From patchwork Mon Jul 6 13:08:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 11645733 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A529B13B4 for ; Mon, 6 Jul 2020 13:08:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96EFB2073E for ; Mon, 6 Jul 2020 13:08:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729225AbgGFNIY (ORCPT ); Mon, 6 Jul 2020 09:08:24 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:55582 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728940AbgGFNIY (ORCPT ); Mon, 6 Jul 2020 09:08:24 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jsQr6-0006d5-KC; Mon, 06 Jul 2020 13:08:20 +0000 From: Colin King To: James Smart , Dick Kennedy , "James E . J . Bottomley" , "Martin K . Petersen" , linux-scsi@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][next] scsi: lpfc: fix less than zero comparison on unsigned int computation Date: Mon, 6 Jul 2020 14:08:20 +0100 Message-Id: <20200706130820.487271-1-colin.king@canonical.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Colin Ian King The expressions start_idx - dbg_cnt is evaluated using unsigned int arthithmetic (since these variables are unsigned ints) and hence can never be less than zero, so the less than comparison is never true. Re-write the expression to check for start_idx being less than dbg_cnt. Addresses-Coverity: ("Unsigned compared against 0") Fixes: 372c187b8a70 ("scsi: lpfc: Add an internal trace log buffer") Signed-off-by: Colin Ian King --- drivers/scsi/lpfc/lpfc_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c index 7285b0114837..ce5afe7b11d0 100644 --- a/drivers/scsi/lpfc/lpfc_init.c +++ b/drivers/scsi/lpfc/lpfc_init.c @@ -14152,7 +14152,7 @@ void lpfc_dmp_dbg(struct lpfc_hba *phba) if ((start_idx + dbg_cnt) > (DBG_LOG_SZ - 1)) { temp_idx = (start_idx + dbg_cnt) % DBG_LOG_SZ; } else { - if ((start_idx - dbg_cnt) < 0) { + if (start_idx < dbg_cnt) { start_idx = DBG_LOG_SZ - (dbg_cnt - start_idx); temp_idx = 0; } else {