fs/binfmt_elf_fdpic.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
   3  *
   4  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells ([email protected])
   6  * Derived from binfmt_elf.c
   7  */
   8
   9 #include <linux/module.h>
  10
  11 #include <linux/fs.h>
  12 #include <linux/stat.h>
  13 #include <linux/sched.h>
  14 #include <linux/sched/coredump.h>
  15 #include <linux/sched/task_stack.h>
  16 #include <linux/sched/cputime.h>
  17 #include <linux/mm.h>
  18 #include <linux/mman.h>
  19 #include <linux/errno.h>
  20 #include <linux/signal.h>
  21 #include <linux/binfmts.h>
  22 #include <linux/string.h>
  23 #include <linux/file.h>
  24 #include <linux/fcntl.h>
  25 #include <linux/slab.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/security.h>
  28 #include <linux/highmem.h>
  29 #include <linux/highuid.h>
  30 #include <linux/personality.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/init.h>
  33 #include <linux/elf.h>
  34 #include <linux/elf-fdpic.h>
  35 #include <linux/elfcore.h>
  36 #include <linux/coredump.h>
  37 #include <linux/dax.h>
  38 #include <linux/regset.h>
  39
  40 #include <linux/uaccess.h>
  41 #include <asm/param.h>
  42
  43 typedef char *elf_caddr_t;
  44
  45 #if 0
  46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  47 #else
  48 #define kdebug(fmt, ...) do {} while(0)
  49 #endif
  50
  51 #if 0
  52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  53 #else
  54 #define kdcore(fmt, ...) do {} while(0)
  55 #endif
  56
  57 MODULE_LICENSE("GPL");
  58
  59 static int load_elf_fdpic_binary(struct linux_binprm *);
  60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  62                               struct mm_struct *, const char *);
  63
  64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  65                                    struct elf_fdpic_params *,
  66                                    struct elf_fdpic_params *);
  67
  68 #ifndef CONFIG_MMU
  69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  70                                                    struct file *,
  71                                                    struct mm_struct *);
  72 #endif
  73
  74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  75                                              struct file *, struct mm_struct *);
  76
  77 #ifdef CONFIG_ELF_CORE
  78 static int elf_fdpic_core_dump(struct coredump_params *cprm);
  79 #endif
  80
  81 static struct linux_binfmt elf_fdpic_format = {
  82         .module         = THIS_MODULE,
  83         .load_binary    = load_elf_fdpic_binary,
  84 #ifdef CONFIG_ELF_CORE
  85         .core_dump      = elf_fdpic_core_dump,
  86         .min_coredump   = ELF_EXEC_PAGESIZE,
  87 #endif
  88 };
  89
  90 static int __init init_elf_fdpic_binfmt(void)
  91 {
  92         register_binfmt(&elf_fdpic_format);
  93         return 0;
  94 }
  95
  96 static void __exit exit_elf_fdpic_binfmt(void)
  97 {
  98         unregister_binfmt(&elf_fdpic_format);
  99 }
 100
 101 core_initcall(init_elf_fdpic_binfmt);
 102 module_exit(exit_elf_fdpic_binfmt);
 103
 104 static int is_elf(struct elfhdr *hdr, struct file *file)
 105 {
 106         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 107                 return 0;
 108         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 109                 return 0;
 110         if (!elf_check_arch(hdr))
 111                 return 0;
 112         if (!file->f_op->mmap)
 113                 return 0;
 114         return 1;
 115 }
 116
 117 #ifndef elf_check_fdpic
 118 #define elf_check_fdpic(x) 0
 119 #endif
 120
 121 #ifndef elf_check_const_displacement
 122 #define elf_check_const_displacement(x) 0
 123 #endif
 124
 125 static int is_constdisp(struct elfhdr *hdr)
 126 {
 127         if (!elf_check_fdpic(hdr))
 128                 return 1;
 129         if (elf_check_const_displacement(hdr))
 130                 return 1;
 131         return 0;
 132 }
 133
 134 /*****************************************************************************/
 135 /*
 136  * read the program headers table into memory
 137  */
 138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 139                                  struct file *file)
 140 {
 141         struct elf_phdr *phdr;
 142         unsigned long size;
 143         int retval, loop;
 144         loff_t pos = params->hdr.e_phoff;
 145
 146         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 147                 return -ENOMEM;
 148         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 149                 return -ENOMEM;
 150
 151         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 152         params->phdrs = kmalloc(size, GFP_KERNEL);
 153         if (!params->phdrs)
 154                 return -ENOMEM;
 155
 156         retval = kernel_read(file, params->phdrs, size, &pos);
 157         if (unlikely(retval != size))
 158                 return retval < 0 ? retval : -ENOEXEC;
 159
 160         /* determine stack size for this binary */
 161         phdr = params->phdrs;
 162         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 163                 if (phdr->p_type != PT_GNU_STACK)
 164                         continue;
 165
 166                 if (phdr->p_flags & PF_X)
 167                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 168                 else
 169                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 170
 171                 params->stack_size = phdr->p_memsz;
 172                 break;
 173         }
 174
 175         return 0;
 176 }
 177
 178 /*****************************************************************************/
 179 /*
 180  * load an fdpic binary into various bits of memory
 181  */
 182 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 183 {
 184         struct elf_fdpic_params exec_params, interp_params;
 185         struct pt_regs *regs = current_pt_regs();
 186         struct elf_phdr *phdr;
 187         unsigned long stack_size, entryaddr;
 188 #ifdef ELF_FDPIC_PLAT_INIT
 189         unsigned long dynaddr;
 190 #endif
 191 #ifndef CONFIG_MMU
 192         unsigned long stack_prot;
 193 #endif
 194         struct file *interpreter = NULL; /* to shut gcc up */
 195         char *interpreter_name = NULL;
 196         int executable_stack;
 197         int retval, i;
 198         loff_t pos;
 199
 200         kdebug("____ LOAD %d ____", current->pid);
 201
 202         memset(&exec_params, 0, sizeof(exec_params));
 203         memset(&interp_params, 0, sizeof(interp_params));
 204
 205         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 206         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 207
 208         /* check that this is a binary we know how to deal with */
 209         retval = -ENOEXEC;
 210         if (!is_elf(&exec_params.hdr, bprm->file))
 211                 goto error;
 212         if (!elf_check_fdpic(&exec_params.hdr)) {
 213 #ifdef CONFIG_MMU
 214                 /* binfmt_elf handles non-fdpic elf except on nommu */
 215                 goto error;
 216 #else
 217                 /* nommu can only load ET_DYN (PIE) ELF */
 218                 if (exec_params.hdr.e_type != ET_DYN)
 219                         goto error;
 220 #endif
 221         }
 222
 223         /* read the program header table */
 224         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 225         if (retval < 0)
 226                 goto error;
 227
 228         /* scan for a program header that specifies an interpreter */
 229         phdr = exec_params.phdrs;
 230
 231         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 232                 switch (phdr->p_type) {
 233                 case PT_INTERP:
 234                         retval = -ENOMEM;
 235                         if (phdr->p_filesz > PATH_MAX)
 236                                 goto error;
 237                         retval = -ENOENT;
 238                         if (phdr->p_filesz < 2)
 239                                 goto error;
 240
 241                         /* read the name of the interpreter into memory */
 242                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 243                         if (!interpreter_name)
 244                                 goto error;
 245
 246                         pos = phdr->p_offset;
 247                         retval = kernel_read(bprm->file, interpreter_name,
 248                                              phdr->p_filesz, &pos);
 249                         if (unlikely(retval != phdr->p_filesz)) {
 250                                 if (retval >= 0)
 251                                         retval = -ENOEXEC;
