arch/powerpc/kernel/vdso.c

   1 /*
   2  *    Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
   3  *                       <benh@kernel.crashing.org>
   4  *
   5  *  This program is free software; you can redistribute it and/or
   6  *  modify it under the terms of the GNU General Public License
   7  *  as published by the Free Software Foundation; either version
   8  *  2 of the License, or (at your option) any later version.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/errno.h>
  13 #include <linux/sched.h>
  14 #include <linux/kernel.h>
  15 #include <linux/mm.h>
  16 #include <linux/smp.h>
  17 #include <linux/smp_lock.h>
  18 #include <linux/stddef.h>
  19 #include <linux/unistd.h>
  20 #include <linux/slab.h>
  21 #include <linux/user.h>
  22 #include <linux/elf.h>
  23 #include <linux/security.h>
  24 #include <linux/bootmem.h>
  25
  26 #include <asm/pgtable.h>
  27 #include <asm/system.h>
  28 #include <asm/processor.h>
  29 #include <asm/mmu.h>
  30 #include <asm/mmu_context.h>
  31 #include <asm/lmb.h>
  32 #include <asm/machdep.h>
  33 #include <asm/cputable.h>
  34 #include <asm/sections.h>
  35 #include <asm/firmware.h>
  36 #include <asm/vdso.h>
  37 #include <asm/vdso_datapage.h>
  38
  39 #undef DEBUG
  40
  41 #ifdef DEBUG
  42 #define DBG(fmt...) printk(fmt)
  43 #else
  44 #define DBG(fmt...)
  45 #endif
  46
  47 /* Max supported size for symbol names */
  48 #define MAX_SYMNAME     64
  49
  50 extern char vdso32_start, vdso32_end;
  51 static void *vdso32_kbase = &vdso32_start;
  52 unsigned int vdso32_pages;
  53 unsigned long vdso32_sigtramp;
  54 unsigned long vdso32_rt_sigtramp;
  55
  56 #ifdef CONFIG_PPC64
  57 extern char vdso64_start, vdso64_end;
  58 static void *vdso64_kbase = &vdso64_start;
  59 unsigned int vdso64_pages;
  60 unsigned long vdso64_rt_sigtramp;
  61 #endif /* CONFIG_PPC64 */
  62
  63 /*
  64  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
  65  * Once the early boot kernel code no longer needs to muck around
  66  * with it, it will become dynamically allocated
  67  */
  68 static union {
  69         struct vdso_data        data;
  70         u8                      page[PAGE_SIZE];
  71 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
  72 struct vdso_data *vdso_data = &vdso_data_store.data;
  73
  74 /* Format of the patch table */
  75 struct vdso_patch_def
  76 {
  77         unsigned long   ftr_mask, ftr_value;
  78         const char      *gen_name;
  79         const char      *fix_name;
  80 };
  81
  82 /* Table of functions to patch based on the CPU type/revision
  83  *
  84  * Currently, we only change sync_dicache to do nothing on processors
  85  * with a coherent icache
  86  */
  87 static struct vdso_patch_def vdso_patches[] = {
  88         {
  89                 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
  90                 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
  91         },
  92         {
  93                 CPU_FTR_USE_TB, 0,
  94                 "__kernel_gettimeofday", NULL
  95         },
  96 };
  97
  98 /*
  99  * Some infos carried around for each of them during parsing at
 100  * boot time.
