[deliverable/linux.git] / arch / x86 / vdso / vdso32-setup.c

/*
 * (C) Copyright 2002 Linus Torvalds
 * Portions based on the vdso-randomization code from exec-shield:
 * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
 *
 * This file contains the needed initializations to support sysenter.
 */

#include <linux/init.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/mm_types.h>

#include <asm/cpufeature.h>
#include <asm/processor.h>
#include <asm/vdso.h>

#ifdef CONFIG_COMPAT_VDSO
#define VDSO_DEFAULT	0
#else
#define VDSO_DEFAULT	1
#endif

/*
 * Should the kernel map a VDSO page into processes and pass its
 * address down to glibc upon exec()?
 */
unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;

static int __init vdso32_setup(char *s)
{
	vdso32_enabled = simple_strtoul(s, NULL, 0);

	if (vdso32_enabled > 1)
		pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");

	return 1;
}

/*
 * For consistency, the argument vdso32=[012] affects the 32-bit vDSO
 * behavior on both 64-bit and 32-bit kernels.
 * On 32-bit kernels, vdso=[012] means the same thing.
 */
__setup("vdso32=", vdso32_setup);

#ifdef CONFIG_X86_32
__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
#endif

#ifdef CONFIG_X86_64

#define	vdso32_sysenter()	(boot_cpu_has(X86_FEATURE_SYSENTER32))
#define	vdso32_syscall()	(boot_cpu_has(X86_FEATURE_SYSCALL32))

#else  /* CONFIG_X86_32 */

#define vdso32_sysenter()	(boot_cpu_has(X86_FEATURE_SEP))
#define vdso32_syscall()	(0)

#endif	/* CONFIG_X86_64 */

#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
const struct vdso_image *selected_vdso32;
#endif

int __init sysenter_setup(void)
{
#ifdef CONFIG_COMPAT
	if (vdso32_syscall())
		selected_vdso32 = &vdso_image_32_syscall;
	else
#endif
	if (vdso32_sysenter())
		selected_vdso32 = &vdso_image_32_sysenter;
	else
		selected_vdso32 = &vdso_image_32_int80;

	init_vdso_image(selected_vdso32);

	return 0;
}

#ifdef CONFIG_X86_64

subsys_initcall(sysenter_setup);

#ifdef CONFIG_SYSCTL
/* Register vsyscall32 into the ABI table */
#include <linux/sysctl.h>

static struct ctl_table abi_table2[] = {
	{
		.procname	= "vsyscall32",
		.data		= &vdso32_enabled,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec
	},
	{}
};

static struct ctl_table abi_root_table2[] = {
	{
		.procname = "abi",
		.mode = 0555,
		.child = abi_table2
	},
	{}
};

static __init int ia32_binfmt_init(void)
{
	register_sysctl_table(abi_root_table2);
	return 0;
}
__initcall(ia32_binfmt_init);
#endif

#else  /* CONFIG_X86_32 */

struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
	return NULL;
}

int in_gate_area(struct mm_struct *mm, unsigned long addr)
{
	return 0;
}

int in_gate_area_no_mm(unsigned long addr)
{
	return 0;
}

#endif	/* CONFIG_X86_64 */
Commit	Line	Data
	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/cpufeature.h>
	15	#include <asm/processor.h>
	16	#include <asm/vdso.h>
	17
	18	#ifdef CONFIG_COMPAT_VDSO
	19	#define VDSO_DEFAULT 0
	20	#else
	21	#define VDSO_DEFAULT 1
	22	#endif
	23
	24	/*
	25	* Should the kernel map a VDSO page into processes and pass its
	26	* address down to glibc upon exec()?
	27	*/
	28	unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
	29
	30	static int __init vdso32_setup(char *s)
	31	{
	32	vdso32_enabled = simple_strtoul(s, NULL, 0);
	33
	34	if (vdso32_enabled > 1)
	35	pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
	36
	37	return 1;
	38	}
	39
	40	/*
	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.
	44	*/
	45	__setup("vdso32=", vdso32_setup);
	46
	47	#ifdef CONFIG_X86_32
	48	__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
	49	#endif
	50
	51	#ifdef CONFIG_X86_64
	52
	53	#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
	54	#define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
	55
	56	#else /* CONFIG_X86_32 */
	57
	58	#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
	59	#define vdso32_syscall() (0)
	60
	61	#endif /* CONFIG_X86_64 */
	62
	63	#if defined(CONFIG_X86_32) \|\| defined(CONFIG_COMPAT)
	64	const struct vdso_image *selected_vdso32;
	65	#endif
	66
	67	int __init sysenter_setup(void)
	68	{
	69	#ifdef CONFIG_COMPAT
	70	if (vdso32_syscall())
	71	selected_vdso32 = &vdso_image_32_syscall;
	72	else
	73	#endif
	74	if (vdso32_sysenter())
	75	selected_vdso32 = &vdso_image_32_sysenter;
	76	else
	77	selected_vdso32 = &vdso_image_32_int80;
	78
	79	init_vdso_image(selected_vdso32);
	80
	81	return 0;
	82	}
	83
	84	#ifdef CONFIG_X86_64
	85
	86	subsys_initcall(sysenter_setup);
	87
	88	#ifdef CONFIG_SYSCTL
	89	/* Register vsyscall32 into the ABI table */
	90	#include <linux/sysctl.h>
	91
	92	static struct ctl_table abi_table2[] = {
	93	{
	94	.procname = "vsyscall32",
	95	.data = &vdso32_enabled,
	96	.maxlen = sizeof(int),
	97	.mode = 0644,
	98	.proc_handler = proc_dointvec
	99	},
	100	{}
	101	};
	102
	103	static struct ctl_table abi_root_table2[] = {
	104	{
	105	.procname = "abi",
	106	.mode = 0555,
	107	.child = abi_table2
	108	},
	109	{}
	110	};
	111
	112	static __init int ia32_binfmt_init(void)
	113	{
	114	register_sysctl_table(abi_root_table2);
	115	return 0;
	116	}
	117	__initcall(ia32_binfmt_init);
	118	#endif
	119
	120	#else /* CONFIG_X86_32 */
	121
	122	struct vm_area_struct get_gate_vma(struct mm_struct mm)
	123	{
	124	return NULL;
	125	}
	126
	127	int in_gate_area(struct mm_struct *mm, unsigned long addr)
	128	{
	129	return 0;
	130	}
	131
	132	int in_gate_area_no_mm(unsigned long addr)
	133	{
	134	return 0;
	135	}
	136
	137	#endif /* CONFIG_X86_64 */