Re: [PATCH v3 16/16] objtool,x86: Rewrite retpoline thunk calls

From: Peter Zijlstra
Date: Tue Jun 08 2021 - 13:23:05 EST


On Tue, Jun 08, 2021 at 09:58:03AM -0700, Nathan Chancellor wrote:
> On 6/7/2021 1:54 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> > On Mon, Jun 7, 2021 at 2:46 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > >
> >
> > Thanks, the below diff resolves the linker error reported in
> > https://github.com/ClangBuiltLinux/linux/issues/1388
> >
> > Both readelf implementations seem happy with the results, too.
> >
> > Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> >
> > Nathan,
> > Can you please test the below diff and see if that resolves your boot
> > issue reported in:
> > https://github.com/ClangBuiltLinux/linux/issues/1384
>
> Unfortunately, it does not appear to resolve that issue.
>
> $ git log -2 --decorate=no --oneline
> eea6a9d6d277 Peter's fix
> 614124bea77e Linux 5.13-rc5
>
> $ strings /mnt/c/Users/natec/Linux/kernel-investigation | grep microsoft
> 5.13.0-rc5-microsoft-standard-WSL2-00001-geea6a9d6d277
> (nathan@archlinux-ax161) #3 SMP Tue Jun 8 09:46:19 MST 2021
>
> My VM still never makes it to userspace.

Since it's a VM, can you use the gdb-stub to ask it where it's stuck?