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[81.2.115.148]) by smtp.gmail.com with ESMTPSA id l1sm3162649wrb.1.2020.11.06.09.11.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Nov 2020 09:11:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=QhdTsNE656tCSH0NDovdU3as+214FeSLljyeY/SGz5M=; b=X5nO/VDOGnJSTvMSrC9dJNpaAAh5GvemOQF6NG2wwUF6rcGcXDaY33lp+Lsnta0HI9 ttoDZnr4m/W0O9U8CiPmMTSW3OtzrJXiNRZiMhvOthGWoz6g9SMrIXuXaamg6hhCCB+F OBwIIPaqefmxEGwJHXPTrO9gQIQuo1/9PzdQtQku+uEWOG9dd5vel3mXj/AuqDKBG7aY nkRS+e9Hq8VT7TK1l/xPU7CybaylTFoIZvYM9+mGbiAhydlTbHGGy+ixMbb85sovPh+d H2Yt1eTKRmcc1iu5pGdiXpnUjKlLQ1z9CEhtrjqtUYp6jjpvJBnV+Hl1bwjIV8wZO14B P33g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=QhdTsNE656tCSH0NDovdU3as+214FeSLljyeY/SGz5M=; b=b94fZei8BtwB7vcg10LA6gAJNWIYqEjU4v5fKUvsbicgFEPD7CSrnwOUiyVBmiGK1U U/ScRN9+84rlCksrSJD2NlRgL1zJTGyaEO1hibb1+/5vS+5KcmOBxpLLnhckafR/X4tV bUTN4Q8ihSzDRCEzRq/75TLzHt1LUbWXQurpTKzsXW6pSOlBJ19rmkJvnG8OqbExqG50 zKcP8biDwLFpJGWIHV8Llv6BOtLNdw5+nG+op/qpHaxbwCjEyuiWj4lwja9hyzqjd7E7 FbYei9F2ZmAIWRomHkBxE5TakTLd506HCTGxYQ1yoxeyINa0IeqstJTw3fUy5k7oT9g7 E7Ng== X-Gm-Message-State: AOAM532/gjHPV7Xz8y4/69iMboggzZDjxTI9eNwKbeEAQDmNOWbPNSpX xHo6BnjdZNHpNs56XnWHqXIs3jA61BmUvg== X-Google-Smtp-Source: ABdhPJx6W0XmIxaopniDiBl5L3OD0tuUdW0BkeGt71ef2/tXefEfZ6kLSdIsKVacBRYfonC24ufROA== X-Received: by 2002:a05:600c:2048:: with SMTP id p8mr574200wmg.165.1604682718310; Fri, 06 Nov 2020 09:11:58 -0800 (PST) From: Peter Maydell To: qemu-devel@nongnu.org Subject: [PATCH for-5.2 2/4] hw/net/can/ctucan: Avoid unused value in ctucan_send_ready_buffers() Date: Fri, 6 Nov 2020 17:11:51 +0000 Message-Id: <20201106171153.32673-3-peter.maydell@linaro.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201106171153.32673-1-peter.maydell@linaro.org> References: <20201106171153.32673-1-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::341; envelope-from=peter.maydell@linaro.org; helo=mail-wm1-x341.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-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: Jason Wang , Vikram Garhwal , Pavel Pisa Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @linaro.org) Content-Type: text/plain; charset="utf-8" Coverity points out that in ctucan_send_ready_buffers() we set buff_st_mask =3D 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 --- hw/net/can/ctucan_core.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) diff --git a/hw/net/can/ctucan_core.c b/hw/net/can/ctucan_core.c index ea09bf71a0c..f2ce978e5ec 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; =20 if (!s->mode_settings.s.ena) { return; @@ -256,10 +254,7 @@ static void ctucan_send_ready_buffers(CtuCanCoreState = *s) for (i =3D 0; i < CTUCAN_CORE_TXBUF_NUM; i++) { uint32_t prio; =20 - buff_st_mask =3D 0xf << (i * 4); - buff_st =3D (s->tx_status.u32 >> (i * 4)) & 0xf; - - if (buff_st !=3D TXT_RDY) { + if (extract32(s->tx_status.u32, i * 4, 4) !=3D TXT_RDY) { continue; } prio =3D (s->tx_priority.u32 >> (i * 4)) & 0x7; @@ -271,10 +266,7 @@ static void ctucan_send_ready_buffers(CtuCanCoreState = *s) if (buff2tx_idx =3D=3D -1) { break; } - buff_st_mask =3D 0xf << (buff2tx_idx * 4); - buff_st =3D (s->tx_status.u32 >> (buff2tx_idx * 4)) & 0xf; int_stat.u32 =3D 0; - buff_st =3D TXT_RDY; pf =3D s->tx_buffer[buff2tx_idx].data; ctucan_buff2frame(pf, &frame); s->status.s.idle =3D 0; @@ -283,12 +275,11 @@ static void ctucan_send_ready_buffers(CtuCanCoreState= *s) s->status.s.idle =3D 1; s->status.s.txs =3D 0; s->tx_fr_ctr.s.tx_fr_ctr_val++; - buff_st =3D TXT_TOK; int_stat.s.txi =3D 1; int_stat.s.txbhci =3D 1; s->int_stat.u32 |=3D int_stat.u32 & ~s->int_mask.u32; - s->tx_status.u32 =3D (s->tx_status.u32 & ~buff_st_mask) | - (buff_st << (buff2tx_idx * 4)); + s->tx_status.u32 =3D deposit32(s->tx_status.u32, + buff2tx_idx * 4, 4, TXT_TOK); } while (1); } =20 --=20 2.20.1