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 #include <linux/regset.h>
  39
  40 #include <linux/uaccess.h>
  41 #include <asm/param.h>
  42
  43 typedef char *elf_caddr_t;
  44
  45 #if 0
  46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  47 #else
  48 #define kdebug(fmt, ...) do {} while(0)
  49 #endif
  50
  51 #if 0
  52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  53 #else
  54 #define kdcore(fmt, ...) do {} while(0)
  55 #endif
  56
  57 MODULE_LICENSE("GPL");
  58
  59 static int load_elf_fdpic_binary(struct linux_binprm *);
  60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  62                               struct mm_struct *, const char *);
  63
  64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  65                                    struct elf_fdpic_params *,
  66                                    struct elf_fdpic_params *);
  67
  68 #ifndef CONFIG_MMU
  69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  70                                                    struct file *,
  71                                                    struct mm_struct *);
  72 #endif
  73
  74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  75                                              struct file *, struct mm_struct *);
  76
  77 #ifdef CONFIG_ELF_CORE
  78 static int elf_fdpic_core_dump(struct coredump_params *cprm);
  79 #endif
  80
  81 static struct linux_binfmt elf_fdpic_format = {
  82         .module         = THIS_MODULE,
  83         .load_binary    = load_elf_fdpic_binary,
  84 #ifdef CONFIG_ELF_CORE
  85         .core_dump      = elf_fdpic_core_dump,
  86         .min_coredump   = ELF_EXEC_PAGESIZE,
  87 #endif
  88 };
  89
  90 static int __init init_elf_fdpic_binfmt(void)
  91 {
  92         register_binfmt(&elf_fdpic_format);
  93         return 0;
  94 }
  95
  96 static void __exit exit_elf_fdpic_binfmt(void)
  97 {
  98         unregister_binfmt(&elf_fdpic_format);
  99 }
 100
 101 core_initcall(init_elf_fdpic_binfmt);
 102 module_exit(exit_elf_fdpic_binfmt);
 103
 104 static int is_elf(struct elfhdr *hdr, struct file *file)
 105 {
 106         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 107                 return 0;
 108         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 109                 return 0;
 110         if (!elf_check_arch(hdr))
 111                 return 0;
 112         if (!file->f_op->mmap)
 113                 return 0;
 114         return 1;
 115 }
 116
 117 #ifndef elf_check_fdpic
 118 #define elf_check_fdpic(x) 0
 119 #endif
 120
 121 #ifndef elf_check_const_displacement
 122 #define elf_check_const_displacement(x) 0
 123 #endif
 124
 125 static int is_constdisp(struct elfhdr *hdr)
 126 {
 127         if (!elf_check_fdpic(hdr))
 128                 return 1;
 129         if (elf_check_const_displacement(hdr))
 130                 return 1;
 131         return 0;
 132 }
 133
 134 /*****************************************************************************/
 135 /*
 136  * read the program headers table into memory
 137  */
 138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 139                                  struct file *file)
 140 {
 141         struct elf_phdr *phdr;
 142         unsigned long size;
 143         int retval, loop;
 144         loff_t pos = params->hdr.e_phoff;
 145
 146         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 147                 return -ENOMEM;
 148         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 149                 return -ENOMEM;
 150
 151         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 152         params->phdrs = kmalloc(size, GFP_KERNEL);
 153         if (!params->phdrs)
 154                 return -ENOMEM;
 155
 156         retval = kernel_read(file, params->phdrs, size, &pos);
 157         if (unlikely(retval != size))
 158                 return retval < 0 ? retval : -ENOEXEC;
 159
 160         /* determine stack size for this binary */
 161         phdr = params->phdrs;
 162         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 163                 if (phdr->p_type != PT_GNU_STACK)
 164                         continue;
 165
 166                 if (phdr->p_flags & PF_X)
 167                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 168                 else
 169                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 170
 171                 params->stack_size = phdr->p_memsz;
 172                 break;
 173         }
 174
 175         return 0;
 176 }
 177
 178 /*****************************************************************************/
 179 /*
 180  * load an fdpic binary into various bits of memory
 181  */
 182 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 183 {
 184         struct elf_fdpic_params exec_params, interp_params;
 185         struct pt_regs *regs = current_pt_regs();
 186         struct elf_phdr *phdr;
 187         unsigned long stack_size, entryaddr;
 188 #ifdef ELF_FDPIC_PLAT_INIT
 189         unsigned long dynaddr;
 190 #endif
 191 #ifndef CONFIG_MMU
 192         unsigned long stack_prot;
 193 #endif
 194         struct file *interpreter = NULL; /* to shut gcc up */
 195         char *interpreter_name = NULL;
 196         int executable_stack;
 197         int retval, i;
 198         loff_t pos;
 199
 200         kdebug("____ LOAD %d ____", current->pid);
 201
 202         memset(&exec_params, 0, sizeof(exec_params));
 203         memset(&interp_params, 0, sizeof(interp_params));
 204
 205         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 206         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 207
 208         /* check that this is a binary we know how to deal with */
 209         retval = -ENOEXEC;
 210         if (!is_elf(&exec_params.hdr, bprm->file))
 211                 goto error;
 212         if (!elf_check_fdpic(&exec_params.hdr)) {
 213 #ifdef CONFIG_MMU
 214                 /* binfmt_elf handles non-fdpic elf except on nommu */
 215                 goto error;
 216 #else
 217                 /* nommu can only load ET_DYN (PIE) ELF */
 218                 if (exec_params.hdr.e_type != ET_DYN)
 219                         goto error;
 220 #endif
 221         }
 222
 223         /* read the program header table */
 224         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 225         if (retval < 0)
 226                 goto error;
 227
 228         /* scan for a program header that specifies an interpreter */
