arch/powerpc/kernel/vdso.c

   1
   2 /*
   3  *    Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
   4  *                       <benh@kernel.crashing.org>
   5  *
   6  *  This program is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU General Public License
   8  *  as published by the Free Software Foundation; either version
   9  *  2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/errno.h>
  14 #include <linux/sched.h>
  15 #include <linux/kernel.h>
  16 #include <linux/mm.h>
  17 #include <linux/smp.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 #include <linux/lmb.h>
  26
  27 #include <asm/pgtable.h>
  28 #include <asm/system.h>
  29 #include <asm/processor.h>
  30 #include <asm/mmu.h>
  31 #include <asm/mmu_context.h>
  32 #include <asm/prom.h>
  33 #include <asm/machdep.h>
  34 #include <asm/cputable.h>
  35 #include <asm/sections.h>
  36 #include <asm/firmware.h>
  37 #include <asm/vdso.h>
  38 #include <asm/vdso_datapage.h>
  39
  40 #include "setup.h"
  41
  42 #undef DEBUG
  43
  44 #ifdef DEBUG
  45 #define DBG(fmt...) printk(fmt)
  46 #else
  47 #define DBG(fmt...)
  48 #endif
  49
  50 /* Max supported size for symbol names */
  51 #define MAX_SYMNAME     64
  52
  53 extern char vdso32_start, vdso32_end;
  54 static void *vdso32_kbase = &vdso32_start;
  55 static unsigned int vdso32_pages;
  56 static struct page **vdso32_pagelist;
  57 unsigned long vdso32_sigtramp;
  58 unsigned long vdso32_rt_sigtramp;
  59
  60 #ifdef CONFIG_PPC64
  61 extern char vdso64_start, vdso64_end;
  62 static void *vdso64_kbase = &vdso64_start;
  63 static unsigned int vdso64_pages;
  64 static struct page **vdso64_pagelist;
  65 unsigned long vdso64_rt_sigtramp;
  66 #endif /* CONFIG_PPC64 */
  67
  68 static int vdso_ready;
  69
  70 /*
  71  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
  72  * Once the early boot kernel code no longer needs to muck around
  73  * with it, it will become dynamically allocated
  74  */
  75 static union {
  76         struct vdso_data        data;
  77         u8                      page[PAGE_SIZE];
  78 } vdso_data_store __page_aligned_data;
  79 struct vdso_data *vdso_data = &vdso_data_store.data;
  80
  81 /* Format of the patch table */
  82 struct vdso_patch_def
  83 {
  84         unsigned long   ftr_mask, ftr_value;
  85         const char      *gen_name;
  86         const char      *fix_name;
  87 };
  88
  89 /* Table of functions to patch based on the CPU type/revision
  90  *
  91  * Currently, we only change sync_dicache to do nothing on processors
  92  * with a coherent icache
  93  */
  94 static struct vdso_patch_def vdso_patches[] = {
  95         {
  96                 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
  97                 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
  98         },
  99         {
 100                 CPU_FTR_USE_TB, 0,
 101                 "__kernel_gettimeofday", NULL
 102         },
 103         {
 104                 CPU_FTR_USE_TB, 0,
 105                 "__kernel_clock_gettime", NULL
 106         },
 107         {
 108                 CPU_FTR_USE_TB, 0,
 109                 "__kernel_clock_getres", NULL
 110         },
 111         {
 112                 CPU_FTR_USE_TB, 0,
 113                 "__kernel_get_tbfreq", NULL
 114         },
 115 };
 116
 117 /*
 118  * Some infos carried around for each of them during parsing at
 119  * boot time.
 120  */
 121 struct lib32_elfinfo
 122 {
 123         Elf32_Ehdr      *hdr;           /* ptr to ELF */
 124         Elf32_Sym       *dynsym;        /* ptr to .dynsym section */
 125         unsigned long   dynsymsize;     /* size of .dynsym section */
 126         char            *dynstr;        /* ptr to .dynstr section */
 127         unsigned long   text;           /* offset of .text section in .so */
 128 };
 129
 130 struct lib64_elfinfo
 131 {
 132         Elf64_Ehdr      *hdr;
 133         Elf64_Sym       *dynsym;
 134         unsigned long   dynsymsize;
 135         char            *dynstr;
 136         unsigned long   text;
 137 };
 138
 139
 140 #ifdef __DEBUG
 141 static void dump_one_vdso_page(struct page *pg, struct page *upg)
 142 {
 143         printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
 144                page_count(pg),
 145                pg->flags);
 146         if (upg && !IS_ERR(upg) /* && pg != upg*/) {
 147                 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
 148                                                        << PAGE_SHIFT),
 149                        page_count(upg),
 150                        upg->flags);
 151         }
 152         printk("\n");
 153 }
 154
 155 static void dump_vdso_pages(struct vm_area_struct * vma)
 156 {
 157         int i;
 158
 159         if (!vma || test_thread_flag(TIF_32BIT)) {
 160                 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
 161                 for (i=0; i<vdso32_pages; i++) {
 162                         struct page *pg = virt_to_page(vdso32_kbase +
 163                                                        i*PAGE_SIZE);
 164                         struct page *upg = (vma && vma->vm_mm) ?
