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 1CT5p1-0003sa-Cl for user-mode-linux-devel@lists.sourceforge.net; Sat, 13 Nov 2004 13:52:39 -0800 Received: from nevyn.them.org ([66.93.172.17] ident=Debian-exim) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:RC4-SHA:128) (Exim 4.41) id 1CT5ox-0006mI-Oo for user-mode-linux-devel@lists.sourceforge.net; Sat, 13 Nov 2004 13:52:39 -0800 From: Daniel Jacobowitz Message-ID: <20041113215233.GA31209@nevyn.them.org> References: <20041113211443.GA27963@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041113211443.GA27963@nevyn.them.org> Subject: [uml-devel] Re: Debian bug 271069, gdb startup fails 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: Sat, 13 Nov 2004 16:52:33 -0500 To: 271069-submitter@bugs.debian.org, 271069@bugs.debian.org, user-mode-linux-devel@lists.sourceforge.net On Sat, Nov 13, 2004 at 04:14:43PM -0500, Daniel Jacobowitz wrote: > History: > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=271069 > > I've been looking at this bug. I've already fixed the EINTR problem; > I didn't see your patch (not sure why the BTS didn't forward it to me). > But 2.6.10-rc1 does the same thing outside of UML, so I needed to fix > it anyway. > > However, GDB startup still fails in UML using './linux debug'. Here's > what happens: > > - GDB forks > - the child issues TRACEME > - GDB waits for it, successfully now that EINTR is handled > - GDB issues PTRACE_SETOPTIONS (returns -EINVAL because the proxy > does not support it) > - GDB decides that the feature isn't available (good so far; it isn't) > - GDB tries to clean up. It sends PTRACE_KILL to the child it forked. > - GDB waits for the child to exit. Which it never does. > > I imagine the proxy is just not able to cope with this. It certainly > doesn't look as if it can. For instance, arg2 is completely ignored > except for PTRACE_ATTACH; I think what has happened is that the > PTRACE_KILL was sent to the wrong process. And the waitpids are > probably waiting for the wrong process too. > > I think the only way to fix this is to teach the UML proxy to get out > of the way if the pid is not the expected one, for at least PTRACE_KILL > and waitpid; but it should probably continue to return failure for > PTRACE_SETOPTIONS. Actually, while the proxy probably should be fixed anyway, I've worked around this in GDB. It will be in the Debian 6.3-2 packages, which I'm working on right now. Should "kill" work from the GDB prompt? If so, that does need some work in the proxy. -- Daniel Jacobowitz ------------------------------------------------------- This SF.Net email is sponsored by: InterSystems CACHE FREE OODBMS DOWNLOAD - A multidimensional database that combines robust object and relational technologies, making it a perfect match for Java, C++,COM, XML, ODBC and JDBC. www.intersystems.com/match8 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel