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 elf32_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         if (elf_check_fdpic(&exec_params.hdr))
 349                 set_personality(PER_LINUX_FDPIC);
 350         else
 351                 set_personality(PER_LINUX);
 352         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 353                 current->personality |= READ_IMPLIES_EXEC;
 354
 355         setup_new_exec(bprm);
 356
 357         set_binfmt(&elf_fdpic_format);
 358
 359         current->mm->start_code = 0;
 360         current->mm->end_code = 0;
 361         current->mm->start_stack = 0;
 362         current->mm->start_data = 0;
 363         current->mm->end_data = 0;
 364         current->mm->context.exec_fdpic_loadmap = 0;
 365         current->mm->context.interp_fdpic_loadmap = 0;
 366
 367 #ifdef CONFIG_MMU
 368         elf_fdpic_arch_lay_out_mm(&exec_params,
 369                                   &interp_params,
 370                                   &current->mm->start_stack,
 371                                   &current->mm->start_brk);
 372
 373         retval = setup_arg_pages(bprm, current->mm->start_stack,
 374                                  executable_stack);
 375         if (retval < 0)
 376                 goto error;
 377 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
 378         retval = arch_setup_additional_pages(bprm, !!interpreter_name);
 379         if (retval < 0)
 380                 goto error;
 381 #endif
 382 #endif
 383
 384         /* load the executable and interpreter into memory */
 385         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 386                                     "executable");
 387         if (retval < 0)
 388                 goto error;
 389
 390         if (interpreter_name) {
 391                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 392                                             current->mm, "interpreter");
 393                 if (retval < 0) {
 394                         printk(KERN_ERR "Unable to load interpreter\n");
 395                         goto error;
 396                 }
 397
 398                 allow_write_access(interpreter);
 399                 fput(interpreter);
 400                 interpreter = NULL;
 401         }
 402
 403 #ifdef CONFIG_MMU
 404         if (!current->mm->start_brk)
 405                 current->mm->start_brk = current->mm->end_data;
 406
 407         current->mm->brk = current->mm->start_brk =
 408                 PAGE_ALIGN(current->mm->start_brk);
 409
 410 #else
 411         /* create a stack area and zero-size brk area */
 412         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 413         if (stack_size < PAGE_SIZE * 2)
 414                 stack_size = PAGE_SIZE * 2;
 415
 416         stack_prot = PROT_READ | PROT_WRITE;
 417         if (executable_stack == EXSTACK_ENABLE_X ||
 418             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 419                 stack_prot |= PROT_EXEC;
 420
 421         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 422                                          MAP_PRIVATE | MAP_ANONYMOUS |
 423                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 424                                          0);
 425
 426         if (IS_ERR_VALUE(current->mm->start_brk)) {
 427                 retval = current->mm->start_brk;
 428                 current->mm->start_brk = 0;
 429                 goto error;
 430         }
 431
 432         current->mm->brk = current->mm->start_brk;
 433         current->mm->context.end_brk = current->mm->start_brk;
 434         current->mm->start_stack = current->mm->start_brk + stack_size;
 435 #endif
 436
 437         retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
 438                                          &interp_params);
 439         if (retval < 0)
 440                 goto error;
 441
 442         kdebug("- start_code  %lx", current->mm->start_code);
 443         kdebug("- end_code    %lx", current->mm->end_code);
 444         kdebug("- start_data  %lx", current->mm->start_data);
 445         kdebug("- end_data    %lx", current->mm->end_data);
 446         kdebug("- start_brk   %lx", current->mm->start_brk);
 447         kdebug("- brk         %lx", current->mm->brk);
 448         kdebug("- start_stack %lx", current->mm->start_stack);
 449
 450 #ifdef ELF_FDPIC_PLAT_INIT
 451         /*
 452          * The ABI may specify that certain registers be set up in special
 453          * ways (on i386 %edx is the address of a DT_FINI function, for
 454          * example.  This macro performs whatever initialization to
 455          * the regs structure is required.
 456          */
 457         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 458         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 459                             dynaddr);
 460 #endif
 461
 462         finalize_exec(bprm);
 463         /* everything is now ready... get the userspace context ready to roll */
 464         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 465         start_thread(regs, entryaddr, current->mm->start_stack);
 466
 467         retval = 0;
 468
 469 error:
 470         if (interpreter) {
 471                 allow_write_access(interpreter);
 472                 fput(interpreter);
 473         }
 474         kfree(interpreter_name);
 475         kfree(exec_params.phdrs);
 476         kfree(exec_params.loadmap);
 477         kfree(interp_params.phdrs);
 478         kfree(interp_params.loadmap);
 479         return retval;
 480 }
 481
 482 /*****************************************************************************/
 483
 484 #ifndef ELF_BASE_PLATFORM
 485 /*
 486  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 487  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 488  * will be copied to the user stack in the same manner as AT_PLATFORM.
