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