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-rw-r--r--arch/x86/kernel/asm-offsets_64.c1
-rw-r--r--arch/x86/kernel/process.c10
-rw-r--r--arch/x86/kernel/process_64.c1
3 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index e3a5175a444b..bf51e51d808d 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -66,6 +66,7 @@ int main(void)
OFFSET(TSS_ist, tss_struct, x86_tss.ist);
OFFSET(TSS_sp0, tss_struct, x86_tss.sp0);
+ OFFSET(TSS_sp1, tss_struct, x86_tss.sp1);
BLANK();
#ifdef CONFIG_CC_STACKPROTECTOR
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 35d674157fda..86e83762e3b3 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -56,6 +56,16 @@ __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = {
* Poison it.
*/
.sp0 = (1UL << (BITS_PER_LONG-1)) + 1,
+
+#ifdef CONFIG_X86_64
+ /*
+ * .sp1 is cpu_current_top_of_stack. The init task never
+ * runs user code, but cpu_current_top_of_stack should still
+ * be well defined before the first context switch.
+ */
+ .sp1 = TOP_OF_INIT_STACK,
+#endif
+
#ifdef CONFIG_X86_32
.ss0 = __KERNEL_DS,
.ss1 = __KERNEL_CS,
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 01b119bebb68..157f81816915 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -461,6 +461,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
* Switch the PDA and FPU contexts.
*/
this_cpu_write(current_task, next_p);
+ this_cpu_write(cpu_current_top_of_stack, task_top_of_stack(next_p));
/* Reload sp0. */
update_sp0(next_p);
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