The following commit has been merged into the core/rcu branch of tip: Commit-ID: a7eb937b67b64b8b4645f1ebca3ac2079c6de81b Gitweb: https://git.kernel.org/tip/a7eb937b67b64b8b4645f1ebca3ac2079c6de81b Author: Paul E. McKenney <[email protected]> AuthorDate: Fri, 09 Oct 2020 19:51:55 -07:00 Committer: Paul E. McKenney <[email protected]> CommitterDate: Fri, 06 Nov 2020 17:13:57 -08:00
rcutorture: Don't do need_resched() testing if ->sync is NULL If cur_ops->sync is NULL, rcu_torture_fwd_prog_nr() will nevertheless attempt to call through it. This commit therefore flags cases where neither need_resched() nor call_rcu() forward-progress testing can be performed due to NULL function pointers, and also causes rcu_torture_fwd_prog_nr() to take an early exit if cur_ops->sync() is NULL. Reported-by: Tom Rix <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/rcu/rcutorture.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index e7d52fd..4dfd113 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1923,7 +1923,9 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp, unsigned long stopat; static DEFINE_TORTURE_RANDOM(trs); - if (cur_ops->call && cur_ops->sync && cur_ops->cb_barrier) { + if (!cur_ops->sync) + return; // Cannot do need_resched() forward progress testing without ->sync. + if (cur_ops->call && cur_ops->cb_barrier) { init_rcu_head_on_stack(&fcs.rh); selfpropcb = true; } @@ -2149,8 +2151,8 @@ static int __init rcu_torture_fwd_prog_init(void) if (!fwd_progress) return 0; /* Not requested, so don't do it. */ - if (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0 || - cur_ops == &rcu_busted_ops) { + if ((!cur_ops->sync && !cur_ops->call) || + !cur_ops->stall_dur || cur_ops->stall_dur() <= 0 || cur_ops == &rcu_busted_ops) { VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test"); return 0; }
