3 * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
4 * <benh@kernel.crashing.org>
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.
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/memblock.h>
25 #include <asm/cpu_has_feature.h>
26 #include <asm/pgtable.h>
27 #include <asm/processor.h>
29 #include <asm/mmu_context.h>
31 #include <asm/machdep.h>
32 #include <asm/cputable.h>
33 #include <asm/sections.h>
34 #include <asm/firmware.h>
36 #include <asm/vdso_datapage.h>
37 #include <asm/setup.h>
42 #define DBG(fmt...) printk(fmt)
47 /* Max supported size for symbol names */
48 #define MAX_SYMNAME 64
50 /* The alignment of the vDSO */
51 #define VDSO_ALIGNMENT (1 << 16)
53 static unsigned int vdso32_pages
;
54 static void *vdso32_kbase
;
55 static struct page
**vdso32_pagelist
;
56 unsigned long vdso32_sigtramp
;
57 unsigned long vdso32_rt_sigtramp
;
60 extern char vdso32_start
, vdso32_end
;
64 extern char vdso64_start
, vdso64_end
;
65 static void *vdso64_kbase
= &vdso64_start
;
66 static unsigned int vdso64_pages
;
67 static struct page
**vdso64_pagelist
;
68 unsigned long vdso64_rt_sigtramp
;
69 #endif /* CONFIG_PPC64 */
71 static int vdso_ready
;
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
79 struct vdso_data data
;
81 } vdso_data_store __page_aligned_data
;
82 struct vdso_data
*vdso_data
= &vdso_data_store
.data
;
84 /* Format of the patch table */
87 unsigned long ftr_mask
, ftr_value
;
92 /* Table of functions to patch based on the CPU type/revision
94 * Currently, we only change sync_dicache to do nothing on processors
95 * with a coherent icache
97 static struct vdso_patch_def vdso_patches
[] = {
99 CPU_FTR_COHERENT_ICACHE
, CPU_FTR_COHERENT_ICACHE
,
100 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
104 CPU_FTR_USE_RTC
, CPU_FTR_USE_RTC
,
105 "__kernel_gettimeofday", NULL
108 CPU_FTR_USE_RTC
, CPU_FTR_USE_RTC
,
109 "__kernel_clock_gettime", NULL
112 CPU_FTR_USE_RTC
, CPU_FTR_USE_RTC
,
113 "__kernel_clock_getres", NULL
116 CPU_FTR_USE_RTC
, CPU_FTR_USE_RTC
,
117 "__kernel_get_tbfreq", NULL
120 CPU_FTR_USE_RTC
, CPU_FTR_USE_RTC
,
121 "__kernel_time", NULL
127 * Some infos carried around for each of them during parsing at
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 */
143 unsigned long dynsymsize
;
150 * This is called from binfmt_elf, we create the special vma for the
151 * vDSO and insert it into the mm struct tree
153 int arch_setup_additional_pages(struct linux_binprm
*bprm
, int uses_interp
)
155 struct mm_struct
*mm
= current
->mm
;
156 struct page
**vdso_pagelist
;
157 unsigned long vdso_pages
;
158 unsigned long vdso_base
;
165 if (is_32bit_task()) {
166 vdso_pagelist
= vdso32_pagelist
;
167 vdso_pages
= vdso32_pages
;
168 vdso_base
= VDSO32_MBASE
;
170 vdso_pagelist
= vdso64_pagelist
;
171 vdso_pages
= vdso64_pages
;
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.
180 vdso_pagelist
= vdso32_pagelist
;
181 vdso_pages
= vdso32_pages
;
182 vdso_base
= VDSO32_MBASE
;
185 current
->mm
->context
.vdso_base
= 0;
187 /* vDSO has a problem and was disabled, just don't "enable" it for the
192 /* Add a page to the vdso size for the data page */
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.
201 if (down_write_killable(&mm
->mmap_sem
))
203 vdso_base
= get_unmapped_area(NULL
, vdso_base
,
204 (vdso_pages
<< PAGE_SHIFT
) +
205 ((VDSO_ALIGNMENT
- 1) & PAGE_MASK
),
207 if (IS_ERR_VALUE(vdso_base
)) {
212 /* Add required alignment. */
213 vdso_base
= ALIGN(vdso_base
, VDSO_ALIGNMENT
);
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).
