Commit f2d84b65 authored Aug 07, 2009 by Zhaolei Committed by Frederic Weisbecker Aug 18, 2009

ftrace: Unify effect of writing to trace_options and option/*



"echo noglobal-clock > trace_options" can be used to change trace
clock but "echo 0 > options/global-clock" can't. The flag toggling
will be silently accepted without actually changing the clock callback.

We can fix it by using set_tracer_flags() in
trace_options_core_write().

Changelog:
v1->v2: Simplified switch() after Li Zefan <lizf@cn.fujitsu.com>'s
        suggestion

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

parent df4ecf15

kernel/trace/trace.c

+2 −10

Original line number	Diff line number	Diff line
		@@ -3896,17 +3896,9 @@ trace_options_core_write(struct file filp, const char __user ubuf, size_t cnt,
		if (ret < 0)
		return ret;

		switch (val) {
		case 0:
		trace_flags &= ~(1 << index);
		break;
		case 1:
		trace_flags \|= 1 << index;
		break;

		default:
		if (val != 0 && val != 1)
		return -EINVAL;
		}
		set_tracer_flags(1 << index, val);

		*ppos += cnt;

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