[PATCH] Disabling OF functions that use sysfs if CONFIG_SYSFS disabled

[Gaurav Minocha]

This patch is to the fix the recent runtime bug in kernel
reported by <fengguang...@intel.com>

Mail Subject: [OF test] BUG: unable to handle kernel NULL
 pointer dereference at 00000038

Tested on x86 and arm architecture
---
 drivers/of/base.c    |   29 +++++++++++++++++++++++++++++
 drivers/of/dynamic.c |    7 +++++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index d8574ad..1d4d74e 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -131,6 +131,7 @@ static const char *safe_name(struct kobject *kobj, const 
char *orig_name)
        return name;
 }
 
+#if defined(CONFIG_SYSFS)
 int __of_add_property_sysfs(struct device_node *np, struct property *pp)
 {
        int rc;
@@ -151,7 +152,14 @@ int __of_add_property_sysfs(struct device_node *np, struct 
property *pp)
        WARN(rc, "error adding attribute %s to node %s\n", pp->name, 
np->full_name);
        return rc;
 }
+#else
+int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+{
+       return 0;
+}
+#endif
 
+#if defined(CONFIG_SYSFS)
 int __of_attach_node_sysfs(struct device_node *np)
 {
        const char *name;
@@ -181,6 +189,12 @@ int __of_attach_node_sysfs(struct device_node *np)
 
        return 0;
 }
+#else
+int __of_attach_node_sysfs(struct device_node *np)
+{
+       return 0;
+}
+#endif
 
 static int __init of_init(void)
 {
@@ -1711,12 +1725,19 @@ int __of_remove_property(struct device_node *np, struct 
property *prop)
        return 0;
 }
 
+#if defined(CONFIG_SYSFS)
 void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
 {
        /* at early boot, bail here and defer setup to of_init() */
        if (of_kset && of_node_is_attached(np))
                sysfs_remove_bin_file(&np->kobj, &prop->attr);
 }
+#else
+void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
+{
+
+}
+#endif
 
 /**
  * of_remove_property - Remove a property from a node.
@@ -1774,6 +1795,7 @@ int __of_update_property(struct device_node *np, struct 
property *newprop,
        return 0;
 }
 
+#if defined(CONFIG_SYSFS)
 void __of_update_property_sysfs(struct device_node *np, struct property 
*newprop,
                struct property *oldprop)
 {
@@ -1785,6 +1807,13 @@ void __of_update_property_sysfs(struct device_node *np, 
struct property *newprop
                sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
        __of_add_property_sysfs(np, newprop);
 }
+#else
+void __of_update_property_sysfs(struct device_node *np, struct property 
*newprop,
+               struct property *oldprop)
+{
+
+}
+#endif
 
 /*
  * of_update_property - Update a property in a node, if the property does
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 54fecc4..c3d9eae 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -41,6 +41,7 @@ void of_node_put(struct device_node *node)
 }
 EXPORT_SYMBOL(of_node_put);
 
+#if defined(CONFIG_SYSFS)
 void __of_detach_node_sysfs(struct device_node *np)
 {
        struct property *pp;
@@ -59,6 +60,12 @@ void __of_detach_node_sysfs(struct device_node *np)
        /* finally remove the kobj_init ref */
        of_node_put(np);
 }
+#else
+void __of_detach_node_sysfs(struct device_node *np)
+{
+
+}
+#endif
 
 static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
 
-- 
1.7.9.5

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