xref: /linux/arch/powerpc/kernel/vdso.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/firmware.h>
37 #include <asm/vdso.h>
38 #include <asm/vdso_datapage.h>
39 
40 #undef DEBUG
41 
42 #ifdef DEBUG
43 #define DBG(fmt...) printk(fmt)
44 #else
45 #define DBG(fmt...)
46 #endif
47 
48 /* Max supported size for symbol names */
49 #define MAX_SYMNAME	64
50 
51 extern char vdso32_start, vdso32_end;
52 static void *vdso32_kbase = &vdso32_start;
53 unsigned int vdso32_pages;
54 unsigned long vdso32_sigtramp;
55 unsigned long vdso32_rt_sigtramp;
56 
57 #ifdef CONFIG_PPC64
58 extern char vdso64_start, vdso64_end;
59 static void *vdso64_kbase = &vdso64_start;
60 unsigned int vdso64_pages;
61 unsigned long vdso64_rt_sigtramp;
62 #endif /* CONFIG_PPC64 */
63 
64 /*
65  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
66  * Once the early boot kernel code no longer needs to muck around
67  * with it, it will become dynamically allocated
68  */
69 static union {
70 	struct vdso_data	data;
71 	u8			page[PAGE_SIZE];
72 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
73 struct vdso_data *vdso_data = &vdso_data_store.data;
74 
75 /* Format of the patch table */
76 struct vdso_patch_def
77 {
78 	unsigned long	ftr_mask, ftr_value;
79 	const char	*gen_name;
80 	const char	*fix_name;
81 };
82 
83 /* Table of functions to patch based on the CPU type/revision
84  *
85  * Currently, we only change sync_dicache to do nothing on processors
86  * with a coherent icache
87  */
88 static struct vdso_patch_def vdso_patches[] = {
89 	{
90 		CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
91 		"__kernel_sync_dicache", "__kernel_sync_dicache_p5"
92 	},
93 	{
94 		CPU_FTR_USE_TB, 0,
95 		"__kernel_gettimeofday", NULL
96 	},
97 };
98 
99 /*
100  * Some infos carried around for each of them during parsing at
101  * boot time.
102  */
103 struct lib32_elfinfo
104 {
105 	Elf32_Ehdr	*hdr;		/* ptr to ELF */
106 	Elf32_Sym	*dynsym;	/* ptr to .dynsym section */
107 	unsigned long	dynsymsize;	/* size of .dynsym section */
108 	char		*dynstr;	/* ptr to .dynstr section */
109 	unsigned long	text;		/* offset of .text section in .so */
110 };
111 
112 struct lib64_elfinfo
113 {
114 	Elf64_Ehdr	*hdr;
115 	Elf64_Sym	*dynsym;
116 	unsigned long	dynsymsize;
117 	char		*dynstr;
118 	unsigned long	text;
119 };
120 
121 
122 #ifdef __DEBUG
123 static void dump_one_vdso_page(struct page *pg, struct page *upg)
124 {
125 	printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
126 	       page_count(pg),
127 	       pg->flags);
128 	if (upg/* && pg != upg*/) {
129 		printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
130 						       << PAGE_SHIFT),
131 		       page_count(upg),
132 		       upg->flags);
133 	}
134 	printk("\n");
135 }
136 
137 static void dump_vdso_pages(struct vm_area_struct * vma)
138 {
139 	int i;
140 
141 	if (!vma || test_thread_flag(TIF_32BIT)) {
142 		printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
143 		for (i=0; i<vdso32_pages; i++) {
144 			struct page *pg = virt_to_page(vdso32_kbase +
145 						       i*PAGE_SIZE);
146 			struct page *upg = (vma && vma->vm_mm) ?
147 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
148 				: NULL;
149 			dump_one_vdso_page(pg, upg);
150 		}
151 	}
152 	if (!vma || !test_thread_flag(TIF_32BIT)) {
153 		printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
154 		for (i=0; i<vdso64_pages; i++) {
155 			struct page *pg = virt_to_page(vdso64_kbase +
156 						       i*PAGE_SIZE);
157 			struct page *upg = (vma && vma->vm_mm) ?
158 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
159 				: NULL;
160 			dump_one_vdso_page(pg, upg);
161 		}
162 	}
163 }
164 #endif /* DEBUG */
165 
166 /*
167  * Keep a dummy vma_close for now, it will prevent VMA merging.
