Commit e404b321 authored Feb 19, 2012 by Andrey Vagin Committed by Steven Rostedt Feb 20, 2012

tracing: Don't print an extra separator of flags

If __print_flags() is used after another __print_*() function, the
temp seq_file buffer will not be empty on entry, and the delimiter will
be printed even though there's just one field. We get something like:

	|S

instead of just:

	S

This is because the length of the temp seq buffer is used to determine
if the delimiter is printed or not. But this algorithm fails when
the seq buffer is not empty on entry, and the delimiter will be printed
because it thinks that a previous field was already printed.

Link: http://lkml.kernel.org/r/1329650167-480655-1-git-send-email-avagin@openvz.org



Signed-off-by: Andrew Vagin <avagin@openvz.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent 09bda443

kernel/trace/trace_output.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -300,7 +300,7 @@ ftrace_print_flags_seq(struct trace_seq p, const char delim,
		unsigned long mask;
		const char *str;
		const char *ret = p->buffer + p->len;
		int i;
		int i, first = 1;

		for (i = 0; flag_array[i].name && flags; i++) {

		@@ -310,8 +310,10 @@ ftrace_print_flags_seq(struct trace_seq p, const char delim,

		str = flag_array[i].name;
		flags &= ~mask;
		if (p->len && delim)
		if (!first && delim)
		trace_seq_puts(p, delim);
		else
		first = 0;
		trace_seq_puts(p, str);
		}