fs/binfmt_elf_fdpic.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
   3  *
   4  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  * Derived from binfmt_elf.c
   7  */
   8
   9 #include <linux/module.h>
  10
  11 #include <linux/fs.h>
  12 #include <linux/stat.h>
  13 #include <linux/sched.h>
  14 #include <linux/sched/coredump.h>
  15 #include <linux/sched/task_stack.h>
  16 #include <linux/sched/cputime.h>
  17 #include <linux/mm.h>
  18 #include <linux/mman.h>
  19 #include <linux/errno.h>
  20 #include <linux/signal.h>
  21 #include <linux/binfmts.h>
  22 #include <linux/string.h>
  23 #include <linux/file.h>
  24 #include <linux/fcntl.h>
  25 #include <linux/slab.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/security.h>
  28 #include <linux/highmem.h>
  29 #include <linux/highuid.h>
  30 #include <linux/personality.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/init.h>
  33 #include <linux/elf.h>
  34 #include <linux/elf-fdpic.h>
  35 #include <linux/elfcore.h>
  36 #include <linux/coredump.h>
  37 #include <linux/dax.h>
  38
  39 #include <linux/uaccess.h>
  40 #include <asm/param.h>
  41
  42 typedef char *elf_caddr_t;
  43
  44 #if 0
  45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  46 #else
  47 #define kdebug(fmt, ...) do {} while(0)
  48 #endif
  49
  50 #if 0
  51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  52 #else
  53 #define kdcore(fmt, ...) do {} while(0)
  54 #endif
  55
  56 MODULE_LICENSE("GPL");
  57
  58 static int load_elf_fdpic_binary(struct linux_binprm *);
  59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  61                               struct mm_struct *, const char *);
  62
  63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  64                                    struct elf_fdpic_params *,
  65                                    struct elf_fdpic_params *);
  66
  67 #ifndef CONFIG_MMU
  68 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  69                                                    struct file *,
  70                                                    struct mm_struct *);
  71 #endif
  72
  73 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  74                                              struct file *, struct mm_struct *);
  75
  76 #ifdef CONFIG_ELF_CORE
  77 static int elf_fdpic_core_dump(struct coredump_params *cprm);
  78 #endif
  79
  80 static struct linux_binfmt elf_fdpic_format = {
  81         .module         = THIS_MODULE,
  82         .load_binary    = load_elf_fdpic_binary,
  83 #ifdef CONFIG_ELF_CORE
  84         .core_dump      = elf_fdpic_core_dump,
  85 #endif
  86         .min_coredump   = ELF_EXEC_PAGESIZE,
  87 };
  88
  89 static int __init init_elf_fdpic_binfmt(void)
  90 {
  91         register_binfmt(&elf_fdpic_format);
  92         return 0;
  93 }
  94
  95 static void __exit exit_elf_fdpic_binfmt(void)
  96 {
  97         unregister_binfmt(&elf_fdpic_format);
  98 }
  99
 100 core_initcall(init_elf_fdpic_binfmt);
 101 module_exit(exit_elf_fdpic_binfmt);
 102
 103 static int is_elf(struct elfhdr *hdr, struct file *file)
 104 {
 105         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 106                 return 0;
 107         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 108                 return 0;
 109         if (!elf_check_arch(hdr))
 110                 return 0;
 111         if (!file->f_op->mmap)
 112                 return 0;
 113         return 1;
 114 }
 115
 116 #ifndef elf_check_fdpic
 117 #define elf_check_fdpic(x) 0
 118 #endif
 119
 120 #ifndef elf_check_const_displacement
 121 #define elf_check_const_displacement(x) 0
 122 #endif
 123
 124 static int is_constdisp(struct elfhdr *hdr)
 125 {
 126         if (!elf_check_fdpic(hdr))
 127                 return 1;
 128         if (elf_check_const_displacement(hdr))
 129                 return 1;
 130         return 0;
 131 }
 132
 133 /*****************************************************************************/
 134 /*
 135  * read the program headers table into memory
 136  */
 137 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 138                                  struct file *file)
 139 {
 140         struct elf32_phdr *phdr;
 141         unsigned long size;
 142         int retval, loop;
 143         loff_t pos = params->hdr.e_phoff;
 144
 145         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 146                 return -ENOMEM;
 147         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 148                 return -ENOMEM;
 149
 150         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 151         params->phdrs = kmalloc(size, GFP_KERNEL);
 152         if (!params->phdrs)
 153                 return -ENOMEM;
 154
 155         retval = kernel_read(file, params->phdrs, size, &pos);
 156         if (unlikely(retval != size))
 157                 return retval < 0 ? retval : -ENOEXEC;
 158
 159         /* determine stack size for this binary */
 160         phdr = params->phdrs;
 161         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 162                 if (phdr->p_type != PT_GNU_STACK)
 163                         continue;
 164
 165                 if (phdr->p_flags & PF_X)
 166                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 167                 else
 168                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 169
 170                 params->stack_size = phdr->p_memsz;
 171                 break;
 172         }
 173
 174         return 0;
 175 }
 176
 177 /*****************************************************************************/
 178 /*
 179  * load an fdpic binary into various bits of memory
 180  */
 181 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 182 {
 183         struct elf_fdpic_params exec_params, interp_params;
 184         struct pt_regs *regs = current_pt_regs();
 185         struct elf_phdr *phdr;
 186         unsigned long stack_size, entryaddr;
 187 #ifdef ELF_FDPIC_PLAT_INIT
 188         unsigned long dynaddr;
 189 #endif
 190 #ifndef CONFIG_MMU
 191         unsigned long stack_prot;
 192 #endif
 193         struct file *interpreter = NULL; /* to shut gcc up */
 194         char *interpreter_name = NULL;
 195         int executable_stack;
 196         int retval, i;
 197         loff_t pos;
 198
 199         kdebug("____ LOAD %d ____", current->pid);
 200
 201         memset(&exec_params, 0, sizeof(exec_params));
 202         memset(&interp_params, 0, sizeof(interp_params));
 203
 204         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 205         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 206
 207         /* check that this is a binary we know how to deal with */
 208         retval = -ENOEXEC;
 209         if (!is_elf(&exec_params.hdr, bprm->file))
 210                 goto error;
 211         if (!elf_check_fdpic(&exec_params.hdr)) {
 212 #ifdef CONFIG_MMU
 213                 /* binfmt_elf handles non-fdpic elf except on nommu */
 214                 goto error;
 215 #else
 216                 /* nommu can only load ET_DYN (PIE) ELF */
 217                 if (exec_params.hdr.e_type != ET_DYN)
 218                         goto error;
 219 #endif
 220         }
 221
 222         /* read the program header table */
 223         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 224         if (retval < 0)
 225                 goto error;
 226
 227         /* scan for a program header that specifies an interpreter */
 228         phdr = exec_params.phdrs;
 229
 230         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 231                 switch (phdr->p_type) {
 232                 case PT_INTERP:
 233                         retval = -ENOMEM;
 234                         if (phdr->p_filesz > PATH_MAX)
 235                                 goto error;
 236                         retval = -ENOENT;
 237                         if (phdr->p_filesz < 2)
 238                                 goto error;
 239
 240                         /* read the name of the interpreter into memory */
 241                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 242                         if (!interpreter_name)
 243                                 goto error;
 244
 245                         pos = phdr->p_offset;
 246                         retval = kernel_read(bprm->file, interpreter_name,
 247                                              phdr->p_filesz, &pos);
 248                         if (unlikely(retval != phdr->p_filesz)) {
 249                                 if (retval >= 0)
 250                                         retval = -ENOEXEC;
 251                                 goto error;
 252                         }
 253
 254                         retval = -ENOENT;
 255                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 256                                 goto error;
 257
 258                         kdebug("Using ELF interpreter %s", interpreter_name);
 259
 260                         /* replace the program with the interpreter */
 261                         interpreter = open_exec(interpreter_name);
 262                         retval = PTR_ERR(interpreter);
 263                         if (IS_ERR(interpreter)) {
 264                                 interpreter = NULL;
 265                                 goto error;
 266                         }
 267
 268                         /*
 269                          * If the binary is not readable then enforce
 270                          * mm->dumpable = 0 regardless of the interpreter's
 271                          * permissions.
