xref: /linux/arch/powerpc/kernel/vdso.c (revision b454cc6636d254fbf6049b73e9560aee76fb04a3)
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 unsigned int vdso32_pages;
55 unsigned long vdso32_sigtramp;
56 unsigned long vdso32_rt_sigtramp;
57 
58 #ifdef CONFIG_PPC64
59 extern char vdso64_start, vdso64_end;
60 static void *vdso64_kbase = &vdso64_start;
61 unsigned int vdso64_pages;
62 unsigned long vdso64_rt_sigtramp;
63 #endif /* CONFIG_PPC64 */
64 
65 /*
66  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
67  * Once the early boot kernel code no longer needs to muck around
68  * with it, it will become dynamically allocated
69  */
70 static union {
71 	struct vdso_data	data;
72 	u8			page[PAGE_SIZE];
73 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
74 struct vdso_data *vdso_data = &vdso_data_store.data;
75 
76 /* Format of the patch table */
77 struct vdso_patch_def
78 {
79 	unsigned long	ftr_mask, ftr_value;
80 	const char	*gen_name;
81 	const char	*fix_name;
82 };
83 
84 /* Table of functions to patch based on the CPU type/revision
85  *
86  * Currently, we only change sync_dicache to do nothing on processors
87  * with a coherent icache
88  */
89 static struct vdso_patch_def vdso_patches[] = {
90 	{
91 		CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
92 		"__kernel_sync_dicache", "__kernel_sync_dicache_p5"
93 	},
94 	{
95 		CPU_FTR_USE_TB, 0,
96 		"__kernel_gettimeofday", NULL
97 	},
98 };
99 
100 /*
101  * Some infos carried around for each of them during parsing at
102  * boot time.
103  */
104 struct lib32_elfinfo
105 {
106 	Elf32_Ehdr	*hdr;		/* ptr to ELF */
107 	Elf32_Sym	*dynsym;	/* ptr to .dynsym section */
108 	unsigned long	dynsymsize;	/* size of .dynsym section */
109 	char		*dynstr;	/* ptr to .dynstr section */
110 	unsigned long	text;		/* offset of .text section in .so */
111 };
112 
113 struct lib64_elfinfo
114 {
115 	Elf64_Ehdr	*hdr;
116 	Elf64_Sym	*dynsym;
117 	unsigned long	dynsymsize;
118 	char		*dynstr;
119 	unsigned long	text;
120 };
121 
122 
123 #ifdef __DEBUG
124 static void dump_one_vdso_page(struct page *pg, struct page *upg)
125 {
126 	printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
127 	       page_count(pg),
128 	       pg->flags);
129 	if (upg/* && pg != upg*/) {
130 		printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
131 						       << PAGE_SHIFT),
132 		       page_count(upg),
133 		       upg->flags);
134 	}
135 	printk("\n");
136 }
137 
138 static void dump_vdso_pages(struct vm_area_struct * vma)
139 {
140 	int i;
141 
142 	if (!vma || test_thread_flag(TIF_32BIT)) {
143 		printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
144 		for (i=0; i<vdso32_pages; i++) {
145 			struct page *pg = virt_to_page(vdso32_kbase +
146 						       i*PAGE_SIZE);
147 			struct page *upg = (vma && vma->vm_mm) ?
148 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
149 				: NULL;
150 			dump_one_vdso_page(pg, upg);
151 		}
152 	}
153 	if (!vma || !test_thread_flag(TIF_32BIT)) {
154 		printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
155 		for (i=0; i<vdso64_pages; i++) {
156 			struct page *pg = virt_to_page(vdso64_kbase +
157 						       i*PAGE_SIZE);
158 			struct page *upg = (vma && vma->vm_mm) ?
159 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
160 				: NULL;
161 			dump_one_vdso_page(pg, upg);
162 		}
163 	}
164 }
165 #endif /* DEBUG */
166 
167 /*
168  * Keep a dummy vma_close for now, it will prevent VMA merging.
