RE: [PATCH] block: Check ADMIN before NICE for IOPRIO_CLASS_RT

From: Alistair Delva

Sent: 15 November 2021 19:09

...

...

...

•                   if (!capable(CAP_SYS_NICE) && !capable(CAP_SYS_ADMIN))
  

•                   if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_NICE))
                            return -EPERM;
  

Isn't the real problem that you actually want to test: if (!capable(CAP_SYS_NICE | CAP_SYS_ADMIN)) return -EPERM; so that you only get the fail 'splat' when neither is set.

This will be true whenever more than one capability enables something.

Possibly this needs something like: int capabale_or(unsigned int, ...); #define capabale_or(...) capabable_or(__VA_LIST__, ~0u)

David

- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)