arch/powerpc/kernel/vdso.c

   1 /*
   2  *  linux/arch/ppc64/kernel/vdso.c
   3  *
   4  *    Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
   5  *                       <benh@kernel.crashing.org>
   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/config.h>
  14 #include <linux/module.h>
  15 #include <linux/errno.h>
  16 #include <linux/sched.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mm.h>
  19 #include <linux/smp.h>
  20 #include <linux/smp_lock.h>
  21 #include <linux/stddef.h>
  22 #include <linux/unistd.h>
  23 #include <linux/slab.h>
  24 #include <linux/user.h>
  25 #include <linux/elf.h>
  26 #include <linux/security.h>
  27 #include <linux/bootmem.h>
  28
  29 #include <asm/pgtable.h>
  30 #include <asm/system.h>
  31 #include <asm/processor.h>
  32 #include <asm/mmu.h>
  33 #include <asm/mmu_context.h>
  34 #include <asm/lmb.h>
  35 #include <asm/machdep.h>
  36 #include <asm/cputable.h>
  37 #include <asm/sections.h>
  38 #include <asm/vdso.h>
  39 #include <asm/vdso_datapage.h>
  40
  41 #undef DEBUG
  42
  43 #ifdef DEBUG
  44 #define DBG(fmt...) printk(fmt)
  45 #else
  46 #define DBG(fmt...)
  47 #endif
  48
  49 /* Max supported size for symbol names */
  50 #define MAX_SYMNAME     64
  51
  52 extern char vdso32_start, vdso32_end;
  53 static void *vdso32_kbase = &vdso32_start;
  54 unsigned int vdso32_pages;
  55 unsigned long vdso32_sigtramp;
  56 unsigned long vdso32_rt_sigtramp;
  57
  58 #ifdef CONFIG_PPC64
  59 extern char vdso64_start, vdso64_end;
  60 static void *vdso64_kbase = &vdso64_start;
  61 unsigned int vdso64_pages;
  62 unsigned long vdso64_rt_sigtramp;
  63 #endif /* CONFIG_PPC64 */
  64
  65 /*
  66  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
  67  * Once the early boot kernel code no longer needs to muck around
  68  * with it, it will become dynamically allocated
  69  */
  70 static union {
  71         struct vdso_data        data;
  72         u8                      page[PAGE_SIZE];
  73 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
  74 struct vdso_data *vdso_data = &vdso_data_store.data;
  75
  76 /* Format of the patch table */
  77 struct vdso_patch_def
  78 {
  79         unsigned long   ftr_mask, ftr_value;
  80         const char      *gen_name;
  81         const char      *fix_name;
  82 };
  83
  84 /* Table of functions to patch based on the CPU type/revision
  85  *
  86  * Currently, we only change sync_dicache to do nothing on processors
  87  * with a coherent icache
  88  */
  89 static struct vdso_patch_def vdso_patches[] = {
  90         {
  91                 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
  92                 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
  93         },
  94         {
  95                 CPU_FTR_USE_TB, 0,
  96                 "__kernel_gettimeofday", NULL
  97         },
  98 };
  99
 100 /*
 101  * Some infos carried around for each of them during parsing at
 102  * boot time.
 103  */
 104 struct lib32_elfinfo
 105 {
 106         Elf32_Ehdr      *hdr;           /* ptr to ELF */
 107         Elf32_Sym       *dynsym;        /* ptr to .dynsym section */
 108         unsigned long   dynsymsize;     /* size of .dynsym section */
 109         char            *dynstr;        /* ptr to .dynstr section */
 110         unsigned long   text;           /* offset of .text section in .so */
 111 };
 112
 113 struct lib64_elfinfo
 114 {
 115         Elf64_Ehdr      *hdr;
 116         Elf64_Sym       *dynsym;
 117         unsigned long   dynsymsize;
 118         char            *dynstr;
 119         unsigned long   text;
 120 };
 121
 122
 123 #ifdef __DEBUG
 124 static void dump_one_vdso_page(struct page *pg, struct page *upg)
 125 {
 126         printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
 127                page_count(pg),
 128                pg->flags);
 129         if (upg/* && pg != upg*/) {
 130                 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
 131                                                        << PAGE_SHIFT),
 132                        page_count(upg),
 133                        upg->flags);
 134         }
 135         printk("\n");
 136 }
 137
 138 static void dump_vdso_pages(struct vm_area_struct * vma)
 139 {
 140         int i;
 141
 142         if (!vma || test_thread_flag(TIF_32BIT)) {
 143                 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
 144                 for (i=0; i<vdso32_pages; i++) {
 145                         struct page *pg = virt_to_page(vdso32_kbase +
 146                                                        i*PAGE_SIZE);
 147                         struct page *upg = (vma && vma->vm_mm) ?
