diff options
Diffstat (limited to 'arch/ppc64/kernel/vdso.c')
| -rw-r--r-- | arch/ppc64/kernel/vdso.c | 625 |
1 files changed, 0 insertions, 625 deletions
diff --git a/arch/ppc64/kernel/vdso.c b/arch/ppc64/kernel/vdso.c deleted file mode 100644 index 1bbacac4498..00000000000 --- a/arch/ppc64/kernel/vdso.c +++ /dev/null @@ -1,625 +0,0 @@ -/* - * linux/arch/ppc64/kernel/vdso.c - * - * Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp. - * <benh@kernel.crashing.org> - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#include <linux/config.h> -#include <linux/module.h> -#include <linux/errno.h> -#include <linux/sched.h> -#include <linux/kernel.h> -#include <linux/mm.h> -#include <linux/smp.h> -#include <linux/smp_lock.h> -#include <linux/stddef.h> -#include <linux/unistd.h> -#include <linux/slab.h> -#include <linux/user.h> -#include <linux/elf.h> -#include <linux/security.h> -#include <linux/bootmem.h> - -#include <asm/pgtable.h> -#include <asm/system.h> -#include <asm/processor.h> -#include <asm/mmu.h> -#include <asm/mmu_context.h> -#include <asm/machdep.h> -#include <asm/cputable.h> -#include <asm/sections.h> -#include <asm/systemcfg.h> -#include <asm/vdso.h> - -#undef DEBUG - -#ifdef DEBUG -#define DBG(fmt...) printk(fmt) -#else -#define DBG(fmt...) -#endif - - -/* - * The vDSOs themselves are here - */ -extern char vdso64_start, vdso64_end; -extern char vdso32_start, vdso32_end; - -static void *vdso64_kbase = &vdso64_start; -static void *vdso32_kbase = &vdso32_start; - -unsigned int vdso64_pages; -unsigned int vdso32_pages; - -/* Signal trampolines user addresses */ - -unsigned long vdso64_rt_sigtramp; -unsigned long vdso32_sigtramp; -unsigned long vdso32_rt_sigtramp; - -/* Format of the patch table */ -struct vdso_patch_def -{ - u32 pvr_mask, pvr_value; - const char *gen_name; - const char *fix_name; -}; - -/* Table of functions to patch based on the CPU type/revision - * - * TODO: Improve by adding whole lists for each entry - */ -static struct vdso_patch_def vdso_patches[] = { - { - 0xffff0000, 0x003a0000, /* POWER5 */ - "__kernel_sync_dicache", "__kernel_sync_dicache_p5" - }, - { - 0xffff0000, 0x003b0000, /* POWER5 */ - "__kernel_sync_dicache", "__kernel_sync_dicache_p5" - }, -}; - -/* - * Some infos carried around for each of them during parsing at - * boot time. - */ -struct lib32_elfinfo -{ - Elf32_Ehdr *hdr; /* ptr to ELF */ - Elf32_Sym *dynsym; /* ptr to .dynsym section */ - unsigned long dynsymsize; /* size of .dynsym section */ - char *dynstr; /* ptr to .dynstr section */ - unsigned long text; /* offset of .text section in .so */ -}; - -struct lib64_elfinfo -{ - Elf64_Ehdr *hdr; - Elf64_Sym *dynsym; - unsigned long dynsymsize; - char *dynstr; - unsigned long text; -}; - - -#ifdef __DEBUG -static void dump_one_vdso_page(struct page *pg, struct page *upg) -{ - printk("kpg: %p (c:%d,f:%08lx)", __va(page_to_pfn(pg) << PAGE_SHIFT), - page_count(pg), - pg->flags); - if (upg/* && pg != upg*/) { - printk(" upg: %p (c:%d,f:%08lx)", __va(page_to_pfn(upg) << PAGE_SHIFT), - page_count(upg), - upg->flags); - } - printk("\n"); -} - -static void dump_vdso_pages(struct vm_area_struct * vma) -{ - int i; - - if (!vma || test_thread_flag(TIF_32BIT)) { - printk("vDSO32 @ %016lx:\n", (unsigned long)vdso32_kbase); - for (i=0; i<vdso32_pages; i++) { - struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE); - struct page *upg = (vma && vma->vm_mm) ? - follow_page(vma->vm_mm, vma->vm_start + i*PAGE_SIZE, 0) - : NULL; - dump_one_vdso_page(pg, upg); - } - } - if (!vma || !test_thread_flag(TIF_32BIT)) { - printk("vDSO64 @ %016lx:\n", (unsigned long)vdso64_kbase); - for (i=0; i<vdso64_pages; i++) { - struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE); - struct page *upg = (vma && vma->vm_mm) ? - follow_page(vma->vm_mm, vma->vm_start + i*PAGE_SIZE, 0) - : NULL; - dump_one_vdso_page(pg, upg); - } - } -} -#endif /* DEBUG */ - -/* - * Keep a dummy vma_close for now, it will prevent VMA merging. - */ -static void vdso_vma_close(struct vm_area_struct * vma) -{ -} - -/* - * Our nopage() function, maps in the actual vDSO kernel pages, they will - * be mapped read-only by do_no_page(), and eventually COW'ed, either - * right away for an initial write access, or by do_wp_page(). - */ -static struct page * vdso_vma_nopage(struct vm_area_struct * vma, - unsigned long address, int *type) -{ - unsigned long offset = address - vma->vm_start; - struct page *pg; - void *vbase = test_thread_flag(TIF_32BIT) ? vdso32_kbase : vdso64_kbase; - - DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n", - current->comm, address, offset); - - if (address < vma->vm_start || address > vma->vm_end) - return NOPAGE_SIGBUS; - - /* - * Last page is systemcfg. - */ - if ((vma->vm_end - address) <= PAGE_SIZE) - pg = virt_to_page(_systemcfg); - else - pg = virt_to_page(vbase + offset); - - get_page(pg); - DBG(" ->page count: %d\n", page_count(pg)); - - return pg; -} - -static struct vm_operations_struct vdso_vmops = { - .close = vdso_vma_close, - .nopage = vdso_vma_nopage, -}; - -/* - * This is called from binfmt_elf, we create the special vma for the - * vDSO and insert it into the mm struct tree - */ -int arch_setup_additional_pages(struct linux_binprm *bprm, int executable_stack) -{ - struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; - unsigned long vdso_pages; - unsigned long vdso_base; - - if (test_thread_flag(TIF_32BIT)) { - vdso_pages = vdso32_pages; - vdso_base = VDSO32_MBASE; - } else { - vdso_pages = vdso64_pages; - vdso_base = VDSO64_MBASE; - } - - current->thread.vdso_base = 0; - - /* vDSO has a problem and was disabled, just don't "enable" it for the - * process - */ - if (vdso_pages == 0) - return 0; - - vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); - if (vma == NULL) - return -ENOMEM; - - memset(vma, 0, sizeof(*vma)); - - /* - * pick a base address for the vDSO in process space. We try to put it - * at vdso_base which is the "natural" base for it, but we might fail - * and end up putting it elsewhere. - */ - vdso_base = get_unmapped_area(NULL, vdso_base, - vdso_pages << PAGE_SHIFT, 0, 0); - if (vdso_base & ~PAGE_MASK) { - kmem_cache_free(vm_area_cachep, vma); - return (int)vdso_base; - } - - current->thread.vdso_base = vdso_base; - - vma->vm_mm = mm; - vma->vm_start = current->thread.vdso_base; - - /* - * the VMA size is one page more than the vDSO since systemcfg - * is mapped in the last one - */ - vma->vm_end = vma->vm_start + ((vdso_pages + 1) << PAGE_SHIFT); - - /* - * our vma flags don't have VM_WRITE so by default, the process isn't allowed - * to write those pages. - * gdb