arch/powerpc/kernel/vdso.c

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This source file includes following definitions.
arch_setup_additional_pages
arch_vma_name
find_section32
find_symbol32
find_function32
vdso_do_func_patch32
find_function32
vdso_do_func_patch32
find_section64
find_symbol64
find_function64
vdso_do_func_patch64
vdso_do_find_sections
vdso_setup_trampolines
vdso_fixup_datapage
vdso_fixup_features
vdso_fixup_alt_funcs
vdso_setup
vdso_setup_syscall_map
vdso_getcpu_init
vdso_init
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 
   3 /*
   4  *    Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
   5  *                       <benh@kernel.crashing.org>
   6  */
   7 
   8 #include <linux/errno.h>
   9 #include <linux/sched.h>
  10 #include <linux/kernel.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/stddef.h>
  14 #include <linux/unistd.h>
  15 #include <linux/slab.h>
  16 #include <linux/user.h>
  17 #include <linux/elf.h>
  18 #include <linux/security.h>
  19 #include <linux/memblock.h>
  20 
  21 #include <asm/pgtable.h>
  22 #include <asm/processor.h>
  23 #include <asm/mmu.h>
  24 #include <asm/mmu_context.h>
  25 #include <asm/prom.h>
  26 #include <asm/machdep.h>
  27 #include <asm/cputable.h>
  28 #include <asm/sections.h>
  29 #include <asm/firmware.h>
  30 #include <asm/vdso.h>
  31 #include <asm/vdso_datapage.h>
  32 #include <asm/setup.h>
  33 
  34 #undef DEBUG
  35 
  36 #ifdef DEBUG
  37 #define DBG(fmt...) printk(fmt)
  38 #else
  39 #define DBG(fmt...)
  40 #endif
  41 
  42 /* Max supported size for symbol names */
  43 #define MAX_SYMNAME     64
  44 
  45 /* The alignment of the vDSO */
  46 #define VDSO_ALIGNMENT  (1 << 16)
  47 
  48 static unsigned int vdso32_pages;
  49 static void *vdso32_kbase;
  50 static struct page **vdso32_pagelist;
  51 unsigned long vdso32_sigtramp;
  52 unsigned long vdso32_rt_sigtramp;
  53 
  54 #ifdef CONFIG_VDSO32
  55 extern char vdso32_start, vdso32_end;
  56 #endif
  57 
  58 #ifdef CONFIG_PPC64
  59 extern char vdso64_start, vdso64_end;
  60 static void *vdso64_kbase = &vdso64_start;
  61 static unsigned int vdso64_pages;
  62 static struct page **vdso64_pagelist;
  63 unsigned long vdso64_rt_sigtramp;
  64 #endif /* CONFIG_PPC64 */
  65 
  66 static int vdso_ready;
  67 
  68 /*
  69  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
  70  * Once the early boot kernel code no longer needs to muck around
  71  * with it, it will become dynamically allocated
  72  */
  73 static union {
  74         struct vdso_data        data;
  75         u8                      page[PAGE_SIZE];
  76 } vdso_data_store __page_aligned_data;
  77 struct vdso_data *vdso_data = &vdso_data_store.data;
  78 
  79 /* Format of the patch table */
  80 struct vdso_patch_def
  81 {
  82         unsigned long   ftr_mask, ftr_value;
  83         const char      *gen_name;
  84         const char      *fix_name;
  85 };
  86 
  87 /* Table of functions to patch based on the CPU type/revision
  88  *
  89  * Currently, we only change sync_dicache to do nothing on processors
  90  * with a coherent icache
  91  */
  92 static struct vdso_patch_def vdso_patches[] = {
  93         {
  94                 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
  95                 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
  96         },
  97 };
  98 
  99 /*
 100  * Some infos carried around for each of them during parsing at
 101  * boot time.
 102  */
 103 struct lib32_elfinfo
 104 {
 105         Elf32_Ehdr      *hdr;           /* ptr to ELF */
 106         Elf32_Sym       *dynsym;        /* ptr to .dynsym section */
 107         unsigned long   dynsymsize;     /* size of .dynsym section */
 108         char            *dynstr;        /* ptr to .dynstr section */
 109         unsigned long   text;           /* offset of .text section in .so */
 110 };
 111 
 112 struct lib64_elfinfo
 113 {
 114         Elf64_Ehdr      *hdr;
 115         Elf64_Sym       *dynsym;
 116         unsigned long   dynsymsize;
 117         char            *dynstr;
 118         unsigned long   text;
 119 };
 120 
 121 
 122 /*
 123  * This is called from binfmt_elf, we create the special vma for the
 124  * vDSO and insert it into the mm struct tree
 125  */
 126 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 127 {
 128         struct mm_struct *mm = current->mm;
 129         struct page **vdso_pagelist;
 130         unsigned long vdso_pages;
 131         unsigned long vdso_base;
 132         int rc;
 133 
 134         if (!vdso_ready)
 135                 return 0;
 136 
 137 #ifdef CONFIG_PPC64
 138         if (is_32bit_task()) {
 139                 vdso_pagelist = vdso32_pagelist;
 140                 vdso_pages = vdso32_pages;
 141                 vdso_base = VDSO32_MBASE;
 142         } else {
 143                 vdso_pagelist = vdso64_pagelist;
 144                 vdso_pages = vdso64_pages;
 145                 /*
 146                  * On 64bit we don't have a preferred map address. This
 147                  * allows get_unmapped_area to find an area near other mmaps
 148                  * and most likely share a SLB entry.
 149                  */
 150                 vdso_base = 0;
 151         }
 152 #else
 153         vdso_pagelist = vdso32_pagelist;
 154         vdso_pages = vdso32_pages;
 155         vdso_base = VDSO32_MBASE;
 156 #endif
 157 
 158         current->mm->context.vdso_base = 0;
 159 
 160         /* vDSO has a problem and was disabled, just don't "enable" it for the
 161          * process
 162          */
 163         if (vdso_pages == 0)
 164                 return 0;
 165         /* Add a page to the vdso size for the data page */
 166         vdso_pages ++;
 167 
 168         /*
 169          * pick a base address for the vDSO in process space. We try to put it
 170          * at vdso_base which is the "natural" base for it, but we might fail
 171          * and end up putting it elsewhere.
 172          * Add enough to the size so that the result can be aligned.
 173          */
 174         if (down_write_killable(&mm->mmap_sem))
 175                 return -EINTR;
 176         vdso_base = get_unmapped_area(NULL, vdso_base,
 177                                       (vdso_pages << PAGE_SHIFT) +
 178                                       ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
 179                                       0, 0);
 180         if (IS_ERR_VALUE(vdso_base)) {
 181                 rc = vdso_base;
 182                 goto fail_mmapsem;
 183         }
 184 
 185         /* Add required alignment. */
 186         vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
 187 
 188         /*
 189          * Put vDSO base into mm struct. We need to do this before calling
 190          * install_special_mapping or the perf counter mmap tracking code
 191          * will fail to recognise it as a vDSO (since arch_vma_name fails).
 192          */
 193         current->mm->context.vdso_base = vdso_base;
 194 
 195         /*
 196          * our vma flags don't have VM_WRITE so by default, the process isn't
 197          * allowed to write those pages.
 198          * gdb can break that with ptrace interface, and thus trigger COW on
 199          * those pages but it's then your responsibility to never do that on
 200          * the "data" page of the vDSO or you'll stop getting kernel updates
 201          * and your nice userland gettimeofday will be totally dead.
 202          * It's fine to use that for setting breakpoints in the vDSO code
 203          * pages though.
