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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 1C052C25B10 for ; Mon, 6 May 2024 22:50:54 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4VYGph5B0tz3cVV for ; Tue, 7 May 2024 08:50:52 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2604:1380:4641:c500::1; helo=dfw.source.kernel.org; envelope-from=srs0=huxk=mj=goodmis.org=rostedt@kernel.org; receiver=lists.ozlabs.org) Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4VYGp63VTTz30TP for ; Tue, 7 May 2024 08:50:22 +1000 (AEST) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 8B5D861359; Mon, 6 May 2024 22:50:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7B1AC116B1; Mon, 6 May 2024 22:50:14 +0000 (UTC) Date: Mon, 6 May 2024 18:50:20 -0400 From: Steven Rostedt To: Christophe Leroy Subject: Re: [PATCH v3] kprobe/ftrace: bail out if ftrace was killed Message-ID: <20240506185020.2f156bc8@gandalf.local.home> In-Reply-To: References: <20240501162956.229427-1-stephen.s.brennan@oracle.com> X-Mailer: Claws Mail 3.20.0git84 (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-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , "x86@kernel.org" , Dave Hansen , Stephen Brennan , "James E.J. Bottomley" , Guo Ren , "H. Peter Anvin" , Alexander Gordeev , WANG Xuerui , "linux-s390@vger.kernel.org" , Helge Deller , Huacai Chen , "linux-csky@vger.kernel.org" , "Aneesh Kumar K.V" , Ingo Molnar , "Naveen N. Rao" , Christian Borntraeger , Sven Schnelle , Albert Ou , Vasily Gorbik , Heiko Carstens , Nicholas Piggin , Borislav Petkov , "loongarch@lists.linux.dev" , Paul Walmsley , Thomas Gleixner , "linux-parisc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-riscv@lists.infradead.org" , Palmer Dabbelt , Masami Hiramatsu , "linux-trace-kernel@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, 6 May 2024 14:46:57 +0000 Christophe Leroy wrote: > Isn't it safer to provide a fonction rather than a direct access to a > variable ? > > By the way, wouldn't it be more performant to use a static branch (jump > label) ? A static branch could work, but the point of this is that if ftrace failed, it was likely due to an issue with text modification. Do we want to stop it via text modification? -- Steve