[PATCH 7/9] drivers/char/mmtimer.c: Remove useless kfree

From: Peter Senna Tschudin
Date: Wed Sep 12 2012 - 11:08:33 EST


From: Peter Senna Tschudin <peter.senna@xxxxxxxxx>

Remove useless kfree() and clean up code related to the removal.

The semantic patch that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
position p1,p2;
expression x;
@@

if (x@p1 == NULL) { ... kfree@p2(x); ... return ...; }

@unchanged exists@
position r.p1,r.p2;
expression e <= r.x,x,e1;
iterator I;
statement S;
@@

if (x@p1 == NULL) { ... when != I(x,...) S
when != e = e1
when != e += e1
when != e -= e1
when != ++e
when != --e
when != e++
when != e--
when != &e
kfree@p2(x); ... return ...; }

@ok depends on unchanged exists@
position any r.p1;
position r.p2;
expression x;
@@

... when != true x@p1 == NULL
kfree@p2(x);

@depends on !ok && unchanged@
position r.p2;
expression x;
@@

*kfree@p2(x);
// </smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@xxxxxxxxx>

---
drivers/char/mmtimer.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c
index 33dc229..3d6c067 100644
--- a/drivers/char/mmtimer.c
+++ b/drivers/char/mmtimer.c
@@ -826,7 +826,7 @@ static int __init mmtimer_init(void)

/* Allocate list of node ptrs to mmtimer_t's */
timers = kzalloc(sizeof(struct mmtimer_node)*maxn, GFP_KERNEL);
- if (timers == NULL) {
+ if (!timers) {
printk(KERN_ERR "%s: failed to allocate memory for device\n",
MMTIMER_NAME);
goto out3;
@@ -848,7 +848,6 @@ static int __init mmtimer_init(void)
return 0;

out3:
- kfree(timers);
misc_deregister(&mmtimer_miscdev);
out2:
free_irq(SGI_MMTIMER_VECTOR, NULL);

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