From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> v4.14.137-rt65-rc1 stable review patch. If anyone has any objections, please let me know. ----------- [ Upstream commit 978315462d3ea3cf6cfacd34c563ec1eb02a3aa5 ] It is possible to ignore the validation for a certain lock by using: lockdep_set_novalidate_class() on it. Each invocation will assign a new name to the class it created for created __lockdep_no_validate__. That means that once lockdep_set_novalidate_class() has been used on two locks then class->name won't match lock->name for the first lock triggering the warning. So ignore changed non-matching ->name pointer for the special __lockdep_no_validate__ class. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Link: http://lkml.kernel.org/r/20190517212234.32611-1-bigeasy@xxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx> --- kernel/locking/lockdep.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index e576d234f3ea..f194de27123d 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -719,7 +719,8 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass) * Huh! same key, different name? Did someone trample * on some memory? We're most confused. */ - WARN_ON_ONCE(class->name != lock->name); + WARN_ON_ONCE(class->name != lock->name && + lock->key != &__lockdep_no_validate__); return class; } } -- 2.14.1
