   unit
1063                          */
1064                         if (!dvset) {
1065                                 maddr = load_addr;
1066                                 delta_vaddr = phdr->p_vaddr;
1067                                 dvset = 1;
1068                         } else {
1069                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1070                                 flags |= MAP_FIXED;
1071                         }
1072                         break;
1073
1074                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1075                         /* contiguity handled later */
1076                         break;
1077
1078                 default:
1079                         BUG();
1080                 }
1081
1082                 maddr &= PAGE_MASK;
1083
1084                 /* create the mapping */
1085                 disp = phdr->p_vaddr & ~PAGE_MASK;
1086                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1087                                 phdr->p_offset - disp);
1088
1089                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1090                        loop, phdr->p_memsz + disp, prot, flags,
1091                        phdr->p_offset - disp, maddr);
1092
1093                 if (IS_ERR_VALUE(maddr))
1094                         return (int) maddr;
1095
1096                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1097                     ELF_FDPIC_FLAG_CONTIGUOUS)
1098                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1099
1100                 seg->addr = maddr + disp;
1101                 seg->p_vaddr = phdr->p_vaddr;
1102                 seg->p_memsz = phdr->p_memsz;
1103
1104                 /* map the ELF header address if in this segment */
1105                 if (phdr->p_offset == 0)
1106                         params->elfhdr_addr = seg->addr;
1107
1108                 /* clear the bit between beginning of mapping and beginning of
1109                  * PT_LOAD */
1110                 if (prot & PROT_WRITE && disp > 0) {
1111                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1112                         if (clear_user((void __user *) maddr, disp))
1113                                 return -EFAULT;
1114                         maddr += disp;
1115                 }
1116
1117                 /* clear any space allocated but not loaded
1118                  * - on uClinux we can just clear the lot
1119                  * - on MMU linux we'll get a SIGBUS beyond the last page
1120                  *   extant in the file
1121                  */
1122                 excess = phdr->p_memsz - phdr->p_filesz;
1123                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1124
1125 #ifdef CONFIG_MMU
1126                 if (excess > excess1) {
1127                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1128                         unsigned long xmaddr;
1129
1130                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1131                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1132                                          prot, flags, 0);
1133
1134                         kdebug("mmap[%d] <anon>"
1135                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1136                                loop, xaddr, excess - excess1, prot, flags,
1137                                xmaddr);
1138
1139                         if (xmaddr != xaddr)
1140                                 return -ENOMEM;
1141                 }
1142
1143                 if (prot & PROT_WRITE && excess1 > 0) {
1144                         kdebug("clear[%d] ad=%lx sz=%lx",
1145                                loop, maddr + phdr->p_filesz, excess1);
1146                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1147                                        excess1))
1148                                 return -EFAULT;
1149                 }
1150
1151 #else
1152                 if (excess > 0) {
1153                         kdebug("clear[%d] ad=%lx sz=%lx",
1154                                loop, maddr + phdr->p_filesz, excess);
1155                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1156                                 return -EFAULT;
1157                 }
1158 #endif
1159
1160                 if (mm) {
1161                         if (phdr->p_flags & PF_X) {
1162                                 if (!mm->start_code) {
1163                                         mm->start_code = maddr;
1164                                         mm->end_code = maddr + phdr->p_memsz;
1165                                 }
1166                         } else if (!mm->start_data) {
1167                                 mm->start_data = maddr;
1168                                 mm->end_data = maddr + phdr->p_memsz;
1169                         }
1170                 }
1171
1172                 seg++;
1173         }
1174
1175         return 0;
1176 }
1177
1178 /*****************************************************************************/
1179 /*
1180  * ELF-FDPIC core dumper
1181  *
1182  * Modelled on fs/exec.c:aout_core_dump()
1183  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1184  *
1185  * Modelled on fs/binfmt_elf.c core dumper
1186  */
1187 #ifdef CONFIG_ELF_CORE
1188
1189 /*
1190  * Decide whether a segment is worth dumping; default is yes to be
1191  * sure (missing info is worse than too much; etc).
