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[2607:7c80:54:e::133]) by mx.google.com with ESMTPS id h69si23590535pfc.100.2019.04.25.11.17.53 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 25 Apr 2019 11:17:53 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of peterz@infradead.org designates 2607:7c80:54:e::133 as permitted sender) client-ip=2607:7c80:54:e::133; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20170209 header.b=a2ZfRHVi; spf=pass (google.com: best guess record for domain of peterz@infradead.org designates 2607:7c80:54:e::133 as permitted sender) smtp.mailfrom=peterz@infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=tRoNJ8c4cbN57uzpVjJsLti1b65Ha0XS4q1OKT5SUhc=; b=a2ZfRHViaari4YLFzrqFZ4Xcv pPtn0t/Ikwnz+zDeTwk5ZwWrGRVlT58S1XUXFSR8UgdTWRWewHdmfi4Subbyk8BKZwyNIG9unYqRE ALVHeVhS1e7uwc9LiONexeLx6a1SPYdmNRcLVe9GKIvDolsrpFXatNsNNIdTw21e/BJU5Dzhgy5ka 2lkgXtDWh8vQ0B1s4dKgSvZ/lZT23l0RSn0J3QDJjFMaHw2aIPTeZ+Ug3Pe6X1dqSAuPRxjAc55Yb zKoCB0V6hKaeSVzY626itIKuX52IEH2PzF9nn3cwyYwucKNtPk/jTGTHqzLOiQgxvd7UEy1pISpqQ iPcq7BOgw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hJiwK-0008P9-UW; Thu, 25 Apr 2019 18:17:45 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id E5895203C072C; Thu, 25 Apr 2019 20:17:42 +0200 (CEST) Date: Thu, 25 Apr 2019 20:17:42 +0200 From: Peter Zijlstra To: Rick Edgecombe Cc: Borislav Petkov , Andy Lutomirski , Ingo Molnar , linux-kernel@vger.kernel.org, x86@kernel.org, hpa@zytor.com, Thomas Gleixner , Nadav Amit , Dave Hansen , linux_dti@icloud.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, akpm@linux-foundation.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, will.deacon@arm.com, ard.biesheuvel@linaro.org, kristen@linux.intel.com, deneen.t.dock@intel.com, Nadav Amit Subject: Re: [PATCH v4 04/23] x86/mm: Save DRs when loading a temporary mm Message-ID: <20190425181742.GZ11158@hirez.programming.kicks-ass.net> References: <20190422185805.1169-1-rick.p.edgecombe@intel.com> <20190422185805.1169-5-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190422185805.1169-5-rick.p.edgecombe@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) 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: On Mon, Apr 22, 2019 at 11:57:46AM -0700, Rick Edgecombe wrote: > From: Nadav Amit > > Prevent user watchpoints from mistakenly firing while the temporary mm > is being used. As the addresses that of the temporary mm might overlap > those of the user-process, this is necessary to prevent wrong signals > or worse things from happening. Ooh, goody, that would be fun indeed. > Cc: Andy Lutomirski Acked-by: Peter Zijlstra (Intel) > Signed-off-by: Nadav Amit > Signed-off-by: Rick Edgecombe