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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 4745BCA1005 for ; Tue, 2 Sep 2025 21:42:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=vafXsShjHcqkqqUbmMwx8jDPKmy/omG9aRFir+yZ4Po=; b=nVGcXaXRygEuI/1phOLOS56L1l Ex7l4KULeV6lqRwgG33/VX5rc1wZYDCAfUqQTLN4RKHrtwR3Qi1IoYv+mIte+uFRgHhI7qKfHkixr rrwoILQk6XM8zo5gRdIy0VwlD7kMOcGh7uBr7Y04XsChTUMQQnjmnv1Y0U0ahYw4N/UjfnEyAI/AW 3L23zAed+WIsBG2/4oULdAN+1mehTf/xJjLOxnm0Lv2WO2H1bx7Wgw4vqdMtrqMGEpm8Cnw62b7qS CQ5ZIejl+8MGIJRvxAcAfVgtj/a1DWO20qoijEWnqzlj1NSDEH0RtdiClKVLL/UNw9jSODXL2Re/1 2/CgarMw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1utYm6-00000002AaJ-1qjh; Tue, 02 Sep 2025 21:42:46 +0000 Received: from smtprelay0013.hostedemail.com ([216.40.44.13] helo=relay.hostedemail.com) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1utRml-00000000IJP-3vEC for linux-arm-kernel@lists.infradead.org; Tue, 02 Sep 2025 14:15:01 +0000 Received: from omf14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id B0BE3118DE0; Tue, 2 Sep 2025 14:14:57 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf14.hostedemail.com (Postfix) with ESMTPA id D75B22F; Tue, 2 Sep 2025 14:14:55 +0000 (UTC) Date: Tue, 2 Sep 2025 10:14:54 -0400 From: Steven Rostedt To: Luo Gengkun Cc: "Masami Hiramatsu (Google)" , mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, Mark Rutland Subject: Re: [PATCH] tracing: Fix tracing_marker may trigger page fault during preempt_disable Message-ID: <20250902101454.08ac4b51@batman.local.home> In-Reply-To: References: <20250819105152.2766363-1-luogengkun@huaweicloud.com> <20250819135008.5f1ba00e@gandalf.local.home> <436e4fa7-f8c7-4c23-a28a-4e5eebe2f854@huaweicloud.com> <20250829082604.1e3fd06e@gandalf.local.home> <20250902005645.8c6436b535731a4917745c5d@kernel.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: beakny4makx9cgn6wr3cpdqnepb7zwzk X-Rspamd-Server: rspamout08 X-Rspamd-Queue-Id: D75B22F X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/Vny/0m1YTHEB86J0KxD22azBiTD+a6Bc= X-HE-Tag: 1756822495-445596 X-HE-Meta: U2FsdGVkX184HKgOFkdHQFjK+vres2d7VudWt6HZdwYteDupaA5t8163Q1Cdzk5ffctsf+ji2tSeR5xXFP78YjW2zatrfZOwMQS2KXzu0/20/e5PEAyxQMHxTSY4wf58CvnSFV56gUR4RcAoGgEb7lyEro680Ri5G+pxONAwzgKFUOsfdU6EyC8jTEMSzTopv8FcBjcoOSWn5N/xHneyLIJ4gUrAyNA9C2KxeawuR5JgDJ9qcoy5jJisn1wz87OJ3F60Ef9bNyFGDjoS8aDfzta/VXK187CkvGH+uEbQPqMcpDc60Hi/LzR9u1XxahZwvUupmWNHDPJzAhT4eRnnmOz/bJDsUuBVg85WDSVDvNy9pa4VYNXIIw== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250902_071500_030525_B0D0CFBA X-CRM114-Status: GOOD ( 12.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 2 Sep 2025 11:47:32 +0800 Luo Gengkun wrote: > > If this does not check the preempt flag, it is a problem. > > Maybe arm64 needs to do fixup and abort instead of do_mem_abort()? > > My kernel was built without CONFIG_PREEMPT_COUNT, so the preempt_disable() > does nothing more than act as a barrier. In this case, it can pass the > check by schedule(). Perhaps this is another issue? This is why I never triggered it. I always have PREEMPT_COUNT enabled. I have tests that test without it, but I don't think those tests access trace_marker, and if they do, they don't stress it. -- Steve