arch/powerpc/kernel/vdso.c

   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 #ifdef CONFIG_PPC32
  98         {
  99                 CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
 100                 "__kernel_gettimeofday", NULL
 101         },
 102         {
 103                 CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
 104                 "__kernel_clock_gettime", NULL
 105         },
 106         {
 107                 CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
 108                 "__kernel_clock_getres", NULL
 109         },
 110         {
 111                 CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
 112                 "__kernel_get_tbfreq", NULL
 113         },
 114         {
 115                 CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
 116                 "__kernel_time", NULL
 117         },
 118 #endif
 119 };
 120
 121 /*
 122  * Some infos carried around for each of them during parsing at
 123  * boot time.
 124  */
 125 struct lib32_elfinfo
 126 {
 127         Elf32_Ehdr      *hdr;           /* ptr to ELF */
 128         Elf32_Sym       *dynsym;        /* ptr to .dynsym section */
 129         unsigned long   dynsymsize;     /* size of .dynsym section */
 130         char            *dynstr;        /* ptr to .dynstr section */
 131         unsigned long   text;           /* offset of .text section in .so */
 132 };
 133
 134 struct lib64_elfinfo
 135 {
 136         Elf64_Ehdr      *hdr;
 137         Elf64_Sym       *dynsym;
 138         unsigned long   dynsymsize;
 139         char            *dynstr;
 140         unsigned long   text;
 141 };
 142
 143
 144 /*
 145  * This is called from binfmt_elf, we create the special vma for the
 146  * vDSO and insert it into the mm struct tree
 147  */
 148 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 149 {
 150         struct mm_struct *mm = current->mm;
 151         struct page **vdso_pagelist;
 152         unsigned long vdso_pages;
 153         unsigned long vdso_base;
 154         int rc;
 155
 156         if (!vdso_ready)
 157                 return 0;
 158
 159 #ifdef CONFIG_PPC64
 160         if (is_32bit_task()) {
 161                 vdso_pagelist = vdso32_pagelist;
 162                 vdso_pages = vdso32_pages;
 163                 vdso_base = VDSO32_MBASE;
 164         } else {
 165                 vdso_pagelist = vdso64_pagelist;
 166                 vdso_pages = vdso64_pages;
 167                 /*
 168                  * On 64bit we don't have a preferred map address. This
 169                  * allows get_unmapped_area to find an area near other mmaps
 170                  * and most likely share a SLB entry.
 171                  */
 172                 vdso_base = 0;
 173         }
 174 #else
 175         vdso_pagelist = vdso32_pagelist;
 176         vdso_pages = vdso32_pages;
 177         vdso_base = VDSO32_MBASE;
 178 #endif
 179
 180         current->mm->context.vdso_base = 0;
 181
 182         /* vDSO has a problem and was disabled, just don't "enable" it for the
 183          * process
 184          */
 185         if (vdso_pages == 0)
 186                 return 0;
 187         /* Add a page to the vdso size for the data page */
 188         vdso_pages ++;
 189
 190         /*
 191          * pick a base address for the vDSO in process space. We try to put it
 192          * at vdso_base which is the "natural" base for it, but we might fail
 193          * and end up putting it elsewhere.
 194          * Add enough to the size so that the result can be aligned.
 195          */
 196         if (down_write_killable(&mm->mmap_sem))
 197                 return -EINTR;
 198         vdso_base = get_unmapped_area(NULL, vdso_base,
 199                                       (vdso_pages << PAGE_SHIFT) +
 200                                       ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
 201                                       0, 0);
 202         if (IS_ERR_VALUE(vdso_base)) {
 203                 rc = vdso_base;
 204                 goto fail_mmapsem;
 205         }
 206
 207         /* Add required alignment. */
 208         vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
 209
 210         /*
 211          * Put vDSO base into mm struct. We need to do this before calling
 212          * install_special_mapping or the perf counter mmap tracking code
 213          * will fail to recognise it as a vDSO (since arch_vma_name fails).
 214          */
 215         current->mm->context.vdso_base = vdso_base;
 216
 217         /*
 218          * our vma flags don't have VM_WRITE so by default, the process isn't
 219          * allowed to write those pages.
 220          * gdb can break that with ptrace interface, and thus trigger COW on
 221          * those pages but it's then your responsibility to never do that on
 222          * the "data" page of the vDSO or you'll stop getting kernel updates
 223          * and your nice userland gettimeofday will be totally dead.
 224          * It's fine to use that for setting breakpoints in the vDSO code
 225          * pages though.
 226          */
 227         rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
 228                                      VM_READ|VM_EXEC|
 229                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
 230                                      vdso_pagelist);
 231         if (rc) {
 232                 current->mm->context.vdso_base = 0;
 233                 goto fail_mmapsem;
 234         }
 235
 236         up_write(&mm->mmap_sem);
 237         return 0;
 238
 239  fail_mmapsem:
 240         up_write(&mm->mmap_sem);
 241         return rc;
 242 }
 243
 244 const char *arch_vma_name(struct vm_area_struct *vma)
 245 {
 246         if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
 247                 return "[vdso]";
 248         return NULL;
 249 }
 250
 251
 252
 253 #ifdef CONFIG_VDSO32
 254 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
 255                                   unsigned long *size)
 256 {
 257         Elf32_Shdr *sechdrs;
 258         unsigned int i;
 259         char *secnames;
 260
 261         /* Grab section headers and strings so we can tell who is who */
 262         sechdrs = (void *)ehdr + ehdr->e_shoff;
 263         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 264
 265         /* Find the section they want */
 266         for (i = 1; i < ehdr->e_shnum; i++) {
 267                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 268                         if (size)
 269                                 *size = sechdrs[i].sh_size;
 270                         return (void *)ehdr + sechdrs[i].sh_offset;
 271                 }
 272         }
 273         *size = 0;
 274         return NULL;
 275 }
 276
 277 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
 278                                         const char *symname)
 279 {
 280         unsigned int i;
 281         char name[MAX_SYMNAME], *c;
 282
 283         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
 284                 if (lib->dynsym[i].st_name == 0)
 285                         continue;
 286                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 287                         MAX_SYMNAME);
 288                 c = strchr(name, '@');
 289                 if (c)
 290                         *c = 0;
 291                 if (strcmp(symname, name) == 0)
 292                         return &lib->dynsym[i];
 293         }
 294         return NULL;
 295 }
 296
 297 /* Note that we assume the section is .text and the symbol is relative to
 298  * the library base
 299  */
 300 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 301                                             const char *symname)
 302 {
 303         Elf32_Sym *sym = find_symbol32(lib, symname);
 304
 305         if (sym == NULL) {
 306                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
 307                        symname);
 308                 return 0;
 309         }
 310         return sym->st_value - VDSO32_LBASE;
 311 }
 312
 313 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
 314                                        struct lib64_elfinfo *v64,
 315                                        const char *orig, const char *fix)
 316 {
 317         Elf32_Sym *sym32_gen, *sym32_fix;
 318
 319         sym32_gen = find_symbol32(v32, orig);
 320         if (sym32_gen == NULL) {
 321                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
 322                 return -1;
 323         }
 324         if (fix == NULL) {
 325                 sym32_gen->st_name = 0;
 326                 return 0;
 327         }
 328         sym32_fix = find_symbol32(v32, fix);
 329         if (sym32_fix == NULL) {
 330                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
 331                 return -1;
 332         }
 333         sym32_gen->st_value = sym32_fix->st_value;
 334         sym32_gen->st_size = sym32_fix->st_size;
 335         sym32_gen->st_info = sym32_fix->st_info;
 336         sym32_gen->st_other = sym32_fix->st_other;
 337         sym32_gen->st_shndx = sym32_fix->st_shndx;
 338
 339         return 0;
 340 }
 341 #else /* !CONFIG_VDSO32 */
 342 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
 343                                             const char *symname)
 344 {
 345         return 0;
 346 }
 347
 348 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