 101  */
 102 struct lib32_elfinfo
 103 {
 104         Elf32_Ehdr      *hdr;           /* ptr to ELF */
 105         Elf32_Sym       *dynsym;        /* ptr to .dynsym section */
 106         unsigned long   dynsymsize;     /* size of .dynsym section */
 107         char            *dynstr;        /* ptr to .dynstr section */
 108         unsigned long   text;           /* offset of .text section in .so */
 109 };
 110
 111 struct lib64_elfinfo
 112 {
 113         Elf64_Ehdr      *hdr;
 114         Elf64_Sym       *dynsym;
 115         unsigned long   dynsymsize;
 116         char            *dynstr;
 117         unsigned long   text;
 118 };
 119
 120
 121 #ifdef __DEBUG
 122 static void dump_one_vdso_page(struct page *pg, struct page *upg)
 123 {
 124         printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
 125                page_count(pg),
 126                pg->flags);
 127         if (upg/* && pg != upg*/) {
 128                 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
 129                                                        << PAGE_SHIFT),
 130                        page_count(upg),
 131                        upg->flags);
 132         }
 133         printk("\n");
 134 }
 135
 136 static void dump_vdso_pages(struct vm_area_struct * vma)
 137 {
 138         int i;
 139
 140         if (!vma || test_thread_flag(TIF_32BIT)) {
 141                 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
 142                 for (i=0; i<vdso32_pages; i++) {
 143                         struct page *pg = virt_to_page(vdso32_kbase +
 144                                                        i*PAGE_SIZE);
 145                         struct page *upg = (vma && vma->vm_mm) ?
 146                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
 147                                 : NULL;
 148                         dump_one_vdso_page(pg, upg);
 149                 }
 150         }
 151         if (!vma || !test_thread_flag(TIF_32BIT)) {
 152                 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
 153                 for (i=0; i<vdso64_pages; i++) {
 154                         struct page *pg = virt_to_page(vdso64_kbase +
 155                                                        i*PAGE_SIZE);
 156                         struct page *upg = (vma && vma->vm_mm) ?
 157                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
 158                                 : NULL;
 159                         dump_one_vdso_page(pg, upg);
 160                 }
 161         }
 162 }
 163 #endif /* DEBUG */
 164
 165 /*
 166  * Keep a dummy vma_close for now, it will prevent VMA merging.
 167  */
 168 static void vdso_vma_close(struct vm_area_struct * vma)
 169 {
 170 }
 171
 172 /*
 173  * Our nopage() function, maps in the actual vDSO kernel pages, they will
 174  * be mapped read-only by do_no_page(), and eventually COW'ed, either
 175  * right away for an initial write access, or by do_wp_page().
 176  */
 177 static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
 178                                      unsigned long address, int *type)
 179 {
 180         unsigned long offset = address - vma->vm_start;
 181         struct page *pg;
 182 #ifdef CONFIG_PPC64
 183         void *vbase = (vma->vm_mm->task_size > TASK_SIZE_USER32) ?
 184                 vdso64_kbase : vdso32_kbase;
 185 #else
 186         void *vbase = vdso32_kbase;
 187 #endif
 188
 189         DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
 190             current->comm, address, offset);
 191
 192         if (address < vma->vm_start || address > vma->vm_end)
 193                 return NOPAGE_SIGBUS;
 194
 195         /*
 196          * Last page is systemcfg.
 197          */
 198         if ((vma->vm_end - address) <= PAGE_SIZE)
 199                 pg = virt_to_page(vdso_data);
 200         else
 201                 pg = virt_to_page(vbase + offset);
 202
 203         get_page(pg);
 204         DBG(" ->page count: %d\n", page_count(pg));
 205
 206         return pg;
 207 }
 208
 209 static struct vm_operations_struct vdso_vmops = {
 210         .close  = vdso_vma_close,
 211         .nopage = vdso_vma_nopage,
 212 };
 213
 214 /*
 215  * This is called from binfmt_elf, we create the special vma for the
 216  * vDSO and insert it into the mm struct tree
 217  */
 218 int arch_setup_additional_pages(struct linux_binprm *bprm,
 219                                 int executable_stack)
 220 {
 221         struct mm_struct *mm = current->mm;
 222         struct vm_area_struct *vma;
 223         unsigned long vdso_pages;
 224         unsigned long vdso_base;
 225         int rc;
 226
 227 #ifdef CONFIG_PPC64
 228         if (test_thread_flag(TIF_32BIT)) {
 229                 vdso_pages = vdso32_pages;
 230                 vdso_base = VDSO32_MBASE;
 231         } else {
 232                 vdso_pages = vdso64_pages;
 233                 vdso_base = VDSO64_MBASE;
 234         }
 235 #else
 236         vdso_pages = vdso32_pages;
 237         vdso_base = VDSO32_MBASE;
 238 #endif
 239
 240         current->mm->context.vdso_base = 0;
 241
 242         /* vDSO has a problem and was disabled, just don't "enable" it for the
 243          * process
 244          */
 245         if (vdso_pages == 0)
 246                 return 0;
 247         /* Add a page to the vdso size for the data page */
 248         vdso_pages ++;
 249
 250         /*
 251          * pick a base address for the vDSO in process space. We try to put it
 252          * at vdso_base which is the "natural" base for it, but we might fail
 253          * and end up putting it elsewhere.
 254          */
 255         down_write(&mm->mmap_sem);
 256         vdso_base = get_unmapped_area(NULL, vdso_base,
 257                                       vdso_pages << PAGE_SHIFT, 0, 0);
 258         if (IS_ERR_VALUE(vdso_base)) {
 259                 rc = vdso_base;
 260                 goto fail_mmapsem;
 261         }
 262
 263
 264         /* Allocate a VMA structure and fill it up */
 265         vma = kmem_cache_zalloc(vm_area_cachep, SLAB_KERNEL);
 266         if (vma == NULL) {
 267                 rc = -ENOMEM;
 268                 goto fail_mmapsem;
 269         }
 270         vma->vm_mm = mm;
 271         vma->vm_start = vdso_base;
 272         vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
 273
 274         /*
 275          * our vma flags don't have VM_WRITE so by default, the process isn't
 276          * allowed to write those pages.
 277          * gdb can break that with ptrace interface, and thus trigger COW on
 278          * those pages but it's then your responsibility to never do that on
 279          * the "data" page of the vDSO or you'll stop getting kernel updates
 280          * and your nice userland gettimeofday will be totally dead.
 281          * It's fine to use that for setting breakpoints in the vDSO code
 282          * pages though
 283          */
 284         vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC;
 285         vma->vm_flags |= mm->def_flags;
 286         vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
 287         vma->vm_ops = &vdso_vmops;
 288
 289         /* Insert new VMA */
 290         rc = insert_vm_struct(mm, vma);
 291         if (rc)
 292                 goto fail_vma;
 293
 294         /* Put vDSO base into mm struct and account for memory usage */
 295         current->mm->context.vdso_base = vdso_base;
 296         mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 297         up_write(&mm->mmap_sem);
 298         return 0;
 299
 300  fail_vma:
 301         kmem_cache_free(vm_area_cachep, vma);
 302  fail_mmapsem:
 303         up_write(&mm->mmap_sem);
 304         return rc;
 305 }
 306
 307 const char *arch_vma_name(struct vm_area_struct *vma)
 308 {
 309         if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
 310                 return "[vdso]";
 311         return NULL;
 312 }
 313
 314
 315
 316 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
 317                                   unsigned long *size)
 318 {
 319         Elf32_Shdr *sechdrs;
 320         unsigned int i;
 321         char *secnames;
 322
 323         /* Grab section headers and strings so we can tell who is who */
 324         sechdrs = (void *)ehdr + ehdr->e_shoff;
 325         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 326
 327         /* Find the section they want */
 328         for (i = 1; i < ehdr->e_shnum; i++) {
 329                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 330                         if (size)
 331                                 *size = sechdrs[i].sh_size;
 332                         return (void *)ehdr + sechdrs[i].sh_offset;
 333                 }
 334         }
 335         *size = 0;
 336         return NULL;
 337 }
 338
 339 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
 340                                         const char *symname)
 341 {
 342         unsigned int i;
 343         char name[MAX_SYMNAME], *c;
 344
 345         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
 346                 if (lib->dynsym[i].st_name == 0)
 347                         continue;
 348                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 349                         MAX_SYMNAME);
 350                 c = strchr(name, '@');
 351                 if (c)
 352                         *c = 0;
 353                 if (strcmp(symname, name) == 0)
 354                         return &lib->dynsym[i];
 355         }
 356         return NULL;
 357 }
 358
 359 /* Note that we assume the section is .text and the symbol is relative to
 360  * the library base
 361  */
 362 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 363                                             const char *symname)
 364 {
 365         Elf32_Sym *sym = find_symbol32(lib, symname);
 366
 367         if (sym == NULL) {
 368                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
 369                        symname);
 370                 return 0;
