2 files changed, 19 insertions, 3 deletions

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index db6839b53195..e03cc952f233 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -450,7 +450,6 @@ static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
 {
         struct task_struct *tsk = current;
 
-        clear_fpu(tsk);
         return __copy_from_user(&tsk->thread.xstate->fsave, buf,
                                 sizeof(struct i387_fsave_struct));
 }
@@ -461,7 +460,6 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf)
         struct user_i387_ia32_struct env;
         int err;
 
-        clear_fpu(tsk);
         err = __copy_from_user(&tsk->thread.xstate->fxsave, &buf->_fxsr_env[0],
                                sizeof(struct i387_fxsave_struct));
         /* mxcsr reserved bits must be masked to zero for security reasons */
@@ -478,6 +476,16 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf)
         int err;
 
         if (HAVE_HWFP) {
+                struct task_struct *tsk = current;
+
+                clear_fpu(tsk);
+
+                if (!used_math()) {
+                        err = init_fpu(tsk);
+                        if (err)
+                                return err;
+                }
+
                 if (cpu_has_fxsr)
                         err = restore_i387_fxsave(buf);
                 else
diff --git a/include/asm-x86/i387.h b/include/asm-x86/i387.h
index da2adb45f6e3..6b722d315936 100644
--- a/include/asm-x86/i387.h
+++ b/include/asm-x86/i387.h
@@ -175,7 +175,15 @@ static inline int save_i387(struct _fpstate __user *buf)
  */
 static inline int restore_i387(struct _fpstate __user *buf)
 {
-        set_used_math();
+        struct task_struct *tsk = current;
+        int err;
+
+        if (!used_math()) {
+                err = init_fpu(tsk);
+                if (err)
+                        return err;
+        }
+
         if (!(task_thread_info(current)->status & TS_USEDFPU)) {
                 clts();
                 task_thread_info(current)->status |= TS_USEDFPU;