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 #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 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, vma->vm_start + i*PAGE_SIZE, 0)
 149                                 : NULL;
 150                         dump_one_vdso_page(pg, upg);
 151                 }
 152         }
 153         if (!vma || !test_thread_flag(TIF_32BIT)) {
 154                 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
 155                 for (i=0; i<vdso64_pages; i++) {
 156                         struct page *pg = virt_to_page(vdso64_kbase +
 157                                                        i*PAGE_SIZE);
 158                         struct page *upg = (vma && vma->vm_mm) ?
 159                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
 160                                 : NULL;
 161                         dump_one_vdso_page(pg, upg);
 162                 }
 163         }
 164 }
 165 #endif /* DEBUG */
 166
 167 /*
 168  * Keep a dummy vma_close for now, it will prevent VMA merging.
 169  */
 170 static void vdso_vma_close(struct vm_area_struct * vma)
 171 {
 172 }
 173
 174 /*
 175  * Our nopage() function, maps in the actual vDSO kernel pages, they will
 176  * be mapped read-only by do_no_page(), and eventually COW'ed, either
 177  * right away for an initial write access, or by do_wp_page().
 178  */
 179 static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
 180                                      unsigned long address, int *type)
 181 {
 182         unsigned long offset = address - vma->vm_start;
 183         struct page *pg;
 184 #ifdef CONFIG_PPC64
 185         void *vbase = (vma->vm_mm->task_size > TASK_SIZE_USER32) ?
 186                 vdso64_kbase : vdso32_kbase;
 187 #else
 188         void *vbase = vdso32_kbase;
 189 #endif
 190
 191         DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
 192             current->comm, address, offset);
 193
 194         if (address < vma->vm_start || address > vma->vm_end)
 195                 return NOPAGE_SIGBUS;
 196
 197         /*
 198          * Last page is systemcfg.
 199          */
 200         if ((vma->vm_end - address) <= PAGE_SIZE)
 201                 pg = virt_to_page(vdso_data);
 202         else
 203                 pg = virt_to_page(vbase + offset);
 204
 205         get_page(pg);
 206         DBG(" ->page count: %d\n", page_count(pg));
 207
 208         return pg;
 209 }
 210
 211 static struct vm_operations_struct vdso_vmops = {
 212         .close  = vdso_vma_close,
 213         .nopage = vdso_vma_nopage,
 214 };
 215
 216 /*
 217  * This is called from binfmt_elf, we create the special vma for the
 218  * vDSO and insert it into the mm struct tree
 219  */
 220 int arch_setup_additional_pages(struct linux_binprm *bprm,
 221                                 int executable_stack)
 222 {
 223         struct mm_struct *mm = current->mm;
 224         struct vm_area_struct *vma;
 225         unsigned long vdso_pages;
 226         unsigned long vdso_base;
 227         int rc;
 228
 229 #ifdef CONFIG_PPC64
 230         if (test_thread_flag(TIF_32BIT)) {
 231                 vdso_pages = vdso32_pages;
 232                 vdso_base = VDSO32_MBASE;
 233         } else {
 234                 vdso_pages = vdso64_pages;
 235                 vdso_base = VDSO64_MBASE;
 236         }
 237 #else
 238         vdso_pages = vdso32_pages;
 239         vdso_base = VDSO32_MBASE;
 240 #endif
 241
 242         current->mm->context.vdso_base = 0;
 243
 244         /* vDSO has a problem and was disabled, just don't "enable" it for the
 245          * process
 246          */
 247         if (vdso_pages == 0)
 248                 return 0;
 249         /* Add a page to the vdso size for the data page */
 250         vdso_pages ++;
 251
 252         /*
 253          * pick a base address for the vDSO in process space. We try to put it
 254          * at vdso_base which is the "natural" base for it, but we might fail
 255          * and end up putting it elsewhere.
