From patchwork Fri Apr 5 11:27:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengguang Xu X-Patchwork-Id: 10887223 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1FB311390 for ; Fri, 5 Apr 2019 11:28:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0982F284D1 for ; Fri, 5 Apr 2019 11:28:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F18C928AF7; Fri, 5 Apr 2019 11:28:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 74C26284D1 for ; Fri, 5 Apr 2019 11:28:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730826AbfDEL2Q (ORCPT ); Fri, 5 Apr 2019 07:28:16 -0400 Received: from mout.gmx.net ([212.227.15.15]:58211 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730596AbfDEL2Q (ORCPT ); Fri, 5 Apr 2019 07:28:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1554463689; bh=jJrPSfQTr4No0lWk1eMDZc/F6tH0SR8gySoZ6VcA9iA=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date; b=FbaP232Q+xD7ON3kUuBCbKULxsqjfYQyq0OYfTqZoX1eDPskasikCUR/bNHu/zTIx A9M/H08jJbvBgT9J/8OuikUMNZQJnTpCiHTcHRZcmn1L8sreIcbxoDHZ5tV0wgwYS+ l5RSfNw0e7WEpr7Ep1dnsIdOt2geXgoOCI1GUApQ= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from localhost.localdomain ([218.18.229.179]) by mail.gmx.com (mrgmx003 [212.227.17.184]) with ESMTPSA (Nemesis) id 0Lvkwm-1grcaC1qsW-017UOQ; Fri, 05 Apr 2019 13:28:09 +0200 From: Chengguang Xu To: gregkh@linuxfoundation.org, dan.carpenter@oracle.com Cc: linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, Chengguang Xu Subject: [PATCH v3 1/4] chardev: add additional check for minor range overlap Date: Fri, 5 Apr 2019 19:27:08 +0800 Message-Id: <20190405112711.25275-1-cgxu519@gmx.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Provags-ID: V03:K1:GONALFeqSIXyNTeH1jhDtUDnupuHpBWfELLKFDqXg2amsQTebA1 GqgK2rz5ICW7+iQpPxUSrTMvoXywUv4XOHg6CYd3y8cALQxWMuvt7PZcDtodn9ZSEy4PwpY zHpYus/1josu+w4mu7R0LH2IP+BbepwAtDivrGs4MbD8034cWrussTEC1mPxvmT7ibQ0fzf MqRbBrAITfDioJrXVINgQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:CG3qgfyAqWs=:tn2eDjIBG2B4o4I6kO1VPx 4il5izmLvJdcR6rsWnqNTsbJHGJFqUompMTz9UcPXeX/IiAoOSYyZiCrmAnk+XsxvDJ3LrCzt CL7CBQhOFIIAlRw0yntPVUeuyxx3T9QMc+ds0yLuzWREKWAPhNyu3+p32JbG5JQHC56FAaw1g 4R/FNlImrfOZliODimsPp0fMhpHnmWvwdW5V0Y7/ABpcHWxFaGN71FCsO7MxauSo5vwM+4VyT 8Rw8CputfOeeWNCbDEBh7ixrfGbFFh00zdQMPiPLnA0H/HrWYdjr8qH7pID3Vk86HrGYaby8F i/JnHsblLgJ8O7mGzHF+RZ5y/I9/29k5MkNzj0HcP3fHEil92jVhQw0kuhQagfEVxFrtoY3vL AiZV684GKKjKCnVB+Igcf4JRPPUw8bx8BhmtD0QJY8hvNttGuNV491iaYM7ZfHzIYwy2PTcCv lo7VhguLTfYMr7ECatNWA2emyakccwQJhP5X7cQEvUg6d2KgfjB7kJ+tipX7EToBuFbFyQZj0 BaEL3X9PwES9DCM46ZKx8cRCFt3fUowfrAxptVSG6U4UvAvzEvHt9Hk7HYA2yIRPlxTrjWQY/ BjE+EThOwxDpNxHfUYG/2DU5XuSNVl28lCTKojpHmxOlX04sgckhZLxFqfsm9DXLvQDeITpNP 3jUBDuSypMc4/31NBswG2S9PoXSmaVCRqCl4WZDtXm4i5Y5j0qklmJgByCGZfWKPq24rU6Nog L/HdfuQcCbFOLk6InlHJDStzg/W7dGa5Zjg1zrTbetPZh/ljBOlKAnoeRFqACSWJ0ZOqiWQKX Ws+K5PDMR2n3rzNqd58h3NXzzCt8IZs3z1fVVUSzmxnqkcVCBKXXMNr6B0nl/RvMEL7TKY9qB