[PATCH 5/5 v2] arm: add missing of_node_put

Julia Lawall
2015-10-10T21:41:42Z

for_each_child_of_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

The of_node_put is duplicated in front of each error return, because the
function contains a later error return that is beyond the end of the
for_each_child_of_node and thus doesn't need of_node_put.

The semantic patch that fixes this problem is as follows
(http://coccinelle.lip6.fr):

// <smpl>
@@
expression root,e;
local idexpression child;
iterator name for_each_child_of_node;
@@

for_each_child_of_node(root, child) {
... when != of_node_put(child)
when != e = child
(
return child;
|
+ of_node_put(child);
? return ...;
)
...
}

@@
expression root,e;
local idexpression child;
@@

for_each_child_of_node(root, child) {
... when != of_node_put(child)
when != e = child
+ of_node_put(child);
? break;
...
}
... when != child
// </smpl>

Additionally, concatenated a string in an affected line to avoid introducing
a checkpatch warning.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---

v2: Fixed the returns as well, adjusted a string in a test expression.

arch/arm/kernel/devtree.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index 11c54de..65addcb 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -101,6 +101,7 @@ void __init arm_dt_init_cpu_maps(void)
if (of_property_read_u32(cpu, "reg", &hwid)) {
pr_debug(" * %s missing reg property\n",
cpu->full_name);
+ of_node_put(cpu);
return;
}

@@ -108,8 +109,10 @@ void __init arm_dt_init_cpu_maps(void)
* 8 MSBs must be set to 0 in the DT since the reg property
* defines the MPIDR[23:0].
*/
- if (hwid & ~MPIDR_HWID_BITMASK)
+ if (hwid & ~MPIDR_HWID_BITMASK) {
+ of_node_put(cpu);
return;
+ }

/*
* Duplicate MPIDRs are a recipe for disaster.
@@ -119,9 +122,11 @@ void __init arm_dt_init_cpu_maps(void)
* to avoid matching valid MPIDR[23:0] values.
*/
for (j = 0; j < cpuidx; j++)
- if (WARN(tmp_map[j] = hwid, "Duplicate /cpu reg "
- "properties in the DT\n"))
+ if (WARN(tmp_map[j] = hwid,
+ "Duplicate /cpu reg properties in the DT\n")) {
+ of_node_put(cpu);
return;
+ }

/*
* Build a stashed array of MPIDR values. Numbering scheme
@@ -143,6 +148,7 @@ void __init arm_dt_init_cpu_maps(void)
"max cores %u, capping them\n",
cpuidx, nr_cpu_ids)) {
cpuidx = nr_cpu_ids;
+ of_node_put(cpu);
break;
}