 229         phdr = exec_params.phdrs;
 230
 231         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 232                 switch (phdr->p_type) {
 233                 case PT_INTERP:
 234                         retval = -ENOMEM;
 235                         if (phdr->p_filesz > PATH_MAX)
 236                                 goto error;
 237                         retval = -ENOENT;
 238                         if (phdr->p_filesz < 2)
 239                                 goto error;
 240
 241                         /* read the name of the interpreter into memory */
 242                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 243                         if (!interpreter_name)
 244                                 goto error;
 245
 246                         pos = phdr->p_offset;
 247                         retval = kernel_read(bprm->file, interpreter_name,
 248                                              phdr->p_filesz, &pos);
 249                         if (unlikely(retval != phdr->p_filesz)) {
 250                                 if (retval >= 0)
 251                                         retval = -ENOEXEC;
 252                                 goto error;
 253                         }
 254
 255                         retval = -ENOENT;
 256                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 257                                 goto error;
 258
 259                         kdebug("Using ELF interpreter %s", interpreter_name);
 260
 261                         /* replace the program with the interpreter */
 262                         interpreter = open_exec(interpreter_name);
 263                         retval = PTR_ERR(interpreter);
 264                         if (IS_ERR(interpreter)) {
 265                                 interpreter = NULL;
 266                                 goto error;
 267                         }
 268
 269                         /*
 270                          * If the binary is not readable then enforce
 271                          * mm->dumpable = 0 regardless of the interpreter's
 272                          * permissions.
 273                          */
 274                         would_dump(bprm, interpreter);
 275
 276                         pos = 0;
 277                         retval = kernel_read(interpreter, bprm->buf,
 278                                         BINPRM_BUF_SIZE, &pos);
 279                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
 280                                 if (retval >= 0)
 281                                         retval = -ENOEXEC;
 282                                 goto error;
 283                         }
 284
 285                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 286                         break;
 287
 288                 case PT_LOAD:
 289 #ifdef CONFIG_MMU
 290                         if (exec_params.load_addr == 0)
 291                                 exec_params.load_addr = phdr->p_vaddr;
 292 #endif
 293                         break;
 294                 }
 295
 296         }
 297
 298         if (is_constdisp(&exec_params.hdr))
 299                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 300
 301         /* perform insanity checks on the interpreter */
 302         if (interpreter_name) {
 303                 retval = -ELIBBAD;
 304                 if (!is_elf(&interp_params.hdr, interpreter))
 305                         goto error;
 306
 307                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 308
 309                 /* read the interpreter's program header table */
 310                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 311                 if (retval < 0)
 312                         goto error;
 313         }
 314
 315         stack_size = exec_params.stack_size;
 316         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 317                 executable_stack = EXSTACK_ENABLE_X;
 318         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 319                 executable_stack = EXSTACK_DISABLE_X;
 320         else
 321                 executable_stack = EXSTACK_DEFAULT;
 322
 323         if (stack_size == 0) {
 324                 stack_size = interp_params.stack_size;
 325                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 326                         executable_stack = EXSTACK_ENABLE_X;
 327                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 328                         executable_stack = EXSTACK_DISABLE_X;
 329                 else
 330                         executable_stack = EXSTACK_DEFAULT;
 331         }
 332
 333         retval = -ENOEXEC;
 334         if (stack_size == 0)
 335                 stack_size = 131072UL; /* same as exec.c's default commit */
 336
 337         if (is_constdisp(&interp_params.hdr))
 338                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 339
 340         /* flush all traces of the currently running executable */
 341         retval = begin_new_exec(bprm);
 342         if (retval)
 343                 goto error;
 344
 345         /* there's now no turning back... the old userspace image is dead,
 346          * defunct, deceased, etc.
 347          */
 348         SET_PERSONALITY(exec_params.hdr);
 349         if (elf_check_fdpic(&exec_params.hdr))
 350                 current->personality |= PER_LINUX_FDPIC;
 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         retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
 437                                          &interp_params);
 438         if (retval < 0)
 439                 goto error;
 440
 441         kdebug("- start_code  %lx", current->mm->start_code);
 442         kdebug("- end_code    %lx", current->mm->end_code);
 443         kdebug("- start_data  %lx", current->mm->start_data);
 444         kdebug("- end_data    %lx", current->mm->end_data);
 445         kdebug("- start_brk   %lx", current->mm->start_brk);
 446         kdebug("- brk         %lx", current->mm->brk);
 447         kdebug("- start_stack %lx", current->mm->start_stack);
 448
 449 #ifdef ELF_FDPIC_PLAT_INIT
 450         /*
 451          * The ABI may specify that certain registers be set up in special
 452          * ways (on i386 %edx is the address of a DT_FINI function, for
 453          * example.  This macro performs whatever initialization to
 454          * the regs structure is required.
