From: Jeff Moyer Signed-off-by: Jeff Moyer Cc: Nick Piggin Signed-off-by: Andrew Morton --- lib/radix-tree.c | 20 ++++++++++++++++---- 1 files changed, 16 insertions(+), 4 deletions(-) diff -puN lib/radix-tree.c~fix-the-max-path-calculation-in-radix-treec-update lib/radix-tree.c --- a/lib/radix-tree.c~fix-the-max-path-calculation-in-radix-treec-update +++ a/lib/radix-tree.c @@ -61,9 +61,13 @@ struct radix_tree_path { #define RADIX_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long)) #define RADIX_TREE_MAX_PATH (DIV_ROUND_UP(RADIX_TREE_INDEX_BITS, \ - RADIX_TREE_MAP_SHIFT) + 1) + RADIX_TREE_MAP_SHIFT)) -static unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH] __read_mostly; +/* + * The height_to_maxindex array needs to be one deeper than the maximum + * path as height 0 holds only 1 entry. + */ +static unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH + 1] __read_mostly; /* * Radix tree node cache. @@ -493,7 +497,11 @@ EXPORT_SYMBOL(radix_tree_tag_set); void *radix_tree_tag_clear(struct radix_tree_root *root, unsigned long index, unsigned int tag) { - struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path; + /* + * The radix tree path needs to be one longer than the maximum path + * since the "list" is null terminated. + */ + struct radix_tree_path path[RADIX_TREE_MAX_PATH + 1], *pathp = path; struct radix_tree_node *slot = NULL; unsigned int height, shift; @@ -935,7 +943,11 @@ static inline void radix_tree_shrink(str */ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) { - struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path; + /* + * The radix tree path needs to be one longer than the maximum path + * since the "list" is null terminated. + */ + struct radix_tree_path path[RADIX_TREE_MAX_PATH + 1], *pathp = path; struct radix_tree_node *slot = NULL; struct radix_tree_node *to_free; unsigned int height, shift; _