From patchwork Tue Oct 12 13:25:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 12552597 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B415FC433FE for ; Tue, 12 Oct 2021 13:23:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9629D6101D for ; Tue, 12 Oct 2021 13:23:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236861AbhJLNZu (ORCPT ); Tue, 12 Oct 2021 09:25:50 -0400 Received: from foss.arm.com ([217.140.110.172]:42152 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236848AbhJLNZt (ORCPT ); Tue, 12 Oct 2021 09:25:49 -0400 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 7DAE21063; Tue, 12 Oct 2021 06:23:47 -0700 (PDT) Received: from monolith.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7DAAD3F66F; Tue, 12 Oct 2021 06:23:46 -0700 (PDT) From: Alexandru Elisei To: will@kernel.org, julien.thierry.kdev@gmail.com, kvm@vger.kernel.org Cc: andre.przywara@arm.com, jean-philippe@linaro.org Subject: [PATCH v2 kvmtool 3/7] pci: Fix pci_dev_* print macros Date: Tue, 12 Oct 2021 14:25:06 +0100 Message-Id: <20211012132510.42134-4-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211012132510.42134-1-alexandru.elisei@arm.com> References: <20211012132510.42134-1-alexandru.elisei@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Evaluate the "pci_hdr" argument before attempting to deference a field. This fixes cryptic errors like this one, which came about during a debugging session: vfio/pci.c: In function 'vfio_pci_bar_activate': include/kvm/pci.h:18:40: error: invalid type argument of '->' (have 'struct pci_device_header') pr_warning("[%04x:%04x] " fmt, pci_hdr->vendor_id, pci_hdr->device_id, ##__VA_ARGS__) ^~ vfio/pci.c:482:3: note: in expansion of macro 'pci_dev_warn' pci_dev_warn(&vdev->pci.hdr, "%s: BAR4\n", __func__); This is caused by the operator precedence rules in C, where pointer deference via "->" has a higher precedence than taking the address with the ampersand symbol. When the macro is substituted, it becomes &vdev->pci.hdr->vendor_id and it dereferences vdev->pci.hdr, which is not a pointer, instead of dereferencing &vdev->pci.hdr, which is a pointer, and quite likely what the author intended. Reviewed-by: Andre Przywara Signed-off-by: Alexandru Elisei --- include/kvm/pci.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/include/kvm/pci.h b/include/kvm/pci.h index 0f2d5bb..d6eb398 100644 --- a/include/kvm/pci.h +++ b/include/kvm/pci.h @@ -13,15 +13,15 @@ #include "kvm/kvm-arch.h" #define pci_dev_err(pci_hdr, fmt, ...) \ - pr_err("[%04x:%04x] " fmt, pci_hdr->vendor_id, pci_hdr->device_id, ##__VA_ARGS__) + pr_err("[%04x:%04x] " fmt, (pci_hdr)->vendor_id, (pci_hdr)->device_id, ##__VA_ARGS__) #define pci_dev_warn(pci_hdr, fmt, ...) \ - pr_warning("[%04x:%04x] " fmt, pci_hdr->vendor_id, pci_hdr->device_id, ##__VA_ARGS__) + pr_warning("[%04x:%04x] " fmt, (pci_hdr)->vendor_id, (pci_hdr)->device_id, ##__VA_ARGS__) #define pci_dev_info(pci_hdr, fmt, ...) \ - pr_info("[%04x:%04x] " fmt, pci_hdr->vendor_id, pci_hdr->device_id, ##__VA_ARGS__) + pr_info("[%04x:%04x] " fmt, (pci_hdr)->vendor_id, (pci_hdr)->device_id, ##__VA_ARGS__) #define pci_dev_dbg(pci_hdr, fmt, ...) \ - pr_debug("[%04x:%04x] " fmt, pci_hdr->vendor_id, pci_hdr->device_id, ##__VA_ARGS__) + pr_debug("[%04x:%04x] " fmt, (pci_hdr)->vendor_id, (pci_hdr)->device_id, ##__VA_ARGS__) #define pci_dev_die(pci_hdr, fmt, ...) \ - die("[%04x:%04x] " fmt, pci_hdr->vendor_id, pci_hdr->device_id, ##__VA_ARGS__) + die("[%04x:%04x] " fmt, (pci_hdr)->vendor_id, (pci_hdr)->device_id, ##__VA_ARGS__) /* * PCI Configuration Mechanism #1 I/O ports. See Section 3.7.4.1.