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/pgtable.h>
26 #include <asm/processor.h>
28 #include <asm/mmu_context.h>
30 #include <asm/machdep.h>
31 #include <asm/cputable.h>
32 #include <asm/sections.h>
33 #include <asm/firmware.h>
35 #include <asm/vdso_datapage.h>
36 #include <asm/setup.h>
41 #define DBG(fmt...) printk(fmt)
46 /* Max supported size for symbol names */
47 #define MAX_SYMNAME 64
49 /* The alignment of the vDSO */
50 #define VDSO_ALIGNMENT (1 << 16)
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 __page_aligned_data;
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
116 "__kernel_time", NULL
121 * Some infos carried around for each of them during parsing at
126 Elf32_Ehdr *hdr; /* ptr to ELF */
127 Elf32_Sym *dynsym; /* ptr to .dynsym section */
128 unsigned long dynsymsize; /* size of .dynsym section */
129 char *dynstr; /* ptr to .dynstr section */
130 unsigned long text; /* offset of .text section in .so */
137 unsigned long dynsymsize;
144 static void dump_one_vdso_page(struct page *pg, struct page *upg)
146 printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT),
149 if (upg && !IS_ERR(upg) /* && pg != upg*/) {
150 printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg)
158 static void dump_vdso_pages(struct vm_area_struct * vma)
162 if (!vma || is_32bit_task()) {
163 printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase);
164 for (i=0; i<vdso32_pages; i++) {
165 struct page *pg = virt_to_page(vdso32_kbase +
167 struct page *upg = (vma && vma->vm_mm) ?
168 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
170 dump_one_vdso_page(pg, upg);
173 if (!vma || !is_32bit_task()) {
174 printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase);
175 for (i=0; i<vdso64_pages; i++) {
176 struct page *pg = virt_to_page(vdso64_kbase +
178 struct page *upg = (vma && vma->vm_mm) ?
179 follow_page(vma, vma->vm_start + i*PAGE_SIZE, 0)
181 dump_one_vdso_page(pg, upg);
188 * This is called from binfmt_elf, we create the special vma for the
189 * vDSO and insert it into the mm struct tree
191 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
193 struct mm_struct *mm = current->mm;
194 struct page **vdso_pagelist;
195 unsigned long vdso_pages;
196 unsigned long vdso_base;
203 if (is_32bit_task()) {
204 vdso_pagelist = vdso32_pagelist;
205 vdso_pages = vdso32_pages;
206 vdso_base = VDSO32_MBASE;
208 vdso_pagelist = vdso64_pagelist;
209 vdso_pages = vdso64_pages;
211 * On 64bit we don't have a preferred map address. This
212 * allows get_unmapped_area to find an area near other mmaps
213 * and most likely share a SLB entry.
218 vdso_pagelist = vdso32_pagelist;
219 vdso_pages = vdso32_pages;
220 vdso_base = VDSO32_MBASE;
223 current->mm->context.vdso_base = 0;
225 /* vDSO has a problem and was disabled, just don't "enable" it for the
230 /* Add a page to the vdso size for the data page */
234 * pick a base address for the vDSO in process space. We try to put it
235 * at vdso_base which is the "natural" base for it, but we might fail
236 * and end up putting it elsewhere.
237 * Add enough to the size so that the result can be aligned.
239 down_write(&mm->mmap_sem);
240 vdso_base = get_unmapped_area(NULL, vdso_base,
241 (vdso_pages << PAGE_SHIFT) +
242 ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
244 if (IS_ERR_VALUE(vdso_base)) {
249 /* Add required alignment. */
250 vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
253 * Put vDSO base into mm struct. We need to do this before calling
254 * install_special_mapping or the perf counter mmap tracking code
255 * will fail to recognise it as a vDSO (since arch_vma_name fails).
257 current->mm->context.vdso_base = vdso_base;
260 * our vma flags don't have VM_WRITE so by default, the process isn't
261 * allowed to write those pages.
262 * gdb can break that with ptrace interface, and thus trigger COW on
263 * those pages but it's then your responsibility to never do that on
264 * the "data" page of the vDSO or you'll stop getting kernel updates
265 * and your nice userland gettimeofday will be totally dead.
266 * It's fine to use that for setting breakpoints in the vDSO code
269 rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
271 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
274 current->mm->context.vdso_base = 0;
278 up_write(&mm->mmap_sem);
282 up_write(&mm->mmap_sem);
286 const char *arch_vma_name(struct vm_area_struct *vma)
288 if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
295 static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname,
302 /* Grab section headers and strings so we can tell who is who */
303 sechdrs = (void *)ehdr + ehdr->e_shoff;
304 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
306 /* Find the section they want */
307 for (i = 1; i < ehdr->e_shnum; i++) {
308 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
310 *size = sechdrs[i].sh_size;
311 return (void *)ehdr + sechdrs[i].sh_offset;
318 static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
322 char name[MAX_SYMNAME], *c;
324 for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) {
325 if (lib->dynsym[i].st_name == 0)
327 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
329 c = strchr(name, '@');
332 if (strcmp(symname, name) == 0)
333 return &lib->dynsym[i];
338 /* Note that we assume the section is .text and the symbol is relative to
341 static unsigned long __init find_function32(struct lib32_elfinfo *lib,
344 Elf32_Sym *sym = find_symbol32(lib, symname);
347 printk(KERN_WARNING "vDSO32: function %s not found !\n",
351 return sym->st_value - VDSO32_LBASE;
354 static int __init vdso_do_func_patch32(struct lib32_elfinfo *v32,
355 struct lib64_elfinfo *v64,
356 const char *orig, const char *fix)
358 Elf32_Sym *sym32_gen, *sym32_fix;
360 sym32_gen = find_symbol32(v32, orig);
361 if (sym32_gen == NULL) {
362 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig);
366 sym32_gen->st_name = 0;
369 sym32_fix = find_symbol32(v32, fix);
370 if (sym32_fix == NULL) {
371 printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix);
374 sym32_gen->st_value = sym32_fix->st_value;
375 sym32_gen->st_size = sym32_fix->st_size;
376 sym32_gen->st_info = sym32_fix->st_info;
377 sym32_gen->st_other = sym32_fix->st_other;
378 sym32_gen->st_shndx = sym32_fix->st_shndx;
386 static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname,
393 /* Grab section headers and strings so we can tell who is who */
394 sechdrs = (void *)ehdr + ehdr->e_shoff;
395 secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset;
397 /* Find the section they want */
398 for (i = 1; i < ehdr->e_shnum; i++) {
399 if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) {
401 *size = sechdrs[i].sh_size;
402 return (void *)ehdr + sechdrs[i].sh_offset;
410 static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
414 char name[MAX_SYMNAME], *c;
416 for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) {
417 if (lib->dynsym[i].st_name == 0)
419 strlcpy(name, lib->dynstr + lib->dynsym[i].st_name,
421 c = strchr(name, '@');
424 if (strcmp(symname, name) == 0)
425 return &lib->dynsym[i];
430 /* Note that we assume the section is .text and the symbol is relative to
433 static unsigned long __init find_function64(struct lib64_elfinfo *lib,
436 Elf64_Sym *sym = find_symbol64(lib, symname);
439 printk(KERN_WARNING "vDSO64: function %s not found !\n",
443 #ifdef VDS64_HAS_DESCRIPTORS
444 return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) -
447 return sym->st_value - VDSO64_LBASE;
451 static int __init vdso_do_func_patch64(struct lib32_elfinfo *v32,
452 struct lib64_elfinfo *v64,
453 const char *orig, const char *fix)
455 Elf64_Sym *sym64_gen, *sym64_fix;
457 sym64_gen = find_symbol64(v64, orig);
458 if (sym64_gen == NULL) {
459 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig);
463 sym64_gen->st_name = 0;
466 sym64_fix = find_symbol64(v64, fix);
467 if (sym64_fix == NULL) {
468 printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix);
471 sym64_gen->st_value = sym64_fix->st_value;
472 sym64_gen->st_size = sym64_fix->st_size;
473 sym64_gen->st_info = sym64_fix->st_info;
