Re: BISECTED: Re: source line numbers with x86_64 modules?

[ebiederm@xmission.com (Eric W. Biederman)]

Dave Anderson <anderson@redhat.com> writes:

> Actually it's not a problem with the vmlinux file, but rather with kernel
> module object files.  The crash utility has an embedded gdb module which
> is invoked as "gdb vmlinux", and to get line numbers, the crash utility
> simply uses the relevant built-in gdb function to get them.  And line
> numbers work fine with the base kernel code from the vmlinux file.
>
> The debuginfo data of kernel modules can be subsequently added to the
> crash session by doing a gdb "add-symbol-file" command for any or all
> kernel modules.  But getting correct line number information for kernel
> modules has been a crap-shoot in the past, depending upon architecture
> and/or kernel version.  For example, they don't work with 2.6.9-based
> RHEL4 x86_64 kernel modules, but work fine with 2.6.18-based RHEL5 x86_64
> kernels.
>
> Looking at Mike's suspect kernel patch list, I don't see anything that
> would have any relationship to the issue.  Perhaps there was a build tool
> change during the same timeframe? 

It look like Mike just built a series of kernels and had a problem,
which should preclude a tool change.

That said.  Does this feature of crash work in 2.6.29?  If not is
there enough interest to track this down, and fix it if it is a kernel
bug?

If we are going to be using these tools we need them working on the
latest and greatest kernels, not some weird enterprise branch, for
fuddy duddies.

Eric