xref: /linux/arch/powerpc/kernel/vdso.c (revision 5e8d780d745c1619aba81fe7166c5a4b5cad2b84)
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 	int rc;
227 
228 #ifdef CONFIG_PPC64
229 	if (test_thread_flag(TIF_32BIT)) {
230 		vdso_pages = vdso32_pages;
231 		vdso_base = VDSO32_MBASE;
232 	} else {
233 		vdso_pages = vdso64_pages;
234 		vdso_base = VDSO64_MBASE;
235 	}
236 #else
237 	vdso_pages = vdso32_pages;
238 	vdso_base = VDSO32_MBASE;
239 #endif
240 
241 	current->mm->context.vdso_base = 0;
242 
243 	/* vDSO has a problem and was disabled, just don't "enable" it for the
244 	 * process
245 	 */
246 	if (vdso_pages == 0)
247 		return 0;
248 	/* Add a page to the vdso size for the data page */
249 	vdso_pages ++;
250 
251 	/*
252 	 * pick a base address for the vDSO in process space. We try to put it
253 	 * at vdso_base which is the "natural" base for it, but we might fail
254 	 * and end up putting it elsewhere.
255 	 */
256 	down_write(&mm->mmap_sem);
257 	vdso_base = get_unmapped_area(NULL, vdso_base,
258 				      vdso_pages << PAGE_SHIFT, 0, 0);
259 	if (IS_ERR_VALUE(vdso_base)) {
260 		rc = vdso_base;
261 		goto fail_mmapsem;
262 	}
263 
264 
265 	/* Allocate a VMA structure and fill it up */
266 	vma = kmem_cache_zalloc(vm_area_cachep, SLAB_KERNEL);
267 	if (vma == NULL) {
268 		rc = -ENOMEM;
269 		goto fail_mmapsem;
270 	}
271 	vma->vm_mm = mm;
272 	vma->vm_start = 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 	/* Insert new VMA */
291 	rc = insert_vm_struct(mm, vma);
292 	if (rc)
293 		goto fail_vma;
294 
295 	/* Put vDSO base into mm struct and account for memory usage */
296 	current->mm->context.vdso_base = vdso_base;
297 	mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
298 	up_write(&mm->mmap_sem);
299 	return 0;
300 
301  fail_vma:
302 	kmem_cache_free(vm_area_cachep, vma);
303  fail_mmapsem:
304 	up_write(&mm->mmap_sem);
305 	return rc;
306 }
307 
308 const char *arch_vma_name(struct vm_area_struct *vma)
309 {
310 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
311 		return "[vdso]";
312 	return NULL;
313 }
314 
315 
316 
317 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
318 				  unsigned long *size)
319 {
320 	Elf32_Shdr *sechdrs;
321 	unsigned int i;
322 	char *secnames;
323 
324 	/* Grab section headers and strings so we can tell who is who */
325 	sechdrs = (void *)ehdr + ehdr->e_shoff;
326 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
327 
328 	/* Find the section they want */
329 	for (i = 1; i < ehdr->e_shnum; i++) {
330 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
331 			if (size)
332 				*size = sechdrs[i].sh_size;
333 			return (void *)ehdr + sechdrs[i].sh_offset;
334 		}
335 	}
336 	*size = 0;
337 	return NULL;
338 }
339 
340 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
341 					const char *symname)
342 {
343 	unsigned int i;
344 	char name[MAX_SYMNAME], *c;
345 
346 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
347 		if (lib->dynsym[i].st_name == 0)
348 			continue;
349 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
350 			MAX_SYMNAME);
351 		c = strchr(name, '@');
352 		if (c)
353 			*c = 0;
354 		if (strcmp(symname, name) == 0)
355 			return &lib->dynsym[i];
356 	}
357 	return NULL;
358 }
359 
360 /* Note that we assume the section is .text and the symbol is relative to
361  * the library base
362  */
363 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
364 					    const char *symname)
365 {
366 	Elf32_Sym *sym = find_symbol32(lib, symname);
367 
368 	if (sym == NULL) {
369 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
370 		       symname);
371 		return 0;
372 	}
373 	return sym->st_value - VDSO32_LBASE;
374 }
375 
376 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
377 				struct lib64_elfinfo *v64,
378 				const char *orig, const char *fix)
379 {
380 	Elf32_Sym *sym32_gen, *sym32_fix;
381 
382 	sym32_gen = find_symbol32(v32, orig);
383 	if (sym32_gen == NULL) {
384 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
385 		return -1;
386 	}
387 	if (fix == NULL) {
388 		sym32_gen->st_name = 0;
389 		return 0;
390 	}
391 	sym32_fix = find_symbol32(v32, fix);
392 	if (sym32_fix == NULL) {
393 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
394 		return -1;
395 	}
396 	sym32_gen->st_value = sym32_fix->st_value;
397 	sym32_gen->st_size = sym32_fix->st_size;
398 	sym32_gen->st_info = sym32_fix->st_info;
399 	sym32_gen->st_other = sym32_fix->st_other;
400 	sym32_gen->st_shndx = sym32_fix->st_shndx;
401 
402 	return 0;
403 }
404 
405 
406 #ifdef CONFIG_PPC64
407 
408 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
409 				  unsigned long *size)
410 {
411 	Elf64_Shdr *sechdrs;
412 	unsigned int i;
413 	char *secnames;
414 
415 	/* Grab section headers and strings so we can tell who is who */
416 	sechdrs = (void *)ehdr + ehdr->e_shoff;
417 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
418 
419 	/* Find the section they want */
420 	for (i = 1; i < ehdr->e_shnum; i++) {
421 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
422 			if (size)
423 				*size = sechdrs[i].sh_size;
424 			return (void *)ehdr + sechdrs[i].sh_offset;
425 		}
426 	}
427 	if (size)
428 		*size = 0;
429 	return NULL;
430 }
431 
432 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
433 					const char *symname)
434 {
435 	unsigned int i;
436 	char name[MAX_SYMNAME], *c;
437 
438 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
439 		if (lib->dynsym[i].st_name == 0)
440 			continue;
441 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
442 			MAX_SYMNAME);
443 		c = strchr(name, '@');
444 		if (c)
445 			*c = 0;
446 		if (strcmp(symname, name) == 0)
447 			return &lib->dynsym[i];
448 	}
449 	return NULL;
450 }
451 
452 /* Note that we assume the section is .text and the symbol is relative to
453  * the library base
454  */
455 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
456 					    const char *symname)
457 {
458 	Elf64_Sym *sym = find_symbol64(lib, symname);
459 
460 	if (sym == NULL) {
461 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
462 		       symname);
463 		return 0;
464 	}
465 #ifdef VDS64_HAS_DESCRIPTORS
466 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
467 		VDSO64_LBASE;
468 #else
469 	return sym->st_value - VDSO64_LBASE;
470 #endif
471 }
472 
473 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
474 				struct lib64_elfinfo *v64,
475 				const char *orig, const char *fix)
476 {
477 	Elf64_Sym *sym64_gen, *sym64_fix;
478 
479 	sym64_gen = find_symbol64(v64, orig);
480 	if (sym64_gen == NULL) {
481 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
482 		return -1;
483 	}
484 	if (fix == NULL) {
485 		sym64_gen->st_name = 0;
486 		return 0;
487 	}
488 	sym64_fix = find_symbol64(v64, fix);
489 	if (sym64_fix == NULL) {
490 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
491 		return -1;
492 	}
493 	sym64_gen->st_value = sym64_fix->st_value;
