On Monday, November 25, 2013 11:45:50 AM Yinghai Lu wrote: > On Mon, Nov 25, 2013 at 3:22 AM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > > > > Well, is_removed is only used by pci_destroy_dev() in your patch, right? > > > > That means its only role is to protect the device from being destroyed > > twice (or more times) in a row, but that surely would be a bug? I don't > > see how that can legitimately happen at least, so what exactly is the > > scenario? > > The thread: > https://patchwork.kernel.org/patch/3119001/ Thanks for the pointer. Well, so we have a bug in there and it is a *race* so adding a device flag is not going to really help. Besides, if the put_device() really frees the struct pci_dev, accessing the flag itself would be a use-after-free, wouldn't it? What seems to be necessary is a lock preventing the /sys/bus/pci/devices/.../remove interface from being used on multiple devices in parallel. Of course, it also has to protect against removals from hotplug events racing with removals from /sys/bus/pci/devices/.../remove. In any case, it is beyond the scope of the $subject patch, though. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
