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-rw-r--r--arch/um/drivers/line.c764
1 files changed, 764 insertions, 0 deletions
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
new file mode 100644
index 000000000..02b0befd6
--- /dev/null
+++ b/arch/um/drivers/line.c
@@ -0,0 +1,764 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/irqreturn.h>
+#include <linux/kd.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+
+#include "chan.h"
+#include <irq_kern.h>
+#include <irq_user.h>
+#include <kern_util.h>
+#include <os.h>
+
+#define LINE_BUFSIZE 4096
+
+static irqreturn_t line_interrupt(int irq, void *data)
+{
+ struct chan *chan = data;
+ struct line *line = chan->line;
+
+ if (line)
+ chan_interrupt(line, irq);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * Returns the free space inside the ring buffer of this line.
+ *
+ * Should be called while holding line->lock (this does not modify data).
+ */
+static unsigned int write_room(struct line *line)
+{
+ int n;
+
+ if (line->buffer == NULL)
+ return LINE_BUFSIZE - 1;
+
+ /* This is for the case where the buffer is wrapped! */
+ n = line->head - line->tail;
+
+ if (n <= 0)
+ n += LINE_BUFSIZE; /* The other case */
+ return n - 1;
+}
+
+unsigned int line_write_room(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+ unsigned long flags;
+ unsigned int room;
+
+ spin_lock_irqsave(&line->lock, flags);
+ room = write_room(line);
+ spin_unlock_irqrestore(&line->lock, flags);
+
+ return room;
+}
+
+unsigned int line_chars_in_buffer(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+ unsigned long flags;
+ unsigned int ret;
+
+ spin_lock_irqsave(&line->lock, flags);
+ /* write_room subtracts 1 for the needed NULL, so we readd it.*/
+ ret = LINE_BUFSIZE - (write_room(line) + 1);
+ spin_unlock_irqrestore(&line->lock, flags);
+
+ return ret;
+}
+
+/*
+ * This copies the content of buf into the circular buffer associated with
+ * this line.
+ * The return value is the number of characters actually copied, i.e. the ones
+ * for which there was space: this function is not supposed to ever flush out
+ * the circular buffer.
+ *
+ * Must be called while holding line->lock!
+ */
+static int buffer_data(struct line *line, const char *buf, int len)
+{
+ int end, room;
+
+ if (line->buffer == NULL) {
+ line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
+ if (line->buffer == NULL) {
+ printk(KERN_ERR "buffer_data - atomic allocation "
+ "failed\n");
+ return 0;
+ }
+ line->head = line->buffer;
+ line->tail = line->buffer;
+ }
+
+ room = write_room(line);
+ len = (len > room) ? room : len;
+
+ end = line->buffer + LINE_BUFSIZE - line->tail;
+
+ if (len < end) {
+ memcpy(line->tail, buf, len);
+ line->tail += len;
+ }
+ else {
+ /* The circular buffer is wrapping */
+ memcpy(line->tail, buf, end);
+ buf += end;
+ memcpy(line->buffer, buf, len - end);
+ line->tail = line->buffer + len - end;
+ }
+
+ return len;
+}
+
+/*
+ * Flushes the ring buffer to the output channels. That is, write_chan is
+ * called, passing it line->head as buffer, and an appropriate count.
+ *
+ * On exit, returns 1 when the buffer is empty,
+ * 0 when the buffer is not empty on exit,
+ * and -errno when an error occurred.
+ *
+ * Must be called while holding line->lock!*/
+static int flush_buffer(struct line *line)
+{
+ int n, count;
+
+ if ((line->buffer == NULL) || (line->head == line->tail))
+ return 1;
+
+ if (line->tail < line->head) {
+ /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
+ count = line->buffer + LINE_BUFSIZE - line->head;
+
+ n = write_chan(line->chan_out, line->head, count,
+ line->write_irq);
+ if (n < 0)
+ return n;
+ if (n == count) {
+ /*
+ * We have flushed from ->head to buffer end, now we
+ * must flush only from the beginning to ->tail.
