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/config.h>
12 #include <linux/module.h>
13 #include <linux/errno.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
17 #include <linux/smp.h>
18 #include <linux/smp_lock.h>
19 #include <linux/stddef.h>
20 #include <linux/unistd.h>
21 #include <linux/slab.h>
22 #include <linux/user.h>
23 #include <linux/elf.h>
24 #include <linux/security.h>
25 #include <linux/bootmem.h>
27 #include <asm/pgtable.h>
28 #include <asm/system.h>
29 #include <asm/processor.h>
31 #include <asm/mmu_context.h>
33 #include <asm/machdep.h>
34 #include <asm/cputable.h>
35 #include <asm/sections.h>
36 #include <asm/firmware.h>
38 #include <asm/vdso_datapage.h>
43 #define DBG(fmt...) printk(fmt)
48 /* Max supported size for symbol names */
49 #define MAX_SYMNAME 64
51 extern char vdso32_start
, vdso32_end
;
52 static void *vdso32_kbase
= &vdso32_start
;
53 unsigned int vdso32_pages
;
54 unsigned long vdso32_sigtramp
;
55 unsigned long vdso32_rt_sigtramp
;
58 extern char vdso64_start
, vdso64_end
;
59 static void *vdso64_kbase
= &vdso64_start
;
60 unsigned int vdso64_pages
;
61 unsigned long vdso64_rt_sigtramp
;
62 #endif /* CONFIG_PPC64 */
65 * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
66 * Once the early boot kernel code no longer needs to muck around
67 * with it, it will become dynamically allocated
70 struct vdso_data data
;
72 } vdso_data_store
__attribute__((__section__(".data.page_aligned")));
73 struct vdso_data
*vdso_data
= &vdso_data_store
.data
;
75 /* Format of the patch table */
78 unsigned long ftr_mask
, ftr_value
;
83 /* Table of functions to patch based on the CPU type/revision
85 * Currently, we only change sync_dicache to do nothing on processors
86 * with a coherent icache
88 static struct vdso_patch_def vdso_patches
[] = {
90 CPU_FTR_COHERENT_ICACHE
, CPU_FTR_COHERENT_ICACHE
,
91 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
95 "__kernel_gettimeofday", NULL
100 * Some infos carried around for each of them during parsing at
105 Elf32_Ehdr
*hdr
; /* ptr to ELF */
106 Elf32_Sym
*dynsym
; /* ptr to .dynsym section */
107 unsigned long dynsymsize
; /* size of .dynsym section */
108 char *dynstr
; /* ptr to .dynstr section */
109 unsigned long text
; /* offset of .text section in .so */
116 unsigned long dynsymsize
;
123 static void dump_one_vdso_page(struct page
*pg
, struct page
*upg
)
125 printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg
) << PAGE_SHIFT
),
128 if (upg
/* && pg != upg*/) {
129 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg
)
137 static void dump_vdso_pages(struct vm_area_struct
* vma
)
141 if (!vma
|| test_thread_flag(TIF_32BIT
)) {
142 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase
);
143 for (i
=0; i
<vdso32_pages
; i
++) {
144 struct page
*pg
= virt_to_page(vdso32_kbase
+
146 struct page
*upg
= (vma
&& vma
->vm_mm
) ?
147 follow_page(vma
, vma
->vm_start
+ i
*PAGE_SIZE
, 0)
149 dump_one_vdso_page(pg
, upg
);
152 if (!vma
|| !test_thread_flag(TIF_32BIT
)) {
153 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase
);
154 for (i
=0; i
<vdso64_pages
; i
++) {
155 struct page
*pg
= virt_to_page(vdso64_kbase
+
157 struct page
*upg
= (vma
&& vma
->vm_mm
) ?
158 follow_page(vma
, vma
->vm_start
+ i
*PAGE_SIZE
, 0)
160 dump_one_vdso_page(pg
, upg
);
167 * Keep a dummy vma_close for now, it will prevent VMA merging.
169 static void vdso_vma_close(struct vm_area_struct
* vma
)
174 * Our nopage() function, maps in the actual vDSO kernel pages, they will
175 * be mapped read-only by do_no_page(), and eventually COW'ed, either
176 * right away for an initial write access, or by do_wp_page().
