VisionFive2 Linux kernel

StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)

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author: Thomas Gleixner <tglx@linutronix.de> 2021-09-23 18:54:46 +0200 committer: Minda Chen <minda.chen@starfivetech.com> 2023-11-06 19:24:43 +0800 commit: 1fec6ba6b573fee535feac7caa88fdadce38b974 parent: d24dda5fcf99e6d3b86107a9dd94d69c2cc2be34
Commit Summary:
locking/rt: Take RCU nesting into account for __might_resched()
Diffstat:
1 file changed, 13 insertions, 3 deletions
diff --git a/kernel/locking/spinlock_rt.c b/kernel/locking/spinlock_rt.c
index c5289240cfb4..b2e553f9255b 100644
--- a/kernel/locking/spinlock_rt.c
+++ b/kernel/locking/spinlock_rt.c
@@ -24,6 +24,17 @@
 #define RT_MUTEX_BUILD_SPINLOCKS
 #include "rtmutex.c"
 
+/*
+ * __might_resched() skips the state check as rtlocks are state
+ * preserving. Take RCU nesting into account as spin/read/write_lock() can
+ * legitimately nest into an RCU read side critical section.
+ */
+#define RTLOCK_RESCHED_OFFSETS						\
+	(rcu_preempt_depth() << MIGHT_RESCHED_RCU_SHIFT)
+
+#define rtlock_might_resched()						\
+	__might_resched(__FILE__, __LINE__, RTLOCK_RESCHED_OFFSETS)
+
 static __always_inline void rtlock_lock(struct rt_mutex_base *rtm)
 {
 	if (unlikely(!rt_mutex_cmpxchg_acquire(rtm, NULL, current)))
@@ -32,7 +43,7 @@ static __always_inline void rtlock_lock(struct rt_mutex_base *rtm)
 
 static __always_inline void __rt_spin_lock(spinlock_t *lock)
 {
-	__might_resched(__FILE__, __LINE__, 0);
+	rtlock_might_resched();
 	rtlock_lock(&lock->lock);
 	rcu_read_lock();
 	migrate_disable();
@@ -210,7 +221,7 @@ EXPORT_SYMBOL(rt_write_trylock);
 
 void __sched rt_read_lock(rwlock_t *rwlock)
 {
-	__might_resched(__FILE__, __LINE__, 0);
+	rtlock_might_resched();
 	rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_);
 	rwbase_read_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT);
 	rcu_read_lock();
@@ -220,7 +231,7 @@ EXPORT_SYMBOL(rt_read_lock);
 
 void __sched rt_write_lock(rwlock_t *rwlock)
 {
-	__might_resched(__FILE__, __LINE__, 0);
+	rtlock_might_resched();
 	rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
 	rwbase_write_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT);
 	rcu_read_lock();