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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57F3FC2D0CE for ; Fri, 24 Jan 2020 04:59:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 255612072C for ; Fri, 24 Jan 2020 04:59:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LgS4/gVS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729545AbgAXE73 (ORCPT ); Thu, 23 Jan 2020 23:59:29 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:37824 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729476AbgAXE72 (ORCPT ); Thu, 23 Jan 2020 23:59:28 -0500 Received: by mail-pg1-f196.google.com with SMTP id q127so392507pga.4; Thu, 23 Jan 2020 20:59:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=oOSQMwxHrwpswTLtDsPfKJzl+DtBJm84K0zAoJhjCSc=; b=LgS4/gVSwk+VUuIpn31qywoCF6O/vIt9PEnG13y9vr0YNNMriFnwVVpWKaztD/TO2w HAVvQjQU+mqiW0wF24cqZSOd7H81NKnP7ukMolSGgWZ9gzALpzXmOiBAQDp3wK+cpLx5 HYFGAyXibXCeUdFp1ILPs3oHyynj9I52glMPJ/L4Cr8J3QSJEQVyfgBhiPoe5Q071jNi 5+A2y2Bn7SARBRQpM/cCFo6AlBVbi1mTWZIbWcCUDIvbuCmtwt3FE5eoFzWF/8lQ9s9H xV/R2Rx5R9ZD7tRoCbRBGvAf5qq289qt2nurAZL7S8EKrsq5CX6miuQihItnmc/mDIJH HB8w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=oOSQMwxHrwpswTLtDsPfKJzl+DtBJm84K0zAoJhjCSc=; b=UzEwi5eUfBRYxmcR+SwA/8zp90ouW9g6Ghb2x8Jz6f42ZBcsP2m750uCFXyutq3/Ev NrxdRGmIm0GbZDbvYX5mdI0Pg1kY1RP5wzZed+qC+oc2xaKeZmlpQm8TgvXkJmXLNUWg hnwGkB32z0wWD42R8A7eYKp9bm6J4lJIoV/P2og17mxAzeNl6yjFX7O4wm0uT4QkDHpX x2A6ghz44Tv21XuEYzzGGpdR/Y1rGLV4N5fDP6QgjM9lXc6GTB9blGUcgQ2RdGDOeaQm Rw9lI++OenlJ1JPaOwrCysVwINTcDDdYclhoCBTPZL8QjrFRgYMYnRgo2LkLprT3GsFA Uf2w== X-Gm-Message-State: APjAAAU1hkZTwws4O5sa+uS6QmuZ6abJexIDP5AaFRMUoy9KtUbFs0sj q/Wkrcpo5bcKp873xwTFaA== X-Google-Smtp-Source: APXvYqzZmm/J/2bN7SPdZkjqtyzQWQPFVFUb3O9enD9Larc5uGqsZiP5cy3GcbEniXFpRsttYfbCbQ== X-Received: by 2002:a65:4c82:: with SMTP id m2mr2003067pgt.432.1579841968170; Thu, 23 Jan 2020 20:59:28 -0800 (PST) Received: from madhuparna-HP-Notebook.nitk.ac.in ([2402:3a80:1ee5:e37b:209c:91b0:b68a:515f]) by smtp.gmail.com with ESMTPSA id m22sm4949610pgn.8.2020.01.23.20.59.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2020 20:59:27 -0800 (PST) From: madhuparnabhowmik10@gmail.com To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, ebiederm@xmission.com, christian.brauner@ubuntu.com, oleg@redhat.com, paulmck@kernel.org Cc: joel@joelfernandes.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, frextrite@gmail.com, rcu@vger.kernel.org, Madhuparna Bhowmik Subject: [PATCH] sched.h: Annotate sighand_struct with __rcu Date: Fri, 24 Jan 2020 10:29:08 +0530 Message-Id: <20200124045908.26389-1-madhuparnabhowmik10@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Madhuparna Bhowmik This patch fixes the following sparse errors by annotating the sighand_struct with __rcu kernel/fork.c:1511:9: error: incompatible types in comparison expression kernel/exit.c:100:19: error: incompatible types in comparison expression kernel/signal.c:1370:27: error: incompatible types in comparison expression This fix introduces the following sparse error in signal.c due to checking the sighand pointer without rcu primitives: kernel/signal.c:1386:21: error: incompatible types in comparison expression This new sparse error is also fixed in this patch. Signed-off-by: Madhuparna Bhowmik --- include/linux/sched.h | 2 +- kernel/signal.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index b511e178a89f..7a351360ad54 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -918,7 +918,7 @@ struct task_struct { /* Signal handlers: */ struct signal_struct *signal; - struct sighand_struct *sighand; + struct sighand_struct __rcu *sighand; sigset_t blocked; sigset_t real_blocked; /* Restored if set_restore_sigmask() was used: */ diff --git a/kernel/signal.c b/kernel/signal.c index bcd46f547db3..9ad8dea93dbb 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1383,7 +1383,7 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, * must see ->sighand == NULL. */ spin_lock_irqsave(&sighand->siglock, *flags); - if (likely(sighand == tsk->sighand)) + if (likely(sighand == rcu_access_pointer(tsk->sighand))) break; spin_unlock_irqrestore(&sighand->siglock, *flags); } -- 2.17.1