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12#include <linux/errno.h>
13#include <linux/sched.h>
14#include <linux/kernel.h>
15#include <linux/mm.h>
16#include <linux/smp.h>
17#include <linux/stddef.h>
18#include <linux/unistd.h>
19#include <linux/slab.h>
20#include <linux/user.h>
21#include <linux/elf.h>
22#include <linux/security.h>
23#include <linux/memblock.h>
24
25#include <asm/cpu_has_feature.h>
26#include <asm/pgtable.h>
27#include <asm/processor.h>
28#include <asm/mmu.h>
29#include <asm/mmu_context.h>
30#include <asm/prom.h>
31#include <asm/machdep.h>
32#include <asm/cputable.h>
33#include <asm/sections.h>
34#include <asm/firmware.h>
35#include <asm/vdso.h>
36#include <asm/vdso_datapage.h>
37#include <asm/setup.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
48#define MAX_SYMNAME 64
49
50
51#define VDSO_ALIGNMENT (1 << 16)
52
53static unsigned int vdso32_pages;
54static void *vdso32_kbase;
55static struct page **vdso32_pagelist;
56unsigned long vdso32_sigtramp;
57unsigned long vdso32_rt_sigtramp;
58
59#ifdef CONFIG_VDSO32
60extern char vdso32_start, vdso32_end;
61#endif
62
63#ifdef CONFIG_PPC64
64extern char vdso64_start, vdso64_end;
65static void *vdso64_kbase = &vdso64_start;
66static unsigned int vdso64_pages;
67static struct page **vdso64_pagelist;
68unsigned long vdso64_rt_sigtramp;
69#endif
70
71static int vdso_ready;
72
73
74
75
76
77
78static union {
79 struct vdso_data data;
80 u8 page[PAGE_SIZE];
81} vdso_data_store __page_aligned_data;
82struct vdso_data *vdso_data = &vdso_data_store.data;
83
84
85struct vdso_patch_def
86{
87 unsigned long ftr_mask, ftr_value;
88 const char *gen_name;
89 const char *fix_name;
90};
91
92
93
94
95
96
97static struct vdso_patch_def vdso_patches[] = {
98 {
99 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
100 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
101 },
102 {
103 CPU_FTR_USE_TB, 0,
104 "__kernel_gettimeofday", NULL
105 },
106 {
107 CPU_FTR_USE_TB, 0,
108 "__kernel_clock_gettime", NULL
109 },
110 {
111 CPU_FTR_USE_TB, 0,
112 "__kernel_clock_getres", NULL
113 },
114 {
115 CPU_FTR_USE_TB, 0,
116 "__kernel_get_tbfreq", NULL
117 },
118 {
119 CPU_FTR_USE_TB, 0,
120 "__kernel_time", NULL
121 },
122};
123
124
125
126
127
128struct lib32_elfinfo
129{
130 Elf32_Ehdr *hdr;
131 Elf32_Sym *dynsym;
132 unsigned long dynsymsize;
133 char *dynstr;
134 unsigned long text;
135};
136
137struct lib64_elfinfo
138{
139 Elf64_Ehdr *hdr;
140 Elf64_Sym *dynsym;
141 unsigned long dynsymsize;
142 char *dynstr;
143 unsigned long text;
144};
145
146
147
148
149
150
151int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
152{
153 struct mm_struct *mm = current->mm;
154 struct page **vdso_pagelist;
155 unsigned long vdso_pages;
156 unsigned long vdso_base;
157 int rc;
158
159 if (!vdso_ready)
160 return 0;
161
162#ifdef CONFIG_PPC64
163 if (is_32bit_task()) {
164 vdso_pagelist = vdso32_pagelist;
165 vdso_pages = vdso32_pages;
166 vdso_base = VDSO32_MBASE;
167 } else {
168 vdso_pagelist = vdso64_pagelist;
169 vdso_pages = vdso64_pages;
170
171
172
173
174
175 vdso_base = 0;
176 }
177#else
178 vdso_pagelist = vdso32_pagelist;
179 vdso_pages = vdso32_pages;
180 vdso_base = VDSO32_MBASE;
181#endif
182
183 current->mm->context.vdso_base = 0;
184
185
186
187
188 if (vdso_pages == 0)
189 return 0;
190
191 vdso_pages ++;
192
193
194
195
196
197
198
199 if (down_write_killable(&mm->mmap_sem))
200 return -EINTR;
201 vdso_base = get_unmapped_area(NULL, vdso_base,
202 (vdso_pages << PAGE_SHIFT) +
203 ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
204 0, 0);
205 if (IS_ERR_VALUE(vdso_base)) {
206 rc = vdso_base;
207 goto fail_mmapsem;
208 }
209
210
211 vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
212
213
214
215
216
217
218 current->mm->context.vdso_base = vdso_base;
219
220
221
222
223
224
225
226
227
228
229
230 rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
231 VM_READ|VM_EXEC|
232 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
233 vdso_pagelist);
234 if (rc) {
235 current->mm->context.vdso_base = 0;
236 goto fail_mmapsem;
237 }
238
239 up_write(&mm->mmap_sem);
