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/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/stddef.h>
  18 #include <linux/unistd.h>
  19 #include <linux/slab.h>
  20 #include <linux/user.h>
  21 #include <linux/elf.h>
  22 #include <linux/security.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/memblock.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/prom.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 #include "setup.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 /* The alignment of the vDSO */
  53 #define VDSO_ALIGNMENT  (1 << 16)
  54
  55 extern char vdso32_start, vdso32_end;
  56 static void *vdso32_kbase = &vdso32_start;
  57 static unsigned int vdso32_pages;
  58 static struct page **vdso32_pagelist;
  59 unsigned long vdso32_sigtramp;
  60 unsigned long vdso32_rt_sigtramp;
  61
  62 #ifdef CONFIG_PPC64
  63 extern char vdso64_start, vdso64_end;
  64 static void *vdso64_kbase = &vdso64_start;
  65 static unsigned int vdso64_pages;
  66 static struct page **vdso64_pagelist;
  67 unsigned long vdso64_rt_sigtramp;
  68 #endif /* CONFIG_PPC64 */
  69
  70 static int vdso_ready;
  71
  72 /*
  73  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
  74  * Once the early boot kernel code no longer needs to muck around
  75  * with it, it will become dynamically allocated
  76  */
  77 static union {
  78         struct vdso_data        data;
  79         u8                      page[PAGE_SIZE];
  80 } vdso_data_store __page_aligned_data;
  81 struct vdso_data *vdso_data = &vdso_data_store.data;
  82
  83 /* Format of the patch table */
  84 struct vdso_patch_def
  85 {
  86         unsigned long   ftr_mask, ftr_value;
  87         const char      *gen_name;
  88         const char      *fix_name;
  89 };
  90
  91 /* Table of functions to patch based on the CPU type/revision
  92  *
  93  * Currently, we only change sync_dicache to do nothing on processors
  94  * with a coherent icache
  95  */
  96 static struct vdso_patch_def vdso_patches[] = {
  97         {
  98                 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
  99                 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
 100         },
 101         {
 102                 CPU_FTR_USE_TB, 0,
 103                 "__kernel_gettimeofday", NULL
 104         },
 105         {
 106                 CPU_FTR_USE_TB, 0,
 107                 "__kernel_clock_gettime", NULL
 108         },
 109         {
 110                 CPU_FTR_USE_TB, 0,
 111                 "__kernel_clock_getres", NULL
 112         },
 113         {
 114                 CPU_FTR_USE_TB, 0,
 115                 "__kernel_get_tbfreq", NULL
 116         },
 117 };
 118
 119 /*
 120  * Some infos carried around for each of them during parsing at
 121  * boot time.
 122  */
 123 struct lib32_elfinfo
 124 {
 125         Elf32_Ehdr      *hdr;           /* ptr to ELF */
 126         Elf32_Sym       *dynsym;        /* ptr to .dynsym section */
 127         unsigned long   dynsymsize;     /* size of .dynsym section */
 128         char            *dynstr;        /* ptr to .dynstr section */
 129         unsigned long   text;           /* offset of .text section in .so */
 130 };
 131
 132 struct lib64_elfinfo
 133 {
 134         Elf64_Ehdr      *hdr;
 135         Elf64_Sym       *dynsym;
 136         unsigned long   dynsymsize;
 137         char            *dynstr;
 138         unsigned long   text;
 139 };
 140
 141
 142 #ifdef __DEBUG
 143 static void dump_one_vdso_page(struct page *pg, struct page *upg)
 144 {
 145         printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
 146                page_count(pg),
 147                pg->flags);
 148         if (upg && !IS_ERR(upg) /* && pg != upg*/) {
 149                 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
 150                                                        << PAGE_SHIFT),
 151                        page_count(upg),
 152                        upg->flags);
 153         }
 154         printk("\n");
 155 }
 156
 157 static void dump_vdso_pages(struct vm_area_struct * vma)
 158 {
 159         int i;
 160
 161         if (!vma || is_32bit_task()) {
 162                 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
 163                 for (i=0; i<vdso32_pages; i++) {
 164                         struct page *pg = virt_to_page(vdso32_kbase +
 165                                                        i*PAGE_SIZE);
 166                         struct page *upg = (vma && vma->vm_mm) ?
 167                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
 168                                 : NULL;
 169                         dump_one_vdso_page(pg, upg);
 170                 }
 171         }
 172         if (!vma || !is_32bit_task()) {
 173                 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
 174                 for (i=0; i<vdso64_pages; i++) {
 175                         struct page *pg = virt_to_page(vdso64_kbase +
 176                                                        i*PAGE_SIZE);
 177                         struct page *upg = (vma && vma->vm_mm) ?
 178                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
 179                                 : NULL;
 180                         dump_one_vdso_page(pg, upg);
 181                 }
 182         }
 183 }
 184 #endif /* DEBUG */
 185
 186 /*
 187  * This is called from binfmt_elf, we create the special vma for the
 188  * vDSO and insert it into the mm struct tree
 189  */
 190 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 191 {
 192         struct mm_struct *mm = current->mm;
 193         struct page **vdso_pagelist;
 194         unsigned long vdso_pages;
 195         unsigned long vdso_base;
 196         int rc;
 197
 198         if (!vdso_ready)
 199                 return 0;
 200
 201 #ifdef CONFIG_PPC64
 202         if (is_32bit_task()) {
 203                 vdso_pagelist = vdso32_pagelist;
 204                 vdso_pages = vdso32_pages;
 205                 vdso_base = VDSO32_MBASE;
 206         } else {
 207                 vdso_pagelist = vdso64_pagelist;
 208                 vdso_pages = vdso64_pages;
 209                 /*
 210                  * On 64bit we don't have a preferred map address. This
 211                  * allows get_unmapped_area to find an area near other mmaps
 212                  * and most likely share a SLB entry.
 213                  */
 214                 vdso_base = 0;
 215         }
 216 #else
 217         vdso_pagelist = vdso32_pagelist;
 218         vdso_pages = vdso32_pages;
 219         vdso_base = VDSO32_MBASE;
 220 #endif
 221
 222         current->mm->context.vdso_base = 0;
 223
 224         /* vDSO has a problem and was disabled, just don't "enable" it for the
 225          * process
 226          */
 227         if (vdso_pages == 0)
 228                 return 0;
 229         /* Add a page to the vdso size for the data page */
 230         vdso_pages ++;
 231
 232         /*
 233          * pick a base address for the vDSO in process space. We try to put it
 234          * at vdso_base which is the "natural" base for it, but we might fail
 235          * and end up putting it elsewhere.
 236          * Add enough to the size so that the result can be aligned.
 237          */
 238         down_write(&mm->mmap_sem);
 239         vdso_base = get_unmapped_area(NULL, vdso_base,
 240                                       (vdso_pages << PAGE_SHIFT) +
 241                                       ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
 242                                       0, 0);
 243         if (IS_ERR_VALUE(vdso_base)) {
 244                 rc = vdso_base;
 245                 goto fail_mmapsem;
 246         }
 247
 248         /* Add required alignment. */
 249         vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
 250
 251         /*
 252          * Put vDSO base into mm struct. We need to do this before calling
 253          * install_special_mapping or the perf counter mmap tracking code
 254          * will fail to recognise it as a vDSO (since arch_vma_name fails).
 255          */
 256         current->mm->context.vdso_base = vdso_base;
 257
 258         /*
 259          * our vma flags don't have VM_WRITE so by default, the process isn't
 260          * allowed to write those pages.
 261          * gdb can break that with ptrace interface, and thus trigger COW on
 262          * those pages but it's then your responsibility to never do that on
 263          * the "data" page of the vDSO or you'll stop getting kernel updates
 264          * and your nice userland gettimeofday will be totally dead.
 265          * It's fine to use that for setting breakpoints in the vDSO code
 266          * pages though.
 267          */
 268         rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
 269                                      VM_READ|VM_EXEC|
 270                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
 271                                      vdso_pagelist);
 272         if (rc) {
 273                 current->mm->context.vdso_base = 0;
 274                 goto fail_mmapsem;
 275         }
 276
 277         up_write(&mm->mmap_sem);
 278         return 0;
 279
 280  fail_mmapsem:
 281         up_write(&mm->mmap_sem);
 282         return rc;
 283 }
 284
 285 const char *arch_vma_name(struct vm_area_struct *vma)
 286 {
 287         if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
 288                 return "[vdso]";
 289         return NULL;
 290 }
 291
 292
 293
 294 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
 295                                   unsigned long *size)
 296 {
 297         Elf32_Shdr *sechdrs;
 298         unsigned int i;
 299         char *secnames;
 300
 301         /* Grab section headers and strings so we can tell who is who */
 302         sechdrs = (void *)ehdr + ehdr->e_shoff;
 303         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 304
 305         /* Find the section they want */
 306         for (i = 1; i < ehdr->e_shnum; i++) {
 307                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 308                         if (size)
 309                                 *size = sechdrs[i].sh_size;
 310                         return (void *)ehdr + sechdrs[i].sh_offset;
 311                 }
 312         }
 313         *size = 0;
 314         return NULL;
 315 }
 316
 317 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
 318                                         const char *symname)
 319 {
 320         unsigned int i;
 321         char name[MAX_SYMNAME], *c;
 322
 323         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
 324                 if (lib->dynsym[i].st_name == 0)
 325                         continue;
 326                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 327                         MAX_SYMNAME);
 328                 c = strchr(name, '@');
 329                 if (c)
 330                         *c = 0;
 331                 if (strcmp(symname, name) == 0)
 332                         return &lib->dynsym[i];
 333         }
 334         return NULL;
 335 }
 336
 337 /* Note that we assume the section is .text and the symbol is relative to
 338  * the library base
 339  */
 340 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 341                                             const char *symname)
 342 {
 343         Elf32_Sym *sym = find_symbol32(lib, symname);
 344
 345         if (sym == NULL) {
 346                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
 347                        symname);
 348                 return 0;
 349         }
 350         return sym->st_value - VDSO32_LBASE;
 351 }
 352
 353 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
 354                                        struct lib64_elfinfo *v64,
 355                                        const char *orig, const char *fix)
 356 {
 357         Elf32_Sym *sym32_gen, *sym32_fix;
 358
 359         sym32_gen = find_symbol32(v32, orig);
 360         if (sym32_gen == NULL) {
 361                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
 362                 return -1;
 363         }
 364         if (fix == NULL) {
 365                 sym32_gen->st_name = 0;
 366                 return 0;
 367         }
 368         sym32_fix = find_symbol32(v32, fix);
 369         if (sym32_fix == NULL) {
 370                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
 371                 return -1;
 372         }
 373         sym32_gen->st_value = sym32_fix->st_value;
 374         sym32_gen->st_size = sym32_fix->st_size;
 375         sym32_gen->st_info = sym32_fix->st_info;
 376         sym32_gen->st_other = sym32_fix->st_other;
 377         sym32_gen->st_shndx = sym32_fix->st_shndx;
 378
 379         return 0;
 380 }
 381
 382
 383 #ifdef CONFIG_PPC64
 384
 385 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
 386                                   unsigned long *size)
 387 {
 388         Elf64_Shdr *sechdrs;
 389         unsigned int i;
 390         char *secnames;
 391
 392         /* Grab section headers and strings so we can tell who is who */
 393         sechdrs = (void *)ehdr + ehdr->e_shoff;
 394         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 395
 396         /* Find the section they want */
 397         for (i = 1; i < ehdr->e_shnum; i++) {
 398                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 399                         if (size)
 400                                 *size = sechdrs[i].sh_size;
 401                         return (void *)ehdr + sechdrs[i].sh_offset;
 402                 }
 403         }
 404         if (size)
 405                 *size = 0;
 406         return NULL;
 407 }
 408
 409 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
 410                                         const char *symname)
 411 {
 412         unsigned int i;
 413         char name[MAX_SYMNAME], *c;
 414
 415         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
 416                 if (lib->dynsym[i].st_name == 0)
 417                         continue;
 418                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 419                         MAX_SYMNAME);
 420                 c = strchr(name, '@');
 421                 if (c)
 422                         *c = 0;
 423                 if (strcmp(symname, name) == 0)
 424                         return &lib->dynsym[i];
 425         }
 426         return NULL;
 427 }
 428
 429 /* Note that we assume the section is .text and the symbol is relative to
 430  * the library base
 431  */
 432 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
 433                                             const char *symname)
 434 {
 435         Elf64_Sym *sym = find_symbol64(lib, symname);
 436
 437         if (sym == NULL) {
 438                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
 439                        symname);
 440                 return 0;
 441         }
 442 #ifdef VDS64_HAS_DESCRIPTORS
 443         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
 444                 VDSO64_LBASE;
 445 #else
 446         return sym->st_value - VDSO64_LBASE;
 447 #endif
 448 }
 449
 450 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
 451                                        struct lib64_elfinfo *v64,
 452                                        const char *orig, const char *fix)
 453 {
 454         Elf64_Sym *sym64_gen, *sym64_fix;
 455
 456         sym64_gen = find_symbol64(v64, orig);
 457         if (sym64_gen == NULL) {
 458                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
 459                 return -1;
 460         }
 461         if (fix == NULL) {
 462                 sym64_gen->st_name = 0;
 463                 return 0;
 464         }
 465         sym64_fix = find_symbol64(v64, fix);
 466         if (sym64_fix == NULL) {
 467                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
 468                 return -1;
 469         }
 470         sym64_gen->st_value = sym64_fix->st_value;
 471         sym64_gen->st_size = sym64_fix->st_size;
 472         sym64_gen->st_info = sym64_fix->st_info;
 473         sym64_gen->st_other = sym64_fix->st_other;
 474         sym64_gen->st_shndx = sym64_fix->st_shndx;
 475
 476         return 0;
 477 }
 478
 479 #endif /* CONFIG_PPC64 */
 480
 481
 482 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
 483                                         struct lib64_elfinfo *v64)
 484 {
 485         void *sect;
 486
 487         /*
 488          * Locate symbol tables & text section
 489          */
 490
 491         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
 492         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
 493         if (v32->dynsym == NULL || v32->dynstr == NULL) {
 494                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
 495                 return -1;
 496         }
 497         sect = find_section32(v32->hdr, ".text", NULL);
 498         if (sect == NULL) {
 499                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
 500                 return -1;
 501         }
 502         v32->text = sect - vdso32_kbase;
 503
 504 #ifdef CONFIG_PPC64
 505         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
 506         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
 507         if (v64->dynsym == NULL || v64->dynstr == NULL) {
 508                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
 509                 return -1;
 510         }
 511         sect = find_section64(v64->hdr, ".text", NULL);
 512         if (sect == NULL) {
 513                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
 514                 return -1;
 515         }
 516         v64->text = sect - vdso64_kbase;
 517 #endif /* CONFIG_PPC64 */
 518
 519         return 0;
 520 }
 521
 522 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
 523                                           struct lib64_elfinfo *v64)
 524 {
 525         /*
 526          * Find signal trampolines
 527          */
 528
 529 #ifdef CONFIG_PPC64
 530         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
 531 #endif
 532         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
 533         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
 534 }
 535
 536 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
 537                                        struct lib64_elfinfo *v64)
 538 {
 539         Elf32_Sym *sym32;
 540 #ifdef CONFIG_PPC64
 541         Elf64_Sym *sym64;
 542
 543         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
 544         if (sym64 == NULL) {
 545                 printk(KERN_ERR "vDSO64: Can't find symbol "
 546                        "__kernel_datapage_offset !\n");
 547                 return -1;
 548         }
 549         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
 550                 (vdso64_pages << PAGE_SHIFT) -
 551                 (sym64->st_value - VDSO64_LBASE);
 552 #endif /* CONFIG_PPC64 */
