From 0bcfc4fae5b37b480d1a617b342935d359b3476c Mon Sep 17 00:00:00 2001 From: grog Date: Tue, 13 Apr 1999 01:18:51 +0000 Subject: Update description of how to analyse kernel dumps. --- share/man/man4/vinum.4 | 114 +++++++++++++++++++++++-------------------------- 1 file changed, 54 insertions(+), 60 deletions(-) (limited to 'share/man/man4/vinum.4') diff --git a/share/man/man4/vinum.4 b/share/man/man4/vinum.4 index db1a0c6..5f66c54 100644 --- a/share/man/man4/vinum.4 +++ b/share/man/man4/vinum.4 @@ -858,47 +858,28 @@ command if you have this kind of trouble. In order to analyse a panic which you suspect comes from .Nm you will need to build a debug kernel. See the online handbook for more details -of how to do this. Be sure to include the -.Nm ddb -debugger. To do this, put the following lines in your kernel configuration -file: -.Bd -literal -options DDB -options BREAK_TO_DEBUGGER -options DDB_UNATTENDED -.Ed -.Pp -The -.Li DDB_UNATTENDED -tells the kernel to reboot on a panic; otherwise it will remain in the -.Nm ddb -prompt until it receives input. +of how to do this. .Pp -You will need some additional steps to get symbolic information for the +Perform the following steps to analyse a .Nm -kernel loadable module: +problem: .Bl -enum .It -If possible, make a copy of or a link to the debug kernel at -.Pa /var/crash/kernel.gdb, -since the -.Cm gdb -initialization file looks for it in this location. +Copy the files +.Pa /usr/src/sys/modules/vinum/.gdbinit.crash , +.Pa /usr/src/sys/modules/vinum/.gdbinit.kernel , +.Pa /usr/src/sys/modules/vinum/.gdbinit.serial , +.Pa /usr/src/sys/modules/vinum/.gdbinit.vinum +and +.Pa /usr/src/sys/modules/vinum/.gdbinit.vinum.paths +to the directory in which you will be performing the analysis, typically +.Pa /var/crash . .It Make sure that you build the .Nm -module with debugging information. This is the normal situation with the -standard -.Pa Makefile. -.It -Copy the file -.Pa /usr/src/sys/modules/vinum/.gdbinit.crash -to the directory in which you will be performing the analysis, typically -.Pa /var/crash , -and call it -.Pa .gdbinit . -.It -If the version of +module with debugging information. The standard +.Pa Makefile +builds a module with debugging symbols by default. If the version of .Nm in .Pa /modules @@ -924,40 +905,51 @@ or .Pa /usr/src/sys/modules/vinum/vinum.ko (if you have built .Nm -in this directory). Modify the -.Pa .gdbinit -file accordingly. +in this directory). Modify the file +.Pa .gdbinit.vinum.paths +accordingly. .It -If you have not named your debug kernel -.Pa /var/crash/kernel.gdb, -edit -.Pa .gdbinit -to indicate the correct location. -.P -If you are remote debugging via a serial connection, copy the file -.Pa /usr/src/sys/modules/vinum/.gdbinit.crash -as -.Pa .gdbinit -to the directory in which you perform the debugging, and start it with -.Bd -literal -offset indent -gdb -k +Either take a dump or use remote serial +.Cm gdb +to analyse the problem. To analyse a dump, say +.Pa /var/crash/vmcore.5 , +link +.Pa /var/crash/.gdbinit.crash +to +.Pa /var/crash/.gdbinit +and enter: +.Bd -literal +# cd /var/crash +# gdb -k kernel.debug vmcore.5 .Ed .Pp -.Cd gdb -will automatically establish the connection; the remote machine must already be -in +This example assumes that you have installed the correct debug kernel at +.Pa /var/crash/kernel.debug . +If not, substitute the correct name of the debug kernel. +.Pp +To perform remote serial debugging, +link +.Pa /var/crash/.gdbinit.serial +to +.Pa /var/crash/.gdbinit and enter +.Bd -literal +# cd /var/crash +# gdb -k kernel.debug +.Ed +.Pp +In this case, the +.Pa .gdbinit +file performs the functions necessary to establish connection. The remote +machine must already be in debug mode: enter the kernel debugger and select .Nm gdb . -This +The serial .Pa .gdbinit file expects the serial connection to run at 38400 bits per second; if you run at a different speed, edit the file accordingly (look for the .Ar remotebaud specification). -.It -Either take a dump or use -.Cm gdb -to analyse the problem. Enter the output of the shell script shown above. The -following example shows a remote debugging session using the +.Pp +The following example shows a remote debugging session using the .Ar debug command of .Nm vinum(8): @@ -1007,7 +999,9 @@ Debugger ("vinum debug"); .if t .vs .if t .ps .Pp -This is an indication that the address specifications are correct. +This is an indication that the address specifications are correct. If you get +some other output, your symbols and the kernel module are out of sync, and the +trace will be meaningless. .El .Pp For an initial investigation, the most important information is the output of -- cgit v1.1