 204          */
 205         rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
 206                                      VM_READ|VM_EXEC|
 207                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
 208                                      vdso_pagelist);
 209         if (rc) {
 210                 current->mm->context.vdso_base = 0;
 211                 goto fail_mmapsem;
 212         }
 213 
 214         up_write(&mm->mmap_sem);
 215         return 0;
 216 
 217  fail_mmapsem:
 218         up_write(&mm->mmap_sem);
 219         return rc;
 220 }
 221 
 222 const char *arch_vma_name(struct vm_area_struct *vma)
 223 {
 224         if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
 225                 return "[vdso]";
 226         return NULL;
 227 }
 228 
 229 
 230 
 231 #ifdef CONFIG_VDSO32
 232 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
 233                                   unsigned long *size)
 234 {
 235         Elf32_Shdr *sechdrs;
 236         unsigned int i;
 237         char *secnames;
 238 
 239         /* Grab section headers and strings so we can tell who is who */
 240         sechdrs = (void *)ehdr + ehdr->e_shoff;
 241         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 242 
 243         /* Find the section they want */
 244         for (i = 1; i < ehdr->e_shnum; i++) {
 245                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 246                         if (size)
 247                                 *size = sechdrs[i].sh_size;
 248                         return (void *)ehdr + sechdrs[i].sh_offset;
 249                 }
 250         }
 251         *size = 0;
 252         return NULL;
 253 }
 254 
 255 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
 256                                         const char *symname)
 257 {
 258         unsigned int i;
 259         char name[MAX_SYMNAME], *c;
 260 
 261         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
 262                 if (lib->dynsym[i].st_name == 0)
 263                         continue;
 264                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 265                         MAX_SYMNAME);
 266                 c = strchr(name, '@');
 267                 if (c)
 268                         *c = 0;
 269                 if (strcmp(symname, name) == 0)
 270                         return &lib->dynsym[i];
 271         }
 272         return NULL;
 273 }
 274 
 275 /* Note that we assume the section is .text and the symbol is relative to
 276  * the library base
 277  */
 278 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 279                                             const char *symname)
 280 {
 281         Elf32_Sym *sym = find_symbol32(lib, symname);
 282 
 283         if (sym == NULL) {
 284                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
 285                        symname);
 286                 return 0;
 287         }
 288         return sym->st_value - VDSO32_LBASE;
 289 }
 290 
 291 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
 292                                        struct lib64_elfinfo *v64,
 293                                        const char *orig, const char *fix)
 294 {
 295         Elf32_Sym *sym32_gen, *sym32_fix;
 296 
 297         sym32_gen = find_symbol32(v32, orig);
 298         if (sym32_gen == NULL) {
 299                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
 300                 return -1;
 301         }
 302         if (fix == NULL) {
 303                 sym32_gen->st_name = 0;
 304                 return 0;
 305         }
 306         sym32_fix = find_symbol32(v32, fix);
 307         if (sym32_fix == NULL) {
 308                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
 309                 return -1;
 310         }
 311         sym32_gen->st_value = sym32_fix->st_value;
 312         sym32_gen->st_size = sym32_fix->st_size;
 313         sym32_gen->st_info = sym32_fix->st_info;
 314         sym32_gen->st_other = sym32_fix->st_other;
 315         sym32_gen->st_shndx = sym32_fix->st_shndx;
 316 
 317         return 0;
 318 }
 319 #else /* !CONFIG_VDSO32 */
 320 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 321                                             const char *symname)
 322 {
 323         return 0;
 324 }
 325 
 326 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
 327                                        struct lib64_elfinfo *v64,
 328                                        const char *orig, const char *fix)
 329 {
 330         return 0;
 331 }
 332 #endif /* CONFIG_VDSO32 */
 333 
 334 
 335 #ifdef CONFIG_PPC64
 336 
 337 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
 338                                   unsigned long *size)
 339 {
 340         Elf64_Shdr *sechdrs;
 341         unsigned int i;
