drivers/video/pnx4008: eliminate double free

The function framebuffer_release just calls kfree, so calling kfree
subsequently on the same argument represents a double free.  The comments with
the definition of framebuffer_release in drivers/video/fbsysfs.c suggest that
a more elaborate definition of this function is planned, such that the
splitting up of framebuffer_release and kfree as done in the second instance
might someday make sense, but it does not make sense now.

This was found using the following semantic match.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E;
@@

* kfree(E);
...
* framebuffer_release(E);

@@
expression E;
@@

* framebuffer_release(E);
...
* kfree(E);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Grigory Tolstolytkin <gtolstolytkin@ru.mvista.com>
Cc: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/video/pnx4008/pnxrgbfb.c b/drivers/video/pnx4008/pnxrgbfb.c
index 685761a0732c2d4196b727875af516627e9ae2a8..4db6b48a87155b1f7316ad6f5145d37922edec8f 100644 (file)
--- a/drivers/video/pnx4008/pnxrgbfb.c
+++ b/drivers/video/pnx4008/pnxrgbfb.c
@@ -100,7 +100,6 @@ static int rgbfb_remove(struct platform_device *pdev)
                fb_dealloc_cmap(&info->cmap);
                framebuffer_release(info);
                platform_set_drvdata(pdev, NULL);
-               kfree(info);
        }
 
        pnx4008_free_dum_channel(channel_owned, pdev->id);
@@ -168,23 +167,21 @@ static int __devinit rgbfb_probe(struct platform_device *pdev)
 
        ret = fb_alloc_cmap(&info->cmap, 256, 0);
        if (ret < 0)
-               goto err2;
+               goto err1;
 
        ret = register_framebuffer(info);
        if (ret < 0)
-               goto err3;
+               goto err2;
        platform_set_drvdata(pdev, info);
 
        return 0;
 
-err3:
-       fb_dealloc_cmap(&info->cmap);
 err2:
-       framebuffer_release(info);
+       fb_dealloc_cmap(&info->cmap);
 err1:
        pnx4008_free_dum_channel(channel_owned, pdev->id);
 err0:
-       kfree(info);
+       framebuffer_release(info);
 err:
        return ret;
 }