 371         }
 372         return sym->st_value - VDSO32_LBASE;
 373 }
 374
 375 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
 376                                 struct lib64_elfinfo *v64,
 377                                 const char *orig, const char *fix)
 378 {
 379         Elf32_Sym *sym32_gen, *sym32_fix;
 380
 381         sym32_gen = find_symbol32(v32, orig);
 382         if (sym32_gen == NULL) {
 383                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
 384                 return -1;
 385         }
 386         if (fix == NULL) {
 387                 sym32_gen->st_name = 0;
 388                 return 0;
 389         }
 390         sym32_fix = find_symbol32(v32, fix);
 391         if (sym32_fix == NULL) {
 392                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
 393                 return -1;
 394         }
 395         sym32_gen->st_value = sym32_fix->st_value;
 396         sym32_gen->st_size = sym32_fix->st_size;
 397         sym32_gen->st_info = sym32_fix->st_info;
 398         sym32_gen->st_other = sym32_fix->st_other;
 399         sym32_gen->st_shndx = sym32_fix->st_shndx;
 400
 401         return 0;
 402 }
 403
 404
 405 #ifdef CONFIG_PPC64
 406
 407 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
 408                                   unsigned long *size)
 409 {
 410         Elf64_Shdr *sechdrs;
 411         unsigned int i;
 412         char *secnames;
 413
 414         /* Grab section headers and strings so we can tell who is who */
 415         sechdrs = (void *)ehdr + ehdr->e_shoff;
 416         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 417
 418         /* Find the section they want */
 419         for (i = 1; i < ehdr->e_shnum; i++) {
 420                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 421                         if (size)
 422                                 *size = sechdrs[i].sh_size;
 423                         return (void *)ehdr + sechdrs[i].sh_offset;
 424                 }
 425         }
 426         if (size)
 427                 *size = 0;
 428         return NULL;
 429 }
 430
 431 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
 432                                         const char *symname)
 433 {
 434         unsigned int i;
 435         char name[MAX_SYMNAME], *c;
 436
 437         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
 438                 if (lib->dynsym[i].st_name == 0)
 439                         continue;
 440                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 441                         MAX_SYMNAME);
 442                 c = strchr(name, '@');
 443                 if (c)
 444                         *c = 0;
 445                 if (strcmp(symname, name) == 0)
 446                         return &lib->dynsym[i];
 447         }
 448         return NULL;
 449 }
 450
 451 /* Note that we assume the section is .text and the symbol is relative to
 452  * the library base
 453  */
 454 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
 455                                             const char *symname)
 456 {
 457         Elf64_Sym *sym = find_symbol64(lib, symname);
 458
 459         if (sym == NULL) {
 460                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
 461                        symname);
 462                 return 0;
 463         }
 464 #ifdef VDS64_HAS_DESCRIPTORS
 465         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
 466                 VDSO64_LBASE;
 467 #else
 468         return sym->st_value - VDSO64_LBASE;
 469 #endif
 470 }
 471
 472 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
 473                                 struct lib64_elfinfo *v64,
 474                                 const char *orig, const char *fix)
 475 {
 476         Elf64_Sym *sym64_gen, *sym64_fix;
 477
 478         sym64_gen = find_symbol64(v64, orig);
 479         if (sym64_gen == NULL) {
 480                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
 481                 return -1;
 482         }
 483         if (fix == NULL) {
 484                 sym64_gen->st_name = 0;
 485                 return 0;
 486         }
 487         sym64_fix = find_symbol64(v64, fix);
 488         if (sym64_fix == NULL) {
 489                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
 490                 return -1;
 491         }
 492         sym64_gen->st_value = sym64_fix->st_value;