 489  */
 490 #define ELF_BASE_PLATFORM NULL
 491 #endif
 492
 493 /*
 494  * present useful information to the program by shovelling it onto the new
 495  * process's stack
 496  */
 497 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 498                                    struct mm_struct *mm,
 499                                    struct elf_fdpic_params *exec_params,
 500                                    struct elf_fdpic_params *interp_params)
 501 {
 502         const struct cred *cred = current_cred();
 503         unsigned long sp, csp, nitems;
 504         elf_caddr_t __user *argv, *envp;
 505         size_t platform_len = 0, len;
 506         char *k_platform, *k_base_platform;
 507         char __user *u_platform, *u_base_platform, *p;
 508         int loop;
 509         int nr; /* reset for each csp adjustment */
 510         unsigned long flags = 0;
 511
 512 #ifdef CONFIG_MMU
 513         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 514          * by the processes running on the same package. One thing we can do is
 515          * to shuffle the initial stack for them, so we give the architecture
 516          * an opportunity to do so here.
 517          */
 518         sp = arch_align_stack(bprm->p);
 519 #else
 520         sp = mm->start_stack;
 521
 522         /* stack the program arguments and environment */
 523         if (transfer_args_to_stack(bprm, &sp) < 0)
 524                 return -EFAULT;
 525         sp &= ~15;
 526 #endif
 527
 528         /*
 529          * If this architecture has a platform capability string, copy it
 530          * to userspace.  In some cases (Sparc), this info is impossible
 531          * for userspace to get any other way, in others (i386) it is
 532          * merely difficult.
 533          */
 534         k_platform = ELF_PLATFORM;
 535         u_platform = NULL;
 536
 537         if (k_platform) {
 538                 platform_len = strlen(k_platform) + 1;
 539                 sp -= platform_len;
 540                 u_platform = (char __user *) sp;
 541                 if (copy_to_user(u_platform, k_platform, platform_len) != 0)
 542                         return -EFAULT;
 543         }
 544
 545         /*
 546          * If this architecture has a "base" platform capability
 547          * string, copy it to userspace.
 548          */
 549         k_base_platform = ELF_BASE_PLATFORM;
 550         u_base_platform = NULL;
 551
 552         if (k_base_platform) {
 553                 platform_len = strlen(k_base_platform) + 1;
 554                 sp -= platform_len;
 555                 u_base_platform = (char __user *) sp;
 556                 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 557                         return -EFAULT;
 558         }
 559
 560         sp &= ~7UL;
 561
 562         /* stack the load map(s) */
 563         len = sizeof(struct elf32_fdpic_loadmap);
 564         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 565         sp = (sp - len) & ~7UL;
 566         exec_params->map_addr = sp;
 567
 568         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 569                 return -EFAULT;
 570
 571         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 572
 573         if (interp_params->loadmap) {
 574                 len = sizeof(struct elf32_fdpic_loadmap);
 575                 len += sizeof(struct elf32_fdpic_loadseg) *
 576                         interp_params->loadmap->nsegs;
 577                 sp = (sp - len) & ~7UL;
 578                 interp_params->map_addr = sp;
 579
 580                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 581                                  len) != 0)
 582                         return -EFAULT;
 583
 584                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 585         }
 586
 587         /* force 16 byte _final_ alignment here for generality */
 588 #define DLINFO_ITEMS 15
 589
 590         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 591                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 592
 593         if (bprm->have_execfd)
 594                 nitems++;
 595
 596         csp = sp;
 597         sp -= nitems * 2 * sizeof(unsigned long);
 598         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 599         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 600         sp -= 1 * sizeof(unsigned long);                /* argc */
 601
 602         csp -= sp & 15UL;
 603         sp -= sp & 15UL;
 604
 605         /* put the ELF interpreter info on the stack */
 606 #define NEW_AUX_ENT(id, val)                                            \
 607         do {                                                            \
 608                 struct { unsigned long _id, _val; } __user *ent, v;     \
 609                                                                         \
 610                 ent = (void __user *) csp;                              \
 611                 v._id = (id);                                           \
 612                 v._val = (val);                                         \
 613                 if (copy_to_user(ent + nr, &v, sizeof(v)))              \
 614                         return -EFAULT;                                 \
 615                 nr++;                                                   \
 616         } while (0)
 617
 618         nr = 0;
 619         csp -= 2 * sizeof(unsigned long);
 620         NEW_AUX_ENT(AT_NULL, 0);
 621         if (k_platform) {
 622                 nr = 0;
 623                 csp -= 2 * sizeof(unsigned long);
 624                 NEW_AUX_ENT(AT_PLATFORM,
 625                             (elf_addr_t) (unsigned long) u_platform);
 626         }
 627
 628         if (k_base_platform) {
 629                 nr = 0;
 630                 csp -= 2 * sizeof(unsigned long);
 631                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 632                             (elf_addr_t) (unsigned long) u_base_platform);
 633         }
 634
 635         if (bprm->have_execfd) {
 636                 nr = 0;
 637                 csp -= 2 * sizeof(unsigned long);
 638                 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
 639         }
 640
 641         nr = 0;
 642         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 643         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 644 #ifdef ELF_HWCAP2
 645         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 646 #endif
 647         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 648         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 649         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 650         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 651         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 652         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 653         if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
 654                 flags |= AT_FLAGS_PRESERVE_ARGV0;
 655         NEW_AUX_ENT(AT_FLAGS,   flags);
 656         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 657         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 658         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 659         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 660         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 661         NEW_AUX_ENT(AT_SECURE,  bprm->secureexec);
 662         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 663
 664 #ifdef ARCH_DLINFO
 665         nr = 0;
 666         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 667
 668         /* ARCH_DLINFO must come last so platform specific code can enforce
 669          * special alignment requirements on the AUXV if necessary (eg. PPC).
 670          */
 671         ARCH_DLINFO;
 672 #endif
 673 #undef NEW_AUX_ENT
 674
 675         /* allocate room for argv[] and envv[] */
 676         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 677         envp = (elf_caddr_t __user *) csp;
 678         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 679         argv = (elf_caddr_t __user *) csp;
 680
 681         /* stack argc */
 682         csp -= sizeof(unsigned long);
 683         if (put_user(bprm->argc, (unsigned long __user *) csp))
 684                 return -EFAULT;
 685
 686         BUG_ON(csp != sp);
 687
 688         /* fill in the argv[] array */
 689 #ifdef CONFIG_MMU
 690         current->mm->arg_start = bprm->p;
 691 #else
 692         current->mm->arg_start = current->mm->start_stack -
 693                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 694 #endif
 695
 696         p = (char __user *) current->mm->arg_start;
 697         for (loop = bprm->argc; loop > 0; loop--) {
 698                 if (put_user((elf_caddr_t) p, argv++))
 699                         return -EFAULT;
 700                 len = strnlen_user(p, MAX_ARG_STRLEN);
 701                 if (!len || len > MAX_ARG_STRLEN)
 702                         return -EINVAL;
 703                 p += len;
 704         }
 705         if (put_user(NULL, argv))
 706                 return -EFAULT;
 707         current->mm->arg_end = (unsigned long) p;
 708
 709         /* fill in the envv[] array */
 710         current->mm->env_start = (unsigned long) p;
 711         for (loop = bprm->envc; loop > 0; loop--) {
 712                 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
 713                         return -EFAULT;
 714                 len = strnlen_user(p, MAX_ARG_STRLEN);
 715                 if (!len || len > MAX_ARG_STRLEN)
 716                         return -EINVAL;
 717                 p += len;
 718         }
 719         if (put_user(NULL, envp))
 720                 return -EFAULT;
 721         current->mm->env_end = (unsigned long) p;
 722
 723         mm->start_stack = (unsigned long) sp;
 724         return 0;
 725 }
 726
 727 /*****************************************************************************/
 728 /*
 729  * load the appropriate binary image (executable or interpreter) into memory
 730  * - we assume no MMU is available
 731  * - if no other PIC bits are set in params->hdr->e_flags
 732  *   - we assume that the LOADable segments in the binary are independently relocatable
 733  *   - we assume R/O executable segments are shareable
 734  * - else
 735  *   - we assume the loadable parts of the image to require fixed displacement
 736  *   - the image is not shareable
 737  */
 738 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 739                               struct file *file,
 740                               struct mm_struct *mm,
 741                               const char *what)
 742 {
 743         struct elf32_fdpic_loadmap *loadmap;
 744 #ifdef CONFIG_MMU
 745         struct elf32_fdpic_loadseg *mseg;
 746         unsigned long load_addr;
 747 #endif
 748         struct elf32_fdpic_loadseg *seg;
 749         struct elf32_phdr *phdr;
 750         unsigned nloads, tmp;
 751         unsigned long stop;
 752         int loop, ret;
 753
 754         /* allocate a load map table */
 755         nloads = 0;
 756         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 757                 if (params->phdrs[loop].p_type == PT_LOAD)
 758                         nloads++;
 759
 760         if (nloads == 0)
 761                 return -ELIBBAD;
 762
 763         loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL);
 764         if (!loadmap)
 765                 return -ENOMEM;
 766
 767         params->loadmap = loadmap;
 768
 769         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 770         loadmap->nsegs = nloads;
 771
 772         /* map the requested LOADs into the memory space */
 773         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 774         case ELF_FDPIC_FLAG_CONSTDISP:
 775         case ELF_FDPIC_FLAG_CONTIGUOUS:
 776 #ifndef CONFIG_MMU
 777                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 778                 if (ret < 0)
 779                         return ret;
 780                 break;
 781 #endif
 782         default:
 783                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 784                 if (ret < 0)
 785                         return ret;
 786                 break;
 787         }
 788
 789         /* map the entry point */
 790         if (params->hdr.e_entry) {
 791                 seg = loadmap->segs;
 792                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 793                         if (params->hdr.e_entry >= seg->p_vaddr &&
 794                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 795                                 params->entry_addr =
 796                                         (params->hdr.e_entry - seg->p_vaddr) +
 797                                         seg->addr;
 798                                 break;
 799                         }
 800                 }
 801         }
 802
 803         /* determine where the program header table has wound up if mapped */
 804         stop = params->hdr.e_phoff;
 805         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 806         phdr = params->phdrs;
 807
 808         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 809                 if (phdr->p_type != PT_LOAD)
 810                         continue;
 811
 812                 if (phdr->p_offset > params->hdr.e_phoff ||
 813                     phdr->p_offset + phdr->p_filesz < stop)
 814                         continue;
 815
 816                 seg = loadmap->segs;
 817                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 818                         if (phdr->p_vaddr >= seg->p_vaddr &&
 819                             phdr->p_vaddr + phdr->p_filesz <=
 820                             seg->p_vaddr + seg->p_memsz) {
 821                                 params->ph_addr =
 822                                         (phdr->p_vaddr - seg->p_vaddr) +
 823                                         seg->addr +
 824                                         params->hdr.e_phoff - phdr->p_offset;
 825                                 break;
 826                         }
 827                 }
 828                 break;
 829         }
 830
 831         /* determine where the dynamic section has wound up if there is one */
 832         phdr = params->phdrs;
 833         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 834                 if (phdr->p_type != PT_DYNAMIC)
 835                         continue;
 836
 837                 seg = loadmap->segs;
 838                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 839                         if (phdr->p_vaddr >= seg->p_vaddr &&
 840                             phdr->p_vaddr + phdr->p_memsz <=
 841                             seg->p_vaddr + seg->p_memsz) {
 842                                 Elf32_Dyn __user *dyn;
 843                                 Elf32_Sword d_tag;
 844
 845                                 params->dynamic_addr =
 846                                         (phdr->p_vaddr - seg->p_vaddr) +
 847                                         seg->addr;
 848
 849                                 /* check the dynamic section contains at least
