[PATCH v2] sbus: Introduce the use of the managed version of kzalloc

[PATCH v2] sbus: 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>
---
v2: remove random return points introduces by me in v1

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 v2] sbus: Introduce the use of the managed version of kzalloc

[Sam Ravnborg]

Hi Himangi.

On Sun, May 25, 2014 at 04:28:25PM +0530, Himangi Saraogi wrote:
> 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.
This version looks much better.
If you in the subject replaces sbus: with display7seg: then you can add my:
Acked-by: Sam Ravnborg <sam@ravnborg.org>

"sbus:" is very generic, but this patch touches only
this single driver.

	Sam