xref: /linux/arch/powerpc/kernel/vdso.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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 #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 = (vma->vm_mm->task_size > TASK_SIZE_USER32) ?
184 		vdso64_kbase : vdso32_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 	int rc;
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->mm->context.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 	/* Add a page to the vdso size for the data page */
248 	vdso_pages ++;
249 
250 	/*
251 	 * pick a base address for the vDSO in process space. We try to put it
252 	 * at vdso_base which is the "natural" base for it, but we might fail
253 	 * and end up putting it elsewhere.
254 	 */
255 	down_write(&mm->mmap_sem);
256 	vdso_base = get_unmapped_area(NULL, vdso_base,
257 				      vdso_pages << PAGE_SHIFT, 0, 0);
258 	if (IS_ERR_VALUE(vdso_base)) {
259 		rc = vdso_base;
260 		goto fail_mmapsem;
261 	}
262 
263 
264 	/* Allocate a VMA structure and fill it up */
265 	vma = kmem_cache_zalloc(vm_area_cachep, SLAB_KERNEL);
266 	if (vma == NULL) {
267 		rc = -ENOMEM;
268 		goto fail_mmapsem;
269 	}
270 	vma->vm_mm = mm;
271 	vma->vm_start = 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 	/* Insert new VMA */
290 	rc = insert_vm_struct(mm, vma);
291 	if (rc)
292 		goto fail_vma;
293 
294 	/* Put vDSO base into mm struct and account for memory usage */
295 	current->mm->context.vdso_base = vdso_base;
296 	mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
297 	up_write(&mm->mmap_sem);
298 	return 0;
299 
300  fail_vma:
301 	kmem_cache_free(vm_area_cachep, vma);
302  fail_mmapsem:
303 	up_write(&mm->mmap_sem);
304 	return rc;
305 }
306 
307 const char *arch_vma_name(struct vm_area_struct *vma)
308 {
309 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
310 		return "[vdso]";
311 	return NULL;
312 }
313 
314 
315 
316 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
317 				  unsigned long *size)
318 {
319 	Elf32_Shdr *sechdrs;
320 	unsigned int i;
321 	char *secnames;
322 
323 	/* Grab section headers and strings so we can tell who is who */
324 	sechdrs = (void *)ehdr + ehdr->e_shoff;
325 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
326 
327 	/* Find the section they want */
328 	for (i = 1; i < ehdr->e_shnum; i++) {
329 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
330 			if (size)
331 				*size = sechdrs[i].sh_size;
332 			return (void *)ehdr + sechdrs[i].sh_offset;
333 		}
334 	}
335 	*size = 0;
336 	return NULL;
337 }
338 
339 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
340 					const char *symname)
341 {
342 	unsigned int i;
343 	char name[MAX_SYMNAME], *c;
344 
345 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
346 		if (lib->dynsym[i].st_name == 0)
347 			continue;
348 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
349 			MAX_SYMNAME);
350 		c = strchr(name, '@');
351 		if (c)
352 			*c = 0;
353 		if (strcmp(symname, name) == 0)
354 			return &lib->dynsym[i];
355 	}
356 	return NULL;
357 }
358 
359 /* Note that we assume the section is .text and the symbol is relative to
360  * the library base
361  */
362 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
363 					    const char *symname)
364 {
365 	Elf32_Sym *sym = find_symbol32(lib, symname);
366 
367 	if (sym == NULL) {
368 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
369 		       symname);
370 		return 0;
371 	}
372 	return sym->st_value - VDSO32_LBASE;
373 }
374 
375 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
376 				struct lib64_elfinfo *v64,
377 				const char *orig, const char *fix)
378 {
379 	Elf32_Sym *sym32_gen, *sym32_fix;
380 
381 	sym32_gen = find_symbol32(v32, orig);
382 	if (sym32_gen == NULL) {
383 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
384 		return -1;
385 	}
386 	if (fix == NULL) {
387 		sym32_gen->st_name = 0;
388 		return 0;
389 	}
390 	sym32_fix = find_symbol32(v32, fix);
391 	if (sym32_fix == NULL) {
392 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
393 		return -1;
394 	}
395 	sym32_gen->st_value = sym32_fix->st_value;
396 	sym32_gen->st_size = sym32_fix->st_size;
397 	sym32_gen->st_info = sym32_fix->st_info;
398 	sym32_gen->st_other = sym32_fix->st_other;
399 	sym32_gen->st_shndx = sym32_fix->st_shndx;
400 
401 	return 0;
402 }
403 
404 
405 #ifdef CONFIG_PPC64
406 
407 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
408 				  unsigned long *size)
409 {
410 	Elf64_Shdr *sechdrs;
411 	unsigned int i;
412 	char *secnames;
413 
414 	/* Grab section headers and strings so we can tell who is who */
415 	sechdrs = (void *)ehdr + ehdr->e_shoff;
416 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
417 
418 	/* Find the section they want */
419 	for (i = 1; i < ehdr->e_shnum; i++) {
420 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
421 			if (size)
422 				*size = sechdrs[i].sh_size;
423 			return (void *)ehdr + sechdrs[i].sh_offset;
424 		}
425 	}
426 	if (size)
427 		*size = 0;
428 	return NULL;
429 }
430 
