Hi Greg, The edac pci sysfs generic layer uses a static
kobject as a placeholder parent where edac pci drivers
are inserted. An atomic count is used to know when
to kobject_init_add_add or kobject_put the static kobject.
The issue with this is that the name gets double freed
on the second module load as edac does not clear it, and
kobject_cleanup does not clear it.
The quick fix was to clear the static kobj name before
calling kobject_init, but that seems a bit fragile as it
involves knowing the internals of kobject_put. Perhaps
the name should be cleared before calling the kobject
release method? Something like this (not even compile
tested):
diff --git a/lib/kobject.c b/lib/kobject.c
index 718e510..7dfe906 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -552,6 +552,9 @@ static void kobject_cleanup(struct kobject *kobj)
if (t && t->release) {
pr_debug("kobject: '%s' (%p): calling ktype release\n",
kobject_name(kobj), kobj);
+
+ /* avoid double free with static kobjects... */
+ kobj->name = NULL;
t->release(kobj);
}
What do you think? I'm happy to implement and test whatever
you think is best...
The edac code in question is drivers/edac/edac_pci_sysfs.c,
the static kobject is called edac_pci_top_main_kobj...
Arthur
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