On Sun, Sep 19, 2021 at 02:38:28PM +0800, Liu Yi L wrote: > Linux now includes multiple device-passthrough frameworks (e.g. VFIO and > vDPA) to manage secure device access from the userspace. One critical task > of those frameworks is to put the assigned device in a secure, IOMMU- > protected context so user-initiated DMAs are prevented from doing harm to > the rest of the system. Some bot will probably send this too, but it has compile warnings and needs to be rebased to 5.15-rc1 drivers/iommu/iommufd/iommufd.c:269:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (refcount_read(&ioas->refs) > 1) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/iommu/iommufd/iommufd.c:277:9: note: uninitialized use occurs here return ret; ^~~ drivers/iommu/iommufd/iommufd.c:269:2: note: remove the 'if' if its condition is always true if (refcount_read(&ioas->refs) > 1) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/iommu/iommufd/iommufd.c:253:17: note: initialize the variable 'ret' to silence this warning int ioasid, ret; ^ = 0 drivers/iommu/iommufd/iommufd.c:727:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (idev->dev == dev || idev->dev_cookie == dev_cookie) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/iommu/iommufd/iommufd.c:767:17: note: uninitialized use occurs here return ERR_PTR(ret); ^~~ drivers/iommu/iommufd/iommufd.c:727:3: note: remove the 'if' if its condition is always false if (idev->dev == dev || idev->dev_cookie == dev_cookie) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/iommu/iommufd/iommufd.c:727:7: warning: variable 'ret' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized] if (idev->dev == dev || idev->dev_cookie == dev_cookie) { ^~~~~~~~~~~~~~~~ drivers/iommu/iommufd/iommufd.c:767:17: note: uninitialized use occurs here return ERR_PTR(ret); ^~~ drivers/iommu/iommufd/iommufd.c:727:7: note: remove the '||' if its condition is always false if (idev->dev == dev || idev->dev_cookie == dev_cookie) { ^~~~~~~~~~~~~~~~~~~ drivers/iommu/iommufd/iommufd.c:717:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 Jason