scripts/coccinelle/free: add NULL test before freeing functions

Warns or generates patch for NULL check before the following functions:

kfree
usb_free_urb
debugfs_remove
debugfs_remove_recursive

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Gilles Muller <Gilles.Muller@lip6.fr>
Cc: Joe Perches <joe@perches.com>
Cc: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Fabian Frederick 2014-08-08 14:23:29 -07:00 committed by Linus Torvalds
parent 56106da793
commit 791dfeb495

View File

@ -0,0 +1,52 @@
/// NULL check before some freeing functions is not needed.
///
/// Based on checkpatch warning
/// "kfree(NULL) is safe this check is probably not required"
/// and kfreeaddr.cocci by Julia Lawall.
///
/// Comments: -
/// Options: --no-includes --include-headers
virtual patch
virtual org
virtual report
virtual context
@r2 depends on patch@
expression E;
@@
- if (E)
(
- kfree(E);
+ kfree(E);
|
- debugfs_remove(E);
+ debugfs_remove(E);
|
- debugfs_remove_recursive(E);
+ debugfs_remove_recursive(E);
|
- usb_free_urb(E);
+ usb_free_urb(E);
)
@r depends on context || report || org @
expression E;
position p;
@@
* if (E)
* \(kfree@p\|debugfs_remove@p\|debugfs_remove_recursive@p\|usb_free_urb\)(E);
@script:python depends on org@
p << r.p;
@@
cocci.print_main("NULL check before that freeing function is not needed", p)
@script:python depends on report@
p << r.p;
@@
msg = "WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values."
coccilib.report.print_report(p[0], msg)