 148                                 follow_page(vma->vm_mm, vma->vm_start +
 149                                             i*PAGE_SIZE, 0)
 150                                 : NULL;
 151                         dump_one_vdso_page(pg, upg);
 152                 }
 153         }
 154         if (!vma || !test_thread_flag(TIF_32BIT)) {
 155                 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
 156                 for (i=0; i<vdso64_pages; i++) {
 157                         struct page *pg = virt_to_page(vdso64_kbase +
 158                                                        i*PAGE_SIZE);
 159                         struct page *upg = (vma && vma->vm_mm) ?
 160                                 follow_page(vma->vm_mm, vma->vm_start +
 161                                             i*PAGE_SIZE, 0)
 162                                 : NULL;
 163                         dump_one_vdso_page(pg, upg);
 164                 }
 165         }
 166 }
 167 #endif /* DEBUG */
 168
 169 /*
 170  * Keep a dummy vma_close for now, it will prevent VMA merging.
 171  */
 172 static void vdso_vma_close(struct vm_area_struct * vma)
 173 {
 174 }
 175
 176 /*
 177  * Our nopage() function, maps in the actual vDSO kernel pages, they will
 178  * be mapped read-only by do_no_page(), and eventually COW'ed, either
 179  * right away for an initial write access, or by do_wp_page().
 180  */
 181 static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
 182                                      unsigned long address, int *type)
 183 {
 184         unsigned long offset = address - vma->vm_start;
 185         struct page *pg;
 186 #ifdef CONFIG_PPC64
 187         void *vbase = test_thread_flag(TIF_32BIT) ?
 188                 vdso32_kbase : vdso64_kbase;
 189 #else
 190         void *vbase = vdso32_kbase;
 191 #endif
 192
 193         DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
 194             current->comm, address, offset);
 195
 196         if (address < vma->vm_start || address > vma->vm_end)
 197                 return NOPAGE_SIGBUS;
 198
 199         /*
 200          * Last page is systemcfg.
 201          */
 202         if ((vma->vm_end - address) <= PAGE_SIZE)
 203                 pg = virt_to_page(vdso_data);
 204         else
 205                 pg = virt_to_page(vbase + offset);
 206
 207         get_page(pg);
 208         DBG(" ->page count: %d\n", page_count(pg));
 209
 210         return pg;
 211 }
 212
 213 static struct vm_operations_struct vdso_vmops = {
 214         .close  = vdso_vma_close,
 215         .nopage = vdso_vma_nopage,
 216 };
 217
 218 /*
 219  * This is called from binfmt_elf, we create the special vma for the
 220  * vDSO and insert it into the mm struct tree
 221  */
 222 int arch_setup_additional_pages(struct linux_binprm *bprm,
 223                                 int executable_stack)
 224 {
 225         struct mm_struct *mm = current->mm;
 226         struct vm_area_struct *vma;
 227         unsigned long vdso_pages;
 228         unsigned long vdso_base;
 229
 230 #ifdef CONFIG_PPC64
 231         if (test_thread_flag(TIF_32BIT)) {
 232                 vdso_pages = vdso32_pages;
 233                 vdso_base = VDSO32_MBASE;
 234         } else {
 235                 vdso_pages = vdso64_pages;
 236                 vdso_base = VDSO64_MBASE;
 237         }
 238 #else
 239         vdso_pages = vdso32_pages;
 240         vdso_base = VDSO32_MBASE;
 241 #endif
 242
 243         current->thread.vdso_base = 0;
 244
 245         /* vDSO has a problem and was disabled, just don't "enable" it for the
 246          * process
 247          */
 248         if (vdso_pages == 0)
 249                 return 0;
 250
 251         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 252         if (vma == NULL)
 253                 return -ENOMEM;
 254
 255         memset(vma, 0, sizeof(*vma));
 256
 257         /* Add a page to the vdso size for the data page */
 258         vdso_pages ++;
 259
 260         /*
 261          * pick a base address for the vDSO in process space. We try to put it
 262          * at vdso_base which is the "natural" base for it, but we might fail
 263          * and end up putting it elsewhere.
