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 ([email protected])
   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 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) {
 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                 fput(interpreter);
 398                 interpreter = NULL;
 399         }
 400
 401 #ifdef CONFIG_MMU
 402         if (!current->mm->start_brk)
 403                 current->mm->start_brk = current->mm->end_data;
 404
 405         current->mm->brk = current->mm->start_brk =
 406                 PAGE_ALIGN(current->mm->start_brk);
 407
 408 #else
 409         /* create a stack area and zero-size brk area */
 410         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 411         if (stack_size < PAGE_SIZE * 2)
 412                 stack_size = PAGE_SIZE * 2;
 413
 414         stack_prot = PROT_READ | PROT_WRITE;
 415         if (executable_stack == EXSTACK_ENABLE_X ||
 416             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 417                 stack_prot |= PROT_EXEC;
 418
 419         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 420                                          MAP_PRIVATE | MAP_ANONYMOUS |
 421                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 422                                          0);
 423
 424         if (IS_ERR_VALUE(current->mm->start_brk)) {
 425                 retval = current->mm->start_brk;
 426                 current->mm->start_brk = 0;
 427                 goto error;
 428         }
 429
 430         current->mm->brk = current->mm->start_brk;
 431         current->mm->context.end_brk = current->mm->start_brk;
 432         current->mm->start_stack = current->mm->start_brk + stack_size;
 433 #endif
 434
 435         retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
 436                                          &interp_params);
 437         if (retval < 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                 fput(interpreter);
 470         kfree(interpreter_name);
 471         kfree(exec_params.phdrs);
 472         kfree(exec_params.loadmap);
 473         kfree(interp_params.phdrs);
 474         kfree(interp_params.loadmap);
 475         return retval;
 476 }
 477
 478 /*****************************************************************************/
 479
 480 #ifndef ELF_BASE_PLATFORM
 481 /*
 482  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 483  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 484  * will be copied to the user stack in the same manner as AT_PLATFORM.
 485  */
 486 #define ELF_BASE_PLATFORM NULL
 487 #endif
 488
 489 /*
 490  * present useful information to the program by shovelling it onto the new
 491  * process's stack
 492  */
 493 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 494                                    struct mm_struct *mm,
 495                                    struct elf_fdpic_params *exec_params,
 496                                    struct elf_fdpic_params *interp_params)
 497 {
 498         const struct cred *cred = current_cred();
 499         unsigned long sp, csp, nitems;
 500         elf_caddr_t __user *argv, *envp;
 501         size_t platform_len = 0, len;
 502         char *k_platform, *k_base_platform;
 503         char __user *u_platform, *u_base_platform, *p;
 504         int loop;
 505         unsigned long flags = 0;
 506         int ei_index;
 507         elf_addr_t *elf_info;
 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 elf_fdpic_loadmap);
 561         len += sizeof(struct elf_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 elf_fdpic_loadmap);
 572                 len += sizeof(struct elf_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         /* Create the ELF interpreter info */
 603         elf_info = (elf_addr_t *)mm->saved_auxv;
 604         /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
 605 #define NEW_AUX_ENT(id, val) \
 606         do { \
 607                 *elf_info++ = id; \
 608                 *elf_info++ = val; \
 609         } while (0)
 610
 611 #ifdef ARCH_DLINFO
 612         /*
 613          * ARCH_DLINFO must come first so PPC can do its special alignment of
 614          * AUXV.