1192  * Personally I'd include everything, and use the coredump limit...
1193  *
1194  * I think we should skip something. But I am not sure how. H.J.
1195  */
1196 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1197 {
1198         int dump_ok;
1199
1200         /* Do not dump I/O mapped devices or special mappings */
1201         if (vma->vm_flags & VM_IO) {
1202                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1203                 return 0;
1204         }
1205
1206         /* If we may not read the contents, don't allow us to dump
1207          * them either. "dump_write()" can't handle it anyway.
1208          */
1209         if (!(vma->vm_flags & VM_READ)) {
1210                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1211                 return 0;
1212         }
1213
1214         /* support for DAX */
1215         if (vma_is_dax(vma)) {
1216                 if (vma->vm_flags & VM_SHARED) {
1217                         dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
1218                         kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
1219                                vma->vm_flags, dump_ok ? "yes" : "no");
1220                 } else {
1221                         dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
1222                         kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
1223                                vma->vm_flags, dump_ok ? "yes" : "no");
1224                 }
1225                 return dump_ok;
1226         }
1227
1228         /* By default, dump shared memory if mapped from an anonymous file. */
1229         if (vma->vm_flags & VM_SHARED) {
1230                 if (file_inode(vma->vm_file)->i_nlink == 0) {
1231                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1232                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1233                                vma->vm_flags, dump_ok ? "yes" : "no");
1234                         return dump_ok;
1235                 }
1236
1237                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1238                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1239                        vma->vm_flags, dump_ok ? "yes" : "no");
1240                 return dump_ok;
1241         }
1242
1243 #ifdef CONFIG_MMU
1244         /* By default, if it hasn't been written to, don't write it out */
1245         if (!vma->anon_vma) {
1246                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1247                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1248                        vma->vm_flags, dump_ok ? "yes" : "no");
1249                 return dump_ok;
1250         }
1251 #endif
1252
1253         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1254         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1255                dump_ok ? "yes" : "no");
1256         return dump_ok;
1257 }
1258
1259 /* An ELF note in memory */
1260 struct memelfnote
1261 {
1262         const char *name;
1263         int type;
1264         unsigned int datasz;
1265         void *data;
1266 };
1267
1268 static int notesize(struct memelfnote *en)
1269 {
1270         int sz;
1271
1272         sz = sizeof(struct elf_note);
1273         sz += roundup(strlen(en->name) + 1, 4);
1274         sz += roundup(en->datasz, 4);
1275
1276         return sz;
1277 }
1278
1279 /* #define DEBUG */
1280
1281 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1282 {
1283         struct elf_note en;
1284         en.n_namesz = strlen(men->name) + 1;
1285         en.n_descsz = men->datasz;
1286         en.n_type = men->type;
1287
1288         return dump_emit(cprm, &en, sizeof(en)) &&
1289                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1290                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1291 }
1292
1293 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1294 {
1295         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1296         elf->e_ident[EI_CLASS] = ELF_CLASS;
1297         elf->e_ident[EI_DATA] = ELF_DATA;
1298         elf->e_ident[EI_VERSION] = EV_CURRENT;
1299         elf->e_ident[EI_OSABI] = ELF_OSABI;
1300         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1301
1302         elf->e_type = ET_CORE;
1303         elf->e_machine = ELF_ARCH;
1304         elf->e_version = EV_CURRENT;
1305         elf->e_entry = 0;
1306         elf->e_phoff = sizeof(struct elfhdr);
1307         elf->e_shoff = 0;
1308         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1309         elf->e_ehsize = sizeof(struct elfhdr);
1310         elf->e_phentsize = sizeof(struct elf_phdr);
1311         elf->e_phnum = segs;
1312         elf->e_shentsize = 0;
1313         elf->e_shnum = 0;
1314         elf->e_shstrndx = 0;
1315         return;
1316 }
1317
1318 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1319 {
1320         phdr->p_type = PT_NOTE;
1321         phdr->p_offset = offset;
1322         phdr->p_vaddr = 0;
1323         phdr->p_paddr = 0;
1324         phdr->p_filesz = sz;
1325         phdr->p_memsz = 0;
1326         phdr->p_flags = 0;
1327         phdr->p_align = 0;
1328         return;
1329 }
1330
1331 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1332                 unsigned int sz, void *data)
1333 {
1334         note->name = name;
1335         note->type = type;
1336         note->datasz = sz;
1337         note->data = data;
1338         return;
1339 }
1340
1341 /*
1342  * fill up all the fields in prstatus from the given task struct, except
1343  * registers which need to be filled up separately.
1344  */
1345 static void fill_prstatus(struct elf_prstatus *prstatus,
1346                           struct task_struct *p, long signr)
1347 {
1348         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1349         prstatus->pr_sigpend = p->pending.signal.sig[0];
1350         prstatus->pr_sighold = p->blocked.sig[0];
1351         rcu_read_lock();
1352         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1353         rcu_read_unlock();
1354         prstatus->pr_pid = task_pid_vnr(p);
1355         prstatus->pr_pgrp = task_pgrp_vnr(p);
1356         prstatus->pr_sid = task_session_vnr(p);
1357         if (thread_group_leader(p)) {
1358                 struct task_cputime cputime;
1359
1360                 /*
1361                  * This is the record for the group leader.  It shows the
1362                  * group-wide total, not its individual thread total.
1363                  */
1364                 thread_group_cputime(p, &cputime);
1365                 prstatus->pr_utime = ns_to_timeval(cputime.utime);
1366                 prstatus->pr_stime = ns_to_timeval(cputime.stime);
1367         } else {
1368                 u64 utime, stime;
1369
1370                 task_cputime(p, &utime, &stime);
1371                 prstatus->pr_utime = ns_to_timeval(utime);
1372                 prstatus->pr_stime = ns_to_timeval(stime);
1373         }
1374         prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
1375         prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
1376
1377         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1378         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1379 }
1380
1381 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1382                        struct mm_struct *mm)
1383 {
1384         const struct cred *cred;
1385         unsigned int i, len;
1386
1387         /* first copy the parameters from user space */
1388         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1389
1390         len = mm->arg_end - mm->arg_start;
1391         if (len >= ELF_PRARGSZ)
1392                 len = ELF_PRARGSZ - 1;
1393         if (copy_from_user(&psinfo->pr_psargs,
1394                            (const char __user *) mm->arg_start, len))
1395                 return -EFAULT;
1396         for (i = 0; i < len; i++)
1397                 if (psinfo->pr_psargs[i] == 0)
1398                         psinfo->pr_psargs[i] = ' ';
1399         psinfo->pr_psargs[len] = 0;
1400
1401         rcu_read_lock();
1402         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1403         rcu_read_unlock();
1404         psinfo->pr_pid = task_pid_vnr(p);
1405         psinfo->pr_pgrp = task_pgrp_vnr(p);
1406         psinfo->pr_sid = task_session_vnr(p);
1407
1408         i = p->state ? ffz(~p->state) + 1 : 0;
1409         psinfo->pr_state = i;
1410         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1411         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1412         psinfo->pr_nice = task_nice(p);
1413         psinfo->pr_flag = p->flags;
1414         rcu_read_lock();
1415         cred = __task_cred(p);
1416         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1417         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1418         rcu_read_unlock();
1419         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1420
1421         return 0;
1422 }
1423
1424 /* Here is the structure in which status of each thread is captured. */
1425 struct elf_thread_status
1426 {
1427         struct list_head list;
1428         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1429         elf_fpregset_t fpu;             /* NT_PRFPREG */
1430         struct task_struct *thread;
1431 #ifdef ELF_CORE_COPY_XFPREGS
1432         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1433 #endif
1434         struct memelfnote notes[3];
1435         int num_notes;
1436 };
1437
1438 /*
1439  * In order to add the specific thread information for the elf file format,
1440  * we need to keep a linked list of every thread's pr_status and then create
1441  * a single section for them in the final core file.
