xref: /openbmc/linux/arch/powerpc/kernel/vdso.c (revision b34e08d5)
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/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/memblock.h>
25 
26 #include <asm/pgtable.h>
27 #include <asm/processor.h>
28 #include <asm/mmu.h>
29 #include <asm/mmu_context.h>
30 #include <asm/prom.h>
31 #include <asm/machdep.h>
32 #include <asm/cputable.h>
33 #include <asm/sections.h>
34 #include <asm/firmware.h>
35 #include <asm/vdso.h>
36 #include <asm/vdso_datapage.h>
37 #include <asm/setup.h>
38 
39 #undef DEBUG
40 
41 #ifdef DEBUG
42 #define DBG(fmt...) printk(fmt)
43 #else
44 #define DBG(fmt...)
45 #endif
46 
47 /* Max supported size for symbol names */
48 #define MAX_SYMNAME	64
49 
50 /* The alignment of the vDSO */
51 #define VDSO_ALIGNMENT	(1 << 16)
52 
53 extern char vdso32_start, vdso32_end;
54 static void *vdso32_kbase = &vdso32_start;
55 static unsigned int vdso32_pages;
56 static struct page **vdso32_pagelist;
57 unsigned long vdso32_sigtramp;
58 unsigned long vdso32_rt_sigtramp;
59 
60 #ifdef CONFIG_PPC64
61 extern char vdso64_start, vdso64_end;
62 static void *vdso64_kbase = &vdso64_start;
63 static unsigned int vdso64_pages;
64 static struct page **vdso64_pagelist;
65 unsigned long vdso64_rt_sigtramp;
66 #endif /* CONFIG_PPC64 */
67 
68 static int vdso_ready;
69 
70 /*
71  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
72  * Once the early boot kernel code no longer needs to muck around
73  * with it, it will become dynamically allocated
74  */
75 static union {
76 	struct vdso_data	data;
77 	u8			page[PAGE_SIZE];
78 } vdso_data_store __page_aligned_data;
79 struct vdso_data *vdso_data = &vdso_data_store.data;
80 
81 /* Format of the patch table */
82 struct vdso_patch_def
83 {
84 	unsigned long	ftr_mask, ftr_value;
85 	const char	*gen_name;
86 	const char	*fix_name;
87 };
88 
89 /* Table of functions to patch based on the CPU type/revision
90  *
91  * Currently, we only change sync_dicache to do nothing on processors
92  * with a coherent icache
93  */
94 static struct vdso_patch_def vdso_patches[] = {
95 	{
96 		CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
97 		"__kernel_sync_dicache", "__kernel_sync_dicache_p5"
98 	},
99 	{
100 		CPU_FTR_USE_TB, 0,
101 		"__kernel_gettimeofday", NULL
102 	},
103 	{
104 		CPU_FTR_USE_TB, 0,
105 		"__kernel_clock_gettime", NULL
106 	},
107 	{
108 		CPU_FTR_USE_TB, 0,
109 		"__kernel_clock_getres", NULL
110 	},
111 	{
112 		CPU_FTR_USE_TB, 0,
113 		"__kernel_get_tbfreq", NULL
114 	},
115 	{
116 		CPU_FTR_USE_TB, 0,
117 		"__kernel_time", NULL
118 	},
119 };
120 
121 /*
122  * Some infos carried around for each of them during parsing at
123  * boot time.
124  */
125 struct lib32_elfinfo
126 {
127 	Elf32_Ehdr	*hdr;		/* ptr to ELF */
128 	Elf32_Sym	*dynsym;	/* ptr to .dynsym section */
129 	unsigned long	dynsymsize;	/* size of .dynsym section */
130 	char		*dynstr;	/* ptr to .dynstr section */
131 	unsigned long	text;		/* offset of .text section in .so */
132 };
133 
134 struct lib64_elfinfo
135 {
136 	Elf64_Ehdr	*hdr;
137 	Elf64_Sym	*dynsym;
138 	unsigned long	dynsymsize;
139 	char		*dynstr;
140 	unsigned long	text;
141 };
142 
143 
144 #ifdef __DEBUG
145 static void dump_one_vdso_page(struct page *pg, struct page *upg)
146 {
147 	printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
148 	       page_count(pg),
149 	       pg->flags);
150 	if (upg && !IS_ERR(upg) /* && pg != upg*/) {
151 		printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
152 						       << PAGE_SHIFT),
153 		       page_count(upg),
154 		       upg->flags);
155 	}
156 	printk("\n");
157 }
158 
159 static void dump_vdso_pages(struct vm_area_struct * vma)
160 {
161 	int i;
162 
163 	if (!vma || is_32bit_task()) {
164 		printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
165 		for (i=0; i<vdso32_pages; i++) {
166 			struct page *pg = virt_to_page(vdso32_kbase +
167 						       i*PAGE_SIZE);
168 			struct page *upg = (vma && vma->vm_mm) ?
