"Input/output error" when using cuda-gdb ?

Hello, I got a question while using cuda-gdb
when I stepped into one kernel function and set breakpoint, it returned info:

Warning:
Cannot insert breakpoint 4.
Error accessing memory address 0xd8: Input/output error.

cuda-gdb used to work before, but when I modified the code(pad zeros to global memory)
it always showed the “I/O” error??

(cuda-gdb) s

Warning:

Cannot insert breakpoint 0.

Error accessing memory address 0x0: Input/output error.

Have a similar problem, cannot believe there is no replay!?

Wow, that sounds serious. Can you paste your code?