From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752343Ab2L0CGG (ORCPT ); Wed, 26 Dec 2012 21:06:06 -0500 Received: from mail-wi0-f177.google.com ([209.85.212.177]:64653 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752287Ab2L0CF7 (ORCPT ); Wed, 26 Dec 2012 21:05:59 -0500 From: Michal Nazarewicz To: David Rientjes Cc: Andrew Morton , Marek Szyprowski , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] cma: use unsigned type for count argument In-Reply-To: Organization: Google Inc References: <52fd3c7b677ff01f1cd6d54e38a567b463ec1294.1355938871.git.mina86@mina86.com> <20121220153525.97841100.akpm@linux-foundation.org> User-Agent: Notmuch/ (http://notmuchmail.org) Emacs/24.3.50.1 (x86_64-unknown-linux-gnu) X-Face: PbkBB1w#)bOqd`iCe"Ds{e+!C7`pkC9a|f)Qo^BMQvy\q5x3?vDQJeN(DS?|-^$uMti[3D*#^_Ts"pU$jBQLq~Ud6iNwAw_r_o_4]|JO?]}P_}Nc&"p#D(ZgUb4uCNPe7~a[DbPG0T~!&c.y$Ur,=N4RT>]dNpd;KFrfMCylc}gc??'U2j,!8%xdD Face: 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 X-PGP: 50751FF4 X-PGP-FP: AC1F 5F5C D418 88F8 CC84 5858 2060 4012 5075 1FF4 Date: Thu, 27 Dec 2012 03:05:49 +0100 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="=-=-=" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable > On Sat, 22 Dec 2012, Michal Nazarewicz wrote: >> So I think just adding the following, should be sufficient to make >> everyone happy: >>=20 >> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous= .c >> index e34e3e0..e91743b 100644 >> --- a/drivers/base/dma-contiguous.c >> +++ b/drivers/base/dma-contiguous.c >> @@ -320,7 +320,7 @@ struct page *dma_alloc_from_contiguous(struct device= *dev, unsigned int count, >> pr_debug("%s(cma %p, count %u, align %u)\n", __func__, (void *)cma, >> count, align); >>=20=20 >> - if (!count) >> + if (!count || count > INT_MAX) >> return NULL; >>=20=20 >> mask =3D (1 << align) - 1; > On Thu, Dec 27 2012, David Rientjes wrote: > How is this different than leaving the formal to have a signed type, i.e.= =20 > drop your patch, and testing for count <=3D 0 instead? Not much different I guess. I don't have strong opinions to be honest, except that I feel unsigned is the proper type to use, on top of which I think bitmap_set() should use unsigned, so in case anyone ever bothers to change it, CMA will be ready. :P --=20 Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=3D./ `o ..o | Computer Science, Micha=C5=82 =E2=80=9Cmina86=E2=80=9D Nazarewicz = (o o) ooo +------------------ooO--(_)--Ooo-- --=-=-= Content-Type: multipart/signed; boundary="==-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" --==-=-= Content-Type: text/plain --==-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJQ26z9AAoJECBgQBJQdR/0FLsP+wXrMoNqTvrzcm44rlE94pb9 J4dpiQH2rSHTWsR3xfdwmoupgrL2WnLb5PRz6tfvf69bdWRhlkmz5OTR1sld95Mi pB/bwmhdaSknDx8qufJCoaqTAlMD328RBktU8vvpSxZwQZJbqA2sod2lHT4La+aT 38mGGfIWhOHEKNZlgqm91DLOkwptHn0NPCs4udfEMC3lWiTfpp78KOeFM7OPeb4W GiiunyocX/Y2oez09X63JvFBVFopx0l3rtKbAKAiKW/QRnfgEsshDg/t4rWKnILY 3l+EZBTBsuYaWSaPcgtWZtu04fkOqVF6Dq8lrqw+HjfIvmh8x9X+M7srIwxhR773 rIENo0XVC6dbov0qvuMd9VlnMhQl1vf9n5UIFGTSnjIpY6rn8puOoXNHCUj8YahN ZMrQxzK7pdJ+yroW/3iaqDjgOyqdNE9sbJ34dM5bGW64cuTxsr5o8iiPD6Vj1oa1 ShY0Xx8V2+J2LQGRHUGIywXu2E499JbIQv/LLDPKm0SWLdANRrGn6TfcD0644Qp2 PM/2cff5xC7PfOxpLipeagJ/RuZRmxZsGcu2gfgXG4wUZJ2ej43qSBmqQQ1Q5hjv aXdqvgM5q0cHT/yjO2Oe0IwTjl4V1RTQJgrsGIzak3GnjVZaVYbcGcKmDU/gLVSK 3TRe56LEL6ILhJPJnxh2 =gJWR -----END PGP SIGNATURE----- --==-=-=-- --=-=-=--