 252                                 goto error;
 253                         }
 254
 255                         retval = -ENOENT;
 256                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 257                                 goto error;
 258
 259                         kdebug("Using ELF interpreter %s", interpreter_name);
 260
 261                         /* replace the program with the interpreter */
 262                         interpreter = open_exec(interpreter_name);
 263                         retval = PTR_ERR(interpreter);
 264                         if (IS_ERR(interpreter)) {
 265                                 interpreter = NULL;
 266                                 goto error;
 267                         }
 268
 269                         /*
 270                          * If the binary is not readable then enforce
 271                          * mm->dumpable = 0 regardless of the interpreter's
 272                          * permissions.
 273                          */
 274                         would_dump(bprm, interpreter);
 275
 276                         pos = 0;
 277                         retval = kernel_read(interpreter, bprm->buf,
 278                                         BINPRM_BUF_SIZE, &pos);
 279                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
 280                                 if (retval >= 0)
 281                                         retval = -ENOEXEC;
 282                                 goto error;
 283                         }
 284
 285                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 286                         break;
 287
 288                 case PT_LOAD:
 289 #ifdef CONFIG_MMU
 290                         if (exec_params.load_addr == 0)
 291                                 exec_params.load_addr = phdr->p_vaddr;
 292 #endif
 293                         break;
 294                 }
 295
 296         }
 297
 298         if (is_constdisp(&exec_params.hdr))
 299                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 300
 301         /* perform insanity checks on the interpreter */
 302         if (interpreter_name) {
 303                 retval = -ELIBBAD;
 304                 if (!is_elf(&interp_params.hdr, interpreter))
 305                         goto error;
 306
 307                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 308
 309                 /* read the interpreter's program header table */
 310                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 311                 if (retval < 0)
 312                         goto error;
 313         }
 314
 315         stack_size = exec_params.stack_size;
 316         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 317                 executable_stack = EXSTACK_ENABLE_X;
 318         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 319                 executable_stack = EXSTACK_DISABLE_X;
 320         else
 321                 executable_stack = EXSTACK_DEFAULT;
 322
 323         if (stack_size == 0 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) {
 324                 stack_size = interp_params.stack_size;
 325                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 326                         executable_stack = EXSTACK_ENABLE_X;
 327                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 328                         executable_stack = EXSTACK_DISABLE_X;
 329                 else
 330                         executable_stack = EXSTACK_DEFAULT;
 331         }
 332
 333         retval = -ENOEXEC;
 334         if (stack_size == 0)
 335                 stack_size = 131072UL; /* same as exec.c's default commit */
 336
 337         if (is_constdisp(&interp_params.hdr))
 338                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 339
 340         /* flush all traces of the currently running executable */
 341         retval = begin_new_exec(bprm);
 342         if (retval)
 343                 goto error;
 344
 345         /* there's now no turning back... the old userspace image is dead,
 346          * defunct, deceased, etc.
 347          */
 348         SET_PERSONALITY(exec_params.hdr);
 349         if (elf_check_fdpic(&exec_params.hdr))
 350                 current->personality |= PER_LINUX_FDPIC;
 351         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 352                 current->personality |= READ_IMPLIES_EXEC;
 353
 354         setup_new_exec(bprm);
 355
 356         set_binfmt(&elf_fdpic_format);
 357
 358         current->mm->start_code = 0;
 359         current->mm->end_code = 0;
 360         current->mm->start_stack = 0;
 361         current->mm->start_data = 0;
 362         current->mm->end_data = 0;
 363         current->mm->context.exec_fdpic_loadmap = 0;
 364         current->mm->context.interp_fdpic_loadmap = 0;
 365
 366 #ifdef CONFIG_MMU
 367         elf_fdpic_arch_lay_out_mm(&exec_params,
 368                                   &interp_params,
 369                                   &current->mm->start_stack,
 370                                   &current->mm->start_brk);
 371
 372         retval = setup_arg_pages(bprm, current->mm->start_stack,
 373                                  executable_stack);
 374         if (retval < 0)
 375                 goto error;
 376 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
 377         retval = arch_setup_additional_pages(bprm, !!interpreter_name);
 378         if (retval < 0)
 379                 goto error;
 380 #endif
 381 #endif
 382
 383         /* load the executable and interpreter into memory */
 384         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 385                                     "executable");
 386         if (retval < 0)
 387                 goto error;
 388
 389         if (interpreter_name) {
 390                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 391                                             current->mm, "interpreter");
 392                 if (retval < 0) {
 393                         printk(KERN_ERR "Unable to load interpreter\n");
 394                         goto error;
 395                 }
 396
 397                 allow_write_access(interpreter);
 398                 fput(interpreter);
 399                 interpreter = NULL;
 400         }
 401
 402 #ifdef CONFIG_MMU
 403         if (!current->mm->start_brk)
 404                 current->mm->start_brk = current->mm->end_data;
 405
 406         current->mm->brk = current->mm->start_brk =
 407                 PAGE_ALIGN(current->mm->start_brk);
 408
 409 #else
 410         /* create a stack area and zero-size brk area */
 411         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 412         if (stack_size < PAGE_SIZE * 2)
 413                 stack_size = PAGE_SIZE * 2;
 414
 415         stack_prot = PROT_READ | PROT_WRITE;
 416         if (executable_stack == EXSTACK_ENABLE_X ||
 417             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 418                 stack_prot |= PROT_EXEC;
 419
 420         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 421                                          MAP_PRIVATE | MAP_ANONYMOUS |
 422                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 423                                          0);
 424
 425         if (IS_ERR_VALUE(current->mm->start_brk)) {
 426                 retval = current->mm->start_brk;
 427                 current->mm->start_brk = 0;
 428                 goto error;
 429         }
 430
 431         current->mm->brk = current->mm->start_brk;
 432         current->mm->context.end_brk = current->mm->start_brk;
 433         current->mm->start_stack = current->mm->start_brk + stack_size;
 434 #endif
 435
 436         retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
 437                                          &interp_params);
 438         if (retval < 0)
 439                 goto error;
 440
 441         kdebug("- start_code  %lx", current->mm->start_code);
 442         kdebug("- end_code    %lx", current->mm->end_code);
 443         kdebug("- start_data  %lx", current->mm->start_data);
 444         kdebug("- end_data    %lx", current->mm->end_data);
 445         kdebug("- start_brk   %lx", current->mm->start_brk);
 446         kdebug("- brk         %lx", current->mm->brk);
 447         kdebug("- start_stack %lx", current->mm->start_stack);
 448
 449 #ifdef ELF_FDPIC_PLAT_INIT
 450         /*
 451          * The ABI may specify that certain registers be set up in special
 452          * ways (on i386 %edx is the address of a DT_FINI function, for
 453          * example.  This macro performs whatever initialization to
 454          * the regs structure is required.
