Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753263AbbHTQAu (ORCPT ); Thu, 20 Aug 2015 12:00:50 -0400 Received: from mail-pd0-f171.google.com ([209.85.192.171]:36764 "EHLO mail-pd0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751665AbbHTQAt (ORCPT ); Thu, 20 Aug 2015 12:00:49 -0400 Date: Fri, 21 Aug 2015 00:57:55 +0900 From: Namhyung Kim To: Dean Nelson Cc: a.p.zijlstra@chello.org, mingo@redhat.com, rostedt@goodmis.org, acme@kernel.org, linux-kernel@vger.kernel.org, jolsa@kernel.org Subject: Re: [PATCH v3] tools lib traceevent: add checks for returned EVENT_ERROR type Message-ID: <20150820155755.GA16635@danjae.kornet> References: <20150820151632.13927.13791.email-sent-by-dnelson@teal> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20150820151632.13927.13791.email-sent-by-dnelson@teal> User-Agent: Mutt/1.5.23+102 (2ca89bed6448) (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2457 Lines: 68 On Thu, Aug 20, 2015 at 11:16:32AM -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 > [root@aarch64 ~]# > > 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 Acked-by: Namhyung Kim Thank you for fixing this! Namhyung > --- > Changes in v3: > - The desire was that a goto be used, not what I'd done in v2. > > Changes in v2: > - Moved the second hunk's check for EVENT_ERROR to a separate line. > > tools/lib/traceevent/event-parse.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c > index cc25f05..ed765a9 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); > @@ -1939,6 +1942,12 @@ process_op(struct event_format *event, struct print_arg *arg, char **tok) > goto out_warn_free; > > type = process_arg_token(event, right, tok, type); > + if (type == EVENT_ERROR) { > + free_arg(right); > + /* token was freed in process_arg_token() via *tok */ > + token = NULL; > + goto out_free; > + } > > if (right->type == PRINT_OP && > get_op_prio(arg->op.op) < get_op_prio(right->op.op)) { -- 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/