169 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
170 				: NULL;
171 			dump_one_vdso_page(pg, upg);
172 		}
173 	}
174 	if (!vma || !is_32bit_task()) {
175 		printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
176 		for (i=0; i<vdso64_pages; i++) {
177 			struct page *pg = virt_to_page(vdso64_kbase +
178 						       i*PAGE_SIZE);
179 			struct page *upg = (vma && vma->vm_mm) ?
180 				follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
181 				: NULL;
182 			dump_one_vdso_page(pg, upg);
183 		}
184 	}
185 }
186 #endif /* DEBUG */
187 
188 /*
189  * This is called from binfmt_elf, we create the special vma for the
190  * vDSO and insert it into the mm struct tree
191  */
192 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
193 {
194 	struct mm_struct *mm = current->mm;
195 	struct page **vdso_pagelist;
196 	unsigned long vdso_pages;
197 	unsigned long vdso_base;
198 	int rc;
199 
200 	if (!vdso_ready)
201 		return 0;
202 
203 #ifdef CONFIG_PPC64
204 	if (is_32bit_task()) {
205 		vdso_pagelist = vdso32_pagelist;
206 		vdso_pages = vdso32_pages;
207 		vdso_base = VDSO32_MBASE;
208 	} else {
209 		vdso_pagelist = vdso64_pagelist;
210 		vdso_pages = vdso64_pages;
211 		/*
212 		 * On 64bit we don't have a preferred map address. This
213 		 * allows get_unmapped_area to find an area near other mmaps
214 		 * and most likely share a SLB entry.
215 		 */
216 		vdso_base = 0;
217 	}
218 #else
219 	vdso_pagelist = vdso32_pagelist;
220 	vdso_pages = vdso32_pages;
221 	vdso_base = VDSO32_MBASE;
222 #endif
223 
224 	current->mm->context.vdso_base = 0;
225 
226 	/* vDSO has a problem and was disabled, just don't "enable" it for the
227 	 * process
228 	 */
229 	if (vdso_pages == 0)
230 		return 0;
231 	/* Add a page to the vdso size for the data page */
232 	vdso_pages ++;
233 
234 	/*
235 	 * pick a base address for the vDSO in process space. We try to put it
236 	 * at vdso_base which is the "natural" base for it, but we might fail
237 	 * and end up putting it elsewhere.
238 	 * Add enough to the size so that the result can be aligned.
239 	 */
240 	down_write(&mm->mmap_sem);
241 	vdso_base = get_unmapped_area(NULL, vdso_base,
242 				      (vdso_pages << PAGE_SHIFT) +
243 				      ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
244 				      0, 0);
245 	if (IS_ERR_VALUE(vdso_base)) {
246 		rc = vdso_base;
247 		goto fail_mmapsem;
248 	}
249 
250 	/* Add required alignment. */
251 	vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
252 
253 	/*
254 	 * Put vDSO base into mm struct. We need to do this before calling
255 	 * install_special_mapping or the perf counter mmap tracking code
256 	 * will fail to recognise it as a vDSO (since arch_vma_name fails).
257 	 */
258 	current->mm->context.vdso_base = vdso_base;
259 
260 	/*
261 	 * our vma flags don't have VM_WRITE so by default, the process isn't
262 	 * allowed to write those pages.
263 	 * gdb can break that with ptrace interface, and thus trigger COW on
264 	 * those pages but it's then your responsibility to never do that on
265 	 * the "data" page of the vDSO or you'll stop getting kernel updates
266 	 * and your nice userland gettimeofday will be totally dead.
267 	 * It's fine to use that for setting breakpoints in the vDSO code
268 	 * pages though.