178 static struct page
* vdso_vma_nopage(struct vm_area_struct
* vma
,
179 unsigned long address
, int *type
)
181 unsigned long offset
= address
- vma
->vm_start
;
184 void *vbase
= (vma
->vm_mm
->task_size
> TASK_SIZE_USER32
) ?
185 vdso64_kbase
: vdso32_kbase
;
187 void *vbase
= vdso32_kbase
;
190 DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
191 current
->comm
, address
, offset
);
193 if (address
< vma
->vm_start
|| address
> vma
->vm_end
)
194 return NOPAGE_SIGBUS
;
197 * Last page is systemcfg.
199 if ((vma
->vm_end
- address
) <= PAGE_SIZE
)
200 pg
= virt_to_page(vdso_data
);
202 pg
= virt_to_page(vbase
+ offset
);
205 DBG(" ->page count: %d\n", page_count(pg
));
210 static struct vm_operations_struct vdso_vmops
= {
211 .close
= vdso_vma_close
,
212 .nopage
= vdso_vma_nopage
,
216 * This is called from binfmt_elf, we create the special vma for the
217 * vDSO and insert it into the mm struct tree
219 int arch_setup_additional_pages(struct linux_binprm
*bprm
,
220 int executable_stack
)
222 struct mm_struct
*mm
= current
->mm
;
223 struct vm_area_struct
*vma
;
224 unsigned long vdso_pages
;
225 unsigned long vdso_base
;
228 if (test_thread_flag(TIF_32BIT
)) {
229 vdso_pages
= vdso32_pages
;
230 vdso_base
= VDSO32_MBASE
;
232 vdso_pages
= vdso64_pages
;
233 vdso_base
= VDSO64_MBASE
;
236 vdso_pages
= vdso32_pages
;
237 vdso_base
= VDSO32_MBASE
;
240 current
->thread
.vdso_base
= 0;
242 /* vDSO has a problem and was disabled, just don't "enable" it for the
248 vma
= kmem_cache_alloc(vm_area_cachep
, SLAB_KERNEL
);
252 memset(vma
, 0, sizeof(*vma
));
254 /* Add a page to the vdso size for the data page */
258 * pick a base address for the vDSO in process space. We try to put it
259 * at vdso_base which is the "natural" base for it, but we might fail
260 * and end up putting it elsewhere.
262 vdso_base
= get_unmapped_area(NULL
, vdso_base
,
263 vdso_pages
<< PAGE_SHIFT
, 0, 0);
264 if (vdso_base
& ~PAGE_MASK
) {
265 kmem_cache_free(vm_area_cachep
, vma
);
266 return (int)vdso_base
;
269 current
->thread
.vdso_base
= vdso_base
;
272 vma
->vm_start
= current
->thread
.vdso_base
;
273 vma
->vm_end
= vma
->vm_start
+ (vdso_pages
<< PAGE_SHIFT
);
276 * our vma flags don't have VM_WRITE so by default, the process isn't
277 * allowed to write those pages.
278 * gdb can break that with ptrace interface, and thus trigger COW on
279 * those pages but it's then your responsibility to never do that on
280 * the "data" page of the vDSO or you'll stop getting kernel updates
281 * and your nice userland gettimeofday will be totally dead.
