[PATCH v4 1/2] tty: add compat_ioctl callbacks

From: Aleksa Sarai
Date: Sat Jun 03 2017 - 10:15:37 EST


In order to avoid future diversions between fs/compat_ioctl.c and
drivers/tty/pty.c, define .compat_ioctl callbacks for the relevant
tty_operations structs. Since both pty_unix98_ioctl() and
pty_bsd_ioctl() are compatible between 32-bit and 64-bit userspace no
special translation is required.

Signed-off-by: Aleksa Sarai <asarai@xxxxxxx>
---
drivers/tty/pty.c | 22 ++++++++++++++++++++++
fs/compat_ioctl.c | 6 ------
2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 65799575c666..2a6bd9ae3f8b 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -481,6 +481,16 @@ static int pty_bsd_ioctl(struct tty_struct *tty,
return -ENOIOCTLCMD;
}

+static long pty_bsd_compat_ioctl(struct tty_struct *tty,
+ unsigned int cmd, unsigned long arg)
+{
+ /*
+ * PTY ioctls don't require any special translation between 32-bit and
+ * 64-bit userspace, they are already compatible.
+ */
+ return pty_bsd_ioctl(tty, cmd, arg);
+}
+
static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
/*
* not really modular, but the easiest way to keep compat with existing
@@ -502,6 +512,7 @@ static const struct tty_operations master_pty_ops_bsd = {
.chars_in_buffer = pty_chars_in_buffer,
.unthrottle = pty_unthrottle,
.ioctl = pty_bsd_ioctl,
+ .compat_ioctl = pty_bsd_compat_ioctl,
.cleanup = pty_cleanup,
.resize = pty_resize,
.remove = pty_remove
@@ -609,6 +620,16 @@ static int pty_unix98_ioctl(struct tty_struct *tty,
return -ENOIOCTLCMD;
}

+static long pty_unix98_compat_ioctl(struct tty_struct *tty,
+ unsigned int cmd, unsigned long arg)
+{
+ /*
+ * PTY ioctls don't require any special translation between 32-bit and
+ * 64-bit userspace, they are already compatible.
+ */
+ return pty_unix98_ioctl(tty, cmd, arg);
+}
+
/**
* ptm_unix98_lookup - find a pty master
* @driver: ptm driver
@@ -681,6 +702,7 @@ static const struct tty_operations ptm_unix98_ops = {
.chars_in_buffer = pty_chars_in_buffer,
.unthrottle = pty_unthrottle,
.ioctl = pty_unix98_ioctl,
+ .compat_ioctl = pty_unix98_compat_ioctl,
.resize = pty_resize,
.cleanup = pty_cleanup
};
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 6116d5275a3e..112b3e1e20e3 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -866,8 +866,6 @@ COMPATIBLE_IOCTL(TIOCGDEV)
COMPATIBLE_IOCTL(TIOCCBRK)
COMPATIBLE_IOCTL(TIOCGSID)
COMPATIBLE_IOCTL(TIOCGICOUNT)
-COMPATIBLE_IOCTL(TIOCGPKT)
-COMPATIBLE_IOCTL(TIOCGPTLCK)
COMPATIBLE_IOCTL(TIOCGEXCL)
/* Little t */
COMPATIBLE_IOCTL(TIOCGETD)
@@ -883,16 +881,12 @@ COMPATIBLE_IOCTL(TIOCMGET)
COMPATIBLE_IOCTL(TIOCMBIC)
COMPATIBLE_IOCTL(TIOCMBIS)
COMPATIBLE_IOCTL(TIOCMSET)
-COMPATIBLE_IOCTL(TIOCPKT)
COMPATIBLE_IOCTL(TIOCNOTTY)
COMPATIBLE_IOCTL(TIOCSTI)
COMPATIBLE_IOCTL(TIOCOUTQ)
COMPATIBLE_IOCTL(TIOCSPGRP)
COMPATIBLE_IOCTL(TIOCGPGRP)
-COMPATIBLE_IOCTL(TIOCGPTN)
-COMPATIBLE_IOCTL(TIOCSPTLCK)
COMPATIBLE_IOCTL(TIOCSERGETLSR)
-COMPATIBLE_IOCTL(TIOCSIG)
#ifdef TIOCSRS485
COMPATIBLE_IOCTL(TIOCSRS485)
#endif
--
2.13.0