tty: add compat_ioctl
Add compat_ioctl method for tty code to allow processing of 32 bit ioctl
calls on 64 bit systems by tty core, tty drivers, and line disciplines.
Based on patch by Arnd Bergmann:
http://www.uwsg.iu.edu/hypermail/linux/kernel/0511.0/1732.html
[akpm@linux-foundation.org: make things static]
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index 6ac3ca4..b3d4ccc 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -1544,21 +1544,18 @@
}
struct tty_ldisc tty_ldisc_N_TTY = {
- TTY_LDISC_MAGIC, /* magic */
- "n_tty", /* name */
- 0, /* num */
- 0, /* flags */
- n_tty_open, /* open */
- n_tty_close, /* close */
- n_tty_flush_buffer, /* flush_buffer */
- n_tty_chars_in_buffer, /* chars_in_buffer */
- read_chan, /* read */
- write_chan, /* write */
- n_tty_ioctl, /* ioctl */
- n_tty_set_termios, /* set_termios */
- normal_poll, /* poll */
- NULL, /* hangup */
- n_tty_receive_buf, /* receive_buf */
- n_tty_write_wakeup /* write_wakeup */
+ .magic = TTY_LDISC_MAGIC,
+ .name = "n_tty",
+ .open = n_tty_open,
+ .close = n_tty_close,
+ .flush_buffer = n_tty_flush_buffer,
+ .chars_in_buffer = n_tty_chars_in_buffer,
+ .read = read_chan,
+ .write = write_chan,
+ .ioctl = n_tty_ioctl,
+ .set_termios = n_tty_set_termios,
+ .poll = normal_poll,
+ .receive_buf = n_tty_receive_buf,
+ .write_wakeup = n_tty_write_wakeup
};
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index fc662e4..fe62c21 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -151,6 +151,12 @@
static int tty_release(struct inode *, struct file *);
int tty_ioctl(struct inode * inode, struct file * file,
unsigned int cmd, unsigned long arg);
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file * file, unsigned int cmd,
+ unsigned long arg);
+#else
+#define tty_compat_ioctl NULL
+#endif
static int tty_fasync(int fd, struct file * filp, int on);
static void release_tty(struct tty_struct *tty, int idx);
static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
@@ -1143,8 +1149,8 @@
return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
}
-static int hung_up_tty_ioctl(struct inode * inode, struct file * file,
- unsigned int cmd, unsigned long arg)
+static long hung_up_tty_ioctl(struct file * file,
+ unsigned int cmd, unsigned long arg)
{
return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
}
@@ -1155,6 +1161,7 @@
.write = tty_write,
.poll = tty_poll,
.ioctl = tty_ioctl,
+ .compat_ioctl = tty_compat_ioctl,
.open = tty_open,
.release = tty_release,
.fasync = tty_fasync,
@@ -1167,6 +1174,7 @@
.write = tty_write,
.poll = tty_poll,
.ioctl = tty_ioctl,
+ .compat_ioctl = tty_compat_ioctl,
.open = ptmx_open,
.release = tty_release,
.fasync = tty_fasync,
@@ -1179,6 +1187,7 @@
.write = redirected_tty_write,
.poll = tty_poll,
.ioctl = tty_ioctl,
+ .compat_ioctl = tty_compat_ioctl,
.open = tty_open,
.release = tty_release,
.fasync = tty_fasync,
@@ -1189,7 +1198,8 @@
.read = hung_up_tty_read,
.write = hung_up_tty_write,
.poll = hung_up_tty_poll,
- .ioctl = hung_up_tty_ioctl,
+ .unlocked_ioctl = hung_up_tty_ioctl,
+ .compat_ioctl = hung_up_tty_ioctl,
.release = tty_release,
};
@@ -3357,6 +3367,32 @@
return retval;
}
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file * file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct tty_struct *tty = file->private_data;
+ struct tty_ldisc *ld;
+ int retval = -ENOIOCTLCMD;
+
+ if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+ return -EINVAL;
+
+ if (tty->driver->compat_ioctl) {
+ retval = (tty->driver->compat_ioctl)(tty, file, cmd, arg);
+ if (retval != -ENOIOCTLCMD)
+ return retval;
+ }
+
+ ld = tty_ldisc_ref_wait(tty);
+ if (ld->compat_ioctl)
+ retval = ld->compat_ioctl(tty, file, cmd, arg);
+ tty_ldisc_deref(ld);
+
+ return retval;
+}
+#endif
/*
* This implements the "Secure Attention Key" --- the idea is to
@@ -3689,6 +3725,7 @@
driver->write_room = op->write_room;
driver->chars_in_buffer = op->chars_in_buffer;
driver->ioctl = op->ioctl;
+ driver->compat_ioctl = op->compat_ioctl;
driver->set_termios = op->set_termios;
driver->throttle = op->throttle;
driver->unthrottle = op->unthrottle;
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 659487e..85c95cd 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -52,6 +52,11 @@
* This routine allows the tty driver to implement
* device-specific ioctl's. If the ioctl number passed in cmd
* is not recognized by the driver, it should return ENOIOCTLCMD.
+ *
+ * long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
+ * unsigned int cmd, unsigned long arg);
+ *
+ * implement ioctl processing for 32 bit process on 64 bit system
*
* void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
*
@@ -132,6 +137,8 @@
int (*chars_in_buffer)(struct tty_struct *tty);
int (*ioctl)(struct tty_struct *tty, struct file * file,
unsigned int cmd, unsigned long arg);
+ long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
+ unsigned int cmd, unsigned long arg);
void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
void (*throttle)(struct tty_struct * tty);
void (*unthrottle)(struct tty_struct * tty);
@@ -193,6 +200,8 @@
int (*chars_in_buffer)(struct tty_struct *tty);
int (*ioctl)(struct tty_struct *tty, struct file * file,
unsigned int cmd, unsigned long arg);
+ long (*compat_ioctl)(struct tty_struct *tty, struct file * file,
+ unsigned int cmd, unsigned long arg);
void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
void (*throttle)(struct tty_struct * tty);
void (*unthrottle)(struct tty_struct * tty);
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index d75932e..6226504 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -59,6 +59,11 @@
* low-level driver can "grab" an ioctl request before the line
* discpline has a chance to see it.
*
+ * long (*compat_ioctl)(struct tty_struct * tty, struct file * file,
+ * unsigned int cmd, unsigned long arg);
+ *
+ * Process ioctl calls from 32-bit process on 64-bit system
+ *
* void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
*
* This function notifies the line discpline that a change has
@@ -118,6 +123,8 @@
const unsigned char * buf, size_t nr);
int (*ioctl)(struct tty_struct * tty, struct file * file,
unsigned int cmd, unsigned long arg);
+ long (*compat_ioctl)(struct tty_struct * tty, struct file * file,
+ unsigned int cmd, unsigned long arg);
void (*set_termios)(struct tty_struct *tty, struct ktermios * old);
unsigned int (*poll)(struct tty_struct *, struct file *,
struct poll_table_struct *);