 615          * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
 616          * ARCH_DLINFO changes
 617          */
 618         ARCH_DLINFO;
 619 #endif
 620         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 621 #ifdef ELF_HWCAP2
 622         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 623 #endif
 624         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 625         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 626         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 627         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 628         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 629         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 630         if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
 631                 flags |= AT_FLAGS_PRESERVE_ARGV0;
 632         NEW_AUX_ENT(AT_FLAGS,   flags);
 633         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 634         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 635         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 636         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 637         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 638         NEW_AUX_ENT(AT_SECURE,  bprm->secureexec);
 639         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 640         if (k_platform)
 641                 NEW_AUX_ENT(AT_PLATFORM,
 642                             (elf_addr_t)(unsigned long)u_platform);
 643         if (k_base_platform)
 644                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 645                             (elf_addr_t)(unsigned long)u_base_platform);
 646         if (bprm->have_execfd)
 647                 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
 648 #undef NEW_AUX_ENT
 649         /* AT_NULL is zero; clear the rest too */
 650         memset(elf_info, 0, (char *)mm->saved_auxv +
 651                sizeof(mm->saved_auxv) - (char *)elf_info);
 652
 653         /* And advance past the AT_NULL entry.  */
 654         elf_info += 2;
 655
 656         ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
 657         csp -= ei_index * sizeof(elf_addr_t);
 658
 659         /* Put the elf_info on the stack in the right place.  */
 660         if (copy_to_user((void __user *)csp, mm->saved_auxv,
 661                          ei_index * sizeof(elf_addr_t)))
 662                 return -EFAULT;
 663
 664         /* allocate room for argv[] and envv[] */
 665         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 666         envp = (elf_caddr_t __user *) csp;
 667         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 668         argv = (elf_caddr_t __user *) csp;
 669
 670         /* stack argc */
 671         csp -= sizeof(unsigned long);
 672         if (put_user(bprm->argc, (unsigned long __user *) csp))
 673                 return -EFAULT;
 674
 675         BUG_ON(csp != sp);
 676
 677         /* fill in the argv[] array */
 678 #ifdef CONFIG_MMU
 679         current->mm->arg_start = bprm->p;
 680 #else
 681         current->mm->arg_start = current->mm->start_stack -
 682                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 683 #endif
 684
 685         p = (char __user *) current->mm->arg_start;
 686         for (loop = bprm->argc; loop > 0; loop--) {
 687                 if (put_user((elf_caddr_t) p, argv++))
 688                         return -EFAULT;
 689                 len = strnlen_user(p, MAX_ARG_STRLEN);
 690                 if (!len || len > MAX_ARG_STRLEN)
 691                         return -EINVAL;
 692                 p += len;
 693         }
 694         if (put_user(NULL, argv))
 695                 return -EFAULT;
 696         current->mm->arg_end = (unsigned long) p;
 697
 698         /* fill in the envv[] array */
 699         current->mm->env_start = (unsigned long) p;
 700         for (loop = bprm->envc; loop > 0; loop--) {
 701                 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
 702                         return -EFAULT;
 703                 len = strnlen_user(p, MAX_ARG_STRLEN);
 704                 if (!len || len > MAX_ARG_STRLEN)
 705                         return -EINVAL;
 706                 p += len;
 707         }
 708         if (put_user(NULL, envp))
 709                 return -EFAULT;
 710         current->mm->env_end = (unsigned long) p;
 711
 712         mm->start_stack = (unsigned long) sp;
 713         return 0;
 714 }
 715
 716 /*****************************************************************************/
 717 /*
 718  * load the appropriate binary image (executable or interpreter) into memory
 719  * - we assume no MMU is available
 720  * - if no other PIC bits are set in params->hdr->e_flags
 721  *   - we assume that the LOADable segments in the binary are independently relocatable
 722  *   - we assume R/O executable segments are shareable
 723  * - else
 724  *   - we assume the loadable parts of the image to require fixed displacement
 725  *   - the image is not shareable
 726  */
 727 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 728                               struct file *file,
 729                               struct mm_struct *mm,
 730                               const char *what)
 731 {
 732         struct elf_fdpic_loadmap *loadmap;
 733 #ifdef CONFIG_MMU
 734         struct elf_fdpic_loadseg *mseg;
 735         unsigned long load_addr;
 736 #endif
 737         struct elf_fdpic_loadseg *seg;
 738         struct elf_phdr *phdr;
 739         unsigned nloads, tmp;
 740         unsigned long stop;
 741         int loop, ret;
 742
 743         /* allocate a load map table */
 744         nloads = 0;
 745         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 746                 if (params->phdrs[loop].p_type == PT_LOAD)
 747                         nloads++;
 748
 749         if (nloads == 0)
 750                 return -ELIBBAD;
 751
 752         loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL);
 753         if (!loadmap)
 754                 return -ENOMEM;
 755
 756         params->loadmap = loadmap;
 757
 758         loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
 759         loadmap->nsegs = nloads;
