Merge branch 'master' of git+ssh://galak@master.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6] / 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/config.h>
12 #include <linux/module.h>
13 #include <linux/errno.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/smp.h>
18 #include <linux/smp_lock.h>
19 #include <linux/stddef.h>
20 #include <linux/unistd.h>
21 #include <linux/slab.h>
22 #include <linux/user.h>
23 #include <linux/elf.h>
24 #include <linux/security.h>
25 #include <linux/bootmem.h>
26
27 #include <asm/pgtable.h>
28 #include <asm/system.h>
29 #include <asm/processor.h>
30 #include <asm/mmu.h>
31 #include <asm/mmu_context.h>
32 #include <asm/lmb.h>
33 #include <asm/machdep.h>
34 #include <asm/cputable.h>
35 #include <asm/sections.h>
36 #include <asm/vdso.h>
37 #include <asm/vdso_datapage.h>
38
39 #undef DEBUG
40
41 #ifdef DEBUG
42 #define DBG(fmt...) printk(fmt)
43 #else
44 #define DBG(fmt...)
45 #endif
46
47 /* Max supported size for symbol names */
48 #define MAX_SYMNAME     64
49
50 extern char vdso32_start, vdso32_end;
51 static void *vdso32_kbase = &vdso32_start;
52 unsigned int vdso32_pages;
53 unsigned long vdso32_sigtramp;
54 unsigned long vdso32_rt_sigtramp;
55
56 #ifdef CONFIG_PPC64
57 extern char vdso64_start, vdso64_end;
58 static void *vdso64_kbase = &vdso64_start;
59 unsigned int vdso64_pages;
60 unsigned long vdso64_rt_sigtramp;
61 #endif /* CONFIG_PPC64 */
62
63 /*
64  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
65  * Once the early boot kernel code no longer needs to muck around
66  * with it, it will become dynamically allocated
67  */
68 static union {
69         struct vdso_data        data;
70         u8                      page[PAGE_SIZE];
71 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
72 struct vdso_data *vdso_data = &vdso_data_store.data;
73
74 /* Format of the patch table */
75 struct vdso_patch_def
76 {
77         unsigned long   ftr_mask, ftr_value;
78         const char      *gen_name;
79         const char      *fix_name;
80 };
81
82 /* Table of functions to patch based on the CPU type/revision
83  *
84  * Currently, we only change sync_dicache to do nothing on processors
85  * with a coherent icache
86  */
87 static struct vdso_patch_def vdso_patches[] = {
88         {
89                 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
90                 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
91         },
92         {
93                 CPU_FTR_USE_TB, 0,
94                 "__kernel_gettimeofday", NULL
95         },
96 };
97
98 /*
99  * Some infos carried around for each of them during parsing at
100  * boot time.
101  */
102 struct lib32_elfinfo
103 {
104         Elf32_Ehdr      *hdr;           /* ptr to ELF */
105         Elf32_Sym       *dynsym;        /* ptr to .dynsym section */
106         unsigned long   dynsymsize;     /* size of .dynsym section */
107         char            *dynstr;        /* ptr to .dynstr section */
108         unsigned long   text;           /* offset of .text section in .so */
109 };
110
111 struct lib64_elfinfo
112 {
113         Elf64_Ehdr      *hdr;
114         Elf64_Sym       *dynsym;
115         unsigned long   dynsymsize;
116         char            *dynstr;
117         unsigned long   text;
118 };
119
120
121 #ifdef __DEBUG
122 static void dump_one_vdso_page(struct page *pg, struct page *upg)
123 {
124         printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
125                page_count(pg),
126                pg->flags);
127         if (upg/* && pg != upg*/) {
128                 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
129                                                        << PAGE_SHIFT),
130                        page_count(upg),
131                        upg->flags);
132         }
133         printk("\n");
134 }
135
136 static void dump_vdso_pages(struct vm_area_struct * vma)
137 {
138         int i;
139
140         if (!vma || test_thread_flag(TIF_32BIT)) {
141                 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
142                 for (i=0; i<vdso32_pages; i++) {
143                         struct page *pg = virt_to_page(vdso32_kbase +
144                                                        i*PAGE_SIZE);
145                         struct page *upg = (vma && vma->vm_mm) ?
