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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 653E8C4332F for ; Sat, 11 Nov 2023 06:12:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229815AbjKKGMO convert rfc822-to-8bit (ORCPT ); Sat, 11 Nov 2023 01:12:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229502AbjKKGMO (ORCPT ); Sat, 11 Nov 2023 01:12:14 -0500 Received: from mail-ot1-f50.google.com (mail-ot1-f50.google.com [209.85.210.50]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D173D55; Fri, 10 Nov 2023 22:12:11 -0800 (PST) Received: by mail-ot1-f50.google.com with SMTP id 46e09a7af769-6d30d9f4549so1578452a34.0; Fri, 10 Nov 2023 22:12:11 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699683130; x=1700287930; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=F18ZfBJDbteJpzF3orYa0y+zwvcNIr/l7qVlsuvq6RY=; b=ciiKjWfOv5Br0/3YOAwqbIVtu9Ey/BNj8fhQDhDwD8HarF1V1uEyQVl9iyyfwS3gx4 J0D1QNK55QdK74fsy7rO0fgUDKehKuCBfGZpfj64KzJglrWEdmIE5qEq/kVxfsgikRRm 8p/4ET94b/sBTRu6Ef8Mm8nu4Ytk/k2xDp7sVqemPe+eDIoIgZET+SngIMtz5HdPieK+ CapXcLhmp6YVtDV4bXKq4tW/36atVdNVvKUX43x8G7BtA7ALcl0cWb8PbZvmHS5Qx4ap TdzO/puD+ZDsHzQYrW0FU7QAk4rGHmTch5Y2WDMVSGNtrRkDif0adY1QX42KFcrAFbfs 0O+g== X-Gm-Message-State: AOJu0Ywd7ChJ8WoK3ZmcTccALk/+k02jZ7pD+j+yxDo1k7H3pfSYZwoy 38baNBLYf3sw9cboMSKOnac7eDrtKjVgL8YvbMA= X-Google-Smtp-Source: AGHT+IGm/ncW6tg2O+/GY8fy3Ui1xaM/XhX0zayiBwqhafMsRJUlmlrCiiMLnmQ4fMHM1pr2yytjj7ZAgno+DypQkLY= X-Received: by 2002:a05:6870:7d08:b0:1f4:a992:a15f with SMTP id os8-20020a0568707d0800b001f4a992a15fmr1994226oab.43.1699683130507; Fri, 10 Nov 2023 22:12:10 -0800 (PST) MIME-Version: 1.0 References: <6456d4d523841fb97b639433731540b8783529a1.1699487758.git.jpoimboe@kernel.org> In-Reply-To: <6456d4d523841fb97b639433731540b8783529a1.1699487758.git.jpoimboe@kernel.org> From: Namhyung Kim Date: Fri, 10 Nov 2023 22:11:59 -0800 Message-ID: Subject: Re: [PATCH RFC 03/10] perf: Simplify get_perf_callchain() user logic To: Josh Poimboeuf Cc: Peter Zijlstra , Steven Rostedt , Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, x86@kernel.org, Indu Bhagat , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Mark Brown , linux-toolchains@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-toolchains@vger.kernel.org On Wed, Nov 8, 2023 at 4:44 PM Josh Poimboeuf wrote: > > Simplify the get_perf_callchain() user logic a bit. task_pt_regs() > should never be NULL. > > Signed-off-by: Josh Poimboeuf Acked-by: Namhyung Kim Thanks, Namhyung > --- > kernel/events/callchain.c | 16 +++++++--------- > 1 file changed, 7 insertions(+), 9 deletions(-) > > diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c > index aa5f9d11c28d..2bee8b6fda0e 100644 > --- a/kernel/events/callchain.c > +++ b/kernel/events/callchain.c > @@ -202,20 +202,18 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, bool user, > > if (user) { > if (!user_mode(regs)) { > - if (current->mm) > - regs = task_pt_regs(current); > - else > - regs = NULL; > + if (!current->mm) > + goto exit_put; > + regs = task_pt_regs(current); > } > > - if (regs) { > - if (add_mark) > - perf_callchain_store_context(&ctx, PERF_CONTEXT_USER); > + if (add_mark) > + perf_callchain_store_context(&ctx, PERF_CONTEXT_USER); > > - perf_callchain_user(&ctx, regs); > - } > + perf_callchain_user(&ctx, regs); > } > > +exit_put: > put_callchain_entry(rctx); > > return entry; > -- > 2.41.0 >