431 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
432 					const char *symname)
433 {
434 	unsigned int i;
435 	char name[MAX_SYMNAME], *c;
436 
437 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
438 		if (lib->dynsym[i].st_name == 0)
439 			continue;
440 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
441 			MAX_SYMNAME);
442 		c = strchr(name, '@');
443 		if (c)
444 			*c = 0;
445 		if (strcmp(symname, name) == 0)
446 			return &lib->dynsym[i];
447 	}
448 	return NULL;
449 }
450 
451 /* Note that we assume the section is .text and the symbol is relative to
452  * the library base
453  */
454 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
455 					    const char *symname)
456 {
457 	Elf64_Sym *sym = find_symbol64(lib, symname);
458 
459 	if (sym == NULL) {
460 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
461 		       symname);
462 		return 0;
463 	}
464 #ifdef VDS64_HAS_DESCRIPTORS
465 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
466 		VDSO64_LBASE;
467 #else
468 	return sym->st_value - VDSO64_LBASE;
469 #endif
470 }
471 
472 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
473 				struct lib64_elfinfo *v64,
474 				const char *orig, const char *fix)
475 {
476 	Elf64_Sym *sym64_gen, *sym64_fix;
477 
478 	sym64_gen = find_symbol64(v64, orig);
479 	if (sym64_gen == NULL) {
480 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
481 		return -1;
482 	}
483 	if (fix == NULL) {
484 		sym64_gen->st_name = 0;
485 		return 0;
486 	}
487 	sym64_fix = find_symbol64(v64, fix);
488 	if (sym64_fix == NULL) {
489 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
490 		return -1;
491 	}
492 	sym64_gen->st_value = sym64_fix->st_value;
493 	sym64_gen->st_size = sym64_fix->st_size;
494 	sym64_gen->st_info = sym64_fix->st_info;
495 	sym64_gen->st_other = sym64_fix->st_other;
496 	sym64_gen->st_shndx = sym64_fix->st_shndx;
497 
498 	return 0;
499 }
500 
501 #endif /* CONFIG_PPC64 */
502 
503 
504 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
505 					struct lib64_elfinfo *v64)
506 {
507 	void *sect;
508 
509 	/*
510 	 * Locate symbol tables & text section
511 	 */
512 
513 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
514 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
515 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
516 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
517 		return -1;
518 	}
519 	sect = find_section32(v32->hdr, ".text", NULL);
520 	if (sect == NULL) {
521 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
522 		return -1;
523 	}
524 	v32->text = sect - vdso32_kbase;
525 
526 #ifdef CONFIG_PPC64
527 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
528 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
529 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
530 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
531 		return -1;
532 	}
533 	sect = find_section64(v64->hdr, ".text", NULL);
534 	if (sect == NULL) {
535 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
536 		return -1;
537 	}
538 	v64->text = sect - vdso64_kbase;
539 #endif /* CONFIG_PPC64 */
540 
541 	return 0;
542 }
543 
544 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
545 					  struct lib64_elfinfo *v64)
546 {
547 	/*
548 	 * Find signal trampolines
549 	 */
550 
551 #ifdef CONFIG_PPC64
552 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
553 #endif
554 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
555 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
556 }
557 
558 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
559 				       struct lib64_elfinfo *v64)
560 {
561 	Elf32_Sym *sym32;
562 #ifdef CONFIG_PPC64
563 	Elf64_Sym *sym64;
564 
565        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
566 	if (sym64 == NULL) {
567 		printk(KERN_ERR "vDSO64: Can't find symbol "
568 		       "__kernel_datapage_offset !\n");
569 		return -1;
570 	}
571 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
572 		(vdso64_pages << PAGE_SHIFT) -
573 		(sym64->st_value - VDSO64_LBASE);
574 #endif /* CONFIG_PPC64 */
575 
576 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
577 	if (sym32 == NULL) {
578 		printk(KERN_ERR "vDSO32: Can't find symbol "
579 		       "__kernel_datapage_offset !\n");
580 		return -1;
581 	}
582 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
583 		(vdso32_pages << PAGE_SHIFT) -
584 		(sym32->st_value - VDSO32_LBASE);
585 
586 	return 0;
587 }
588 
589 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
590 				       struct lib64_elfinfo *v64)
591 {
592 	int i;
593 
594 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
595 		struct vdso_patch_def *patch = &vdso_patches[i];
596 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
597 			== patch->ftr_value;
598 		if (!match)
599 			continue;
600 
601 		DBG("replacing %s with %s...\n", patch->gen_name,
602 		    patch->fix_name ? "NONE" : patch->fix_name);
603 
604 		/*
605 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
606 		 * patch the "." symbol on 64 bits.