 272                          */
 273                         would_dump(bprm, interpreter);
 274
 275                         pos = 0;
 276                         retval = kernel_read(interpreter, bprm->buf,
 277                                         BINPRM_BUF_SIZE, &pos);
 278                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
 279                                 if (retval >= 0)
 280                                         retval = -ENOEXEC;
 281                                 goto error;
 282                         }
 283
 284                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 285                         break;
 286
 287                 case PT_LOAD:
 288 #ifdef CONFIG_MMU
 289                         if (exec_params.load_addr == 0)
 290                                 exec_params.load_addr = phdr->p_vaddr;
 291 #endif
 292                         break;
 293                 }
 294
 295         }
 296
 297         if (is_constdisp(&exec_params.hdr))
 298                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 299
 300         /* perform insanity checks on the interpreter */
 301         if (interpreter_name) {
 302                 retval = -ELIBBAD;
 303                 if (!is_elf(&interp_params.hdr, interpreter))
 304                         goto error;
 305
 306                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 307
 308                 /* read the interpreter's program header table */
 309                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 310                 if (retval < 0)
 311                         goto error;
 312         }
 313
 314         stack_size = exec_params.stack_size;
 315         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 316                 executable_stack = EXSTACK_ENABLE_X;
 317         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 318                 executable_stack = EXSTACK_DISABLE_X;
 319         else
 320                 executable_stack = EXSTACK_DEFAULT;
 321
 322         if (stack_size == 0) {
 323                 stack_size = interp_params.stack_size;
 324                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 325                         executable_stack = EXSTACK_ENABLE_X;
 326                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 327                         executable_stack = EXSTACK_DISABLE_X;
 328                 else
 329                         executable_stack = EXSTACK_DEFAULT;
 330         }
 331
 332         retval = -ENOEXEC;
 333         if (stack_size == 0)
 334                 stack_size = 131072UL; /* same as exec.c's default commit */
 335
 336         if (is_constdisp(&interp_params.hdr))
 337                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 338
 339         /* flush all traces of the currently running executable */
 340         retval = begin_new_exec(bprm);
 341         if (retval)
 342                 goto error;
 343
 344         /* there's now no turning back... the old userspace image is dead,
 345          * defunct, deceased, etc.
 346          */
 347         if (elf_check_fdpic(&exec_params.hdr))
 348                 set_personality(PER_LINUX_FDPIC);
 349         else
 350                 set_personality(PER_LINUX);
 351         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 352                 current->personality |= READ_IMPLIES_EXEC;
 353
 354         setup_new_exec(bprm);
 355
 356         set_binfmt(&elf_fdpic_format);
 357
 358         current->mm->start_code = 0;
 359         current->mm->end_code = 0;
 360         current->mm->start_stack = 0;
 361         current->mm->start_data = 0;
 362         current->mm->end_data = 0;
 363         current->mm->context.exec_fdpic_loadmap = 0;
 364         current->mm->context.interp_fdpic_loadmap = 0;
 365
 366 #ifdef CONFIG_MMU
 367         elf_fdpic_arch_lay_out_mm(&exec_params,
 368                                   &interp_params,
 369                                   &current->mm->start_stack,
 370                                   &current->mm->start_brk);
 371
 372         retval = setup_arg_pages(bprm, current->mm->start_stack,
 373                                  executable_stack);
 374         if (retval < 0)
 375                 goto error;
 376 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
 377         retval = arch_setup_additional_pages(bprm, !!interpreter_name);
 378         if (retval < 0)
 379                 goto error;
 380 #endif
 381 #endif
 382
 383         /* load the executable and interpreter into memory */
 384         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 385                                     "executable");
 386         if (retval < 0)
 387                 goto error;
 388
 389         if (interpreter_name) {
 390                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 391                                             current->mm, "interpreter");
 392                 if (retval < 0) {
 393                         printk(KERN_ERR "Unable to load interpreter\n");
 394                         goto error;
 395                 }
 396
 397                 allow_write_access(interpreter);
 398                 fput(interpreter);
 399                 interpreter = NULL;
 400         }
 401
 402 #ifdef CONFIG_MMU
 403         if (!current->mm->start_brk)
 404                 current->mm->start_brk = current->mm->end_data;
 405
 406         current->mm->brk = current->mm->start_brk =
 407                 PAGE_ALIGN(current->mm->start_brk);
 408
 409 #else
 410         /* create a stack area and zero-size brk area */
 411         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 412         if (stack_size < PAGE_SIZE * 2)
 413                 stack_size = PAGE_SIZE * 2;
 414
 415         stack_prot = PROT_READ | PROT_WRITE;
 416         if (executable_stack == EXSTACK_ENABLE_X ||
 417             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 418                 stack_prot |= PROT_EXEC;
 419
 420         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 421                                          MAP_PRIVATE | MAP_ANONYMOUS |
 422                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 423                                          0);
 424
 425         if (IS_ERR_VALUE(current->mm->start_brk)) {
 426                 retval = current->mm->start_brk;
 427                 current->mm->start_brk = 0;
 428                 goto error;
 429         }
 430
 431         current->mm->brk = current->mm->start_brk;
 432         current->mm->context.end_brk = current->mm->start_brk;
 433         current->mm->start_stack = current->mm->start_brk + stack_size;
 434 #endif
 435
 436         if (create_elf_fdpic_tables(bprm, current->mm,
 437                                     &exec_params, &interp_params) < 0)
 438                 goto error;
 439
 440         kdebug("- start_code  %lx", current->mm->start_code);
 441         kdebug("- end_code    %lx", current->mm->end_code);
 442         kdebug("- start_data  %lx", current->mm->start_data);
 443         kdebug("- end_data    %lx", current->mm->end_data);
 444         kdebug("- start_brk   %lx", current->mm->start_brk);
 445         kdebug("- brk         %lx", current->mm->brk);
 446         kdebug("- start_stack %lx", current->mm->start_stack);
 447
 448 #ifdef ELF_FDPIC_PLAT_INIT
 449         /*
 450          * The ABI may specify that certain registers be set up in special
 451          * ways (on i386 %edx is the address of a DT_FINI function, for
 452          * example.  This macro performs whatever initialization to
 453          * the regs structure is required.
 454          */
 455         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 456         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 457                             dynaddr);
 458 #endif
 459
 460         finalize_exec(bprm);
 461         /* everything is now ready... get the userspace context ready to roll */
 462         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 463         start_thread(regs, entryaddr, current->mm->start_stack);
 464
 465         retval = 0;
 466
 467 error:
 468         if (interpreter) {
 469                 allow_write_access(interpreter);
 470                 fput(interpreter);
 471         }
 472         kfree(interpreter_name);
 473         kfree(exec_params.phdrs);
 474         kfree(exec_params.loadmap);
 475         kfree(interp_params.phdrs);
 476         kfree(interp_params.loadmap);
 477         return retval;
 478 }
 479
 480 /*****************************************************************************/
 481
 482 #ifndef ELF_BASE_PLATFORM
 483 /*
 484  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 485  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 486  * will be copied to the user stack in the same manner as AT_PLATFORM.
 487  */
 488 #define ELF_BASE_PLATFORM NULL
 489 #endif
 490
 491 /*
 492  * present useful information to the program by shovelling it onto the new
 493  * process's stack
 494  */
 495 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 496                                    struct mm_struct *mm,
 497                                    struct elf_fdpic_params *exec_params,
 498                                    struct elf_fdpic_params *interp_params)
 499 {
 500         const struct cred *cred = current_cred();
 501         unsigned long sp, csp, nitems;
 502         elf_caddr_t __user *argv, *envp;
 503         size_t platform_len = 0, len;
 504         char *k_platform, *k_base_platform;
 505         char __user *u_platform, *u_base_platform, *p;
 506         int loop;
 507         int nr; /* reset for each csp adjustment */
 508
 509 #ifdef CONFIG_MMU
 510         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 511          * by the processes running on the same package. One thing we can do is
 512          * to shuffle the initial stack for them, so we give the architecture
 513          * an opportunity to do so here.
 514          */
 515         sp = arch_align_stack(bprm->p);
 516 #else
 517         sp = mm->start_stack;
 518
 519         /* stack the program arguments and environment */
 520         if (transfer_args_to_stack(bprm, &sp) < 0)
 521                 return -EFAULT;
 522         sp &= ~15;
 523 #endif
 524
 525         /*
 526          * If this architecture has a platform capability string, copy it
 527          * to userspace.  In some cases (Sparc), this info is impossible
 528          * for userspace to get any other way, in others (i386) it is
 529          * merely difficult.
 530          */
 531         k_platform = ELF_PLATFORM;
 532         u_platform = NULL;
 533
 534         if (k_platform) {
 535                 platform_len = strlen(k_platform) + 1;
 536                 sp -= platform_len;
 537                 u_platform = (char __user *) sp;
 538                 if (copy_to_user(u_platform, k_platform, platform_len) != 0)
 539                         return -EFAULT;
 540         }
 541
 542         /*
 543          * If this architecture has a "base" platform capability
 544          * string, copy it to userspace.
 545          */
 546         k_base_platform = ELF_BASE_PLATFORM;
 547         u_base_platform = NULL;
 548
 549         if (k_base_platform) {
 550                 platform_len = strlen(k_base_platform) + 1;
 551                 sp -= platform_len;
 552                 u_base_platform = (char __user *) sp;
 553                 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 554                         return -EFAULT;
 555         }
 556
 557         sp &= ~7UL;
 558
 559         /* stack the load map(s) */
 560         len = sizeof(struct elf32_fdpic_loadmap);
 561         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 562         sp = (sp - len) & ~7UL;
 563         exec_params->map_addr = sp;
 564
 565         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 566                 return -EFAULT;
 567
 568         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 569
 570         if (interp_params->loadmap) {
 571                 len = sizeof(struct elf32_fdpic_loadmap);
 572                 len += sizeof(struct elf32_fdpic_loadseg) *
 573                         interp_params->loadmap->nsegs;
 574                 sp = (sp - len) & ~7UL;
 575                 interp_params->map_addr = sp;
 576
 577                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 578                                  len) != 0)
 579                         return -EFAULT;
 580
 581                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 582         }
 583
 584         /* force 16 byte _final_ alignment here for generality */
 585 #define DLINFO_ITEMS 15
 586
 587         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 588                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 589
 590         if (bprm->have_execfd)
 591                 nitems++;
 592
 593         csp = sp;
 594         sp -= nitems * 2 * sizeof(unsigned long);
 595         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 596         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 597         sp -= 1 * sizeof(unsigned long);                /* argc */
 598
 599         csp -= sp & 15UL;
 600         sp -= sp & 15UL;
 601
 602         /* put the ELF interpreter info on the stack */
 603 #define NEW_AUX_ENT(id, val)                                            \
 604         do {                                                            \
 605                 struct { unsigned long _id, _val; } __user *ent, v;     \
 606                                                                         \
 607                 ent = (void __user *) csp;                              \
 608                 v._id = (id);                                           \
 609                 v._val = (val);                                         \
 610                 if (copy_to_user(ent + nr, &v, sizeof(v)))              \
 611                         return -EFAULT;                                 \
 612                 nr++;                                                   \
 613         } while (0)
 614
 615         nr = 0;
 616         csp -= 2 * sizeof(unsigned long);
 617         NEW_AUX_ENT(AT_NULL, 0);
 618         if (k_platform) {
 619                 nr = 0;
 620                 csp -= 2 * sizeof(unsigned long);
 621                 NEW_AUX_ENT(AT_PLATFORM,
 622                             (elf_addr_t) (unsigned long) u_platform);
 623         }
 624
 625         if (k_base_platform) {
 626                 nr = 0;
 627                 csp -= 2 * sizeof(unsigned long);
 628                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 629                             (elf_addr_t) (unsigned long) u_base_platform);
 630         }
 631
 632         if (bprm->have_execfd) {
 633                 nr = 0;
 634                 csp -= 2 * sizeof(unsigned long);
 635                 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
 636         }
 637
 638         nr = 0;
 639         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 640         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 641 #ifdef ELF_HWCAP2
 642         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 643 #endif
 644         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 645         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 646         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 647         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 648         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 649         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 650         NEW_AUX_ENT(AT_FLAGS,   0);
 651         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 652         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 653         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 654         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 655         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 656         NEW_AUX_ENT(AT_SECURE,  bprm->secureexec);
 657         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 658
 659 #ifdef ARCH_DLINFO
 660         nr = 0;
 661         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 662
 663         /* ARCH_DLINFO must come last so platform specific code can enforce
 664          * special alignment requirements on the AUXV if necessary (eg. PPC).