 455          */
 456         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 457         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 458                             dynaddr);
 459 #endif
 460
 461         finalize_exec(bprm);
 462         /* everything is now ready... get the userspace context ready to roll */
 463         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 464         start_thread(regs, entryaddr, current->mm->start_stack);
 465
 466         retval = 0;
 467
 468 error:
 469         if (interpreter) {
 470                 allow_write_access(interpreter);
 471                 fput(interpreter);
 472         }
 473         kfree(interpreter_name);
 474         kfree(exec_params.phdrs);
 475         kfree(exec_params.loadmap);
 476         kfree(interp_params.phdrs);
 477         kfree(interp_params.loadmap);
 478         return retval;
 479 }
 480
 481 /*****************************************************************************/
 482
 483 #ifndef ELF_BASE_PLATFORM
 484 /*
 485  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 486  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 487  * will be copied to the user stack in the same manner as AT_PLATFORM.
 488  */
 489 #define ELF_BASE_PLATFORM NULL
 490 #endif
 491
 492 /*
 493  * present useful information to the program by shovelling it onto the new
 494  * process's stack
 495  */
 496 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 497                                    struct mm_struct *mm,
 498                                    struct elf_fdpic_params *exec_params,
 499                                    struct elf_fdpic_params *interp_params)
 500 {
 501         const struct cred *cred = current_cred();
 502         unsigned long sp, csp, nitems;
 503         elf_caddr_t __user *argv, *envp;
 504         size_t platform_len = 0, len;
 505         char *k_platform, *k_base_platform;
 506         char __user *u_platform, *u_base_platform, *p;
 507         int loop;
 508         unsigned long flags = 0;
 509         int ei_index;
 510         elf_addr_t *elf_info;
 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 elf_fdpic_loadmap);
 564         len += sizeof(struct elf_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 elf_fdpic_loadmap);
 575                 len += sizeof(struct elf_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 #ifdef ELF_HWCAP2
 596         nitems++;
 597 #endif
 598
 599         csp = sp;
 600         sp -= nitems * 2 * sizeof(unsigned long);
 601         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 602         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 603         sp -= 1 * sizeof(unsigned long);                /* argc */
 604
 605         csp -= sp & 15UL;
 606         sp -= sp & 15UL;
 607
 608         /* Create the ELF interpreter info */
 609         elf_info = (elf_addr_t *)mm->saved_auxv;
 610         /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
 611 #define NEW_AUX_ENT(id, val) \
 612         do { \
 613                 *elf_info++ = id; \
 614                 *elf_info++ = val; \
 615         } while (0)
 616
 617 #ifdef ARCH_DLINFO
 618         /*
 619          * ARCH_DLINFO must come first so PPC can do its special alignment of
 620          * AUXV.
 621          * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
 622          * ARCH_DLINFO changes
 623          */
 624         ARCH_DLINFO;
 625 #endif
 626         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 627 #ifdef ELF_HWCAP2
 628         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 629 #endif
 630 #ifdef ELF_HWCAP3
 631         NEW_AUX_ENT(AT_HWCAP3,  ELF_HWCAP3);
 632 #endif
 633 #ifdef ELF_HWCAP4
 634         NEW_AUX_ENT(AT_HWCAP4,  ELF_HWCAP4);
 635 #endif
 636         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 637         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 638         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 639         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 640         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 641         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 642         if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
 643                 flags |= AT_FLAGS_PRESERVE_ARGV0;
 644         NEW_AUX_ENT(AT_FLAGS,   flags);
 645         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 646         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 647         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 648         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 649         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 650         NEW_AUX_ENT(AT_SECURE,  bprm->secureexec);
 651         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 652         if (k_platform)
 653                 NEW_AUX_ENT(AT_PLATFORM,
 654                             (elf_addr_t)(unsigned long)u_platform);
 655         if (k_base_platform)
 656                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 657                             (elf_addr_t)(unsigned long)u_base_platform);
 658         if (bprm->have_execfd)
 659                 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
 660 #undef NEW_AUX_ENT
 661         /* AT_NULL is zero; clear the rest too */
 662         memset(elf_info, 0, (char *)mm->saved_auxv +
 663                sizeof(mm->saved_auxv) - (char *)elf_info);
 664
 665         /* And advance past the AT_NULL entry.  */
 666         elf_info += 2;
 667
 668         ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
 669         csp -= ei_index * sizeof(elf_addr_t);
 670
 671         /* Put the elf_info on the stack in the right place.  */
 672         if (copy_to_user((void __user *)csp, mm->saved_auxv,
 673                          ei_index * sizeof(elf_addr_t)))
 674                 return -EFAULT;
 675
 676         /* allocate room for argv[] and envv[] */
 677         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 678         envp = (elf_caddr_t __user *) csp;
 679         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 680         argv = (elf_caddr_t __user *) csp;
 681
 682         /* stack argc */
 683         csp -= sizeof(unsigned long);
 684         if (put_user(bprm->argc, (unsigned long __user *) csp))
 685                 return -EFAULT;
 686
 687         BUG_ON(csp != sp);
 688
 689         /* fill in the argv[] array */
 690 #ifdef CONFIG_MMU
 691         current->mm->arg_start = bprm->p;
 692 #else
 693         current->mm->arg_start = current->mm->start_stack -
 694                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 695 #endif
 696
 697         p = (char __user *) current->mm->arg_start;
 698         for (loop = bprm->argc; loop > 0; loop--) {
 699                 if (put_user((elf_caddr_t) p, argv++))
 700                         return -EFAULT;
 701                 len = strnlen_user(p, MAX_ARG_STRLEN);
 702                 if (!len || len > MAX_ARG_STRLEN)
 703                         return -EINVAL;
 704                 p += len;
 705         }
 706         if (put_user(NULL, argv))
 707                 return -EFAULT;
 708         current->mm->arg_end = (unsigned long) p;
 709
 710         /* fill in the envv[] array */
 711         current->mm->env_start = (unsigned long) p;
 712         for (loop = bprm->envc; loop > 0; loop--) {
 713                 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
 714                         return -EFAULT;
 715                 len = strnlen_user(p, MAX_ARG_STRLEN);
 716                 if (!len || len > MAX_ARG_STRLEN)
 717                         return -EINVAL;
 718                 p += len;
 719         }
 720         if (put_user(NULL, envp))
 721                 return -EFAULT;
 722         current->mm->env_end = (unsigned long) p;
 723
 724         mm->start_stack = (unsigned long) sp;
 725         return 0;
 726 }
 727
 728 /*****************************************************************************/
 729 /*
 730  * load the appropriate binary image (executable or interpreter) into memory
 731  * - we assume no MMU is available
 732  * - if no other PIC bits are set in params->hdr->e_flags
 733  *   - we assume that the LOADable segments in the binary are independently relocatable
 734  *   - we assume R/O executable segments are shareable
 735  * - else
 736  *   - we assume the loadable parts of the image to require fixed displacement
 737  *   - the image is not shareable
 738  */
 739 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 740                               struct file *file,
 741                               struct mm_struct *mm,
 742                               const char *what)
 743 {
 744         struct elf_fdpic_loadmap *loadmap;
 745 #ifdef CONFIG_MMU
 746         struct elf_fdpic_loadseg *mseg;
 747         unsigned long load_addr;
 748 #endif
 749         struct elf_fdpic_loadseg *seg;
 750         struct elf_phdr *phdr;
 751         unsigned nloads, tmp;
 752         unsigned long stop;
 753         int loop, ret;
 754
 755         /* allocate a load map table */
 756         nloads = 0;
 757         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 758                 if (params->phdrs[loop].p_type == PT_LOAD)
 759                         nloads++;
 760
 761         if (nloads == 0)
 762                 return -ELIBBAD;
 763
 764         loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL);
 765         if (!loadmap)
 766                 return -ENOMEM;
 767
 768         params->loadmap = loadmap;
 769
 770         loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
 771         loadmap->nsegs = nloads;
 772
 773         /* map the requested LOADs into the memory space */
 774         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 775         case ELF_FDPIC_FLAG_CONSTDISP:
 776         case ELF_FDPIC_FLAG_CONTIGUOUS:
 777 #ifndef CONFIG_MMU
 778                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 779                 if (ret < 0)
 780                         return ret;
 781                 break;
 782 #endif
 783         default:
 784                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 785                 if (ret < 0)
 786                         return ret;
 787                 break;
 788         }
 789
 790         /* map the entry point */
 791         if (params->hdr.e_entry) {
 792                 seg = loadmap->segs;
 793                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 794                         if (params->hdr.e_entry >= seg->p_vaddr &&
 795                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 796                                 params->entry_addr =
 797                                         (params->hdr.e_entry - seg->p_vaddr) +
 798                                         seg->addr;
 799                                 break;
 800                         }
 801                 }
 802         }
 803
 804         /* determine where the program header table has wound up if mapped */
 805         stop = params->hdr.e_phoff;
 806         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 807         phdr = params->phdrs;
 808
 809         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 810                 if (phdr->p_type != PT_LOAD)
 811                         continue;
 812
 813                 if (phdr->p_offset > params->hdr.e_phoff ||
 814                     phdr->p_offset + phdr->p_filesz < stop)
 815                         continue;
 816
 817                 seg = loadmap->segs;
 818                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 819                         if (phdr->p_vaddr >= seg->p_vaddr &&
 820                             phdr->p_vaddr + phdr->p_filesz <=
 821                             seg->p_vaddr + seg->p_memsz) {
 822                                 params->ph_addr =
 823                                         (phdr->p_vaddr - seg->p_vaddr) +
 824                                         seg->addr +
 825                                         params->hdr.e_phoff - phdr->p_offset;
 826                                 break;
 827                         }
 828                 }
 829                 break;
 830         }
 831
 832         /* determine where the dynamic section has wound up if there is one */
 833         phdr = params->phdrs;
 834         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 835                 if (phdr->p_type != PT_DYNAMIC)
 836                         continue;
 837
 838                 seg = loadmap->segs;
 839                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 840                         if (phdr->p_vaddr >= seg->p_vaddr &&
 841                             phdr->p_vaddr + phdr->p_memsz <=
 842                             seg->p_vaddr + seg->p_memsz) {
 843                                 Elf_Dyn __user *dyn;
 844                                 Elf_Sword d_tag;
 845
 846                                 params->dynamic_addr =
 847                                         (phdr->p_vaddr - seg->p_vaddr) +
 848                                         seg->addr;
 849
 850                                 /* check the dynamic section contains at least
 851                                  * one item, and that the last item is a NULL
 852                                  * entry */
 853                                 if (phdr->p_memsz == 0 ||
 854                                     phdr->p_memsz % sizeof(Elf_Dyn) != 0)
 855                                         goto dynamic_error;
 856
 857                                 tmp = phdr->p_memsz / sizeof(Elf_Dyn);
 858                                 dyn = (Elf_Dyn __user *)params->dynamic_addr;
 859                                 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
 860                                     d_tag != 0)
 861                                         goto dynamic_error;
 862                                 break;
 863                         }
 864                 }
 865                 break;
 866         }
 867
 868         /* now elide adjacent segments in the load map on MMU linux
 869          * - on uClinux the holes between may actually be filled with system
 870          *   stuff or stuff from other processes
 871          */
 872 #ifdef CONFIG_MMU
 873         nloads = loadmap->nsegs;
 874         mseg = loadmap->segs;
 875         seg = mseg + 1;
 876         for (loop = 1; loop < nloads; loop++) {
 877                 /* see if we have a candidate for merging */
 878                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 879                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 880                         if (load_addr == (seg->addr & PAGE_MASK)) {
 881                                 mseg->p_memsz +=
 882                                         load_addr -
 883                                         (mseg->addr + mseg->p_memsz);
 884                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 885                                 mseg->p_memsz += seg->p_memsz;
 886                                 loadmap->nsegs--;
 887                                 continue;
 888                         }
 889                 }
 890
 891                 mseg++;
 892                 if (mseg != seg)
 893                         *mseg = *seg;
 894         }
 895 #endif
 896
 897         kdebug("Mapped Object [%s]:", what);
 898         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 899         kdebug("- entry    : %lx", params->entry_addr);
