Messages in this thread | | | Date | Thu, 16 Mar 2006 22:48:30 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] unshare: Use rcu_assign_pointer when setting sighand |
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On Thu, Mar 16, 2006 at 10:31:38AM -0700, Eric W. Biederman wrote: > > The sighand pointer only needs the rcu_read_lock on the > read side. So only depending on task_lock protection > when setting this pointer is not enough. We also need > a memory barrier to ensure the initialization is seen first. > > Use rcu_assign_pointer as it does this for us, and clearly > documents that we are setting an rcu readable pointer.
Good catch!
Acked-by: Paul E. McKenney <paulmck@us.ibm.com> > Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> > > > --- > > kernel/fork.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > f0cdb649b7140927777f4355631648b396ee235b > diff --git a/kernel/fork.c b/kernel/fork.c > index d2706e9..2f24553 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -1573,7 +1573,7 @@ asmlinkage long sys_unshare(unsigned lon > > if (new_sigh) { > sigh = current->sighand; > - current->sighand = new_sigh; > + rcu_assign_pointer(current->sighand, new_sigh); > new_sigh = sigh; > } > > -- > 1.2.4.g2d33 > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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