blob: 80bba0dc000e8e8fc6a09a72b43043e156cf4bcc [file] [log] [blame]
/* Copyright 2005 Andi Kleen, SuSE Labs.
* Licensed under GPL, v.2
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/random.h>
#include <asm/ia32.h>
/* Notebook: move the mmap code from sys_x86_64.c over here. */
void arch_pick_mmap_layout(struct mm_struct *mm)
if (current_thread_info()->flags & _TIF_IA32)
return ia32_pick_mmap_layout(mm);
mm->mmap_base = TASK_UNMAPPED_BASE;
if (current->flags & PF_RANDOMIZE) {
/* Add 28bit randomness which is about 40bits of address space
because mmap base has to be page aligned.
or ~1/128 of the total user VM
(total user address space is 47bits) */
unsigned rnd = get_random_int() & 0xfffffff;
mm->mmap_base += ((unsigned long)rnd) << PAGE_SHIFT;
mm->get_unmapped_area = arch_get_unmapped_area;
mm->unmap_area = arch_unmap_area;