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Commit 600da3cf authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
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tools lib traceevent: Check string is really printable 



When libtraceevent parses format fields, it assumes that array of 1 byte
is string but it's not always true. The kvm_emulate_insn contains 15 u8
array of insn that contains (binary) instructions. Thus when it's
printed, it'll have broken output like below:

  kvm_emulate_insn:     [FAILED TO PARSE] rip=3238197797 csbase=0 len=2 \
  insn=<89>P^]<B4>& flags=5 failed=0

With this patch:

  kvm_emulate_insn:     [FAILED TO PARSE] rip=3238197797 csbase=0 len=2 \
  insn=ARRAY[89, 10, 5d, c3, 8d, b4, 26, 00, 00, 00, 00, 55, 89, e5, 3e] flags=5 failed=0

Suggested-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1340352615-20737-2-git-send-email-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 860df583

tools/lib/traceevent/event-parse.c

+13 −1
Original line number Diff line number Diff line
@@ -3589,6 +3589,16 @@ static void print_mac_arg(struct trace_seq *s, int mac, void *data, int size, 
	trace_seq_printf(s, fmt, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]);

}



static int is_printable_array(char *p, unsigned int len)

{

	unsigned int i;



	for (i = 0; i < len && p[i]; i++)

		if (!isprint(p[i]))

		    return 0;

	return 1;

}



static void print_event_fields(struct trace_seq *s, void *data, int size,

			       struct event_format *event)

{
@@ -3608,7 +3618,8 @@ static void print_event_fields(struct trace_seq *s, void *data, int size, 
				len = offset >> 16;

				offset &= 0xffff;

			}

			if (field->flags & FIELD_IS_STRING) {

			if (field->flags & FIELD_IS_STRING &&

			    is_printable_array(data + offset, len)) {

				trace_seq_printf(s, "%s", (char *)data + offset);

			} else {

				trace_seq_puts(s, "ARRAY[");
@@ -3619,6 +3630,7 @@ static void print_event_fields(struct trace_seq *s, void *data, int size, 
							 *((unsigned char *)data + offset + i));

				}

				trace_seq_putc(s, ']');

				field->flags &= ~FIELD_IS_STRING;

			}

		} else {

			val = pevent_read_number(event->pevent, data + field->offset,