 665          */
 666         ARCH_DLINFO;
 667 #endif
 668 #undef NEW_AUX_ENT
 669
 670         /* allocate room for argv[] and envv[] */
 671         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 672         envp = (elf_caddr_t __user *) csp;
 673         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 674         argv = (elf_caddr_t __user *) csp;
 675
 676         /* stack argc */
 677         csp -= sizeof(unsigned long);
 678         if (put_user(bprm->argc, (unsigned long __user *) csp))
 679                 return -EFAULT;
 680
 681         BUG_ON(csp != sp);
 682
 683         /* fill in the argv[] array */
 684 #ifdef CONFIG_MMU
 685         current->mm->arg_start = bprm->p;
 686 #else
 687         current->mm->arg_start = current->mm->start_stack -
 688                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 689 #endif
 690
 691         p = (char __user *) current->mm->arg_start;
 692         for (loop = bprm->argc; loop > 0; loop--) {
 693                 if (put_user((elf_caddr_t) p, argv++))
 694                         return -EFAULT;
 695                 len = strnlen_user(p, MAX_ARG_STRLEN);
 696                 if (!len || len > MAX_ARG_STRLEN)
 697                         return -EINVAL;
 698                 p += len;
 699         }
 700         if (put_user(NULL, argv))
 701                 return -EFAULT;
 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                 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
 708                         return -EFAULT;
 709                 len = strnlen_user(p, MAX_ARG_STRLEN);
 710                 if (!len || len > MAX_ARG_STRLEN)
 711                         return -EINVAL;
 712                 p += len;
 713         }
 714         if (put_user(NULL, envp))
 715                 return -EFAULT;
 716         current->mm->env_end = (unsigned long) p;
 717
 718         mm->start_stack = (unsigned long) sp;
 719         return 0;
 720 }
 721
 722 /*****************************************************************************/
 723 /*
 724  * load the appropriate binary image (executable or interpreter) into memory
 725  * - we assume no MMU is available
 726  * - if no other PIC bits are set in params->hdr->e_flags
 727  *   - we assume that the LOADable segments in the binary are independently relocatable
 728  *   - we assume R/O executable segments are shareable
 729  * - else
 730  *   - we assume the loadable parts of the image to require fixed displacement
 731  *   - the image is not shareable
 732  */
 733 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 734                               struct file *file,
 735                               struct mm_struct *mm,
 736                               const char *what)
 737 {
 738         struct elf32_fdpic_loadmap *loadmap;
 739 #ifdef CONFIG_MMU
 740         struct elf32_fdpic_loadseg *mseg;
 741 #endif
 742         struct elf32_fdpic_loadseg *seg;
 743         struct elf32_phdr *phdr;
 744         unsigned long load_addr, stop;
 745         unsigned nloads, tmp;
 746         size_t size;
 747         int loop, ret;
 748
 749         /* allocate a load map table */
 750         nloads = 0;
 751         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 752                 if (params->phdrs[loop].p_type == PT_LOAD)
 753                         nloads++;
 754
 755         if (nloads == 0)
 756                 return -ELIBBAD;
 757
 758         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 759         loadmap = kzalloc(size, GFP_KERNEL);
 760         if (!loadmap)
 761                 return -ENOMEM;
 762
 763         params->loadmap = loadmap;
 764
 765         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 766         loadmap->nsegs = nloads;
 767
 768         load_addr = params->load_addr;
 769         seg = loadmap->segs;
 770
 771         /* map the requested LOADs into the memory space */
 772         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 773         case ELF_FDPIC_FLAG_CONSTDISP:
 774         case ELF_FDPIC_FLAG_CONTIGUOUS:
 775 #ifndef CONFIG_MMU
 776                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 777                 if (ret < 0)
 778                         return ret;
 779                 break;
 780 #endif
 781         default:
 782                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 783                 if (ret < 0)
 784                         return ret;
 785                 break;
 786         }
 787
 788         /* map the entry point */
 789         if (params->hdr.e_entry) {
 790                 seg = loadmap->segs;
 791                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 792                         if (params->hdr.e_entry >= seg->p_vaddr &&
 793                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 794                                 params->entry_addr =
 795                                         (params->hdr.e_entry - seg->p_vaddr) +
 796                                         seg->addr;
 797                                 break;
 798                         }
 799                 }
 800         }
 801
 802         /* determine where the program header table has wound up if mapped */
 803         stop = params->hdr.e_phoff;
 804         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 805         phdr = params->phdrs;
 806
 807         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 808                 if (phdr->p_type != PT_LOAD)
 809                         continue;
 810
 811                 if (phdr->p_offset > params->hdr.e_phoff ||
 812                     phdr->p_offset + phdr->p_filesz < stop)
 813                         continue;
 814
 815                 seg = loadmap->segs;
 816                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 817                         if (phdr->p_vaddr >= seg->p_vaddr &&
 818                             phdr->p_vaddr + phdr->p_filesz <=
 819                             seg->p_vaddr + seg->p_memsz) {
 820                                 params->ph_addr =
 821                                         (phdr->p_vaddr - seg->p_vaddr) +
 822                                         seg->addr +
 823                                         params->hdr.e_phoff - phdr->p_offset;
 824                                 break;
 825                         }
 826                 }
 827                 break;
 828         }
 829
 830         /* determine where the dynamic section has wound up if there is one */
 831         phdr = params->phdrs;
 832         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 833                 if (phdr->p_type != PT_DYNAMIC)
 834                         continue;
 835
 836                 seg = loadmap->segs;
 837                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 838                         if (phdr->p_vaddr >= seg->p_vaddr &&
 839                             phdr->p_vaddr + phdr->p_memsz <=
 840                             seg->p_vaddr + seg->p_memsz) {
 841                                 Elf32_Dyn __user *dyn;
 842                                 Elf32_Sword d_tag;
 843
 844                                 params->dynamic_addr =
 845                                         (phdr->p_vaddr - seg->p_vaddr) +
 846                                         seg->addr;
 847
 848                                 /* check the dynamic section contains at least
 849                                  * one item, and that the last item is a NULL
 850                                  * entry */
 851                                 if (phdr->p_memsz == 0 ||
 852                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 853                                         goto dynamic_error;
 854
 855                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 856                                 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
 857                                 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
 858                                     d_tag != 0)
 859                                         goto dynamic_error;
 860                                 break;
 861                         }
 862                 }
 863                 break;
 864         }
 865
 866         /* now elide adjacent segments in the load map on MMU linux
 867          * - on uClinux the holes between may actually be filled with system
 868          *   stuff or stuff from other processes
 869          */
 870 #ifdef CONFIG_MMU
 871         nloads = loadmap->nsegs;
 872         mseg = loadmap->segs;
 873         seg = mseg + 1;
 874         for (loop = 1; loop < nloads; loop++) {
 875                 /* see if we have a candidate for merging */
 876                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 877                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 878                         if (load_addr == (seg->addr & PAGE_MASK)) {
 879                                 mseg->p_memsz +=
 880                                         load_addr -
 881                                         (mseg->addr + mseg->p_memsz);
 882                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 883                                 mseg->p_memsz += seg->p_memsz;
