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Message-ID: <1449360735.20344.6.camel@perches.com>
Subject: Re: [PATCH] staging: speakup: kobjects.c: fix char argument to %02x
From: Joe Perches <joe@perches.com>
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        William Hubbs <w.d.hubbs@gmail.com>,
        Chris Brannon <chris@the-brannons.com>, Kirk Reiser <kirk@reisers.ca>,
        Samuel Thibault <samuel.thibault@ens-lyon.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: speakup@linux-speakup.org, devel@driverdev.osuosl.org,
        linux-kernel@vger.kernel.org
Date: Sat, 05 Dec 2015 16:12:15 -0800
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References: <1449360347-20089-1-git-send-email-linux@rasmusvillemoes.dk>
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On Sun, 2015-12-06 at 01:05 +0100, Rasmus Villemoes wrote:
> If char is signed and ch happens to be negative, printing ch with
> "%02x" will not do as intended (when ch is -19, one will get
> "ffffffed"). Fix that by masking with 0xff.

I presume there are a lot of these in the kernel.
Did you use a tool to find this or just inspection?