From patchwork Tue Mar 19 15:55:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tzvetomir Stoyanov X-Patchwork-Id: 10859911 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 21D0B1390 for ; Tue, 19 Mar 2019 15:55:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 086C629780 for ; Tue, 19 Mar 2019 15:55:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F0C3D2979F; Tue, 19 Mar 2019 15:55:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 931F42978E for ; Tue, 19 Mar 2019 15:55:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727196AbfCSPzn (ORCPT ); Tue, 19 Mar 2019 11:55:43 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:35431 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727163AbfCSPzn (ORCPT ); Tue, 19 Mar 2019 11:55:43 -0400 Received: by mail-wm1-f67.google.com with SMTP id f8so2393787wmh.0 for ; Tue, 19 Mar 2019 08:55:41 -0700 (PDT) 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=uk3prq7PM5NWRxFeku/sMfCiWVMc5DcibNxNMdyfE4M=; b=RrYgBMtc2ToMhW943OIySPNwnd2JNMvtBspUFygMLKaA5MCRcO8uuly5PYAkXpwbdz U7HqA7FMGQl515TRJslvZEJDVvUv3TcAEhjsLfoVwuMUzDThr/Sf7MND72spxteRzPBL 28c2RI2H5weCiO6JYgE7b0dJGVrympyHJaM37JWZ6dIE67H/b7aqJAp8/H3wTIaq/9Eo gYeJe9tnZTAHM8evOeDO1pdqyylNXWZA5wQeYdAfYLjXNm3I8lAJSeMRVFyPjFMIUYFc sX+yWwVQIZwAPBktn3Uaw2f2zA3BNqWPhzEMm3ovl/Vf1JzLExWFmNPusNfvlww6iZkb cL1Q== X-Gm-Message-State: APjAAAXc+KQTdGig9pIpRS1FFODGIGCldIAXixR9w0q0sT0c4z/caooj 6vFev9SBE3bT7e7iiMkFLRk= X-Google-Smtp-Source: APXvYqwNPLyhuNERIeifubw6T7vGecCzhOTJ9y3rSOldVzgjOO3QnT4HVLIMyMic8Soz+RA+9qjH8Q== X-Received: by 2002:a7b:c3c5:: with SMTP id t5mr4210152wmj.110.1553010941276; Tue, 19 Mar 2019 08:55:41 -0700 (PDT) Received: from oberon.eng.vmware.com ([146.247.46.5]) by smtp.gmail.com with ESMTPSA id t15sm9365911wrr.16.2019.03.19.08.55.40 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 19 Mar 2019 08:55:40 -0700 (PDT) From: Tzvetomir Stoyanov To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org Subject: [PATCH v7 3/9] trace-cmd: Fix tracecmd_read_page_record() to read more than one event Date: Tue, 19 Mar 2019 17:55:30 +0200 Message-Id: <20190319155536.19381-4-tstoyanov@vmware.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190319155536.19381-1-tstoyanov@vmware.com> References: <20190319155536.19381-1-tstoyanov@vmware.com> MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The kbuffer_next_event() will return the next event on the sub buffer. If we pass in the last_record to tracecmd_read_page_record(), it initializes the sub buffer, and by calling kbuffer_next_event() (instead of kbuffer_read_event()), the second event on the sub buffer is returned. This causes the match of the last_record not to match if the last_record happens to be the first event on the sub buffer. Signed-off-by: Tzvetomir Stoyanov --- lib/trace-cmd/trace-input.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c index be6720c..0a6e820 100644 --- a/lib/trace-cmd/trace-input.c +++ b/lib/trace-cmd/trace-input.c @@ -1679,18 +1679,22 @@ tracecmd_read_page_record(struct tep_handle *pevent, void *page, int size, goto out_free; } - do { + ptr = kbuffer_read_event(kbuf, &ts); + while (ptr < last_record->data) { ptr = kbuffer_next_event(kbuf, NULL); if (!ptr) break; - } while (ptr < last_record->data); + if (ptr == last_record->data) + break; + } if (ptr != last_record->data) { warning("tracecmd_read_page_record: could not find last_record"); goto out_free; } - } + ptr = kbuffer_next_event(kbuf, &ts); + } else + ptr = kbuffer_read_event(kbuf, &ts); - ptr = kbuffer_read_event(kbuf, &ts); if (!ptr) goto out_free;