 165                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
 166                                 : NULL;
 167                         dump_one_vdso_page(pg, upg);
 168                 }
 169         }
 170         if (!vma || !test_thread_flag(TIF_32BIT)) {
 171                 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
 172                 for (i=0; i<vdso64_pages; i++) {
 173                         struct page *pg = virt_to_page(vdso64_kbase +
 174                                                        i*PAGE_SIZE);
 175                         struct page *upg = (vma && vma->vm_mm) ?
 176                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
 177                                 : NULL;
 178                         dump_one_vdso_page(pg, upg);
 179                 }
 180         }
 181 }
 182 #endif /* DEBUG */
 183
 184 /*
 185  * This is called from binfmt_elf, we create the special vma for the
 186  * vDSO and insert it into the mm struct tree
 187  */
 188 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 189 {
 190         struct mm_struct *mm = current->mm;
 191         struct page **vdso_pagelist;
 192         unsigned long vdso_pages;
 193         unsigned long vdso_base;
 194         int rc;
 195
 196         if (!vdso_ready)
 197                 return 0;
 198
 199 #ifdef CONFIG_PPC64
 200         if (test_thread_flag(TIF_32BIT)) {
 201                 vdso_pagelist = vdso32_pagelist;
 202                 vdso_pages = vdso32_pages;
 203                 vdso_base = VDSO32_MBASE;
 204         } else {
 205                 vdso_pagelist = vdso64_pagelist;
 206                 vdso_pages = vdso64_pages;
 207                 /*
 208                  * On 64bit we don't have a preferred map address. This
 209                  * allows get_unmapped_area to find an area near other mmaps
 210                  * and most likely share a SLB entry.
 211                  */
 212                 vdso_base = 0;
 213         }
 214 #else
 215         vdso_pagelist = vdso32_pagelist;
 216         vdso_pages = vdso32_pages;
 217         vdso_base = VDSO32_MBASE;
 218 #endif
 219
 220         current->mm->context.vdso_base = 0;
 221
 222         /* vDSO has a problem and was disabled, just don't "enable" it for the
 223          * process
 224          */
 225         if (vdso_pages == 0)
 226                 return 0;
 227         /* Add a page to the vdso size for the data page */
 228         vdso_pages ++;
 229
 230         /*
 231          * pick a base address for the vDSO in process space. We try to put it
 232          * at vdso_base which is the "natural" base for it, but we might fail
 233          * and end up putting it elsewhere.
 234          */
 235         down_write(&mm->mmap_sem);
 236         vdso_base = get_unmapped_area(NULL, vdso_base,
 237                                       vdso_pages << PAGE_SHIFT, 0, 0);
 238         if (IS_ERR_VALUE(vdso_base)) {
 239                 rc = vdso_base;
 240                 goto fail_mmapsem;
 241         }
 242
 243         /*
 244          * Put vDSO base into mm struct. We need to do this before calling
 245          * install_special_mapping or the perf counter mmap tracking code
 246          * will fail to recognise it as a vDSO (since arch_vma_name fails).
 247          */
 248         current->mm->context.vdso_base = vdso_base;
 249
 250         /*
 251          * our vma flags don't have VM_WRITE so by default, the process isn't
 252          * allowed to write those pages.
 253          * gdb can break that with ptrace interface, and thus trigger COW on
 254          * those pages but it's then your responsibility to never do that on
 255          * the "data" page of the vDSO or you'll stop getting kernel updates
 256          * and your nice userland gettimeofday will be totally dead.
 257          * It's fine to use that for setting breakpoints in the vDSO code
 258          * pages though
 259          *
 260          * Make sure the vDSO gets into every core dump.
