xref: /linux/arch/powerpc/kernel/vdso.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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/module.h>
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/smp_lock.h>
18 #include <linux/stddef.h>
19 #include <linux/unistd.h>
20 #include <linux/slab.h>
21 #include <linux/user.h>
22 #include <linux/elf.h>
23 #include <linux/security.h>
24 #include <linux/bootmem.h>
25 
26 #include <asm/pgtable.h>
27 #include <asm/system.h>
28 #include <asm/processor.h>
29 #include <asm/mmu.h>
30 #include <asm/mmu_context.h>
31 #include <asm/lmb.h>
32 #include <asm/machdep.h>
33 #include <asm/cputable.h>
34 #include <asm/sections.h>
35 #include <asm/firmware.h>
36 #include <asm/vdso.h>
37 #include <asm/vdso_datapage.h>
38 
39 #include "setup.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 static unsigned int vdso32_pages;
55 static struct page **vdso32_pagelist;
56 unsigned long vdso32_sigtramp;
57 unsigned long vdso32_rt_sigtramp;
58 
59 #ifdef CONFIG_PPC64
60 extern char vdso64_start, vdso64_end;
61 static void *vdso64_kbase = &vdso64_start;
62 static unsigned int vdso64_pages;
63 static struct page **vdso64_pagelist;
64 unsigned long vdso64_rt_sigtramp;
65 #endif /* CONFIG_PPC64 */
66 
67 static int vdso_ready;
68 
69 /*
70  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
71  * Once the early boot kernel code no longer needs to muck around
72  * with it, it will become dynamically allocated
73  */
74 static union {
75 	struct vdso_data	data;
76 	u8			page[PAGE_SIZE];
77 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
78 struct vdso_data *vdso_data = &vdso_data_store.data;
79 
80 /* Format of the patch table */
81 struct vdso_patch_def
82 {
83 	unsigned long	ftr_mask, ftr_value;
84 	const char	*gen_name;
85 	const char	*fix_name;
86 };
87 
88 /* Table of functions to patch based on the CPU type/revision
89  *
90  * Currently, we only change sync_dicache to do nothing on processors
91  * with a coherent icache
92  */
93 static struct vdso_patch_def vdso_patches[] = {
94 	{
95 		CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
96 		"__kernel_sync_dicache", "__kernel_sync_dicache_p5"
97 	},
98 	{
99 		CPU_FTR_USE_TB, 0,
100 		"__kernel_gettimeofday", NULL
101 	},
102 };
103 
104 /*
105  * Some infos carried around for each of them during parsing at
106  * boot time.
107  */
108 struct lib32_elfinfo
109 {
110 	Elf32_Ehdr	*hdr;		/* ptr to ELF */
111 	Elf32_Sym	*dynsym;	/* ptr to .dynsym section */
112 	unsigned long	dynsymsize;	/* size of .dynsym section */
113 	char		*dynstr;	/* ptr to .dynstr section */
114 	unsigned long	text;		/* offset of .text section in .so */
115 };
116 
117 struct lib64_elfinfo
118 {
119 	Elf64_Ehdr	*hdr;
120 	Elf64_Sym	*dynsym;
121 	unsigned long	dynsymsize;
122 	char		*dynstr;
123 	unsigned long	text;
124 };
125 
126 
127 #ifdef __DEBUG
128 static void dump_one_vdso_page(struct page *pg, struct page *upg)
129 {
130 	printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
131 	       page_count(pg),
132 	       pg->flags);
133 	if (upg/* && pg != upg*/) {
134 		printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
135 						       << PAGE_SHIFT),
136 		       page_count(upg),
137 		       upg->flags);
138 	}
139 	printk("\n");
140 }
141 
142 static void dump_vdso_pages(struct vm_area_struct * vma)
143 {
144 	int i;
145 
146 	if (!vma || test_thread_flag(TIF_32BIT)) {
147 		printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
148 		for (i=0; i<vdso32_pages; i++) {
149 			struct page *pg = virt_to_page(vdso32_kbase +
150 						       i*PAGE_SIZE);
151 			struct page *upg = (vma && vma->vm_mm) ?
152 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
153 				: NULL;
154 			dump_one_vdso_page(pg, upg);
155 		}
156 	}
157 	if (!vma || !test_thread_flag(TIF_32BIT)) {
158 		printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
159 		for (i=0; i<vdso64_pages; i++) {
160 			struct page *pg = virt_to_page(vdso64_kbase +
161 						       i*PAGE_SIZE);
162 			struct page *upg = (vma && vma->vm_mm) ?