 760
 761         /* map the requested LOADs into the memory space */
 762         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 763         case ELF_FDPIC_FLAG_CONSTDISP:
 764         case ELF_FDPIC_FLAG_CONTIGUOUS:
 765 #ifndef CONFIG_MMU
 766                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 767                 if (ret < 0)
 768                         return ret;
 769                 break;
 770 #endif
 771         default:
 772                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 773                 if (ret < 0)
 774                         return ret;
 775                 break;
 776         }
 777
 778         /* map the entry point */
 779         if (params->hdr.e_entry) {
 780                 seg = loadmap->segs;
 781                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 782                         if (params->hdr.e_entry >= seg->p_vaddr &&
 783                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 784                                 params->entry_addr =
 785                                         (params->hdr.e_entry - seg->p_vaddr) +
 786                                         seg->addr;
 787                                 break;
 788                         }
 789                 }
 790         }
 791
 792         /* determine where the program header table has wound up if mapped */
 793         stop = params->hdr.e_phoff;
 794         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 795         phdr = params->phdrs;
 796
 797         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 798                 if (phdr->p_type != PT_LOAD)
 799                         continue;
 800
 801                 if (phdr->p_offset > params->hdr.e_phoff ||
 802                     phdr->p_offset + phdr->p_filesz < stop)
 803                         continue;
 804
 805                 seg = loadmap->segs;
 806                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 807                         if (phdr->p_vaddr >= seg->p_vaddr &&
 808                             phdr->p_vaddr + phdr->p_filesz <=
 809                             seg->p_vaddr + seg->p_memsz) {
 810                                 params->ph_addr =
 811                                         (phdr->p_vaddr - seg->p_vaddr) +
 812                                         seg->addr +
 813                                         params->hdr.e_phoff - phdr->p_offset;
 814                                 break;
 815                         }
 816                 }
 817                 break;
 818         }
 819
 820         /* determine where the dynamic section has wound up if there is one */
 821         phdr = params->phdrs;
 822         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 823                 if (phdr->p_type != PT_DYNAMIC)
 824                         continue;
 825
 826                 seg = loadmap->segs;
 827                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 828                         if (phdr->p_vaddr >= seg->p_vaddr &&
 829                             phdr->p_vaddr + phdr->p_memsz <=
 830                             seg->p_vaddr + seg->p_memsz) {
 831                                 Elf_Dyn __user *dyn;
 832                                 Elf_Sword d_tag;
 833
 834                                 params->dynamic_addr =
 835                                         (phdr->p_vaddr - seg->p_vaddr) +
 836                                         seg->addr;
 837
 838                                 /* check the dynamic section contains at least
 839                                  * one item, and that the last item is a NULL
 840                                  * entry */
 841                                 if (phdr->p_memsz == 0 ||
 842                                     phdr->p_memsz % sizeof(Elf_Dyn) != 0)
 843                                         goto dynamic_error;
 844
 845                                 tmp = phdr->p_memsz / sizeof(Elf_Dyn);
 846                                 dyn = (Elf_Dyn __user *)params->dynamic_addr;
 847                                 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
 848                                     d_tag != 0)
 849                                         goto dynamic_error;
 850                                 break;
 851                         }
 852                 }
 853                 break;
 854         }
 855
 856         /* now elide adjacent segments in the load map on MMU linux
 857          * - on uClinux the holes between may actually be filled with system
 858          *   stuff or stuff from other processes
 859          */
 860 #ifdef CONFIG_MMU
 861         nloads = loadmap->nsegs;
 862         mseg = loadmap->segs;
 863         seg = mseg + 1;
 864         for (loop = 1; loop < nloads; loop++) {
 865                 /* see if we have a candidate for merging */
 866                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 867                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 868                         if (load_addr == (seg->addr & PAGE_MASK)) {
 869                                 mseg->p_memsz +=
 870                                         load_addr -
 871                                         (mseg->addr + mseg->p_memsz);
 872                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 873                                 mseg->p_memsz += seg->p_memsz;
 874                                 loadmap->nsegs--;
 875                                 continue;
 876                         }
 877                 }
 878
 879                 mseg++;
 880                 if (mseg != seg)
 881                         *mseg = *seg;
 882         }
 883 #endif
 884
 885         kdebug("Mapped Object [%s]:", what);
 886         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 887         kdebug("- entry    : %lx", params->entry_addr);
 888         kdebug("- PHDR[]   : %lx", params->ph_addr);
 889         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 890         seg = loadmap->segs;
 891         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 892                 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]",
 893                        loop,
 894                        (unsigned long long) seg->addr,
 895                        (unsigned long long) seg->addr + seg->p_memsz - 1,
 896                        (unsigned long long) seg->p_vaddr,
 897                        (unsigned long long) seg->p_memsz);
 898
 899         return 0;
 900
 901 dynamic_error:
 902         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 903                what, file_inode(file)->i_ino);
 904         return -ELIBBAD;
 905 }
 906
 907 /*****************************************************************************/
 908 /*
 909  * map a file with constant displacement under uClinux
 910  */
 911 #ifndef CONFIG_MMU
 912 static int elf_fdpic_map_file_constdisp_on_uclinux(
 913         struct elf_fdpic_params *params,
 914         struct file *file,
 915         struct mm_struct *mm)
 916 {
 917         struct elf_fdpic_loadseg *seg;
 918         struct elf_phdr *phdr;
 919         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
 920         int loop, ret;
 921
 922         load_addr = params->load_addr;
 923         seg = params->loadmap->segs;
 924
 925         /* determine the bounds of the contiguous overall allocation we must
 926          * make */
 927         phdr = params->phdrs;
 928         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 929                 if (params->phdrs[loop].p_type != PT_LOAD)
 930                         continue;
 931
 932                 if (base > phdr->p_vaddr)
 933                         base = phdr->p_vaddr;
 934                 if (top < phdr->p_vaddr + phdr->p_memsz)
 935                         top = phdr->p_vaddr + phdr->p_memsz;
 936         }
 937
 938         /* allocate one big anon block for everything */
 939         maddr = vm_mmap(NULL, load_addr, top - base,
 940                         PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
 941         if (IS_ERR_VALUE(maddr))
 942                 return (int) maddr;
 943
 944         if (load_addr != 0)
 945                 load_addr += PAGE_ALIGN(top - base);
 946
 947         /* and then load the file segments into it */
 948         phdr = params->phdrs;
 949         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 950                 if (params->phdrs[loop].p_type != PT_LOAD)
 951                         continue;
 952
 953                 seg->addr = maddr + (phdr->p_vaddr - base);
 954                 seg->p_vaddr = phdr->p_vaddr;
 955                 seg->p_memsz = phdr->p_memsz;
 956
 957                 ret = read_code(file, seg->addr, phdr->p_offset,
 958                                        phdr->p_filesz);
 959                 if (ret < 0)
 960                         return ret;
 961
 962                 /* map the ELF header address if in this segment */
 963                 if (phdr->p_offset == 0)
 964                         params->elfhdr_addr = seg->addr;
 965
 966                 /* clear any space allocated but not loaded */
 967                 if (phdr->p_filesz < phdr->p_memsz) {
 968                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
 969                                        phdr->p_memsz - phdr->p_filesz))
 970                                 return -EFAULT;
 971                 }
 972
 973                 if (mm) {
 974                         if (phdr->p_flags & PF_X) {
 975                                 if (!mm->start_code) {
 976                                         mm->start_code = seg->addr;
 977                                         mm->end_code = seg->addr +
 978                                                 phdr->p_memsz;
 979                                 }
 980                         } else if (!mm->start_data) {
 981                                 mm->start_data = seg->addr;
 982                                 mm->end_data = seg->addr + phdr->p_memsz;
 983                         }
 984                 }
 985
 986                 seg++;
 987         }
 988
 989         return 0;
 990 }
 991 #endif
 992
 993 /*****************************************************************************/
 994 /*
 995  * map a binary by direct mmap() of the individual PT_LOAD segments
 996  */
 997 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 998                                              struct file *file,
 999                                              struct mm_struct *mm)
1000 {
1001         struct elf_fdpic_loadseg *seg;
1002         struct elf_phdr *phdr;
1003         unsigned long load_addr, delta_vaddr;
1004         int loop, dvset;
1005
1006         load_addr = params->load_addr;
1007         delta_vaddr = 0;
1008         dvset = 0;
1009
1010         seg = params->loadmap->segs;
1011
1012         /* deal with each load segment separately */
1013         phdr = params->phdrs;
1014         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1015                 unsigned long maddr, disp, excess, excess1;
1016                 int prot = 0, flags;
1017
1018                 if (phdr->p_type != PT_LOAD)
1019                         continue;
1020
1021                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1022                        (unsigned long) phdr->p_vaddr,
1023                        (unsigned long) phdr->p_offset,
1024                        (unsigned long) phdr->p_filesz,
1025                        (unsigned long) phdr->p_memsz);
1026
1027                 /* determine the mapping parameters */
1028                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1029                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1030                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1031
1032                 flags = MAP_PRIVATE;
1033                 maddr = 0;
1034
1035                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1036                 case ELF_FDPIC_FLAG_INDEPENDENT:
1037                         /* PT_LOADs are independently locatable */
1038                         break;
1039
1040                 case ELF_FDPIC_FLAG_HONOURVADDR:
1041                         /* the specified virtual address must be honoured */
1042                         maddr = phdr->p_vaddr;
1043                         flags |= MAP_FIXED;
