Re: [Kgdb-bugreport] kgdb 2.3 hangs

[Ming Z. <mi...@el...>]

this is part of the grub.conf for target box.


title 2.6.13-386-kgdb
        root (hd0,0)
        kernel /vmlinuz-2.6.13-386-kgdb ro root=/dev/hda6 kgdbwait
nmi_watchdog=1


ming

On Mon, 2006-01-30 at 11:58 -0500, Ming Zhang wrote:
> On Mon, 2006-01-30 at 12:26 +0530, Amit Kale wrote:
> > Tom, Ming,
> > 
> > module debugging patch uses read memory packets, so it won't have any smp 
> > issues.
> > 
> > Have you passed "nmi_watchdog=1" to kernel through grub.conf file? Please also 
> > check the output of dmesg, to confirm that NMI watchdog in deed works. If it 
> > doesn't you'll see a message in dmesg output. If nmi_watchdog=1 doesn't work 
> > try nmi_watchdog=2. (Yeah, seems like a joke, but that's exactly what it 
> > is :-)
> 
> yes, i knew this nmi trick, it is funny.
> 
> > 
> > I see two different issues here.
> > 
> > 1. You could go ahead after turning off console messages over kgdb. This 
> > should be required. I would like to see a dump of packets with this option 
> > turned on. We'll get some idea about why this option is causing a problem.
> 
> i selected it, compiled, and loaded the new kernel. got this.
> 
> ----------------------------
> This GDB was configured as "i686-pc-linux-gnu"...
> (gdb) set remotebaud 57600
> (gdb) set debug remote 1
> (gdb) set solib-search-path /root/kgdb/module26
> (gdb) target remote /dev/ttyS0
> Remote debugging using /dev/ttyS0
> Sending packet: $Hc-1#09...Ack
> Packet received: OK
> Sending packet: $qC#b4...Ack
> Packet received: QC0000000000008000
> Sending packet: $qOffsets#4b...Ack
> Packet received:
> Sending packet: $?#3f...Ack
> Packet received: S05
> Sending packet: $Hg8000#77...Ack
> Packet received: OK
> Sending packet: $g#67...Ack
> Packet received:
> 01000000c01a64c000000000728362c0209f60c0249f60c07b8362c042f762c
> 08bbf14c08600000060000000680000007b0000007b000000ffff0000ffff0000
> breakpoint () at kernel/kgdb.c:1776
> 1776            atomic_set(&kgdb_setting_breakpoint, 0);
> Sending packet: $mc0566328,4#9e...Packet instead of Ack, ignoring it
> Packet instead of Ack, ignoring it
> Packet instead of Ack, ignoring it
> Packet instead of Ack, ignoring it
> Packet instead of Ack, ignoring it
> Bad checksum, sentsum=0xd1, csum=0x9b, buf=28356c0
> Packet instead of Ack, ignoring it
> Packet instead of Ack, ignoring it
> Bad checksum, sentsum=0xd1, csum=0x9b, buf=28356c0
> Packet instead of Ack, ignoring it
> Packet instead of Ack, ignoring it
> Bad checksum, sentsum=0xd1, csum=0x9b, buf=28356c0
> Packet instead of Ack, ignoring it
> Packet instead of Ack, ignoring it
> Bad checksum, sentsum=0xd1, csum=0x9b, buf=28356c0
> Packet instead of Ack, ignoring it
> putpkt: Junk: 286356c0#d1
> ----------------------------
> 
> then after a while, saw this. seems that serial link is broken
> 
> 
> Sending packet: $mc0566328,4#9e...putpkt: write failed: Input/output
> error.
> 
> (gdb) c
> Continuing.
> Sending packet: $Z0,c014bc80,1#38...putpkt: write failed: Input/output
> error.
> (gdb) c
> Continuing.
> Sending packet: $Z0,c014bc80,1#38...putpkt: write failed: Input/output
> error.
> 
> 
> > 
> > I have seen a bug report earlier where console message packets got mixed up 
> > with regular gdb packets, don't know how. Couldn't reproduce it later. I 
> > think we should print a message from kgdb indicating that smp isn't working. 
> > Perhaps halt kernel at that point.
> > 
> > 2. The output you have sent is rather limited. Could you send the _whole_ 
> > output. That is right from the point where gdb prints it's initial version 
> > no. etc. to the point where debugging fails.
> > 
> > -Amit
> > 
> > On Friday 27 Jan 2006 9:12 pm, Ming Zhang wrote:
> > > On Fri, 2006-01-27 at 08:31 -0700, Tom Rini wrote:
> > > > On Fri, Jan 27, 2006 at 10:12:46AM -0500, Ming Zhang wrote:
> > > > > thanks for the hint.
> > > > >
> > > > > now i deselect the "console message over kgdb" and use this 'set debug
> > > > > remote 1', the boot process is good.
> > > > >
> > > > >
> > > > > now is another problem.
> > > > >
> > > > > it hangs when loading module.
> > > >
> > > > You need to have a custom compiled GDB with the patches found in CVS,
> > > > if you've also got the 'module.patch' patch applied.
> > >
> > > i run the gdb_mod 2.3 from download page. i assumed that is the one you
> > > mentioned.
> > >
> > > > But I'll admit I haven't tested module autoloading stuff on SMP, but it
> > > > should work.
> > >
> > > though i am using a dual opteron, i already disabled SMP and choose P4
> > > for a 32bit compilation.
> > >
> > > ming
> > >
> > >
> > >
> > >
> > >
> > >
> > > -------------------------------------------------------
> > > This SF.net email is sponsored by: Splunk Inc. Do you grep through log
> > > files for problems?  Stop!  Download the new AJAX search engine that makes
> > > searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!
> > > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642
> > > _______________________________________________
> > > Kgdb-bugreport mailing list
> > > Kgd...@li...
> > > https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
>