From patchwork Mon Nov 21 15:43:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Yingliang X-Patchwork-Id: 1707438 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4NGBYk4fZpz23nP for ; Tue, 22 Nov 2022 02:45:46 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4NGBYj6MJzz3cKk for ; Tue, 22 Nov 2022 02:45:45 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=45.249.212.189; helo=szxga03-in.huawei.com; envelope-from=yangyingliang@huawei.com; receiver=) Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (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 4NGBYT27Ssz3bc5 for ; Tue, 22 Nov 2022 02:45:29 +1100 (AEDT) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4NGBTW327tzFqSM; Mon, 21 Nov 2022 23:42:07 +0800 (CST) Received: from dggpemm500007.china.huawei.com (7.185.36.183) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 21 Nov 2022 23:45:21 +0800 Received: from huawei.com (10.175.103.91) by dggpemm500007.china.huawei.com (7.185.36.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 21 Nov 2022 23:45:21 +0800 From: Yang Yingliang To: , , , , Subject: [PATCH v2] ocxl: fix pci device refcount leak when calling get_function_0() Date: Mon, 21 Nov 2022 23:43:39 +0800 Message-ID: <20221121154339.4088935-1-yangyingliang@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.103.91] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500007.china.huawei.com (7.185.36.183) X-CFilter-Loop: Reflected 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: linuxppc-dev@lists.ozlabs.org, yangyingliang@huawei.com Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" get_function_0() calls pci_get_domain_bus_and_slot(), as comment says, it returns a pci device with refcount increment, so after using it, pci_dev_put() needs be called. Get the device reference when get_function_0() is not called, so pci_dev_put() can be called in the error path and callers unconditionally. And add comment above get_dvsec_vendor0() to tell callers to call pci_dev_put(). Fixes: 87db7579ebd5 ("ocxl: control via sysfs whether the FPGA is reloaded on a link reset") Suggested-by: Andrew Donnellan Signed-off-by: Yang Yingliang Acked-by: Andrew Donnellan Acked-by: Frederic Barrat --- v1 -> v2: Add comment above get_dvsec_vendor0(). Get reference where dev is function 0, and call pci_dev_put() unconditionally in callers. --- drivers/misc/ocxl/config.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c index e401a51596b9..92ab49705f64 100644 --- a/drivers/misc/ocxl/config.c +++ b/drivers/misc/ocxl/config.c @@ -193,6 +193,18 @@ static int read_dvsec_vendor(struct pci_dev *dev) return 0; } +/** + * get_dvsec_vendor0() - Find a related PCI device (function 0) + * @dev: PCI device to match + * @dev0: The PCI device (function 0) found + * @out_pos: The position of PCI device (function 0) + * + * Returns 0 on success, negative on failure. + * + * NOTE: If it's successful, the reference of dev0 is increased, + * so after using it, the callers must call pci_dev_put() to give + * up the reference. + */ static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0, int *out_pos) { @@ -202,10 +214,14 @@ static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0, dev = get_function_0(dev); if (!dev) return -1; + } else { + dev = pci_dev_get(dev); } pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID); - if (!pos) + if (!pos) { + pci_dev_put(dev); return -1; + } *dev0 = dev; *out_pos = pos; return 0; @@ -222,6 +238,7 @@ int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val) pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, &reset_reload); + pci_dev_put(dev0); *val = !!(reset_reload & BIT(0)); return 0; } @@ -243,6 +260,7 @@ int ocxl_config_set_reset_reload(struct pci_dev *dev, int val) reset_reload &= ~BIT(0); pci_write_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, reset_reload); + pci_dev_put(dev0); return 0; }