 261          * Dumping its contents makes post-mortem fully interpretable later
 262          * without matching up the same kernel and hardware config to see
 263          * what PC values meant.
 264          */
 265         rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
 266                                      VM_READ|VM_EXEC|
 267                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
 268                                      VM_ALWAYSDUMP,
 269                                      vdso_pagelist);
 270         if (rc) {
 271                 current->mm->context.vdso_base = 0;
 272                 goto fail_mmapsem;
 273         }
 274
 275         up_write(&mm->mmap_sem);
 276         return 0;
 277
 278  fail_mmapsem:
 279         up_write(&mm->mmap_sem);
 280         return rc;
 281 }
 282
 283 const char *arch_vma_name(struct vm_area_struct *vma)
 284 {
 285         if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
 286                 return "[vdso]";
 287         return NULL;
 288 }
 289
 290
 291
 292 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
 293                                   unsigned long *size)
 294 {
 295         Elf32_Shdr *sechdrs;
 296         unsigned int i;
 297         char *secnames;
 298
 299         /* Grab section headers and strings so we can tell who is who */
 300         sechdrs = (void *)ehdr + ehdr->e_shoff;
 301         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 302
 303         /* Find the section they want */
 304         for (i = 1; i < ehdr->e_shnum; i++) {
 305                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 306                         if (size)
 307                                 *size = sechdrs[i].sh_size;
 308                         return (void *)ehdr + sechdrs[i].sh_offset;
 309                 }
 310         }
 311         *size = 0;
 312         return NULL;
 313 }
 314
 315 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
 316                                         const char *symname)
 317 {
 318         unsigned int i;
 319         char name[MAX_SYMNAME], *c;
 320
 321         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
 322                 if (lib->dynsym[i].st_name == 0)
 323                         continue;
 324                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 325                         MAX_SYMNAME);
 326                 c = strchr(name, '@');
 327                 if (c)
 328                         *c = 0;
 329                 if (strcmp(symname, name) == 0)
 330                         return &lib->dynsym[i];
 331         }
 332         return NULL;
 333 }
 334
 335 /* Note that we assume the section is .text and the symbol is relative to
 336  * the library base
 337  */
 338 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 339                                             const char *symname)
 340 {
 341         Elf32_Sym *sym = find_symbol32(lib, symname);
 342
 343         if (sym == NULL) {
 344                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
 345                        symname);
 346                 return 0;
 347         }
 348         return sym->st_value - VDSO32_LBASE;
 349 }
 350
 351 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
 352                                        struct lib64_elfinfo *v64,
 353                                        const char *orig, const char *fix)
 354 {
 355         Elf32_Sym *sym32_gen, *sym32_fix;
 356
 357         sym32_gen = find_symbol32(v32, orig);
 358         if (sym32_gen == NULL) {
 359                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
 360                 return -1;
 361         }
 362         if (fix == NULL) {
 363                 sym32_gen->st_name = 0;
 364                 return 0;
 365         }
 366         sym32_fix = find_symbol32(v32, fix);
 367         if (sym32_fix == NULL) {
 368                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
 369                 return -1;
 370         }
 371         sym32_gen->st_value = sym32_fix->st_value;
 372         sym32_gen->st_size = sym32_fix->st_size;
 373         sym32_gen->st_info = sym32_fix->st_info;
 374         sym32_gen->st_other = sym32_fix->st_other;
 375         sym32_gen->st_shndx = sym32_fix->st_shndx;
 376
 377         return 0;
 378 }
 379
 380
 381 #ifdef CONFIG_PPC64
 382
 383 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
 384                                   unsigned long *size)
 385 {
 386         Elf64_Shdr *sechdrs;
 387         unsigned int i;
 388         char *secnames;
 389
 390         /* Grab section headers and strings so we can tell who is who */
 391         sechdrs = (void *)ehdr + ehdr->e_shoff;
 392         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 393
 394         /* Find the section they want */
 395         for (i = 1; i < ehdr->e_shnum; i++) {
 396                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 397                         if (size)
 398                                 *size = sechdrs[i].sh_size;
 399                         return (void *)ehdr + sechdrs[i].sh_offset;
 400                 }
 401         }
 402         if (size)
 403                 *size = 0;
