From patchwork Mon Aug 15 18:04:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 12944023 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2DBAC00140 for ; Mon, 15 Aug 2022 19:35:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343584AbiHOTfY (ORCPT ); Mon, 15 Aug 2022 15:35:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245185AbiHOTeI (ORCPT ); Mon, 15 Aug 2022 15:34:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9210DB1FD; Mon, 15 Aug 2022 11:45:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B7E9F611E8; Mon, 15 Aug 2022 18:45:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA547C433D7; Mon, 15 Aug 2022 18:45:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660589117; bh=OaTRRyi9soEAGUwezZ6afXq9Tx652YqDV8+1EJl6L4w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OVgYaqYpkGTQJnjtfC4vuzlxPsnUebLINnnq+qFOJVXnCwJ82HC27qcXyVoOK757O mlzArjpr6zjSsPK3d1Kfx3wjv2IZbmrmdMHneuquLQ06ag99nwo2kzt+wCvUizYxxJ ENotdOj9DrK5h9qeyJLmoCMpQsH6EnvJXCGN65Fg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adrian Hunter , Andi Kleen , Ian Rogers , Jiri Olsa , kvm@vger.kernel.org, Namhyung Kim , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 5.15 618/779] perf tools: Fix dso_id inode generation comparison Date: Mon, 15 Aug 2022 20:04:22 +0200 Message-Id: <20220815180403.780906129@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Adrian Hunter [ Upstream commit 68566a7cf56bf3148797c218ed45a9de078ef47c ] Synthesized MMAP events have zero ino_generation, so do not compare them to DSOs with a real ino_generation otherwise we end up with a DSO without a build id. Fixes: 0e3149f86b99ddab ("perf dso: Move dso_id from 'struct map' to 'struct dso'") Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Ian Rogers Cc: Jiri Olsa Cc: kvm@vger.kernel.org Cc: Namhyung Kim Link: https://lore.kernel.org/r/20220711093218.10967-2-adrian.hunter@intel.com [ Added clarification to the comment from Ian + more detailed explanation from Adrian ] Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/dsos.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c index 183a81d5b2f9..2db91121bdaf 100644 --- a/tools/perf/util/dsos.c +++ b/tools/perf/util/dsos.c @@ -20,8 +20,19 @@ static int __dso_id__cmp(struct dso_id *a, struct dso_id *b) if (a->ino > b->ino) return -1; if (a->ino < b->ino) return 1; - if (a->ino_generation > b->ino_generation) return -1; - if (a->ino_generation < b->ino_generation) return 1; + /* + * Synthesized MMAP events have zero ino_generation, avoid comparing + * them with MMAP events with actual ino_generation. + * + * I found it harmful because the mismatch resulted in a new + * dso that did not have a build ID whereas the original dso did have a + * build ID. The build ID was essential because the object was not found + * otherwise. - Adrian + */ + if (a->ino_generation && b->ino_generation) { + if (a->ino_generation > b->ino_generation) return -1; + if (a->ino_generation < b->ino_generation) return 1; + } return 0; }