From nobody Fri Apr 26 11:32:47 2024 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 DC768C00140 for ; Fri, 5 Aug 2022 22:07:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241736AbiHEWG7 (ORCPT ); Fri, 5 Aug 2022 18:06:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241631AbiHEWGz (ORCPT ); Fri, 5 Aug 2022 18:06:55 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1AE9012633; Fri, 5 Aug 2022 15:06:50 -0700 (PDT) Received: from BRIANROB-L1.corp.microsoft.com (unknown [167.220.2.188]) by linux.microsoft.com (Postfix) with ESMTPSA id 9B69921004C2; Fri, 5 Aug 2022 15:06:49 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 9B69921004C2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1659737209; bh=/bvKYXvcNa1VqgjhFy5rDeM3s0yxjUJLpsBciRViLEA=; h=From:To:Cc:Subject:Date:From; b=puKQIFxtxDE07SIARfngERKQFwY75FFLc5eWTRGMke2ZeRd+HHE9jkMAROCIg7bUR wI/Gu9DX3IG/7luLlfvk4pGBEMb5qQ3MqJOHoMx3zj7fgh4INl88r+bF//0uRKDL5B 86ib6QS0i1xaTt9cy3QJ1mVqlcs/YQT90xbUKtsA= From: Brian Robbins To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] perf inject jit: Ignore memfd and anonymous mmap events if jitdump present Date: Fri, 5 Aug 2022 15:06:45 -0700 Message-Id: <20220805220645.95855-1-brianrob@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Some processes store jitted code in memfd mappings to avoid having rwx mappings. These processes map the code with a writeable mapping and a read-execute mapping. They write the code using the writeable mapping and then unmap the writeable mapping. All subsequent execution is through the read-execute mapping. perf inject --jit ignores //anon* mappings for each process where a jitdump is present because it expects to inject mmap events for each jitted code range, and said jitted code ranges will overlap with the //anon* mappings. Ignore /memfd: and [anon:* mappings so that jitted code contained in /memfd: and [anon:* mappings is treated the same way as jitted code contained in //anon* mappings. Signed-off-by: Brian Robbins Acked-by: Ian Rogers --- tools/perf/util/jitdump.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c index a23255773c60..4e6632203704 100644 --- a/tools/perf/util/jitdump.c +++ b/tools/perf/util/jitdump.c @@ -845,8 +845,13 @@ jit_process(struct perf_session *session, if (jit_detect(filename, pid, nsi)) { nsinfo__put(nsi); =20 - // Strip //anon* mmaps if we processed a jitdump for this pid - if (jit_has_pid(machine, pid) && (strncmp(filename, "//anon", 6) =3D=3D = 0)) + /* + * Strip //anon*, [anon:* and /memfd:* mmaps if we processed a jitdump f= or this pid + */ + if (jit_has_pid(machine, pid) && + ((strncmp(filename, "//anon", 6) =3D=3D 0) || + (strncmp(filename, "[anon:", 6) =3D=3D 0) || + (strncmp(filename, "/memfd:", 7) =3D=3D 0))) return 1; =20 return 0; --=20 2.25.1