can break that with ptrace interface, and thus trigger COW on those - * pages but it's then your responsibility to never do that on the "data" page - * of the vDSO or you'll stop getting kernel updates and your nice userland - * gettimeofday will be totally dead. It's fine to use that for setting - * breakpoints in the vDSO code pages though - */ - vma->vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC | VM_RESERVED; - vma->vm_flags |= mm->def_flags; - vma->vm_page_prot = protection_map[vma->vm_flags & 0x7]; - vma->vm_ops = &vdso_vmops; - - down_write(&mm->mmap_sem); - if (insert_vm_struct(mm, vma)) { - up_write(&mm->mmap_sem); - kmem_cache_free(vm_area_cachep, vma); - return -ENOMEM; - } - mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; - up_write(&mm->mmap_sem); - - return 0; -} - -static void * __init find_section32(Elf32_Ehdr *ehdr, const char *secname, - unsigned long *size) -{ - Elf32_Shdr *sechdrs; - unsigned int i; - char *secnames; - - /* Grab section headers and strings so we can tell who is who */ - sechdrs = (void *)ehdr + ehdr->e_shoff; - secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset; - - /* Find the section they want */ - for (i = 1; i < ehdr->e_shnum; i++) { - if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) { - if (size) - *size = sechdrs[i].sh_size; - return (void *)ehdr + sechdrs[i].sh_offset; - } - } - *size = 0; - return NULL; -} - -static void * __init find_section64(Elf64_Ehdr *ehdr, const char *secname, - unsigned long *size) -{ - Elf64_Shdr *sechdrs; - unsigned int i; - char *secnames; - - /* Grab section headers and strings so we can tell who is who */ - sechdrs = (void *)ehdr + ehdr->e_shoff; - secnames = (void *)ehdr + sechdrs[ehdr->e_shstrndx].sh_offset; - - /* Find the section they want */ - for (i = 1; i < ehdr->e_shnum; i++) { - if (strcmp(secnames+sechdrs[i].sh_name, secname) == 0) { - if (size) - *size = sechdrs[i].sh_size; - return (void *)ehdr + sechdrs[i].sh_offset; - } - } - if (size) - *size = 0; - return NULL; -} - -static Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib, const char *symname) -{ - unsigned int i; - char name[32], *c; - - for (i = 0; i < (lib->dynsymsize / sizeof(Elf32_Sym)); i++) { - if (lib->dynsym[i].st_name == 0) - continue; - strlcpy(name, lib->dynstr + lib->dynsym[i].st_name, 32); - c = strchr(name, '@'); - if (c) - *c = 0; - if (strcmp(symname, name) == 0) - return &lib->dynsym[i]; - } - return NULL; -} - -static Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib, const char *symname) -{ - unsigned int i; - char name[32], *c; - - for (i = 0; i < (lib->dynsymsize / sizeof(Elf64_Sym)); i++) { - if (lib->dynsym[i].st_name == 0) - continue; - strlcpy(name, lib->dynstr + lib->dynsym[i].st_name, 32); - c = strchr(name, '@'); - if (c) - *c = 0; - if (strcmp(symname, name) == 0) - return &lib->dynsym[i]; - } - return NULL; -} - -/* Note that we assume the section is .text and the symbol is relative to - * the library base - */ -static unsigned long __init find_function32(struct lib32_elfinfo *lib, const char *symname) -{ - Elf32_Sym *sym = find_symbol32(lib, symname); - - if (sym == NULL) { - printk(KERN_WARNING "vDSO32: function %s not found !