diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 78936f4ff513..7cad513538d8 100644
--- a/arch/riscv/include/asm/hwprobe.h
+++ b/arch/riscv/include/asm/hwprobe.h
@@ -10,4 +10,9 @@
 
 #define RISCV_HWPROBE_MAX_KEY 5
 
+static inline bool riscv_hwprobe_key_is_valid(__s64 key)
+{
+	return key >= 0 && key <= RISCV_HWPROBE_MAX_KEY;
+}
+
 #endif
diff --git a/arch/riscv/kernel/vdso/hwprobe.c b/arch/riscv/kernel/vdso/hwprobe.c
index d40bec6ac078..cadf725ef798 100644
--- a/arch/riscv/kernel/vdso/hwprobe.c
+++ b/arch/riscv/kernel/vdso/hwprobe.c
@@ -37,7 +37,7 @@ int __vdso_riscv_hwprobe(struct riscv_hwprobe *pairs, size_t pair_count,
 
 	/* This is something we can handle, fill out the pairs. */
 	while (p < end) {
-		if (p->key <= RISCV_HWPROBE_MAX_KEY) {
+		if (riscv_hwprobe_key_is_valid(p->key)) {
 			p->value = avd->all_cpu_hwprobe_values[p->key];
 
 		} else {