 342         char *secnames;
 343 
 344         /* Grab section headers and strings so we can tell who is who */
 345         sechdrs = (void *)ehdr + ehdr->e_shoff;
 346         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 347 
 348         /* Find the section they want */
 349         for (i = 1; i < ehdr->e_shnum; i++) {
 350                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 351                         if (size)
 352                                 *size = sechdrs[i].sh_size;
 353                         return (void *)ehdr + sechdrs[i].sh_offset;
 354                 }
 355         }
 356         if (size)
 357                 *size = 0;
 358         return NULL;
 359 }
 360 
 361 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
 362                                         const char *symname)
 363 {
 364         unsigned int i;
 365         char name[MAX_SYMNAME], *c;
 366 
 367         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
 368                 if (lib->dynsym[i].st_name == 0)
 369                         continue;
 370                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 371                         MAX_SYMNAME);
 372                 c = strchr(name, '@');
 373                 if (c)
 374                         *c = 0;
 375                 if (strcmp(symname, name) == 0)
 376                         return &lib->dynsym[i];
 377         }
 378         return NULL;
 379 }
 380 
 381 /* Note that we assume the section is .text and the symbol is relative to
 382  * the library base
 383  */
 384 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
 385                                             const char *symname)
 386 {
 387         Elf64_Sym *sym = find_symbol64(lib, symname);
 388 
 389         if (sym == NULL) {
 390                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
 391                        symname);
 392                 return 0;
 393         }
 394 #ifdef VDS64_HAS_DESCRIPTORS
 395         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
 396                 VDSO64_LBASE;
 397 #else
 398         return sym->st_value - VDSO64_LBASE;
 399 #endif
 400 }
 401 
 402 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
 403                                        struct lib64_elfinfo *v64,
 404                                        const char *orig, const char *fix)
 405 {
 406         Elf64_Sym *sym64_gen, *sym64_fix;
 407 
 408         sym64_gen = find_symbol64(v64, orig);
 409         if (sym64_gen == NULL) {
 410                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
 411                 return -1;
 412         }
 413         if (fix == NULL) {
 414                 sym64_gen->st_name = 0;
 415                 return 0;
 416         }
 417         sym64_fix = find_symbol64(v64, fix);
 418         if (sym64_fix == NULL) {
 419                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
 420                 return -1;
 421         }
 422         sym64_gen->st_value = sym64_fix->st_value;
 423         sym64_gen->st_size = sym64_fix->st_size;
 424         sym64_gen->st_info = sym64_fix->st_info;
 425         sym64_gen->st_other = sym64_fix->st_other;
 426         sym64_gen->st_shndx = sym64_fix->st_shndx;
 427 
 428         return 0;
 429 }
 430 
 431 #endif /* CONFIG_PPC64 */
 432 
 433 
 434 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
 435                                         struct lib64_elfinfo *v64)
 436 {
 437         void *sect;
 438 
 439         /*
 440          * Locate symbol tables & text section
 441          */
 442 
 443 #ifdef CONFIG_VDSO32
 444         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
 445         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
 446         if (v32->dynsym == NULL || v32->dynstr == NULL) {
 447                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
 448                 return -1;
 449         }
 450         sect = find_section32(v32->hdr, ".text", NULL);
 451         if (sect == NULL) {
 452                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
 453                 return -1;
 454         }
 455         v32->text = sect - vdso32_kbase;
 456 #endif
 457 
 458 #ifdef CONFIG_PPC64
 459         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
 460         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
 461         if (v64->dynsym == NULL || v64->dynstr == NULL) {
 462                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
 463                 return -1;
 464         }
 465         sect = find_section64(v64->hdr, ".text", NULL);
 466         if (sect == NULL) {
 467                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
 468                 return -1;
 469         }
 470         v64->text = sect - vdso64_kbase;
