fs/binfmt_elf_fdpic.c

   1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
   2  *
   3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  * Derived from binfmt_elf.c
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14
  15 #include <linux/fs.h>
  16 #include <linux/stat.h>
  17 #include <linux/sched.h>
  18 #include <linux/mm.h>
  19 #include <linux/mman.h>
  20 #include <linux/errno.h>
  21 #include <linux/signal.h>
  22 #include <linux/binfmts.h>
  23 #include <linux/string.h>
  24 #include <linux/file.h>
  25 #include <linux/fcntl.h>
  26 #include <linux/slab.h>
  27 #include <linux/pagemap.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/smp_lock.h>
  34 #include <linux/elf.h>
  35 #include <linux/elf-fdpic.h>
  36 #include <linux/elfcore.h>
  37
  38 #include <asm/uaccess.h>
  39 #include <asm/param.h>
  40 #include <asm/pgalloc.h>
  41
  42 typedef char *elf_caddr_t;
  43 #ifndef elf_addr_t
  44 #define elf_addr_t unsigned long
  45 #endif
  46
  47 #if 0
  48 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  49 #else
  50 #define kdebug(fmt, ...) do {} while(0)
  51 #endif
  52
  53 #if 0
  54 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  55 #else
  56 #define kdcore(fmt, ...) do {} while(0)
  57 #endif
  58
  59 MODULE_LICENSE("GPL");
  60
  61 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
  62 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  63 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  64                               struct mm_struct *, const char *);
  65
  66 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  67                                    struct elf_fdpic_params *,
  68                                    struct elf_fdpic_params *);
  69
  70 #ifndef CONFIG_MMU
  71 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  72                                             unsigned long *);
  73 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  74                                                    struct file *,
  75                                                    struct mm_struct *);
  76 #endif
  77
  78 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  79                                              struct file *, struct mm_struct *);
  80
  81 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  82 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *);
  83 #endif
  84
  85 static struct linux_binfmt elf_fdpic_format = {
  86         .module         = THIS_MODULE,
  87         .load_binary    = load_elf_fdpic_binary,
  88 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  89         .core_dump      = elf_fdpic_core_dump,
  90 #endif
  91         .min_coredump   = ELF_EXEC_PAGESIZE,
  92 };
  93
  94 static int __init init_elf_fdpic_binfmt(void)
  95 {
  96         return register_binfmt(&elf_fdpic_format);
  97 }
  98
  99 static void __exit exit_elf_fdpic_binfmt(void)
 100 {
 101         unregister_binfmt(&elf_fdpic_format);
 102 }
 103
 104 core_initcall(init_elf_fdpic_binfmt);
 105 module_exit(exit_elf_fdpic_binfmt);
 106
 107 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 108 {
 109         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 110                 return 0;
 111         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 112                 return 0;
 113         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 114                 return 0;
 115         if (!file->f_op || !file->f_op->mmap)
 116                 return 0;
 117         return 1;
 118 }
 119
 120 /*****************************************************************************/
 121 /*
 122  * read the program headers table into memory
 123  */
 124 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 125                                  struct file *file)
 126 {
 127         struct elf32_phdr *phdr;
 128         unsigned long size;
 129         int retval, loop;
 130
 131         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 132                 return -ENOMEM;
 133         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 134                 return -ENOMEM;
 135
 136         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 137         params->phdrs = kmalloc(size, GFP_KERNEL);
 138         if (!params->phdrs)
 139                 return -ENOMEM;
 140
 141         retval = kernel_read(file, params->hdr.e_phoff,
 142                              (char *) params->phdrs, size);
 143         if (retval < 0)
 144                 return retval;
 145
 146         /* determine stack size for this binary */
 147         phdr = params->phdrs;
 148         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 149                 if (phdr->p_type != PT_GNU_STACK)
 150                         continue;
 151
 152                 if (phdr->p_flags & PF_X)
 153                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 154                 else
 155                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 156
 157                 params->stack_size = phdr->p_memsz;
 158                 break;
 159         }
 160
 161         return 0;
 162 }
 163
 164 /*****************************************************************************/
 165 /*
 166  * load an fdpic binary into various bits of memory
 167  */
 168 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
 169                                  struct pt_regs *regs)
 170 {
 171         struct elf_fdpic_params exec_params, interp_params;
 172         struct elf_phdr *phdr;
 173         unsigned long stack_size, entryaddr;
 174 #ifndef CONFIG_MMU
 175         unsigned long fullsize;
 176 #endif
 177 #ifdef ELF_FDPIC_PLAT_INIT
 178         unsigned long dynaddr;
 179 #endif
 180         struct file *interpreter = NULL; /* to shut gcc up */
 181         char *interpreter_name = NULL;
 182         int executable_stack;
 183         int retval, i;
 184
 185         memset(&exec_params, 0, sizeof(exec_params));
 186         memset(&interp_params, 0, sizeof(interp_params));
 187
 188         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 189         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 190
 191         /* check that this is a binary we know how to deal with */
 192         retval = -ENOEXEC;
 193         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 194                 goto error;
 195
 196         /* read the program header table */
 197         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 198         if (retval < 0)
 199                 goto error;
 200
 201         /* scan for a program header that specifies an interpreter */
 202         phdr = exec_params.phdrs;
 203
 204         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 205                 switch (phdr->p_type) {
 206                 case PT_INTERP:
 207                         retval = -ENOMEM;
 208                         if (phdr->p_filesz > PATH_MAX)
 209                                 goto error;
 210                         retval = -ENOENT;
 211                         if (phdr->p_filesz < 2)
 212                                 goto error;
 213
 214                         /* read the name of the interpreter into memory */
 215                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 216                         if (!interpreter_name)
 217                                 goto error;
 218
 219                         retval = kernel_read(bprm->file,
 220                                              phdr->p_offset,
 221                                              interpreter_name,
 222                                              phdr->p_filesz);
 223                         if (retval < 0)
 224                                 goto error;
 225
 226                         retval = -ENOENT;
 227                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 228                                 goto error;
 229
 230                         kdebug("Using ELF interpreter %s", interpreter_name);
 231
 232                         /* replace the program with the interpreter */
 233                         interpreter = open_exec(interpreter_name);
 234                         retval = PTR_ERR(interpreter);
 235                         if (IS_ERR(interpreter)) {
 236                                 interpreter = NULL;
 237                                 goto error;
 238                         }
 239
 240                         retval = kernel_read(interpreter, 0, bprm->buf,
 241                                              BINPRM_BUF_SIZE);
 242                         if (retval < 0)
 243                                 goto error;
 244
 245                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 246                         break;
 247
 248                 case PT_LOAD:
 249 #ifdef CONFIG_MMU
 250                         if (exec_params.load_addr == 0)
 251                                 exec_params.load_addr = phdr->p_vaddr;
 252 #endif
 253                         break;
 254                 }
 255
 256         }
 257
 258         if (elf_check_const_displacement(&exec_params.hdr))
 259                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 260
 261         /* perform insanity checks on the interpreter */
 262         if (interpreter_name) {