220 current
->mm
->context
.vdso_base
= vdso_base
;
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
232 rc
= install_special_mapping(mm
, vdso_base
, vdso_pages
<< PAGE_SHIFT
,
234 VM_MAYREAD
|VM_MAYWRITE
|VM_MAYEXEC
,
237 current
->mm
->context
.vdso_base
= 0;
241 up_write(&mm
->mmap_sem
);
245 up_write(&mm
->mmap_sem
);
249 const char *arch_vma_name(struct vm_area_struct
*vma
)
251 if (vma
->vm_mm
&& vma
->vm_start
== vma
->vm_mm
->context
.vdso_base
)
259 static void * __init
find_section32(Elf32_Ehdr
*ehdr
, const char *secname
,
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
;
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) {
274 *size
= sechdrs
[i
].sh_size
;
275 return (void *)ehdr
+ sechdrs
[i
].sh_offset
;
282 static Elf32_Sym
* __init
find_symbol32(struct lib32_elfinfo
*lib
,
286 char name
[MAX_SYMNAME
], *c
;
288 for (i
= 0; i
< (lib
->dynsymsize
/ sizeof(Elf32_Sym
)); i
++) {
289 if (lib
->dynsym
[i
].st_name
== 0)
291 strlcpy(name
, lib
->dynstr
+ lib
->dynsym
[i
].st_name
,
293 c
= strchr(name
, '@');
296 if (strcmp(symname
, name
) == 0)
297 return &lib
->dynsym
[i
];
302 /* Note that we assume the section is .text and the symbol is relative to
305 static unsigned long __init
find_function32(struct lib32_elfinfo
*lib
,
308 Elf32_Sym
*sym
= find_symbol32(lib
, symname
);
311 printk(KERN_WARNING
"vDSO32: function %s not found !\n",
315 return sym
->st_value
- VDSO32_LBASE
;
318 static int __init
vdso_do_func_patch32(struct lib32_elfinfo
*v32
,
319 struct lib64_elfinfo
*v64
,
320 const char *orig
, const char *fix
)
322 Elf32_Sym
*sym32_gen
, *sym32_fix
;
324 sym32_gen
= find_symbol32(v32
, orig
);
325 if (sym32_gen
== NULL
) {
326 printk(KERN_ERR
"vDSO32: Can't find symbol %s !\n", orig
);
330 sym32_gen
->st_name
= 0;
333 sym32_fix
= find_symbol32(v32
, fix
);
334 if (sym32_fix
== NULL
) {
335 printk(KERN_ERR
"vDSO32: Can't find symbol %s !\n", fix
);
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
;
346 #else /* !CONFIG_VDSO32 */
347 static unsigned long __init
find_function32(struct lib32_elfinfo
*lib
,
353 static int __init
vdso_do_func_patch32(struct lib32_elfinfo
*v32
,
354 struct lib64_elfinfo
*v64
,
355 const char *orig
, const char *fix
)
359 #endif /* CONFIG_VDSO32 */
364 static void * __init
find_section64(Elf64_Ehdr
*ehdr
, const char *secname
,
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
;
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) {
379 *size
= sechdrs
[i
].sh_size
;
380 return (void *)ehdr
+ sechdrs
[i
].sh_offset
;
388 static Elf64_Sym
* __init
find_symbol64(struct lib64_elfinfo
*lib
,
392 char name
[MAX_SYMNAME
], *c
;
394 for (i
= 0; i
< (lib
->dynsymsize
/ sizeof(Elf64_Sym
)); i
++) {
395 if (lib
->dynsym
[i
].st_name
== 0)
397 strlcpy(name
, lib
->dynstr
+ lib
->dynsym
[i
].st_name
,
399 c
= strchr(name
, '@');
402 if (strcmp(symname
, name
) == 0)
403 return &lib
->dynsym
[i
];
408 /* Note that we assume the section is .text and the symbol is relative to
411 static unsigned long __init
find_function64(struct lib64_elfinfo
*lib
,
414 Elf64_Sym
*sym
= find_symbol64(lib
, symname
);
417 printk(KERN_WARNING
"vDSO64: function %s not found !\n",
421 #ifdef VDS64_HAS_DESCRIPTORS
422 return *((u64
*)(vdso64_kbase
+ sym
->st_value
- VDSO64_LBASE
)) -
425 return sym
->st_value
- VDSO64_LBASE
;
429 static int __init
vdso_do_func_patch64(struct lib32_elfinfo
*v32
,
430 struct lib64_elfinfo
*v64
,
431 const char *orig
, const char *fix
)
433 Elf64_Sym
*sym64_gen
, *sym64_fix
;
435 sym64_gen
= find_symbol64(v64
, orig
);
436 if (sym64_gen
== NULL
) {
437 printk(KERN_ERR
