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, int uses_interp)
189 struct mm_struct *mm = current->mm;
190 struct page **vdso_pagelist;
191 unsigned long vdso_pages;
192 unsigned long vdso_base;
199 if (test_thread_flag(TIF_32BIT)) {
200 vdso_pagelist = vdso32_pagelist;
201 vdso_pages = vdso32_pages;
202 vdso_base = VDSO32_MBASE;
204 vdso_pagelist = vdso64_pagelist;
205 vdso_pages = vdso64_pages;
206 vdso_base = VDSO64_MBASE;
209 vdso_pagelist = vdso32_pagelist;
210 vdso_pages = vdso32_pages;
211 vdso_base = VDSO32_MBASE;
214 current->mm->context.vdso_base = 0;
216 /* vDSO has a problem and was disabled, just don't "enable" it for the
221 /* Add a page to the vdso size for the data page */
225 * pick a base address for the vDSO in process space. We try to put it
226 * at vdso_base which is the "natural" base for it, but we might fail
227 * and end up putting it elsewhere.
229 down_write(&mm->mmap_sem);
230 vdso_base = get_unmapped_area(NULL, vdso_base,
231 vdso_pages << PAGE_SHIFT, 0, 0);
232 if (IS_ERR_VALUE(vdso_base)) {
238 * our vma flags don't have VM_WRITE so by default, the process isn't
239 * allowed to write those pages.
240 * gdb can break that with ptrace interface, and thus trigger COW on
241 * those pages but it's then your responsibility to never do that on
242 * the "data" page of the vDSO or you'll stop getting kernel updates
243 * and your nice userland gettimeofday will be totally dead.
244 * It's fine to use that for setting breakpoints in the vDSO code
247 * Make sure the vDSO gets into every core dump.
248 * Dumping its contents makes post-mortem fully interpretable later
249 * without matching up the same kernel and hardware config to see
250 * what PC values meant.
252 rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
254 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
260 /* Put vDSO base into mm struct */
261 current->mm->context.vdso_base = vdso_base;
263 up_write(&mm->mmap_sem);
267 up_write(&mm->mmap_sem);
271 const char *arch_vma_name(struct vm_area_struct *vma)
273 if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
280 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
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;
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) {
295 *size = sechdrs[i].sh_size;
296 return (void *)ehdr + sechdrs[i].sh_offset;
303 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
307 char name[MAX_SYMNAME], *c;
309 for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
310 if (lib->dynsym[i].st_name == 0)
312 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
314 c = strchr(name, '@');
317 if (strcmp(symname, name) == 0)
318 return &lib->dynsym[i];
323 /* Note that we assume the section is .text and the symbol is relative to
326 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
329 Elf32_Sym *sym = find_symbol32(lib, symname);
332 printk(KERN_WARNING "vDSO32: function %s not found !\n",
336 return sym->st_value - VDSO32_LBASE;
339 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
340 struct lib64_elfinfo *v64,
341 const char *orig, const char *fix)
343 Elf32_Sym *sym32_gen, *sym32_fix;
345 sym32_gen = find_symbol32(v32, orig);
346 if (sym32_gen == NULL) {
347 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
351 sym32_gen->st_name = 0;
354 sym32_fix = find_symbol32(v32, fix);
355 if (sym32_fix == NULL) {
356 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
359 sym32_gen->st_value = sym32_fix->st_value;
360 sym32_gen->st_size = sym32_fix->st_size;
361 sym32_gen->st_info = sym32_fix->st_info;
362 sym32_gen->st_other = sym32_fix->st_other;
363 sym32_gen->st_shndx = sym32_fix->st_shndx;
371 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
378 /* Grab section headers and strings so we can tell who is who */
379 sechdrs = (void *)ehdr + ehdr->e_shoff;
380 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
382 /* Find the section they want */
383 for (i = 1; i < ehdr->e_shnum; i++) {
384 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
386 *size = sechdrs[i].sh_size;
387 return (void *)ehdr + sechdrs[i].sh_offset;
395 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
399 char name[MAX_SYMNAME], *c;
401 for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
402 if (lib->dynsym[i].st_name == 0)
404 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
406 c = strchr(name, '@');
409 if (strcmp(symname, name) == 0)
410 return &lib->dynsym[i];
415 /* Note that we assume the section is .text and the symbol is relative to
418 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
421 Elf64_Sym *sym = find_symbol64(lib, symname);
424 printk(KERN_WARNING "vDSO64: function %s not found !\n",
428 #ifdef VDS64_HAS_DESCRIPTORS
429 return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
432 return sym->st_value - VDSO64_LBASE;
436 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
437 struct lib64_elfinfo *v64,
438 const char *orig, const char *fix)
440 Elf64_Sym *sym64_gen, *sym64_fix;
442 sym64_gen = find_symbol64(v64, orig);
443 if (sym64_gen == NULL) {
444 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
448 sym64_gen->st_name = 0;
451 sym64_fix = find_symbol64(v64, fix);
452 if (sym64_fix == NULL) {
453 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
456 sym64_gen->st_value = sym64_fix->st_value;
457 sym64_gen->st_size = sym64_fix->st_size;
458 sym64_gen->st_info = sym64_fix->st_info;
459 sym64_gen->st_other = sym64_fix->st_other;
460 sym64_gen->st_shndx = sym64_fix->st_shndx;
465 #endif /* CONFIG_PPC64 */
468 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
469 struct lib64_elfinfo *v64)
474 * Locate symbol tables & text section
477 v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
478 v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
479 if (v32->dynsym == NULL || v32->dynstr == NULL) {
480 printk(KERN_ERR "vDSO32: required symbol section not found\n");
483 sect = find_section32(v32->hdr, ".text", NULL);
485 printk(KERN_ERR "vDSO32: the .text section was not found\n");
488 v32->text = sect - vdso32_kbase;
491 v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
492 v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
493 if (v64->dynsym == NULL || v64->dynstr == NULL) {
494 printk(KERN_ERR "vDSO64: required symbol section not found\n");
497 sect = find_section64(v64->hdr, ".text", NULL);
499 printk(KERN_ERR "vDSO64: the .text section was not found\n");
502 v64->text = sect - vdso64_kbase;
503 #endif /* CONFIG_PPC64 */
508 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
509 struct lib64_elfinfo *v64)
512 * Find signal trampolines
516 vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
518 vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32");
519 vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
522 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
523 struct lib64_elfinfo *v64)
529 sym64 = find_symbol64(v64, "__kernel_datapage_offset");
531 printk(KERN_ERR "vDSO64: Can't find symbol "
532 "__kernel_datapage_offset !\n");
535 *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
536 (vdso64_pages << PAGE_SHIFT) -
537 (sym64->st_value - VDSO64_LBASE);
538 #endif /* CONFIG_PPC64 */
540 sym32 = find_symbol32(v32, "__kernel_datapage_offset");
542 printk(KERN_ERR "vDSO32: Can't find symbol "
543 "__kernel_datapage_offset !\n");
546 *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
547 (vdso32_pages << PAGE_SHIFT) -
548 (sym32->st_value - VDSO32_LBASE);
554 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
555 struct lib64_elfinfo *v64)
558 unsigned long size32;
562 unsigned long size64;
564 start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
566 do_feature_fixups(cur_cpu_spec->cpu_features,
567 start64, start64 + size64);
569 start64 = find_section64(v64->hdr, "__mmu_ftr_fixup", &size64);
571 do_feature_fixups(cur_cpu_spec->mmu_features,
572 start64, start64 + size64);
574 start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
576 do_feature_fixups(powerpc_firmware_features,
577 start64, start64 + size64);
579 start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
581 do_lwsync_fixups(cur_cpu_spec->cpu_features,
582 start64, start64 + size64);
583 #endif /* CONFIG_PPC64 */
585 start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
587 do_feature_fixups(cur_cpu_spec->cpu_features,
588 start32, start32 + size32);
590 start32 = find_section32(v32->hdr, "__mmu_ftr_fixup", &size32);
592 do_feature_fixups(cur_cpu_spec->mmu_features,
593 start32, start32 + size32);
596 start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
598 do_feature_fixups(powerpc_firmware_features,
599 start32, start32 + size32);
600 #endif /* CONFIG_PPC64 */
602 start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
604 do_lwsync_fixups(cur_cpu_spec->cpu_features,
605 start32, start32 + size32);
610 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
611 struct lib64_elfinfo *v64)
615 for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
616 struct vdso_patch_def *patch = &vdso_patches[i];
617 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
622 DBG("replacing %s with %s...\n", patch->gen_name,
623 patch->fix_name ? "NONE" : patch->fix_name);
626 * Patch the 32 bits and 64 bits symbols. Note that we do not
627 * patch the "." symbol on 64 bits.
628 * It would be easy to do, but doesn't seem to be necessary,
629 * patching the OPD symbol is enough.