 850                                  * one item, and that the last item is a NULL
 851                                  * entry */
 852                                 if (phdr->p_memsz == 0 ||
 853                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 854                                         goto dynamic_error;
 855
 856                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 857                                 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
 858                                 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
 859                                     d_tag != 0)
 860                                         goto dynamic_error;
 861                                 break;
 862                         }
 863                 }
 864                 break;
 865         }
 866
 867         /* now elide adjacent segments in the load map on MMU linux
 868          * - on uClinux the holes between may actually be filled with system
 869          *   stuff or stuff from other processes
 870          */
 871 #ifdef CONFIG_MMU
 872         nloads = loadmap->nsegs;
 873         mseg = loadmap->segs;
 874         seg = mseg + 1;
 875         for (loop = 1; loop < nloads; loop++) {
 876                 /* see if we have a candidate for merging */
 877                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 878                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 879                         if (load_addr == (seg->addr & PAGE_MASK)) {
 880                                 mseg->p_memsz +=
 881                                         load_addr -
 882                                         (mseg->addr + mseg->p_memsz);
 883                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 884                                 mseg->p_memsz += seg->p_memsz;
 885                                 loadmap->nsegs--;
 886                                 continue;
 887                         }
 888                 }
 889
 890                 mseg++;
 891                 if (mseg != seg)
 892                         *mseg = *seg;
 893         }
 894 #endif
 895
 896         kdebug("Mapped Object [%s]:", what);
 897         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 898         kdebug("- entry    : %lx", params->entry_addr);
 899         kdebug("- PHDR[]   : %lx", params->ph_addr);
 900         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 901         seg = loadmap->segs;
 902         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 903                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 904                        loop,
 905                        seg->addr, seg->addr + seg->p_memsz - 1,
 906                        seg->p_vaddr, seg->p_memsz);
 907
 908         return 0;
 909
 910 dynamic_error:
 911         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 912                what, file_inode(file)->i_ino);
 913         return -ELIBBAD;
 914 }
 915
 916 /*****************************************************************************/
 917 /*
 918  * map a file with constant displacement under uClinux
 919  */
 920 #ifndef CONFIG_MMU
 921 static int elf_fdpic_map_file_constdisp_on_uclinux(
 922         struct elf_fdpic_params *params,
 923         struct file *file,
 924         struct mm_struct *mm)
 925 {
 926         struct elf32_fdpic_loadseg *seg;
 927         struct elf32_phdr *phdr;
 928         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
 929         int loop, ret;
 930
 931         load_addr = params->load_addr;
 932         seg = params->loadmap->segs;
 933
 934         /* determine the bounds of the contiguous overall allocation we must
 935          * make */
 936         phdr = params->phdrs;
 937         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 938                 if (params->phdrs[loop].p_type != PT_LOAD)
 939                         continue;
 940
 941                 if (base > phdr->p_vaddr)
 942                         base = phdr->p_vaddr;
 943                 if (top < phdr->p_vaddr + phdr->p_memsz)
 944                         top = phdr->p_vaddr + phdr->p_memsz;
 945         }
 946
 947         /* allocate one big anon block for everything */
 948         maddr = vm_mmap(NULL, load_addr, top - base,
 949                         PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
 950         if (IS_ERR_VALUE(maddr))
 951                 return (int) maddr;
 952
 953         if (load_addr != 0)
 954                 load_addr += PAGE_ALIGN(top - base);
 955
 956         /* and then load the file segments into it */
 957         phdr = params->phdrs;
 958         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 959                 if (params->phdrs[loop].p_type != PT_LOAD)
 960                         continue;
 961
 962                 seg->addr = maddr + (phdr->p_vaddr - base);
 963                 seg->p_vaddr = phdr->p_vaddr;
 964                 seg->p_memsz = phdr->p_memsz;
 965
 966                 ret = read_code(file, seg->addr, phdr->p_offset,
 967                                        phdr->p_filesz);
 968                 if (ret < 0)
 969                         return ret;
 970
 971                 /* map the ELF header address if in this segment */
 972                 if (phdr->p_offset == 0)
 973                         params->elfhdr_addr = seg->addr;
 974
 975                 /* clear any space allocated but not loaded */
 976                 if (phdr->p_filesz < phdr->p_memsz) {
 977                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
 978                                        phdr->p_memsz - phdr->p_filesz))
 979                                 return -EFAULT;
 980                 }
 981
 982                 if (mm) {
 983                         if (phdr->p_flags & PF_X) {
 984                                 if (!mm->start_code) {
 985                                         mm->start_code = seg->addr;
 986                                         mm->end_code = seg->addr +
 987                                                 phdr->p_memsz;
 988                                 }
 989                         } else if (!mm->start_data) {
 990                                 mm->start_data = seg->addr;
 991                                 mm->end_data = seg->addr + phdr->p_memsz;
 992                         }
 993                 }
 994
 995                 seg++;
 996         }
 997
 998         return 0;
 999 }
1000 #endif
1001
1002 /*****************************************************************************/
1003 /*
1004  * map a binary by direct mmap() of the individual PT_LOAD segments
1005  */
1006 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1007                                              struct file *file,
1008                                              struct mm_struct *mm)
1009 {
1010         struct elf32_fdpic_loadseg *seg;
1011         struct elf32_phdr *phdr;
1012         unsigned long load_addr, delta_vaddr;
1013         int loop, dvset;
1014
1015         load_addr = params->load_addr;
1016         delta_vaddr = 0;
1017         dvset = 0;
1018
1019         seg = params->loadmap->segs;
1020
1021         /* deal with each load segment separately */
1022         phdr = params->phdrs;
1023         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1024                 unsigned long maddr, disp, excess, excess1;
1025                 int prot = 0, flags;
1026
1027                 if (phdr->p_type != PT_LOAD)
1028                         continue;
1029
1030                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1031                        (unsigned long) phdr->p_vaddr,
1032                        (unsigned long) phdr->p_offset,
1033                        (unsigned long) phdr->p_filesz,
1034                        (unsigned long) phdr->p_memsz);
1035
1036                 /* determine the mapping parameters */
1037                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1038                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1039                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1040
1041                 flags = MAP_PRIVATE;
1042                 maddr = 0;
1043
1044                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1045                 case ELF_FDPIC_FLAG_INDEPENDENT:
1046                         /* PT_LOADs are independently locatable */
1047                         break;
1048
1049                 case ELF_FDPIC_FLAG_HONOURVADDR:
1050                         /* the specified virtual address must be honoured */
1051                         maddr = phdr->p_vaddr;
1052                         flags |= MAP_FIXED;
1053                         break;
1054
1055                 case ELF_FDPIC_FLAG_CONSTDISP:
1056                         /* constant displacement
1057                          * - can be mapped anywhere, but must be mapped as a
1058                          *   unit
1059                          */
1060                         if (!dvset) {
1061                                 maddr = load_addr;
1062                                 delta_vaddr = phdr->p_vaddr;
1063                                 dvset = 1;
1064                         } else {
1065                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1066                                 flags |= MAP_FIXED;
1067                         }
1068                         break;
1069
1070                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1071                         /* contiguity handled later */
1072                         break;
1073
1074                 default:
1075                         BUG();
1076                 }
1077
1078                 maddr &= PAGE_MASK;
1079
1080                 /* create the mapping */
1081                 disp = phdr->p_vaddr & ~PAGE_MASK;
1082                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1083                                 phdr->p_offset - disp);
1084
1085                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1086                        loop, phdr->p_memsz + disp, prot, flags,
1087                        phdr->p_offset - disp, maddr);
1088
1089                 if (IS_ERR_VALUE(maddr))
1090                         return (int) maddr;
1091
1092                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1093                     ELF_FDPIC_FLAG_CONTIGUOUS)
1094                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1095
1096                 seg->addr = maddr + disp;
1097                 seg->p_vaddr = phdr->p_vaddr;
1098                 seg->p_memsz = phdr->p_memsz;
1099
1100                 /* map the ELF header address if in this segment */
1101                 if (phdr->p_offset == 0)
1102                         params->elfhdr_addr = seg->addr;
1103
1104                 /* clear the bit between beginning of mapping and beginning of
1105                  * PT_LOAD */
1106                 if (prot & PROT_WRITE && disp > 0) {
1107                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1108                         if (clear_user((void __user *) maddr, disp))
1109                                 return -EFAULT;
1110                         maddr += disp;
1111                 }
1112
1113                 /* clear any space allocated but not loaded
1114                  * - on uClinux we can just clear the lot
1115                  * - on MMU linux we'll get a SIGBUS beyond the last page
1116                  *   extant in the file
1117                  */
1118                 excess = phdr->p_memsz - phdr->p_filesz;
1119                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1120
1121 #ifdef CONFIG_MMU
1122                 if (excess > excess1) {
1123                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1124                         unsigned long xmaddr;
1125
1126                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1127                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1128                                          prot, flags, 0);
1129
1130                         kdebug("mmap[%d] <anon>"
1131                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1132                                loop, xaddr, excess - excess1, prot, flags,
1133                                xmaddr);
1134
1135                         if (xmaddr != xaddr)
1136                                 return -ENOMEM;
1137                 }
1138
1139                 if (prot & PROT_WRITE && excess1 > 0) {
1140                         kdebug("clear[%d] ad=%lx sz=%lx",
1141                                loop, maddr + phdr->p_filesz, excess1);
1142                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1143                                        excess1))
1144                                 return -EFAULT;
1145                 }
1146
1147 #else
1148                 if (excess > 0) {
1149                         kdebug("clear[%d] ad=%lx sz=%lx",
1150                                loop, maddr + phdr->p_filesz, excess);
1151                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1152                                 return -EFAULT;
1153                 }
1154 #endif
1155
1156                 if (mm) {
1157                         if (phdr->p_flags & PF_X) {
1158                                 if (!mm->start_code) {
1159                                         mm->start_code = maddr;
1160                                         mm->end_code = maddr + phdr->p_memsz;
1161                                 }
1162                         } else if (!mm->start_data) {
1163                                 mm->start_data = maddr;
1164                                 mm->end_data = maddr + phdr->p_memsz;
1165                         }
1166                 }
1167
1168                 seg++;
1169         }
1170
1171         return 0;
1172 }
1173
1174 /*****************************************************************************/
1175 /*
1176  * ELF-FDPIC core dumper
1177  *
1178  * Modelled on fs/exec.c:aout_core_dump()
1179  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1180  *
1181  * Modelled on fs/binfmt_elf.c core dumper
1182  */
1183 #ifdef CONFIG_ELF_CORE
1184
1185 struct elf_prstatus_fdpic
1186 {
1187         struct elf_prstatus_common      common;
1188         elf_gregset_t pr_reg;   /* GP registers */
1189         /* When using FDPIC, the loadmap addresses need to be communicated
1190          * to GDB in order for GDB to do the necessary relocations.  The
1191          * fields (below) used to communicate this information are placed
1192          * immediately after ``pr_reg'', so that the loadmap addresses may
1193          * be viewed as part of the register set if so desired.
1194          */
1195         unsigned long pr_exec_fdpic_loadmap;
1196         unsigned long pr_interp_fdpic_loadmap;
1197         int pr_fpvalid;         /* True if math co-processor being used.  */
1198 };
1199
1200 /* An ELF note in memory */
1201 struct memelfnote
1202 {
1203         const char *name;
1204         int type;
1205         unsigned int datasz;
1206         void *data;
1207 };
1208
1209 static int notesize(struct memelfnote *en)
1210 {
1211         int sz;
1212
1213         sz = sizeof(struct elf_note);
1214         sz += roundup(strlen(en->name) + 1, 4);
1215         sz += roundup(en->datasz, 4);
1216
1217         return sz;
1218 }
1219
1220 /* #define DEBUG */
1221
1222 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1223 {
1224         struct elf_note en;
1225         en.n_namesz = strlen(men->name) + 1;
1226         en.n_descsz = men->datasz;
1227         en.n_type = men->type;
1228
1229         return dump_emit(cprm, &en, sizeof(en)) &&
1230                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1231                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1232 }
1233
1234 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1235 {
1236         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1237         elf->e_ident[EI_CLASS] = ELF_CLASS;
1238         elf->e_ident[EI_DATA] = ELF_DATA;
1239         elf->e_ident[EI_VERSION] = EV_CURRENT;
1240         elf->e_ident[EI_OSABI] = ELF_OSABI;
1241         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1242
1243         elf->e_type = ET_CORE;
1244         elf->e_machine = ELF_ARCH;
1245         elf->e_version = EV_CURRENT;
1246         elf->e_entry = 0;
1247         elf->e_phoff = sizeof(struct elfhdr);
1248         elf->e_shoff = 0;
1249         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1250         elf->e_ehsize = sizeof(struct elfhdr);
1251         elf->e_phentsize = sizeof(struct elf_phdr);
1252         elf->e_phnum = segs;
1253         elf->e_shentsize = 0;
1254         elf->e_shnum = 0;
1255         elf->e_shstrndx = 0;
1256         return;
1257 }
1258
1259 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1260 {
1261         phdr->p_type = PT_NOTE;
1262         phdr->p_offset = offset;
1263         phdr->p_vaddr = 0;
1264         phdr->p_paddr = 0;
1265         phdr->p_filesz = sz;
1266         phdr->p_memsz = 0;
1267         phdr->p_flags = 0;
1268         phdr->p_align = 4;
1269         return;
1270 }
1271
1272 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1273                 unsigned int sz, void *data)
1274 {
1275         note->name = name;
1276         note->type = type;
1277         note->datasz = sz;
1278         note->data = data;
1279         return;
1280 }
1281
1282 /*
1283  * fill up all the fields in prstatus from the given task struct, except
1284  * registers which need to be filled up separately.
1285  */
1286 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1287                           struct task_struct *p, long signr)
1288 {
1289         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1290         prstatus->pr_sigpend = p->pending.signal.sig[0];
1291         prstatus->pr_sighold = p->blocked.sig[0];
1292         rcu_read_lock();
1293         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1294         rcu_read_unlock();
1295         prstatus->pr_pid = task_pid_vnr(p);
1296         prstatus->pr_pgrp = task_pgrp_vnr(p);
1297         prstatus->pr_sid = task_session_vnr(p);
1298         if (thread_group_leader(p)) {
1299                 struct task_cputime cputime;
1300
1301                 /*
1302                  * This is the record for the group leader.  It shows the
1303                  * group-wide total, not its individual thread total.
1304                  */
1305                 thread_group_cputime(p, &cputime);
1306                 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1307                 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1308         } else {
1309                 u64 utime, stime;
1310
1311                 task_cputime(p, &utime, &stime);
1312                 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1313                 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1314         }
1315         prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1316         prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1317 }
1318
1319 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1320                        struct mm_struct *mm)
1321 {
1322         const struct cred *cred;
1323         unsigned int i, len;
1324         unsigned int state;
1325
1326         /* first copy the parameters from user space */
1327         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1328
1329         len = mm->arg_end - mm->arg_start;
1330         if (len >= ELF_PRARGSZ)
1331                 len = ELF_PRARGSZ - 1;
1332         if (copy_from_user(&psinfo->pr_psargs,
1333                            (const char __user *) mm->arg_start, len))
1334                 return -EFAULT;
1335         for (i = 0; i < len; i++)
1336                 if (psinfo->pr_psargs[i] == 0)
1337                         psinfo->pr_psargs[i] = ' ';
1338         psinfo->pr_psargs[len] = 0;
1339
1340         rcu_read_lock();
1341         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1342         rcu_read_unlock();
1343         psinfo->pr_pid = task_pid_vnr(p);
1344         psinfo->pr_pgrp = task_pgrp_vnr(p);
1345         psinfo->pr_sid = task_session_vnr(p);
1346
1347         state = READ_ONCE(p->__state);
1348         i = state ? ffz(~state) + 1 : 0;
1349         psinfo->pr_state = i;
1350         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1351         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1352         psinfo->pr_nice = task_nice(p);
1353         psinfo->pr_flag = p->flags;
1354         rcu_read_lock();
1355         cred = __task_cred(p);
1356         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1357         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1358         rcu_read_unlock();
1359         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1360
1361         return 0;
1362 }
1363
1364 /* Here is the structure in which status of each thread is captured. */
1365 struct elf_thread_status
1366 {
1367         struct elf_thread_status *next;
1368         struct elf_prstatus_fdpic prstatus;     /* NT_PRSTATUS */
1369         elf_fpregset_t fpu;             /* NT_PRFPREG */
1370         struct memelfnote notes[2];
1371         int num_notes;
1372 };
1373
1374 /*
1375  * In order to add the specific thread information for the elf file format,
1376  * we need to keep a linked list of every thread's pr_status and then create
1377  * a single section for them in the final core file.
1378  */
1379 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1380 {
1381         const struct user_regset_view *view = task_user_regset_view(p);
1382         struct elf_thread_status *t;
1383         int i, ret;
1384
1385         t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1386         if (!t)
1387                 return t;
1388
1389         fill_prstatus(&t->prstatus.common, p, signr);
1390         t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1391         t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1392         regset_get(p, &view->regsets[0],
1393                    sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1394
1395         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1396                   &t->prstatus);
1397         t->num_notes++;
1398         *sz += notesize(&t->notes[0]);
1399
1400         for (i = 1; i < view->n; ++i) {
1401                 const struct user_regset *regset = &view->regsets[i];
1402                 if (regset->core_note_type != NT_PRFPREG)
1403                         continue;
1404                 if (regset->active && regset->active(p, regset) <= 0)
1405                         continue;
1406                 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1407                 if (ret >= 0)
1408                         t->prstatus.pr_fpvalid = 1;
1409                 break;
1410         }
1411
1412         if (t->prstatus.pr_fpvalid) {
1413                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1414                           &t->fpu);
1415                 t->num_notes++;
1416                 *sz += notesize(&t->notes[1]);
1417         }
1418         return t;
1419 }
1420
1421 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1422                              elf_addr_t e_shoff, int segs)
1423 {
1424         elf->e_shoff = e_shoff;
1425         elf->e_shentsize = sizeof(*shdr4extnum);
1426         elf->e_shnum = 1;
1427         elf->e_shstrndx = SHN_UNDEF;
1428
1429         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1430
1431         shdr4extnum->sh_type = SHT_NULL;
1432         shdr4extnum->sh_size = elf->e_shnum;
1433         shdr4extnum->sh_link = elf->e_shstrndx;
1434         shdr4extnum->sh_info = segs;
1435 }
1436
1437 /*
1438  * dump the segments for an MMU process
1439  */
1440 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1441                                     struct core_vma_metadata *vma_meta,
1442                                     int vma_count)
1443 {
1444         int i;
1445
1446         for (i = 0; i < vma_count; i++) {
1447                 struct core_vma_metadata *meta = vma_meta + i;
1448
1449                 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1450                         return false;
1451         }
1452         return true;
1453 }
1454
1455 /*
1456  * Actual dumper
1457  *
1458  * This is a two-pass process; first we find the offsets of the bits,
1459  * and then they are actually written out.  If we run out of core limit
1460  * we just truncate.
