Hi Michal,
There is indeed a bug, thanks for reporting it.
I am not sure your patch is the right way to fix. I guess it's crashing because
pthread_t is some kind of pointer on your system. But after a quick search I
did not find something saying that an implementation of pthread forbid thre
thread ID to be 0 (correct me if I am wrong). It might even break the
portability of the code. So I guess, setting the appropriate nutscan_avail_*
variable to 0 might be a better way.
Let me know what you think of the attached patch.
Regards,
Fred
--
Eaton Opensource Team - http://opensource.eaton.com
-----------------------------
-----------------------------
________________________________________
From: nut-upsdev-bounces+fredericbohe=eaton....@lists.alioth.debian.org
[nut-upsdev-bounces+fredericbohe=eaton....@lists.alioth.debian.org] on behalf
of Michal Hlavinka [[email protected]]
Sent: Thursday, September 06, 2012 3:24 PM
To: NUT Developers
Subject: [Nut-upsdev] nut-scanner pthread issue
Hi,
the terminating part of nut-scanner can crash in pthread code, because
some threads won't exist. For example snmp part:
==============================
if( allow_snmp && nutscan_avail_snmp ) {
if( start_ip == NULL ) {
printq(quiet,"No start IP, skipping SNMP\n");
}
else {
printq(quiet,"Scanning SNMP bus.\n");
#ifdef HAVE_PTHREAD
if(
pthread_create(&thread[TYPE_SNMP],NULL,run_snmp,&snmp_sec)) {
nutscan_avail_snmp = 0;
}
#else
dev[TYPE_SNMP] =
nutscan_scan_snmp(start_ip,end_ip,timeout,&snmp_sec);
#endif /* HAVE_PTHREAD */
}
}
==============================
if start_ip==NULL, pthread is not created, but later...
if( allow_snmp && nutscan_avail_snmp && thread[TYPE_SNMP]) {
pthread_join(thread[TYPE_SNMP],NULL);
}
it calls pthread_join with threan[TYPE_SNMP]==0,
pthread_join(0, ?) behaviour is undefined, on my system undefined=crashes.
I used attached patch to get rid of it.
Cheers,
Michal
/me is back from vacation and going to another one tmrw, so I won't be
reachable for some time (again)
Index: nut-scanner.c
===================================================================
--- nut-scanner.c (revision 3719)
+++ nut-scanner.c (working copy)
@@ -371,6 +371,7 @@
if( allow_snmp && nutscan_avail_snmp ) {
if( start_ip == NULL ) {
printq(quiet,"No start IP, skipping SNMP\n");
+ nutscan_avail_snmp = 0;
}
else {
printq(quiet,"Scanning SNMP bus.\n");
@@ -398,6 +399,7 @@
if( allow_oldnut && nutscan_avail_nut) {
if( start_ip == NULL ) {
printq(quiet,"No start IP, skipping NUT bus (old connect method)\n");
+ nutscan_avail_nut = 0;
}
else {
printq(quiet,"Scanning NUT bus (old connect method).\n");
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