 404         return NULL;
 405 }
 406
 407 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
 408                                         const char *symname)
 409 {
 410         unsigned int i;
 411         char name[MAX_SYMNAME], *c;
 412
 413         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
 414                 if (lib->dynsym[i].st_name == 0)
 415                         continue;
 416                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 417                         MAX_SYMNAME);
 418                 c = strchr(name, '@');
 419                 if (c)
 420                         *c = 0;
 421                 if (strcmp(symname, name) == 0)
 422                         return &lib->dynsym[i];
 423         }
 424         return NULL;
 425 }
 426
 427 /* Note that we assume the section is .text and the symbol is relative to
 428  * the library base
 429  */
 430 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
 431                                             const char *symname)
 432 {
 433         Elf64_Sym *sym = find_symbol64(lib, symname);
 434
 435         if (sym == NULL) {
 436                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
 437                        symname);
 438                 return 0;
 439         }
 440 #ifdef VDS64_HAS_DESCRIPTORS
 441         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
 442                 VDSO64_LBASE;
 443 #else
 444         return sym->st_value - VDSO64_LBASE;
 445 #endif
 446 }
 447
 448 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
 449                                        struct lib64_elfinfo *v64,
 450                                        const char *orig, const char *fix)
 451 {
 452         Elf64_Sym *sym64_gen, *sym64_fix;
 453
 454         sym64_gen = find_symbol64(v64, orig);
 455         if (sym64_gen == NULL) {
 456                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
 457                 return -1;
 458         }
 459         if (fix == NULL) {
 460                 sym64_gen->st_name = 0;
 461                 return 0;
 462         }
 463         sym64_fix = find_symbol64(v64, fix);
 464         if (sym64_fix == NULL) {
 465                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
 466                 return -1;
 467         }
 468         sym64_gen->st_value = sym64_fix->st_value;
 469         sym64_gen->st_size = sym64_fix->st_size;
 470         sym64_gen->st_info = sym64_fix->st_info;
 471         sym64_gen->st_other = sym64_fix->st_other;
 472         sym64_gen->st_shndx = sym64_fix->st_shndx;
 473
 474         return 0;
 475 }
 476
 477 #endif /* CONFIG_PPC64 */
 478
 479
 480 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
 481                                         struct lib64_elfinfo *v64)
 482 {
 483         void *sect;
 484
 485         /*
 486          * Locate symbol tables & text section
 487          */
 488
 489         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
 490         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
 491         if (v32->dynsym == NULL || v32->dynstr == NULL) {
 492                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
 493                 return -1;
 494         }
 495         sect = find_section32(v32->hdr, ".text", NULL);
 496         if (sect == NULL) {
 497                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
 498                 return -1;
 499         }
 500         v32->text = sect - vdso32_kbase;
 501
 502 #ifdef CONFIG_PPC64
 503         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
 504         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
 505         if (v64->dynsym == NULL || v64->dynstr == NULL) {
 506                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
 507                 return -1;
 508         }
 509         sect = find_section64(v64->hdr, ".text", NULL);
 510         if (sect == NULL) {
 511                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
 512                 return -1;
 513         }
 514         v64->text = sect - vdso64_kbase;
 515 #endif /* CONFIG_PPC64 */
 516
 517         return 0;
 518 }
 519
 520 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
 521                                           struct lib64_elfinfo *v64)
 522 {
 523         /*
 524          * Find signal trampolines
 525          */
 526
 527 #ifdef CONFIG_PPC64
 528         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
 529 #endif
 530         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
 531         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
 532 }
 533
 534 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
 535                                        struct lib64_elfinfo *v64)
 536 {
 537         Elf32_Sym *sym32;
 538 #ifdef CONFIG_PPC64
 539         Elf64_Sym *sym64;
 540
 541         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
 542         if (sym64 == NULL) {
 543                 printk(KERN_ERR "vDSO64: Can't find symbol "
 544                        "__kernel_datapage_offset !\n");
 545                 return -1;
 546         }
 547         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
