From patchwork Tue Nov 10 21:52:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Pisa X-Patchwork-Id: 322891 Delivered-To: patch@linaro.org Received: by 2002:a05:6e02:5ce:0:0:0:0 with SMTP id l14csp593818ils; Tue, 10 Nov 2020 13:58:05 -0800 (PST) X-Google-Smtp-Source: ABdhPJwQNX8la5dW+YAJFYb9HFHzwL127qwozyirohulIBIW8aZueD9n15IStJ0REPGvKPVZIz4I X-Received: by 2002:a25:c6d5:: with SMTP id k204mr13524307ybf.363.1605045485598; Tue, 10 Nov 2020 13:58:05 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1605045485; cv=none; d=google.com; s=arc-20160816; b=qkDl/6fVbUr/aPDgqeAR19yFOp8hoIsZkZQNE+mpObKB4uQiyGv64wozM3yPZSbc8h 0a49YSh4hdctngoupZi2ca0A29dvRcBUx/D9GVF/mzH3LmPj+HLrzGyLHJ5t1huQWD/q NAGfvWb6o5FtlqqOQ90XVuHfPpWh7Bz5rcIm1z0Hx+gCHSvFW14KYl3JAX4NKtB181Lp eBM5Rf3yjKWfcJapolHYaS04ODCuy0tgYrZv+FSTvwO7aVZNrwJl3Qbb1DH01AB3RUWc 5WFwDU0DrP0HSoQNHm1BfF2Y4HBrdosNrNhnQa6eWUTv1LbQlL4WRjzCer6wiGf1oT/I TDpw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:cc:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:content-transfer-encoding :mime-version:references:in-reply-to:message-id:date:subject:to:from; bh=Idr2nK2RVq6MdGHXHJTt1bPBmEmi7zAbi4pKIQ/C3CE=; b=HLYm4P0YhQVUPQXNES6eGyDUK0p0ViU1MRmojuRHjNRrSGkUy3a4C9si8p/nj3EvNi S3lydyTxCG9jBYU4AWBO3DsCjSRJC+0CI311Pwj7g2DSANx7bb7Nrmtxs2laV9riol3t sFC6Zp/kGLS63VKpQGuwwzaKwZZ6meLUlz5aOv5OPFBfNMQ/pg8e1YKiAzzEg8plCvhu 6B+iJ7OSbCF31r0BlTp2qWRn4Kv0ufsGHMEVtUFk1rEgn/soE593GuHuLSE0an1zdSOx p9Flbk6Od2BaeGcxFUCXKUzKAbOJLbfgMO/z8diwSPfeTua3UFNXXkgsublRfLODKPUO Q5NQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org" Return-Path: Received: from lists.gnu.org (lists.gnu.org. [209.51.188.17]) by mx.google.com with ESMTPS id d31si48463ybi.184.2020.11.10.13.58.05 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 10 Nov 2020 13:58:05 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org" Received: from localhost ([::1]:57258 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kcbeO-0007kA-8X for patch@linaro.org; Tue, 10 Nov 2020 16:58:04 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34534) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kcbbG-0007im-9u for qemu-devel@nongnu.org; Tue, 10 Nov 2020 16:54:50 -0500 Received: from relay.felk.cvut.cz ([2001:718:2:1611:0:1:0:70]:14116) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kcbbB-0002cS-7N for qemu-devel@nongnu.org; Tue, 10 Nov 2020 16:54:50 -0500 Received: from cmp.felk.cvut.cz (haar.felk.cvut.cz [147.32.84.19]) by relay.felk.cvut.cz (8.15.2/8.15.2) with ESMTP id 0AALrblo095295; Tue, 10 Nov 2020 22:53:37 +0100 (CET) (envelope-from pisa@cmp.felk.cvut.cz) Received: from haar.felk.cvut.cz (localhost [127.0.0.1]) by cmp.felk.cvut.cz (8.14.0/8.12.3/SuSE Linux 0.6) with ESMTP id 0AALrbxs028066; Tue, 10 Nov 2020 22:53:37 +0100 Received: (from pisa@localhost) by haar.felk.cvut.cz (8.14.0/8.13.7/Submit) id 0AALraeB028065; Tue, 10 Nov 2020 22:53:36 +0100 From: Pavel Pisa To: qemu-devel@nongnu.org, Peter Maydell Subject: [PATCH for-5.2 v3 2/4] hw/net/can/ctucan: Avoid unused value in ctucan_send_ready_buffers() Date: Tue, 10 Nov 2020 22:52:48 +0100 Message-Id: <96562ba01919479f7f311050e914419ed3c2f194.1605044619.git.pisa@cmp.felk.cvut.cz> X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 X-FELK-MailScanner-Information: X-MailScanner-ID: 0AALrblo095295 X-FELK-MailScanner: Found to be clean X-FELK-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-0.099, required 6, BAYES_00 -0.50, KHOP_HELO_FCRDNS 0.40, SPF_HELO_NONE 0.00, SPF_NONE 0.00) X-FELK-MailScanner-From: pisa@cmp.felk.cvut.cz X-FELK-MailScanner-Watermark: 1605650019.10731@7y1gp9Ofs2U+1lucnbn/Qg Received-SPF: none client-ip=2001:718:2:1611:0:1:0:70; envelope-from=pisa@cmp.felk.cvut.cz; helo=relay.felk.cvut.cz X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/10 16:54:16 X-ACL-Warn: Detected OS = ??? X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pavel Pisa , Jason Wang , Vikram Garhwal , Ondrej Ille , =?utf-8?q?Jan_Charv=C3=A1t?= Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" From: Peter Maydell Coverity points out that in ctucan_send_ready_buffers() we set buff_st_mask = 0xf << (i * 4) inside the loop, but then we never use it before overwriting it later. The only thing we use the mask for is as part of the code that is inserting the new buff_st field into tx_status. That is more comprehensibly written using deposit32(), so do that and drop the mask variable entirely. We also update the buff_st local variable at multiple points during this function, but nothing can ever see these intermediate values, so just drop those, write the final TXT_TOK as a fixed constant value, and collapse the only remaining set/use of buff_st down into an extract32(). Fixes: Coverity CID 1432869 Signed-off-by: Peter Maydell Acked-by: Pavel Pisa Tested-by: Pavel Pisa --- hw/net/can/ctucan_core.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) -- 2.20.1 diff --git a/hw/net/can/ctucan_core.c b/hw/net/can/ctucan_core.c index 8486f429d7..f49c76261c 100644 --- a/hw/net/can/ctucan_core.c +++ b/hw/net/can/ctucan_core.c @@ -240,8 +240,6 @@ static void ctucan_send_ready_buffers(CtuCanCoreState *s) uint8_t *pf; int buff2tx_idx; uint32_t tx_prio_max; - unsigned int buff_st; - uint32_t buff_st_mask; if (!s->mode_settings.s.ena) { return; @@ -256,10 +254,7 @@ static void ctucan_send_ready_buffers(CtuCanCoreState *s) for (i = 0; i < CTUCAN_CORE_TXBUF_NUM; i++) { uint32_t prio; - buff_st_mask = 0xf << (i * 4); - buff_st = (s->tx_status.u32 >> (i * 4)) & 0xf; - - if (buff_st != TXT_RDY) { + if (extract32(s->tx_status.u32, i * 4, 4) != TXT_RDY) { continue; } prio = (s->tx_priority.u32 >> (i * 4)) & 0x7; @@ -271,10 +266,7 @@ static void ctucan_send_ready_buffers(CtuCanCoreState *s) if (buff2tx_idx == -1) { break; } - buff_st_mask = 0xf << (buff2tx_idx * 4); - buff_st = (s->tx_status.u32 >> (buff2tx_idx * 4)) & 0xf; int_stat.u32 = 0; - buff_st = TXT_RDY; pf = s->tx_buffer[buff2tx_idx].data; ctucan_buff2frame(pf, &frame); s->status.s.idle = 0; @@ -283,12 +275,11 @@ static void ctucan_send_ready_buffers(CtuCanCoreState *s) s->status.s.idle = 1; s->status.s.txs = 0; s->tx_fr_ctr.s.tx_fr_ctr_val++; - buff_st = TXT_TOK; int_stat.s.txi = 1; int_stat.s.txbhci = 1; s->int_stat.u32 |= int_stat.u32 & ~s->int_mask.u32; - s->tx_status.u32 = (s->tx_status.u32 & ~buff_st_mask) | - (buff_st << (buff2tx_idx * 4)); + s->tx_status.u32 = deposit32(s->tx_status.u32, + buff2tx_idx * 4, 4, TXT_TOK); } while (1); }