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: Kaixiong Yu <yukaixiong@xxxxxxxxxx>
Reviewed-by: Kees Cook <kees@xxxxxxxxxx>
---
v4:
- const qualify struct ctl_table vdso_table
---
---
arch/x86/entry/vdso/vdso32-setup.c | 16 +++++++++++-----
kernel/sysctl.c | 8 +-------
2 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso32-setup.c b/arch/x86/entry/vdso/vdso32-setup.c
index 76e4e74f35b5..f71625f99bf9 100644
--- a/arch/x86/entry/vdso/vdso32-setup.c
+++ b/arch/x86/entry/vdso/vdso32-setup.c
@@ -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 struct ctl_table abi_table2[] = {
+static const struct ctl_table vdso_table[] = {
{
+#ifdef CONFIG_X86_64
.procname = "vsyscall32",
+#elif (defined(CONFIG_X86_32) && !defined(CONFIG_UML))
+ .procname = "vdso_enabled",
+#endif
.data = &vdso32_enabled,
.maxlen = sizeof(int),
.mode = 0644,
@@ -71,10 +73,14 @@ static 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);
+#elif (defined(CONFIG_X86_32) && !defined(CONFIG_UML))
+ register_sysctl_init("vm", vdso_table);
+#endif
return 0;
}
__initcall(ia32_binfmt_init);
#endif /* CONFIG_SYSCTL */
-#endif /* CONFIG_X86_64 */
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 860dea8f1587..7ff07b7560b4 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2013,17 +2013,11 @@ static struct ctl_table kern_table[] = {
};
static 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,
--
2.34.1
