Jonathan Adams's Weblog

Debugging smf(5)-managed processes

Recently, I've seen a couple questions (internally and externally) about the best way to debug something controlled by smf(5); since the process isn't started up directly, the usual ways of running things under a debugger aren't effective. If you don't need to debug the initialization process, it's also easy; just attach the debugger after the daemon is running.

If you need to debug the initialization, however, you need some way to stop the process before it does so. The easiest way is to use dtrace(1M). The following script:

# cat > stop_daemon.d <<\EOF
#!/usr/sbin/dtrace -s

#pragma D option quiet
#pragma D option destructive

BEGIN
{
        printf("READY\n");
}

proc:::start
/execname == $$1/
{
        stop();
        printf("stopped %d\n", pid);
        exit(0);
}
EOF
# chmod +x stop_daemon.d

# ./stop_daemon fmd &
# READY
svcadm restart fmd
# stopped 5678
mdb -p 5678
Loading modules: [ fmd ld.so.1 ... ]
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Technorati Tag: Solaris
Technorati Tag: Dtrace

Posted at 10:45AM May 19, 2005 by jwadams in Solaris  |  Comments[2]