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=-0.4 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,T_DKIM_INVALID autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 0D9D2C5CFC0 for ; Thu, 14 Jun 2018 23:35:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF4AD208B5 for ; Thu, 14 Jun 2018 23:35:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Lpd0b2j8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF4AD208B5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965155AbeFNXfH (ORCPT ); Thu, 14 Jun 2018 19:35:07 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:34339 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965056AbeFNXfF (ORCPT ); Thu, 14 Jun 2018 19:35:05 -0400 Received: by mail-pg0-f67.google.com with SMTP id q4-v6so3611221pgr.1 for ; Thu, 14 Jun 2018 16:35:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=QQNKtzgcetzD86rnRxV18V5fUo1RGn/dAr7kXklW984=; b=Lpd0b2j8lZ+cdOP+mO8pAvySQGlkOIr1Icdq5z1bYR6bavhGNUfothWV9No3jQGY2x JqA5NKln0ejaa6WxJPygaGrQIW1W/PQvUALoGww+45+RC8OyQDr0tEUkuhAA6yMkWpIo bfss6fpT1sdEwSdCbSIgqfGv7Il3i68DKsBkUSJf5jwHLfV7hYESVeNJynsJJVfC6yxM Ezf3Trtl02OVHu+TTQcfC42oQJILMJAk/f5NLr7VolQBs2Q5eqO3lptu3RctNAiuSIWa evPHRsDDjibdECqUMVpiUgfpDvGaADAbLVHbICRGEKpDhAUbjcmhWCUWg7FX9plBTF9s j9PQ== 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; bh=QQNKtzgcetzD86rnRxV18V5fUo1RGn/dAr7kXklW984=; b=baecebo0NxQz85XGr55xh/k3F/xeDIZGN9CDGrfcG8SgA+uWVU66TYE8L8iTrZCPaa O1LDnSlaMdLBbHbymT7mOGqNnucCtSZr3YHEyaZV/aeGrqfRltH3nlEOVSO13FzCaSsF 0bur/h5JGbyjfM1SHR8G5bFw43vlcz5Ky1humgapIbXSoRelOSjdwUow+6bA5QtMvzGd HI813NydBBV8HwQnko69xYmQlt3oLLUHJLfqiYhK7Bt2Jfqn8FPPn8BGV8tG4gwvxyb+ XIcoeBrcO0dIg9+Dkse2ELcmXGS0HvBzcasTnsXV9np4p42y/vfac3vBDZuFrXchYFwt OsWw== X-Gm-Message-State: APt69E3rPS0qMyNW+RN/uIRFpcJ0eOLZcIMDHkqKO2OEHdyF73p+BSbr ZfmfIdMyqIAlDPTXjHJBuDg= X-Google-Smtp-Source: ADUXVKLuRoNPyPsfZzB73ax2akzAGYBa2Iv1JLEL5wCLOhjbb6HlYvJFAViI2czhkW3l9eLkjo0YNg== X-Received: by 2002:a65:6147:: with SMTP id o7-v6mr4025702pgv.163.1529019305540; Thu, 14 Jun 2018 16:35:05 -0700 (PDT) Received: from localhost ([103.88.46.82]) by smtp.gmail.com with ESMTPSA id l11-v6sm6840491pff.50.2018.06.14.16.35.03 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Jun 2018 16:35:05 -0700 (PDT) From: Zhouyang Jia Cc: Zhouyang Jia , Boris Ostrovsky , Juergen Gross , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] xen: add error handling for xenbus_printf Date: Fri, 15 Jun 2018 07:34:52 +0800 Message-Id: <1529019293-55493-1-git-send-email-jiazhouyang09@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1528775073-39322-1-git-send-email-jiazhouyang09@gmail.com> References: <1528775073-39322-1-git-send-email-jiazhouyang09@gmail.com> To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When xenbus_printf fails, the lack of error-handling code may cause unexpected results. This patch adds error-handling code after calling xenbus_printf. Signed-off-by: Zhouyang Jia --- v1->v2: - Add __func__. --- drivers/xen/manage.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 8835065..c93d8ef 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -289,8 +289,15 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path, return; } - if (sysrq_key != '\0') - xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); + if (sysrq_key != '\0') { + err = xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); + if (err) { + pr_err("%s: Error %d writing sysrq in control/sysrq\n", + __func__, err); + xenbus_transaction_end(xbt, 1); + return; + } + } err = xenbus_transaction_end(xbt, 0); if (err == -EAGAIN) @@ -342,7 +349,12 @@ static int setup_shutdown_watcher(void) continue; snprintf(node, FEATURE_PATH_SIZE, "feature-%s", shutdown_handlers[idx].command); - xenbus_printf(XBT_NIL, "control", node, "%u", 1); + err = xenbus_printf(XBT_NIL, "control", node, "%u", 1); + if (err) { + pr_err("%s: Error %d writing %s\n", __func__, + err, node); + return err; + } } return 0; -- 2.7.4