ftrace: make ftrace_printk usable with the other tracers

Currently ftrace_printk only works with the ftrace tracer, switch it to an
iter_ctrl setting so we can make us of them with other tracers too.

[rostedt@redhat.com: tweak to the disable condition]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 6 insertions, 3 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d24101cfc425..8a00d6c5c0f5 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -235,6 +235,7 @@ static const char *trace_options[] = {
         "block",
         "stacktrace",
         "sched-tree",
+        "ftrace_printk",
         NULL
 };
 
@@ -3091,9 +3092,10 @@ static __init void tracer_init_debugfs(void)
 
 int __ftrace_printk(unsigned long ip, const char *fmt, ...)
 {
-        struct trace_array *tr = &global_trace;
         static DEFINE_SPINLOCK(trace_buf_lock);
         static char trace_buf[TRACE_BUF_SIZE];
+
+        struct trace_array *tr = &global_trace;
         struct trace_array_cpu *data;
         struct trace_entry *entry;
         unsigned long flags;
@@ -3101,7 +3103,7 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...)
         va_list ap;
         int cpu, len = 0, write, written = 0;
 
-        if (likely(!ftrace_function_enabled))
+        if (!(trace_flags & TRACE_ITER_PRINTK) || !tr->ctrl || tracing_disabled)
                 return 0;
 
         local_irq_save(flags);
@@ -3109,7 +3111,7 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...)
         data = tr->data[cpu];
         disabled = atomic_inc_return(&data->disabled);
 
-        if (unlikely(disabled != 1 || !ftrace_function_enabled))
+        if (unlikely(disabled != 1))
                 goto out;
 
         spin_lock(&trace_buf_lock);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 50b6d7a6f01a..5f54c875c8be 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -356,6 +356,7 @@ enum trace_iterator_flags {
         TRACE_ITER_BLOCK                = 0x80,
         TRACE_ITER_STACKTRACE           = 0x100,
         TRACE_ITER_SCHED_TREE           = 0x200,
+        TRACE_ITER_PRINTK               = 0x400,
 };
 
 #endif /* _LINUX_KERNEL_TRACE_H */