xref: /openbmc/linux/arch/powerpc/kernel/vdso.c (revision a09d2831)
1 
2 /*
3  *    Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
4  *			 <benh@kernel.crashing.org>
5  *
6  *  This program is free software; you can redistribute it and/or
7  *  modify it under the terms of the GNU General Public License
8  *  as published by the Free Software Foundation; either version
9  *  2 of the License, or (at your option) any later version.
10  */
11 
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/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 #include <linux/lmb.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/prom.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 #include "setup.h"
41 
42 #undef DEBUG
43 
44 #ifdef DEBUG
45 #define DBG(fmt...) printk(fmt)
46 #else
47 #define DBG(fmt...)
48 #endif
49 
50 /* Max supported size for symbol names */
51 #define MAX_SYMNAME	64
52 
53 /* The alignment of the vDSO */
54 #define VDSO_ALIGNMENT	(1 << 16)
55 
56 extern char vdso32_start, vdso32_end;
57 static void *vdso32_kbase = &vdso32_start;
58 static unsigned int vdso32_pages;
59 static struct page **vdso32_pagelist;
60 unsigned long vdso32_sigtramp;
61 unsigned long vdso32_rt_sigtramp;
62 
63 #ifdef CONFIG_PPC64
64 extern char vdso64_start, vdso64_end;
65 static void *vdso64_kbase = &vdso64_start;
66 static unsigned int vdso64_pages;
67 static struct page **vdso64_pagelist;
68 unsigned long vdso64_rt_sigtramp;
69 #endif /* CONFIG_PPC64 */
70 
71 static int vdso_ready;
72 
73 /*
74  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
75  * Once the early boot kernel code no longer needs to muck around
76  * with it, it will become dynamically allocated
77  */
78 static union {
79 	struct vdso_data	data;
80 	u8			page[PAGE_SIZE];
81 } vdso_data_store __page_aligned_data;
82 struct vdso_data *vdso_data = &vdso_data_store.data;
83 
84 /* Format of the patch table */
85 struct vdso_patch_def
86 {
87 	unsigned long	ftr_mask, ftr_value;
88 	const char	*gen_name;
89 	const char	*fix_name;
90 };
91 
92 /* Table of functions to patch based on the CPU type/revision
93  *
94  * Currently, we only change sync_dicache to do nothing on processors
95  * with a coherent icache
96  */
97 static struct vdso_patch_def vdso_patches[] = {
98 	{
99 		CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
100 		"__kernel_sync_dicache", "__kernel_sync_dicache_p5"
101 	},
102 	{
103 		CPU_FTR_USE_TB, 0,
104 		"__kernel_gettimeofday", NULL
105 	},
106 	{
107 		CPU_FTR_USE_TB, 0,
108 		"__kernel_clock_gettime", NULL
109 	},
110 	{
111 		CPU_FTR_USE_TB, 0,
112 		"__kernel_clock_getres", NULL
113 	},
114 	{
115 		CPU_FTR_USE_TB, 0,
116 		"__kernel_get_tbfreq", NULL
117 	},
118 };
119 
120 /*
121  * Some infos carried around for each of them during parsing at
122  * boot time.
123  */
124 struct lib32_elfinfo
125 {
126 	Elf32_Ehdr	*hdr;		/* ptr to ELF */
127 	Elf32_Sym	*dynsym;	/* ptr to .dynsym section */
128 	unsigned long	dynsymsize;	/* size of .dynsym section */
129 	char		*dynstr;	/* ptr to .dynstr section */
130 	unsigned long	text;		/* offset of .text section in .so */
131 };
132 
133 struct lib64_elfinfo
134 {
135 	Elf64_Ehdr	*hdr;
136 	Elf64_Sym	*dynsym;
137 	unsigned long	dynsymsize;
138 	char		*dynstr;
139 	unsigned long	text;
140 };
141 
142 
143 #ifdef __DEBUG
144 static void dump_one_vdso_page(struct page *pg, struct page *upg)
145 {
146 	printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
147 	       page_count(pg),
148 	       pg->flags);
149 	if (upg && !IS_ERR(upg) /* && pg != upg*/) {
150 		printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
151 						       << PAGE_SHIFT),
152 		       page_count(upg),
153 		       upg->flags);
154 	}
155 	printk("\n");
156 }
157 
158 static void dump_vdso_pages(struct vm_area_struct * vma)
159 {
160 	int i;
161 
162 	if (!vma || test_thread_flag(TIF_32BIT)) {
163 		printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
164 		for (i=0; i<vdso32_pages; i++) {
165 			struct page *pg = virt_to_page(vdso32_kbase +
166 						       i*PAGE_SIZE);
167 			struct page *upg = (vma && vma->vm_mm) ?
168 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
169 				: NULL;
170 			dump_one_vdso_page(pg, upg);
171 		}
172 	}
173 	if (!vma || !test_thread_flag(TIF_32BIT)) {
174 		printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
175 		for (i=0; i<vdso64_pages; i++) {
176 			struct page *pg = virt_to_page(vdso64_kbase +
177 						       i*PAGE_SIZE);
178 			struct page *upg = (vma && vma->vm_mm) ?
179 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
180 				: NULL;
181 			dump_one_vdso_page(pg, upg);
182 		}
183 	}
184 }
185 #endif /* DEBUG */
186 
187 /*
188  * This is called from binfmt_elf, we create the special vma for the
189  * vDSO and insert it into the mm struct tree
190  */
191 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
192 {
193 	struct mm_struct *mm = current->mm;
194 	struct page **vdso_pagelist;
195 	unsigned long vdso_pages;
196 	unsigned long vdso_base;
197 	int rc;
198 
199 	if (!vdso_ready)
200 		return 0;
201 
202 #ifdef CONFIG_PPC64
203 	if (test_thread_flag(TIF_32BIT)) {
204 		vdso_pagelist = vdso32_pagelist;
205 		vdso_pages = vdso32_pages;
206 		vdso_base = VDSO32_MBASE;
207 	} else {
208 		vdso_pagelist = vdso64_pagelist;
209 		vdso_pages = vdso64_pages;
210 		/*
211 		 * On 64bit we don't have a preferred map address. This
212 		 * allows get_unmapped_area to find an area near other mmaps
213 		 * and most likely share a SLB entry.
214 		 */
215 		vdso_base = 0;
216 	}
217 #else
218 	vdso_pagelist = vdso32_pagelist;
219 	vdso_pages = vdso32_pages;
220 	vdso_base = VDSO32_MBASE;
221 #endif
222 
223 	current->mm->context.vdso_base = 0;
224 
225 	/* vDSO has a problem and was disabled, just don't "enable" it for the
226 	 * process
227 	 */
228 	if (vdso_pages == 0)
229 		return 0;
230 	/* Add a page to the vdso size for the data page */
231 	vdso_pages ++;
232 
233 	/*
234 	 * pick a base address for the vDSO in process space. We try to put it
235 	 * at vdso_base which is the "natural" base for it, but we might fail
236 	 * and end up putting it elsewhere.
237 	 * Add enough to the size so that the result can be aligned.
238 	 */
239 	down_write(&mm->mmap_sem);
240 	vdso_base = get_unmapped_area(NULL, vdso_base,
241 				      (vdso_pages << PAGE_SHIFT) +
242 				      ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
243 				      0, 0);
244 	if (IS_ERR_VALUE(vdso_base)) {
245 		rc = vdso_base;
246 		goto fail_mmapsem;
247 	}
248 
249 	/* Add required alignment. */
250 	vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
251 
252 	/*
253 	 * Put vDSO base into mm struct. We need to do this before calling
254 	 * install_special_mapping or the perf counter mmap tracking code
255 	 * will fail to recognise it as a vDSO (since arch_vma_name fails).
256 	 */
257 	current->mm->context.vdso_base = vdso_base;
258 
259 	/*
260 	 * our vma flags don't have VM_WRITE so by default, the process isn't
261 	 * allowed to write those pages.
262 	 * gdb can break that with ptrace interface, and thus trigger COW on
263 	 * those pages but it's then your responsibility to never do that on
264 	 * the "data" page of the vDSO or you'll stop getting kernel updates
265 	 * and your nice userland gettimeofday will be totally dead.
266 	 * It's fine to use that for setting breakpoints in the vDSO code
267 	 * pages though
268 	 *
269 	 * Make sure the vDSO gets into every core dump.