1044                         break;
1045
1046                 case ELF_FDPIC_FLAG_CONSTDISP:
1047                         /* constant displacement
1048                          * - can be mapped anywhere, but must be mapped as a
1049                          *   unit
1050                          */
1051                         if (!dvset) {
1052                                 maddr = load_addr;
1053                                 delta_vaddr = phdr->p_vaddr;
1054                                 dvset = 1;
1055                         } else {
1056                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1057                                 flags |= MAP_FIXED;
1058                         }
1059                         break;
1060
1061                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1062                         /* contiguity handled later */
1063                         break;
1064
1065                 default:
1066                         BUG();
1067                 }
1068
1069                 maddr &= PAGE_MASK;
1070
1071                 /* create the mapping */
1072                 disp = phdr->p_vaddr & ~PAGE_MASK;
1073                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1074                                 phdr->p_offset - disp);
1075
1076                 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx",
1077                        loop, (unsigned long long) phdr->p_memsz + disp,
1078                        prot, flags, (unsigned long long) phdr->p_offset - disp,
1079                        maddr);
1080
1081                 if (IS_ERR_VALUE(maddr))
1082                         return (int) maddr;
1083
1084                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1085                     ELF_FDPIC_FLAG_CONTIGUOUS)
1086                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1087
1088                 seg->addr = maddr + disp;
1089                 seg->p_vaddr = phdr->p_vaddr;
1090                 seg->p_memsz = phdr->p_memsz;
1091
1092                 /* map the ELF header address if in this segment */
1093                 if (phdr->p_offset == 0)
1094                         params->elfhdr_addr = seg->addr;
1095
1096                 /* clear the bit between beginning of mapping and beginning of
1097                  * PT_LOAD */
1098                 if (prot & PROT_WRITE && disp > 0) {
1099                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1100                         if (clear_user((void __user *) maddr, disp))
1101                                 return -EFAULT;
1102                         maddr += disp;
1103                 }
1104
1105                 /* clear any space allocated but not loaded
1106                  * - on uClinux we can just clear the lot
1107                  * - on MMU linux we'll get a SIGBUS beyond the last page
1108                  *   extant in the file
1109                  */
1110                 excess = phdr->p_memsz - phdr->p_filesz;
1111                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1112
1113 #ifdef CONFIG_MMU
1114                 if (excess > excess1) {
1115                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1116                         unsigned long xmaddr;
1117
1118                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1119                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1120                                          prot, flags, 0);
1121
1122                         kdebug("mmap[%d] <anon>"
1123                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1124                                loop, xaddr, excess - excess1, prot, flags,
1125                                xmaddr);
1126
1127                         if (xmaddr != xaddr)
1128                                 return -ENOMEM;
1129                 }
1130
1131                 if (prot & PROT_WRITE && excess1 > 0) {
1132                         kdebug("clear[%d] ad=%lx sz=%lx",
1133                                loop, maddr + phdr->p_filesz, excess1);
1134                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1135                                        excess1))
1136                                 return -EFAULT;
1137                 }
1138
1139 #else
1140                 if (excess > 0) {
1141                         kdebug("clear[%d] ad=%llx sz=%lx", loop,
1142                                (unsigned long long) maddr + phdr->p_filesz,
1143                                excess);
1144                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1145                                 return -EFAULT;
1146                 }
1147 #endif
1148
1149                 if (mm) {
1150                         if (phdr->p_flags & PF_X) {
1151                                 if (!mm->start_code) {
1152                                         mm->start_code = maddr;
1153                                         mm->end_code = maddr + phdr->p_memsz;
1154                                 }
1155                         } else if (!mm->start_data) {
1156                                 mm->start_data = maddr;
1157                                 mm->end_data = maddr + phdr->p_memsz;
1158                         }
1159                 }
1160
1161                 seg++;
1162         }
1163
1164         return 0;
1165 }
1166
1167 /*****************************************************************************/
1168 /*
1169  * ELF-FDPIC core dumper
1170  *
1171  * Modelled on fs/exec.c:aout_core_dump()
1172  * Jeremy Fitzhardinge <[email protected]>
1173  *
1174  * Modelled on fs/binfmt_elf.c core dumper
1175  */
1176 #ifdef CONFIG_ELF_CORE
1177
1178 struct elf_prstatus_fdpic
1179 {
1180         struct elf_prstatus_common      common;
1181         elf_gregset_t pr_reg;   /* GP registers */
1182         /* When using FDPIC, the loadmap addresses need to be communicated
1183          * to GDB in order for GDB to do the necessary relocations.  The
1184          * fields (below) used to communicate this information are placed
1185          * immediately after ``pr_reg'', so that the loadmap addresses may
1186          * be viewed as part of the register set if so desired.
