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[2a01:7a0:2:106d:700::1]) by mx.google.com with ESMTPS id v26si6837895wmc.7.2019.04.04.09.23.56 for (version=TLS1_2 cipher=AES128-SHA bits=128/128); Thu, 04 Apr 2019 09:23:56 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of bigeasy@linutronix.de designates 2a01:7a0:2:106d:700::1 as permitted sender) client-ip=2a01:7a0:2:106d:700::1; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of bigeasy@linutronix.de designates 2a01:7a0:2:106d:700::1 as permitted sender) smtp.mailfrom=bigeasy@linutronix.de Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1hC59a-0005f2-1o; Thu, 04 Apr 2019 18:23:50 +0200 Date: Thu, 4 Apr 2019 18:23:50 +0200 From: Sebastian Andrzej Siewior To: Tycho Andersen Cc: Andy Lutomirski , Khalid Aziz , iommu@lists.linux-foundation.org, X86 ML , LKML , Linux-MM , Khalid Aziz Subject: Re: [RFC PATCH v9 02/13] x86: always set IF before oopsing from page fault Message-ID: <20190404162349.rvkaozmtozamdoar@linutronix.de> References: <20190404013956.GA3365@cisco> <20190404154727.GA14030@cisco> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190404154727.GA14030@cisco> User-Agent: NeoMutt/20180716 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: - stepping on del button while browsing though CCs. On 2019-04-04 09:47:27 [-0600], Tycho Andersen wrote: > > Hmm. do_exit() isn't really meant to be "try your best to leave the > > system somewhat usable without returning" -- it's a function that, > > other than in OOPSes, is called from a well-defined state. So I think > > rewind_stack_do_exit() is probably a better spot. But we need to > > rewind the stack and *then* turn on IRQs, since we otherwise risk > > exploding quite badly. > > Ok, sounds good. I guess we can include something like this patch in > the next series. The tracing infrastructure probably doesn't know that the interrupts are back on. Also if you were holding a spin lock then your preempt count isn't 0 which means that might_sleep() will trigger a splat (in your backtrace it was zero). > Thanks, > > Tycho Sebastian