146                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
147                                 : NULL;
148                         dump_one_vdso_page(pg, upg);
149                 }
150         }
151         if (!vma || !test_thread_flag(TIF_32BIT)) {
152                 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
153                 for (i=0; i<vdso64_pages; i++) {
154                         struct page *pg = virt_to_page(vdso64_kbase +
155                                                        i*PAGE_SIZE);
156                         struct page *upg = (vma && vma->vm_mm) ?
157                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
158                                 : NULL;
159                         dump_one_vdso_page(pg, upg);
160                 }
161         }
162 }
163 #endif /* DEBUG */
164
165 /*
166  * Keep a dummy vma_close for now, it will prevent VMA merging.
167  */
168 static void vdso_vma_close(struct vm_area_struct * vma)
169 {
170 }
171
172 /*
173  * Our nopage() function, maps in the actual vDSO kernel pages, they will
174  * be mapped read-only by do_no_page(), and eventually COW'ed, either
175  * right away for an initial write access, or by do_wp_page().
176  */
177 static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
178                                      unsigned long address, int *type)
179 {
180         unsigned long offset = address - vma->vm_start;
181         struct page *pg;
182 #ifdef CONFIG_PPC64
183         void *vbase = test_thread_flag(TIF_32BIT) ?
184                 vdso32_kbase : vdso64_kbase;
185 #else
186         void *vbase = vdso32_kbase;
187 #endif
188
189         DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
190             current->comm, address, offset);
191
192         if (address < vma->vm_start || address > vma->vm_end)
193                 return NOPAGE_SIGBUS;
194
195         /*
196          * Last page is systemcfg.
197          */
198         if ((vma->vm_end - address) <= PAGE_SIZE)
199                 pg = virt_to_page(vdso_data);
200         else
201                 pg = virt_to_page(vbase + offset);
202
203         get_page(pg);
204         DBG(" ->page count: %d\n", page_count(pg));
205
206         return pg;
207 }
208
209 static struct vm_operations_struct vdso_vmops = {
210         .close  = vdso_vma_close,
211         .nopage = vdso_vma_nopage,
212 };
213
214 /*
215  * This is called from binfmt_elf, we create the special vma for the
216  * vDSO and insert it into the mm struct tree
217  */
218 int arch_setup_additional_pages(struct linux_binprm *bprm,
219                                 int executable_stack)
220 {
221         struct mm_struct *mm = current->mm;
222         struct vm_area_struct *vma;
223         unsigned long vdso_pages;
224         unsigned long vdso_base;
225
226 #ifdef CONFIG_PPC64
227         if (test_thread_flag(TIF_32BIT)) {
228                 vdso_pages = vdso32_pages;
229                 vdso_base = VDSO32_MBASE;
230         } else {
231                 vdso_pages = vdso64_pages;
232                 vdso_base = VDSO64_MBASE;
233         }
234 #else
235         vdso_pages = vdso32_pages;
236         vdso_base = VDSO32_MBASE;
237 #endif
238
239         current->thread.vdso_base = 0;
240
241         /* vDSO has a problem and was disabled, just don't "enable" it for the
242          * process
243          */
244         if (vdso_pages == 0)
245                 return 0;
246
247         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
248         if (vma == NULL)
249                 return -ENOMEM;
250
251         memset(vma, 0, sizeof(*vma));
252
253         /* Add a page to the vdso size for the data page */
254         vdso_pages ++;
255
256         /*
257          * pick a base address for the vDSO in process space. We try to put it
258          * at vdso_base which is the "natural" base for it, but we might fail
259          * and end up putting it elsewhere.
260          */
261         vdso_base = get_unmapped_area(NULL, vdso_base,
262                                       vdso_pages << PAGE_SHIFT, 0, 0);
263         if (vdso_base & ~PAGE_MASK) {
264                 kmem_cache_free(vm_area_cachep, vma);
265                 return (int)vdso_base;
266         }
267
268         current->thread.vdso_base = vdso_base;
269
270         vma->vm_mm = mm;
271         vma->vm_start = current->thread.vdso_base;
272         vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
273
274         /*
275          * our vma flags don't have VM_WRITE so by default, the process isn't
276          * allowed to write those pages.
277          * gdb can break that with ptrace interface, and thus trigger COW on
278          * those pages but it's then your responsibility to never do that on
279          * the "data" page of the vDSO or you'll stop getting kernel updates
280          * and your nice userland gettimeofday will be totally dead.
