Commit 50d88758 authored Mar 18, 2009 by Thomas Gleixner Committed by Ingo Molnar Mar 18, 2009

tracing: fix trace_find_cmdline()



Impact: prevent stale command line output

In case there is no valid command line mapping for a pid
trace_find_cmdline() returns without updating the comm buffer. The
trace dump keeps the previous entry which results in confusing trace
output:

     <idle>-0     [000]   280.702056 ....
     <idle>-23456 [000]   280.702080 ....

Update the comm buffer with "<...>" when no mapping is found.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 2c7eea4c

kernel/trace/trace.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -787,12 +787,11 @@ void trace_find_cmdline(int pid, char comm[])

		__raw_spin_lock(&trace_cmdline_lock);
		map = map_pid_to_cmdline[pid];
		if (map == NO_CMDLINE_MAP)
		goto out;

		if (map != NO_CMDLINE_MAP)
		strcpy(comm, saved_cmdlines[map]);
		else
		strcpy(comm, "<...>");

		out:
		__raw_spin_unlock(&trace_cmdline_lock);
		}