Re: [PATCH 7/8] percpu: add __percpu sparse annotations to hw_breakpoint

Al Viro
2010-01-26T02:33:33Z

On Tue, Jan 26, 2010 at 11:16:42AM +0900, Tejun Heo wrote:

> # define RELOC_HIDE(ptr, off) \
> ({ unsigned long __ptr; \
> __ptr = (unsigned long) (ptr); \
> (typeof(ptr)) (__ptr + (off)); })
>
> #define __verify_pcpu_ptr(ptr) do { \
> const void __percpu *__vpp_verify = (typeof(ptr))NULL; \
> (void)__vpp_verify; \
> } while (0)
>
> /* Weird cast keeps both GCC and sparse happy. */
> #define SHIFT_PERCPU_PTR(__p, __offset) ({ \
> __verify_pcpu_ptr((__p)); \
> RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)); \
> })
>
> #define per_cpu(var, cpu) \
> (*SHIFT_PERCPU_PTR(&(var), per_cpu_offset(cpu)))

Eh... You are leaving that noderef in place in case of array. And _that_
is not an address space, so casts to AS 0 won't do you any good.