Re: [PATCH v2] objtool: fix objtool regression on x32 systems

From: Josh Poimboeuf
Date: Wed May 18 2022 - 14:08:32 EST


On Wed, May 18, 2022 at 09:28:57AM -0400, Mikulas Patocka wrote:
>
>
> On Mon, 16 May 2022, Peter Zijlstra wrote:
>
> > On Mon, May 16, 2022 at 11:56:21AM -0400, Mikulas Patocka wrote:
> > >
> > > With this patch, the compiled kernel works. With kernels 5.17 or older, it
> > > also works. I bisected it and the breakage is caused by the commit
> > > 4abff6d48dbc.
> >
> > Sure; but it works doesn't mean there aren't more latent issues. ILP32
> > hosted (cross) builds just aren't a thing I've ever considered. If we
> > really want to go support that then we should at least audit the whole
> > thing.
> >
> > A quick look seems to suggest at least all the 'offset' fields should be
> > u64 or something. The only reason that works is because -mcmodel=kernel
> > keeps everything in the 2G range to make s32 immediates work. But it
> > isn't right.
>
> There are many 'offset' variables and its hard to determine which should
> be 64-bit. Would it be possible to commit this patch, so that kernel 5.18
> can be compiled on x32 distributions? And you can do code refactoring in
> the next merge window.

I believe Peter is going ahead with merging this for 5.18, and your v2
looks identical to what he already has here:

https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/log/?h=objtool/urgent

--
Josh