2 * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
3 * <benh@kernel.crashing.org>
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.
11 #include <linux/module.h>
12 #include <linux/errno.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.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/lmb.h>
26 #include <asm/pgtable.h>
27 #include <asm/system.h>
28 #include <asm/processor.h>
30 #include <asm/mmu_context.h>
32 #include <asm/machdep.h>
33 #include <asm/cputable.h>
34 #include <asm/sections.h>
35 #include <asm/firmware.h>
37 #include <asm/vdso_datapage.h>
44 #define DBG(fmt...) printk(fmt)
49 /* Max supported size for symbol names */
50 #define MAX_SYMNAME 64
52 extern char vdso32_start
, vdso32_end
;
53 static void *vdso32_kbase
= &vdso32_start
;
54 static unsigned int vdso32_pages
;
55 static struct page
**vdso32_pagelist
;
56 unsigned long vdso32_sigtramp
;
57 unsigned long vdso32_rt_sigtramp
;
60 extern char vdso64_start
, vdso64_end
;
61 static void *vdso64_kbase
= &vdso64_start
;
62 static unsigned int vdso64_pages
;
63 static struct page
**vdso64_pagelist
;
64 unsigned long vdso64_rt_sigtramp
;
65 #endif /* CONFIG_PPC64 */
67 static int vdso_ready
;
70 * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
71 * Once the early boot kernel code no longer needs to muck around
72 * with it, it will become dynamically allocated
75 struct vdso_data data
;
77 } vdso_data_store
__attribute__((__section__(".data.page_aligned")));
78 struct vdso_data
*vdso_data
= &vdso_data_store
.data
;
80 /* Format of the patch table */
83 unsigned long ftr_mask
, ftr_value
;
88 /* Table of functions to patch based on the CPU type/revision
90 * Currently, we only change sync_dicache to do nothing on processors
91 * with a coherent icache
93 static struct vdso_patch_def vdso_patches
[] = {
95 CPU_FTR_COHERENT_ICACHE
, CPU_FTR_COHERENT_ICACHE
,
96 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
100 "__kernel_gettimeofday", NULL
104 "__kernel_clock_gettime", NULL
108 "__kernel_clock_getres", NULL
112 "__kernel_get_tbfreq", NULL
117 * Some infos carried around for each of them during parsing at
122 Elf32_Ehdr
*hdr
; /* ptr to ELF */
123 Elf32_Sym
*dynsym
; /* ptr to .dynsym section */
124 unsigned long dynsymsize
; /* size of .dynsym section */
125 char *dynstr
; /* ptr to .dynstr section */
126 unsigned long text
; /* offset of .text section in .so */
133 unsigned long dynsymsize
;
140 static void dump_one_vdso_page(struct page
*pg
, struct page
*upg
)
142 printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg
) << PAGE_SHIFT
),
145 if (upg
&& !IS_ERR(upg
) /* && pg != upg*/) {
146 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg
)
154 static void dump_vdso_pages(struct vm_area_struct
* vma
)
158 if (!vma
|| test_thread_flag(TIF_32BIT
)) {
159 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase
);
160 for (i
=0; i
<vdso32_pages
; i
++) {
161 struct page
*pg
= virt_to_page(vdso32_kbase
+
163 struct page
*upg
= (vma
&& vma
->vm_mm
) ?
164 follow_page(vma
, vma
->vm_start
+ i
*PAGE_SIZE
, 0)
166 dump_one_vdso_page(pg
, upg
);
169 if (!vma
|| !test_thread_flag(TIF_32BIT
)) {
170 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase
);
171 for (i
=0; i
<vdso64_pages
; i
++) {
172 struct page
*pg
= virt_to_page(vdso64_kbase
+
174 struct page
*upg
= (vma
&& vma
->vm_mm
) ?