 256          */
 257         down_write(&mm->mmap_sem);
 258         vdso_base = get_unmapped_area(NULL, vdso_base,
 259                                       vdso_pages << PAGE_SHIFT, 0, 0);
 260         if (IS_ERR_VALUE(vdso_base)) {
 261                 rc = vdso_base;
 262                 goto fail_mmapsem;
 263         }
 264
 265
 266         /* Allocate a VMA structure and fill it up */
 267         vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 268         if (vma == NULL) {
 269                 rc = -ENOMEM;
 270                 goto fail_mmapsem;
 271         }
 272         vma->vm_mm = mm;
 273         vma->vm_start = vdso_base;
 274         vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
 275
 276         /*
 277          * our vma flags don't have VM_WRITE so by default, the process isn't
 278          * allowed to write those pages.
 279          * gdb can break that with ptrace interface, and thus trigger COW on
 280          * those pages but it's then your responsibility to never do that on
 281          * the "data" page of the vDSO or you'll stop getting kernel updates
 282          * and your nice userland gettimeofday will be totally dead.
 283          * It's fine to use that for setting breakpoints in the vDSO code
 284          * pages though
 285          */
 286         vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC;
 287         /*
 288          * Make sure the vDSO gets into every core dump.
 289          * Dumping its contents makes post-mortem fully interpretable later
 290          * without matching up the same kernel and hardware config to see
 291          * what PC values meant.
 292          */
 293         vma->vm_flags |= VM_ALWAYSDUMP;
 294         vma->vm_flags |= mm->def_flags;
 295         vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
 296         vma->vm_ops = &vdso_vmops;
 297
 298         /* Insert new VMA */
 299         rc = insert_vm_struct(mm, vma);
 300         if (rc)
 301                 goto fail_vma;
 302
 303         /* Put vDSO base into mm struct and account for memory usage */
 304         current->mm->context.vdso_base = vdso_base;
 305         mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 306         up_write(&mm->mmap_sem);
 307         return 0;
 308
 309  fail_vma:
 310         kmem_cache_free(vm_area_cachep, vma);
 311  fail_mmapsem:
 312         up_write(&mm->mmap_sem);
 313         return rc;
 314 }
 315
 316 const char *arch_vma_name(struct vm_area_struct *vma)
 317 {
 318         if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
 319                 return "[vdso]";
 320         return NULL;
 321 }
 322
 323
 324
 325 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
 326                                   unsigned long *size)
 327 {
 328         Elf32_Shdr *sechdrs;
 329         unsigned int i;
 330         char *secnames;
 331
 332         /* Grab section headers and strings so we can tell who is who */
 333         sechdrs = (void *)ehdr + ehdr->e_shoff;
 334         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 335
 336         /* Find the section they want */
 337         for (i = 1; i < ehdr->e_shnum; i++) {
 338                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 339                         if (size)
 340                                 *size = sechdrs[i].sh_size;
 341                         return (void *)ehdr + sechdrs[i].sh_offset;
 342                 }
 343         }
 344         *size = 0;
 345         return NULL;
 346 }
 347
 348 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
 349                                         const char *symname)
 350 {
 351         unsigned int i;
 352         char name[MAX_SYMNAME], *c;
 353
 354         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
 355                 if (lib->dynsym[i].st_name == 0)
 356                         continue;
 357                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 358                         MAX_SYMNAME);
 359                 c = strchr(name, '@');
 360                 if (c)
 361                         *c = 0;
 362                 if (strcmp(symname, name) == 0)
 363                         return &lib->dynsym[i];
 364         }
 365         return NULL;
 366 }
 367
 368 /* Note that we assume the section is .text and the symbol is relative to
 369  * the library base
 370  */
 371 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 372                                             const char *symname)
 373 {
 374         Elf32_Sym *sym = find_symbol32(lib, symname);
 375
 376         if (sym == NULL) {
 377                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
 378                        symname);
 379                 return 0;
 380         }
 381         return sym->st_value - VDSO32_LBASE;
 382 }
 383
 384 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
 385                                 struct lib64_elfinfo *v64,
