[PATCH] display7seg: Introduce the use of the managed version of kzalloc

[PATCH] display7seg: Introduce the use of the managed version of kzalloc

[Himangi Saraogi]

This patch moves data allocated using kzalloc to managed data allocated
using devm_kzalloc and cleans now unnecessary kfrees in probe and remove
functions. The header file is added to make the devm function explicitly
available.

The following Coccinelle semantic patch was used for making a part of
the change:

@platform@
identifier p, probefn, removefn;
@@
struct platform_driver p = {
  .probe = probefn,
  .remove = removefn,
};

@prb@
identifier platform.probefn, pdev;
expression e, e1, e2;
@@
probefn(struct platform_device *pdev, ...) {
  <+...
- e = kzalloc(e1, e2)
+ e = devm_kzalloc(&pdev->dev, e1, e2)
  ...
?-kfree(e);
  ...+>
}

@rem depends on prb@
identifier platform.removefn;
expression e;
@@
removefn(...) {
  <...
- kfree(e);
  ...>
}

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
---
Not compile tested due to incompatible architecture.

 drivers/sbus/char/display7seg.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
index 7c71e7b..b48899c 100644
--- a/drivers/sbus/char/display7seg.c
+++ b/drivers/sbus/char/display7seg.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
  */
 
+#include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/fs.h>
@@ -180,7 +181,7 @@ static int d7s_probe(struct platform_device *op)
 	if (d7s_device)
 		goto out;
 
-	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
 	err = -ENOMEM;
 	if (!p)
 		goto out;
@@ -231,7 +232,6 @@ out_iounmap:
 	of_iounmap(&op->resource[0], p->regs, sizeof(u8));
 
 out_free:
-	kfree(p);
 	goto out;
 }
 
@@ -251,7 +251,6 @@ static int d7s_remove(struct platform_device *op)
 
 	misc_deregister(&d7s_miscdev);
 	of_iounmap(&op->resource[0], p->regs, sizeof(u8));
-	kfree(p);
 
 	return 0;
 }
-- 
1.9.1

Re: [PATCH] display7seg: Introduce the use of the managed version of kzalloc

[David Miller]

From: Himangi Saraogi <himangi774@gmail.com>
Date: Tue, 27 May 2014 03:02:07 +0530

> This patch moves data allocated using kzalloc to managed data allocated
> using devm_kzalloc and cleans now unnecessary kfrees in probe and remove
> functions. The header file is added to make the devm function explicitly
> available.
> 
> The following Coccinelle semantic patch was used for making a part of
> the change:
 ...
> Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
> Acked-by: Julia Lawall <julia.lawall@lip6.fr>
> Acked-by: Sam Ravnborg <sam@ravnborg.org>

Applied to sparc-next.