[PATCH linux-next] sparc: Add missing of_node_put

[PATCH linux-next] sparc: Add missing of_node_put

[Nicolas Palix]

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;
struct device_node *n1;
statement S;
identifier f;
expression E;
expression *ptr != NULL;
@@

n@p1 = of_find_node_by_name(...)
...
if (!n) S
... when != of_node_put(n)
    when != n1 = f(n,...)
    when != E = n
    when any
    when strict
(
  return \(0\|<+...n...+>\|ptr\);
|
return@p2 ...;
|
  of_node_put(n);
|
  n1 = f(n,...)
|
  E = 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 <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
 arch/sparc/kernel/sun4c_irq.c |    2 ++
 arch/sparc/kernel/sun4d_irq.c |    1 +
 arch/sparc/kernel/sun4m_irq.c |    2 ++
 3 files changed, 5 insertions(+)

diff --git a/arch/sparc/kernel/sun4c_irq.c b/arch/sparc/kernel/sun4c_irq.c
index 5dc8a57..326b8b1 100644
--- a/arch/sparc/kernel/sun4c_irq.c
+++ b/arch/sparc/kernel/sun4c_irq.c
@@ -160,6 +160,7 @@ static void __init sun4c_init_timers(irq_handler_t counter_fn)
 	sun4c_timers = (void __iomem *) (unsigned long) addr[0];
 
 	irq = of_get_property(dp, "intr", NULL);
+	of_node_put(dp);
 	if (!irq) {
 		prom_printf("sun4c_init_timers: No intr property\n");
 		prom_halt();
@@ -200,6 +201,7 @@ void __init sun4c_init_IRQ(void)
 	}
 
 	addr = of_get_property(dp, "address", NULL);
+	of_node_put(dp);
 	if (!addr) {
 		prom_printf("sun4c_init_IRQ: No address property\n");
 		prom_halt();
diff --git a/arch/sparc/kernel/sun4d_irq.c b/arch/sparc/kernel/sun4d_irq.c
index d3cb76c..63bc805 100644
--- a/arch/sparc/kernel/sun4d_irq.c
+++ b/arch/sparc/kernel/sun4d_irq.c
@@ -508,6 +508,7 @@ static void __init sun4d_init_timers(irq_handler_t counter_fn)
 	 * bootbus.
 	 */
 	reg = of_get_property(dp, "reg", NULL);
+	of_node_put(dp);
 	if (!reg) {
 		prom_printf("sun4d_init_timers: No reg property\n");
 		prom_halt();
diff --git a/arch/sparc/kernel/sun4m_irq.c b/arch/sparc/kernel/sun4m_irq.c
index f103171..a1335c1 100644
--- a/arch/sparc/kernel/sun4m_irq.c
+++ b/arch/sparc/kernel/sun4m_irq.c
@@ -374,6 +374,7 @@ static void __init sun4m_init_timers(irq_handler_t counter_fn)
 	}
 
 	addr = of_get_property(dp, "address", &len);
+	of_node_put(dp);
 	if (!addr) {
 		printk(KERN_ERR "sun4m_init_timers: No 'address' prop.\n");
 		return;
@@ -437,6 +438,7 @@ void __init sun4m_init_IRQ(void)
 	}
 
 	addr = of_get_property(dp, "address", &len);
+	of_node_put(dp);
 	if (!addr) {
 		printk(KERN_ERR "sun4m_init_IRQ: No 'address' prop.\n");
 		return;

Re: [PATCH linux-next] sparc: Add missing of_node_put

[David Miller]

From: Nicolas Palix <npalix@diku.dk>
Date: Tue, 2 Dec 2008 11:30:06 +0100

> 
> 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.

Applied to sparc-next-2.6, thanks.

I'm not going to add this to sparc-2.6 or stable, it doesn't
fix any real bugs on sparc (no hot plugged OF nodes, ever)
and adding it to sparc-2.6 would potentitally create some
difficult conflicts in sparc-next-2.6 since we're just finishing
a full merge of arch/sparc64 into arch/sparc there.