Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cEyrg-0002Uc-Nr for pgsql-hackers@arkaria.postgresql.org; Thu, 08 Dec 2016 13:36:00 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.84_2) (envelope-from ) id 1cEyrg-00035Y-0U for pgsql-hackers@arkaria.postgresql.org; Thu, 08 Dec 2016 13:36:00 +0000 Received: from makus.postgresql.org ([2001:4800:1501:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1cEyqH-0001Pd-0j for pgsql-hackers@postgreSQL.org; Thu, 08 Dec 2016 13:34:33 +0000 Received: from out4-smtp.messagingengine.com ([66.111.4.28]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1cEyqA-0002iW-BI for pgsql-hackers@postgreSQL.org; Thu, 08 Dec 2016 13:34:31 +0000 Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id EDBBE20897; Thu, 8 Dec 2016 08:34:24 -0500 (EST) Received: from frontend1 ([10.202.2.160]) by compute7.internal (MEProxy); Thu, 08 Dec 2016 08:34:24 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s= smtpout; bh=k9fQNBtPWrlpcf3e3FtK6p1eSNw=; b=T7L1V+gRmBqnYRElwesM zlAqic+o3ZySuWPScn17wXOHMIWEOZsTGLwORjbEAAPmtvGo1UswXb6M1tRzwVqc FYi1Xi8iGX/AWPhWUvbKg5ZOazEXG0GcsqnESo72Gwvt7Np4pXcEhKMIdzT6VoAL dZ/oSC/gjZLbB/WUopAV/xU= X-ME-Sender: X-Sasl-enc: tbnLEi4dTpiIwx2XvIunTrEQO3mM8H94iz69GSInQSgI 1481204064 Received: from april.local (c-73-13-66-39.hsd1.pa.comcast.net [73.13.66.39]) by mail.messagingengine.com (Postfix) with ESMTPA id B10D37E398; Thu, 8 Dec 2016 08:34:24 -0500 (EST) Subject: Re: Back-patch use of unnamed POSIX semaphores for Linux? To: Tom Lane References: <32387.1481079186@sss.pgh.pa.us> <722c489e-810a-be9c-f005-3b6bdcb4c59f@2ndquadrant.com> <27169.1481121490@sss.pgh.pa.us> Cc: pgsql-hackers@postgreSQL.org From: Peter Eisentraut Organization: 2ndQuadrant Message-ID: Date: Thu, 8 Dec 2016 08:34:24 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <27169.1481121490@sss.pgh.pa.us> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -2.6 (--) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-hackers Precedence: bulk Sender: pgsql-hackers-owner@postgresql.org On 12/7/16 9:38 AM, Tom Lane wrote: >> Even with that change, dynamic shared memory is still vulnerable to be >> removed. > Really? I thought we concluded that it is safe because it is detectably > attached to running processes. The DSM implementation uses POSIX shared memory, which doesn't have an attachment count like SysV shared memory. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers