Re: [PATCH v5 12/15] objtool: Add support for more complex UACCESS control

[Peter Zijlstra]

On Wed, Jan 15, 2025 at 11:42:52PM +0100, Christophe Leroy wrote:

> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index 91436f4b3622..54625f09d831 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -2422,6 +2422,14 @@ static int __annotate_late(struct objtool_file *file, 
> int type, struct instructi
>               insn->dead_end = false;
>               break;
>  
> +     case ANNOTYPE_UACCESS_BEGIN:
> +             insn->type = INSN_STAC;
> +             break;
> +
> +     case ANNOTYPE_UACCESS_END:
> +             insn->type = INSN_CLAC;
> +             break;

I would feel better if this had something like:

        if (insn->type != INSN_OTHER)
                WARN_INSN(insn, "over-riding instruction type: %d", insn->type);

Adding these annotations to control flow instruction would be bad etc.