[Xenomai-core] [PATCH] Fix tiny memory leaks around rt_task_self()

[Xenomai-core] [PATCH] Fix tiny memory leaks around rt_task_self()

[Jan Kiszka]

Nothing critical, but when using rt_task_self != NULL as a hint if the
caller is Xenomai-mapped or not, this stall malloc can become at least
unpleasant. This is also material for stable.

Jan

---

Index: xenomai/ChangeLog
===================================================================
--- xenomai/ChangeLog	(Revision 3698)
+++ xenomai/ChangeLog	(Arbeitskopie)
@@ -1,3 +1,8 @@
+2008-04-11  Jan Kiszka  <jan.kiszka@domain.hid>
+
+	* src/skins/native/task.c: Fix tiny memory leaks of the task's
+	self-reference key.
+
 2008-04-10  Philippe Gerum  <rpm@xenomai.org>
 
 	* src/skins/*: Force minimum stack size to 32k, in order to work
Index: xenomai/src/skins/native/task.c
===================================================================
--- xenomai/src/skins/native/task.c	(Revision 3698)
+++ xenomai/src/skins/native/task.c	(Arbeitskopie)
@@ -52,6 +52,11 @@ static void rt_task_sigharden(int sig)
 	XENOMAI_SYSCALL1(__xn_sys_migrate, XENOMAI_XENO_DOMAIN);
 }
 
+static void rt_task_cleanup_tskey(void *arg)
+{
+	free(pthread_getspecific(__native_tskey));
+}
+
 static void *rt_task_trampoline(void *cookie)
 {
 	struct rt_task_iargs *iargs = (struct rt_task_iargs *)cookie;
@@ -92,8 +97,11 @@ static void *rt_task_trampoline(void *co
 		err = XENOMAI_SYSCALL2(__xn_sys_barrier, &entry, &cookie);
 	while (err == -EINTR);
 
-	if (!err)
+	if (!err) {
+		pthread_cleanup_push(rt_task_cleanup_tskey, NULL);
 		entry(cookie);
+		pthread_cleanup_pop(1);
+	}
 
       fail:
 
@@ -294,8 +302,10 @@ RT_TASK *rt_task_self(void)
 	self = (RT_TASK *)malloc(sizeof(*self));
 
 	if (!self ||
-	    XENOMAI_SKINCALL1(__native_muxid, __native_task_self, self) != 0)
+	    XENOMAI_SKINCALL1(__native_muxid, __native_task_self, self) != 0) {
+		free(self);
 		return NULL;
+	}
 
 	pthread_setspecific(__native_tskey, self);
 

Re: [Xenomai-core] [PATCH] Fix tiny memory leaks around rt_task_self()

[Gilles Chanteperdrix]

Jan Kiszka wrote:
 > Nothing critical, but when using rt_task_self != NULL as a hint if the
 > caller is Xenomai-mapped or not, this stall malloc can become at least
 > unpleasant. This is also material for stable.

This looks useless: TSD cleanup routines are automatically called
upon thread termination. It is even worse: you risk a double free if you
do not re-set pthread_setspecific after having called free.

-- 


					    Gilles.

Re: [Xenomai-core] [PATCH] Fix tiny memory leaks around rt_task_self()

[Jan Kiszka]

Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>  > Nothing critical, but when using rt_task_self != NULL as a hint if the
>  > caller is Xenomai-mapped or not, this stall malloc can become at least
>  > unpleasant. This is also material for stable.
> 
> This looks useless: TSD cleanup routines are automatically called
> upon thread termination. It is even worse: you risk a double free if you
> do not re-set pthread_setspecific after having called free.

Ah, I missed the already existing cleanup in init.c. Then we are done
with this patch:

Index: xenomai/ChangeLog
===================================================================
--- xenomai/ChangeLog	(Revision 3698)
+++ xenomai/ChangeLog	(Arbeitskopie)
@@ -1,3 +1,8 @@
+2008-04-11  Jan Kiszka  <jan.kiszka@domain.hid>
+
+	* src/skins/native/task.c (rt_task_self): Fix tiny memory leak
+	when being invoked over a non-Xenomai thread.
+
 2008-04-10  Philippe Gerum  <rpm@xenomai.org>
 
 	* src/skins/*: Force minimum stack size to 32k, in order to work
Index: xenomai/src/skins/native/task.c
===================================================================
--- xenomai/src/skins/native/task.c	(Revision 3698)
+++ xenomai/src/skins/native/task.c	(Arbeitskopie)
@@ -294,8 +294,10 @@ RT_TASK *rt_task_self(void)
 	self = (RT_TASK *)malloc(sizeof(*self));
 
 	if (!self ||
-	    XENOMAI_SKINCALL1(__native_muxid, __native_task_self, self) != 0)
+	    XENOMAI_SKINCALL1(__native_muxid, __native_task_self, self) != 0) {
+		free(self);
 		return NULL;
+	}
 
 	pthread_setspecific(__native_tskey, self);