xref: /openbmc/linux/arch/powerpc/kernel/vdso.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/slab.h>
20 #include <linux/user.h>
21 #include <linux/elf.h>
22 #include <linux/security.h>
23 #include <linux/bootmem.h>
24 #include <linux/lmb.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/prom.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 static unsigned int vdso32_pages;
55 static struct page **vdso32_pagelist;
56 unsigned long vdso32_sigtramp;
57 unsigned long vdso32_rt_sigtramp;
58 
59 #ifdef CONFIG_PPC64
60 extern char vdso64_start, vdso64_end;
61 static void *vdso64_kbase = &vdso64_start;
62 static unsigned int vdso64_pages;
63 static struct page **vdso64_pagelist;
64 unsigned long vdso64_rt_sigtramp;
65 #endif /* CONFIG_PPC64 */
66 
67 static int vdso_ready;
68 
69 /*
70  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
71  * Once the early boot kernel code no longer needs to muck around
72  * with it, it will become dynamically allocated
73  */
74 static union {
75 	struct vdso_data	data;
76 	u8			page[PAGE_SIZE];
77 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
78 struct vdso_data *vdso_data = &vdso_data_store.data;
79 
80 /* Format of the patch table */
81 struct vdso_patch_def
82 {
83 	unsigned long	ftr_mask, ftr_value;
84 	const char	*gen_name;
85 	const char	*fix_name;
86 };
87 
88 /* Table of functions to patch based on the CPU type/revision
89  *
90  * Currently, we only change sync_dicache to do nothing on processors
91  * with a coherent icache
92  */
93 static struct vdso_patch_def vdso_patches[] = {
94 	{
95 		CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
96 		"__kernel_sync_dicache", "__kernel_sync_dicache_p5"
97 	},
98 	{
99 		CPU_FTR_USE_TB, 0,
100 		"__kernel_gettimeofday", NULL
101 	},
102 	{
103 		CPU_FTR_USE_TB, 0,
104 		"__kernel_clock_gettime", NULL
105 	},
106 	{
107 		CPU_FTR_USE_TB, 0,
108 		"__kernel_clock_getres", NULL
109 	},
110 	{
111 		CPU_FTR_USE_TB, 0,
112 		"__kernel_get_tbfreq", NULL
113 	},
114 };
115 
116 /*
117  * Some infos carried around for each of them during parsing at
118  * boot time.
119  */
120 struct lib32_elfinfo
121 {
122 	Elf32_Ehdr	*hdr;		/* ptr to ELF */
123 	Elf32_Sym	*dynsym;	/* ptr to .dynsym section */
124 	unsigned long	dynsymsize;	/* size of .dynsym section */
125 	char		*dynstr;	/* ptr to .dynstr section */
126 	unsigned long	text;		/* offset of .text section in .so */
127 };
128 
129 struct lib64_elfinfo
130 {
131 	Elf64_Ehdr	*hdr;
132 	Elf64_Sym	*dynsym;
133 	unsigned long	dynsymsize;
134 	char		*dynstr;
135 	unsigned long	text;
136 };
137 
138 
139 #ifdef __DEBUG
140 static void dump_one_vdso_page(struct page *pg, struct page *upg)
141 {
142 	printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
143 	       page_count(pg),
144 	       pg->flags);
145 	if (upg && !IS_ERR(upg) /* && pg != upg*/) {
146 		printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
147 						       << PAGE_SHIFT),
148 		       page_count(upg),
149 		       upg->flags);
150 	}
151 	printk("\n");
152 }
153 
154 static void dump_vdso_pages(struct vm_area_struct * vma)
155 {
156 	int i;
157 
158 	if (!vma || test_thread_flag(TIF_32BIT)) {
159 		printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
160 		for (i=0; i<vdso32_pages; i++) {
161 			struct page *pg = virt_to_page(vdso32_kbase +
162 						       i*PAGE_SIZE);
163 			struct page *upg = (vma && vma->vm_mm) ?
164 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
165 				: NULL;
166 			dump_one_vdso_page(pg, upg);
167 		}
168 	}
169 	if (!vma || !test_thread_flag(TIF_32BIT)) {
170 		printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
171 		for (i=0; i<vdso64_pages; i++) {
172 			struct page *pg = virt_to_page(vdso64_kbase +
173 						       i*PAGE_SIZE);
174 			struct page *upg = (vma && vma->vm_mm) ?
175 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
176 				: NULL;
177 			dump_one_vdso_page(pg, upg);
178 		}
179 	}
180 }
181 #endif /* DEBUG */
182 
183 /*
184  * This is called from binfmt_elf, we create the special vma for the
185  * vDSO and insert it into the mm struct tree
186  */
187 int arch_setup_additional_pages(struct linux_binprm *bprm,
188 				int executable_stack)
189 {
190 	struct mm_struct *mm = current->mm;
191 	struct page **vdso_pagelist;
192 	unsigned long vdso_pages;
193 	unsigned long vdso_base;
194 	int rc;
195 
196 	if (!vdso_ready)
197 		return 0;
198 
199 #ifdef CONFIG_PPC64
200 	if (test_thread_flag(TIF_32BIT)) {
201 		vdso_pagelist = vdso32_pagelist;
202 		vdso_pages = vdso32_pages;
203 		vdso_base = VDSO32_MBASE;
204 	} else {
205 		vdso_pagelist = vdso64_pagelist;
206 		vdso_pages = vdso64_pages;
207 		vdso_base = VDSO64_MBASE;
208 	}
209 #else
210 	vdso_pagelist = vdso32_pagelist;
211 	vdso_pages = vdso32_pages;
212 	vdso_base = VDSO32_MBASE;
213 #endif
214 
215 	current->mm->context.vdso_base = 0;
216 
217 	/* vDSO has a problem and was disabled, just don't "enable" it for the
218 	 * process
219 	 */
220 	if (vdso_pages == 0)
221 		return 0;
222 	/* Add a page to the vdso size for the data page */
223 	vdso_pages ++;
224 
225 	/*
226 	 * pick a base address for the vDSO in process space. We try to put it
227 	 * at vdso_base which is the "natural" base for it, but we might fail
228 	 * and end up putting it elsewhere.
229 	 */
230 	down_write(&mm->mmap_sem);
231 	vdso_base = get_unmapped_area(NULL, vdso_base,
232 				      vdso_pages << PAGE_SHIFT, 0, 0);
233 	if (IS_ERR_VALUE(vdso_base)) {
234 		rc = vdso_base;
235 		goto fail_mmapsem;
236 	}
237 
238 	/*
239 	 * our vma flags don't have VM_WRITE so by default, the process isn't
240 	 * allowed to write those pages.
241 	 * gdb can break that with ptrace interface, and thus trigger COW on
242 	 * those pages but it's then your responsibility to never do that on
243 	 * the "data" page of the vDSO or you'll stop getting kernel updates
244 	 * and your nice userland gettimeofday will be totally dead.
245 	 * It's fine to use that for setting breakpoints in the vDSO code
246 	 * pages though
247 	 *
248 	 * Make sure the vDSO gets into every core dump.
249 	 * Dumping its contents makes post-mortem fully interpretable later
250 	 * without matching up the same kernel and hardware config to see
251 	 * what PC values meant.
252 	 */
253 	rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
254 				     VM_READ|VM_EXEC|
255 				     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
256 				     VM_ALWAYSDUMP,
257 				     vdso_pagelist);
258 	if (rc)
259 		goto fail_mmapsem;
260 
261 	/* Put vDSO base into mm struct */
262 	current->mm->context.vdso_base = vdso_base;
263 
264 	up_write(&mm->mmap_sem);
265 	return 0;
266 
267  fail_mmapsem:
268 	up_write(&mm->mmap_sem);
269 	return rc;
270 }
271 
272 const char *arch_vma_name(struct vm_area_struct *vma)
273 {
274 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
275 		return "[vdso]";
276 	return NULL;
277 }
278 
279 
280 
281 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
282 				  unsigned long *size)
283 {
284 	Elf32_Shdr *sechdrs;
285 	unsigned int i;
286 	char *secnames;
287 
288 	/* Grab section headers and strings so we can tell who is who */
289 	sechdrs = (void *)ehdr + ehdr->e_shoff;
290 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
291 
292 	/* Find the section they want */
293 	for (i = 1; i < ehdr->e_shnum; i++) {
294 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
295 			if (size)
296 				*size = sechdrs[i].sh_size;
297 			return (void *)ehdr + sechdrs[i].sh_offset;
298 		}
299 	}
300 	*size = 0;
301 	return NULL;
302 }
303 
304 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
305 					const char *symname)
306 {
307 	unsigned int i;
308 	char name[MAX_SYMNAME], *c;
309 
310 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
311 		if (lib->dynsym[i].st_name == 0)
312 			continue;
313 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
314 			MAX_SYMNAME);
315 		c = strchr(name, '@');
316 		if (c)
317 			*c = 0;
318 		if (strcmp(symname, name) == 0)
319 			return &lib->dynsym[i];
320 	}
321 	return NULL;
322 }
323 
324 /* Note that we assume the section is .text and the symbol is relative to
325  * the library base
326  */
327 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
328 					    const char *symname)
329 {
330 	Elf32_Sym *sym = find_symbol32(lib, symname);
331 
332 	if (sym == NULL) {
333 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
334 		       symname);
335 		return 0;
336 	}
337 	return sym->st_value - VDSO32_LBASE;
338 }
339 
340 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
341 				       struct lib64_elfinfo *v64,
342 				       const char *orig, const char *fix)
343 {
344 	Elf32_Sym *sym32_gen, *sym32_fix;
345 
346 	sym32_gen = find_symbol32(v32, orig);
347 	if (sym32_gen == NULL) {
348 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
349 		return -1;
350 	}
351 	if (fix == NULL) {
352 		sym32_gen->st_name = 0;
353 		return 0;
354 	}
355 	sym32_fix = find_symbol32(v32, fix);
356 	if (sym32_fix == NULL) {
357 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
358 		return -1;
359 	}
360 	sym32_gen->st_value = sym32_fix->st_value;
361 	sym32_gen->st_size = sym32_fix->st_size;
362 	sym32_gen->st_info = sym32_fix->st_info;
363 	sym32_gen->st_other = sym32_fix->st_other;
364 	sym32_gen->st_shndx = sym32_fix->st_shndx;
365 
366 	return 0;
367 }
368 
369 
370 #ifdef CONFIG_PPC64
371 
372 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
373 				  unsigned long *size)
374 {
375 	Elf64_Shdr *sechdrs;
376 	unsigned int i;
377 	char *secnames;
378 
379 	/* Grab section headers and strings so we can tell who is who */
380 	sechdrs = (void *)ehdr + ehdr->e_shoff;
381 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
382 
383 	/* Find the section they want */
384 	for (i = 1; i < ehdr->e_shnum; i++) {
385 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
386 			if (size)
387 				*size = sechdrs[i].sh_size;
388 			return (void *)ehdr + sechdrs[i].sh_offset;
389 		}
390 	}
391 	if (size)
392 		*size = 0;
393 	return NULL;
394 }
395 
396 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
397 					const char *symname)
398 {
