Unnecessary Relocation Hiding
have a question. Why shall we need a RELOC_HIDE() macro in thedefinition of per_cpu()? Maybe the question is actually why we need
macro RELOC_HIDE() at all. I changed the following line in
include/asm-generic/percpu.h, from
#define per_cpu(var, cpu) (*RELOC_HIDE(&per_cpu__##var, __per_cpu_offset))
to
#define per_cpu(var, cpu) (*((unsigned long)(&per_cpu__##var) +
__per_cpu_offset))
I recompiled the code and it works well on my Intel Dual-core laptop.
It essentially the same as to change the definition of RELOC_HIDE(),
from
#define RELOC_HIDE(ptr, off) \
({ unsigned long __ptr; \
__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
(typeof(ptr)) (__ptr + (off)); })
to
#define RELOC_HIDE(ptr, off) \
({ unsigned long __ptr; \
__ptr = (unsigned long)ptr; \
(typeof(ptr)) (__ptr + (off)); })
Why shouldn't we have a pure C solution in this part?
Best Regards.
Feng,Dong
页:
[1]