 263                 retval = -ELIBBAD;
 264                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 265                         goto error;
 266
 267                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 268
 269                 /* read the interpreter's program header table */
 270                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 271                 if (retval < 0)
 272                         goto error;
 273         }
 274
 275         stack_size = exec_params.stack_size;
 276         if (stack_size < interp_params.stack_size)
 277                 stack_size = interp_params.stack_size;
 278
 279         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 280                 executable_stack = EXSTACK_ENABLE_X;
 281         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 282                 executable_stack = EXSTACK_DISABLE_X;
 283         else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 284                 executable_stack = EXSTACK_ENABLE_X;
 285         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 286                 executable_stack = EXSTACK_DISABLE_X;
 287         else
 288                 executable_stack = EXSTACK_DEFAULT;
 289
 290         retval = -ENOEXEC;
 291         if (stack_size == 0)
 292                 goto error;
 293
 294         if (elf_check_const_displacement(&interp_params.hdr))
 295                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 296
 297         /* flush all traces of the currently running executable */
 298         retval = flush_old_exec(bprm);
 299         if (retval)
 300                 goto error;
 301
 302         /* there's now no turning back... the old userspace image is dead,
 303          * defunct, deceased, etc. after this point we have to exit via
 304          * error_kill */
 305         set_personality(PER_LINUX_FDPIC);
 306         set_binfmt(&elf_fdpic_format);
 307
 308         current->mm->start_code = 0;
 309         current->mm->end_code = 0;
 310         current->mm->start_stack = 0;
 311         current->mm->start_data = 0;
 312         current->mm->end_data = 0;
 313         current->mm->context.exec_fdpic_loadmap = 0;
 314         current->mm->context.interp_fdpic_loadmap = 0;
 315
 316         current->flags &= ~PF_FORKNOEXEC;
 317
 318 #ifdef CONFIG_MMU
 319         elf_fdpic_arch_lay_out_mm(&exec_params,
 320                                   &interp_params,
 321                                   &current->mm->start_stack,
 322                                   &current->mm->start_brk);
 323
 324         retval = setup_arg_pages(bprm, current->mm->start_stack,
 325                                  executable_stack);
 326         if (retval < 0) {
 327                 send_sig(SIGKILL, current, 0);
 328                 goto error_kill;
 329         }
 330 #endif
 331
 332         /* load the executable and interpreter into memory */
 333         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 334                                     "executable");
 335         if (retval < 0)
 336                 goto error_kill;
 337
 338         if (interpreter_name) {
 339                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 340                                             current->mm, "interpreter");
 341                 if (retval < 0) {
 342                         printk(KERN_ERR "Unable to load interpreter\n");
 343                         goto error_kill;
 344                 }
 345
 346                 allow_write_access(interpreter);
 347                 fput(interpreter);
 348                 interpreter = NULL;
 349         }
 350
 351 #ifdef CONFIG_MMU
 352         if (!current->mm->start_brk)
 353                 current->mm->start_brk = current->mm->end_data;
 354
 355         current->mm->brk = current->mm->start_brk =
 356                 PAGE_ALIGN(current->mm->start_brk);
 357
 358 #else
 359         /* create a stack and brk area big enough for everyone
 360          * - the brk heap starts at the bottom and works up
 361          * - the stack starts at the top and works down
 362          */
 363         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 364         if (stack_size < PAGE_SIZE * 2)
 365                 stack_size = PAGE_SIZE * 2;
 366
 367         down_write(&current->mm->mmap_sem);
 368         current->mm->start_brk = do_mmap(NULL, 0, stack_size,
 369                                          PROT_READ | PROT_WRITE | PROT_EXEC,
 370                                          MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN,
 371                                          0);
 372
 373         if (IS_ERR_VALUE(current->mm->start_brk)) {
 374                 up_write(&current->mm->mmap_sem);
 375                 retval = current->mm->start_brk;
 376                 current->mm->start_brk = 0;
 377                 goto error_kill;
 378         }
 379
 380         /* expand the stack mapping to use up the entire allocation granule */
 381         fullsize = ksize((char *) current->mm->start_brk);
 382         if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
 383                                     fullsize, 0, 0)))
 384                 stack_size = fullsize;
 385         up_write(&current->mm->mmap_sem);
 386
 387         current->mm->brk = current->mm->start_brk;
 388         current->mm->context.end_brk = current->mm->start_brk;
 389         current->mm->context.end_brk +=
 390                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 391         current->mm->start_stack = current->mm->start_brk + stack_size;
 392 #endif
 393
 394         compute_creds(bprm);
 395         current->flags &= ~PF_FORKNOEXEC;
 396         if (create_elf_fdpic_tables(bprm, current->mm,
 397                                     &exec_params, &interp_params) < 0)
 398                 goto error_kill;
 399
 400         kdebug("- start_code  %lx", current->mm->start_code);
 401         kdebug("- end_code    %lx", current->mm->end_code);
 402         kdebug("- start_data  %lx", current->mm->start_data);
 403         kdebug("- end_data    %lx", current->mm->end_data);
 404         kdebug("- start_brk   %lx", current->mm->start_brk);
 405         kdebug("- brk         %lx", current->mm->brk);
 406         kdebug("- start_stack %lx", current->mm->start_stack);
 407
 408 #ifdef ELF_FDPIC_PLAT_INIT
 409         /*
 410          * The ABI may specify that certain registers be set up in special
 411          * ways (on i386 %edx is the address of a DT_FINI function, for
 412          * example.  This macro performs whatever initialization to
 413          * the regs structure is required.
 414          */
 415         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 416         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 417                             dynaddr);
 418 #endif
 419
 420         /* everything is now ready... get the userspace context ready to roll */
 421         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 422         start_thread(regs, entryaddr, current->mm->start_stack);
 423
 424         if (unlikely(current->ptrace & PT_PTRACED)) {
 425                 if (current->ptrace & PT_TRACE_EXEC)
 426                         ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
 427                 else
 428                         send_sig(SIGTRAP, current, 0);
 429         }
 430
 431         retval = 0;
 432
 433 error:
 434         if (interpreter) {
 435                 allow_write_access(interpreter);
 436                 fput(interpreter);
 437         }
 438         kfree(interpreter_name);
 439         kfree(exec_params.phdrs);
 440         kfree(exec_params.loadmap);
 441         kfree(interp_params.phdrs);
 442         kfree(interp_params.loadmap);
 443         return retval;
 444
 445         /* unrecoverable error - kill the process */
 446 error_kill:
 447         send_sig(SIGSEGV, current, 0);
 448         goto error;
 449
 450 }
 451
 452 /*****************************************************************************/
 453 /*
 454  * present useful information to the program
 455  */
 456 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 457                                    struct mm_struct *mm,
 458                                    struct elf_fdpic_params *exec_params,
 459                                    struct elf_fdpic_params *interp_params)
 460 {
 461         unsigned long sp, csp, nitems;
 462         elf_caddr_t __user *argv, *envp;
 463         size_t platform_len = 0, len;
 464         char *k_platform;
 465         char __user *u_platform, *p;
 466         long hwcap;
 467         int loop;
 468
 469         /* we're going to shovel a whole load of stuff onto the stack */
 470 #ifdef CONFIG_MMU
 471         sp = bprm->p;
 472 #else
 473         sp = mm->start_stack;
 474
 475         /* stack the program arguments and environment */
 476         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 477                 return -EFAULT;
 478 #endif
 479
 480         /* get hold of platform and hardware capabilities masks for the machine
 481          * we are running on.  In some cases (Sparc), this info is impossible
 482          * to get, in others (i386) it is merely difficult.
 483          */
 484         hwcap = ELF_HWCAP;
 485         k_platform = ELF_PLATFORM;
 486         u_platform = NULL;
 487
 488         if (k_platform) {
 489                 platform_len = strlen(k_platform) + 1;
 490                 sp -= platform_len;
 491                 u_platform = (char __user *) sp;
 492                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 493                         return -EFAULT;
 494         }
 495
 496 #if defined(__i386__) && defined(CONFIG_SMP)
 497         /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 498          * by the processes running on the same package. One thing we can do is
 499          * to shuffle the initial stack for them.
 500          *
 501          * the conditionals here are unneeded, but kept in to make the code
 502          * behaviour the same as pre change unless we have hyperthreaded
 503          * processors. This keeps Mr Marcelo Person happier but should be
 504          * removed for 2.5
 505          */
 506         if (smp_num_siblings > 1)
 507                 sp = sp - ((current->pid % 64) << 7);
 508 #endif
 509
 510         sp &= ~7UL;
 511
 512         /* stack the load map(s) */
 513         len = sizeof(struct elf32_fdpic_loadmap);
 514         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 515         sp = (sp - len) & ~7UL;
 516         exec_params->map_addr = sp;
 517
 518         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 519                 return -EFAULT;
 520
 521         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 522
 523         if (interp_params->loadmap) {
 524                 len = sizeof(struct elf32_fdpic_loadmap);
 525                 len += sizeof(struct elf32_fdpic_loadseg) *
 526                         interp_params->loadmap->nsegs;
 527                 sp = (sp - len) & ~7UL;
 528                 interp_params->map_addr = sp;
 529
 530                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 531                                  len) != 0)
 532                         return -EFAULT;
 533
 534                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 535         }
 536
 537         /* force 16 byte _final_ alignment here for generality */
 538 #define DLINFO_ITEMS 13
 539
 540         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
 541 #ifdef DLINFO_ARCH_ITEMS
 542         nitems += DLINFO_ARCH_ITEMS;
 543 #endif
 544
 545         csp = sp;
 546         sp -= nitems * 2 * sizeof(unsigned long);
 547         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 548         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 549         sp -= 1 * sizeof(unsigned long);                /* argc */
 550
 551         csp -= sp & 15UL;
 552         sp -= sp & 15UL;
 553
 554         /* put the ELF interpreter info on the stack */
 555 #define NEW_AUX_ENT(nr, id, val)                                        \
 556         do {                                                            \
 557                 struct { unsigned long _id, _val; } __user *ent;        \
 558                                                                         \
 559                 ent = (void __user *) csp;                              \
 560                 __put_user((id), &ent[nr]._id);                         \
 561                 __put_user((val), &ent[nr]._val);                       \
 562         } while (0)
 563
 564         csp -= 2 * sizeof(unsigned long);
 565         NEW_AUX_ENT(0, AT_NULL, 0);
 566         if (k_platform) {
 567                 csp -= 2 * sizeof(unsigned long);
 568                 NEW_AUX_ENT(0, AT_PLATFORM,
 569                             (elf_addr_t) (unsigned long) u_platform);
 570         }
 571
 572         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 573         NEW_AUX_ENT( 0, AT_HWCAP,       hwcap);
 574         NEW_AUX_ENT( 1, AT_PAGESZ,      PAGE_SIZE);
 575         NEW_AUX_ENT( 2, AT_CLKTCK,      CLOCKS_PER_SEC);
 576         NEW_AUX_ENT( 3, AT_PHDR,        exec_params->ph_addr);
 577         NEW_AUX_ENT( 4, AT_PHENT,       sizeof(struct elf_phdr));
 578         NEW_AUX_ENT( 5, AT_PHNUM,       exec_params->hdr.e_phnum);
 579         NEW_AUX_ENT( 6, AT_BASE,        interp_params->elfhdr_addr);
 580         NEW_AUX_ENT( 7, AT_FLAGS,       0);
 581         NEW_AUX_ENT( 8, AT_ENTRY,       exec_params->entry_addr);
 582         NEW_AUX_ENT( 9, AT_UID,         (elf_addr_t) current->uid);
 583         NEW_AUX_ENT(10, AT_EUID,        (elf_addr_t) current->euid);
 584         NEW_AUX_ENT(11, AT_GID,         (elf_addr_t) current->gid);
 585         NEW_AUX_ENT(12, AT_EGID,        (elf_addr_t) current->egid);
 586
 587 #ifdef ARCH_DLINFO
 588         /* ARCH_DLINFO must come last so platform specific code can enforce
 589          * special alignment requirements on the AUXV if necessary (eg. PPC).
 590          */
 591         ARCH_DLINFO;
 592 #endif
 593 #undef NEW_AUX_ENT
 594
 595         /* allocate room for argv[] and envv[] */
 596         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 597         envp = (elf_caddr_t __user *) csp;
 598         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 599         argv = (elf_caddr_t __user *) csp;
 600
 601         /* stack argc */
 602         csp -= sizeof(unsigned long);
 603         __put_user(bprm->argc, (unsigned long __user *) csp);
 604
 605         BUG_ON(csp != sp);
 606
 607         /* fill in the argv[] array */
 608 #ifdef CONFIG_MMU
 609         current->mm->arg_start = bprm->p;
 610 #else
 611         current->mm->arg_start = current->mm->start_stack -
 612                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 613 #endif
 614
 615         p = (char __user *) current->mm->arg_start;
 616         for (loop = bprm->argc; loop > 0; loop--) {
 617                 __put_user((elf_caddr_t) p, argv++);
 618                 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
 619                 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
 620                         return -EINVAL;
 621                 p += len;
 622         }
 623         __put_user(NULL, argv);
 624         current->mm->arg_end = (unsigned long) p;
 625
 626         /* fill in the envv[] array */
 627         current->mm->env_start = (unsigned long) p;
 628         for (loop = bprm->envc; loop > 0; loop--) {
 629                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 630                 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
 631                 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
 632                         return -EINVAL;
 633                 p += len;
 634         }
 635         __put_user(NULL, envp);
 636         current->mm->env_end = (unsigned long) p;
 637
 638         mm->start_stack = (unsigned long) sp;
 639         return 0;
 640 }
 641
 642 /*****************************************************************************/
 643 /*
 644  * transfer the program arguments and environment from the holding pages onto
 645  * the stack
 646  */
 647 #ifndef CONFIG_MMU
 648 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 649                                             unsigned long *_sp)
 650 {
 651         unsigned long index, stop, sp;
 652         char *src;
 653         int ret = 0;
 654
 655         stop = bprm->p >> PAGE_SHIFT;
 656         sp = *_sp;
 657
 658         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 659                 src = kmap(bprm->page[index]);
 660                 sp -= PAGE_SIZE;
 661                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 662                         ret = -EFAULT;
 663                 kunmap(bprm->page[index]);
 664                 if (ret < 0)
 665                         goto out;
 666         }
 667
 668         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 669
 670 out:
 671         return ret;
 672 }
 673 #endif
 674
 675 /*****************************************************************************/
 676 /*
 677  * load the appropriate binary image (executable or interpreter) into memory
 678  * - we assume no MMU is available
 679  * - if no other PIC bits are set in params->hdr->e_flags
 680  *   - we assume that the LOADable segments in the binary are independently relocatable
 681  *   - we assume R/O executable segments are shareable
 682  * - else
 683  *   - we assume the loadable parts of the image to require fixed displacement
 684  *   - the image is not shareable
 685  */
 686 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 687                               struct file *file,
 688                               struct mm_struct *mm,
 689                               const char *what)
 690 {
 691         struct elf32_fdpic_loadmap *loadmap;
 692 #ifdef CONFIG_MMU
 693         struct elf32_fdpic_loadseg *mseg;
 694 #endif
 695         struct elf32_fdpic_loadseg *seg;
 696         struct elf32_phdr *phdr;
 697         unsigned long load_addr, stop;
 698         unsigned nloads, tmp;
 699         size_t size;
 700         int loop, ret;
 701
 702         /* allocate a load map table */
 703         nloads = 0;
 704         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 705                 if (params->phdrs[loop].p_type == PT_LOAD)
 706                         nloads++;
 707
 708         if (nloads == 0)
 709                 return -ELIBBAD;
 710
 711         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 712         loadmap = kmalloc(size, GFP_KERNEL);
 713         if (!loadmap)
 714                 return -ENOMEM;
 715
 716         params->loadmap = loadmap;
 717         memset(loadmap, 0, size);
 718
 719         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 720         loadmap->nsegs = nloads;
 721
 722         load_addr = params->load_addr;
 723         seg = loadmap->segs;
 724
 725         /* map the requested LOADs into the memory space */
 726         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 727         case ELF_FDPIC_FLAG_CONSTDISP:
 728         case ELF_FDPIC_FLAG_CONTIGUOUS:
 729 #ifndef CONFIG_MMU
 730                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 731                 if (ret < 0)
 732                         return ret;
 733                 break;
 734 #endif
 735         default:
 736                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 737                 if (ret < 0)
 738                         return ret;
 739                 break;
 740         }
 741
 742         /* map the entry point */
 743         if (params->hdr.e_entry) {
 744                 seg = loadmap->segs;
 745                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 746                         if (params->hdr.e_entry >= seg->p_vaddr &&
 747                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 748                                 params->entry_addr =
 749                                         (params->hdr.e_entry - seg->p_vaddr) +
 750                                         seg->addr;
 751                                 break;
 752                         }
 753                 }
 754         }
 755
 756         /* determine where the program header table has wound up if mapped */
 757         stop = params->hdr.e_phoff;
 758         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 759         phdr = params->phdrs;
 760
 761         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 762                 if (phdr->p_type != PT_LOAD)
 763                         continue;
 764
 765                 if (phdr->p_offset > params->hdr.e_phoff ||
 766                     phdr->p_offset + phdr->p_filesz < stop)
 767                         continue;
 768
 769                 seg = loadmap->segs;
 770                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 771                         if (phdr->p_vaddr >= seg->p_vaddr &&
 772                             phdr->p_vaddr + phdr->p_filesz <=
 773                             seg->p_vaddr + seg->p_memsz) {
 774                                 params->ph_addr =
 775                                         (phdr->p_vaddr - seg->p_vaddr) +
 776                                         seg->addr +
 777                                         params->hdr.e_phoff - phdr->p_offset;
 778                                 break;
 779                         }
 780                 }
 781                 break;
 782         }
 783
 784         /* determine where the dynamic section has wound up if there is one */
 785         phdr = params->phdrs;
 786         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 787                 if (phdr->p_type != PT_DYNAMIC)
 788                         continue;
 789
 790                 seg = loadmap->segs;
 791                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 792                         if (phdr->p_vaddr >= seg->p_vaddr &&
 793                             phdr->p_vaddr + phdr->p_memsz <=
 794                             seg->p_vaddr + seg->p_memsz) {
 795                                 params->dynamic_addr =
 796                                         (phdr->p_vaddr - seg->p_vaddr) +
 797                                         seg->addr;
 798
 799                                 /* check the dynamic section contains at least
 800                                  * one item, and that the last item is a NULL
 801                                  * entry */
 802                                 if (phdr->p_memsz == 0 ||
 803                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 804                                         goto dynamic_error;
 805
 806                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 807                                 if (((Elf32_Dyn *)
 808                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 809                                         goto dynamic_error;
 810                                 break;
 811                         }
 812                 }
 813                 break;
 814         }
 815
 816         /* now elide adjacent segments in the load map on MMU linux
 817          * - on uClinux the holes between may actually be filled with system
 818          *   stuff or stuff from other processes
 819          */
 820 #ifdef CONFIG_MMU
 821         nloads = loadmap->nsegs;
 822         mseg = loadmap->segs;
 823         seg = mseg + 1;
 824         for (loop = 1; loop < nloads; loop++) {
 825                 /* see if we have a candidate for merging */
 826                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 827                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 828                         if (load_addr == (seg->addr & PAGE_MASK)) {
 829                                 mseg->p_memsz +=
 830                                         load_addr -
 831                                         (mseg->addr + mseg->p_memsz);
 832                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 833                                 mseg->p_memsz += seg->p_memsz;
 834                                 loadmap->nsegs--;
 835                                 continue;
 836                         }
 837                 }
 838
 839                 mseg++;
 840                 if (mseg != seg)
 841                         *mseg = *seg;
 842         }
 843 #endif
 844
 845         kdebug("Mapped Object [%s]:", what);
 846         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 847         kdebug("- entry    : %lx", params->entry_addr);
 848         kdebug("- PHDR[]   : %lx", params->ph_addr);
 849         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 850         seg = loadmap->segs;
 851         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 852                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 853                        loop,
 854                        seg->addr, seg->addr + seg->p_memsz - 1,
 855                        seg->p_vaddr, seg->p_memsz);
 856
 857         return 0;
 858
 859 dynamic_error:
 860         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 861                what, file->f_dentry->d_inode->i_ino);
 862         return -ELIBBAD;
 863 }
 864
 865 /*****************************************************************************/
 866 /*
 867  * map a file with constant displacement under uClinux
 868  */
 869 #ifndef CONFIG_MMU
 870 static int elf_fdpic_map_file_constdisp_on_uclinux(
 871         struct elf_fdpic_params *params,
 872         struct file *file,
 873         struct mm_struct *mm)
 874 {
 875         struct elf32_fdpic_loadseg *seg;
 876         struct elf32_phdr *phdr;
 877         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 878         loff_t fpos;
 879         int loop, ret;
 880
 881         load_addr = params->load_addr;
 882         seg = params->loadmap->segs;
 883
 884         /* determine the bounds of the contiguous overall allocation we must
 885          * make */
 886         phdr = params->phdrs;
 887         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 888                 if (params->phdrs[loop].p_type != PT_LOAD)
 889                         continue;
 890
 891                 if (base > phdr->p_vaddr)
 892                         base = phdr->p_vaddr;
 893                 if (top < phdr->p_vaddr + phdr->p_memsz)
 894                         top = phdr->p_vaddr + phdr->p_memsz;
 895         }
 896
 897         /* allocate one big anon block for everything */
 898         mflags = MAP_PRIVATE;
 899         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 900                 mflags |= MAP_EXECUTABLE;
 901
 902         down_write(&mm->mmap_sem);
 903         maddr = do_mmap(NULL, load_addr, top - base,
 904                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 905         up_write(&mm->mmap_sem);
 906         if (IS_ERR_VALUE(maddr))
 907                 return (int) maddr;
 908
 909         if (load_addr != 0)
 910                 load_addr += PAGE_ALIGN(top - base);
 911
 912         /* and then load the file segments into it */
 913         phdr = params->phdrs;
 914         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 915                 if (params->phdrs[loop].p_type != PT_LOAD)
 916                         continue;
 917
 918                 fpos = phdr->p_offset;
 919
 920                 seg->addr = maddr + (phdr->p_vaddr - base);
 921                 seg->p_vaddr = phdr->p_vaddr;
 922                 seg->p_memsz = phdr->p_memsz;
 923
 924                 ret = file->f_op->read(file, (void *) seg->addr,
 925                                        phdr->p_filesz, &fpos);
 926                 if (ret < 0)
 927                         return ret;