399 	unsigned int i;
400 	char name[MAX_SYMNAME], *c;
401 
402 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
403 		if (lib->dynsym[i].st_name == 0)
404 			continue;
405 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
406 			MAX_SYMNAME);
407 		c = strchr(name, '@');
408 		if (c)
409 			*c = 0;
410 		if (strcmp(symname, name) == 0)
411 			return &lib->dynsym[i];
412 	}
413 	return NULL;
414 }
415 
416 /* Note that we assume the section is .text and the symbol is relative to
417  * the library base
418  */
419 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
420 					    const char *symname)
421 {
422 	Elf64_Sym *sym = find_symbol64(lib, symname);
423 
424 	if (sym == NULL) {
425 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
426 		       symname);
427 		return 0;
428 	}
429 #ifdef VDS64_HAS_DESCRIPTORS
430 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
431 		VDSO64_LBASE;
432 #else
433 	return sym->st_value - VDSO64_LBASE;
434 #endif
435 }
436 
437 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
438 				       struct lib64_elfinfo *v64,
439 				       const char *orig, const char *fix)
440 {
441 	Elf64_Sym *sym64_gen, *sym64_fix;
442 
443 	sym64_gen = find_symbol64(v64, orig);
444 	if (sym64_gen == NULL) {
445 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
446 		return -1;
447 	}
448 	if (fix == NULL) {
449 		sym64_gen->st_name = 0;
450 		return 0;
451 	}
452 	sym64_fix = find_symbol64(v64, fix);
453 	if (sym64_fix == NULL) {
454 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
455 		return -1;
456 	}
457 	sym64_gen->st_value = sym64_fix->st_value;
458 	sym64_gen->st_size = sym64_fix->st_size;
459 	sym64_gen->st_info = sym64_fix->st_info;
460 	sym64_gen->st_other = sym64_fix->st_other;
461 	sym64_gen->st_shndx = sym64_fix->st_shndx;
462 
463 	return 0;
464 }
465 
466 #endif /* CONFIG_PPC64 */
467 
468 
469 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
470 					struct lib64_elfinfo *v64)
471 {
472 	void *sect;
473 
474 	/*
475 	 * Locate symbol tables & text section
476 	 */
477 
478 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
479 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
480 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
481 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
482 		return -1;
483 	}
484 	sect = find_section32(v32->hdr, ".text", NULL);
485 	if (sect == NULL) {
486 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
487 		return -1;
488 	}
489 	v32->text = sect - vdso32_kbase;
490 
491 #ifdef CONFIG_PPC64
492 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
493 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
494 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
495 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
496 		return -1;
497 	}
498 	sect = find_section64(v64->hdr, ".text", NULL);
499 	if (sect == NULL) {
500 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
501 		return -1;
502 	}
503 	v64->text = sect - vdso64_kbase;
504 #endif /* CONFIG_PPC64 */
505 
506 	return 0;
507 }
508 
509 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
510 					  struct lib64_elfinfo *v64)
511 {
512 	/*
513 	 * Find signal trampolines
514 	 */
515 
516 #ifdef CONFIG_PPC64
517 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
518 #endif
519 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
520 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
521 }
522 
523 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
524 				       struct lib64_elfinfo *v64)
525 {
526 	Elf32_Sym *sym32;
527 #ifdef CONFIG_PPC64
528 	Elf64_Sym *sym64;
529 
530        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
531 	if (sym64 == NULL) {
532 		printk(KERN_ERR "vDSO64: Can't find symbol "
533 		       "__kernel_datapage_offset !\n");
534 		return -1;
535 	}
536 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
537 		(vdso64_pages << PAGE_SHIFT) -
