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v4.17
  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/memblock.h>
 24
 25#include <asm/cpu_has_feature.h>
 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
 
 
 53static unsigned int vdso32_pages;
 54static void *vdso32_kbase;
 55static struct page **vdso32_pagelist;
 56unsigned long vdso32_sigtramp;
 57unsigned long vdso32_rt_sigtramp;
 58
 59#ifdef CONFIG_VDSO32
 60extern char vdso32_start, vdso32_end;
 61#endif
 62
 63#ifdef CONFIG_PPC64
 64extern char vdso64_start, vdso64_end;
 65static void *vdso64_kbase = &vdso64_start;
 66static unsigned int vdso64_pages;
 67static struct page **vdso64_pagelist;
 68unsigned long vdso64_rt_sigtramp;
 69#endif /* CONFIG_PPC64 */
 70
 71static 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 */
 78static union {
 79	struct vdso_data	data;
 80	u8			page[PAGE_SIZE];
 81} vdso_data_store __page_aligned_data;
 82struct vdso_data *vdso_data = &vdso_data_store.data;
 83
 84/* Format of the patch table */
 85struct 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 */
 97static 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#ifdef CONFIG_PPC32
103	{
104		CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
105		"__kernel_gettimeofday", NULL
106	},
107	{
108		CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
109		"__kernel_clock_gettime", NULL
110	},
111	{
112		CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
113		"__kernel_clock_getres", NULL
114	},
115	{
116		CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
117		"__kernel_get_tbfreq", NULL
118	},
119	{
120		CPU_FTR_USE_RTC, CPU_FTR_USE_RTC,
121		"__kernel_time", NULL
122	},
123#endif
124};
125
126/*
127 * Some infos carried around for each of them during parsing at
128 * boot time.
129 */
130struct lib32_elfinfo
131{
132	Elf32_Ehdr	*hdr;		/* ptr to ELF */
133	Elf32_Sym	*dynsym;	/* ptr to .dynsym section */
134	unsigned long	dynsymsize;	/* size of .dynsym section */
135	char		*dynstr;	/* ptr to .dynstr section */
136	unsigned long	text;		/* offset of .text section in .so */
137};
138
139struct lib64_elfinfo
140{
141	Elf64_Ehdr	*hdr;
142	Elf64_Sym	*dynsym;
143	unsigned long	dynsymsize;
144	char		*dynstr;
145	unsigned long	text;
146};
147
148
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
149/*
150 * This is called from binfmt_elf, we create the special vma for the
151 * vDSO and insert it into the mm struct tree
152 */
153int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
154{
155	struct mm_struct *mm = current->mm;
156	struct page **vdso_pagelist;
157	unsigned long vdso_pages;
158	unsigned long vdso_base;
159	int rc;
160
161	if (!vdso_ready)
162		return 0;
163
164#ifdef CONFIG_PPC64
165	if (is_32bit_task()) {
166		vdso_pagelist = vdso32_pagelist;
167		vdso_pages = vdso32_pages;
168		vdso_base = VDSO32_MBASE;
169	} else {
170		vdso_pagelist = vdso64_pagelist;
171		vdso_pages = vdso64_pages;
172		/*
173		 * On 64bit we don't have a preferred map address. This
174		 * allows get_unmapped_area to find an area near other mmaps
175		 * and most likely share a SLB entry.
176		 */
177		vdso_base = 0;
178	}
179#else
180	vdso_pagelist = vdso32_pagelist;
181	vdso_pages = vdso32_pages;
182	vdso_base = VDSO32_MBASE;
183#endif
184
185	current->mm->context.vdso_base = 0;
186
187	/* vDSO has a problem and was disabled, just don't "enable" it for the
188	 * process
189	 */
190	if (vdso_pages == 0)
191		return 0;
192	/* Add a page to the vdso size for the data page */
193	vdso_pages ++;
194
195	/*
196	 * pick a base address for the vDSO in process space. We try to put it
197	 * at vdso_base which is the "natural" base for it, but we might fail
198	 * and end up putting it elsewhere.
199	 * Add enough to the size so that the result can be aligned.
200	 */
201	if (down_write_killable(&mm->mmap_sem))
202		return -EINTR;
203	vdso_base = get_unmapped_area(NULL, vdso_base,
204				      (vdso_pages << PAGE_SHIFT) +
205				      ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
206				      0, 0);
207	if (IS_ERR_VALUE(vdso_base)) {
208		rc = vdso_base;
209		goto fail_mmapsem;
210	}
211
212	/* Add required alignment. */
213	vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
214
215	/*
216	 * Put vDSO base into mm struct. We need to do this before calling
217	 * install_special_mapping or the perf counter mmap tracking code
218	 * will fail to recognise it as a vDSO (since arch_vma_name fails).
219	 */
220	current->mm->context.vdso_base = vdso_base;
221
222	/*
223	 * our vma flags don't have VM_WRITE so by default, the process isn't
224	 * allowed to write those pages.
225	 * gdb can break that with ptrace interface, and thus trigger COW on
226	 * those pages but it's then your responsibility to never do that on
227	 * the "data" page of the vDSO or you'll stop getting kernel updates
228	 * and your nice userland gettimeofday will be totally dead.
229	 * It's fine to use that for setting breakpoints in the vDSO code
230	 * pages though.
231	 */
232	rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
233				     VM_READ|VM_EXEC|
234				     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
235				     vdso_pagelist);
236	if (rc) {
237		current->mm->context.vdso_base = 0;
238		goto fail_mmapsem;
239	}
240
241	up_write(&mm->mmap_sem);
242	return 0;
243
244 fail_mmapsem:
245	up_write(&mm->mmap_sem);
246	return rc;
247}
248
249const char *arch_vma_name(struct vm_area_struct *vma)
250{
251	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
252		return "[vdso]";
253	return NULL;
254}
255
256
257
258#ifdef CONFIG_VDSO32
259static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
260				  unsigned long *size)
261{
262	Elf32_Shdr *sechdrs;
263	unsigned int i;
264	char *secnames;
265
266	/* Grab section headers and strings so we can tell who is who */
267	sechdrs = (void *)ehdr + ehdr->e_shoff;
268	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
269
270	/* Find the section they want */
271	for (i = 1; i < ehdr->e_shnum; i++) {
272		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
273			if (size)
274				*size = sechdrs[i].sh_size;
275			return (void *)ehdr + sechdrs[i].sh_offset;
276		}
277	}
278	*size = 0;
279	return NULL;
280}
281
282static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
283					const char *symname)
284{
285	unsigned int i;
286	char name[MAX_SYMNAME], *c;
287
288	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
289		if (lib->dynsym[i].st_name == 0)
290			continue;
291		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
292			MAX_SYMNAME);
293		c = strchr(name, '@');
294		if (c)
295			*c = 0;
296		if (strcmp(symname, name) == 0)
297			return &lib->dynsym[i];
298	}
299	return NULL;
300}
301
302/* Note that we assume the section is .text and the symbol is relative to
303 * the library base
304 */
305static unsigned long __init find_function32(struct lib32_elfinfo *lib,
306					    const char *symname)
307{
308	Elf32_Sym *sym = find_symbol32(lib, symname);
309
310	if (sym == NULL) {
311		printk(KERN_WARNING "vDSO32: function %s not found !\n",
312		       symname);
313		return 0;
314	}
315	return sym->st_value - VDSO32_LBASE;
316}
317
318static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
319				       struct lib64_elfinfo *v64,
320				       const char *orig, const char *fix)
321{
322	Elf32_Sym *sym32_gen, *sym32_fix;
323
324	sym32_gen = find_symbol32(v32, orig);
325	if (sym32_gen == NULL) {
326		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
327		return -1;
328	}
329	if (fix == NULL) {
330		sym32_gen->st_name = 0;
331		return 0;
332	}
333	sym32_fix = find_symbol32(v32, fix);
334	if (sym32_fix == NULL) {
335		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
336		return -1;
337	}
338	sym32_gen->st_value = sym32_fix->st_value;
339	sym32_gen->st_size = sym32_fix->st_size;
