From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 35C0CBA45 for ; Tue, 7 Mar 2023 18:09:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C468C433A0; Tue, 7 Mar 2023 18:09:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678212553; bh=6UUeGEX5GlhzaR1SlSF1KWn04741UKjkHzpSXTw1kj4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o6+qOlnIK9c/SQx1434BPy/EDJDpwxOdbO0In5E8VSJRY7/n0ScDXSdNwEydz1RYu YVD5ufjCtCYwzDhGhDKN27RDXl3uJHz1C6YBgrm0qQYHRSTqOT7CsPICqeGyLsNwgz BAAB6AaaSeXKZ8gVr4JGL5f/YlqLAMiX3FgxrGxI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Viresh Kumar , Oleksandr Tyshchenko , Stefano Stabellini , Juergen Gross , Sasha Levin Subject: [PATCH 6.1 221/885] xen/grant-dma-iommu: Implement a dummy probe_device() callback Date: Tue, 7 Mar 2023 17:52:35 +0100 Message-Id: <20230307170011.685160180@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170001.594919529@linuxfoundation.org> References: <20230307170001.594919529@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Oleksandr Tyshchenko [ Upstream commit 2062f9fb6445451b189595e295765c69f43bc12e ] Update stub IOMMU driver (which main purpose is to reuse generic IOMMU device-tree bindings by Xen grant DMA-mapping layer on Arm) according to the recent changes done in the following commit 57365a04c921 ("iommu: Move bus setup to IOMMU device registration"). With probe_device() callback being called during IOMMU device registration, the uninitialized callback just leads to the "kernel NULL pointer dereference" issue during boot. Fix that by adding a dummy callback. Looks like the release_device() callback is not mandatory to be implemented as IOMMU framework makes sure that callback is initialized before dereferencing. Reported-by: Viresh Kumar Fixes: 57365a04c921 ("iommu: Move bus setup to IOMMU device registration") Signed-off-by: Oleksandr Tyshchenko Tested-by: Viresh Kumar Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/20230208153649.3604857-1-olekstysh@gmail.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin --- drivers/xen/grant-dma-iommu.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/xen/grant-dma-iommu.c b/drivers/xen/grant-dma-iommu.c index 16b8bc0c0b33d..6a9fe02c6bfcc 100644 --- a/drivers/xen/grant-dma-iommu.c +++ b/drivers/xen/grant-dma-iommu.c @@ -16,8 +16,15 @@ struct grant_dma_iommu_device { struct iommu_device iommu; }; -/* Nothing is really needed here */ -static const struct iommu_ops grant_dma_iommu_ops; +static struct iommu_device *grant_dma_iommu_probe_device(struct device *dev) +{ + return ERR_PTR(-ENODEV); +} + +/* Nothing is really needed here except a dummy probe_device callback */ +static const struct iommu_ops grant_dma_iommu_ops = { + .probe_device = grant_dma_iommu_probe_device, +}; static const struct of_device_id grant_dma_iommu_of_match[] = { { .compatible = "xen,grant-dma" }, -- 2.39.2