 455          */
 456         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 457         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 458                             dynaddr);
 459 #endif
 460
 461         finalize_exec(bprm);
 462         /* everything is now ready... get the userspace context ready to roll */
 463         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 464         start_thread(regs, entryaddr, current->mm->start_stack);
 465
 466         retval = 0;
 467
 468 error:
 469         if (interpreter) {
 470                 allow_write_access(interpreter);
 471                 fput(interpreter);
 472         }
 473         kfree(interpreter_name);
 474         kfree(exec_params.phdrs);
 475         kfree(exec_params.loadmap);
 476         kfree(interp_params.phdrs);
 477         kfree(interp_params.loadmap);
 478         return retval;
 479 }
 480
 481 /*****************************************************************************/
 482
 483 #ifndef ELF_BASE_PLATFORM
 484 /*
 485  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 486  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 487  * will be copied to the user stack in the same manner as AT_PLATFORM.
 488  */
 489 #define ELF_BASE_PLATFORM NULL
 490 #endif
 491
 492 /*
 493  * present useful information to the program by shovelling it onto the new
 494  * process's stack
 495  */
 496 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 497                                    struct mm_struct *mm,
 498                                    struct elf_fdpic_params *exec_params,
 499                                    struct elf_fdpic_params *interp_params)
 500 {
 501         const struct cred *cred = current_cred();
 502         unsigned long sp, csp, nitems;
 503         elf_caddr_t __user *argv, *envp;
 504         size_t platform_len = 0, len;
 505         char *k_platform, *k_base_platform;
 506         char __user *u_platform, *u_base_platform, *p;
 507         int loop;
 508         int nr; /* reset for each csp adjustment */
 509         unsigned long flags = 0;
 510
 511 #ifdef CONFIG_MMU
 512         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 513          * by the processes running on the same package. One thing we can do is
 514          * to shuffle the initial stack for them, so we give the architecture
 515          * an opportunity to do so here.
 516          */
 517         sp = arch_align_stack(bprm->p);
 518 #else
 519         sp = mm->start_stack;
 520
 521         /* stack the program arguments and environment */
 522         if (transfer_args_to_stack(bprm, &sp) < 0)
 523                 return -EFAULT;
 524         sp &= ~15;
 525 #endif
 526
 527         /*
 528          * If this architecture has a platform capability string, copy it
 529          * to userspace.  In some cases (Sparc), this info is impossible
 530          * for userspace to get any other way, in others (i386) it is
 531          * merely difficult.
 532          */
 533         k_platform = ELF_PLATFORM;
 534         u_platform = NULL;
 535
 536         if (k_platform) {
 537                 platform_len = strlen(k_platform) + 1;
 538                 sp -= platform_len;
 539                 u_platform = (char __user *) sp;
 540                 if (copy_to_user(u_platform, k_platform, platform_len) != 0)
 541                         return -EFAULT;
 542         }
 543
 544         /*
 545          * If this architecture has a "base" platform capability
 546          * string, copy it to userspace.
 547          */
 548         k_base_platform = ELF_BASE_PLATFORM;
 549         u_base_platform = NULL;
 550
 551         if (k_base_platform) {
 552                 platform_len = strlen(k_base_platform) + 1;
 553                 sp -= platform_len;
 554                 u_base_platform = (char __user *) sp;
 555                 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 556                         return -EFAULT;
 557         }
 558
 559         sp &= ~7UL;
 560
 561         /* stack the load map(s) */
 562         len = sizeof(struct elf_fdpic_loadmap);
 563         len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs;
 564         sp = (sp - len) & ~7UL;
 565         exec_params->map_addr = sp;
 566
 567         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 568                 return -EFAULT;
 569
 570         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 571
 572         if (interp_params->loadmap) {
 573                 len = sizeof(struct elf_fdpic_loadmap);
 574                 len += sizeof(struct elf_fdpic_loadseg) *
 575                         interp_params->loadmap->nsegs;
 576                 sp = (sp - len) & ~7UL;
 577                 interp_params->map_addr = sp;
 578
 579                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 580                                  len) != 0)
 581                         return -EFAULT;
 582
 583                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 584         }
 585
 586         /* force 16 byte _final_ alignment here for generality */
 587 #define DLINFO_ITEMS 15
 588
 589         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 590                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 591
 592         if (bprm->have_execfd)
 593                 nitems++;
 594
 595         csp = sp;
 596         sp -= nitems * 2 * sizeof(unsigned long);
 597         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 598         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 599         sp -= 1 * sizeof(unsigned long);                /* argc */
 600
 601         csp -= sp & 15UL;
 602         sp -= sp & 15UL;
 603
 604         /* put the ELF interpreter info on the stack */
 605 #define NEW_AUX_ENT(id, val)                                            \
 606         do {                                                            \
 607                 struct { unsigned long _id, _val; } __user *ent, v;     \
 608                                                                         \
 609                 ent = (void __user *) csp;                              \
 610                 v._id = (id);                                           \
 611                 v._val = (val);                                         \
 612                 if (copy_to_user(ent + nr, &v, sizeof(v)))              \
 613                         return -EFAULT;                                 \
 614                 nr++;                                                   \
 615         } while (0)
 616
 617         nr = 0;
 618         csp -= 2 * sizeof(unsigned long);
 619         NEW_AUX_ENT(AT_NULL, 0);
 620         if (k_platform) {
 621                 nr = 0;
 622                 csp -= 2 * sizeof(unsigned long);
 623                 NEW_AUX_ENT(AT_PLATFORM,
 624                             (elf_addr_t) (unsigned long) u_platform);
 625         }
 626
 627         if (k_base_platform) {
 628                 nr = 0;
 629                 csp -= 2 * sizeof(unsigned long);
 630                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 631                             (elf_addr_t) (unsigned long) u_base_platform);
 632         }
 633
 634         if (bprm->have_execfd) {
 635                 nr = 0;
 636                 csp -= 2 * sizeof(unsigned long);
 637                 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
 638         }
 639
 640         nr = 0;
 641         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 642         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 643 #ifdef ELF_HWCAP2
 644         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 645 #endif
 646         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 647         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 648         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 649         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 650         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 651         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 652         if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
 653                 flags |= AT_FLAGS_PRESERVE_ARGV0;
 654         NEW_AUX_ENT(AT_FLAGS,   flags);
 655         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 656         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 657         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 658         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 659         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 660         NEW_AUX_ENT(AT_SECURE,  bprm->secureexec);
 661         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 662
 663 #ifdef ARCH_DLINFO
 664         nr = 0;
 665         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 666
 667         /* ARCH_DLINFO must come last so platform specific code can enforce
 668          * special alignment requirements on the AUXV if necessary (eg. PPC).