240 return 0;
241
242 fail_mmapsem:
243 up_write(&mm->mmap_sem);
244 return rc;
245}
246
247const char *arch_vma_name(struct vm_area_struct *vma)
248{
249 if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
250 return "[vdso]";
251 return NULL;
252}
253
254
255
256#ifdef CONFIG_VDSO32
257static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
258 unsigned long *size)
259{
260 Elf32_Shdr *sechdrs;
261 unsigned int i;
262 char *secnames;
263
264
265 sechdrs = (void *)ehdr + ehdr->e_shoff;
266 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
267
268
269 for (i = 1; i < ehdr->e_shnum; i++) {
270 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
271 if (size)
272 *size = sechdrs[i].sh_size;
273 return (void *)ehdr + sechdrs[i].sh_offset;
274 }
275 }
276 *size = 0;
277 return NULL;
278}
279
280static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
281 const char *symname)
282{
283 unsigned int i;
284 char name[MAX_SYMNAME], *c;
285
286 for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
287 if (lib->dynsym[i].st_name == 0)
288 continue;
289 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
290 MAX_SYMNAME);
291 c = strchr(name, '@');
292 if (c)
293 *c = 0;
294 if (strcmp(symname, name) == 0)
295 return &lib->dynsym[i];
296 }
297 return NULL;
298}
299
300
301
302
303static unsigned long __init find_function32(struct lib32_elfinfo *lib,
304 const char *symname)
305{
306 Elf32_Sym *sym = find_symbol32(lib, symname);
307
308 if (sym == NULL) {
309 printk(KERN_WARNING "vDSO32: function %s not found !\n",
310 symname);
311 return 0;
312 }
313 return sym->st_value - VDSO32_LBASE;
314}
315
316static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
317 struct lib64_elfinfo *v64,
318 const char *orig, const char *fix)
319{
320 Elf32_Sym *sym32_gen, *sym32_fix;
321
322 sym32_gen = find_symbol32(v32, orig);
323 if (sym32_gen == NULL) {
324 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
325 return -1;
326 }
327 if (fix == NULL) {
328 sym32_gen->st_name = 0;
329 return 0;
330 }
331 sym32_fix = find_symbol32(v32, fix);
332 if (sym32_fix == NULL) {
333 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
334 return -1;
335 }
336 sym32_gen->st_value = sym32_fix->st_value;
337 sym32_gen->st_size = sym32_fix->st_size;
338 sym32_gen->st_info = sym32_fix->st_info;
339 sym32_gen->st_other = sym32_fix->st_other;
340 sym32_gen->st_shndx = sym32_fix->st_shndx;
341
342 return 0;
343}
344#else
345static unsigned long __init find_function32(struct lib32_elfinfo *lib,
346 const char *symname)
347{
348 return 0;
349}
350
351static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
352 struct lib64_elfinfo *v64,
353 const char *orig, const char *fix)
354{
355 return 0;
356}
357#endif
358
359
360#ifdef CONFIG_PPC64
361
362static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
363 unsigned long *size)
364{
365 Elf64_Shdr *sechdrs;
366 unsigned int i;
367 char *secnames;
368
369
370 sechdrs = (void *)ehdr + ehdr->e_shoff;
371 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
372
373
374 for (i = 1; i < ehdr->e_shnum; i++) {
375 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
376 if (size)
377 *size = sechdrs[i].sh_size;
378 return (void *)ehdr + sechdrs[i].sh_offset;
379 }
380 }
381 if (size)
382 *size = 0;
383 return NULL;
384}
385
386static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
387 const char *symname)
388{
389 unsigned int i;
390 char name[MAX_SYMNAME], *c;
391
392 for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
393 if (lib->dynsym[i].st_name == 0)
394 continue;
395 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
396 MAX_SYMNAME);
397 c = strchr(name, '@');
398 if (c)
399 *c = 0;
400 if (strcmp(symname, name) == 0)
401 return &lib->dynsym[i];
402 }
403 return NULL;
404}
405
406
407
408
409static unsigned long __init find_function64(struct lib64_elfinfo *lib,
410 const char *symname)
411{
412 Elf64_Sym *sym = find_symbol64(lib, symname);
413
414 if (sym == NULL) {
415 printk(KERN_WARNING "vDSO64: function %s not found !\n",
416 symname);
417 return 0;
418 }
419#ifdef VDS64_HAS_DESCRIPTORS