340	sym32_gen->st_info = sym32_fix->st_info;
341	sym32_gen->st_other = sym32_fix->st_other;
342	sym32_gen->st_shndx = sym32_fix->st_shndx;
343
344	return 0;
345}
346#else /* !CONFIG_VDSO32 */
347static unsigned long __init find_function32(struct lib32_elfinfo *lib,
348					    const char *symname)
349{
350	return 0;
351}
352
353static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
354				       struct lib64_elfinfo *v64,
355				       const char *orig, const char *fix)
356{
357	return 0;
358}
359#endif /* CONFIG_VDSO32 */
360
361
362#ifdef CONFIG_PPC64
363
364static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
365				  unsigned long *size)
366{
367	Elf64_Shdr *sechdrs;
368	unsigned int i;
369	char *secnames;
370
371	/* Grab section headers and strings so we can tell who is who */
372	sechdrs = (void *)ehdr + ehdr->e_shoff;
373	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
374
375	/* Find the section they want */
376	for (i = 1; i < ehdr->e_shnum; i++) {
377		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
378			if (size)
379				*size = sechdrs[i].sh_size;
380			return (void *)ehdr + sechdrs[i].sh_offset;
381		}
382	}
383	if (size)
384		*size = 0;
385	return NULL;
386}
387
388static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
389					const char *symname)
390{
391	unsigned int i;
392	char name[MAX_SYMNAME], *c;
393
394	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
395		if (lib->dynsym[i].st_name == 0)
396			continue;
397		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
398			MAX_SYMNAME);
399		c = strchr(name, '@');
400		if (c)
401			*c = 0;
402		if (strcmp(symname, name) == 0)
403			return &lib->dynsym[i];
404	}
405	return NULL;
406}
407
408/* Note that we assume the section is .text and the symbol is relative to
409 * the library base
410 */
411static unsigned long __init find_function64(struct lib64_elfinfo *lib,
412					    const char *symname)
413{
414	Elf64_Sym *sym = find_symbol64(lib, symname);
415
416	if (sym == NULL) {
417		printk(KERN_WARNING "vDSO64: function %s not found !\n",
418		       symname);
419		return 0;
420	}
421#ifdef VDS64_HAS_DESCRIPTORS
422	return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
423		VDSO64_LBASE;
424#else
425	return sym->st_value - VDSO64_LBASE;
426#endif
427}
428
429static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
430				       struct lib64_elfinfo *v64,
431				       const char *orig, const char *fix)
432{
433	Elf64_Sym *sym64_gen, *sym64_fix;
434
435	sym64_gen = find_symbol64(v64, orig);
436	if (sym64_gen == NULL) {
437		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
438		return -1;
439	}
440	if (fix == NULL) {
441		sym64_gen->st_name = 0;
442		return 0;
443	}
444	sym64_fix = find_symbol64(v64, fix);
445	if (sym64_fix == NULL) {
446		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
447		return -1;
448	}
449	sym64_gen->st_value = sym64_fix->st_value;
450	sym64_gen->st_size = sym64_fix->st_size;
451	sym64_gen->st_info = sym64_fix->st_info;
452	sym64_gen->st_other = sym64_fix->st_other;
453	sym64_gen->st_shndx = sym64_fix->st_shndx;
454
455	return 0;
456}
457
458#endif /* CONFIG_PPC64 */
459
460
461static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
462					struct lib64_elfinfo *v64)
463{
464	void *sect;
465
466	/*
467	 * Locate symbol tables & text section
468	 */
469
470#ifdef CONFIG_VDSO32
471	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
472	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
473	if (v32->dynsym == NULL || v32->dynstr == NULL) {
474		printk(KERN_ERR "vDSO32: required symbol section not found\n");
475		return -1;
476	}
477	sect = find_section32(v32->hdr, ".text", NULL);
478	if (sect == NULL) {
479		printk(KERN_ERR "vDSO32: the .text section was not found\n");
480		return -1;
481	}
482	v32->text = sect - vdso32_kbase;
483#endif
484
485#ifdef CONFIG_PPC64
486	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
487	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
488	if (v64->dynsym == NULL || v64->dynstr == NULL) {
489		printk(KERN_ERR "vDSO64: required symbol section not found\n");
490		return -1;
491	}
492	sect = find_section64(v64->hdr, ".text", NULL);
493	if (sect == NULL) {
494		printk(KERN_ERR "vDSO64: the .text section was not found\n");
495		return -1;
496	}
497	v64->text = sect - vdso64_kbase;
498#endif /* CONFIG_PPC64 */
499
500	return 0;
501}
502
503static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
504					  struct lib64_elfinfo *v64)
505{
506	/*
507	 * Find signal trampolines
508	 */
509
510#ifdef CONFIG_PPC64
511	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
512#endif
513	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
514	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
515}
516
517static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
518				       struct lib64_elfinfo *v64)
519{
520#ifdef CONFIG_VDSO32
521	Elf32_Sym *sym32;
522#endif
523#ifdef CONFIG_PPC64
524	Elf64_Sym *sym64;
525
526       	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
527	if (sym64 == NULL) {
528		printk(KERN_ERR "vDSO64: Can't find symbol "
529		       "__kernel_datapage_offset !\n");
530		return -1;
531	}
532	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
533		(vdso64_pages << PAGE_SHIFT) -
534		(sym64->st_value - VDSO64_LBASE);
535#endif /* CONFIG_PPC64 */
536
537#ifdef CONFIG_VDSO32
538	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
539	if (sym32 == NULL) {
540		printk(KERN_ERR "vDSO32: Can't find symbol "
541		       "__kernel_datapage_offset !\n");
542		return -1;
543	}
544	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
545		(vdso32_pages << PAGE_SHIFT) -
546		(sym32->st_value - VDSO32_LBASE);
547#endif
548
549	return 0;
550}
551
552
553static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
554				      struct lib64_elfinfo *v64)
555{
556	unsigned long size;
557	void *start;
558
559#ifdef CONFIG_PPC64
560	start = find_section64(v64->hdr, "__ftr_fixup", &size);
561	if (start)
 
 
 
562		do_feature_fixups(cur_cpu_spec->cpu_features,
563				  start, start + size);
564
565	start = find_section64(v64->hdr, "__mmu_ftr_fixup", &size);
566	if (start)
567		do_feature_fixups(cur_cpu_spec->mmu_features,
568				  start, start + size);
569
570	start = find_section64(v64->hdr, "__fw_ftr_fixup", &size);
571	if (start)
572		do_feature_fixups(powerpc_firmware_features,
573				  start, start + size);
574
575	start = find_section64(v64->hdr, "__lwsync_fixup", &size);
576	if (start)
577		do_lwsync_fixups(cur_cpu_spec->cpu_features,
578				 start, start + size);
579#endif /* CONFIG_PPC64 */
580
581#ifdef CONFIG_VDSO32
582	start = find_section32(v32->hdr, "__ftr_fixup", &size);
583	if (start)
584		do_feature_fixups(cur_cpu_spec->cpu_features,
585				  start, start + size);
586
587	start = find_section32(v32->hdr, "__mmu_ftr_fixup", &size);
588	if (start)
589		do_feature_fixups(cur_cpu_spec->mmu_features,
590				  start, start + size);
591
592#ifdef CONFIG_PPC64
593	start = find_section32(v32->hdr, "__fw_ftr_fixup", &size);
594	if (start)
595		do_feature_fixups(powerpc_firmware_features,
596				  start, start + size);
597#endif /* CONFIG_PPC64 */
598
599	start = find_section32(v32->hdr, "__lwsync_fixup", &size);
600	if (start)
601		do_lwsync_fixups(cur_cpu_spec->cpu_features,
602				 start, start + size);
603#endif
604
605	return 0;
606}
607
608static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
609				       struct lib64_elfinfo *v64)
610{
611	int i;
612
613	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
614		struct vdso_patch_def *patch = &vdso_patches[i];
615		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
616			== patch->ftr_value;
617		if (!match)
618			continue;
619
620		DBG("replacing %s with %s...\n", patch->gen_name,
621		    patch->fix_name ? "NONE" : patch->fix_name);
622
623		/*
624		 * Patch the 32 bits and 64 bits symbols. Note that we do not
625		 * patch the "." symbol on 64 bits.
626		 * It would be easy to do, but doesn't seem to be necessary,
627		 * patching the OPD symbol is enough.