 928
 929                 /* map the ELF header address if in this segment */
 930                 if (phdr->p_offset == 0)
 931                         params->elfhdr_addr = seg->addr;
 932
 933                 /* clear any space allocated but not loaded */
 934                 if (phdr->p_filesz < phdr->p_memsz)
 935                         clear_user((void *) (seg->addr + phdr->p_filesz),
 936                                    phdr->p_memsz - phdr->p_filesz);
 937
 938                 if (mm) {
 939                         if (phdr->p_flags & PF_X) {
 940                                 mm->start_code = seg->addr;
 941                                 mm->end_code = seg->addr + phdr->p_memsz;
 942                         } else if (!mm->start_data) {
 943                                 mm->start_data = seg->addr;
 944 #ifndef CONFIG_MMU
 945                                 mm->end_data = seg->addr + phdr->p_memsz;
 946 #endif
 947                         }
 948
 949 #ifdef CONFIG_MMU
 950                         if (seg->addr + phdr->p_memsz > mm->end_data)
 951                                 mm->end_data = seg->addr + phdr->p_memsz;
 952 #endif
 953                 }
 954
 955                 seg++;
 956         }
 957
 958         return 0;
 959 }
 960 #endif
 961
 962 /*****************************************************************************/
 963 /*
 964  * map a binary by direct mmap() of the individual PT_LOAD segments
 965  */
 966 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 967                                              struct file *file,
 968                                              struct mm_struct *mm)
 969 {
 970         struct elf32_fdpic_loadseg *seg;
 971         struct elf32_phdr *phdr;
 972         unsigned long load_addr, delta_vaddr;
 973         int loop, dvset;
 974
 975         load_addr = params->load_addr;
 976         delta_vaddr = 0;
 977         dvset = 0;
 978
 979         seg = params->loadmap->segs;
 980
 981         /* deal with each load segment separately */
 982         phdr = params->phdrs;
 983         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 984                 unsigned long maddr, disp, excess, excess1;
 985                 int prot = 0, flags;
 986
 987                 if (phdr->p_type != PT_LOAD)
 988                         continue;
 989
 990                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
 991                        (unsigned long) phdr->p_vaddr,
 992                        (unsigned long) phdr->p_offset,
 993                        (unsigned long) phdr->p_filesz,
 994                        (unsigned long) phdr->p_memsz);
 995
 996                 /* determine the mapping parameters */
 997                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
 998                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
 999                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1000
1001                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1002                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1003                         flags |= MAP_EXECUTABLE;
1004
1005                 maddr = 0;
1006
1007                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1008                 case ELF_FDPIC_FLAG_INDEPENDENT:
1009                         /* PT_LOADs are independently locatable */
1010                         break;
1011
1012                 case ELF_FDPIC_FLAG_HONOURVADDR:
1013                         /* the specified virtual address must be honoured */
1014                         maddr = phdr->p_vaddr;
1015                         flags |= MAP_FIXED;
1016                         break;
1017
1018                 case ELF_FDPIC_FLAG_CONSTDISP:
1019                         /* constant displacement
1020                          * - can be mapped anywhere, but must be mapped as a
1021                          *   unit
1022                          */
1023                         if (!dvset) {
1024                                 maddr = load_addr;
1025                                 delta_vaddr = phdr->p_vaddr;
1026                                 dvset = 1;
1027                         } else {
1028                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1029                                 flags |= MAP_FIXED;
1030                         }
1031                         break;
1032
1033                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1034                         /* contiguity handled later */
1035                         break;
1036
1037                 default:
1038                         BUG();
1039                 }
1040
1041                 maddr &= PAGE_MASK;
1042
1043                 /* create the mapping */
1044                 disp = phdr->p_vaddr & ~PAGE_MASK;
1045                 down_write(&mm->mmap_sem);
1046                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1047                                 phdr->p_offset - disp);
1048                 up_write(&mm->mmap_sem);
1049
1050                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1051                        loop, phdr->p_memsz + disp, prot, flags,
1052                        phdr->p_offset - disp, maddr);
1053
1054                 if (IS_ERR_VALUE(maddr))
1055                         return (int) maddr;
1056
1057                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1058                     ELF_FDPIC_FLAG_CONTIGUOUS)
1059                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1060
1061                 seg->addr = maddr + disp;
1062                 seg->p_vaddr = phdr->p_vaddr;
1063                 seg->p_memsz = phdr->p_memsz;
1064
1065                 /* map the ELF header address if in this segment */
1066                 if (phdr->p_offset == 0)
1067                         params->elfhdr_addr = seg->addr;
1068
1069                 /* clear the bit between beginning of mapping and beginning of
1070                  * PT_LOAD */
1071                 if (prot & PROT_WRITE && disp > 0) {
1072                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1073                         clear_user((void __user *) maddr, disp);
1074                         maddr += disp;
1075                 }
1076
1077                 /* clear any space allocated but not loaded
1078                  * - on uClinux we can just clear the lot
1079                  * - on MMU linux we'll get a SIGBUS beyond the last page
1080                  *   extant in the file
1081                  */
1082                 excess = phdr->p_memsz - phdr->p_filesz;
1083                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1084
1085 #ifdef CONFIG_MMU
1086                 if (excess > excess1) {
1087                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1088                         unsigned long xmaddr;
1089
1090                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1091                         down_write(&mm->mmap_sem);
1092                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1093                                          prot, flags, 0);
1094                         up_write(&mm->mmap_sem);
1095
1096                         kdebug("mmap[%d] <anon>"
1097                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1098                                loop, xaddr, excess - excess1, prot, flags,
1099                                xmaddr);
1100
1101                         if (xmaddr != xaddr)
1102                                 return -ENOMEM;
1103                 }
1104
1105                 if (prot & PROT_WRITE && excess1 > 0) {
1106                         kdebug("clear[%d] ad=%lx sz=%lx",
1107                                loop, maddr + phdr->p_filesz, excess1);
1108                         clear_user((void __user *) maddr + phdr->p_filesz,
1109                                    excess1);
1110                 }
1111
1112 #else
1113                 if (excess > 0) {
1114                         kdebug("clear[%d] ad=%lx sz=%lx",
1115                                loop, maddr + phdr->p_filesz, excess);
1116                         clear_user((void *) maddr + phdr->p_filesz, excess);
1117                 }
1118 #endif
1119
1120                 if (mm) {
1121                         if (phdr->p_flags & PF_X) {
1122                                 mm->start_code = maddr;
1123                                 mm->end_code = maddr + phdr->p_memsz;
1124                         } else if (!mm->start_data) {
1125                                 mm->start_data = maddr;
1126                                 mm->end_data = maddr + phdr->p_memsz;
1127                         }
1128                 }
1129
1130                 seg++;
1131         }
1132
1133         return 0;
1134 }
1135
1136 /*****************************************************************************/
1137 /*
1138  * ELF-FDPIC core dumper
1139  *
1140  * Modelled on fs/exec.c:aout_core_dump()
1141  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1142  *
1143  * Modelled on fs/binfmt_elf.c core dumper
1144  */
1145 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1146
1147 /*
1148  * These are the only things you should do on a core-file: use only these
1149  * functions to write out all the necessary info.
