tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/*
2 * (C) Copyright 2002 Linus Torvalds
3 * Portions based on the vdso-randomization code from exec-shield:
4 * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
5 *
6 * This file contains the needed initializations to support sysenter.
7 */
8
9#include <linux/init.h>
10#include <linux/smp.h>
11#include <linux/kernel.h>
12#include <linux/mm_types.h>
13
14#include <asm/processor.h>
15#include <asm/vdso.h>
16
17#ifdef CONFIG_COMPAT_VDSO
18#define VDSO_DEFAULT 0
19#else
20#define VDSO_DEFAULT 1
21#endif
22
23/*
24 * Should the kernel map a VDSO page into processes and pass its
25 * address down to glibc upon exec()?
26 */
27unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
28
29static int __init vdso32_setup(char *s)
30{
31 vdso32_enabled = simple_strtoul(s, NULL, 0);
32
33 if (vdso32_enabled > 1)
34 pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
35
36 return 1;
37}
38
39/*
40 * For consistency, the argument vdso32=[012] affects the 32-bit vDSO
41 * behavior on both 64-bit and 32-bit kernels.
42 * On 32-bit kernels, vdso=[012] means the same thing.
43 */
44__setup("vdso32=", vdso32_setup);
45
46#ifdef CONFIG_X86_32
47__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
48#endif
49
50int __init sysenter_setup(void)
51{
52 init_vdso_image(&vdso_image_32);
53
54 return 0;
55}
56
57#ifdef CONFIG_X86_64
58
59subsys_initcall(sysenter_setup);
60
61#ifdef CONFIG_SYSCTL
62/* Register vsyscall32 into the ABI table */
63#include <linux/sysctl.h>
64
65static struct ctl_table abi_table2[] = {
66 {
67 .procname = "vsyscall32",
68 .data = &vdso32_enabled,
69 .maxlen = sizeof(int),
70 .mode = 0644,
71 .proc_handler = proc_dointvec
72 },
73 {}
74};
75
76static struct ctl_table abi_root_table2[] = {
77 {
78 .procname = "abi",
79 .mode = 0555,
80 .child = abi_table2
81 },
82 {}
83};
84
85static __init int ia32_binfmt_init(void)
86{
87 register_sysctl_table(abi_root_table2);
88 return 0;
89}
90__initcall(ia32_binfmt_init);
91#endif /* CONFIG_SYSCTL */
92
93#endif /* CONFIG_X86_64 */