diff options
Diffstat (limited to 'arch/x86_64/ia32')
-rw-r--r-- | arch/x86_64/ia32/Makefile | 3 | ||||
-rw-r--r-- | arch/x86_64/ia32/mmap32.c | 78 |
2 files changed, 80 insertions, 1 deletions
diff --git a/arch/x86_64/ia32/Makefile b/arch/x86_64/ia32/Makefile index 051608d55920..929e6b0771f8 100644 --- a/arch/x86_64/ia32/Makefile +++ b/arch/x86_64/ia32/Makefile | |||
@@ -3,7 +3,8 @@ | |||
3 | # | 3 | # |
4 | 4 | ||
5 | obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o tls32.o \ | 5 | obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o tls32.o \ |
6 | ia32_binfmt.o fpu32.o ptrace32.o syscall32.o syscall32_syscall.o | 6 | ia32_binfmt.o fpu32.o ptrace32.o syscall32.o syscall32_syscall.o \ |
7 | mmap32.o | ||
7 | 8 | ||
8 | sysv-$(CONFIG_SYSVIPC) := ipc32.o | 9 | sysv-$(CONFIG_SYSVIPC) := ipc32.o |
9 | obj-$(CONFIG_IA32_EMULATION) += $(sysv-y) | 10 | obj-$(CONFIG_IA32_EMULATION) += $(sysv-y) |
diff --git a/arch/x86_64/ia32/mmap32.c b/arch/x86_64/ia32/mmap32.c new file mode 100644 index 000000000000..079f4132575c --- /dev/null +++ b/arch/x86_64/ia32/mmap32.c | |||
@@ -0,0 +1,78 @@ | |||
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 | |||
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 | |||
46 | if (current->flags & PF_RANDOMIZE) | ||
47 | random_factor = get_random_int() % (1024*1024); | ||
48 | |||
49 | if (gap < MIN_GAP) | ||
50 | gap = MIN_GAP; | ||
51 | else if (gap > MAX_GAP) | ||
52 | gap = MAX_GAP; | ||
53 | |||
54 | return PAGE_ALIGN(TASK_SIZE - gap - random_factor); | ||
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 | */ | ||
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) || | ||
69 | current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY) { | ||
70 | mm->mmap_base = TASK_UNMAPPED_BASE; | ||
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 | } | ||