From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E2A632BEC2A for ; Sun, 11 Oct 2026 14:24:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791728684; cv=none; b=Mz9Ru76Q8DZJmDuet35B2UNKZFL328utVNHJmFKdN3BX+dHPl6iUeodX21cwB8ii70uppq36zWnYa3L5KVpylbWI23uBmSqOTMxx/ROnoRSutkKlrmEc5tjYGbNjp9IIp05NXEo2yFoNOW69AP9OFv3DfcEFY8dm3pJdxtUKgtQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791728684; c=relaxed/simple; bh=ySoVsxr6Izm5qYfouLLYWrkciqn9D4QnRCqqQnGrIzw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aV8vgwMVuIoGN4CpOM1nGrrgn35cp5CCRkTCaX3KPfzusMRsmWZDyolN018KledbUblOiJlc+7l1A5/fug+SUUGzTBokA+kf9TIPUJvhwR3VbixgK8F+HiqkJhqCia8dCSGpojaicgoSUzgWeL2OqBF3XOwWE337/BTSeoVGdrw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=gAJtSi5j; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gAJtSi5j" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1791728681; 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=KMzdZtm4NHCuovIEyOrY8wGVEtAQ8c37M6WZWDg8apY=; b=gAJtSi5j7jSZwzP2QqXj2xcd6XZDEr/eOmFkehkXE1wRcVesESwFs95yDIz5ZHpnCnduhy Emdcp3H72e+ieisPwnp6Fx8bO4cP7NfDf9p5c86kwqs7maTNZwbw+gxPoSxABjYY5Ed2dQ H0F53ydYhav3be6Eoih4WvkjxHZEVb4= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-42-3e15T4w_PS2KXNAafuyrSg-1; Sun, 11 Oct 2026 14:24:38 +0000 X-MC-Unique: 3e15T4w_PS2KXNAafuyrSg-1 X-Mimecast-MFC-AGG-ID: 3e15T4w_PS2KXNAafuyrSg_1791728677 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8E0E8195411F; Sun, 11 Oct 2026 14:24:37 +0000 (UTC) Received: from onestero-thinkpadp1gen7.tpbc.csb (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 2B6101956095; Sun, 11 Oct 2026 14:24:35 +0000 (UTC) Received: by onestero-thinkpadp1gen7.tpbc.csb (nbSMTP-1.00) for uid 13628 oleg@redhat.com; Sun, 11 Oct 2026 16:24:37 +0200 (CEST) Date: Sun, 11 Oct 2026 16:24:34 +0200 From: Oleg Nesterov To: Nickolai Zeldovich Cc: Christian Brauner , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] exit: fix lost-update race on the child_subreaper bitfields Message-ID: References: <20261011123440.768054-1-nickolai@csail.mit.edu> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261011123440.768054-1-nickolai@csail.mit.edu> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 10/11, Nickolai Zeldovich wrote: > > --- a/include/linux/sched/signal.h > +++ b/include/linux/sched/signal.h > @@ -130,8 +130,8 @@ struct signal_struct { > * process will inherit a flag if they should look for a > * child_subreaper process at exit. > */ > - unsigned int is_child_subreaper:1; > - unsigned int has_child_subreaper:1; > + bool is_child_subreaper; > + bool has_child_subreaper; > unsigned int autoreap:1; Thanks, Acked-by: Oleg Nesterov perhaps it makes sense to add something like signal_struct::atomic_flags later... Oleg.