2 files changed, 7 insertions, 6 deletions

diff --git a/arch/x86/include/uapi/asm/ldt.h b/arch/x86/include/uapi/asm/ldt.h
index 46727eb37bfe..6e1aaf73852a 100644
--- a/arch/x86/include/uapi/asm/ldt.h
+++ b/arch/x86/include/uapi/asm/ldt.h
@@ -28,6 +28,13 @@ struct user_desc {
         unsigned int  seg_not_present:1;
         unsigned int  useable:1;
 #ifdef __x86_64__
+        /*
+         * Because this bit is not present in 32-bit user code, user
+         * programs can pass uninitialized values here.  Therefore, in
+         * any context in which a user_desc comes from a 32-bit program,
+         * the kernel must act as though lm == 0, regardless of the
+         * actual value.
+         */
         unsigned int  lm:1;
 #endif
 };
diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c
index 3e551eee87b9..4e942f31b1a7 100644
--- a/arch/x86/kernel/tls.c
+++ b/arch/x86/kernel/tls.c
@@ -55,12 +55,6 @@ static bool tls_desc_okay(const struct user_desc *info)
         if (info->seg_not_present)
                 return false;
 
-#ifdef CONFIG_X86_64
-        /* The L bit makes no sense for data. */
-        if (info->lm)
-                return false;
-#endif
-
         return true;
 }