x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack

[pandora-kernel.git] / arch / x86 / kernel / ldt.c

diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 4ac4531..ea69726 100644 (file)
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -230,17 +230,6 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
                }
        }
 
-       /*
-        * On x86-64 we do not support 16-bit segments due to
-        * IRET leaking the high bits of the kernel stack address.
-        */
-#ifdef CONFIG_X86_64
-       if (!ldt_info.seg_32bit) {
-               error = -EINVAL;
-               goto out_unlock;
-       }
-#endif
-
        fill_ldt(&ldt, &ldt_info);
        if (oldmode)
                ldt.avl = 0;