perf debug: fix hex dump partial final line

The loop counter math in trace_event was much more complicated than
necessary, resulting in incorrectly decoding the human-readable
portion of the partial last line of hexdump in "perf trace -D" output:

.  0020:  00 00 00 00 00 00 00 00 2f 73 62 69 6e 2f 69 6e  ......../sbin/i
.  0030:  69 74 00 00 00 00 00 00                          /sbin/i

With this fixed (and simpler!) code, we get the correct output:

.  0020:  00 00 00 00 00 00 00 00 2f 73 62 69 6e 2f 69 6e  ......../sbin/in
.  0030:  69 74 00 00 00 00 00 00                          it......

Cc: Ingo Molnar <mingo@elte.hu>
LPU-Reference: <20100612024404.GA24469@hexapodia.org>
Signed-off-by: Andy Isaacson <adi@hexapodia.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index 6cddff2bc970..318dab15d177 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -86,12 +86,10 @@ void trace_event(event_t *event)
                         dump_printf_color("  ", color);
                         for (j = 0; j < 15-(i & 15); j++)
                                 dump_printf_color("   ", color);
-                        for (j = 0; j < (i & 15); j++) {
-                                if (isprint(raw_event[i-15+j]))
-                                        dump_printf_color("%c", color,
-                                                          raw_event[i-15+j]);
-                                else
-                                        dump_printf_color(".", color);
+                        for (j = i & ~15; j <= i; j++) {
+                                dump_printf_color("%c", color,
+                                                isprint(raw_event[j]) ?
+                                                raw_event[j] : '.');
                         }
                         dump_printf_color("\n", color);
                 }