Re: [PATCH] x86-64: Fix TLSDESC relaxation for x32

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Mon, Jan 20, 2020 at 7:18 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 20.01.2020 15:55, H.J. Lu wrote:
> > We need to support both sequences for x32.  For both GDesc -> IE/LE
> > transitions,
> >
> > 67 ff 10              call    *x@TLSCALL(%eax)
> >
> > should relaxed to
> >
> > 0f 1f 00              nopl    (%rax)
>
> Since, like it is phrased here, the patch also uses this
> unconditionally, I wonder if this is the best choice: Linux,
> for example, has a number of cases where it wouldn't use
> this NOP form even on 64-bit.
>

Assembler has been using this 3-byte NOP in 64-bit for
a long time.  What other options are you suggesting?


-- 
H.J.