Revert "x86-64, modify_ldt: Make support for 16-bit segments a runtime option"

commit 7ed6fb9b5a5510e4ef78ab27419184741169978a upstream.

This reverts commit fa81511bb0bbb2b1aace3695ce869da9762624ff in
preparation of merging in the proper fix (espfix64).

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 3e0ccbf..4ac4531 100644 (file)
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -21,8 +21,6 @@
 #include <asm/mmu_context.h>
 #include <asm/syscalls.h>
 
-int sysctl_ldt16 = 0;
-
 #ifdef CONFIG_SMP
 static void flush_ldt(void *current_mm)
 {
@@ -237,7 +235,7 @@ 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 && !sysctl_ldt16) {
+       if (!ldt_info.seg_32bit) {
                error = -EINVAL;
                goto out_unlock;
        }

diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 51bdc05..468d591 100644 (file)
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -41,7 +41,6 @@ enum {
 #ifdef CONFIG_X86_64
 #define vdso_enabled                   sysctl_vsyscall32
 #define arch_setup_additional_pages    syscall32_setup_pages
-extern int sysctl_ldt16;
 #endif
 
 /*
@@ -389,13 +388,6 @@ 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
-       },
        {}
 };