diff --git a/arch/mips/include/asm/asmmacro.h b/arch/mips/include/asm/asmmacro.h
index 4986bf5ffd297c4f41ca876fe78b4b2bb29f0e2a..cd9a98bc8f606197a15b70d729aa66a0431f3e0e 100644
--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -426,4 +426,24 @@
 	ld_d	31, THREAD_FPR31, \thread
 	.endm
 
+	.macro	msa_init_upper wd
+#ifdef CONFIG_64BIT
+	insert_d \wd, 1
+#else
+	insert_w \wd, 2
+	insert_w \wd, 3
+#endif
+	.if	31-\wd
+	msa_init_upper	(\wd+1)
+	.endif
+	.endm
+
+	.macro	msa_init_all_upper
+	.set	push
+	.set	noat
+	not	$1, zero
+	msa_init_upper	0
+	.set	pop
+	.endm
+
 #endif /* _ASM_ASMMACRO_H */
diff --git a/arch/mips/include/asm/msa.h b/arch/mips/include/asm/msa.h
index e80e85c1334f56250ab2b78e69bba6611ae508b3..fe25a17bc7834336edcae558f19d9c503797d704 100644
--- a/arch/mips/include/asm/msa.h
+++ b/arch/mips/include/asm/msa.h
@@ -16,6 +16,7 @@
 
 extern void _save_msa(struct task_struct *);
 extern void _restore_msa(struct task_struct *);
+extern void _init_msa_upper(void);
 
 static inline void enable_msa(void)
 {
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index 1a1aef04312d370e9c9601365b3428a78ac53c17..4c4ec1812420b873663d682d706860f394d7db00 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -144,6 +144,11 @@ LEAF(_restore_msa)
 	jr	ra
 	END(_restore_msa)
 
+LEAF(_init_msa_upper)
+	msa_init_all_upper
+	jr	ra
+	END(_init_msa_upper)
+
 #endif
 
 /*
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 649c151fe1dbcb77cc6165da5a504ef828f5eac9..1ed84577d3e318c50b6a1546fafd39440c6ddc8f 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1089,13 +1089,15 @@ static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
 
 static int enable_restore_fp_context(int msa)
 {
-	int err, was_fpu_owner;
+	int err, was_fpu_owner, prior_msa;
 
 	if (!used_math()) {
 		/* First time FP context user. */
 		err = init_fpu();
-		if (msa && !err)
+		if (msa && !err) {
 			enable_msa();
+			_init_msa_upper();
+		}
 		if (!err)
 			set_used_math();
 		return err;
@@ -1147,18 +1149,37 @@ static int enable_restore_fp_context(int msa)
 	/*
 	 * If this is the first time that the task is using MSA and it has
 	 * previously used scalar FP in this time slice then we already nave
-	 * FP context which we shouldn't clobber.
+	 * FP context which we shouldn't clobber. We do however need to clear
+	 * the upper 64b of each vector register so that this task has no
+	 * opportunity to see data left behind by another.
 	 */
-	if (!test_and_set_thread_flag(TIF_MSA_CTX_LIVE) && was_fpu_owner)
+	prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
+	if (!prior_msa && was_fpu_owner) {
+		_init_msa_upper();
 		return 0;
+	}
 
-	/* We need to restore the vector context. */
-	restore_msa(current);
+	if (!prior_msa) {
+		/*
+		 * Restore the least significant 64b of each vector register
+		 * from the existing scalar FP context.
+		 */
+		_restore_fp(current);
 
-	/* Restore the scalar FP control & status register */
-	if (!was_fpu_owner)
-		asm volatile("ctc1 %0, $31" : : "r"(current->thread.fpu.fcr31));
+		/*
+		 * The task has not formerly used MSA, so clear the upper 64b
+		 * of each vector register such that it cannot see data left
+		 * behind by another task.
+		 */
+		_init_msa_upper();
+	} else {
+		/* We need to restore the vector context. */
+		restore_msa(current);
 
+		/* Restore the scalar FP control & status register */
+		if (!was_fpu_owner)
+			asm volatile("ctc1 %0, $31" : : "r"(current->thread.fpu.fcr31));
+	}
 	return 0;
 }