kernel-fxtec-pro1x/arch/um/drivers/chan_kern.c
Paolo 'Blaisorblade' Giarrusso fac97ae0b1 [PATCH] uml: replace printk with "stack-friendly" printf - to report console failure
User get *a lot* confused when consoles don't work but we don't report
anything.  And, as reported in the comment, using printk to report "your
console doesn't work" isn't likely to go that far.

Fix the problem on the base of this: stack consumption by host printf().  Use
kernel sprintf() and os_write_file, using a wild guess that one page will be
enough for the message, to preallocate the buffer with kmalloc().

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22 22:17:37 -07:00

611 lines
13 KiB
C

/*
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/string.h>
#include <linux/tty_flip.h>
#include <asm/irq.h>
#include "chan_kern.h"
#include "user_util.h"
#include "kern.h"
#include "irq_user.h"
#include "sigio.h"
#include "line.h"
#include "os.h"
/* XXX: could well be moved to somewhere else, if needed. */
static int my_printf(const char * fmt, ...)
__attribute__ ((format (printf, 1, 2)));
static int my_printf(const char * fmt, ...)
{
/* Yes, can be called on atomic context.*/
char *buf = kmalloc(4096, GFP_ATOMIC);
va_list args;
int r;
if (!buf) {
/* We print directly fmt.
* Yes, yes, yes, feel free to complain. */
r = strlen(fmt);
} else {
va_start(args, fmt);
r = vsprintf(buf, fmt, args);
va_end(args);
fmt = buf;
}
if (r)
r = os_write_file(1, fmt, r);
return r;
}
#ifdef CONFIG_NOCONFIG_CHAN
/* Despite its name, there's no added trailing newline. */
static int my_puts(const char * buf)
{
return os_write_file(1, buf, strlen(buf));
}
static void *not_configged_init(char *str, int device, struct chan_opts *opts)
{
my_puts("Using a channel type which is configured out of "
"UML\n");
return(NULL);
}
static int not_configged_open(int input, int output, int primary, void *data,
char **dev_out)
{
my_puts("Using a channel type which is configured out of "
"UML\n");
return(-ENODEV);
}
static void not_configged_close(int fd, void *data)
{
my_puts("Using a channel type which is configured out of "
"UML\n");
}
static int not_configged_read(int fd, char *c_out, void *data)
{
my_puts("Using a channel type which is configured out of "
"UML\n");
return(-EIO);
}
static int not_configged_write(int fd, const char *buf, int len, void *data)
{
my_puts("Using a channel type which is configured out of "
"UML\n");
return(-EIO);
}
static int not_configged_console_write(int fd, const char *buf, int len,
void *data)
{
my_puts("Using a channel type which is configured out of "
"UML\n");
return(-EIO);
}
static int not_configged_window_size(int fd, void *data, unsigned short *rows,
unsigned short *cols)
{
my_puts("Using a channel type which is configured out of "
"UML\n");
return(-ENODEV);
}
static void not_configged_free(void *data)
{
my_puts("Using a channel type which is configured out of "
"UML\n");
}
static struct chan_ops not_configged_ops = {
.init = not_configged_init,
.open = not_configged_open,
.close = not_configged_close,
.read = not_configged_read,
.write = not_configged_write,
.console_write = not_configged_console_write,
.window_size = not_configged_window_size,
.free = not_configged_free,
.winch = 0,
};
#endif /* CONFIG_NOCONFIG_CHAN */
void generic_close(int fd, void *unused)
{
os_close_file(fd);
}
int generic_read(int fd, char *c_out, void *unused)
{
int n;
n = os_read_file(fd, c_out, sizeof(*c_out));
if(n == -EAGAIN)
return(0);
else if(n == 0)
return(-EIO);
return(n);
}
/* XXX Trivial wrapper around os_write_file */
int generic_write(int fd, const char *buf, int n, void *unused)
{
return(os_write_file(fd, buf, n));
}
int generic_window_size(int fd, void *unused, unsigned short *rows_out,
unsigned short *cols_out)
{
int rows, cols;
int ret;
ret = os_window_size(fd, &rows, &cols);
if(ret < 0)
return(ret);
ret = ((*rows_out != rows) || (*cols_out != cols));
*rows_out = rows;
*cols_out = cols;
return(ret);
}
void generic_free(void *data)
{
kfree(data);
}
static void tty_receive_char(struct tty_struct *tty, char ch)
{
if(tty == NULL) return;
if(I_IXON(tty) && !I_IXOFF(tty) && !tty->raw) {
if(ch == STOP_CHAR(tty)){
stop_tty(tty);
