a4b28c73bba067e3fc7734b1c87dc46b67f1ceea
[sfrench/cifs-2.6.git] / arch / powerpc / kernel / vdso.c
1 /*
2  *    Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
3  *                       <benh@kernel.crashing.org>
4  *
5  *  This program is free software; you can redistribute it and/or
6  *  modify it under the terms of the GNU General Public License
7  *  as published by the Free Software Foundation; either version
8  *  2 of the License, or (at your option) any later version.
9  */
10
11 #include <linux/module.h>
12 #include <linux/errno.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/mm.h>
16 #include <linux/smp.h>
17 #include <linux/smp_lock.h>
18 #include <linux/stddef.h>
19 #include <linux/unistd.h>
20 #include <linux/slab.h>
21 #include <linux/user.h>
22 #include <linux/elf.h>
23 #include <linux/security.h>
24 #include <linux/bootmem.h>
25
26 #include <asm/pgtable.h>
27 #include <asm/system.h>
28 #include <asm/processor.h>
29 #include <asm/mmu.h>
30 #include <asm/mmu_context.h>
31 #include <asm/lmb.h>
32 #include <asm/machdep.h>
33 #include <asm/cputable.h>
34 #include <asm/sections.h>
35 #include <asm/firmware.h>
36 #include <asm/vdso.h>
37 #include <asm/vdso_datapage.h>
38
39 #include "setup.h"
40
41 #undef DEBUG
42
43 #ifdef DEBUG
44 #define DBG(fmt...) printk(fmt)
45 #else
46 #define DBG(fmt...)
47 #endif
48
49 /* Max supported size for symbol names */
50 #define MAX_SYMNAME     64
51
52 extern char vdso32_start, vdso32_end;
53 static void *vdso32_kbase = &vdso32_start;
54 unsigned int vdso32_pages;
55 unsigned long vdso32_sigtramp;
56 unsigned long vdso32_rt_sigtramp;
57
58 #ifdef CONFIG_PPC64
59 extern char vdso64_start, vdso64_end;
60 static void *vdso64_kbase = &vdso64_start;
61 unsigned int vdso64_pages;
62 unsigned long vdso64_rt_sigtramp;
63 #endif /* CONFIG_PPC64 */
64
65 /*
66  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
67  * Once the early boot kernel code no longer needs to muck around
68  * with it, it will become dynamically allocated
69  */
70 static union {
71         struct vdso_data        data;
72         u8                      page[PAGE_SIZE];
73 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
74 struct vdso_data *vdso_data = &vdso_data_store.data;
75
76 /* Format of the patch table */
77 struct vdso_patch_def
78 {
79         unsigned long   ftr_mask, ftr_value;
80         const char      *gen_name;
81         const char      *fix_name;
82 };
83
84 /* Table of functions to patch based on the CPU type/revision
85  *
86  * Currently, we only change sync_dicache to do nothing on processors
87  * with a coherent icache
88  */
89 static struct vdso_patch_def vdso_patches[] = {
90         {
91                 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
92                 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
93         },
94         {
95                 CPU_FTR_USE_TB, 0,
96                 "__kernel_gettimeofday", NULL
97         },
98 };
99
100 /*
101  * Some infos carried around for each of them during parsing at
102  * boot time.
103  */
104 struct lib32_elfinfo
105 {
106         Elf32_Ehdr      *hdr;           /* ptr to ELF */
107         Elf32_Sym       *dynsym;        /* ptr to .dynsym section */
108         unsigned long   dynsymsize;     /* size of .dynsym section */
109         char            *dynstr;        /* ptr to .dynstr section */
110         unsigned long   text;           /* offset of .text section in .so */
111 };
112
113 struct lib64_elfinfo
114 {
115         Elf64_Ehdr      *hdr;
116         Elf64_Sym       *dynsym;
117         unsigned long   dynsymsize;
118         char            *dynstr;
119         unsigned long   text;
120 };
121
122
123 #ifdef __DEBUG
124 static void dump_one_vdso_page(struct page *pg, struct page *upg)
125 {
126         printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
127                page_count(pg),
128                pg->flags);
129         if (upg/* && pg != upg*/) {
130                 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
131                                                        << PAGE_SHIFT),
132                        page_count(upg),
133                        upg->flags);
134         }
135         printk("\n");
136 }
137
138 static void dump_vdso_pages(struct vm_area_struct * vma)
139 {
140         int i;
141
142         if (!vma || test_thread_flag(TIF_32BIT)) {
143                 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
144                 for (i=0; i<vdso32_pages; i++) {
145                         struct page *pg = virt_to_page(vdso32_kbase +
146                                                        i*PAGE_SIZE);
147                         struct page *upg = (vma && vma->vm_mm) ?
148                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
149                                 : NULL;
150                         dump_one_vdso_page(pg, upg);
151                 }
152         }
153         if (!vma || !test_thread_flag(TIF_32BIT)) {
154                 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
155                 for (i=0; i<vdso64_pages; i++) {
156                         struct page *pg = virt_to_page(vdso64_kbase +
157                                                        i*PAGE_SIZE);
158                         struct page *upg = (vma && vma->vm_mm) ?
159                                 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
160                                 : NULL;
161                         dump_one_vdso_page(pg, upg);
162                 }
163         }
164 }
165 #endif /* DEBUG */
166
167 /*
168  * Keep a dummy vma_close for now, it will prevent VMA merging.
169  */
170 static void vdso_vma_close(struct vm_area_struct * vma)
171 {
172 }
173
174 /*
175  * Our nopage() function, maps in the actual vDSO kernel pages, they will
176  * be mapped read-only by do_no_page(), and eventually COW'ed, either
177  * right away for an initial write access, or by do_wp_page().
178  */
179 static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
180                                      unsigned long address, int *type)
181 {
182         unsigned long offset = address - vma->vm_start;
183         struct page *pg;
184 #ifdef CONFIG_PPC64
185         void *vbase = (vma->vm_mm->task_size > TASK_SIZE_USER32) ?
186                 vdso64_kbase : vdso32_kbase;
187 #else
188         void *vbase = vdso32_kbase;
189 #endif
190
191         DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
192             current->comm, address, offset);
193
194         if (address < vma->vm_start || address > vma->vm_end)
195                 return NOPAGE_SIGBUS;
196
197         /*
198          * Last page is systemcfg.
199          */
200         if ((vma->vm_end - address) <= PAGE_SIZE)
201                 pg = virt_to_page(vdso_data);
202         else
203                 pg = virt_to_page(vbase + offset);
204
205         get_page(pg);
206         DBG(" ->page count: %d\n", page_count(pg));
207
208         return pg;
209 }
210
211 static struct vm_operations_struct vdso_vmops = {
212         .close  = vdso_vma_close,
213         .nopage = vdso_vma_nopage,
214 };
215
216 /*
217  * This is called from binfmt_elf, we create the special vma for the
218  * vDSO and insert it into the mm struct tree
219  */
220 int arch_setup_additional_pages(struct linux_binprm *bprm,
221                                 int executable_stack)
222 {
223         struct mm_struct *mm = current->mm;
224         struct vm_area_struct *vma;
225         unsigned long vdso_pages;
226         unsigned long vdso_base;
227         int rc;
228
229 #ifdef CONFIG_PPC64
230         if (test_thread_flag(TIF_32BIT)) {
231                 vdso_pages = vdso32_pages;
232                 vdso_base = VDSO32_MBASE;
233         } else {
234                 vdso_pages = vdso64_pages;
235                 vdso_base = VDSO64_MBASE;
236         }
237 #else
238         vdso_pages = vdso32_pages;
239         vdso_base = VDSO32_MBASE;
240 #endif
241
242         current->mm->context.vdso_base = 0;
243
244         /* vDSO has a problem and was disabled, just don't "enable" it for the
245          * process
246          */
247         if (vdso_pages == 0)
248                 return 0;
249         /* Add a page to the vdso size for the data page */
250         vdso_pages ++;
251
252         /*
253          * pick a base address for the vDSO in process space. We try to put it
254          * at vdso_base which is the "natural" base for it, but we might fail
255          * and end up putting it elsewhere.
256          */
257         down_write(&mm->mmap_sem);
258         vdso_base = get_unmapped_area(NULL, vdso_base,
259                                       vdso_pages << PAGE_SHIFT, 0, 0);
260         if (IS_ERR_VALUE(vdso_base)) {
261                 rc = vdso_base;
262                 goto fail_mmapsem;
263         }
264
265
266         /* Allocate a VMA structure and fill it up */
267         vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
268         if (vma == NULL) {
269                 rc = -ENOMEM;
270                 goto fail_mmapsem;
271         }
272         vma->vm_mm = mm;
273         vma->vm_start = vdso_base;
274         vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
275
276         /*
277          * our vma flags don't have VM_WRITE so by default, the process isn't
278          * allowed to write those pages.
279          * gdb can break that with ptrace interface, and thus trigger COW on
280          * those pages but it's then your responsibility to never do that on
281          * the "data" page of the vDSO or you'll stop getting kernel updates
282          * and your nice userland gettimeofday will be totally dead.
283          * It's fine to use that for setting breakpoints in the vDSO code
284          * pages though
285          */
286         vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC;
287         vma->vm_flags |= mm->def_flags;
288         vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
289         vma->vm_ops = &vdso_vmops;
290
291         /* Insert new VMA */
292         rc = insert_vm_struct(mm, vma);
293         if (rc)
294                 goto fail_vma;
295
296         /* Put vDSO base into mm struct and account for memory usage */
297         current->mm->context.vdso_base = vdso_base;
298         mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
299         up_write(&mm->mmap_sem);
300         return 0;
301
302  fail_vma:
303         kmem_cache_free(vm_area_cachep, vma);
304  fail_mmapsem:
305         up_write(&mm->mmap_sem);
306         return rc;
307 }
308
309 const char *arch_vma_name(struct vm_area_struct *vma)
310 {
311         if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
312                 return "[vdso]";
313         return NULL;
314 }
315
316
317
318 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
319                                   unsigned long *size)
320 {
321         Elf32_Shdr *sechdrs;
322         unsigned int i;
323         char *secnames;
324
325         /* Grab section headers and strings so we can tell who is who */
326         sechdrs = (void *)ehdr + ehdr->e_shoff;
327         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
328
329         /* Find the section they want */
330         for (i = 1; i < ehdr->e_shnum; i++) {
331                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
332                         if (size)
333                                 *size = sechdrs[i].sh_size;
334                         return (void *)ehdr + sechdrs[i].sh_offset;
335                 }
336         }
337         *size = 0;
338         return NULL;
339 }
340
341 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
342                                         const char *symname)
343 {
344         unsigned int i;
345         char name[MAX_SYMNAME], *c;
346
347         for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
348                 if (lib->dynsym[i].st_name == 0)
349                         continue;
350                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
351                         MAX_SYMNAME);
352                 c = strchr(name, '@');
353                 if (c)
354                         *c = 0;
355                 if (strcmp(symname, name) == 0)
356                         return &lib->dynsym[i];
357         }
358         return NULL;
359 }
360
361 /* Note that we assume the section is .text and the symbol is relative to
362  * the library base
363  */
364 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
365                                             const char *symname)
366 {
367         Elf32_Sym *sym = find_symbol32(lib, symname);
368
369         if (sym == NULL) {
370                 printk(KERN_WARNING "vDSO32: function %s not found !\n",
371                        symname);
372                 return 0;
373         }
374         return sym->st_value - VDSO32_LBASE;
375 }
376
377 static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
378                                 struct lib64_elfinfo *v64,
379                                 const char *orig, const char *fix)
380 {
381         Elf32_Sym *sym32_gen, *sym32_fix;
382
383         sym32_gen = find_symbol32(v32, orig);
384         if (sym32_gen == NULL) {
385                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
