1 files changed, 7 insertions, 1 deletions

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index c67685337c5a..97fb3e5737f5 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -49,7 +49,13 @@
  */
 __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = {
         .x86_tss = {
-                .sp0 = TOP_OF_INIT_STACK,
+                /*
+                 * .sp0 is only used when entering ring 0 from a lower
+                 * privilege level.  Since the init task never runs anything
+                 * but ring 0 code, there is no need for a valid value here.
+                 * Poison it.
+                 */
+                .sp0 = (1UL << (BITS_PER_LONG-1)) + 1,
 #ifdef CONFIG_X86_32
                 .ss0 = __KERNEL_DS,
                 .ss1 = __KERNEL_CS,