538 		(sym64->st_value - VDSO64_LBASE);
539 #endif /* CONFIG_PPC64 */
540 
541 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
542 	if (sym32 == NULL) {
543 		printk(KERN_ERR "vDSO32: Can't find symbol "
544 		       "__kernel_datapage_offset !\n");
545 		return -1;
546 	}
547 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
548 		(vdso32_pages << PAGE_SHIFT) -
549 		(sym32->st_value - VDSO32_LBASE);
550 
551 	return 0;
552 }
553 
554 
555 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
556 				      struct lib64_elfinfo *v64)
557 {
558 	void *start32;
559 	unsigned long size32;
560 
561 #ifdef CONFIG_PPC64
562 	void *start64;
563 	unsigned long size64;
564 
565 	start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
566 	if (start64)
567 		do_feature_fixups(cur_cpu_spec->cpu_features,
568 				  start64, start64 + size64);
569 
570 	start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
571 	if (start64)
572 		do_feature_fixups(powerpc_firmware_features,
573 				  start64, start64 + size64);
574 
575 	start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
576 	if (start64)
577 		do_lwsync_fixups(cur_cpu_spec->cpu_features,
578 				 start64, start64 + size64);
579 #endif /* CONFIG_PPC64 */
580 
581 	start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
582 	if (start32)
583 		do_feature_fixups(cur_cpu_spec->cpu_features,
584 				  start32, start32 + size32);
585 
586 #ifdef CONFIG_PPC64
587 	start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
588 	if (start32)
589 		do_feature_fixups(powerpc_firmware_features,
590 				  start32, start32 + size32);
591 #endif /* CONFIG_PPC64 */
592 
593 	start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
594 	if (start32)
595 		do_lwsync_fixups(cur_cpu_spec->cpu_features,
596 				 start32, start32 + size32);
597 
598 	return 0;
599 }
600 
601 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
602 				       struct lib64_elfinfo *v64)
603 {
604 	int i;
605 
606 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
607 		struct vdso_patch_def *patch = &vdso_patches[i];
608 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
609 			== patch->ftr_value;
610 		if (!match)
611 			continue;
612 
613 		DBG("replacing %s with %s...\n", patch->gen_name,
614 		    patch->fix_name ? "NONE" : patch->fix_name);
615 
616 		/*
617 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
618 		 * patch the "." symbol on 64 bits.
619 		 * It would be easy to do, but doesn't seem to be necessary,
620 		 * patching the OPD symbol is enough.
621 		 */
622 		vdso_do_func_patch32(v32, v64, patch->gen_name,
623 				     patch->fix_name);
624 #ifdef CONFIG_PPC64
625 		vdso_do_func_patch64(v32, v64, patch->gen_name,
626 				     patch->fix_name);
627 #endif /* CONFIG_PPC64 */
628 	}
629 
630 	return 0;
631 }
632 
633 
634 static __init int vdso_setup(void)
635 {
636 	struct lib32_elfinfo	v32;
637 	struct lib64_elfinfo	v64;
638 
639 	v32.hdr = vdso32_kbase;
640 #ifdef CONFIG_PPC64
641 	v64.hdr = vdso64_kbase;
642 #endif
643 	if (vdso_do_find_sections(&v32, &v64))
644 		return -1;
645 
646 	if (vdso_fixup_datapage(&v32, &v64))
647 		return -1;
648 
649 	if (vdso_fixup_features(&v32, &v64))
650 		return -1;
651 
652 	if (vdso_fixup_alt_funcs(&v32, &v64))
653 		return -1;
654 
655 	vdso_setup_trampolines(&v32, &v64);
656 
657 	return 0;
658 }
659 
660 /*
661  * Called from setup_arch to initialize the bitmap of available
662  * syscalls in the systemcfg page
663  */
664 static void __init vdso_setup_syscall_map(void)
665 {
666 	unsigned int i;
667 	extern unsigned long *sys_call_table;
668 	extern unsigned long sys_ni_syscall;
669 
670 
671 	for (i = 0; i < __NR_syscalls; i++) {
672 #ifdef CONFIG_PPC64
673 		if (sys_call_table[i*2] != sys_ni_syscall)
674 			vdso_data->syscall_map_64[i >> 5] |=
675 				0x80000000UL >> (i & 0x1f);
676 		if (sys_call_table[i*2+1] != sys_ni_syscall)
677 			vdso_data->syscall_map_32[i >> 5] |=