1461  */
1462 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1463 {
1464         int has_dumped = 0;
1465         int segs;
1466         int i;
1467         struct elfhdr *elf = NULL;
1468         loff_t offset = 0, dataoff;
1469         struct memelfnote psinfo_note, auxv_note;
1470         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1471         struct elf_thread_status *thread_list = NULL;
1472         int thread_status_size = 0;
1473         elf_addr_t *auxv;
1474         struct elf_phdr *phdr4note = NULL;
1475         struct elf_shdr *shdr4extnum = NULL;
1476         Elf_Half e_phnum;
1477         elf_addr_t e_shoff;
1478         struct core_thread *ct;
1479         struct elf_thread_status *tmp;
1480
1481         /* alloc memory for large data structures: too large to be on stack */
1482         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1483         if (!elf)
1484                 goto end_coredump;
1485         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1486         if (!psinfo)
1487                 goto end_coredump;
1488
1489         for (ct = current->signal->core_state->dumper.next;
1490                                         ct; ct = ct->next) {
1491                 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1492                                              ct->task, &thread_status_size);
1493                 if (!tmp)
1494                         goto end_coredump;
1495
1496                 tmp->next = thread_list;
1497                 thread_list = tmp;
1498         }
1499
1500         /* now collect the dump for the current */
1501         tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1502                                      current, &thread_status_size);
1503         if (!tmp)
1504                 goto end_coredump;
1505         tmp->next = thread_list;
1506         thread_list = tmp;
1507
1508         segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1509
1510         /* for notes section */
1511         segs++;
1512
1513         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1514          * this, kernel supports extended numbering. Have a look at
1515          * include/linux/elf.h for further information. */
1516         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1517
1518         /* Set up header */
1519         fill_elf_fdpic_header(elf, e_phnum);
1520
1521         has_dumped = 1;
1522         /*
1523          * Set up the notes in similar form to SVR4 core dumps made
1524          * with info from their /proc.
1525          */
1526
1527         fill_psinfo(psinfo, current->group_leader, current->mm);
1528         fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1529         thread_status_size += notesize(&psinfo_note);
1530
1531         auxv = (elf_addr_t *) current->mm->saved_auxv;
1532         i = 0;
1533         do
1534                 i += 2;
1535         while (auxv[i - 2] != AT_NULL);
1536         fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1537         thread_status_size += notesize(&auxv_note);
1538
1539         offset = sizeof(*elf);                          /* ELF header */
1540         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1541
1542         /* Write notes phdr entry */
1543         phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1544         if (!phdr4note)
1545                 goto end_coredump;
1546
1547         fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1548         offset += thread_status_size;
1549
1550         /* Page-align dumped data */
1551         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1552
1553         offset += cprm->vma_data_size;
1554         offset += elf_core_extra_data_size(cprm);
1555         e_shoff = offset;
1556
1557         if (e_phnum == PN_XNUM) {
1558                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1559                 if (!shdr4extnum)
1560                         goto end_coredump;
1561                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1562         }
1563
1564         offset = dataoff;
1565
1566         if (!dump_emit(cprm, elf, sizeof(*elf)))
1567                 goto end_coredump;
1568
1569         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1570                 goto end_coredump;
1571
1572         /* write program headers for segments dump */
1573         for (i = 0; i < cprm->vma_count; i++) {
1574                 struct core_vma_metadata *meta = cprm->vma_meta + i;
1575                 struct elf_phdr phdr;
1576                 size_t sz;
1577
1578                 sz = meta->end - meta->start;
1579
1580                 phdr.p_type = PT_LOAD;
1581                 phdr.p_offset = offset;
1582                 phdr.p_vaddr = meta->start;
1583                 phdr.p_paddr = 0;
1584                 phdr.p_filesz = meta->dump_size;
1585                 phdr.p_memsz = sz;
1586                 offset += phdr.p_filesz;
1587                 phdr.p_flags = 0;
1588                 if (meta->flags & VM_READ)
1589                         phdr.p_flags |= PF_R;
1590                 if (meta->flags & VM_WRITE)
1591                         phdr.p_flags |= PF_W;
1592                 if (meta->flags & VM_EXEC)
1593                         phdr.p_flags |= PF_X;
1594                 phdr.p_align = ELF_EXEC_PAGESIZE;
1595
1596                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1597                         goto end_coredump;
1598         }
1599
1600         if (!elf_core_write_extra_phdrs(cprm, offset))
1601                 goto end_coredump;
1602
1603         /* write out the notes section */
1604         if (!writenote(thread_list->notes, cprm))
1605                 goto end_coredump;
1606         if (!writenote(&psinfo_note, cprm))
1607                 goto end_coredump;
1608         if (!writenote(&auxv_note, cprm))
1609                 goto end_coredump;
1610         for (i = 1; i < thread_list->num_notes; i++)
1611                 if (!writenote(thread_list->notes + i, cprm))
1612                         goto end_coredump;
1613
1614         /* write out the thread status notes section */
1615         for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1616                 for (i = 0; i < tmp->num_notes; i++)
1617                         if (!writenote(&tmp->notes[i], cprm))
1618                                 goto end_coredump;
1619         }
1620
1621         dump_skip_to(cprm, dataoff);
1622
1623         if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1624                 goto end_coredump;
1625
1626         if (!elf_core_write_extra_data(cprm))
1627                 goto end_coredump;
1628
1629         if (e_phnum == PN_XNUM) {
1630                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1631                         goto end_coredump;
1632         }
1633
1634         if (cprm->file->f_pos != offset) {
1635                 /* Sanity check */
1636                 printk(KERN_WARNING
1637                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1638                        cprm->file->f_pos, offset);
1639         }
1640
1641 end_coredump:
1642         while (thread_list) {
1643                 tmp = thread_list;
1644                 thread_list = thread_list->next;
1645                 kfree(tmp);
1646         }
1647         kfree(phdr4note);
1648         kfree(elf);
1649         kfree(psinfo);
1650         kfree(shdr4extnum);
1651         return has_dumped;
1652 }
1653
1654 #endif          /* CONFIG_ELF_CORE */