420 return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
421 VDSO64_LBASE;
422#else
423 return sym->st_value - VDSO64_LBASE;
424#endif
425}
426
427static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
428 struct lib64_elfinfo *v64,
429 const char *orig, const char *fix)
430{
431 Elf64_Sym *sym64_gen, *sym64_fix;
432
433 sym64_gen = find_symbol64(v64, orig);
434 if (sym64_gen == NULL) {
435 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
436 return -1;
437 }
438 if (fix == NULL) {
439 sym64_gen->st_name = 0;
440 return 0;
441 }
442 sym64_fix = find_symbol64(v64, fix);
443 if (sym64_fix == NULL) {
444 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
445 return -1;
446 }
447 sym64_gen->st_value = sym64_fix->st_value;
448 sym64_gen->st_size = sym64_fix->st_size;
449 sym64_gen->st_info = sym64_fix->st_info;
450 sym64_gen->st_other = sym64_fix->st_other;
451 sym64_gen->st_shndx = sym64_fix->st_shndx;
452
453 return 0;
454}
455
456#endif
457
458
459static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
460 struct lib64_elfinfo *v64)
461{
462 void *sect;
463
464
465
466
467
468#ifdef CONFIG_VDSO32
469 v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
470 v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
471 if (v32->dynsym == NULL || v32->dynstr == NULL) {
472 printk(KERN_ERR "vDSO32: required symbol section not found\n");
473 return -1;
474 }
475 sect = find_section32(v32->hdr, ".text", NULL);
476 if (sect == NULL) {
477 printk(KERN_ERR "vDSO32: the .text section was not found\n");
478 return -1;
479 }
480 v32->text = sect - vdso32_kbase;
481#endif
482
483#ifdef CONFIG_PPC64
484 v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
485 v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
486 if (v64->dynsym == NULL || v64->dynstr == NULL) {
487 printk(KERN_ERR "vDSO64: required symbol section not found\n");
488 return -1;
489 }
490 sect = find_section64(v64->hdr, ".text", NULL);
491 if (sect == NULL) {
492 printk(KERN_ERR "vDSO64: the .text section was not found\n");
493 return -1;
494 }
495 v64->text = sect - vdso64_kbase;
496#endif
497
498 return 0;
499}
500
501static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
502 struct lib64_elfinfo *v64)
503{
504
505
506
507
508#ifdef CONFIG_PPC64
509 vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
510#endif
511 vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32");
512 vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
513}
514
515static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
516 struct lib64_elfinfo *v64)
517{
518#ifdef CONFIG_VDSO32
519 Elf32_Sym *sym32;
520#endif
521#ifdef CONFIG_PPC64
522 Elf64_Sym *sym64;
523
524 sym64 = find_symbol64(v64, "__kernel_datapage_offset");
525 if (sym64 == NULL) {
526 printk(KERN_ERR "vDSO64: Can't find symbol "
527 "__kernel_datapage_offset !\n");
528 return -1;
529 }
530 *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
531 (vdso64_pages << PAGE_SHIFT) -
532 (sym64->st_value - VDSO64_LBASE);
533#endif
534
535#ifdef CONFIG_VDSO32
536 sym32 = find_symbol32(v32, "__kernel_datapage_offset");
537 if (sym32 == NULL) {
538 printk(KERN_ERR "vDSO32: Can't find symbol "
539 "__kernel_datapage_offset !\n");
540 return -1;
541 }
542 *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
543 (vdso32_pages << PAGE_SHIFT) -
544 (sym32->st_value - VDSO32_LBASE);
545#endif
546
547 return 0;
548}
549
550
551static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
552 struct lib64_elfinfo *v64)
553{
554 unsigned long size;
555 void *start;
556
557#ifdef CONFIG_PPC64
558 start = find_section64(v64->hdr, "__ftr_fixup", &size);
559 if (start)
560 do_feature_fixups(cur_cpu_spec->cpu_features,
561 start, start + size);
562
563 start = find_section64(v64->hdr, "__mmu_ftr_fixup", &size);
564 if (start)
565 do_feature_fixups(cur_cpu_spec->mmu_features,
566 start, start + size);
567
568 start = find_section64(v64->hdr, "__fw_ftr_fixup", &size);
569 if (start)
570 do_feature_fixups(powerpc_firmware_features,
571 start, start + size);
572
573 start = find_section64(v64->hdr, "__lwsync_fixup", &size);