 349                                        struct lib64_elfinfo *v64,
 350                                        const char *orig, const char *fix)
 351 {
 352         return 0;
 353 }
 354 #endif /* CONFIG_VDSO32 */
 355
 356
 357 #ifdef CONFIG_PPC64
 358
 359 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
 360                                   unsigned long *size)
 361 {
 362         Elf64_Shdr *sechdrs;
 363         unsigned int i;
 364         char *secnames;
 365
 366         /* Grab section headers and strings so we can tell who is who */
 367         sechdrs = (void *)ehdr + ehdr->e_shoff;
 368         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
 369
 370         /* Find the section they want */
 371         for (i = 1; i < ehdr->e_shnum; i++) {
 372                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
 373                         if (size)
 374                                 *size = sechdrs[i].sh_size;
 375                         return (void *)ehdr + sechdrs[i].sh_offset;
 376                 }
 377         }
 378         if (size)
 379                 *size = 0;
 380         return NULL;
 381 }
 382
 383 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
 384                                         const char *symname)
 385 {
 386         unsigned int i;
 387         char name[MAX_SYMNAME], *c;
 388
 389         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
 390                 if (lib->dynsym[i].st_name == 0)
 391                         continue;
 392                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
 393                         MAX_SYMNAME);
 394                 c = strchr(name, '@');
 395                 if (c)
 396                         *c = 0;
 397                 if (strcmp(symname, name) == 0)
 398                         return &lib->dynsym[i];
 399         }
 400         return NULL;
 401 }
 402
 403 /* Note that we assume the section is .text and the symbol is relative to
 404  * the library base
 405  */
 406 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
 407                                             const char *symname)
 408 {
 409         Elf64_Sym *sym = find_symbol64(lib, symname);
 410
 411         if (sym == NULL) {
 412                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
 413                        symname);
 414                 return 0;
 415         }
 416 #ifdef VDS64_HAS_DESCRIPTORS
 417         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
 418                 VDSO64_LBASE;
 419 #else
 420         return sym->st_value - VDSO64_LBASE;
 421 #endif
 422 }
 423
 424 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
 425                                        struct lib64_elfinfo *v64,
 426                                        const char *orig, const char *fix)
 427 {
 428         Elf64_Sym *sym64_gen, *sym64_fix;
 429
 430         sym64_gen = find_symbol64(v64, orig);
 431         if (sym64_gen == NULL) {
 432                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
 433                 return -1;
 434         }
 435         if (fix == NULL) {
 436                 sym64_gen->st_name = 0;
 437                 return 0;
 438         }
 439         sym64_fix = find_symbol64(v64, fix);
 440         if (sym64_fix == NULL) {
 441                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
 442                 return -1;
 443         }
 444         sym64_gen->st_value = sym64_fix->st_value;
 445         sym64_gen->st_size = sym64_fix->st_size;
 446         sym64_gen->st_info = sym64_fix->st_info;
 447         sym64_gen->st_other = sym64_fix->st_other;
 448         sym64_gen->st_shndx = sym64_fix->st_shndx;
 449
 450         return 0;
 451 }
 452
 453 #endif /* CONFIG_PPC64 */
 454
 455
 456 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
 457                                         struct lib64_elfinfo *v64)
 458 {
 459         void *sect;
 460
 461         /*
 462          * Locate symbol tables & text section
 463          */
 464
 465 #ifdef CONFIG_VDSO32
 466         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
 467         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
 468         if (v32->dynsym == NULL || v32->dynstr == NULL) {
 469                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
 470                 return -1;
 471         }
 472         sect = find_section32(v32->hdr, ".text", NULL);
 473         if (sect == NULL) {
 474                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
 475                 return -1;
 476         }
 477         v32->text = sect - vdso32_kbase;
 478 #endif
 479
 480 #ifdef CONFIG_PPC64
 481         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
 482         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
 483         if (v64->dynsym == NULL || v64->dynstr == NULL) {
 484                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
 485                 return -1;
 486         }
 487         sect = find_section64(v64->hdr, ".text", NULL);
 488         if (sect == NULL) {
 489                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
 490                 return -1;
 491         }
 492         v64->text = sect - vdso64_kbase;
 493 #endif /* CONFIG_PPC64 */
 494
 495         return 0;
 496 }
 497
 498 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
 499                                           struct lib64_elfinfo *v64)
 500 {
 501         /*
 502          * Find signal trampolines
 503          */
 504
 505 #ifdef CONFIG_PPC64
 506         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
 507 #endif
 508         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
 509         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
 510 }
 511
 512 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
 513                                        struct lib64_elfinfo *v64)
 514 {
 515 #ifdef CONFIG_VDSO32
 516         Elf32_Sym *sym32;
 517 #endif
 518 #ifdef CONFIG_PPC64
 519         Elf64_Sym *sym64;
 520
 521         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
 522         if (sym64 == NULL) {
 523                 printk(KERN_ERR "vDSO64: Can't find symbol "
 524                        "__kernel_datapage_offset !\n");
 525                 return -1;
 526         }
 527         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
 528                 (vdso64_pages << PAGE_SHIFT) -
 529                 (sym64->st_value - VDSO64_LBASE);
 530 #endif /* CONFIG_PPC64 */
 531
 532 #ifdef CONFIG_VDSO32
 533         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
 534         if (sym32 == NULL) {
 535                 printk(KERN_ERR "vDSO32: Can't find symbol "
 536                        "__kernel_datapage_offset !\n");
 537                 return -1;
 538         }
 539         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
 540                 (vdso32_pages << PAGE_SHIFT) -
 541                 (sym32->st_value - VDSO32_LBASE);
 542 #endif
 543
 544         return 0;
 545 }
 546
 547
 548 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
 549                                       struct lib64_elfinfo *v64)
 550 {
 551         unsigned long size;
 552         void *start;
 553
 554 #ifdef CONFIG_PPC64
 555         start = find_section64(v64->hdr, "__ftr_fixup", &size);
 556         if (start)
 557                 do_feature_fixups(cur_cpu_spec->cpu_features,
 558                                   start, start + size);
 559
 560         start = find_section64(v64->hdr, "__mmu_ftr_fixup", &size);
 561         if (start)
 562                 do_feature_fixups(cur_cpu_spec->mmu_features,
 563                                   start, start + size);
 564
 565         start = find_section64(v64->hdr, "__fw_ftr_fixup", &size);
 566         if (start)
 567                 do_feature_fixups(powerpc_firmware_features,
 568                                   start, start + size);
 569
 570         start = find_section64(v64->hdr, "__lwsync_fixup", &size);
 571         if (start)
 572                 do_lwsync_fixups(cur_cpu_spec->cpu_features,
 573                                  start, start + size);
 574 #endif /* CONFIG_PPC64 */
 575
 576 #ifdef CONFIG_VDSO32
 577         start = find_section32(v32->hdr, "__ftr_fixup", &size);
 578         if (start)
 579                 do_feature_fixups(cur_cpu_spec->cpu_features,
 580                                   start, start + size);
 581
 582         start = find_section32(v32->hdr, "__mmu_ftr_fixup", &size);
 583         if (start)
 584                 do_feature_fixups(cur_cpu_spec->mmu_features,
 585                                   start, start + size);
 586
 587 #ifdef CONFIG_PPC64
 588         start = find_section32(v32->hdr, "__fw_ftr_fixup", &size);
 589         if (start)
 590                 do_feature_fixups(powerpc_firmware_features,
 591                                   start, start + size);
 592 #endif /* CONFIG_PPC64 */
 593
 594         start = find_section32(v32->hdr, "__lwsync_fixup", &size);
 595         if (start)
 596                 do_lwsync_fixups(cur_cpu_spec->cpu_features,
 597                                  start, start + size);
 598 #endif
 599
 600         return 0;
 601 }
 602
 603 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
 604                                        struct lib64_elfinfo *v64)
 605 {
 606         int i;
 607
 608         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
 609                 struct vdso_patch_def *patch = &vdso_patches[i];
 610                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
 611                         == patch->ftr_value;
 612                 if (!match)
 613                         continue;
 614
 615                 DBG("replacing %s with %s...\n", patch->gen_name,
 616                     patch->fix_name ? "NONE" : patch->fix_name);
 617
 618                 /*
 619                  * Patch the 32 bits and 64 bits symbols. Note that we do not
 620                  * patch the "." symbol on 64 bits.
 621                  * It would be easy to do, but doesn't seem to be necessary,
 622                  * patching the OPD symbol is enough.
 623                  */
 624                 vdso_do_func_patch32(v32, v64, patch->gen_name,
 625                                      patch->fix_name);
 626 #ifdef CONFIG_PPC64
 627                 vdso_do_func_patch64(v32, v64, patch->gen_name,
 628                                      patch->fix_name);
 629 #endif /* CONFIG_PPC64 */
 630         }
 631
 632         return 0;
 633 }
 634
 635
 636 static __init int vdso_setup(void)
 637 {
 638         struct lib32_elfinfo    v32;
 639         struct lib64_elfinfo    v64;
 640
 641         v32.hdr = vdso32_kbase;
 642 #ifdef CONFIG_PPC64
 643         v64.hdr = vdso64_kbase;
 644 #endif
 645         if (vdso_do_find_sections(&v32, &v64))
 646                 return -1;
 647
 648         if (vdso_fixup_datapage(&v32, &v64))
 649                 return -1;
 650
 651         if (vdso_fixup_features(&v32, &v64))
 652                 return -1;
 653
 654         if (vdso_fixup_alt_funcs(&v32, &v64))
 655                 return -1;
 656
 657         vdso_setup_trampolines(&v32, &v64);
 658
 659         return 0;
 660 }
 661
 662 /*
 663  * Called from setup_arch to initialize the bitmap of available
 664  * syscalls in the systemcfg page
 665  */
 666 static void __init vdso_setup_syscall_map(void)
 667 {
 668         unsigned int i;
 669         extern unsigned long *sys_call_table;
 670 #ifdef CONFIG_PPC64
 671         extern unsigned long *compat_sys_call_table;
 672 #endif
 673         extern unsigned long sys_ni_syscall;
 674
 675
 676         for (i = 0; i < NR_syscalls; i++) {
 677 #ifdef CONFIG_PPC64
 678                 if (sys_call_table[i] != sys_ni_syscall)
 679                         vdso_data->syscall_map_64[i >> 5] |=
 680                                 0x80000000UL >> (i & 0x1f);
 681                 if (compat_sys_call_table[i] != sys_ni_syscall)
 682                         vdso_data->syscall_map_32[i >> 5] |=
 683                                 0x80000000UL >> (i & 0x1f);
 684 #else /* CONFIG_PPC64 */
 685                 if (sys_call_table[i] != sys_ni_syscall)
 686                         vdso_data->syscall_map_32[i >> 5] |=
 687                                 0x80000000UL >> (i & 0x1f);
 688 #endif /* CONFIG_PPC64 */
 689         }
 690 }
 691
 692 #ifdef CONFIG_PPC64
 693 int vdso_getcpu_init(void)
 694 {
 695         unsigned long cpu, node, val;
 696
 697         /*
 698          * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
 699          * in the next 16 bits.  The VDSO uses this to implement getcpu().
 700          */
 701         cpu = get_cpu();
 702         WARN_ON_ONCE(cpu > 0xffff);
 703
 704         node = cpu_to_node(cpu);
 705         WARN_ON_ONCE(node > 0xffff);
 706
 707         val = (cpu & 0xfff) | ((node & 0xffff) << 16);
 708         mtspr(SPRN_SPRG_VDSO_WRITE, val);
 709         get_paca()->sprg_vdso = val;
 710
 711         put_cpu();
 712
 713         return 0;
 714 }
 715 /* We need to call this before SMP init */
 716 early_initcall(vdso_getcpu_init);
 717 #endif
 718
 719 static int __init vdso_init(void)
 720 {
 721         int i;
 722
 723 #ifdef CONFIG_PPC64
 724         /*
 725          * Fill up the "systemcfg" stuff for backward compatibility
 726          */
 727         strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
 728         vdso_data->version.major = SYSTEMCFG_MAJOR;
 729         vdso_data->version.minor = SYSTEMCFG_MINOR;
 730         vdso_data->processor = mfspr(SPRN_PVR);
 731         /*
 732          * Fake the old platform number for pSeries and add
 733          * in LPAR bit if necessary
 734          */
 735         vdso_data->platform = 0x100;
 736         if (firmware_has_feature(FW_FEATURE_LPAR))
 737                 vdso_data->platform |= 1;
 738         vdso_data->physicalMemorySize = memblock_phys_mem_size();
 739         vdso_data->dcache_size = ppc64_caches.l1d.size;
 740         vdso_data->dcache_line_size = ppc64_caches.l1d.line_size;
 741         vdso_data->icache_size = ppc64_caches.l1i.size;
 742         vdso_data->icache_line_size = ppc64_caches.l1i.line_size;
 743         vdso_data->dcache_block_size = ppc64_caches.l1d.block_size;
 744         vdso_data->icache_block_size = ppc64_caches.l1i.block_size;
 745         vdso_data->dcache_log_block_size = ppc64_caches.l1d.log_block_size;
 746         vdso_data->icache_log_block_size = ppc64_caches.l1i.log_block_size;
 747
 748         /*
 749          * Calculate the size of the 64 bits vDSO
 750          */
 751         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
 752         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
 753 #else
 754         vdso_data->dcache_block_size = L1_CACHE_BYTES;
 755         vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
 756         vdso_data->icache_block_size = L1_CACHE_BYTES;
 757         vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
 758 #endif /* CONFIG_PPC64 */
 759
 760
 761 #ifdef CONFIG_VDSO32
 762         vdso32_kbase = &vdso32_start;
 763
 764         /*
 765          * Calculate the size of the 32 bits vDSO
 766          */
 767         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
 768         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
 769 #endif
 770
 771
 772         /*
 773          * Setup the syscall map in the vDOS
 774          */
 775         vdso_setup_syscall_map();
 776
 777         /*
 778          * Initialize the vDSO images in memory, that is do necessary
 779          * fixups of vDSO symbols, locate trampolines, etc...
 780          */
 781         if (vdso_setup()) {
 782                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
 783                 vdso32_pages = 0;
 784 #ifdef CONFIG_PPC64
 785                 vdso64_pages = 0;
 786 #endif
 787                 return 0;
 788         }
 789
 790 #ifdef CONFIG_VDSO32
 791         /* Make sure pages are in the correct state */
 792         vdso32_pagelist = kcalloc(vdso32_pages + 2, sizeof(struct page *),
 793                                   GFP_KERNEL);
 794         BUG_ON(vdso32_pagelist == NULL);
 795         for (i = 0; i < vdso32_pages; i++) {
 796                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
 797                 get_page(pg);
 798                 vdso32_pagelist[i] = pg;
 799         }
 800         vdso32_pagelist[i++] = virt_to_page(vdso_data);
 801         vdso32_pagelist[i] = NULL;
 802 #endif
 803
 804 #ifdef CONFIG_PPC64
 805         vdso64_pagelist = kcalloc(vdso64_pages + 2, sizeof(struct page *),
 806                                   GFP_KERNEL);
 807         BUG_ON(vdso64_pagelist == NULL);
 808         for (i = 0; i < vdso64_pages; i++) {
 809                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
 810                 get_page(pg);
 811                 vdso64_pagelist[i] = pg;
 812         }
 813         vdso64_pagelist[i++] = virt_to_page(vdso_data);
 814         vdso64_pagelist[i] = NULL;
 815 #endif /* CONFIG_PPC64 */
 816
 817         get_page(virt_to_page(vdso_data));
 818
 819         smp_wmb();
 820         vdso_ready = 1;
 821
 822         return 0;
 823 }
 824 arch_initcall(vdso_init);