169  */
170 static void vdso_vma_close(struct vm_area_struct * vma)
171 {
172 }
173 
174 /*
175  * Our nopage() function, maps in the actual vDSO kernel pages, they will
176  * be mapped read-only by do_no_page(), and eventually COW'ed, either
177  * right away for an initial write access, or by do_wp_page().
178  */
179 static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
180 				     unsigned long address, int *type)
181 {
182 	unsigned long offset = address - vma->vm_start;
183 	struct page *pg;
184 #ifdef CONFIG_PPC64
185 	void *vbase = (vma->vm_mm->task_size > TASK_SIZE_USER32) ?
186 		vdso64_kbase : vdso32_kbase;
187 #else
188 	void *vbase = vdso32_kbase;
189 #endif
190 
191 	DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
192 	    current->comm, address, offset);
193 
194 	if (address < vma->vm_start || address > vma->vm_end)
195 		return NOPAGE_SIGBUS;
196 
197 	/*
198 	 * Last page is systemcfg.
199 	 */
200 	if ((vma->vm_end - address) <= PAGE_SIZE)
201 		pg = virt_to_page(vdso_data);
202 	else
203 		pg = virt_to_page(vbase + offset);
204 
205 	get_page(pg);
206 	DBG(" ->page count: %d\n", page_count(pg));
207 
208 	return pg;
209 }
210 
211 static struct vm_operations_struct vdso_vmops = {
212 	.close	= vdso_vma_close,
213 	.nopage	= vdso_vma_nopage,
214 };
215 
216 /*
217  * This is called from binfmt_elf, we create the special vma for the
218  * vDSO and insert it into the mm struct tree
219  */
220 int arch_setup_additional_pages(struct linux_binprm *bprm,
221 				int executable_stack)
222 {
223 	struct mm_struct *mm = current->mm;
224 	struct vm_area_struct *vma;
225 	unsigned long vdso_pages;
226 	unsigned long vdso_base;
227 	int rc;
228 
229 #ifdef CONFIG_PPC64
230 	if (test_thread_flag(TIF_32BIT)) {
231 		vdso_pages = vdso32_pages;
232 		vdso_base = VDSO32_MBASE;
233 	} else {
234 		vdso_pages = vdso64_pages;
235 		vdso_base = VDSO64_MBASE;
236 	}
237 #else
238 	vdso_pages = vdso32_pages;
239 	vdso_base = VDSO32_MBASE;
240 #endif
241 
242 	current->mm->context.vdso_base = 0;
243 
244 	/* vDSO has a problem and was disabled, just don't "enable" it for the
245 	 * process
246 	 */
247 	if (vdso_pages == 0)
248 		return 0;
249 	/* Add a page to the vdso size for the data page */
250 	vdso_pages ++;
251 
252 	/*
253 	 * pick a base address for the vDSO in process space. We try to put it
254 	 * at vdso_base which is the "natural" base for it, but we might fail
255 	 * and end up putting it elsewhere.
256 	 */
257 	down_write(&mm->mmap_sem);
258 	vdso_base = get_unmapped_area(NULL, vdso_base,
259 				      vdso_pages << PAGE_SHIFT, 0, 0);
260 	if (IS_ERR_VALUE(vdso_base)) {
261 		rc = vdso_base;
262 		goto fail_mmapsem;
263 	}
264 
265 
266 	/* Allocate a VMA structure and fill it up */
267 	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
268 	if (vma == NULL) {
269 		rc = -ENOMEM;
270 		goto fail_mmapsem;
271 	}
272 	vma->vm_mm = mm;
273 	vma->vm_start = vdso_base;
274 	vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
275 
276 	/*
277 	 * our vma flags don't have VM_WRITE so by default, the process isn't
278 	 * allowed to write those pages.
279 	 * gdb can break that with ptrace interface, and thus trigger COW on
280 	 * those pages but it's then your responsibility to never do that on
281 	 * the "data" page of the vDSO or you'll stop getting kernel updates
282 	 * and your nice userland gettimeofday will be totally dead.
283 	 * It's fine to use that for setting breakpoints in the vDSO code
284 	 * pages though
285 	 */
286 	vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC;
287 	/*
288 	 * Make sure the vDSO gets into every core dump.
289 	 * Dumping its contents makes post-mortem fully interpretable later
290 	 * without matching up the same kernel and hardware config to see
291 	 * what PC values meant.
292 	 */
293 	vma->vm_flags |= VM_ALWAYSDUMP;
294 	vma->vm_flags |= mm->def_flags;
295 	vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
296 	vma->vm_ops = &vdso_vmops;
297 
298 	/* Insert new VMA */
299 	rc = insert_vm_struct(mm, vma);
300 	if (rc)
301 		goto fail_vma;
302 
303 	/* Put vDSO base into mm struct and account for memory usage */
304 	current->mm->context.vdso_base = vdso_base;
305 	mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
306 	up_write(&mm->mmap_sem);
307 	return 0;
308 
309  fail_vma:
310 	kmem_cache_free(vm_area_cachep, vma);
311  fail_mmapsem:
312 	up_write(&mm->mmap_sem);
313 	return rc;
314 }
315 
316 const char *arch_vma_name(struct vm_area_struct *vma)
317 {
318 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
319 		return "[vdso]";
320 	return NULL;
321 }
322 
323 
324 
325 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
326 				  unsigned long *size)
327 {
328 	Elf32_Shdr *sechdrs;
329 	unsigned int i;
330 	char *secnames;
331 
332 	/* Grab section headers and strings so we can tell who is who */
333 	sechdrs = (void *)ehdr + ehdr->e_shoff;
334 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
335 
336 	/* Find the section they want */
337 	for (i = 1; i < ehdr->e_shnum; i++) {
338 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
339 			if (size)
340 				*size = sechdrs[i].sh_size;
341 			return (void *)ehdr + sechdrs[i].sh_offset;
342 		}
343 	}
344 	*size = 0;
345 	return NULL;
346 }
347 
348 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
349 					const char *symname)
350 {
351 	unsigned int i;
352 	char name[MAX_SYMNAME], *c;
353 
354 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
355 		if (lib->dynsym[i].st_name == 0)
356 			continue;
357 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
358 			MAX_SYMNAME);
359 		c = strchr(name, '@');
360 		if (c)
361 			*c = 0;
362 		if (strcmp(symname, name) == 0)
363 			return &lib->dynsym[i];
364 	}
365 	return NULL;
366 }
367 
368 /* Note that we assume the section is .text and the symbol is relative to
369  * the library base
370  */
371 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
372 					    const char *symname)
373 {
374 	Elf32_Sym *sym = find_symbol32(lib, symname);
375 
376 	if (sym == NULL) {
377 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
378 		       symname);
379 		return 0;
380 	}
381 	return sym->st_value - VDSO32_LBASE;
382 }
383 
384 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
385 				struct lib64_elfinfo *v64,
386 				const char *orig, const char *fix)
387 {
388 	Elf32_Sym *sym32_gen, *sym32_fix;
389 
390 	sym32_gen = find_symbol32(v32, orig);
391 	if (sym32_gen == NULL) {
392 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
393 		return -1;
394 	}
395 	if (fix == NULL) {
396 		sym32_gen->st_name = 0;
397 		return 0;
398 	}
399 	sym32_fix = find_symbol32(v32, fix);
400 	if (sym32_fix == NULL) {
