| Message ID | 1339791195-26389-8-git-send-email-paulmck@linux.vnet.ibm.com |
|---|---|
| State | Superseded |
| Headers | show |
On Fri, Jun 15, 2012 at 01:13:09PM -0700, Paul E. McKenney wrote: > From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> > > The return value from rcu_assign_pointer() is not used, and using it > would be quite ugly, for example: > > q = rcu_assign_pointer(global_p, p); > > To prevent this sort of ugliness from spreading, this commit wraps > rcu_assign_pointer() in a do-while loop. > > Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > Reported-by: Josh Triplett <josh@joshtriplett.org> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> > include/linux/rcupdate.h | 6 +++--- > 1 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h > index f2cca02..2f6ec55 100644 > --- a/include/linux/rcupdate.h > +++ b/include/linux/rcupdate.h > @@ -514,10 +514,10 @@ static inline void rcu_preempt_sleep_check(void) > (_________p1); \ > }) > #define __rcu_assign_pointer(p, v, space) \ > - ({ \ > + do { \ > smp_wmb(); \ > (p) = (typeof(*v) __force space *)(v); \ > - }) > + } while (0) > > > /** > @@ -852,7 +852,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) > * > * Assigns the specified value to the specified RCU-protected > * pointer, ensuring that any concurrent RCU readers will see > - * any prior initialization. Returns the value assigned. > + * any prior initialization. > * > * Inserts memory barriers on architectures that require them > * (which is most of them), and also prevents the compiler from > -- > 1.7.8 >
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index f2cca02..2f6ec55 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -514,10 +514,10 @@ static inline void rcu_preempt_sleep_check(void) (_________p1); \ }) #define __rcu_assign_pointer(p, v, space) \ - ({ \ + do { \ smp_wmb(); \ (p) = (typeof(*v) __force space *)(v); \ - }) + } while (0) /** @@ -852,7 +852,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) * * Assigns the specified value to the specified RCU-protected * pointer, ensuring that any concurrent RCU readers will see - * any prior initialization. Returns the value assigned. + * any prior initialization. * * Inserts memory barriers on architectures that require them * (which is most of them), and also prevents the compiler from