When reviewing test results noticed that /testsuite/systemtap.examples/process/strace.stp had the following warning: WARNING: never-assigned local variable 'retstr' (similar: argstr, status, name, _target_set, thread_argstr): identifier 'retstr' at strace.stp:49:38 source: report(name,thread_argstr[tid()],retstr) Noticed that a number of the syscall.*.return and nd_syscall.*.return are missing retstr variable. Below is the list from x86_64 of syscalls missing retstr. $ stap -L 'syscall.*.return' |grep -v retstr syscall.accept.return syscall.accept4.return syscall.bind.return syscall.compat_signalfd.return _entry_tvar_tid:long syscall.compat_sys_msgctl.return _entry_tvar_tid:long syscall.compat_sys_msgrcv.return _entry_tvar_tid:long syscall.compat_sys_msgsnd.return _entry_tvar_tid:long syscall.compat_sys_recvmsg.return _entry_tvar_tid:long syscall.compat_sys_semctl.return _entry_tvar_tid:long syscall.compat_sys_semtimedop.return _entry_tvar_tid:long syscall.compat_sys_sendmsg.return _entry_tvar_tid:long syscall.compat_sys_shmat.return _entry_tvar_tid:long syscall.compat_sys_shmctl.return _entry_tvar_tid:long syscall.connect.return syscall.epoll_create.return _entry_tvar_tid:long syscall.getpeername.return syscall.getsockname.return syscall.getsockopt.return syscall.listen.return syscall.msgget.return syscall.pipe.return _entry_tvar_tid:long syscall.recv.return syscall.recvfrom.return syscall.recvmsg.return syscall.semget.return syscall.semop.return syscall.send.return syscall.sendmmsg.return syscall.sendmsg.return syscall.sendto.return syscall.setsockopt.return syscall.shmdt.return syscall.shmget.return syscall.shutdown.return syscall.signalfd.return _entry_tvar_tid:long syscall.socket.return syscall.socketpair.return syscall.wait4.return _entry_tvar_tid:long Some are syscall.*.return also missing name variable: $ stap -L "syscall.*.return"|grep -v name syscall.accept.return syscall.accept4.return syscall.bind.return syscall.compat_signalfd.return _entry_tvar_tid:long syscall.compat_sys_msgctl.return _entry_tvar_tid:long syscall.compat_sys_msgrcv.return _entry_tvar_tid:long syscall.compat_sys_msgsnd.return _entry_tvar_tid:long syscall.compat_sys_recvmsg.return _entry_tvar_tid:long syscall.compat_sys_semctl.return _entry_tvar_tid:long syscall.compat_sys_semtimedop.return _entry_tvar_tid:long syscall.compat_sys_sendmsg.return _entry_tvar_tid:long syscall.compat_sys_shmat.return _entry_tvar_tid:long syscall.compat_sys_shmctl.return _entry_tvar_tid:long syscall.connect.return syscall.epoll_create.return _entry_tvar_tid:long syscall.getsockopt.return syscall.listen.return syscall.msgget.return syscall.pipe.return _entry_tvar_tid:long syscall.recv.return syscall.recvfrom.return syscall.recvmsg.return syscall.semget.return syscall.semop.return syscall.send.return syscall.sendmmsg.return syscall.sendmsg.return syscall.sendto.return syscall.setsockopt.return syscall.shmdt.return syscall.shmget.return syscall.shutdown.return syscall.signalfd.return _entry_tvar_tid:long syscall.socket.return syscall.socketpair.return syscall.wait4.return _entry_tvar_tid:long
Fixed in commit 4f4f173ad325b2e2e6228a2fd109953769a7d905.