From patchwork Wed Jun 17 10:54:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 11609689 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DDBAF618 for ; Wed, 17 Jun 2020 10:55:16 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 AFCE3208B3 for ; Wed, 17 Jun 2020 10:55:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="rYhpfQL2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AFCE3208B3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=2izSrIyfeEaqRfdObKcAq3ZETKzQ2XZKiwfJKtZOlMI=; b=rYhpfQL2u1lUuE Z2T65CHJKU2vHjik4kQJfLRtv5/eEF2QPG5eQGwFHZpmT+9e6T29EvD/OxOR/a0NsE38FiX9ZyCg5 nATxle4LklmbhYxlE4/WTbc7A9x0r7L64ZgVYHBRb4DPmqOje1aFR6uVQ+YpfeS4WZgJwMFcpyv17 1mnTiXPmCIdHrQM7W2zaTZHm6vlPNR9/8rgw34CM5VAt3ojTkgexGl2s+Tkdy9IRPKVlLmPYqIT9t 9k4Qc+NCWIbEZZz9/TKTpbzWr1UpbiTcYdgwnY+dEfc3FKBFOqILGw+kNIEQ3OZ36F9eOg+FLUKnC r8TAzQ7DSBYbbpM9JaZg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jlViq-0000GK-5S; Wed, 17 Jun 2020 10:55:12 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jlVin-0007zZ-1n for linux-arm-kernel@lists.infradead.org; Wed, 17 Jun 2020 10:55:10 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 86BF3C0A; Wed, 17 Jun 2020 03:55:08 -0700 (PDT) Received: from e112269-lin.arm.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 384F03F71F; Wed, 17 Jun 2020 03:55:06 -0700 (PDT) From: Steven Price To: Catalin Marinas , Marc Zyngier , Will Deacon Subject: [PATCH v2] KVM: arm64: kvm_reset_vcpu() return code incorrect with SVE Date: Wed, 17 Jun 2020 11:54:56 +0100 Message-Id: <20200617105456.28245-1-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200617_035509_183653_557CE32B X-CRM114-Status: GOOD ( 10.97 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [217.140.110.172 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Suzuki K Poulose , linux-kernel@vger.kernel.org, Dave Martin , James Morse , Julien Thierry , Steven Price , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org If SVE is enabled then 'ret' can be assigned the return value of kvm_vcpu_enable_sve() which may be 0 causing future "goto out" sites to erroneously return 0 on failure rather than -EINVAL as expected. Remove the initialisation of 'ret' and make setting the return value explicit to avoid this situation in the future. Fixes: 9a3cdf26e336 ("KVM: arm64/sve: Allow userspace to enable SVE for vcpus") Reported-by: James Morse Signed-off-by: Steven Price --- Changes since v1: * Fix embarrassing accidental inversion of the if() test The problematic chunk isn't visible in the diff, so reproduced here: if (!kvm_arm_vcpu_sve_finalized(vcpu)) { if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) { ret = kvm_vcpu_enable_sve(vcpu); if (ret) goto out; } } else { kvm_vcpu_reset_sve(vcpu); } arch/arm64/kvm/reset.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index d3b209023727..6ed36be51b4b 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -245,7 +245,7 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu) */ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) { - int ret = -EINVAL; + int ret; bool loaded; u32 pstate; @@ -269,15 +269,19 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) { - if (kvm_vcpu_enable_ptrauth(vcpu)) + if (kvm_vcpu_enable_ptrauth(vcpu)) { + ret = -EINVAL; goto out; + } } switch (vcpu->arch.target) { default: if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) { - if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) + if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) { + ret = -EINVAL; goto out; + } pstate = VCPU_RESET_PSTATE_SVC; } else { pstate = VCPU_RESET_PSTATE_EL1;