 669          */
 670         ARCH_DLINFO;
 671 #endif
 672 #undef NEW_AUX_ENT
 673
 674         /* allocate room for argv[] and envv[] */
 675         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 676         envp = (elf_caddr_t __user *) csp;
 677         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 678         argv = (elf_caddr_t __user *) csp;
 679
 680         /* stack argc */
 681         csp -= sizeof(unsigned long);
 682         if (put_user(bprm->argc, (unsigned long __user *) csp))
 683                 return -EFAULT;
 684
 685         BUG_ON(csp != sp);
 686
 687         /* fill in the argv[] array */
 688 #ifdef CONFIG_MMU
 689         current->mm->arg_start = bprm->p;
 690 #else
 691         current->mm->arg_start = current->mm->start_stack -
 692                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 693 #endif
 694
 695         p = (char __user *) current->mm->arg_start;
 696         for (loop = bprm->argc; loop > 0; loop--) {
 697                 if (put_user((elf_caddr_t) p, argv++))
 698                         return -EFAULT;
 699                 len = strnlen_user(p, MAX_ARG_STRLEN);
 700                 if (!len || len > MAX_ARG_STRLEN)
 701                         return -EINVAL;
 702                 p += len;
 703         }
 704         if (put_user(NULL, argv))
 705                 return -EFAULT;
 706         current->mm->arg_end = (unsigned long) p;
 707
 708         /* fill in the envv[] array */
 709         current->mm->env_start = (unsigned long) p;
 710         for (loop = bprm->envc; loop > 0; loop--) {
 711                 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
 712                         return -EFAULT;
 713                 len = strnlen_user(p, MAX_ARG_STRLEN);
 714                 if (!len || len > MAX_ARG_STRLEN)
 715                         return -EINVAL;
 716                 p += len;
 717         }
 718         if (put_user(NULL, envp))
 719                 return -EFAULT;
 720         current->mm->env_end = (unsigned long) p;
 721
 722         mm->start_stack = (unsigned long) sp;
 723         return 0;
 724 }
 725
 726 /*****************************************************************************/
 727 /*
 728  * load the appropriate binary image (executable or interpreter) into memory
 729  * - we assume no MMU is available
 730  * - if no other PIC bits are set in params->hdr->e_flags
 731  *   - we assume that the LOADable segments in the binary are independently relocatable
 732  *   - we assume R/O executable segments are shareable
 733  * - else
 734  *   - we assume the loadable parts of the image to require fixed displacement
 735  *   - the image is not shareable
 736  */
 737 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 738                               struct file *file,
 739                               struct mm_struct *mm,
 740                               const char *what)
 741 {
 742         struct elf_fdpic_loadmap *loadmap;
 743 #ifdef CONFIG_MMU
 744         struct elf_fdpic_loadseg *mseg;
 745         unsigned long load_addr;
 746 #endif
 747         struct elf_fdpic_loadseg *seg;
 748         struct elf_phdr *phdr;
 749         unsigned nloads, tmp;
 750         unsigned long stop;
 751         int loop, ret;
 752
 753         /* allocate a load map table */
 754         nloads = 0;
 755         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 756                 if (params->phdrs[loop].p_type == PT_LOAD)
 757                         nloads++;
 758
 759         if (nloads == 0)
 760                 return -ELIBBAD;
 761
 762         loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL);
 763         if (!loadmap)
 764                 return -ENOMEM;
 765
 766         params->loadmap = loadmap;
 767
 768         loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
 769         loadmap->nsegs = nloads;
 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                                 Elf_Dyn __user *dyn;
 842                                 Elf_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(Elf_Dyn) != 0)
 853                                         goto dynamic_error;
 854
 855                                 tmp = phdr->p_memsz / sizeof(Elf_Dyn);
 856                                 dyn = (Elf_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] : %08llx-%08llx [va=%llx ms=%llx]",
 903                        loop,
 904                        (unsigned long long) seg->addr,
 905                        (unsigned long long) seg->addr + seg->p_memsz - 1,
 906                        (unsigned long long) seg->p_vaddr,
 907                        (unsigned long long) seg->p_memsz);
 908
 909         return 0;
 910
 911 dynamic_error:
 912         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 913                what, file_inode(file)->i_ino);
 914         return -ELIBBAD;
 915 }
 916
 917 /*****************************************************************************/
 918 /*
 919  * map a file with constant displacement under uClinux
 920  */
 921 #ifndef CONFIG_MMU
 922 static int elf_fdpic_map_file_constdisp_on_uclinux(
 923         struct elf_fdpic_params *params,
 924         struct file *file,
 925         struct mm_struct *mm)
 926 {
 927         struct elf_fdpic_loadseg *seg;
 928         struct elf_phdr *phdr;
 929         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
 930         int loop, ret;
 931
 932         load_addr = params->load_addr;
 933         seg = params->loadmap->segs;
 934
 935         /* determine the bounds of the contiguous overall allocation we must
 936          * make */
 937         phdr = params->phdrs;
 938         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 939                 if (params->phdrs[loop].p_type != PT_LOAD)
 940                         continue;
 941
 942                 if (base > phdr->p_vaddr)
 943                         base = phdr->p_vaddr;
 944                 if (top < phdr->p_vaddr + phdr->p_memsz)
 945                         top = phdr->p_vaddr + phdr->p_memsz;
 946         }
 947
 948         /* allocate one big anon block for everything */
 949         maddr = vm_mmap(NULL, load_addr, top - base,
 950                         PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 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 elf_fdpic_loadseg *seg;
1012         struct elf_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;
1043                 maddr = 0;
1044
1045                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1046                 case ELF_FDPIC_FLAG_INDEPENDENT:
1047                         /* PT_LOADs are independently locatable */
1048                         break;
1049
1050                 case ELF_FDPIC_FLAG_HONOURVADDR:
1051                         /* the specified virtual address must be honoured */
1052                         maddr = phdr->p_vaddr;
1053                         flags |= MAP_FIXED;
1054                         break;
1055
1056                 case ELF_FDPIC_FLAG_CONSTDISP:
1057                         /* constant displacement
1058                          * - can be mapped anywhere, but must be mapped as a
1059                          *   unit
1060                          */
1061                         if (!dvset) {
1062                                 maddr = load_addr;
1063                                 delta_vaddr = phdr->p_vaddr;
1064                                 dvset = 1;
1065                         } else {
1066                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1067                                 flags |= MAP_FIXED;
1068                         }
1069                         break;
1070
1071                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1072                         /* contiguity handled later */
1073                         break;
1074
1075                 default:
1076                         BUG();
1077                 }
1078
1079                 maddr &= PAGE_MASK;
1080
1081                 /* create the mapping */
1082                 disp = phdr->p_vaddr & ~PAGE_MASK;
1083                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1084                                 phdr->p_offset - disp);
1085
1086                 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx",
1087                        loop, (unsigned long long) phdr->p_memsz + disp,
1088                        prot, flags, (unsigned long long) phdr->p_offset - disp,
1089                        maddr);
1090
1091                 if (IS_ERR_VALUE(maddr))
1092                         return (int) maddr;
1093
1094                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1095                     ELF_FDPIC_FLAG_CONTIGUOUS)
1096                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1097
1098                 seg->addr = maddr + disp;
1099                 seg->p_vaddr = phdr->p_vaddr;
1100                 seg->p_memsz = phdr->p_memsz;
1101
1102                 /* map the ELF header address if in this segment */
1103                 if (phdr->p_offset == 0)
1104                         params->elfhdr_addr = seg->addr;
1105
1106                 /* clear the bit between beginning of mapping and beginning of
1107                  * PT_LOAD */
1108                 if (prot & PROT_WRITE && disp > 0) {
1109                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1110                         if (clear_user((void __user *) maddr, disp))
1111                                 return -EFAULT;
1112                         maddr += disp;
1113                 }
1114
1115                 /* clear any space allocated but not loaded
1116                  * - on uClinux we can just clear the lot
1117                  * - on MMU linux we'll get a SIGBUS beyond the last page
1118                  *   extant in the file
1119                  */
1120                 excess = phdr->p_memsz - phdr->p_filesz;
1121                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1122
1123 #ifdef CONFIG_MMU
1124                 if (excess > excess1) {
1125                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1126                         unsigned long xmaddr;
1127
1128                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1129                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1130                                          prot, flags, 0);
1131
1132                         kdebug("mmap[%d] <anon>"
1133                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1134                                loop, xaddr, excess - excess1, prot, flags,
1135                                xmaddr);
1136
1137                         if (xmaddr != xaddr)
1138                                 return -ENOMEM;
1139                 }
1140
1141                 if (prot & PROT_WRITE && excess1 > 0) {
1142                         kdebug("clear[%d] ad=%lx sz=%lx",
1143                                loop, maddr + phdr->p_filesz, excess1);
1144                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1145                                        excess1))
1146                                 return -EFAULT;
1147                 }
1148
1149 #else
1150                 if (excess > 0) {
1151                         kdebug("clear[%d] ad=%llx sz=%lx", loop,
1152                                (unsigned long long) maddr + phdr->p_filesz,
1153                                excess);
1154                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1155                                 return -EFAULT;
1156                 }
1157 #endif
1158
1159                 if (mm) {
1160                         if (phdr->p_flags & PF_X) {
1161                                 if (!mm->start_code) {
1162                                         mm->start_code = maddr;
1163                                         mm->end_code = maddr + phdr->p_memsz;
1164                                 }
1165                         } else if (!mm->start_data) {
1166                                 mm->start_data = maddr;
1167                                 mm->end_data = maddr + phdr->p_memsz;
1168                         }
1169                 }
1170
1171                 seg++;
1172         }
1173
1174         return 0;
1175 }
1176
1177 /*****************************************************************************/
1178 /*
1179  * ELF-FDPIC core dumper
1180  *
1181  * Modelled on fs/exec.c:aout_core_dump()
1182  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1183  *
1184  * Modelled on fs/binfmt_elf.c core dumper
1185  */
1186 #ifdef CONFIG_ELF_CORE
1187
1188 struct elf_prstatus_fdpic
1189 {
1190         struct elf_prstatus_common      common;
1191         elf_gregset_t pr_reg;   /* GP registers */
1192         /* When using FDPIC, the loadmap addresses need to be communicated
1193          * to GDB in order for GDB to do the necessary relocations.  The
1194          * fields (below) used to communicate this information are placed
1195          * immediately after ``pr_reg'', so that the loadmap addresses may
1196          * be viewed as part of the register set if so desired.
