Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[karo-tx-linux.git] / arch / arm64 / kernel / debug-monitors.c

diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index cebf78661a553775003bfee8ec89f65e33e3ec55..253021ef2769078e69793288a8cc067aebb76d34 100644 (file)
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -201,7 +201,7 @@ void unregister_step_hook(struct step_hook *hook)
 }
 
 /*
- * Call registered single step handers
+ * Call registered single step handlers
  * There is no Syndrome info to check for determining the handler.
  * So we call all the registered handlers, until the right handler is
  * found which returns zero.
@@ -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;
 }