[Crash-utility] Re: source line numbers and modules (on x86_64)

On Wed, Apr 30, 2008 at 6:43 PM, Dave Anderson <anderson(a)redhat.com&gt; wrote: > Mike Snitzer wrote: > > >> Hi, >> >> I searched the archives and found that you've discussed an issue I'm >> seeing with x86_64 kernels where crash doesn't have line numbers for >> modules' symbols: >> https://www.redhat.com/archives/crash-utility/2008-January/msg00021.html >> >> I'm using crash-4.0-6.3 on a RHEL5U1 x86_64 system with a custom >> 2.6.22.19 kernel. Given that the RHEL5U1 x86_64 kernels clearly do >> provide accurate line numbers for modules, has anyone identified how >> that is? I have to believe the redhat kernel is patched to fix this >> issue. >> >> I looked over the various redhat patches that are applied to RHEL5's >> 2.6.18 sources but can't see a patch that stands out as specifically >> addressing this x86_64 issue. But I could easily be overlooking some >> patch. >> >> please advise, thanks. >> Mike >> >> ps. please cc me as I've not yet been able to join the list >> >> >> > You're on the list now... > > Anyway, there are no kernel patches applied to RHEL5 kernels > to make it work that I'm aware of. That being said, I don't > have an answer as to why they don't work for modules on your > custom kernel (or why they don't work in RHEL4 kernels...). > I configured my x86_64 kernel to be relocatable. Could this be the reason for modules' line number debug data being off? From: http://people.redhat.com/anderson/crash.changelog.html#4_0_4_5 "Using /proc/kallsyms or a --reloc=[size] as a command line argument is similar to using a System.map file, in that it results in the loss of the use of line number debug data."

Still doesn't explain why RHEL4 isn't happy in this regard either... I'm trying a non-relocatable variant of my kernel now and will report back with the results.