On Tue, 2009-08-11 at 13:03 -0400, Robert P. J. Day wrote: > Kernel and module debugging with gdb: http://cli.gs/LHaA4a. > > Enjoy. > > rday > -- > > ======================================================================== > Robert P. J. Day Waterloo, Ontario, CANADA > > Linux Consulting, Training and Annoying Kernel Pedantry. > > Web page: http://crashcourse.ca > Twitter: http://twitter.com/rpjday > ======================================================================== > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx > Please read the FAQ at http://kernelnewbies.org/FAQ > Hi Robert and all, The article is quite interesting, however it seems hard to scratch together relevant (should read : not outdated thus wrong) on debugging kernel modules on a *remote* target.. I've been scouring away for yonks here and I don't seem to be getting anywhere in a hurry :-( I've recompiled my target's kernel with remote KGDB enabled, (sysfs et al for possible manual configuration), full debug on the kernel - just in case - but trying to pass kernel command argument using kgdbwait (preceded with kgdboc=ttyS0,115200 eg. or kgdbcon etc) doesn't seem to get the booting to halt and wait for the gdbmod debugger.... (I've also tried the sysrq-g break and consorts, no avail either). I've had a close look at the kernel/kgdb.c source - added some extra temp debug messages to try to track code flow and it seems I'm not even entering these funcs. Is there anyone here that can shed some more light on this black magic cursed trick ? I'm using gdbmod-2.4 btw. So, basically : I'm continuing trying to find out if there is a way to step through kernel module code invoked on a remote (ARM) target by insmod/modprobe. (gdbmod 2.4 claims it automatically picks up when module is inserted, but at this stage the kernel just happily boots up and chugs away, ignoring the wait for remote debugger...?.) kgdb's URL has docs (kgdb_docu_full-2.4) but - as per usual - they're either just plain wrong (eg. the syntax doesn't comply whatsoever with the Documentation -> Docbook kgdb explained syntax) or others don't seem to correlate with one another. It seems almost like a 'brute force' test of all permutations of these various "solutions" is perhaps soon the only way to remain sane.. :-) Googling other resources seems to just bring up unanswered posts on forums here and there where people seem to be just as confused as I am :-) In short, if anyone drops around here and has done this before (kernel = 2.6.29.4, using built in remote kgdb), I would love to hear from them to see if perhaps they've got a suggestion. I don't mind doing the hard work to learn it properly - but it's always more enjoyable when one is actually working towards something fruitful in the end... ! -- Best regards, Kris -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
