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Commit fb5a613b authored by Andreea-Cristina Bernat's avatar Andreea-Cristina Bernat Committed by Steven Rostedt
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kernel: trace_syscalls: Replace rcu_assign_pointer() with RCU_INIT_POINTER() 

The uses of "rcu_assign_pointer()" are NULLing out the pointers.
According to RCU_INIT_POINTER()'s block comment:
"1.   This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.

The following Coccinelle semantic patch was used:
@@
@@

- rcu_assign_pointer
+ RCU_INIT_POINTER
  (..., NULL)

Link: http://lkml.kernel.org/p/20140822142822.GA32391@ada



Signed-off-by: default avatarAndreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 3a630178

kernel/trace/trace_syscalls.c

+2 −2
Original line number Diff line number Diff line
@@ -425,7 +425,7 @@ static void unreg_event_syscall_enter(struct ftrace_event_file *file, 
		return;

	mutex_lock(&syscall_trace_lock);

	tr->sys_refcount_enter--;

	rcu_assign_pointer(tr->enter_syscall_files[num], NULL);

	RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL);

	if (!tr->sys_refcount_enter)

		unregister_trace_sys_enter(ftrace_syscall_enter, tr);

	mutex_unlock(&syscall_trace_lock);
@@ -463,7 +463,7 @@ static void unreg_event_syscall_exit(struct ftrace_event_file *file, 
		return;

	mutex_lock(&syscall_trace_lock);

	tr->sys_refcount_exit--;

	rcu_assign_pointer(tr->exit_syscall_files[num], NULL);

	RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL);

	if (!tr->sys_refcount_exit)

		unregister_trace_sys_exit(ftrace_syscall_exit, tr);

	mutex_unlock(&syscall_trace_lock);