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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-01-12 09:52:44 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-04-11 15:31:01 -0700 |
| commit | 8ed00760203d8018bee042fbfe8e076579be2c2b (patch) | |
| tree | d436cccfe36000d8561e63aaabd378920da7f0c3 /kernel/rcu/srcutree.c | |
| parent | 3123109284176b1532874591f7c81f3837bbdc17 (diff) | |
| download | linux-8ed00760203d8018bee042fbfe8e076579be2c2b.tar.gz linux-8ed00760203d8018bee042fbfe8e076579be2c2b.tar.bz2 linux-8ed00760203d8018bee042fbfe8e076579be2c2b.zip | |
srcu: Tighten cleanup_srcu_struct() GP checks
Currently, cleanup_srcu_struct() checks for a grace period in progress,
but it does not check for a grace period that has not yet started but
which might start at any time. Such a situation could result in a
use-after-free bug, so this commit adds a check for a grace period that
is needed but not yet started to cleanup_srcu_struct().
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/srcutree.c')
| -rw-r--r-- | kernel/rcu/srcutree.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 6833d8887181..d30e4db04506 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -382,9 +382,11 @@ void cleanup_srcu_struct(struct srcu_struct *ssp) return; /* Forgot srcu_barrier(), so just leak it! */ } if (WARN_ON(rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq)) != SRCU_STATE_IDLE) || + WARN_ON(rcu_seq_current(&ssp->srcu_gp_seq) != ssp->srcu_gp_seq_needed) || WARN_ON(srcu_readers_active(ssp))) { - pr_info("%s: Active srcu_struct %p state: %d\n", - __func__, ssp, rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq))); + pr_info("%s: Active srcu_struct %p read state: %d gp state: %lu/%lu\n", + __func__, ssp, rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq)), + rcu_seq_current(&ssp->srcu_gp_seq), ssp->srcu_gp_seq_needed); return; /* Caller forgot to stop doing call_srcu()? */ } free_percpu(ssp->sda); |