1 files changed, 10 insertions, 0 deletions
diff --git a/lib/libc/signal/sigaddset.c b/lib/libc/signal/sigaddset.c
new file mode 100644
index 00000000..33e74bd0
--- /dev/null
+++ b/lib/libc/signal/sigaddset.c
@@ -0,0 +1,10 @@
+#include <signal.h>
+
+int sigaddset(sigset_t *set, int signo)
+{
+	if (signo < 1 || signo > 64) {
+		return -1;
+	}
+	*set |= (1ULL << (signo - 1));
+	return 0;
+}