From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1F6IV5-0003pk-7C for user-mode-linux-devel@lists.sourceforge.net; Mon, 06 Feb 2006 18:22:39 -0800 Received: from [198.99.130.12] (helo=saraswathi.solana.com) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1F6IV4-00044G-Ht for user-mode-linux-devel@lists.sourceforge.net; Mon, 06 Feb 2006 18:22:39 -0800 Message-Id: <200602070223.k172NxuT009664@ccure.user-mode-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: Jeff Dike Subject: [uml-devel] [PATCH 4/8] UML - Close TUN/TAP file descriptors 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, 06 Feb 2006 21:23:59 -0500 To: akpm@osdl.org Cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, Robert Hillen When UML opens a TUN/TAP device, the file descriptor could be copied into later, long-lived threads, holding the device open even after the interface is taken down, preventing it from being brought up again. This patch makes these descriptors close-on-exec so that they disappear from helper processes, and adds CLONE_FILES to a UML helper thread so that the descriptors are closed in the thread when they are closed elsewhere in UML. Signed-off-by: Jeff Dike Index: linux-2.6.15/arch/um/drivers/chan_user.c =================================================================== --- linux-2.6.15.orig/arch/um/drivers/chan_user.c 2006-01-03 17:39:46.000000000 -0500 +++ linux-2.6.15/arch/um/drivers/chan_user.c 2006-02-06 17:35:47.000000000 -0500 @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -73,7 +74,6 @@ static void winch_handler(int sig) struct winch_data { int pty_fd; int pipe_fd; - int close_me; }; static int winch_thread(void *arg) @@ -84,7 +84,6 @@ static int winch_thread(void *arg) int count, err; char c = 1; - os_close_file(data->close_me); pty_fd = data->pty_fd; pipe_fd = data->pipe_fd; count = os_write_file(pipe_fd, &c, sizeof(c)); @@ -153,15 +152,16 @@ static int winch_tramp(int fd, struct tt } data = ((struct winch_data) { .pty_fd = fd, - .pipe_fd = fds[1], - .close_me = fds[0] } ); - err = run_helper_thread(winch_thread, &data, 0, &stack, 0); + .pipe_fd = fds[1] } ); + /* CLONE_FILES so this thread doesn't hold open files which are open + * now, but later closed. This is a problem with /dev/net/tun. + */ + err = run_helper_thread(winch_thread, &data, CLONE_FILES, &stack, 0); if(err < 0){ printk("fork of winch_thread failed - errno = %d\n", errno); goto out_close; } - os_close_file(fds[1]); *fd_out = fds[0]; n = os_read_file(fds[0], &c, sizeof(c)); if(n != sizeof(c)){ @@ -169,13 +169,12 @@ static int winch_tramp(int fd, struct tt printk("read failed, err = %d\n", -n); printk("fd %d will not support SIGWINCH\n", fd); err = -EINVAL; - goto out_close1; + goto out_close; } return err ; out_close: os_close_file(fds[1]); - out_close1: os_close_file(fds[0]); out: return err; Index: linux-2.6.15/arch/um/os-Linux/drivers/tuntap_user.c =================================================================== --- linux-2.6.15.orig/arch/um/os-Linux/drivers/tuntap_user.c 2006-01-03 17:39:46.000000000 -0500 +++ linux-2.6.15/arch/um/os-Linux/drivers/tuntap_user.c 2006-02-06 17:35:47.000000000 -0500 @@ -122,6 +122,7 @@ static int tuntap_open_tramp(char *gate, return(-EINVAL); } *fd_out = ((int *) CMSG_DATA(cmsg))[0]; + os_set_exec_close(*fd_out, 1); return(0); } @@ -137,7 +138,8 @@ static int tuntap_open(void *data) return(err); if(pri->fixed_config){ - pri->fd = os_open_file("/dev/net/tun", of_rdwr(OPENFLAGS()), 0); + pri->fd = os_open_file("/dev/net/tun", + of_cloexec(of_rdwr(OPENFLAGS())), 0); if(pri->fd < 0){ printk("Failed to open /dev/net/tun, err = %d\n", -pri->fd); ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel