From:   Seunggyun Lee <sglee97@dankook.ac.kr>
To:     bhelgaas@google.com
Cc:     linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] pci/mmap: add pci device EBUSY check
Date:   Tue,  7 Feb 2023 20:39:49 +0900
Message-Id: <20230207113949.17943-1-sglee97@dankook.ac.kr>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When using a pci device through the vfio-pci driver, other software was
also able to access the pci device memory through sysfs.

To prevent this, when mmap is performed through sysfs, a process of
checking whether the device is in use is added.

Signed-off-by: Seunggyun Lee <sglee97@dankook.ac.kr>
---
 drivers/pci/mmap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/mmap.c b/drivers/pci/mmap.c
index 4504039056d1..4c9df2e23e03 100644
--- a/drivers/pci/mmap.c
+++ b/drivers/pci/mmap.c
@@ -25,6 +25,8 @@ int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
 {
 	unsigned long size;
 	int ret;
+	if (pdev->driver)
+		return -1;
 
 	size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
 	if (vma->vm_pgoff + vma_pages(vma) > size)
-- 
2.25.1