On Fri, Jul 17, 2020 at 8:44 PM Richard Guy Briggs [off-list ref] wrote:

On 2020-07-05 11:11, Paul Moore wrote:

quoted

On Sat, Jun 27, 2020 at 9:23 AM Richard Guy Briggs [off-list ref] wrote:

quoted

Add audit container identifier auxiliary record to user event standalone
records.

Signed-off-by: Richard Guy Briggs <redacted>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
---
 kernel/audit.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index 54dd2cb69402..997c34178ee8 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c

@@ -1507,6 +1504,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                audit_log_n_untrustedstring(ab, str, data_len);
                        }
                        audit_log_end(ab);
+                       rcu_read_lock();
+                       cont = _audit_contobj_get(current);
+                       rcu_read_unlock();
+                       audit_log_container_id(context, cont);
+                       rcu_read_lock();
+                       _audit_contobj_put(cont);
+                       rcu_read_unlock();
+                       audit_free_context(context);

I haven't searched the entire patchset, but it seems like the pattern
above happens a couple of times in this patchset, yes?  If so would it
make sense to wrap the above get/log/put in a helper function?

I've redone the locking with an rcu lock around the get and a spinlock
around the put.  It occurs to me that putting an rcu lock around the
whole thing and doing a get without the refcount increment would save
us the spinlock and put and be fine since we'd be fine with stale but
consistent information traversing the contobj list from this point to
report it.  Problem with that is needing to use GFP_ATOMIC due to the
rcu lock.  If I stick with the spinlock around the put then I can use
GFP_KERNEL and just grab the spinlock while traversing the contobj list.

quoted

Not a big deal either way, I'm pretty neutral on it at this point in
the patchset but thought it might be worth mentioning in case you
noticed the same and were on the fence.

There is only one other place this is used, in audit_log_exit in
auditsc.c.  I had noted the pattern but wasn't sure it was worth it.
Inline or not?  Should we just let the compiler decide?

I'm generally not a fan of explicit inlines unless it has been shown
to be a real problem.

-- 
paul moore
www.paul-moore.com