Re: [PATCH-ugly] kmemtrace: casting a gfp_t requires __force

[Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>]

* Harvey Harrison (harvey.harrison@gmail.com) wrote:
> On Fri, 2008-11-07 at 22:20 +0300, Alexey Dobriyan wrote:
> > On Fri, Nov 07, 2008 at 10:58:41AM -0800, Harvey Harrison wrote:
> > > --- a/include/linux/kmemtrace.h
> > > +++ b/include/linux/kmemtrace.h
> > > @@ -34,7 +34,7 @@ static inline void kmemtrace_mark_alloc_node(enum kmemtrace_type_id type_id,
> > >  		   "bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d",
> > >  		   type_id, call_site, (unsigned long) ptr,
> > >  		   (unsigned long) bytes_req, (unsigned long) bytes_alloc,
> > > -		   (unsigned long) gfp_flags, node);
> > > +		   (__force unsigned long)gfp_flags, node);
> > 
> > gfp_t is "unsigned int" actually. These casts are bogus.
> > 
> > Subject: How do I printk <type> correctly?
> > 
> > If variable is of Type	use	printk format specifier.
> > ---------------------------------------------------------
> > 		int			%d or %x
> > 		unsigned int		%u or %x
> > 		long			%ld ot %lx
> > 		unsigned long		%lu or %lx
> > 		long long		%lld or %llx
> > 		unsigned long long	%llu or %llx
> > 		size_t			%zu or %zx
> > 		ssize_t			%zd or %zx
> > 
> 
> Perhaps add gfp_t to the list ;-)
> 

I think a cast

(__force unsigned) could be required for checker ?

#ifdef __CHECKER__
#define __bitwise__ __attribute__((bitwise))
#else
#define __bitwise__
#endif

typedef unsigned __bitwise__ gfp_t;

OTOH, adding a

%uB to printk so it supports bitwise variables may not hurt...

Mathieu

> Thanks.
> 
> Harvey
> 

-- 
Mathieu Desnoyers
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