Merge branch 'master'
[linux-2.6] / arch / powerpc / kernel / vdso.c
1 /*
2  *  linux/arch/ppc64/kernel/vdso.c
3  *
4  *    Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
5  *                       <benh@kernel.crashing.org>
6  *
7  *  This program is free software; you can redistribute it and/or
8  *  modify it under the terms of the GNU General Public License
9  *  as published by the Free Software Foundation; either version
10  *  2 of the License, or (at your option) any later version.
11  */
12
13 #include <linux/config.h>
14 #include <linux/module.h>
15 #include <linux/errno.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/mm.h>
19 #include <linux/smp.h>
20 #include <linux/smp_lock.h>
21 #include <linux/stddef.h>
22 #include <linux/unistd.h>
23 #include <linux/slab.h>
24 #include <linux/user.h>
25 #include <linux/elf.h>
26 #include <linux/security.h>
27 #include <linux/bootmem.h>
28
29 #include <asm/pgtable.h>
30 #include <asm/system.h>
31 #include <asm/processor.h>
32 #include <asm/mmu.h>
33 #include <asm/mmu_context.h>
34 #include <asm/lmb.h>
35 #include <asm/machdep.h>
36 #include <asm/cputable.h>
37 #include <asm/sections.h>
38 #include <asm/vdso.h>
39 #include <asm/vdso_datapage.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
228 #ifdef CONFIG_PPC64
229         if (test_thread_flag(TIF_32BIT)) {
230                 vdso_pages = vdso32_pages;
231                 vdso_base = VDSO32_MBASE;
232         } else {
233                 vdso_pages = vdso64_pages;
234                 vdso_base = VDSO64_MBASE;
235         }
236 #else
237         vdso_pages = vdso32_pages;
238         vdso_base = VDSO32_MBASE;
239 #endif
240
241         current->thread.vdso_base = 0;
242
243         /* vDSO has a problem and was disabled, just don't "enable" it for the
244          * process
245          */
246         if (vdso_pages == 0)
247                 return 0;
248
249         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
250         if (vma == NULL)
251                 return -ENOMEM;
252
253         memset(vma, 0, sizeof(*vma));
254
255         /* Add a page to the vdso size for the data page */
256         vdso_pages ++;
257
258         /*
259          * pick a base address for the vDSO in process space. We try to put it
260          * at vdso_base which is the "natural" base for it, but we might fail
261          * and end up putting it elsewhere.
262          */
263         vdso_base = get_unmapped_area(NULL, vdso_base,
264                                       vdso_pages << PAGE_SHIFT, 0, 0);
265         if (vdso_base & ~PAGE_MASK) {
266                 kmem_cache_free(vm_area_cachep, vma);
267                 return (int)vdso_base;
268         }
269
270         current->thread.vdso_base = vdso_base;
271
272         vma->vm_mm = mm;
273         vma->vm_start = current->thread.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         vma->vm_flags |= mm->def_flags;
288         vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
289         vma->vm_ops = &vdso_vmops;
290
291         down_write(&mm->mmap_sem);
292         if (insert_vm_struct(mm, vma)) {
293                 up_write(&mm->mmap_sem);
294                 kmem_cache_free(vm_area_cachep, vma);
295                 return -ENOMEM;
296         }
297         mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
298         up_write(&mm->mmap_sem);
299
300         return 0;
301 }
302
303 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
304                                   unsigned long *size)
305 {
306         Elf32_Shdr *sechdrs;
307         unsigned int i;
308         char *secnames;
309
310         /* Grab section headers and strings so we can tell who is who */
311         sechdrs = (void *)ehdr + ehdr->e_shoff;
312         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
313
314         /* Find the section they want */
315         for (i = 1; i < ehdr->e_shnum; i++) {
316                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
317                         if (size)
318                                 *size = sechdrs[i].sh_size;
319                         return (void *)ehdr + sechdrs[i].sh_offset;
320                 }
321         }
322         *size = 0;
323         return NULL;
324 }
325
326 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
327                                         const char *symname)
328 {
329         unsigned int i;
330         char name[MAX_SYMNAME], *c;
331
332         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
333                 if (lib->dynsym[i].st_name == 0)
334                         continue;
335                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
