> One example of the problems with extra layers what this patch fixes: > mmap_pgoff() should never be using SHM_HUGE_* logic. This was > introduced by: > > 091d0d55b28 (shm: fix null pointer deref when userspace specifies invalid > hugepage size) > > It is obviously harmless but lets just rip out the whole thing -- > the shmget.2 manpage will need updating, as it should not be > describing kernel internals.
The SHM_* defines were supposed to be exported to user space, but somehow they didn't make it into uapi. But something like this is useful, it's a much nicer interface for users than to hard code the bit position So I would rather if you move it to uapi instead of removing. What the kernel uses internally doesn't really matter. -Andi