281          * It's fine to use that for setting breakpoints in the vDSO code
282          * pages though
283          */
284         vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
285         vma->vm_flags |= mm->def_flags;
286         vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
287         vma->vm_ops = &vdso_vmops;
288
289         down_write(&mm->mmap_sem);
290         if (insert_vm_struct(mm, vma)) {
291                 up_write(&mm->mmap_sem);
292                 kmem_cache_free(vm_area_cachep, vma);
293                 return -ENOMEM;
294         }
295         mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
296         up_write(&mm->mmap_sem);
297
298         return 0;
299 }
300
301 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
302                                   unsigned long *size)
303 {
304         Elf32_Shdr *sechdrs;
305         unsigned int i;
306         char *secnames;
307
308         /* Grab section headers and strings so we can tell who is who */
309         sechdrs = (void *)ehdr + ehdr->e_shoff;
310         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
311
312         /* Find the section they want */
313         for (i = 1; i < ehdr->e_shnum; i++) {
314                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
315                         if (size)
316                                 *size = sechdrs[i].sh_size;
317                         return (void *)ehdr + sechdrs[i].sh_offset;
318                 }
319         }
320         *size = 0;
321         return NULL;
322 }
323
324 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
325                                         const char *symname)
326 {
327         unsigned int i;
328         char name[MAX_SYMNAME], *c;
329
330         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
331                 if (lib->dynsym[i].st_name == 0)
332                         continue;
333                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
334                         MAX_SYMNAME);
335                 c = strchr(name, '@');
336                 if (c)
337                         *c = 0;
338                 if (strcmp(symname, name) == 0)
339                         return &lib->dynsym[i];
340         }
341         return NULL;
342 }
343
344 /* Note that we assume the section is .text and the symbol is relative to
345  * the library base
346  */
347 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
348                                             const char *symname)
349 {
350         Elf32_Sym *sym = find_symbol32(lib, symname);
351
352         if (sym == NULL) {
353                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
354                        symname);
355                 return 0;
356         }
357         return sym->st_value - VDSO32_LBASE;
358 }
359
360 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
361                                 struct lib64_elfinfo *v64,
362                                 const char *orig, const char *fix)
363 {
364         Elf32_Sym *sym32_gen, *sym32_fix;
365
366         sym32_gen = find_symbol32(v32, orig);
367         if (sym32_gen == NULL) {
368                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
369                 return -1;
370         }
371         if (fix == NULL) {
372                 sym32_gen->st_name = 0;
373                 return 0;
374         }
375         sym32_fix = find_symbol32(v32, fix);
376         if (sym32_fix == NULL) {
377                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
378                 return -1;
379         }
380         sym32_gen->st_value = sym32_fix->st_value;
381         sym32_gen->st_size = sym32_fix->st_size;
382         sym32_gen->st_info = sym32_fix->st_info;
383         sym32_gen->st_other = sym32_fix->st_other;
384         sym32_gen->st_shndx = sym32_fix->st_shndx;
385
386         return 0;
387 }
388
389
390 #ifdef CONFIG_PPC64
391
392 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
393                                   unsigned long *size)
394 {
395         Elf64_Shdr *sechdrs;
396         unsigned int i;
397         char *secnames;
398
399         /* Grab section headers and strings so we can tell who is who */
400         sechdrs = (void *)ehdr + ehdr->e_shoff;
401         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
402
403         /* Find the section they want */
404         for (i = 1; i < ehdr->e_shnum; i++) {
405                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
406                         if (size)
407                                 *size = sechdrs[i].sh_size;
408                         return (void *)ehdr + sechdrs[i].sh_offset;
409                 }
410         }
411         if (size)
412                 *size = 0;
413         return NULL;
414 }
415
416 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
417                                         const char *symname)
418 {
419         unsigned int i;
420         char name[MAX_SYMNAME], *c;
421
422         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
423                 if (lib->dynsym[i].st_name == 0)
424                         continue;
425                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
426                         MAX_SYMNAME);
427                 c = strchr(name, '@');
428                 if (c)
429                         *c = 0;
430                 if (strcmp(symname, name) == 0)
431                         return &lib->dynsym[i];
432         }
433         return NULL;
434 }
435
436 /* Note that we assume the section is .text and the symbol is relative to
437  * the library base
438  */
