| Message ID | 20180518165624.13993-1-hch@lst.de |
|---|---|
| State | Accepted |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI/sysfs: do not allow enabling/disabling a device with a driver | expand |
On Fri, May 18, 2018 at 06:56:24PM +0200, Christoph Hellwig wrote: > 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@lst.de> Nice, looks like you beat me to it, and used device locking that I missed. Acked-by: Keith Busch <keith.busch@intel.com> Bjorn, Please disregard https://marc.info/?l=linux-pci&m=152666267830742&w=2
Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
On Fri, May 18, 2018 at 06:56:24PM +0200, Christoph Hellwig wrote: > 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@lst.de> Applied to pci/enumeration for v4.18, thanks! > --- > 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 >
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; }
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@lst.de> --- drivers/pci/pci-sysfs.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)