[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel

This patch moves the vdso's to arch/powerpc, adds support for the 32
bits vdso to the 32 bits kernel, rename systemcfg (finally !), and adds
some new (still untested) routines to both vdso's: clock_gettime() with
support for CLOCK_REALTIME and CLOCK_MONOTONIC, clock_getres() (same
clocks) and get_tbfreq() for glibc to retreive the timebase frequency.

Tom,Steve: The implementation of get_tbfreq() I've done for 32 bits
returns a long long (r3, r4) not a long. This is such that if we ever
add support for >4Ghz timebases on ppc32, the userland interface won't
have to change.

I have tested gettimeofday() using some glibc patches in both ppc32 and
ppc64 kernels using 32 bits userland (I haven't had a chance to test a
64 bits userland yet, but the implementation didn't change and was
tested earlier). I haven't tested yet the new functions.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 746 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
new file mode 100644
index 000000000000..0d4d8bec0df4
--- /dev/null
+++ b/arch/powerpc/kernel/vdso.c
@@ -0,0 +1,746 @@
+/*
+ *  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/lmb.h>
+#include <asm/machdep.h>
+#include <asm/cputable.h>
+#include <asm/sections.h>
+#include <asm/vdso.h>
+#include <asm/vdso_datapage.h>
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(fmt...) printk(fmt)
+#else
+#define DBG(fmt...)
+#endif
+
+/* Max supported size for symbol names */
+#define MAX_SYMNAME     64
+
+extern char vdso32_start, vdso32_end;
+static void *vdso32_kbase = &vdso32_start;
+unsigned int vdso32_pages;
+unsigned long vdso32_sigtramp;
+unsigned long vdso32_rt_sigtramp;
+
+#ifdef CONFIG_PPC64
+extern char vdso64_start, vdso64_end;
+static void *vdso64_kbase = &vdso64_start;
+unsigned int vdso64_pages;
+unsigned long vdso64_rt_sigtramp;
+#endif /* CONFIG_PPC64 */
+
+/*
+ * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
+ * Once the early boot kernel code no longer needs to muck around
+ * with it, it will become dynamically allocated
+ */
+static union {
+        struct vdso_data        data;
+        u8                      page[PAGE_SIZE];
+} vdso_data_store __attribute__((__section__(".data.page_aligned")));
+struct vdso_data *vdso_data = &vdso_data_store.data;
+
+/* Format of the patch table */
+struct vdso_patch_def
+{
+        unsigned long   ftr_mask, ftr_value;
+        const char      *gen_name;
+        const char      *fix_name;
+};
+
+/* Table of functions to patch based on the CPU type/revision
+ *
+ * Currently, we only change sync_dicache to do nothing on processors
+ * with a coherent icache
+ */
+static struct vdso_patch_def vdso_patches[] = {
+        {
+                CPU_FTR_COHERENT_ICACHE, CPU_FTR_COHERENT_ICACHE,
+                "__kernel_sync_dicache", "__kernel_sync_dicache_p5"
+        },
+        {
+                CPU_FTR_USE_TB, 0,
+                "__kernel_gettimeofday", NULL
+        },
+};
+
+/*
+ * 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;
+#ifdef CONFIG_PPC64
+        void *vbase = test_thread_flag(TIF_32BIT) ?
+                vdso32_kbase : vdso64_kbase;
+#else
+        void *vbase = vdso32_kbase;
+#endif
+
+        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(vdso_data);
+        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;
+
+#ifdef CONFIG_PPC64
+        if (test_thread_flag(TIF_32BIT)) {
+                vdso_pages = vdso32_pages;
+                vdso_base = VDSO32_MBASE;
+        } else {
+                vdso_pages = vdso64_pages;
+                vdso_base = VDSO64_MBASE;
+        }
+#else
+        vdso_pages = vdso32_pages;
+        vdso_base = VDSO32_MBASE;
+#endif
+
+        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));
+
+        /* Add a page to the vdso size for the data page */
+        vdso_pages ++;
+
+        /*
+         * 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;
+        vma->vm_end = vma->vm_start + (vdso_pages << 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 Elf32_Sym * __init find_symbol32(struct lib32_elfinfo *lib,
+                                        const char *symname)
+{
+        unsigned int i;
+        char name[MAX_SYMNAME], *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,
+                        MAX_SYMNAME);
+                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;
+}
+
+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;
+        }
+        if (fix == NULL) {
+                sym32_gen->st_name = 0;
+                return 0;
+        }
+        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;
+}
+
+
+#ifdef CONFIG_PPC64
+
+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 Elf64_Sym * __init find_symbol64(struct lib64_elfinfo *lib,
+                                        const char *symname)
+{
+        unsigned int i;
+        char name[MAX_SYMNAME], *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,
+                        MAX_SYMNAME);
+                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_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 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;
+        }
+        if (fix == NULL) {
+                sym64_gen->st_name = 0;
+                return 0;
