How to get the host name of kill signal sender in systemtap script - kill

Question

all,
I encounter a problem when use systemtap script.
I don't know how to get the host name of kill signal sender in systemtap script.
for example. I am execute kill -9 xclock_process_pid in server 'sf1'. at the same time, I run 1.stap -x xclock_process_pid to monitor xclock,
is there any method to obtain the server name 'sf1' in systemtap script when send a kill -9 xclock_process_pid in 'sf1'?
but I am encounter some problem. my 1.stap is shown below:
#!/usr/bin/env stap
function hostname:string () %{
STAP_RETURN(current->nsproxy->uts_ns->name.nodename);
%}
probe oneshot {
log(hostname())
}
when I run 'stap -g 1.stap' will reprot the following error Could you help me? semantic error: probe point mismatch at position 0 (alternatives: __nfs __scheduler __signal __tcpmib __vm _linuxmib _signal _sunrpc _syscall _vfs begin begin(number) end end(number) error error(number) generic ioblock ioblock_trace ioscheduler ioscheduler_trace ipmib irq_handler kernel kprobe kprocess linuxmib module(string) nd_syscall netdev never nfs nfsd perf process process(number) process(string) procfs procfs(string) scheduler scsi signal socket softirq stap staprun sunrpc syscall tcp tcpmib timer tty udp vfs vm workqueue): identifier 'oneshot' at systemtap.stap:87:7 while resolving probe point oneshot source: probe oneshot { ^ Pass 2: analysis failed. Try again with another '--vp 01' option.

Answer 1

In other words, you're asking how to get the hostname of the current machine. A TCP/IP-level hostname is not in reach. The sethostname(2) level name is not easy to reach, being hidden inside kernel variables behind locked utsname()-> fields.
If safety were not a problem, you could do it via an embedded-C function for 4.8 era kernels:
function hostname:string () %{
STAP_RETURN(current->nsproxy->uts_ns->name.nodename);
%}
probe oneshot {
log(hostname())
}
that you would run with stap -g ... (guru mode).