401 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
402 		return -1;
403 	}
404 	sym32_gen->st_value = sym32_fix->st_value;
405 	sym32_gen->st_size = sym32_fix->st_size;
406 	sym32_gen->st_info = sym32_fix->st_info;
407 	sym32_gen->st_other = sym32_fix->st_other;
408 	sym32_gen->st_shndx = sym32_fix->st_shndx;
409 
410 	return 0;
411 }
412 
413 
414 #ifdef CONFIG_PPC64
415 
416 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
417 				  unsigned long *size)
418 {
419 	Elf64_Shdr *sechdrs;
420 	unsigned int i;
421 	char *secnames;
422 
423 	/* Grab section headers and strings so we can tell who is who */
424 	sechdrs = (void *)ehdr + ehdr->e_shoff;
425 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
426 
427 	/* Find the section they want */
428 	for (i = 1; i < ehdr->e_shnum; i++) {
429 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
430 			if (size)
431 				*size = sechdrs[i].sh_size;
432 			return (void *)ehdr + sechdrs[i].sh_offset;
433 		}
434 	}
435 	if (size)
436 		*size = 0;
437 	return NULL;
438 }
439 
440 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
441 					const char *symname)
442 {
443 	unsigned int i;
444 	char name[MAX_SYMNAME], *c;
445 
446 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
447 		if (lib->dynsym[i].st_name == 0)
448 			continue;
449 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
450 			MAX_SYMNAME);
451 		c = strchr(name, '@');
452 		if (c)
453 			*c = 0;
454 		if (strcmp(symname, name) == 0)
455 			return &lib->dynsym[i];
456 	}
457 	return NULL;
458 }
459 
460 /* Note that we assume the section is .text and the symbol is relative to
461  * the library base
462  */
463 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
464 					    const char *symname)
465 {
466 	Elf64_Sym *sym = find_symbol64(lib, symname);
467 
468 	if (sym == NULL) {
469 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
470 		       symname);
471 		return 0;
472 	}
473 #ifdef VDS64_HAS_DESCRIPTORS
474 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
475 		VDSO64_LBASE;
476 #else
477 	return sym->st_value - VDSO64_LBASE;
478 #endif
479 }
480 
481 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
482 				struct lib64_elfinfo *v64,
483 				const char *orig, const char *fix)
484 {
485 	Elf64_Sym *sym64_gen, *sym64_fix;
486 
487 	sym64_gen = find_symbol64(v64, orig);
488 	if (sym64_gen == NULL) {
489 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
490 		return -1;
491 	}
492 	if (fix == NULL) {
493 		sym64_gen->st_name = 0;
494 		return 0;
495 	}
496 	sym64_fix = find_symbol64(v64, fix);
497 	if (sym64_fix == NULL) {
498 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
499 		return -1;
500 	}
501 	sym64_gen->st_value = sym64_fix->st_value;
502 	sym64_gen->st_size = sym64_fix->st_size;
503 	sym64_gen->st_info = sym64_fix->st_info;
504 	sym64_gen->st_other = sym64_fix->st_other;
505 	sym64_gen->st_shndx = sym64_fix->st_shndx;
506 
507 	return 0;
508 }
509 
510 #endif /* CONFIG_PPC64 */
511 
512 
513 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
514 					struct lib64_elfinfo *v64)
515 {
516 	void *sect;
517 
518 	/*
519 	 * Locate symbol tables & text section
520 	 */
521 
522 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
523 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
524 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
525 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
526 		return -1;
527 	}
528 	sect = find_section32(v32->hdr, ".text", NULL);
529 	if (sect == NULL) {
530 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
531 		return -1;
532 	}
533 	v32->text = sect - vdso32_kbase;