494 	sym64_gen->st_size = sym64_fix->st_size;
495 	sym64_gen->st_info = sym64_fix->st_info;
496 	sym64_gen->st_other = sym64_fix->st_other;
497 	sym64_gen->st_shndx = sym64_fix->st_shndx;
498 
499 	return 0;
500 }
501 
502 #endif /* CONFIG_PPC64 */
503 
504 
505 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
506 					struct lib64_elfinfo *v64)
507 {
508 	void *sect;
509 
510 	/*
511 	 * Locate symbol tables & text section
512 	 */
513 
514 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
515 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
516 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
517 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
518 		return -1;
519 	}
520 	sect = find_section32(v32->hdr, ".text", NULL);
521 	if (sect == NULL) {
522 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
523 		return -1;
524 	}
525 	v32->text = sect - vdso32_kbase;
526 
527 #ifdef CONFIG_PPC64
528 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
529 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
530 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
531 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
532 		return -1;
533 	}
534 	sect = find_section64(v64->hdr, ".text", NULL);
535 	if (sect == NULL) {
536 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
537 		return -1;
538 	}
539 	v64->text = sect - vdso64_kbase;
540 #endif /* CONFIG_PPC64 */
541 
542 	return 0;
543 }
544 
545 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
546 					  struct lib64_elfinfo *v64)
547 {
548 	/*
549 	 * Find signal trampolines
550 	 */
551 
552 #ifdef CONFIG_PPC64
553 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
554 #endif
555 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
556 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
557 }
558 
559 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
560 				       struct lib64_elfinfo *v64)
561 {
562 	Elf32_Sym *sym32;
563 #ifdef CONFIG_PPC64
564 	Elf64_Sym *sym64;
565 
566        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
567 	if (sym64 == NULL) {
568 		printk(KERN_ERR "vDSO64: Can't find symbol "
569 		       "__kernel_datapage_offset !\n");
570 		return -1;
571 	}
572 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
573 		(vdso64_pages << PAGE_SHIFT) -
574 		(sym64->st_value - VDSO64_LBASE);
575 #endif /* CONFIG_PPC64 */
576 
577 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
578 	if (sym32 == NULL) {
579 		printk(KERN_ERR "vDSO32: Can't find symbol "
580 		       "__kernel_datapage_offset !\n");
581 		return -1;
582 	}
583 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
584 		(vdso32_pages << PAGE_SHIFT) -
585 		(sym32->st_value - VDSO32_LBASE);
586 
587 	return 0;
588 }
589 
590 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
591 				       struct lib64_elfinfo *v64)
592 {
593 	int i;
594 
595 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
596 		struct vdso_patch_def *patch = &vdso_patches[i];
597 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
598 			== patch->ftr_value;
599 		if (!match)
600 			continue;
601 
602 		DBG("replacing %s with %s...\n", patch->gen_name,
603 		    patch->fix_name ? "NONE" : patch->fix_name);
604 
605 		/*
606 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
607 		 * patch the "." symbol on 64 bits.
608 		 * It would be easy to do, but doesn't seem to be necessary,
609 		 * patching the OPD symbol is enough.
