* Licensed under the GPL
*/
+#include "linux/kernel.h"
#include "linux/sched.h"
#include "linux/slab.h"
#include "linux/list.h"
#include "irq_user.h"
#include "line.h"
#include "kern.h"
-#include "user_util.h"
#include "kern_util.h"
#include "os.h"
#include "irq_kern.h"
#define LINE_BUFSIZE 4096
-static irqreturn_t line_interrupt(int irq, void *data, struct pt_regs *unused)
+static irqreturn_t line_interrupt(int irq, void *data)
{
struct chan *chan = data;
struct line *line = chan->line;
return IRQ_HANDLED;
}
-static void line_timer_cb(void *arg)
+static void line_timer_cb(struct work_struct *work)
{
- struct line *line = arg;
+ struct line *line = container_of(work, struct line, task.work);
if(!line->throttled)
chan_interrupt(&line->chan_list, &line->task, line->tty,
/*XXX: copied from line_write, verify if it is correct!*/
if(tty->stopped)
return;
- //return 0;
spin_lock_irqsave(&line->lock, flags);
err = flush_buffer(line);
return ret;
}
-void line_set_termios(struct tty_struct *tty, struct termios * old)
+void line_set_termios(struct tty_struct *tty, struct ktermios * old)
{
/* nothing */
}
-static struct {
+static const struct {
int cmd;
char *level;
char *name;
reactivate_chan(&line->chan_list, line->driver->read_irq);
}
-static irqreturn_t line_write_interrupt(int irq, void *data,
- struct pt_regs *unused)
+static irqreturn_t line_write_interrupt(int irq, void *data)
{
struct chan *chan = data;
struct line *line = chan->line;
struct tty_struct *tty = line->tty;
int err;
- /* Interrupts are enabled here because we registered the interrupt with
+ /* Interrupts are disabled here because we registered the interrupt with
* IRQF_DISABLED (see line_setup_irq).*/
- spin_lock_irq(&line->lock);
+ spin_lock(&line->lock);
err = flush_buffer(line);
if (err == 0) {
return IRQ_NONE;
line->head = line->buffer;
line->tail = line->buffer;
}
- spin_unlock_irq(&line->lock);
+ spin_unlock(&line->lock);
if(tty == NULL)
return IRQ_NONE;
int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
{
- struct line_driver *driver = line->driver;
+ const struct line_driver *driver = line->driver;
int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
if (input)
return err;
}
+/* Normally, a driver like this can rely mostly on the tty layer
+ * locking, particularly when it comes to the driver structure.
+ * However, in this case, mconsole requests can come in "from the
+ * side", and race with opens and closes.
+ *
+ * mconsole config requests will want to be sure the device isn't in
+ * use, and get_config, open, and close will want a stable
+ * configuration. The checking and modification of the configuration
+ * is done under a spinlock. Checking whether the device is in use is
+ * line->tty->count > 1, also under the spinlock.
+ *
+ * tty->count serves to decide whether the device should be enabled or
+ * disabled on the host. If it's equal to 1, then we are doing the
+ * first open or last close. Otherwise, open and close just return.
+ */
+
int line_open(struct line *lines, struct tty_struct *tty)
{
- struct line *line;
+ struct line *line = &lines[tty->index];
int err = -ENODEV;
- line = &lines[tty->index];
- tty->driver_data = line;
+ spin_lock(&line->count_lock);
+ if(!line->valid)
+ goto out_unlock;
- /* The IRQ which takes this lock is not yet enabled and won't be run
- * before the end, so we don't need to use spin_lock_irq.*/
- spin_lock(&line->lock);
+ err = 0;
+ if(tty->count > 1)
+ goto out_unlock;
+
+ spin_unlock(&line->count_lock);
tty->driver_data = line;
line->tty = tty;
- if(!line->valid)
- goto out;
- if(tty->count == 1){
- /* Here the device is opened, if necessary, and interrupt
- * is registered.
- */
- enable_chan(line);
- INIT_WORK(&line->task, line_timer_cb, line);
+ err = enable_chan(line);
+ if (err)
+ return err;
- if(!line->sigio){
- chan_enable_winch(&line->chan_list, tty);
- line->sigio = 1;
- }
+ INIT_DELAYED_WORK(&line->task, line_timer_cb);
- chan_window_size(&line->chan_list, &tty->winsize.ws_row,
- &tty->winsize.ws_col);
+ if(!line->sigio){
+ chan_enable_winch(&line->chan_list, tty);
+ line->sigio = 1;
}
- err = 0;
-out:
- spin_unlock(&line->lock);
+ chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+ &tty->winsize.ws_col);
+
+ return err;
+
+out_unlock:
+ spin_unlock(&line->count_lock);
return err;
}
{
struct line *line = tty->driver_data;
- /* XXX: I assume this should be called in process context, not with
- * interrupts disabled!