 471 #endif /* CONFIG_PPC64 */
 472 
 473         return 0;
 474 }
 475 
 476 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
 477                                           struct lib64_elfinfo *v64)
 478 {
 479         /*
 480          * Find signal trampolines
 481          */
 482 
 483 #ifdef CONFIG_PPC64
 484         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
 485 #endif
 486         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
 487         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
 488 }
 489 
 490 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
 491                                        struct lib64_elfinfo *v64)
 492 {
 493 #ifdef CONFIG_VDSO32
 494         Elf32_Sym *sym32;
 495 #endif
 496 #ifdef CONFIG_PPC64
 497         Elf64_Sym *sym64;
 498 
 499         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
 500         if (sym64 == NULL) {
 501                 printk(KERN_ERR "vDSO64: Can't find symbol "
 502                        "__kernel_datapage_offset !\n");
 503                 return -1;
 504         }
 505         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
 506                 (vdso64_pages << PAGE_SHIFT) -
 507                 (sym64->st_value - VDSO64_LBASE);
 508 #endif /* CONFIG_PPC64 */
 509 
 510 #ifdef CONFIG_VDSO32
 511         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
 512         if (sym32 == NULL) {
 513                 printk(KERN_ERR "vDSO32: Can't find symbol "
 514                        "__kernel_datapage_offset !\n");
 515                 return -1;
 516         }
 517         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
 518                 (vdso32_pages << PAGE_SHIFT) -
 519                 (sym32->st_value - VDSO32_LBASE);
 520 #endif
 521 
 522         return 0;
 523 }
 524 
 525 
 526 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
 527                                       struct lib64_elfinfo *v64)
 528 {
 529         unsigned long size;
 530         void *start;
 531 
 532 #ifdef CONFIG_PPC64
 533         start = find_section64(v64->hdr, "__ftr_fixup", &size);
 534         if (start)
 535                 do_feature_fixups(cur_cpu_spec->cpu_features,
 536                                   start, start + size);
 537 
 538         start = find_section64(v64->hdr, "__mmu_ftr_fixup", &size);
 539         if (start)
 540                 do_feature_fixups(cur_cpu_spec->mmu_features,
 541                                   start, start + size);
 542 
 543         start = find_section64(v64->hdr, "__fw_ftr_fixup", &size);
 544         if (start)
 545                 do_feature_fixups(powerpc_firmware_features,
 546                                   start, start + size);
 547 
 548         start = find_section64(v64->hdr, "__lwsync_fixup", &size);
 549         if (start)
 550                 do_lwsync_fixups(cur_cpu_spec->cpu_features,
 551                                  start, start + size);
 552 #endif /* CONFIG_PPC64 */
 553 
 554 #ifdef CONFIG_VDSO32
 555         start = find_section32(v32->hdr, "__ftr_fixup", &size);
 556         if (start)
 557                 do_feature_fixups(cur_cpu_spec->cpu_features,
 558                                   start, start + size);
 559 
 560         start = find_section32(v32->hdr, "__mmu_ftr_fixup", &size);
 561         if (start)
 562                 do_feature_fixups(cur_cpu_spec->mmu_features,
 563                                   start, start + size);
 564 
 565 #ifdef CONFIG_PPC64
 566         start = find_section32(v32->hdr, "__fw_ftr_fixup", &size);
 567         if (start)
 568                 do_feature_fixups(powerpc_firmware_features,
 569                                   start, start + size);
 570 #endif /* CONFIG_PPC64 */
 571 
 572         start = find_section32(v32->hdr, "__lwsync_fixup", &size);
 573         if (start)
 574                 do_lwsync_fixups(cur_cpu_spec->cpu_features,
 575                                  start, start + size);
 576 #endif
 577 
 578         return 0;
 579 }
 580 
 581 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
 582                                        struct lib64_elfinfo *v64)
 583 {
 584         int i;
 585 
 586         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
 587                 struct vdso_patch_def *patch = &vdso_patches[i];
 588                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
 589                         == patch->ftr_value;
 590                 if (!match)
 591                         continue;
 592 
 593                 DBG("replacing %s with %s...\n", patch->gen_name,
 594                     patch->fix_name ? "NONE" : patch->fix_name);
 595 
 596                 /*
 597                  * Patch the 32 bits and 64 bits symbols. Note that we do not
 598                  * patch the "." symbol on 64 bits.
