This is a note to let you know that I've just added the patch titled idr test suite: Create anchor before launching throbber to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: idr-test-suite-create-anchor-before-launching-throbb.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dc4c5cb86e5a04c5c99dff1545731abb598a492d Author: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Date: Thu Apr 1 07:46:49 2021 -0400 idr test suite: Create anchor before launching throbber [ Upstream commit 094ffbd1d8eaa27ed426feb8530cb1456348b018 ] The throbber could race with creation of the anchor entry and cause the IDR to have zero entries in it, which would cause the test to fail. Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/testing/radix-tree/idr-test.c b/tools/testing/radix-tree/idr-test.c index 4a9b451b7ba0..6ce7460f3c7a 100644 --- a/tools/testing/radix-tree/idr-test.c +++ b/tools/testing/radix-tree/idr-test.c @@ -301,11 +301,11 @@ void idr_find_test_1(int anchor_id, int throbber_id) pthread_t throbber; time_t start = time(NULL); - pthread_create(&throbber, NULL, idr_throbber, &throbber_id); - BUG_ON(idr_alloc(&find_idr, xa_mk_value(anchor_id), anchor_id, anchor_id + 1, GFP_KERNEL) != anchor_id); + pthread_create(&throbber, NULL, idr_throbber, &throbber_id); + rcu_read_lock(); do { int id = 0;