These changes are a raw update to a vanilla kernel 4.1.10, with the

[kvmfornfv.git] / kernel / arch / arm64 / kernel / debug-monitors.c

diff --git a/kernel/arch/arm64/kernel/debug-monitors.c b/kernel/arch/arm64/kernel/debug-monitors.c
index b056369..70654d8 100644 (file)
--- a/kernel/arch/arm64/kernel/debug-monitors.c
+++ b/kernel/arch/arm64/kernel/debug-monitors.c
@@ -271,20 +271,21 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
  * Use reader/writer locks instead of plain spinlock.
  */
 static LIST_HEAD(break_hook);
-static DEFINE_RWLOCK(break_hook_lock);
+static DEFINE_SPINLOCK(break_hook_lock);
 
 void register_break_hook(struct break_hook *hook)
 {
-       write_lock(&break_hook_lock);
-       list_add(&hook->node, &break_hook);
-       write_unlock(&break_hook_lock);
+       spin_lock(&break_hook_lock);
+       list_add_rcu(&hook->node, &break_hook);
+       spin_unlock(&break_hook_lock);
 }
 
 void unregister_break_hook(struct break_hook *hook)
 {
-       write_lock(&break_hook_lock);
-       list_del(&hook->node);
-       write_unlock(&break_hook_lock);
+       spin_lock(&break_hook_lock);
+       list_del_rcu(&hook->node);
+       spin_unlock(&break_hook_lock);
+       synchronize_rcu();
 }
 
 static int call_break_hook(struct pt_regs *regs, unsigned int esr)
@@ -292,11 +293,11 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr)
        struct break_hook *hook;
        int (*fn)(struct pt_regs *regs, unsigned int esr) = NULL;
 
-       read_lock(&break_hook_lock);
-       list_for_each_entry(hook, &break_hook, node)
+       rcu_read_lock();
+       list_for_each_entry_rcu(hook, &break_hook, node)
                if ((esr & hook->esr_mask) == hook->esr_val)
                        fn = hook->fn;
-       read_unlock(&break_hook_lock);
+       rcu_read_unlock();
 
        return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
 }