574 if (start)
575 do_lwsync_fixups(cur_cpu_spec->cpu_features,
576 start, start + size);
577#endif
578
579#ifdef CONFIG_VDSO32
580 start = find_section32(v32->hdr, "__ftr_fixup", &size);
581 if (start)
582 do_feature_fixups(cur_cpu_spec->cpu_features,
583 start, start + size);
584
585 start = find_section32(v32->hdr, "__mmu_ftr_fixup", &size);
586 if (start)
587 do_feature_fixups(cur_cpu_spec->mmu_features,
588 start, start + size);
589
590#ifdef CONFIG_PPC64
591 start = find_section32(v32->hdr, "__fw_ftr_fixup", &size);
592 if (start)
593 do_feature_fixups(powerpc_firmware_features,
594 start, start + size);
595#endif
596
597 start = find_section32(v32->hdr, "__lwsync_fixup", &size);
598 if (start)
599 do_lwsync_fixups(cur_cpu_spec->cpu_features,
600 start, start + size);
601#endif
602
603 return 0;
604}
605
606static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
607 struct lib64_elfinfo *v64)
608{
609 int i;
610
611 for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
612 struct vdso_patch_def *patch = &vdso_patches[i];
613 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
614 == patch->ftr_value;
615 if (!match)
616 continue;
617
618 DBG("replacing %s with %s...\n", patch->gen_name,
619 patch->fix_name ? "NONE" : patch->fix_name);
620
621
622
623
624
625
626
627 vdso_do_func_patch32(v32, v64, patch->gen_name,
628 patch->fix_name);
629#ifdef CONFIG_PPC64
630 vdso_do_func_patch64(v32, v64, patch->gen_name,
631 patch->fix_name);
632#endif
633 }
634
635 return 0;
636}
637
638
639static __init int vdso_setup(void)
640{
641 struct lib32_elfinfo v32;
642 struct lib64_elfinfo v64;
643
644 v32.hdr = vdso32_kbase;
645#ifdef CONFIG_PPC64
646 v64.hdr = vdso64_kbase;
647#endif
648 if (vdso_do_find_sections(&v32, &v64))
649 return -1;
650
651 if (vdso_fixup_datapage(&v32, &v64))
652 return -1;
653
654 if (vdso_fixup_features(&v32, &v64))
655 return -1;
656
657 if (vdso_fixup_alt_funcs(&v32, &v64))
658 return -1;
659
660 vdso_setup_trampolines(&v32, &v64);
661
662 return 0;
663}
664
665
666
667
668
669static void __init vdso_setup_syscall_map(void)
670{
671 unsigned int i;
672 extern unsigned long *sys_call_table;
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*2] != sys_ni_syscall)
679 vdso_data->syscall_map_64[i >> 5] |=
680 0x80000000UL >> (i & 0x1f);
681 if (sys_call_table[i*2+1] != sys_ni_syscall)
682 vdso_data->syscall_map_32[i >> 5] |=
683 0x80000000UL >> (i & 0x1f);
684#else
685 if (sys_call_table[i] != sys_ni_syscall)
686 vdso_data->syscall_map_32[i >> 5] |=
687 0x80000000UL >> (i & 0x1f);
688#endif
689 }
690}
691
692#ifdef CONFIG_PPC64
693int vdso_getcpu_init(void)
694{
695 unsigned long cpu, node, val;
696
697
698
699
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
716early_initcall(vdso_getcpu_init);
717#endif
718
719static int __init vdso_init(void)
720{
721 int i;
722
723#ifdef CONFIG_PPC64
724
725
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
733
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
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
759
760
761#ifdef CONFIG_VDSO32
762 vdso32_kbase = &vdso32_start;
763
764
765
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
774
775 vdso_setup_syscall_map();
776
777
778
779
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
792 vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
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 ClearPageReserved(pg);
798 get_page(pg);
799 vdso32_pagelist[i] = pg;
800 }
801 vdso32_pagelist[i++] = virt_to_page(vdso_data);
802 vdso32_pagelist[i] = NULL;
803#endif
804
805#ifdef CONFIG_PPC64
806 vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
807 GFP_KERNEL);
808 BUG_ON(vdso64_pagelist == NULL);
809 for (i = 0; i < vdso64_pages; i++) {
810 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
811 ClearPageReserved(pg);
812 get_page(pg);
813 vdso64_pagelist[i] = pg;
814 }
815 vdso64_pagelist[i++] = virt_to_page(vdso_data);
816 vdso64_pagelist[i] = NULL;
817#endif
818
819 get_page(virt_to_page(vdso_data));
820
821 smp_wmb();
822 vdso_ready = 1;
823
824 return 0;
825}
826arch_initcall(vdso_init);
827