From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755644AbbAFNxO (ORCPT ); Tue, 6 Jan 2015 08:53:14 -0500 Received: from us01smtprelay-2.synopsys.com ([198.182.60.111]:52859 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755268AbbAFNxK (ORCPT ); Tue, 6 Jan 2015 08:53:10 -0500 From: Vineet Gupta To: , CC: , , , , , , , Vineet Gupta Subject: [PATCH 4/5] perf tools: [uclibc] don't rely on glibc malloc working for sz 0 Date: Tue, 6 Jan 2015 19:22:14 +0530 Message-ID: <1420552335-26886-5-git-send-email-vgupta@synopsys.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1420552335-26886-1-git-send-email-vgupta@synopsys.com> References: <1420552335-26886-1-git-send-email-vgupta@synopsys.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.12.196.223] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When running perf on ARC (uClibc based userspace), ran into this issue ------------->8---------------- [ARCLinux]$ ./perf record ls bin etc perf sys debug init perf.data tmp [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.001 MB perf.data (~24 samples) ] [ARCLinux]$ ./perf report incompatible file format (rerun with -v to learn more) ------------->8---------------- The problem happens in the following call stack when zalloc is called with size zero glibc default / uClibc with MALLOC_GLIBC_COMPAT are OK, but not if that config option is not enabled. cmd_report perf_session__new perf_session__open perf_session__read_header read_attr(fd, header, &f_attr) nr_ids = f_attr.ids.size / sizeof(u64); <-- 0 perf_evsel__alloc_id(vsel, 1, nr_ids) zalloc(ncpus * nthreads * sizeof(u64)) <-- 0 header.c: read_attr() (gdb) p *f_attr $17 = { attr = { type = 0, size = 96, config = 0, { sample_period = 4000, sample_freq = 4000 }, ... ids = { offset = 104, size = 0 <------ } } Signed-off-by: Vineet Gupta --- tools/perf/util/header.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index b20e40c74468..43671068ce75 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2532,7 +2532,7 @@ int perf_session__read_header(struct perf_session *session) */ perf_evlist__add(session->evlist, evsel); - nr_ids = f_attr.ids.size / sizeof(u64); + nr_ids = f_attr.ids.size / sizeof(u64) ? : 1; /* * We don't have the cpu and thread maps on the header, so * for allocating the perf_sample_id table we fake 1 cpu and -- 1.9.1