439 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
440                                             const char *symname)
441 {
442         Elf64_Sym *sym = find_symbol64(lib, symname);
443
444         if (sym == NULL) {
445                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
446                        symname);
447                 return 0;
448         }
449 #ifdef VDS64_HAS_DESCRIPTORS
450         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
451                 VDSO64_LBASE;
452 #else
453         return sym->st_value - VDSO64_LBASE;
454 #endif
455 }
456
457 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
458                                 struct lib64_elfinfo *v64,
459                                 const char *orig, const char *fix)
460 {
461         Elf64_Sym *sym64_gen, *sym64_fix;
462
463         sym64_gen = find_symbol64(v64, orig);
464         if (sym64_gen == NULL) {
465                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
466                 return -1;
467         }
468         if (fix == NULL) {
469                 sym64_gen->st_name = 0;
470                 return 0;
471         }
472         sym64_fix = find_symbol64(v64, fix);
473         if (sym64_fix == NULL) {
474                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
475                 return -1;
476         }
477         sym64_gen->st_value = sym64_fix->st_value;
478         sym64_gen->st_size = sym64_fix->st_size;
479         sym64_gen->st_info = sym64_fix->st_info;
480         sym64_gen->st_other = sym64_fix->st_other;
481         sym64_gen->st_shndx = sym64_fix->st_shndx;
482
483         return 0;
484 }
485
486 #endif /* CONFIG_PPC64 */
487
488
489 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
490                                         struct lib64_elfinfo *v64)
491 {
492         void *sect;
493
494         /*
495          * Locate symbol tables & text section
496          */
497
498         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
499         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
500         if (v32->dynsym == NULL || v32->dynstr == NULL) {
501                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
502                 return -1;
503         }
504         sect = find_section32(v32->hdr, ".text", NULL);
505         if (sect == NULL) {
506                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
507                 return -1;
508         }
509         v32->text = sect - vdso32_kbase;
510
511 #ifdef CONFIG_PPC64
512         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
513         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
514         if (v64->dynsym == NULL || v64->dynstr == NULL) {
515                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
516                 return -1;
517         }
518         sect = find_section64(v64->hdr, ".text", NULL);
519         if (sect == NULL) {
520                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
521                 return -1;
522         }
523         v64->text = sect - vdso64_kbase;
524 #endif /* CONFIG_PPC64 */
525
526         return 0;
527 }
528
529 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
530                                           struct lib64_elfinfo *v64)
531 {
532         /*
533          * Find signal trampolines
534          */
535
536 #ifdef CONFIG_PPC64
537         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
538 #endif
539         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
540         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
541 }
542
543 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
544                                        struct lib64_elfinfo *v64)
545 {
546         Elf32_Sym *sym32;
547 #ifdef CONFIG_PPC64
548         Elf64_Sym *sym64;
549
550         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
551         if (sym64 == NULL) {
552                 printk(KERN_ERR "vDSO64: Can't find symbol "
553                        "__kernel_datapage_offset !\n");
554                 return -1;
555         }
556         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
557                 (vdso64_pages << PAGE_SHIFT) -
558                 (sym64->st_value - VDSO64_LBASE);
559 #endif /* CONFIG_PPC64 */
560
561         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
562         if (sym32 == NULL) {
563                 printk(KERN_ERR "vDSO32: Can't find symbol "
564                        "__kernel_datapage_offset !\n");
565                 return -1;
566         }
567         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
568                 (vdso32_pages << PAGE_SHIFT) -
569                 (sym32->st_value - VDSO32_LBASE);
570
571         return 0;
572 }
573
574 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
575                                        struct lib64_elfinfo *v64)
576 {
577         int i;
578
579         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
580                 struct vdso_patch_def *patch = &vdso_patches[i];
581                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
582                         == patch->ftr_value;
583                 if (!match)
584                         continue;
585
586                 DBG("replacing %s with %s...\n", patch->gen_name,
587                     patch->fix_name ? "NONE" : patch->fix_name);
588
589                 /*
590                  * Patch the 32 bits and 64 bits symbols. Note that we do not
591                  * patch the "." symbol on 64 bits.
592                  * It would be easy to do, but doesn't seem to be necessary,
593                  * patching the OPD symbol is enough.
