[mirror_ubuntu-eoan-kernel.git] / arch / x86 / entry / 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/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");
		vdso32_enabled = 0;
	}

	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

int __init sysenter_setup(void)
{
	init_vdso_image(&vdso_image_32);

	return 0;
}

#ifdef CONFIG_X86_64

subsys_initcall(sysenter_setup);

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

static const int zero;
static const int one = 1;

static struct ctl_table abi_table2[] = {
	{
		.procname	= "vsyscall32",
		.data		= &vdso32_enabled,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_minmax,
		.extra1		= (int *)&zero,
		.extra2		= (int *)&one,
	},
	{}
};

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 /* CONFIG_SYSCTL */

#endif	/* CONFIG_X86_64 */
Commit	Line	Data
1da177e4	1	/*
1da177e4	2	* (C) Copyright 2002 Linus Torvalds
e6e5494c IM	3	* Portions based on the vdso-randomization code from exec-shield:
e6e5494c IM	4	* Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
1da177e4 LT	5	*
	6	* This file contains the needed initializations to support sysenter.
	7	*/
	8
	9	#include <linux/init.h>
	10	#include <linux/smp.h>
18d0a6fd AL	11	#include <linux/kernel.h>
18d0a6fd AL	12	#include <linux/mm_types.h>
1da177e4	13
18d0a6fd	14	#include <asm/processor.h>
6c3652ef	15	#include <asm/vdso.h>
1dbf527c	16
1dbf527c	17	#ifdef CONFIG_COMPAT_VDSO
b0b49f26	18	#define VDSO_DEFAULT 0
1dbf527c	19	#else
b0b49f26	20	#define VDSO_DEFAULT 1
1dbf527c	21	#endif
1da177e4	22
e6e5494c IM	23	/*
	24	* Should the kernel map a VDSO page into processes and pass its
	25	* address down to glibc upon exec()?
	26	*/
3d7ee969	27	unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
e6e5494c	28
3d7ee969	29	static int __init vdso32_setup(char *s)
e6e5494c	30	{
3d7ee969	31	vdso32_enabled = simple_strtoul(s, NULL, 0);
e6e5494c	32
c06989da	33	if (vdso32_enabled > 1) {
b0b49f26	34	pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
c06989da MK	35	vdso32_enabled = 0;
c06989da MK	36	}
b0b49f26	37
e6e5494c IM	38	return 1;
	39	}
	40
af65d648 RM	41	/*
	42	* For consistency, the argument vdso32=[012] affects the 32-bit vDSO
	43	* behavior on both 64-bit and 32-bit kernels.
	44	* On 32-bit kernels, vdso=[012] means the same thing.
	45	*/
3d7ee969	46	__setup("vdso32=", vdso32_setup);
e6e5494c	47
af65d648	48	#ifdef CONFIG_X86_32
3d7ee969	49	__setup_param("vdso=", vdso_setup, vdso32_setup, 0);
af65d648	50	#endif
1da177e4	51
a6c4e076	52	int __init sysenter_setup(void)
1da177e4	53	{
0a6d1fa0	54	init_vdso_image(&vdso_image_32);
1da177e4	55
1da177e4 LT	56	return 0;
1da177e4 LT	57	}
e6e5494c	58
af65d648 RM	59	#ifdef CONFIG_X86_64
af65d648 RM	60
d7a0380d	61	subsys_initcall(sysenter_setup);
af65d648	62
a97f52e6 RM	63	#ifdef CONFIG_SYSCTL
	64	/* Register vsyscall32 into the ABI table */
	65	#include <linux/sysctl.h>
	66
c06989da MK	67	static const int zero;
	68	static const int one = 1;
	69
f07d91ed	70	static struct ctl_table abi_table2[] = {
a97f52e6 RM	71	{
a97f52e6 RM	72	.procname = "vsyscall32",
3d7ee969	73	.data = &vdso32_enabled,
a97f52e6 RM	74	.maxlen = sizeof(int),
a97f52e6 RM	75	.mode = 0644,
c06989da MK	76	.proc_handler = proc_dointvec_minmax,
	77	.extra1 = (int *)&zero,
	78	.extra2 = (int *)&one,
a97f52e6 RM	79	},
	80	{}
	81	};
	82
f07d91ed	83	static struct ctl_table abi_root_table2[] = {
a97f52e6	84	{
a97f52e6 RM	85	.procname = "abi",
	86	.mode = 0555,
	87	.child = abi_table2
	88	},
	89	{}
	90	};
	91
	92	static __init int ia32_binfmt_init(void)
	93	{
	94	register_sysctl_table(abi_root_table2);
	95	return 0;
	96	}
	97	__initcall(ia32_binfmt_init);
a6c19dfe	98	#endif /* CONFIG_SYSCTL */
af65d648 RM	99
af65d648 RM	100	#endif /* CONFIG_X86_64 */