270 	 * Dumping its contents makes post-mortem fully interpretable later
271 	 * without matching up the same kernel and hardware config to see
272 	 * what PC values meant.
273 	 */
274 	rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
275 				     VM_READ|VM_EXEC|
276 				     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
277 				     VM_ALWAYSDUMP,
278 				     vdso_pagelist);
279 	if (rc) {
280 		current->mm->context.vdso_base = 0;
281 		goto fail_mmapsem;
282 	}
283 
284 	up_write(&mm->mmap_sem);
285 	return 0;
286 
287  fail_mmapsem:
288 	up_write(&mm->mmap_sem);
289 	return rc;
290 }
291 
292 const char *arch_vma_name(struct vm_area_struct *vma)
293 {
294 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
295 		return "[vdso]";
296 	return NULL;
297 }
298 
299 
300 
301 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
302 				  unsigned long *size)
303 {
304 	Elf32_Shdr *sechdrs;
305 	unsigned int i;
306 	char *secnames;
307 
308 	/* Grab section headers and strings so we can tell who is who */
309 	sechdrs = (void *)ehdr + ehdr->e_shoff;
310 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
311 
312 	/* Find the section they want */
313 	for (i = 1; i < ehdr->e_shnum; i++) {
314 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
315 			if (size)
316 				*size = sechdrs[i].sh_size;
317 			return (void *)ehdr + sechdrs[i].sh_offset;
318 		}
319 	}
320 	*size = 0;
321 	return NULL;
322 }
323 
324 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
325 					const char *symname)
326 {
327 	unsigned int i;
328 	char name[MAX_SYMNAME], *c;
329 
330 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
331 		if (lib->dynsym[i].st_name == 0)
332 			continue;
333 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
334 			MAX_SYMNAME);
335 		c = strchr(name, '@');
336 		if (c)
337 			*c = 0;
338 		if (strcmp(symname, name) == 0)
339 			return &lib->dynsym[i];
340 	}
341 	return NULL;
342 }
343 
344 /* Note that we assume the section is .text and the symbol is relative to
345  * the library base
346  */
347 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
348 					    const char *symname)
349 {
350 	Elf32_Sym *sym = find_symbol32(lib, symname);
351 
352 	if (sym == NULL) {
353 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
354 		       symname);
355 		return 0;
356 	}
357 	return sym->st_value - VDSO32_LBASE;
358 }
359 
360 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
361 				       struct lib64_elfinfo *v64,
362 				       const char *orig, const char *fix)
363 {
364 	Elf32_Sym *sym32_gen, *sym32_fix;
365 
366 	sym32_gen = find_symbol32(v32, orig);
367 	if (sym32_gen == NULL) {
368 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
369 		return -1;
370 	}
371 	if (fix == NULL) {
372 		sym32_gen->st_name = 0;
373 		return 0;
374 	}
375 	sym32_fix = find_symbol32(v32, fix);
376 	if (sym32_fix == NULL) {
377 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
378 		return -1;
379 	}
380 	sym32_gen->st_value = sym32_fix->st_value;
381 	sym32_gen->st_size = sym32_fix->st_size;
382 	sym32_gen->st_info = sym32_fix->st_info;
383 	sym32_gen->st_other = sym32_fix->st_other;
384 	sym32_gen->st_shndx = sym32_fix->st_shndx;
385 
386 	return 0;
387 }
388 
389 
390 #ifdef CONFIG_PPC64
391 
392 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
393 				  unsigned long *size)
394 {
395 	Elf64_Shdr *sechdrs;
396 	unsigned int i;
397 	char *secnames;
398 
399 	/* Grab section headers and strings so we can tell who is who */
400 	sechdrs = (void *)ehdr + ehdr->e_shoff;
401 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
402 
403 	/* Find the section they want */
404 	for (i = 1; i < ehdr->e_shnum; i++) {
405 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
406 			if (size)
407 				*size = sechdrs[i].sh_size;
408 			return (void *)ehdr + sechdrs[i].sh_offset;
409 		}
410 	}
411 	if (size)
412 		*size = 0;
413 	return NULL;
414 }
415 
416 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
417 					const char *symname)
