[PATCH] [makedumpfile] Follow debuginfo link of vmlinux file
jlan at sgi.com
Tue May 29 13:44:07 EDT 2007
Ken'ichi Ohmichi wrote:
> Hi Jay,
> Sorry for the late response.
> 2007/05/24 12:44:26 -0700, Jay Lan <jlan at sgi.com> wrote:
>> Bernhard Walle wrote:
>>> * Dave Anderson <anderson at redhat.com> [2007-05-24 20:31]:
>>>> The crash utility hides the details of there being a separate debug
>>>> file in the same way the gdb does when working with a binary executable
>>>> that has a separate debuginfo file. It tries *not* to be ambiguous,
>>>> i.e., the point is to stay true to the "crash vmlinux vmcore" model.
>>> It's documented in the GDB documentation:
>> Thanks for the pointer, Bernhard. I installed kernel-debuginfo rpm
>> but crash still failed to find the debug information... I had to
>> copy the kernel-<version>.debug to /boot for it to work.
>> So, i think it is a good idea for makedumpfile to follow the same
>> convension as crash and gdb, Ken'ichi?
> No, I don't think it is worthy that a kernel file is specified *only*
> for getting the path to a debuginfo file. It is smart to specify
> a debuginfo file directly. The crash utility needs both a kernel
> file and a debuginfo file, but makedumpfile needs only a debuginfo
> file as I said.
> BTW, I recommend using a makedumpfile's CONFIGFILE instead of a
> debuginfo file. If a system has a CONFIGFILE, makedumpfile can
> run without a debuginfo file. It is smaller than a debuginfo file,
> and it is easy to distribute it to each system.
> I don't think each system should have a debuginfo file, because the
> file is big and a user may analyze a dumpfile on a remote analysis
Any way to make kernel debugging easier is great news!!! However...
If i run makedumpfile -x option to produce a dumpfile as below:
# makedumpfile -c -d 31 -x VMLINUX VMCORE DUMPFILE
The size of these files are:
16468 -rw------- 1 jlan wheel 16983716 2007-05-29 10:23 DUMPFILE
1719048 -r-------- 1 jlan wheel 1760303684 2007-05-24 11:35 VMCORE
55488 -rwxr-xr-x 1 jlan wheel 56819470 2007-05-24 11:33 VMLINUX
and crash was able to read and analyze the DUMPFILE together with the
Now when i used makedumpfile -g option to generate a CONFIGFILE:
# makedumpfile -g CONFIGFILE -x VMLINUX
the size of CONFIGFILE is only 696 bytes. Besides, makedumpfile
failed to generate a DUMPFILE using the CONFIGFILE:
# makedumpfile -c -d 31 -i CONFIGFILE VMCORE DUMPFILE
CONFIGFILE and VMCORE don't match.
I think the CONFIGFILE is too small to be good?
What did i miss here?
> Ken'ichi Ohmichi
More information about the kexec