From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Bennett Subject: kernel panic w/ax25 in FC4 Date: Sun, 29 Jan 2006 20:13:04 -0600 Message-ID: <1138587184.10860.57.camel@localhost> Reply-To: jabennett@insightbb.com Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-hams-owner@vger.kernel.org List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-hams@vger.kernel.org Hey guys, I routinely read the emails in this list and don't remember seeing anything like this before. If this issue has been previously discussed, my apologies. FC4 built from CDs. Updated everything with yum. Latest libax25, ax25-tools built from tarballs. Rebuilt kernel using 'kernel-2.6.14-1.1656_FC4.src.rpm' sources. Rebuilt kernel because I needed mkiss for a TNC attached to a serial port. TNC is an MFJ-1274 using TAPR firmware 1.1.8 or 1.1.7b (can't remember which). Machine in question was a P3-500 w/256 MB. Previously installed and ran RH9 with a 2.4 kernel on it for the last year with no problems. This was an 'upgrade' which is actually a new install (never have found that upgrade paths work well). Due to time constraints, I had to leave and finish building and configuring the machine remotely. This build/hardware configuration was similar to several other builds completed in the last two months. When starting ax25 (kissattach), there was a kernel panic every time. Tried 2.6.11 and 2.6.12, but the TIOCSETD error kept popping up. Went back to 2.6.14. Finally decided there must be a hardware problem with this particular box that was not on the others. Grabbed another machine that was identical to an installation running at another QTH (P3-866 w/512MB). Built and checked on the bench here. All worked as it should. Today I drove to the remote site, installed the new box, and immediately got a kernel panic. After some investigation, I discovered that the TNC had dropped out of the KISS mode. If the TNC was disconnected or the power was off when doing a kissattach, no problems. The instant the TNC was switched on or was on when invoking kissattach there was a kernel panic. Using minicom, I put the errant TNC back into the KISS mode. Everything now works. I suspect that when mkiss receives certain characters from the TNC when in the normal (?) mode, it is causing a segmentation fault of some kind that causes the panic. I know this has not been an issue in the past with other kernels (i.e., 2.4). While it doesn't happen very often, TNCs do drop out of KISS if something screwy happens. Hopefully someone on this list is the maintainer and can take a look at the code. I scanned through 'kissattach' and didn't see anything that could cause the problem. It's fairly simple program. At least the week-long siege of frustration is finally over... 73 -- John Bennett Evansville, IN Amateur Radio Web: http://n4xi.home.insightbb.com Where am I? http://www.findu.com/cgi-bin/find.cgi?N4XI Bike Racing Web: http://xibike.home.insightbb.com Live Strong - Lance Armstrong Foundation: http://www.laf.org/