+ */
+ line->head = line->buffer;
+ } else {
+ line->head += n;
+ return 0;
+ }
+ }
+
+ count = line->tail - line->head;
+ n = write_chan(line->chan_out, line->head, count,
+ line->write_irq);
+
+ if (n < 0)
+ return n;
+
+ line->head += n;
+ return line->head == line->tail;
+}
+
+void line_flush_buffer(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&line->lock, flags);
+ flush_buffer(line);
+ spin_unlock_irqrestore(&line->lock, flags);
+}
+
+/*
+ * We map both ->flush_chars and ->put_char (which go in pair) onto
+ * ->flush_buffer and ->write. Hope it's not that bad.
+ */
+void line_flush_chars(struct tty_struct *tty)
+{
+ line_flush_buffer(tty);
+}
+
+int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
+{
+ struct line *line = tty->driver_data;
+ unsigned long flags;
+ int n, ret = 0;
+
+ spin_lock_irqsave(&line->lock, flags);
+ if (line->head != line->tail)
+ ret = buffer_data(line, buf, len);
+ else {
+ n = write_chan(line->chan_out, buf, len,
+ line->write_irq);
+ if (n < 0) {
+ ret = n;
+ goto out_up;
+ }
+
+ len -= n;
+ ret += n;
+ if (len > 0)
+ ret += buffer_data(line, buf + n, len);
+ }
+out_up:
+ spin_unlock_irqrestore(&line->lock, flags);
+ return ret;
+}
+
+void line_throttle(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+
+ deactivate_chan(line->chan_in, line->read_irq);
+ line->throttled = 1;
+}
+
+void line_unthrottle(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+
+ line->throttled = 0;
+ chan_interrupt(line, line->read_irq);
+}
+
+static irqreturn_t line_write_interrupt(int irq, void *data)
+{
+ struct chan *chan = data;
+ struct line *line = chan->line;
+ int err;
+
+ /*
+ * Interrupts are disabled here because genirq keep irqs disabled when
+ * calling the action handler.
+ */
+
+ spin_lock(&line->lock);
+ err = flush_buffer(line);
+ if (err == 0) {
+ spin_unlock(&line->lock);
+ return IRQ_NONE;
+ } else if ((err < 0) && (err != -EAGAIN)) {
+ line->head = line->buffer;
+ line->tail = line->buffer;
+ }
+ spin_unlock(&line->lock);
+
+ tty_port_tty_wakeup(&line->port);
+
+ return IRQ_HANDLED;
+}
+
+int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
+{
+ const struct line_driver *driver = line->driver;
+ int err;
+
+ if (input) {
+ err = um_request_irq(UM_IRQ_ALLOC, fd, IRQ_READ,
+ line_interrupt, 0,
+ driver->read_irq_name, data);
+ if (err < 0)
+ return err;
+
+ line->read_irq = err;
+ }
+
+ if (output) {
+ err = um_request_irq(UM_IRQ_ALLOC, fd, IRQ_WRITE,
+ line_write_interrupt, 0,
+ driver->write_irq_name, data);
+ if (err < 0)
+ return err;
+
+ line->write_irq = err;
+ }
+
+ return 0;
+}
+
+static int line_activate(struct tty_port *port, struct tty_struct *tty)
+{
+ int ret;
+ struct line *line = tty->driver_data;
+
+ ret = enable_chan(line);
+ if (ret)
+ return ret;
+
+ if (!line->sigio) {
+ chan_enable_winch(line->chan_out, port);
