31 lines
893 B
C
31 lines
893 B
C
|
/* Copyright 2005 Andi Kleen, SuSE Labs.
|
||
|
|
* Licensed under GPL, v.2
|
||
|
|
*/
|
||
|
|
#include <linux/config.h>
|
||
|
|
#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)
|
||
|
|
{
|
||
|
|
#ifdef CONFIG_IA32_EMULATION
|
||
|
|
if (current_thread_info()->flags & _TIF_IA32)
|
||
|
|
return ia32_pick_mmap_layout(mm);
|
||
|
|
#endif
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|