From patchwork Fri Mar 11 04:47:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jim Cromie X-Patchwork-Id: 12777384 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F07E9C433EF for ; Fri, 11 Mar 2022 04:48:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6B2CB10E29C; Fri, 11 Mar 2022 04:48:18 +0000 (UTC) Received: from mail-il1-x129.google.com (mail-il1-x129.google.com [IPv6:2607:f8b0:4864:20::129]) by gabe.freedesktop.org (Postfix) with ESMTPS id 00BB410E29C; Fri, 11 Mar 2022 04:48:16 +0000 (UTC) Received: by mail-il1-x129.google.com with SMTP id b14so5242932ilf.6; Thu, 10 Mar 2022 20:48:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=oAf0LosuiaLpXGtYs0EMjapukN/Wz4GaZEg3vD6y6ak=; b=FGomt3SpUqyItDxQTS6QatofCRhiZIi82c83FcZW5lAA7Hia4dUP0QS/5UI8s6V1iG p9ewH/E8qTORsPj4+OnlwfDOXUVrf8HA+fTwEUNyHVWnEW32jyMqS0HEMeua00mED9fG Jt5WhOje3GPSyOyvOMadpj6kIzq9ffhFw1is+8tPx5sOzNgcO1DanXFs7auqvAQR2OBg O5UhHrzIh8D2tX1MtSnEyQ5Xl0wYsAOwDwWqf53yNtM1nYFJb6c8e8muyyQDgIBl6Ddw xd1IC+TTQp3rkOr7C1IvU2aLj6DFtJpHblfIL1P1+F7+iR/oDHQO/VvQ8mZgMhLKEvdi yJug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=oAf0LosuiaLpXGtYs0EMjapukN/Wz4GaZEg3vD6y6ak=; b=bOhRfXS92SYcm0rjfiwngIGaGvoFnJwDbM8ag3Kv/YDXcgFHiQwcCKl7t6BjO62aXF 0z/+rE48Hxs780OdDPWfRdNP2EZrN5+d/HtMXmhxmaxki8xsWw/iTe1KIjXAZZcc32i9 KsGHR1XFzic/t/8+4T5Bz3B6UNy/KOMtwkW0Vh1Awv5z+9+G+hBY2oL+ro0oRlinjUwy dvy4a7Kds8hqjrsSGg1DW9YbArqFgJqdcpY9p4PgBCgHl58xj0ctD+F/69oXUxwLO2oM XjVglbT7nhMB1WAwUL/WndqbjY56ElR4N5+jb3sWEPy73jupQ6u4kvLyBgKcO5kVQYEY MOcw== X-Gm-Message-State: AOAM532Sc4oC+LauYGULIKx44/2cnt0GFRS5rqg/ylk3fDlK1cprf+gQ gpGbzM/6CLgLTkmH6Em50kwZKVZ+Dd2Ltw== X-Google-Smtp-Source: ABdhPJwFZHg/BgFkwfNAHNLyEDOYNqmvUk/C+4ceSxeoTbqDRVietvJzifHbTMNcdfYqz0MT1Xo4PA== X-Received: by 2002:a05:6e02:1946:b0:2c7:730d:3e35 with SMTP id x6-20020a056e02194600b002c7730d3e35mr2075171ilu.179.1646974096273; Thu, 10 Mar 2022 20:48:16 -0800 (PST) Received: from frodo.hsd1.co.comcast.net ([2601:284:8204:2010::f10e]) by smtp.googlemail.com with ESMTPSA id q9-20020a5edb09000000b00645c7a00cbbsm3529834iop.20.2022.03.10.20.48.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Mar 2022 20:48:15 -0800 (PST) From: Jim Cromie To: jbaron@akamai.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org Date: Thu, 10 Mar 2022 21:47:52 -0700 Message-Id: <20220311044756.425777-2-jim.cromie@gmail.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220311044756.425777-1-jim.cromie@gmail.com> References: <20220311044756.425777-1-jim.cromie@gmail.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 1/5] dyndbg: fix static_branch manipulation X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jim Cromie , daniel.vetter@ffwll.ch, intel-gfx@lists.freedesktop.org, vincent.whitchurch@axis.com, linux@rasmusvillemoes.dk, dri-devel@lists.freedesktop.org, seanpaul@chromium.org, amd-gfx@lists.freedesktop.org, joe@perches.com, intel-gvt-dev@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" In https://lore.kernel.org/lkml/20211209150910.GA23668@axis.com/ Vincent's patch commented on, and worked around, a bug toggling static_branch's, when a 2nd PRINTK-ish flag was added. The bug results in a premature static_branch_disable when the 1st of 2 flags was disabled. The cited commit computed newflags, but then in the JUMP_LABEL block, failed to use that result, instead using just one of the terms in it. Using newflags instead made the code work properly. This is Vincents test-case, reduced. It needs the 2nd flag to work properly, but it's explanatory here. pt_test() { echo 5 > /sys/module/dynamic_debug/verbose site="module tcp" # just one callsite echo " $site =_ " > /proc/dynamic_debug/control # clear it # A B ~A ~B for flg in +T +p "-T #broke here" -p; do echo " $site $flg " > /proc/dynamic_debug/control done; # A B ~B ~A for flg in +T +p "-p #broke here" -T; do echo " $site $flg " > /proc/dynamic_debug/control done } pt_test Fixes: 84da83a6ffc0 dyndbg: combine flags & mask into a struct, simplify with it CC: vincent.whitchurch@axis.com Signed-off-by: Jim Cromie Acked-by: Jason Baron --- .drop @stable, no exposed bug. --- lib/dynamic_debug.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index dd7f56af9aed..a56c1286ffa4 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -211,10 +211,11 @@ static int ddebug_change(const struct ddebug_query *query, continue; #ifdef CONFIG_JUMP_LABEL if (dp->flags & _DPRINTK_FLAGS_PRINT) { - if (!(modifiers->flags & _DPRINTK_FLAGS_PRINT)) + if (!(newflags & _DPRINTK_FLAGS_PRINT)) static_branch_disable(&dp->key.dd_key_true); - } else if (modifiers->flags & _DPRINTK_FLAGS_PRINT) + } else if (newflags & _DPRINTK_FLAGS_PRINT) { static_branch_enable(&dp->key.dd_key_true); + } #endif dp->flags = newflags; v4pr_info("changed %s:%d [%s]%s =%s\n",