336                         MAX_SYMNAME);
337                 c = strchr(name, '@');
338                 if (c)
339                         *c = 0;
340                 if (strcmp(symname, name) == 0)
341                         return &lib->dynsym[i];
342         }
343         return NULL;
344 }
345
346 /* Note that we assume the section is .text and the symbol is relative to
347  * the library base
348  */
349 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
350                                             const char *symname)
351 {
352         Elf32_Sym *sym = find_symbol32(lib, symname);
353
354         if (sym == NULL) {
355                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
356                        symname);
357                 return 0;
358         }
359         return sym->st_value - VDSO32_LBASE;
360 }
361
362 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
363                                 struct lib64_elfinfo *v64,
364                                 const char *orig, const char *fix)
365 {
366         Elf32_Sym *sym32_gen, *sym32_fix;
367
368         sym32_gen = find_symbol32(v32, orig);
369         if (sym32_gen == NULL) {
370                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
371                 return -1;
372         }
373         if (fix == NULL) {
374                 sym32_gen->st_name = 0;
375                 return 0;
376         }
377         sym32_fix = find_symbol32(v32, fix);
378         if (sym32_fix == NULL) {
379                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
380                 return -1;
381         }
382         sym32_gen->st_value = sym32_fix->st_value;
383         sym32_gen->st_size = sym32_fix->st_size;
384         sym32_gen->st_info = sym32_fix->st_info;
385         sym32_gen->st_other = sym32_fix->st_other;
386         sym32_gen->st_shndx = sym32_fix->st_shndx;
387
388         return 0;
389 }
390
391
392 #ifdef CONFIG_PPC64
393
394 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
395                                   unsigned long *size)
396 {
397         Elf64_Shdr *sechdrs;
398         unsigned int i;
399         char *secnames;
400
401         /* Grab section headers and strings so we can tell who is who */
402         sechdrs = (void *)ehdr + ehdr->e_shoff;
403         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
404
405         /* Find the section they want */
406         for (i = 1; i < ehdr->e_shnum; i++) {
407                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
408                         if (size)
409                                 *size = sechdrs[i].sh_size;
410                         return (void *)ehdr + sechdrs[i].sh_offset;
411                 }
412         }
413         if (size)
414                 *size = 0;
415         return NULL;
416 }
417
418 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
419                                         const char *symname)
420 {
421         unsigned int i;
422         char name[MAX_SYMNAME], *c;
423
424         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
425                 if (lib->dynsym[i].st_name == 0)
426                         continue;
427                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
428                         MAX_SYMNAME);
429                 c = strchr(name, '@');
430                 if (c)
431                         *c = 0;
432                 if (strcmp(symname, name) == 0)
433                         return &lib->dynsym[i];
434         }
435         return NULL;
436 }
437
438 /* Note that we assume the section is .text and the symbol is relative to
439  * the library base
440  */
441 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
442                                             const char *symname)
443 {
444         Elf64_Sym *sym = find_symbol64(lib, symname);
445
446         if (sym == NULL) {
447                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
448                        symname);
449                 return 0;
450         }
451 #ifdef VDS64_HAS_DESCRIPTORS
452         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
453                 VDSO64_LBASE;
454 #else
455         return sym->st_value - VDSO64_LBASE;
456 #endif
457 }
458
459 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
460                                 struct lib64_elfinfo *v64,
461                                 const char *orig, const char *fix)
462 {
463         Elf64_Sym *sym64_gen, *sym64_fix;
464
465         sym64_gen = find_symbol64(v64, orig);
466         if (sym64_gen == NULL) {
467                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
468                 return -1;
469         }
470         if (fix == NULL) {
471                 sym64_gen->st_name = 0;
472                 return 0;
473         }
474         sym64_fix = find_symbol64(v64, fix);
475         if (sym64_fix == NULL) {
476                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
477                 return -1;
478         }
479         sym64_gen->st_value = sym64_fix->st_value;
480         sym64_gen->st_size = sym64_fix->st_size;
481         sym64_gen->st_info = sym64_fix->st_info;
482         sym64_gen->st_other = sym64_fix->st_other;
483         sym64_gen->st_shndx = sym64_fix->st_shndx;
484
485         return 0;
486 }
487
488 #endif /* CONFIG_PPC64 */
489
490
491 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
492                                         struct lib64_elfinfo *v64)
493 {
494         void *sect;
495
496         /*
497          * Locate symbol tables & text section
498          */
499
500         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
501         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
502         if (v32->dynsym == NULL || v32->dynstr == NULL) {
503                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
504                 return -1;
505         }
506         sect = find_section32(v32->hdr, ".text", NULL);
507         if (sect == NULL) {
508                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
509                 return -1;
510         }
511         v32->text = sect - vdso32_kbase;
512
513 #ifdef CONFIG_PPC64
514         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
515         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
516         if (v64->dynsym == NULL || v64->dynstr == NULL) {
517                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
518                 return -1;
519         }
520         sect = find_section64(v64->hdr, ".text", NULL);
521         if (sect == NULL) {
522                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
523                 return -1;
524         }
525         v64->text = sect - vdso64_kbase;
526 #endif /* CONFIG_PPC64 */
527
528         return 0;
529 }
530
531 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
532                                           struct lib64_elfinfo *v64)
533 {
534         /*
535          * Find signal trampolines
536          */
537
538 #ifdef CONFIG_PPC64
539         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
540 #endif
541         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
542         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
543 }
544
545 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
546                                        struct lib64_elfinfo *v64)
547 {
548         Elf32_Sym *sym32;
549 #ifdef CONFIG_PPC64
550         Elf64_Sym *sym64;
551
552         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
553         if (sym64 == NULL) {
554                 printk(KERN_ERR "vDSO64: Can't find symbol "
555                        "__kernel_datapage_offset !\n");
556                 return -1;
557         }
558         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
559                 (vdso64_pages << PAGE_SHIFT) -
560                 (sym64->st_value - VDSO64_LBASE);
561 #endif /* CONFIG_PPC64 */
562
563         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
564         if (sym32 == NULL) {
565                 printk(KERN_ERR "vDSO32: Can't find symbol "
566                        "__kernel_datapage_offset !\n");
567                 return -1;
568         }
569         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
570                 (vdso32_pages << PAGE_SHIFT) -
571                 (sym32->st_value - VDSO32_LBASE);
572
573         return 0;
574 }
575
576 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
577                                        struct lib64_elfinfo *v64)
578 {
579         int i;
580
581         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
582                 struct vdso_patch_def *patch = &vdso_patches[i];
583                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
584                         == patch->ftr_value;
585                 if (!match)
586                         continue;
587
588                 DBG("replacing %s with %s...\n", patch->gen_name,
589                     patch->fix_name ? "NONE" : patch->fix_name);
590
591                 /*
592                  * Patch the 32 bits and 64 bits symbols. Note that we do not
593                  * patch the "." symbol on 64 bits.
594                  * It would be easy to do, but doesn't seem to be necessary,
595                  * patching the OPD symbol is enough.
