radix-tree: add test for radix_tree_locate_item()

Add a unit test that provides coverage for the bug fixed in the commit
entitled "radix-tree: rewrite radix_tree_locate_item fix" from Hugh
Dickins.  I've verified that this test fails before his patch due to
miscalculated 'index' values in __locate() in lib/radix-tree.c, and
passes with his fix.

Link: http://lkml.kernel.org/r/1462307263-20623-1-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ross Zwisler 2016-05-20 17:02:49 -07:00 committed by Linus Torvalds
parent 0a2efc6c80
commit eb73f7f330
2 changed files with 15 additions and 1 deletions

View File

@ -0,0 +1 @@
/* An empty file stub that allows radix-tree.c to compile. */

View File

@ -232,7 +232,7 @@ void copy_tag_check(void)
item_kill_tree(&tree);
}
void __locate_check(struct radix_tree_root *tree, unsigned long index,
static void __locate_check(struct radix_tree_root *tree, unsigned long index,
unsigned order)
{
struct item *item;
@ -248,12 +248,25 @@ void __locate_check(struct radix_tree_root *tree, unsigned long index,
}
}
static void __order_0_locate_check(void)
{
RADIX_TREE(tree, GFP_KERNEL);
int i;
for (i = 0; i < 50; i++)
__locate_check(&tree, rand() % INT_MAX, 0);
item_kill_tree(&tree);
}
static void locate_check(void)
{
RADIX_TREE(tree, GFP_KERNEL);
unsigned order;
unsigned long offset, index;
__order_0_locate_check();
for (order = 0; order < 20; order++) {
for (offset = 0; offset < (1 << (order + 3));
offset += (1UL << order)) {