xref: /linux/arch/powerpc/kernel/vdso.c (revision 606d099cdd1080bbb50ea50dc52d98252f8f10a1)
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 	vma->vm_flags |= mm->def_flags;
288 	vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
289 	vma->vm_ops = &vdso_vmops;
290 
291 	/* Insert new VMA */
292 	rc = insert_vm_struct(mm, vma);
293 	if (rc)
294 		goto fail_vma;
295 
296 	/* Put vDSO base into mm struct and account for memory usage */
297 	current->mm->context.vdso_base = vdso_base;
298 	mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
299 	up_write(&mm->mmap_sem);
300 	return 0;
301 
302  fail_vma:
303 	kmem_cache_free(vm_area_cachep, vma);
304  fail_mmapsem:
305 	up_write(&mm->mmap_sem);
306 	return rc;
307 }
308 
309 const char *arch_vma_name(struct vm_area_struct *vma)
310 {
311 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
312 		return "[vdso]";
313 	return NULL;
314 }
315 
316 
317 
318 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
319 				  unsigned long *size)
320 {
321 	Elf32_Shdr *sechdrs;
322 	unsigned int i;
323 	char *secnames;
324 
325 	/* Grab section headers and strings so we can tell who is who */
326 	sechdrs = (void *)ehdr + ehdr->e_shoff;
327 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
328 
329 	/* Find the section they want */
330 	for (i = 1; i < ehdr->e_shnum; i++) {
331 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
332 			if (size)
333 				*size = sechdrs[i].sh_size;
334 			return (void *)ehdr + sechdrs[i].sh_offset;
335 		}
336 	}
337 	*size = 0;
338 	return NULL;
339 }
340 
341 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
342 					const char *symname)
343 {
344 	unsigned int i;
345 	char name[MAX_SYMNAME], *c;
346 
347 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
348 		if (lib->dynsym[i].st_name == 0)
349 			continue;
350 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
351 			MAX_SYMNAME);
352 		c = strchr(name, '@');
353 		if (c)
354 			*c = 0;
355 		if (strcmp(symname, name) == 0)
356 			return &lib->dynsym[i];
357 	}
358 	return NULL;
359 }
360 
361 /* Note that we assume the section is .text and the symbol is relative to
362  * the library base
363  */
364 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
365 					    const char *symname)
366 {
367 	Elf32_Sym *sym = find_symbol32(lib, symname);
368 
369 	if (sym == NULL) {
370 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
371 		       symname);
372 		return 0;
373 	}
374 	return sym->st_value - VDSO32_LBASE;
375 }
376 
377 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
378 				struct lib64_elfinfo *v64,
379 				const char *orig, const char *fix)
380 {
381 	Elf32_Sym *sym32_gen, *sym32_fix;
382 
383 	sym32_gen = find_symbol32(v32, orig);
384 	if (sym32_gen == NULL) {
385 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
386 		return -1;
387 	}
388 	if (fix == NULL) {
389 		sym32_gen->st_name = 0;
390 		return 0;
391 	}
392 	sym32_fix = find_symbol32(v32, fix);
393 	if (sym32_fix == NULL) {
394 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
395 		return -1;
396 	}
397 	sym32_gen->st_value = sym32_fix->st_value;
398 	sym32_gen->st_size = sym32_fix->st_size;
399 	sym32_gen->st_info = sym32_fix->st_info;
400 	sym32_gen->st_other = sym32_fix->st_other;
401 	sym32_gen->st_shndx = sym32_fix->st_shndx;
402 
403 	return 0;
404 }
405 
406 
407 #ifdef CONFIG_PPC64
408 
409 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
410 				  unsigned long *size)
411 {
412 	Elf64_Shdr *sechdrs;
413 	unsigned int i;
414 	char *secnames;
415 
416 	/* Grab section headers and strings so we can tell who is who */
417 	sechdrs = (void *)ehdr + ehdr->e_shoff;
418 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
419 
420 	/* Find the section they want */
421 	for (i = 1; i < ehdr->e_shnum; i++) {
422 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
423 			if (size)
424 				*size = sechdrs[i].sh_size;
425 			return (void *)ehdr + sechdrs[i].sh_offset;
426 		}
427 	}
428 	if (size)
429 		*size = 0;
430 	return NULL;
431 }
432 
433 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
434 					const char *symname)
435 {
436 	unsigned int i;
437 	char name[MAX_SYMNAME], *c;
438 
439 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
440 		if (lib->dynsym[i].st_name == 0)
441 			continue;
442 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
443 			MAX_SYMNAME);
444 		c = strchr(name, '@');
445 		if (c)
446 			*c = 0;
447 		if (strcmp(symname, name) == 0)
448 			return &lib->dynsym[i];
449 	}
450 	return NULL;
451 }
452 
453 /* Note that we assume the section is .text and the symbol is relative to
454  * the library base
455  */
456 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
457 					    const char *symname)
458 {
459 	Elf64_Sym *sym = find_symbol64(lib, symname);
460 
461 	if (sym == NULL) {
462 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
463 		       symname);
464 		return 0;
465 	}
466 #ifdef VDS64_HAS_DESCRIPTORS
467 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
468 		VDSO64_LBASE;
469 #else
470 	return sym->st_value - VDSO64_LBASE;
471 #endif
