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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,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 45488C04A6B for ; Wed, 8 May 2019 13:32:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18C8E21530 for ; Wed, 8 May 2019 13:32:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557322331; bh=rU/iHRxN7bFo6mkmI5rjfeZUhjBfRfMxbQW/mz8LX9g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SkkZI/TOeZQBbfZuHOSixJ5gIowu//yMVjom4ANHTVngFe0MJ2PbKGg6iW8n7fH64 j4j5QuXxDbhIt6sxjDQEfWPCj8fg5n5s+uSJVRMehVGzEzzbxkyyaNDuFm4z1mXIwQ lc5SdDMECkc24LpjZBTiEKfSBR+6YdKkX0XHxMn8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728216AbfEHNcK (ORCPT ); Wed, 8 May 2019 09:32:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:51052 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725778AbfEHNcJ (ORCPT ); Wed, 8 May 2019 09:32:09 -0400 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DB22320644; Wed, 8 May 2019 13:32:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557322328; bh=rU/iHRxN7bFo6mkmI5rjfeZUhjBfRfMxbQW/mz8LX9g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BEjge+nDQ/Zd2QV2h43aZstY+qUkKs2ZUhIRCvBiTyW/2mt2grWKGmPWfMisLsc59 fkyNGVja7ZmrodKg2gGnfL8UvJynWefpTBSGN3psBz3ZHShHHgxxo6rhGgjHZ4OcU/ 4Ig68Nyix6FiCc3u5xEPvIO8trDe4jNL/lpgWmIU= From: Masami Hiramatsu To: Steven Rostedt , Linus Torvalds , Shuah Khan , Arnaldo Carvalho de Melo , Peter Zijlstra Cc: mhiramat@kernel.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Ingo Molnar , Andrew Morton , Changbin Du , Jann Horn , Kees Cook , Andy Lutomirski , Alexei Starovoitov , Nadav Amit , Joel Fernandes , yhs@fb.com Subject: [PATCH v7 1/6] x86/uaccess: Allow access_ok() in irq context if pagefault_disabled Date: Wed, 8 May 2019 22:32:02 +0900 Message-Id: <155732232257.12756.4973477342508107797.stgit@devnote2> X-Mailer: git-send-email 2.17.1 In-Reply-To: <155732230159.12756.15040196512285621636.stgit@devnote2> References: <155732230159.12756.15040196512285621636.stgit@devnote2> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org WARN_ON_IN_IRQ() assumes that the access_ok() and following user memory access can sleep. But this assumption is not always correct; when the pagefault is disabled, following memory access will just returns -EFAULT and never sleep. Add pagefault_disabled() check in WARN_ON_ONCE() so that it can ignore the case we call it with disabling pagefault. For this purpose, this modified pagefault_disabled() as an inline function. Signed-off-by: Masami Hiramatsu --- arch/x86/include/asm/uaccess.h | 4 +++- include/linux/uaccess.h | 5 ++++- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 1954dd5552a2..11581dc098d5 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -66,7 +66,9 @@ static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, un }) #ifdef CONFIG_DEBUG_ATOMIC_SLEEP -# define WARN_ON_IN_IRQ() WARN_ON_ONCE(!in_task()) +static inline bool pagefault_disabled(void); +# define WARN_ON_IN_IRQ() \ + WARN_ON_ONCE(!in_task() && !pagefault_disabled()) #else # define WARN_ON_IN_IRQ() #endif diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 37b226e8df13..ef3032db1aef 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -203,7 +203,10 @@ static inline void pagefault_enable(void) /* * Is the pagefault handler disabled? If so, user access methods will not sleep. */ -#define pagefault_disabled() (current->pagefault_disabled != 0) +static inline bool pagefault_disabled(void) +{ + return current->pagefault_disabled != 0; +} /* * The pagefault handler is in general disabled by pagefault_disable() or