summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/switch_to.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm/switch_to.h')
-rw-r--r--arch/x86/include/asm/switch_to.h16
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index eb5f7999a893..36bd243843d6 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -87,15 +87,25 @@ static inline void refresh_sysenter_cs(struct thread_struct *thread)
#endif
/* This is used when switching tasks or entering/exiting vm86 mode. */
-static inline void update_sp0(struct task_struct *task)
+static inline void update_task_stack(struct task_struct *task)
{
- /* On x86_64, sp0 always points to the entry trampoline stack, which is constant: */
+ /* sp0 always points to the entry trampoline stack, which is constant: */
#ifdef CONFIG_X86_32
- load_sp0(task->thread.sp0);
+ if (static_cpu_has(X86_FEATURE_XENPV))
+ load_sp0(task->thread.sp0);
+ else
+ this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0);
#else
+ /*
+ * x86-64 updates x86_tss.sp1 via cpu_current_top_of_stack. That
+ * doesn't work on x86-32 because sp1 and
+ * cpu_current_top_of_stack have different values (because of
+ * the non-zero stack-padding on 32bit).
+ */
if (static_cpu_has(X86_FEATURE_XENPV))
load_sp0(task_top_of_stack(task));
#endif
+
}
#endif /* _ASM_X86_SWITCH_TO_H */