[PATCH] perf script: Fix hex dump character output

From: Adrian Hunter
Date: Wed Jan 12 2022 - 03:51:02 EST


Using grep -C with perf script -D can give erroneous results as grep loses
lines due to non-printable characters, for example, below the 0020, 0060
and 0070 lines are missing:

$ perf script -D | grep -C10 AUX | head
. 0010: 08 00 00 00 00 00 00 00 1f 00 00 00 00 00 00 00 ................
. 0030: 01 00 00 00 00 00 00 00 00 04 00 00 00 00 00 00 ................
. 0040: 00 08 00 00 00 00 00 00 02 00 00 00 00 00 00 00 ................
. 0050: 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................
. 0080: 02 00 00 00 00 00 00 00 1b 00 00 00 00 00 00 00 ................
. 0090: 00 00 00 00 00 00 00 00 ........

0 0 0x450 [0x98]: PERF_RECORD_AUXTRACE_INFO type: 1
PMU Type 8
Time Shift 31

perf's isprint() is a custom implementation from the kernel, but the
kernel's _ctype appears to include characters from Latin-1 Supplement which
is not compatible with, for example, UTF-8. Fix by checking also isascii().

After:

$ tools/perf/perf script -D | grep -C10 AUX | head
. 0010: 08 00 00 00 00 00 00 00 1f 00 00 00 00 00 00 00 ................
. 0020: 03 84 32 2f 00 00 00 00 63 7c 4f d2 fa ff ff ff ..2/....c|O.....
. 0030: 01 00 00 00 00 00 00 00 00 04 00 00 00 00 00 00 ................
. 0040: 00 08 00 00 00 00 00 00 02 00 00 00 00 00 00 00 ................
. 0050: 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................
. 0060: 00 02 00 00 00 00 00 00 00 c0 03 00 00 00 00 00 ................
. 0070: e2 00 00 00 00 00 00 00 02 00 00 00 00 00 00 00 ................
. 0080: 02 00 00 00 00 00 00 00 1b 00 00 00 00 00 00 00 ................
. 0090: 00 00 00 00 00 00 00 00 ........

Fixes: 3052ba56bcb589 ("tools perf: Move from sane_ctype.h obtained from git to the Linux's original")
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/debug.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index c7a9fa0ffae9..7b5eec300d66 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -189,7 +189,7 @@ static int trace_event_printer(enum binary_printer_ops op,
break;
case BINARY_PRINT_CHAR_DATA:
printed += color_fprintf(fp, color, "%c",
- isprint(ch) ? ch : '.');
+ isprint(ch) && isascii(ch) ? ch : '.');
break;
case BINARY_PRINT_CHAR_PAD:
printed += color_fprintf(fp, color, " ");
--
2.25.1