--- /home/vishal/Android/Sdk/ndk-bundle/platforms/android-21/arch-arm/usr/include/sys/sem.h	2016-10-12 15:11:58.000000000 +0530
+++ ./usr/include/sys/sem.h	2017-01-24 08:23:25.150726158 +0530
@@ -31,4 +31,14 @@
 
 #include <linux/sem.h>
 
+#ifdef TERMUX_SEMOPS_STUBS
+
+#include <sys/syscall.h>
+
+#define semop(semid, sops, nsops)  syscall(__NR_semop, semid, sops, nsops)
+#define semget(key, nsems, semflg) syscall(__NR_semget, key, nsems, semflg)
+#define semctl(semid, semnum, cmd, ...) syscall(__NR_semctl, semid, semnum, cmd, __VA_ARGS__)
+
+#endif /* TERMUX_SEMOPS_STUBS */
+
 #endif /* _SYS_SEM_H_ */