diff options
Diffstat (limited to 'arch/x86/mm/mmap_64.c')
| -rw-r--r-- | arch/x86/mm/mmap_64.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/x86/mm/mmap_64.c b/arch/x86/mm/mmap_64.c new file mode 100644 index 000000000000..80bba0dc000e --- /dev/null +++ b/arch/x86/mm/mmap_64.c @@ -0,0 +1,29 @@ +/* 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) +{ +#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; +} + |