 900         kdebug("- PHDR[]   : %lx", params->ph_addr);
 901         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 902         seg = loadmap->segs;
 903         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 904                 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]",
 905                        loop,
 906                        (unsigned long long) seg->addr,
 907                        (unsigned long long) seg->addr + seg->p_memsz - 1,
 908                        (unsigned long long) seg->p_vaddr,
 909                        (unsigned long long) seg->p_memsz);
 910
 911         return 0;
 912
 913 dynamic_error:
 914         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 915                what, file_inode(file)->i_ino);
 916         return -ELIBBAD;
 917 }
 918
 919 /*****************************************************************************/
 920 /*
 921  * map a file with constant displacement under uClinux
 922  */
 923 #ifndef CONFIG_MMU
 924 static int elf_fdpic_map_file_constdisp_on_uclinux(
 925         struct elf_fdpic_params *params,
 926         struct file *file,
 927         struct mm_struct *mm)
 928 {
 929         struct elf_fdpic_loadseg *seg;
 930         struct elf_phdr *phdr;
 931         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
 932         int loop, ret;
 933
 934         load_addr = params->load_addr;
 935         seg = params->loadmap->segs;
 936
 937         /* determine the bounds of the contiguous overall allocation we must
 938          * make */
 939         phdr = params->phdrs;
 940         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 941                 if (params->phdrs[loop].p_type != PT_LOAD)
 942                         continue;
 943
 944                 if (base > phdr->p_vaddr)
 945                         base = phdr->p_vaddr;
 946                 if (top < phdr->p_vaddr + phdr->p_memsz)
 947                         top = phdr->p_vaddr + phdr->p_memsz;
 948         }
 949
 950         /* allocate one big anon block for everything */
 951         maddr = vm_mmap(NULL, load_addr, top - base,
 952                         PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
 953         if (IS_ERR_VALUE(maddr))
 954                 return (int) maddr;
 955
 956         if (load_addr != 0)
 957                 load_addr += PAGE_ALIGN(top - base);
 958
 959         /* and then load the file segments into it */
 960         phdr = params->phdrs;
 961         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 962                 if (params->phdrs[loop].p_type != PT_LOAD)
 963                         continue;
 964
 965                 seg->addr = maddr + (phdr->p_vaddr - base);
 966                 seg->p_vaddr = phdr->p_vaddr;
 967                 seg->p_memsz = phdr->p_memsz;
 968
 969                 ret = read_code(file, seg->addr, phdr->p_offset,
 970                                        phdr->p_filesz);
 971                 if (ret < 0)
 972                         return ret;
 973
 974                 /* map the ELF header address if in this segment */
 975                 if (phdr->p_offset == 0)
 976                         params->elfhdr_addr = seg->addr;
 977
 978                 /* clear any space allocated but not loaded */
 979                 if (phdr->p_filesz < phdr->p_memsz) {
 980                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
 981                                        phdr->p_memsz - phdr->p_filesz))
 982                                 return -EFAULT;
 983                 }
 984
 985                 if (mm) {
 986                         if (phdr->p_flags & PF_X) {
 987                                 if (!mm->start_code) {
 988                                         mm->start_code = seg->addr;
 989                                         mm->end_code = seg->addr +
 990                                                 phdr->p_memsz;
 991                                 }
 992                         } else if (!mm->start_data) {
 993                                 mm->start_data = seg->addr;
 994                                 mm->end_data = seg->addr + phdr->p_memsz;
 995                         }
 996                 }
 997
 998                 seg++;
 999         }
1000
1001         return 0;
1002 }
1003 #endif
1004
1005 /*****************************************************************************/
1006 /*
1007  * map a binary by direct mmap() of the individual PT_LOAD segments
1008  */
1009 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1010                                              struct file *file,
1011                                              struct mm_struct *mm)
1012 {
1013         struct elf_fdpic_loadseg *seg;
1014         struct elf_phdr *phdr;
1015         unsigned long load_addr, delta_vaddr;
1016         int loop, dvset;
1017
1018         load_addr = params->load_addr;
1019         delta_vaddr = 0;
1020         dvset = 0;
1021
1022         seg = params->loadmap->segs;
1023
1024         /* deal with each load segment separately */
1025         phdr = params->phdrs;
1026         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1027                 unsigned long maddr, disp, excess, excess1;
1028                 int prot = 0, flags;
1029
1030                 if (phdr->p_type != PT_LOAD)
1031                         continue;
1032
1033                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1034                        (unsigned long) phdr->p_vaddr,
1035                        (unsigned long) phdr->p_offset,
1036                        (unsigned long) phdr->p_filesz,
1037                        (unsigned long) phdr->p_memsz);
1038
1039                 /* determine the mapping parameters */
1040                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1041                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1042                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1043
1044                 flags = MAP_PRIVATE;
1045                 maddr = 0;
1046
1047                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1048                 case ELF_FDPIC_FLAG_INDEPENDENT:
1049                         /* PT_LOADs are independently locatable */
1050                         break;
1051
1052                 case ELF_FDPIC_FLAG_HONOURVADDR:
1053                         /* the specified virtual address must be honoured */
1054                         maddr = phdr->p_vaddr;
1055                         flags |= MAP_FIXED;
1056                         break;
1057
1058                 case ELF_FDPIC_FLAG_CONSTDISP:
1059                         /* constant displacement
1060                          * - can be mapped anywhere, but must be mapped as a
1061                          *   unit
1062                          */
1063                         if (!dvset) {
1064                                 maddr = load_addr;
1065                                 delta_vaddr = phdr->p_vaddr;
1066                                 dvset = 1;
1067                         } else {
1068                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1069                                 flags |= MAP_FIXED;
1070                         }
1071                         break;
1072
1073                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1074                         /* contiguity handled later */
1075                         break;
1076
1077                 default:
1078                         BUG();
1079                 }
1080
1081                 maddr &= PAGE_MASK;
1082
1083                 /* create the mapping */
1084                 disp = phdr->p_vaddr & ~PAGE_MASK;
1085                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1086                                 phdr->p_offset - disp);