 884                                 loadmap->nsegs--;
 885                                 continue;
 886                         }
 887                 }
 888
 889                 mseg++;
 890                 if (mseg != seg)
 891                         *mseg = *seg;
 892         }
 893 #endif
 894
 895         kdebug("Mapped Object [%s]:", what);
 896         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 897         kdebug("- entry    : %lx", params->entry_addr);
 898         kdebug("- PHDR[]   : %lx", params->ph_addr);
 899         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 900         seg = loadmap->segs;
 901         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 902                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 903                        loop,
 904                        seg->addr, seg->addr + seg->p_memsz - 1,
 905                        seg->p_vaddr, seg->p_memsz);
 906
 907         return 0;
 908
 909 dynamic_error:
 910         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 911                what, file_inode(file)->i_ino);
 912         return -ELIBBAD;
 913 }
 914
 915 /*****************************************************************************/
 916 /*
 917  * map a file with constant displacement under uClinux
 918  */
 919 #ifndef CONFIG_MMU
 920 static int elf_fdpic_map_file_constdisp_on_uclinux(
 921         struct elf_fdpic_params *params,
 922         struct file *file,
 923         struct mm_struct *mm)
 924 {
 925         struct elf32_fdpic_loadseg *seg;
 926         struct elf32_phdr *phdr;
 927         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 928         int loop, ret;
 929
 930         load_addr = params->load_addr;
 931         seg = params->loadmap->segs;
 932
 933         /* determine the bounds of the contiguous overall allocation we must
 934          * make */
 935         phdr = params->phdrs;
 936         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 937                 if (params->phdrs[loop].p_type != PT_LOAD)
 938                         continue;
 939
 940                 if (base > phdr->p_vaddr)
 941                         base = phdr->p_vaddr;
 942                 if (top < phdr->p_vaddr + phdr->p_memsz)
 943                         top = phdr->p_vaddr + phdr->p_memsz;
 944         }
 945
 946         /* allocate one big anon block for everything */
 947         mflags = MAP_PRIVATE;
 948         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 949                 mflags |= MAP_EXECUTABLE;
 950
 951         maddr = vm_mmap(NULL, load_addr, top - base,
 952                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 953         if (IS_ERR_VALUE(maddr))
 954                 return (int) maddr;
 955
 956         if (load_addr != 0)
 957                 load_addr += PAGE_ALIGN(top - base);
 958
 959         /* and then load the file segments into it */
 960         phdr = params->phdrs;
 961         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 962                 if (params->phdrs[loop].p_type != PT_LOAD)
 963                         continue;
 964
 965                 seg->addr = maddr + (phdr->p_vaddr - base);
 966                 seg->p_vaddr = phdr->p_vaddr;
 967                 seg->p_memsz = phdr->p_memsz;
 968
 969                 ret = read_code(file, seg->addr, phdr->p_offset,
 970                                        phdr->p_filesz);
 971                 if (ret < 0)
 972                         return ret;
 973
 974                 /* map the ELF header address if in this segment */
 975                 if (phdr->p_offset == 0)
 976                         params->elfhdr_addr = seg->addr;
 977
 978                 /* clear any space allocated but not loaded */
 979                 if (phdr->p_filesz < phdr->p_memsz) {
 980                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
 981                                        phdr->p_memsz - phdr->p_filesz))
 982                                 return -EFAULT;
 983                 }
 984
 985                 if (mm) {
 986                         if (phdr->p_flags & PF_X) {
 987                                 if (!mm->start_code) {
 988                                         mm->start_code = seg->addr;
 989                                         mm->end_code = seg->addr +
 990                                                 phdr->p_memsz;
 991                                 }
 992                         } else if (!mm->start_data) {
 993                                 mm->start_data = seg->addr;
 994                                 mm->end_data = seg->addr + phdr->p_memsz;
 995                         }
 996                 }
 997
 998                 seg++;
 999         }
1000
1001         return 0;
1002 }
1003 #endif
1004
1005 /*****************************************************************************/
1006 /*
1007  * map a binary by direct mmap() of the individual PT_LOAD segments
1008  */
1009 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1010                                              struct file *file,
1011                                              struct mm_struct *mm)
1012 {
1013         struct elf32_fdpic_loadseg *seg;
1014         struct elf32_phdr *phdr;
1015         unsigned long load_addr, delta_vaddr;
1016         int loop, dvset;
1017
1018         load_addr = params->load_addr;
1019         delta_vaddr = 0;
1020         dvset = 0;
1021
1022         seg = params->loadmap->segs;
1023
1024         /* deal with each load segment separately */
1025         phdr = params->phdrs;
1026         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1027                 unsigned long maddr, disp, excess, excess1;
1028                 int prot = 0, flags;
1029
1030                 if (phdr->p_type != PT_LOAD)
1031                         continue;
1032
1033                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1034                        (unsigned long) phdr->p_vaddr,
1035                        (unsigned long) phdr->p_offset,
1036                        (unsigned long) phdr->p_filesz,
1037                        (unsigned long) phdr->p_memsz);
1038
1039                 /* determine the mapping parameters */
1040                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1041                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1042                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1043
1044                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1045                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1046                         flags |= MAP_EXECUTABLE;
1047
1048                 maddr = 0;
1049
1050                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1051                 case ELF_FDPIC_FLAG_INDEPENDENT:
1052                         /* PT_LOADs are independently locatable */
1053                         break;
1054
1055                 case ELF_FDPIC_FLAG_HONOURVADDR:
1056                         /* the specified virtual address must be honoured */
1057                         maddr = phdr->p_vaddr;
1058                         flags |= MAP_FIXED;
1059                         break;
1060
1061                 case ELF_FDPIC_FLAG_CONSTDISP:
1062                         /* constant displacement
1063                          * - can be mapped anywhere, but must be mapped as a
1064                          *   unit
1065                          */
1066                         if (!dvset) {
1067                                 maddr = load_addr;
1068                                 delta_vaddr = phdr->p_vaddr;
1069                                 dvset = 1;
1070                         } else {
1071                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1072                                 flags |= MAP_FIXED;
1073                         }
1074                         break;
1075
1076                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1077                         /* contiguity handled later */
1078                         break;
1079
1080                 default:
1081                         BUG();
1082                 }
1083
1084                 maddr &= PAGE_MASK;
1085
1086                 /* create the mapping */
1087                 disp = phdr->p_vaddr & ~PAGE_MASK;
1088                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1089                                 phdr->p_offset - disp);
1090
1091                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1092                        loop, phdr->p_memsz + disp, prot, flags,
1093                        phdr->p_offset - disp, maddr);
1094
1095                 if (IS_ERR_VALUE(maddr))
1096                         return (int) maddr;
1097
1098                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1099                     ELF_FDPIC_FLAG_CONTIGUOUS)
1100                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1101
1102                 seg->addr = maddr + disp;
1103                 seg->p_vaddr = phdr->p_vaddr;
1104                 seg->p_memsz = phdr->p_memsz;
1105
1106                 /* map the ELF header address if in this segment */
1107                 if (phdr->p_offset == 0)
1108                         params->elfhdr_addr = seg->addr;
1109
1110                 /* clear the bit between beginning of mapping and beginning of
1111                  * PT_LOAD */
1112                 if (prot & PROT_WRITE && disp > 0) {
1113                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1114                         if (clear_user((void __user *) maddr, disp))
1115                                 return -EFAULT;
1116                         maddr += disp;
1117                 }
1118
1119                 /* clear any space allocated but not loaded
1120                  * - on uClinux we can just clear the lot
1121                  * - on MMU linux we'll get a SIGBUS beyond the last page
1122                  *   extant in the file
1123                  */
1124                 excess = phdr->p_memsz - phdr->p_filesz;
1125                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1126
1127 #ifdef CONFIG_MMU
1128                 if (excess > excess1) {
1129                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1130                         unsigned long xmaddr;
1131
1132                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1133                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1134                                          prot, flags, 0);
1135
1136                         kdebug("mmap[%d] <anon>"
1137                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1138                                loop, xaddr, excess - excess1, prot, flags,
1139                                xmaddr);
1140
1141                         if (xmaddr != xaddr)
1142                                 return -ENOMEM;
1143                 }
1144
1145                 if (prot & PROT_WRITE && excess1 > 0) {
1146                         kdebug("clear[%d] ad=%lx sz=%lx",
1147                                loop, maddr + phdr->p_filesz, excess1);
1148                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1149                                        excess1))
1150                                 return -EFAULT;
1151                 }
1152
1153 #else
1154                 if (excess > 0) {
1155                         kdebug("clear[%d] ad=%lx sz=%lx",
1156                                loop, maddr + phdr->p_filesz, excess);
1157                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1158                                 return -EFAULT;
1159                 }
1160 #endif
1161
1162                 if (mm) {
1163                         if (phdr->p_flags & PF_X) {
1164                                 if (!mm->start_code) {
1165                                         mm->start_code = maddr;
1166                                         mm->end_code = maddr + phdr->p_memsz;
1167                                 }
1168                         } else if (!mm->start_data) {
1169                                 mm->start_data = maddr;
1170                                 mm->end_data = maddr + phdr->p_memsz;
1171                         }
1172                 }
1173
1174                 seg++;
1175         }
1176
1177         return 0;
1178 }
1179
1180 /*****************************************************************************/
1181 /*
1182  * ELF-FDPIC core dumper
1183  *
1184  * Modelled on fs/exec.c:aout_core_dump()
1185  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1186  *
1187  * Modelled on fs/binfmt_elf.c core dumper
1188  */
1189 #ifdef CONFIG_ELF_CORE
1190
1191 /*
1192  * Decide whether a segment is worth dumping; default is yes to be
1193  * sure (missing info is worse than too much; etc).
1194  * Personally I'd include everything, and use the coredump limit...
1195  *
1196  * I think we should skip something. But I am not sure how. H.J.
1197  */
1198 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1199 {
1200         int dump_ok;
1201
1202         /* Do not dump I/O mapped devices or special mappings */
1203         if (vma->vm_flags & VM_IO) {
1204                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1205                 return 0;
1206         }
1207
1208         /* If we may not read the contents, don't allow us to dump
1209          * them either. "dump_write()" can't handle it anyway.
1210          */
1211         if (!(vma->vm_flags & VM_READ)) {
1212                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1213                 return 0;
1214         }
1215
1216         /* support for DAX */
1217         if (vma_is_dax(vma)) {
1218                 if (vma->vm_flags & VM_SHARED) {
1219                         dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
1220                         kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
1221                                vma->vm_flags, dump_ok ? "yes" : "no");
1222                 } else {
1223                         dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
1224                         kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
1225                                vma->vm_flags, dump_ok ? "yes" : "no");
1226                 }
1227                 return dump_ok;
1228         }
1229
1230         /* By default, dump shared memory if mapped from an anonymous file. */
1231         if (vma->vm_flags & VM_SHARED) {
1232                 if (file_inode(vma->vm_file)->i_nlink == 0) {
1233                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1234                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1235                                vma->vm_flags, dump_ok ? "yes" : "no");
1236                         return dump_ok;
1237                 }
1238
1239                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1240                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1241                        vma->vm_flags, dump_ok ? "yes" : "no");
1242                 return dump_ok;
1243         }
1244
1245 #ifdef CONFIG_MMU
1246         /* By default, if it hasn't been written to, don't write it out */
1247         if (!vma->anon_vma) {
1248                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1249                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1250                        vma->vm_flags, dump_ok ? "yes" : "no");
1251                 return dump_ok;
1252         }
1253 #endif
1254
1255         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1256         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1257                dump_ok ? "yes" : "no");
1258         return dump_ok;
1259 }
1260
1261 /* An ELF note in memory */
1262 struct memelfnote
1263 {
1264         const char *name;
1265         int type;
1266         unsigned int datasz;
1267         void *data;
1268 };
1269
1270 static int notesize(struct memelfnote *en)
1271 {
1272         int sz;
1273
1274         sz = sizeof(struct elf_note);
1275         sz += roundup(strlen(en->name) + 1, 4);
1276         sz += roundup(en->datasz, 4);
1277
1278         return sz;
1279 }
1280
1281 /* #define DEBUG */
1282
1283 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1284 {
1285         struct elf_note en;
1286         en.n_namesz = strlen(men->name) + 1;
1287         en.n_descsz = men->datasz;
1288         en.n_type = men->type;
1289
1290         return dump_emit(cprm, &en, sizeof(en)) &&
1291                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1292                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1293 }
1294
1295 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1296 {
1297         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1298         elf->e_ident[EI_CLASS] = ELF_CLASS;
1299         elf->e_ident[EI_DATA] = ELF_DATA;
1300         elf->e_ident[EI_VERSION] = EV_CURRENT;
1301         elf->e_ident[EI_OSABI] = ELF_OSABI;
1302         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1303
1304         elf->e_type = ET_CORE;
1305         elf->e_machine = ELF_ARCH;
1306         elf->e_version = EV_CURRENT;
1307         elf->e_entry = 0;
1308         elf->e_phoff = sizeof(struct elfhdr);
1309         elf->e_shoff = 0;
1310         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1311         elf->e_ehsize = sizeof(struct elfhdr);
1312         elf->e_phentsize = sizeof(struct elf_phdr);
1313         elf->e_phnum = segs;
1314         elf->e_shentsize = 0;
1315         elf->e_shnum = 0;
1316         elf->e_shstrndx = 0;
1317         return;
1318 }
1319
1320 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1321 {
1322         phdr->p_type = PT_NOTE;
1323         phdr->p_offset = offset;
1324         phdr->p_vaddr = 0;
1325         phdr->p_paddr = 0;
1326         phdr->p_filesz = sz;
1327         phdr->p_memsz = 0;
1328         phdr->p_flags = 0;
1329         phdr->p_align = 0;
1330         return;
1331 }
1332
1333 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1334                 unsigned int sz, void *data)
1335 {
1336         note->name = name;
1337         note->type = type;
1338         note->datasz = sz;
1339         note->data = data;
1340         return;
1341 }
1342
1343 /*
1344  * fill up all the fields in prstatus from the given task struct, except
1345  * registers which need to be filled up separately.