269 	 */
270 	rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
271 				     VM_READ|VM_EXEC|
272 				     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
273 				     vdso_pagelist);
274 	if (rc) {
275 		current->mm->context.vdso_base = 0;
276 		goto fail_mmapsem;
277 	}
278 
279 	up_write(&mm->mmap_sem);
280 	return 0;
281 
282  fail_mmapsem:
283 	up_write(&mm->mmap_sem);
284 	return rc;
285 }
286 
287 const char *arch_vma_name(struct vm_area_struct *vma)
288 {
289 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
290 		return "[vdso]";
291 	return NULL;
292 }
293 
294 
295 
296 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
297 				  unsigned long *size)
298 {
299 	Elf32_Shdr *sechdrs;
300 	unsigned int i;
301 	char *secnames;
302 
303 	/* Grab section headers and strings so we can tell who is who */
304 	sechdrs = (void *)ehdr + ehdr->e_shoff;
305 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
306 
307 	/* Find the section they want */
308 	for (i = 1; i < ehdr->e_shnum; i++) {
309 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
310 			if (size)
311 				*size = sechdrs[i].sh_size;
312 			return (void *)ehdr + sechdrs[i].sh_offset;
313 		}
314 	}
315 	*size = 0;
316 	return NULL;
317 }
318 
319 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
320 					const char *symname)
321 {
322 	unsigned int i;
323 	char name[MAX_SYMNAME], *c;
324 
325 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
326 		if (lib->dynsym[i].st_name == 0)
327 			continue;
328 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
329 			MAX_SYMNAME);
330 		c = strchr(name, '@');
331 		if (c)
332 			*c = 0;
333 		if (strcmp(symname, name) == 0)
334 			return &lib->dynsym[i];
335 	}
336 	return NULL;
337 }
338 
339 /* Note that we assume the section is .text and the symbol is relative to
340  * the library base
341  */
342 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
343 					    const char *symname)
344 {
345 	Elf32_Sym *sym = find_symbol32(lib, symname);
346 
347 	if (sym == NULL) {
348 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
349 		       symname);
350 		return 0;
351 	}
352 	return sym->st_value - VDSO32_LBASE;
353 }
354 
355 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
356 				       struct lib64_elfinfo *v64,
357 				       const char *orig, const char *fix)
358 {
359 	Elf32_Sym *sym32_gen, *sym32_fix;
360 
361 	sym32_gen = find_symbol32(v32, orig);
362 	if (sym32_gen == NULL) {
363 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
364 		return -1;
365 	}
366 	if (fix == NULL) {
367 		sym32_gen->st_name = 0;
368 		return 0;
369 	}
370 	sym32_fix = find_symbol32(v32, fix);
371 	if (sym32_fix == NULL) {
372 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
373 		return -1;
374 	}
375 	sym32_gen->st_value = sym32_fix->st_value;
376 	sym32_gen->st_size = sym32_fix->st_size;
377 	sym32_gen->st_info = sym32_fix->st_info;
378 	sym32_gen->st_other = sym32_fix->st_other;
379 	sym32_gen->st_shndx = sym32_fix->st_shndx;
380 
381 	return 0;
382 }
383 
384 
385 #ifdef CONFIG_PPC64
386 
387 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
388 				  unsigned long *size)
389 {
390 	Elf64_Shdr *sechdrs;
391 	unsigned int i;
392 	char *secnames;
393 
394 	/* Grab section headers and strings so we can tell who is who */
395 	sechdrs = (void *)ehdr + ehdr->e_shoff;
396 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
397 
398 	/* Find the section they want */
399 	for (i = 1; i < ehdr->e_shnum; i++) {
400 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
401 			if (size)
402 				*size = sechdrs[i].sh_size;
403 			return (void *)ehdr + sechdrs[i].sh_offset;
404 		}
405 	}
406 	if (size)
407 		*size = 0;
408 	return NULL;
409 }
410 
411 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
412 					const char *symname)
413 {
414 	unsigned int i;
415 	char name[MAX_SYMNAME], *c;
416 
417 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
418 		if (lib->dynsym[i].st_name == 0)
419 			continue;
420 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
421 			MAX_SYMNAME);
422 		c = strchr(name, '@');
423 		if (c)
424 			*c = 0;
425 		if (strcmp(symname, name) == 0)
426 			return &lib->dynsym[i];
427 	}
428 	return NULL;
429 }
430 
431 /* Note that we assume the section is .text and the symbol is relative to
432  * the library base
433  */
434 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
435 					    const char *symname)
436 {
437 	Elf64_Sym *sym = find_symbol64(lib, symname);
438 
439 	if (sym == NULL) {
440 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
441 		       symname);
442 		return 0;
443 	}
444 #ifdef VDS64_HAS_DESCRIPTORS
445 	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
446 		VDSO64_LBASE;
447 #else
448 	return sym->st_value - VDSO64_LBASE;
449 #endif
450 }
451 
452 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
453 				       struct lib64_elfinfo *v64,
454 				       const char *orig, const char *fix)
455 {
456 	Elf64_Sym *sym64_gen, *sym64_fix;
457 
458 	sym64_gen = find_symbol64(v64, orig);
459 	if (sym64_gen == NULL) {
460 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
461 		return -1;
462 	}
463 	if (fix == NULL) {
464 		sym64_gen->st_name = 0;
465 		return 0;
466 	}
467 	sym64_fix = find_symbol64(v64, fix);
468 	if (sym64_fix == NULL) {
469 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
470 		return -1;
471 	}
472 	sym64_gen->st_value = sym64_fix->st_value;
473 	sym64_gen->st_size = sym64_fix->st_size;
474 	sym64_gen->st_info = sym64_fix->st_info;
475 	sym64_gen->st_other = sym64_fix->st_other;
476 	sym64_gen->st_shndx = sym64_fix->st_shndx;
477 
478 	return 0;
479 }
480 
481 #endif /* CONFIG_PPC64 */
482 
483 
484 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
485 					struct lib64_elfinfo *v64)
486 {
487 	void *sect;
488 
489 	/*
490 	 * Locate symbol tables & text section
491 	 */
492 
493 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
494 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
495 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
496 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
497 		return -1;
498 	}
499 	sect = find_section32(v32->hdr, ".text", NULL);
500 	if (sect == NULL) {
501 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
502 		return -1;
503 	}
504 	v32->text = sect - vdso32_kbase;
505 
506 #ifdef CONFIG_PPC64
507 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
508 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
509 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
510 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
511 		return -1;
512 	}
513 	sect = find_section64(v64->hdr, ".text", NULL);
514 	if (sect == NULL) {
515 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
516 		return -1;
517 	}
518 	v64->text = sect - vdso64_kbase;
519 #endif /* CONFIG_PPC64 */
520 
521 	return 0;
522 }
523 
524 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
525 					  struct lib64_elfinfo *v64)
526 {
527 	/*
528 	 * Find signal trampolines
529 	 */
530 
531 #ifdef CONFIG_PPC64
532 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
533 #endif
534 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
535 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
536 }
537 
538 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
539 				       struct lib64_elfinfo *v64)
540 {
541 	Elf32_Sym *sym32;
542 #ifdef CONFIG_PPC64
543 	Elf64_Sym *sym64;
544 
545        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
546 	if (sym64 == NULL) {
547 		printk(KERN_ERR "vDSO64: Can't find symbol "
548 		       "__kernel_datapage_offset !\n");
549 		return -1;
550 	}
551 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
552 		(vdso64_pages << PAGE_SHIFT) -
553 		(sym64->st_value - VDSO64_LBASE);
554 #endif /* CONFIG_PPC64 */
555 
556 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
557 	if (sym32 == NULL) {
558 		printk(KERN_ERR "vDSO32: Can't find symbol "
559 		       "__kernel_datapage_offset !\n");
560 		return -1;
561 	}
562 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
563 		(vdso32_pages << PAGE_SHIFT) -
564 		(sym32->st_value - VDSO32_LBASE);
565 
566 	return 0;
567 }
568 
569 
570 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
571 				      struct lib64_elfinfo *v64)
572 {
573 	void *start32;
574 	unsigned long size32;
