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);
53 #define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
54 #define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
56 #else /* CONFIG_X86_32 */
58 #define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
59 #define vdso32_syscall() (0)
61 #endif /* CONFIG_X86_64 */
63 #if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
64 const struct vdso_image *selected_vdso32;
67 int __init sysenter_setup(void)
71 selected_vdso32 = &vdso_image_32_syscall;
74 if (vdso32_sysenter())
75 selected_vdso32 = &vdso_image_32_sysenter;
77 selected_vdso32 = &vdso_image_32_int80;
79 init_vdso_image(selected_vdso32);
86 subsys_initcall(sysenter_setup);
89 /* Register vsyscall32 into the ABI table */
90 #include <linux/sysctl.h>
92 static struct ctl_table abi_table2[] = {
94 .procname = "vsyscall32",
95 .data = &vdso32_enabled,
96 .maxlen = sizeof(int),
98 .proc_handler = proc_dointvec
103 static struct ctl_table abi_root_table2[] = {
112 static __init int ia32_binfmt_init(void)
114 register_sysctl_table(abi_root_table2);
117 __initcall(ia32_binfmt_init);
120 #else /* CONFIG_X86_32 */
122 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
127 int in_gate_area(struct mm_struct *mm, unsigned long addr)
132 int in_gate_area_no_mm(unsigned long addr)
137 #endif /* CONFIG_X86_64 */