282 * It's fine to use that for setting breakpoints in the vDSO code
285 vma
->vm_flags
= VM_READ
| VM_EXEC
| VM_MAYREAD
| VM_MAYWRITE
| VM_MAYEXEC
;
286 vma
->vm_flags
|= mm
->def_flags
;
287 vma
->vm_page_prot
= protection_map
[vma
->vm_flags
& 0x7];
288 vma
->vm_ops
= &vdso_vmops
;
290 down_write(&mm
->mmap_sem
);
291 if (insert_vm_struct(mm
, vma
)) {
292 up_write(&mm
->mmap_sem
);
293 kmem_cache_free(vm_area_cachep
, vma
);
296 mm
->total_vm
+= (vma
->vm_end
- vma
->vm_start
) >> PAGE_SHIFT
;
297 up_write(&mm
->mmap_sem
);
302 static void * __init
find_section32(Elf32_Ehdr
*ehdr
, const char *secname
,
309 /* Grab section headers and strings so we can tell who is who */
310 sechdrs
= (void *)ehdr
+ ehdr
->e_shoff
;
311 secnames
= (void *)ehdr
+ sechdrs
[ehdr
->e_shstrndx
].sh_offset
;
313 /* Find the section they want */
314 for (i
= 1; i
< ehdr
->e_shnum
; i
++) {
315 if (strcmp(secnames
+sechdrs
[i
].sh_name
, secname
) == 0) {
317 *size
= sechdrs
[i
].sh_size
;
318 return (void *)ehdr
+ sechdrs
[i
].sh_offset
;
325 static Elf32_Sym
* __init
find_symbol32(struct lib32_elfinfo
*lib
,
329 char name
[MAX_SYMNAME
], *c
;
331 for (i
= 0; i
< (lib
->dynsymsize
/ sizeof(Elf32_Sym
)); i
++) {
332 if (lib
->dynsym
[i
].st_name
== 0)
334 strlcpy(name
, lib
->dynstr
+ lib
->dynsym
[i
].st_name
,
336 c
= strchr(name
, '@');
339 if (strcmp(symname
, name
) == 0)
340 return &lib
->dynsym
[i
];
345 /* Note that we assume the section is .text and the symbol is relative to
348 static unsigned long __init
find_function32(struct lib32_elfinfo
*lib
,
351 Elf32_Sym
*sym
= find_symbol32(lib
, symname
);
354 printk(KERN_WARNING
"vDSO32: function %s not found !\n",
358 return sym
->st_value
- VDSO32_LBASE
;
361 static int vdso_do_func_patch32(struct lib32_elfinfo
*v32
,
362 struct lib64_elfinfo
*v64
,
363 const char *orig
, const char *fix
)
365 Elf32_Sym
*sym32_gen
, *sym32_fix
;
367 sym32_gen
= find_symbol32(v32
, orig
);
368 if (sym32_gen
== NULL
) {
369 printk(KERN_ERR
"vDSO32: Can't find symbol %s !\n", orig
);
373 sym32_gen
->st_name
= 0;
376 sym32_fix
= find_symbol32(v32
, fix
);
377 if (sym32_fix
== NULL
) {
378 printk(KERN_ERR
"vDSO32: Can't find symbol %s !\n", fix
);
381 sym32_gen
->st_value
= sym32_fix
->st_value
;
382 sym32_gen
->st_size
= sym32_fix
->st_size
;
383 sym32_gen
->st_info
= sym32_fix
->st_info
;
384 sym32_gen
->st_other
= sym32_fix
->st_other
;
385 sym32_gen
->st_shndx
= sym32_fix
->st_shndx
;
393 static void * __init
find_section64(Elf64_Ehdr
*ehdr
, const char *secname
,
400 /* Grab section headers and strings so we can tell who is who */
401 sechdrs
= (void *)ehdr
+ ehdr
->e_shoff
;
402 secnames
= (void *)ehdr
+ sechdrs
[ehdr
->e_shstrndx
].sh_offset
;
404 /* Find the section they want */
405 for (i
= 1; i
< ehdr
->e_shnum
; i
++) {
406 if (strcmp(secnames
+sechdrs
[i
].sh_name
, secname
) == 0) {
408 *size
= sechdrs
[i
].sh_size
;
409 return (void *)ehdr
+ sechdrs
[i
].sh_offset
;
417 static Elf64_Sym
* __init
find_symbol64(struct lib64_elfinfo
*lib
,
421 char name
[MAX_SYMNAME
], *c
;
423 for (i
= 0; i
< (lib
->dynsymsize
/ sizeof(Elf64_Sym
)); i
++) {
424 if (lib
->dynsym
[i
].st_name
== 0)
426 strlcpy(name
, lib
->dynstr
+ lib
->dynsym
[i
].st_name
,
428 c
= strchr(name
, '@');
431 if (strcmp(symname
, name
) == 0)
432 return &lib
->dynsym
[i
];
437 /* Note that we assume the section is .text and the symbol is relative to
440 static unsigned long __init
find_function64(struct lib64_elfinfo
