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-rw-r--r--arch/ppc64/kernel/vdso.c625
1 files changed, 0 insertions, 625 deletions
diff --git a/arch/ppc64/kernel/vdso.c b/arch/ppc64/kernel/vdso.c
deleted file mode 100644
index 1bbacac44988..000000000000
--- a/arch/ppc64/kernel/vdso.c
+++ /dev/null
@@ -1,625 +0,0 @@
1/*
2 * linux/arch/ppc64/kernel/vdso.c
3 *
4 * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
5 * <benh@kernel.crashing.org>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13#include <linux/config.h>
14#include <linux/module.h>
15#include <linux/errno.h>
16#include <linux/sched.h>
17#include <linux/kernel.h>
18#include <linux/mm.h>
19#include <linux/smp.h>
20#include <linux/smp_lock.h>
21#include <linux/stddef.h>
22#include <linux/unistd.h>
23#include <linux/slab.h>
24#include <linux/user.h>
25#include <linux/elf.h>
26#include <linux/security.h>
27#include <linux/bootmem.h>
28
29#include <asm/pgtable.h>
30#include <asm/system.h>
31#include <asm/processor.h>
32#include <asm/mmu.h>
33#include <asm/mmu_context.h>
34#include <asm/machdep.h>
35#include <asm/cputable.h>
36#include <asm/sections.h>
37#include <asm/systemcfg.h>
38#include <asm/vdso.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
49/*
50 * The vDSOs themselves are here
51 */
52extern char vdso64_start, vdso64_end;
53extern char vdso32_start, vdso32_end;
54
55static void *vdso64_kbase = &vdso64_start;
56static void *vdso32_kbase = &vdso32_start;
57
58unsigned int vdso64_pages;
59unsigned int vdso32_pages;
60
61/* Signal trampolines user addresses */
62
63unsigned long vdso64_rt_sigtramp;
64unsigned long vdso32_sigtramp;
65unsigned long vdso32_rt_sigtramp;
66
67/* Format of the patch table */
68struct vdso_patch_def
69{
70 u32 pvr_mask, pvr_value;
71 const char *gen_name;
72 const char *fix_name;
73};
74
75/* Table of functions to patch based on the CPU type/revision
76 *
77 * TODO: Improve by adding whole lists for each entry
78 */
79static struct vdso_patch_def vdso_patches[] = {
80 {
81 0xffff0000, 0x003a0000, /* POWER5 */
82 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
83 },
84 {
85 0xffff0000, 0x003b0000, /* POWER5 */
86 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
87 },
88};
89
90/*
91 * Some infos carried around for each of them during parsing at
92 * boot time.
93 */
94struct lib32_elfinfo
95{
96 Elf32_Ehdr *hdr; /* ptr to ELF */
97 Elf32_Sym *dynsym; /* ptr to .dynsym section */
98 unsigned long dynsymsize; /* size of .dynsym section */
99 char *dynstr; /* ptr to .dynstr section */
100 unsigned long text; /* offset of .text section in .so */
101};
102
103struct lib64_elfinfo
104{
105 Elf64_Ehdr *hdr;
106 Elf64_Sym *dynsym;
107 unsigned long dynsymsize;
108 char *dynstr;
109 unsigned long text;
110};
111
112
113#ifdef __DEBUG
114static void dump_one_vdso_page(struct page *pg, struct page *upg)
115{
116 printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
117 page_count(pg),
118 pg->flags);
119 if (upg/* && pg != upg*/) {
120 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg) << PAGE_SHIFT),
121 page_count(upg),
122 upg->flags);
123 }
124 printk("\n");
125}
126
127static void dump_vdso_pages(struct vm_area_struct * vma)
128{
129 int i;
130
131 if (!vma || test_thread_flag(TIF_32BIT)) {
132 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
133 for (i=0; i<vdso32_pages; i++) {
134 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
135 struct page *upg = (vma && vma->vm_mm) ?
136 follow_page(vma->vm_mm, vma->vm_start + i*PAGE_SIZE, 0)
137 : NULL;
138 dump_one_vdso_page(pg, upg);
139 }
140 }
141 if (!vma || !test_thread_flag(TIF_32BIT)) {
142 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
143 for (i=0; i<vdso64_pages; i++) {
144 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
145 struct page *upg = (vma && vma->vm_mm) ?
146 follow_page(vma->vm_mm, vma->vm_start + i*PAGE_SIZE, 0)
147 : NULL;
148 dump_one_vdso_page(pg, upg);
149 }
150 }
151}
152#endif /* DEBUG */
153
154/*
155 * Keep a dummy vma_close for now, it will prevent VMA merging.
