The patch titled
From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
has been added to the -mm tree. Its filename is
radix-tree-fix-contiguous-iterator.patch
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From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Subject: radix-tree: fix contiguous iterator
Fix a bug in the macro radix_tree_for_each_contig().
If radix_tree_next_slot() sees NULL in next slot it returns NULL, but
following radix_tree_next_chunk() switches iterating into next chunk. As
result iterating becomes non-contiguous and breaks vfs "splice" and all
its users.
More details at https://lkml.org/lkml/2012/6/5/64
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Reported-by: Hans de Bruin <jmdebruin@xxxxxxxxx>
Reported-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
Reported-by: Toralf Foerster <toralf.foerster@xxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [3.4.x]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/radix-tree.h | 5 ++++-
lib/radix-tree.c | 3 +++
2 files changed, 7 insertions(+), 1 deletion(-)
diff -puN include/linux/radix-tree.h~radix-tree-fix-contiguous-iterator include/linux/radix-tree.h
--- a/include/linux/radix-tree.h~radix-tree-fix-contiguous-iterator
+++ a/include/linux/radix-tree.h
@@ -368,8 +368,11 @@ radix_tree_next_slot(void **slot, struct
iter->index++;
if (likely(*slot))
return slot;
- if (flags & RADIX_TREE_ITER_CONTIG)
+ if (flags & RADIX_TREE_ITER_CONTIG) {
+ /* forbid switching to the next chunk */
+ iter->next_index = 0;
break;
+ }
}
}
return NULL;
diff -puN lib/radix-tree.c~radix-tree-fix-contiguous-iterator lib/radix-tree.c
--- a/lib/radix-tree.c~radix-tree-fix-contiguous-iterator
+++ a/lib/radix-tree.c
@@ -686,6 +686,9 @@ void **radix_tree_next_chunk(struct radi
* during iterating; it can be zero only at the beginning.
* And we cannot overflow iter->next_index in a single step,
* because RADIX_TREE_MAP_SHIFT < BITS_PER_LONG.
+ *
+ * This condition also used by radix_tree_next_slot() to stop
+ * contiguous iterating, and forbid swithing to the next chunk.
*/
index = iter->next_index;
if (!index && iter->index)
_
Subject: From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
Patches currently in -mm which might be from khlebnikov@xxxxxxxxxx are
linux-next.patch
radix-tree-fix-contiguous-iterator.patch
mm-correctly-synchronize-rss-counters-at-exit-exec.patch
c-r-prctl-add-ability-to-set-new-mm_struct-exe_file-update-after-mm-num_exe_file_vmas-removal.patch
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