418 {
419 	unsigned int i;
420 	char name[MAX_SYMNAME], *c;
421 
422 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
423 		if (lib->dynsym[i].st_name == 0)
424 			continue;
425 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
426 			MAX_SYMNAME);
427 		c = strchr(name, '@');
428 		if (c)
429 			*c = 0;
430 		if (strcmp(symname, name) == 0)
431 			return &lib->dynsym[i];
432 	}
433 	return NULL;
434 }
435 
436 /* Note that we assume the section is .text and the symbol is relative to
437  * the library base
438  */
439 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
440 					    const char *symname)
441 {
442 	Elf64_Sym *sym = find_symbol64(lib, symname);
443 
444 	if (sym == NULL) {
445 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
446 		       symname);
447 		return 0;
448 	}
449 #ifdef VDS64_HAS_DESCRIPTORS
450 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
451 		VDSO64_LBASE;
452 #else
453 	return sym->st_value - VDSO64_LBASE;
454 #endif
455 }
456 
457 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
458 				       struct lib64_elfinfo *v64,
459 				       const char *orig, const char *fix)
460 {
461 	Elf64_Sym *sym64_gen, *sym64_fix;
462 
463 	sym64_gen = find_symbol64(v64, orig);
464 	if (sym64_gen == NULL) {
465 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
466 		return -1;
467 	}
468 	if (fix == NULL) {
469 		sym64_gen->st_name = 0;
470 		return 0;
471 	}
472 	sym64_fix = find_symbol64(v64, fix);
473 	if (sym64_fix == NULL) {
474 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
475 		return -1;
476 	}
477 	sym64_gen->st_value = sym64_fix->st_value;
478 	sym64_gen->st_size = sym64_fix->st_size;
479 	sym64_gen->st_info = sym64_fix->st_info;
480 	sym64_gen->st_other = sym64_fix->st_other;
481 	sym64_gen->st_shndx = sym64_fix->st_shndx;
482 
483 	return 0;
484 }
485 
486 #endif /* CONFIG_PPC64 */
487 
488 
489 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
490 					struct lib64_elfinfo *v64)
491 {
492 	void *sect;
493 
494 	/*
495 	 * Locate symbol tables & text section
496 	 */
497 
498 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
499 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
500 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
501 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
502 		return -1;
503 	}
504 	sect = find_section32(v32->hdr, ".text", NULL);
505 	if (sect == NULL) {
506 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
507 		return -1;
508 	}
509 	v32->text = sect - vdso32_kbase;
510 
511 #ifdef CONFIG_PPC64
512 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
513 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
514 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
515 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
516 		return -1;
517 	}
518 	sect = find_section64(v64->hdr, ".text", NULL);
519 	if (sect == NULL) {
520 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
521 		return -1;
522 	}
523 	v64->text = sect - vdso64_kbase;
524 #endif /* CONFIG_PPC64 */
525 
526 	return 0;
527 }
528 
529 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
530 					  struct lib64_elfinfo *v64)
531 {
532 	/*
533 	 * Find signal trampolines
534 	 */
535 
536 #ifdef CONFIG_PPC64
537 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
538 #endif
539 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
540 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
541 }
542 
543 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
544 				       struct lib64_elfinfo *v64)
545 {
546 	Elf32_Sym *sym32;
547 #ifdef CONFIG_PPC64
548 	Elf64_Sym *sym64;
549 
550        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
551 	if (sym64 == NULL) {
552 		printk(KERN_ERR "vDSO64: Can't find symbol "
553 		       "__kernel_datapage_offset !\n");
554 		return -1;
555 	}
556 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
557 		(vdso64_pages << PAGE_SHIFT) -
558 		(sym64->st_value - VDSO64_LBASE);
559 #endif /* CONFIG_PPC64 */
560 
561 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
562 	if (sym32 == NULL) {
563 		printk(KERN_ERR "vDSO32: Can't find symbol "
564 		       "__kernel_datapage_offset !\n");
565 		return -1;
566 	}
567 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
568 		(vdso32_pages << PAGE_SHIFT) -
569 		(sym32->st_value - VDSO32_LBASE);
570 
571 	return 0;
572 }
573 
574 
575 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
576 				      struct lib64_elfinfo *v64)
577 {
578 	void *start32;
579 	unsigned long size32;
580 
581 #ifdef CONFIG_PPC64
582 	void *start64;
583 	unsigned long size64;
584 
585 	start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
586 	if (start64)
587 		do_feature_fixups(cur_cpu_spec->cpu_features,
588 				  start64, start64 + size64);
589 
590 	start64 = find_section64(v64->hdr, "__mmu_ftr_fixup", &size64);
591 	if (start64)
592 		do_feature_fixups(cur_cpu_spec->mmu_features,
593 				  start64, start64 + size64);
594 
595 	start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
596 	if (start64)
597 		do_feature_fixups(powerpc_firmware_features,
598 				  start64, start64 + size64);
599 
600 	start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
601 	if (start64)
602 		do_lwsync_fixups(cur_cpu_spec->cpu_features,
603 				 start64, start64 + size64);
604 #endif /* CONFIG_PPC64 */
605 
606 	start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
607 	if (start32)
608 		do_feature_fixups(cur_cpu_spec->cpu_features,
609 				  start32, start32 + size32);
610 
611 	start32 = find_section32(v32->hdr, "__mmu_ftr_fixup", &size32);
612 	if (start32)
613 		do_feature_fixups(cur_cpu_spec->mmu_features,
614 				  start32, start32 + size32);
615 
616 #ifdef CONFIG_PPC64
617 	start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
618 	if (start32)
619 		do_feature_fixups(powerpc_firmware_features,
620 				  start32, start32 + size32);
621 #endif /* CONFIG_PPC64 */
622 
623 	start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
624 	if (start32)
625 		do_lwsync_fixups(cur_cpu_spec->cpu_features,
626 				 start32, start32 + size32);
627 
628 	return 0;
629 }
630 
631 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
632 				       struct lib64_elfinfo *v64)
633 {
634 	int i;
635 
636 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
637 		struct vdso_patch_def *patch = &vdso_patches[i];
638 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
639 			== patch->ftr_value;
640 		if (!match)
641 			continue;
642 
643 		DBG("replacing %s with %s...\n", patch->gen_name,
644 		    patch->fix_name ? "NONE" : patch->fix_name);
645 
646 		/*
647 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
648 		 * patch the "." symbol on 64 bits.
649 		 * It would be easy to do, but doesn't seem to be necessary,
650 		 * patching the OPD symbol is enough.
651 		 */
652 		vdso_do_func_patch32(v32, v64, patch->gen_name,
653 				     patch->fix_name);
654 #ifdef CONFIG_PPC64
655 		vdso_do_func_patch64(v32, v64, patch->gen_name,
656 				     patch->fix_name);
657 #endif /* CONFIG_PPC64 */
658 	}
659 
660 	return 0;
661 }
662 
663 
664 static __init int vdso_setup(void)
665 {
666 	struct lib32_elfinfo	v32;
667 	struct lib64_elfinfo	v64;
668 
669 	v32.hdr = vdso32_kbase;
670 #ifdef CONFIG_PPC64
671 	v64.hdr = vdso64_kbase;
672 #endif
673 	if (vdso_do_find_sections(&v32, &v64))
674 		return -1;
675 
676 	if (vdso_fixup_datapage(&v32, &v64))
677 		return -1;
678 
679 	if (vdso_fixup_features(&v32, &v64))
680 		return -1;
681 
682 	if (vdso_fixup_alt_funcs(&v32, &v64))
683 		return -1;
684 
685 	vdso_setup_trampolines(&v32, &v64);
686 
687 	return 0;
688 }
689 
690 /*
691  * Called from setup_arch to initialize the bitmap of available
692  * syscalls in the systemcfg page
693  */
694 static void __init vdso_setup_syscall_map(void)
695 {
696 	unsigned int i;
697 	extern unsigned long *sys_call_table;
698 	extern unsigned long sys_ni_syscall;
699 
700 
701 	for (i = 0; i < __NR_syscalls; i++) {
702 #ifdef CONFIG_PPC64
703 		if (sys_call_table[i*2] != sys_ni_syscall)