1187          */
1188         unsigned long pr_exec_fdpic_loadmap;
1189         unsigned long pr_interp_fdpic_loadmap;
1190         int pr_fpvalid;         /* True if math co-processor being used.  */
1191 };
1192
1193 /* An ELF note in memory */
1194 struct memelfnote
1195 {
1196         const char *name;
1197         int type;
1198         unsigned int datasz;
1199         void *data;
1200 };
1201
1202 static int notesize(struct memelfnote *en)
1203 {
1204         int sz;
1205
1206         sz = sizeof(struct elf_note);
1207         sz += roundup(strlen(en->name) + 1, 4);
1208         sz += roundup(en->datasz, 4);
1209
1210         return sz;
1211 }
1212
1213 /* #define DEBUG */
1214
1215 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1216 {
1217         struct elf_note en;
1218         en.n_namesz = strlen(men->name) + 1;
1219         en.n_descsz = men->datasz;
1220         en.n_type = men->type;
1221
1222         return dump_emit(cprm, &en, sizeof(en)) &&
1223                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1224                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1225 }
1226
1227 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1228 {
1229         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1230         elf->e_ident[EI_CLASS] = ELF_CLASS;
1231         elf->e_ident[EI_DATA] = ELF_DATA;
1232         elf->e_ident[EI_VERSION] = EV_CURRENT;
1233         elf->e_ident[EI_OSABI] = ELF_OSABI;
1234         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1235
1236         elf->e_type = ET_CORE;
1237         elf->e_machine = ELF_ARCH;
1238         elf->e_version = EV_CURRENT;
1239         elf->e_entry = 0;
1240         elf->e_phoff = sizeof(struct elfhdr);
1241         elf->e_shoff = 0;
1242         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1243         elf->e_ehsize = sizeof(struct elfhdr);
1244         elf->e_phentsize = sizeof(struct elf_phdr);
1245         elf->e_phnum = segs;
1246         elf->e_shentsize = 0;
1247         elf->e_shnum = 0;
1248         elf->e_shstrndx = 0;
1249         return;
1250 }
1251
1252 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1253 {
1254         phdr->p_type = PT_NOTE;
1255         phdr->p_offset = offset;
1256         phdr->p_vaddr = 0;
1257         phdr->p_paddr = 0;
1258         phdr->p_filesz = sz;
1259         phdr->p_memsz = 0;
1260         phdr->p_flags = 0;
1261         phdr->p_align = 4;
1262         return;
1263 }
1264
1265 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1266                 unsigned int sz, void *data)
1267 {
1268         note->name = name;
1269         note->type = type;
1270         note->datasz = sz;
1271         note->data = data;
1272         return;
1273 }
1274
1275 /*
1276  * fill up all the fields in prstatus from the given task struct, except
1277  * registers which need to be filled up separately.
1278  */
1279 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1280                           struct task_struct *p, long signr)
1281 {
1282         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1283         prstatus->pr_sigpend = p->pending.signal.sig[0];
1284         prstatus->pr_sighold = p->blocked.sig[0];
1285         rcu_read_lock();
1286         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1287         rcu_read_unlock();
1288         prstatus->pr_pid = task_pid_vnr(p);
1289         prstatus->pr_pgrp = task_pgrp_vnr(p);
1290         prstatus->pr_sid = task_session_vnr(p);
1291         if (thread_group_leader(p)) {
1292                 struct task_cputime cputime;
1293
1294                 /*
1295                  * This is the record for the group leader.  It shows the
1296                  * group-wide total, not its individual thread total.
1297                  */
1298                 thread_group_cputime(p, &cputime);
1299                 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1300                 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1301         } else {
1302                 u64 utime, stime;
1303
1304                 task_cputime(p, &utime, &stime);
1305                 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1306                 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1307         }
1308         prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1309         prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1310 }
1311
1312 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1313                        struct mm_struct *mm)
1314 {
1315         const struct cred *cred;
1316         unsigned int i, len;
1317         unsigned int state;
1318
1319         /* first copy the parameters from user space */
1320         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1321
1322         len = mm->arg_end - mm->arg_start;
1323         if (len >= ELF_PRARGSZ)
1324                 len = ELF_PRARGSZ - 1;
1325         if (copy_from_user(&psinfo->pr_psargs,
1326                            (const char __user *) mm->arg_start, len))
1327                 return -EFAULT;
1328         for (i = 0; i < len; i++)
1329                 if (psinfo->pr_psargs[i] == 0)
1330                         psinfo->pr_psargs[i] = ' ';
1331         psinfo->pr_psargs[len] = 0;
1332
1333         rcu_read_lock();
1334         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1335         rcu_read_unlock();
1336         psinfo->pr_pid = task_pid_vnr(p);
1337         psinfo->pr_pgrp = task_pgrp_vnr(p);
1338         psinfo->pr_sid = task_session_vnr(p);
1339
1340         state = READ_ONCE(p->__state);
1341         i = state ? ffz(~state) + 1 : 0;
1342         psinfo->pr_state = i;
1343         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1344         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1345         psinfo->pr_nice = task_nice(p);
1346         psinfo->pr_flag = p->flags;
1347         rcu_read_lock();
1348         cred = __task_cred(p);
1349         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1350         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1351         rcu_read_unlock();
1352         get_task_comm(psinfo->pr_fname, p);
1353
1354         return 0;
1355 }
1356
1357 /* Here is the structure in which status of each thread is captured. */
1358 struct elf_thread_status
1359 {
1360         struct elf_thread_status *next;
1361         struct elf_prstatus_fdpic prstatus;     /* NT_PRSTATUS */
1362         elf_fpregset_t fpu;             /* NT_PRFPREG */
1363         struct memelfnote notes[2];
1364         int num_notes;
1365 };
1366
1367 /*
1368  * In order to add the specific thread information for the elf file format,
1369  * we need to keep a linked list of every thread's pr_status and then create
1370  * a single section for them in the final core file.