472 }
473 
474 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
475 				struct lib64_elfinfo *v64,
476 				const char *orig, const char *fix)
477 {
478 	Elf64_Sym *sym64_gen, *sym64_fix;
479 
480 	sym64_gen = find_symbol64(v64, orig);
481 	if (sym64_gen == NULL) {
482 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
483 		return -1;
484 	}
485 	if (fix == NULL) {
486 		sym64_gen->st_name = 0;
487 		return 0;
488 	}
489 	sym64_fix = find_symbol64(v64, fix);
490 	if (sym64_fix == NULL) {
491 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
492 		return -1;
493 	}
494 	sym64_gen->st_value = sym64_fix->st_value;
495 	sym64_gen->st_size = sym64_fix->st_size;
496 	sym64_gen->st_info = sym64_fix->st_info;
497 	sym64_gen->st_other = sym64_fix->st_other;
498 	sym64_gen->st_shndx = sym64_fix->st_shndx;
499 
500 	return 0;
501 }
502 
503 #endif /* CONFIG_PPC64 */
504 
505 
506 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
507 					struct lib64_elfinfo *v64)
508 {
509 	void *sect;
510 
511 	/*
512 	 * Locate symbol tables & text section
513 	 */
514 
515 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
516 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
517 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
518 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
519 		return -1;
520 	}
521 	sect = find_section32(v32->hdr, ".text", NULL);
522 	if (sect == NULL) {
523 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
524 		return -1;
525 	}
526 	v32->text = sect - vdso32_kbase;
527 
528 #ifdef CONFIG_PPC64
529 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
530 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
531 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
532 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
533 		return -1;
534 	}
535 	sect = find_section64(v64->hdr, ".text", NULL);
536 	if (sect == NULL) {
537 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
538 		return -1;
539 	}
540 	v64->text = sect - vdso64_kbase;
541 #endif /* CONFIG_PPC64 */
542 
543 	return 0;
544 }
545 
546 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
547 					  struct lib64_elfinfo *v64)
548 {
549 	/*
550 	 * Find signal trampolines
551 	 */
552 
553 #ifdef CONFIG_PPC64
554 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
555 #endif
556 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
557 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
558 }
559 
560 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
561 				       struct lib64_elfinfo *v64)
562 {
563 	Elf32_Sym *sym32;
564 #ifdef CONFIG_PPC64
565 	Elf64_Sym *sym64;
566 
567        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
568 	if (sym64 == NULL) {
569 		printk(KERN_ERR "vDSO64: Can't find symbol "
570 		       "__kernel_datapage_offset !\n");
571 		return -1;
572 	}
573 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
574 		(vdso64_pages << PAGE_SHIFT) -
575 		(sym64->st_value - VDSO64_LBASE);
576 #endif /* CONFIG_PPC64 */
577 
578 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
579 	if (sym32 == NULL) {
580 		printk(KERN_ERR "vDSO32: Can't find symbol "
581 		       "__kernel_datapage_offset !\n");
582 		return -1;
583 	}
584 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
585 		(vdso32_pages << PAGE_SHIFT) -
586 		(sym32->st_value - VDSO32_LBASE);
587 
588 	return 0;
589 }
590 
591 
592 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
593 				      struct lib64_elfinfo *v64)
594 {
595 	void *start32;
596 	unsigned long size32;
597 
598 #ifdef CONFIG_PPC64
599 	void *start64;
600 	unsigned long size64;
601 
602 	start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
603 	if (start64)
604 		do_feature_fixups(cur_cpu_spec->cpu_features,
605 				  start64, start64 + size64);
606 
607 	start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
608 	if (start64)
609 		do_feature_fixups(powerpc_firmware_features,
610 				  start64, start64 + size64);
611 #endif /* CONFIG_PPC64 */
612 
613 	start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
614 	if (start32)
615 		do_feature_fixups(cur_cpu_spec->cpu_features,
616 				  start32, start32 + size32);
617 
618 #ifdef CONFIG_PPC64
619 	start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
620 	if (start32)
621 		do_feature_fixups(powerpc_firmware_features,
622 				  start32, start32 + size32);
623 #endif /* CONFIG_PPC64 */
624 
625 	return 0;
626 }
627 
628 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
629 				       struct lib64_elfinfo *v64)
630 {
631 	int i;
632 
633 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
634 		struct vdso_patch_def *patch = &vdso_patches[i];
635 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
636 			== patch->ftr_value;
637 		if (!match)
638 			continue;
639 
640 		DBG("replacing %s with %s...\n", patch->gen_name,
641 		    patch->fix_name ? "NONE" : patch->fix_name);
642 
643 		/*
644 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
645 		 * patch the "." symbol on 64 bits.
646 		 * It would be easy to do, but doesn't seem to be necessary,
647 		 * patching the OPD symbol is enough.
