diff --git a/arch/um/kernel/time_kern.c b/arch/um/kernel/time_kern.c
index 6fa4e1b892b7407bfa4d082f782a5225777f60a8..3c7626cdba4be3c2a1364d7c429f317d232f20b8 100644
--- a/arch/um/kernel/time_kern.c
+++ b/arch/um/kernel/time_kern.c
@@ -187,8 +187,9 @@ void timer_handler(int sig, union uml_pt_regs *regs)
 {
 	local_irq_disable();
 	irq_enter();
-	update_process_times(CHOOSE_MODE(user_context(UPT_SP(regs)),
-					 (regs)->skas.is_user));
+	update_process_times(CHOOSE_MODE(
+	                     (UPT_SC(regs) && user_context(UPT_SP(regs))),
+			     (regs)->skas.is_user));
 	irq_exit();
 	local_irq_enable();
 	if(current_thread->cpu == 0)
diff --git a/arch/um/kernel/tt/trap_user.c b/arch/um/kernel/tt/trap_user.c
index a414c529fbcd78b91350db486527a1bf37742c2a..b5d9d64d91e403b82b8d7a6fe525091122b6d9a7 100644
--- a/arch/um/kernel/tt/trap_user.c
+++ b/arch/um/kernel/tt/trap_user.c
@@ -18,7 +18,7 @@ void sig_handler_common_tt(int sig, void *sc_ptr)
 {
 	struct sigcontext *sc = sc_ptr;
 	struct tt_regs save_regs, *r;
-	int save_errno = errno, is_user;
+	int save_errno = errno, is_user = 0;
 	void (*handler)(int, union uml_pt_regs *);
 
 	/* This is done because to allow SIGSEGV to be delivered inside a SEGV
@@ -35,7 +35,8 @@ void sig_handler_common_tt(int sig, void *sc_ptr)
                 GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
         }
 	save_regs = *r;
-	is_user = user_context(SC_SP(sc));
+	if (sc)
+		is_user = user_context(SC_SP(sc));
 	r->sc = sc;
 	if(sig != SIGUSR2) 
 		r->syscall = -1;