ftrace: allow trace_pipe to block on all reads

We expect things like "cat" to block on reads to trace_pipe. That's what
trace_pipe is for.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9197782..fd4ecc2 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2231,8 +2231,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
        start = 0;
 
        while (trace_empty(iter)) {
-               if (!(trace_flags & TRACE_ITER_BLOCK))
-                       return -EWOULDBLOCK;
                /*
                 * This is a make-shift waitqueue. The reason we don't use
                 * an actual wait queue is because: