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 X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D19A5C2D0C2 for ; Fri, 3 Jan 2020 10:06:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4DB7206DB for ; Fri, 3 Jan 2020 10:06:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="b+NrfTvw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727479AbgACKGi (ORCPT ); Fri, 3 Jan 2020 05:06:38 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:42723 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725972AbgACKGi (ORCPT ); Fri, 3 Jan 2020 05:06:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578045997; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ZgNCvHnH6fEsEKaBVmrvYkgbCQvWwHoRKudXkBxEyBQ=; b=b+NrfTvwAWzv+hJ8CVUkVPAcq7k5y5LCQEfzvfMBe9Je9hw0kV+3Oj5deMhcOAoUW1TMV4 nfMQnR2uYvT3iAsBh4xPKZR1cQj++RXp8y5kvBa3Romqc4y6AhJ5L9bl5eh4tbTC4z3Nrx 2I2IsL5FX58sze/XpBmNGQLst96YLqE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-312-GF823iyCOMSqBMIrpUoZrg-1; Fri, 03 Jan 2020 05:06:34 -0500 X-MC-Unique: GF823iyCOMSqBMIrpUoZrg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E4691800EB8; Fri, 3 Jan 2020 10:06:32 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.44]) by smtp.corp.redhat.com (Postfix) with SMTP id 2D89E60BF7; Fri, 3 Jan 2020 10:06:31 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 3 Jan 2020 11:06:31 +0100 (CET) Date: Fri, 3 Jan 2020 11:06:28 +0100 From: Oleg Nesterov To: akpm@linux-foundation.org Cc: arnd@arndb.de, christian.brauner@ubuntu.com, deepa.kernel@gmail.com, ebiederm@xmission.com, guro@fb.com, linux-kernel@vger.kernel.org, trix@redhat.com Subject: Re: + signal-move-print_dropped_signal.patch added to -mm tree Message-ID: <20200103100628.GA16577@redhat.com> References: <20200102215029.PWaCMXI_O%akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200102215029.PWaCMXI_O%akpm@linux-foundation.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: Tom Rix > Subject: kernel/signal.c: move print_dropped_signal > > If the allocation of 'q' fails, the signal will be dropped. Well, not necessarily... See the comment above TRACE_SIGNAL_LOSE_INFO in __send_signal(). > To ensure > that this is reported, move print_dropped_signal to be inside the '(q == > NULL)' if-check. OK, but print_dropped_signal() says "reached RLIMIT_SIGPENDING", this is misleading if kmem_cache_alloc() fails. > Link: http://lkml.kernel.org/r/20191203180221.7038-1-trix@redhat.com > Signed-off-by: Tom Rix > Reviewed-by: Andrew Morton > Cc: "Eric W. Biederman" > Cc: Christian Brauner > Cc: Arnd Bergmann > Cc: Roman Gushchin > Cc: Deepa Dinamani > Cc: Oleg Nesterov > Signed-off-by: Andrew Morton > --- > > kernel/signal.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > --- a/kernel/signal.c~signal-move-print_dropped_signal > +++ a/kernel/signal.c > @@ -427,11 +427,10 @@ __sigqueue_alloc(int sig, struct task_st > atomic_read(&user->sigpending) <= > task_rlimit(t, RLIMIT_SIGPENDING)) { > q = kmem_cache_alloc(sigqueue_cachep, flags); > - } else { > - print_dropped_signal(sig); > } > > if (unlikely(q == NULL)) { > + print_dropped_signal(sig); > atomic_dec(&user->sigpending); > free_uid(user); > } else { > _ > > Patches currently in -mm which might be from trix@redhat.com are > > signal-move-print_dropped_signal.patch >