- */
- spin_lock_irq(&line->lock);
+ /* If line_open fails (and tty->driver_data is never set),
+ * tty_open will call line_close. So just return in this case.
+ */
+ if(line == NULL)
+ return;
/* We ignore the error anyway! */
flush_buffer(line);
- if(tty->count == 1){
- line->tty = NULL;
- tty->driver_data = NULL;
+ spin_lock(&line->count_lock);
+ if(!line->valid)
+ goto out_unlock;
- if(line->sigio){
- unregister_winch(tty);
- line->sigio = 0;
- }
+ if(tty->count > 1)
+ goto out_unlock;
+
+ spin_unlock(&line->count_lock);
+
+ line->tty = NULL;
+ tty->driver_data = NULL;
+
+ if(line->sigio){
+ unregister_winch(tty);
+ line->sigio = 0;
}
- spin_unlock_irq(&line->lock);
+ return;
+
+out_unlock:
+ spin_unlock(&line->count_lock);
}
void close_lines(struct line *lines, int nlines)
close_chan(&lines[i].chan_list, 0);
}
+static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
+ char **error_out)
+{
+ struct line *line = &lines[n];
+ int err = -EINVAL;
+
+ spin_lock(&line->count_lock);
+
+ if(line->tty != NULL){
+ *error_out = "Device is already open";
+ goto out;
+ }
+
+ if (line->init_pri <= init_prio){
+ line->init_pri = init_prio;
+ if (!strcmp(init, "none"))
+ line->valid = 0;
+ else {
+ line->init_str = init;
+ line->valid = 1;
+ }
+ }
+ err = 0;
+out:
+ spin_unlock(&line->count_lock);
+ return err;
+}
+
/* Common setup code for both startup command line and mconsole initialization.
- * @lines contains the the array (of size @num) to modify;
+ * @lines contains the array (of size @num) to modify;
* @init is the setup string;
+ * @error_out is an error string in the case of failure;
*/
-int line_setup(struct line *lines, unsigned int num, char *init)
+int line_setup(struct line *lines, unsigned int num, char *init,
+ char **error_out)
{
- int i, n;
+ int i, n, err;
char *end;
if(*init == '=') {
else {
n = simple_strtoul(init, &end, 0);
if(*end != '='){
- printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
- init);
- return 0;
+ *error_out = "Couldn't parse device number";
+ return -EINVAL;
}
init = end;
}
init++;
if (n >= (signed int) num) {
- printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
- n, num - 1);
- return 0;
+ *error_out = "Device number out of range";
+ return -EINVAL;
}
else if (n >= 0){
- if (lines[n].tty != NULL) {
- printk("line_setup - device %d is open\n", n);
- return 0;
- }
- if (lines[n].init_pri <= INIT_ONE){
- lines[n].init_pri = INIT_ONE;
- if (!strcmp(init, "none"))
- lines[n].valid = 0;
- else {
- lines[n].init_str = init;
- lines[n].valid = 1;
- }
- }
+ err = setup_one_line(lines, n, init, INIT_ONE, error_out);
+ if(err)
+ return err;
}
else {
for(i = 0; i < num; i++){
- if(lines[i].init_pri <= INIT_ALL){
- lines[i].init_pri = INIT_ALL;
- if(!strcmp(init, "none")) lines[i].valid = 0;
- else {
- lines[i].init_str = init;
- lines[i].valid = 1;
- }
- }
+ err = setup_one_line(lines, i, init, INIT_ALL,
+ error_out);
+ if(err)
+ return err;
}
}
return n == -1 ? num : n;
}
int line_config(struct line *lines, unsigned int num, char *str,
- struct chan_opts *opts)
+ const struct chan_opts *opts, char **error_out)
{
struct line *line;
char *new;
int n;
if(*str == '='){
- printk("line_config - can't configure all devices from "
- "mconsole\n");
- return 1;
+ *error_out = "Can't configure all devices from mconsole";
+ return -EINVAL;
}
new = kstrdup(str, GFP_KERNEL);
if(new == NULL){
- printk("line_config - kstrdup failed\n");
- return 1;
+ *error_out = "Failed to allocate memory";
+ return -ENOMEM;
}
- n = line_setup(lines, num, new);
+ n = line_setup(lines, num, new, error_out);
if(n < 0)
- return 1;
+ return n;
line = &lines[n];
- return parse_chan_pair(line->init_str, line, n, opts);
+ return parse_chan_pair(line->init_str, line, n, opts, error_out);
}
int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
line = &lines[dev];
- spin_lock(&line->lock);
+ spin_lock(&line->count_lock);
if(!line->valid)
CONFIG_CHUNK(str, size, n, "none", 1);
else if(line->tty == NULL)
CONFIG_CHUNK(str, size, n, line->init_str, 1);
else n = chan_config_string(&line->chan_list, str, size, error_out);
