unlike other si_code defines, SYS_ is not in the posix reserved namespace which is likely the reason why SYS_SECCOMP was previously missing (was new in linux v3.5).
@@ -261,6 +261,8 @@ void (*sigset(int, void (*)(int)))(int);
#if defined(_BSD_SOURCE) || defined(_GNU_SOURCE)
#define NSIG _NSIG
typedef void (*sig_t)(int);
+
+#define SYS_SECCOMP 1
#endif
#ifdef _GNU_SOURCE