linux-kernel - Re: [PATCH 1/2] objtool: Optimize re-writing jump

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Message-ID: <20211008065550.zge5zkbfrki5osv2@treble>
Date:   Thu, 7 Oct 2021 23:55:50 -0700
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     linux-kernel@...r.kernel.org, mbenes@...e.cz
Subject: Re: [PATCH 1/2] objtool: Optimize re-writing jump_label

On Thu, Oct 07, 2021 at 11:22:12PM +0200, Peter Zijlstra wrote:
> There's no point to re-write the jump_label NOP when it's already a NOP.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
> ---
>  tools/objtool/check.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -1397,7 +1397,7 @@ static int handle_jump_alt(struct objtoo
>  		return -1;
>  	}
>  
> -	if (special_alt->key_addend & 2) {
> +	if ((special_alt->key_addend & 2) && orig_insn->type != INSN_NOP) {
>  		struct reloc *reloc = insn_reloc(file, orig_insn);
>  
>  		if (reloc) {

While you're at it, a comment would be very helpful for that whole
clause.

-- 
Josh