Commit 7ab215f2 authored Feb 17, 2020 by Masami Hiramatsu Committed by Steven Rostedt (VMware) Feb 20, 2020

tracing: Clear trace_state when starting trace

Clear trace_state data structure when starting trace
in __synth_event_trace_start() internal function.

Currently trace_state is initialized only in the
synth_event_trace_start() API, but the trace_state
in synth_event_trace() and synth_event_trace_array()
are on the stack without initialization.
This means those APIs will see wrong parameters and
wil skip closing process in __synth_event_trace_end()
because trace_state->disabled may be !0.

Link: http://lkml.kernel.org/r/158193315899.8868.1781259176894639952.stgit@devnote2



Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent 08d9e686

kernel/trace/trace_events_hist.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1824,6 +1824,8 @@ __synth_event_trace_start(struct trace_event_file *file,
		int entry_size, fields_size = 0;
		int ret = 0;

		memset(trace_state, '\0', sizeof(*trace_state));

		/*
		* Normal event tracing doesn't get called at all unless the
		* ENABLED bit is set (which attaches the probe thus allowing
		@@ -2063,8 +2065,6 @@ int synth_event_trace_start(struct trace_event_file *file,
		if (!trace_state)
		return -EINVAL;

		memset(trace_state, '\0', sizeof(*trace_state));

		ret = __synth_event_trace_start(file, trace_state);
		if (ret == -ENOENT)
		ret = 0; /* just disabled, not really an error */

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