 386                                 const char *orig, const char *fix)
 387 {
 388         Elf32_Sym *sym32_gen, *sym32_fix;
 389
 390         sym32_gen = find_symbol32(v32, orig);
 391         if (sym32_gen == NULL) {
 392                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
 393                 return -1;
 394         }
 395         if (fix == NULL) {
 396                 sym32_gen->st_name = 0;
 397                 return 0;
 398         }
 399         sym32_fix = find_symbol32(v32, fix);
 400         if (sym32_fix == NULL) {
 401                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
 402                 return -1;
 403         }
 404         sym32_gen->st_value = sym32_fix->st_value;
 405         sym32_gen->st_size = sym32_fix->st_size;
 406         sym32_gen->st_info = sym32_fix->st_info;
 407         sym32_gen->st_other = sym32_fix->st_other;
 408         sym32_gen->st_shndx = sym32_fix->st_shndx;
 409
 410         return 0;
 411 }
 412
 413
 414 #ifdef CONFIG_PPC64
 415
 416 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
 417                                   unsigned long *size)
 418 {
 419         Elf64_Shdr *sechdrs;
 420         unsigned int i;
 421         char *secnames;
 422
 423         /* Grab section headers and strings so we can tell who is who */
 424         sechdrs = (void *)ehdr + ehdr->e_shoff;
 425         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 426
 427         /* Find the section they want */
 428         for (i = 1; i < ehdr->e_shnum; i++) {
 429                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 430                         if (size)
 431                                 *size = sechdrs[i].sh_size;
 432                         return (void *)ehdr + sechdrs[i].sh_offset;
 433                 }
 434         }
 435         if (size)
 436                 *size = 0;
 437         return NULL;
 438 }
 439
 440 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
 441                                         const char *symname)
 442 {
 443         unsigned int i;
 444         char name[MAX_SYMNAME], *c;
 445
 446         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
 447                 if (lib->dynsym[i].st_name == 0)
 448                         continue;
 449                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 450                         MAX_SYMNAME);
 451                 c = strchr(name, '@');
 452                 if (c)
 453                         *c = 0;
 454                 if (strcmp(symname, name) == 0)
 455                         return &lib->dynsym[i];
 456         }
 457         return NULL;
 458 }
 459
 460 /* Note that we assume the section is .text and the symbol is relative to
 461  * the library base
 462  */
 463 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
 464                                             const char *symname)
 465 {
 466         Elf64_Sym *sym = find_symbol64(lib, symname);
 467
 468         if (sym == NULL) {
 469                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
 470                        symname);
 471                 return 0;
 472         }
 473 #ifdef VDS64_HAS_DESCRIPTORS
 474         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
 475                 VDSO64_LBASE;
 476 #else
 477         return sym->st_value - VDSO64_LBASE;
 478 #endif
 479 }
 480
 481 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
 482                                 struct lib64_elfinfo *v64,
 483                                 const char *orig, const char *fix)
 484 {
 485         Elf64_Sym *sym64_gen, *sym64_fix;
 486
 487         sym64_gen = find_symbol64(v64, orig);
 488         if (sym64_gen == NULL) {
 489                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
 490                 return -1;
 491         }
 492         if (fix == NULL) {
 493                 sym64_gen->st_name = 0;
 494                 return 0;
 495         }
 496         sym64_fix = find_symbol64(v64, fix);
 497         if (sym64_fix == NULL) {
 498                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
 499                 return -1;
 500         }
 501         sym64_gen->st_value = sym64_fix->st_value;
 502         sym64_gen->st_size = sym64_fix->st_size;
 503         sym64_gen->st_info = sym64_fix->st_info;
 504         sym64_gen->st_other = sym64_fix->st_other;
 505         sym64_gen->st_shndx = sym64_fix->st_shndx;
 506
 507         return 0;
 508 }
 509
 510 #endif /* CONFIG_PPC64 */
 511
 512
 513 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
 514                                         struct lib64_elfinfo *v64)
 515 {
 516         void *sect;
 517
 518         /*
 519          * Locate symbol tables & text section
 520          */
 521
 522         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
 523         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
 524         if (v32->dynsym == NULL || v32->dynstr == NULL) {
 525                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
 526                 return -1;
 527         }
 528         sect = find_section32(v32->hdr, ".text", NULL);
 529         if (sect == NULL) {
 530                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
 531                 return -1;
 532         }
 533         v32->text = sect - vdso32_kbase;
 534
 535 #ifdef CONFIG_PPC64
 536         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
 537         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
 538         if (v64->dynsym == NULL || v64->dynstr == NULL) {
 539                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
 540                 return -1;
 541         }
 542         sect = find_section64(v64->hdr, ".text", NULL);
 543         if (sect == NULL) {
 544                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
 545                 return -1;
 546         }
 547         v64->text = sect - vdso64_kbase;
 548 #endif /* CONFIG_PPC64 */
 549
 550         return 0;
 551 }
 552
 553 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
 554                                           struct lib64_elfinfo *v64)
 555 {
 556         /*
 557          * Find signal trampolines
 558          */
 559
 560 #ifdef CONFIG_PPC64
 561         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
 562 #endif
 563         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
 564         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
 565 }
 566
 567 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
 568                                        struct lib64_elfinfo *v64)
 569 {
 570         Elf32_Sym *sym32;
 571 #ifdef CONFIG_PPC64
 572         Elf64_Sym *sym64;
 573
 574         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
 575         if (sym64 == NULL) {
 576                 printk(KERN_ERR "vDSO64: Can't find symbol "
 577                        "__kernel_datapage_offset !\n");
 578                 return -1;
 579         }
 580         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
 581                 (vdso64_pages << PAGE_SHIFT) -
 582                 (sym64->st_value - VDSO64_LBASE);
 583 #endif /* CONFIG_PPC64 */
 584
 585         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
 586         if (sym32 == NULL) {
 587                 printk(KERN_ERR "vDSO32: Can't find symbol "
 588                        "__kernel_datapage_offset !\n");
 589                 return -1;
 590         }
 591         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
 592                 (vdso32_pages << PAGE_SHIFT) -
 593                 (sym32->st_value - VDSO32_LBASE);
 594
 595         return 0;
 596 }
 597
 598
 599 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
 600                                       struct lib64_elfinfo *v64)
 601 {
 602         void *start32;
 603         unsigned long size32;
 604
 605 #ifdef CONFIG_PPC64
 606         void *start64;
 607         unsigned long size64;
 608
 609         start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
 610         if (start64)
 611                 do_feature_fixups(cur_cpu_spec->cpu_features,
 612                                   start64, start64 + size64);
 613
 614         start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
 615         if (start64)
 616                 do_feature_fixups(powerpc_firmware_features,
 617                                   start64, start64 + size64);
 618 #endif /* CONFIG_PPC64 */
 619
 620         start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
 621         if (start32)
 622                 do_feature_fixups(cur_cpu_spec->cpu_features,
 623                                   start32, start32 + size32);
 624
 625 #ifdef CONFIG_PPC64
 626         start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
 627         if (start32)
 628                 do_feature_fixups(powerpc_firmware_features,
 629                                   start32, start32 + size32);
 630 #endif /* CONFIG_PPC64 */
 631
 632         return 0;
 633 }
 634
 635 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
 636                                        struct lib64_elfinfo *v64)
 637 {
 638         int i;
 639
 640         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
 641                 struct vdso_patch_def *patch = &vdso_patches[i];
 642                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
 643                         == patch->ftr_value;
 644                 if (!match)
 645                         continue;
 646
 647                 DBG("replacing %s with %s...\n", patch->gen_name,
 648                     patch->fix_name ? "NONE" : patch->fix_name);
 649
 650                 /*
 651                  * Patch the 32 bits and 64 bits symbols. Note that we do not
 652                  * patch the "." symbol on 64 bits.
 653                  * It would be easy to do, but doesn't seem to be necessary,
 654                  * patching the OPD symbol is enough.
