1 files changed, 6 insertions, 1 deletions

diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 79ae939970d3..fcd06f7526de 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -135,7 +135,12 @@ void __init early_fixup_exception(struct pt_regs *regs, int trapnr)
         if (early_recursion_flag > 2)
                 goto halt_loop;
 
-        if (regs->cs != __KERNEL_CS)
+        /*
+         * Old CPUs leave the high bits of CS on the stack
+         * undefined.  I'm not sure which CPUs do this, but at least
+         * the 486 DX works this way.
+         */
+        if ((regs->cs & 0xFFFF) != __KERNEL_CS)
                 goto fail;
 
         /*