Do not assume all Linux has linux/random.h.

Add missing sys/syscall.h include

config.h.in

@@ -467,6 +467,9 @@
 /* Define to 1 to enable Linux audit support. */
 #undef HAVE_LINUX_AUDIT
 
+/* Define to 1 if you have the <linux/random.h> header file. */
+#undef HAVE_LINUX_RANDOM_H
+
 /* Define to 1 if you have the `lockf' function. */
 #undef HAVE_LOCKF
 

configure

@@ -15953,6 +15953,19 @@ cat >>confdefs.h <<_ACEOF
 #define HAVE_DECL_SECCOMP_SET_MODE_FILTER $ac_have_decl
 _ACEOF
 
+		# We call getrandom via syscall(3) in case it is not in libc
+		for ac_header in linux/random.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "linux/random.h" "ac_cv_header_linux_random_h" "$ac_includes_default"
+if test "x$ac_cv_header_linux_random_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LINUX_RANDOM_H 1
+_ACEOF
+
+fi
+
+done
+
 		;;
     *-*-gnu*)
 		# lockf() is broken on the Hurd

configure.ac

@@ -2058,6 +2058,8 @@ case "$host" in
 #include <linux/seccomp.h>
 #include <linux/filter.h>
 		])
+		# We call getrandom via syscall(3) in case it is not in libc
+		AC_CHECK_HEADERS([linux/random.h])
 		;;
     *-*-gnu*)
 		# lockf() is broken on the Hurd

lib/util/getentropy.c

@@ -35,9 +35,12 @@
 #endif
 #include <sys/stat.h>
 #include <sys/time.h>
-#ifdef __linux__
+#ifdef HAVE_SYS_SYSCALL
-#include <linux/types.h>
+# include <sys/syscall.h>
-#include <linux/random.h>
+#endif
+#ifdef HAVE_LINUX_RANDOM_H
+# include <linux/types.h>
+# include <linux/random.h>
 #endif
 #include <errno.h>
 #include <fcntl.h>