- spin_unlock(&line->lock);
+ spin_unlock(&line->count_lock);
return n;
}
return n;
}
-int line_remove(struct line *lines, unsigned int num, int n)
+int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
{
int err;
char config[sizeof("conxxxx=none\0")];
sprintf(config, "%d=none", n);
- err = line_setup(lines, num, config);
+ err = line_setup(lines, num, config, error_out);
if(err >= 0)
err = 0;
return err;
}
-struct tty_driver *line_register_devfs(struct lines *set,
- struct line_driver *line_driver,
- struct tty_operations *ops, struct line *lines,
- int nlines)
+struct tty_driver *register_lines(struct line_driver *line_driver,
+ const struct tty_operations *ops,
+ struct line *lines, int nlines)
{
int i;
struct tty_driver *driver = alloc_tty_driver(nlines);
void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
{
struct line *line;
+ char *error;
int i;
for(i = 0; i < nlines; i++){
if(line->init_str == NULL)
printk("lines_init - kstrdup returned NULL\n");
- if(parse_chan_pair(line->init_str, line, i, opts)){
- printk("parse_chan_pair failed for device %d\n", i);
+ if(parse_chan_pair(line->init_str, line, i, opts, &error)){
+ printk("parse_chan_pair failed for device %d : %s\n",
+ i, error);
line->valid = 0;
}
}
int tty_fd;
int pid;
struct tty_struct *tty;
+ unsigned long stack;
};
-static irqreturn_t winch_interrupt(int irq, void *data, struct pt_regs *unused)
+static void free_winch(struct winch *winch, int free_irq_ok)
+{
+ list_del(&winch->list);
+
+ if (winch->pid != -1)
+ os_kill_process(winch->pid, 1);
+ if (winch->fd != -1)
+ os_close_file(winch->fd);
+ if (winch->stack != 0)
+ free_stack(winch->stack, 0);
+ if (free_irq_ok)
+ free_irq(WINCH_IRQ, winch);
+ kfree(winch);
+}
+
+static irqreturn_t winch_interrupt(int irq, void *data)
{
struct winch *winch = data;
struct tty_struct *tty;
"errno = %d\n", -err);
printk("fd %d is losing SIGWINCH support\n",
winch->tty_fd);
+ free_winch(winch, 0);
return IRQ_HANDLED;
}
goto out;
}
}
- tty = winch->tty;
+ tty = winch->tty;
if (tty != NULL) {
line = tty->driver_data;
chan_window_size(&line->chan_list, &tty->winsize.ws_row,
&tty->winsize.ws_col);
- kill_pg(tty->pgrp, SIGWINCH, 1);
+ kill_pgrp(tty->pgrp, SIGWINCH, 1);
}
out:
if(winch->fd != -1)
return IRQ_HANDLED;
}
-void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty)
+void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
+ unsigned long stack)
{
struct winch *winch;
winch = kmalloc(sizeof(*winch), GFP_KERNEL);
if (winch == NULL) {
printk("register_winch_irq - kmalloc failed\n");
- return;
+ goto cleanup;
}
*winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
.fd = fd,
.tty_fd = tty_fd,
.pid = pid,
- .tty = tty });
+ .tty = tty,
+ .stack = stack });
+
+ if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
+ IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
+ "winch", winch) < 0) {
+ printk("register_winch_irq - failed to register IRQ\n");
+ goto out_free;
+ }
spin_lock(&winch_handler_lock);
list_add(&winch->list, &winch_handlers);
spin_unlock(&winch_handler_lock);
- if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
- IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
- "winch", winch) < 0)
- printk("register_winch_irq - failed to register IRQ\n");
-}
-
-static void free_winch(struct winch *winch)
-{
- list_del(&winch->list);
-
- if(winch->pid != -1)
- os_kill_process(winch->pid, 1);
- if(winch->fd != -1)
- os_close_file(winch->fd);
+ return;
- free_irq(WINCH_IRQ, winch);
+ out_free:
kfree(winch);
+ cleanup:
+ os_kill_process(pid, 1);
+ os_close_file(fd);
+ if (stack != 0)
+ free_stack(stack, 0);
}
static void unregister_winch(struct tty_struct *tty)
list_for_each(ele, &winch_handlers){
winch = list_entry(ele, struct winch, list);
if(winch->tty == tty){
- free_winch(winch);
+ free_winch(winch, 1);
break;
}
}
list_for_each_safe(ele, next, &winch_handlers){
winch = list_entry(ele, struct winch, list);
- free_winch(winch);
+ free_winch(winch, 1);
}
spin_unlock(&winch_handler_lock);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff