xref: /openbmc/linux/arch/powerpc/kernel/vdso.c (revision 3a83e4e6)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 /*
4  *    Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
5  *			 <benh@kernel.crashing.org>
6  */
7 
8 #include <linux/errno.h>
9 #include <linux/sched.h>
10 #include <linux/kernel.h>
11 #include <linux/mm.h>
12 #include <linux/smp.h>
13 #include <linux/stddef.h>
14 #include <linux/unistd.h>
15 #include <linux/slab.h>
16 #include <linux/user.h>
17 #include <linux/elf.h>
18 #include <linux/security.h>
19 #include <linux/memblock.h>
20 
21 #include <asm/processor.h>
22 #include <asm/mmu.h>
23 #include <asm/mmu_context.h>
24 #include <asm/prom.h>
25 #include <asm/machdep.h>
26 #include <asm/cputable.h>
27 #include <asm/sections.h>
28 #include <asm/firmware.h>
29 #include <asm/vdso.h>
30 #include <asm/vdso_datapage.h>
31 #include <asm/setup.h>
32 
33 #undef DEBUG
34 
35 #ifdef DEBUG
36 #define DBG(fmt...) printk(fmt)
37 #else
38 #define DBG(fmt...)
39 #endif
40 
41 /* Max supported size for symbol names */
42 #define MAX_SYMNAME	64
43 
44 /* The alignment of the vDSO */
45 #define VDSO_ALIGNMENT	(1 << 16)
46 
47 static unsigned int vdso32_pages;
48 static void *vdso32_kbase;
49 static struct page **vdso32_pagelist;
50 unsigned long vdso32_sigtramp;
51 unsigned long vdso32_rt_sigtramp;
52 
53 #ifdef CONFIG_VDSO32
54 extern char vdso32_start, vdso32_end;
55 #endif
56 
57 #ifdef CONFIG_PPC64
58 extern char vdso64_start, vdso64_end;
59 static void *vdso64_kbase = &vdso64_start;
60 static unsigned int vdso64_pages;
61 static struct page **vdso64_pagelist;
62 unsigned long vdso64_rt_sigtramp;
63 #endif /* CONFIG_PPC64 */
64 
65 static int vdso_ready;
66 
67 /*
68  * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
69  * Once the early boot kernel code no longer needs to muck around
70  * with it, it will become dynamically allocated
71  */
72 static union {
73 	struct vdso_data	data;
74 	u8			page[PAGE_SIZE];
75 } vdso_data_store __page_aligned_data;
76 struct vdso_data *vdso_data = &vdso_data_store.data;
77 
78 /* Format of the patch table */
79 struct vdso_patch_def
80 {
81 	unsigned long	ftr_mask, ftr_value;
82 	const char	*gen_name;
83 	const char	*fix_name;
84 };
85 
86 /* Table of functions to patch based on the CPU type/revision
87  *
88  * Currently, we only change sync_dicache to do nothing on processors
89  * with a coherent icache
90  */
91 static struct vdso_patch_def vdso_patches[] = {
92 	{
93 		CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
94 		"__kernel_sync_dicache", "__kernel_sync_dicache_p5"
95 	},
96 };
97 
98 /*
99  * Some infos carried around for each of them during parsing at
100  * boot time.
101  */
102 struct lib32_elfinfo
103 {
104 	Elf32_Ehdr	*hdr;		/* ptr to ELF */
105 	Elf32_Sym	*dynsym;	/* ptr to .dynsym section */
106 	unsigned long	dynsymsize;	/* size of .dynsym section */
107 	char		*dynstr;	/* ptr to .dynstr section */
108 	unsigned long	text;		/* offset of .text section in .so */
109 };
110 
111 struct lib64_elfinfo
112 {
113 	Elf64_Ehdr	*hdr;
114 	Elf64_Sym	*dynsym;
115 	unsigned long	dynsymsize;
116 	char		*dynstr;
117 	unsigned long	text;
118 };
119 
120 
121 /*
122  * This is called from binfmt_elf, we create the special vma for the
123  * vDSO and insert it into the mm struct tree
124  */
125 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
126 {
127 	struct mm_struct *mm = current->mm;
128 	struct page **vdso_pagelist;
129 	unsigned long vdso_pages;
130 	unsigned long vdso_base;
131 	int rc;
132 
133 	if (!vdso_ready)
134 		return 0;
135 
136 #ifdef CONFIG_PPC64
137 	if (is_32bit_task()) {
138 		vdso_pagelist = vdso32_pagelist;
139 		vdso_pages = vdso32_pages;
140 		vdso_base = VDSO32_MBASE;
141 	} else {
142 		vdso_pagelist = vdso64_pagelist;
143 		vdso_pages = vdso64_pages;
144 		/*
145 		 * On 64bit we don't have a preferred map address. This
146 		 * allows get_unmapped_area to find an area near other mmaps
147 		 * and most likely share a SLB entry.