175 follow_page(vma
, vma
->vm_start
+ i
*PAGE_SIZE
, 0)
177 dump_one_vdso_page(pg
, upg
);
184 * This is called from binfmt_elf, we create the special vma for the
185 * vDSO and insert it into the mm struct tree
187 int arch_setup_additional_pages(struct linux_binprm
*bprm
,
188 int executable_stack
)
190 struct mm_struct
*mm
= current
->mm
;
191 struct page
**vdso_pagelist
;
192 unsigned long vdso_pages
;
193 unsigned long vdso_base
;
200 if (test_thread_flag(TIF_32BIT
)) {
201 vdso_pagelist
= vdso32_pagelist
;
202 vdso_pages
= vdso32_pages
;
203 vdso_base
= VDSO32_MBASE
;
205 vdso_pagelist
= vdso64_pagelist
;
206 vdso_pages
= vdso64_pages
;
207 vdso_base
= VDSO64_MBASE
;
210 vdso_pagelist
= vdso32_pagelist
;
211 vdso_pages
= vdso32_pages
;
212 vdso_base
= VDSO32_MBASE
;
215 current
->mm
->context
.vdso_base
= 0;
217 /* vDSO has a problem and was disabled, just don't "enable" it for the
222 /* Add a page to the vdso size for the data page */
226 * pick a base address for the vDSO in process space. We try to put it
227 * at vdso_base which is the "natural" base for it, but we might fail
228 * and end up putting it elsewhere.
230 down_write(&mm
->mmap_sem
);
231 vdso_base
= get_unmapped_area(NULL
, vdso_base
,
232 vdso_pages
<< PAGE_SHIFT
, 0, 0);
233 if (IS_ERR_VALUE(vdso_base
)) {
239 * our vma flags don't have VM_WRITE so by default, the process isn't
240 * allowed to write those pages.
241 * gdb can break that with ptrace interface, and thus trigger COW on
242 * those pages but it's then your responsibility to never do that on
243 * the "data" page of the vDSO or you'll stop getting kernel updates
244 * and your nice userland gettimeofday will be totally dead.
245 * It's fine to use that for setting breakpoints in the vDSO code
248 * Make sure the vDSO gets into every core dump.
249 * Dumping its contents makes post-mortem fully interpretable later
250 * without matching up the same kernel and hardware config to see
251 * what PC values meant.
253 rc
= install_special_mapping(mm
, vdso_base
, vdso_pages
<< PAGE_SHIFT
,
255 VM_MAYREAD
|VM_MAYWRITE
|VM_MAYEXEC
|
261 /* Put vDSO base into mm struct */
262 current
->mm
->context
.vdso_base
= vdso_base
;
264 up_write(&mm
->mmap_sem
);
268 up_write(&mm
->mmap_sem
);
272 const char *arch_vma_name(struct vm_area_struct
*vma
)
274 if (vma
->vm_mm
&& vma
->vm_start
== vma
->vm_mm
->context
.vdso_base
)
281 static void * __init
find_section32(Elf32_Ehdr
*ehdr
, const char *secname
,
288 /* Grab section headers and strings so we can tell who is who */
289 sechdrs
= (void *)ehdr
+ ehdr
->e_shoff
;
290 secnames
= (void *)ehdr
+ sechdrs
[ehdr
->e_shstrndx
].sh_offset
;
292 /* Find the section they want */
293 for (i
= 1; i
< ehdr
->e_shnum
; i
++) {
294 if (strcmp(secnames
+sechdrs
[i
].sh_name
, secname
) == 0) {
296 *size
= sechdrs
[i
].sh_size
;
297 return (void *)ehdr
+ sechdrs
[i
].sh_offset
;
304 static Elf32_Sym
* __init
find_symbol32(struct lib32_elfinfo
*lib
,
308 char name
[MAX_SYMNAME
], *c
;
310 for (i
= 0; i
< (lib
->dynsymsize
/ sizeof(Elf32_Sym
)); i
++) {
311 if (lib
->dynsym
[i
].st_name
== 0)
313 strlcpy(name
, lib
->dynstr
+ lib
->dynsym
[i
].st_name
,
315 c
= strchr(name
, '@');
318 if (strcmp(symname
, name
) == 0)
319 return &lib
->dynsym
[i
];
324 /* Note that we assume the section is .text and the symbol is relative to
327 static unsigned long __init
find_function32(struct lib32_elfinfo
*lib
,
330 Elf32_Sym
*sym
= find_symbol32(lib
, symname
);
333 printk(KERN_WARNING
"vDSO32: function %s not found !\n",
337 return sym
->st_value
- VDSO32_LBASE
;
340 static int __init
vdso_do_func_patch32(struct lib32_elfinfo
*v32
,
341 struct lib64_elfinfo
*v64
,
342 const char *orig
, const char *fix
)
344 Elf32_Sym
*sym32_gen
, *sym32_fix
;
346 sym32_gen
= find_symbol32(v32
, orig
);
347 if (sym32_gen
== NULL
) {
348 printk(KERN_ERR
"vDSO32: Can't find symbol %s !\n", orig
);
352 sym32_gen
->st_name
= 0;
355 sym32_fix
= find_symbol32(v32
, fix
);
356 if (sym32_fix
== NULL
) {
357 printk(KERN_ERR
"vDSO32: Can't find symbol %s !\n", fix
);
360 sym32_gen
->st_value
= sym32_fix
->st_value
;
361 sym32_gen
->st_size
= sym32_fix
->st_size
;
362 sym32_gen
->st_info
= sym32_fix
->st_info
;
363 sym32_gen
->st_other
= sym32_fix
->st_other
;
364 sym32_gen
->st_shndx
= sym32_fix
->st_shndx
;
372 static void * __init
find_section64(Elf64_Ehdr
*ehdr
, const char *secname
,
379 /* Grab section headers and strings so we can tell who is who */
380 sechdrs
= (void *)ehdr
+ ehdr
->e_shoff
;
381 secnames
= (void *)ehdr
+ sechdrs
[ehdr
->e_shstrndx
].sh_offset
;
383 /* Find the section they want */
384 for (i
= 1; i
< ehdr
->e_shnum
; i
++) {
385 if (strcmp(secnames
+sechdrs
[i
].sh_name
, secname
) == 0) {
387 *size
= sechdrs
[i
].sh_size
;
388 return (void *)ehdr
+ sechdrs
[i
].sh_offset
;
396 static Elf64_Sym
* __init
find_symbol64(struct lib64_elfinfo
*lib
,
400 char name
[MAX_SYMNAME
], *c
;
402 for (i
= 0; i
< (lib
->dynsymsize
/ sizeof(Elf64_Sym
)); i
++) {
403 if (lib
->dynsym
[i
].st_name
== 0)
405 strlcpy(name
, lib
->dynstr
+ lib
->dynsym
[i
].st_name
,
407 c
= strchr(name
, '@');
410 if (strcmp(symname
, name
) == 0)
411 return &lib
->dynsym
[i
];
416 /* Note that we assume the section is .text and the symbol is relative to
419 static unsigned long __init
find_function64(struct lib64_elfinfo
*lib
,
422 Elf64_Sym
*sym
= find_symbol64(lib
, symname
);
425 printk(KERN_WARNING
"vDSO64: function %s not found !\n",
429 #ifdef VDS64_HAS_DESCRIPTORS
430 return *((u64
*)(vdso64_kbase
+ sym
->st_value
- VDSO64_LBASE
)) -
433 return sym
->st_value
- VDSO64_LBASE
;
437 static int __init
vdso_do_func_patch64(struct lib32_elfinfo
*v32
,
438 struct lib64_elfinfo
*v64
,
439 const char *orig
, const char *fix
)
441 Elf64_Sym
*sym64_gen
, *sym64_fix
;
443 sym64_gen
= find_symbol64(v64
, orig
);
444 if (sym64_gen
== NULL
) {
445 printk(KERN_ERR
"vDSO64: Can't find symbol %s !\n", orig
);
449 sym64_gen
->st_name
= 0;
