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[2620:137:e000::1:20]) by mx.google.com with ESMTP id x21-20020a170906149500b008f100fd5096si9815488ejc.887.2023.03.28.01.56.06; Tue, 28 Mar 2023 01:56:29 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@suse.com header.s=susede1 header.b=fJXUKWAN; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=suse.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229684AbjC1Ip4 (ORCPT + 99 others); Tue, 28 Mar 2023 04:45:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229747AbjC1Ipx (ORCPT ); Tue, 28 Mar 2023 04:45:53 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 547B84C05 for ; Tue, 28 Mar 2023 01:45:52 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id E5E36219CB; Tue, 28 Mar 2023 08:45:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1679993150; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=yXUBjKrqwM53T7UrMckHmjpZFpuDk2TlKdZU+l+grfw=; b=fJXUKWANRW8UbMDWIBWa1Ugqequ8HMpEy8gvoVbpd6zkULAMbQGG4p9jGgHdqu6qTdxLhc 46qW60UcAgbI86aHUuh8Utl7D1GVZkBPPdOIqW5XcHq1NFUqRVZGRbgoBwPsx68xwhMFHV KFpMEV+ONinzbFqgbDt2HwSgfcmEXwg= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id B38E31390D; Tue, 28 Mar 2023 08:45:50 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id RdNgKj6pImThLgAAMHmgww (envelope-from ); Tue, 28 Mar 2023 08:45:50 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org Cc: Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , xen-devel@lists.xenproject.org, Dan Carpenter Subject: [PATCH] xen/pciback: don't call pcistub_device_put() under lock Date: Tue, 28 Mar 2023 10:45:49 +0200 Message-Id: <20230328084549.20695-1-jgross@suse.com> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 X-Spam-Status: No, score=-2.5 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1761601167837424772?= X-GMAIL-MSGID: =?utf-8?q?1761601167837424772?= pcistub_device_put() shouldn't be called under spinlock, as it can sleep. For this reason pcistub_device_get_pci_dev() needs to be modified: instead of always calling pcistub_device_get() just do the call of pcistub_device_get() only if it is really needed. This removes the need to call pcistub_device_put(). Reported-by: Dan Carpenter Link: https://lore.kernel.org/lkml/Y+JUIl64UDmdkboh@kadam/ Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko --- drivers/xen/xen-pciback/pci_stub.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c index bba527620507..e34b623e4b41 100644 --- a/drivers/xen/xen-pciback/pci_stub.c +++ b/drivers/xen/xen-pciback/pci_stub.c @@ -194,8 +194,6 @@ static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev, struct pci_dev *pci_dev = NULL; unsigned long flags; - pcistub_device_get(psdev); - spin_lock_irqsave(&psdev->lock, flags); if (!psdev->pdev) { psdev->pdev = pdev; @@ -203,8 +201,8 @@ static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev, } spin_unlock_irqrestore(&psdev->lock, flags); - if (!pci_dev) - pcistub_device_put(psdev); + if (pci_dev) + pcistub_device_get(psdev); return pci_dev; }