+ line->sigio = 1;
+ }
+
+ chan_window_size(line, &tty->winsize.ws_row,
+ &tty->winsize.ws_col);
+
+ return 0;
+}
+
+static void unregister_winch(struct tty_struct *tty);
+
+static void line_destruct(struct tty_port *port)
+{
+ struct tty_struct *tty = tty_port_tty_get(port);
+ struct line *line = tty->driver_data;
+
+ if (line->sigio) {
+ unregister_winch(tty);
+ line->sigio = 0;
+ }
+}
+
+static const struct tty_port_operations line_port_ops = {
+ .activate = line_activate,
+ .destruct = line_destruct,
+};
+
+int line_open(struct tty_struct *tty, struct file *filp)
+{
+ struct line *line = tty->driver_data;
+
+ return tty_port_open(&line->port, tty, filp);
+}
+
+int line_install(struct tty_driver *driver, struct tty_struct *tty,
+ struct line *line)
+{
+ int ret;
+
+ ret = tty_standard_install(driver, tty);
+ if (ret)
+ return ret;
+
+ tty->driver_data = line;
+
+ return 0;
+}
+
+void line_close(struct tty_struct *tty, struct file * filp)
+{
+ struct line *line = tty->driver_data;
+
+ tty_port_close(&line->port, tty, filp);
+}
+
+void line_hangup(struct tty_struct *tty)
+{
+ struct line *line = tty->driver_data;
+
+ tty_port_hangup(&line->port);
+}
+
+void close_lines(struct line *lines, int nlines)
+{
+ int i;
+
+ for(i = 0; i < nlines; i++)
+ close_chan(&lines[i]);
+}
+
+int setup_one_line(struct line *lines, int n, char *init,
+ const struct chan_opts *opts, char **error_out)
+{
+ struct line *line = &lines[n];
+ struct tty_driver *driver = line->driver->driver;
+ int err = -EINVAL;
+
+ if (line->port.count) {
+ *error_out = "Device is already open";
+ goto out;
+ }
+
+ if (!strcmp(init, "none")) {
+ if (line->valid) {
+ line->valid = 0;
+ kfree(line->init_str);
+ tty_unregister_device(driver, n);
+ parse_chan_pair(NULL, line, n, opts, error_out);
+ err = 0;
+ }
+ } else {
+ char *new = kstrdup(init, GFP_KERNEL);
+ if (!new) {
+ *error_out = "Failed to allocate memory";
+ return -ENOMEM;
+ }
+ if (line->valid) {
+ tty_unregister_device(driver, n);
+ kfree(line->init_str);
+ }
+ line->init_str = new;
+ line->valid = 1;
+ err = parse_chan_pair(new, line, n, opts, error_out);
+ if (!err) {
+ struct device *d = tty_port_register_device(&line->port,
+ driver, n, NULL);
+ if (IS_ERR(d)) {
+ *error_out = "Failed to register device";
+ err = PTR_ERR(d);
+ parse_chan_pair(NULL, line, n, opts, error_out);
+ }
+ }
+ if (err) {
+ line->init_str = NULL;
+ line->valid = 0;
+ kfree(new);
+ }
+ }
+out:
+ return err;
+}
+
+/*
+ * Common setup code for both startup command line and mconsole initialization.
+ * @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(char **conf, unsigned int num, char **def,
+ char *init, char *name)
+{
+ char *error;
+
+ if (*init == '=') {
+ /*
+ * We said con=/ssl= instead of con#=, so we are configuring all
+ * consoles at once.
