From patchwork Mon Jun 5 07:30:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: sunliming X-Patchwork-Id: 690410 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 0EED6C7EE23 for ; Mon, 5 Jun 2023 07:31:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229897AbjFEHa7 (ORCPT ); Mon, 5 Jun 2023 03:30:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230336AbjFEHag (ORCPT ); Mon, 5 Jun 2023 03:30:36 -0400 Received: from mail-pf1-f194.google.com (mail-pf1-f194.google.com [209.85.210.194]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A967AD; Mon, 5 Jun 2023 00:30:35 -0700 (PDT) Received: by mail-pf1-f194.google.com with SMTP id d2e1a72fcca58-6532671ccc7so3281078b3a.2; Mon, 05 Jun 2023 00:30:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685950235; x=1688542235; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=21KuDm7E1j2X3eQMy2+wyemXDR46+T1mk758fuRtSIk=; b=A+Pm9AHqWhyveo120GfD7atXQovD87STrmE+NDVi+DsK5MlM139SVxs53py0xS8OXo oNZ1QCe//0aKE+sz3DP+igig8MP2buKRah2lWfIwOS+3Cgc5PkGF0zHY04jZdt7mqCCE 6Sx8ajnAROBO2M2tKUfPz1KXiJQBPLVCeLlk55P1bmW69TER7C0Hu9uYAJAajum3y+NG cMZ1cg9OQM6oMeRcVPtqLA1m/itvmhQCGCrKtzQ1ELZY8OxkOZFp5a65RgrisT8Ibvz5 0Cf6DovTmOdQ3aXijEhHeH/EvIZpnDY+uFaPiWUM+iTU7C9DS5ypv2F9iykPKYczfPyL OKnw== X-Gm-Message-State: AC+VfDyVlEe4ze0rSP/l9pdNPdxasQ7T3q184ulov/QMjmkAwpsFRvXC wSYTu/StxdHEZxh5/8GQuw== X-Google-Smtp-Source: ACHHUZ7ChMAQp+vzlxKyflCK6VPC2O6GMjChXE7QQC6hkM9zpe9c3D4YQmRAdK98Dmpmd4xpLk9ZBw== X-Received: by 2002:a05:6a20:8e19:b0:116:e916:4b5b with SMTP id y25-20020a056a208e1900b00116e9164b5bmr1229383pzj.25.1685950234884; Mon, 05 Jun 2023 00:30:34 -0700 (PDT) Received: from localhost.localdomain ([116.128.244.169]) by smtp.gmail.com with ESMTPSA id 128-20020a630786000000b0053ba104c113sm5200419pgh.72.2023.06.05.00.30.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Jun 2023 00:30:34 -0700 (PDT) From: sunliming To: mhiramat@kernel.org, beaub@linux.microsoft.com, rostedt@goodmis.org, shuah@kernel.org Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kelulanainsley@gmail.com, sunliming Subject: [PATCH V2 1/4] tracing/user_events: Fix the incorrect trace record for empty arguments events Date: Mon, 5 Jun 2023 15:30:20 +0800 Message-Id: <20230605073023.923316-1-sunliming@kylinos.cn> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The user_events support events that has empty arguments. But the trace event is discarded and not really committed when the arguments is empty. Fix this by not attempting to copy in zero-length data. Signed-off-by: sunliming --- kernel/trace/trace_events_user.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c index 0d91dac206ff..698703a3d234 100644 --- a/kernel/trace/trace_events_user.c +++ b/kernel/trace/trace_events_user.c @@ -1399,7 +1399,7 @@ static void user_event_ftrace(struct user_event *user, struct iov_iter *i, if (unlikely(!entry)) return; - if (unlikely(!copy_nofault(entry + 1, i->count, i))) + if (unlikely(i->count != 0 && !copy_nofault(entry + 1, i->count, i))) goto discard; if (!list_empty(&user->validators) && @@ -1440,7 +1440,7 @@ static void user_event_perf(struct user_event *user, struct iov_iter *i, perf_fetch_caller_regs(regs); - if (unlikely(!copy_nofault(perf_entry + 1, i->count, i))) + if (unlikely(i->count != 0 && !copy_nofault(perf_entry + 1, i->count, i))) goto discard; if (!list_empty(&user->validators) &&