Index: head/sys/libkern/strdup.c
===================================================================
--- head/sys/libkern/strdup.c
+++ head/sys/libkern/strdup.c
@@ -40,13 +40,22 @@
 #include <sys/malloc.h>
 
 char *
-strdup(const char *string, struct malloc_type *type)
+strdup_flags(const char *string, struct malloc_type *type, int flags)
 {
 	size_t len;
 	char *copy;
 
 	len = strlen(string) + 1;
-	copy = malloc(len, type, M_WAITOK);
+	copy = malloc(len, type, flags);
+	if (copy == NULL)
+		return (NULL);
 	bcopy(string, copy, len);
 	return (copy);
+}
+
+char *
+strdup(const char *string, struct malloc_type *type)
+{
+
+	return (strdup_flags(string, type, M_WAITOK));
 }
Index: head/sys/sys/libkern.h
===================================================================
--- head/sys/sys/libkern.h
+++ head/sys/sys/libkern.h
@@ -173,6 +173,7 @@
 int	 strcmp(const char *, const char *);
 char	*strcpy(char * __restrict, const char * __restrict);
 size_t	 strcspn(const char * __restrict, const char * __restrict) __pure;
+char	*strdup_flags(const char *__restrict, struct malloc_type *, int);
 char	*strdup(const char *__restrict, struct malloc_type *);
 char	*strncat(char *, const char *, size_t);
 char	*strndup(const char *__restrict, size_t, struct malloc_type *);