*lib
,
443 Elf64_Sym
*sym
= find_symbol64(lib
, symname
);
446 printk(KERN_WARNING
"vDSO64: function %s not found !\n",
450 #ifdef VDS64_HAS_DESCRIPTORS
451 return *((u64
*)(vdso64_kbase
+ sym
->st_value
- VDSO64_LBASE
)) -
454 return sym
->st_value
- VDSO64_LBASE
;
458 static int vdso_do_func_patch64(struct lib32_elfinfo
*v32
,
459 struct lib64_elfinfo
*v64
,
460 const char *orig
, const char *fix
)
462 Elf64_Sym
*sym64_gen
, *sym64_fix
;
464 sym64_gen
= find_symbol64(v64
, orig
);
465 if (sym64_gen
== NULL
) {
466 printk(KERN_ERR
"vDSO64: Can't find symbol %s !\n", orig
);
470 sym64_gen
->st_name
= 0;
473 sym64_fix
= find_symbol64(v64
, fix
);
474 if (sym64_fix
== NULL
) {
475 printk(KERN_ERR
"vDSO64: Can't find symbol %s !\n", fix
);
478 sym64_gen
->st_value
= sym64_fix
->st_value
;
479 sym64_gen
->st_size
= sym64_fix
->st_size
;
480 sym64_gen
->st_info
= sym64_fix
->st_info
;
481 sym64_gen
->st_other
= sym64_fix
->st_other
;
482 sym64_gen
->st_shndx
= sym64_fix
->st_shndx
;
487 #endif /* CONFIG_PPC64 */
490 static __init
int vdso_do_find_sections(struct lib32_elfinfo
*v32
,
491 struct lib64_elfinfo
*v64
)
496 * Locate symbol tables & text section
499 v32
->dynsym
= find_section32(v32
->hdr
, ".dynsym", &v32
->dynsymsize
);
500 v32
->dynstr
= find_section32(v32
->hdr
, ".dynstr", NULL
);
501 if (v32
->dynsym
== NULL
|| v32
->dynstr
== NULL
) {
502 printk(KERN_ERR
"vDSO32: required symbol section not found\n");
505 sect
= find_section32(v32
->hdr
, ".text", NULL
);
507 printk(KERN_ERR
"vDSO32: the .text section was not found\n");
510 v32
->text
= sect
- vdso32_kbase
;
513 v64
->dynsym
= find_section64(v64
->hdr
, ".dynsym", &v64
->dynsymsize
);
514 v64
->dynstr
= find_section64(v64
->hdr
, ".dynstr", NULL
);
515 if (v64
->dynsym
== NULL
|| v64
->dynstr
== NULL
) {
516 printk(KERN_ERR
"vDSO64: required symbol section not found\n");
519 sect
= find_section64(v64
->hdr
, ".text", NULL
);
521 printk(KERN_ERR
"vDSO64: the .text section was not found\n");
524 v64
->text
= sect
- vdso64_kbase
;
525 #endif /* CONFIG_PPC64 */
530 static __init
void vdso_setup_trampolines(struct lib32_elfinfo
*v32
,
531 struct lib64_elfinfo
*v64
)
534 * Find signal trampolines
538 vdso64_rt_sigtramp
= find_function64(v64
, "__kernel_sigtramp_rt64");
540 vdso32_sigtramp
= find_function32(v32
, "__kernel_sigtramp32");
541 vdso32_rt_sigtramp
= find_function32(v32
, "__kernel_sigtramp_rt32");
544 static __init
int vdso_fixup_datapage(struct lib32_elfinfo
*v32
,
545 struct lib64_elfinfo
*v64
)
551 sym64
= find_symbol64(v64
, "__kernel_datapage_offset");
553 printk(KERN_ERR
"vDSO64: Can't find symbol "
554 "__kernel_datapage_offset !\n");
557 *((int *)(vdso64_kbase
+ sym64
->st_value
- VDSO64_LBASE
)) =
558 (vdso64_pages
<< PAGE_SHIFT
) -
559 (sym64
->st_value
- VDSO64_LBASE
);
560 #endif /* CONFIG_PPC64 */
562 sym32
= find_symbol32(v32
, "__kernel_datapage_offset");
564 printk(KERN_ERR
"vDSO32: Can't find symbol "
565 "__kernel_datapage_offset !\n");
568 *((int *)(vdso32_kbase
+ (sym32
->st_value
- VDSO32_LBASE
))) =
569 (vdso32_pages
<< PAGE_SHIFT
) -
570 (sym32
->st_value
- VDSO32_LBASE
);
575 static __init
int vdso_fixup_alt_funcs(struct lib32_elfinfo
*v32
,
576 struct lib64_elfinfo
*v64
)
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
)
587 DBG("replacing %s with %s...\n", patch
->gen_name
,
588 patch
->fix_name
? "NONE" : patch
->fix_name
);
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.
