Re: [PATCH 3/3] objtool/x86: Fix NOP decode

Peter Zijlstra
2025-09-25T10:42:56Z

On Thu, Sep 25, 2025 at 12:03:23PM +0200, Peter Zijlstra wrote:

> > > > > case 0x90:
> > > > > + if (prefix != 0xf3) /* REP NOP := PAUSE */
> > > > > + insn->type = INSN_NOP;
> > > > > break;

> > What about 0x49 0x90, which is xchg (XCHG r8,rAX) ?

I've made that:

case 0x90:
if (rex_b) /* XCHG %r8, %rax */
break;

if (prefix == 0xf3) /* REP NOP := PAUSE */
break;

insn->type = INSN_NOP;
break;