596                  */
597                 vdso_do_func_patch32(v32, v64, patch->gen_name,
598                                      patch->fix_name);
599 #ifdef CONFIG_PPC64
600                 vdso_do_func_patch64(v32, v64, patch->gen_name,
601                                      patch->fix_name);
602 #endif /* CONFIG_PPC64 */
603         }
604
605         return 0;
606 }
607
608
609 static __init int vdso_setup(void)
610 {
611         struct lib32_elfinfo    v32;
612         struct lib64_elfinfo    v64;
613
614         v32.hdr = vdso32_kbase;
615 #ifdef CONFIG_PPC64
616         v64.hdr = vdso64_kbase;
617 #endif
618         if (vdso_do_find_sections(&v32, &v64))
619                 return -1;
620
621         if (vdso_fixup_datapage(&v32, &v64))
622                 return -1;
623
624         if (vdso_fixup_alt_funcs(&v32, &v64))
625                 return -1;
626
627         vdso_setup_trampolines(&v32, &v64);
628
629         return 0;
630 }
631
632 /*
633  * Called from setup_arch to initialize the bitmap of available
634  * syscalls in the systemcfg page
635  */
636 static void __init vdso_setup_syscall_map(void)
637 {
638         unsigned int i;
639         extern unsigned long *sys_call_table;
640         extern unsigned long sys_ni_syscall;
641
642
643         for (i = 0; i < __NR_syscalls; i++) {
644 #ifdef CONFIG_PPC64
645                 if (sys_call_table[i*2] != sys_ni_syscall)
646                         vdso_data->syscall_map_64[i >> 5] |=
647                                 0x80000000UL >> (i & 0x1f);
648                 if (sys_call_table[i*2+1] != sys_ni_syscall)
649                         vdso_data->syscall_map_32[i >> 5] |=
650                                 0x80000000UL >> (i & 0x1f);
651 #else /* CONFIG_PPC64 */
652                 if (sys_call_table[i] != sys_ni_syscall)
653                         vdso_data->syscall_map_32[i >> 5] |=
654                                 0x80000000UL >> (i & 0x1f);
655 #endif /* CONFIG_PPC64 */
656         }
657 }
658
659
660 void __init vdso_init(void)
661 {
662         int i;
663
664 #ifdef CONFIG_PPC64
665         /*
666          * Fill up the "systemcfg" stuff for backward compatiblity
667          */
668         strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
669         vdso_data->version.major = SYSTEMCFG_MAJOR;
670         vdso_data->version.minor = SYSTEMCFG_MINOR;
671         vdso_data->processor = mfspr(SPRN_PVR);
672         vdso_data->platform = _machine;
673         vdso_data->physicalMemorySize = lmb_phys_mem_size();
674         vdso_data->dcache_size = ppc64_caches.dsize;
675         vdso_data->dcache_line_size = ppc64_caches.dline_size;
676         vdso_data->icache_size = ppc64_caches.isize;
677         vdso_data->icache_line_size = ppc64_caches.iline_size;
678
679         /*
680          * Calculate the size of the 64 bits vDSO
681          */
682         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
683         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
684 #endif /* CONFIG_PPC64 */
685
686
687         /*
688          * Calculate the size of the 32 bits vDSO
689          */
690         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
691         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
692
693
694         /*
695          * Setup the syscall map in the vDOS
696          */
697         vdso_setup_syscall_map();
698         /*
699          * Initialize the vDSO images in memory, that is do necessary
700          * fixups of vDSO symbols, locate trampolines, etc...
701          */
702         if (vdso_setup()) {
703                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
704                 vdso32_pages = 0;
705 #ifdef CONFIG_PPC64
706                 vdso64_pages = 0;
707 #endif
708                 return;
709         }
710
711         /* Make sure pages are in the correct state */
712         for (i = 0; i < vdso32_pages; i++) {
713                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
714                 ClearPageReserved(pg);
715                 get_page(pg);
716
717         }
718 #ifdef CONFIG_PPC64
719         for (i = 0; i < vdso64_pages; i++) {
720                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
721                 ClearPageReserved(pg);
722                 get_page(pg);
723         }
724 #endif /* CONFIG_PPC64 */
725
726         get_page(virt_to_page(vdso_data));
727 }
728
729 int in_gate_area_no_task(unsigned long addr)
730 {
731         return 0;
732 }
733
734 int in_gate_area(struct task_struct *task, unsigned long addr)
735 {
736         return 0;
737 }
738
739 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
740 {
741         return NULL;
742 }
743