1087
1088                 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx",
1089                        loop, (unsigned long long) phdr->p_memsz + disp,
1090                        prot, flags, (unsigned long long) phdr->p_offset - disp,
1091                        maddr);
1092
1093                 if (IS_ERR_VALUE(maddr))
1094                         return (int) maddr;
1095
1096                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1097                     ELF_FDPIC_FLAG_CONTIGUOUS)
1098                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1099
1100                 seg->addr = maddr + disp;
1101                 seg->p_vaddr = phdr->p_vaddr;
1102                 seg->p_memsz = phdr->p_memsz;
1103
1104                 /* map the ELF header address if in this segment */
1105                 if (phdr->p_offset == 0)
1106                         params->elfhdr_addr = seg->addr;
1107
1108                 /* clear the bit between beginning of mapping and beginning of
1109                  * PT_LOAD */
1110                 if (prot & PROT_WRITE && disp > 0) {
1111                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1112                         if (clear_user((void __user *) maddr, disp))
1113                                 return -EFAULT;
1114                         maddr += disp;
1115                 }
1116
1117                 /* clear any space allocated but not loaded
1118                  * - on uClinux we can just clear the lot
1119                  * - on MMU linux we'll get a SIGBUS beyond the last page
1120                  *   extant in the file
1121                  */
1122                 excess = phdr->p_memsz - phdr->p_filesz;
1123                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1124
1125 #ifdef CONFIG_MMU
1126                 if (excess > excess1) {
1127                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1128                         unsigned long xmaddr;
1129
1130                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1131                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1132                                          prot, flags, 0);
1133
1134                         kdebug("mmap[%d] <anon>"
1135                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1136                                loop, xaddr, excess - excess1, prot, flags,
1137                                xmaddr);
1138
1139                         if (xmaddr != xaddr)
1140                                 return -ENOMEM;
1141                 }
1142
1143                 if (prot & PROT_WRITE && excess1 > 0) {
1144                         kdebug("clear[%d] ad=%lx sz=%lx",
1145                                loop, maddr + phdr->p_filesz, excess1);
1146                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1147                                        excess1))
1148                                 return -EFAULT;
1149                 }
1150
1151 #else
1152                 if (excess > 0) {
1153                         kdebug("clear[%d] ad=%llx sz=%lx", loop,
1154                                (unsigned long long) maddr + phdr->p_filesz,
1155                                excess);
1156                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1157                                 return -EFAULT;
1158                 }
1159 #endif
1160
1161                 if (mm) {
1162                         if (phdr->p_flags & PF_X) {
1163                                 if (!mm->start_code) {
1164                                         mm->start_code = maddr;
1165                                         mm->end_code = maddr + phdr->p_memsz;
1166                                 }
1167                         } else if (!mm->start_data) {
1168                                 mm->start_data = maddr;
1169                                 mm->end_data = maddr + phdr->p_memsz;
1170                         }
1171                 }
1172
1173                 seg++;
1174         }
1175
1176         return 0;
1177 }
1178
1179 /*****************************************************************************/
1180 /*
1181  * ELF-FDPIC core dumper
1182  *
1183  * Modelled on fs/exec.c:aout_core_dump()
1184  * Jeremy Fitzhardinge <[email protected]>
1185  *
1186  * Modelled on fs/binfmt_elf.c core dumper
1187  */
1188 #ifdef CONFIG_ELF_CORE
1189
1190 struct elf_prstatus_fdpic
1191 {
1192         struct elf_prstatus_common      common;
1193         elf_gregset_t pr_reg;   /* GP registers */
1194         /* When using FDPIC, the loadmap addresses need to be communicated
1195          * to GDB in order for GDB to do the necessary relocations.  The
1196          * fields (below) used to communicate this information are placed
1197          * immediately after ``pr_reg'', so that the loadmap addresses may
1198          * be viewed as part of the register set if so desired.
1199          */
1200         unsigned long pr_exec_fdpic_loadmap;
1201         unsigned long pr_interp_fdpic_loadmap;
1202         int pr_fpvalid;         /* True if math co-processor being used.  */
1203 };
1204
1205 /* An ELF note in memory */
1206 struct memelfnote
1207 {
1208         const char *name;
1209         int type;
1210         unsigned int datasz;
1211         void *data;
1212 };
1213
1214 static int notesize(struct memelfnote *en)
1215 {
1216         int sz;
1217
1218         sz = sizeof(struct elf_note);
1219         sz += roundup(strlen(en->name) + 1, 4);
1220         sz += roundup(en->datasz, 4);
1221
1222         return sz;
1223 }
1224
1225 /* #define DEBUG */
1226
1227 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1228 {
1229         struct elf_note en;
1230         en.n_namesz = strlen(men->name) + 1;
1231         en.n_descsz = men->datasz;
1232         en.n_type = men->type;
1233
1234         return dump_emit(cprm, &en, sizeof(en)) &&
1235                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1236                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1237 }
1238
1239 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1240 {
1241         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1242         elf->e_ident[EI_CLASS] = ELF_CLASS;
1243         elf->e_ident[EI_DATA] = ELF_DATA;
1244         elf->e_ident[EI_VERSION] = EV_CURRENT;
1245         elf->e_ident[EI_OSABI] = ELF_OSABI;
1246         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1247
1248         elf->e_type = ET_CORE;
1249         elf->e_machine = ELF_ARCH;
1250         elf->e_version = EV_CURRENT;
1251         elf->e_entry = 0;
1252         elf->e_phoff = sizeof(struct elfhdr);
1253         elf->e_shoff = 0;
1254         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1255         elf->e_ehsize = sizeof(struct elfhdr);
1256         elf->e_phentsize = sizeof(struct elf_phdr);
1257         elf->e_phnum = segs;
1258         elf->e_shentsize = 0;
1259         elf->e_shnum = 0;
1260         elf->e_shstrndx = 0;
1261         return;
1262 }
1263
1264 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1265 {
1266         phdr->p_type = PT_NOTE;
1267         phdr->p_offset = offset;
1268         phdr->p_vaddr = 0;
1269         phdr->p_paddr = 0;
1270         phdr->p_filesz = sz;
1271         phdr->p_memsz = 0;
1272         phdr->p_flags = 0;
1273         phdr->p_align = 4;
1274         return;
1275 }
1276
1277 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1278                 unsigned int sz, void *data)
1279 {
1280         note->name = name;
1281         note->type = type;
1282         note->datasz = sz;
1283         note->data = data;
1284         return;
1285 }
1286
1287 /*
1288  * fill up all the fields in prstatus from the given task struct, except
1289  * registers which need to be filled up separately.
