see linux commit 1d7637d89cfce54a4f4a41c2325288c2f47470e8 signal: Expose SYS_USER_DISPATCH si_code type
@@ -263,6 +263,7 @@ void (*sigset(int, void (*)(int)))(int);
typedef void (*sig_t)(int);
#define SYS_SECCOMP 1
+#define SYS_USER_DISPATCH 2
#endif
#ifdef _GNU_SOURCE