534 
535 #ifdef CONFIG_PPC64
536 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
537 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
538 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
539 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
540 		return -1;
541 	}
542 	sect = find_section64(v64->hdr, ".text", NULL);
543 	if (sect == NULL) {
544 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
545 		return -1;
546 	}
547 	v64->text = sect - vdso64_kbase;
548 #endif /* CONFIG_PPC64 */
549 
550 	return 0;
551 }
552 
553 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
554 					  struct lib64_elfinfo *v64)
555 {
556 	/*
557 	 * Find signal trampolines
558 	 */
559 
560 #ifdef CONFIG_PPC64
561 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
562 #endif
563 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
564 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
565 }
566 
567 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
568 				       struct lib64_elfinfo *v64)
569 {
570 	Elf32_Sym *sym32;
571 #ifdef CONFIG_PPC64
572 	Elf64_Sym *sym64;
573 
574        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
575 	if (sym64 == NULL) {
576 		printk(KERN_ERR "vDSO64: Can't find symbol "
577 		       "__kernel_datapage_offset !\n");
578 		return -1;
579 	}
580 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
581 		(vdso64_pages << PAGE_SHIFT) -
582 		(sym64->st_value - VDSO64_LBASE);
583 #endif /* CONFIG_PPC64 */
584 
585 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
586 	if (sym32 == NULL) {
587 		printk(KERN_ERR "vDSO32: Can't find symbol "
588 		       "__kernel_datapage_offset !\n");
589 		return -1;
590 	}
591 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
592 		(vdso32_pages << PAGE_SHIFT) -
593 		(sym32->st_value - VDSO32_LBASE);
594 
595 	return 0;
596 }
597 
598 
599 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
600 				      struct lib64_elfinfo *v64)
601 {
602 	void *start32;
603 	unsigned long size32;
604 
605 #ifdef CONFIG_PPC64
606 	void *start64;
607 	unsigned long size64;
608 
609 	start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
610 	if (start64)
611 		do_feature_fixups(cur_cpu_spec->cpu_features,
612 				  start64, start64 + size64);
613 
614 	start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
615 	if (start64)
616 		do_feature_fixups(powerpc_firmware_features,
617 				  start64, start64 + size64);
618 #endif /* CONFIG_PPC64 */
619 
620 	start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
621 	if (start32)
622 		do_feature_fixups(cur_cpu_spec->cpu_features,
623 				  start32, start32 + size32);
624 
625 #ifdef CONFIG_PPC64
626 	start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
627 	if (start32)
628 		do_feature_fixups(powerpc_firmware_features,
629 				  start32, start32 + size32);
630 #endif /* CONFIG_PPC64 */
631 
632 	return 0;
633 }
634 
635 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
636 				       struct lib64_elfinfo *v64)
637 {
638 	int i;
639 
640 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
641 		struct vdso_patch_def *patch = &vdso_patches[i];
642 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
643 			== patch->ftr_value;
644 		if (!match)
645 			continue;
646 
647 		DBG("replacing %s with %s...\n", patch->gen_name,
648 		    patch->fix_name ? "NONE" : patch->fix_name);
649 
650 		/*
651 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
652 		 * patch the "." symbol on 64 bits.
653 		 * It would be easy to do, but doesn't seem to be necessary,
654 		 * patching the OPD symbol is enough.
