On 1/11/20 4:10 PM, Kirill A. Shutemov wrote: > On Fri, Jan 10, 2020 at 08:47:39AM -0700, Jens Axboe wrote: >> This adds support for doing madvise(2) through io_uring. We assume that >> any operation can block, and hence punt everything async. This could be >> improved, but hard to make bullet proof. The async punt ensures it's >> safe. >> >> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > > How capability checks work with io_uring? > > MADV_HWPOISON requires CAP_SYS_ADMIN and I just want to make sure it will > not open a way around. There are two ways the request can get invoked from io_uring: 1) Inline from the system call, personality is the application (of course) in that case. 2) Async helper, personality (creds, mm, etc) are inherited from the ring. So it should be totally safe, and madvise is no different than the other system calls supported in that regard. -- Jens Axboe
