From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 22 Aug 2012 19:09:05 +0000 (-0400)
Subject: Fix: vppid context should test for current nsproxy
X-Git-Tag: v2.1.0-rc1~12
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=de544ea58e0231054bb62e2c814c662b894d6e25;p=lttng-modules.git

Fix: vppid context should test for current nsproxy

Triggers a NULL pointer exception with tracing scheduling events with
vppid context activated.

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/lttng-context-vppid.c b/lttng-context-vppid.c
index 3d55fc5d..365d9739 100644
--- a/lttng-context-vppid.c
+++ b/lttng-context-vppid.c
@@ -48,11 +48,12 @@ void vppid_record(struct lttng_ctx_field *field,
 	pid_t vppid;
 
 	/*
-	 * nsproxy can be NULL when scheduled out of exit.
+	 * current nsproxy can be NULL when scheduled out of exit. pid_vnr uses
+	 * the current thread nsproxy to perform the lookup.
 	 */
 	rcu_read_lock();
 	parent = rcu_dereference(current->real_parent);
-	if (!parent->nsproxy)
+	if (!current->nsproxy)
 		vppid = 0;
 	else
 		vppid = task_tgid_vnr(parent);