From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754137AbbCSJxS (ORCPT ); Thu, 19 Mar 2015 05:53:18 -0400 Received: from mx2.parallels.com ([199.115.105.18]:42535 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753487AbbCSJxL (ORCPT ); Thu, 19 Mar 2015 05:53:11 -0400 From: Vladimir Davydov To: CC: Andrew Morton , Oleg Nesterov , Richard Weinberger , "Paul E. McKenney" Subject: [PATCH] signal: improve warning about using SI_TKILL in rt_[tg]sigqueueinfo Date: Thu, 19 Mar 2015 12:53:01 +0300 Message-ID: <1426758781-11746-1-git-send-email-vdavydov@parallels.com> X-Mailer: git-send-email 1.7.10.4 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sending SI_TKILL from rt_[tg]sigqueueinfo was deprecated, so now we issue a warning on the first attempt of doing it. We use WARN_ON_ONCE, which is not informative and, what is worse, taints the kernel, making the trinity syscall fuzzer complain false-positively from time to time. This patch therefore substitutes the WARN_ON_ONCE with a pr_warn_once. Signed-off-by: Vladimir Davydov --- kernel/signal.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index a390499943e4..3cbcd94457af 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2993,8 +2993,11 @@ static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info) */ if ((info->si_code >= 0 || info->si_code == SI_TKILL) && (task_pid_vnr(current) != pid)) { - /* We used to allow any < 0 si_code */ - WARN_ON_ONCE(info->si_code < 0); + /* We used to allow SI_TKILL */ + if (info->si_code == SI_TKILL) + pr_warn_once("%s (%d): Sending SI_TKILL from " + "rt_sigqueueinfo is deprecated\n", + current->comm, current->pid); return -EPERM; } info->si_signo = sig; @@ -3041,10 +3044,13 @@ static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) /* Not even root can pretend to send signals from the kernel. * Nor can they impersonate a kill()/tgkill(), which adds source info. */ - if (((info->si_code >= 0 || info->si_code == SI_TKILL)) && + if ((info->si_code >= 0 || info->si_code == SI_TKILL) && (task_pid_vnr(current) != pid)) { - /* We used to allow any < 0 si_code */ - WARN_ON_ONCE(info->si_code < 0); + /* We used to allow SI_TKILL */ + if (info->si_code == SI_TKILL) + pr_warn_once("%s (%d): Sending SI_TKILL from " + "rt_tgsigqueueinfo is deprecated\n", + current->comm, current->pid); return -EPERM; } info->si_signo = sig; -- 1.7.10.4