148 		 */
149 		vdso_base = 0;
150 	}
151 #else
152 	vdso_pagelist = vdso32_pagelist;
153 	vdso_pages = vdso32_pages;
154 	vdso_base = VDSO32_MBASE;
155 #endif
156 
157 	current->mm->context.vdso_base = 0;
158 
159 	/* vDSO has a problem and was disabled, just don't "enable" it for the
160 	 * process
161 	 */
162 	if (vdso_pages == 0)
163 		return 0;
164 	/* Add a page to the vdso size for the data page */
165 	vdso_pages ++;
166 
167 	/*
168 	 * pick a base address for the vDSO in process space. We try to put it
169 	 * at vdso_base which is the "natural" base for it, but we might fail
170 	 * and end up putting it elsewhere.
171 	 * Add enough to the size so that the result can be aligned.
172 	 */
173 	if (mmap_write_lock_killable(mm))
174 		return -EINTR;
175 	vdso_base = get_unmapped_area(NULL, vdso_base,
176 				      (vdso_pages << PAGE_SHIFT) +
177 				      ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
178 				      0, 0);
179 	if (IS_ERR_VALUE(vdso_base)) {
180 		rc = vdso_base;
181 		goto fail_mmapsem;
182 	}
183 
184 	/* Add required alignment. */
185 	vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
186 
187 	/*
188 	 * Put vDSO base into mm struct. We need to do this before calling
189 	 * install_special_mapping or the perf counter mmap tracking code
190 	 * will fail to recognise it as a vDSO (since arch_vma_name fails).
191 	 */
192 	current->mm->context.vdso_base = vdso_base;
193 
194 	/*
195 	 * our vma flags don't have VM_WRITE so by default, the process isn't
196 	 * allowed to write those pages.
197 	 * gdb can break that with ptrace interface, and thus trigger COW on
198 	 * those pages but it's then your responsibility to never do that on
199 	 * the "data" page of the vDSO or you'll stop getting kernel updates
200 	 * and your nice userland gettimeofday will be totally dead.
201 	 * It's fine to use that for setting breakpoints in the vDSO code
202 	 * pages though.
203 	 */
204 	rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
205 				     VM_READ|VM_EXEC|
206 				     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
207 				     vdso_pagelist);
208 	if (rc) {
209 		current->mm->context.vdso_base = 0;
210 		goto fail_mmapsem;
211 	}
212 
213 	mmap_write_unlock(mm);
214 	return 0;
215 
216  fail_mmapsem:
217 	mmap_write_unlock(mm);
218 	return rc;
219 }
220 
221 const char *arch_vma_name(struct vm_area_struct *vma)
222 {
223 	if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
224 		return "[vdso]";
225 	return NULL;
226 }
227 
228 
229 
230 #ifdef CONFIG_VDSO32
231 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
232 				  unsigned long *size)
233 {
234 	Elf32_Shdr *sechdrs;
235 	unsigned int i;
236 	char *secnames;
237 
238 	/* Grab section headers and strings so we can tell who is who */
239 	sechdrs = (void *)ehdr + ehdr->e_shoff;
240 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
241 
242 	/* Find the section they want */
243 	for (i = 1; i < ehdr->e_shnum; i++) {
244 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
245 			if (size)
246 				*size = sechdrs[i].sh_size;
247 			return (void *)ehdr + sechdrs[i].sh_offset;
248 		}
249 	}
250 	*size = 0;
251 	return NULL;
252 }
253 
254 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
255 					const char *symname)
256 {
257 	unsigned int i;
258 	char name[MAX_SYMNAME], *c;
259 
260 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
261 		if (lib->dynsym[i].st_name == 0)
262 			continue;
263 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
264 			MAX_SYMNAME);
265 		c = strchr(name, '@');
266 		if (c)
267 			*c = 0;
268 		if (strcmp(symname, name) == 0)
269 			return &lib->dynsym[i];
270 	}
271 	return NULL;
272 }
273 
274 /* Note that we assume the section is .text and the symbol is relative to
275  * the library base
276  */
277 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
278 					    const char *symname)
279 {
280 	Elf32_Sym *sym = find_symbol32(lib, symname);
281 
282 	if (sym == NULL) {
283 		printk(KERN_WARNING "vDSO32: function %s not found !\n",
284 		       symname);
285 		return 0;
286 	}
287 	return sym->st_value - VDSO32_LBASE;
288 }
289 
290 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
291 				       struct lib64_elfinfo *v64,
292 				       const char *orig, const char *fix)
293 {
294 	Elf32_Sym *sym32_gen, *sym32_fix;
295 
296 	sym32_gen = find_symbol32(v32, orig);
297 	if (sym32_gen == NULL) {
298 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
299 		return -1;
300 	}
301 	if (fix == NULL) {
302 		sym32_gen->st_name = 0;
303 		return 0;
304 	}
305 	sym32_fix = find_symbol32(v32, fix);
306 	if (sym32_fix == NULL) {
307 		printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
308 		return -1;
309 	}
310 	sym32_gen->st_value = sym32_fix->st_value;
311 	sym32_gen->st_size = sym32_fix->st_size;
312 	sym32_gen->st_info = sym32_fix->st_info;
313 	sym32_gen->st_other = sym32_fix->st_other;
314 	sym32_gen->st_shndx = sym32_fix->st_shndx;
315 
316 	return 0;
317 }
318 #else /* !CONFIG_VDSO32 */
319 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
320 					    const char *symname)
321 {
322 	return 0;
323 }
324 
325 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
326 				       struct lib64_elfinfo *v64,
327 				       const char *orig, const char *fix)
328 {
329 	return 0;
330 }
331 #endif /* CONFIG_VDSO32 */
332 
333 
334 #ifdef CONFIG_PPC64
335 
336 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
337 				  unsigned long *size)
338 {
339 	Elf64_Shdr *sechdrs;
340 	unsigned int i;
341 	char *secnames;
342 
343 	/* Grab section headers and strings so we can tell who is who */
344 	sechdrs = (void *)ehdr + ehdr->e_shoff;
345 	secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
346 
347 	/* Find the section they want */
348 	for (i = 1; i < ehdr->e_shnum; i++) {
349 		if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
350 			if (size)
351 				*size = sechdrs[i].sh_size;
352 			return (void *)ehdr + sechdrs[i].sh_offset;
353 		}
354 	}
355 	if (size)
356 		*size = 0;
357 	return NULL;
358 }
359 
360 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
361 					const char *symname)
362 {
363 	unsigned int i;
364 	char name[MAX_SYMNAME], *c;
365 
366 	for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
367 		if (lib->dynsym[i].st_name == 0)
368 			continue;
369 		strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
370 			MAX_SYMNAME);
371 		c = strchr(name, '@');
372 		if (c)
373 			*c = 0;
374 		if (strcmp(symname, name) == 0)
375 			return &lib->dynsym[i];
376 	}
377 	return NULL;
378 }
379 
380 /* Note that we assume the section is .text and the symbol is relative to
381  * the library base
382  */
383 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
384 					    const char *symname)
385 {
386 	Elf64_Sym *sym = find_symbol64(lib, symname);
387 
388 	if (sym == NULL) {
389 		printk(KERN_WARNING "vDSO64: function %s not found !\n",
390 		       symname);
391 		return 0;
392 	}
393 	return sym->st_value - VDSO64_LBASE;
394 }
395 
396 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
397 				       struct lib64_elfinfo *v64,
398 				       const char *orig, const char *fix)
399 {
400 	Elf64_Sym *sym64_gen, *sym64_fix;
401 
402 	sym64_gen = find_symbol64(v64, orig);
403 	if (sym64_gen == NULL) {
404 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
405 		return -1;
406 	}
407 	if (fix == NULL) {
408 		sym64_gen->st_name = 0;
409 		return 0;
410 	}
411 	sym64_fix = find_symbol64(v64, fix);
412 	if (sym64_fix == NULL) {
413 		printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
414 		return -1;
415 	}
416 	sym64_gen->st_value = sym64_fix->st_value;
417 	sym64_gen->st_size = sym64_fix->st_size;
418 	sym64_gen->st_info = sym64_fix->st_info;
419 	sym64_gen->st_other = sym64_fix->st_other;
420 	sym64_gen->st_shndx = sym64_fix->st_shndx;
421 
422 	return 0;
423 }
424 
425 #endif /* CONFIG_PPC64 */
426 
427 
428 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
429 					struct lib64_elfinfo *v64)
430 {
431 	void *sect;
432 
433 	/*
434 	 * Locate symbol tables & text section
435 	 */
436 
437 #ifdef CONFIG_VDSO32
438 	v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
439 	v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
440 	if (v32->dynsym == NULL || v32->dynstr == NULL) {
441 		printk(KERN_ERR "vDSO32: required symbol section not found\n");
442 		return -1;
443 	}
444 	sect = find_section32(v32->hdr, ".text", NULL);
445 	if (sect == NULL) {
446 		printk(KERN_ERR "vDSO32: the .text section was not found\n");
447 		return -1;
448 	}
449 	v32->text = sect - vdso32_kbase;
450 #endif
451 
452 #ifdef CONFIG_PPC64
453 	v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
454 	v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
455 	if (v64->dynsym == NULL || v64->dynstr == NULL) {
456 		printk(KERN_ERR "vDSO64: required symbol section not found\n");
457 		return -1;
458 	}
459 	sect = find_section64(v64->hdr, ".text", NULL);
460 	if (sect == NULL) {
461 		printk(KERN_ERR "vDSO64: the .text section was not found\n");
462 		return -1;
463 	}
464 	v64->text = sect - vdso64_kbase;
465 #endif /* CONFIG_PPC64 */
466 
467 	return 0;
468 }
469 
470 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
471 					  struct lib64_elfinfo *v64)
472 {
473 	/*
474 	 * Find signal trampolines
475 	 */
476 
477 #ifdef CONFIG_PPC64
478 	vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
479 #endif
480 	vdso32_sigtramp	   = find_function32(v32, "__kernel_sigtramp32");
481 	vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
482 }
483 
484 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
485 				       struct lib64_elfinfo *v64)
486 {
487 #ifdef CONFIG_VDSO32
488 	Elf32_Sym *sym32;
489 #endif
490 #ifdef CONFIG_PPC64
491 	Elf64_Sym *sym64;
492 
493        	sym64 = find_symbol64(v64, "__kernel_datapage_offset");
494 	if (sym64 == NULL) {
495 		printk(KERN_ERR "vDSO64: Can't find symbol "
496 		       "__kernel_datapage_offset !\n");
497 		return -1;
498 	}
499 	*((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
500 		(vdso64_pages << PAGE_SHIFT) -
501 		(sym64->st_value - VDSO64_LBASE);
502 #endif /* CONFIG_PPC64 */
503 
504 #ifdef CONFIG_VDSO32
505 	sym32 = find_symbol32(v32, "__kernel_datapage_offset");
506 	if (sym32 == NULL) {
507 		printk(KERN_ERR "vDSO32: Can't find symbol "
508 		       "__kernel_datapage_offset !\n");
509 		return -1;
510 	}
511 	*((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
512 		(vdso32_pages << PAGE_SHIFT) -
513 		(sym32->st_value - VDSO32_LBASE);
514 #endif
515 
516 	return 0;
517 }
518 
519 
520 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
521 				      struct lib64_elfinfo *v64)
522 {
523 	unsigned long size;
524 	void *start;
525 
526 #ifdef CONFIG_PPC64
527 	start = find_section64(v64->hdr, "__ftr_fixup", &size);
528 	if (start)
529 		do_feature_fixups(cur_cpu_spec->cpu_features,
530 				  start, start + size);
531 
532 	start = find_section64(v64->hdr, "__mmu_ftr_fixup", &size);
533 	if (start)
534 		do_feature_fixups(cur_cpu_spec->mmu_features,
535 				  start, start + size);
536 
537 	start = find_section64(v64->hdr, "__fw_ftr_fixup", &size);
538 	if (start)
539 		do_feature_fixups(powerpc_firmware_features,
540 				  start, start + size);
541 
542 	start = find_section64(v64->hdr, "__lwsync_fixup", &size);
543 	if (start)
544 		do_lwsync_fixups(cur_cpu_spec->cpu_features,
545 				 start, start + size);
546 #endif /* CONFIG_PPC64 */
547 
548 #ifdef CONFIG_VDSO32
549 	start = find_section32(v32->hdr, "__ftr_fixup", &size);
550 	if (start)
551 		do_feature_fixups(cur_cpu_spec->cpu_features,
552 				  start, start + size);
553 
554 	start = find_section32(v32->hdr, "__mmu_ftr_fixup", &size);
555 	if (start)
556 		do_feature_fixups(cur_cpu_spec->mmu_features,
557 				  start, start + size);
558 
559 #ifdef CONFIG_PPC64
560 	start = find_section32(v32->hdr, "__fw_ftr_fixup", &size);
561 	if (start)
562 		do_feature_fixups(powerpc_firmware_features,
563 				  start, start + size);
564 #endif /* CONFIG_PPC64 */
565 
566 	start = find_section32(v32->hdr, "__lwsync_fixup", &size);
567 	if (start)
568 		do_lwsync_fixups(cur_cpu_spec->cpu_features,
569 				 start, start + size);
570 #endif
571 
572 	return 0;
573 }
574 
575 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
576 				       struct lib64_elfinfo *v64)
577 {
578 	int i;
579 
580 	for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
581 		struct vdso_patch_def *patch = &vdso_patches[i];
582 		int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
583 			== patch->ftr_value;
584 		if (!match)
585 			continue;
586 
587 		DBG("replacing %s with %s...\n", patch->gen_name,
588 		    patch->fix_name ? "NONE" : patch->fix_name);
589 
590 		/*
591 		 * Patch the 32 bits and 64 bits symbols. Note that we do not
592 		 * patch the "." symbol on 64 bits.
593 		 * It would be easy to do, but doesn't seem to be necessary,
594 		 * patching the OPD symbol is enough.
595 		 */
596 		vdso_do_func_patch32(v32, v64, patch->gen_name,
597 				     patch->fix_name);
598 #ifdef CONFIG_PPC64
599 		vdso_do_func_patch64(v32, v64, patch->gen_name,
600 				     patch->fix_name);
601 #endif /* CONFIG_PPC64 */
602 	}
603 
604 	return 0;
605 }
606 
607 
608 static __init int vdso_setup(void)
609 {
610 	struct lib32_elfinfo	v32;
611 	struct lib64_elfinfo	v64;
612 
613 	v32.hdr = vdso32_kbase;
614 #ifdef CONFIG_PPC64
615 	v64.hdr = vdso64_kbase;
616 #endif
617 	if (vdso_do_find_sections(&v32, &v64))
618 		return -1;
619 
620 	if (vdso_fixup_datapage(&v32, &v64))
621 		return -1;
622 
623 	if (vdso_fixup_features(&v32, &v64))
624 		return -1;
625 
626 	if (vdso_fixup_alt_funcs(&v32, &v64))
627 		return -1;
628 
629 	vdso_setup_trampolines(&v32, &v64);
630 
631 	return 0;
632 }
633 
634 /*
635  * Called from setup_arch to initialize the bitmap of available
636  * syscalls in the systemcfg page
637  */
638 static void __init vdso_setup_syscall_map(void)
639 {
640 	unsigned int i;
641 	extern unsigned long *sys_call_table;
642 #ifdef CONFIG_PPC64
643 	extern unsigned long *compat_sys_call_table;
644 #endif
645 	extern unsigned long sys_ni_syscall;
646 
647 
648 	for (i = 0; i < NR_syscalls; i++) {
649 #ifdef CONFIG_PPC64
650 		if (sys_call_table[i] != sys_ni_syscall)
651 			vdso_data->syscall_map_64[i >> 5] |=
652 				0x80000000UL >> (i & 0x1f);
653 		if (IS_ENABLED(CONFIG_COMPAT) &&
654 		    compat_sys_call_table[i] != sys_ni_syscall)
655 			vdso_data->syscall_map_32[i >> 5] |=
656 				0x80000000UL >> (i & 0x1f);
657 #else /* CONFIG_PPC64 */
658 		if (sys_call_table[i] != sys_ni_syscall)
659 			vdso_data->syscall_map_32[i >> 5] |=
660 				0x80000000UL >> (i & 0x1f);
661 #endif /* CONFIG_PPC64 */
662 	}
663 }
664 
665 #ifdef CONFIG_PPC64
666 int vdso_getcpu_init(void)
667 {
668 	unsigned long cpu, node, val;
669 
670 	/*
671 	 * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
672 	 * in the next 16 bits.  The VDSO uses this to implement getcpu().