156 */
157static void vdso_vma_close(struct vm_area_struct * vma)
158{
159}
160
161/*
162 * Our nopage() function, maps in the actual vDSO kernel pages, they will
163 * be mapped read-only by do_no_page(), and eventually COW'ed, either
164 * right away for an initial write access, or by do_wp_page().
165 */
166static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
167 unsigned long address, int *type)
168{
169 unsigned long offset = address - vma->vm_start;
170 struct page *pg;
171 void *vbase = test_thread_flag(TIF_32BIT) ? vdso32_kbase : vdso64_kbase;
172
173 DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
174 current->comm, address, offset);
175
176 if (address < vma->vm_start || address > vma->vm_end)
177 return NOPAGE_SIGBUS;
178
179 /*
180 * Last page is systemcfg.
181 */
182 if ((vma->vm_end - address) <= PAGE_SIZE)
183 pg = virt_to_page(_systemcfg);
184 else
185 pg = virt_to_page(vbase + offset);
186
187 get_page(pg);
188 DBG(" ->page count: %d\n", page_count(pg));
189
190 return pg;
191}
192
193static struct vm_operations_struct vdso_vmops = {
194 .close = vdso_vma_close,
195 .nopage = vdso_vma_nopage,
196};
197
198/*
199 * This is called from binfmt_elf, we create the special vma for the
200 * vDSO and insert it into the mm struct tree
201 */
202int arch_setup_additional_pages(struct linux_binprm *bprm, int executable_stack)
203{
204 struct mm_struct *mm = current->mm;
205 struct vm_area_struct *vma;
206 unsigned long vdso_pages;
207 unsigned long vdso_base;
208
209 if (test_thread_flag(TIF_32BIT)) {
210 vdso_pages = vdso32_pages;
211 vdso_base = VDSO32_MBASE;
212 } else {
213 vdso_pages = vdso64_pages;
214 vdso_base = VDSO64_MBASE;
215 }
216
217 current->thread.vdso_base = 0;
218
219 /* vDSO has a problem and was disabled, just don't "enable" it for the
220 * process
221 */
222 if (vdso_pages == 0)
223 return 0;
224
225 vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
226 if (vma == NULL)
227 return -ENOMEM;
228
229 memset(vma, 0, sizeof(*vma));
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 */
236 vdso_base = get_unmapped_area(NULL, vdso_base,
237 vdso_pages << PAGE_SHIFT, 0, 0);
238 if (vdso_base & ~PAGE_MASK) {
239 kmem_cache_free(vm_area_cachep, vma);
240 return (int)vdso_base;
241 }
242
243 current->thread.vdso_base = vdso_base;
244
245 vma->vm_mm = mm;
246 vma->vm_start = current->thread.vdso_base;
247
248 /*
249 * the VMA size is one page more than the vDSO since systemcfg
250 * is mapped in the last one
251 */
252 vma->vm_end = vma->vm_start + ((vdso_pages + 1) << PAGE_SHIFT);
253
254 /*
255 * our vma flags don't have VM_WRITE so by default, the process isn't allowed
256 * to write those pages.
257 * gdb can break that with ptrace interface, and thus trigger COW on those
258 * pages but it's then your responsibility to never do that on the "data" page
259 * of the vDSO or you'll stop getting kernel updates and your nice userland
260 * gettimeofday will be totally dead. It's fine to use that for setting
261 * breakpoints in the vDSO code pages though
262 */
263 vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC | VM_RESERVED;
264 vma->vm_flags |= mm->def_flags;
265 vma->vm_page_prot = protection_map[vma->vm_flags & 0x7];
266 vma->vm_ops = &vdso_vmops;
267
268 down_write(&mm->mmap_sem);
269 if (insert_vm_struct(mm, vma)) {
270 up_write(&mm->mmap_sem);
271 kmem_cache_free(vm_area_cachep, vma);
272 return -ENOMEM;
273 }
274 mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
275 up_write(&mm->mmap_sem);
276
277 return 0;
278}
279
280static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
281 unsigned long *size)
282{
283 Elf32_Shdr *sechdrs;
284 unsigned int i;
285 char *secnames;
286
287 /* Grab section headers and strings so we can tell who is who */
288 sechdrs = (void *)ehdr + ehdr->e_shoff;
289 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
290
291 /* Find the section they want */
292 for (i = 1; i < ehdr->e_shnum; i++) {
293 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
294 if (size)
295 *size = sechdrs[i].sh_size;
296 return (void *)ehdr + sechdrs[i].sh_offset;
297 }
298 }
299 *size = 0;
300 return NULL;
301}
302
303static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
304 unsigned long *size)
305{
306 Elf64_Shdr *sechdrs;
307 unsigned int i;
308 char *secnames;
309
310 /* Grab section headers and strings so we can tell who is who */
