From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BC94ECAAA1 for ; Fri, 9 Sep 2022 13:23:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230161AbiIINXL (ORCPT ); Fri, 9 Sep 2022 09:23:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229585AbiIINXF (ORCPT ); Fri, 9 Sep 2022 09:23:05 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F54C10B578; Fri, 9 Sep 2022 06:23:05 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D246561FE4; Fri, 9 Sep 2022 13:23:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C240C43142; Fri, 9 Sep 2022 13:23:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662729784; bh=Wk0bJyJfH/o7KA0o1KB3udTJXEgUndQ3l/7kpVZGGXE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CIHFhOb91bNGL4jXREjW5SAvMLo2tjvzE0L4Jbv+m+n21Eu0thmTMJ32wsDd0bxWS TfFo7qVcVFRJinDcdIy56QcROZ8o5w/HidlGqB4P+kdqHTguCqec6Jx+E1Hw8vYxq7 E5tUK/pEh9U+8P6Ef3MaBtcDDFS9rZLB55xsHAyuKAvjxK84jPFhqkGp3etF7ppoQd tTersIwy7UZtQv0aURTrcrRCUGE0gisr9McdLNf7XBJsV/dvs19o1eF8/RHkW5GR92 Tu3vDEQ79Oh9c2ZRa/dEwrYZOsXOqsOiJdb8VCC0oyvUl/cAmfBLDI361TNOOQfK8I Xh6VsMt0jkXEA== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 6F2D6404A1; Fri, 9 Sep 2022 10:23:01 -0300 (-03) Date: Fri, 9 Sep 2022 10:23:01 -0300 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Jiri Olsa , Ingo Molnar , Peter Zijlstra , LKML , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Marco Elver , Song Liu Subject: Re: [PATCH v3] perf test: Skip sigtrap test on old kernels Message-ID: References: <20220908230150.4105955-1-namhyung@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220908230150.4105955-1-namhyung@kernel.org> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Thu, Sep 08, 2022 at 04:01:50PM -0700, Namhyung Kim escreveu: > If it runs on an old kernel, perf_event_open would fail because of the > new fields sigtrap and sig_data. Just skipping the test could miss an > actual bug in the kernel. > > Let's check BTF (when we have libbpf) if it has the sigtrap field in the > perf_event_attr. Otherwise, we can check it with a minimal event config. Thanks, applied. - Arnaldo > Cc: Marco Elver > Acked-by: Song Liu > Signed-off-by: Namhyung Kim > --- > tools/perf/tests/sigtrap.c | 65 +++++++++++++++++++++++++++++++++++++- > 1 file changed, 64 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/tests/sigtrap.c b/tools/perf/tests/sigtrap.c > index e32ece90e164..1de7478ec189 100644 > --- a/tools/perf/tests/sigtrap.c > +++ b/tools/perf/tests/sigtrap.c > @@ -54,6 +54,63 @@ static struct perf_event_attr make_event_attr(void) > return attr; > } > > +#ifdef HAVE_BPF_SKEL > +#include > + > +static bool attr_has_sigtrap(void) > +{ > + bool ret = false; > + struct btf *btf; > + const struct btf_type *t; > + const struct btf_member *m; > + const char *name; > + int i, id; > + > + btf = btf__load_vmlinux_btf(); > + if (btf == NULL) { > + /* should be an old kernel */ > + return false; > + } > + > + id = btf__find_by_name_kind(btf, "perf_event_attr", BTF_KIND_STRUCT); > + if (id < 0) > + goto out; > + > + t = btf__type_by_id(btf, id); > + for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) { > + name = btf__name_by_offset(btf, m->name_off); > + if (!strcmp(name, "sigtrap")) { > + ret = true; > + break; > + } > + } > +out: > + btf__free(btf); > + return ret; > +} > +#else /* !HAVE_BPF_SKEL */ > +static bool attr_has_sigtrap(void) > +{ > + struct perf_event_attr attr = { > + .type = PERF_TYPE_SOFTWARE, > + .config = PERF_COUNT_SW_DUMMY, > + .size = sizeof(attr), > + .remove_on_exec = 1, /* Required by sigtrap. */ > + .sigtrap = 1, /* Request synchronous SIGTRAP on event. */ > + }; > + int fd; > + bool ret = false; > + > + fd = sys_perf_event_open(&attr, 0, -1, -1, perf_event_open_cloexec_flag()); > + if (fd >= 0) { > + ret = true; > + close(fd); > + } > + > + return ret; > +} > +#endif /* HAVE_BPF_SKEL */ > + > static void > sigtrap_handler(int signum __maybe_unused, siginfo_t *info, void *ucontext __maybe_unused) > { > @@ -139,7 +196,13 @@ static int test__sigtrap(struct test_suite *test __maybe_unused, int subtest __m > > fd = sys_perf_event_open(&attr, 0, -1, -1, perf_event_open_cloexec_flag()); > if (fd < 0) { > - pr_debug("FAILED sys_perf_event_open(): %s\n", str_error_r(errno, sbuf, sizeof(sbuf))); > + if (attr_has_sigtrap()) { > + pr_debug("FAILED sys_perf_event_open(): %s\n", > + str_error_r(errno, sbuf, sizeof(sbuf))); > + } else { > + pr_debug("perf_event_attr doesn't have sigtrap\n"); > + ret = TEST_SKIP; > + } > goto out_restore_sigaction; > } > > -- > 2.37.2.789.g6183377224-goog -- - Arnaldo