From 675a0813609f9097e323261b1cc4b9dc3f50d40b Mon Sep 17 00:00:00 2001 From: Harvey Harrison Date: Wed, 30 Jan 2008 13:31:10 +0100 Subject: x86: unify mmap_{32|64}.c mmap_is_ia32 always true for X86_32, or while emulating IA32 on X86_64 Randomization not supported on X86_32 in legacy layout. Both layouts allow randomization on X86_64. Signed-off-by: Harvey Harrison Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/mmap_64.c | 116 -------------------------------------------------- 1 file changed, 116 deletions(-) delete mode 100644 arch/x86/mm/mmap_64.c (limited to 'arch/x86/mm/mmap_64.c') diff --git a/arch/x86/mm/mmap_64.c b/arch/x86/mm/mmap_64.c deleted file mode 100644 index 119bf34ec529..000000000000 --- a/arch/x86/mm/mmap_64.c +++ /dev/null @@ -1,116 +0,0 @@ -/* - * linux/arch/x86-64/mm/mmap.c - * - * flexible mmap layout support - * - * Based on code by Ingo Molnar and Andi Kleen, copyrighted - * as follows: - * - * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. - * All Rights Reserved. - * Copyright 2005 Andi Kleen, SUSE Labs. - * Copyright 2007 Jiri Kosina, SUSE Labs. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * - */ - -#include -#include -#include -#include -#include -#include - -/* - * Top of mmap area (just below the process stack). - * - * Leave an at least ~128 MB hole. - */ -#define MIN_GAP (128*1024*1024) -#define MAX_GAP (TASK_SIZE/6*5) - -static unsigned long mmap_base(void) -{ - unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur; - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return TASK_SIZE - (gap & PAGE_MASK); -} - -static int mmap_is_32(void) -{ -#ifdef CONFIG_IA32_EMULATION - if (test_thread_flag(TIF_IA32)) - return 1; -#endif - return 0; -} - -static int mmap_is_legacy(void) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -/* - * This function, called very early during the creation of a new - * process VM image, sets up which VM layout function to use: - */ -void arch_pick_mmap_layout(struct mm_struct *mm) -{ - int rnd = 0; - 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) - */ - rnd = get_random_int() & 0xfffffff; - } - - /* - * Fall back to the standard layout if the personality - * bit is set, or if the expected stack growth is unlimited: - */ - if (mmap_is_32()) { -#ifdef CONFIG_IA32_EMULATION - /* ia32_pick_mmap_layout has its own. */ - return ia32_pick_mmap_layout(mm); -#endif - } else if (mmap_is_legacy()) { - mm->mmap_base = TASK_UNMAPPED_BASE; - mm->get_unmapped_area = arch_get_unmapped_area; - mm->unmap_area = arch_unmap_area; - } else { - mm->mmap_base = mmap_base(); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; - mm->unmap_area = arch_unmap_area_topdown; - if (current->flags & PF_RANDOMIZE) - rnd = -rnd; - } - if (current->flags & PF_RANDOMIZE) - mm->mmap_base += ((long)rnd) << PAGE_SHIFT; -} -- cgit v1.2.3-59-g8ed1b