678 				0x80000000UL >> (i & 0x1f);
679 #else /* CONFIG_PPC64 */
680 		if (sys_call_table[i] != sys_ni_syscall)
681 			vdso_data->syscall_map_32[i >> 5] |=
682 				0x80000000UL >> (i & 0x1f);
683 #endif /* CONFIG_PPC64 */
684 	}
685 }
686 
687 
688 static int __init vdso_init(void)
689 {
690 	int i;
691 
692 #ifdef CONFIG_PPC64
693 	/*
694 	 * Fill up the "systemcfg" stuff for backward compatiblity
695 	 */
696 	strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
697 	vdso_data->version.major = SYSTEMCFG_MAJOR;
698 	vdso_data->version.minor = SYSTEMCFG_MINOR;
699 	vdso_data->processor = mfspr(SPRN_PVR);
700 	/*
701 	 * Fake the old platform number for pSeries and iSeries and add
702 	 * in LPAR bit if necessary
703 	 */
704 	vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
705 	if (firmware_has_feature(FW_FEATURE_LPAR))
706 		vdso_data->platform |= 1;
707 	vdso_data->physicalMemorySize = lmb_phys_mem_size();
708 	vdso_data->dcache_size = ppc64_caches.dsize;
709 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
710 	vdso_data->icache_size = ppc64_caches.isize;
711 	vdso_data->icache_line_size = ppc64_caches.iline_size;
712 
713 	/* XXXOJN: Blocks should be added to ppc64_caches and used instead */
714 	vdso_data->dcache_block_size = ppc64_caches.dline_size;
715 	vdso_data->icache_block_size = ppc64_caches.iline_size;
716 	vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
717 	vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
718 
719 	/*
720 	 * Calculate the size of the 64 bits vDSO
721 	 */
722 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
723 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
724 #else
725 	vdso_data->dcache_block_size = L1_CACHE_BYTES;
726 	vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
727 	vdso_data->icache_block_size = L1_CACHE_BYTES;
728 	vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
729 #endif /* CONFIG_PPC64 */
730 
731 
732 	/*
733 	 * Calculate the size of the 32 bits vDSO
734 	 */
735 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
736 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
737 
738 
739 	/*
740 	 * Setup the syscall map in the vDOS
741 	 */
742 	vdso_setup_syscall_map();
743 
744 	/*
745 	 * Initialize the vDSO images in memory, that is do necessary
746 	 * fixups of vDSO symbols, locate trampolines, etc...
747 	 */
748 	if (vdso_setup()) {
749 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
750 		vdso32_pages = 0;
751 #ifdef CONFIG_PPC64
752 		vdso64_pages = 0;
753 #endif
754 		return 0;
755 	}
756 
757 	/* Make sure pages are in the correct state */
758 	vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
759 				  GFP_KERNEL);
760 	BUG_ON(vdso32_pagelist == NULL);
761 	for (i = 0; i < vdso32_pages; i++) {
762 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
763 		ClearPageReserved(pg);
764 		get_page(pg);
765 		vdso32_pagelist[i] = pg;
766 	}
767 	vdso32_pagelist[i++] = virt_to_page(vdso_data);
768 	vdso32_pagelist[i] = NULL;
769 
770 #ifdef CONFIG_PPC64
771 	vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
772 				  GFP_KERNEL);
773 	BUG_ON(vdso64_pagelist == NULL);
774 	for (i = 0; i < vdso64_pages; i++) {
775 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
776 		ClearPageReserved(pg);
777 		get_page(pg);
778 		vdso64_pagelist[i] = pg;
779 	}
780 	vdso64_pagelist[i++] = virt_to_page(vdso_data);
781 	vdso64_pagelist[i] = NULL;
782 #endif /* CONFIG_PPC64 */
783 
784 	get_page(virt_to_page(vdso_data));
785 
786 	smp_wmb();
787 	vdso_ready = 1;
788 
789 	return 0;
790 }
791 #ifdef CONFIG_PPC_MERGE
792 arch_initcall(vdso_init);
793 #endif
794 
795 int in_gate_area_no_task(unsigned long addr)
796 {
797 	return 0;
798 }
799 
800 int in_gate_area(struct task_struct *task, unsigned long addr)
801 {
802 	return 0;
803 }
804 
805 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
806 {
807 	return NULL;
808 }
809 
810