648 		 */
649 		vdso_do_func_patch32(v32, v64, patch->gen_name,
650 				     patch->fix_name);
651 #ifdef CONFIG_PPC64
652 		vdso_do_func_patch64(v32, v64, patch->gen_name,
653 				     patch->fix_name);
654 #endif /* CONFIG_PPC64 */
655 	}
656 
657 	return 0;
658 }
659 
660 
661 static __init int vdso_setup(void)
662 {
663 	struct lib32_elfinfo	v32;
664 	struct lib64_elfinfo	v64;
665 
666 	v32.hdr = vdso32_kbase;
667 #ifdef CONFIG_PPC64
668 	v64.hdr = vdso64_kbase;
669 #endif
670 	if (vdso_do_find_sections(&v32, &v64))
671 		return -1;
672 
673 	if (vdso_fixup_datapage(&v32, &v64))
674 		return -1;
675 
676 	if (vdso_fixup_features(&v32, &v64))
677 		return -1;
678 
679 	if (vdso_fixup_alt_funcs(&v32, &v64))
680 		return -1;
681 
682 	vdso_setup_trampolines(&v32, &v64);
683 
684 	return 0;
685 }
686 
687 /*
688  * Called from setup_arch to initialize the bitmap of available
689  * syscalls in the systemcfg page
690  */
691 static void __init vdso_setup_syscall_map(void)
692 {
693 	unsigned int i;
694 	extern unsigned long *sys_call_table;
695 	extern unsigned long sys_ni_syscall;
696 
697 
698 	for (i = 0; i < __NR_syscalls; i++) {
699 #ifdef CONFIG_PPC64
700 		if (sys_call_table[i*2] != sys_ni_syscall)
701 			vdso_data->syscall_map_64[i >> 5] |=
702 				0x80000000UL >> (i & 0x1f);
703 		if (sys_call_table[i*2+1] != sys_ni_syscall)
704 			vdso_data->syscall_map_32[i >> 5] |=
705 				0x80000000UL >> (i & 0x1f);
706 #else /* CONFIG_PPC64 */
707 		if (sys_call_table[i] != sys_ni_syscall)
708 			vdso_data->syscall_map_32[i >> 5] |=
709 				0x80000000UL >> (i & 0x1f);
710 #endif /* CONFIG_PPC64 */
711 	}
712 }
713 
714 
715 void __init vdso_init(void)
716 {
717 	int i;
718 
719 #ifdef CONFIG_PPC64
720 	/*
721 	 * Fill up the "systemcfg" stuff for backward compatiblity
722 	 */
723 	strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
724 	vdso_data->version.major = SYSTEMCFG_MAJOR;
725 	vdso_data->version.minor = SYSTEMCFG_MINOR;
726 	vdso_data->processor = mfspr(SPRN_PVR);
727 	/*
728 	 * Fake the old platform number for pSeries and iSeries and add
729 	 * in LPAR bit if necessary
730 	 */
731 	vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
732 	if (firmware_has_feature(FW_FEATURE_LPAR))
733 		vdso_data->platform |= 1;
734 	vdso_data->physicalMemorySize = lmb_phys_mem_size();
735 	vdso_data->dcache_size = ppc64_caches.dsize;
736 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
737 	vdso_data->icache_size = ppc64_caches.isize;
738 	vdso_data->icache_line_size = ppc64_caches.iline_size;
739 
740 	/*
741 	 * Calculate the size of the 64 bits vDSO
742 	 */
743 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
744 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
745 #endif /* CONFIG_PPC64 */
746 
747 
748 	/*
749 	 * Calculate the size of the 32 bits vDSO
750 	 */
751 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
752 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
753 
754 
755 	/*
756 	 * Setup the syscall map in the vDOS
757 	 */
758 	vdso_setup_syscall_map();
759 
760 	/*
761 	 * Initialize the vDSO images in memory, that is do necessary
762 	 * fixups of vDSO symbols, locate trampolines, etc...
763 	 */
764 	if (vdso_setup()) {
765 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
766 		vdso32_pages = 0;
767 #ifdef CONFIG_PPC64
768 		vdso64_pages = 0;
769 #endif
770 		return;
771 	}
772 
773 	/* Make sure pages are in the correct state */
774 	for (i = 0; i < vdso32_pages; i++) {
775 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
776 		ClearPageReserved(pg);
777 		get_page(pg);
778 
779 	}
780 #ifdef CONFIG_PPC64
781 	for (i = 0; i < vdso64_pages; i++) {
782 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
783 		ClearPageReserved(pg);
784 		get_page(pg);
785 	}
786 #endif /* CONFIG_PPC64 */
787 
788 	get_page(virt_to_page(vdso_data));
789 }
790 
791 int in_gate_area_no_task(unsigned long addr)
792 {
793 	return 0;
794 }
795 
796 int in_gate_area(struct task_struct *task, unsigned long addr)
797 {
798 	return 0;
799 }
800 
801 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
802 {
803 	return NULL;
804 }
805 
806