The patch titled
Subject: radix tree test suite: iteration test misuses RCU
has been added to the -mm tree. Its filename is
radix-tree-test-suite-iteration-test-misuses-rcu.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/radix-tree-test-suite-iteration-test-misuses-rcu.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/radix-tree-test-suite-iteration-test-misuses-rcu.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
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------------------------------------------------------
From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Subject: radix tree test suite: iteration test misuses RCU
Each thread needs to register itself with RCU, otherwise the reading
thread's read lock has no effect and the freeing thread will free the
memory in the tree without waiting for the read lock to be dropped.
Link: http://lkml.kernel.org/r/1480369871-5271-42-git-send-email-mawilcox@xxxxxxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Tested-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/radix-tree/iteration_check.c | 28 +++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)
diff -puN tools/testing/radix-tree/iteration_check.c~radix-tree-test-suite-iteration-test-misuses-rcu tools/testing/radix-tree/iteration_check.c
--- a/tools/testing/radix-tree/iteration_check.c~radix-tree-test-suite-iteration-test-misuses-rcu
+++ a/tools/testing/radix-tree/iteration_check.c
@@ -29,6 +29,8 @@ static void *add_entries_fn(void *arg)
{
int pgoff;
+ rcu_register_thread();
+
while (!test_complete) {
for (pgoff = 0; pgoff < 100; pgoff++) {
pthread_mutex_lock(&tree_lock);
@@ -38,6 +40,8 @@ static void *add_entries_fn(void *arg)
}
}
+ rcu_unregister_thread();
+
return NULL;
}
@@ -53,6 +57,8 @@ static void *tagged_iteration_fn(void *a
struct radix_tree_iter iter;
void **slot;
+ rcu_register_thread();
+
while (!test_complete) {
rcu_read_lock();
radix_tree_for_each_tagged(slot, &tree, &iter, 0, TAG) {
@@ -72,12 +78,18 @@ static void *tagged_iteration_fn(void *a
continue;
}
- if (rand_r(&seeds[0]) % 50 == 0)
+ if (rand_r(&seeds[0]) % 50 == 0) {
slot = radix_tree_iter_next(&iter);
+ rcu_read_unlock();
+ rcu_barrier();
+ rcu_read_lock();
+ }
}
rcu_read_unlock();
}
+ rcu_unregister_thread();
+
return NULL;
}
@@ -93,6 +105,8 @@ static void *untagged_iteration_fn(void
struct radix_tree_iter iter;
void **slot;
+ rcu_register_thread();
+
while (!test_complete) {
rcu_read_lock();
radix_tree_for_each_slot(slot, &tree, &iter, 0) {
@@ -112,12 +126,18 @@ static void *untagged_iteration_fn(void
continue;
}
- if (rand_r(&seeds[1]) % 50 == 0)
+ if (rand_r(&seeds[1]) % 50 == 0) {
slot = radix_tree_iter_next(&iter);
+ rcu_read_unlock();
+ rcu_barrier();
+ rcu_read_lock();
+ }
}
rcu_read_unlock();
}
+ rcu_unregister_thread();
+
return NULL;
}
@@ -127,6 +147,8 @@ static void *untagged_iteration_fn(void
*/
static void *remove_entries_fn(void *arg)
{
+ rcu_register_thread();
+
while (!test_complete) {
int pgoff;
@@ -137,6 +159,8 @@ static void *remove_entries_fn(void *arg
pthread_mutex_unlock(&tree_lock);
}
+ rcu_unregister_thread();
+
return NULL;
}
_
Patches currently in -mm which might be from mawilcox@xxxxxxxxxxxxx are
radix-tree-test-suite-fix-compilation.patch
radix-tree-test-suite-iteration-test-misuses-rcu.patch
radix-tree-test-suite-use-rcu_barrier.patch
radix-tree-test-suite-handle-exceptional-entries.patch
radix-tree-test-suite-record-order-in-each-item.patch
btrfs-fix-race-in-btrfs_free_dummy_fs_info.patch
radix-tree-improve-multiorder-iterators.patch
radix-tree-delete-radix_tree_locate_item.patch
radix-tree-delete-radix_tree_range_tag_if_tagged.patch
radix-tree-fix-replacement-for-multiorder-entries.patch
radix-tree-test-suite-check-multiorder-iteration.patch
tpm-use-idr_find-not-idr_find_slowpath.patch
rxrpc-abstract-away-knowledge-of-idr-internals.patch
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