diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/powerpc/mm/mmap_64.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/powerpc/mm/mmap_64.c | 101 |
1 files changed, 0 insertions, 101 deletions
diff --git a/ANDROID_3.4.5/arch/powerpc/mm/mmap_64.c b/ANDROID_3.4.5/arch/powerpc/mm/mmap_64.c deleted file mode 100644 index 67a42ed0..00000000 --- a/ANDROID_3.4.5/arch/powerpc/mm/mmap_64.c +++ /dev/null @@ -1,101 +0,0 @@ -/* - * flexible mmap layout support - * - * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. - * All Rights Reserved. - * - * 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 - * - * - * Started by Ingo Molnar <mingo@elte.hu> - */ - -#include <linux/personality.h> -#include <linux/mm.h> -#include <linux/random.h> -#include <linux/sched.h> - -/* - * Top of mmap area (just below the process stack). - * - * Leave at least a ~128 MB hole on 32bit applications. - * - * On 64bit applications we randomise the stack by 1GB so we need to - * space our mmap start address by a further 1GB, otherwise there is a - * chance the mmap area will end up closer to the stack than our ulimit - * requires. - */ -#define MIN_GAP32 (128*1024*1024) -#define MIN_GAP64 ((128 + 1024)*1024*1024UL) -#define MIN_GAP ((is_32bit_task()) ? MIN_GAP32 : MIN_GAP64) -#define MAX_GAP (TASK_SIZE/6*5) - -static inline int mmap_is_legacy(void) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -static unsigned long mmap_rnd(void) -{ - unsigned long rnd = 0; - - if (current->flags & PF_RANDOMIZE) { - /* 8MB for 32bit, 1GB for 64bit */ - if (is_32bit_task()) - rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT))); - else - rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT))); - } - return rnd << PAGE_SHIFT; -} - -static inline unsigned long mmap_base(void) -{ - unsigned long gap = rlimit(RLIMIT_STACK); - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return PAGE_ALIGN(TASK_SIZE - gap - mmap_rnd()); -} - -/* - * 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) -{ - /* - * Fall back to the standard layout if the personality - * bit is set, or if the expected stack growth is unlimited: - */ - 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; - } -} |