474 sym64_gen->st_other = sym64_fix->st_other;
475 sym64_gen->st_shndx = sym64_fix->st_shndx;
480 #endif /* CONFIG_PPC64 */
483 static __init int vdso_do_find_sections(struct lib32_elfinfo *v32,
484 struct lib64_elfinfo *v64)
489 * Locate symbol tables & text section
492 v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize);
493 v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL);
494 if (v32->dynsym == NULL || v32->dynstr == NULL) {
495 printk(KERN_ERR "vDSO32: required symbol section not found\n");
498 sect = find_section32(v32->hdr, ".text", NULL);
500 printk(KERN_ERR "vDSO32: the .text section was not found\n");
503 v32->text = sect - vdso32_kbase;
506 v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize);
507 v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL);
508 if (v64->dynsym == NULL || v64->dynstr == NULL) {
509 printk(KERN_ERR "vDSO64: required symbol section not found\n");
512 sect = find_section64(v64->hdr, ".text", NULL);
514 printk(KERN_ERR "vDSO64: the .text section was not found\n");
517 v64->text = sect - vdso64_kbase;
518 #endif /* CONFIG_PPC64 */
523 static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
524 struct lib64_elfinfo *v64)
527 * Find signal trampolines
531 vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
533 vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32");
534 vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32");
537 static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32,
538 struct lib64_elfinfo *v64)
544 sym64 = find_symbol64(v64, "__kernel_datapage_offset");
546 printk(KERN_ERR "vDSO64: Can't find symbol "
547 "__kernel_datapage_offset !\n");
550 *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) =
551 (vdso64_pages << PAGE_SHIFT) -
552 (sym64->st_value - VDSO64_LBASE);
553 #endif /* CONFIG_PPC64 */
555 sym32 = find_symbol32(v32, "__kernel_datapage_offset");
557 printk(KERN_ERR "vDSO32: Can't find symbol "
558 "__kernel_datapage_offset !\n");
561 *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) =
562 (vdso32_pages << PAGE_SHIFT) -
563 (sym32->st_value - VDSO32_LBASE);
569 static __init int vdso_fixup_features(struct lib32_elfinfo *v32,
570 struct lib64_elfinfo *v64)
573 unsigned long size32;
577 unsigned long size64;
579 start64 = find_section64(v64->hdr, "__ftr_fixup", &size64);
581 do_feature_fixups(cur_cpu_spec->cpu_features,
582 start64, start64 + size64);
584 start64 = find_section64(v64->hdr, "__mmu_ftr_fixup", &size64);
586 do_feature_fixups(cur_cpu_spec->mmu_features,
587 start64, start64 + size64);
589 start64 = find_section64(v64->hdr, "__fw_ftr_fixup", &size64);
591 do_feature_fixups(powerpc_firmware_features,
592 start64, start64 + size64);
594 start64 = find_section64(v64->hdr, "__lwsync_fixup", &size64);
596 do_lwsync_fixups(cur_cpu_spec->cpu_features,
597 start64, start64 + size64);
598 #endif /* CONFIG_PPC64 */
600 start32 = find_section32(v32->hdr, "__ftr_fixup", &size32);
602 do_feature_fixups(cur_cpu_spec->cpu_features,
603 start32, start32 + size32);
605 start32 = find_section32(v32->hdr, "__mmu_ftr_fixup", &size32);
607 do_feature_fixups(cur_cpu_spec->mmu_features,
608 start32, start32 + size32);
611 start32 = find_section32(v32->hdr, "__fw_ftr_fixup", &size32);
613 do_feature_fixups(powerpc_firmware_features,
614 start32, start32 + size32);
615 #endif /* CONFIG_PPC64 */
617 start32 = find_section32(v32->hdr, "__lwsync_fixup", &size32);
619 do_lwsync_fixups(cur_cpu_spec->cpu_features,
620 start32, start32 + size32);
625 static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
626 struct lib64_elfinfo *v64)
630 for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
631 struct vdso_patch_def *patch = &vdso_patches[i];
632 int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
637 DBG("replacing %s with %s...\n", patch->gen_name,
638 patch->fix_name ? "NONE" : patch->fix_name);
641 * Patch the 32 bits and 64 bits symbols. Note that we do not
642 * patch the "." symbol on 64 bits.
643 * It would be easy to do, but doesn't seem to be necessary,
644 * patching the OPD symbol is enough.
