[PATCH] perf tools: Fix printable strings in python3 scripts

[Jiri Olsa <jolsa@kernel.org>]

Hagen reported broken strings in python3 tracepoint scripts:

  make PYTHON=python3
  ./perf record -e sched:sched_switch -a -- sleep 5
  ./perf script --gen-script py
  ./perf script -s ./perf-script.py

  [..]
  sched__sched_switch      7 563231.759525792        0 swapper   \
  prev_comm=bytearray(b'swapper/7\x00\x00\x00\x00\x00\x00\x00'), \
  prev_pid=0, prev_prio=120, prev_state=, next_comm=bytearray(b'mutex-thread-co\x00'),

The problem is in is_printable_array function that does not take
zero byte into account and claim such string as not printable,
so the code will create byte array instead of string.

Cc: stable@vger.kernel.org
Fixes: 249de6e07458 ("perf script python: Fix string vs byte array resolving")
Tested-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/print_binary.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/print_binary.c b/tools/perf/util/print_binary.c
index 599a1543871d..13fdc51c61d9 100644
--- a/tools/perf/util/print_binary.c
+++ b/tools/perf/util/print_binary.c
@@ -50,7 +50,7 @@ int is_printable_array(char *p, unsigned int len)
 
 	len--;
 
-	for (i = 0; i < len; i++) {
+	for (i = 0; i < len && p[i]; i++) {
 		if (!isprint(p[i]) && !isspace(p[i]))
 			return 0;
 	}
-- 
2.26.2