linux/arch/um/drivers/stdio_console.c
Jeff Dike d14ad81f80 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>
2007-07-16 09:05:38 -07:00

206 lines
5.0 KiB
C

/*
* Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/posix_types.h"
#include "linux/tty.h"
#include "linux/tty_flip.h"
#include "linux/types.h"
#include "linux/major.h"
#include "linux/kdev_t.h"
#include "linux/console.h"
#include "linux/string.h"
#include "linux/sched.h"
#include "linux/list.h"
#include "linux/init.h"
#include "linux/interrupt.h"
#include "linux/slab.h"
#include "linux/hardirq.h"
#include "asm/current.h"
#include "asm/irq.h"
#include "stdio_console.h"
#include "line.h"
#include "chan_kern.h"
#include "kern_util.h"
#include "irq_user.h"
#include "mconsole_kern.h"
#include "init.h"
#define MAX_TTYS (16)
/* Referenced only by tty_driver below - presumably it's locked correctly
* by the tty driver.
*/
static struct tty_driver *console_driver;
void stdio_announce(char *dev_name, int dev)
{
printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
dev_name);
}
/* Almost const, except that xterm_title may be changed in an initcall */
static struct chan_opts opts = {
.announce = stdio_announce,
.xterm_title = "Virtual Console #%d",
.raw = 1,
};
static int con_config(char *str, char **error_out);
static int con_get_config(char *dev, char *str, int size, char **error_out);
static int con_remove(int n, char **con_remove);
/* Const, except for .mc.list */
static struct line_driver driver = {
.name = "UML console",
.device_name = "tty",
.major = TTY_MAJOR,
.minor_start = 0,
.type = TTY_DRIVER_TYPE_CONSOLE,
.subtype = SYSTEM_TYPE_CONSOLE,
.read_irq = CONSOLE_IRQ,
.read_irq_name = "console",
.write_irq = CONSOLE_WRITE_IRQ,
.write_irq_name = "console-write",
.mc = {
.list = LIST_HEAD_INIT(driver.mc.list),
.name = "con",
.config = con_config,
.get_config = con_get_config,
.id = line_id,
.remove = con_remove,
},
};
/* The array is initialized by line_init, at initcall time. The
* elements are locked individually as needed.
*/
static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
[ 1 ... MAX_TTYS - 1 ] =
LINE_INIT(CONFIG_CON_CHAN, &driver) };
static int con_config(char *str, char **error_out)
{
return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out);
}
static int con_get_config(char *dev, char *str, int size, char **error_out)
{
return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
}
static int con_remove(int n, char **error_out)
{
return line_remove(vts, ARRAY_SIZE(vts), n, error_out);
}
static int con_open(struct tty_struct *tty, struct file *filp)
{
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 */
static int con_init_done = 0;
static const struct tty_operations console_ops = {
.open = con_open,
.close = line_close,
.write = line_write,
.put_char = line_put_char,
.write_room = line_write_room,
.chars_in_buffer = line_chars_in_buffer,
.flush_buffer = line_flush_buffer,
.flush_chars = line_flush_chars,
.set_termios = line_set_termios,
.ioctl = line_ioctl,
.throttle = line_throttle,
.unthrottle = line_unthrottle,
};
static void uml_console_write(struct console *console, const char *string,
unsigned len)
{
struct line *line = &vts[console->index];
unsigned long flags;
spin_lock_irqsave(&line->lock, flags);
console_write_chan(&line->chan_list, string, len);
spin_unlock_irqrestore(&line->lock, flags);
}
static struct tty_driver *uml_console_device(struct console *c, int *index)
{
*index = c->index;
return console_driver;
}
static int uml_console_setup(struct console *co, char *options)
{
struct line *line = &vts[co->index];
return console_open_chan(line, co);
}
/* No locking for register_console call - relies on single-threaded initcalls */
static struct console stdiocons = {
.name = "tty",
.write = uml_console_write,
.device = uml_console_device,
.setup = uml_console_setup,
.flags = CON_PRINTBUFFER|CON_ANYTIME,
.index = -1,
};
int stdio_init(void)
{
char *new_title;
console_driver = register_lines(&driver, &console_ops, vts,
ARRAY_SIZE(vts));
if (console_driver == NULL)
return -1;
printk(KERN_INFO "Initialized stdio console driver\n");
new_title = add_xterm_umid(opts.xterm_title);
if(new_title != NULL)
opts.xterm_title = new_title;
lines_init(vts, ARRAY_SIZE(vts), &opts);
con_init_done = 1;
register_console(&stdiocons);
return 0;
}
late_initcall(stdio_init);
static void console_exit(void)
{
if (!con_init_done)
return;
close_lines(vts, ARRAY_SIZE(vts));
}
__uml_exitcall(console_exit);
static int console_chan_setup(char *str)
{
char *error;
int ret;
ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
if(ret < 0)
printk(KERN_ERR "Failed to set up console with "
"configuration string \"%s\" : %s\n", str, error);
return 1;
}
__setup("con", console_chan_setup);
__channel_help(console_chan_setup, "con");