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[PATCH] i386 vDSO: use install_special_mapping

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This patch uses install_special_mapping for the i386 vDSO setup, consolidating
duplicated code.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Roland McGrath 2007-02-08 14:20:42 -08:00 committed by Linus Torvalds
parent fa5dc22f85
commit 7d91d53190
1 changed files with 11 additions and 42 deletions
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53
arch/i386/kernel/sysenter.c
View file

@ -70,11 +70,12 @@ void enable_sep_cpu(void)
*/
extern const char vsyscall_int80_start, vsyscall_int80_end;
extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
static void *syscall_page;
static struct page *syscall_pages[1];
int __init sysenter_setup(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);
#ifdef CONFIG_COMPAT_VDSO
__set_fixmap(FIX_VDSO, __pa(syscall_page), PAGE_READONLY);
@ -96,31 +97,12 @@ int __init sysenter_setup(void)
}
#ifndef CONFIG_COMPAT_VDSO
static struct page *syscall_nopage(struct vm_area_struct *vma,
unsigned long adr, int *type)
{
struct page *p = virt_to_page(adr - vma->vm_start + syscall_page);
get_page(p);
return p;
}
/* Prevent VMA merging */
static void syscall_vma_close(struct vm_area_struct *vma)
{
}
static struct vm_operations_struct syscall_vm_ops = {
.close = syscall_vma_close,
.nopage = syscall_nopage,
};
/* Defined in vsyscall-sysenter.S */
extern void SYSENTER_RETURN;
/* Setup a VMA at program startup for the vsyscall page */
int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
unsigned long addr;
int ret;
@ -132,38 +114,25 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)
goto up_fail;
}
vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (!vma) {
ret = -ENOMEM;
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;
/*
* MAYWRITE to allow gdb to COW and set breakpoints
*
* Make sure the vDSO gets into every core dump.
* Dumping its contents makes post-mortem fully interpretable later
* without matching up the same kernel and hardware config to see
* what PC values meant.
*/
vma->vm_flags |= VM_ALWAYSDUMP;
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);
ret = install_special_mapping(mm, addr, PAGE_SIZE,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
VM_ALWAYSDUMP,
syscall_pages);
if (ret)
goto up_fail;
}
current->mm->context.vdso = (void *)addr;
current_thread_info()->sysenter_return =
(void *)VDSO_SYM(&SYSENTER_RETURN);
mm->total_vm++;
up_fail:
up_write(&mm->mmap_sem);
return ret;