Hi, I have a scenario and would like to understand how the kernel is expected to behave when I change the CSpace of a TCB when it is blocked on an EP.
1. A TCB (say TCB_1) is blocked on seL4_reply() on an endpoint (say EP_1). 2. Now, another PD, which has the capability to TCB_1, changes the CSpace of TCB_1 by using seL4_TCB_SetSpace(). Let's assume that the VSpace is identical.
This new CSpace can be different from the old CSpace in 4 ways: A. It doesn't have the endpoint EP_1 B. It has the endpoint EP_1 but at a different CSlot. C. It has the endpoint EP_1 at the same CSlot. But since it is a different CSpace(so CNodes shared), it is a minted copy of the EP_1. Let's call it EP_1-prime. D. It has the endpoint EP_1 at the same CSlot, and it is the same EP as I have shared the CNode containing the EP_1 from the original CSpace. New and old CSpaces share the CNode containing that EP_1 like two trees sharing a sub-tree.
I think scenario D should work as if nothing happened, but I do not know what to expect in scenarios A, B, and C. I will try these out soon, but I wanted your input as I did not find a clear answer in the manual.
Best, Sid