uml: handle errors on opening host side of consoles

If the host side of a console can't be opened, this will now produce visible
error messages.

enable_chan now returns a status and this is passed up to con_open and
ssl_open, which will complain if anything went wrong.

The default host device for the serial line driver is now a pts device rather
than a pty device since lots of hosts have LEGACY_PTYS disabled.  This had
always been failing on such hosts, but silently.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/um/defconfig b/arch/um/defconfig
index e5b2df9..a25cd25 100644 (file)
--- a/arch/um/defconfig
+++ b/arch/um/defconfig
@@ -189,7 +189,7 @@ CONFIG_XTERM_CHAN=y
 # CONFIG_NOCONFIG_CHAN is not set
 CONFIG_CON_ZERO_CHAN="fd:0,fd:1"
 CONFIG_CON_CHAN="xterm"
-CONFIG_SSL_CHAN="pty"
+CONFIG_SSL_CHAN="pts"
 CONFIG_UNIX98_PTYS=y
 CONFIG_LEGACY_PTYS=y
 CONFIG_LEGACY_PTY_COUNT=256

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 3aa3516..368d3e9 100644 (file)
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -203,22 +203,37 @@ void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
        }
 }
 
-void enable_chan(struct line *line)
+int enable_chan(struct line *line)
 {
        struct list_head *ele;
        struct chan *chan;
+       int err;
 
        list_for_each(ele, &line->chan_list){
                chan = list_entry(ele, struct chan, list);
-               if(open_one_chan(chan))
+               err = open_one_chan(chan);
+               if (err) {
+                       if (chan->primary)
+                               goto out_close;
+
                        continue;
+               }
 
                if(chan->enabled)
                        continue;
-               line_setup_irq(chan->fd, chan->input, chan->output, line,
-                              chan);
+               err = line_setup_irq(chan->fd, chan->input, chan->output, line,
+                                    chan);
+               if (err)
+                       goto out_close;
+
                chan->enabled = 1;
        }
+
+       return 0;
+
+ out_close:
+       close_chan(&line->chan_list, 0);
+       return err;
 }
 
 /* Items are added in IRQ context, when free_irq can't be called, and

diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 4bd40bb..1fb3e51 100644 (file)
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -454,7 +454,10 @@ int line_open(struct line *lines, struct tty_struct *tty)
        tty->driver_data = line;
        line->tty = tty;
 
-       enable_chan(line);
+       err = enable_chan(line);
+       if (err)
+               return err;
+
        INIT_DELAYED_WORK(&line->task, line_timer_cb);
 
        if(!line->sigio){

diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index b4ecf8d..875d60d 100644 (file)
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -97,7 +97,13 @@ static int ssl_remove(int n, char **error_out)
 
 static int ssl_open(struct tty_struct *tty, struct file *filp)
 {
-       return line_open(serial_lines, tty);
+       int err = line_open(serial_lines, tty);
+
+       if (err)
+               printk(KERN_ERR "Failed to open serial line %d, err = %d\n",
+                      tty->index, err);
+
+       return err;
 }
 
 #if 0

diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index e312488..656036e 100644 (file)
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -99,7 +99,12 @@ static int con_remove(int n, char **error_out)
 
 static int con_open(struct tty_struct *tty, struct file *filp)
 {
-       return line_open(vts, tty);
+       int err = line_open(vts, tty);
+       if (err)
+               printk(KERN_ERR "Failed to open console %d, err = %d\n",
+                      tty->index, err);
+
+       return err;
 }
 
 /* Set in an initcall, checked in an exitcall */

diff --git a/arch/um/include/chan_kern.h b/arch/um/include/chan_kern.h
index c4b41bb..624b510 100644 (file)
--- a/arch/um/include/chan_kern.h
+++ b/arch/um/include/chan_kern.h
@@ -40,7 +40,7 @@ extern int console_open_chan(struct line *line, struct console *co);
 extern void deactivate_chan(struct list_head *chans, int irq);
 extern void reactivate_chan(struct list_head *chans, int irq);
 extern void chan_enable_winch(struct list_head *chans, struct tty_struct *tty);
-extern void enable_chan(struct line *line);
+extern int enable_chan(struct line *line);
 extern void close_chan(struct list_head *chans, int delay_free_irq);
 extern int chan_window_size(struct list_head *chans, 
                             unsigned short *rows_out,