From patchwork Fri Feb 22 14:28:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tzvetomir Stoyanov X-Patchwork-Id: 10826165 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 8A3341399 for ; Fri, 22 Feb 2019 14:28:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7892B303F5 for ; Fri, 22 Feb 2019 14:28:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6D0EA327D6; Fri, 22 Feb 2019 14:28:43 +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 223F4303F5 for ; Fri, 22 Feb 2019 14:28:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726356AbfBVO2n (ORCPT ); Fri, 22 Feb 2019 09:28:43 -0500 Received: from mail-wm1-f66.google.com ([209.85.128.66]:50926 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726214AbfBVO2m (ORCPT ); Fri, 22 Feb 2019 09:28:42 -0500 Received: by mail-wm1-f66.google.com with SMTP id x7so2147046wmj.0 for ; Fri, 22 Feb 2019 06:28:41 -0800 (PST) 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=HnuS1SZce2e8Vt/K0vAcYwiqXI05JrMdLulLQvdq6bF0kTywCAH3YKHEiEM25+C3Go WPrRkqrkoSfYBNQhHJoPl976b2jZr1Iwikr1DCZSPjNlnAhFzvorUdt0mYWlUP/3iIYo QbQA+BaNNNMryutKmfSffouFUAC0yYdx/nYHEUgC03jsqUevhtgybKZhy7F93z355p2W 2TNWAhSXyr2KaxU+bAaqwT4XCcNsGrW+qo2tpHgbl1jwFn+JcFrLeUR8bTWlVUEN9gVt dQlLi/8fUAyss5v+MbKrrFCFZHs3xUigli+HxrF4wGuk8ZrrvtGFcukRW04i/sE2Oo5u CTzg== X-Gm-Message-State: AHQUAuYcF4cbcUr3r7a5XLFU1gHRwhOta5v6tOfh8jl6KUiZMVl3IKMg 8bY4RRG7UvjibvI4zpzTX0g= X-Google-Smtp-Source: AHgI3IZ8MG7uey6n/EPR7G2Kg8jIayhMEbgwB9c5XTjxlHrxpHwwAb6t/WOTH92WX7GOi731Kp7QLw== X-Received: by 2002:a1c:a9d0:: with SMTP id s199mr2642048wme.142.1550845720993; Fri, 22 Feb 2019 06:28:40 -0800 (PST) Received: from oberon.eng.vmware.com ([146.247.46.5]) by smtp.gmail.com with ESMTPSA id q9sm848987wrv.26.2019.02.22.06.28.40 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 22 Feb 2019 06:28:40 -0800 (PST) From: Tzvetomir Stoyanov To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org Subject: [PATCH v4 3/7] trace-cmd: Fix tracecmd_read_page_record() to read more than one event Date: Fri, 22 Feb 2019 16:28:32 +0200 Message-Id: <20190222142836.12596-4-tstoyanov@vmware.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190222142836.12596-1-tstoyanov@vmware.com> References: <20190222142836.12596-1-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;