610 		 */
611 		vdso_do_func_patch32(v32, v64, patch->gen_name,
612 				     patch->fix_name);
613 #ifdef CONFIG_PPC64
614 		vdso_do_func_patch64(v32, v64, patch->gen_name,
615 				     patch->fix_name);
616 #endif /* CONFIG_PPC64 */
617 	}
618 
619 	return 0;
620 }
621 
622 
623 static __init int vdso_setup(void)
624 {
625 	struct lib32_elfinfo	v32;
626 	struct lib64_elfinfo	v64;
627 
628 	v32.hdr = vdso32_kbase;
629 #ifdef CONFIG_PPC64
630 	v64.hdr = vdso64_kbase;
631 #endif
632 	if (vdso_do_find_sections(&v32, &v64))
633 		return -1;
634 
635 	if (vdso_fixup_datapage(&v32, &v64))
636 		return -1;
637 
638 	if (vdso_fixup_alt_funcs(&v32, &v64))
639 		return -1;
640 
641 	vdso_setup_trampolines(&v32, &v64);
642 
643 	return 0;
644 }
645 
646 /*
647  * Called from setup_arch to initialize the bitmap of available
648  * syscalls in the systemcfg page
649  */
650 static void __init vdso_setup_syscall_map(void)
651 {
652 	unsigned int i;
653 	extern unsigned long *sys_call_table;
654 	extern unsigned long sys_ni_syscall;
655 
656 
657 	for (i = 0; i < __NR_syscalls; i++) {
658 #ifdef CONFIG_PPC64
659 		if (sys_call_table[i*2] != sys_ni_syscall)
660 			vdso_data->syscall_map_64[i >> 5] |=
661 				0x80000000UL >> (i & 0x1f);
662 		if (sys_call_table[i*2+1] != sys_ni_syscall)
663 			vdso_data->syscall_map_32[i >> 5] |=
664 				0x80000000UL >> (i & 0x1f);
665 #else /* CONFIG_PPC64 */
666 		if (sys_call_table[i] != sys_ni_syscall)
667 			vdso_data->syscall_map_32[i >> 5] |=
668 				0x80000000UL >> (i & 0x1f);
669 #endif /* CONFIG_PPC64 */
670 	}
671 }
672 
673 
674 void __init vdso_init(void)
675 {
676 	int i;
677 
678 #ifdef CONFIG_PPC64
679 	/*
680 	 * Fill up the "systemcfg" stuff for backward compatiblity
681 	 */
682 	strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
683 	vdso_data->version.major = SYSTEMCFG_MAJOR;
684 	vdso_data->version.minor = SYSTEMCFG_MINOR;
685 	vdso_data->processor = mfspr(SPRN_PVR);
686 	/*
687 	 * Fake the old platform number for pSeries and iSeries and add
688 	 * in LPAR bit if necessary
689 	 */
690 	vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
691 	if (firmware_has_feature(FW_FEATURE_LPAR))
692 		vdso_data->platform |= 1;
693 	vdso_data->physicalMemorySize = lmb_phys_mem_size();
694 	vdso_data->dcache_size = ppc64_caches.dsize;
695 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
696 	vdso_data->icache_size = ppc64_caches.isize;
697 	vdso_data->icache_line_size = ppc64_caches.iline_size;
698 
699 	/*
700 	 * Calculate the size of the 64 bits vDSO
701 	 */
702 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
703 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
704 #endif /* CONFIG_PPC64 */
705 
706 
707 	/*
708 	 * Calculate the size of the 32 bits vDSO
709 	 */
710 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
711 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
712 
713 
714 	/*
715 	 * Setup the syscall map in the vDOS
716 	 */
717 	vdso_setup_syscall_map();
718 	/*
719 	 * Initialize the vDSO images in memory, that is do necessary
720 	 * fixups of vDSO symbols, locate trampolines, etc...
721 	 */
722 	if (vdso_setup()) {
723 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
724 		vdso32_pages = 0;
725 #ifdef CONFIG_PPC64
726 		vdso64_pages = 0;
727 #endif
728 		return;
729 	}
730 
731 	/* Make sure pages are in the correct state */
732 	for (i = 0; i < vdso32_pages; i++) {
733 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
734 		ClearPageReserved(pg);
735 		get_page(pg);
736 
737 	}
738 #ifdef CONFIG_PPC64
739 	for (i = 0; i < vdso64_pages; i++) {
740 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
741 		ClearPageReserved(pg);
742 		get_page(pg);
743 	}
744 #endif /* CONFIG_PPC64 */
745 
746 	get_page(virt_to_page(vdso_data));
747 }
748 
749 int in_gate_area_no_task(unsigned long addr)
750 {
751 	return 0;
752 }
753 
754 int in_gate_area(struct task_struct *task, unsigned long addr)
755 {
756 	return 0;
757 }
758 
759 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
760 {
761 	return NULL;
762 }
763 
764