575 
576 #ifdef CONFIG_PPC64
577 	void *start64;
578 	unsigned long size64;
579 
580 	start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
581 	if (start64)
582 		do_feature_fixups(cur_cpu_spec->cpu_features,
583 				  start64, start64 + size64);
584 
585 	start64 = find_section64(v64->hdr, "__mmu_ftr_fixup", &size64);
586 	if (start64)
587 		do_feature_fixups(cur_cpu_spec->mmu_features,
588 				  start64, start64 + size64);
589 
590 	start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
591 	if (start64)
592 		do_feature_fixups(powerpc_firmware_features,
593 				  start64, start64 + size64);
594 
595 	start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
596 	if (start64)
597 		do_lwsync_fixups(cur_cpu_spec->cpu_features,
598 				 start64, start64 + size64);
599 #endif /* CONFIG_PPC64 */
600 
601 	start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
602 	if (start32)
603 		do_feature_fixups(cur_cpu_spec->cpu_features,
604 				  start32, start32 + size32);
605 
606 	start32 = find_section32(v32->hdr, "__mmu_ftr_fixup", &size32);
607 	if (start32)
608 		do_feature_fixups(cur_cpu_spec->mmu_features,
609 				  start32, start32 + size32);
610 
611 #ifdef CONFIG_PPC64
612 	start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
613 	if (start32)
614 		do_feature_fixups(powerpc_firmware_features,
615 				  start32, start32 + size32);
616 #endif /* CONFIG_PPC64 */
617 
618 	start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
619 	if (start32)
620 		do_lwsync_fixups(cur_cpu_spec->cpu_features,
621 				 start32, start32 + size32);
622 
623 	return 0;
624 }
625 
626 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
627 				       struct lib64_elfinfo *v64)
628 {
629 	int i;
630 
631 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
632 		struct vdso_patch_def *patch = &vdso_patches[i];
633 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
634 			== patch->ftr_value;
635 		if (!match)
636 			continue;
637 
638 		DBG("replacing %s with %s...\n", patch->gen_name,
639 		    patch->fix_name ? "NONE" : patch->fix_name);
640 
641 		/*
642 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
643 		 * patch the "." symbol on 64 bits.
644 		 * It would be easy to do, but doesn't seem to be necessary,
645 		 * patching the OPD symbol is enough.
646 		 */
647 		vdso_do_func_patch32(v32, v64, patch->gen_name,
648 				     patch->fix_name);
649 #ifdef CONFIG_PPC64
650 		vdso_do_func_patch64(v32, v64, patch->gen_name,
651 				     patch->fix_name);
652 #endif /* CONFIG_PPC64 */
653 	}
654 
655 	return 0;
656 }
657 
658 
659 static __init int vdso_setup(void)
660 {
661 	struct lib32_elfinfo	v32;
662 	struct lib64_elfinfo	v64;
663 
664 	v32.hdr = vdso32_kbase;
665 #ifdef CONFIG_PPC64
666 	v64.hdr = vdso64_kbase;
667 #endif
668 	if (vdso_do_find_sections(&v32, &v64))
669 		return -1;
670 
671 	if (vdso_fixup_datapage(&v32, &v64))
672 		return -1;
673 
674 	if (vdso_fixup_features(&v32, &v64))
675 		return -1;
676 
677 	if (vdso_fixup_alt_funcs(&v32, &v64))
678 		return -1;
679 
680 	vdso_setup_trampolines(&v32, &v64);
681 
682 	return 0;
683 }
684 
685 /*
686  * Called from setup_arch to initialize the bitmap of available
687  * syscalls in the systemcfg page
688  */
689 static void __init vdso_setup_syscall_map(void)
690 {
691 	unsigned int i;
692 	extern unsigned long *sys_call_table;
693 	extern unsigned long sys_ni_syscall;
694 
695 
696 	for (i = 0; i < __NR_syscalls; i++) {
697 #ifdef CONFIG_PPC64
698 		if (sys_call_table[i*2] != sys_ni_syscall)
699 			vdso_data->syscall_map_64[i >> 5] |=
700 				0x80000000UL >> (i & 0x1f);
701 		if (sys_call_table[i*2+1] != sys_ni_syscall)
702 			vdso_data->syscall_map_32[i >> 5] |=
703 				0x80000000UL >> (i & 0x1f);
704 #else /* CONFIG_PPC64 */
705 		if (sys_call_table[i] != sys_ni_syscall)
706 			vdso_data->syscall_map_32[i >> 5] |=
707 				0x80000000UL >> (i & 0x1f);
708 #endif /* CONFIG_PPC64 */
709 	}
710 }
711 
712 #ifdef CONFIG_PPC64
713 int vdso_getcpu_init(void)
714 {
715 	unsigned long cpu, node, val;
716 
717 	/*
718 	 * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
719 	 * in the next 16 bits.  The VDSO uses this to implement getcpu().
