Commit a33e2881 authored by Kaixiong Yu's avatar Kaixiong Yu Committed by Joel Granados
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x86: vdso: move the sysctl to arch/x86/entry/vdso/vdso32-setup.c 



When CONFIG_X86_32 is defined and CONFIG_UML is not defined,
vdso_enabled belongs to arch/x86/entry/vdso/vdso32-setup.c.
So, move it into its own file.

Before this patch, vdso_enabled was allowed to be set to
a value exceeding 1 on x86_32 architecture. After this patch is
applied, vdso_enabled is not permitted to set the value more than 1.
It does not matter, because according to the function load_vdso32(),
only vdso_enabled is set to 1, VDSO would be enabled. Other values
all mean "disabled". The same limitation could be seen in the
function vdso32_setup().

Signed-off-by: default avatarKaixiong Yu <yukaixiong@huawei.com>
Reviewed-by: default avatarKees Cook <kees@kernel.org>
Signed-off-by: default avatarJoel Granados <joel.granados@kernel.org>
parent 52e66823

arch/x86/entry/vdso/vdso32-setup.c

+11 −5
Original line number Diff line number Diff line
@@ -51,15 +51,17 @@ __setup("vdso32=", vdso32_setup); 
__setup_param("vdso=", vdso_setup, vdso32_setup, 0);

#endif



#ifdef CONFIG_X86_64



#ifdef CONFIG_SYSCTL

/* Register vsyscall32 into the ABI table */

#include <linux/sysctl.h>



static const struct ctl_table abi_table2[] = {

static const struct ctl_table vdso_table[] = {

	{

#ifdef CONFIG_X86_64

		.procname	= "vsyscall32",

#else

		.procname	= "vdso_enabled",

#endif

		.data		= &vdso32_enabled,

		.maxlen		= sizeof(int),

		.mode		= 0644,
@@ -71,10 +73,14 @@ static const struct ctl_table abi_table2[] = { 


static __init int ia32_binfmt_init(void)

{

	register_sysctl("abi", abi_table2);

#ifdef CONFIG_X86_64

	/* Register vsyscall32 into the ABI table */

	register_sysctl("abi", vdso_table);

#else

	register_sysctl_init("vm", vdso_table);

#endif

	return 0;

}

__initcall(ia32_binfmt_init);

#endif /* CONFIG_SYSCTL */

#endif	/* CONFIG_X86_64 */

kernel/sysctl.c

+1 −7
Original line number Diff line number Diff line
@@ -2013,17 +2013,11 @@ static const struct ctl_table kern_table[] = { 
};



static const struct ctl_table vm_table[] = {

#if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \

   (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))

#if defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL)

	{

		.procname	= "vdso_enabled",

#ifdef CONFIG_X86_32

		.data		= &vdso32_enabled,

		.maxlen		= sizeof(vdso32_enabled),

#else

		.data		= &vdso_enabled,

		.maxlen		= sizeof(vdso_enabled),

#endif

		.mode		= 0644,

		.proc_handler	= proc_dointvec,

		.extra1		= SYSCTL_ZERO,