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>
25 #include <asm/pgtable.h>
26 #include <asm/system.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>
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 static unsigned int vdso32_pages;
54 static struct page **vdso32_pagelist;
55 unsigned long vdso32_sigtramp;
56 unsigned long vdso32_rt_sigtramp;
59 extern char vdso64_start, vdso64_end;
60 static void *vdso64_kbase = &vdso64_start;
61 static unsigned int vdso64_pages;
62 static struct page **vdso64_pagelist;
63 unsigned long vdso64_rt_sigtramp;
64 #endif /* CONFIG_PPC64 */
66 static int vdso_ready;
69 * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
70 * Once the early boot kernel code no longer needs to muck around
71 * with it, it will become dynamically allocated
74 struct vdso_data data;
76 } vdso_data_store __attribute__((__section__(".data.page_aligned")));
77 struct vdso_data *vdso_data = &vdso_data_store.data;
79 /* Format of the patch table */
82 unsigned long ftr_mask, ftr_value;
87 /* Table of functions to patch based on the CPU type/revision
89 * Currently, we only change sync_dicache to do nothing on processors
90 * with a coherent icache
92 static struct vdso_patch_def vdso_patches[] = {
94 CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
95 "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
99 "__kernel_gettimeofday", NULL
103 "__kernel_clock_gettime", NULL
107 "__kernel_clock_getres", NULL
111 "__kernel_get_tbfreq", NULL
116 * Some infos carried around for each of them during parsing at
121 Elf32_Ehdr *hdr; /* ptr to ELF */
122 Elf32_Sym *dynsym; /* ptr to .dynsym section */
123 unsigned long dynsymsize; /* size of .dynsym section */
124 char *dynstr; /* ptr to .dynstr section */
125 unsigned long text; /* offset of .text section in .so */
132 unsigned long dynsymsize;
139 static void dump_one_vdso_page(struct page *pg, struct page *upg)
141 printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
144 if (upg/* && pg != upg*/) {
145 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
153 static void dump_vdso_pages(struct vm_area_struct * vma)
157 if (!vma || test_thread_flag(TIF_32BIT)) {
158 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
159 for (i=0; i<vdso32_pages; i++) {
160 struct page *pg = virt_to_page(vdso32_kbase +
162 struct page *upg = (vma && vma->vm_mm) ?
163 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
165 dump_one_vdso_page(pg, upg);
168 if (!vma || !test_thread_flag(TIF_32BIT)) {
169 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
170 for (i=0; i<vdso64_pages; i++) {
171 struct page *pg = virt_to_page(vdso64_kbase +
173 struct page *upg = (vma && vma->vm_mm) ?
174 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
176 dump_one_vdso_page(pg, upg);
183 * This is called from binfmt_elf, we create the special vma for the
184 * vDSO and insert it into the mm struct tree
186 int arch_setup_additional_pages(struct linux_binprm *bprm,
187 int executable_stack)
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 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 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, "__fw_ftr_fixup", &size64);
571 do_feature_fixups(powerpc_firmware_features,
572 start64, start64 + size64);
573 #endif /* CONFIG_PPC64 */
575 start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
577 do_feature_fixups(cur_cpu_spec->cpu_features,
578 start32, start32 + size32);
581 start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
583 do_feature_fixups(powerpc_firmware_features,
584 start32, start32 + size32);
585 #endif /* CONFIG_PPC64 */
590 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
591 struct lib64_elfinfo *v64)
595 for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
596 struct vdso_patch_def *patch = &vdso_patches[i];
597 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
602 DBG("replacing %s with %s...\n", patch->gen_name,
603 patch->fix_name ? "NONE" : patch->fix_name);
606 * Patch the 32 bits and 64 bits symbols. Note that we do not
607 * patch the "." symbol on 64 bits.
608 * It would be easy to do, but doesn't seem to be necessary,
609 * patching the OPD symbol is enough.
611 vdso_do_func_patch32(v32, v64, patch->gen_name,
614 vdso_do_func_patch64(v32, v64, patch->gen_name,
616 #endif /* CONFIG_PPC64 */
623 static __init int vdso_setup(void)
625 struct lib32_elfinfo v32;
626 struct lib64_elfinfo v64;
628 v32.hdr = vdso32_kbase;
630 v64.hdr = vdso64_kbase;
632 if (vdso_do_find_sections(&v32, &v64))
635 if (vdso_fixup_datapage(&v32, &v64))
638 if (vdso_fixup_features(&v32, &v64))
641 if (vdso_fixup_alt_funcs(&v32, &v64))
644 vdso_setup_trampolines(&v32, &v64);
650 * Called from setup_arch to initialize the bitmap of available
651 * syscalls in the systemcfg page
653 static void __init vdso_setup_syscall_map(void)
656 extern unsigned long *sys_call_table;
657 extern unsigned long sys_ni_syscall;
660 for (i = 0; i < __NR_syscalls; i++) {
662 if (sys_call_table[i*2] != sys_ni_syscall)
663 vdso_data->syscall_map_64[i >> 5] |=
664 0x80000000UL >> (i & 0x1f);
665 if (sys_call_table[i*2+1] != sys_ni_syscall)
666 vdso_data->syscall_map_32[i >> 5] |=
667 0x80000000UL >> (i & 0x1f);
668 #else /* CONFIG_PPC64 */
669 if (sys_call_table[i] != sys_ni_syscall)
670 vdso_data->syscall_map_32[i >> 5] |=
671 0x80000000UL >> (i & 0x1f);
672 #endif /* CONFIG_PPC64 */
677 static int __init vdso_init(void)
683 * Fill up the "systemcfg" stuff for backward compatiblity
685 strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
686 vdso_data->version.major = SYSTEMCFG_MAJOR;
687 vdso_data->version.minor = SYSTEMCFG_MINOR;
688 vdso_data->processor = mfspr(SPRN_PVR);
690 * Fake the old platform number for pSeries and iSeries and add
691 * in LPAR bit if necessary
693 vdso_data->platform = machine_is(iseries) ? 0x200 : 0x100;
694 if (firmware_has_feature(FW_FEATURE_LPAR))
695 vdso_data->platform |= 1;
696 vdso_data->physicalMemorySize = lmb_phys_mem_size();
697 vdso_data->dcache_size = ppc64_caches.dsize;
698 vdso_data->dcache_line_size = ppc64_caches.dline_size;
699 vdso_data->icache_size = ppc64_caches.isize;
700 vdso_data->icache_line_size = ppc64_caches.iline_size;
702 /* XXXOJN: Blocks should be added to ppc64_caches and used instead */
703 vdso_data->dcache_block_size = ppc64_caches.dline_size;
704 vdso_data->icache_block_size = ppc64_caches.iline_size;
705 vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
706 vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
709 * Calculate the size of the 64 bits vDSO
711 vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
712 DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
714 vdso_data->dcache_block_size = L1_CACHE_BYTES;
715 vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
716 vdso_data->icache_block_size = L1_CACHE_BYTES;
717 vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
718 #endif /* CONFIG_PPC64 */
722 * Calculate the size of the 32 bits vDSO
724 vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
725 DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
729 * Setup the syscall map in the vDOS
731 vdso_setup_syscall_map();
734 * Initialize the vDSO images in memory, that is do necessary
735 * fixups of vDSO symbols, locate trampolines, etc...
738 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
746 /* Make sure pages are in the correct state */
747 vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
749 BUG_ON(vdso32_pagelist == NULL);
750 for (i = 0; i < vdso32_pages; i++) {
751 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
752 ClearPageReserved(pg);
754 vdso32_pagelist[i] = pg;
756 vdso32_pagelist[i++] = virt_to_page(vdso_data);
757 vdso32_pagelist[i] = NULL;
760 vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
762 BUG_ON(vdso64_pagelist == NULL);
763 for (i = 0; i < vdso64_pages; i++) {
764 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
765 ClearPageReserved(pg);
767 vdso64_pagelist[i] = pg;
769 vdso64_pagelist[i++] = virt_to_page(vdso_data);
770 vdso64_pagelist[i] = NULL;
771 #endif /* CONFIG_PPC64 */
773 get_page(virt_to_page(vdso_data));
780 #ifdef CONFIG_PPC_MERGE
781 arch_initcall(vdso_init);
784 int in_gate_area_no_task(unsigned long addr)
789 int in_gate_area(struct task_struct *task, unsigned long addr)
794 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)