 264          */
 265         vdso_base = get_unmapped_area(NULL, vdso_base,
 266                                       vdso_pages << PAGE_SHIFT, 0, 0);
 267         if (vdso_base & ~PAGE_MASK) {
 268                 kmem_cache_free(vm_area_cachep, vma);
 269                 return (int)vdso_base;
 270         }
 271
 272         current->thread.vdso_base = vdso_base;
 273
 274         vma->vm_mm = mm;
 275         vma->vm_start = current->thread.vdso_base;
 276         vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
 277
 278         /*
 279          * our vma flags don't have VM_WRITE so by default, the process isn't
 280          * allowed to write those pages.
 281          * gdb can break that with ptrace interface, and thus trigger COW on
 282          * those pages but it's then your responsibility to never do that on
 283          * the "data" page of the vDSO or you'll stop getting kernel updates
 284          * and your nice userland gettimeofday will be totally dead.
 285          * It's fine to use that for setting breakpoints in the vDSO code
 286          * pages though
 287          */
 288         vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
 289         vma->vm_flags |= mm->def_flags;
 290         vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
 291         vma->vm_ops = &vdso_vmops;
 292
 293         down_write(&mm->mmap_sem);
 294         if (insert_vm_struct(mm, vma)) {
 295                 up_write(&mm->mmap_sem);
 296                 kmem_cache_free(vm_area_cachep, vma);
 297                 return -ENOMEM;
 298         }
 299         mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 300         up_write(&mm->mmap_sem);
 301
 302         return 0;
 303 }
 304
 305 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
 306                                   unsigned long *size)
 307 {
 308         Elf32_Shdr *sechdrs;
 309         unsigned int i;
 310         char *secnames;
 311
 312         /* Grab section headers and strings so we can tell who is who */
 313         sechdrs = (void *)ehdr + ehdr->e_shoff;
 314         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 315
 316         /* Find the section they want */
 317         for (i = 1; i < ehdr->e_shnum; i++) {
 318                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 319                         if (size)
 320                                 *size = sechdrs[i].sh_size;
 321                         return (void *)ehdr + sechdrs[i].sh_offset;
 322                 }
 323         }
 324         *size = 0;
 325         return NULL;
 326 }
 327
 328 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
 329                                         const char *symname)
 330 {
 331         unsigned int i;
 332         char name[MAX_SYMNAME], *c;
 333
 334         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
 335                 if (lib->dynsym[i].st_name == 0)
 336                         continue;
 337                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 338                         MAX_SYMNAME);
 339                 c = strchr(name, '@');
 340                 if (c)
 341                         *c = 0;
 342                 if (strcmp(symname, name) == 0)
 343                         return &lib->dynsym[i];
 344         }
 345         return NULL;
 346 }
 347
 348 /* Note that we assume the section is .text and the symbol is relative to
 349  * the library base
 350  */
 351 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 352                                             const char *symname)
 353 {
 354         Elf32_Sym *sym = find_symbol32(lib, symname);
 355
 356         if (sym == NULL) {
 357                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
 358                        symname);
 359                 return 0;
 360         }
 361         return sym->st_value - VDSO32_LBASE;
 362 }
 363
 364 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
 365                                 struct lib64_elfinfo *v64,
 366                                 const char *orig, const char *fix)
 367 {
 368         Elf32_Sym *sym32_gen, *sym32_fix;
 369
 370         sym32_gen = find_symbol32(v32, orig);
