On Tue, Jan 27, 2009 at 4:55 PM, Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: > Dave Anderson <anderson@xxxxxxxxxx> 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 is correct, I just built/booted/tested a series of kernels one after the other as part of the standard git bisect procedure. No tools were changed. > 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. This feature of crash does not work with 2.6.29, nor does it work with any kernel I've tried >= 2.6.21. Andi Kleen shared with me that he sees the same problem with a recent crash and 2.6.28. AFAIK I found the regression point relative to linux (commit: 7460ed28). The verdict is clearly still out on where the actual bug lives (linux vs crash). Mike -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
