From: Dave Kleikamp <shaggy@austin.ibm.com>
I was looking through the radix tree code and came across what I think
is a bug in radix_tree_delete.
for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
if (pathp[0].node->tags[tag][idx]) {
tags[tag] = 1;
nr_cleared_tags--;
break;
}
}
The above loop should only be executed if tags[tag] is zero. Otherwise,
when walking up the tree, we can decrement nr_cleared_tags twice or more
for the same value of tag, thus potentially exiting the outer loop too
early.
Ensure that nr_cleared_tags is only decremented once for each tag.
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/lib/radix-tree.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff -puN lib/radix-tree.c~radix_tree_delete-fix lib/radix-tree.c
--- 25/lib/radix-tree.c~radix_tree_delete-fix 2004-11-10 22:36:19.268336368 -0800
+++ 25-akpm/lib/radix-tree.c 2004-11-10 22:36:19.273335608 -0800
@@ -701,8 +701,10 @@ void *radix_tree_delete(struct radix_tre
for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
int idx;
- if (!tags[tag])
- tag_clear(pathp[0].node, tag, pathp[0].offset);
+ if (tags[tag])
+ continue;
+
+ tag_clear(pathp[0].node, tag, pathp[0].offset);
for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
if (pathp[0].node->tags[tag][idx]) {
_