1150  */
1151 static int dump_write(struct file *file, const void *addr, int nr)
1152 {
1153         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1154 }
1155
1156 static int dump_seek(struct file *file, loff_t off)
1157 {
1158         if (file->f_op->llseek) {
1159                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1160                         return 0;
1161         } else {
1162                 file->f_pos = off;
1163         }
1164         return 1;
1165 }
1166
1167 /*
1168  * Decide whether a segment is worth dumping; default is yes to be
1169  * sure (missing info is worse than too much; etc).
1170  * Personally I'd include everything, and use the coredump limit...
1171  *
1172  * I think we should skip something. But I am not sure how. H.J.
1173  */
1174 static int maydump(struct vm_area_struct *vma)
1175 {
1176         /* Do not dump I/O mapped devices or special mappings */
1177         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1178                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1179                 return 0;
1180         }
1181
1182         /* If we may not read the contents, don't allow us to dump
1183          * them either. "dump_write()" can't handle it anyway.
1184          */
1185         if (!(vma->vm_flags & VM_READ)) {
1186                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1187                 return 0;
1188         }
1189
1190         /* Dump shared memory only if mapped from an anonymous file. */
1191         if (vma->vm_flags & VM_SHARED) {
1192                 if (vma->vm_file->f_dentry->d_inode->i_nlink == 0) {
1193                         kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1194                         return 1;
1195                 }
1196
1197                 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1198                 return 0;
1199         }
1200
1201 #ifdef CONFIG_MMU
1202         /* If it hasn't been written to, don't write it out */
1203         if (!vma->anon_vma) {
1204                 kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);
1205                 return 0;
1206         }
1207 #endif
1208
1209         kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);
1210         return 1;
1211 }
1212
1213 /* An ELF note in memory */
1214 struct memelfnote
1215 {
1216         const char *name;
1217         int type;
1218         unsigned int datasz;
1219         void *data;
1220 };
1221
1222 static int notesize(struct memelfnote *en)
1223 {
1224         int sz;
1225
1226         sz = sizeof(struct elf_note);
1227         sz += roundup(strlen(en->name) + 1, 4);
1228         sz += roundup(en->datasz, 4);
1229
1230         return sz;
1231 }
1232
1233 /* #define DEBUG */
1234
1235 #define DUMP_WRITE(addr, nr)    \
1236         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1237 #define DUMP_SEEK(off)  \
1238         do { if (!dump_seek(file, (off))) return 0; } while(0)
1239
1240 static int writenote(struct memelfnote *men, struct file *file)
1241 {
1242         struct elf_note en;
1243
1244         en.n_namesz = strlen(men->name) + 1;
1245         en.n_descsz = men->datasz;
1246         en.n_type = men->type;
1247
1248         DUMP_WRITE(&en, sizeof(en));
1249         DUMP_WRITE(men->name, en.n_namesz);
1250         /* XXX - cast from long long to long to avoid need for libgcc.a */
1251         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1252         DUMP_WRITE(men->data, men->datasz);
1253         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1254
1255         return 1;
1256 }
1257 #undef DUMP_WRITE
1258 #undef DUMP_SEEK
1259
1260 #define DUMP_WRITE(addr, nr)    \
1261         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1262                 goto end_coredump;
1263 #define DUMP_SEEK(off)  \
1264         if (!dump_seek(file, (off))) \
1265                 goto end_coredump;
1266
1267 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1268 {
1269         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1270         elf->e_ident[EI_CLASS] = ELF_CLASS;
1271         elf->e_ident[EI_DATA] = ELF_DATA;
1272         elf->e_ident[EI_VERSION] = EV_CURRENT;
1273         elf->e_ident[EI_OSABI] = ELF_OSABI;
1274         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1275
1276         elf->e_type = ET_CORE;
1277         elf->e_machine = ELF_ARCH;
1278         elf->e_version = EV_CURRENT;
1279         elf->e_entry = 0;
1280         elf->e_phoff = sizeof(struct elfhdr);
1281         elf->e_shoff = 0;
1282         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1283         elf->e_ehsize = sizeof(struct elfhdr);
1284         elf->e_phentsize = sizeof(struct elf_phdr);
1285         elf->e_phnum = segs;
1286         elf->e_shentsize = 0;
1287         elf->e_shnum = 0;
1288         elf->e_shstrndx = 0;
1289         return;
1290 }
1291
1292 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1293 {
1294         phdr->p_type = PT_NOTE;
1295         phdr->p_offset = offset;
1296         phdr->p_vaddr = 0;
1297         phdr->p_paddr = 0;
1298         phdr->p_filesz = sz;
1299         phdr->p_memsz = 0;
1300         phdr->p_flags = 0;
1301         phdr->p_align = 0;
1302         return;
1303 }
1304
1305 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1306                 unsigned int sz, void *data)
1307 {
1308         note->name = name;
1309         note->type = type;
1310         note->datasz = sz;
1311         note->data = data;
1312         return;
1313 }
1314
1315 /*
1316  * fill up all the fields in prstatus from the given task struct, except
1317  * registers which need to be filled up seperately.
1318  */
1319 static void fill_prstatus(struct elf_prstatus *prstatus,
1320                           struct task_struct *p, long signr)
1321 {
1322         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1323         prstatus->pr_sigpend = p->pending.signal.sig[0];
1324         prstatus->pr_sighold = p->blocked.sig[0];
1325         prstatus->pr_pid = p->pid;
1326         prstatus->pr_ppid = p->parent->pid;
1327         prstatus->pr_pgrp = process_group(p);
1328         prstatus->pr_sid = p->signal->session;
1329         if (thread_group_leader(p)) {
1330                 /*
1331                  * This is the record for the group leader.  Add in the
1332                  * cumulative times of previous dead threads.  This total
1333                  * won't include the time of each live thread whose state
1334                  * is included in the core dump.  The final total reported
1335                  * to our parent process when it calls wait4 will include
1336                  * those sums as well as the little bit more time it takes
1337                  * this and each other thread to finish dying after the
1338                  * core dump synchronization phase.
1339                  */
1340                 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1341                                    &prstatus->pr_utime);
1342                 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1343                                    &prstatus->pr_stime);
1344         } else {
1345                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1346                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1347         }
1348         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1349         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1350
1351         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1352         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1353 }
1354
1355 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1356                        struct mm_struct *mm)
1357 {
1358         unsigned int i, len;
1359
1360         /* first copy the parameters from user space */
1361         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1362
1363         len = mm->arg_end - mm->arg_start;
1364         if (len >= ELF_PRARGSZ)
1365                 len = ELF_PRARGSZ - 1;
1366         if (copy_from_user(&psinfo->pr_psargs,
1367                            (const char __user *) mm->arg_start, len))
1368                 return -EFAULT;
1369         for (i = 0; i < len; i++)
1370                 if (psinfo->pr_psargs[i] == 0)
1371                         psinfo->pr_psargs[i] = ' ';
1372         psinfo->pr_psargs[len] = 0;
1373
1374         psinfo->pr_pid = p->pid;
1375         psinfo->pr_ppid = p->parent->pid;
1376         psinfo->pr_pgrp = process_group(p);
1377         psinfo->pr_sid = p->signal->session;
1378
1379         i = p->state ? ffz(~p->state) + 1 : 0;
1380         psinfo->pr_state = i;
1381         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1382         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1383         psinfo->pr_nice = task_nice(p);
1384         psinfo->pr_flag = p->flags;
1385         SET_UID(psinfo->pr_uid, p->uid);
1386         SET_GID(psinfo->pr_gid, p->gid);
1387         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1388
1389         return 0;
1390 }
1391
1392 /* Here is the structure in which status of each thread is captured. */
1393 struct elf_thread_status
1394 {
1395         struct list_head list;
1396         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1397         elf_fpregset_t fpu;             /* NT_PRFPREG */
1398         struct task_struct *thread;
1399 #ifdef ELF_CORE_COPY_XFPREGS
1400         elf_fpxregset_t xfpu;           /* NT_PRXFPREG */
1401 #endif
1402         struct memelfnote notes[3];
1403         int num_notes;
1404 };
1405
1406 /*
1407  * In order to add the specific thread information for the elf file format,
1408  * we need to keep a linked list of every thread's pr_status and then create
1409  * a single section for them in the final core file.
1410  */
1411 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1412 {
1413         struct task_struct *p = t->thread;
1414         int sz = 0;
1415
1416         t->num_notes = 0;
1417
1418         fill_prstatus(&t->prstatus, p, signr);
1419         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1420
1421         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1422                   &t->prstatus);
1423         t->num_notes++;
1424         sz += notesize(&t->notes[0]);
1425
1426         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1427         if (t->prstatus.pr_fpvalid) {
1428                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1429                           &t->fpu);
1430                 t->num_notes++;
1431                 sz += notesize(&t->notes[1]);
1432         }
1433
1434 #ifdef ELF_CORE_COPY_XFPREGS
1435         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1436                 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1437                           &t->xfpu);
1438                 t->num_notes++;
1439                 sz += notesize(&t->notes[2]);
1440         }
1441 #endif
1442         return sz;
1443 }
1444
1445 /*
1446  * dump the segments for an MMU process
1447  */
1448 #ifdef CONFIG_MMU
1449 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1450                                    size_t *size, unsigned long *limit)
1451 {
1452         struct vm_area_struct *vma;
1453
1454         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1455                 unsigned long addr;
1456
1457                 if (!maydump(vma))
1458                         continue;
1459
1460                 for (addr = vma->vm_start;
1461                      addr < vma->vm_end;
1462                      addr += PAGE_SIZE
1463                      ) {
1464                         struct vm_area_struct *vma;
1465                         struct page *page;
1466
1467                         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1468                                            &page, &vma) <= 0) {
1469                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1470                         }
1471                         else if (page == ZERO_PAGE(addr)) {
1472                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1473                                 page_cache_release(page);
1474                         }
1475                         else {
1476                                 void *kaddr;
1477
1478                                 flush_cache_page(vma, addr, page_to_pfn(page));
1479                                 kaddr = kmap(page);
1480                                 if ((*size += PAGE_SIZE) > *limit ||
1481                                     !dump_write(file, kaddr, PAGE_SIZE)
1482                                     ) {
1483                                         kunmap(page);
1484                                         page_cache_release(page);
1485                                         return -EIO;
1486                                 }
1487                                 kunmap(page);
1488                                 page_cache_release(page);
1489                         }
1490                 }
1491         }
1492
1493         return 0;
1494
1495 end_coredump:
1496         return -EFBIG;
1497 }
1498 #endif
1499
1500 /*
1501  * dump the segments for a NOMMU process
1502  */
1503 #ifndef CONFIG_MMU
1504 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1505                                    size_t *size, unsigned long *limit)
1506 {
1507         struct vm_list_struct *vml;
1508
1509         for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1510         struct vm_area_struct *vma = vml->vma;
1511
1512                 if (!maydump(vma))
1513                         continue;
1514
1515                 if ((*size += PAGE_SIZE) > *limit)
1516                         return -EFBIG;
1517
1518                 if (!dump_write(file, (void *) vma->vm_start,
1519                                 vma->vm_end - vma->vm_start))
1520                         return -EIO;
1521         }
1522
1523         return 0;
1524 }
1525 #endif
1526
1527 /*
1528  * Actual dumper
1529  *
1530  * This is a two-pass process; first we find the offsets of the bits,
1531  * and then they are actually written out.  If we run out of core limit
1532  * we just truncate.
1533  */
1534 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1535                                struct file *file)
1536 {
1537 #define NUM_NOTES       6
1538         int has_dumped = 0;
1539         mm_segment_t fs;
1540         int segs;
1541         size_t size = 0;
1542         int i;
1543         struct vm_area_struct *vma;
1544         struct elfhdr *elf = NULL;
1545         loff_t offset = 0, dataoff;
1546         unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1547         int numnote;
1548         struct memelfnote *notes = NULL;
1549         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1550         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1551         struct task_struct *g, *p;
1552         LIST_HEAD(thread_list);
1553         struct list_head *t;
1554         elf_fpregset_t *fpu = NULL;
1555 #ifdef ELF_CORE_COPY_XFPREGS
1556         elf_fpxregset_t *xfpu = NULL;
1557 #endif
1558         int thread_status_size = 0;
1559 #ifndef CONFIG_MMU
1560         struct vm_list_struct *vml;
1561 #endif
1562         elf_addr_t *auxv;
1563
1564         /*
1565          * We no longer stop all VM operations.
1566          *
1567          * This is because those proceses that could possibly change map_count
1568          * or the mmap / vma pages are now blocked in do_exit on current
1569          * finishing this core dump.
1570          *
1571          * Only ptrace can touch these memory addresses, but it doesn't change
1572          * the map_count or the pages allocated. So no possibility of crashing
1573          * exists while dumping the mm->vm_next areas to the core file.
1574          */
1575
1576         /* alloc memory for large data structures: too large to be on stack */
1577         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1578         if (!elf)
1579                 goto cleanup;
1580         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1581         if (!prstatus)
1582                 goto cleanup;
1583         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1584         if (!psinfo)
1585                 goto cleanup;
1586         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1587         if (!notes)
1588                 goto cleanup;
1589         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1590         if (!fpu)
1591                 goto cleanup;
1592 #ifdef ELF_CORE_COPY_XFPREGS
1593         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1594         if (!xfpu)
1595                 goto cleanup;
1596 #endif
1597
1598         if (signr) {
1599                 struct elf_thread_status *tmp;
1600                 read_lock(&tasklist_lock);
1601                 do_each_thread(g,p)
1602                         if (current->mm == p->mm && current != p) {
1603                                 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1604                                 if (!tmp) {
1605                                         read_unlock(&tasklist_lock);
1606                                         goto cleanup;
1607                                 }
1608                                 INIT_LIST_HEAD(&tmp->list);
1609                                 tmp->thread = p;
1610                                 list_add(&tmp->list, &thread_list);
1611                         }
1612                 while_each_thread(g,p);
1613                 read_unlock(&tasklist_lock);
1614                 list_for_each(t, &thread_list) {
1615                         struct elf_thread_status *tmp;
1616                         int sz;
1617
1618                         tmp = list_entry(t, struct elf_thread_status, list);
1619                         sz = elf_dump_thread_status(signr, tmp);
1620                         thread_status_size += sz;
1621                 }
1622         }
1623
1624         /* now collect the dump for the current */
1625         fill_prstatus(prstatus, current, signr);
1626         elf_core_copy_regs(&prstatus->pr_reg, regs);
1627
1628 #ifdef CONFIG_MMU
1629         segs = current->mm->map_count;
1630 #else
1631         segs = 0;
1632         for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1633             segs++;
1634 #endif
1635 #ifdef ELF_CORE_EXTRA_PHDRS
1636         segs += ELF_CORE_EXTRA_PHDRS;
1637 #endif
1638
1639         /* Set up header */
1640         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1641
1642         has_dumped = 1;
1643         current->flags |= PF_DUMPCORE;
1644
1645         /*
1646          * Set up the notes in similar form to SVR4 core dumps made
1647          * with info from their /proc.
1648          */
1649
1650         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1651         fill_psinfo(psinfo, current->group_leader, current->mm);
1652         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1653
1654         numnote = 2;
1655
1656         auxv = (elf_addr_t *) current->mm->saved_auxv;
1657
1658         i = 0;
1659         do
1660                 i += 2;
1661         while (auxv[i - 2] != AT_NULL);
1662         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1663                   i * sizeof(elf_addr_t), auxv);
1664
1665         /* Try to dump the FPU. */
1666         if ((prstatus->pr_fpvalid =
1667              elf_core_copy_task_fpregs(current, regs, fpu)))
1668                 fill_note(notes + numnote++,
1669                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1670 #ifdef ELF_CORE_COPY_XFPREGS
1671         if (elf_core_copy_task_xfpregs(current, xfpu))
1672                 fill_note(notes + numnote++,
1673                           "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1674 #endif
1675
1676         fs = get_fs();
1677         set_fs(KERNEL_DS);
1678
1679         DUMP_WRITE(elf, sizeof(*elf));
1680         offset += sizeof(*elf);                         /* Elf header */
1681         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1682
1683         /* Write notes phdr entry */
1684         {
1685                 struct elf_phdr phdr;
1686                 int sz = 0;
1687
1688                 for (i = 0; i < numnote; i++)
1689                         sz += notesize(notes + i);
1690
1691                 sz += thread_status_size;
1692
1693                 fill_elf_note_phdr(&phdr, sz, offset);
1694                 offset += sz;
1695                 DUMP_WRITE(&phdr, sizeof(phdr));
1696         }
1697
1698         /* Page-align dumped data */
1699         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1700
1701         /* write program headers for segments dump */
1702         for (
1703 #ifdef CONFIG_MMU
1704                 vma = current->mm->mmap; vma; vma = vma->vm_next
1705 #else
1706                         vml = current->mm->context.vmlist; vml; vml = vml->next
1707 #endif
1708              ) {
1709                 struct elf_phdr phdr;
1710                 size_t sz;
1711
1712 #ifndef CONFIG_MMU
1713                 vma = vml->vma;
1714 #endif
1715
1716                 sz = vma->vm_end - vma->vm_start;
1717
1718                 phdr.p_type = PT_LOAD;
1719                 phdr.p_offset = offset;
1720                 phdr.p_vaddr = vma->vm_start;
1721                 phdr.p_paddr = 0;
1722                 phdr.p_filesz = maydump(vma) ? sz : 0;
1723                 phdr.p_memsz = sz;
1724                 offset += phdr.p_filesz;
1725                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1726                 if (vma->vm_flags & VM_WRITE)
1727                         phdr.p_flags |= PF_W;
1728                 if (vma->vm_flags & VM_EXEC)
1729                         phdr.p_flags |= PF_X;
1730                 phdr.p_align = ELF_EXEC_PAGESIZE;
1731
1732                 DUMP_WRITE(&phdr, sizeof(phdr));
1733         }
1734
1735 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1736         ELF_CORE_WRITE_EXTRA_PHDRS;
1737 #endif
1738
1739         /* write out the notes section */
1740         for (i = 0; i < numnote; i++)
1741                 if (!writenote(notes + i, file))
1742                         goto end_coredump;
1743
1744         /* write out the thread status notes section */
1745         list_for_each(t, &thread_list) {
1746                 struct elf_thread_status *tmp =
1747                                 list_entry(t, struct elf_thread_status, list);
1748
1749                 for (i = 0; i < tmp->num_notes; i++)
1750                         if (!writenote(&tmp->notes[i], file))
1751                                 goto end_coredump;
1752         }
1753
1754         DUMP_SEEK(dataoff);
1755
1756         if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)
1757                 goto end_coredump;
1758
1759 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1760         ELF_CORE_WRITE_EXTRA_DATA;
1761 #endif
1762
1763         if (file->f_pos != offset) {
1764                 /* Sanity check */
1765                 printk(KERN_WARNING
1766                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1767                        file->f_pos, offset);
1768         }
1769
1770 end_coredump:
1771         set_fs(fs);
1772
1773 cleanup:
1774         while (!list_empty(&thread_list)) {
1775                 struct list_head *tmp = thread_list.next;
1776                 list_del(tmp);
1777                 kfree(list_entry(tmp, struct elf_thread_status, list));
1778         }
1779
1780         kfree(elf);
1781         kfree(prstatus);
1782         kfree(psinfo);
1783         kfree(notes);
1784         kfree(fpu);
1785 #ifdef ELF_CORE_COPY_XFPREGS
1786         kfree(xfpu);
1787 #endif
1788         return has_dumped;
1789 #undef NUM_NOTES
1790 }
1791
1792 #endif          /* USE_ELF_CORE_DUMP */