1290  */
1291 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1292                           struct task_struct *p, long signr)
1293 {
1294         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1295         prstatus->pr_sigpend = p->pending.signal.sig[0];
1296         prstatus->pr_sighold = p->blocked.sig[0];
1297         rcu_read_lock();
1298         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1299         rcu_read_unlock();
1300         prstatus->pr_pid = task_pid_vnr(p);
1301         prstatus->pr_pgrp = task_pgrp_vnr(p);
1302         prstatus->pr_sid = task_session_vnr(p);
1303         if (thread_group_leader(p)) {
1304                 struct task_cputime cputime;
1305
1306                 /*
1307                  * This is the record for the group leader.  It shows the
1308                  * group-wide total, not its individual thread total.
1309                  */
1310                 thread_group_cputime(p, &cputime);
1311                 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1312                 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1313         } else {
1314                 u64 utime, stime;
1315
1316                 task_cputime(p, &utime, &stime);
1317                 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1318                 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1319         }
1320         prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1321         prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1322 }
1323
1324 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1325                        struct mm_struct *mm)
1326 {
1327         const struct cred *cred;
1328         unsigned int i, len;
1329         unsigned int state;
1330
1331         /* first copy the parameters from user space */
1332         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1333
1334         len = mm->arg_end - mm->arg_start;
1335         if (len >= ELF_PRARGSZ)
1336                 len = ELF_PRARGSZ - 1;
1337         if (copy_from_user(&psinfo->pr_psargs,
1338                            (const char __user *) mm->arg_start, len))
1339                 return -EFAULT;
1340         for (i = 0; i < len; i++)
1341                 if (psinfo->pr_psargs[i] == 0)
1342                         psinfo->pr_psargs[i] = ' ';
1343         psinfo->pr_psargs[len] = 0;
1344
1345         rcu_read_lock();
1346         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1347         rcu_read_unlock();
1348         psinfo->pr_pid = task_pid_vnr(p);
1349         psinfo->pr_pgrp = task_pgrp_vnr(p);
1350         psinfo->pr_sid = task_session_vnr(p);
1351
1352         state = READ_ONCE(p->__state);
1353         i = state ? ffz(~state) + 1 : 0;
1354         psinfo->pr_state = i;
1355         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1356         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1357         psinfo->pr_nice = task_nice(p);
1358         psinfo->pr_flag = p->flags;
1359         rcu_read_lock();
1360         cred = __task_cred(p);
1361         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1362         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1363         rcu_read_unlock();
1364         get_task_comm(psinfo->pr_fname, p);
1365
1366         return 0;
1367 }
1368
1369 /* Here is the structure in which status of each thread is captured. */
1370 struct elf_thread_status
1371 {
1372         struct elf_thread_status *next;
1373         struct elf_prstatus_fdpic prstatus;     /* NT_PRSTATUS */
1374         elf_fpregset_t fpu;             /* NT_PRFPREG */
1375         struct memelfnote notes[2];
1376         int num_notes;
1377 };
1378
1379 /*
1380  * In order to add the specific thread information for the elf file format,
1381  * we need to keep a linked list of every thread's pr_status and then create
1382  * a single section for them in the final core file.
1383  */
1384 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1385 {
1386         const struct user_regset_view *view = task_user_regset_view(p);
1387         struct elf_thread_status *t;
1388         int i, ret;
1389
1390         t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1391         if (!t)
1392                 return t;
1393
1394         fill_prstatus(&t->prstatus.common, p, signr);
1395         t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1396         t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1397         regset_get(p, &view->regsets[0],
1398                    sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1399
1400         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1401                   &t->prstatus);
1402         t->num_notes++;
1403         *sz += notesize(&t->notes[0]);
1404
1405         for (i = 1; i < view->n; ++i) {
1406                 const struct user_regset *regset = &view->regsets[i];
1407                 if (regset->core_note_type != NT_PRFPREG)
1408                         continue;
1409                 if (regset->active && regset->active(p, regset) <= 0)
1410                         continue;
1411                 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1412                 if (ret >= 0)
1413                         t->prstatus.pr_fpvalid = 1;
1414                 break;
1415         }
1416
1417         if (t->prstatus.pr_fpvalid) {
1418                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1419                           &t->fpu);
1420                 t->num_notes++;
1421                 *sz += notesize(&t->notes[1]);
1422         }
1423         return t;
1424 }
1425
1426 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1427                              elf_addr_t e_shoff, int segs)
1428 {
1429         elf->e_shoff = e_shoff;
1430         elf->e_shentsize = sizeof(*shdr4extnum);
1431         elf->e_shnum = 1;
1432         elf->e_shstrndx = SHN_UNDEF;
1433
1434         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1435
1436         shdr4extnum->sh_type = SHT_NULL;
1437         shdr4extnum->sh_size = elf->e_shnum;
1438         shdr4extnum->sh_link = elf->e_shstrndx;
1439         shdr4extnum->sh_info = segs;
1440 }
1441
1442 /*
1443  * dump the segments for an MMU process
1444  */
1445 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1446                                     struct core_vma_metadata *vma_meta,
1447                                     int vma_count)
1448 {
1449         int i;
1450
1451         for (i = 0; i < vma_count; i++) {
1452                 struct core_vma_metadata *meta = vma_meta + i;
1453
1454                 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1455                         return false;
1456         }
1457         return true;
1458 }
1459
1460 /*
1461  * Actual dumper
1462  *
1463  * This is a two-pass process; first we find the offsets of the bits,
1464  * and then they are actually written out.  If we run out of core limit
1465  * we just truncate.
