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Date:   Sat, 30 Jul 2022 09:20:06 +0800
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Subject: Re: [PATCH] tracing: Do PTR_ERR() after IS_ERR()
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To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org,
        yuzhe@nfschina.com, renyu@nfschina.com, jiaming@nfschina.com
References: <20220727153519.6697-1-liqiong@nfschina.com>
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From:   =?UTF-8?B?5p2O5Yqb55C8?= <liqiong@nfschina.com>
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在 2022/7/30 00:56, Steven Rostedt 写道:
> 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

I got it, Thanks.