1197          */
1198         unsigned long pr_exec_fdpic_loadmap;
1199         unsigned long pr_interp_fdpic_loadmap;
1200         int pr_fpvalid;         /* True if math co-processor being used.  */
1201 };
1202
1203 /* An ELF note in memory */
1204 struct memelfnote
1205 {
1206         const char *name;
1207         int type;
1208         unsigned int datasz;
1209         void *data;
1210 };
1211
1212 static int notesize(struct memelfnote *en)
1213 {
1214         int sz;
1215
1216         sz = sizeof(struct elf_note);
1217         sz += roundup(strlen(en->name) + 1, 4);
1218         sz += roundup(en->datasz, 4);
1219
1220         return sz;
1221 }
1222
1223 /* #define DEBUG */
1224
1225 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1226 {
1227         struct elf_note en;
1228         en.n_namesz = strlen(men->name) + 1;
1229         en.n_descsz = men->datasz;
1230         en.n_type = men->type;
1231
1232         return dump_emit(cprm, &en, sizeof(en)) &&
1233                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1234                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1235 }
1236
1237 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1238 {
1239         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1240         elf->e_ident[EI_CLASS] = ELF_CLASS;
1241         elf->e_ident[EI_DATA] = ELF_DATA;
1242         elf->e_ident[EI_VERSION] = EV_CURRENT;
1243         elf->e_ident[EI_OSABI] = ELF_OSABI;
1244         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1245
1246         elf->e_type = ET_CORE;
1247         elf->e_machine = ELF_ARCH;
1248         elf->e_version = EV_CURRENT;
1249         elf->e_entry = 0;
1250         elf->e_phoff = sizeof(struct elfhdr);
1251         elf->e_shoff = 0;
1252         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1253         elf->e_ehsize = sizeof(struct elfhdr);
1254         elf->e_phentsize = sizeof(struct elf_phdr);
1255         elf->e_phnum = segs;
1256         elf->e_shentsize = 0;
1257         elf->e_shnum = 0;
1258         elf->e_shstrndx = 0;
1259         return;
1260 }
1261
1262 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1263 {
1264         phdr->p_type = PT_NOTE;
1265         phdr->p_offset = offset;
1266         phdr->p_vaddr = 0;
1267         phdr->p_paddr = 0;
1268         phdr->p_filesz = sz;
1269         phdr->p_memsz = 0;
1270         phdr->p_flags = 0;
1271         phdr->p_align = 4;
1272         return;
1273 }
1274
1275 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1276                 unsigned int sz, void *data)
1277 {
1278         note->name = name;
1279         note->type = type;
1280         note->datasz = sz;
1281         note->data = data;
1282         return;
1283 }
1284
1285 /*
1286  * fill up all the fields in prstatus from the given task struct, except
1287  * registers which need to be filled up separately.
1288  */
1289 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1290                           struct task_struct *p, long signr)
1291 {
1292         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1293         prstatus->pr_sigpend = p->pending.signal.sig[0];
1294         prstatus->pr_sighold = p->blocked.sig[0];
1295         rcu_read_lock();
1296         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1297         rcu_read_unlock();
1298         prstatus->pr_pid = task_pid_vnr(p);
1299         prstatus->pr_pgrp = task_pgrp_vnr(p);
1300         prstatus->pr_sid = task_session_vnr(p);
1301         if (thread_group_leader(p)) {
1302                 struct task_cputime cputime;
1303
1304                 /*
1305                  * This is the record for the group leader.  It shows the
1306                  * group-wide total, not its individual thread total.
