From patchwork Tue Apr 7 04:35:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 11477535 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 802761744 for ; Tue, 7 Apr 2020 04:37:17 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 55E212075E for ; Tue, 7 Apr 2020 04:37:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="MuR1+ga9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 55E212075E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:41000 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jLfzA-0001QH-EL for patchwork-qemu-devel@patchwork.kernel.org; Tue, 07 Apr 2020 00:37:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52267) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jLfyK-0007xr-4j for qemu-devel@nongnu.org; Tue, 07 Apr 2020 00:36:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jLfyI-0004AI-Pv for qemu-devel@nongnu.org; Tue, 07 Apr 2020 00:36:24 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:40749 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jLfyH-00045P-Hp; Tue, 07 Apr 2020 00:36:22 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 48xF3K17Xkz9sSM; Tue, 7 Apr 2020 14:36:13 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1586234173; bh=wHn1JzecR9WBH37KuCbf5xiT7j7lqDDU4hZhIafKUII=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MuR1+ga9CypNOZPJUydw3KR+swa7KTDGsu6rREC25IwzuO4yyPfpWebBBwbv1tIm7 Kjhl+146k6s4/oyuDQv8/+KKhTqKt5h6qNzpamt4kgG7SHZvadxwvVpkp6wAYWa14K ikg0GX2kB52NsJpflbG+ouaaMWOfM7v6/mYDFDGs= From: David Gibson To: peter.maydell@linaro.org Subject: [PULL 02/10] vfio/spapr: Fix page size calculation Date: Tue, 7 Apr 2020 14:35:58 +1000 Message-Id: <20200407043606.291546-3-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200407043606.291546-1-david@gibson.dropbear.id.au> References: <20200407043606.291546-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 203.11.71.1 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: aik@ozlabs.ru, qemu-devel@nongnu.org, groug@kaod.org, qemu-ppc@nongnu.org, clg@kaod.org, David Gibson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" From: Alexey Kardashevskiy Coverity detected an issue (CID 1421903) with potential call of clz64(0) which returns 64 which make it do "<<" with a negative number. This checks the mask and avoids undefined behaviour. In practice pgsizes and memory_region_iommu_get_min_page_size() always have some common page sizes and even if they did not, the resulting page size would be 0x8000.0000.0000.0000 (gcc 9.2) and ioctl(VFIO_IOMMU_SPAPR_TCE_CREATE) would fail anyway. Signed-off-by: Alexey Kardashevskiy Message-Id: <20200324063912.25063-1-aik@ozlabs.ru> Reviewed-by: Greg Kurz Signed-off-by: David Gibson --- hw/vfio/spapr.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c index 33692fc86f..2900bd1941 100644 --- a/hw/vfio/spapr.c +++ b/hw/vfio/spapr.c @@ -147,7 +147,7 @@ int vfio_spapr_create_window(VFIOContainer *container, { int ret = 0; IOMMUMemoryRegion *iommu_mr = IOMMU_MEMORY_REGION(section->mr); - uint64_t pagesize = memory_region_iommu_get_min_page_size(iommu_mr); + uint64_t pagesize = memory_region_iommu_get_min_page_size(iommu_mr), pgmask; unsigned entries, bits_total, bits_per_level, max_levels; struct vfio_iommu_spapr_tce_create create = { .argsz = sizeof(create) }; long rampagesize = qemu_minrampagesize(); @@ -159,8 +159,8 @@ int vfio_spapr_create_window(VFIOContainer *container, if (pagesize > rampagesize) { pagesize = rampagesize; } - pagesize = 1ULL << (63 - clz64(container->pgsizes & - (pagesize | (pagesize - 1)))); + pgmask = container->pgsizes & (pagesize | (pagesize - 1)); + pagesize = pgmask ? (1ULL << (63 - clz64(pgmask))) : 0; if (!pagesize) { error_report("Host doesn't support page size 0x%"PRIx64 ", the supported mask is 0x%lx",