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Date:   Fri, 29 Jul 2022 12:56:47 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     liqiong <liqiong@nfschina.com>
Cc:     Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org,
        yuzhe@nfschina.com, renyu@nfschina.com, jiaming@nfschina.com
Subject: Re: [PATCH] tracing: Do PTR_ERR() after IS_ERR()
Message-ID: <20220729125647.746379e5@rorschach.local.home>
In-Reply-To: <efce3a4c-4480-99f5-0229-a44009ebe9d8@nfschina.com>
References: <20220727153519.6697-1-liqiong@nfschina.com>
        <20220727122847.6b00e29d@rorschach.local.home>
        <efce3a4c-4480-99f5-0229-a44009ebe9d8@nfschina.com>
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On Thu, 28 Jul 2022 08:28:08 +0800
liqiong <liqiong@nfschina.com> wrote:

> It's all right, assign  PTR_ERR()  to 'ret'  anyway.
> But this assignment is valid only at the "IS_ERR()" path.
> Maybe it is better put "PTR_ERR()" at error path, keep the code clear.

No it does not. It adds unnecessary brackets.

It is common in the kernel to have:

	ret = ERROR;
	if (some_condition())
		goto out;

	ret = ERROR1;
	if (some_other_condition())
		goto out;

	ret = ERROR2;
	if (some_new_condition())
		goto out;

	ret = 0;
out:
	return ret;

And your change breaks this.

-- Steve