 371         if (sym32_gen == NULL) {
 372                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
 373                 return -1;
 374         }
 375         if (fix == NULL) {
 376                 sym32_gen->st_name = 0;
 377                 return 0;
 378         }
 379         sym32_fix = find_symbol32(v32, fix);
 380         if (sym32_fix == NULL) {
 381                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
 382                 return -1;
 383         }
 384         sym32_gen->st_value = sym32_fix->st_value;
 385         sym32_gen->st_size = sym32_fix->st_size;
 386         sym32_gen->st_info = sym32_fix->st_info;
 387         sym32_gen->st_other = sym32_fix->st_other;
 388         sym32_gen->st_shndx = sym32_fix->st_shndx;
 389
 390         return 0;
 391 }
 392
 393
 394 #ifdef CONFIG_PPC64
 395
 396 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
 397                                   unsigned long *size)
 398 {
 399         Elf64_Shdr *sechdrs;
 400         unsigned int i;
 401         char *secnames;
 402
 403         /* Grab section headers and strings so we can tell who is who */
 404         sechdrs = (void *)ehdr + ehdr->e_shoff;
 405         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 406
 407         /* Find the section they want */
 408         for (i = 1; i < ehdr->e_shnum; i++) {
 409                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 410                         if (size)
 411                                 *size = sechdrs[i].sh_size;
 412                         return (void *)ehdr + sechdrs[i].sh_offset;
 413                 }
 414         }
 415         if (size)
 416                 *size = 0;
 417         return NULL;
 418 }
 419
 420 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
 421                                         const char *symname)
 422 {
 423         unsigned int i;
 424         char name[MAX_SYMNAME], *c;
 425
 426         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
 427                 if (lib->dynsym[i].st_name == 0)
 428                         continue;
 429                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 430                         MAX_SYMNAME);
 431                 c = strchr(name, '@');
 432                 if (c)
 433                         *c = 0;
 434                 if (strcmp(symname, name) == 0)
 435                         return &lib->dynsym[i];
 436         }
 437         return NULL;
 438 }
 439
 440 /* Note that we assume the section is .text and the symbol is relative to
 441  * the library base
 442  */
 443 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
 444                                             const char *symname)
 445 {
 446         Elf64_Sym *sym = find_symbol64(lib, symname);
 447
 448         if (sym == NULL) {
 449                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
 450                        symname);
 451                 return 0;
 452         }
 453 #ifdef VDS64_HAS_DESCRIPTORS
 454         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
 455                 VDSO64_LBASE;
 456 #else
 457         return sym->st_value - VDSO64_LBASE;
 458 #endif
 459 }
 460
 461 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
 462                                 struct lib64_elfinfo *v64,
 463                                 const char *orig, const char *fix)
 464 {
 465         Elf64_Sym *sym64_gen, *sym64_fix;
 466
 467         sym64_gen = find_symbol64(v64, orig);
 468         if (sym64_gen == NULL) {
 469                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
 470                 return -1;
 471         }
 472         if (fix == NULL) {
 473                 sym64_gen->st_name = 0;
 474                 return 0;
 475         }
 476         sym64_fix = find_symbol64(v64, fix);
 477         if (sym64_fix == NULL) {
 478                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
 479                 return -1;
 480         }
 481         sym64_gen->st_value = sym64_fix->st_value;
 482         sym64_gen->st_size = sym64_fix->st_size;
 483         sym64_gen->st_info = sym64_fix->st_info;
 484         sym64_gen->st_other = sym64_fix->st_other;
 485         sym64_gen->st_shndx = sym64_fix->st_shndx;
