6.12-stable review patch. If anyone has any objections, please let me know.
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From: Eder Zulian ezulian@redhat.com
[ Upstream commit 5c2e7736e20d9b348a44cafbfa639fe2653fbc34 ]
When PREEMPT_RT=y, spin locks are mapped to rt_mutex types, so using spinlock_check() + __raw_spin_lock_init() to initialize spin locks is incorrect, and would cause build errors.
Introduce __spin_lock_init() to initialize a spin lock with lockdep rquired information for PREEMPT_RT builds, and use it in the Rust helper.
Fixes: d2d6422f8bd1 ("x86: Allow to enable PREEMPT_RT.") Closes: https://lore.kernel.org/oe-kbuild-all/202409251238.vetlgXE9-lkp@intel.com/ Reported-by: kernel test robot lkp@intel.com Signed-off-by: Eder Zulian ezulian@redhat.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Boqun Feng boqun.feng@gmail.com Tested-by: Boqun Feng boqun.feng@gmail.com Link: https://lore.kernel.org/r/20241107163223.2092690-2-ezulian@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/spinlock_rt.h | 15 +++++++-------- rust/helpers/spinlock.c | 8 ++++++-- 2 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h index babc3e0287791..6175cd682ca0d 100644 --- a/include/linux/spinlock_rt.h +++ b/include/linux/spinlock_rt.h @@ -16,22 +16,21 @@ static inline void __rt_spin_lock_init(spinlock_t *lock, const char *name, } #endif
-#define spin_lock_init(slock) \ +#define __spin_lock_init(slock, name, key, percpu) \ do { \ - static struct lock_class_key __key; \ - \ rt_mutex_base_init(&(slock)->lock); \ - __rt_spin_lock_init(slock, #slock, &__key, false); \ + __rt_spin_lock_init(slock, name, key, percpu); \ } while (0)
-#define local_spin_lock_init(slock) \ +#define _spin_lock_init(slock, percpu) \ do { \ static struct lock_class_key __key; \ - \ - rt_mutex_base_init(&(slock)->lock); \ - __rt_spin_lock_init(slock, #slock, &__key, true); \ + __spin_lock_init(slock, #slock, &__key, percpu); \ } while (0)
+#define spin_lock_init(slock) _spin_lock_init(slock, false) +#define local_spin_lock_init(slock) _spin_lock_init(slock, true) + extern void rt_spin_lock(spinlock_t *lock) __acquires(lock); extern void rt_spin_lock_nested(spinlock_t *lock, int subclass) __acquires(lock); extern void rt_spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *nest_lock) __acquires(lock); diff --git a/rust/helpers/spinlock.c b/rust/helpers/spinlock.c index acc1376b833c7..92f7fc4184253 100644 --- a/rust/helpers/spinlock.c +++ b/rust/helpers/spinlock.c @@ -7,10 +7,14 @@ void rust_helper___spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key) { #ifdef CONFIG_DEBUG_SPINLOCK +# if defined(CONFIG_PREEMPT_RT) + __spin_lock_init(lock, name, key, false); +# else /*!CONFIG_PREEMPT_RT */ __raw_spin_lock_init(spinlock_check(lock), name, key, LD_WAIT_CONFIG); -#else +# endif /* CONFIG_PREEMPT_RT */ +#else /* !CONFIG_DEBUG_SPINLOCK */ spin_lock_init(lock); -#endif +#endif /* CONFIG_DEBUG_SPINLOCK */ }
void rust_helper_spin_lock(spinlock_t *lock)