On 06/25/2013 12:35 AM, Richard Henderson wrote: > On 06/24/2013 12:37 AM, Vineet Gupta wrote: >> Aha, I see what's happening. For historical reasons, ARC Linux kernel stack >> unwinder relies on .debug_frame (vs. .eh_frame) for stack unwinding. Being >> non >> allocatable it would default to address zero hence the orig absolute >> relocations >> would work for most ports. However in our case we force it allocatable in >> kernel >> builds and thus it is relocated to 0x8abcdefg, thus the usage of absolute >> relocations ends up generating the invalid reference. >> >> Thus it seems we do need the special section relative reference. >> >> Thanks a bunch for clarifying. > It seems like it would be easier to change the kernel to use .eh_frame > rather than adding relocation types and changing the tool chain...
Yes that is what we concluded as well. Although the current issue manifests only as objdump/readelf splat with kernel binary - the unwinder itself in kernel works OK. But .eh_frame is what others do so we might as well follow suite given that ARC gcc 4.8 now has started generating one. -Vineet
