From: Linus Torvalds > Sent: 15 August 2018 16:44 > On Wed, Aug 15, 2018 at 5:38 AM David Laight <david.lai...@aculab.com> wrote: > > > > Never mind the version of gcc, the x86 kernel doesn't build with the > > default kernel options because the ORC unwinder hits a bug in libelf > > (in objtool) that was only fixed late last year. > > > > It isn't even obvious from the build log what has gone wrong. > > Can you give more details? We should try to work around it. > > It's one thing to care about a compiler that is almost a decade old. > At some point we just have to let it go. > > But some libelf bug that is less than a year old is likely to bite people.
See https://lkml.org/lkml/2017/9/10/186 for the libelf fix. It isn't anything like as rare as those emails suggest. An 'allmodconfig' build fails on a lot of object files after 4.15-rc9. When I fell over the problem I found a few reports on the ubuntu lists but they all just said the ubuntu version was unsupported. There is this patch I did https://lkml.org/lkml/2018/7/26/266 that got no comments. But really something needs to be done to objtool. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