628		 */
629		vdso_do_func_patch32(v32, v64, patch->gen_name,
630				     patch->fix_name);
631#ifdef CONFIG_PPC64
632		vdso_do_func_patch64(v32, v64, patch->gen_name,
633				     patch->fix_name);
634#endif /* CONFIG_PPC64 */
635	}
636
637	return 0;
638}
639
640
641static __init int vdso_setup(void)
642{
643	struct lib32_elfinfo	v32;
644	struct lib64_elfinfo	v64;
645
646	v32.hdr = vdso32_kbase;
647#ifdef CONFIG_PPC64
648	v64.hdr = vdso64_kbase;
649#endif
650	if (vdso_do_find_sections(&v32, &v64))
651		return -1;
652
653	if (vdso_fixup_datapage(&v32, &v64))
654		return -1;
655
656	if (vdso_fixup_features(&v32, &v64))
657		return -1;
658
659	if (vdso_fixup_alt_funcs(&v32, &v64))
660		return -1;
661
662	vdso_setup_trampolines(&v32, &v64);
663
664	return 0;
665}
666
667/*
668 * Called from setup_arch to initialize the bitmap of available
669 * syscalls in the systemcfg page
670 */
671static void __init vdso_setup_syscall_map(void)
672{
673	unsigned int i;
674	extern unsigned long *sys_call_table;
675	extern unsigned long sys_ni_syscall;
676
677
678	for (i = 0; i < NR_syscalls; i++) {
679#ifdef CONFIG_PPC64
680		if (sys_call_table[i*2] != sys_ni_syscall)
681			vdso_data->syscall_map_64[i >> 5] |=
682				0x80000000UL >> (i & 0x1f);
683		if (sys_call_table[i*2+1] != sys_ni_syscall)
684			vdso_data->syscall_map_32[i >> 5] |=
685				0x80000000UL >> (i & 0x1f);
686#else /* CONFIG_PPC64 */
687		if (sys_call_table[i] != sys_ni_syscall)
688			vdso_data->syscall_map_32[i >> 5] |=
689				0x80000000UL >> (i & 0x1f);
690#endif /* CONFIG_PPC64 */
691	}
692}
693
694#ifdef CONFIG_PPC64
695int vdso_getcpu_init(void)
696{
697	unsigned long cpu, node, val;
698
699	/*
700	 * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
701	 * in the next 16 bits.  The VDSO uses this to implement getcpu().
702	 */
703	cpu = get_cpu();
704	WARN_ON_ONCE(cpu > 0xffff);
705
706	node = cpu_to_node(cpu);
707	WARN_ON_ONCE(node > 0xffff);
708
709	val = (cpu & 0xfff) | ((node & 0xffff) << 16);
710	mtspr(SPRN_SPRG_VDSO_WRITE, val);
711	get_paca()->sprg_vdso = val;
712
713	put_cpu();
714
715	return 0;
716}
717/* We need to call this before SMP init */
718early_initcall(vdso_getcpu_init);
719#endif
720
721static int __init vdso_init(void)
722{
723	int i;
724
725#ifdef CONFIG_PPC64
726	/*
727	 * Fill up the "systemcfg" stuff for backward compatibility
728	 */
729	strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
730	vdso_data->version.major = SYSTEMCFG_MAJOR;
731	vdso_data->version.minor = SYSTEMCFG_MINOR;
732	vdso_data->processor = mfspr(SPRN_PVR);
733	/*
734	 * Fake the old platform number for pSeries and add
735	 * in LPAR bit if necessary
736	 */
737	vdso_data->platform = 0x100;
738	if (firmware_has_feature(FW_FEATURE_LPAR))
739		vdso_data->platform |= 1;
740	vdso_data->physicalMemorySize = memblock_phys_mem_size();
741	vdso_data->dcache_size = ppc64_caches.l1d.size;
742	vdso_data->dcache_line_size = ppc64_caches.l1d.line_size;
743	vdso_data->icache_size = ppc64_caches.l1i.size;
744	vdso_data->icache_line_size = ppc64_caches.l1i.line_size;
745	vdso_data->dcache_block_size = ppc64_caches.l1d.block_size;
746	vdso_data->icache_block_size = ppc64_caches.l1i.block_size;
747	vdso_data->dcache_log_block_size = ppc64_caches.l1d.log_block_size;
748	vdso_data->icache_log_block_size = ppc64_caches.l1i.log_block_size;
 
 
749
750	/*
751	 * Calculate the size of the 64 bits vDSO
752	 */
753	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
754	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
755#else
756	vdso_data->dcache_block_size = L1_CACHE_BYTES;
757	vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
758	vdso_data->icache_block_size = L1_CACHE_BYTES;
759	vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
760#endif /* CONFIG_PPC64 */
761
762
763#ifdef CONFIG_VDSO32
764	vdso32_kbase = &vdso32_start;
765
766	/*
767	 * Calculate the size of the 32 bits vDSO
768	 */
769	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
770	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
771#endif
772
773
774	/*
775	 * Setup the syscall map in the vDOS
776	 */
777	vdso_setup_syscall_map();
778
779	/*
780	 * Initialize the vDSO images in memory, that is do necessary
781	 * fixups of vDSO symbols, locate trampolines, etc...