 493         sym64_gen->st_size = sym64_fix->st_size;
 494         sym64_gen->st_info = sym64_fix->st_info;
 495         sym64_gen->st_other = sym64_fix->st_other;
 496         sym64_gen->st_shndx = sym64_fix->st_shndx;
 497
 498         return 0;
 499 }
 500
 501 #endif /* CONFIG_PPC64 */
 502
 503
 504 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
 505                                         struct lib64_elfinfo *v64)
 506 {
 507         void *sect;
 508
 509         /*
 510          * Locate symbol tables & text section
 511          */
 512
 513         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
 514         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
 515         if (v32->dynsym == NULL || v32->dynstr == NULL) {
 516                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
 517                 return -1;
 518         }
 519         sect = find_section32(v32->hdr, ".text", NULL);
 520         if (sect == NULL) {
 521                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
 522                 return -1;
 523         }
 524         v32->text = sect - vdso32_kbase;
 525
 526 #ifdef CONFIG_PPC64
 527         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
 528         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
 529         if (v64->dynsym == NULL || v64->dynstr == NULL) {
 530                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
 531                 return -1;
 532         }
 533         sect = find_section64(v64->hdr, ".text", NULL);
 534         if (sect == NULL) {
 535                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
 536                 return -1;
 537         }
 538         v64->text = sect - vdso64_kbase;
 539 #endif /* CONFIG_PPC64 */
 540
 541         return 0;
 542 }
 543
 544 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
 545                                           struct lib64_elfinfo *v64)
 546 {
 547         /*
 548          * Find signal trampolines
 549          */
 550
 551 #ifdef CONFIG_PPC64
 552         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
 553 #endif
 554         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
 555         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
 556 }
 557
 558 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
 559                                        struct lib64_elfinfo *v64)
 560 {
 561         Elf32_Sym *sym32;
 562 #ifdef CONFIG_PPC64
 563         Elf64_Sym *sym64;
 564
 565         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
 566         if (sym64 == NULL) {
 567                 printk(KERN_ERR "vDSO64: Can't find symbol "
 568                        "__kernel_datapage_offset !\n");
 569                 return -1;
 570         }
 571         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
 572                 (vdso64_pages << PAGE_SHIFT) -
 573                 (sym64->st_value - VDSO64_LBASE);
 574 #endif /* CONFIG_PPC64 */
 575
 576         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
 577         if (sym32 == NULL) {
 578                 printk(KERN_ERR "vDSO32: Can't find symbol "
 579                        "__kernel_datapage_offset !\n");
 580                 return -1;
 581         }
 582         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
 583                 (vdso32_pages << PAGE_SHIFT) -
 584                 (sym32->st_value - VDSO32_LBASE);
 585
 586         return 0;
 587 }
 588
 589 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
 590                                        struct lib64_elfinfo *v64)
 591 {
 592         int i;
 593
 594         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
 595                 struct vdso_patch_def *patch = &vdso_patches[i];
 596                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
 597                         == patch->ftr_value;
 598                 if (!match)
 599                         continue;
 600
 601                 DBG("replacing %s with %s...\n", patch->gen_name,
 602                     patch->fix_name ? "NONE" : patch->fix_name);
 603
 604                 /*
 605                  * Patch the 32 bits and 64 bits symbols. Note that we do not
 606                  * patch the "." symbol on 64 bits.
 607                  * It would be easy to do, but doesn't seem to be necessary,
 608                  * patching the OPD symbol is enough.
