linux/kernel/rcu
Paul E. McKenney 314eeb43e5 rcu: Add *_ONCE() and data_race() to rcu_node ->exp_tasks plus locking
There are lockless loads from the rcu_node structure's ->exp_tasks field,
so this commit causes all stores to use WRITE_ONCE() and all lockless
loads to use READ_ONCE() or data_race(), with the latter for debug
prints.  This code also did a unprotected traversal of the linked list
pointed into by ->exp_tasks, so this commit also acquires the rcu_node
structure's ->lock to properly protect this traversal.  This list was
traversed unprotected only when printing an RCU CPU stall warning for
an expedited grace period, so the odds of seeing this in production are
not all that high.

This data race was reported by KCSAN.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:01:15 -07:00
..
Kconfig rcu: Use CONFIG_PREEMPTION where appropriate 2019-12-09 12:37:51 -08:00
Kconfig.debug rcu: Add support for consolidated-RCU reader checking 2019-08-09 11:00:35 -07:00
Makefile rcu: Provide debug symbols and line numbers in KCSAN runs 2020-02-20 15:58:21 -08:00
rcu_segcblist.c rcu: Remove dead code from rcu_segcblist_insert_pend_cbs() 2020-02-20 15:58:23 -08:00
rcu_segcblist.h rcu: Remove kfree_rcu() special casing and lazy-callback handling 2020-01-24 10:24:31 -08:00
rcu.h Merge branches 'doc.2020.02.27a', 'fixes.2020.03.21a', 'kfree_rcu.2020.02.20a', 'locktorture.2020.02.20a', 'ovld.2020.02.20a', 'rcu-tasks.2020.02.20a', 'srcu.2020.02.20a' and 'torture.2020.02.20a' into HEAD 2020-03-21 17:15:11 -07:00
rcuperf.c rcuperf: Measure memory footprint during kfree_rcu() test 2020-02-20 16:03:31 -08:00
rcutorture.c rcutorture: Manually clean up after rcu_barrier() failure 2020-02-20 16:03:31 -08:00
srcutiny.c rcu: Use CONFIG_PREEMPTION where appropriate 2019-12-09 12:37:51 -08:00
srcutree.c srcu: Add KCSAN stubs 2020-04-27 11:01:15 -07:00
sync.c rcu/sync: Simplify the state machine 2019-05-28 09:05:23 -07:00
tiny.c rcu: Remove kfree_rcu() special casing and lazy-callback handling 2020-01-24 10:24:31 -08:00
tree_exp.h rcu: Add *_ONCE() and data_race() to rcu_node ->exp_tasks plus locking 2020-04-27 11:01:15 -07:00
tree_plugin.h rcu: Add *_ONCE() and data_race() to rcu_node ->exp_tasks plus locking 2020-04-27 11:01:15 -07:00
tree_stall.h Merge branches 'doc.2020.02.27a', 'fixes.2020.03.21a', 'kfree_rcu.2020.02.20a', 'locktorture.2020.02.20a', 'ovld.2020.02.20a', 'rcu-tasks.2020.02.20a', 'srcu.2020.02.20a' and 'torture.2020.02.20a' into HEAD 2020-03-21 17:15:11 -07:00
tree.c rcu: Mark rcu_state.ncpus to detect concurrent writes 2020-04-27 11:01:15 -07:00
tree.h rcu: React to callback overload by aggressively seeking quiescent states 2020-02-20 16:00:20 -08:00
update.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-30 16:17:15 -07:00