782	 */
783	if (vdso_setup()) {
784		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
785		vdso32_pages = 0;
786#ifdef CONFIG_PPC64
787		vdso64_pages = 0;
788#endif
789		return 0;
790	}
791
792#ifdef CONFIG_VDSO32
793	/* Make sure pages are in the correct state */
794	vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
795				  GFP_KERNEL);
796	BUG_ON(vdso32_pagelist == NULL);
797	for (i = 0; i < vdso32_pages; i++) {
798		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
799		ClearPageReserved(pg);
800		get_page(pg);
801		vdso32_pagelist[i] = pg;
802	}
803	vdso32_pagelist[i++] = virt_to_page(vdso_data);
804	vdso32_pagelist[i] = NULL;
805#endif
806
807#ifdef CONFIG_PPC64
808	vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
809				  GFP_KERNEL);
810	BUG_ON(vdso64_pagelist == NULL);
811	for (i = 0; i < vdso64_pages; i++) {
812		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
813		ClearPageReserved(pg);
814		get_page(pg);
815		vdso64_pagelist[i] = pg;
816	}
817	vdso64_pagelist[i++] = virt_to_page(vdso_data);
818	vdso64_pagelist[i] = NULL;
819#endif /* CONFIG_PPC64 */
820
821	get_page(virt_to_page(vdso_data));
822
823	smp_wmb();
824	vdso_ready = 1;
825
826	return 0;
827}
828arch_initcall(vdso_init);
v3.5.6
  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
 54extern char vdso32_start, vdso32_end;
 55static void *vdso32_kbase = &vdso32_start;
 56static unsigned int vdso32_pages;
 
 57static struct page **vdso32_pagelist;
 58unsigned long vdso32_sigtramp;
 59unsigned long vdso32_rt_sigtramp;
 60
 
 
 
 
 61#ifdef CONFIG_PPC64
 62extern char vdso64_start, vdso64_end;
 63static void *vdso64_kbase = &vdso64_start;
 64static unsigned int vdso64_pages;
 65static struct page **vdso64_pagelist;
 66unsigned long vdso64_rt_sigtramp;
 67#endif /* CONFIG_PPC64 */
 68
 69static 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 */
 76static union {
 77	struct vdso_data	data;
 78	u8			page[PAGE_SIZE];
 79} vdso_data_store __page_aligned_data;
 80struct vdso_data *vdso_data = &vdso_data_store.data;
 81
 82/* Format of the patch table */
 83struct 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 */
 95static 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 */
122struct 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
131struct 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
142static 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
156static 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 */
189int 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
284const 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
 
293static 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
316static 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 */
339static 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
352static 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
384static 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
408static 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 */
431static 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
449static 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
481static __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
521static __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
535static __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
567static __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
623static __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
656static __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 */
686static 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
710static 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}
813arch_initcall(vdso_init);
814
815int in_gate_area_no_mm(unsigned long addr)
816{
817	return 0;
818}
819
820int in_gate_area(struct mm_struct *mm, unsigned long addr)
821{
822	return 0;
823}
824
825struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
826{
827	return NULL;
828}
829