diff mbox series

coccinelle: adjust NULL check before free()

Message ID 20200419095602.19393-1-xypron.glpk@gmx.de
State Accepted
Commit c11f0d88ba462976335a4990a30a99d1d0b49195
Headers show
Series coccinelle: adjust NULL check before free() | expand

Commit Message

Heinrich Schuchardt April 19, 2020, 9:56 a.m. UTC 
The free() function checks if its argument is NULL. We should avoid
checking for NULL before calling free like in

????if (result->tds)
????????free(result->tds);

The list of relevant functions differs between Linux and U-Boot, e.g. we
use free().

Adjust the list of relevant functions.

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
 scripts/coccinelle/free/ifnullfree.cocci | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

--
2.25.1

Comments

Tom Rini April 26, 2020, 11:27 a.m. UTC | #1 
On Sun, Apr 19, 2020 at 11:56:02AM +0200, Heinrich Schuchardt wrote:

> The free() function checks if its argument is NULL. We should avoid
> checking for NULL before calling free like in
> 
> ????if (result->tds)
> ????????free(result->tds);
> 
> The list of relevant functions differs between Linux and U-Boot, e.g. we
> use free().
> 
> Adjust the list of relevant functions.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>

Applied to u-boot/master, thanks!
diff mbox series

Patch

diff --git a/scripts/coccinelle/free/ifnullfree.cocci b/scripts/coccinelle/free/ifnullfree.cocci
index 14a4cd98e8..2d59545d7d 100644
--- a/scripts/coccinelle/free/ifnullfree.cocci
+++ b/scripts/coccinelle/free/ifnullfree.cocci
@@ -1,10 +1,11 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
 /// 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.
 ///
-// Copyright: (C) 2014 Fabian Frederick.  GPLv2.
+// Copyright: (C) 2014 Fabian Frederick.
 // Comments: -
 // Options: --no-includes --include-headers

@@ -18,21 +19,19 @@  expression E;
 @@
 - if (E != NULL)
 (
-  kfree(E);
+  free(E);
 |
-  kzfree(E);
+  kfree(E);
 |
-  debugfs_remove(E);
+  vfree(E);
 |
-  debugfs_remove_recursive(E);
+  vfree_recursive(E);
 |
-  usb_free_urb(E);
+  kmem_cache_free(E);
 |
   kmem_cache_destroy(E);
 |
-  mempool_destroy(E);
-|
-  dma_pool_destroy(E);
+  gzfree(E);
 )

 @r depends on context || report || org @
@@ -41,9 +40,8 @@  position p;
 @@

 * if (E != NULL)
-*	\(kfree at p\|kzfree at p\|debugfs_remove at p\|debugfs_remove_recursive at p\|
-*         usb_free_urb at p\|kmem_cache_destroy at p\|mempool_destroy at p\|
-*         dma_pool_destroy at p\)(E);
+*	\(free at p\|kfree at p\|vfree at p\|debugfs_remove_recursive at p\|
+*         kmem_cache_free at p\|kmem_cache_destroy at p\|gzfree at p\)(E);

 @script:python depends on org@
 p << r.p;
@@ -55,5 +53,5 @@  cocci.print_main("NULL check before that freeing function is not needed", p)
 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."
+msg = "WARNING: NULL check before some freeing functions is not needed."
 coccilib.report.print_report(p[0], msg)