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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 76EE2C43381 for ; Tue, 26 Feb 2019 08:59:24 +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 E683E213A2 for ; Tue, 26 Feb 2019 08:59:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Uq4iAkH4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E683E213A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com 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 447t6K5sh3zDqHp for ; Tue, 26 Feb 2019 19:59:21 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::644; helo=mail-pl1-x644.google.com; envelope-from=npiggin@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="Uq4iAkH4"; dkim-atps=neutral Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 447sxJ5Jv3zDqDL for ; Tue, 26 Feb 2019 19:51:32 +1100 (AEDT) Received: by mail-pl1-x644.google.com with SMTP id r14so5888278pls.12 for ; Tue, 26 Feb 2019 00:51:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=B+b/BiQ0qghbLj8l9sRsG12oACod+AAcyqEHA3gxsgk=; b=Uq4iAkH4uJsZCdUUh5NlkkPnB4fbFcs6rnotcvAFcR2QGsJXqH5PWDV6RbK5/r5iD3 7jMwHxM6GIdXJgBIkmjcKx84LEGz45cj8DmWxGY9hf8TORZdOjJrExtXiCr8dr3yiEO2 0HN5aOHgs/9rKyv5d0iJxxP438vQtoTMwX40wSGF+BET9br+a9wNBYsUGLZPR2Ka5XVe ePXenUmXWLjYQh62RHDtGvbFSPxVdD1KcDDXubjorvdlaHek9AT0NT59mu5NNCJBfZbq 29ZIk/k/9bTS9zkjaF72kdN7IPg5kpUPgZAERWeRgg16BioYSKDgtB/dEJmu2A20bvT5 RtSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=B+b/BiQ0qghbLj8l9sRsG12oACod+AAcyqEHA3gxsgk=; b=HCwG7DG9XIzTRaAr5jiYuRlu+S/j/VrIHQ7KHqVInUevf3P7LB7gbVevZJD7470bdb M1KbUGt6qjS86eO0s94wTzViuLSlQj0HP9d37COBpp0GrPAFKhkqefRARdkTu/zGjE7r +45YER6zzb0qK43YeswDR5V5YDgETeDRQQw1hoO5PgzmsfQPcmJN1KSgEjYdIw5Lnu6J 0DIFyTFo8bXGp0zU4XR5uBlsH7TxKX8QAJTkIEGuMEnPLj46RcTG9HiUEVsurhnHF8wd YFOICgY9nCxEdmCAL/jZshP2WGVbKhTsDIC44eUV5UdQdz+CJoj0MZu2YaMsqaCAS6xQ hAbQ== X-Gm-Message-State: AHQUAuYTcZN6dedHmVBE3gmHPutT8fF8IA5DiBcvftBPTbPjZH4uAKtv 1SnQxdSrFAayhFoDTu57SssvH7Ra X-Google-Smtp-Source: AHgI3IZ+4DaqiTtO8/TsZ/025BqAjOL3dDO4RTylyuV/p+YOQK2BdknQqFop6/XkH2Z+SCPrhl0+ow== X-Received: by 2002:a17:902:8643:: with SMTP id y3mr24630965plt.195.1551171090648; Tue, 26 Feb 2019 00:51:30 -0800 (PST) Received: from roar.local0.net ([125.254.1.96]) by smtp.gmail.com with ESMTPSA id t10sm29217103pfa.151.2019.02.26.00.51.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Feb 2019 00:51:30 -0800 (PST) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v4 4/4] powerpc/64s: Fix data interrupts vs d-side MCE reentrancy Date: Tue, 26 Feb 2019 18:51:10 +1000 Message-Id: <20190226085110.29653-5-npiggin@gmail.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20190226085110.29653-1-npiggin@gmail.com> References: <20190226085110.29653-1-npiggin@gmail.com> 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: Nicholas Piggin Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Handlers for interrupts that set DAR / DSISR, set MSR[RI] before those SPRs are read. If a d-side machine check hits in this window, DAR / DSISR will be clobbered silently, leading to random corruption. Fix this by having handlers save those registers before setting MSR[RI]. Signed-off-by: Nicholas Piggin --- arch/powerpc/kernel/exceptions-64s.S | 36 ++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 