1442  */
1443 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1444 {
1445         struct task_struct *p = t->thread;
1446         int sz = 0;
1447
1448         t->num_notes = 0;
1449
1450         fill_prstatus(&t->prstatus, p, signr);
1451         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1452
1453         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1454                   &t->prstatus);
1455         t->num_notes++;
1456         sz += notesize(&t->notes[0]);
1457
1458         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1459         if (t->prstatus.pr_fpvalid) {
1460                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1461                           &t->fpu);
1462                 t->num_notes++;
1463                 sz += notesize(&t->notes[1]);
1464         }
1465
1466 #ifdef ELF_CORE_COPY_XFPREGS
1467         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1468                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1469                           sizeof(t->xfpu), &t->xfpu);
1470                 t->num_notes++;
1471                 sz += notesize(&t->notes[2]);
1472         }
1473 #endif
1474         return sz;
1475 }
1476
1477 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1478                              elf_addr_t e_shoff, int segs)
1479 {
1480         elf->e_shoff = e_shoff;
1481         elf->e_shentsize = sizeof(*shdr4extnum);
1482         elf->e_shnum = 1;
1483         elf->e_shstrndx = SHN_UNDEF;
1484
1485         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1486
1487         shdr4extnum->sh_type = SHT_NULL;
1488         shdr4extnum->sh_size = elf->e_shnum;
1489         shdr4extnum->sh_link = elf->e_shstrndx;
1490         shdr4extnum->sh_info = segs;
1491 }
1492
1493 /*
1494  * dump the segments for an MMU process
1495  */
1496 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1497 {
1498         struct vm_area_struct *vma;
1499
1500         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1501 #ifdef CONFIG_MMU
1502                 unsigned long addr;
1503 #endif
1504
1505                 if (!maydump(vma, cprm->mm_flags))
1506                         continue;
1507
1508 #ifdef CONFIG_MMU
1509                 for (addr = vma->vm_start; addr < vma->vm_end;
1510                                                         addr += PAGE_SIZE) {
1511                         bool res;
1512                         struct page *page = get_dump_page(addr);
1513                         if (page) {
1514                                 void *kaddr = kmap(page);
1515                                 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1516                                 kunmap(page);
1517                                 put_page(page);
1518                         } else {
1519                                 res = dump_skip(cprm, PAGE_SIZE);
1520                         }
1521                         if (!res)
1522                                 return false;
1523                 }
1524 #else
1525                 if (!dump_emit(cprm, (void *) vma->vm_start,
1526                                 vma->vm_end - vma->vm_start))
1527                         return false;
1528 #endif
1529         }
1530         return true;
1531 }
1532
1533 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1534 {
1535         struct vm_area_struct *vma;
1536         size_t size = 0;
1537
1538         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1539                 if (maydump(vma, mm_flags))
1540                         size += vma->vm_end - vma->vm_start;
1541         return size;
1542 }
1543
1544 /*
1545  * Actual dumper
1546  *
1547  * This is a two-pass process; first we find the offsets of the bits,
1548  * and then they are actually written out.  If we run out of core limit
1549  * we just truncate.