720 	 */
721 	cpu = get_cpu();
722 	WARN_ON_ONCE(cpu > 0xffff);
723 
724 	node = cpu_to_node(cpu);
725 	WARN_ON_ONCE(node > 0xffff);
726 
727 	val = (cpu & 0xfff) | ((node & 0xffff) << 16);
728 	mtspr(SPRN_SPRG_VDSO_WRITE, val);
729 	get_paca()->sprg_vdso = val;
730 
731 	put_cpu();
732 
733 	return 0;
734 }
735 /* We need to call this before SMP init */
736 early_initcall(vdso_getcpu_init);
737 #endif
738 
739 static int __init vdso_init(void)
740 {
741 	int i;
742 
743 #ifdef CONFIG_PPC64
744 	/*
745 	 * Fill up the "systemcfg" stuff for backward compatibility
746 	 */
747 	strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
748 	vdso_data->version.major = SYSTEMCFG_MAJOR;
749 	vdso_data->version.minor = SYSTEMCFG_MINOR;
750 	vdso_data->processor = mfspr(SPRN_PVR);
751 	/*
752 	 * Fake the old platform number for pSeries and add
753 	 * in LPAR bit if necessary
754 	 */
755 	vdso_data->platform = 0x100;
756 	if (firmware_has_feature(FW_FEATURE_LPAR))
757 		vdso_data->platform |= 1;
758 	vdso_data->physicalMemorySize = memblock_phys_mem_size();
759 	vdso_data->dcache_size = ppc64_caches.dsize;
760 	vdso_data->dcache_line_size = ppc64_caches.dline_size;
761 	vdso_data->icache_size = ppc64_caches.isize;
762 	vdso_data->icache_line_size = ppc64_caches.iline_size;
763 
764 	/* XXXOJN: Blocks should be added to ppc64_caches and used instead */
765 	vdso_data->dcache_block_size = ppc64_caches.dline_size;
766 	vdso_data->icache_block_size = ppc64_caches.iline_size;
767 	vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
768 	vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
769 
770 	/*
771 	 * Calculate the size of the 64 bits vDSO
772 	 */
773 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
774 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
775 #else
776 	vdso_data->dcache_block_size = L1_CACHE_BYTES;
777 	vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
778 	vdso_data->icache_block_size = L1_CACHE_BYTES;
779 	vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
780 #endif /* CONFIG_PPC64 */
781 
782 
783 	/*
784 	 * Calculate the size of the 32 bits vDSO
785 	 */
786 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
787 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
788 
789 
790 	/*
791 	 * Setup the syscall map in the vDOS
792 	 */
793 	vdso_setup_syscall_map();
794 
795 	/*
796 	 * Initialize the vDSO images in memory, that is do necessary
797 	 * fixups of vDSO symbols, locate trampolines, etc...
798 	 */
799 	if (vdso_setup()) {
800 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
801 		vdso32_pages = 0;
802 #ifdef CONFIG_PPC64
803 		vdso64_pages = 0;
804 #endif
805 		return 0;
806 	}
807 
808 	/* Make sure pages are in the correct state */
809 	vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
810 				  GFP_KERNEL);
811 	BUG_ON(vdso32_pagelist == NULL);
812 	for (i = 0; i < vdso32_pages; i++) {
813 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
814 		ClearPageReserved(pg);
815 		get_page(pg);
816 		vdso32_pagelist[i] = pg;
817 	}
818 	vdso32_pagelist[i++] = virt_to_page(vdso_data);
819 	vdso32_pagelist[i] = NULL;
820 
821 #ifdef CONFIG_PPC64
822 	vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
823 				  GFP_KERNEL);
824 	BUG_ON(vdso64_pagelist == NULL);
825 	for (i = 0; i < vdso64_pages; i++) {
826 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
827 		ClearPageReserved(pg);
828 		get_page(pg);
829 		vdso64_pagelist[i] = pg;
830 	}
831 	vdso64_pagelist[i++] = virt_to_page(vdso_data);
832 	vdso64_pagelist[i] = NULL;
833 #endif /* CONFIG_PPC64 */
834 
835 	get_page(virt_to_page(vdso_data));
836 
837 	smp_wmb();
838 	vdso_ready = 1;
839 
840 	return 0;
841 }
842 arch_initcall(vdso_init);
843 
844 int in_gate_area_no_mm(unsigned long addr)
845 {
846 	return 0;
847 }
848 
849 int in_gate_area(struct mm_struct *mm, unsigned long addr)
850 {
851 	return 0;
852 }
853 
854 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
855 {
856 	return NULL;
857 }
858 
859