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Date:   Tue, 16 Oct 2018 19:06:51 +0100
From:   Al Viro <viro@ZenIV.linux.org.uk>
To:     Alessandro Rubini <rubini@gnudd.com>
Cc:     uwe@kleine-koenig.org, gregkh@linuxfoundation.org, corbet@lwn.net,
        linux-kernel@vger.kernel.org, thierry.reding@gmail.com,
        Michal.Vokac@ysoft.com, akpm@linux-foundation.org,
        kernel@pengutronix.de
Subject: Re: [PATCH RFC] err.h: document that PTR_ERR should only be used if
 IS_ERR returns true
Message-ID: <20181016180650.GZ32577@ZenIV.linux.org.uk>
References: <20181014202807.16412-1-uwe@kleine-koenig.org>
 <20181015093708.GA22876@mail.gnudd.com>
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On Mon, Oct 15, 2018 at 11:37:08AM +0200, Alessandro Rubini wrote:

> OTOH I admit you can compare any value with -EINVAL, after PTR_ERR.
> But in general you first detect the error condition and then split
> among error (or print a message according to the exact value.

	if (IS_ERR(p) && PTR_ERR(p) == -ENOENT)
instead of
	if (p == ERR_PTR(-ENOENT))

is ugly, obfuscating what's going on for no good reason and I'm going
to keep killing those every time I run into one...