From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:43972 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754210AbeEHILl (ORCPT ); Tue, 8 May 2018 04:11:41 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Zijlstra , Jiri Olsa , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , syzbot+9c0d616860575a73166a@syzkaller.appspotmail.com, syzbot+4e9ae7fa46233396f64d@syzkaller.appspotmail.com, Mathieu Desnoyers , "Steven Rostedt (VMware)" Subject: [PATCH 4.16 10/52] tracepoint: Do not warn on ENOMEM Date: Tue, 8 May 2018 10:10:08 +0200 Message-Id: <20180508073929.363979577@linuxfoundation.org> In-Reply-To: <20180508073928.058320984@linuxfoundation.org> References: <20180508073928.058320984@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathieu Desnoyers commit d66a270be3310d7aa132fec0cea77d3d32a0ff75 upstream. Tracepoint should only warn when a kernel API user does not respect the required preconditions (e.g. same tracepoint enabled twice, or called to remove a tracepoint that does not exist). Silence warning in out-of-memory conditions, given that the error is returned to the caller. This ensures that out-of-memory error-injection testing does not trigger warnings in tracepoint.c, which were seen by syzbot. Link: https://lkml.kernel.org/r/001a114465e241a8720567419a72@google.com Link: https://lkml.kernel.org/r/001a1140e0de15fc910567464190@google.com Link: http://lkml.kernel.org/r/20180315124424.32319-1-mathieu.desnoyers@efficios.com CC: Peter Zijlstra CC: Jiri Olsa CC: Arnaldo Carvalho de Melo CC: Alexander Shishkin CC: Namhyung Kim CC: stable@vger.kernel.org Fixes: de7b2973903c6 ("tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints") Reported-by: syzbot+9c0d616860575a73166a@syzkaller.appspotmail.com Reported-by: syzbot+4e9ae7fa46233396f64d@syzkaller.appspotmail.com Signed-off-by: Mathieu Desnoyers Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/tracepoint.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -207,7 +207,7 @@ static int tracepoint_add_func(struct tr lockdep_is_held(&tracepoints_mutex)); old = func_add(&tp_funcs, func, prio); if (IS_ERR(old)) { - WARN_ON_ONCE(1); + WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM); return PTR_ERR(old); } @@ -239,7 +239,7 @@ static int tracepoint_remove_func(struct lockdep_is_held(&tracepoints_mutex)); old = func_remove(&tp_funcs, func); if (IS_ERR(old)) { - WARN_ON_ONCE(1); + WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM); return PTR_ERR(old); }