[PATCH] SH vdso: use install_special_mapping()

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 49 deletions

diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
index deb46941f315..7b0f66f03319 100644
--- a/arch/sh/kernel/vsyscall/vsyscall.c
+++ b/arch/sh/kernel/vsyscall/vsyscall.c
@@ -37,11 +37,12 @@ __setup("vdso=", vdso_setup);
  * of the ELF DSO images included therein.
  */
 extern const char vsyscall_trapa_start, vsyscall_trapa_end;
-static void *syscall_page;
+static struct page *syscall_pages[1];
 
 int __init vsyscall_init(void)
 {
-        syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
+        void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
+        syscall_pages[0] = virt_to_page(syscall_page);
 
         /*
          * XXX: Map this page to a fixmap entry if we get around
@@ -55,37 +56,10 @@ int __init vsyscall_init(void)
         return 0;
 }
 
-static struct page *syscall_vma_nopage(struct vm_area_struct *vma,
-                                       unsigned long address, int *type)
-{
-        unsigned long offset = address - vma->vm_start;
-        struct page *page;
-
-        if (address < vma->vm_start || address > vma->vm_end)
-                return NOPAGE_SIGBUS;
-
-        page = virt_to_page(syscall_page + offset);
-
-        get_page(page);
-
-        return page;
-}
-
-/* Prevent VMA merging */
-static void syscall_vma_close(struct vm_area_struct *vma)
-{
-}
-
-static struct vm_operations_struct syscall_vm_ops = {
-        .nopage = syscall_vma_nopage,
-        .close  = syscall_vma_close,
-};
-
 /* Setup a VMA at program startup for the vsyscall page */
 int arch_setup_additional_pages(struct linux_binprm *bprm,
                                 int executable_stack)
 {
-        struct vm_area_struct *vma;
         struct mm_struct *mm = current->mm;
         unsigned long addr;
         int ret;
@@ -97,30 +71,16 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
                 goto up_fail;
         }
 
-        vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
-        if (!vma) {
-                ret = -ENOMEM;
+        ret = install_special_mapping(mm, addr, PAGE_SIZE,
+                                      VM_READ | VM_EXEC |
+                                      VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC |
+                                      VM_ALWAYSDUMP,
+                                      syscall_pages);
+        if (unlikely(ret))
                 goto up_fail;
-        }
-
-        vma->vm_start = addr;
-        vma->vm_end = addr + PAGE_SIZE;
-        /* MAYWRITE to allow gdb to COW and set breakpoints */
-        vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE;
-        vma->vm_flags |= mm->def_flags;
-        vma->vm_page_prot = protection_map[vma->vm_flags & 7];
-        vma->vm_ops = &syscall_vm_ops;
-        vma->vm_mm = mm;
-
-        ret = insert_vm_struct(mm, vma);
-        if (unlikely(ret)) {
-                kmem_cache_free(vm_area_cachep, vma);
-                goto up_fail;
-        }
 
         current->mm->context.vdso = (void *)addr;
 
-        mm->total_vm++;
 up_fail:
         up_write(&mm->mmap_sem);
         return ret;