386                 return -1;
387         }
388         if (fix == NULL) {
389                 sym32_gen->st_name = 0;
390                 return 0;
391         }
392         sym32_fix = find_symbol32(v32, fix);
393         if (sym32_fix == NULL) {
394                 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
395                 return -1;
396         }
397         sym32_gen->st_value = sym32_fix->st_value;
398         sym32_gen->st_size = sym32_fix->st_size;
399         sym32_gen->st_info = sym32_fix->st_info;
400         sym32_gen->st_other = sym32_fix->st_other;
401         sym32_gen->st_shndx = sym32_fix->st_shndx;
402
403         return 0;
404 }
405
406
407 #ifdef CONFIG_PPC64
408
409 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
410                                   unsigned long *size)
411 {
412         Elf64_Shdr *sechdrs;
413         unsigned int i;
414         char *secnames;
415
416         /* Grab section headers and strings so we can tell who is who */
417         sechdrs = (void *)ehdr + ehdr->e_shoff;
418         secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
419
420         /* Find the section they want */
421         for (i = 1; i < ehdr->e_shnum; i++) {
422                 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
423                         if (size)
424                                 *size = sechdrs[i].sh_size;
425                         return (void *)ehdr + sechdrs[i].sh_offset;
426                 }
427         }
428         if (size)
429                 *size = 0;
430         return NULL;
431 }
432
433 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
434                                         const char *symname)
435 {
436         unsigned int i;
437         char name[MAX_SYMNAME], *c;
438
439         for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
440                 if (lib->dynsym[i].st_name == 0)
441                         continue;
442                 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
443                         MAX_SYMNAME);
444                 c = strchr(name, '@');
445                 if (c)
446                         *c = 0;
447                 if (strcmp(symname, name) == 0)
448                         return &lib->dynsym[i];
449         }
450         return NULL;
451 }
452
453 /* Note that we assume the section is .text and the symbol is relative to
454  * the library base
455  */
456 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
457                                             const char *symname)
458 {
459         Elf64_Sym *sym = find_symbol64(lib, symname);
460
461         if (sym == NULL) {
462                 printk(KERN_WARNING "vDSO64: function %s not found !\n",
463                        symname);
464                 return 0;
465         }
466 #ifdef VDS64_HAS_DESCRIPTORS
467         return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
468                 VDSO64_LBASE;
469 #else
470         return sym->st_value - VDSO64_LBASE;
471 #endif
472 }
473
474 static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
475                                 struct lib64_elfinfo *v64,
476                                 const char *orig, const char *fix)
477 {
478         Elf64_Sym *sym64_gen, *sym64_fix;
479
480         sym64_gen = find_symbol64(v64, orig);
481         if (sym64_gen == NULL) {
482                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
483                 return -1;
484         }
485         if (fix == NULL) {
486                 sym64_gen->st_name = 0;
487                 return 0;
488         }
489         sym64_fix = find_symbol64(v64, fix);
490         if (sym64_fix == NULL) {
491                 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
492                 return -1;
493         }
494         sym64_gen->st_value = sym64_fix->st_value;
495         sym64_gen->st_size = sym64_fix->st_size;
496         sym64_gen->st_info = sym64_fix->st_info;
497         sym64_gen->st_other = sym64_fix->st_other;
498         sym64_gen->st_shndx = sym64_fix->st_shndx;
499
500         return 0;
501 }
502
503 #endif /* CONFIG_PPC64 */
504
505
506 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
507                                         struct lib64_elfinfo *v64)
508 {
509         void *sect;
510
511         /*
512          * Locate symbol tables & text section
513          */
514
515         v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
516         v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
517         if (v32->dynsym == NULL || v32->dynstr == NULL) {
518                 printk(KERN_ERR "vDSO32: required symbol section not found\n");
519                 return -1;
520         }
521         sect = find_section32(v32->hdr, ".text", NULL);
