lkml.org 
[lkml]   [2012]   [Jul]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4/6] drivers/cpuidle/sysfs.c: ensure a consistent return value in error case
Date
From: Julia Lawall <Julia.Lawall@lip6.fr>

Typically, the return value desired for the failure of a function with an
integer return value is a negative integer. In these cases, the return
value is sometimes a negative integer and sometimes 0, due to a subsequent
initialization of the return variable within the loop.

A simplified version of the semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)

//<smpl>
@r exists@
identifier ret;
position p;
constant C;
expression e1,e3,e4;
statement S;
@@

ret = -C
... when != ret = e3
when any
if@p (...) S
... when any
if (\(ret != 0\|ret < 0\|ret > 0\) || ...) { ... return ...; }
... when != ret = e3
when any
*if@p (...)
{
... when != ret = e4
return ret;
}
//</smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
drivers/cpuidle/sysfs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 5f809e3..06df57c 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -361,15 +361,17 @@ static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
*/
int cpuidle_add_state_sysfs(struct cpuidle_device *device)
{
- int i, ret = -ENOMEM;
+ int i, ret;
struct cpuidle_state_kobj *kobj;
struct cpuidle_driver *drv = cpuidle_get_driver();

/* state statistics */
for (i = 0; i < device->state_count; i++) {
kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
- if (!kobj)
+ if (!kobj) {
+ ret = -ENOMEM;
goto error_state;
+ }
kobj->state = &drv->states[i];
kobj->state_usage = &device->states_usage[i];
init_completion(&kobj->kobj_unregister);


\
 
 \ /
  Last update: 2012-07-14 19:41    [W:0.121 / U:0.172 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site