Commit 947fdaad authored by Xiubo Li's avatar Xiubo Li Committed by Grant Likely

of: fix race between search and remove in of_update_property()

The of_update_property() is intented to update a property in a node
and if the property does not exist, will add it.

The second search of the property is possibly won't be found, that
maybe removed by other thread just before the second search begain.

Using the __of_find_property() and __of_add_property() instead and
move them into lock operations.
Signed-off-by: default avatarXiubo Li <Li.Xiubo@freescale.com>
[grant.likely: conflict with another change in same function]
Signed-off-by: default avatarGrant Likely <grant.likely@linaro.org>
parent d2d3d7cd
......@@ -1800,7 +1800,7 @@ int of_update_property(struct device_node *np, struct property *newprop)
{
struct property **next, *oldprop;
unsigned long flags;
int rc, found = 0;
int rc;
rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
if (rc)
......@@ -1809,30 +1809,34 @@ int of_update_property(struct device_node *np, struct property *newprop)
if (!newprop->name)
return -EINVAL;
oldprop = of_find_property(np, newprop->name, NULL);
if (!oldprop)
return of_add_property(np, newprop);
raw_spin_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
while (*next) {
oldprop = __of_find_property(np, newprop->name, NULL);
if (!oldprop) {
/* add the new node */
rc = __of_add_property(np, newprop);
} else while (*next) {
/* replace the node */
if (*next == oldprop) {
/* found the node */
newprop->next = oldprop->next;
*next = newprop;
oldprop->next = np->deadprops;
np->deadprops = oldprop;
found = 1;
break;
}
next = &(*next)->next;
}
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (!found)
return -ENODEV;
if (rc)
return rc;
/* At early boot, bail out and defer setup to of_init() */
if (!of_kset)
return 0;
/* Update the sysfs attribute */
sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
if (oldprop)
sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
__of_add_property_sysfs(np, newprop);
return 0;
......
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