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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-09-20 14:54:41 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-10-20 15:02:27 -0700 |
| commit | 36f65f1d1553e35cd9e6b281271f40d639a128c3 (patch) | |
| tree | 91ad8b870888afc8299876118c7f1a60ff60a6ad /kernel/rcu | |
| parent | 27120e7d2c4d5c438b76f9c6330037a52ad0722e (diff) | |
| download | linux-36f65f1d1553e35cd9e6b281271f40d639a128c3.tar.bz2 | |
srcu: Check for consistent global per-srcu_struct NMI safety
This commit adds runtime checks to verify that a given srcu_struct uses
consistent NMI-safe (or not) read-side primitives globally, but based
on the per-CPU data. These global checks are made by the grace-period
code that must scan the srcu_data structures anyway, and are done only
in kernels built with CONFIG_PROVE_RCU=y.
Link: https://lore.kernel.org/all/20220910221947.171557773@linutronix.de/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/srcutree.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 30575864fcfa..87ae6f5c1eda 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -429,13 +429,18 @@ static unsigned long srcu_readers_lock_idx(struct srcu_struct *ssp, int idx) static unsigned long srcu_readers_unlock_idx(struct srcu_struct *ssp, int idx) { int cpu; + unsigned long mask = 0; unsigned long sum = 0; for_each_possible_cpu(cpu) { struct srcu_data *cpuc = per_cpu_ptr(ssp->sda, cpu); sum += atomic_long_read(&cpuc->srcu_unlock_count[idx]); + if (IS_ENABLED(CONFIG_PROVE_RCU)) + mask = mask | READ_ONCE(cpuc->srcu_nmi_safety); } + WARN_ONCE(IS_ENABLED(CONFIG_PROVE_RCU) && (mask & (mask >> 1)), + "Mixed NMI-safe readers for srcu_struct at %ps.\n", ssp); return sum; } |