673 	 */
674 	cpu = get_cpu();
675 	WARN_ON_ONCE(cpu > 0xffff);
676 
677 	node = cpu_to_node(cpu);
678 	WARN_ON_ONCE(node > 0xffff);
679 
680 	val = (cpu & 0xffff) | ((node & 0xffff) << 16);
681 	mtspr(SPRN_SPRG_VDSO_WRITE, val);
682 	get_paca()->sprg_vdso = val;
683 
684 	put_cpu();
685 
686 	return 0;
687 }
688 /* We need to call this before SMP init */
689 early_initcall(vdso_getcpu_init);
690 #endif
691 
692 static int __init vdso_init(void)
693 {
694 	int i;
695 
696 #ifdef CONFIG_PPC64
697 	/*
698 	 * Fill up the "systemcfg" stuff for backward compatibility
699 	 */
700 	strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
701 	vdso_data->version.major = SYSTEMCFG_MAJOR;
702 	vdso_data->version.minor = SYSTEMCFG_MINOR;
703 	vdso_data->processor = mfspr(SPRN_PVR);
704 	/*
705 	 * Fake the old platform number for pSeries and add
706 	 * in LPAR bit if necessary
707 	 */
708 	vdso_data->platform = 0x100;
709 	if (firmware_has_feature(FW_FEATURE_LPAR))
710 		vdso_data->platform |= 1;
711 	vdso_data->physicalMemorySize = memblock_phys_mem_size();
712 	vdso_data->dcache_size = ppc64_caches.l1d.size;
713 	vdso_data->dcache_line_size = ppc64_caches.l1d.line_size;
714 	vdso_data->icache_size = ppc64_caches.l1i.size;
715 	vdso_data->icache_line_size = ppc64_caches.l1i.line_size;
716 	vdso_data->dcache_block_size = ppc64_caches.l1d.block_size;
717 	vdso_data->icache_block_size = ppc64_caches.l1i.block_size;
718 	vdso_data->dcache_log_block_size = ppc64_caches.l1d.log_block_size;
719 	vdso_data->icache_log_block_size = ppc64_caches.l1i.log_block_size;
720 
721 	/*
722 	 * Calculate the size of the 64 bits vDSO
723 	 */
724 	vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
725 	DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
726 #endif /* CONFIG_PPC64 */
727 
728 
729 #ifdef CONFIG_VDSO32
730 	vdso32_kbase = &vdso32_start;
731 
732 	/*
733 	 * Calculate the size of the 32 bits vDSO
734 	 */
735 	vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
736 	DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
737 #endif
738 
739 
740 	/*
741 	 * Setup the syscall map in the vDOS
742 	 */
743 	vdso_setup_syscall_map();
744 
745 	/*
746 	 * Initialize the vDSO images in memory, that is do necessary
747 	 * fixups of vDSO symbols, locate trampolines, etc...
748 	 */
749 	if (vdso_setup()) {
750 		printk(KERN_ERR "vDSO setup failure, not enabled !\n");
751 		vdso32_pages = 0;
752 #ifdef CONFIG_PPC64
753 		vdso64_pages = 0;
754 #endif
755 		return 0;
756 	}
757 
758 #ifdef CONFIG_VDSO32
759 	/* Make sure pages are in the correct state */
760 	vdso32_pagelist = kcalloc(vdso32_pages + 2, sizeof(struct page *),
761 				  GFP_KERNEL);
762 	BUG_ON(vdso32_pagelist == NULL);
763 	for (i = 0; i < vdso32_pages; i++) {
764 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
765 		get_page(pg);
766 		vdso32_pagelist[i] = pg;
767 	}
768 	vdso32_pagelist[i++] = virt_to_page(vdso_data);
769 	vdso32_pagelist[i] = NULL;
770 #endif
771 
772 #ifdef CONFIG_PPC64
773 	vdso64_pagelist = kcalloc(vdso64_pages + 2, sizeof(struct page *),
774 				  GFP_KERNEL);
775 	BUG_ON(vdso64_pagelist == NULL);
776 	for (i = 0; i < vdso64_pages; i++) {
777 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
778 		get_page(pg);
779 		vdso64_pagelist[i] = pg;
780 	}
781 	vdso64_pagelist[i++] = virt_to_page(vdso_data);
782 	vdso64_pagelist[i] = NULL;
783 #endif /* CONFIG_PPC64 */
784 
785 	get_page(virt_to_page(vdso_data));
786 
787 	smp_wmb();
788 	vdso_ready = 1;
789 
790 	return 0;
791 }
792 arch_initcall(vdso_init);
793