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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 3E2A9C7112A for ; Mon, 15 Oct 2018 04:47:55 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EA7AC20842 for ; Mon, 15 Oct 2018 04:47:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA7AC20842 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 42YQt03Xq9zF39J for ; Mon, 15 Oct 2018 15:47:52 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 42YPrC3NC8zF35x for ; Mon, 15 Oct 2018 15:01:15 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix) id 42YPrB5Y38z9sjH; Mon, 15 Oct 2018 15:01:14 +1100 (AEDT) Received: by ozlabs.org (Postfix, from userid 1034) id 42YPrB3CMKzB2xZ; Mon, 15 Oct 2018 15:01:14 +1100 (AEDT) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 48e7b76957457f9a6f086ca2bbe49ec1ffd75f84 In-Reply-To: <20181013131836.26764-1-mpe@ellerman.id.au> To: Michael Ellerman , linuxppc-dev@ozlabs.org From: Michael Ellerman Subject: Re: [1/6] powerpc/64s/hash: Convert SLB miss handlers to C Message-Id: <42YPrB3CMKzB2xZ@ozlabs.org> Date: Mon, 15 Oct 2018 15:01:14 +1100 (AEDT) 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: aneesh.kumar@linux.vnet.ibm.com, npiggin@gmail.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sat, 2018-10-13 at 13:18:31 UTC, Michael Ellerman wrote: > From: Nicholas Piggin > > This patch moves SLB miss handlers completely to C, using the standard > exception handler macros to set up the stack and branch to C. > > This can be done because the segment containing the kernel stack is > always bolted, so accessing it with relocation on will not cause an > SLB exception. > > Arbitrary kernel memory must not be accessed when handling kernel > space SLB misses, so care should be taken there. However user SLB > misses can access any kernel memory, which can be used to move some > fields out of the paca (in later patches). > > User SLB misses could quite easily reconcile IRQs and set up a first > class kernel environment and exit via ret_from_except, however that > doesn't seem to be necessary at the moment, so we only do that if a > bad fault is encountered. > > [ Credit to Aneesh for bug fixes, error checks, and improvements to > bad address handling, etc ] > > Signed-off-by: Nicholas Piggin > [mpe: Disallow tracing for all of slb.c for now.] > Signed-off-by: Michael Ellerman Series applied to powerpc next. https://git.kernel.org/powerpc/c/48e7b76957457f9a6f086ca2bbe49e cheers