From mboxrd@z Thu Jan 1 00:00:00 1970 From: hannes.weisbach@mailbox.tu-dresden.de (Hannes Weisbach) Date: Sat, 25 Apr 2015 16:13:11 +0200 Subject: [lttng-dev] [BUG] lttng-sessiond In-Reply-To: <480136718.35882.1429900335415.JavaMail.zimbra@efficios.com> References: <3E06425C-5C41-4BF7-8156-A62C4E9B5E60@mailbox.tu-dresden.de> <1230298824.35208.1429817200877.JavaMail.zimbra@efficios.com> <1795330554.35257.1429820009277.JavaMail.zimbra@efficios.com> <480136718.35882.1429900335415.JavaMail.zimbra@efficios.com> Message-ID: <4DCF299D-B929-42DB-B514-5219DAF3105F@mailbox.tu-dresden.de> >> However, loading multiple probes with >> either --kmod-probes or --extra-kmod-probes still does not work: >> $ sudo lttng-sessiond -vvv --extra-kmod-probes=sched,napi >> [...] >> DEBUG1 - 11:42:18.492870 [5358/5358]: Modprobe successfully lttng-probe-napi >> (in modprobe_lttng() at modprobe.c:285) >> sh: 1: Syntax error: "(" unexpected >> DEBUG1 - 11:42:18.495037 [5358/5358]: Unable to load optional module (null); >> continuing (in modprobe_lttng() at modprobe.c:281) >> [...] > > Why do you need to load those explicitly ? They should be > already loaded by default. I don't get those errors here. I don't need them. They're just examples. Albeit they are loaded by default, using --kmod-probes or --extra-kmod-probes should work, no? > Which shell are you using (sh symlink) ? Can you reproduce > using bash ? I added a bit of debug output, namely the string that gets passed to system(): DBG("system(%s)", modprobe); Result: $ sudo lttng-sessiond -vvv --kmod-probes="sched,napi" [?] DEBUG1 - 16:02:21.372257 [4227/4227]: system(/sbin/modprobe -q lttng-probe-napi) (in modprobe_lttng() at modprobe.c:263) DEBUG1 - 16:02:21.381980 [4227/4227]: Modprobe successfully lttng-probe-napi (in modprobe_lttng() at modprobe.c:286) DEBUG1 - 16:02:21.382306 [4227/4227]: system(/sbin/modprobe -q (null)) (in modprobe_lttng() at modprobe.c:263) sh: 1: Syntax error: "(" unexpected DEBUG1 - 16:02:21.384942 [4227/4227]: Unable to load optional module (null); continuing (in modprobe_lttng() at modprobe.c:282) The problem is not with sh. It is that a NULL pointer is passed to snprintf in modprobe.c:254. My guess is, that splitting the argument of --kmod-probes and --extra-kmod-probes (probably using strtok) is somehow broken. If you can tell where in the source of lttng-sessiond argument parsing happens I can step through the code to see what is going on. Best regards, Hannes -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 203 bytes Desc: Message signed with OpenPGP using GPGMail URL: