On Tue, Dec 06, 2022 at 01:55:47PM -0800, Steve Sistare wrote: > The first task to pin any pages becomes the dma owner, and becomes the only > task allowed to pin. This prevents an application from exceeding the > initial task's RLIMIT_MEMLOCK by fork'ing and pinning in children. We do not need to play games with the RLIMIT here - RLIMIT is inherently insecure and if fork is available then the process can blow past the sandbox limit. There is nothing we can do to prevent this in the kernel, so don't even try. iommufd offers the user based limit tracking which prevents this properly. And we are working on cgroup based limit tracking that is the best option to solve this problem. I would rather see us focus on the cgroup stuff than this. Jason