704 			vdso_data->syscall_map_64[i >> 5] |=
705 				0x80000000UL >> (i & 0x1f);
706 		if (sys_call_table[i*2+1] != sys_ni_syscall)
707 			vdso_data->syscall_map_32[i >> 5] |=
708 				0x80000000UL >> (i & 0x1f);
709 #else /* CONFIG_PPC64 */
710 		if (sys_call_table[i] != sys_ni_syscall)
711 			vdso_data->syscall_map_32[i >> 5] |=
712 				0x80000000UL >> (i & 0x1f);
713 #endif /* CONFIG_PPC64 */
714 	}
715 }
716 
717 
718 static int __init vdso_init(void)
719 {
720 	int i;
721 
722 #ifdef CONFIG_PPC64
723 	/*
724 	 * Fill up the "systemcfg" stuff for backward compatibility
725 	 */
726 	strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
727 	vdso_data->version.major = SYSTEMCFG_MAJOR;
728 	vdso_data->version.minor = SYSTEMCFG_MINOR;
729 	vdso_data->processor = mfspr(SPRN_PVR);
730 	/*
731 	 * Fake the old platform number for pSeries and iSeries and add
732 	 * in LPAR bit if necessary
733 	 */
734 	vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
735 	if (firmware_has_feature(FW_FEATURE_LPAR))
736 		vdso_data->platform |= 1;
737 	vdso_data->physicalMemorySize = lmb_phys_mem_size();
738 	vdso_data->dcache_size = ppc64_caches.dsize;
739 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
740 	vdso_data->icache_size = ppc64_caches.isize;
741 	vdso_data->icache_line_size = ppc64_caches.iline_size;
742 
743 	/* XXXOJN: Blocks should be added to ppc64_caches and used instead */
744 	vdso_data->dcache_block_size = ppc64_caches.dline_size;
745 	vdso_data->icache_block_size = ppc64_caches.iline_size;
746 	vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
747 	vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
748 
749 	/*
750 	 * Calculate the size of the 64 bits vDSO
751 	 */
752 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
753 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
754 #else
755 	vdso_data->dcache_block_size = L1_CACHE_BYTES;
756 	vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
757 	vdso_data->icache_block_size = L1_CACHE_BYTES;
758 	vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
759 #endif /* CONFIG_PPC64 */
760 
761 
762 	/*
763 	 * Calculate the size of the 32 bits vDSO
764 	 */
765 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
766 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
767 
768 
769 	/*
770 	 * Setup the syscall map in the vDOS
771 	 */
772 	vdso_setup_syscall_map();
773 
774 	/*
775 	 * Initialize the vDSO images in memory, that is do necessary
776 	 * fixups of vDSO symbols, locate trampolines, etc...
777 	 */
778 	if (vdso_setup()) {
779 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
780 		vdso32_pages = 0;
781 #ifdef CONFIG_PPC64
782 		vdso64_pages = 0;
783 #endif
784 		return 0;
785 	}
786 
787 	/* Make sure pages are in the correct state */
788 	vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
789 				  GFP_KERNEL);
790 	BUG_ON(vdso32_pagelist == NULL);
791 	for (i = 0; i < vdso32_pages; i++) {
792 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
793 		ClearPageReserved(pg);
794 		get_page(pg);
795 		vdso32_pagelist[i] = pg;
796 	}
797 	vdso32_pagelist[i++] = virt_to_page(vdso_data);
798 	vdso32_pagelist[i] = NULL;
799 
800 #ifdef CONFIG_PPC64
801 	vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
802 				  GFP_KERNEL);
803 	BUG_ON(vdso64_pagelist == NULL);
804 	for (i = 0; i < vdso64_pages; i++) {
805 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
806 		ClearPageReserved(pg);
807 		get_page(pg);
808 		vdso64_pagelist[i] = pg;
809 	}
810 	vdso64_pagelist[i++] = virt_to_page(vdso_data);
811 	vdso64_pagelist[i] = NULL;
812 #endif /* CONFIG_PPC64 */
813 
814 	get_page(virt_to_page(vdso_data));
815 
816 	smp_wmb();
817 	vdso_ready = 1;
818 
819 	return 0;
820 }
821 arch_initcall(vdso_init);
822 
823 int in_gate_area_no_task(unsigned long addr)
824 {
825 	return 0;
826 }
827 
828 int in_gate_area(struct task_struct *task, unsigned long addr)
829 {
830 	return 0;
831 }
832 
833 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
834 {
835 	return NULL;
836 }
837 
838