 599                  * It would be easy to do, but doesn't seem to be necessary,
 600                  * patching the OPD symbol is enough.
 601                  */
 602                 vdso_do_func_patch32(v32, v64, patch->gen_name,
 603                                      patch->fix_name);
 604 #ifdef CONFIG_PPC64
 605                 vdso_do_func_patch64(v32, v64, patch->gen_name,
 606                                      patch->fix_name);
 607 #endif /* CONFIG_PPC64 */
 608         }
 609 
 610         return 0;
 611 }
 612 
 613 
 614 static __init int vdso_setup(void)
 615 {
 616         struct lib32_elfinfo    v32;
 617         struct lib64_elfinfo    v64;
 618 
 619         v32.hdr = vdso32_kbase;
 620 #ifdef CONFIG_PPC64
 621         v64.hdr = vdso64_kbase;
 622 #endif
 623         if (vdso_do_find_sections(&v32, &v64))
 624                 return -1;
 625 
 626         if (vdso_fixup_datapage(&v32, &v64))
 627                 return -1;
 628 
 629         if (vdso_fixup_features(&v32, &v64))
 630                 return -1;
 631 
 632         if (vdso_fixup_alt_funcs(&v32, &v64))
 633                 return -1;
 634 
 635         vdso_setup_trampolines(&v32, &v64);
 636 
 637         return 0;
 638 }
 639 
 640 /*
 641  * Called from setup_arch to initialize the bitmap of available
 642  * syscalls in the systemcfg page
 643  */
 644 static void __init vdso_setup_syscall_map(void)
 645 {
 646         unsigned int i;
 647         extern unsigned long *sys_call_table;
 648 #ifdef CONFIG_PPC64
 649         extern unsigned long *compat_sys_call_table;
 650 #endif
 651         extern unsigned long sys_ni_syscall;
 652 
 653 
 654         for (i = 0; i < NR_syscalls; i++) {
 655 #ifdef CONFIG_PPC64
 656                 if (sys_call_table[i] != sys_ni_syscall)
 657                         vdso_data->syscall_map_64[i >> 5] |=
 658                                 0x80000000UL >> (i & 0x1f);
 659                 if (compat_sys_call_table[i] != sys_ni_syscall)
 660                         vdso_data->syscall_map_32[i >> 5] |=
 661                                 0x80000000UL >> (i & 0x1f);
 662 #else /* CONFIG_PPC64 */
 663                 if (sys_call_table[i] != sys_ni_syscall)
 664                         vdso_data->syscall_map_32[i >> 5] |=
 665                                 0x80000000UL >> (i & 0x1f);
 666 #endif /* CONFIG_PPC64 */
 667         }
 668 }
 669 
 670 #ifdef CONFIG_PPC64
 671 int vdso_getcpu_init(void)
 672 {
 673         unsigned long cpu, node, val;
 674 
 675         /*
 676          * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
 677          * in the next 16 bits.  The VDSO uses this to implement getcpu().
