Messages in this thread Patch in this message | | | Date | Tue, 12 Jul 2016 10:11:56 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH 10/10] perf script python: Fix string vs byte array resolving |
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On Mon, Jul 11, 2016 at 11:54:52AM -0400, Steven Rostedt wrote: > On Sun, 10 Jul 2016 13:08:02 +0200 > Jiri Olsa <jolsa@kernel.org> wrote: > > > Jirka reported that python code returns all arrays as strings. > > This makes impossible to get all items for byte array tracepoint > > field containing 0x00 value item. > > > > Fixing this by scanning full length of the array and returning > > it as PyByteArray object in case non printable byte is found. > > > > Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org> > > Reported-and-tested-by: Jiri Pirko <jiri@mellanox.com> > > Link: http://lkml.kernel.org/n/tip-22f4vhhz5uytegkggy1on8u3@git.kernel.org > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > > --- > > .../util/scripting-engines/trace-event-python.c | 34 ++++++++++++++++++---- > > 1 file changed, 28 insertions(+), 6 deletions(-) > > > > diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c > > index ff134700bf30..75e9790ebb96 100644 > > --- a/tools/perf/util/scripting-engines/trace-event-python.c > > +++ b/tools/perf/util/scripting-engines/trace-event-python.c > > @@ -386,6 +386,16 @@ exit: > > return pylist; > > } > > > > +static int is_printable_array(char *p, unsigned int len) > > +{ > > + unsigned int i; > > + > > + for (i = 0; i < len; i++) > > + if (!isprint(p[i]) && !isspace(p[i])) > > + return 0; > > I believe this will return the wrong result if you pass in a string > that has '\0' in it. Try it out: > > char a[] = "hello"; > > printf("a=%s is %d\n", a, is_printable_array(a, sizeof(a))); > > and see what you get?
ugh, forgot the last 0 byte.. how about attached change?
I wonder it'd be less pain to present all arrays as PyByteArray, it might be no difference for python users anyway ;-)
thanks, jirka
--- diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c index 75e9790ebb96..9f810e6c739a 100644 --- a/tools/perf/util/scripting-engines/trace-event-python.c +++ b/tools/perf/util/scripting-engines/trace-event-python.c @@ -390,11 +390,13 @@ static int is_printable_array(char *p, unsigned int len) { unsigned int i; - for (i = 0; i < len; i++) + /* Exclude the last zero byte of string.. */ + for (i = 0; i < len - 1; i++) if (!isprint(p[i]) && !isspace(p[i])) return 0; - return 1; + /* ... and check its presence in the last byte. */ + return p[i] == 0; } static void python_process_tracepoint(struct perf_sample *sample,
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