iPh6hbqQ2Erp6exrwUo82qdMkGIZOzS60A8Bf7PMyEHzjK2qb21+o3z/XpkLiY Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Current overlap checking cannot correctly handle a case which is baseminor < existing baseminor && baseminor + minorct > existing baseminor + minorct. Signed-off-by: Chengguang Xu --- v1->v2: - Split fix and cleanup patches. - Remove printing minor range in chrdev_show(). fs/char_dev.c | 6 ++++++ 1 file changed, 6 insertions(+) -- 2.20.1 diff --git a/fs/char_dev.c b/fs/char_dev.c index a279c58fe360..8a63cfa29005 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -159,6 +159,12 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor, ret = -EBUSY; goto out; } + + if (new_min < old_min && new_max > old_max) { + ret = -EBUSY; + goto out; + } + } cd->next = *cp; From patchwork Fri Apr 5 11:27:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengguang Xu X-Patchwork-Id: 10887225 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4EC001575 for ; Fri, 5 Apr 2019 11:28:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 38098284D1 for ; Fri, 5 Apr 2019 11:28:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 29FCB28AF7; Fri, 5 Apr 2019 11:28:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CEB40284D1 for ; Fri, 5 Apr 2019 11:28:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730969AbfDEL22 (ORCPT ); Fri, 5 Apr 2019 07:28:28 -0400 Received: from mout.gmx.net ([212.227.15.15]:51463 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730596AbfDEL21 (ORCPT ); Fri, 5 Apr 2019 07:28:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1554463701; bh=eB0d8bRKJNF0pxzFQ4JOHuFwAynoXOaA1xLNFPODCXI=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=E1Wj+iroFgufGaXvd4NrlzfXzT1pIciGdMbjC5out3s/cSccrGL5dFlIinyjOnCEg 1A1Bue2WtD8VsqeaqniKqCFQjKYcePVAbYVl4FMnk85OMJMTfMrcrm9EolwcfAtUxX p2mE0fFrvjTdPx5X63NyrAXyoUW95Vb4gwu2nb3k= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from localhost.localdomain ([218.18.229.179]) by mail.gmx.com (mrgmx003 [212.227.17.184]) with ESMTPSA (Nemesis) id 0MOOdZ-1hFNgX2nMD-005sCx; Fri, 05 Apr 2019 13:28:21 +0200 From: Chengguang Xu To: gregkh@linuxfoundation.org, dan.carpenter@oracle.com Cc: linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, Chengguang Xu Subject: [PATCH v3 2/4] chardev: add a check for given minor range Date: Fri, 5 Apr 2019 19:27:09 +0800 Message-Id: <20190405112711.25275-2-cgxu519@gmx.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190405112711.25275-1-cgxu519@gmx.com> References: <20190405112711.25275-1-cgxu519@gmx.com> MIME-Version: 1.0 X-Provags-ID: V03:K1:v+vEPlB9H0WzUYD2hnP2dSErdbpgsgQzPhNb85qo3sHTlhAknv+ VW9D9Cy8y03hZl7Kh1q8TqMe7GotCD01nhyxmwAe1euSrFI+Lx8ATbZNKj3h+s7uQDuuApK L+KcImu1+ZSlOHW5HnBP8nWocOuUJiSH/vkwV8g1oJ6kuByk/odnVfQn5HpI/irMbmaxpu1 mPdsP8SwG9hi0kurhvVEQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:g7NsMmNeRao=:yUKwb0WqaCJXkQLJPwIqv+ KArAGSXQqurQnd00Gw88bin/XXyYp6snaHIIypxdIgqBJCn3OkLjfyTIR87NcXqRHDOyFymgj 3OuL5tS8+CS4w1piXg+FYc6cQohPIwKMeN7CHcd0J148LmQM5fL9sEwarrG1mS7dP7//+yK7W Gh9jvucZvtQ6SxnorlRuZ/ur9pfORJhSyZP4BcmOlsIOOshMkY35WdUPZjJ1widlES8g0n3c8 VornYq7Ik27zBfI9hTRDei5GK5+7+eN4UX0qUjUmOdCJ5+p4895JiFVu1X4psW3gzBo+K62W/ lVSpOhyWnxhTawuw9KzAvybXUdY44NDmdbJUvSkuA/5KgyMMjW1JxUfqIsq4t2xdgYoBBsKv6 z9kIJd7O5Wi4UCy5HmO0xsg8svHrTmznA97HKlQ3VPaKqMDXr+fm6X6dVeQvXNO/TLjiXtwTm NhQtgb1+2DTyNtoI+GvxmjVCwtfmnue0jWRNU9fxEqRQwBSfLTZthEj1qWZauuIidU8poYACW WJr/dLJ2g7vEIrcESGvn42c5pL94m6v6gnL6GXHX5OSJmGdVc/UxrKMlW5TvOYCt1xv3qaXdk xQvFruUUSIu60330rHHWmRwWNcJlWXvvPHN545D0wDgSu+ZjhWvPmv0GPi/ocntxutcag47ds QiX9N4QzgFAWAMh6TreLNjl7QN8v0ZyoTLwFG4zcLXDebgm+qG8C2okCiPIom8/pSQ/DU9uyw Wsd2SPT2CCb6I69V0XGadzrjepcoPK3h361FU9TEdM76WA9Rsi62TE9CjxzVTuEzfjjo1sUcw jSDrQXT3slK/MIDdFJGy+ERFor4jzwFjyUTHk90h7wDCuz3ZWHGfJksyuuu9YI1Ydwwu+87Lw ZDskLjYVRhTAgatqVs9nUUYgIFCMvtKexoDmqnUKWn1GaYP/njc45Q3pwCy6Or Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP register_chrdev_region() carefully checks minor range before calling __register_chrdev_region() but there is another path from alloc_chrdev_region() which does not check the range properly. So add a check for given minor range in __register_chrdev_region(). Signed-off-by: Chengguang Xu --- v1->v2: - Split fix and cleanup patches. - Remove printing minor range in chrdev_show(). fs/char_dev.c | 6 ++++++ 1 file changed, 6 insertions(+) -- 2.20.1 diff --git a/fs/char_dev.c b/fs/char_dev.c index 8a63cfa29005..6803e98414f1 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -104,6 +104,12 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor, int ret = 0; int i; + if (minorct > MINORMASK + 1 - baseminor) { + pr_err("CHRDEV \"%s\" minor range requested (%u-%u) is out of range of maximum range (%u-%u) for a single major\n", + name, baseminor, baseminor + minorct - 1, 0, MINORMASK); + return ERR_PTR(-EINVAL); + } + cd = kzalloc(sizeof(struct char_device_struct), GFP_KERNEL); if (cd == NULL) return ERR_PTR(-ENOMEM); From patchwork Fri Apr 5 11:27:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengguang Xu X-Patchwork-Id: 10887227 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0CDD71575 for ; Fri, 5 Apr 2019 11:28:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EBDF3284D1 for ; Fri, 5 Apr 2019 11:28:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E03AA28AF7; Fri, 5 Apr 2019 11:28:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7B429284D1 for ; Fri, 5 Apr 2019 11:28:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730777AbfDEL2h (ORCPT ); Fri, 5 Apr 2019 07:28:37 -0400 Received: from mout.gmx.net ([212.227.15.18]:43009 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730596AbfDEL2h (ORCPT ); Fri, 5 Apr 2019 07:28:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1554463710; bh=AcH2Y+kPjwVm0m0grrJWswjKGQxCRIPY8vyUMqtB6Ao=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=FK09yYeU3831ykwrE1BQLRjd3vlMlEadDnDfLut5O29xj8Ks0E1sAUl7MQgfzwt5R