ARM: 8154/1: use _install_special_mapping for sigpage

_install_special_mapping allows the VMA to be identifed in
/proc/pid/maps without the use of arch_vma_name, providing a
slight net reduction in object size:

  text    data     bss     dec     hex filename
  2996      96     144    3236     ca4 arch/arm/kernel/process.o (before)
  2956     104     144    3204     c84 arch/arm/kernel/process.o (after)

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Nathan Lynch 2014-09-22 22:08:42 +01:00 committed by Russell King
parent 75c349062a
commit 02e0409a65
1 changed files with 16 additions and 8 deletions

View File

@ -472,19 +472,23 @@ int in_gate_area_no_mm(unsigned long addr)
const char *arch_vma_name(struct vm_area_struct *vma)
{
return is_gate_vma(vma) ? "[vectors]" :
(vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
"[sigpage]" : NULL;
return is_gate_vma(vma) ? "[vectors]" : NULL;
}
static struct page *signal_page;
extern struct page *get_signal_page(void);
static const struct vm_special_mapping sigpage_mapping = {
.name = "[sigpage]",
.pages = &signal_page,
};
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long addr;
int ret;
int ret = 0;
if (!signal_page)
signal_page = get_signal_page();
@ -498,12 +502,16 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
goto up_fail;
}
ret = install_special_mapping(mm, addr, PAGE_SIZE,
vma = _install_special_mapping(mm, addr, PAGE_SIZE,
VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
&signal_page);
&sigpage_mapping);
if (ret == 0)
mm->context.sigpage = addr;
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto up_fail;
}
mm->context.sigpage = addr;
up_fail:
up_write(&mm->mmap_sem);