522         if (sect == NULL) {
523                 printk(KERN_ERR "vDSO32: the .text section was not found\n");
524                 return -1;
525         }
526         v32->text = sect - vdso32_kbase;
527
528 #ifdef CONFIG_PPC64
529         v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
530         v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
531         if (v64->dynsym == NULL || v64->dynstr == NULL) {
532                 printk(KERN_ERR "vDSO64: required symbol section not found\n");
533                 return -1;
534         }
535         sect = find_section64(v64->hdr, ".text", NULL);
536         if (sect == NULL) {
537                 printk(KERN_ERR "vDSO64: the .text section was not found\n");
538                 return -1;
539         }
540         v64->text = sect - vdso64_kbase;
541 #endif /* CONFIG_PPC64 */
542
543         return 0;
544 }
545
546 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
547                                           struct lib64_elfinfo *v64)
548 {
549         /*
550          * Find signal trampolines
551          */
552
553 #ifdef CONFIG_PPC64
554         vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
555 #endif
556         vdso32_sigtramp    = find_function32(v32, "__kernel_sigtramp32");
557         vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
558 }
559
560 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
561                                        struct lib64_elfinfo *v64)
562 {
563         Elf32_Sym *sym32;
564 #ifdef CONFIG_PPC64
565         Elf64_Sym *sym64;
566
567         sym64 = find_symbol64(v64, "__kernel_datapage_offset");
568         if (sym64 == NULL) {
569                 printk(KERN_ERR "vDSO64: Can't find symbol "
570                        "__kernel_datapage_offset !\n");
571                 return -1;
572         }
573         *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
574                 (vdso64_pages << PAGE_SHIFT) -
575                 (sym64->st_value - VDSO64_LBASE);
576 #endif /* CONFIG_PPC64 */
577
578         sym32 = find_symbol32(v32, "__kernel_datapage_offset");
579         if (sym32 == NULL) {
580                 printk(KERN_ERR "vDSO32: Can't find symbol "
581                        "__kernel_datapage_offset !\n");
582                 return -1;
583         }
584         *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
585                 (vdso32_pages << PAGE_SHIFT) -
586                 (sym32->st_value - VDSO32_LBASE);
587
588         return 0;
589 }
590
591
592 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
593                                       struct lib64_elfinfo *v64)
594 {
595         void *start32;
596         unsigned long size32;
597
598 #ifdef CONFIG_PPC64
599         void *start64;
600         unsigned long size64;
601
602         start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
603         if (start64)
604                 do_feature_fixups(cur_cpu_spec->cpu_features,
605                                   start64, start64 + size64);
606
607         start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
608         if (start64)
609                 do_feature_fixups(powerpc_firmware_features,
610                                   start64, start64 + size64);
611 #endif /* CONFIG_PPC64 */
612
613         start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
614         if (start32)
615                 do_feature_fixups(cur_cpu_spec->cpu_features,
616                                   start32, start32 + size32);
617
618 #ifdef CONFIG_PPC64
619         start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
620         if (start32)
621                 do_feature_fixups(powerpc_firmware_features,
622                                   start32, start32 + size32);
623 #endif /* CONFIG_PPC64 */
624
625         return 0;
626 }
627
628 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
629                                        struct lib64_elfinfo *v64)
630 {
631         int i;
632
633         for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
634                 struct vdso_patch_def *patch = &vdso_patches[i];
635                 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
636                         == patch->ftr_value;
637                 if (!match)
638                         continue;
639
640                 DBG("replacing %s with %s...\n", patch->gen_name,
641                     patch->fix_name ? "NONE" : patch->fix_name);
642
643                 /*
644                  * Patch the 32 bits and 64 bits symbols. Note that we do not
645                  * patch the "." symbol on 64 bits.
646                  * It would be easy to do, but doesn't seem to be necessary,
647                  * patching the OPD symbol is enough.
648                  */
649                 vdso_do_func_patch32(v32, v64, patch->gen_name,
650                                      patch->fix_name);
651 #ifdef CONFIG_PPC64
652                 vdso_do_func_patch64(v32, v64, patch->gen_name,
653                                      patch->fix_name);
654 #endif /* CONFIG_PPC64 */
655         }
656
657         return 0;
658 }
659
660
661 static __init int vdso_setup(void)
662 {
663         struct lib32_elfinfo    v32;
664         struct lib64_elfinfo    v64;
665
666         v32.hdr = vdso32_kbase;
667 #ifdef CONFIG_PPC64
668         v64.hdr = vdso64_kbase;
669 #endif
670         if (vdso_do_find_sections(&v32, &v64))
671                 return -1;
672
673         if (vdso_fixup_datapage(&v32, &v64))
674                 return -1;
675
676         if (vdso_fixup_features(&v32, &v64))
677                 return -1;
678
679         if (vdso_fixup_alt_funcs(&v32, &v64))
680                 return -1;
681
682         vdso_setup_trampolines(&v32, &v64);
683
684         return 0;
685 }
686
687 /*
688  * Called from setup_arch to initialize the bitmap of available
689  * syscalls in the systemcfg page
690  */
691 static void __init vdso_setup_syscall_map(void)
692 {
693         unsigned int i;
694         extern unsigned long *sys_call_table;
695         extern unsigned long sys_ni_syscall;
696
697
698         for (i = 0; i < __NR_syscalls; i++) {
699 #ifdef CONFIG_PPC64
700                 if (sys_call_table[i*2] != sys_ni_syscall)
701                         vdso_data->syscall_map_64[i >> 5] |=
702                                 0x80000000UL >> (i & 0x1f);
703                 if (sys_call_table[i*2+1] != sys_ni_syscall)
704                         vdso_data->syscall_map_32[i >> 5] |=
705                                 0x80000000UL >> (i & 0x1f);
706 #else /* CONFIG_PPC64 */
707                 if (sys_call_table[i] != sys_ni_syscall)
708                         vdso_data->syscall_map_32[i >> 5] |=
709                                 0x80000000UL >> (i & 0x1f);
710 #endif /* CONFIG_PPC64 */
711         }
712 }
713
714
715 void __init vdso_init(void)
716 {
717         int i;
718
719 #ifdef CONFIG_PPC64
720         /*
721          * Fill up the "systemcfg" stuff for backward compatiblity
722          */
723         strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
724         vdso_data->version.major = SYSTEMCFG_MAJOR;
725         vdso_data->version.minor = SYSTEMCFG_MINOR;
726         vdso_data->processor = mfspr(SPRN_PVR);
727         /*
728          * Fake the old platform number for pSeries and iSeries and add
729          * in LPAR bit if necessary
730          */
731         vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
732         if (firmware_has_feature(FW_FEATURE_LPAR))
733                 vdso_data->platform |= 1;
734         vdso_data->physicalMemorySize = lmb_phys_mem_size();
735         vdso_data->dcache_size = ppc64_caches.dsize;
736         vdso_data->dcache_line_size = ppc64_caches.dline_size;
737         vdso_data->icache_size = ppc64_caches.isize;
738         vdso_data->icache_line_size = ppc64_caches.iline_size;
739
740         /*
741          * Calculate the size of the 64 bits vDSO
742          */
743         vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
744         DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
745 #endif /* CONFIG_PPC64 */
746
747
748         /*
749          * Calculate the size of the 32 bits vDSO
750          */
751         vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
752         DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
753
754
755         /*
756          * Setup the syscall map in the vDOS
757          */
758         vdso_setup_syscall_map();
759
760         /*
761          * Initialize the vDSO images in memory, that is do necessary
762          * fixups of vDSO symbols, locate trampolines, etc...
763          */
764         if (vdso_setup()) {
765                 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
766                 vdso32_pages = 0;
767 #ifdef CONFIG_PPC64
768                 vdso64_pages = 0;
769 #endif
770                 return;
771         }
772
773         /* Make sure pages are in the correct state */
774         for (i = 0; i < vdso32_pages; i++) {
775                 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
776                 ClearPageReserved(pg);
777                 get_page(pg);
778
779         }
780 #ifdef CONFIG_PPC64
781         for (i = 0; i < vdso64_pages; i++) {
782                 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
783                 ClearPageReserved(pg);
784                 get_page(pg);
785         }
786 #endif /* CONFIG_PPC64 */
787
788         get_page(virt_to_page(vdso_data));
789 }
790
791 int in_gate_area_no_task(unsigned long addr)
792 {
793         return 0;
794 }
795
796 int in_gate_area(struct task_struct *task, unsigned long addr)
797 {
798         return 0;
799 }
800
801 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
802 {
803         return NULL;
804 }
805