 609                  */
 610                 vdso_do_func_patch32(v32, v64, patch->gen_name,
 611                                      patch->fix_name);
 612 #ifdef CONFIG_PPC64
 613                 vdso_do_func_patch64(v32, v64, patch->gen_name,
 614                                      patch->fix_name);
 615 #endif /* CONFIG_PPC64 */
 616         }
 617
 618         return 0;
 619 }
 620
 621
 622 static __init int vdso_setup(void)
 623 {
 624         struct lib32_elfinfo    v32;
 625         struct lib64_elfinfo    v64;
 626
 627         v32.hdr = vdso32_kbase;
 628 #ifdef CONFIG_PPC64
 629         v64.hdr = vdso64_kbase;
 630 #endif
 631         if (vdso_do_find_sections(&v32, &v64))
 632                 return -1;
 633
 634         if (vdso_fixup_datapage(&v32, &v64))
 635                 return -1;
 636
 637         if (vdso_fixup_alt_funcs(&v32, &v64))
 638                 return -1;
 639
 640         vdso_setup_trampolines(&v32, &v64);
 641
 642         return 0;
 643 }
 644
 645 /*
 646  * Called from setup_arch to initialize the bitmap of available
 647  * syscalls in the systemcfg page
 648  */
 649 static void __init vdso_setup_syscall_map(void)
 650 {
 651         unsigned int i;
 652         extern unsigned long *sys_call_table;
 653         extern unsigned long sys_ni_syscall;
 654
 655
 656         for (i = 0; i < __NR_syscalls; i++) {
 657 #ifdef CONFIG_PPC64
 658                 if (sys_call_table[i*2] != sys_ni_syscall)
 659                         vdso_data->syscall_map_64[i >> 5] |=
 660                                 0x80000000UL >> (i & 0x1f);
 661                 if (sys_call_table[i*2+1] != sys_ni_syscall)
 662                         vdso_data->syscall_map_32[i >> 5] |=
 663                                 0x80000000UL >> (i & 0x1f);
 664 #else /* CONFIG_PPC64 */
 665                 if (sys_call_table[i] != sys_ni_syscall)
 666                         vdso_data->syscall_map_32[i >> 5] |=
 667                                 0x80000000UL >> (i & 0x1f);
 668 #endif /* CONFIG_PPC64 */
 669         }
 670 }
 671
 672
 673 void __init vdso_init(void)
 674 {
 675         int i;
 676
 677 #ifdef CONFIG_PPC64
 678         /*
 679          * Fill up the "systemcfg" stuff for backward compatiblity
 680          */
 681         strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
 682         vdso_data->version.major = SYSTEMCFG_MAJOR;
 683         vdso_data->version.minor = SYSTEMCFG_MINOR;
 684         vdso_data->processor = mfspr(SPRN_PVR);
 685         /*
 686          * Fake the old platform number for pSeries and iSeries and add
 687          * in LPAR bit if necessary
 688          */
 689         vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
 690         if (firmware_has_feature(FW_FEATURE_LPAR))
 691                 vdso_data->platform |= 1;
 692         vdso_data->physicalMemorySize = lmb_phys_mem_size();
 693         vdso_data->dcache_size = ppc64_caches.dsize;
 694         vdso_data->dcache_line_size = ppc64_caches.dline_size;
 695         vdso_data->icache_size = ppc64_caches.isize;
 696         vdso_data->icache_line_size = ppc64_caches.iline_size;
 697
 698         /*
 699          * Calculate the size of the 64 bits vDSO
 700          */
 701         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
 702         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
 703 #endif /* CONFIG_PPC64 */
 704
 705
 706         /*
 707          * Calculate the size of the 32 bits vDSO
 708          */
 709         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
 710         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
 711
 712
 713         /*
 714          * Setup the syscall map in the vDOS
 715          */
 716         vdso_setup_syscall_map();
 717         /*
 718          * Initialize the vDSO images in memory, that is do necessary
 719          * fixups of vDSO symbols, locate trampolines, etc...
 720          */
 721         if (vdso_setup()) {
 722                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
 723                 vdso32_pages = 0;
 724 #ifdef CONFIG_PPC64
 725                 vdso64_pages = 0;
 726 #endif
 727                 return;
 728         }
 729
 730         /* Make sure pages are in the correct state */
 731         for (i = 0; i < vdso32_pages; i++) {
 732                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
 733                 ClearPageReserved(pg);
 734                 get_page(pg);
 735
 736         }
 737 #ifdef CONFIG_PPC64
 738         for (i = 0; i < vdso64_pages; i++) {
 739                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
 740                 ClearPageReserved(pg);
 741                 get_page(pg);
 742         }
 743 #endif /* CONFIG_PPC64 */
 744
 745         get_page(virt_to_page(vdso_data));
 746 }
 747
 748 int in_gate_area_no_task(unsigned long addr)
 749 {
 750         return 0;
 751 }
 752
 753 int in_gate_area(struct task_struct *task, unsigned long addr)
 754 {
 755         return 0;
 756 }
 757
 758 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 759 {
 760         return NULL;
 761 }
 762