1307                  */
1308                 thread_group_cputime(p, &cputime);
1309                 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1310                 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1311         } else {
1312                 u64 utime, stime;
1313
1314                 task_cputime(p, &utime, &stime);
1315                 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1316                 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1317         }
1318         prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1319         prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1320 }
1321
1322 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1323                        struct mm_struct *mm)
1324 {
1325         const struct cred *cred;
1326         unsigned int i, len;
1327         unsigned int state;
1328
1329         /* first copy the parameters from user space */
1330         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1331
1332         len = mm->arg_end - mm->arg_start;
1333         if (len >= ELF_PRARGSZ)
1334                 len = ELF_PRARGSZ - 1;
1335         if (copy_from_user(&psinfo->pr_psargs,
1336                            (const char __user *) mm->arg_start, len))
1337                 return -EFAULT;
1338         for (i = 0; i < len; i++)
1339                 if (psinfo->pr_psargs[i] == 0)
1340                         psinfo->pr_psargs[i] = ' ';
1341         psinfo->pr_psargs[len] = 0;
1342
1343         rcu_read_lock();
1344         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1345         rcu_read_unlock();
1346         psinfo->pr_pid = task_pid_vnr(p);
1347         psinfo->pr_pgrp = task_pgrp_vnr(p);
1348         psinfo->pr_sid = task_session_vnr(p);
1349
1350         state = READ_ONCE(p->__state);
1351         i = state ? ffz(~state) + 1 : 0;
1352         psinfo->pr_state = i;
1353         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1354         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1355         psinfo->pr_nice = task_nice(p);
1356         psinfo->pr_flag = p->flags;
1357         rcu_read_lock();
1358         cred = __task_cred(p);
1359         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1360         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1361         rcu_read_unlock();
1362         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1363
1364         return 0;
1365 }
1366
1367 /* Here is the structure in which status of each thread is captured. */
1368 struct elf_thread_status
1369 {
1370         struct elf_thread_status *next;
1371         struct elf_prstatus_fdpic prstatus;     /* NT_PRSTATUS */
1372         elf_fpregset_t fpu;             /* NT_PRFPREG */
1373         struct memelfnote notes[2];
1374         int num_notes;
1375 };
1376
1377 /*
1378  * In order to add the specific thread information for the elf file format,
1379  * we need to keep a linked list of every thread's pr_status and then create
1380  * a single section for them in the final core file.
1381  */
1382 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1383 {
1384         const struct user_regset_view *view = task_user_regset_view(p);
1385         struct elf_thread_status *t;
1386         int i, ret;
1387
1388         t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1389         if (!t)
1390                 return t;
1391
1392         fill_prstatus(&t->prstatus.common, p, signr);
1393         t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1394         t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1395         regset_get(p, &view->regsets[0],
1396                    sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1397
1398         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1399                   &t->prstatus);
1400         t->num_notes++;
1401         *sz += notesize(&t->notes[0]);
1402
1403         for (i = 1; i < view->n; ++i) {
1404                 const struct user_regset *regset = &view->regsets[i];
1405                 if (regset->core_note_type != NT_PRFPREG)
1406                         continue;
1407                 if (regset->active && regset->active(p, regset) <= 0)
1408                         continue;
1409                 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1410                 if (ret >= 0)
1411                         t->prstatus.pr_fpvalid = 1;
1412                 break;
1413         }
1414
1415         if (t->prstatus.pr_fpvalid) {
1416                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1417                           &t->fpu);
1418                 t->num_notes++;
1419                 *sz += notesize(&t->notes[1]);
1420         }
1421         return t;
1422 }
1423
1424 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1425                              elf_addr_t e_shoff, int segs)
1426 {
1427         elf->e_shoff = e_shoff;
1428         elf->e_shentsize = sizeof(*shdr4extnum);
1429         elf->e_shnum = 1;
1430         elf->e_shstrndx = SHN_UNDEF;
1431
1432         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1433
1434         shdr4extnum->sh_type = SHT_NULL;
1435         shdr4extnum->sh_size = elf->e_shnum;
1436         shdr4extnum->sh_link = elf->e_shstrndx;
1437         shdr4extnum->sh_info = segs;
1438 }
1439
1440 /*
1441  * dump the segments for an MMU process
1442  */
1443 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1444                                     struct core_vma_metadata *vma_meta,
1445                                     int vma_count)
1446 {
1447         int i;
1448
1449         for (i = 0; i < vma_count; i++) {
1450                 struct core_vma_metadata *meta = vma_meta + i;
1451
1452                 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1453                         return false;
1454         }
1455         return true;
1456 }
1457
1458 /*
1459  * Actual dumper
1460  *
1461  * This is a two-pass process; first we find the offsets of the bits,
1462  * and then they are actually written out.  If we run out of core limit
1463  * we just truncate.