311 sechdrs = (void *)ehdr + ehdr->e_shoff;
312 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
313
314 /* Find the section they want */
315 for (i = 1; i < ehdr->e_shnum; i++) {
316 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
317 if (size)
318 *size = sechdrs[i].sh_size;
319 return (void *)ehdr + sechdrs[i].sh_offset;
320 }
321 }
322 if (size)
323 *size = 0;
324 return NULL;
325}
326
327static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib, const char *symname)
328{
329 unsigned int i;
330 char name[32], *c;
331
332 for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
333 if (lib->dynsym[i].st_name == 0)
334 continue;
335 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name, 32);
336 c = strchr(name, '@');
337 if (c)
338 *c = 0;
339 if (strcmp(symname, name) == 0)
340 return &lib->dynsym[i];
341 }
342 return NULL;
343}
344
345static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib, const char *symname)
346{
347 unsigned int i;
348 char name[32], *c;
349
350 for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
351 if (lib->dynsym[i].st_name == 0)
352 continue;
353 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name, 32);
354 c = strchr(name, '@');
355 if (c)
356 *c = 0;
357 if (strcmp(symname, name) == 0)
358 return &lib->dynsym[i];
359 }
360 return NULL;
361}
362
363/* Note that we assume the section is .text and the symbol is relative to
364 * the library base
365 */
366static unsigned long __init find_function32(struct lib32_elfinfo *lib, const char *symname)
367{
368 Elf32_Sym *sym = find_symbol32(lib, symname);
369
370 if (sym == NULL) {
371 printk(KERN_WARNING "vDSO32: function %s not found !\n", symname);
372 return 0;
373 }
374 return sym->st_value - VDSO32_LBASE;
375}
376
377/* Note that we assume the section is .text and the symbol is relative to
378 * the library base
379 */
380static unsigned long __init find_function64(struct lib64_elfinfo *lib, const char *symname)
381{
382 Elf64_Sym *sym = find_symbol64(lib, symname);
383
384 if (sym == NULL) {
385 printk(KERN_WARNING "vDSO64: function %s not found !\n", symname);
386 return 0;
387 }
388#ifdef VDS64_HAS_DESCRIPTORS
389 return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) - VDSO64_LBASE;
390#else
391 return sym->st_value - VDSO64_LBASE;
392#endif
393}
394
395
396static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
397 struct lib64_elfinfo *v64)
398{
399 void *sect;
400
401 /*
402 * Locate symbol tables & text section
403 */
404
405 v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
406 v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
407 if (v32->dynsym == NULL || v32->dynstr == NULL) {
408 printk(KERN_ERR "vDSO32: a required symbol section was not found\n");
409 return -1;
410 }
411 sect = find_section32(v32->hdr, ".text", NULL);
412 if (sect == NULL) {
413 printk(KERN_ERR "vDSO32: the .text section was not found\n");
414 return -1;
415 }
416 v32->text = sect - vdso32_kbase;
417
418 v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
419 v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
420 if (v64->dynsym == NULL || v64->dynstr == NULL) {
421 printk(KERN_ERR "vDSO64: a required symbol section was not found\n");
422 return -1;
423 }
424 sect = find_section64(v64->hdr, ".text", NULL);
425 if (sect == NULL) {
426 printk(KERN_ERR "vDSO64: the .text section was not found\n");
427 return -1;
428 }
429 v64->text = sect - vdso64_kbase;
430
431 return 0;
432}
433
434static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
435 struct lib64_elfinfo *v64)
436{
437 /*
438 * Find signal trampolines
439 */
440
441 vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
442 vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32");
443 vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
444}
445
446static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
447 struct lib64_elfinfo *v64)
448{
449 Elf32_Sym *sym32;
450 Elf64_Sym *sym64;
451
452 sym32 = find_symbol32(v32, "__kernel_datapage_offset");
453 if (sym32 == NULL) {
454 printk(KERN_ERR "vDSO32: Can't find symbol __kernel_datapage_offset !\n");
455 return -1;
456 }
457 *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
458 (vdso32_pages << PAGE_SHIFT) - (sym32->st_value - VDSO32_LBASE);
459
460 sym64 = find_symbol64(v64, "__kernel_datapage_offset");
461 if (sym64 == NULL) {
462 printk(KERN_ERR "vDSO64: Can't find symbol __kernel_datapage_offset !\n");
463 return -1;
464 }
465 *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
466 (vdso64_pages << PAGE_SHIFT) - (sym64->st_value - VDSO64_LBASE);
467
468 return 0;
469}
470
471static int vdso_do_func_patch32(struct lib32_elfinfo *v32,
472 struct lib64_elfinfo *v64,
473 const char *orig, const char *fix)
474{
475 Elf32_Sym *sym32_gen, *sym32_fix;
476
477 sym32_gen = find_symbol32(v32, orig);
478 if (sym32_gen == NULL) {
479 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
480 return -1;
481 }
482 sym32_fix = find_symbol32(v32, fix);
483 if (sym32_fix == NULL) {
484 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
485 return -1;
486 }
487 sym32_gen->st_value = sym32_fix->st_value;
488 sym32_gen->st_size = sym32_fix->st_size;
489 sym32_gen->st_info = sym32_fix->st_info;
490 sym32_gen->st_other = sym32_fix->st_other;
491 sym32_gen->st_shndx = sym32_fix->st_shndx;
492
493 return 0;
494}
495
496static int vdso_do_func_patch64(struct lib32_elfinfo *v32,
497 struct lib64_elfinfo *v64,
498 const char *orig, const char *fix)
499{
500 Elf64_Sym *sym64_gen, *sym64_fix;
501
502 sym64_gen = find_symbol64(v64, orig);
503 if (sym64_gen == NULL) {
504 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
505 return -1;
506 }
507 sym64_fix = find_symbol64(v64, fix);
508 if (sym64_fix == NULL) {
509 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
510 return -1;
511 }
512 sym64_gen->st_value = sym64_fix->st_value;
513 sym64_gen->st_size = sym64_fix->st_size;
514 sym64_gen->st_info = sym64_fix->st_info;
515 sym64_gen->st_other = sym64_fix->st_other;
516 sym64_gen->st_shndx = sym64_fix->st_shndx;
517
518 return 0;
519}
520
521static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
522 struct lib64_elfinfo *v64)
523{
524 u32 pvr;
525 int i;
526
527 pvr = mfspr(SPRN_PVR);
528 for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
529 struct vdso_patch_def *patch = &vdso_patches[i];
530 int match = (pvr & patch->pvr_mask) == patch->pvr_value;
531
532 DBG("patch %d (mask: %x, pvr: %x) : %s\n",
533 i, patch->pvr_mask, patch->pvr_value, match ? "match" : "skip");
534
535 if (!match)
536 continue;
537
538 DBG("replacing %s with %s...\n", patch->gen_name, patch->fix_name);
539
540 /*
541 * Patch the 32 bits and 64 bits symbols. Note that we do not patch
542 * the "." symbol on 64 bits. It would be easy to do, but doesn't
543 * seem to be necessary, patching the OPD symbol is enough.
544 */
545 vdso_do_func_patch32(v32, v64, patch->gen_name, patch->fix_name);
546 vdso_do_func_patch64(v32, v64, patch->gen_name, patch->fix_name);
547 }
548
549 return 0;
550}
551
552
553static __init int vdso_setup(void)
554{
555 struct lib32_elfinfo v32;
556 struct lib64_elfinfo v64;
557
558 v32.hdr = vdso32_kbase;
559 v64.hdr = vdso64_kbase;
560
561 if (vdso_do_find_sections(&v32, &v64))
562 return -1;
563
564 if (vdso_fixup_datapage(&v32, &v64))
565 return -1;
566
567 if (vdso_fixup_alt_funcs(&v32, &v64))
568 return -1;
569
570 vdso_setup_trampolines(&v32, &v64);
571
572 return 0;
573}
574
575void __init vdso_init(void)
576{
577 int i;
578
579 vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
580 vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
581
582 DBG("vdso64_kbase: %p, 0x%x pages, vdso32_kbase: %p, 0x%x pages\n",
583 vdso64_kbase, vdso64_pages, vdso32_kbase, vdso32_pages);
584
585 /*
586 * Initialize the vDSO images in memory, that is do necessary
587 * fixups of vDSO symbols, locate trampolines, etc...
588 */
589 if (vdso_setup()) {
590 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
591 /* XXX should free pages here ? */
592 vdso64_pages = vdso32_pages = 0;
593 return;
594 }
595
596 /* Make sure pages are in the correct state */
597 for (i = 0; i < vdso64_pages; i++) {
598 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
599 ClearPageReserved(pg);
600 get_page(pg);
601 }
602 for (i = 0; i < vdso32_pages; i++) {
603 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
604 ClearPageReserved(pg);
605 get_page(pg);
606 }
607
608 get_page(virt_to_page(_systemcfg));
609}
610
611int in_gate_area_no_task(unsigned long addr)
612{
613 return 0;
614}
615
616int in_gate_area(struct task_struct *task, unsigned long addr)
617{
618 return 0;
619}
620
621struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
622{
623 return NULL;
624}
625
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