diff options
Diffstat (limited to 'arch/x86_64/mm')
| -rw-r--r-- | arch/x86_64/mm/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86_64/mm/mmap.c | 30 |
2 files changed, 31 insertions, 1 deletions
diff --git a/arch/x86_64/mm/Makefile b/arch/x86_64/mm/Makefile index 1d232a87f11..d25ac86fe27 100644 --- a/arch/x86_64/mm/Makefile +++ b/arch/x86_64/mm/Makefile @@ -2,7 +2,7 @@ # Makefile for the linux x86_64-specific parts of the memory manager. # -obj-y := init.o fault.o ioremap.o extable.o pageattr.o +obj-y := init.o fault.o ioremap.o extable.o pageattr.o mmap.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_NUMA) += numa.o obj-$(CONFIG_K8_NUMA) += k8topology.o diff --git a/arch/x86_64/mm/mmap.c b/arch/x86_64/mm/mmap.c new file mode 100644 index 00000000000..43e9b99bdf2 --- /dev/null +++ b/arch/x86_64/mm/mmap.c @@ -0,0 +1,30 @@ +/* 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; +} + |