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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED 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 9BD9EC433E0 for ; Tue, 2 Mar 2021 12:53:29 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2CD666186A for ; Tue, 2 Mar 2021 12:53:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CD666186A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9B79089DE6; Tue, 2 Mar 2021 12:53:28 +0000 (UTC) X-Greylist: delayed 5668 seconds by postgrey-1.36 at gabe; Tue, 02 Mar 2021 12:53:27 UTC Received: from userp2120.oracle.com (userp2120.oracle.com [156.151.31.85]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5FD4089DE6 for ; Tue, 2 Mar 2021 12:53:27 +0000 (UTC) Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 122BIwKM149510; Tue, 2 Mar 2021 11:18:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2020-01-29; bh=DueUpErQBDDiP8EnJhjLa7TSuQFS0AjMi3SC+jzYoWU=; b=SnaSJeM7WqXY+8WIw9LV+i04tFw+k2iBIEwW3HAUDPhXgIlQvMGottHG8WbAiKDPJQek //8p5Jo56bVE9JflZrE81dDk8DiK2FXzxm6JkpXJb7rQvCAHWJx2b6QfTLqshl91TLJ9 7ztD/AieHZjLwTJvpP/XyINkESCKl/YmCSBUnsn6bhQRV0aOWym0c3dtA1ad4yMjMAoJ eXtG5uBnhOYxqzTVO8XKoFVVo7Pjv4AIf86SB7vwcQC18GjS/f7fMrg6tAFVLPSQ9gUt YD3WngfnhqztiwR3gYRPaOn4YRSldj9MrWsdshWXDtp7UOIJNDR+IU1Z2SQIcJtUSLSV YQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 36yeqmy5d8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 Mar 2021 11:18:58 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 122BF2cT076174; Tue, 2 Mar 2021 11:18:57 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3020.oracle.com with ESMTP id 36yyyyqvd7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 Mar 2021 11:18:57 +0000 Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 122BItAJ006183; Tue, 2 Mar 2021 11:18:55 GMT Received: from mwanda (/102.36.221.92) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 02 Mar 2021 11:18:55 +0000 Date: Tue, 2 Mar 2021 14:18:48 +0300 From: Dan Carpenter To: matthew.auld@intel.com Message-ID: MIME-Version: 1.0 Content-Disposition: inline X-Proofpoint-IMR: 1 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9910 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxlogscore=999 phishscore=0 bulkscore=0 mlxscore=0 spamscore=0 suspectscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103020094 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9910 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 clxscore=1015 priorityscore=1501 mlxlogscore=999 suspectscore=0 malwarescore=0 impostorscore=0 bulkscore=0 adultscore=0 mlxscore=0 phishscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103020095 Subject: [Intel-gfx] [bug report] drm/i915: buddy allocator X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" [ Sorry, I don't know why Smatch is complaining about two year old code. The warning is valid enough, though. - dan ] Hello Matthew Auld, The patch 14d1b9a6247c: "drm/i915: buddy allocator" from Aug 9, 2019, leads to the following static checker warning: drivers/gpu/drm/i915/selftests/i915_buddy.c:169 igt_check_blocks() warn: variable dereferenced before check 'block' (see line 126) drivers/gpu/drm/i915/selftests/i915_buddy.c 111 static int igt_check_blocks(struct i915_buddy_mm *mm, 112 struct list_head *blocks, 113 u64 expected_size, 114 bool is_contiguous) 115 { 116 struct i915_buddy_block *block; 117 struct i915_buddy_block *prev; 118 u64 total; 119 int err = 0; 120 121 block = NULL; 122 prev = NULL; 123 total = 0; 124 125 list_for_each_entry(block, blocks, link) { ^^^^^ "block" is the list iterator so it can't be NULL. 126 err = igt_check_block(mm, block); 127 128 if (!i915_buddy_block_is_allocated(block)) { 129 pr_err("block not allocated\n"), 130 err = -EINVAL; 131 } 132 133 if (is_contiguous && prev) { 134 u64 prev_block_size; 135 u64 prev_offset; 136 u64 offset; 137 138 prev_offset = i915_buddy_block_offset(prev); 139 prev_block_size = i915_buddy_block_size(mm, prev); 140 offset = i915_buddy_block_offset(block); 141 142 if (offset != (prev_offset + prev_block_size)) { 143 pr_err("block offset mismatch\n"); 144 err = -EINVAL; 145 } 146 } 147 148 if (err) 149 break; 150 151 total += i915_buddy_block_size(mm, block); 152 prev = block; 153 } 154 155 if (!err) { 156 if (total != expected_size) { 157 pr_err("size mismatch, expected=%llx, found=%llx\n", 158 expected_size, total); 159 err = -EINVAL; 160 } 161 return err; 162 } 163 164 if (prev) { 165 pr_err("prev block, dump:\n"); 166 igt_dump_block(mm, prev); 167 } 168 169 if (block) { ^^^^^ This is impossible. It's not clear what was intended... 170 pr_err("bad block, dump:\n"); 171 igt_dump_block(mm, block); 172 } 173 174 return err; 175 } regards, dan carpenter _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx