Le 17/06/2022 à 06:20, Liang He a écrit :
In opal_powercap_init(), of_find_compatible_node() will return
a node pointer with refcount incremented. We should use of_node_put()
in fail path or when it is not used anymore.
Besides, for_each_child_of_node() will automatically *inc* and *dec*
refcount during iteration. However, we should add the of_node_put()
if there is a break.
Hi,

I'm not sure that your patch is right here. Because of this *inc* and *dec* things, do we still need to of_node_put(powercap) once we have entered for_each_child_of_node?
I think that this reference will be released on the first iteration of 
the loop.

Maybe of_node_put(powercap) should be duplicated everywhere it is relevant and removed from the error handling path?
Or an additional reference should be taken before the loop?
Or adding a new label with "powercap = NULL" and branching there when needed?
CJ

Signed-off-by: Liang He <win...@126.com>
---
  arch/powerpc/platforms/powernv/opal-powercap.c | 5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/opal-powercap.c 
b/arch/powerpc/platforms/powernv/opal-powercap.c
index 64506b46e77b..b102477d3f95 100644
--- a/arch/powerpc/platforms/powernv/opal-powercap.c
+++ b/arch/powerpc/platforms/powernv/opal-powercap.c
@@ -153,7 +153,7 @@ void __init opal_powercap_init(void)
        pcaps = kcalloc(of_get_child_count(powercap), sizeof(*pcaps),
                        GFP_KERNEL);
        if (!pcaps)
-               return;
+               goto out_powercap;
powercap_kobj = kobject_create_and_add("powercap", opal_kobj);
        if (!powercap_kobj) {
@@ -236,6 +236,9 @@ void __init opal_powercap_init(void)
                kfree(pcaps[i].pg.name);
        }
        kobject_put(powercap_kobj);
+       of_node_put(node);
  out_pcaps:
        kfree(pcaps);
+out_powercap:
+       of_node_put(powercap);
  }


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