return;
}
else if(ch == START_CHAR(tty)){
start_tty(tty);
return;
}
}
if((tty->flip.flag_buf_ptr == NULL) ||
(tty->flip.char_buf_ptr == NULL))
return;
tty_insert_flip_char(tty, ch, TTY_NORMAL);
}
static int open_one_chan(struct chan *chan, int input, int output, int primary)
{
int fd;
if(chan->opened) return(0);
if(chan->ops->open == NULL) fd = 0;
else fd = (*chan->ops->open)(input, output, primary, chan->data,
&chan->dev);
if(fd < 0) return(fd);
chan->fd = fd;
chan->opened = 1;
return(0);
}
int open_chan(struct list_head *chans)
{
struct list_head *ele;
struct chan *chan;
int ret, err = 0;
list_for_each(ele, chans){
chan = list_entry(ele, struct chan, list);
ret = open_one_chan(chan, chan->input, chan->output,
chan->primary);
if(chan->primary) err = ret;
}
return(err);
}
void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
{
struct list_head *ele;
struct chan *chan;
list_for_each(ele, chans){
chan = list_entry(ele, struct chan, list);
if(chan->primary && chan->output && chan->ops->winch){
register_winch(chan->fd, tty);
return;
}
}
}
void enable_chan(struct list_head *chans, struct tty_struct *tty)
{
struct list_head *ele;
struct chan *chan;
list_for_each(ele, chans){
chan = list_entry(ele, struct chan, list);
if(!chan->opened) continue;
line_setup_irq(chan->fd, chan->input, chan->output, tty);
}
}
void close_chan(struct list_head *chans)
{
struct chan *chan;
/* Close in reverse order as open in case more than one of them
* refers to the same device and they save and restore that device's
* state. Then, the first one opened will have the original state,
* so it must be the last closed.
*/
list_for_each_entry_reverse(chan, chans, list) {
if(!chan->opened) continue;
if(chan->ops->close != NULL)
(*chan->ops->close)(chan->fd, chan->data);
chan->opened = 0;
chan->fd = -1;
}
}
int write_chan(struct list_head *chans, const char *buf, int len,
int write_irq)
{
struct list_head *ele;
struct chan *chan = NULL;
int n, ret = 0;
list_for_each(ele, chans) {
chan = list_entry(ele, struct chan, list);
if (!chan->output || (chan->ops->write == NULL))
continue;
n = chan->ops->write(chan->fd, buf, len, chan->data);
if (chan->primary) {
ret = n;
if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
reactivate_fd(chan->fd, write_irq);
}
}
return(ret);
}
int console_write_chan(struct list_head *chans, const char *buf, int len)
{
struct list_head *ele;
struct chan *chan;
int n, ret = 0;
list_for_each(ele, chans){
chan = list_entry(ele, struct chan, list);
if(!chan->output || (chan->ops->console_write == NULL))
continue;
n = chan->ops->console_write(chan->fd, buf, len, chan->data);
if(chan->primary) ret = n;
}
return(ret);
}
int console_open_chan(struct line *line, struct console *co, struct chan_opts *opts)
{
if (!list_empty(&line->chan_list))
return 0;
if (0 != parse_chan_pair(line->init_str, &line->chan_list,
line->init_pri, co->index, opts))
return -1;
if (0 != open_chan(&line->chan_list))
return -1;
printk("Console initialized on /dev/%s%d\n",co->name,co->index);
return 0;
}
int chan_window_size(struct list_head *chans, unsigned short *rows_out,
unsigned short *cols_out)
{
struct list_head *ele;
struct chan *chan;
list_for_each(ele, chans){
chan = list_entry(ele, struct chan, list);
if(chan->primary){
if(chan->ops->window_size == NULL) return(0);
return(chan->ops->window_size(chan->fd, chan->data,
rows_out, cols_out));
}
}
return(0);
}
void free_one_chan(struct chan *chan)
{
list_del(&chan->list);
if(chan->ops->free != NULL)
(*chan->ops->free)(chan->data);
free_irq_by_fd(chan->fd);
if(chan->primary && chan->output) ignore_sigio_fd(chan->fd);
kfree(chan);
}
void free_chan(struct list_head *chans)
{
struct list_head *ele, *next;
struct chan *chan;
list_for_each_safe(ele, next, chans){
chan = list_entry(ele, struct chan, list);
free_one_chan(chan);
}
}
static int one_chan_config_string(struct chan *chan, char *str, int size,
char **error_out)
{
int n = 0;
if(chan == NULL){
CONFIG_CHUNK(str, size, n, "none", 1);
return(n);
}
CONFIG_CHUNK(str, size, n, chan->ops->type, 0);
if(chan->dev == NULL){
CONFIG_CHUNK(str, size, n, "", 1);
return(n);
}
CONFIG_CHUNK(str, size, n, ":", 0);
CONFIG_CHUNK(str, size, n, chan->dev, 0);
