From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Date: Fri, 16 Jun 2017 22:44:37 +0000 Subject: endian bitshift defects [ was: staging: fusb302: don't bitshift __le16 type ] Message-Id: <1497653077.10546.23.camel@perches.com> List-Id: References: <20170616174556.2358-1-fransklaver@gmail.com> In-Reply-To: <20170616174556.2358-1-fransklaver@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Frans Klaver , Greg Kroah-Hartman , kernel-janitors Cc: Guenter Roeck , Yueyao Zhu , Rui Miguel Silva , Guru Das Srinagesh , Javier Martinez Canillas , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org On Fri, 2017-06-16 at 19:45 +0200, Frans Klaver wrote: > The header field in struct pd_message is declared as an __le16 type. The > data in the message is supposed to be little endian. This means we don't > have to go and shift the individual bytes into position when we're > filling the buffer, we can just copy the contents right away. As an > added benefit we don't get fishy results on big endian systems anymore. Thanks for pointing this out. There are several instances of this class of error. Here's a cocci script to find them. This is best used with cocci's --all-includes option like: $ spatch --all-includes --very-quiet --sp-file lebe_bitshifts.cocci . [ many defects...] $ cat lebe_bitshifts.cocci @@ typedef __le16, __le32, __le64,=A0=A0__be16, __be32, __be64; { __le16, __le32, __le64,=A0=A0__be16, __be32, __be64 } a; expression b; @@ * a << b @@ { __le16, __le32, __le64,=A0=A0__be16, __be32, __be64 } a; expression b; @@ * a <<=3D b @@ { __le16, __le32, __le64,=A0=A0__be16, __be32, __be64 } a; expression b; @@ * a >> b @@ { __le16, __le32, __le64,=A0=A0__be16, __be32, __be64 } a; expression b; @@ * a >>=3D b $ -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html