1346  */
1347 static void fill_prstatus(struct elf_prstatus *prstatus,
1348                           struct task_struct *p, long signr)
1349 {
1350         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1351         prstatus->pr_sigpend = p->pending.signal.sig[0];
1352         prstatus->pr_sighold = p->blocked.sig[0];
1353         rcu_read_lock();
1354         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1355         rcu_read_unlock();
1356         prstatus->pr_pid = task_pid_vnr(p);
1357         prstatus->pr_pgrp = task_pgrp_vnr(p);
1358         prstatus->pr_sid = task_session_vnr(p);
1359         if (thread_group_leader(p)) {
1360                 struct task_cputime cputime;
1361
1362                 /*
1363                  * This is the record for the group leader.  It shows the
1364                  * group-wide total, not its individual thread total.
1365                  */
1366                 thread_group_cputime(p, &cputime);
1367                 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1368                 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1369         } else {
1370                 u64 utime, stime;
1371
1372                 task_cputime(p, &utime, &stime);
1373                 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1374                 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1375         }
1376         prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1377         prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1378
1379         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1380         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1381 }
1382
1383 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1384                        struct mm_struct *mm)
1385 {
1386         const struct cred *cred;
1387         unsigned int i, len;
1388
1389         /* first copy the parameters from user space */
1390         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1391
1392         len = mm->arg_end - mm->arg_start;
1393         if (len >= ELF_PRARGSZ)
1394                 len = ELF_PRARGSZ - 1;
1395         if (copy_from_user(&psinfo->pr_psargs,
1396                            (const char __user *) mm->arg_start, len))
1397                 return -EFAULT;
1398         for (i = 0; i < len; i++)
1399                 if (psinfo->pr_psargs[i] == 0)
1400                         psinfo->pr_psargs[i] = ' ';
1401         psinfo->pr_psargs[len] = 0;
1402
1403         rcu_read_lock();
1404         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1405         rcu_read_unlock();
1406         psinfo->pr_pid = task_pid_vnr(p);
1407         psinfo->pr_pgrp = task_pgrp_vnr(p);
1408         psinfo->pr_sid = task_session_vnr(p);
1409
1410         i = p->state ? ffz(~p->state) + 1 : 0;
1411         psinfo->pr_state = i;
1412         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1413         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1414         psinfo->pr_nice = task_nice(p);
1415         psinfo->pr_flag = p->flags;
1416         rcu_read_lock();
1417         cred = __task_cred(p);
1418         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1419         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1420         rcu_read_unlock();
1421         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1422
1423         return 0;
1424 }
1425
1426 /* Here is the structure in which status of each thread is captured. */
1427 struct elf_thread_status
1428 {
1429         struct list_head list;
1430         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1431         elf_fpregset_t fpu;             /* NT_PRFPREG */
1432         struct task_struct *thread;
1433 #ifdef ELF_CORE_COPY_XFPREGS
1434         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1435 #endif
1436         struct memelfnote notes[3];
1437         int num_notes;
1438 };
1439
1440 /*
1441  * In order to add the specific thread information for the elf file format,
1442  * we need to keep a linked list of every thread's pr_status and then create
1443  * a single section for them in the final core file.
1444  */
1445 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1446 {
1447         struct task_struct *p = t->thread;
1448         int sz = 0;
1449
1450         t->num_notes = 0;
1451
1452         fill_prstatus(&t->prstatus, p, signr);
1453         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1454
1455         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1456                   &t->prstatus);
1457         t->num_notes++;
1458         sz += notesize(&t->notes[0]);
1459
1460         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1461         if (t->prstatus.pr_fpvalid) {
1462                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1463                           &t->fpu);
1464                 t->num_notes++;
1465                 sz += notesize(&t->notes[1]);
1466         }
1467
1468 #ifdef ELF_CORE_COPY_XFPREGS
1469         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1470                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1471                           sizeof(t->xfpu), &t->xfpu);
1472                 t->num_notes++;
1473                 sz += notesize(&t->notes[2]);
1474         }
1475 #endif
1476         return sz;
1477 }
1478
1479 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1480                              elf_addr_t e_shoff, int segs)
1481 {
1482         elf->e_shoff = e_shoff;
1483         elf->e_shentsize = sizeof(*shdr4extnum);
1484         elf->e_shnum = 1;
1485         elf->e_shstrndx = SHN_UNDEF;
1486
1487         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1488
1489         shdr4extnum->sh_type = SHT_NULL;
1490         shdr4extnum->sh_size = elf->e_shnum;
1491         shdr4extnum->sh_link = elf->e_shstrndx;
1492         shdr4extnum->sh_info = segs;
1493 }
1494
1495 /*
1496  * dump the segments for an MMU process
1497  */
1498 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1499 {
1500         struct vm_area_struct *vma;
1501
1502         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1503 #ifdef CONFIG_MMU
1504                 unsigned long addr;
1505 #endif
1506
1507                 if (!maydump(vma, cprm->mm_flags))
1508                         continue;
1509
1510 #ifdef CONFIG_MMU
1511                 for (addr = vma->vm_start; addr < vma->vm_end;
1512                                                         addr += PAGE_SIZE) {
1513                         bool res;
1514                         struct page *page = get_dump_page(addr);
1515                         if (page) {
1516                                 void *kaddr = kmap(page);
1517                                 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1518                                 kunmap(page);
1519                                 put_page(page);
1520                         } else {
1521                                 res = dump_skip(cprm, PAGE_SIZE);
1522                         }
1523                         if (!res)
1524                                 return false;
1525                 }
1526 #else
1527                 if (!dump_emit(cprm, (void *) vma->vm_start,
1528                                 vma->vm_end - vma->vm_start))
1529                         return false;
1530 #endif
1531         }
1532         return true;
1533 }
1534
1535 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1536 {
1537         struct vm_area_struct *vma;
1538         size_t size = 0;
1539
1540         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1541                 if (maydump(vma, mm_flags))
1542                         size += vma->vm_end - vma->vm_start;
1543         return size;
1544 }
1545
1546 /*
1547  * Actual dumper
1548  *
1549  * This is a two-pass process; first we find the offsets of the bits,
1550  * and then they are actually written out.  If we run out of core limit
1551  * we just truncate.
1552  */
1553 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1554 {
1555 #define NUM_NOTES       6
1556         int has_dumped = 0;
1557         int segs;
1558         int i;
1559         struct vm_area_struct *vma;
1560         struct elfhdr *elf = NULL;
1561         loff_t offset = 0, dataoff;
1562         int numnote;
1563         struct memelfnote *notes = NULL;
1564         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1565         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1566         LIST_HEAD(thread_list);
1567         struct list_head *t;
1568         elf_fpregset_t *fpu = NULL;
1569 #ifdef ELF_CORE_COPY_XFPREGS
1570         elf_fpxregset_t *xfpu = NULL;
1571 #endif
1572         int thread_status_size = 0;
1573         elf_addr_t *auxv;
1574         struct elf_phdr *phdr4note = NULL;
1575         struct elf_shdr *shdr4extnum = NULL;
1576         Elf_Half e_phnum;
1577         elf_addr_t e_shoff;
1578         struct core_thread *ct;
1579         struct elf_thread_status *tmp;
1580
1581         /*
1582          * We no longer stop all VM operations.
1583          *
1584          * This is because those proceses that could possibly change map_count
1585          * or the mmap / vma pages are now blocked in do_exit on current
1586          * finishing this core dump.
1587          *
1588          * Only ptrace can touch these memory addresses, but it doesn't change
1589          * the map_count or the pages allocated. So no possibility of crashing
1590          * exists while dumping the mm->vm_next areas to the core file.
1591          */
1592
1593         /* alloc memory for large data structures: too large to be on stack */
1594         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1595         if (!elf)
1596                 goto end_coredump;
1597         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1598         if (!prstatus)
1599                 goto end_coredump;
1600         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1601         if (!psinfo)
1602                 goto end_coredump;
1603         notes = kmalloc_array(NUM_NOTES, sizeof(struct memelfnote),
1604                               GFP_KERNEL);
1605         if (!notes)
1606                 goto end_coredump;
1607         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1608         if (!fpu)
1609                 goto end_coredump;
1610 #ifdef ELF_CORE_COPY_XFPREGS
1611         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1612         if (!xfpu)
1613                 goto end_coredump;
1614 #endif
1615
1616         for (ct = current->mm->core_state->dumper.next;
1617                                         ct; ct = ct->next) {
1618                 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1619                 if (!tmp)
1620                         goto end_coredump;
1621
1622                 tmp->thread = ct->task;
1623                 list_add(&tmp->list, &thread_list);
1624         }
1625
1626         list_for_each(t, &thread_list) {
1627                 struct elf_thread_status *tmp;
1628                 int sz;
1629
1630                 tmp = list_entry(t, struct elf_thread_status, list);
1631                 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1632                 thread_status_size += sz;
1633         }
1634
1635         /* now collect the dump for the current */
1636         fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1637         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1638
1639         segs = current->mm->map_count;
1640         segs += elf_core_extra_phdrs();
1641
1642         /* for notes section */
1643         segs++;
1644
1645         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1646          * this, kernel supports extended numbering. Have a look at
1647          * include/linux/elf.h for further information. */
1648         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1649
1650         /* Set up header */
1651         fill_elf_fdpic_header(elf, e_phnum);
1652
1653         has_dumped = 1;
1654         /*
1655          * Set up the notes in similar form to SVR4 core dumps made
1656          * with info from their /proc.
1657          */
1658
1659         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1660         fill_psinfo(psinfo, current->group_leader, current->mm);
1661         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1662
1663         numnote = 2;
1664
1665         auxv = (elf_addr_t *) current->mm->saved_auxv;
1666
1667         i = 0;
1668         do
1669                 i += 2;
1670         while (auxv[i - 2] != AT_NULL);
1671         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1672                   i * sizeof(elf_addr_t), auxv);
1673
1674         /* Try to dump the FPU. */
1675         if ((prstatus->pr_fpvalid =
1676              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1677                 fill_note(notes + numnote++,
1678                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1679 #ifdef ELF_CORE_COPY_XFPREGS
1680         if (elf_core_copy_task_xfpregs(current, xfpu))
1681                 fill_note(notes + numnote++,
1682                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1683 #endif
1684
1685         offset += sizeof(*elf);                         /* Elf header */
1686         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1687
1688         /* Write notes phdr entry */
1689         {
1690                 int sz = 0;
1691
1692                 for (i = 0; i < numnote; i++)
1693                         sz += notesize(notes + i);
1694
1695                 sz += thread_status_size;
1696
1697                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1698                 if (!phdr4note)
1699                         goto end_coredump;
1700
1701                 fill_elf_note_phdr(phdr4note, sz, offset);
1702                 offset += sz;
1703         }
1704
1705         /* Page-align dumped data */
1706         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1707
1708         offset += elf_core_vma_data_size(cprm->mm_flags);
1709         offset += elf_core_extra_data_size();
1710         e_shoff = offset;
1711
1712         if (e_phnum == PN_XNUM) {
1713                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1714                 if (!shdr4extnum)
1715                         goto end_coredump;
1716                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1717         }
1718
1719         offset = dataoff;
1720
1721         if (!dump_emit(cprm, elf, sizeof(*elf)))
1722                 goto end_coredump;
1723
1724         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1725                 goto end_coredump;
1726
1727         /* write program headers for segments dump */
1728         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1729                 struct elf_phdr phdr;
1730                 size_t sz;
1731
1732                 sz = vma->vm_end - vma->vm_start;
1733
1734                 phdr.p_type = PT_LOAD;
1735                 phdr.p_offset = offset;
1736                 phdr.p_vaddr = vma->vm_start;
1737                 phdr.p_paddr = 0;
1738                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1739                 phdr.p_memsz = sz;
1740                 offset += phdr.p_filesz;
1741                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1742                 if (vma->vm_flags & VM_WRITE)
1743                         phdr.p_flags |= PF_W;
1744                 if (vma->vm_flags & VM_EXEC)
1745                         phdr.p_flags |= PF_X;
1746                 phdr.p_align = ELF_EXEC_PAGESIZE;
1747
1748                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1749                         goto end_coredump;
1750         }
1751
1752         if (!elf_core_write_extra_phdrs(cprm, offset))
1753                 goto end_coredump;
1754
1755         /* write out the notes section */
1756         for (i = 0; i < numnote; i++)
1757                 if (!writenote(notes + i, cprm))
1758                         goto end_coredump;
1759
1760         /* write out the thread status notes section */
1761         list_for_each(t, &thread_list) {
1762                 struct elf_thread_status *tmp =
1763                                 list_entry(t, struct elf_thread_status, list);
1764
1765                 for (i = 0; i < tmp->num_notes; i++)
1766                         if (!writenote(&tmp->notes[i], cprm))
1767                                 goto end_coredump;
1768         }
1769
1770         if (!dump_skip(cprm, dataoff - cprm->pos))
1771                 goto end_coredump;
1772
1773         if (!elf_fdpic_dump_segments(cprm))
1774                 goto end_coredump;
1775
1776         if (!elf_core_write_extra_data(cprm))
1777                 goto end_coredump;
1778
1779         if (e_phnum == PN_XNUM) {
1780                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1781                         goto end_coredump;
1782         }
1783
1784         if (cprm->file->f_pos != offset) {
1785                 /* Sanity check */
1786                 printk(KERN_WARNING
1787                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1788                        cprm->file->f_pos, offset);
1789         }
1790
1791 end_coredump:
1792         while (!list_empty(&thread_list)) {
1793                 struct list_head *tmp = thread_list.next;
1794                 list_del(tmp);
1795                 kfree(list_entry(tmp, struct elf_thread_status, list));
1796         }
1797         kfree(phdr4note);
1798         kfree(elf);
1799         kfree(prstatus);
1800         kfree(psinfo);
1801         kfree(notes);
1802         kfree(fpu);
1803         kfree(shdr4extnum);
1804 #ifdef ELF_CORE_COPY_XFPREGS
1805         kfree(xfpu);
1806 #endif
1807         return has_dumped;
1808 #undef NUM_NOTES
1809 }
1810
1811 #endif          /* CONFIG_ELF_CORE */