607 		 * It would be easy to do, but doesn't seem to be necessary,
608 		 * patching the OPD symbol is enough.
609 		 */
610 		vdso_do_func_patch32(v32, v64, patch->gen_name,
611 				     patch->fix_name);
612 #ifdef CONFIG_PPC64
613 		vdso_do_func_patch64(v32, v64, patch->gen_name,
614 				     patch->fix_name);
615 #endif /* CONFIG_PPC64 */
616 	}
617 
618 	return 0;
619 }
620 
621 
622 static __init int vdso_setup(void)
623 {
624 	struct lib32_elfinfo	v32;
625 	struct lib64_elfinfo	v64;
626 
627 	v32.hdr = vdso32_kbase;
628 #ifdef CONFIG_PPC64
629 	v64.hdr = vdso64_kbase;
630 #endif
631 	if (vdso_do_find_sections(&v32, &v64))
632 		return -1;
633 
634 	if (vdso_fixup_datapage(&v32, &v64))
635 		return -1;
636 
637 	if (vdso_fixup_alt_funcs(&v32, &v64))
638 		return -1;
639 
640 	vdso_setup_trampolines(&v32, &v64);
641 
642 	return 0;
643 }
644 
645 /*
646  * Called from setup_arch to initialize the bitmap of available
647  * syscalls in the systemcfg page
648  */
649 static void __init vdso_setup_syscall_map(void)
650 {
651 	unsigned int i;
652 	extern unsigned long *sys_call_table;
653 	extern unsigned long sys_ni_syscall;
654 
655 
656 	for (i = 0; i < __NR_syscalls; i++) {
657 #ifdef CONFIG_PPC64
658 		if (sys_call_table[i*2] != sys_ni_syscall)
659 			vdso_data->syscall_map_64[i >> 5] |=
660 				0x80000000UL >> (i & 0x1f);
661 		if (sys_call_table[i*2+1] != sys_ni_syscall)
662 			vdso_data->syscall_map_32[i >> 5] |=
663 				0x80000000UL >> (i & 0x1f);
664 #else /* CONFIG_PPC64 */
665 		if (sys_call_table[i] != sys_ni_syscall)
666 			vdso_data->syscall_map_32[i >> 5] |=
667 				0x80000000UL >> (i & 0x1f);
668 #endif /* CONFIG_PPC64 */
669 	}
670 }
671 
672 
673 void __init vdso_init(void)
674 {
675 	int i;
676 
677 #ifdef CONFIG_PPC64
678 	/*
679 	 * Fill up the "systemcfg" stuff for backward compatiblity
680 	 */
681 	strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
682 	vdso_data->version.major = SYSTEMCFG_MAJOR;
683 	vdso_data->version.minor = SYSTEMCFG_MINOR;
684 	vdso_data->processor = mfspr(SPRN_PVR);
685 	/*
686 	 * Fake the old platform number for pSeries and iSeries and add
687 	 * in LPAR bit if necessary
688 	 */
689 	vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
690 	if (firmware_has_feature(FW_FEATURE_LPAR))
691 		vdso_data->platform |= 1;
692 	vdso_data->physicalMemorySize = lmb_phys_mem_size();
693 	vdso_data->dcache_size = ppc64_caches.dsize;
694 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
695 	vdso_data->icache_size = ppc64_caches.isize;
696 	vdso_data->icache_line_size = ppc64_caches.iline_size;
697 
698 	/*
699 	 * Calculate the size of the 64 bits vDSO
700 	 */
701 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
702 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
703 #endif /* CONFIG_PPC64 */
704 
705 
706 	/*
707 	 * Calculate the size of the 32 bits vDSO
708 	 */
709 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
710 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
711 
712 
713 	/*
714 	 * Setup the syscall map in the vDOS
715 	 */
716 	vdso_setup_syscall_map();
717 	/*
718 	 * Initialize the vDSO images in memory, that is do necessary
719 	 * fixups of vDSO symbols, locate trampolines, etc...
720 	 */
721 	if (vdso_setup()) {
722 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
723 		vdso32_pages = 0;
724 #ifdef CONFIG_PPC64
725 		vdso64_pages = 0;
726 #endif
727 		return;
728 	}
729 
730 	/* Make sure pages are in the correct state */
731 	for (i = 0; i < vdso32_pages; i++) {
732 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
733 		ClearPageReserved(pg);
734 		get_page(pg);
735 
736 	}
737 #ifdef CONFIG_PPC64
738 	for (i = 0; i < vdso64_pages; i++) {
739 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
740 		ClearPageReserved(pg);
741 		get_page(pg);
742 	}
743 #endif /* CONFIG_PPC64 */
744 
745 	get_page(virt_to_page(vdso_data));
746 }
747 
748 int in_gate_area_no_task(unsigned long addr)
749 {
750 	return 0;
751 }
752 
753 int in_gate_area(struct task_struct *task, unsigned long addr)
754 {
755 	return 0;
756 }
757 
758 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
759 {
760 	return NULL;
761 }
762 
763