2007-06-14 20:28:50

by Jeff Dike

[permalink] [raw]
Subject: [PATCH 2/5] 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 <[email protected]>
--
arch/um/defconfig | 2 +-
arch/um/drivers/chan_kern.c | 23 +++++++++++++++++++----
arch/um/drivers/line.c | 5 ++++-
arch/um/drivers/ssl.c | 8 +++++++-
arch/um/drivers/stdio_console.c | 7 ++++++-
arch/um/include/chan_kern.h | 2 +-
6 files changed, 38 insertions(+), 9 deletions(-)

Index: linux-2.6.21-mm/arch/um/drivers/chan_kern.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/drivers/chan_kern.c 2007-06-14 15:40:01.000000000 -0400
+++ linux-2.6.21-mm/arch/um/drivers/chan_kern.c 2007-06-14 16:00:23.000000000 -0400
@@ -203,22 +203,37 @@ void chan_enable_winch(struct list_head
}
}

-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
Index: linux-2.6.21-mm/arch/um/drivers/line.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/drivers/line.c 2007-06-14 15:40:01.000000000 -0400
+++ linux-2.6.21-mm/arch/um/drivers/line.c 2007-06-14 16:00:23.000000000 -0400
@@ -454,7 +454,10 @@ int line_open(struct line *lines, struct
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){
Index: linux-2.6.21-mm/arch/um/drivers/ssl.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/drivers/ssl.c 2007-06-14 15:40:01.000000000 -0400
+++ linux-2.6.21-mm/arch/um/drivers/ssl.c 2007-06-14 16:00:23.000000000 -0400
@@ -97,7 +97,13 @@ static int ssl_remove(int n, char **erro

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
Index: linux-2.6.21-mm/arch/um/drivers/stdio_console.c
===================================================================
--- linux-2.6.21-mm.orig/arch/um/drivers/stdio_console.c 2007-06-14 15:40:01.000000000 -0400
+++ linux-2.6.21-mm/arch/um/drivers/stdio_console.c 2007-06-14 16:00:23.000000000 -0400
@@ -99,7 +99,12 @@ static int con_remove(int n, char **erro

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 */
Index: linux-2.6.21-mm/arch/um/include/chan_kern.h
===================================================================
--- linux-2.6.21-mm.orig/arch/um/include/chan_kern.h 2007-06-14 15:40:01.000000000 -0400
+++ linux-2.6.21-mm/arch/um/include/chan_kern.h 2007-06-14 16:00:23.000000000 -0400
@@ -40,7 +40,7 @@ extern int console_open_chan(struct line
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,
Index: linux-2.6.21-mm/arch/um/defconfig
===================================================================
--- linux-2.6.21-mm.orig/arch/um/defconfig 2007-06-14 15:40:01.000000000 -0400
+++ linux-2.6.21-mm/arch/um/defconfig 2007-06-14 16:00:23.000000000 -0400
@@ -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