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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 0F2FBC433DF for ; Thu, 2 Jul 2020 01:35:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA4D720781 for ; Thu, 2 Jul 2020 01:35:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593653719; bh=Vo3x2TRiXq5ViMr6k5CcJOTSHhyC2Yca1owqTu51t0U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=C4KDZiCSYTVlf4zJjRlu05rTHblPOhY4BS/5JICTOhyAwlPaCY97dZteIm5O3tfd9 uaextPedjoxI0DH1x2OX38EQbQEX4ApkmcG3LmPaX4LKFovp+UkD89DOcFfJWAfHET BpgyYibRdkP2grBgPvYE5wMEua8cgb+7K6/LWaOM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728523AbgGBBfR (ORCPT ); Wed, 1 Jul 2020 21:35:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:54100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728371AbgGBBXc (ORCPT ); Wed, 1 Jul 2020 21:23:32 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AB5E22082F; Thu, 2 Jul 2020 01:23:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593653011; bh=Vo3x2TRiXq5ViMr6k5CcJOTSHhyC2Yca1owqTu51t0U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=umyc41LhZIIa0ZUERPq850jeBO7C9lVSvomXEWcmiSsjrnPbrXXe3Bdtr9Mzfik7o 1UTVy/xQf+5lP6Nj6a3f3+UXT17KvH1W+Fnz2o2VEgcJIRVLLGfH4/Dd8VaxFF5ZEl mt9p3ji1+e5BK3DSlYc7UeV4QSW7L0qCCEEwzmMw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Aneesh Kumar K.V" , Michael Ellerman , Sasha Levin , kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.7 29/53] powerpc/kvm/book3s64: Fix kernel crash with nested kvm & DEBUG_VIRTUAL Date: Wed, 1 Jul 2020 21:21:38 -0400 Message-Id: <20200702012202.2700645-29-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200702012202.2700645-1-sashal@kernel.org> References: <20200702012202.2700645-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Aneesh Kumar K.V" [ Upstream commit c1ed1754f271f6b7acb1bfdc8cfb62220fbed423 ] With CONFIG_DEBUG_VIRTUAL=y, __pa() checks for addr value and if it's less than PAGE_OFFSET it leads to a BUG(). #define __pa(x) ({ VIRTUAL_BUG_ON((unsigned long)(x) < PAGE_OFFSET); (unsigned long)(x) & 0x0fffffffffffffffUL; }) kernel BUG at arch/powerpc/kvm/book3s_64_mmu_radix.c:43! cpu 0x70: Vector: 700 (Program Check) at [c0000018a2187360] pc: c000000000161b30: __kvmhv_copy_tofrom_guest_radix+0x130/0x1f0 lr: c000000000161d5c: kvmhv_copy_from_guest_radix+0x3c/0x80 ... kvmhv_copy_from_guest_radix+0x3c/0x80 kvmhv_load_from_eaddr+0x48/0xc0 kvmppc_ld+0x98/0x1e0 kvmppc_load_last_inst+0x50/0x90 kvmppc_hv_emulate_mmio+0x288/0x2b0 kvmppc_book3s_radix_page_fault+0xd8/0x2b0 kvmppc_book3s_hv_page_fault+0x37c/0x1050 kvmppc_vcpu_run_hv+0xbb8/0x1080 kvmppc_vcpu_run+0x34/0x50 kvm_arch_vcpu_ioctl_run+0x2fc/0x410 kvm_vcpu_ioctl+0x2b4/0x8f0 ksys_ioctl+0xf4/0x150 sys_ioctl+0x28/0x80 system_call_exception+0x104/0x1d0 system_call_common+0xe8/0x214 kvmhv_copy_tofrom_guest_radix() uses a NULL value for to/from to indicate direction of copy. Avoid calling __pa() if the value is NULL to avoid the BUG(). Signed-off-by: Aneesh Kumar K.V [mpe: Massage change log a bit to mention CONFIG_DEBUG_VIRTUAL] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200611120159.680284-1-aneesh.kumar@linux.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/kvm/book3s_64_mmu_radix.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index bc6c1aa3d0e92..ef40addd52c65 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -40,7 +40,8 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, /* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */ if (kvmhv_on_pseries()) return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr, - __pa(to), __pa(from), n); + (to != NULL) ? __pa(to): 0, + (from != NULL) ? __pa(from): 0, n); quadrant = 1; if (!pid) -- 2.25.1