594                  */
595                 vdso_do_func_patch32(v32, v64, patch->gen_name,
596                                      patch->fix_name);
597 #ifdef CONFIG_PPC64
598                 vdso_do_func_patch64(v32, v64, patch->gen_name,
599                                      patch->fix_name);
600 #endif /* CONFIG_PPC64 */
601         }
602
603         return 0;
604 }
605
606
607 static __init int vdso_setup(void)
608 {
609         struct lib32_elfinfo    v32;
610         struct lib64_elfinfo    v64;
611
612         v32.hdr = vdso32_kbase;
613 #ifdef CONFIG_PPC64
614         v64.hdr = vdso64_kbase;
615 #endif
616         if (vdso_do_find_sections(&v32, &v64))
617                 return -1;
618
619         if (vdso_fixup_datapage(&v32, &v64))
620                 return -1;
621
622         if (vdso_fixup_alt_funcs(&v32, &v64))
623                 return -1;
624
625         vdso_setup_trampolines(&v32, &v64);
626
627         return 0;
628 }
629
630 /*
631  * Called from setup_arch to initialize the bitmap of available
632  * syscalls in the systemcfg page
633  */
634 static void __init vdso_setup_syscall_map(void)
635 {
636         unsigned int i;
637         extern unsigned long *sys_call_table;
638         extern unsigned long sys_ni_syscall;
639
640
641         for (i = 0; i < __NR_syscalls; i++) {
642 #ifdef CONFIG_PPC64
643                 if (sys_call_table[i*2] != sys_ni_syscall)
644                         vdso_data->syscall_map_64[i >> 5] |=
645                                 0x80000000UL >> (i & 0x1f);
646                 if (sys_call_table[i*2+1] != sys_ni_syscall)
647                         vdso_data->syscall_map_32[i >> 5] |=
648                                 0x80000000UL >> (i & 0x1f);
649 #else /* CONFIG_PPC64 */
650                 if (sys_call_table[i] != sys_ni_syscall)
651                         vdso_data->syscall_map_32[i >> 5] |=
652                                 0x80000000UL >> (i & 0x1f);
653 #endif /* CONFIG_PPC64 */
654         }
655 }
656
657
658 void __init vdso_init(void)
659 {
660         int i;
661
662 #ifdef CONFIG_PPC64
663         /*
664          * Fill up the "systemcfg" stuff for backward compatiblity
665          */
666         strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
667         vdso_data->version.major = SYSTEMCFG_MAJOR;
668         vdso_data->version.minor = SYSTEMCFG_MINOR;
669         vdso_data->processor = mfspr(SPRN_PVR);
670         vdso_data->platform = _machine;
671         vdso_data->physicalMemorySize = lmb_phys_mem_size();
672         vdso_data->dcache_size = ppc64_caches.dsize;
673         vdso_data->dcache_line_size = ppc64_caches.dline_size;
674         vdso_data->icache_size = ppc64_caches.isize;
675         vdso_data->icache_line_size = ppc64_caches.iline_size;
676
677         /*
678          * Calculate the size of the 64 bits vDSO
679          */
680         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
681         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
682 #endif /* CONFIG_PPC64 */
683
684
685         /*
686          * Calculate the size of the 32 bits vDSO
687          */
688         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
689         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
690
691
692         /*
693          * Setup the syscall map in the vDOS
694          */
695         vdso_setup_syscall_map();
696         /*
697          * Initialize the vDSO images in memory, that is do necessary
698          * fixups of vDSO symbols, locate trampolines, etc...
699          */
700         if (vdso_setup()) {
701                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
702                 vdso32_pages = 0;
703 #ifdef CONFIG_PPC64
704                 vdso64_pages = 0;
705 #endif
706                 return;
707         }
708
709         /* Make sure pages are in the correct state */
710         for (i = 0; i < vdso32_pages; i++) {
711                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
712                 ClearPageReserved(pg);
713                 get_page(pg);
714
715         }
716 #ifdef CONFIG_PPC64
717         for (i = 0; i < vdso64_pages; i++) {
718                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
719                 ClearPageReserved(pg);
720                 get_page(pg);
721         }
722 #endif /* CONFIG_PPC64 */
723
724         get_page(virt_to_page(vdso_data));
725 }
726
727 int in_gate_area_no_task(unsigned long addr)
728 {
729         return 0;
730 }
731
732 int in_gate_area(struct task_struct *task, unsigned long addr)
733 {
734         return 0;
735 }
736
737 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
738 {
739         return NULL;
740 }
741