From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1D8RIo-0000GG-AC for user-mode-linux-devel@lists.sourceforge.net; Mon, 07 Mar 2005 15:06:18 -0800 Received: from lakshmi.addtoit.com ([198.99.130.6] helo=lakshmi.solana.com) by sc8-sf-mx2.sourceforge.net with esmtp (Exim 4.41) id 1D8RIm-0000ID-Ob for user-mode-linux-devel@lists.sourceforge.net; Mon, 07 Mar 2005 15:06:18 -0800 Message-Id: <200503080001.j2800Wbc005246@ccure.user-mode-linux.org> In-Reply-To: Your message of "Sun, 06 Mar 2005 19:49:03 +0100." <200503061949.03819.blaisorblade@yahoo.it> References: <200503061949.03819.blaisorblade@yahoo.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: Jeff Dike Subject: [uml-devel] Re: SKAS leftovers: having fun with old code relicts (aka PTRACE_SIGPENDING) Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Mon, 07 Mar 2005 19:00:32 -0500 To: Blaisorblade Cc: user-mode-linux-devel@lists.sourceforge.net blaisorblade@yahoo.it said: > After this story, we come to the question: Jeff, what I missed (apart > that probably it was used in releases before SKAS3)? I don't think it was ever used. The thinking was race avoidance - if a signal hit the process at the same time that it started a system call, or two signals came in at the same time, UML would handle the first, then PTRACE_SIGPENDING to see if there were any more that needed handling. However, the userspace process doesn't receive any signals apart from SIGVTALRM, so this is somewhat moot. If the userspace process did receive important signals (like SIGIO), then not using this could lead to situations where the one running process sleeps for a long time, leaving a SIGIO trapped on the userspace process. And this could lead to deadlocks when the SIGIO was for the I/O that the process was sleeping on. > Could I delete PTRACE_SIGPENDING from the SKAS patch? Yup. Jeff ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel