[PATCH 1/6] oom: Make find_lock_task_mm() sparse-aware

[Greg KH]

On Mon, Feb 06, 2012 at 10:59:09PM +0400, Anton Vorontsov wrote:
> On Mon, Feb 06, 2012 at 08:35:42AM -0800, Greg KH wrote:
> [...]
> > > -extern struct task_struct *find_lock_task_mm(struct task_struct *p);
> > > +extern struct task_struct *__find_lock_task_mm(struct task_struct *p);
> > > +
> > > +#define find_lock_task_mm(p)						\
> > > +({									\
> > > +	struct task_struct *__ret;					\
> > > +									\
> > > +	__cond_lock(&(p)->alloc_lock, __ret = __find_lock_task_mm(p));	\
> > > +	__ret;								\
> > > +})
> > 
> > Please use the proper "do...while" style thing here for multi-line,
> > complex #defines like the rest of the kernel does so that you don't end
> > up debugging horrible problems later.
> 
> Unfortunately this isn't possible in this case. Unlike '({})' GCC
> extension, do-while statement does not evaluate to a value, i.e.
> 'x = do { 123; } while (0);' is illegal.

Ah, you are right, my bad, sorry about that.

greg k-h