Commit fa1f5116 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner
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locking: Make rwsem_assert_held_write_nolockdep() build with PREEMPT_RT=y 



The commit cited below broke the build for PREEMPT_RT because
rwsem_assert_held_write_nolockdep() passes a struct rw_semaphore but
rw_base_assert_held_write() expects struct rwbase_rt. Fixing the type alone
leads to the problem that WARN_ON() is not found because bug.h is missing.

In order to resolve this:

 - Keep the assert (WARN_ON()) in rwsem.h (not rwbase_rt.h)

 - Make rwsem_assert_held_write_nolockdep() do the implementation
   specific (rw_base) writer check.

 - Replace the "inline" with __always_inline which was used before.

Fixes: f70405af ("locking: Add rwsem_assert_held() and rwsem_assert_held_write()")
Reported-by: default avatarClark Williams <williams@redhat.com>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarWaiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20240319182050.U4AzUF3I@linutronix.de
parent fec50db7

include/linux/rwbase_rt.h

+2 −2
Original line number Diff line number Diff line
@@ -31,9 +31,9 @@ static __always_inline bool rw_base_is_locked(const struct rwbase_rt *rwb) 
	return atomic_read(&rwb->readers) != READER_BIAS;

}



static inline void rw_base_assert_held_write(const struct rwbase_rt *rwb)

static __always_inline bool rw_base_is_write_locked(const struct rwbase_rt *rwb)

{

	WARN_ON(atomic_read(&rwb->readers) != WRITER_BIAS);

	return atomic_read(&rwb->readers) == WRITER_BIAS;

}



static __always_inline bool rw_base_is_contended(const struct rwbase_rt *rwb)

include/linux/rwsem.h

+3 −3
Original line number Diff line number Diff line
@@ -167,14 +167,14 @@ static __always_inline int rwsem_is_locked(const struct rw_semaphore *sem) 
	return rw_base_is_locked(&sem->rwbase);

}



static inline void rwsem_assert_held_nolockdep(const struct rw_semaphore *sem)

static __always_inline void rwsem_assert_held_nolockdep(const struct rw_semaphore *sem)

{

	WARN_ON(!rwsem_is_locked(sem));

}



static inline void rwsem_assert_held_write_nolockdep(const struct rw_semaphore *sem)

static __always_inline void rwsem_assert_held_write_nolockdep(const struct rw_semaphore *sem)

{

	rw_base_assert_held_write(sem);

	WARN_ON(!rw_base_is_write_locked(&sem->rwbase));

}



static __always_inline int rwsem_is_contended(struct rw_semaphore *sem)