0b8b57597837..0e6f274788dd 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -582,12 +582,25 @@ EXC_REAL_END(data_access, 0x300, 0x80) TRAMP_REAL_BEGIN(tramp_real_data_access) EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_PR, 0x300) + /* + * DAR/DSISR must be read before setting MSR[RI], because + * a d-side MCE will clobber those registers so is not + * recoverable if they are live. + */ + mfspr r10,SPRN_DAR + mfspr r11,SPRN_DSISR + std r10,PACA_EXGEN+EX_DAR(r13) + stw r11,PACA_EXGEN+EX_DSISR(r13) EXCEPTION_PROLOG_2(data_access_common, EXC_STD) EXC_VIRT_BEGIN(data_access, 0x4300, 0x80) SET_SCRATCH0(r13) /* save r13 */ EXCEPTION_PROLOG_0(PACA_EXGEN) EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0x300) + mfspr r10,SPRN_DAR + mfspr r11,SPRN_DSISR + std r10,PACA_EXGEN+EX_DAR(r13) + stw r11,PACA_EXGEN+EX_DSISR(r13) EXCEPTION_PROLOG_2_RELON(data_access_common, EXC_STD) EXC_VIRT_END(data_access, 0x4300, 0x80) @@ -598,11 +611,8 @@ EXC_COMMON_BEGIN(data_access_common) * Here r13 points to the paca, r9 contains the saved CR, * SRR0 and SRR1 are saved in r11 and r12, * r9 - r13 are saved in paca->exgen. + * EX_DAR and EX_DSISR have saved DAR/DSISR */ - mfspr r10,SPRN_DAR - std r10,PACA_EXGEN+EX_DAR(r13) - mfspr r10,SPRN_DSISR - stw r10,PACA_EXGEN+EX_DSISR(r13) EXCEPTION_PROLOG_COMMON(0x300, PACA_EXGEN) RECONCILE_IRQ_STATE(r10, r11) ld r12,_MSR(r1) @@ -626,20 +636,22 @@ EXC_REAL_END(data_access_slb, 0x380, 0x80) TRAMP_REAL_BEGIN(tramp_real_data_access_slb) EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x380) + mfspr r10,SPRN_DAR + std r10,PACA_EXSLB+EX_DAR(r13) EXCEPTION_PROLOG_2(data_access_slb_common, EXC_STD) EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80) SET_SCRATCH0(r13) /* save r13 */ EXCEPTION_PROLOG_0(PACA_EXSLB) EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x380) + mfspr r10,SPRN_DAR + std r10,PACA_EXSLB+EX_DAR(r13) EXCEPTION_PROLOG_2_RELON(data_access_slb_common, EXC_STD) EXC_VIRT_END(data_access_slb, 0x4380, 0x80) TRAMP_KVM_SKIP(PACA_EXSLB, 0x380) EXC_COMMON_BEGIN(data_access_slb_common) - mfspr r10,SPRN_DAR - std r10,PACA_EXSLB+EX_DAR(r13) EXCEPTION_PROLOG_COMMON(0x380, PACA_EXSLB) ld r4,PACA_EXSLB+EX_DAR(r13) std r4,_DAR(r1) @@ -739,6 +751,10 @@ EXC_REAL_BEGIN(alignment, 0x600, 0x100) SET_SCRATCH0(r13) /* save r13 */ EXCEPTION_PROLOG_0(PACA_EXGEN) EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_PR, 0x600) + mfspr r10,SPRN_DAR + mfspr r11,SPRN_DSISR + std r10,PACA_EXGEN+EX_DAR(r13) + stw r11,PACA_EXGEN+EX_DSISR(r13) EXCEPTION_PROLOG_2(alignment_common, EXC_STD) EXC_REAL_END(alignment, 0x600, 0x100) @@ -746,15 +762,15 @@ EXC_VIRT_BEGIN(alignment, 0x4600, 0x100) SET_SCRATCH0(r13) /* save r13 */ EXCEPTION_PROLOG_0(PACA_EXGEN) EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0x600) + mfspr r10,SPRN_DAR + mfspr r11,SPRN_DSISR + std r10,PACA_EXGEN+EX_DAR(r13) + stw r11,PACA_EXGEN+EX_DSISR(r13) EXCEPTION_PROLOG_2_RELON(alignment_common, EXC_STD) EXC_VIRT_END(alignment, 0x4600, 0x100) TRAMP_KVM(PACA_EXGEN, 0x600) EXC_COMMON_BEGIN(alignment_common) - mfspr r10,SPRN_DAR - std r10,PACA_EXGEN+EX_DAR(r13) - mfspr r10,SPRN_DSISR - stw r10,PACA_EXGEN+EX_DSISR(r13) EXCEPTION_PROLOG_COMMON(0x600, PACA_EXGEN) ld r3,PACA_EXGEN+EX_DAR(r13) lwz r4,PACA_EXGEN+EX_DSISR(r13) -- 2.18.0