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]>
---
arch/powerpc/platforms/chrp/pci.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/platforms/chrp/pci.c b/arch/powerpc/platforms/chrp/pci.c
index d3cde6b..5a72ee5 100644
--- a/arch/powerpc/platforms/chrp/pci.c
+++ b/arch/powerpc/platforms/chrp/pci.c
@@ -141,6 +141,7 @@ hydra_init(void)
of_node_put(np);
return 0;
}
+ of_node_put(np);
Hydra = ioremap(r.start, r.end-r.start);
printk("Hydra Mac I/O at %llx\n", (unsigned long long)r.start);
printk("Hydra Feature_Control was %x",
--
Nicolas Palix
On Tue, 2 Dec 2008 14:34:46 +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/