Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753101AbbHGMQs (ORCPT ); Fri, 7 Aug 2015 08:16:48 -0400 Received: from mail-io0-f171.google.com ([209.85.223.171]:35730 "EHLO mail-io0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751869AbbHGMQr (ORCPT ); Fri, 7 Aug 2015 08:16:47 -0400 MIME-Version: 1.0 In-Reply-To: <20150807105910.GE8624@krava.brq.redhat.com> References: <20150803170804.22235.88475.email-sent-by-dnelson@teal> <20150807105910.GE8624@krava.brq.redhat.com> From: Namhyung Kim Date: Fri, 7 Aug 2015 21:16:27 +0900 X-Google-Sender-Auth: 1gozns8Hpyqg3VTdpXaWHt2Smcg Message-ID: Subject: Re: [PATCH] tools lib traceevent: add checks for returned EVENT_ERROR type To: Jiri Olsa Cc: Dean Nelson , a.p.zijlstra@chello.org, Ingo Molnar , Steven Rostedt , Arnaldo Carvalho de Melo , "linux-kernel@vger.kernel.org" , Jiri Olsa Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2891 Lines: 84 Hi, On Fri, Aug 7, 2015 at 7:59 PM, Jiri Olsa wrote: > On Mon, Aug 03, 2015 at 01:08:05PM -0400, Dean Nelson wrote: >> Running the following perf-stat command on an arm64 system produces the >> following result... >> >> [root@aarch64 ~]# perf stat -e kmem:mm_page_alloc -a sleep 1 >> Warning: [kmem:mm_page_alloc] function sizeof not defined >> Warning: Error: expected type 4 but read 0 >> Segmentation fault Oops, >> [root@aarch64 ~]# > > hum, what kernel are you running on? I dont see that warning > on my system: > > [jolsa@krava perf]$ sudo ./perf stat -e kmem:mm_page_alloc -a sleep 1 > > Performance counter stats for 'system wide': > > 227 kmem:mm_page_alloc > > 1.000762466 seconds time elapsed > > Cc-ing Namhyung Yeah, it seems his kernel has sizeof() somewhere in the event format. Anyway, it's not good to see a segfault. Dean, could you share your event format file? $ sudo cat /sys/kernel/debug/tracing/events/kmem/mm_page_alloc/format Thanks, Namhyung > >> >> The second warning message and SIGSEGV stem from the issue expressed in the >> first warning message, and are the result of ignoring the EVENT_ERROR type >> returned back through the call chain. >> >> Dealing with the first warning message is beyond the scope of this patch. But >> the second warning is addressed by this patch's first hunk. And the SIGSEGV is >> eliminated by its second hunk. >> >> Signed-off-by: Dean Nelson >> --- >> tools/lib/traceevent/event-parse.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c >> index cc25f05..72e2933 100644 >> --- a/tools/lib/traceevent/event-parse.c >> +++ b/tools/lib/traceevent/event-parse.c >> @@ -1680,6 +1680,9 @@ process_cond(struct event_format *event, struct print_arg *top, char **tok) >> type = process_arg(event, left, &token); >> >> again: >> + if (type == EVENT_ERROR) >> + goto out_free; >> + >> /* Handle other operations in the arguments */ >> if (type == EVENT_OP && strcmp(token, ":") != 0) { >> type = process_op(event, left, &token); >> @@ -1940,7 +1943,7 @@ process_op(struct event_format *event, struct print_arg *arg, char **tok) >> >> type = process_arg_token(event, right, tok, type); >> >> - if (right->type == PRINT_OP && >> + if (type != EVENT_ERROR && right->type == PRINT_OP && >> get_op_prio(arg->op.op) < get_op_prio(right->op.op)) { >> struct print_arg tmp; >> -- 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/