 678          */
 679         cpu = get_cpu();
 680         WARN_ON_ONCE(cpu > 0xffff);
 681 
 682         node = cpu_to_node(cpu);
 683         WARN_ON_ONCE(node > 0xffff);
 684 
 685         val = (cpu & 0xfff) | ((node & 0xffff) << 16);
 686         mtspr(SPRN_SPRG_VDSO_WRITE, val);
 687         get_paca()->sprg_vdso = val;
 688 
 689         put_cpu();
 690 
 691         return 0;
 692 }
 693 /* We need to call this before SMP init */
 694 early_initcall(vdso_getcpu_init);
 695 #endif
 696 
 697 static int __init vdso_init(void)
 698 {
 699         int i;
 700 
 701 #ifdef CONFIG_PPC64
 702         /*
 703          * Fill up the "systemcfg" stuff for backward compatibility
 704          */
 705         strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
 706         vdso_data->version.major = SYSTEMCFG_MAJOR;
 707         vdso_data->version.minor = SYSTEMCFG_MINOR;
 708         vdso_data->processor = mfspr(SPRN_PVR);
 709         /*
 710          * Fake the old platform number for pSeries and add
 711          * in LPAR bit if necessary
 712          */
 713         vdso_data->platform = 0x100;
 714         if (firmware_has_feature(FW_FEATURE_LPAR))
 715                 vdso_data->platform |= 1;
 716         vdso_data->physicalMemorySize = memblock_phys_mem_size();
 717         vdso_data->dcache_size = ppc64_caches.l1d.size;
 718         vdso_data->dcache_line_size = ppc64_caches.l1d.line_size;
 719         vdso_data->icache_size = ppc64_caches.l1i.size;
 720         vdso_data->icache_line_size = ppc64_caches.l1i.line_size;
 721         vdso_data->dcache_block_size = ppc64_caches.l1d.block_size;
 722         vdso_data->icache_block_size = ppc64_caches.l1i.block_size;
 723         vdso_data->dcache_log_block_size = ppc64_caches.l1d.log_block_size;
 724         vdso_data->icache_log_block_size = ppc64_caches.l1i.log_block_size;
 725 
 726         /*
 727          * Calculate the size of the 64 bits vDSO
 728          */
 729         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
 730         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
 731 #else
 732         vdso_data->dcache_block_size = L1_CACHE_BYTES;
 733         vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
 734         vdso_data->icache_block_size = L1_CACHE_BYTES;
 735         vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
 736 #endif /* CONFIG_PPC64 */
 737 
 738 
 739 #ifdef CONFIG_VDSO32
 740         vdso32_kbase = &vdso32_start;
 741 
 742         /*
 743          * Calculate the size of the 32 bits vDSO
 744          */
 745         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
 746         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
 747 #endif
 748 
 749 
 750         /*
 751          * Setup the syscall map in the vDOS
 752          */
 753         vdso_setup_syscall_map();
 754 
 755         /*
 756          * Initialize the vDSO images in memory, that is do necessary
 757          * fixups of vDSO symbols, locate trampolines, etc...
 758          */
 759         if (vdso_setup()) {
 760                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
 761                 vdso32_pages = 0;
 762 #ifdef CONFIG_PPC64
 763                 vdso64_pages = 0;
 764 #endif
 765                 return 0;
 766         }
 767 
 768 #ifdef CONFIG_VDSO32
 769         /* Make sure pages are in the correct state */
 770         vdso32_pagelist = kcalloc(vdso32_pages + 2, sizeof(struct page *),
 771                                   GFP_KERNEL);
 772         BUG_ON(vdso32_pagelist == NULL);
 773         for (i = 0; i < vdso32_pages; i++) {
 774                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
 775                 get_page(pg);
 776                 vdso32_pagelist[i] = pg;
 777         }
 778         vdso32_pagelist[i++] = virt_to_page(vdso_data);
 779         vdso32_pagelist[i] = NULL;
 780 #endif
 781 
 782 #ifdef CONFIG_PPC64
 783         vdso64_pagelist = kcalloc(vdso64_pages + 2, sizeof(struct page *),
 784                                   GFP_KERNEL);
 785         BUG_ON(vdso64_pagelist == NULL);
 786         for (i = 0; i < vdso64_pages; i++) {
 787                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
 788                 get_page(pg);
 789                 vdso64_pagelist[i] = pg;
 790         }
 791         vdso64_pagelist[i++] = virt_to_page(vdso_data);
 792         vdso64_pagelist[i] = NULL;
 793 #endif /* CONFIG_PPC64 */
 794 
 795         get_page(virt_to_page(vdso_data));
 796 
 797         smp_wmb();
 798         vdso_ready = 1;
 799 
 800         return 0;
 801 }
 802 arch_initcall(vdso_init);
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root/arch/powerpc/kernel/vdso.c

DEFINITIONS
