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| 1 | /* | |||
| 2 | * linux/arch/x86_64/ia32/mm/mmap.c | |||
| 3 | * | |||
| 4 | * flexible mmap layout support | |||
| 5 | * | |||
| 6 | * Based on the i386 version which was | |||
| 7 | * | |||
| 8 | * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. | |||
| 9 | * All Rights Reserved. | |||
| 10 | * | |||
| 11 | * This program is free software; you can redistribute it and/or modify | |||
| 12 | * it under the terms of the GNU General Public License as published by | |||
| 13 | * the Free Software Foundation; either version 2 of the License, or | |||
| 14 | * (at your option) any later version. | |||
| 15 | * | |||
| 16 | * This program is distributed in the hope that it will be useful, | |||
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |||
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |||
| 19 | * GNU General Public License for more details. | |||
| 20 | * | |||
| 21 | * You should have received a copy of the GNU General Public License | |||
| 22 | * along with this program; if not, write to the Free Software | |||
| 23 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |||
| 24 | * | |||
| 25 | * | |||
| 26 | * Started by Ingo Molnar <mingo@elte.hu> | |||
| 27 | */ | |||
| 28 | ||||
| 29 | #include <linux/personality.h> | |||
| 30 | #include <linux/mm.h> | |||
| 31 | #include <linux/random.h> | |||
| 32 | ||||
| 33 | /* | |||
| 34 | * Top of mmap area (just below the process stack). | |||
| 35 | * | |||
| 36 | * Leave an at least ~128 MB hole. | |||
| 37 | */ | |||
| 38 | #define MIN_GAP (128*1024*1024) | |||
| 39 | #define MAX_GAP (TASK_SIZE/6*5) | |||
| 40 | ||||
| 477 | 0 | 41 | static inline unsigned long mmap_base(struct mm_struct *mm) | |
| 42 | { | |||
| 43 | unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur; | |||
| 44 | unsigned long random_factor = 0; | |||
| 45 | ||||
| 477 | 0 | - | 46 | if (current->flags & PF_RANDOMIZE) |
| 47 | random_factor = get_random_int() % (1024*1024); | |||
| 48 | ||||
| 477 | 0 | - | 49 | if (gap < MIN_GAP) |
| 50 | gap = MIN_GAP; | |||
| 0 | 0 | - | 51 | else if (gap > MAX_GAP) |
| 0 | 0 | - | 51 | ternary-?: test_ti_thread_flag ( current_threa.. |
| 0 | 0 | - | 51 | ternary-?: ( get_current ( ) -> personality & .. |
| 52 | gap = MAX_GAP; | |||
| 0 | 0 | - | 52 | ternary-?: test_ti_thread_flag ( current_thr.. |
| 0 | 0 | - | 52 | ternary-?: ( get_current ( ) -> personality .. |
| 53 | ||||
| 54 | return PAGE_ALIGN(TASK_SIZE - gap - random_factor); | |||
| 477 | 0 | - | 54 | ternary-?: test_ti_thread_flag ( current_threa.. |
| 0 | 477 | - | 54 | ternary-?: ( get_current ( ) -> personality & .. |
| 477 | 54 | return ( ( ( ( test_ti_thread_flag ( current_t.. | ||
| 55 | } | |||
| 56 | ||||
| 57 | /* | |||
| 58 | * This function, called very early during the creation of a new | |||
| 59 | * process VM image, sets up which VM layout function to use: | |||
| 60 | */ | |||
| 477 | 477 | 61 | void ia32_pick_mmap_layout(struct mm_struct *mm) | |
| 62 | { | |||
| 63 | /* | |||
| 64 | * Fall back to the standard layout if the personality | |||
| 65 | * bit is set, or if the expected stack growth is unlimited: | |||
| 66 | */ | |||
| 67 | if (sysctl_legacy_va_layout || | |||
| 68 | (current->personality & ADDR_COMPAT_LAYOUT) || | |||
| 0 | 477 | - | 69 | current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY) { |
| 0 | - | 69 | T || (_) || _ | |
| 0 | - | 69 | F || (T) || _ | |
| 0 | - | 69 | F || (F) || T | |
| 477 | 69 | F || (F) || F | ||
| 70 | mm->mmap_base = TASK_UNMAPPED_BASE; | |||
| 0 | 0 | - | 70 | ternary-?: test_ti_thread_flag ( current_thr.. |
| 0 | 0 | - | 70 | ternary-?: ( get_current ( ) -> personality .. |
| 71 | mm->get_unmapped_area = arch_get_unmapped_area; | |||
| 72 | mm->unmap_area = arch_unmap_area; | |||
| 73 | } else { | |||
| 74 | mm->mmap_base = mmap_base(mm); | |||
| 75 | mm->get_unmapped_area = arch_get_unmapped_area_topdown; | |||
| 76 | mm->unmap_area = arch_unmap_area_topdown; | |||
| 77 | } | |||
| 78 | } | |||
| ***TER 29% (9/31) of SOURCE FILE mmap32.c | ||||