Re: [PATCH 2/3] locking: Add lock context support in do_raw_{read,write}_trylock()

[Marco Elver <elver@google.com>]

On Fri, Mar 13, 2026 at 10:15AM -0700, Bart Van Assche wrote:
> Convert do_raw_{read,write}_trylock() from macros into inline functions
> and annotate these inline functions with __cond_acquires_shared() or
> __cond_acquires() as appropriate. This change is necessary to build
> kernel drivers or subsystems that use rwlock synchronization objects with
> lock context analysis enabled. The return type 'int' matches the return
> type for CONFIG_DEBUG_SPINLOCK=y.
> 
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  include/linux/rwlock.h | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h
> index 21ceefc4a49f..4e67cd934d8f 100644
> --- a/include/linux/rwlock.h
> +++ b/include/linux/rwlock.h
> @@ -37,10 +37,20 @@ extern int do_raw_write_trylock(rwlock_t *lock) __cond_acquires(true, lock);
>   extern void do_raw_write_unlock(rwlock_t *lock) __releases(lock);
>  #else
>  # define do_raw_read_lock(rwlock)	do {__acquire_shared(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0)
> -# define do_raw_read_trylock(rwlock)	arch_read_trylock(&(rwlock)->raw_lock)
> +static inline int do_raw_read_trylock(rwlock_t *rwlock)
> +	__cond_acquires_shared(true, rwlock)
> +	__no_context_analysis
> +{
> +	return arch_read_trylock(&(rwlock)->raw_lock);
> +}
>  # define do_raw_read_unlock(rwlock)	do {arch_read_unlock(&(rwlock)->raw_lock); __release_shared(lock); } while (0)
>  # define do_raw_write_lock(rwlock)	do {__acquire(lock); arch_write_lock(&(rwlock)->raw_lock); } while (0)
> -# define do_raw_write_trylock(rwlock)	arch_write_trylock(&(rwlock)->raw_lock)
> +static inline int do_raw_write_trylock(rwlock_t *rwlock)
> +	__cond_acquires(true, rwlock)
> +	__no_context_analysis
> +{
> +	return arch_write_trylock(&(rwlock)->raw_lock);
> +}
>  # define do_raw_write_unlock(rwlock)	do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
>  #endif

The pre-existing annotations were wrong (from Sparse era, introduced in
b97c4bc16734a) - I think you need to include this to build with
CONFIG_DEBUG_SPINLOCK=n now:

diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h
index 3d1834ef15d5..9e577e649bf9 100644
--- a/include/linux/rwlock.h
+++ b/include/linux/rwlock.h
@@ -36,22 +36,22 @@ do {								\
  extern int do_raw_write_trylock(rwlock_t *lock);
  extern void do_raw_write_unlock(rwlock_t *lock) __releases(lock);
 #else
-# define do_raw_read_lock(rwlock)	do {__acquire_shared(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0)
+# define do_raw_read_lock(rwlock)	do {__acquire_shared(rwlock); arch_read_lock(&(rwlock)->raw_lock); } while (0)
 static inline int do_raw_read_trylock(rwlock_t *rwlock)
 	__cond_acquires_shared(true, rwlock)
 	__no_context_analysis
 {
 	return arch_read_trylock(&(rwlock)->raw_lock);
 }
-# define do_raw_read_unlock(rwlock)	do {arch_read_unlock(&(rwlock)->raw_lock); __release_shared(lock); } while (0)
-# define do_raw_write_lock(rwlock)	do {__acquire(lock); arch_write_lock(&(rwlock)->raw_lock); } while (0)
+# define do_raw_read_unlock(rwlock)	do {arch_read_unlock(&(rwlock)->raw_lock); __release_shared(rwlock); } while (0)
+# define do_raw_write_lock(rwlock)	do {__acquire(rwlock); arch_write_lock(&(rwlock)->raw_lock); } while (0)
 static inline int do_raw_write_trylock(rwlock_t *rwlock)
 	__cond_acquires(true, rwlock)
 	__no_context_analysis
 {
 	return arch_write_trylock(&(rwlock)->raw_lock);
 }
-# define do_raw_write_unlock(rwlock)	do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
+# define do_raw_write_unlock(rwlock)	do {arch_write_unlock(&(rwlock)->raw_lock); __release(rwlock); } while (0)
 #endif
 
 /*
diff --git a/include/linux/rwlock_api_smp.h b/include/linux/rwlock_api_smp.h
index 61a852609eab..25dfee624cf1 100644
--- a/include/linux/rwlock_api_smp.h
+++ b/include/linux/rwlock_api_smp.h
@@ -116,6 +116,7 @@ _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
 #endif
 
 static inline int __raw_read_trylock(rwlock_t *lock)
+	__cond_acquires_shared(true, lock)
 {
 	preempt_disable();
 	if (do_raw_read_trylock(lock)) {
@@ -127,6 +128,7 @@ static inline int __raw_read_trylock(rwlock_t *lock)
 }
 
 static inline int __raw_write_trylock(rwlock_t *lock)
+	__cond_acquires(true, lock)
 {
 	preempt_disable();
 	if (do_raw_write_trylock(lock)) {