\n", symname); - return 0; - } - return sym->st_value - VDSO32_LBASE; -} - -/* Note that we assume the section is .text and the symbol is relative to - * the library base - */ -static unsigned long __init find_function64(struct lib64_elfinfo *lib, const char *symname) -{ - Elf64_Sym *sym = find_symbol64(lib, symname); - - if (sym == NULL) { - printk(KERN_WARNING "vDSO64: function %s not found !\n", symname); - return 0; - } -#ifdef VDS64_HAS_DESCRIPTORS - return *((u64 *)(vdso64_kbase + sym->st_value - VDSO64_LBASE)) - VDSO64_LBASE; -#else - return sym->st_value - VDSO64_LBASE; -#endif -} - - -static __init int vdso_do_find_sections(struct lib32_elfinfo *v32, - struct lib64_elfinfo *v64) -{ - void *sect; - - /* - * Locate symbol tables & text section - */ - - v32->dynsym = find_section32(v32->hdr, ".dynsym", &v32->dynsymsize); - v32->dynstr = find_section32(v32->hdr, ".dynstr", NULL); - if (v32->dynsym == NULL || v32->dynstr == NULL) { - printk(KERN_ERR "vDSO32: a required symbol section was not found\n"); - return -1; - } - sect = find_section32(v32->hdr, ".text", NULL); - if (sect == NULL) { - printk(KERN_ERR "vDSO32: the .text section was not found\n"); - return -1; - } - v32->text = sect - vdso32_kbase; - - v64->dynsym = find_section64(v64->hdr, ".dynsym", &v64->dynsymsize); - v64->dynstr = find_section64(v64->hdr, ".dynstr", NULL); - if (v64->dynsym == NULL || v64->dynstr == NULL) { - printk(KERN_ERR "vDSO64: a required symbol section was not found\n"); - return -1; - } - sect = find_section64(v64->hdr, ".text", NULL); - if (sect == NULL) { - printk(KERN_ERR "vDSO64: the .text section was not found\n"); - return -1; - } - v64->text = sect - vdso64_kbase; - - return 0; -} - -static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32, - struct lib64_elfinfo *v64) -{ - /* - * Find signal trampolines - */ - - vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64"); - vdso32_sigtramp = find_function32(v32, "__kernel_sigtramp32"); - vdso32_rt_sigtramp = find_function32(v32, "__kernel_sigtramp_rt32"); -} - -static __init int vdso_fixup_datapage(struct lib32_elfinfo *v32, - struct lib64_elfinfo *v64) -{ - Elf32_Sym *sym32; - Elf64_Sym *sym64; - - sym32 = find_symbol32(v32, "__kernel_datapage_offset"); - if (sym32 == NULL) { - printk(KERN_ERR "vDSO32: Can't find symbol __kernel_datapage_offset !\n"); - return -1; - } - *((int *)(vdso32_kbase + (sym32->st_value - VDSO32_LBASE))) = - (vdso32_pages << PAGE_SHIFT) - (sym32->st_value - VDSO32_LBASE); - - sym64 = find_symbol64(v64, "__kernel_datapage_offset"); - if (sym64 == NULL) { - printk(KERN_ERR "vDSO64: Can't find symbol __kernel_datapage_offset !\n"); - return -1; - } - *((int *)(vdso64_kbase + sym64->st_value - VDSO64_LBASE)) = - (vdso64_pages << PAGE_SHIFT) - (sym64->st_value - VDSO64_LBASE); - - return 0; -} - -static int vdso_do_func_patch32(struct lib32_elfinfo *v32, - struct lib64_elfinfo *v64, - const char *orig, const char *fix) -{ - Elf32_Sym *sym32_gen, *sym32_fix; - - sym32_gen = find_symbol32(v32, orig); - if (sym32_gen == NULL) { - printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", orig); - return -1; - } - sym32_fix = find_symbol32(v32, fix); - if (sym32_fix == NULL) { - printk(KERN_ERR "vDSO32: Can't find symbol %s !