4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Christoph Hellwig <hch@xxxxxx>
[ Upstream commit 6f5cdfa802733dcb561bf664cc89d203f2fd958f ]
Manipulating the enable_cnt behind the back of the driver will wreak
complete havoc with the kernel state, so disallow it.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Acked-by: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/pci-sysfs.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -180,13 +180,16 @@ static ssize_t enable_store(struct devic
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;
}
