svn commit: r296880 - in head: share/man/man9 sys/kern sys/sys

[Don Lewis]

On 15 Mar, Gleb Smirnoff wrote:
>   Hans,
> 
> On Tue, Mar 15, 2016 at 08:50:11AM +0100, Hans Petter Selasky wrote:
> H> > Modified: head/sys/sys/sysctl.h
> H> > ==============================================================================
> H> > --- head/sys/sys/sysctl.h	Mon Mar 14 23:49:16 2016	(r296879)
> H> > +++ head/sys/sys/sysctl.h	Tue Mar 15 00:05:00 2016	(r296880)
> H> > @@ -204,6 +204,7 @@ int sysctl_handle_long(SYSCTL_HANDLER_AR
> H> >   int sysctl_handle_string(SYSCTL_HANDLER_ARGS);
> H> >   int sysctl_handle_opaque(SYSCTL_HANDLER_ARGS);
> H> >   int sysctl_handle_counter_u64(SYSCTL_HANDLER_ARGS);
> H> > +int sysctl_handle_counter_u64_array(SYSCTL_HANDLER_ARGS);
> H> >
> H> >   int sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS);
> H> >   int sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS);
> H> > @@ -648,6 +649,26 @@ TAILQ_HEAD(sysctl_ctx_list, sysctl_ctx_e
> H> >   	    __ptr, 0, sysctl_handle_counter_u64, "QU", __DESCR(descr));	\
> H> >   })
> H> >
> H> > +/* Oid for an array of counter(9)s.  The pointer and length must be non zero. */
> H> > +#define	SYSCTL_COUNTER_U64_ARRAY(parent, nbr, name, access, ptr, len, descr) \
> H> > +	SYSCTL_OID(parent, nbr, name,					\
> H> > +	    CTLTYPE_OPAQUE | CTLFLAG_MPSAFE | (access),			\
> H> > +	    (ptr), (len), sysctl_handle_counter_u64_array, "S", descr);	\
> H> > +	CTASSERT(((access) & CTLTYPE) == 0 ||				\
> H> > +	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_OPAQUE)
> H> > +
> H> 
> H> Gleb: I suggest you follow the example of the other static SYSCTLs, and 
> H> extend the CTASSERT to also cover the size of the array:
> 
> I agree.
> 
> H> CTASSERT(((access) & CTLTYPE) == 0 ||				\
> H>      (((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_OPAQUE &&	\
> H>       (sizeof(*(ptr)) == 8 * (len))))
> 
> Hardcoding 8 is definitely wrong here. If you come up with correct assert,
> feel free to commit it. I failed to imagine one quickly.
> 
> H> > +#define	SYSCTL_ADD_COUNTER_U64_ARRAY(ctx, parent, nbr, name, access,	\
> H> > +    ptr, len, descr)							\
> H> > +({									\
> H> > +	counter_u64_t *__ptr = (ptr);					\
> H> > +	CTASSERT(((access) & CTLTYPE) == 0 ||				\
> H> > +	    ((access) & SYSCTL_CT_ASSERT_MASK) == CTLTYPE_OPAQUE);	\
> H> 
> H> Same here possibly. Maybe extend the CTASSERT() to also cover the size 
> H> of the array? Would limit the "len" to a constant argument though.
> 
> Of course limiting len to constant for a dynamic oid is something we
> don't want.


How can you do a CTASSERT() on something that isn't known at compile
time?