 486
 487         return 0;
 488 }
 489
 490 #endif /* CONFIG_PPC64 */
 491
 492
 493 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
 494                                         struct lib64_elfinfo *v64)
 495 {
 496         void *sect;
 497
 498         /*
 499          * Locate symbol tables & text section
 500          */
 501
 502         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
 503         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
 504         if (v32->dynsym == NULL || v32->dynstr == NULL) {
 505                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
 506                 return -1;
 507         }
 508         sect = find_section32(v32->hdr, ".text", NULL);
 509         if (sect == NULL) {
 510                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
 511                 return -1;
 512         }
 513         v32->text = sect - vdso32_kbase;
 514
 515 #ifdef CONFIG_PPC64
 516         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
 517         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
 518         if (v64->dynsym == NULL || v64->dynstr == NULL) {
 519                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
 520                 return -1;
 521         }
 522         sect = find_section64(v64->hdr, ".text", NULL);
 523         if (sect == NULL) {
 524                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
 525                 return -1;
 526         }
 527         v64->text = sect - vdso64_kbase;
 528 #endif /* CONFIG_PPC64 */
 529
 530         return 0;
 531 }
 532
 533 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
 534                                           struct lib64_elfinfo *v64)
 535 {
 536         /*
 537          * Find signal trampolines
 538          */
 539
 540 #ifdef CONFIG_PPC64
 541         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
 542 #endif
 543         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
 544         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
 545 }
 546
 547 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
 548                                        struct lib64_elfinfo *v64)
 549 {
 550         Elf32_Sym *sym32;
 551 #ifdef CONFIG_PPC64
 552         Elf64_Sym *sym64;
 553
 554         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
 555         if (sym64 == NULL) {
 556                 printk(KERN_ERR "vDSO64: Can't find symbol "
 557                        "__kernel_datapage_offset !\n");
 558                 return -1;
 559         }
 560         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
 561                 (vdso64_pages << PAGE_SHIFT) -
 562                 (sym64->st_value - VDSO64_LBASE);
 563 #endif /* CONFIG_PPC64 */
 564
 565         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
 566         if (sym32 == NULL) {
 567                 printk(KERN_ERR "vDSO32: Can't find symbol "
 568                        "__kernel_datapage_offset !\n");
 569                 return -1;
 570         }
 571         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
 572                 (vdso32_pages << PAGE_SHIFT) -
 573                 (sym32->st_value - VDSO32_LBASE);
 574
 575         return 0;
 576 }
 577
 578 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
 579                                        struct lib64_elfinfo *v64)
 580 {
 581         int i;
 582
 583         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
 584                 struct vdso_patch_def *patch = &vdso_patches[i];
 585                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
 586                         == patch->ftr_value;
 587                 if (!match)
 588                         continue;
 589
 590                 DBG("replacing %s with %s...\n", patch->gen_name,
 591                     patch->fix_name ? "NONE" : patch->fix_name);
 592
 593                 /*
 594                  * Patch the 32 bits and 64 bits symbols. Note that we do not
 595                  * patch the "." symbol on 64 bits.
 596                  * It would be easy to do, but doesn't seem to be necessary,
 597                  * patching the OPD symbol is enough.
