Commits
Marc Zyngier committed 9791ec7df0e
irqchip/gic-v3-its: Plug allocation race for devices sharing a DevID On systems or VMs where multiple devices share a single DevID (because they sit behind a PCI bridge, or because the HW is broken in funky ways), we reuse the save its_device structure in order to reflect this. It turns out that there is a distinct lack of locking when looking up the its_device, and two device being probed concurrently can result in double allocations. That's obviously not nice. A solution for this is to have a per-ITS mutex that serializes device allocation. A similar issue exists on the freeing side, which can run concurrently with the allocation. On top of now taking the appropriate lock, we also make sure that a shared device is never freed, as we have no way to currently track the life cycle of such object. Reported-by: Zheng Xiang <zhengxiang9@huawei.com> Tested-by: Zheng Xiang <zhengxiang9@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>