 548                 (vdso64_pages << PAGE_SHIFT) -
 549                 (sym64->st_value - VDSO64_LBASE);
 550 #endif /* CONFIG_PPC64 */
 551
 552         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
 553         if (sym32 == NULL) {
 554                 printk(KERN_ERR "vDSO32: Can't find symbol "
 555                        "__kernel_datapage_offset !\n");
 556                 return -1;
 557         }
 558         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
 559                 (vdso32_pages << PAGE_SHIFT) -
 560                 (sym32->st_value - VDSO32_LBASE);
 561
 562         return 0;
 563 }
 564
 565
 566 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
 567                                       struct lib64_elfinfo *v64)
 568 {
 569         void *start32;
 570         unsigned long size32;
 571
 572 #ifdef CONFIG_PPC64
 573         void *start64;
 574         unsigned long size64;
 575
 576         start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
 577         if (start64)
 578                 do_feature_fixups(cur_cpu_spec->cpu_features,
 579                                   start64, start64 + size64);
 580
 581         start64 = find_section64(v64->hdr, "__mmu_ftr_fixup", &size64);
 582         if (start64)
 583                 do_feature_fixups(cur_cpu_spec->mmu_features,
 584                                   start64, start64 + size64);
 585
 586         start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
 587         if (start64)
 588                 do_feature_fixups(powerpc_firmware_features,
 589                                   start64, start64 + size64);
 590
 591         start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
 592         if (start64)
 593                 do_lwsync_fixups(cur_cpu_spec->cpu_features,
 594                                  start64, start64 + size64);
 595 #endif /* CONFIG_PPC64 */
 596
 597         start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
 598         if (start32)
 599                 do_feature_fixups(cur_cpu_spec->cpu_features,
 600                                   start32, start32 + size32);
 601
 602         start32 = find_section32(v32->hdr, "__mmu_ftr_fixup", &size32);
 603         if (start32)
 604                 do_feature_fixups(cur_cpu_spec->mmu_features,
 605                                   start32, start32 + size32);
 606
 607 #ifdef CONFIG_PPC64
 608         start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
 609         if (start32)
 610                 do_feature_fixups(powerpc_firmware_features,
 611                                   start32, start32 + size32);
 612 #endif /* CONFIG_PPC64 */
 613
 614         start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
 615         if (start32)
 616                 do_lwsync_fixups(cur_cpu_spec->cpu_features,
 617                                  start32, start32 + size32);
 618
 619         return 0;
 620 }
 621
 622 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
 623                                        struct lib64_elfinfo *v64)
 624 {
 625         int i;
 626
 627         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
 628                 struct vdso_patch_def *patch = &vdso_patches[i];
 629                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
 630                         == patch->ftr_value;
 631                 if (!match)
 632                         continue;
 633
 634                 DBG("replacing %s with %s...\n", patch->gen_name,
 635                     patch->fix_name ? "NONE" : patch->fix_name);
 636
 637                 /*
 638                  * Patch the 32 bits and 64 bits symbols. Note that we do not
 639                  * patch the "." symbol on 64 bits.
 640                  * It would be easy to do, but doesn't seem to be necessary,
 641                  * patching the OPD symbol is enough.
 642                  */
 643                 vdso_do_func_patch32(v32, v64, patch->gen_name,
 644                                      patch->fix_name);
 645 #ifdef CONFIG_PPC64
 646                 vdso_do_func_patch64(v32, v64, patch->gen_name,
 647                                      patch->fix_name);
 648 #endif /* CONFIG_PPC64 */
 649         }
 650
 651         return 0;
 652 }
 653
 654
 655 static __init int vdso_setup(void)
 656 {
 657         struct lib32_elfinfo    v32;
 658         struct lib64_elfinfo    v64;
 659
 660         v32.hdr = vdso32_kbase;
 661 #ifdef CONFIG_PPC64
 662         v64.hdr = vdso64_kbase;
 663 #endif
 664         if (vdso_do_find_sections(&v32, &v64))
 665                 return -1;
 666
 667         if (vdso_fixup_datapage(&v32, &v64))
 668                 return -1;
 669
 670         if (vdso_fixup_features(&v32, &v64))
 671                 return -1;
 672
 673         if (vdso_fixup_alt_funcs(&v32, &v64))
 674                 return -1;
 675
 676         vdso_setup_trampolines(&v32, &v64);
 677
 678         return 0;
 679 }
 680
 681 /*
 682  * Called from setup_arch to initialize the bitmap of available
 683  * syscalls in the systemcfg page
 684  */
 685 static void __init vdso_setup_syscall_map(void)
 686 {
 687         unsigned int i;
 688         extern unsigned long *sys_call_table;
