On Thu, Jun 28, 2018 at 05:06:29PM +0800, Gao Xiang wrote: > Therefore, this patch introduces simple generic methods to fold > tags into a pointer integer. It currently reuses the last 2 bits > of the pointer for tags, which are safely for all modern platforms. The m68k people will have your head. alignof(unsigned long) == 2 on m68k. Now, kmalloc always returns 8-byte aligned quantities, but if you have: static unsigned long foo; then ((unsigned long)&foo & 2) may be non-zero. > +/* > + * mark these special integers as another type > + * in order to highlight the tagged pointer usage. > + */ > +typedef uintptr_t taggedptr_t; I find this a bit verbose. How about tagptr_t ?