 598                  */
 599                 vdso_do_func_patch32(v32, v64, patch->gen_name,
 600                                      patch->fix_name);
 601 #ifdef CONFIG_PPC64
 602                 vdso_do_func_patch64(v32, v64, patch->gen_name,
 603                                      patch->fix_name);
 604 #endif /* CONFIG_PPC64 */
 605         }
 606
 607         return 0;
 608 }
 609
 610
 611 static __init int vdso_setup(void)
 612 {
 613         struct lib32_elfinfo    v32;
 614         struct lib64_elfinfo    v64;
 615
 616         v32.hdr = vdso32_kbase;
 617 #ifdef CONFIG_PPC64
 618         v64.hdr = vdso64_kbase;
 619 #endif
 620         if (vdso_do_find_sections(&v32, &v64))
 621                 return -1;
 622
 623         if (vdso_fixup_datapage(&v32, &v64))
 624                 return -1;
 625
 626         if (vdso_fixup_alt_funcs(&v32, &v64))
 627                 return -1;
 628
 629         vdso_setup_trampolines(&v32, &v64);
 630
 631         return 0;
 632 }
 633
 634 /*
 635  * Called from setup_arch to initialize the bitmap of available
 636  * syscalls in the systemcfg page
 637  */
 638 static void __init vdso_setup_syscall_map(void)
 639 {
 640         unsigned int i;
 641         extern unsigned long *sys_call_table;
 642         extern unsigned long sys_ni_syscall;
 643
 644
 645         for (i = 0; i < __NR_syscalls; i++) {
 646 #ifdef CONFIG_PPC64
 647                 if (sys_call_table[i*2] != sys_ni_syscall)
 648                         vdso_data->syscall_map_64[i >> 5] |=
 649                                 0x80000000UL >> (i & 0x1f);
 650                 if (sys_call_table[i*2+1] != sys_ni_syscall)
 651                         vdso_data->syscall_map_32[i >> 5] |=
 652                                 0x80000000UL >> (i & 0x1f);
 653 #else /* CONFIG_PPC64 */
 654                 if (sys_call_table[i] != sys_ni_syscall)
 655                         vdso_data->syscall_map_32[i >> 5] |=
 656                                 0x80000000UL >> (i & 0x1f);
 657 #endif /* CONFIG_PPC64 */
 658         }
 659 }
 660
 661
 662 void __init vdso_init(void)
 663 {
 664         int i;
 665
 666 #ifdef CONFIG_PPC64
 667         /*
 668          * Fill up the "systemcfg" stuff for backward compatiblity
 669          */
 670         strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
 671         vdso_data->version.major = SYSTEMCFG_MAJOR;
 672         vdso_data->version.minor = SYSTEMCFG_MINOR;
 673         vdso_data->processor = mfspr(SPRN_PVR);
 674         vdso_data->platform = _machine;
 675         vdso_data->physicalMemorySize = lmb_phys_mem_size();
 676         vdso_data->dcache_size = ppc64_caches.dsize;
 677         vdso_data->dcache_line_size = ppc64_caches.dline_size;
 678         vdso_data->icache_size = ppc64_caches.isize;
 679         vdso_data->icache_line_size = ppc64_caches.iline_size;
 680
 681         /*
 682          * Calculate the size of the 64 bits vDSO
 683          */
 684         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
 685         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
 686 #endif /* CONFIG_PPC64 */
 687
 688
 689         /*
 690          * Calculate the size of the 32 bits vDSO
 691          */
 692         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
 693         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
 694
 695
 696         /*
 697          * Setup the syscall map in the vDOS
 698          */
 699         vdso_setup_syscall_map();
 700         /*
 701          * Initialize the vDSO images in memory, that is do necessary
 702          * fixups of vDSO symbols, locate trampolines, etc...
 703          */
 704         if (vdso_setup()) {
 705                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
 706                 vdso32_pages = 0;
 707 #ifdef CONFIG_PPC64
 708                 vdso64_pages = 0;
 709 #endif
 710                 return;
 711         }
 712
 713         /* Make sure pages are in the correct state */
 714         for (i = 0; i < vdso32_pages; i++) {
 715                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
 716                 ClearPageReserved(pg);
 717                 get_page(pg);
 718
 719         }
 720 #ifdef CONFIG_PPC64
 721         for (i = 0; i < vdso64_pages; i++) {
 722                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
 723                 ClearPageReserved(pg);
 724                 get_page(pg);
 725         }
 726 #endif /* CONFIG_PPC64 */
 727
 728         get_page(virt_to_page(vdso_data));
 729 }
 730
 731 int in_gate_area_no_task(unsigned long addr)
 732 {
 733         return 0;
 734 }
 735
 736 int in_gate_area(struct task_struct *task, unsigned long addr)
 737 {
 738         return 0;
 739 }
 740
 741 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 742 {
 743         return NULL;
 744 }
 745