 689         extern unsigned long sys_ni_syscall;
 690
 691
 692         for (i = 0; i < __NR_syscalls; i++) {
 693 #ifdef CONFIG_PPC64
 694                 if (sys_call_table[i*2] != sys_ni_syscall)
 695                         vdso_data->syscall_map_64[i >> 5] |=
 696                                 0x80000000UL >> (i & 0x1f);
 697                 if (sys_call_table[i*2+1] != sys_ni_syscall)
 698                         vdso_data->syscall_map_32[i >> 5] |=
 699                                 0x80000000UL >> (i & 0x1f);
 700 #else /* CONFIG_PPC64 */
 701                 if (sys_call_table[i] != sys_ni_syscall)
 702                         vdso_data->syscall_map_32[i >> 5] |=
 703                                 0x80000000UL >> (i & 0x1f);
 704 #endif /* CONFIG_PPC64 */
 705         }
 706 }
 707
 708
 709 static int __init vdso_init(void)
 710 {
 711         int i;
 712
 713 #ifdef CONFIG_PPC64
 714         /*
 715          * Fill up the "systemcfg" stuff for backward compatiblity
 716          */
 717         strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
 718         vdso_data->version.major = SYSTEMCFG_MAJOR;
 719         vdso_data->version.minor = SYSTEMCFG_MINOR;
 720         vdso_data->processor = mfspr(SPRN_PVR);
 721         /*
 722          * Fake the old platform number for pSeries and iSeries and add
 723          * in LPAR bit if necessary
 724          */
 725         vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
 726         if (firmware_has_feature(FW_FEATURE_LPAR))
 727                 vdso_data->platform |= 1;
 728         vdso_data->physicalMemorySize = lmb_phys_mem_size();
 729         vdso_data->dcache_size = ppc64_caches.dsize;
 730         vdso_data->dcache_line_size = ppc64_caches.dline_size;
 731         vdso_data->icache_size = ppc64_caches.isize;
 732         vdso_data->icache_line_size = ppc64_caches.iline_size;
 733
 734         /* XXXOJN: Blocks should be added to ppc64_caches and used instead */
 735         vdso_data->dcache_block_size = ppc64_caches.dline_size;
 736         vdso_data->icache_block_size = ppc64_caches.iline_size;
 737         vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
 738         vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
 739
 740         /*
 741          * Calculate the size of the 64 bits vDSO
 742          */
 743         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
 744         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
 745 #else
 746         vdso_data->dcache_block_size = L1_CACHE_BYTES;
 747         vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
 748         vdso_data->icache_block_size = L1_CACHE_BYTES;
 749         vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
 750 #endif /* CONFIG_PPC64 */
 751
 752
 753         /*
 754          * Calculate the size of the 32 bits vDSO
 755          */
 756         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
 757         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
 758
 759
 760         /*
 761          * Setup the syscall map in the vDOS
 762          */
 763         vdso_setup_syscall_map();
 764
 765         /*
 766          * Initialize the vDSO images in memory, that is do necessary
 767          * fixups of vDSO symbols, locate trampolines, etc...
 768          */
 769         if (vdso_setup()) {
 770                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
 771                 vdso32_pages = 0;
 772 #ifdef CONFIG_PPC64
 773                 vdso64_pages = 0;
 774 #endif
 775                 return 0;
 776         }
 777
 778         /* Make sure pages are in the correct state */
 779         vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
 780                                   GFP_KERNEL);
 781         BUG_ON(vdso32_pagelist == NULL);
 782         for (i = 0; i < vdso32_pages; i++) {
 783                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
 784                 ClearPageReserved(pg);
 785                 get_page(pg);
 786                 vdso32_pagelist[i] = pg;
 787         }
 788         vdso32_pagelist[i++] = virt_to_page(vdso_data);
 789         vdso32_pagelist[i] = NULL;
 790
 791 #ifdef CONFIG_PPC64
 792         vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
 793                                   GFP_KERNEL);
 794         BUG_ON(vdso64_pagelist == NULL);
 795         for (i = 0; i < vdso64_pages; i++) {
 796                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
 797                 ClearPageReserved(pg);
 798                 get_page(pg);
 799                 vdso64_pagelist[i] = pg;
 800         }
 801         vdso64_pagelist[i++] = virt_to_page(vdso_data);
 802         vdso64_pagelist[i] = NULL;
 803 #endif /* CONFIG_PPC64 */
 804
 805         get_page(virt_to_page(vdso_data));
 806
 807         smp_wmb();
 808         vdso_ready = 1;
 809
 810         return 0;
 811 }
 812 arch_initcall(vdso_init);
 813
 814 int in_gate_area_no_task(unsigned long addr)
 815 {
 816         return 0;
 817 }
 818
 819 int in_gate_area(struct task_struct *task, unsigned long addr)
 820 {
 821         return 0;
 822 }
 823
 824 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 825 {
 826         return NULL;
 827 }
 828