"vDSO64: Can't find symbol %s !\n", orig
);
441 sym64_gen
->st_name
= 0;
444 sym64_fix
= find_symbol64(v64
, fix
);
445 if (sym64_fix
== NULL
) {
446 printk(KERN_ERR
"vDSO64: Can't find symbol %s !\n", fix
);
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
;
458 #endif /* CONFIG_PPC64 */
461 static __init
int vdso_do_find_sections(struct lib32_elfinfo
*v32
,
462 struct lib64_elfinfo
*v64
)
467 * Locate symbol tables & text section
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");
477 sect
= find_section32(v32
->hdr
, ".text", NULL
);
479 printk(KERN_ERR
"vDSO32: the .text section was not found\n");
482 v32
->text
= sect
- vdso32_kbase
;
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");
492 sect
= find_section64(v64
->hdr
, ".text", NULL
);
494 printk(KERN_ERR
"vDSO64: the .text section was not found\n");
497 v64
->text
= sect
- vdso64_kbase
;
498 #endif /* CONFIG_PPC64 */
503 static __init
void vdso_setup_trampolines(struct lib32_elfinfo
*v32
,
504 struct lib64_elfinfo
*v64
)
507 * Find signal trampolines
511 vdso64_rt_sigtramp
= find_function64(v64
, "__kernel_sigtramp_rt64");
513 vdso32_sigtramp
= find_function32(v32
, "__kernel_sigtramp32");
514 vdso32_rt_sigtramp
= find_function32(v32
, "__kernel_sigtramp_rt32");
517 static __init
int vdso_fixup_datapage(struct lib32_elfinfo
*v32
,
518 struct lib64_elfinfo
*v64
)
526 sym64
= find_symbol64(v64
, "__kernel_datapage_offset");
528 printk(KERN_ERR
"vDSO64: Can't find symbol "
529 "__kernel_datapage_offset !\n");
532 *((int *)(vdso64_kbase
+ sym64
->st_value
- VDSO64_LBASE
)) =
533 (vdso64_pages
<< PAGE_SHIFT
) -
534 (sym64
->st_value
- VDSO64_LBASE
);
535 #endif /* CONFIG_PPC64 */
538 sym32
= find_symbol32(v32
, "__kernel_datapage_offset");
540 printk(KERN_ERR
"vDSO32: Can't find symbol "
541 "__kernel_datapage_offset !\n");
544 *((int *)(vdso32_kbase
+ (sym32
->st_value
- VDSO32_LBASE
))) =
545 (vdso32_pages
<< PAGE_SHIFT
) -
546 (sym32
->st_value
- VDSO32_LBASE
);
553 static __init
int vdso_fixup_features(struct lib32_elfinfo
*v32
,
554 struct lib64_elfinfo
*v64
)
560 start
= find_section64(v64
->hdr
, "__ftr_fixup", &size
);
562 do_feature_fixups(cur_cpu_spec
->cpu_features
,
563 start
, start
+ size
);
565 start
= find_section64(v64
->hdr
, "__mmu_ftr_fixup", &size
);
567 do_feature_fixups(cur_cpu_spec
->mmu_features
,
568 start
, start
+ size
);
570 start
= find_section64(v64
->hdr
, "__fw_ftr_fixup", &size
);
572 do_feature_fixups(powerpc_firmware_features
,
573 start
, start
+ size
);
575 start
= find_section64(v64
->hdr
, "__lwsync_fixup", &size
);
577 do_lwsync_fixups(cur_cpu_spec
->cpu_features
,
578 start
, start
+ size
);
579 #endif /* CONFIG_PPC64 */
582 start
= find_section32(v32
->hdr
, "__ftr_fixup", &size
);
584 do_feature_fixups(cur_cpu_spec
->cpu_features
,
585 start
, start
+ size
);
587 start
= find_section32(v32
->hdr
, "__mmu_ftr_fixup", &size
);
589 do_feature_fixups(cur_cpu_spec
->mmu_features
,
590 start
, start
+ size
);
593 start
= find_section32(v32
->hdr
, "__fw_ftr_fixup", &size
);
595 do_feature_fixups(powerpc_firmware_features
,
596 start
, start
+ size
);
597 #endif /* CONFIG_PPC64 */
599 start
= find_section32(v32
->hdr
, "__lwsync_fixup", &size
);
601 do_lwsync_fixups(cur_cpu_spec
->cpu_features
,
602 start
, start
+ size
);
608 static __init
int vdso_fixup_alt_funcs(struct lib32_elfinfo
*v32
,
609 struct lib64_elfinfo
*v64
)
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
)
620 DBG("replacing %s with %s...\n", patch
->gen_name
,
621 patch
->fix_name
? "NONE" : patch
->fix_name
);
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.
629 vdso_do_func_patch32(v32
, v64
, patch
->gen_name
,
632 vdso_do_func_patch64(v32
, v64
, patch
->gen_name
,
634 #endif /* CONFIG_PPC64 */
641 static __init
int vdso_setup(void)
643 struct lib32_elfinfo v32
;
644 struct lib64_elfinfo v64
;
646 v32
.hdr
= vdso32_kbase
;
648 v64
.hdr
= vdso64_kbase
;
650 if (vdso_do_find_sections(&v32
, &v64
))
653 if (vdso_fixup_datapage(&v32
, &v64
))
656 if (vdso_fixup_features(&v32
, &v64
))
659 if (vdso_fixup_alt_funcs(&v32
, &v64
))
662 vdso_setup_trampolines(&v32
, &v64
);
668 * Called from setup_arch to initialize the bitmap of available
669 * syscalls in the systemcfg page
671 static void __init
vdso_setup_syscall_map(void)
674 extern unsigned long *sys_call_table
;
675 extern unsigned long sys_ni_syscall
;
678 for (i
= 0; i
< NR_syscalls
; i
++) {
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 */
695 int vdso_getcpu_init(void)
697 unsigned long cpu
, node
, val
;
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().
704 WARN_ON_ONCE(cpu
> 0xffff);
706 node
= cpu_to_node(cpu
);
707 WARN_ON_ONCE(node
> 0xffff);
709 val
= (cpu
& 0xfff) | ((node
& 0xffff) << 16);
710 mtspr(SPRN_SPRG_VDSO_WRITE
, val
);
711 get_paca()->sprg_vdso
= val
;
717 /* We need to call this before SMP init */
718 early_initcall(vdso_getcpu_init
);
721 static int __init
vdso_init(void)
727 * Fill up the "systemcfg" stuff for backward compatibility
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
);
734 * Fake the old platform number for pSeries and add
735 * in LPAR bit if necessary
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
;
751 * Calculate the size of the 64 bits vDSO
753 vdso64_pages
= (&vdso64_end
- &vdso64_start
) >> PAGE_SHIFT
;
754 DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase
, vdso64_pages
);
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 */
764 vdso32_kbase
= &vdso32_start
;
767 * Calculate the size of the 32 bits vDSO
769 vdso32_pages
= (&vdso32_end
- &vdso32_start
) >> PAGE_SHIFT
;
770 DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase
, vdso32_pages
);
775 * Setup the syscall map in the vDOS
777 vdso_setup_syscall_map();
780 * Initialize the vDSO images in memory, that is do necessary
781 * fixups of vDSO symbols, locate trampolines, etc...
784 printk(KERN_ERR
"vDSO setup failure, not enabled !\n");
793 /* Make sure pages are in the correct state */
794 vdso32_pagelist
= kcalloc(vdso32_pages
+ 2, sizeof(struct page
*),
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
);
801 vdso32_pagelist
[i
] = pg
;
803 vdso32_pagelist
[i
++] = virt_to_page(vdso_data
);
804 vdso32_pagelist
[i
] = NULL
;
808 vdso64_pagelist
= kcalloc(vdso64_pages
+ 2, sizeof(struct page
*),
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
);
815 vdso64_pagelist
[i
] = pg
;
817 vdso64_pagelist
[i
++] = virt_to_page(vdso_data
);
818 vdso64_pagelist
[i
] = NULL
;
819 #endif /* CONFIG_PPC64 */
821 get_page(virt_to_page(vdso_data
));
828 arch_initcall(vdso_init
);