+ */
+ *def = init + 1;
+ } else {
+ char *end;
+ unsigned n = simple_strtoul(init, &end, 0);
+
+ if (*end != '=') {
+ error = "Couldn't parse device number";
+ goto out;
+ }
+ if (n >= num) {
+ error = "Device number out of range";
+ goto out;
+ }
+ conf[n] = end + 1;
+ }
+ return 0;
+
+out:
+ printk(KERN_ERR "Failed to set up %s with "
+ "configuration string \"%s\" : %s\n", name, init, error);
+ return -EINVAL;
+}
+
+int line_config(struct line *lines, unsigned int num, char *str,
+ const struct chan_opts *opts, char **error_out)
+{
+ char *end;
+ int n;
+
+ if (*str == '=') {
+ *error_out = "Can't configure all devices from mconsole";
+ return -EINVAL;
+ }
+
+ n = simple_strtoul(str, &end, 0);
+ if (*end++ != '=') {
+ *error_out = "Couldn't parse device number";
+ return -EINVAL;
+ }
+ if (n >= num) {
+ *error_out = "Device number out of range";
+ return -EINVAL;
+ }
+
+ return setup_one_line(lines, n, end, opts, error_out);
+}
+
+int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
+ int size, char **error_out)
+{
+ struct line *line;
+ char *end;
+ int dev, n = 0;
+
+ dev = simple_strtoul(name, &end, 0);
+ if ((*end != '\0') || (end == name)) {
+ *error_out = "line_get_config failed to parse device number";
+ return 0;
+ }
+
+ if ((dev < 0) || (dev >= num)) {
+ *error_out = "device number out of range";
+ return 0;
+ }
+
+ line = &lines[dev];
+
+ if (!line->valid)
+ CONFIG_CHUNK(str, size, n, "none", 1);
+ else {
+ struct tty_struct *tty = tty_port_tty_get(&line->port);
+ if (tty == NULL) {
+ CONFIG_CHUNK(str, size, n, line->init_str, 1);
+ } else {
+ n = chan_config_string(line, str, size, error_out);
+ tty_kref_put(tty);
+ }
+ }
+
+ return n;
+}
+
+int line_id(char **str, int *start_out, int *end_out)
+{
+ char *end;
+ int n;
+
+ n = simple_strtoul(*str, &end, 0);
+ if ((*end != '\0') || (end == *str))
+ return -1;
+
+ *str = end;
+ *start_out = n;
+ *end_out = n;
+ return n;
+}
+
+int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
+{
+ if (n >= num) {
+ *error_out = "Device number out of range";
+ return -EINVAL;
+ }
+ return setup_one_line(lines, n, "none", NULL, error_out);
+}
+
+int register_lines(struct line_driver *line_driver,
+ const struct tty_operations *ops,
+ struct line *lines, int nlines)
+{
+ struct tty_driver *driver;
+ int err;
+ int i;
+
+ driver = tty_alloc_driver(nlines, TTY_DRIVER_REAL_RAW |
+ TTY_DRIVER_DYNAMIC_DEV);
+ if (IS_ERR(driver))
+ return PTR_ERR(driver);
+
+ driver->driver_name = line_driver->name;
+ driver->name = line_driver->device_name;
+ driver->major = line_driver->major;
+ driver->minor_start = line_driver->minor_start;
+ driver->type = line_driver->type;
+ driver->subtype = line_driver->subtype;
+ driver->init_termios = tty_std_termios;
+
+ for (i = 0; i < nlines; i++) {
+ tty_port_init(&lines[i].port);
+ lines[i].port.ops = &line_port_ops;
+ spin_lock_init(&lines[i].lock);
+ lines[i].driver = line_driver;
+ INIT_LIST_HEAD(&lines[i].chan_list);
+ }
+ tty_set_operations(driver, ops);
+
+ err = tty_register_driver(driver);
+ if (err) {
+ printk(KERN_ERR "register_lines : can't register %s driver\n",
+ line_driver->name);
+ tty_driver_kref_put(driver);
+ for (i = 0; i < nlines; i++)
+ tty_port_destroy(&lines[i].port);
+ return err;
+ }
+
+ line_driver->driver = driver;
+ mconsole_register_dev(&line_driver->mc);
+ return 0;
+}
+
+static DEFINE_SPINLOCK(winch_handler_lock);
+static LIST_HEAD(winch_handlers);
+
+struct winch {
+ struct list_head list;