cdkXOJjrmnWkVeDsVLjXkXlVcmfALOjBS6k0Q/L+tNVoQ7JST436ZSOrHvtSe6irUj BZ8JuqBi9dsW1X8P2QwSOcMKpDCJY/jKIBGO/eiw= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from localhost.localdomain ([218.18.229.179]) by mail.gmx.com (mrgmx003 [212.227.17.184]) with ESMTPSA (Nemesis) id 0Ldq9D-1gTeDW3VcB-00j4a5; Fri, 05 Apr 2019 13:28:30 +0200 From: Chengguang Xu To: gregkh@linuxfoundation.org, dan.carpenter@oracle.com Cc: linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, Chengguang Xu Subject: [PATCH v3 3/4] chardev: code cleanup for __register_chrdev_region() Date: Fri, 5 Apr 2019 19:27:10 +0800 Message-Id: <20190405112711.25275-3-cgxu519@gmx.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190405112711.25275-1-cgxu519@gmx.com> References: <20190405112711.25275-1-cgxu519@gmx.com> MIME-Version: 1.0 X-Provags-ID: V03:K1:+L48v9102JFn0TemtK4d4YQMjLKPg1HDVNCjtB97oeRWPypJdPV QXO1inBw4D3obyDD2CykZccqFxEltIiCeE+wHaZmkyaNFBENsieqMMZMc/wl3qcx7cgJFep +CKlKCrr/oBQS8HH/cffCN2RnUed01j6KIiRreCSqO5B3jeAFxJV87zrVmE8r6hLZE9sdqv TZICcoI1wjp9Gd1GarfVA== X-UI-Out-Filterresults: notjunk:1;V03:K0:/N4BpP4YNFI=:e+bL/GRUE3t/jwRKdN2X5G G9vTYYeV2gsibcwDCziu7pRg8kXDKy6rp9yNJhu9Ywb+mvQLXub1GoEfO8vHz7GhynoDjVYOP il0wo2ULlbRt2MJNmEQjZ5s+6hgPsFcMqE9slosz2vB0jaDFc+ByaUkaXnvpzHj8rkGmGTTq5 wU0C1cjV9j3+HhjQs0CGDFMiVRjtZ/51lkWqgx5SVwAb90J/dx5+hNSssPdfXHW6fpHpqOKPt M4HZpr30kFFu0YYmVxTff+of1PyviynV7YAGjxOQBvDx6F9zb6gUvDSfPregGUou6dkPgQgo/ bVC5JECsLQzL/IzZolk6kMgaW1+JjfjdScqp3Qm03fxhPFdkIFxnJlkfOxEDzw9kBQkFtmBw7 1TOMIsJ+bpuc0DyH1/PfbsEVRAqMfelKAekh7cMqyYacu2Z7EDynm00+ACpxO5e283qizL8xU x/vuxfxctMRg/2cj71qIcerDccqQdvi0P014uu2i5AY9B1ql5ehaWAmOtztXbICU7u7goYnmK IWCAA3yasKmStBPIOUlL4yyEwNQPbL5+IrIwci1bVfAWkm3o46lIvrffRh9tRjeyDldIXJZAx hIIwek7vVroVbH1/oFGcH2ezvyF7V0kQCYiylxhcCYvUK6L+QTjn1H341qQIFrC8wCsUlC6FR NR5OnR3sRzM3Z7xDlLXIFXNecalvuVqD7kC6sVuDFlr8zymqGmb9OvS60qYEdJC+JS9vIInae qb6rRkrVTLBEGjXKrVa8+UY/PPHYOOVHqqhZkZekRIGcf3UBNWc4kdqMkFHJhLWaFXFpynjQu C7JFCfjuuYSAs5vohIgf+dqTI8BdUUbKTWPVpHUEL77aZHrsxMIep2NKbbiR7d/s7MXdq1mFe 3pQhNbeyRAFXKR5C9IPc65SYHIYLdnyRwQHFvlab9QrZa9Lw7eB2FvH6lEq537 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP It's just code cleanup, not functional change. Signed-off-by: Chengguang Xu --- v1->v2: - Split fix and cleanup patches. - Remove printing minor range in chrdev_show(). v2->v3: - Set variable ret to '-EBUSY' before checking minor range overlap. fs/char_dev.c | 70 +++++++++++++++++++++------------------------------ 1 file changed, 29 insertions(+), 41 deletions(-) -- 2.20.1 diff --git a/fs/char_dev.c b/fs/char_dev.c index 6803e98414f1..47fd0561b03d 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -100,10 +100,16 @@ static struct char_device_struct * __register_chrdev_region(unsigned int major, unsigned int baseminor, int minorct, const char *name) { - struct char_device_struct *cd, **cp; - int ret = 0; + struct char_device_struct *cd, *curr, *prev = NULL; + int ret; int i; + if (major >= CHRDEV_MAJOR_MAX) { + pr_err("CHRDEV \"%s\" major requested (%u) is greater than the maximum (%u)\n", + name, major, CHRDEV_MAJOR_MAX-1); + return ERR_PTR(-EINVAL); + } + if (minorct > MINORMASK + 1 - baseminor) { pr_err("CHRDEV \"%s\" minor range requested (%u-%u) is out of range of maximum range (%u-%u) for a single major\n", name, baseminor, baseminor + minorct - 1, 0, MINORMASK); @@ -126,55 +132,37 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor, major = ret; } - if (major >= CHRDEV_MAJOR_MAX) { - pr_err("CHRDEV \"%s\" major requested (%u) is greater than the maximum (%u)\n", - name, major, CHRDEV_MAJOR_MAX-1); - ret = -EINVAL; - goto out; - } - - cd->major = major; - cd->baseminor = baseminor; - cd->minorct = minorct; - strlcpy(cd->name, name, sizeof(cd->name)); - + ret = -EBUSY; i = major_to_index(major); + for (curr = chrdevs[i]; curr; prev = curr, curr = curr->next) { + if (curr->major < major) + continue; - for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next) - if ((*cp)->major > major || - ((*cp)->major == major && - (((*cp)->baseminor >= baseminor) || - ((*cp)->baseminor + (*cp)->minorct > baseminor)))) + if (curr->major > major) break; - /* Check for overlapping minor ranges. */ - if (*cp && (*cp)->major == major) { - int old_min = (*cp)->baseminor; - int old_max = (*cp)->baseminor + (*cp)->minorct - 1; - int new_min = baseminor; - int new_max = baseminor + minorct - 1; + if (curr->baseminor + curr->minorct <= baseminor) + continue; - /* New driver overlaps from the left. */ - if (new_max >= old_min && new_max <= old_max) { - ret = -EBUSY; - goto out; - } + if (curr->baseminor >= baseminor + minorct) + break; - /* New driver overlaps from the right. */ - if (new_min <= old_max && new_min >= old_min) { - ret = -EBUSY; - goto out; - } + goto out; + } - if (new_min < old_min && new_max > old_max) { - ret = -EBUSY; - goto out; - } + cd->major = major; + cd->baseminor = baseminor; + cd->minorct = minorct; + strlcpy(cd->name, name, sizeof(cd->name)); + if (!prev) { + cd->next = curr; + chrdevs[i] = cd; + } else { + cd->next = prev->next; + prev->next = cd; } - cd->next = *cp; - *cp = cd; mutex_unlock(&chrdevs_lock); return cd; out: From patchwork Fri Apr 5 11:27:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengguang Xu X-Patchwork-Id: 10887229 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E12F51390 for ; 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Fri, 5 Apr 2019 07:28:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1554463716; bh=6fHvPidcPyBfB2ec8H5GPO/3TGnHjppQPxknaY/Obas=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=OnAcZFp3hu62iK6UihzCMKP8bpXsumUQoQlHQUWqZk5HxMdw8tNHms1wStuWq0GVY jZv1mSYRbJjuPxzeUrGGTnKPU5PaWfZBeXDdkNV7Px/E75pwI38BRZ1B2O3uICdF78 FGQ+o2G3OLm1JxCpfbyQTPEud04/qhUw++mK4lKQ= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from localhost.localdomain ([218.18.229.179]) by mail.gmx.com (mrgmx003 [212.227.17.184]) with ESMTPSA (Nemesis) id 0MF4iR-1h9HYG2Rel-00GLXh; Fri, 05 Apr 2019 13:28:36 +0200 From: Chengguang Xu To: gregkh@linuxfoundation.org, dan.carpenter@oracle.com Cc: linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, Chengguang Xu Subject: [PATCH v3 4/4] chardev: update comment based on the code Date: Fri, 5 Apr 2019 19:27:11 +0800 Message-Id: <20190405112711.25275-4-cgxu519@gmx.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190405112711.25275-1-cgxu519@gmx.com> References: <20190405112711.25275-1-cgxu519@gmx.com> MIME-Version: 1.0 X-Provags-ID: V03:K1:MQAtPIdquU8vizTMTxMqZfkfBrCseOhtvEPbYX5jluClV/SBNhW 64goyVoxlTSbiJt67Nao/ASKpncHA/F/SlUSl0Oy3gW2kXZx79fXsLTMF+3Bf1W/WiAzkbi UUg7b5PeIRAWAP8QGXzzzO0xya6LXCjNKD26Sp6/yyo9BMB8Q2CwJqJ1JeSoHHB3mxUYKoc WIEGVQnqmi2BSzxNDnt0A== X-UI-Out-Filterresults: notjunk:1;V03:K0:3j62aQPKGJI=:BEXdWOzFINBZcgqY1MyNec 8k6o6fXHu97i808zRBOm+yOfMSexf/ydKTdReva3b92WECV/EMqrk+OH/JczOV31+J7SFGfD8 KI7MZMFY9FTkwa65cCjEVzs5merJ9hwBjcQi4PSxnZDY8DH1oeMNtxUSjTCU3USnK/RtTGobQ 8ue8Jo/JHHgI7FekoOu74U9y/fT5KzK4brIrcusLmCYWPlOG0S871El2WAVIq3kSI5d8n2lN6 sqdpnzUrZW5Ko5dx4iVj2YZ/hgBaBS011s9OUGEpNxke/CatmbYmxceXEWh3qF8urDOTFfHVY 0pXvlgycpF/fN29f8liNPZmkaovd5Gb0boBZkNRiEsitpJe2s0+zUQu9sC676rYI0z7UctS6a bPRX9RSpcmRrFndovQPEku/nMAVizWalhT9Y8nIK/n7P0MoQCHj90O4PCyKPDotsByovd9FBr K/IFXYwOQtq9FjEjFKDAgBw+TEotEdUzQOjlqL8RCrhfndrOqkzKcMQhoZT9WuSZ3VaAEFnnb 5ZtjC3zOC/zHsy1ILnXpxuZQ/HYPlHLCzTprThyJcxszFPIlinB9ANEtbwAWyYSN7mNLLkATR ehRkL0nu2G4naqdQuLJD0FQrw+DB5D+Jy0YotsJnPXwnSkgF7sgiZ2Jn4CHc6HqAQFeQ4xCX1 ylZc/w8LBb9vaDz3U1smSn3sLjJJSq05G/gupS7Qsp5jQT3ofNzxv0ukXgrcBAlZvHQzszt4w nm82S/x3Q9ob36GCuLGQl3kISae4N+Pn5tPaI50l2k7ijgHx1IVWpl2+LEaki/a4Hp65okij1 CEwKvfkUDwOnX97eqTD5K/a7+jHWKnnxolk9+mzvgYej91eIzsU9krWqgFHR5Gb+WHK3WYT/0 8pzgSoZMPTopmY4YWSats8abMCeHlSr/CFGFfmTbpP5DO8ZQ+cZ18mMlP+EVZp Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The function comment of __register_chrdev_region() is out of date, so update it based on the code. Signed-off-by: Chengguang Xu --- v1->v2: - Split fix and cleanup patches. - Remove printing minor range in chrdev_show(). fs/char_dev.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) -- 2.20.1 diff --git a/fs/char_dev.c b/fs/char_dev.c index 47fd0561b03d..00dfe17871ac 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -88,13 +88,10 @@ static int find_dynamic_major(void) /* * Register a single major with a specified minor range. * - * If major == 0 this functions will dynamically allocate a major and return - * its number. - * - * If major > 0 this function will attempt to reserve the passed range of - * minors and will return zero on success. + * If major == 0 this function will dynamically allocate an unused major. + * If major > 0 this function will attempt to reserve the range of minors + * with given major. * - * Returns a -ve errno on failure. */ static struct char_device_struct * __register_chrdev_region(unsigned int major, unsigned int baseminor,