diff options
Diffstat (limited to '')
| -rw-r--r-- | kernel/rcu/tasks.h | 17 |
1 files changed, 1 insertions, 16 deletions
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index dd9730fd44fb..c789d994e7eb 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1541,22 +1541,7 @@ static void rcu_st_need_qs(struct task_struct *t, u8 v) */ u8 rcu_trc_cmpxchg_need_qs(struct task_struct *t, u8 old, u8 new) { - union rcu_special ret; - union rcu_special trs_old = READ_ONCE(t->trc_reader_special); - union rcu_special trs_new = trs_old; - - if (trs_old.b.need_qs != old) - return trs_old.b.need_qs; - trs_new.b.need_qs = new; - - // Although cmpxchg() appears to KCSAN to update all four bytes, - // only the .b.need_qs byte actually changes. - instrument_atomic_read_write(&t->trc_reader_special.b.need_qs, - sizeof(t->trc_reader_special.b.need_qs)); - // Avoid false-positive KCSAN failures. - ret.s = data_race(cmpxchg(&t->trc_reader_special.s, trs_old.s, trs_new.s)); - - return ret.b.need_qs; + return cmpxchg(&t->trc_reader_special.b.need_qs, old, new); } EXPORT_SYMBOL_GPL(rcu_trc_cmpxchg_need_qs); |