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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 D8A8FC10F03 for ; Thu, 25 Apr 2019 11:05:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADFD9214AE for ; Thu, 25 Apr 2019 11:05:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725955AbfDYLFi (ORCPT ); Thu, 25 Apr 2019 07:05:38 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:39283 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730647AbfDYLFi (ORCPT ); Thu, 25 Apr 2019 07:05:38 -0400 Received: by mail-wm1-f67.google.com with SMTP id n25so9937396wmk.4 for ; Thu, 25 Apr 2019 04:05:37 -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=zdXKbGWqMAYQpUILfeeGn2z07RlCeVs6XoT6MgNnKnc=; b=b6e/JJqEkES21aoMG0wPFrbDy96ex6zwqNR+/prHktZsQXboxqtgTC0NMMJvMANzni v0D4+PUoqojpDHaG7fgFu8vG+LTVYYZq/dDAfN3uADYAwgjyCaC2U/kce6XnY5K1LybW pf/paD05xK5RO4I89o3D/L6zldV37LaRxX0bMKMqdYa2RxyJvOv5FF55AkbJO6J4iqBx DazRnmqFHull3EGsJpcGF9POaEzV7XVN7DT8h7L+176XE0YQgnC5tsehgTk/6UfkCNW9 QxpTzzom3wJjokceTMJGa/xlYlv1AmQH5wOjtmnku1zhh7uauQzl+TSrfJHh9lAnwzOU TClw== X-Gm-Message-State: APjAAAXf8QxfF8OJuevlL6Qwnr2nfpz5IMcA1K+LK+dDf3krZYXullgv WY7uHc4J0O5rVr1Xbxb6+jXI9ijd X-Google-Smtp-Source: APXvYqzpRPECNCzxhPoyXSdHrc9+jcax3jZc0WFpfLCgwsKrRt7gCVaDKDBr1Aelh8oZQLXoTPVMBQ== X-Received: by 2002:a1c:2348:: with SMTP id j69mr3092744wmj.35.1556190336694; Thu, 25 Apr 2019 04:05:36 -0700 (PDT) Received: from oberon.eng.vmware.com ([146.247.46.5]) by smtp.gmail.com with ESMTPSA id a6sm23013606wrp.49.2019.04.25.04.05.35 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 25 Apr 2019 04:05:35 -0700 (PDT) From: Tzvetomir Stoyanov To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org Subject: [PATCH v11 3/9] trace-cmd: Fix tracecmd_read_page_record() to read more than one event Date: Thu, 25 Apr 2019 14:05:25 +0300 Message-Id: <20190425110531.8941-4-tstoyanov@vmware.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190425110531.8941-1-tstoyanov@vmware.com> References: <20190425110531.8941-1-tstoyanov@vmware.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org 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 6624932..ea11d62 100644 --- a/lib/trace-cmd/trace-input.c +++ b/lib/trace-cmd/trace-input.c @@ -1695,18 +1695,22 @@ 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; -- 2.20.1