+        }
+        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;
+}
+
+#endif /* CONFIG_PPC64 */
+
+
+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: required symbol section 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;
+
+#ifdef CONFIG_PPC64
+        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: required symbol section 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;
+#endif /* CONFIG_PPC64 */
+
+        return 0;
+}
+
+static __init void vdso_setup_trampolines(struct lib32_elfinfo *v32,
+                                          struct lib64_elfinfo *v64)
+{
+        /*
+         * Find signal trampolines
+         */
+
+#ifdef CONFIG_PPC64
+        vdso64_rt_sigtramp = find_function64(v64, "__kernel_sigtramp_rt64");
+#endif
+        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;
+#ifdef CONFIG_PPC64
+        Elf64_Sym *sym64;
+
+        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);
+#endif /* CONFIG_PPC64 */
+
+        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);
+
+        return 0;
+}
+
+static __init int vdso_fixup_alt_funcs(struct lib32_elfinfo *v32,
+                                       struct lib64_elfinfo *v64)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(vdso_patches); i++) {
+                struct vdso_patch_def *patch = &vdso_patches[i];
+                int match = (cur_cpu_spec->cpu_features & patch->ftr_mask)
+                        == patch->ftr_value;
+                if (!match)
+                        continue;
+
+                DBG("replacing %s with %s...\n", patch->gen_name,
+                    patch->fix_name ? "NONE" : 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);
+#ifdef CONFIG_PPC64
+                vdso_do_func_patch64(v32, v64, patch->gen_name,
+                                     patch->fix_name);
+#endif /* CONFIG_PPC64 */
+        }
+
+        return 0;
+}
+
+
+static __init int vdso_setup(void)
+{
+        struct lib32_elfinfo    v32;
+        struct lib64_elfinfo    v64;
+
+        v32.hdr = vdso32_kbase;
+#ifdef CONFIG_PPC64
+        v64.hdr = vdso64_kbase;
+#endif
+        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;
+}
+
+/*
+ * Called from setup_arch to initialize the bitmap of available
+ * syscalls in the systemcfg page
+ */
+static void __init vdso_setup_syscall_map(void)
+{
+        unsigned int i;
+        extern unsigned long *sys_call_table;
+        extern unsigned long sys_ni_syscall;
+
+
+        for (i = 0; i < __NR_syscalls; i++) {
+#ifdef CONFIG_PPC64
+                if (sys_call_table[i*2] != sys_ni_syscall)
+                        vdso_data->syscall_map_64[i >> 5] |=
+                                0x80000000UL >> (i & 0x1f);
+                if (sys_call_table[i*2+1] != sys_ni_syscall)
+                        vdso_data->syscall_map_32[i >> 5] |=
+                                0x80000000UL >> (i & 0x1f);
+#else /* CONFIG_PPC64 */
+                if (sys_call_table[i] != sys_ni_syscall)
+                        vdso_data->syscall_map_32[i >> 5] |=
+                                0x80000000UL >> (i & 0x1f);
+#endif /* CONFIG_PPC64 */
+        }
+}
+
+
+void __init vdso_init(void)
+{
+        int i;
+
+#ifdef CONFIG_PPC64
+        /*
+         * Fill up the "systemcfg" stuff for backward compatiblity
+         */
+        strcpy(vdso_data->eye_catcher, "SYSTEMCFG:PPC64");
+        vdso_data->version.major = SYSTEMCFG_MAJOR;
+        vdso_data->version.minor = SYSTEMCFG_MINOR;
+        vdso_data->processor = mfspr(SPRN_PVR);
+        vdso_data->platform = _machine;
+        vdso_data->physicalMemorySize = lmb_phys_mem_size();
+        vdso_data->dcache_size = ppc64_caches.dsize;
+        vdso_data->dcache_line_size = ppc64_caches.dline_size;
+        vdso_data->icache_size = ppc64_caches.isize;
+        vdso_data->icache_line_size = ppc64_caches.iline_size;
+
+        /*
+         * Calculate the size of the 64 bits vDSO
+         */
+        vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT;
+        DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages);
+#endif /* CONFIG_PPC64 */
+
+
+        /*
+         * Calculate the size of the 32 bits vDSO
+         */
+        vdso32_pages = (&vdso32_end - &vdso32_start) >> PAGE_SHIFT;
+        DBG("vdso32_kbase: %p, 0x%x pages\n", vdso32_kbase, vdso32_pages);
+
+
+        /*
+         * Setup the syscall map in the vDOS
+         */
+        vdso_setup_syscall_map();
+        /*
+         * 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");
+                vdso32_pages = 0;
+#ifdef CONFIG_PPC64
+                vdso64_pages = 0;
+#endif
+                return;
+        }
+
+        /* Make sure pages are in the correct state */
+        for (i = 0; i < vdso32_pages; i++) {
+                struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
+                ClearPageReserved(pg);
+                get_page(pg);
+
+        }
+#ifdef CONFIG_PPC64
+        for (i = 0; i < vdso64_pages; i++) {
+                struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
+                ClearPageReserved(pg);
+                get_page(pg);
+        }
+#endif /* CONFIG_PPC64 */
+
+        get_page(virt_to_page(vdso_data));
+}
+
+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;
+}
+