From: David Goulet <dgoulet@efficios.com>
Date: Thu, 16 May 2013 15:30:15 +0000 (-0400)
Subject: Fix: epoll attributes used outside of compat layer
X-Git-Tag: v2.2.0-rc3~60
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=6d737ce48af40e77ca27cb78348e7f3042eab3ed

Fix: epoll attributes used outside of compat layer

This was breaking the poll() support. A lttng_poll_init is added which
basically resets the lttng poll event data structure and in the case of
epoll sets the epfd to -1.

Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 6f9834425..f6e7094bf 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -705,9 +705,9 @@ static void *thread_manage_kernel(void *data)
 
 	/*
 	 * This first step of the while is to clean this structure which could free
-	 * non NULL pointers so zero it before the loop.
+	 * non NULL pointers so initialize it before the loop.
 	 */
-	memset(&events, 0, sizeof(events));
+	lttng_poll_init(&events);
 
 	if (testpoint(thread_manage_kernel)) {
 		goto error_testpoint;
@@ -3108,9 +3108,8 @@ static void *thread_manage_health(void *data)
 
 	rcu_register_thread();
 
-	/* We might hit an error path before this is set once. */
-	memset(&events, 0, sizeof(events));
-	events.epfd = -1;
+	/* We might hit an error path before this is created. */
+	lttng_poll_init(&events);
 
 	/* Create unix socket */
 	sock = lttcomm_create_unix_sock(health_unix_sock_path);
diff --git a/src/common/compat/poll.h b/src/common/compat/poll.h
index e69d59b42..8403880cf 100644
--- a/src/common/compat/poll.h
+++ b/src/common/compat/poll.h
@@ -158,6 +158,17 @@ static inline void lttng_poll_reset(struct lttng_poll_event *events)
 	}
 }
 
+/*
+ * Initialize an already allocated poll event data structure. For epoll(), the
+ * epfd is set to -1 to indicate that it's not usable.
+ */
+static inline void lttng_poll_init(struct lttng_poll_event *events)
+{
+	lttng_poll_reset(events);
+	/* Set fd to -1 so if clean before created, we don't close 0. */
+	events->epfd = -1;
+}
+
 /*
  * Clean the events structure of a lttng_poll_event. It's the caller
  * responsability to free the lttng_poll_event memory.
@@ -317,6 +328,14 @@ extern void compat_poll_set_max_size(void);
 static inline void lttng_poll_reset(struct lttng_poll_event *events)
 {}
 
+/*
+ * Initialize an already allocated poll event data structure.
+ */
+static inline void lttng_poll_init(struct lttng_poll_event *events)
+{
+	memset(events, 0, sizeof(struct lttng_poll_event));
+}
+
 /*
  * Clean the events structure of a lttng_poll_event. It's the caller
  * responsability to free the lttng_poll_event memory.