diff options
| author | Chen-Yu Tsai <[email protected]> | 2023-05-26 15:35:37 +0800 |
|---|---|---|
| committer | Paul E. McKenney <[email protected]> | 2023-06-07 13:42:02 -0700 |
| commit | de29a96acceae732c68a4094d08dc49079eefa02 (patch) | |
| tree | d21bee5b8267b52c4cfb8fcd37941d016bb3329e | |
| parent | ac9a78681b921877518763ba0e89202254349d1b (diff) | |
notifier: Initialize new struct srcu_usage field
In commit 95433f726301 ("srcu: Begin offloading srcu_struct fields to
srcu_update"), a new struct srcu_usage field was added, but was not
properly initialized. This led to a "spinlock bad magic" BUG when the
SRCU notifier was ever used. This was observed in the MediaTek CCI
devfreq driver on next-20230525. The trimmed stack trace is as follows:
BUG: spinlock bad magic on CPU#4, swapper/0/1
lock: 0xffffff80ff529ac0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
Call trace:
spin_bug+0xa4/0xe8
do_raw_spin_lock+0xec/0x120
_raw_spin_lock_irqsave+0x78/0xb8
synchronize_srcu+0x3c/0x168
srcu_notifier_chain_unregister+0x5c/0xa0
cpufreq_unregister_notifier+0x94/0xe0
devfreq_passive_event_handler+0x7c/0x3e0
devfreq_remove_device+0x48/0xe8
Add __SRCU_USAGE_INIT() to SRCU_NOTIFIER_INIT() so that srcu_usage gets
initialized properly.
Reported-by: Jon Hunter <[email protected]>
Fixes: 95433f726301 ("srcu: Begin offloading srcu_struct fields to srcu_update")
Signed-off-by: Chen-Yu Tsai <[email protected]>
Tested-by: AngeloGioacchino Del Regno <[email protected]>
Cc: Matthias Brugger <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: "Michał Mirosław" <[email protected]>
Cc: Dmitry Osipenko <[email protected]>
Cc: Sachin Sant <[email protected]>
Cc: Joel Fernandes (Google) <[email protected]
Tested-by: Jon Hunter <[email protected]>
Acked-by: Zqiang <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
| -rw-r--r-- | include/linux/notifier.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 2aba75145144..86544707236a 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -106,12 +106,22 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); #define RAW_NOTIFIER_INIT(name) { \ .head = NULL } +#ifdef CONFIG_TREE_SRCU #define SRCU_NOTIFIER_INIT(name, pcpu) \ { \ .mutex = __MUTEX_INITIALIZER(name.mutex), \ .head = NULL, \ + .srcuu = __SRCU_USAGE_INIT(name.srcuu), \ .srcu = __SRCU_STRUCT_INIT(name.srcu, name.srcuu, pcpu), \ } +#else +#define SRCU_NOTIFIER_INIT(name, pcpu) \ + { \ + .mutex = __MUTEX_INITIALIZER(name.mutex), \ + .head = NULL, \ + .srcu = __SRCU_STRUCT_INIT(name.srcu, name.srcuu, pcpu), \ + } +#endif #define ATOMIC_NOTIFIER_HEAD(name) \ struct atomic_notifier_head name = \ |