On Tue, Sep 28, 2021 at 11:01:54AM -0700, Sohil Mehta wrote: > On 9/23/2021 5:28 AM, Greg KH wrote: > > On Mon, Sep 13, 2021 at 01:01:29PM -0700, Sohil Mehta wrote: > > > +/* User Interrupt Target Table Entry (UITTE) */ > > > +struct uintr_uitt_entry { > > > + u8 valid; /* bit 0: valid, bit 1-7: reserved */ > > Do you check that the other bits are set to 0? > > I don't have a check but kzalloc() in alloc_uitt() should set it to 0. > > > > + u8 user_vec; > > > + u8 reserved[6]; > > What is this reserved for? > > This is hardware defined structure as well. I should probably mention this > it in the comment above. > > > > + u64 target_upid_addr; > > If this is a pointer, why not say it is a pointer? > > I used a u64 to get the size and alignment of this structure as required by > the hardware. I wasn't sure if using a struct upid * would complicate that. > > Also this field is never used as a pointer by the kernel. It is only used to > program an entry that is read by the hardware. > > Is this reasonable or would you still prefer a pointer? Ok, just document it really well that this is NOT a real address used by the kernel. As it is, that's not obvious at all. And if this crosses the user/kernel boundry, it needs to be __u64 right? thanks, greg k-h