168  */
169 static void vdso_vma_close(struct vm_area_struct * vma)
170 {
171 }
172 
173 /*
174  * Our nopage() function, maps in the actual vDSO kernel pages, they will
175  * be mapped read-only by do_no_page(), and eventually COW'ed, either
176  * right away for an initial write access, or by do_wp_page().
177  */
178 static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
179 				     unsigned long address, int *type)
180 {
181 	unsigned long offset = address - vma->vm_start;
182 	struct page *pg;
183 #ifdef CONFIG_PPC64
184 	void *vbase = (vma->vm_mm->task_size > TASK_SIZE_USER32) ?
185 		vdso64_kbase : vdso32_kbase;
186 #else
187 	void *vbase = vdso32_kbase;
188 #endif
189 
190 	DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
191 	    current->comm, address, offset);
192 
193 	if (address < vma->vm_start || address > vma->vm_end)
194 		return NOPAGE_SIGBUS;
195 
196 	/*
197 	 * Last page is systemcfg.
198 	 */
199 	if ((vma->vm_end - address) <= PAGE_SIZE)
200 		pg = virt_to_page(vdso_data);
201 	else
202 		pg = virt_to_page(vbase + offset);
203 
204 	get_page(pg);
205 	DBG(" ->page count: %d\n", page_count(pg));
206 
207 	return pg;
208 }
209 
210 static struct vm_operations_struct vdso_vmops = {
211 	.close	= vdso_vma_close,
212 	.nopage	= vdso_vma_nopage,
213 };
214 
215 /*
216  * This is called from binfmt_elf, we create the special vma for the
217  * vDSO and insert it into the mm struct tree
218  */
219 int arch_setup_additional_pages(struct linux_binprm *bprm,
220 				int executable_stack)
221 {
222 	struct mm_struct *mm = current->mm;
223 	struct vm_area_struct *vma;
224 	unsigned long vdso_pages;
225 	unsigned long vdso_base;
226 
227 #ifdef CONFIG_PPC64
228 	if (test_thread_flag(TIF_32BIT)) {
229 		vdso_pages = vdso32_pages;
230 		vdso_base = VDSO32_MBASE;
231 	} else {
232 		vdso_pages = vdso64_pages;
233 		vdso_base = VDSO64_MBASE;
234 	}
235 #else
236 	vdso_pages = vdso32_pages;
237 	vdso_base = VDSO32_MBASE;
238 #endif
239 
240 	current->thread.vdso_base = 0;
241 
242 	/* vDSO has a problem and was disabled, just don't "enable" it for the
243 	 * process
244 	 */
245 	if (vdso_pages == 0)
246 		return 0;
247 
248 	vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
249 	if (vma == NULL)
250 		return -ENOMEM;
251 
252 	memset(vma, 0, sizeof(*vma));
253 
254 	/* Add a page to the vdso size for the data page */
255 	vdso_pages ++;
256 
257 	/*
258 	 * pick a base address for the vDSO in process space. We try to put it
259 	 * at vdso_base which is the "natural" base for it, but we might fail
260 	 * and end up putting it elsewhere.
261 	 */
262 	vdso_base = get_unmapped_area(NULL, vdso_base,
263 				      vdso_pages << PAGE_SHIFT, 0, 0);
264 	if (vdso_base & ~PAGE_MASK) {
265 		kmem_cache_free(vm_area_cachep, vma);
266 		return (int)vdso_base;
267 	}
268 
269 	current->thread.vdso_base = vdso_base;
270 
271 	vma->vm_mm = mm;
272 	vma->vm_start = current->thread.vdso_base;
273 	vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
274 
275 	/*
276 	 * our vma flags don't have VM_WRITE so by default, the process isn't
277 	 * allowed to write those pages.
278 	 * gdb can break that with ptrace interface, and thus trigger COW on
279 	 * those pages but it's then your responsibility to never do that on
280 	 * the "data" page of the vDSO or you'll stop getting kernel updates
281 	 * and your nice userland gettimeofday will be totally dead.
282 	 * It's fine to use that for setting breakpoints in the vDSO code
283 	 * pages though
284 	 */
285 	vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
286 	vma->vm_flags |= mm->def_flags;
287 	vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
288 	vma->vm_ops = &vdso_vmops;
289 
290 	down_write(&mm->mmap_sem);
291 	if (insert_vm_struct(mm, vma)) {
292 		up_write(&mm->mmap_sem);
293 		kmem_cache_free(vm_area_cachep, vma);
294 		return -ENOMEM;
295 	}
296 	mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
297 	up_write(&mm->mmap_sem);
298 
299 	return 0;
300 }
301 
302 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
303 				  unsigned long *size)
304 {
305 	Elf32_Shdr *sechdrs;
306 	unsigned int i;
307 	char *secnames;
308 
309 	/* Grab section headers and strings so we can tell who is who */
310 	sechdrs = (void *)ehdr + ehdr->e_shoff;
311 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
312 
313 	/* Find the section they want */
314 	for (i = 1; i < ehdr->e_shnum; i++) {
315 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
316 			if (size)
317 				*size = sechdrs[i].sh_size;
318 			return (void *)ehdr + sechdrs[i].sh_offset;
319 		}
320 	}
321 	*size = 0;
322 	return NULL;
323 }
324 
325 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
326 					const char *symname)
327 {
328 	unsigned int i;
329 	char name[MAX_SYMNAME], *c;
330 
331 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
332 		if (lib->dynsym[i].st_name == 0)
333 			continue;
334 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
335 			MAX_SYMNAME);
336 		c = strchr(name, '@');
337 		if (c)
338 			*c = 0;
339 		if (strcmp(symname, name) == 0)
340 			return &lib->dynsym[i];
341 	}
342 	return NULL;
343 }
344 
345 /* Note that we assume the section is .text and the symbol is relative to
346  * the library base
347  */
348 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
349 					    const char *symname)
350 {
351 	Elf32_Sym *sym = find_symbol32(lib, symname);
352 
353 	if (sym == NULL) {
354 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
355 		       symname);
356 		return 0;
357 	}
358 	return sym->st_value - VDSO32_LBASE;
359 }
360 
361 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
362 				struct lib64_elfinfo *v64,
363 				const char *orig, const char *fix)
364 {
365 	Elf32_Sym *sym32_gen, *sym32_fix;
366 
367 	sym32_gen = find_symbol32(v32, orig);
368 	if (sym32_gen == NULL) {
369 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
370 		return -1;
371 	}
372 	if (fix == NULL) {
373 		sym32_gen->st_name = 0;
374 		return 0;
375 	}
376 	sym32_fix = find_symbol32(v32, fix);
377 	if (sym32_fix == NULL) {
378 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
379 		return -1;
380 	}
381 	sym32_gen->st_value = sym32_fix->st_value;
382 	sym32_gen->st_size = sym32_fix->st_size;
383 	sym32_gen->st_info = sym32_fix->st_info;
384 	sym32_gen->st_other = sym32_fix->st_other;
385 	sym32_gen->st_shndx = sym32_fix->st_shndx;
386 
387 	return 0;
388 }
389 
390 
391 #ifdef CONFIG_PPC64
392 
393 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
394 				  unsigned long *size)
395 {
396 	Elf64_Shdr *sechdrs;
397 	unsigned int i;
398 	char *secnames;
399 
400 	/* Grab section headers and strings so we can tell who is who */
401 	sechdrs = (void *)ehdr + ehdr->e_shoff;
402 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
403 
404 	/* Find the section they want */
405 	for (i = 1; i < ehdr->e_shnum; i++) {
406 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
407 			if (size)
408 				*size = sechdrs[i].sh_size;
409 			return (void *)ehdr + sechdrs[i].sh_offset;
410 		}
411 	}
412 	if (size)
413 		*size = 0;
414 	return NULL;
415 }
416 
417 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
418 					const char *symname)
419 {
420 	unsigned int i;
421 	char name[MAX_SYMNAME], *c;
422 
423 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
424 		if (lib->dynsym[i].st_name == 0)
425 			continue;
426 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
427 			MAX_SYMNAME);
428 		c = strchr(name, '@');
429 		if (c)
430 			*c = 0;
431 		if (strcmp(symname, name) == 0)
432 			return &lib->dynsym[i];
433 	}
434 	return NULL;
435 }
436 
437 /* Note that we assume the section is .text and the symbol is relative to
438  * the library base
439  */
440 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
441 					    const char *symname)
442 {
443 	Elf64_Sym *sym = find_symbol64(lib, symname);
444 
445 	if (sym == NULL) {
446 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
447 		       symname);
448 		return 0;
449 	}
450 #ifdef VDS64_HAS_DESCRIPTORS
451 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
452 		VDSO64_LBASE;
453 #else
454 	return sym->st_value - VDSO64_LBASE;
455 #endif
456 }
457 
458 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
459 				struct lib64_elfinfo *v64,
460 				const char *orig, const char *fix)
461 {
462 	Elf64_Sym *sym64_gen, *sym64_fix;
463 
464 	sym64_gen = find_symbol64(v64, orig);
465 	if (sym64_gen == NULL) {
466 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
467 		return -1;
468 	}
469 	if (fix == NULL) {
470 		sym64_gen->st_name = 0;
471 		return 0;
472 	}
473 	sym64_fix = find_symbol64(v64, fix);
474 	if (sym64_fix == NULL) {
475 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
476 		return -1;
477 	}
478 	sym64_gen->st_value = sym64_fix->st_value;
479 	sym64_gen->st_size = sym64_fix->st_size;
480 	sym64_gen->st_info = sym64_fix->st_info;
481 	sym64_gen->st_other = sym64_fix->st_other;
482 	sym64_gen->st_shndx = sym64_fix->st_shndx;
483 
484 	return 0;
485 }
486 
487 #endif /* CONFIG_PPC64 */
488 
489 
490 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
491 					struct lib64_elfinfo *v64)
492 {
493 	void *sect;
494 
495 	/*
496 	 * Locate symbol tables & text section
497 	 */
498 
499 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
500 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
501 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
502 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
503 		return -1;
504 	}
505 	sect = find_section32(v32->hdr, ".text", NULL);
506 	if (sect == NULL) {
507 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
508 		return -1;
509 	}
510 	v32->text = sect - vdso32_kbase;
511 
512 #ifdef CONFIG_PPC64
513 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
514 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
515 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
516 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
517 		return -1;
518 	}
519 	sect = find_section64(v64->hdr, ".text", NULL);
520 	if (sect == NULL) {
521 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
522 		return -1;
523 	}
524 	v64->text = sect - vdso64_kbase;
525 #endif /* CONFIG_PPC64 */
526 
527 	return 0;
528 }
529 
530 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
531 					  struct lib64_elfinfo *v64)
532 {
533 	/*
534 	 * Find signal trampolines
535 	 */
536 
537 #ifdef CONFIG_PPC64
538 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
539 #endif
540 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
541 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
542 }
543 
544 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
545 				       struct lib64_elfinfo *v64)
546 {
547 	Elf32_Sym *sym32;
548 #ifdef CONFIG_PPC64
549 	Elf64_Sym *sym64;
550 
551        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
552 	if (sym64 == NULL) {
553 		printk(KERN_ERR "vDSO64: Can't find symbol "
554 		       "__kernel_datapage_offset !\n");
555 		return -1;
556 	}
557 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
558 		(vdso64_pages << PAGE_SHIFT) -
559 		(sym64->st_value - VDSO64_LBASE);
560 #endif /* CONFIG_PPC64 */
561 
562 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
563 	if (sym32 == NULL) {
564 		printk(KERN_ERR "vDSO32: Can't find symbol "
565 		       "__kernel_datapage_offset !\n");
566 		return -1;
567 	}
568 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
569 		(vdso32_pages << PAGE_SHIFT) -
570 		(sym32->st_value - VDSO32_LBASE);
571 
572 	return 0;
573 }
574 
575 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
576 				       struct lib64_elfinfo *v64)
577 {
578 	int i;
579 
580 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
581 		struct vdso_patch_def *patch = &vdso_patches[i];
582 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
583 			== patch->ftr_value;
584 		if (!match)
585 			continue;
586 
587 		DBG("replacing %s with %s...\n", patch->gen_name,
588 		    patch->fix_name ? "NONE" : patch->fix_name);
589 
590 		/*
591 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
592 		 * patch the "." symbol on 64 bits.
593 		 * It would be easy to do, but doesn't seem to be necessary,
594 		 * patching the OPD symbol is enough.
