Author: Julia Lawall <julia@diku.dk>
The functions of_find_compatible_node and of_find_node_by_type both
call of_node_get on their result. So any error handling code
thereafter should call of_node_put(np). This is taken care of in the
case where there is a goto out, but not when there is a direct return.
The function irq_alloc_host puts np into the returned structure, which is
stored in the global variable mpc8xx_pic_host, so the reference count
should be set for the lifetime of that variable. The current solution ups
the reference count again in the argument to irq_alloc_host so that it can
be decremented on the way out. This seems a bit unnecessary, and also
doesn't work in the case where irq_alloc_host fails, because then the
reference count only goes does by one, whereas it should go down by two. A
better solution is to not increment the reference count in the argument to
irq_alloc_host and only decrement it on the way out in an error case.
The problem was found using the following semantic match.
(http://www.emn.fr/x-info/coccinelle/)
//
@@
type T,T1,T2;
identifier E;
statement S;
expression x1,x2,x3;
int ret;
@@
T E;
...
* E = \(of_get_parent\|of_find_compatible_node\)(...);
if (E == NULL) S
... when != of_node_put(...,(T1)E,...)
when != if (E != NULL) { ... of_node_put(...,(T1)E,...); ...}
when != x1 = (T1)E
when != E = x3;
when any
if (...) {
... when != of_node_put(...,(T2)E,...)
when != if (E != NULL) { ... of_node_put(...,(T2)E,...); ...}
when != x2 = (T2)E
(
* return;
|
* return ret;
)
}
//
Signed-off-by: Julia Lawall
Cc: Stephen Rothwell
Cc: Benjamin Herrenschmidt
Cc: Kumar Gala
Signed-off-by: Andrew Morton
Signed-off-by: Paul Mackerras
---
arch/powerpc/sysdev/mpc8xx_pic.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/sysdev/mpc8xx_pic.c b/arch/powerpc/sysdev/mpc8xx_pic.c
index 0e74a4b..5d2d552 100644
--- a/arch/powerpc/sysdev/mpc8xx_pic.c
+++ b/arch/powerpc/sysdev/mpc8xx_pic.c
@@ -174,15 +174,19 @@ int mpc8xx_pic_init(void)
goto out;
siu_reg = ioremap(res.start, res.end - res.start + 1);
- if (siu_reg == NULL)
- return -EINVAL;
+ if (siu_reg == NULL) {
+ ret = -EINVAL;
+ goto out;
+ }
- mpc8xx_pic_host = irq_alloc_host(of_node_get(np), IRQ_HOST_MAP_LINEAR,
+ mpc8xx_pic_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
64, &mpc8xx_pic_host_ops, 64);
if (mpc8xx_pic_host == NULL) {
printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
ret = -ENOMEM;
+ goto out;
}
+ return 0;
out:
of_node_put(np); |
---
arch/powerpc/sysdev/mpc8xx_pic.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/sysdev/mpc8xx_pic.c b/arch/powerpc/sysdev/mpc8xx_pic.c
index 0e74a4b..5d2d552 100644
--- a/arch/powerpc/sysdev/mpc8xx_pic.c
+++ b/arch/powerpc/sysdev/mpc8xx_pic.c
@@ -174,15 +174,19 @@ int mpc8xx_pic_init(void)
goto out;
siu_reg = ioremap(res.start, res.end - res.start + 1);
- if (siu_reg == NULL)
- return -EINVAL;
+ if (siu_reg == NULL) {
+ ret = -EINVAL;
+ goto out;
+ }
- mpc8xx_pic_host = irq_alloc_host(of_node_get(np), IRQ_HOST_MAP_LINEAR,
+ mpc8xx_pic_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
64, &mpc8xx_pic_host_ops, 64);
if (mpc8xx_pic_host == NULL) {
printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
ret = -ENOMEM;
+ goto out;
}
+ return 0;
out:
of_node_put(np);