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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13B7FC3279B for ; Mon, 2 Jul 2018 09:17:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C110A25BD5 for ; Mon, 2 Jul 2018 09:17:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oilNGHhV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C110A25BD5 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 S965152AbeGBJRi (ORCPT ); Mon, 2 Jul 2018 05:17:38 -0400 Received: from mail-pg0-f66.google.com ([74.125.83.66]:34476 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965065AbeGBJRC (ORCPT ); Mon, 2 Jul 2018 05:17:02 -0400 Received: by mail-pg0-f66.google.com with SMTP id y5-v6so589747pgv.1; Mon, 02 Jul 2018 02:17:02 -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=EQVId5BaxXTT+wTsMq+BhzFviOhh7WwA7pQZIcCrrpA=; b=oilNGHhVBtMrAOyB1Z9OhOw454sWnzJ6XbWQrnKc6L33huvhOWJBPW4mzZyOTubFIM SApfEM3iFi2VHzhr2n2HNqYnnbEVbNoVhl6hTpSeBw50PQkyWbyXGMEbhLcOBL41DYp0 v+iN1A3dp5AWMnRvn+oGwF1CWiJDvC9JcYHscnAaVEM+SWwT0E+VMPtbRR6K21yPoglb KPOVLXfh8+IhEsgd8F8zosK+A3Zma8G8ypRBLoGzD53TUM9SNW/JomAnPTuzoduN2Oy1 6WMPegk82jAHA/qEPB0iMmeJNKrVxvALKsnV/JWXxof34EhwU8pCc+igPJBbX6/I+QuC cfKg== 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=EQVId5BaxXTT+wTsMq+BhzFviOhh7WwA7pQZIcCrrpA=; b=kBywvG8hqlL9nlvLzqqBfHV35GzePyYgVvamTsyN7FjdqPJCYS0I2JXLhwLo71PtJr K7wXXj03P0lX6qQDz83BME47sR0NyflZRZSrHZ61VawKHKPvnUirH9VcCxPThzsGT8nF Az54Fadc34GzVtT0kXp2DdSCwp9xBDhmxiI5JpoOU8ev3I6HRc+lbc1WUHA034Yxhpzt MQWEreHFEz3bjbsd2EwI/hzx1sc6rEhJZDSUzgcLTNqoTQzSwAGNg7qvoKGk6m0PBSKj 8cctaN5lzF8stEJc1VhA62lAEudInHjQSX3JI0mvYq28OIEtmWVvUNWnmChIeBk3k2QJ MADQ== X-Gm-Message-State: APt69E1tG/8kJMTy6x1w4PRHtFD0fr7eNVv8rVas/AoG5AY7/zAeRL/1 mjhKiYVpEu78Jaif/oOmsyB4gQ== X-Google-Smtp-Source: AAOMgpdFZn4IpLgyriMGm2PXlusTJksmZBi+sDKf3Bgxz1eowYa0P+lzKS5WGL+7dReCKOUL9zbttw== X-Received: by 2002:a65:4545:: with SMTP id x5-v6mr20981422pgr.4.1530523021746; Mon, 02 Jul 2018 02:17:01 -0700 (PDT) Received: from localhost.localdomain ([211.196.191.92]) by smtp.gmail.com with ESMTPSA id 67-v6sm24527627pga.9.2018.07.02.02.16.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 02 Jul 2018 02:17:01 -0700 (PDT) From: Taeung Song To: Alexei Starovoitov , Daniel Borkmann Cc: Teng Qin , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Taeung Song Subject: [PATCH 3/4] samples/bpf: Check the error of write() and read() Date: Mon, 2 Jul 2018 18:14:52 +0900 Message-Id: <1530522893-8961-4-git-send-email-treeze.taeung@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1530522893-8961-1-git-send-email-treeze.taeung@gmail.com> References: <1530522893-8961-1-git-send-email-treeze.taeung@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org test_task_rename() and test_urandom_read() can be failed during write() and read(), So check the result of them. Signed-off-by: Taeung Song --- samples/bpf/test_overhead_user.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/samples/bpf/test_overhead_user.c b/samples/bpf/test_overhead_user.c index 6caf47a..8a88d9c 100644 --- a/samples/bpf/test_overhead_user.c +++ b/samples/bpf/test_overhead_user.c @@ -6,6 +6,7 @@ */ #define _GNU_SOURCE #include +#include #include #include #include @@ -44,8 +45,12 @@ static void test_task_rename(int cpu) exit(1); } start_time = time_get_ns(); - for (i = 0; i < MAX_CNT; i++) - write(fd, buf, sizeof(buf)); + for (i = 0; i < MAX_CNT; i++) { + if (write(fd, buf, sizeof(buf)) < 0) { + printf("task rename failed: %s\n", strerror(errno)); + break; + } + } printf("task_rename:%d: %lld events per sec\n", cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time)); close(fd); @@ -55,7 +60,7 @@ static void test_urandom_read(int cpu) { __u64 start_time; char buf[4]; - int i, fd; + int i, fd, err = 0; fd = open("/dev/urandom", O_RDONLY); if (fd < 0) { @@ -63,8 +68,13 @@ static void test_urandom_read(int cpu) exit(1); } start_time = time_get_ns(); - for (i = 0; i < MAX_CNT; i++) - read(fd, buf, sizeof(buf)); + for (i = 0; i < MAX_CNT; i++) { + err = read(fd, buf, sizeof(buf)); + if (err < 0 || err >= sizeof(buf)) { + printf("failed to read from /dev/urandom: %s\n", strerror(errno)); + break; + } + } printf("urandom_read:%d: %lld events per sec\n", cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time)); close(fd); -- 2.7.4