1371  */
1372 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1373 {
1374         const struct user_regset_view *view = task_user_regset_view(p);
1375         struct elf_thread_status *t;
1376         int i, ret;
1377
1378         t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1379         if (!t)
1380                 return t;
1381
1382         fill_prstatus(&t->prstatus.common, p, signr);
1383         t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1384         t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1385         regset_get(p, &view->regsets[0],
1386                    sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1387
1388         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1389                   &t->prstatus);
1390         t->num_notes++;
1391         *sz += notesize(&t->notes[0]);
1392
1393         for (i = 1; i < view->n; ++i) {
1394                 const struct user_regset *regset = &view->regsets[i];
1395                 if (regset->core_note_type != NT_PRFPREG)
1396                         continue;
1397                 if (regset->active && regset->active(p, regset) <= 0)
1398                         continue;
1399                 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1400                 if (ret >= 0)
1401                         t->prstatus.pr_fpvalid = 1;
1402                 break;
1403         }
1404
1405         if (t->prstatus.pr_fpvalid) {
1406                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1407                           &t->fpu);
1408                 t->num_notes++;
1409                 *sz += notesize(&t->notes[1]);
1410         }
1411         return t;
1412 }
1413
1414 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1415                              elf_addr_t e_shoff, int segs)
1416 {
1417         elf->e_shoff = e_shoff;
1418         elf->e_shentsize = sizeof(*shdr4extnum);
1419         elf->e_shnum = 1;
1420         elf->e_shstrndx = SHN_UNDEF;
1421
1422         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1423
1424         shdr4extnum->sh_type = SHT_NULL;
1425         shdr4extnum->sh_size = elf->e_shnum;
1426         shdr4extnum->sh_link = elf->e_shstrndx;
1427         shdr4extnum->sh_info = segs;
1428 }
1429
1430 /*
1431  * dump the segments for an MMU process
1432  */
1433 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1434                                     struct core_vma_metadata *vma_meta,
1435                                     int vma_count)
1436 {
1437         int i;
1438
1439         for (i = 0; i < vma_count; i++) {
1440                 struct core_vma_metadata *meta = vma_meta + i;
1441
1442                 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1443                         return false;
1444         }
1445         return true;
1446 }
1447
1448 /*
1449  * Actual dumper
1450  *
1451  * This is a two-pass process; first we find the offsets of the bits,
1452  * and then they are actually written out.  If we run out of core limit
1453  * we just truncate.
1454  */
1455 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1456 {
1457         int has_dumped = 0;
1458         int segs;
1459         int i;
1460         struct elfhdr *elf = NULL;
1461         loff_t offset = 0, dataoff;
1462         struct memelfnote psinfo_note, auxv_note;
1463         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1464         struct elf_thread_status *thread_list = NULL;
1465         int thread_status_size = 0;
1466         elf_addr_t *auxv;
1467         struct elf_phdr *phdr4note = NULL;
1468         struct elf_shdr *shdr4extnum = NULL;
1469         Elf_Half e_phnum;
1470         elf_addr_t e_shoff;
1471         struct core_thread *ct;
1472         struct elf_thread_status *tmp;
1473
1474         /* alloc memory for large data structures: too large to be on stack */
1475         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1476         if (!elf)
1477                 goto end_coredump;
1478         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1479         if (!psinfo)
1480                 goto end_coredump;
1481
1482         for (ct = current->signal->core_state->dumper.next;
1483                                         ct; ct = ct->next) {
1484                 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1485                                              ct->task, &thread_status_size);
1486                 if (!tmp)
1487                         goto end_coredump;
1488
1489                 tmp->next = thread_list;
1490                 thread_list = tmp;
1491         }
1492
1493         /* now collect the dump for the current */
1494         tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1495                                      current, &thread_status_size);
1496         if (!tmp)
1497                 goto end_coredump;
1498         tmp->next = thread_list;
1499         thread_list = tmp;
1500
1501         segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1502
1503         /* for notes section */
1504         segs++;
1505
1506         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1507          * this, kernel supports extended numbering. Have a look at
1508          * include/linux/elf.h for further information. */
1509         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1510
1511         /* Set up header */
1512         fill_elf_fdpic_header(elf, e_phnum);
1513
1514         has_dumped = 1;
1515         /*
1516          * Set up the notes in similar form to SVR4 core dumps made
1517          * with info from their /proc.
1518          */
1519
1520         fill_psinfo(psinfo, current->group_leader, current->mm);
1521         fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1522         thread_status_size += notesize(&psinfo_note);
1523
1524         auxv = (elf_addr_t *) current->mm->saved_auxv;
1525         i = 0;
1526         do
1527                 i += 2;
1528         while (auxv[i - 2] != AT_NULL);
1529         fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1530         thread_status_size += notesize(&auxv_note);
1531
1532         offset = sizeof(*elf);                          /* ELF header */
1533         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1534
1535         /* Write notes phdr entry */
1536         phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1537         if (!phdr4note)
1538                 goto end_coredump;
1539
1540         fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1541         offset += thread_status_size;
1542
1543         /* Page-align dumped data */
1544         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1545
1546         offset += cprm->vma_data_size;
1547         offset += elf_core_extra_data_size(cprm);
1548         e_shoff = offset;
1549
1550         if (e_phnum == PN_XNUM) {
1551                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1552                 if (!shdr4extnum)
1553                         goto end_coredump;
1554                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1555         }
1556
1557         offset = dataoff;
1558
1559         if (!dump_emit(cprm, elf, sizeof(*elf)))
1560                 goto end_coredump;
1561
1562         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1563                 goto end_coredump;
1564
1565         /* write program headers for segments dump */
1566         for (i = 0; i < cprm->vma_count; i++) {
1567                 struct core_vma_metadata *meta = cprm->vma_meta + i;
1568                 struct elf_phdr phdr;
1569                 size_t sz;
1570
1571                 sz = meta->end - meta->start;
1572
1573                 phdr.p_type = PT_LOAD;
1574                 phdr.p_offset = offset;
1575                 phdr.p_vaddr = meta->start;
1576                 phdr.p_paddr = 0;
1577                 phdr.p_filesz = meta->dump_size;
1578                 phdr.p_memsz = sz;
1579                 offset += phdr.p_filesz;
1580                 phdr.p_flags = 0;
1581                 if (meta->flags & VM_READ)
1582                         phdr.p_flags |= PF_R;
1583                 if (meta->flags & VM_WRITE)
1584                         phdr.p_flags |= PF_W;
1585                 if (meta->flags & VM_EXEC)
1586                         phdr.p_flags |= PF_X;
1587                 phdr.p_align = ELF_EXEC_PAGESIZE;
1588
1589                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1590                         goto end_coredump;
1591         }
1592
1593         if (!elf_core_write_extra_phdrs(cprm, offset))
1594                 goto end_coredump;
1595
1596         /* write out the notes section */
1597         if (!writenote(thread_list->notes, cprm))
1598                 goto end_coredump;
1599         if (!writenote(&psinfo_note, cprm))
1600                 goto end_coredump;
1601         if (!writenote(&auxv_note, cprm))
1602                 goto end_coredump;
1603         for (i = 1; i < thread_list->num_notes; i++)
1604                 if (!writenote(thread_list->notes + i, cprm))
1605                         goto end_coredump;
1606
1607         /* write out the thread status notes section */
1608         for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1609                 for (i = 0; i < tmp->num_notes; i++)
1610                         if (!writenote(&tmp->notes[i], cprm))
1611                                 goto end_coredump;
1612         }
1613
1614         dump_skip_to(cprm, dataoff);
1615
1616         if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1617                 goto end_coredump;
1618
1619         if (!elf_core_write_extra_data(cprm))
1620                 goto end_coredump;
1621
1622         if (e_phnum == PN_XNUM) {
1623                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1624                         goto end_coredump;
1625         }
1626
1627         if (cprm->file->f_pos != offset) {
1628                 /* Sanity check */
1629                 printk(KERN_WARNING
1630                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1631                        cprm->file->f_pos, offset);
1632         }
1633
1634 end_coredump:
1635         while (thread_list) {
1636                 tmp = thread_list;
1637                 thread_list = thread_list->next;
1638                 kfree(tmp);
1639         }
1640         kfree(phdr4note);
1641         kfree(elf);
1642         kfree(psinfo);
1643         kfree(shdr4extnum);
1644         return has_dumped;
1645 }
1646
1647 #endif          /* CONFIG_ELF_CORE */