From patchwork Mon Jun 5 17:52:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 13267822 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3893FC7EE24 for ; Mon, 5 Jun 2023 17:53:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230374AbjFERxa (ORCPT ); Mon, 5 Jun 2023 13:53:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235187AbjFERx2 (ORCPT ); Mon, 5 Jun 2023 13:53:28 -0400 Received: from smtp11.infineon.com (smtp11.infineon.com [IPv6:2a00:18f0:1e00:4::5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B279100; Mon, 5 Jun 2023 10:53:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1685987607; x=1717523607; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=v9H0eyeHOdjewny8tzzedWjAUOkDdFz5OOsBgwYf/hM=; b=ln13UZZc9v+A3SRds2Y6QsIrFJxYaAQ9U9QlYLX31r2Oh5e2PVuKEx+r Wd655OUxB3/HBPeO96/eC/vG4DCbF4d3PTCXE0iXyPxM9gS1r7mMdvoRz J/VM4E9MrfPC04KPXaJF9hOrQhiML6c3EOazBvnBsJFKMS6ggVrtvtf0W I=; X-IronPort-AV: E=McAfee;i="6600,9927,10732"; a="17446197" X-IronPort-AV: E=Sophos;i="6.00,218,1681164000"; d="scan'208";a="17446197" Received: from unknown (HELO MUCSE814.infineon.com) ([172.23.29.40]) by smtp11.infineon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jun 2023 19:53:24 +0200 Received: from KLUSE818.infineon.com (172.28.156.171) by MUCSE814.infineon.com (172.23.29.40) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Mon, 5 Jun 2023 19:53:24 +0200 Received: from ISCNPC0VBFBX.infineon.com (10.161.6.196) by KLUSE818.infineon.com (172.28.156.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Mon, 5 Jun 2023 19:53:23 +0200 From: Alexander Steffen To: , , CC: Alexander Steffen Subject: [PATCH 1/4] tpm_tis: Explicitly check for error code Date: Mon, 5 Jun 2023 19:52:47 +0200 Message-ID: <20230605175250.2055-2-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.28.0.windows.1 In-Reply-To: <20230605175250.2055-1-Alexander.Steffen@infineon.com> References: <20230605175250.2055-1-Alexander.Steffen@infineon.com> MIME-Version: 1.0 X-Originating-IP: [10.161.6.196] X-ClientProxiedBy: MUCSE817.infineon.com (172.23.29.43) To KLUSE818.infineon.com (172.28.156.171) Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org recv_data either returns the number of received bytes, or a negative value representing an error code. Adding the return value directly to the total number of received bytes therefore looks a little weird, since it might add a negative error code to a sum of bytes. The following check for size < expected usually makes the function return ETIME in that case, so it does not cause too many problems in practice. But to make the code look cleaner and because the caller might still be interested in the original error code, explicitly check for the presence of an error code and pass that through. Change-Id: I5a310daaa71f0acaaf7fff62cadd79d5edaa9207 Signed-off-by: Alexander Steffen --- drivers/char/tpm/tpm_tis_core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 558144fa707a..aaaa136044ae 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -363,8 +363,13 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) goto out; } - size += recv_data(chip, &buf[TPM_HEADER_SIZE], - expected - TPM_HEADER_SIZE); + rc = recv_data(chip, &buf[TPM_HEADER_SIZE], + expected - TPM_HEADER_SIZE); + if (rc < 0) { + size = rc; + goto out; + } + size += rc; if (size < expected) { dev_err(&chip->dev, "Unable to read remainder of result\n"); size = -ETIME;