163 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
164 				: NULL;
165 			dump_one_vdso_page(pg, upg);
166 		}
167 	}
168 }
169 #endif /* DEBUG */
170 
171 /*
172  * This is called from binfmt_elf, we create the special vma for the
173  * vDSO and insert it into the mm struct tree
174  */
175 int arch_setup_additional_pages(struct linux_binprm *bprm,
176 				int executable_stack)
177 {
178 	struct mm_struct *mm = current->mm;
179 	struct page **vdso_pagelist;
180 	unsigned long vdso_pages;
181 	unsigned long vdso_base;
182 	int rc;
183 
184 	if (!vdso_ready)
185 		return 0;
186 
187 #ifdef CONFIG_PPC64
188 	if (test_thread_flag(TIF_32BIT)) {
189 		vdso_pagelist = vdso32_pagelist;
190 		vdso_pages = vdso32_pages;
191 		vdso_base = VDSO32_MBASE;
192 	} else {
193 		vdso_pagelist = vdso64_pagelist;
194 		vdso_pages = vdso64_pages;
195 		vdso_base = VDSO64_MBASE;
196 	}
197 #else
198 	vdso_pagelist = vdso32_pagelist;
199 	vdso_pages = vdso32_pages;
200 	vdso_base = VDSO32_MBASE;
201 #endif
202 
203 	current->mm->context.vdso_base = 0;
204 
205 	/* vDSO has a problem and was disabled, just don't "enable" it for the
206 	 * process
207 	 */
208 	if (vdso_pages == 0)
209 		return 0;
210 	/* Add a page to the vdso size for the data page */
211 	vdso_pages ++;
212 
213 	/*
214 	 * pick a base address for the vDSO in process space. We try to put it
215 	 * at vdso_base which is the "natural" base for it, but we might fail
216 	 * and end up putting it elsewhere.
217 	 */
218 	down_write(&mm->mmap_sem);
219 	vdso_base = get_unmapped_area(NULL, vdso_base,
220 				      vdso_pages << PAGE_SHIFT, 0, 0);
221 	if (IS_ERR_VALUE(vdso_base)) {
222 		rc = vdso_base;
223 		goto fail_mmapsem;
224 	}
225 
226 	/*
227 	 * our vma flags don't have VM_WRITE so by default, the process isn't
228 	 * allowed to write those pages.
229 	 * gdb can break that with ptrace interface, and thus trigger COW on
230 	 * those pages but it's then your responsibility to never do that on
231 	 * the "data" page of the vDSO or you'll stop getting kernel updates
232 	 * and your nice userland gettimeofday will be totally dead.
233 	 * It's fine to use that for setting breakpoints in the vDSO code
234 	 * pages though
235 	 *
236 	 * Make sure the vDSO gets into every core dump.
237 	 * Dumping its contents makes post-mortem fully interpretable later
238 	 * without matching up the same kernel and hardware config to see
239 	 * what PC values meant.
240 	 */
241 	rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
242 				     VM_READ|VM_EXEC|
243 				     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
244 				     VM_ALWAYSDUMP,
245 				     vdso_pagelist);
246 	if (rc)
247 		goto fail_mmapsem;
248 
249 	/* Put vDSO base into mm struct */
250 	current->mm->context.vdso_base = vdso_base;
251 
252 	up_write(&mm->mmap_sem);
253 	return 0;
254 
255  fail_mmapsem:
256 	up_write(&mm->mmap_sem);
257 	return rc;
258 }
259 
260 const char *arch_vma_name(struct vm_area_struct *vma)
261 {
262 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
263 		return "[vdso]";
264 	return NULL;
265 }
266 
267 
268 
269 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
270 				  unsigned long *size)
271 {
272 	Elf32_Shdr *sechdrs;
273 	unsigned int i;
274 	char *secnames;
275 
276 	/* Grab section headers and strings so we can tell who is who */
277 	sechdrs = (void *)ehdr + ehdr->e_shoff;
278 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
279 
280 	/* Find the section they want */
281 	for (i = 1; i < ehdr->e_shnum; i++) {
282 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
283 			if (size)
284 				*size = sechdrs[i].sh_size;
285 			return (void *)ehdr + sechdrs[i].sh_offset;
286 		}
287 	}
288 	*size = 0;
289 	return NULL;
290 }
291 
292 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
293 					const char *symname)
294 {
295 	unsigned int i;
296 	char name[MAX_SYMNAME], *c;
297 
298 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
299 		if (lib->dynsym[i].st_name == 0)