\n", fix); - return -1; - } - sym32_gen->st_value = sym32_fix->st_value; - sym32_gen->st_size = sym32_fix->st_size; - sym32_gen->st_info = sym32_fix->st_info; - sym32_gen->st_other = sym32_fix->st_other; - sym32_gen->st_shndx = sym32_fix->st_shndx; - - return 0; -} - -static int vdso_do_func_patch64(struct lib32_elfinfo *v32, - struct lib64_elfinfo *v64, - const char *orig, const char *fix) -{ - Elf64_Sym *sym64_gen, *sym64_fix; - - sym64_gen = find_symbol64(v64, orig); - if (sym64_gen == NULL) { - printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", orig); - return -1; - } - sym64_fix = find_symbol64(v64, fix); - if (sym64_fix == NULL) { - printk(KERN_ERR "vDSO64: Can't find symbol %s !\n", fix); - return -1; - } - sym64_gen->st_value = sym64_fix->st_value; - sym64_gen->st_size = sym64_fix->st_size; - sym64_gen->st_info = sym64_fix->st_info; - sym64_gen->st_other = sym64_fix->st_other; - sym64_gen->st_shndx = sym64_fix->st_shndx; - - return 0; -} - -static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32, - struct lib64_elfinfo *v64) -{ - u32 pvr; - int i; - - pvr = mfspr(SPRN_PVR); - for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) { - struct vdso_patch_def *patch = &vdso_patches[i]; - int match = (pvr & patch->pvr_mask) == patch->pvr_value; - - DBG("patch %d (mask: %x, pvr: %x) : %s\n", - i, patch->pvr_mask, patch->pvr_value, match ? "match" : "skip"); - - if (!match) - continue; - - DBG("replacing %s with %s...\n", patch->gen_name, patch->fix_name); - - /* - * Patch the 32 bits and 64 bits symbols. Note that we do not patch - * the "." symbol on 64 bits. It would be easy to do, but doesn't - * seem to be necessary, patching the OPD symbol is enough. - */ - vdso_do_func_patch32(v32, v64, patch->gen_name, patch->fix_name); - vdso_do_func_patch64(v32, v64, patch->gen_name, patch->fix_name); - } - - return 0; -} - - -static __init int vdso_setup(void) -{ - struct lib32_elfinfo v32; - struct lib64_elfinfo v64; - - v32.hdr = vdso32_kbase; - v64.hdr = vdso64_kbase; - - if (vdso_do_find_sections(&v32, &v64)) - return -1; - - if (vdso_fixup_datapage(&v32, &v64)) - return -1; - - if (vdso_fixup_alt_funcs(&v32, &v64)) - return -1; - - vdso_setup_trampolines(&v32, &v64); - - return 0; -} - -void __init vdso_init(void) -{ - int i; - - vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT; - vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT; - - DBG("vdso64_kbase: %p, 0x%x pages, vdso32_kbase: %p, 0x%x pages\n", - vdso64_kbase, vdso64_pages, vdso32_kbase, vdso32_pages); - - /* - * Initialize the vDSO images in memory, that is do necessary - * fixups of vDSO symbols, locate trampolines, etc... - */ - if (vdso_setup()) { - printk(KERN_ERR "vDSO setup failure, not enabled !\n"); - /* XXX should free pages here ? */ - vdso64_pages = vdso32_pages = 0; - return; - } - - /* Make sure pages are in the correct state */ - for (i = 0; i < vdso64_pages; i++) { - struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE); - ClearPageReserved(pg); - get_page(pg); - } - for (i = 0; i < vdso32_pages; i++) { - struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE); - ClearPageReserved(pg); - get_page(pg); - } - - get_page(virt_to_page(_systemcfg)); -} - -int in_gate_area_no_task(unsigned long addr) -{ - return 0; -} - -int in_gate_area(struct task_struct *task, unsigned long addr) -{ - return 0; -} - -struct vm_area_struct *get_gate_vma(struct task_struct *tsk) -{ - return NULL; -} - |