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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:	Wed, 12 Sep 2012 17:06:45 +0200
From:	Peter Senna Tschudin <peter.senna@...il.com>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	kernel-janitors@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 7/9] drivers/char/mmtimer.c: Remove useless kfree

From: Peter Senna Tschudin <peter.senna@...il.com>

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@...il.com>

---
 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);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/