From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8512DC4363A for ; Mon, 5 Oct 2020 09:51:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43C4120639 for ; Mon, 5 Oct 2020 09:51:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ulY7zWOi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725946AbgJEJvg (ORCPT ); Mon, 5 Oct 2020 05:51:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725887AbgJEJvg (ORCPT ); Mon, 5 Oct 2020 05:51:36 -0400 Received: from mail-ed1-x541.google.com (mail-ed1-x541.google.com [IPv6:2a00:1450:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F1A1C0613CE; Mon, 5 Oct 2020 02:51:36 -0700 (PDT) Received: by mail-ed1-x541.google.com with SMTP id b12so8564008edz.11; Mon, 05 Oct 2020 02:51:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=xVMDpuwSWx9cJIlM4tDMXRAB/KMvl7kDIIAKzdiSpb0=; b=ulY7zWOimlyfZyK6YnQOs4cmOYoADYddLaILjK5pufzyA382zlw9rdNAX+N/Pd7H1X sfKQuvCMKDvRdReB3myjSx/7m9OcGYZKTJM8qbB5kWKcKsvbV3Q/OIdaUgUBVf6GPgrH QZewG+v46kGHkOvRzctMTv1Qq0i3KqOo1dgLJql//ClV7OI06UJSBYqYaVbLzdumeRAo luod2TT0oee/DTHpVwf6bKcUZpR7UtCKceoXtkZXSaB4fmtTsP8VpJSpqeC4kVSltyja ANR9ooc77082cj4prqPq6KKkZWMYmWCiukGuaPOnevPY3oaAj/z547w6uBiobxnMq52c Km+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=xVMDpuwSWx9cJIlM4tDMXRAB/KMvl7kDIIAKzdiSpb0=; b=WSMNL3IOKcFPKzsNhseaSiBaD/xj97gK4S+72K1dgn3DzBJNa6JSQesJeleey8VN9K Glb/entdZju66YP8VQURkfoFxBnDl1FHYlulbyjR+zsBkLAxTJ+xxpwUznP5t1mFqQ4n A7m9sgCkUDp3mFk0MOGSSphv75UOi93ZXwurDgqWJkLIxClxmM0PXjELh4H5ZCz36fHV 4KqxnKshsDCcH6Ba8x/yypRrIvfiOB32mx3e9vZSv3pgxq4MkpLVAHCFFBQuVEe422zB m1dimwq3N49r3OjjR/oyaw44u7XjCEOtjuQCwF9lyToL5MO/WEqqZqWiUIsSbY3Gj4CF U9DA== X-Gm-Message-State: AOAM533wh9zAeMpfm+WfUslrB5zieyYbye80HZCNPrXBjFcB0Pa1Ixra qUo0enUQy0OYGdNMTknOrFU= X-Google-Smtp-Source: ABdhPJzBrcM6KDwh5g5wHr/FHftugh84YRErwAwekwNfMW9hAWTj3dDVrLQQ44bVLCxmS+IBaZaP3Q== X-Received: by 2002:a05:6402:b68:: with SMTP id cb8mr16580359edb.350.1601891494997; Mon, 05 Oct 2020 02:51:34 -0700 (PDT) Received: from localhost ([217.111.27.204]) by smtp.gmail.com with ESMTPSA id k18sm7758003ejk.42.2020.10.05.02.51.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Oct 2020 02:51:33 -0700 (PDT) Date: Mon, 5 Oct 2020 11:51:32 +0200 From: Thierry Reding To: Dmitry Osipenko Cc: Nicolin Chen , joro@8bytes.org, vdumpa@nvidia.com, jonathanh@nvidia.com, linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 2/3] iommu/tegra-smmu: Rework tegra_smmu_probe_device() Message-ID: <20201005095132.GH425362@ulmo> References: <20201002060807.32138-1-nicoleotsuka@gmail.com> <20201002060807.32138-3-nicoleotsuka@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="a8sldprk+5E/pDEv" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.14.7 (2020-08-29) Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org --a8sldprk+5E/pDEv Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 02, 2020 at 05:22:41PM +0300, Dmitry Osipenko wrote: > 02.10.2020 09:08, Nicolin Chen =D0=BF=D0=B8=D1=88=D0=B5=D1=82: > > static int tegra_smmu_of_xlate(struct device *dev, > > struct of_phandle_args *args) > > { > > + struct platform_device *iommu_pdev =3D of_find_device_by_node(args->n= p); > > + struct tegra_mc *mc =3D platform_get_drvdata(iommu_pdev); > > u32 id =3D args->args[0]; > > =20 > > + of_node_put(args->np); > > + > > + if (!mc || !mc->smmu) > > + return -EPROBE_DEFER; >=20 > platform_get_drvdata(NULL) will crash. >=20 > > + dev_iommu_priv_set(dev, mc->smmu); >=20 > I think put_device(mc->dev) is missed here, doesn't it? Yeah, I think we'd need that here, otherwise we'd be leaking a reference. Worse, even, mc->dev is the same device that owns the SMMU, so we're basically incrementing our own reference here and never releasing it. We also need that put_device(mc->dev) in the error case above because we already hold the reference there. Thierry --a8sldprk+5E/pDEv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAl967KQACgkQ3SOs138+ s6EZ4w//XClEGoJOj1S9ALPjYnZ7yQN7pBPfwPv2qNVwYwkSXvNIRhLa4AfazRm5 DCJCelfgkYONrrtuxyUSzatdpBNFuRFVKDUy3cBuZd/yXaDg83AXc3LWR99jKcNZ LWuszo33+o7JSwz2rlGBfOWG/pEIZ3ffkENDhsIFbuff0dyIpHcB6t4Bk9Oucaag cbQhJkfVYZXBbuz0qolfVkoxzbsYJ+HkWyYR6C2iFa46W4ed/uPAWj8y12nAJhMk rEazHONfPq5T2kup+r5rLMJgt+jCZ7ofsuR+PK7g5S6FIxyF4S3QTFmRvh7uFBSs JsmPElXPTcPFhM70fLvN/HkZjsGyJiLGfRHfcvuibqozGdTGY58ImpNFBrINRUGR AwralPobbGBG+ER7MctmIENYcAODTJLAldodbOcrx7wGWESwsdBg2Vp2Uzn9iI8X IGqtswrhSCZR2dJv6cykZwj6zFrpFWAuKAXZTGSO8qIxIV7QX1Y+CYm0nDg3iwek KEJJAtwuhgNQ/g15SBn9Sq8JqUPZ+0e5TCoO/YyyOalvisC2nWb3IJYsXy+24sz2 lBpXygBpxuv+wQNRmU3cEWlwOgekaSuWXMoHGV0/i70llsuX5UWrO+rXVAReM9k6 4NUFGUgNQGBNygabucLpAatMEcFal1rF72zXio8eFig0ooLWimA= =ny5U -----END PGP SIGNATURE----- --a8sldprk+5E/pDEv--