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 BAAA5EE49A6 for ; Tue, 22 Aug 2023 02:39:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232331AbjHVCjB (ORCPT ); Mon, 21 Aug 2023 22:39:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232272AbjHVCia (ORCPT ); Mon, 21 Aug 2023 22:38:30 -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 CB88A186 for ; Mon, 21 Aug 2023 19:38:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CD37564BF1 for ; Tue, 22 Aug 2023 02:38:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3BEAEC433C7; Tue, 22 Aug 2023 02:38:26 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1qYHI2-001bbS-0z; Mon, 21 Aug 2023 22:38:42 -0400 Message-ID: <20230822023842.120843765@goodmis.org> User-Agent: quilt/0.66 Date: Mon, 21 Aug 2023 22:38:08 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , Sven Schnelle Subject: [for-linus][PATCH 5/8] tracing/synthetic: Allocate one additional element for size References: <20230822023803.605698724@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Schnelle While debugging another issue I noticed that the stack trace contains one invalid entry at the end: -0 [008] d..4. 26.484201: wake_lat: pid=0 delta=2629976084 000000009cc24024 stack=STACK: => __schedule+0xac6/0x1a98 => schedule+0x126/0x2c0 => schedule_timeout+0x150/0x2c0 => kcompactd+0x9ca/0xc20 => kthread+0x2f6/0x3d8 => __ret_from_fork+0x8a/0xe8 => 0x6b6b6b6b6b6b6b6b This is because the code failed to add the one element containing the number of entries to field_size. Link: https://lkml.kernel.org/r/20230816154928.4171614-4-svens@linux.ibm.com Cc: Masami Hiramatsu Fixes: 00cf3d672a9d ("tracing: Allow synthetic events to pass around stacktraces") Signed-off-by: Sven Schnelle Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_synth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 80a2a832f857..9897d0bfcab7 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -528,7 +528,8 @@ static notrace void trace_event_raw_event_synth(void *__data, str_val = (char *)(long)var_ref_vals[val_idx]; if (event->dynamic_fields[i]->is_stack) { - len = *((unsigned long *)str_val); + /* reserve one extra element for size */ + len = *((unsigned long *)str_val) + 1; len *= sizeof(unsigned long); } else { len = fetch_store_strlen((unsigned long)str_val); -- 2.40.1