646 vdso_do_func_patch32(v32, v64, patch->gen_name,
649 vdso_do_func_patch64(v32, v64, patch->gen_name,
651 #endif /* CONFIG_PPC64 */
658 static __init int vdso_setup(void)
660 struct lib32_elfinfo v32;
661 struct lib64_elfinfo v64;
663 v32.hdr = vdso32_kbase;
665 v64.hdr = vdso64_kbase;
667 if (vdso_do_find_sections(&v32, &v64))
670 if (vdso_fixup_datapage(&v32, &v64))
673 if (vdso_fixup_features(&v32, &v64))
676 if (vdso_fixup_alt_funcs(&v32, &v64))
679 vdso_setup_trampolines(&v32, &v64);
685 * Called from setup_arch to initialize the bitmap of available
686 * syscalls in the systemcfg page
688 static void __init vdso_setup_syscall_map(void)
691 extern unsigned long *sys_call_table;
692 extern unsigned long sys_ni_syscall;
695 for (i = 0; i < __NR_syscalls; i++) {
697 if (sys_call_table[i*2] != sys_ni_syscall)
698 vdso_data->syscall_map_64[i >> 5] |=
699 0x80000000UL >> (i & 0x1f);
700 if (sys_call_table[i*2+1] != sys_ni_syscall)
701 vdso_data->syscall_map_32[i >> 5] |=
702 0x80000000UL >> (i & 0x1f);
703 #else /* CONFIG_PPC64 */
704 if (sys_call_table[i] != sys_ni_syscall)
705 vdso_data->syscall_map_32[i >> 5] |=
706 0x80000000UL >> (i & 0x1f);
707 #endif /* CONFIG_PPC64 */
712 int vdso_getcpu_init(void)
714 unsigned long cpu, node, val;
717 * SPRG_VDSO contains the CPU in the bottom 16 bits and the NUMA node
718 * in the next 16 bits. The VDSO uses this to implement getcpu().
721 WARN_ON_ONCE(cpu > 0xffff);
723 node = cpu_to_node(cpu);
724 WARN_ON_ONCE(node > 0xffff);
726 val = (cpu & 0xfff) | ((node & 0xffff) << 16);
727 mtspr(SPRN_SPRG_VDSO_WRITE, val);
728 get_paca()->sprg_vdso = val;
734 /* We need to call this before SMP init */
735 early_initcall(vdso_getcpu_init);
738 static int __init vdso_init(void)
744 * Fill up the "systemcfg" stuff for backward compatibility
746 strcpy((char *)vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
747 vdso_data->version.major = SYSTEMCFG_MAJOR;
748 vdso_data->version.minor = SYSTEMCFG_MINOR;
749 vdso_data->processor = mfspr(SPRN_PVR);
751 * Fake the old platform number for pSeries and add
752 * in LPAR bit if necessary
754 vdso_data->platform = 0x100;
755 if (firmware_has_feature(FW_FEATURE_LPAR))
756 vdso_data->platform |= 1;
757 vdso_data->physicalMemorySize = memblock_phys_mem_size();
758 vdso_data->dcache_size = ppc64_caches.dsize;
759 vdso_data->dcache_line_size = ppc64_caches.dline_size;
760 vdso_data->icache_size = ppc64_caches.isize;
761 vdso_data->icache_line_size = ppc64_caches.iline_size;
763 /* XXXOJN: Blocks should be added to ppc64_caches and used instead */
764 vdso_data->dcache_block_size = ppc64_caches.dline_size;
765 vdso_data->icache_block_size = ppc64_caches.iline_size;
766 vdso_data->dcache_log_block_size = ppc64_caches.log_dline_size;
767 vdso_data->icache_log_block_size = ppc64_caches.log_iline_size;
770 * Calculate the size of the 64 bits vDSO
772 vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
773 DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
775 vdso_data->dcache_block_size = L1_CACHE_BYTES;
776 vdso_data->dcache_log_block_size = L1_CACHE_SHIFT;
777 vdso_data->icache_block_size = L1_CACHE_BYTES;
778 vdso_data->icache_log_block_size = L1_CACHE_SHIFT;
779 #endif /* CONFIG_PPC64 */
783 * Calculate the size of the 32 bits vDSO
785 vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
786 DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
790 * Setup the syscall map in the vDOS
792 vdso_setup_syscall_map();
795 * Initialize the vDSO images in memory, that is do necessary
796 * fixups of vDSO symbols, locate trampolines, etc...
799 printk(KERN_ERR "vDSO setup failure, not enabled !\n");
807 /* Make sure pages are in the correct state */
808 vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 2),
810 BUG_ON(vdso32_pagelist == NULL);
811 for (i = 0; i < vdso32_pages; i++) {
812 struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
813 ClearPageReserved(pg);
815 vdso32_pagelist[i] = pg;
817 vdso32_pagelist[i++] = virt_to_page(vdso_data);
818 vdso32_pagelist[i] = NULL;
821 vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 2),
823 BUG_ON(vdso64_pagelist == NULL);
824 for (i = 0; i < vdso64_pages; i++) {
825 struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
826 ClearPageReserved(pg);
828 vdso64_pagelist[i] = pg;
830 vdso64_pagelist[i++] = virt_to_page(vdso_data);
831 vdso64_pagelist[i] = NULL;
832 #endif /* CONFIG_PPC64 */
834 get_page(virt_to_page(vdso_data));
841 arch_initcall(vdso_init);