linux/tools/testing/radix-tree/test.h

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#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
struct item {
unsigned long index;
};
struct item *item_create(unsigned long index);
int __item_insert(struct radix_tree_root *root, struct item *item,
unsigned order);
int item_insert(struct radix_tree_root *root, unsigned long index);
int item_insert_order(struct radix_tree_root *root, unsigned long index,
unsigned order);
int item_delete(struct radix_tree_root *root, unsigned long index);
struct item *item_lookup(struct radix_tree_root *root, unsigned long index);
void item_check_present(struct radix_tree_root *root, unsigned long index);
void item_check_absent(struct radix_tree_root *root, unsigned long index);
void item_gang_check_present(struct radix_tree_root *root,
unsigned long start, unsigned long nr,
int chunk, int hop);
void item_full_scan(struct radix_tree_root *root, unsigned long start,
unsigned long nr, int chunk);
void item_kill_tree(struct radix_tree_root *root);
void tag_check(void);
void multiorder_checks(void);
radix-tree tests: add iteration test There are four cases I can see where we could end up with a NULL 'slot' in radix_tree_next_slot(). This unit test exercises all four of them, making sure that if in the future we have an unsafe path through radix_tree_next_slot(), we'll catch it. Here are details on the four cases: 1) radix_tree_iter_retry() via a non-tagged iteration like radix_tree_for_each_slot(). In this case we currently aren't seeing a bug because radix_tree_iter_retry() sets iter->next_index = iter->index; which means that in in the else case in radix_tree_next_slot(), 'count' is zero, so we skip over the while() loop and effectively just return NULL without ever dereferencing 'slot'. 2) radix_tree_iter_retry() via tagged iteration like radix_tree_for_each_tagged(). This case was giving us NULL pointer dereferences in testing, and was fixed with this commit: commit 3cb9185c6730 ("radix-tree: fix radix_tree_iter_retry() for tagged iterators.") This fix doesn't explicitly check for 'slot' being NULL, though, it works around the NULL pointer dereference by instead zeroing iter->tags in radix_tree_iter_retry(), which makes us bail out of the if() case in radix_tree_next_slot() before we dereference 'slot'. 3) radix_tree_iter_next() via via a non-tagged iteration like radix_tree_for_each_slot(). This currently happens in shmem_tag_pins() and shmem_partial_swap_usage(). As with non-tagged iteration, 'count' in the else case of radix_tree_next_slot() is zero, so we skip over the while() loop and effectively just return NULL without ever dereferencing 'slot'. 4) radix_tree_iter_next() via tagged iteration like radix_tree_for_each_tagged(). This happens in shmem_wait_for_pins(). radix_tree_iter_next() zeros out iter->tags, so we end up exiting radix_tree_next_slot() here: if (flags & RADIX_TREE_ITER_TAGGED) { void *canon = slot; iter->tags >>= 1; if (unlikely(!iter->tags)) return NULL; Link: http://lkml.kernel.org/r/20160815194237.25967-3-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 20:51:21 +00:00
void iteration_test(void);
struct item *
item_tag_set(struct radix_tree_root *root, unsigned long index, int tag);
struct item *
item_tag_clear(struct radix_tree_root *root, unsigned long index, int tag);
int item_tag_get(struct radix_tree_root *root, unsigned long index, int tag);
void tree_verify_min_height(struct radix_tree_root *root, int maxindex);
void verify_tag_consistency(struct radix_tree_root *root, unsigned int tag);
extern int nr_allocated;
/* Normally private parts of lib/radix-tree.c */
void radix_tree_dump(struct radix_tree_root *root);
int root_tag_get(struct radix_tree_root *root, unsigned int tag);
unsigned long node_maxindex(struct radix_tree_node *);
unsigned long shift_maxindex(unsigned int shift);