452 sym64_fix
= find_symbol64(v64
, fix
);
453 if (sym64_fix
== NULL
) {
454 printk(KERN_ERR
"vDSO64: Can't find symbol %s !\n", fix
);
457 sym64_gen
->st_value
= sym64_fix
->st_value
;
458 sym64_gen
->st_size
= sym64_fix
->st_size
;
459 sym64_gen
->st_info
= sym64_fix
->st_info
;
460 sym64_gen
->st_other
= sym64_fix
->st_other
;
461 sym64_gen
->st_shndx
= sym64_fix
->st_shndx
;
466 #endif /* CONFIG_PPC64 */
469 static __init
int vdso_do_find_sections(struct lib32_elfinfo
*v32
,
470 struct lib64_elfinfo
*v64
)
475 * Locate symbol tables & text section
478 v32
->dynsym
= find_section32(v32
->hdr
, ".dynsym", &v32
->dynsymsize
);
479 v32
->dynstr
= find_section32(v32
->hdr
, ".dynstr", NULL
);
480 if (v32
->dynsym
== NULL
|| v32
->dynstr
== NULL
) {
481 printk(KERN_ERR
"vDSO32: required symbol section not found\n");
484 sect
= find_section32(v32
->hdr
, ".text", NULL
);
486 printk(KERN_ERR
"vDSO32: the .text section was not found\n");
489 v32
->text
= sect
- vdso32_kbase
;
492 v64
->dynsym
= find_section64(v64
->hdr
, ".dynsym", &v64
->dynsymsize
);
493 v64
->dynstr
= find_section64(v64
->hdr
, ".dynstr", NULL
);
494 if (v64
->dynsym
== NULL
|| v64
->dynstr
== NULL
) {
495 printk(KERN_ERR
"vDSO64: required symbol section not found\n");
498 sect
= find_section64(v64
->hdr
, ".text", NULL
);
500 printk(KERN_ERR
"vDSO64: the .text section was not found\n");
503 v64
->text
= sect
- vdso64_kbase
;
504 #endif /* CONFIG_PPC64 */
509 static __init
void vdso_setup_trampolines(struct lib32_elfinfo
*v32
,
510 struct lib64_elfinfo
*v64
)
513 * Find signal trampolines
517 vdso64_rt_sigtramp
= find_function64(v64
, "__kernel_sigtramp_rt64");
519 vdso32_sigtramp
= find_function32(v32
, "__kernel_sigtramp32");
520 vdso32_rt_sigtramp
= find_function32(v32
, "__kernel_sigtramp_rt32");
523 static __init
int vdso_fixup_datapage(struct lib32_elfinfo
*v32
,
524 struct lib64_elfinfo
*v64
)
530 sym64
= find_symbol64(v64
, "__kernel_datapage_offset");
532 printk(KERN_ERR
"vDSO64: Can't find symbol "
533 "__kernel_datapage_offset !\n");
536 *((int *)(vdso64_kbase
+ sym64
->st_value
- VDSO64_LBASE
)) =
537 (vdso64_pages
<< PAGE_SHIFT
) -
538 (sym64
->st_value
- VDSO64_LBASE
);
539 #endif /* CONFIG_PPC64 */
541 sym32
= find_symbol32(v32
, "__kernel_datapage_offset");
543 printk(KERN_ERR
"vDSO32: Can't find symbol "
544 "__kernel_datapage_offset !\n");
547 *((int *)(vdso32_kbase
+ (sym32
->st_value
- VDSO32_LBASE
))) =
548 (vdso32_pages
<< PAGE_SHIFT
) -
549 (sym32
->st_value
- VDSO32_LBASE
);
555 static __init
int vdso_fixup_features(struct lib32_elfinfo
*v32
,
556 struct lib64_elfinfo
*v64
)
559 unsigned long size32
;
563 unsigned long size64
;
565 start64
= find_section64(v64
->hdr
, "__ftr_fixup", &size64
);
567 do_feature_fixups(cur_cpu_spec
->cpu_features
,
568 start64
, start64
+ size64
);
570 start64
= find_section64(v64
->hdr
, "__mmu_ftr_fixup", &size64
);
572 do_feature_fixups(cur_cpu_spec
->mmu_features
,
573 start64
, start64
+ size64
);
575 start64
= find_section64(v64
->hdr
, "__fw_ftr_fixup", &size64
);
577 do_feature_fixups(powerpc_firmware_features
,
578 start64
, start64
+ size64
);
580 start64
= find_section64(v64
->hdr
, "__lwsync_fixup", &size64
);
582 do_lwsync_fixups(cur_cpu_spec
->cpu_features
,
583 start64
, start64
+ size64
);
584 #endif /* CONFIG_PPC64 */
586 start32
= find_section32(v32
->hdr
, "__ftr_fixup", &size32
);
588 do_feature_fixups(cur_cpu_spec
->cpu_features
,
589 start32
, start32
+ size32
);
591 start32
= find_section32(v32
->hdr
, "__mmu_ftr_fixup", &size32
);
593 do_feature_fixups(cur_cpu_spec
->mmu_features
,
594 start32
, start32
+ size32
);
597 start32
= find_section32(v32
->hdr
, "__fw_ftr_fixup", &size32
);
599 do_feature_fixups(powerpc_firmware_features
,
600 start32
, start32
+ size32
);
601 #endif /* CONFIG_PPC64 */
603 start32
= find_section32(v32
->hdr
, "__lwsync_fixup", &size32
);
605 do_lwsync_fixups(cur_cpu_spec
->cpu_features
,
606 start32
, start32
+ size32
);
611 static __init
int vdso_fixup_alt_funcs(struct lib32_elfinfo
*v32
,
612 struct lib64_elfinfo
*v64
)
616 for (i
= 0; i
< ARRAY_SIZE(vdso_patches
); i
++) {
617 struct vdso_patch_def
*patch
= &vdso_patches
[i
];
618 int match
= (cur_cpu_spec
->cpu_features
& patch
->ftr_mask
)
623 DBG("replacing %s with %s...\n", patch
->gen_name
,
624 patch
->fix_name
? "NONE" : patch
->fix_name
);
627 * Patch the 32 bits and 64 bits symbols. Note that we do not
628 * patch the "." symbol on 64 bits.
629 * It would be easy to do, but doesn't seem to be necessary,
630 * patching the OPD symbol is enough.
632 vdso_do_func_patch32(v32
, v64
, patch
->gen_name
,
635 vdso_do_func_patch64(v32
, v64
, patch
->gen_name
,
637 #endif /* CONFIG_PPC64 */
644 static __init
int vdso_setup(void)
646 struct lib32_elfinfo v32
;
647 struct lib64_elfinfo v64
;
649 v32
.hdr
= vdso32_kbase
;
651 v64
.hdr
= vdso64_kbase
;
653 if (vdso_do_find_sections(&v32
, &v64
))
656 if (vdso_fixup_datapage(&v32
, &v64
))
659 if (vdso_fixup_features(&v32
, &v64
))
662 if (vdso_fixup_alt_funcs(&v32
, &v64
))
665 vdso_setup_trampolines(&v32
, &v64
);
671 * Called from setup_arch to initialize the bitmap of available
672 * syscalls in the systemcfg page
674 static void __init
vdso_setup_syscall_map(void)
677 extern unsigned long *sys_call_table
;
678 extern unsigned long sys_ni_syscall
;
681 for (i
= 0; i
< __NR_syscalls
; i
++) {
683 if (sys_call_table
[i
*2] != sys_ni_syscall
)
684 vdso_data
->syscall_map_64
[i
>> 5] |=
685 0x80000000UL
>> (i
& 0x1f);
686 if (sys_call_table
[i
*2+1] != sys_ni_syscall
)
687 vdso_data
->syscall_map_32
[i
>> 5] |=
688 0x80000000UL
>> (i
& 0x1f);
689 #else /* CONFIG_PPC64 */
690 if (sys_call_table
[i
] != sys_ni_syscall
)
691 vdso_data
->syscall_map_32
[i
>> 5] |=
692 0x80000000UL
>> (i
& 0x1f);
693 #endif /* CONFIG_PPC64 */
698 static int __init
vdso_init(void)
704 * Fill up the "systemcfg" stuff for backward compatiblity
706 strcpy((char *)vdso_data
->eye_catcher
, "SYSTEMCFG:PPC64");
707 vdso_data
->version
.major
= SYSTEMCFG_MAJOR
;
708 vdso_data
->version
.minor
= SYSTEMCFG_MINOR
;
709 vdso_data
->processor
= mfspr(SPRN_PVR
);
711 * Fake the old platform number for pSeries and iSeries and add
712 * in LPAR bit if necessary
714 vdso_data
->platform
= machine_is(iseries
) ? 0x200 : 0x100;
715 if (firmware_has_feature(FW_FEATURE_LPAR
))
716 vdso_data
->platform
|= 1;
717 vdso_data
->physicalMemorySize
= lmb_phys_mem_size();
718 vdso_data
->dcache_size
= ppc64_caches
.dsize
;
719 vdso_data
->dcache_line_size
= ppc64_caches
.dline_size
;
720 vdso_data
->icache_size
= ppc64_caches
.isize
;
721 vdso_data
->icache_line_size
= ppc64_caches
.iline_size
;
723 /* XXXOJN: Blocks should be added to ppc64_caches and used instead */
724 vdso_data
->dcache_block_size
= ppc64_caches
.dline_size
;
725 vdso_data
->icache_block_size
= ppc64_caches
.iline_size
;
726 vdso_data
->dcache_log_block_size
= ppc64_caches
.log_dline_size
;
727 vdso_data
->icache_log_block_size
= ppc64_caches
.log_iline_size
;
730 * Calculate the size of the 64 bits vDSO
732 vdso64_pages
= (&vdso64_end
- &vdso64_start
) >> PAGE_SHIFT
;
733 DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase
, vdso64_pages
);
735 vdso_data
->dcache_block_size
= L1_CACHE_BYTES
;
736 vdso_data
->dcache_log_block_size
= L1_CACHE_SHIFT
;
737 vdso_data
->icache_block_size
= L1_CACHE_BYTES
;
738 vdso_data
->icache_log_block_size
= L1_CACHE_SHIFT
;
739 #endif /* CONFIG_PPC64 */
743 * Calculate the size of the 32 bits vDSO
745 vdso32_pages
= (&vdso32_end
- &vdso32_start
) >> PAGE_SHIFT
;
746 DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase
, vdso32_pages
);
750 * Setup the syscall map in the vDOS
752 vdso_setup_syscall_map();
755 * Initialize the vDSO images in memory, that is do necessary
756 * fixups of vDSO symbols, locate trampolines, etc...
759 printk(KERN_ERR
"vDSO setup failure, not enabled !\n");
767 /* Make sure pages are in the correct state */
768 vdso32_pagelist
= kzalloc(sizeof(struct page
*) * (vdso32_pages
+ 2),
770 BUG_ON(vdso32_pagelist
== NULL
);
771 for (i
= 0; i
< vdso32_pages
; i
++) {
772 struct page
*pg
= virt_to_page(vdso32_kbase
+ i
*PAGE_SIZE
);
773 ClearPageReserved(pg
);
775 vdso32_pagelist
[i
] = pg
;
777 vdso32_pagelist
[i
++] = virt_to_page(vdso_data
);
778 vdso32_pagelist
[i
] = NULL
;
781 vdso64_pagelist
= kzalloc(sizeof(struct page
*) * (vdso64_pages
+ 2),
783 BUG_ON(vdso64_pagelist
== NULL
);
784 for (i
= 0; i
< vdso64_pages
; i
++) {
785 struct page
*pg
= virt_to_page(vdso64_kbase
+ i
*PAGE_SIZE
);
786 ClearPageReserved(pg
);
788 vdso64_pagelist
[i
] = pg
;
790 vdso64_pagelist
[i
++] = virt_to_page(vdso_data
);
791 vdso64_pagelist
[i
] = NULL
;
792 #endif /* CONFIG_PPC64 */
794 get_page(virt_to_page(vdso_data
));
801 arch_initcall(vdso_init
);
803 int in_gate_area_no_task(unsigned long addr
)
808 int in_gate_area(struct task_struct
*task
, unsigned long addr
)
813 struct vm_area_struct
*get_gate_vma(struct task_struct
*tsk
)