1550  */
1551 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1552 {
1553 #define NUM_NOTES       6
1554         int has_dumped = 0;
1555         mm_segment_t fs;
1556         int segs;
1557         int i;
1558         struct vm_area_struct *vma;
1559         struct elfhdr *elf = NULL;
1560         loff_t offset = 0, dataoff;
1561         int numnote;
1562         struct memelfnote *notes = NULL;
1563         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1564         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1565         LIST_HEAD(thread_list);
1566         struct list_head *t;
1567         elf_fpregset_t *fpu = NULL;
1568 #ifdef ELF_CORE_COPY_XFPREGS
1569         elf_fpxregset_t *xfpu = NULL;
1570 #endif
1571         int thread_status_size = 0;
1572         elf_addr_t *auxv;
1573         struct elf_phdr *phdr4note = NULL;
1574         struct elf_shdr *shdr4extnum = NULL;
1575         Elf_Half e_phnum;
1576         elf_addr_t e_shoff;
1577         struct core_thread *ct;
1578         struct elf_thread_status *tmp;
1579
1580         /*
1581          * We no longer stop all VM operations.
1582          *
1583          * This is because those proceses that could possibly change map_count
1584          * or the mmap / vma pages are now blocked in do_exit on current
1585          * finishing this core dump.
1586          *
1587          * Only ptrace can touch these memory addresses, but it doesn't change
1588          * the map_count or the pages allocated. So no possibility of crashing
1589          * exists while dumping the mm->vm_next areas to the core file.
1590          */
1591
1592         /* alloc memory for large data structures: too large to be on stack */
1593         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1594         if (!elf)
1595                 goto cleanup;
1596         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1597         if (!prstatus)
1598                 goto cleanup;
1599         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1600         if (!psinfo)
1601                 goto cleanup;
1602         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1603         if (!notes)
1604                 goto cleanup;
1605         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1606         if (!fpu)
1607                 goto cleanup;
1608 #ifdef ELF_CORE_COPY_XFPREGS
1609         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1610         if (!xfpu)
1611                 goto cleanup;
1612 #endif
1613
1614         for (ct = current->mm->core_state->dumper.next;
1615                                         ct; ct = ct->next) {
1616                 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1617                 if (!tmp)
1618                         goto cleanup;
1619
1620                 tmp->thread = ct->task;
1621                 list_add(&tmp->list, &thread_list);
1622         }
1623
1624         list_for_each(t, &thread_list) {
1625                 struct elf_thread_status *tmp;
1626                 int sz;
1627
1628                 tmp = list_entry(t, struct elf_thread_status, list);
1629                 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1630                 thread_status_size += sz;
1631         }
1632
1633         /* now collect the dump for the current */
1634         fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1635         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1636
1637         segs = current->mm->map_count;
1638         segs += elf_core_extra_phdrs();
1639
1640         /* for notes section */
1641         segs++;
1642
1643         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1644          * this, kernel supports extended numbering. Have a look at
1645          * include/linux/elf.h for further information. */
1646         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1647
1648         /* Set up header */
1649         fill_elf_fdpic_header(elf, e_phnum);
1650
1651         has_dumped = 1;
1652         /*
1653          * Set up the notes in similar form to SVR4 core dumps made
1654          * with info from their /proc.
1655          */
1656
1657         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1658         fill_psinfo(psinfo, current->group_leader, current->mm);
1659         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1660
1661         numnote = 2;
1662
1663         auxv = (elf_addr_t *) current->mm->saved_auxv;
1664
1665         i = 0;
1666         do
1667                 i += 2;
1668         while (auxv[i - 2] != AT_NULL);
1669         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1670                   i * sizeof(elf_addr_t), auxv);
1671
1672         /* Try to dump the FPU. */
1673         if ((prstatus->pr_fpvalid =
1674              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1675                 fill_note(notes + numnote++,
1676                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1677 #ifdef ELF_CORE_COPY_XFPREGS
1678         if (elf_core_copy_task_xfpregs(current, xfpu))
1679                 fill_note(notes + numnote++,
1680                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1681 #endif
1682
1683         fs = get_fs();
1684         set_fs(KERNEL_DS);
1685
1686         offset += sizeof(*elf);                         /* Elf header */
1687         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1688
1689         /* Write notes phdr entry */
1690         {
1691                 int sz = 0;
1692
1693                 for (i = 0; i < numnote; i++)
1694                         sz += notesize(notes + i);
1695
1696                 sz += thread_status_size;
1697
1698                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1699                 if (!phdr4note)
1700                         goto end_coredump;
1701
1702                 fill_elf_note_phdr(phdr4note, sz, offset);
1703                 offset += sz;
1704         }
1705
1706         /* Page-align dumped data */
1707         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1708
1709         offset += elf_core_vma_data_size(cprm->mm_flags);
1710         offset += elf_core_extra_data_size();
1711         e_shoff = offset;
1712
1713         if (e_phnum == PN_XNUM) {
1714                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1715                 if (!shdr4extnum)
1716                         goto end_coredump;
1717                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1718         }
1719
1720         offset = dataoff;
1721
1722         if (!dump_emit(cprm, elf, sizeof(*elf)))
1723                 goto end_coredump;
1724
1725         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1726                 goto end_coredump;
1727
1728         /* write program headers for segments dump */
1729         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1730                 struct elf_phdr phdr;
1731                 size_t sz;
1732
1733                 sz = vma->vm_end - vma->vm_start;
1734
1735                 phdr.p_type = PT_LOAD;
1736                 phdr.p_offset = offset;
1737                 phdr.p_vaddr = vma->vm_start;
1738                 phdr.p_paddr = 0;
1739                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1740                 phdr.p_memsz = sz;
1741                 offset += phdr.p_filesz;
1742                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1743                 if (vma->vm_flags & VM_WRITE)
1744                         phdr.p_flags |= PF_W;
1745                 if (vma->vm_flags & VM_EXEC)
1746                         phdr.p_flags |= PF_X;
1747                 phdr.p_align = ELF_EXEC_PAGESIZE;
1748
1749                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1750                         goto end_coredump;
1751         }
1752
1753         if (!elf_core_write_extra_phdrs(cprm, offset))
1754                 goto end_coredump;
1755
1756         /* write out the notes section */
1757         for (i = 0; i < numnote; i++)
1758                 if (!writenote(notes + i, cprm))
1759                         goto end_coredump;
1760
1761         /* write out the thread status notes section */
1762         list_for_each(t, &thread_list) {
1763                 struct elf_thread_status *tmp =
1764                                 list_entry(t, struct elf_thread_status, list);
1765
1766                 for (i = 0; i < tmp->num_notes; i++)
1767                         if (!writenote(&tmp->notes[i], cprm))
1768                                 goto end_coredump;
1769         }
1770
1771         if (!dump_skip(cprm, dataoff - cprm->pos))
1772                 goto end_coredump;
1773
1774         if (!elf_fdpic_dump_segments(cprm))
1775                 goto end_coredump;
1776
1777         if (!elf_core_write_extra_data(cprm))
1778                 goto end_coredump;
1779
1780         if (e_phnum == PN_XNUM) {
1781                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1782                         goto end_coredump;
1783         }
1784
1785         if (cprm->file->f_pos != offset) {
1786                 /* Sanity check */
1787                 printk(KERN_WARNING
1788                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1789                        cprm->file->f_pos, offset);
1790         }
1791
1792 end_coredump:
1793         set_fs(fs);
1794
1795 cleanup:
1796         while (!list_empty(&thread_list)) {
1797                 struct list_head *tmp = thread_list.next;
1798                 list_del(tmp);
1799                 kfree(list_entry(tmp, struct elf_thread_status, list));
1800         }
1801         kfree(phdr4note);
1802         kfree(elf);
1803         kfree(prstatus);
1804         kfree(psinfo);
1805         kfree(notes);
1806         kfree(fpu);
1807         kfree(shdr4extnum);
1808 #ifdef ELF_CORE_COPY_XFPREGS
1809         kfree(xfpu);
1810 #endif
1811         return has_dumped;
1812 #undef NUM_NOTES
1813 }
1814
1815 #endif          /* CONFIG_ELF_CORE */