655 		 */
656 		vdso_do_func_patch32(v32, v64, patch->gen_name,
657 				     patch->fix_name);
658 #ifdef CONFIG_PPC64
659 		vdso_do_func_patch64(v32, v64, patch->gen_name,
660 				     patch->fix_name);
661 #endif /* CONFIG_PPC64 */
662 	}
663 
664 	return 0;
665 }
666 
667 
668 static __init int vdso_setup(void)
669 {
670 	struct lib32_elfinfo	v32;
671 	struct lib64_elfinfo	v64;
672 
673 	v32.hdr = vdso32_kbase;
674 #ifdef CONFIG_PPC64
675 	v64.hdr = vdso64_kbase;
676 #endif
677 	if (vdso_do_find_sections(&v32, &v64))
678 		return -1;
679 
680 	if (vdso_fixup_datapage(&v32, &v64))
681 		return -1;
682 
683 	if (vdso_fixup_features(&v32, &v64))
684 		return -1;
685 
686 	if (vdso_fixup_alt_funcs(&v32, &v64))
687 		return -1;
688 
689 	vdso_setup_trampolines(&v32, &v64);
690 
691 	return 0;
692 }
693 
694 /*
695  * Called from setup_arch to initialize the bitmap of available
696  * syscalls in the systemcfg page
697  */
698 static void __init vdso_setup_syscall_map(void)
699 {
700 	unsigned int i;
701 	extern unsigned long *sys_call_table;
702 	extern unsigned long sys_ni_syscall;
703 
704 
705 	for (i = 0; i < __NR_syscalls; i++) {
706 #ifdef CONFIG_PPC64
707 		if (sys_call_table[i*2] != sys_ni_syscall)
708 			vdso_data->syscall_map_64[i >> 5] |=
709 				0x80000000UL >> (i & 0x1f);
710 		if (sys_call_table[i*2+1] != sys_ni_syscall)
711 			vdso_data->syscall_map_32[i >> 5] |=
712 				0x80000000UL >> (i & 0x1f);
713 #else /* CONFIG_PPC64 */
714 		if (sys_call_table[i] != sys_ni_syscall)
715 			vdso_data->syscall_map_32[i >> 5] |=
716 				0x80000000UL >> (i & 0x1f);
717 #endif /* CONFIG_PPC64 */
718 	}
719 }
720 
721 
722 void __init vdso_init(void)
723 {
724 	int i;
725 
726 #ifdef CONFIG_PPC64
727 	/*
728 	 * Fill up the "systemcfg" stuff for backward compatiblity
729 	 */
730 	strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
731 	vdso_data->version.major = SYSTEMCFG_MAJOR;
732 	vdso_data->version.minor = SYSTEMCFG_MINOR;
733 	vdso_data->processor = mfspr(SPRN_PVR);
734 	/*
735 	 * Fake the old platform number for pSeries and iSeries and add
736 	 * in LPAR bit if necessary
737 	 */
738 	vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
739 	if (firmware_has_feature(FW_FEATURE_LPAR))
740 		vdso_data->platform |= 1;
741 	vdso_data->physicalMemorySize = lmb_phys_mem_size();
742 	vdso_data->dcache_size = ppc64_caches.dsize;
743 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
744 	vdso_data->icache_size = ppc64_caches.isize;
745 	vdso_data->icache_line_size = ppc64_caches.iline_size;
746 
747 	/*
748 	 * Calculate the size of the 64 bits vDSO
749 	 */
750 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
751 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
752 #endif /* CONFIG_PPC64 */
753 
754 
755 	/*
756 	 * Calculate the size of the 32 bits vDSO
757 	 */
758 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
759 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
760 
761 
762 	/*
763 	 * Setup the syscall map in the vDOS
764 	 */
765 	vdso_setup_syscall_map();
766 
767 	/*
768 	 * Initialize the vDSO images in memory, that is do necessary
769 	 * fixups of vDSO symbols, locate trampolines, etc...
770 	 */
771 	if (vdso_setup()) {
772 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
773 		vdso32_pages = 0;
774 #ifdef CONFIG_PPC64
775 		vdso64_pages = 0;
776 #endif
777 		return;
778 	}
779 
780 	/* Make sure pages are in the correct state */
781 	for (i = 0; i < vdso32_pages; i++) {
782 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
783 		ClearPageReserved(pg);
784 		get_page(pg);
785 
786 	}
787 #ifdef CONFIG_PPC64
788 	for (i = 0; i < vdso64_pages; i++) {
789 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
790 		ClearPageReserved(pg);
791 		get_page(pg);
792 	}
793 #endif /* CONFIG_PPC64 */
794 
795 	get_page(virt_to_page(vdso_data));
796 }
797 
798 int in_gate_area_no_task(unsigned long addr)
799 {
800 	return 0;
801 }
802 
803 int in_gate_area(struct task_struct *task, unsigned long addr)
804 {
805 	return 0;
806 }
807 
808 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
809 {
810 	return NULL;
811 }
812 
813