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Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/ldt.c4
-rw-r--r--arch/x86/vdso/vdso32-setup.c8
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index af1d14a9ebda..dcbbaa165bde 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -20,6 +20,8 @@
#include <asm/mmu_context.h>
#include <asm/syscalls.h>
+int sysctl_ldt16 = 0;
+
#ifdef CONFIG_SMP
static void flush_ldt(void *current_mm)
{
@@ -234,7 +236,7 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
* IRET leaking the high bits of the kernel stack address.
*/
#ifdef CONFIG_X86_64
- if (!ldt_info.seg_32bit) {
+ if (!ldt_info.seg_32bit && !sysctl_ldt16) {
error = -EINVAL;
goto out_unlock;
}
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 0faad646f5fd..0f134c7cfc24 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -41,6 +41,7 @@ enum {
#ifdef CONFIG_X86_64
#define vdso_enabled sysctl_vsyscall32
#define arch_setup_additional_pages syscall32_setup_pages
+extern int sysctl_ldt16;
#endif
/*
@@ -380,6 +381,13 @@ static ctl_table abi_table2[] = {
.mode = 0644,
.proc_handler = proc_dointvec
},
+ {
+ .procname = "ldt16",
+ .data = &sysctl_ldt16,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
{}
};