From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752450AbdHPQQD (ORCPT ); Wed, 16 Aug 2017 12:16:03 -0400 Received: from mout.web.de ([212.227.17.11]:62294 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751695AbdHPQQC (ORCPT ); Wed, 16 Aug 2017 12:16:02 -0400 Subject: [PATCH 2/2] fs-qnx6: Less checks in qnx6_mmi_fill_super() after error detection From: SF Markus Elfring To: Fabian Frederick , Kai Bankett , kernel-janitors@vger.kernel.org Cc: LKML References: <55b824fd-3f8a-4ca6-583f-27f584cd237a@users.sourceforge.net> Message-ID: <44582469-f671-267a-0a60-cbe50fd16b51@users.sourceforge.net> Date: Wed, 16 Aug 2017 18:15:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <55b824fd-3f8a-4ca6-583f-27f584cd237a@users.sourceforge.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:9LY+nxcJOTUNHlMUwnm9Jt5WI7SShlS40D2eXsxJJQTUP1jq+k5 GCXjEdGnkN/MaXMVrq1s0ESp9Rnoblyuz2M/9LaPNmcstoMnyJsus0LbutxPkA3G6Ye09IC +tZm9BysliLsbBCewr+PcrBulpNz/P9uSOsPyeJgxWHRN394nUp68L15uZISv8qZi9uPcJq ojiTYlwyWdzwK9RssXmnw== X-UI-Out-Filterresults: notjunk:1;V01:K0:0AjTdi8KXxU=:tETqY0CMDxJc1QBK6lYhx9 Y3ny0f1jIG3rJU1nZUWxFcXk6YAZQrLhh4/FDz1GZBTizwkPM0PZNTN/+6/n07ppo28BxVolF Ztge6EOEp2Yq4MYY9r4boHDC2LLewJnfrY/buGkGCcwRVt3NIQwJUYIKQXHQ90k6I1ePhvphs /WoEWHnQY3I3EttujNZVAmKEw0uiIXPNTSrjXW9ybNFBIrmuoRE14XTxbbVqJF9b/VbrkFMbl r7ZuXkM0m0sbBwx6w2/4pZ6In07vChj7C+IlgIBom/zUKes4Et4QK91UYOlC0hAH7kBzymwbm CIiPKcjZJeagbjO4laSxoMx4YAm/Qw0ODd3A378MNqdGid7hppD5SKr+8FdtShFIL71sODAF7 6LhpwX9L9O0HEUZo2c2tDnL/+gQQ93PpxPmp6kR/8z5suuUbqbojbcI4UIg1ILlsX9GihQ++Q vlHbS9lHLoMZ4KAinyh2U1UifiqWL/s2wXyb1rbspekqSWt5DkVhv9y5GhQwi/0HcNF2BCyGj e7EyscLUela2QVJFp1PvPxWnWkVjkO3ayiQf2uwuZ9fip80KEf9l7gPfe4Ib3NR6TrbFt0uQq rwmv4O/KvMrcvEiyhIKKoS7K/qIlh5XkU2u8AvOeNjyoyH+V9KlJkL/JpQBaopD+vtqpta7pl +maiE8E0mo7l5IN1Rk75vPxVm5I+s2RF7UBl1VVovBjALlVJ+M1M1iEmV1RAhBQS2E14aM3FD 448Fk3lG6SmszaKe46MBYE36Ta4yMvXwevCkqeMm4BjHbYPe9gfBTpbrExXTvs5Gh5fA8SVqY FTpy+eqgVI0nMGKZfS3EZGpdlTdMjFiVJFTNdmGg1oHmB1daIk= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Markus Elfring Date: Wed, 16 Aug 2017 18:00:24 +0200 Two pointer checks could be repeated by the qnx6_mmi_fill_super() function during error handling even if the relevant properties can be determined for the involved variables before by source code analysis. * Adjust jump targets so that extra checks can be omitted at the end. * Delete an initialisation for the variables "bh2" and "qsb" which became unnecessary with this refactoring. Signed-off-by: Markus Elfring --- fs/qnx6/super_mmi.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/fs/qnx6/super_mmi.c b/fs/qnx6/super_mmi.c index fdcfc99e2db6..eb98479f9ec1 100644 --- a/fs/qnx6/super_mmi.c +++ b/fs/qnx6/super_mmi.c @@ -34,9 +34,9 @@ static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb, struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) { - struct buffer_head *bh1, *bh2 = NULL; + struct buffer_head *bh1, *bh2; struct qnx6_mmi_super_block *sb1, *sb2; - struct qnx6_super_block *qsb = NULL; + struct qnx6_super_block *qsb; struct qnx6_sb_info *sbi; __u64 offset; @@ -52,7 +52,7 @@ struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) if (fs32_to_cpu(sbi, sb1->sb_magic) != QNX6_SUPER_MAGIC) { if (!silent) { pr_err("wrong signature (magic) in superblock #1.\n"); - goto out; + goto brelse_first; } } @@ -60,7 +60,7 @@ struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) if (fs32_to_cpu(sbi, sb1->sb_checksum) != crc32_be(0, (char *)(bh1->b_data + 8), 504)) { pr_err("superblock #1 checksum error\n"); - goto out; + goto brelse_first; } /* calculate second superblock blocknumber */ @@ -70,38 +70,38 @@ struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) /* set new blocksize */ if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) { pr_err("unable to set blocksize\n"); - goto out; + goto brelse_first; } /* blocksize invalidates bh - pull it back in */ brelse(bh1); bh1 = sb_bread(s, 0); if (!bh1) - goto out; + goto exit; sb1 = (struct qnx6_mmi_super_block *)bh1->b_data; /* read second superblock */ bh2 = sb_bread(s, offset); if (!bh2) { pr_err("unable to read the second superblock\n"); - goto out; + goto brelse_first; } sb2 = (struct qnx6_mmi_super_block *)bh2->b_data; if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) { if (!silent) pr_err("wrong signature (magic) in superblock #2.\n"); - goto out; + goto brelse_second; } /* checksum check - start at byte 8 and end at byte 512 */ if (fs32_to_cpu(sbi, sb2->sb_checksum) != crc32_be(0, (char *)(bh2->b_data + 8), 504)) { pr_err("superblock #1 checksum error\n"); - goto out; + goto brelse_second; } qsb = kmalloc(sizeof(*qsb), GFP_KERNEL); if (!qsb) - goto out; + goto brelse_second; if (fs64_to_cpu(sbi, sb1->sb_serial) > fs64_to_cpu(sbi, sb2->sb_serial)) { @@ -136,11 +136,10 @@ struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent) /* success */ return sbi->sb; - -out: - if (bh1 != NULL) - brelse(bh1); - if (bh2 != NULL) - brelse(bh2); +brelse_second: + brelse(bh2); +brelse_first: + brelse(bh1); +exit: return NULL; } -- 2.14.0