631 vdso_do_func_patch32(v32, v64, patch->gen_name,
634 vdso_do_func_patch64(v32, v64, patch->gen_name,
636 #endif /* CONFIG_PPC64 */
643 static __init int vdso_setup(void)
645 struct lib32_elfinfo v32;
646 struct lib64_elfinfo v64;
648 v32.hdr = vdso32_kbase;
650 v64.hdr = vdso64_kbase;
652 if (vdso_do_find_sections(&v32, &v64))
655 if (vdso_fixup_datapage(&v32, &v64))
658 if (vdso_fixup_features(&v32, &v64))
661 if (vdso_fixup_alt_funcs(&v32, &v64))
664 vdso_setup_trampolines(&v32, &v64);
670 * Called from setup_arch to initialize the bitmap of available
671 * syscalls in the systemcfg page
673 static void __init vdso_setup_syscall_map(void)
676 extern unsigned long *sys_call_table;
677 extern unsigned long sys_ni_syscall;
680 for (i = 0; i < __NR_syscalls; i++) {
682 if (sys_call_table[i*2] != sys_ni_syscall)
683 vdso_data->syscall_map_64[i >> 5] |=
684 0x80000000UL >> (i & 0x1f);
685 if (sys_call_table[i*2+1] != sys_ni_syscall)
686 vdso_data->syscall_map_32[i >> 5] |=
687 0x80000000UL >> (i & 0x1f);
688 #else /* CONFIG_PPC64 */
689 if (sys_call_table[i] != sys_ni_syscall)
690 vdso_data->syscall_map_32[i >> 5] |=
691 0x80000000UL >> (i & 0x1f);
692 #endif /* CONFIG_PPC64 */
697 static int __init vdso_init(void)
703 * Fill up the "systemcfg" stuff for backward compatiblity
705 strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
706 vdso_data->version.major = SYSTEMCFG_MAJOR;
707 vdso_data->version.minor = SYSTEMCFG_MINOR;
708 vdso_data->processor = mfspr(SPRN_PVR);
710 * Fake the old platform number for pSeries and iSeries and add
711 * in LPAR bit if necessary
713 vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
714 if (firmware_has_feature(FW_FEATURE_LPAR))
715 vdso_data->platform |= 1;
716 vdso_data->physicalMemorySize = lmb_phys_mem_size();
717 vdso_data->dcache_size = ppc64_caches.dsize;
718 vdso_data->dcache_line_size = ppc64_caches.dline_size;
719 vdso_data->icache_size = ppc64_caches.isize;
720 vdso_data->icache_line_size = ppc64_caches.iline_size;
722 /* XXXOJN: Blocks should be added to ppc64_caches and used instead */
723 vdso_data->dcache_block_size = ppc64_caches.dline_size;
724 vdso_data->icache_block_size = ppc64_caches.iline_size;
725 vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
726 vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
729 * Calculate the size of the 64 bits vDSO
731 vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
732 DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
734 vdso_data->dcache_block_size = L1_CACHE_BYTES;
735 vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
736 vdso_data->icache_block_size = L1_CACHE_BYTES;
737 vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
738 #endif /* CONFIG_PPC64 */
742 * Calculate the size of the 32 bits vDSO
744 vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
745 DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
749 * Setup the syscall map in the vDOS
751 vdso_setup_syscall_map();
754 * Initialize the vDSO images in memory, that is do necessary
755 * fixups of vDSO symbols, locate trampolines, etc...
758 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
766 /* Make sure pages are in the correct state */
767 vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
769 BUG_ON(vdso32_pagelist == NULL);
770 for (i = 0; i < vdso32_pages; i++) {
771 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
772 ClearPageReserved(pg);
774 vdso32_pagelist[i] = pg;
776 vdso32_pagelist[i++] = virt_to_page(vdso_data);
777 vdso32_pagelist[i] = NULL;
780 vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
782 BUG_ON(vdso64_pagelist == NULL);
783 for (i = 0; i < vdso64_pages; i++) {
784 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
785 ClearPageReserved(pg);
787 vdso64_pagelist[i] = pg;
789 vdso64_pagelist[i++] = virt_to_page(vdso_data);
790 vdso64_pagelist[i] = NULL;
791 #endif /* CONFIG_PPC64 */
793 get_page(virt_to_page(vdso_data));
800 arch_initcall(vdso_init);
802 int in_gate_area_no_task(unsigned long addr)
807 int in_gate_area(struct task_struct *task, unsigned long addr)
812 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)