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-rw-r--r--include/linux/rbtree.h16
1 files changed, 9 insertions, 7 deletions
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index aa870a4ddf54..57e75ae9910f 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -85,6 +85,11 @@ static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
*rb_link = node;
}
+#define rb_entry_safe(ptr, type, member) \
+ ({ typeof(ptr) ____ptr = (ptr); \
+ ____ptr ? rb_entry(____ptr, type, member) : NULL; \
+ })
+
/**
* rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
* given type safe against removal of rb_node entry
@@ -95,12 +100,9 @@ static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
* @field: the name of the rb_node field within 'type'.
*/
#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
- for (pos = rb_entry(rb_first_postorder(root), typeof(*pos), field),\
- n = rb_entry(rb_next_postorder(&pos->field), \
- typeof(*pos), field); \
- &pos->field; \
- pos = n, \
- n = rb_entry(rb_next_postorder(&pos->field), \
- typeof(*pos), field))
+ for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \
+ pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \
+ typeof(*pos), field); 1; }); \
+ pos = n)
#endif /* _LINUX_RBTREE_H */
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