1466  */
1467 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1468 {
1469         int has_dumped = 0;
1470         int segs;
1471         int i;
1472         struct elfhdr *elf = NULL;
1473         loff_t offset = 0, dataoff;
1474         struct memelfnote psinfo_note, auxv_note;
1475         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1476         struct elf_thread_status *thread_list = NULL;
1477         int thread_status_size = 0;
1478         elf_addr_t *auxv;
1479         struct elf_phdr *phdr4note = NULL;
1480         struct elf_shdr *shdr4extnum = NULL;
1481         Elf_Half e_phnum;
1482         elf_addr_t e_shoff;
1483         struct core_thread *ct;
1484         struct elf_thread_status *tmp;
1485
1486         /* alloc memory for large data structures: too large to be on stack */
1487         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1488         if (!elf)
1489                 goto end_coredump;
1490         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1491         if (!psinfo)
1492                 goto end_coredump;
1493
1494         for (ct = current->signal->core_state->dumper.next;
1495                                         ct; ct = ct->next) {
1496                 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1497                                              ct->task, &thread_status_size);
1498                 if (!tmp)
1499                         goto end_coredump;
1500
1501                 tmp->next = thread_list;
1502                 thread_list = tmp;
1503         }
1504
1505         /* now collect the dump for the current */
1506         tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1507                                      current, &thread_status_size);
1508         if (!tmp)
1509                 goto end_coredump;
1510         tmp->next = thread_list;
1511         thread_list = tmp;
1512
1513         segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1514
1515         /* for notes section */
1516         segs++;
1517
1518         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1519          * this, kernel supports extended numbering. Have a look at
1520          * include/linux/elf.h for further information. */
1521         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1522
1523         /* Set up header */
1524         fill_elf_fdpic_header(elf, e_phnum);
1525
1526         has_dumped = 1;
1527         /*
1528          * Set up the notes in similar form to SVR4 core dumps made
1529          * with info from their /proc.
1530          */
1531
1532         fill_psinfo(psinfo, current->group_leader, current->mm);
1533         fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1534         thread_status_size += notesize(&psinfo_note);
1535
1536         auxv = (elf_addr_t *) current->mm->saved_auxv;
1537         i = 0;
1538         do
1539                 i += 2;
1540         while (auxv[i - 2] != AT_NULL);
1541         fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1542         thread_status_size += notesize(&auxv_note);
1543
1544         offset = sizeof(*elf);                          /* ELF header */
1545         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1546
1547         /* Write notes phdr entry */
1548         phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1549         if (!phdr4note)
1550                 goto end_coredump;
1551
1552         fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1553         offset += thread_status_size;
1554
1555         /* Page-align dumped data */
1556         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1557
1558         offset += cprm->vma_data_size;
1559         offset += elf_core_extra_data_size(cprm);
1560         e_shoff = offset;
1561
1562         if (e_phnum == PN_XNUM) {
1563                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1564                 if (!shdr4extnum)
1565                         goto end_coredump;
1566                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1567         }
1568
1569         offset = dataoff;
1570
1571         if (!dump_emit(cprm, elf, sizeof(*elf)))
1572                 goto end_coredump;
1573
1574         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1575                 goto end_coredump;
1576
1577         /* write program headers for segments dump */
1578         for (i = 0; i < cprm->vma_count; i++) {
1579                 struct core_vma_metadata *meta = cprm->vma_meta + i;
1580                 struct elf_phdr phdr;
1581                 size_t sz;
1582
1583                 sz = meta->end - meta->start;
1584
1585                 phdr.p_type = PT_LOAD;
1586                 phdr.p_offset = offset;
1587                 phdr.p_vaddr = meta->start;
1588                 phdr.p_paddr = 0;
1589                 phdr.p_filesz = meta->dump_size;
1590                 phdr.p_memsz = sz;
1591                 offset += phdr.p_filesz;
1592                 phdr.p_flags = 0;
1593                 if (meta->flags & VM_READ)
1594                         phdr.p_flags |= PF_R;
1595                 if (meta->flags & VM_WRITE)
1596                         phdr.p_flags |= PF_W;
1597                 if (meta->flags & VM_EXEC)
1598                         phdr.p_flags |= PF_X;
1599                 phdr.p_align = ELF_EXEC_PAGESIZE;
1600
1601                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1602                         goto end_coredump;
1603         }
1604
1605         if (!elf_core_write_extra_phdrs(cprm, offset))
1606                 goto end_coredump;
1607
1608         /* write out the notes section */
1609         if (!writenote(thread_list->notes, cprm))
1610                 goto end_coredump;
1611         if (!writenote(&psinfo_note, cprm))
1612                 goto end_coredump;
1613         if (!writenote(&auxv_note, cprm))
1614                 goto end_coredump;
1615         for (i = 1; i < thread_list->num_notes; i++)
1616                 if (!writenote(thread_list->notes + i, cprm))
1617                         goto end_coredump;
1618
1619         /* write out the thread status notes section */
1620         for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1621                 for (i = 0; i < tmp->num_notes; i++)
1622                         if (!writenote(&tmp->notes[i], cprm))
1623                                 goto end_coredump;
1624         }
1625
1626         dump_skip_to(cprm, dataoff);
1627
1628         if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1629                 goto end_coredump;
1630
1631         if (!elf_core_write_extra_data(cprm))
1632                 goto end_coredump;
1633
1634         if (e_phnum == PN_XNUM) {
1635                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1636                         goto end_coredump;
1637         }
1638
1639         if (cprm->file->f_pos != offset) {
1640                 /* Sanity check */
1641                 printk(KERN_WARNING
1642                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1643                        cprm->file->f_pos, offset);
1644         }
1645
1646 end_coredump:
1647         while (thread_list) {
1648                 tmp = thread_list;
1649                 thread_list = thread_list->next;
1650                 kfree(tmp);
1651         }
1652         kfree(phdr4note);
1653         kfree(elf);
1654         kfree(psinfo);
1655         kfree(shdr4extnum);
1656         return has_dumped;
1657 }
1658
1659 #endif          /* CONFIG_ELF_CORE */