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Biederman" , Andrew Morton , Al Viro , Dmitry Safonov <0x7f454c46@gmail.com>, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Andy Lutomirski Subject: Re: [PATCH v2] exec: don't force_sigsegv processes with a pending fatal signal Message-ID: <20190211160255.GC21430@redhat.com> References: <20190205025308.GA24455@visor> <20190205131119.3e388a0a1a69c0a041ed87ef@linux-foundation.org> <20190206031029.GB9368@visor> <87pns2q2ug.fsf@xmission.com> <20190209001638.GA14025@visor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190209001638.GA14025@visor> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 11 Feb 2019 16:02:58 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/08, Ivan Delalande wrote: > > A difference I've noticed with your tree (unrelated to my issue here but > that you may want to look at) is when I run my reproducer under > strace -f, I'm now getting quite a lot of "Exit of unknown pid 12345 > ignored" warnings from strace, which I've never seen with mainline. > My reproducer simply fork-exec tail processes in a loop, and tries to > sigkill them in the parent with a variable delay. Hmm... may be because of PTRACE_EVENT_EXIT problem I mentioned in reply to this change... > > Thank you, > > > diff --git a/kernel/signal.c b/kernel/signal.c > > index 9ca8e5278c8e..5424cb0006bc 100644 > > --- a/kernel/signal.c > > +++ b/kernel/signal.c > > @@ -2393,6 +2393,11 @@ bool get_signal(struct ksignal *ksig) > > goto relock; > > } > > > > + /* Has this task already been marked for death? */ > > + ksig->info.si_signo = signr = SIGKILL; > > + if (signal_group_exit(signal)) > > + goto fatal; > > + > > for (;;) { > > struct k_sigaction *ka; > > > > @@ -2488,6 +2493,7 @@ bool get_signal(struct ksignal *ksig) > > continue; > > } > > > > + fatal: > > spin_unlock_irq(&sighand->siglock); > > > > > > -- > Ivan Delalande > Arista Networks