2016-03-17 21:21:45 +00:00
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#include <linux/gfp.h>
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#include <linux/types.h>
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#include <linux/radix-tree.h>
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#include <linux/rcupdate.h>
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struct item {
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unsigned long index;
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};
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struct item *item_create(unsigned long index);
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2016-05-21 00:02:14 +00:00
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int __item_insert(struct radix_tree_root *root, struct item *item,
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unsigned order);
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2016-03-17 21:21:45 +00:00
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int item_insert(struct radix_tree_root *root, unsigned long index);
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2016-05-21 00:02:14 +00:00
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int item_insert_order(struct radix_tree_root *root, unsigned long index,
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unsigned order);
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2016-03-17 21:21:45 +00:00
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int item_delete(struct radix_tree_root *root, unsigned long index);
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struct item *item_lookup(struct radix_tree_root *root, unsigned long index);
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void item_check_present(struct radix_tree_root *root, unsigned long index);
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void item_check_absent(struct radix_tree_root *root, unsigned long index);
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void item_gang_check_present(struct radix_tree_root *root,
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unsigned long start, unsigned long nr,
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int chunk, int hop);
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void item_full_scan(struct radix_tree_root *root, unsigned long start,
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unsigned long nr, int chunk);
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void item_kill_tree(struct radix_tree_root *root);
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void tag_check(void);
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2016-05-21 00:02:14 +00:00
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void multiorder_checks(void);
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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
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void iteration_test(void);
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2016-03-17 21:21:45 +00:00
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struct item *
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item_tag_set(struct radix_tree_root *root, unsigned long index, int tag);
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struct item *
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item_tag_clear(struct radix_tree_root *root, unsigned long index, int tag);
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int item_tag_get(struct radix_tree_root *root, unsigned long index, int tag);
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void tree_verify_min_height(struct radix_tree_root *root, int maxindex);
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void verify_tag_consistency(struct radix_tree_root *root, unsigned int tag);
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extern int nr_allocated;
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/* Normally private parts of lib/radix-tree.c */
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2016-05-21 00:02:55 +00:00
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void radix_tree_dump(struct radix_tree_root *root);
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2016-03-17 21:21:45 +00:00
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int root_tag_get(struct radix_tree_root *root, unsigned int tag);
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2016-05-21 00:03:16 +00:00
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unsigned long node_maxindex(struct radix_tree_node *);
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unsigned long shift_maxindex(unsigned int shift);
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