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authorMatthew Wilcox <mawilcox@microsoft.com>2016-12-15 02:09:31 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-15 03:04:10 +0300
commite8de4340767dd002978c285e3adddaeda8ac652c (patch)
tree3e14e4a3b7b0874e4e824b7873558a1017d2e368 /tools
parentbbe9d71f2c545398987a6fea5090a6ca76f4a8dc (diff)
downloadlinux-e8de4340767dd002978c285e3adddaeda8ac652c.tar.xz
radix-tree: ensure counts are initialised
radix_tree_join() was freeing nodes with a non-zero ->exceptional count, and radix_tree_split() wasn't zeroing ->exceptional when it allocated the new node. Fix this by making all callers of radix_tree_node_alloc() pass in the new counts (and some other always-initialised fields), which will prevent the problem recurring if in future we decide to do something similar. Link: http://lkml.kernel.org/r/1481667692-14500-3-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/radix-tree/multiorder.c45
1 files changed, 41 insertions, 4 deletions
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 08b4e16dc86f..f79812a5e070 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -355,7 +355,7 @@ void multiorder_tagged_iteration(void)
item_kill_tree(&tree);
}
-static void __multiorder_join(unsigned long index,
+static void multiorder_join1(unsigned long index,
unsigned order1, unsigned order2)
{
unsigned long loc;
@@ -373,7 +373,7 @@ static void __multiorder_join(unsigned long index,
item_kill_tree(&tree);
}
-static void __multiorder_join2(unsigned order1, unsigned order2)
+static void multiorder_join2(unsigned order1, unsigned order2)
{
RADIX_TREE(tree, GFP_KERNEL);
struct radix_tree_node *node;
@@ -393,6 +393,39 @@ static void __multiorder_join2(unsigned order1, unsigned order2)
item_kill_tree(&tree);
}
+/*
+ * This test revealed an accounting bug for exceptional entries at one point.
+ * Nodes were being freed back into the pool with an elevated exception count
+ * by radix_tree_join() and then radix_tree_split() was failing to zero the
+ * count of exceptional entries.
+ */
+static void multiorder_join3(unsigned int order)
+{
+ RADIX_TREE(tree, GFP_KERNEL);
+ struct radix_tree_node *node;
+ void **slot;
+ struct radix_tree_iter iter;
+ unsigned long i;
+
+ for (i = 0; i < (1 << order); i++) {
+ radix_tree_insert(&tree, i, (void *)0x12UL);
+ }
+
+ radix_tree_join(&tree, 0, order, (void *)0x16UL);
+ rcu_barrier();
+
+ radix_tree_split(&tree, 0, 0);
+
+ radix_tree_for_each_slot(slot, &tree, &iter, 0) {
+ radix_tree_iter_replace(&tree, &iter, slot, (void *)0x12UL);
+ }
+
+ __radix_tree_lookup(&tree, 0, &node, NULL);
+ assert(node->exceptional == node->count);
+
+ item_kill_tree(&tree);
+}
+
static void multiorder_join(void)
{
int i, j, idx;
@@ -400,16 +433,20 @@ static void multiorder_join(void)
for (idx = 0; idx < 1024; idx = idx * 2 + 3) {
for (i = 1; i < 15; i++) {
for (j = 0; j < i; j++) {
- __multiorder_join(idx, i, j);
+ multiorder_join1(idx, i, j);
}
}
}
for (i = 1; i < 15; i++) {
for (j = 0; j < i; j++) {
- __multiorder_join2(i, j);
+ multiorder_join2(i, j);
}
}
+
+ for (i = 3; i < 10; i++) {
+ multiorder_join3(i);
+ }
}
static void check_mem(unsigned old_order, unsigned new_order, unsigned alloc)