return(n);
}
static int chan_pair_config_string(struct chan *in, struct chan *out,
char *str, int size, char **error_out)
{
int n;
n = one_chan_config_string(in, str, size, error_out);
str += n;
size -= n;
if(in == out){
CONFIG_CHUNK(str, size, n, "", 1);
return(n);
}
CONFIG_CHUNK(str, size, n, ",", 1);
n = one_chan_config_string(out, str, size, error_out);
str += n;
size -= n;
CONFIG_CHUNK(str, size, n, "", 1);
return(n);
}
int chan_config_string(struct list_head *chans, char *str, int size,
char **error_out)
{
struct list_head *ele;
struct chan *chan, *in = NULL, *out = NULL;
list_for_each(ele, chans){
chan = list_entry(ele, struct chan, list);
if(!chan->primary)
continue;
if(chan->input)
in = chan;
if(chan->output)
out = chan;
}
return(chan_pair_config_string(in, out, str, size, error_out));
}
struct chan_type {
char *key;
struct chan_ops *ops;
};
struct chan_type chan_table[] = {
{ "fd", &fd_ops },
#ifdef CONFIG_NULL_CHAN
{ "null", &null_ops },
#else
{ "null", &not_configged_ops },
#endif
#ifdef CONFIG_PORT_CHAN
{ "port", &port_ops },
#else
{ "port", &not_configged_ops },
#endif
#ifdef CONFIG_PTY_CHAN
{ "pty", &pty_ops },
{ "pts", &pts_ops },
#else
{ "pty", &not_configged_ops },
{ "pts", &not_configged_ops },
#endif
#ifdef CONFIG_TTY_CHAN
{ "tty", &tty_ops },
#else
{ "tty", &not_configged_ops },
#endif
#ifdef CONFIG_XTERM_CHAN
{ "xterm", &xterm_ops },
#else
{ "xterm", &not_configged_ops },
#endif
};
static struct chan *parse_chan(char *str, int pri, int device,
struct chan_opts *opts)
{
struct chan_type *entry;
struct chan_ops *ops;
struct chan *chan;
void *data;
int i;
ops = NULL;
data = NULL;
for(i = 0; i < sizeof(chan_table)/sizeof(chan_table[0]); i++){
entry = &chan_table[i];
if(!strncmp(str, entry->key, strlen(entry->key))){
ops = entry->ops;
str += strlen(entry->key);
break;
}
}
if(ops == NULL){
my_printf("parse_chan couldn't parse \"%s\"\n",
str);
return(NULL);
}
if(ops->init == NULL) return(NULL);
data = (*ops->init)(str, device, opts);
if(data == NULL) return(NULL);
chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
if(chan == NULL) return(NULL);
*chan = ((struct chan) { .list = LIST_HEAD_INIT(chan->list),
.primary = 1,
.input = 0,
.output = 0,
.opened = 0,
.fd = -1,
.pri = pri,
.ops = ops,
.data = data });
return(chan);
}
int parse_chan_pair(char *str, struct list_head *chans, int pri, int device,
struct chan_opts *opts)
{
struct chan *new, *chan;
char *in, *out;
if(!list_empty(chans)){
chan = list_entry(chans->next, struct chan, list);
if(chan->pri >= pri) return(0);
free_chan(chans);
INIT_LIST_HEAD(chans);
}
out = strchr(str, ',');
if(out != NULL){
in = str;
*out = '\0';
out++;
new = parse_chan(in, pri, device, opts);
if(new == NULL) return(-1);
new->input = 1;
list_add(&new->list, chans);
new = parse_chan(out, pri, device, opts);
if(new == NULL) return(-1);
list_add(&new->list, chans);
new->output = 1;
}
else {
new = parse_chan(str, pri, device, opts);
if(new == NULL) return(-1);
list_add(&new->list, chans);
new->input = 1;
new->output = 1;
}
return(0);
}
int chan_out_fd(struct list_head *chans)
{
struct list_head *ele;
struct chan *chan;
list_for_each(ele, chans){
chan = list_entry(ele, struct chan, list);
if(chan->primary && chan->output)
return(chan->fd);
}
return(-1);
}
void chan_interrupt(struct list_head *chans, struct work_struct *task,
struct tty_struct *tty, int irq)
{
struct list_head *ele, *next;
struct chan *chan;
int err;
char c;
list_for_each_safe(ele, next, chans){
chan = list_entry(ele, struct chan, list);
if(!chan->input || (chan->ops->read == NULL)) continue;
do {
if((tty != NULL) &&
(tty->flip.count >= TTY_FLIPBUF_SIZE)){
schedule_work(task);
goto out;
}
err = chan->ops->read(chan->fd, &c, chan->data);
if(err > 0)
tty_receive_char(tty, c);
} while(err > 0);
if(err == 0) reactivate_fd(chan->fd, irq);
if(err == -EIO){
if(chan->primary){
if(tty != NULL)
tty_hangup(tty);
line_disable(tty, irq);
close_chan(chans);
free_chan(chans);
return;
}
else {
if(chan->ops->close != NULL)
chan->ops->close(chan->fd, chan->data);
free_one_chan(chan);
}
}
}
out:
if(tty) tty_flip_buffer_push(tty);
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/