On Fri, Mar 23, 2012 at 12:19:36PM -0400, KOSAKI Motohiro wrote: > On 3/22/2012 5:28 PM, Al Viro wrote: > > On Thu, Mar 22, 2012 at 02:26:47PM -0700, Andrew Morton wrote: > >> It would be nice to find some way of triggering compiler warnings or > >> sparse warnings if someone mixes a 32-bit type with a vm_flags_t. Any > >> thoughts on this? > >> > >> (Maybe that's what __nocast does, but Documentation/sparse.txt doesn't > >> describe it) > > > > Use __bitwise for that - check how gfp_t is handled. > > Hmm.. > > If now we activate __bitwise, really plenty driver start create lots warnings. > Does it make sense? Huh? Why would they? Just adjust definitions of VM_... to include force-cast to vm_flags_t and we should be OK... > In fact, x86-32 keep 32bit vma_t forever. thus all x86 specific driver don't > need any change. Moreover many ancient drivers has no maintainer and I can't > expect such driver will be fixed even though a warning occur. What warning? If something does manual vma->vm_flags = 0xwhatever, then yes, we do want it dealt with. If it's vma->vm_flags |= VM_something, there should be no warnings at all... -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>