595 		 */
596 		vdso_do_func_patch32(v32, v64, patch->gen_name,
597 				     patch->fix_name);
598 #ifdef CONFIG_PPC64
599 		vdso_do_func_patch64(v32, v64, patch->gen_name,
600 				     patch->fix_name);
601 #endif /* CONFIG_PPC64 */
602 	}
603 
604 	return 0;
605 }
606 
607 
608 static __init int vdso_setup(void)
609 {
610 	struct lib32_elfinfo	v32;
611 	struct lib64_elfinfo	v64;
612 
613 	v32.hdr = vdso32_kbase;
614 #ifdef CONFIG_PPC64
615 	v64.hdr = vdso64_kbase;
616 #endif
617 	if (vdso_do_find_sections(&v32, &v64))
618 		return -1;
619 
620 	if (vdso_fixup_datapage(&v32, &v64))
621 		return -1;
622 
623 	if (vdso_fixup_alt_funcs(&v32, &v64))
624 		return -1;
625 
626 	vdso_setup_trampolines(&v32, &v64);
627 
628 	return 0;
629 }
630 
631 /*
632  * Called from setup_arch to initialize the bitmap of available
633  * syscalls in the systemcfg page
634  */
635 static void __init vdso_setup_syscall_map(void)
636 {
637 	unsigned int i;
638 	extern unsigned long *sys_call_table;
639 	extern unsigned long sys_ni_syscall;
640 
641 
642 	for (i = 0; i < __NR_syscalls; i++) {
643 #ifdef CONFIG_PPC64
644 		if (sys_call_table[i*2] != sys_ni_syscall)
645 			vdso_data->syscall_map_64[i >> 5] |=
646 				0x80000000UL >> (i & 0x1f);
647 		if (sys_call_table[i*2+1] != sys_ni_syscall)
648 			vdso_data->syscall_map_32[i >> 5] |=
649 				0x80000000UL >> (i & 0x1f);
650 #else /* CONFIG_PPC64 */
651 		if (sys_call_table[i] != sys_ni_syscall)
652 			vdso_data->syscall_map_32[i >> 5] |=
653 				0x80000000UL >> (i & 0x1f);
654 #endif /* CONFIG_PPC64 */
655 	}
656 }
657 
658 
659 void __init vdso_init(void)
660 {
661 	int i;
662 
663 #ifdef CONFIG_PPC64
664 	/*
665 	 * Fill up the "systemcfg" stuff for backward compatiblity
666 	 */
667 	strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
668 	vdso_data->version.major = SYSTEMCFG_MAJOR;
669 	vdso_data->version.minor = SYSTEMCFG_MINOR;
670 	vdso_data->processor = mfspr(SPRN_PVR);
671 	/*
672 	 * Fake the old platform number for pSeries and iSeries and add
673 	 * in LPAR bit if necessary
674 	 */
675 	vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
676 	if (firmware_has_feature(FW_FEATURE_LPAR))
677 		vdso_data->platform |= 1;
678 	vdso_data->physicalMemorySize = lmb_phys_mem_size();
679 	vdso_data->dcache_size = ppc64_caches.dsize;
680 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
681 	vdso_data->icache_size = ppc64_caches.isize;
682 	vdso_data->icache_line_size = ppc64_caches.iline_size;
683 
684 	/*
685 	 * Calculate the size of the 64 bits vDSO
686 	 */
687 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
688 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
689 #endif /* CONFIG_PPC64 */
690 
691 
692 	/*
693 	 * Calculate the size of the 32 bits vDSO
694 	 */
695 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
696 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
697 
698 
699 	/*
700 	 * Setup the syscall map in the vDOS
701 	 */
702 	vdso_setup_syscall_map();
703 	/*
704 	 * Initialize the vDSO images in memory, that is do necessary
705 	 * fixups of vDSO symbols, locate trampolines, etc...
706 	 */
707 	if (vdso_setup()) {
708 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
709 		vdso32_pages = 0;
710 #ifdef CONFIG_PPC64
711 		vdso64_pages = 0;
712 #endif
713 		return;
714 	}
715 
716 	/* Make sure pages are in the correct state */
717 	for (i = 0; i < vdso32_pages; i++) {
718 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
719 		ClearPageReserved(pg);
720 		get_page(pg);
721 
722 	}
723 #ifdef CONFIG_PPC64
724 	for (i = 0; i < vdso64_pages; i++) {
725 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
726 		ClearPageReserved(pg);
727 		get_page(pg);
728 	}
729 #endif /* CONFIG_PPC64 */
730 
731 	get_page(virt_to_page(vdso_data));
732 }
733 
734 int in_gate_area_no_task(unsigned long addr)
735 {
736 	return 0;
737 }
738 
739 int in_gate_area(struct task_struct *task, unsigned long addr)
740 {
741 	return 0;
742 }
743 
744 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
745 {
746 	return NULL;
747 }
748 
749