On Wed, Nov 27, 2019 at 10:25:57AM -0500, Joel Fernandes wrote: > On Wed, Nov 27, 2019 at 12:29 AM Amol Grover <frextrite(a)gmail.com&gt; wrote: > > > > On Tue, Nov 26, 2019 at 09:29:25PM -0500, Joel Fernandes wrote: > > > On Tue, Nov 26, 2019 at 10:57:23PM +0530, Amol Grover wrote: > > > > add __rcu notation to RCU protected global pointer auditd_conn > > > > > > > > Fixes multiple instances of sparse error: > > > > error: incompatible types in comparison expression > > > > (different address spaces) > > > > > > > > Signed-off-by: Amol Grover <frextrite(a)gmail.com&gt; > > > > --- > > > > kernel/audit.c | 6 ++++-- > > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/kernel/audit.c b/kernel/audit.c > > > > index da8dc0db5bd3..30e7fc9b8da2 100644 > > > > --- a/kernel/audit.c > > > > +++ b/kernel/audit.c > > > > @@ -102,12 +102,14 @@ struct audit_net { > > > > * This struct is RCU protected; you must either hold the RCU lock for reading > > > > * or the associated spinlock for writing. > > > > */ > > > > -static struct auditd_connection { > > > > +struct auditd_connection { > > > > struct pid *pid; > > > > u32 portid; > > > > struct net *net; > > > > struct rcu_head rcu; > > > > -} *auditd_conn = NULL; > > > > +}; > > > > +static struct auditd_connection __rcu *auditd_conn; > > > > +RCU_INIT_POINTER(auditd_conn); > > > > > > Looks like this causes a build error. Always please build test your patches > > > in the very least. And I also did not understand how RCU_INIT_POINTER can > > > even be used outside of a function. In C, executable code cannot be outside > > > functions. > > > > > > Is doing the following not sufficient to fix the sparse issue? > > > > > > thanks, > > > > > > - Joel > > > > > > ---8<----------------------- > > > > > > diff --git a/kernel/audit.c b/kernel/audit.c > > > index 49b6049b26ac..c5d4b5a2dea1 100644 > > > --- a/kernel/audit.c > > > +++ b/kernel/audit.c > > > @@ -108,8 +108,8 @@ struct auditd_connection { > > > struct net *net; > > > struct rcu_head rcu; > > > }; > > > -static struct auditd_connection __rcu *auditd_conn; > > > -RCU_INIT_POINTER(auditd_conn); > > > +static struct auditd_connection __rcu *auditd_conn = NULL; > > > > I ran a quick checkpatch and it gave me this error: > > ERROR: do not initialise statics to NULL > > > > So in order to fix it I decided to INIT the pointer (and failed) > > Well, try to understand the checkpatch error then, and do the right thing :) I read-up a few articles about this. I think I've understood the problem. I'm sending in the ammended patch now. Sorry for this. Won't happen again.