Manpulating the enable_cnt behind the back of the driver will wreck
complete havok with the kernel state, so disallow it.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/pci/pci-sysfs.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 366d93af051d..788a200fb2dc 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -288,13 +288,16 @@ static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (!val) {
- if (pci_is_enabled(pdev))
- pci_disable_device(pdev);
- else
- result = -EIO;
- } else
+ device_lock(dev);
+ if (dev->driver)
+ result = -EBUSY;
+ else if (val)
result = pci_enable_device(pdev);
+ else if (pci_is_enabled(pdev))
+ pci_disable_device(pdev);
+ else
+ result = -EIO;
+ device_unlock(dev);
return result < 0 ? result : count;
}
--
2.17.0
