Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752579AbbDTVXW (ORCPT ); Mon, 20 Apr 2015 17:23:22 -0400 Received: from mail.kernel.org ([198.145.29.136]:40567 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750872AbbDTVXU (ORCPT ); Mon, 20 Apr 2015 17:23:20 -0400 Date: Mon, 20 Apr 2015 18:23:14 -0300 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: David Ahern , Frederic Weisbecker , He Kuang , Ingo Molnar , Jeremie Galarneau , Namhyung Kim , Paul Mackerras , Peter Zijlstra , Sebastian Andrzej Siewior , Tom Zanussi , Wang Nan , lkml Subject: Re: [PATCH 7/7] perf data: Fix signess of value Message-ID: <20150420212314.GR11111@kernel.org> References: <1429372220-6406-1-git-send-email-jolsa@kernel.org> <1429372220-6406-8-git-send-email-jolsa@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1429372220-6406-8-git-send-email-jolsa@kernel.org> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4560 Lines: 137 Em Sat, Apr 18, 2015 at 05:50:20PM +0200, Jiri Olsa escreveu: > From: Wang Nan > > When converting int values, perf first extractes it to a ulonglong, then > feeds it to babeltrace as a signed value. For negative 32 bit values > (for example, return values of failed syscalls), the extracted data > should be something like 0xfffffffe (-2). It becomes a large int64 > value. Babeltrace denies to insert it with > bt_ctf_field_signed_integer_set_value() because it is larger than > 0x7fffffff, the largest positive value a signed 32 bit int can be. There is no such word "signess", it is "signedness", fixing this up. Humm, it seems there is such a word indeed: http://www.urbandictionary.com/define.php?term=Signess But I bet this is the one we want: http://en.wikipedia.org/wiki/Signedness Right? :-) - Arnaldo > This patch introduces adjust_signess(), which fills high bits of > ulonglong with 1 if the value is negative. > > Signed-off-by: Wang Nan > Link: http://lkml.kernel.org/n/tip-bq2fguw8pm8s5rr741mmgias@git.kernel.org > Signed-off-by: Jiri Olsa > --- > tools/perf/util/data-convert-bt.c | 64 +++++++++++++++++++++++++++++++-------- > 1 file changed, 52 insertions(+), 12 deletions(-) > > diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c > index 8eda4ed628e7..977cc3f98d8f 100644 > --- a/tools/perf/util/data-convert-bt.c > +++ b/tools/perf/util/data-convert-bt.c > @@ -166,6 +166,43 @@ get_tracepoint_field_type(struct ctf_writer *cw, struct format_field *field) > return cw->data.u32; > } > > +static unsigned long long adjust_signess(unsigned long long value_int, int size) > +{ > + unsigned long long value_mask; > + > + /* > + * value_mask = (1 << (size * 8 - 1)) - 1. > + * Directly set value_mask for code readers. > + */ > + switch (size) { > + case 1: > + value_mask = 0x7fULL; > + break; > + case 2: > + value_mask = 0x7fffULL; > + break; > + case 4: > + value_mask = 0x7fffffffULL; > + break; > + case 8: > + /* > + * For 64 bit value, return it self. There is no need > + * to fill high bit. > + */ > + /* Fall through */ > + default: > + /* BUG! */ > + return value_int; > + } > + > + /* If it is a positive value, don't adjust. */ > + if ((value_int & (~0ULL - value_mask)) == 0) > + return value_int; > + > + /* Fill upper part of value_int with 1 to make it a negative long long. */ > + return (value_int & value_mask) | ~value_mask; > +} > + > static int add_tracepoint_field_value(struct ctf_writer *cw, > struct bt_ctf_event_class *event_class, > struct bt_ctf_event *event, > @@ -177,7 +214,6 @@ static int add_tracepoint_field_value(struct ctf_writer *cw, > struct bt_ctf_field *field; > const char *name = fmtf->name; > void *data = sample->raw_data; > - unsigned long long value_int; > unsigned long flags = fmtf->flags; > unsigned int n_items; > unsigned int i; > @@ -222,11 +258,6 @@ static int add_tracepoint_field_value(struct ctf_writer *cw, > type = get_tracepoint_field_type(cw, fmtf); > > for (i = 0; i < n_items; i++) { > - if (!(flags & FIELD_IS_STRING)) > - value_int = pevent_read_number( > - fmtf->event->pevent, > - data + offset + i * len, len); > - > if (flags & FIELD_IS_ARRAY) > field = bt_ctf_field_array_get_field(array_field, i); > else > @@ -240,12 +271,21 @@ static int add_tracepoint_field_value(struct ctf_writer *cw, > if (flags & FIELD_IS_STRING) > ret = bt_ctf_field_string_set_value(field, > data + offset + i * len); > - else if (!(flags & FIELD_IS_SIGNED)) > - ret = bt_ctf_field_unsigned_integer_set_value( > - field, value_int); > - else > - ret = bt_ctf_field_signed_integer_set_value( > - field, value_int); > + else { > + unsigned long long value_int; > + > + value_int = pevent_read_number( > + fmtf->event->pevent, > + data + offset + i * len, len); > + > + if (!(flags & FIELD_IS_SIGNED)) > + ret = bt_ctf_field_unsigned_integer_set_value( > + field, value_int); > + else > + ret = bt_ctf_field_signed_integer_set_value( > + field, adjust_signess(value_int, len)); > + } > + > if (ret) { > pr_err("failed to set file value %s\n", name); > goto err_put_field; > -- > 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/