[PATCH v2 1/3] coccinelle: also catch kzfree() issues

From: Yann Droneaud
Date: Mon May 23 2016 - 11:51:27 EST


Since commit 3ef0e5ba4673 ('slab: introduce kzfree()'),
kfree() is no more the only function to be considered:
kzfree() should be recognized too.

In particular, kzfree() must not be called on memory
allocated through devm_*() functions.

Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Yann Droneaud <ydroneaud@xxxxxxxxxx>
---
scripts/coccinelle/free/devm_free.cocci | 2 ++
scripts/coccinelle/free/ifnullfree.cocci | 4 +++-
scripts/coccinelle/free/kfree.cocci | 18 +++++++++++++++---
scripts/coccinelle/free/kfreeaddr.cocci | 6 +++++-
4 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/scripts/coccinelle/free/devm_free.cocci b/scripts/coccinelle/free/devm_free.cocci
index 3d9349012bb3..83c03adec1c5 100644
--- a/scripts/coccinelle/free/devm_free.cocci
+++ b/scripts/coccinelle/free/devm_free.cocci
@@ -48,6 +48,8 @@ position p;
(
* kfree@p(x)
|
+* kzfree@p(x)
+|
* free_irq@p(x)
|
* iounmap@p(x)
diff --git a/scripts/coccinelle/free/ifnullfree.cocci b/scripts/coccinelle/free/ifnullfree.cocci
index 52bd235286fa..14a4cd98e83b 100644
--- a/scripts/coccinelle/free/ifnullfree.cocci
+++ b/scripts/coccinelle/free/ifnullfree.cocci
@@ -20,6 +20,8 @@ expression E;
(
kfree(E);
|
+ kzfree(E);
+|
debugfs_remove(E);
|
debugfs_remove_recursive(E);
@@ -39,7 +41,7 @@ position p;
@@

* if (E != NULL)
-* \(kfree@p\|debugfs_remove@p\|debugfs_remove_recursive@p\|
+* \(kfree@p\|kzfree@p\|debugfs_remove@p\|debugfs_remove_recursive@p\|
* usb_free_urb@p\|kmem_cache_destroy@p\|mempool_destroy@p\|
* dma_pool_destroy@p\)(E);

diff --git a/scripts/coccinelle/free/kfree.cocci b/scripts/coccinelle/free/kfree.cocci
index 577b78056990..ac438da4fd7b 100644
--- a/scripts/coccinelle/free/kfree.cocci
+++ b/scripts/coccinelle/free/kfree.cocci
@@ -20,7 +20,11 @@ expression E;
position p1;
@@

-kfree@p1(E)
+(
+* kfree@p1(E)
+|
+* kzfree@p1(E)
+)

@print expression@
constant char [] c;
@@ -60,7 +64,11 @@ position ok;
@@

while (1) { ...
- kfree@ok(E)
+(
+* kfree@ok(E)
+|
+* kzfree@ok(E)
+)
... when != break;
when != goto l;
when forall
@@ -74,7 +82,11 @@ statement S;
position free.p1!=loop.ok,p2!={print.p,sz.p};
@@

-kfree@p1(E,...)
+(
+* kfree@p1(E,...)
+|
+* kzfree@p1(E,...)
+)
...
(
iter(...,subE,...) S // no use
diff --git a/scripts/coccinelle/free/kfreeaddr.cocci b/scripts/coccinelle/free/kfreeaddr.cocci
index ce8aacc314cb..d46063b1db8b 100644
--- a/scripts/coccinelle/free/kfreeaddr.cocci
+++ b/scripts/coccinelle/free/kfreeaddr.cocci
@@ -16,7 +16,11 @@ identifier f;
position p;
@@

+(
* kfree@p(&e->f)
+|
+* kzfree@p(&e->f)
+)

@script:python depends on org@
p << r.p;
@@ -28,5 +32,5 @@ cocci.print_main("kfree",p)
p << r.p;
@@

-msg = "ERROR: kfree of structure field"
+msg = "ERROR: invalid free of structure field"
coccilib.report.print_report(p[0],msg)
--
2.7.4