596 vdso_do_func_patch32(v32
, v64
, patch
->gen_name
,
599 vdso_do_func_patch64(v32
, v64
, patch
->gen_name
,
601 #endif /* CONFIG_PPC64 */
608 static __init
int vdso_setup(void)
610 struct lib32_elfinfo v32
;
611 struct lib64_elfinfo v64
;
613 v32
.hdr
= vdso32_kbase
;
615 v64
.hdr
= vdso64_kbase
;
617 if (vdso_do_find_sections(&v32
, &v64
))
620 if (vdso_fixup_datapage(&v32
, &v64
))
623 if (vdso_fixup_alt_funcs(&v32
, &v64
))
626 vdso_setup_trampolines(&v32
, &v64
);
632 * Called from setup_arch to initialize the bitmap of available
633 * syscalls in the systemcfg page
635 static void __init
vdso_setup_syscall_map(void)
638 extern unsigned long *sys_call_table
;
639 extern unsigned long sys_ni_syscall
;
642 for (i
= 0; i
< __NR_syscalls
; i
++) {
644 if (sys_call_table
[i
*2] != sys_ni_syscall
)
645 vdso_data
->syscall_map_64
[i
>> 5] |=
646 0x80000000UL
>> (i
& 0x1f);
647 if (sys_call_table
[i
*2+1] != sys_ni_syscall
)
648 vdso_data
->syscall_map_32
[i
>> 5] |=
649 0x80000000UL
>> (i
& 0x1f);
650 #else /* CONFIG_PPC64 */
651 if (sys_call_table
[i
] != sys_ni_syscall
)
652 vdso_data
->syscall_map_32
[i
>> 5] |=
653 0x80000000UL
>> (i
& 0x1f);
654 #endif /* CONFIG_PPC64 */
659 void __init
vdso_init(void)
665 * Fill up the "systemcfg" stuff for backward compatiblity
667 strcpy(vdso_data
->eye_catcher
, "SYSTEMCFG:PPC64");
668 vdso_data
->version
.major
= SYSTEMCFG_MAJOR
;
669 vdso_data
->version
.minor
= SYSTEMCFG_MINOR
;
670 vdso_data
->processor
= mfspr(SPRN_PVR
);
672 * Fake the old platform number for pSeries and iSeries and add
673 * in LPAR bit if necessary
675 vdso_data
->platform
= machine_is(iseries
) ? 0x200 : 0x100;
676 if (firmware_has_feature(FW_FEATURE_LPAR
))
677 vdso_data
->platform
|= 1;
678 vdso_data
->physicalMemorySize
= lmb_phys_mem_size();
679 vdso_data
->dcache_size
= ppc64_caches
.dsize
;
680 vdso_data
->dcache_line_size
= ppc64_caches
.dline_size
;
681 vdso_data
->icache_size
= ppc64_caches
.isize
;
682 vdso_data
->icache_line_size
= ppc64_caches
.iline_size
;
685 * Calculate the size of the 64 bits vDSO
687 vdso64_pages
= (&vdso64_end
- &vdso64_start
) >> PAGE_SHIFT
;
688 DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase
, vdso64_pages
);
689 #endif /* CONFIG_PPC64 */
693 * Calculate the size of the 32 bits vDSO
695 vdso32_pages
= (&vdso32_end
- &vdso32_start
) >> PAGE_SHIFT
;
696 DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase
, vdso32_pages
);
700 * Setup the syscall map in the vDOS
702 vdso_setup_syscall_map();
704 * Initialize the vDSO images in memory, that is do necessary
705 * fixups of vDSO symbols, locate trampolines, etc...
708 printk(KERN_ERR
"vDSO setup failure, not enabled !\n");
716 /* Make sure pages are in the correct state */
717 for (i
= 0; i
< vdso32_pages
; i
++) {
718 struct page
*pg
= virt_to_page(vdso32_kbase
+ i
*PAGE_SIZE
);
719 ClearPageReserved(pg
);
724 for (i
= 0; i
< vdso64_pages
; i
++) {
725 struct page
*pg
= virt_to_page(vdso64_kbase
+ i
*PAGE_SIZE
);
726 ClearPageReserved(pg
);
729 #endif /* CONFIG_PPC64 */
731 get_page(virt_to_page(vdso_data
));
734 int in_gate_area_no_task(unsigned long addr
)
739 int in_gate_area(struct task_struct
*task
, unsigned long addr
)
744 struct vm_area_struct
*get_gate_vma(struct task_struct
*tsk
)