 553
 554         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
 555         if (sym32 == NULL) {
 556                 printk(KERN_ERR "vDSO32: Can't find symbol "
 557                        "__kernel_datapage_offset !\n");
 558                 return -1;
 559         }
 560         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
 561                 (vdso32_pages << PAGE_SHIFT) -
 562                 (sym32->st_value - VDSO32_LBASE);
 563
 564         return 0;
 565 }
 566
 567
 568 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
 569                                       struct lib64_elfinfo *v64)
 570 {
 571         void *start32;
 572         unsigned long size32;
 573
 574 #ifdef CONFIG_PPC64
 575         void *start64;
 576         unsigned long size64;
 577
 578         start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
 579         if (start64)
 580                 do_feature_fixups(cur_cpu_spec->cpu_features,
 581                                   start64, start64 + size64);
 582
 583         start64 = find_section64(v64->hdr, "__mmu_ftr_fixup", &size64);
 584         if (start64)
 585                 do_feature_fixups(cur_cpu_spec->mmu_features,
 586                                   start64, start64 + size64);
 587
 588         start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
 589         if (start64)
 590                 do_feature_fixups(powerpc_firmware_features,
 591                                   start64, start64 + size64);
 592
 593         start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
 594         if (start64)
 595                 do_lwsync_fixups(cur_cpu_spec->cpu_features,
 596                                  start64, start64 + size64);
 597 #endif /* CONFIG_PPC64 */
 598
 599         start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
 600         if (start32)
 601                 do_feature_fixups(cur_cpu_spec->cpu_features,
 602                                   start32, start32 + size32);
 603
 604         start32 = find_section32(v32->hdr, "__mmu_ftr_fixup", &size32);
 605         if (start32)
 606                 do_feature_fixups(cur_cpu_spec->mmu_features,
 607                                   start32, start32 + size32);
 608
 609 #ifdef CONFIG_PPC64
 610         start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
 611         if (start32)
 612                 do_feature_fixups(powerpc_firmware_features,
 613                                   start32, start32 + size32);
 614 #endif /* CONFIG_PPC64 */
 615
 616         start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
 617         if (start32)
 618                 do_lwsync_fixups(cur_cpu_spec->cpu_features,
 619                                  start32, start32 + size32);
 620
 621         return 0;
 622 }
 623
 624 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
 625                                        struct lib64_elfinfo *v64)
 626 {
 627         int i;
 628
 629         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
 630                 struct vdso_patch_def *patch = &vdso_patches[i];
 631                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
 632                         == patch->ftr_value;
 633                 if (!match)
 634                         continue;
 635
 636                 DBG("replacing %s with %s...\n", patch->gen_name,
 637                     patch->fix_name ? "NONE" : patch->fix_name);
 638
 639                 /*
 640                  * Patch the 32 bits and 64 bits symbols. Note that we do not
 641                  * patch the "." symbol on 64 bits.
 642                  * It would be easy to do, but doesn't seem to be necessary,
 643                  * patching the OPD symbol is enough.
 644                  */
 645                 vdso_do_func_patch32(v32, v64, patch->gen_name,
 646                                      patch->fix_name);
 647 #ifdef CONFIG_PPC64
 648                 vdso_do_func_patch64(v32, v64, patch->gen_name,
 649                                      patch->fix_name);
 650 #endif /* CONFIG_PPC64 */
 651         }
 652
 653         return 0;
 654 }
 655
 656
 657 static __init int vdso_setup(void)
 658 {
 659         struct lib32_elfinfo    v32;
 660         struct lib64_elfinfo    v64;
 661
 662         v32.hdr = vdso32_kbase;
 663 #ifdef CONFIG_PPC64
 664         v64.hdr = vdso64_kbase;
 665 #endif
 666         if (vdso_do_find_sections(&v32, &v64))
 667                 return -1;
 668
 669         if (vdso_fixup_datapage(&v32, &v64))
 670                 return -1;
 671
 672         if (vdso_fixup_features(&v32, &v64))
 673                 return -1;
 674
 675         if (vdso_fixup_alt_funcs(&v32, &v64))
 676                 return -1;
 677
 678         vdso_setup_trampolines(&v32, &v64);
 679
 680         return 0;
 681 }
 682
 683 /*
 684  * Called from setup_arch to initialize the bitmap of available
 685  * syscalls in the systemcfg page
 686  */
 687 static void __init vdso_setup_syscall_map(void)
 688 {
 689         unsigned int i;
 690         extern unsigned long *sys_call_table;
 691         extern unsigned long sys_ni_syscall;
 692
 693
 694         for (i = 0; i < __NR_syscalls; i++) {
 695 #ifdef CONFIG_PPC64
 696                 if (sys_call_table[i*2] != sys_ni_syscall)
 697                         vdso_data->syscall_map_64[i >> 5] |=
 698                                 0x80000000UL >> (i & 0x1f);
 699                 if (sys_call_table[i*2+1] != sys_ni_syscall)
 700                         vdso_data->syscall_map_32[i >> 5] |=
 701                                 0x80000000UL >> (i & 0x1f);
 702 #else /* CONFIG_PPC64 */
 703                 if (sys_call_table[i] != sys_ni_syscall)
 704                         vdso_data->syscall_map_32[i >> 5] |=
 705                                 0x80000000UL >> (i & 0x1f);
 706 #endif /* CONFIG_PPC64 */
 707         }
 708 }
 709
 710
 711 static int __init vdso_init(void)
 712 {
 713         int i;
 714
 715 #ifdef CONFIG_PPC64
 716         /*
 717          * Fill up the "systemcfg" stuff for backward compatibility
 718          */
 719         strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
 720         vdso_data->version.major = SYSTEMCFG_MAJOR;
 721         vdso_data->version.minor = SYSTEMCFG_MINOR;
 722         vdso_data->processor = mfspr(SPRN_PVR);
 723         /*
 724          * Fake the old platform number for pSeries and iSeries and add
 725          * in LPAR bit if necessary
 726          */
 727         vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
 728         if (firmware_has_feature(FW_FEATURE_LPAR))
 729                 vdso_data->platform |= 1;
 730         vdso_data->physicalMemorySize = memblock_phys_mem_size();
 731         vdso_data->dcache_size = ppc64_caches.dsize;
 732         vdso_data->dcache_line_size = ppc64_caches.dline_size;
 733         vdso_data->icache_size = ppc64_caches.isize;
 734         vdso_data->icache_line_size = ppc64_caches.iline_size;
 735
 736         /* XXXOJN: Blocks should be added to ppc64_caches and used instead */
 737         vdso_data->dcache_block_size = ppc64_caches.dline_size;
 738         vdso_data->icache_block_size = ppc64_caches.iline_size;
 739         vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
 740         vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
 741
 742         /*
 743          * Calculate the size of the 64 bits vDSO
 744          */
 745         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
 746         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
 747 #else
 748         vdso_data->dcache_block_size = L1_CACHE_BYTES;
 749         vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
 750         vdso_data->icache_block_size = L1_CACHE_BYTES;
 751         vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
 752 #endif /* CONFIG_PPC64 */
 753
 754
 755         /*
 756          * Calculate the size of the 32 bits vDSO
 757          */
 758         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
 759         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
 760
 761
 762         /*
 763          * Setup the syscall map in the vDOS
 764          */
 765         vdso_setup_syscall_map();
 766
 767         /*
 768          * Initialize the vDSO images in memory, that is do necessary
 769          * fixups of vDSO symbols, locate trampolines, etc...
 770          */
 771         if (vdso_setup()) {
 772                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
 773                 vdso32_pages = 0;
 774 #ifdef CONFIG_PPC64
 775                 vdso64_pages = 0;
 776 #endif
 777                 return 0;
 778         }
 779
 780         /* Make sure pages are in the correct state */
 781         vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
 782                                   GFP_KERNEL);
 783         BUG_ON(vdso32_pagelist == NULL);
 784         for (i = 0; i < vdso32_pages; i++) {
 785                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
 786                 ClearPageReserved(pg);
 787                 get_page(pg);
 788                 vdso32_pagelist[i] = pg;
 789         }
 790         vdso32_pagelist[i++] = virt_to_page(vdso_data);
 791         vdso32_pagelist[i] = NULL;
 792
 793 #ifdef CONFIG_PPC64
 794         vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
 795                                   GFP_KERNEL);
 796         BUG_ON(vdso64_pagelist == NULL);
 797         for (i = 0; i < vdso64_pages; i++) {
 798                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
 799                 ClearPageReserved(pg);
 800                 get_page(pg);
 801                 vdso64_pagelist[i] = pg;
 802         }
 803         vdso64_pagelist[i++] = virt_to_page(vdso_data);
 804         vdso64_pagelist[i] = NULL;
 805 #endif /* CONFIG_PPC64 */
 806
 807         get_page(virt_to_page(vdso_data));
 808
 809         smp_wmb();
 810         vdso_ready = 1;
 811
 812         return 0;
 813 }
 814 arch_initcall(vdso_init);
 815
 816 int in_gate_area_no_mm(unsigned long addr)
 817 {
 818         return 0;
 819 }
 820
 821 int in_gate_area(struct mm_struct *mm, unsigned long addr)
 822 {
 823         return 0;
 824 }
 825
 826 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 827 {
 828         return NULL;
 829 }
 830