+ int fd;
+ int tty_fd;
+ int pid;
+ struct tty_port *port;
+ unsigned long stack;
+ struct work_struct work;
+};
+
+static void __free_winch(struct work_struct *work)
+{
+ struct winch *winch = container_of(work, struct winch, work);
+ um_free_irq(WINCH_IRQ, winch);
+
+ if (winch->pid != -1)
+ os_kill_process(winch->pid, 1);
+ if (winch->stack != 0)
+ free_stack(winch->stack, 0);
+ kfree(winch);
+}
+
+static void free_winch(struct winch *winch)
+{
+ int fd = winch->fd;
+ winch->fd = -1;
+ if (fd != -1)
+ os_close_file(fd);
+ __free_winch(&winch->work);
+}
+
+static irqreturn_t winch_interrupt(int irq, void *data)
+{
+ struct winch *winch = data;
+ struct tty_struct *tty;
+ struct line *line;
+ int fd = winch->fd;
+ int err;
+ char c;
+ struct pid *pgrp;
+
+ if (fd != -1) {
+ err = generic_read(fd, &c, NULL);
+ if (err < 0) {
+ if (err != -EAGAIN) {
+ winch->fd = -1;
+ list_del(&winch->list);
+ os_close_file(fd);
+ printk(KERN_ERR "winch_interrupt : "
+ "read failed, errno = %d\n", -err);
+ printk(KERN_ERR "fd %d is losing SIGWINCH "
+ "support\n", winch->tty_fd);
+ INIT_WORK(&winch->work, __free_winch);
+ schedule_work(&winch->work);
+ return IRQ_HANDLED;
+ }
+ goto out;
+ }
+ }
+ tty = tty_port_tty_get(winch->port);
+ if (tty != NULL) {
+ line = tty->driver_data;
+ if (line != NULL) {
+ chan_window_size(line, &tty->winsize.ws_row,
+ &tty->winsize.ws_col);
+ pgrp = tty_get_pgrp(tty);
+ if (pgrp)
+ kill_pgrp(pgrp, SIGWINCH, 1);
+ put_pid(pgrp);
+ }
+ tty_kref_put(tty);
+ }
+ out:
+ return IRQ_HANDLED;
+}
+
+void register_winch_irq(int fd, int tty_fd, int pid, struct tty_port *port,
+ unsigned long stack)
+{
+ struct winch *winch;
+
+ winch = kmalloc(sizeof(*winch), GFP_KERNEL);
+ if (winch == NULL) {
+ printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
+ goto cleanup;
+ }
+
+ *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
+ .fd = fd,
+ .tty_fd = tty_fd,
+ .pid = pid,
+ .port = port,
+ .stack = stack });
+
+ if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
+ IRQF_SHARED, "winch", winch) < 0) {
+ printk(KERN_ERR "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);
+
+ return;
+
+ 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)
+{
+ struct list_head *ele, *next;
+ struct winch *winch;
+ struct tty_struct *wtty;
+
+ spin_lock(&winch_handler_lock);
+
+ list_for_each_safe(ele, next, &winch_handlers) {
+ winch = list_entry(ele, struct winch, list);
+ wtty = tty_port_tty_get(winch->port);
+ if (wtty == tty) {
+ list_del(&winch->list);
+ spin_unlock(&winch_handler_lock);
+ free_winch(winch);
+ break;
+ }
+ tty_kref_put(wtty);
+ }
+ spin_unlock(&winch_handler_lock);
+}
+
+static void winch_cleanup(void)
+{
+ struct winch *winch;
+
+ spin_lock(&winch_handler_lock);
+ while ((winch = list_first_entry_or_null(&winch_handlers,
+ struct winch, list))) {
+ list_del(&winch->list);
+ spin_unlock(&winch_handler_lock);
+
+ free_winch(winch);
+
+ spin_lock(&winch_handler_lock);
+ }
+
+ spin_unlock(&winch_handler_lock);
+}
+__uml_exitcall(winch_cleanup);
+
+char *add_xterm_umid(char *base)
+{
+ char *umid, *title;
+ int len;
+
+ umid = get_umid();
+ if (*umid == '\0')
+ return base;
+
+ len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
+ title = kmalloc(len, GFP_KERNEL);
+ if (title == NULL) {
+ printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
+ return base;
+ }
+
+ snprintf(title, len, "%s (%s)", base, umid);
+ return title;
+}
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