On Tue, Sep 28, 2021 at 11:01:54AM -0700, Sohil Mehta wrote:

On 9/23/2021 5:28 AM, Greg KH wrote:

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On Mon, Sep 13, 2021 at 01:01:29PM -0700, Sohil Mehta wrote:

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+/* 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.

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+	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.

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+	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