1464  */
1465 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1466 {
1467         int has_dumped = 0;
1468         int segs;
1469         int i;
1470         struct elfhdr *elf = NULL;
1471         loff_t offset = 0, dataoff;
1472         struct memelfnote psinfo_note, auxv_note;
1473         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1474         struct elf_thread_status *thread_list = NULL;
1475         int thread_status_size = 0;
1476         elf_addr_t *auxv;
1477         struct elf_phdr *phdr4note = NULL;
1478         struct elf_shdr *shdr4extnum = NULL;
1479         Elf_Half e_phnum;
1480         elf_addr_t e_shoff;
1481         struct core_thread *ct;
1482         struct elf_thread_status *tmp;
1483
1484         /* alloc memory for large data structures: too large to be on stack */
1485         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1486         if (!elf)
1487                 goto end_coredump;
1488         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1489         if (!psinfo)
1490                 goto end_coredump;
1491
1492         for (ct = current->signal->core_state->dumper.next;
1493                                         ct; ct = ct->next) {
1494                 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1495                                              ct->task, &thread_status_size);
1496                 if (!tmp)
1497                         goto end_coredump;
1498
1499                 tmp->next = thread_list;
1500                 thread_list = tmp;
1501         }
1502
1503         /* now collect the dump for the current */
1504         tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1505                                      current, &thread_status_size);
1506         if (!tmp)
1507                 goto end_coredump;
1508         tmp->next = thread_list;
1509         thread_list = tmp;
1510
1511         segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1512
1513         /* for notes section */
1514         segs++;
1515
1516         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1517          * this, kernel supports extended numbering. Have a look at
1518          * include/linux/elf.h for further information. */
1519         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1520
1521         /* Set up header */
1522         fill_elf_fdpic_header(elf, e_phnum);
1523
1524         has_dumped = 1;
1525         /*
1526          * Set up the notes in similar form to SVR4 core dumps made
1527          * with info from their /proc.
1528          */
1529
1530         fill_psinfo(psinfo, current->group_leader, current->mm);
1531         fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1532         thread_status_size += notesize(&psinfo_note);
1533
1534         auxv = (elf_addr_t *) current->mm->saved_auxv;
1535         i = 0;
1536         do
1537                 i += 2;
1538         while (auxv[i - 2] != AT_NULL);
1539         fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1540         thread_status_size += notesize(&auxv_note);
1541
1542         offset = sizeof(*elf);                          /* ELF header */
1543         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1544
1545         /* Write notes phdr entry */
1546         phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1547         if (!phdr4note)
1548                 goto end_coredump;
1549
1550         fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1551         offset += thread_status_size;
1552
1553         /* Page-align dumped data */
1554         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1555
1556         offset += cprm->vma_data_size;
1557         offset += elf_core_extra_data_size(cprm);
1558         e_shoff = offset;
1559
1560         if (e_phnum == PN_XNUM) {
1561                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1562                 if (!shdr4extnum)
1563                         goto end_coredump;
1564                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1565         }
1566
1567         offset = dataoff;
1568
1569         if (!dump_emit(cprm, elf, sizeof(*elf)))
1570                 goto end_coredump;
1571
1572         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1573                 goto end_coredump;
1574
1575         /* write program headers for segments dump */
1576         for (i = 0; i < cprm->vma_count; i++) {
1577                 struct core_vma_metadata *meta = cprm->vma_meta + i;
1578                 struct elf_phdr phdr;
1579                 size_t sz;
1580
1581                 sz = meta->end - meta->start;
1582
1583                 phdr.p_type = PT_LOAD;
1584                 phdr.p_offset = offset;
1585                 phdr.p_vaddr = meta->start;
1586                 phdr.p_paddr = 0;
1587                 phdr.p_filesz = meta->dump_size;
1588                 phdr.p_memsz = sz;
1589                 offset += phdr.p_filesz;
1590                 phdr.p_flags = 0;
1591                 if (meta->flags & VM_READ)
1592                         phdr.p_flags |= PF_R;
1593                 if (meta->flags & VM_WRITE)
1594                         phdr.p_flags |= PF_W;
1595                 if (meta->flags & VM_EXEC)
1596                         phdr.p_flags |= PF_X;
1597                 phdr.p_align = ELF_EXEC_PAGESIZE;
1598
1599                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1600                         goto end_coredump;
1601         }
1602
1603         if (!elf_core_write_extra_phdrs(cprm, offset))
1604                 goto end_coredump;
1605
1606         /* write out the notes section */
1607         if (!writenote(thread_list->notes, cprm))
1608                 goto end_coredump;
1609         if (!writenote(&psinfo_note, cprm))
1610                 goto end_coredump;
1611         if (!writenote(&auxv_note, cprm))
1612                 goto end_coredump;
1613         for (i = 1; i < thread_list->num_notes; i++)
1614                 if (!writenote(thread_list->notes + i, cprm))
1615                         goto end_coredump;
1616
1617         /* write out the thread status notes section */
1618         for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1619                 for (i = 0; i < tmp->num_notes; i++)
1620                         if (!writenote(&tmp->notes[i], cprm))
1621                                 goto end_coredump;
1622         }
1623
1624         dump_skip_to(cprm, dataoff);
1625
1626         if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1627                 goto end_coredump;
1628
1629         if (!elf_core_write_extra_data(cprm))
1630                 goto end_coredump;
1631
1632         if (e_phnum == PN_XNUM) {
1633                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1634                         goto end_coredump;
1635         }
1636
1637         if (cprm->file->f_pos != offset) {
1638                 /* Sanity check */
1639                 printk(KERN_WARNING
1640                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1641                        cprm->file->f_pos, offset);
1642         }
1643
1644 end_coredump:
1645         while (thread_list) {
1646                 tmp = thread_list;
1647                 thread_list = thread_list->next;
1648                 kfree(tmp);
1649         }
1650         kfree(phdr4note);
1651         kfree(elf);
1652         kfree(psinfo);
1653         kfree(shdr4extnum);
1654         return has_dumped;
1655 }
1656
1657 #endif          /* CONFIG_ELF_CORE */