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
6 * This file contains the needed initializations to support sysenter.
9 #include <linux/init.h>
10 #include <linux/smp.h>
11 #include <linux/kernel.h>
12 #include <linux/mm_types.h>
14 #include <asm/cpufeature.h>
15 #include <asm/processor.h>
18 #ifdef CONFIG_COMPAT_VDSO
19 #define VDSO_DEFAULT 0
21 #define VDSO_DEFAULT 1
25 * Should the kernel map a VDSO page into processes and pass its
26 * address down to glibc upon exec()?
28 unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
30 static int __init vdso32_setup(char *s)
32 vdso32_enabled = simple_strtoul(s, NULL, 0);
34 if (vdso32_enabled > 1)
35 pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
41 * For consistency, the argument vdso32=[012] affects the 32-bit vDSO
42 * behavior on both 64-bit and 32-bit kernels.
43 * On 32-bit kernels, vdso=[012] means the same thing.
45 __setup("vdso32=", vdso32_setup);
48 __setup_param("vdso=", vdso_setup, vdso32_setup, 0);
51 int __init sysenter_setup(void)
53 init_vdso_image(&vdso_image_32);
60 subsys_initcall(sysenter_setup);
63 /* Register vsyscall32 into the ABI table */
64 #include <linux/sysctl.h>
66 static struct ctl_table abi_table2[] = {
68 .procname = "vsyscall32",
69 .data = &vdso32_enabled,
70 .maxlen = sizeof(int),
72 .proc_handler = proc_dointvec
77 static struct ctl_table abi_root_table2[] = {
86 static __init int ia32_binfmt_init(void)
88 register_sysctl_table(abi_root_table2);
91 __initcall(ia32_binfmt_init);
92 #endif /* CONFIG_SYSCTL */
94 #endif /* CONFIG_X86_64 */