x86/fpu: Avoid math_state_restore() without used_math() in __restore_xstate_sig()

[firefly-linux-kernel-4.4.55.git] / arch / x86 / kernel / xsave.c

diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 1ee723298e90694ee417c1ea2549a0ef15359573..92f37e7683c502c42e2d50805d4b7542abaadb49 100644 (file)
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -376,7 +376,7 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
                 * thread's fpu state, reconstruct fxstate from the fsave
                 * header. Sanitize the copied state etc.
                 */
-               struct xsave_struct *xsave = &tsk->thread.fpu.state->xsave;
+               struct fpu *fpu = &tsk->thread.fpu;
                struct user_i387_ia32_struct env;
                int err = 0;
 
@@ -390,14 +390,15 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size)
                 */
                drop_fpu(tsk);
 
-               if (__copy_from_user(xsave, buf_fx, state_size) ||
+               if (__copy_from_user(&fpu->state->xsave, buf_fx, state_size) ||
                    __copy_from_user(&env, buf, sizeof(env))) {
+                       fpu_finit(fpu);
                        err = -1;
                } else {
                        sanitize_restored_xstate(tsk, &env, xstate_bv, fx_only);
-                       set_used_math();
                }
 
+               set_used_math();
                if (use_eager_fpu()) {
                        preempt_disable();
                        math_state_restore();