RE: [PATCH 6/6] x86/gsseg: use the LKGS instruction if available for load_gs_index()

[Li, Xin3]

> > +	alternative_io("1: call asm_load_gs_index\n"
> > +		       ".pushsection \".fixup\",\"ax\"\n"
> > +		       "2:	xorl %k[sel], %k[sel]\n"
> > +		       "	jmp 1b\n"
> > +		       ".popsection\n"
> > +		       _ASM_EXTABLE(1b, 2b),
> > +		       _ASM_BYTES(0x3e) LKGS_DI,
> > +		       X86_FEATURE_LKGS,
> > +		       ASM_OUTPUT2([sel] "+D" (sel), ASM_CALL_CONSTRAINT),
> > +		       ASM_NO_INPUT_CLOBBER(_ASM_AX));
> >  }
> 
> I'm very sure none of this was tested... the .fixup section hasn't existed for
> almost a year now.

Weird, did you ever check a kernel dump?

> 
>   e5eefda5aa51 ("x86: Remove .fixup section")