of_node_put is needed before discarding a value received from
of_find_node_by_name, eg in error handling code or when the device
node is no longer used.
The semantic match that catches the bug is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r exists@
local idexpression struct device_node *n;
position p1, p2;
statement S1,S2;
expression E,E1;
expression *ptr != NULL;
@@
(
if (!(n@p1 = of_find_node_by_name(...))) S1
|
n@p1 = of_find_node_by_name(...)
)
<... when != of_node_put(n)
when != if (...) { <+... of_node_put(n) ...+> }
when != true !n || ...
when != n = E
when != E = n
if (!n || ...) S2
...>
(
return \(0\|<+...n...+>\|ptr\);
|
return@p2 ...;
|
n = E1
|
E1 = n
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
print "* file: %s of_find_node_by_name %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>
Signed-off-by: Nicolas Palix <[email protected]>
Signed-off-by: Julia Lawall <[email protected]>
---
drivers/char/hvc_iseries.c | 4 +++-
drivers/char/hvc_vio.c | 4 +++-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/char/hvc_iseries.c b/drivers/char/hvc_iseries.c
index b74a2f8..449727b 100644
--- a/drivers/char/hvc_iseries.c
+++ b/drivers/char/hvc_iseries.c
@@ -575,8 +575,10 @@ static int __init hvc_find_vtys(void)
* of console adapters.
*/
if ((num_found >= MAX_NR_HVC_CONSOLES) ||
- (num_found >= VTTY_PORTS))
+ (num_found >= VTTY_PORTS)) {
+ of_node_put(vty);
break;
+ }
vtermno = of_get_property(vty, "reg", NULL);
if (!vtermno)
diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c
index 019e0b5..bd62dc8 100644
--- a/drivers/char/hvc_vio.c
+++ b/drivers/char/hvc_vio.c
@@ -153,8 +153,10 @@ static int hvc_find_vtys(void)
/* We have statically defined space for only a certain number
* of console adapters.
*/
- if (num_found >= MAX_NR_HVC_CONSOLES)
+ if (num_found >= MAX_NR_HVC_CONSOLES) {
+ of_node_put(vty);
break;
+ }
vtermno = of_get_property(vty, "reg", NULL);
if (!vtermno)
--
Nicolas Palix
On Tue, 2 Dec 2008 14:38:55 +0100 Nicolas Palix <[email protected]> wrote:
>
> of_node_put is needed before discarding a value received from
> of_find_node_by_name, eg in error handling code or when the device
> node is no longer used.
>
> Signed-off-by: Nicolas Palix <[email protected]>
> Signed-off-by: Julia Lawall <[email protected]>
Acked-by: Stephen Rothwell <[email protected]>
--
Cheers,
Stephen Rothwell [email protected]
http://www.canb.auug.org.au/~sfr/