300 			continue;
301 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
302 			MAX_SYMNAME);
303 		c = strchr(name, '@');
304 		if (c)
305 			*c = 0;
306 		if (strcmp(symname, name) == 0)
307 			return &lib->dynsym[i];
308 	}
309 	return NULL;
310 }
311 
312 /* Note that we assume the section is .text and the symbol is relative to
313  * the library base
314  */
315 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
316 					    const char *symname)
317 {
318 	Elf32_Sym *sym = find_symbol32(lib, symname);
319 
320 	if (sym == NULL) {
321 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
322 		       symname);
323 		return 0;
324 	}
325 	return sym->st_value - VDSO32_LBASE;
326 }
327 
328 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
329 				struct lib64_elfinfo *v64,
330 				const char *orig, const char *fix)
331 {
332 	Elf32_Sym *sym32_gen, *sym32_fix;
333 
334 	sym32_gen = find_symbol32(v32, orig);
335 	if (sym32_gen == NULL) {
336 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
337 		return -1;
338 	}
339 	if (fix == NULL) {
340 		sym32_gen->st_name = 0;
341 		return 0;
342 	}
343 	sym32_fix = find_symbol32(v32, fix);
344 	if (sym32_fix == NULL) {
345 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
346 		return -1;
347 	}
348 	sym32_gen->st_value = sym32_fix->st_value;
349 	sym32_gen->st_size = sym32_fix->st_size;
350 	sym32_gen->st_info = sym32_fix->st_info;
351 	sym32_gen->st_other = sym32_fix->st_other;
352 	sym32_gen->st_shndx = sym32_fix->st_shndx;
353 
354 	return 0;
355 }
356 
357 
358 #ifdef CONFIG_PPC64
359 
360 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
361 				  unsigned long *size)
362 {
363 	Elf64_Shdr *sechdrs;
364 	unsigned int i;
365 	char *secnames;
366 
367 	/* Grab section headers and strings so we can tell who is who */
368 	sechdrs = (void *)ehdr + ehdr->e_shoff;
369 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
370 
371 	/* Find the section they want */
372 	for (i = 1; i < ehdr->e_shnum; i++) {
373 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
374 			if (size)
375 				*size = sechdrs[i].sh_size;
376 			return (void *)ehdr + sechdrs[i].sh_offset;
377 		}
378 	}
379 	if (size)
380 		*size = 0;
381 	return NULL;
382 }
383 
384 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
385 					const char *symname)
386 {
387 	unsigned int i;
388 	char name[MAX_SYMNAME], *c;
389 
390 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
391 		if (lib->dynsym[i].st_name == 0)
392 			continue;
393 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
394 			MAX_SYMNAME);
395 		c = strchr(name, '@');
396 		if (c)
397 			*c = 0;
398 		if (strcmp(symname, name) == 0)
399 			return &lib->dynsym[i];
400 	}
401 	return NULL;
402 }
403 
404 /* Note that we assume the section is .text and the symbol is relative to
405  * the library base
406  */
407 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
408 					    const char *symname)
409 {
410 	Elf64_Sym *sym = find_symbol64(lib, symname);
411 
412 	if (sym == NULL) {
413 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
414 		       symname);
415 		return 0;
416 	}
417 #ifdef VDS64_HAS_DESCRIPTORS
418 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
419 		VDSO64_LBASE;
420 #else
421 	return sym->st_value - VDSO64_LBASE;
422 #endif
423 }
424 
425 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
426 				struct lib64_elfinfo *v64,
427 				const char *orig, const char *fix)
428 {
429 	Elf64_Sym *sym64_gen, *sym64_fix;
430 
431 	sym64_gen = find_symbol64(v64, orig);
432 	if (sym64_gen == NULL) {
433 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
434 		return -1;
435 	}
436 	if (fix == NULL) {
437 		sym64_gen->st_name = 0;
438 		return 0;
439 	}
440 	sym64_fix = find_symbol64(v64, fix);
441 	if (sym64_fix == NULL) {
442 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
443 		return -1;
444 	}
445 	sym64_gen->st_value = sym64_fix->st_value;
446 	sym64_gen->st_size = sym64_fix->st_size;
447 	sym64_gen->st_info = sym64_fix->st_info;
