Re: [PATCH] uprobes/x86: allow to probe a "nop" insn with 0x66 prefix

From: Oleg Nesterov
Date: Sun Dec 04 2022 - 12:36:35 EST


On 12/02, Oleg Nesterov wrote:
>
> On 12/02, Thomas Gleixner wrote:
> >
> > On Thu, Dec 01 2022 at 15:26, Oleg Nesterov wrote:
> >
> > > From: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
> > >
> > > Intel icc -hotpatch inserts 2-byte "0x66 0x90" NOP at the start of each
> > > function to reserve extra space for hot-patching, and currently it is not
> > > possible to probe these functions because branch_setup_xol_ops() wrongly
> > > nacks NOP with REP prefix.
> > >
> > > Fixes: 250bbd12c2fe ("uprobes/x86: Refuse to attach uprobe to "word-sized" branch insns")
> > > Reported-by: Seiji Nishikawa <snishika@xxxxxxxxxx>
> > > Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
> >
> > The SOB chain is invalid as it lacks the author's signoff.
>
> Denys, can we have your signed-off-by?

OK, let me turn "From" into "Suggested-by" if this can help to merge this fix.

After all, the patch is really simple, I don't think Denys will object when he
returns.

I am sending v2 with Masami's ack applied.

Oleg.