| From | Bart Van Assche <> | Subject | [PATCH v7 17/23] locking/lockdep: Verify whether lock objects are small enough to be used as class keys | Date | Thu, 14 Feb 2019 15:00:52 -0800 |
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Cc: Peter Zijlstra <peterz@infradead.org> Cc: Waiman Long <longman@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- kernel/locking/lockdep.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index f5df97812dfa..93216e195b4f 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -758,6 +758,17 @@ static bool assign_lock_key(struct lockdep_map *lock) { unsigned long can_addr, addr = (unsigned long)lock; +#ifdef __KERNEL__ + /* + * lockdep_free_key_range() assumes that struct lock_class_key + * objects do not overlap. Since we use the address of lock + * objects as class key for static objects, check whether the + * size of lock_class_key objects does not exceed the size of + * the smallest lock object. + */ + BUILD_BUG_ON(sizeof(struct lock_class_key) > sizeof(raw_spinlock_t)); +#endif + if (__is_kernel_percpu_address(addr, &can_addr)) lock->key = (void *)can_addr; else if (__is_module_percpu_address(addr, &can_addr)) -- 2.21.0.rc0.258.g878e2cd30e-goog
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