448 	sym64_gen->st_other = sym64_fix->st_other;
449 	sym64_gen->st_shndx = sym64_fix->st_shndx;
450 
451 	return 0;
452 }
453 
454 #endif /* CONFIG_PPC64 */
455 
456 
457 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
458 					struct lib64_elfinfo *v64)
459 {
460 	void *sect;
461 
462 	/*
463 	 * Locate symbol tables & text section
464 	 */
465 
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 
479 #ifdef CONFIG_PPC64
480 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
481 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
482 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
483 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
484 		return -1;
485 	}
486 	sect = find_section64(v64->hdr, ".text", NULL);
487 	if (sect == NULL) {
488 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
489 		return -1;
490 	}
491 	v64->text = sect - vdso64_kbase;
492 #endif /* CONFIG_PPC64 */
493 
494 	return 0;
495 }
496 
497 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
498 					  struct lib64_elfinfo *v64)
499 {
500 	/*
501 	 * Find signal trampolines
502 	 */
503 
504 #ifdef CONFIG_PPC64
505 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
506 #endif
507 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
508 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
509 }
510 
511 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
512 				       struct lib64_elfinfo *v64)
513 {
514 	Elf32_Sym *sym32;
515 #ifdef CONFIG_PPC64
516 	Elf64_Sym *sym64;
517 
518        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
519 	if (sym64 == NULL) {
520 		printk(KERN_ERR "vDSO64: Can't find symbol "
521 		       "__kernel_datapage_offset !\n");
522 		return -1;
523 	}
524 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
525 		(vdso64_pages << PAGE_SHIFT) -
526 		(sym64->st_value - VDSO64_LBASE);
527 #endif /* CONFIG_PPC64 */
528 
529 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
530 	if (sym32 == NULL) {
531 		printk(KERN_ERR "vDSO32: Can't find symbol "
532 		       "__kernel_datapage_offset !\n");
533 		return -1;
534 	}
535 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
536 		(vdso32_pages << PAGE_SHIFT) -
537 		(sym32->st_value - VDSO32_LBASE);
538 
539 	return 0;
540 }
541 
542 
543 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
544 				      struct lib64_elfinfo *v64)
545 {
546 	void *start32;
547 	unsigned long size32;
548 
549 #ifdef CONFIG_PPC64
550 	void *start64;
551 	unsigned long size64;
552 
553 	start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
554 	if (start64)
555 		do_feature_fixups(cur_cpu_spec->cpu_features,
556 				  start64, start64 + size64);
557 
558 	start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
559 	if (start64)
560 		do_feature_fixups(powerpc_firmware_features,
561 				  start64, start64 + size64);
562 #endif /* CONFIG_PPC64 */
563 
564 	start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
565 	if (start32)
566 		do_feature_fixups(cur_cpu_spec->cpu_features,
567 				  start32, start32 + size32);
568 
569 #ifdef CONFIG_PPC64
570 	start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
571 	if (start32)
572 		do_feature_fixups(powerpc_firmware_features,
573 				  start32, start32 + size32);
574 #endif /* CONFIG_PPC64 */
575 
576 	return 0;
577 }
578 
579 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
580 				       struct lib64_elfinfo *v64)
581 {
582 	int i;
583 
584 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
585 		struct vdso_patch_def *patch = &vdso_patches[i];
586 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
587 			== patch->ftr_value;
588 		if (!match)
589 			continue;
590 
591 		DBG("replacing %s with %s...\n", patch->gen_name,
592 		    patch->fix_name ? "NONE" : patch->fix_name);
593 
594 		/*
595 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
596 		 * patch the "." symbol on 64 bits.
597 		 * It would be easy to do, but doesn't seem to be necessary,
598 		 * patching the OPD symbol is enough.