 655                  */
 656                 vdso_do_func_patch32(v32, v64, patch->gen_name,
 657                                      patch->fix_name);
 658 #ifdef CONFIG_PPC64
 659                 vdso_do_func_patch64(v32, v64, patch->gen_name,
 660                                      patch->fix_name);
 661 #endif /* CONFIG_PPC64 */
 662         }
 663
 664         return 0;
 665 }
 666
 667
 668 static __init int vdso_setup(void)
 669 {
 670         struct lib32_elfinfo    v32;
 671         struct lib64_elfinfo    v64;
 672
 673         v32.hdr = vdso32_kbase;
 674 #ifdef CONFIG_PPC64
 675         v64.hdr = vdso64_kbase;
 676 #endif
 677         if (vdso_do_find_sections(&v32, &v64))
 678                 return -1;
 679
 680         if (vdso_fixup_datapage(&v32, &v64))
 681                 return -1;
 682
 683         if (vdso_fixup_features(&v32, &v64))
 684                 return -1;
 685
 686         if (vdso_fixup_alt_funcs(&v32, &v64))
 687                 return -1;
 688
 689         vdso_setup_trampolines(&v32, &v64);
 690
 691         return 0;
 692 }
 693
 694 /*
 695  * Called from setup_arch to initialize the bitmap of available
 696  * syscalls in the systemcfg page
 697  */
 698 static void __init vdso_setup_syscall_map(void)
 699 {
 700         unsigned int i;
 701         extern unsigned long *sys_call_table;
 702         extern unsigned long sys_ni_syscall;
 703
 704
 705         for (i = 0; i < __NR_syscalls; i++) {
 706 #ifdef CONFIG_PPC64
 707                 if (sys_call_table[i*2] != sys_ni_syscall)
 708                         vdso_data->syscall_map_64[i >> 5] |=
 709                                 0x80000000UL >> (i & 0x1f);
 710                 if (sys_call_table[i*2+1] != sys_ni_syscall)
 711                         vdso_data->syscall_map_32[i >> 5] |=
 712                                 0x80000000UL >> (i & 0x1f);
 713 #else /* CONFIG_PPC64 */
 714                 if (sys_call_table[i] != sys_ni_syscall)
 715                         vdso_data->syscall_map_32[i >> 5] |=
 716                                 0x80000000UL >> (i & 0x1f);
 717 #endif /* CONFIG_PPC64 */
 718         }
 719 }
 720
 721
 722 void __init vdso_init(void)
 723 {
 724         int i;
 725
 726 #ifdef CONFIG_PPC64
 727         /*
 728          * Fill up the "systemcfg" stuff for backward compatiblity
 729          */
 730         strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
 731         vdso_data->version.major = SYSTEMCFG_MAJOR;
 732         vdso_data->version.minor = SYSTEMCFG_MINOR;
 733         vdso_data->processor = mfspr(SPRN_PVR);
 734         /*
 735          * Fake the old platform number for pSeries and iSeries and add
 736          * in LPAR bit if necessary
 737          */
 738         vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
 739         if (firmware_has_feature(FW_FEATURE_LPAR))
 740                 vdso_data->platform |= 1;
 741         vdso_data->physicalMemorySize = lmb_phys_mem_size();
 742         vdso_data->dcache_size = ppc64_caches.dsize;
 743         vdso_data->dcache_line_size = ppc64_caches.dline_size;
 744         vdso_data->icache_size = ppc64_caches.isize;
 745         vdso_data->icache_line_size = ppc64_caches.iline_size;
 746
 747         /*
 748          * Calculate the size of the 64 bits vDSO
 749          */
 750         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
 751         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
 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;
 778         }
 779
 780         /* Make sure pages are in the correct state */
 781         for (i = 0; i < vdso32_pages; i++) {
 782                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
 783                 ClearPageReserved(pg);
 784                 get_page(pg);
 785
 786         }
 787 #ifdef CONFIG_PPC64
 788         for (i = 0; i < vdso64_pages; i++) {
 789                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
 790                 ClearPageReserved(pg);
 791                 get_page(pg);
 792         }
 793 #endif /* CONFIG_PPC64 */
 794
 795         get_page(virt_to_page(vdso_data));
 796 }
 797
 798 int in_gate_area_no_task(unsigned long addr)
 799 {
 800         return 0;
 801 }
 802
 803 int in_gate_area(struct task_struct *task, unsigned long addr)
 804 {
 805         return 0;
 806 }
 807
 808 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 809 {
 810         return NULL;
 811 }
 812