599 		 */
600 		vdso_do_func_patch32(v32, v64, patch->gen_name,
601 				     patch->fix_name);
602 #ifdef CONFIG_PPC64
603 		vdso_do_func_patch64(v32, v64, patch->gen_name,
604 				     patch->fix_name);
605 #endif /* CONFIG_PPC64 */
606 	}
607 
608 	return 0;
609 }
610 
611 
612 static __init int vdso_setup(void)
613 {
614 	struct lib32_elfinfo	v32;
615 	struct lib64_elfinfo	v64;
616 
617 	v32.hdr = vdso32_kbase;
618 #ifdef CONFIG_PPC64
619 	v64.hdr = vdso64_kbase;
620 #endif
621 	if (vdso_do_find_sections(&v32, &v64))
622 		return -1;
623 
624 	if (vdso_fixup_datapage(&v32, &v64))
625 		return -1;
626 
627 	if (vdso_fixup_features(&v32, &v64))
628 		return -1;
629 
630 	if (vdso_fixup_alt_funcs(&v32, &v64))
631 		return -1;
632 
633 	vdso_setup_trampolines(&v32, &v64);
634 
635 	return 0;
636 }
637 
638 /*
639  * Called from setup_arch to initialize the bitmap of available
640  * syscalls in the systemcfg page
641  */
642 static void __init vdso_setup_syscall_map(void)
643 {
644 	unsigned int i;
645 	extern unsigned long *sys_call_table;
646 	extern unsigned long sys_ni_syscall;
647 
648 
649 	for (i = 0; i < __NR_syscalls; i++) {
650 #ifdef CONFIG_PPC64
651 		if (sys_call_table[i*2] != sys_ni_syscall)
652 			vdso_data->syscall_map_64[i >> 5] |=
653 				0x80000000UL >> (i & 0x1f);
654 		if (sys_call_table[i*2+1] != sys_ni_syscall)
655 			vdso_data->syscall_map_32[i >> 5] |=
656 				0x80000000UL >> (i & 0x1f);
657 #else /* CONFIG_PPC64 */
658 		if (sys_call_table[i] != sys_ni_syscall)
659 			vdso_data->syscall_map_32[i >> 5] |=
660 				0x80000000UL >> (i & 0x1f);
661 #endif /* CONFIG_PPC64 */
662 	}
663 }
664 
665 
666 static int __init vdso_init(void)
667 {
668 	int i;
669 
670 #ifdef CONFIG_PPC64
671 	/*
672 	 * Fill up the "systemcfg" stuff for backward compatiblity
673 	 */
674 	strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
675 	vdso_data->version.major = SYSTEMCFG_MAJOR;
676 	vdso_data->version.minor = SYSTEMCFG_MINOR;
677 	vdso_data->processor = mfspr(SPRN_PVR);
678 	/*
679 	 * Fake the old platform number for pSeries and iSeries and add
680 	 * in LPAR bit if necessary
681 	 */
682 	vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
683 	if (firmware_has_feature(FW_FEATURE_LPAR))
684 		vdso_data->platform |= 1;
685 	vdso_data->physicalMemorySize = lmb_phys_mem_size();
686 	vdso_data->dcache_size = ppc64_caches.dsize;
687 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
688 	vdso_data->icache_size = ppc64_caches.isize;
689 	vdso_data->icache_line_size = ppc64_caches.iline_size;
690 
691 	/*
692 	 * Calculate the size of the 64 bits vDSO
693 	 */
694 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
695 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
696 #endif /* CONFIG_PPC64 */
697 
698 
699 	/*
700 	 * Calculate the size of the 32 bits vDSO
701 	 */
702 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
703 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
704 
705 
706 	/*
707 	 * Setup the syscall map in the vDOS
708 	 */
709 	vdso_setup_syscall_map();
710 
711 	/*
712 	 * Initialize the vDSO images in memory, that is do necessary
713 	 * fixups of vDSO symbols, locate trampolines, etc...
714 	 */
715 	if (vdso_setup()) {
716 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
717 		vdso32_pages = 0;
718 #ifdef CONFIG_PPC64
719 		vdso64_pages = 0;
720 #endif
721 		return 0;
722 	}
723 
724 	/* Make sure pages are in the correct state */
725 	vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
726 				  GFP_KERNEL);
727 	BUG_ON(vdso32_pagelist == NULL);
728 	for (i = 0; i < vdso32_pages; i++) {
729 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
730 		ClearPageReserved(pg);
731 		get_page(pg);
732 		vdso32_pagelist[i] = pg;
733 	}
734 	vdso32_pagelist[i++] = virt_to_page(vdso_data);
735 	vdso32_pagelist[i] = NULL;
736 
737 #ifdef CONFIG_PPC64
738 	vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
739 				  GFP_KERNEL);
740 	BUG_ON(vdso64_pagelist == NULL);
741 	for (i = 0; i < vdso64_pages; i++) {
742 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
743 		ClearPageReserved(pg);
744 		get_page(pg);
745 		vdso64_pagelist[i] = pg;
746 	}
747 	vdso64_pagelist[i++] = virt_to_page(vdso_data);
748 	vdso64_pagelist[i] = NULL;
749 #endif /* CONFIG_PPC64 */
750 
751 	get_page(virt_to_page(vdso_data));
752 
753 	smp_wmb();
754 	vdso_ready = 1;
755 
756 	return 0;
757 }
758 arch_initcall(vdso_init);
759 
760 int in_gate_area_no_task(unsigned long addr)
761 {
762 	return 0;
763 }
764 
765 int in_gate_area(struct task_struct *task, unsigned long addr)
766 {
767 	return 0;
768 }
769 
770 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
771 {
772 	return NULL;
773 }
774 
775