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authorAl Viro <viro@zeniv.linux.org.uk>2018-09-13 22:12:15 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2018-10-13 00:50:53 -0400
commitf0193d3ea73b966b5dbfa272c8228d743b8856ef (patch)
treec882a171c8706f274a7e09d8f7297c36ed750e34 /drivers/tty/n_r3964.c
parent7ee329655189f32f0c17e0bad60c23a69b003e9e (diff)
change semantics of ldisc ->compat_ioctl()
First of all, make it return int. Returning long when native method had never allowed that is ridiculous and inconvenient. More importantly, change the caller; if ldisc ->compat_ioctl() is NULL or returns -ENOIOCTLCMD, tty_compat_ioctl() will try to feed cmd and compat_ptr(arg) to ldisc's native ->ioctl(). That simplifies ->compat_ioctl() instances quite a bit - they only need to deal with ioctls that are neither generic tty ones (those would get shunted off to tty_ioctl()) nor simple compat pointer ones. Note that something like TCFLSH won't reach ->compat_ioctl(), even if ldisc ->ioctl() does handle it - it will be recognized earlier and passed to tty_ioctl() (and ultimately - ldisc ->ioctl()). For many ldiscs it means that NULL ->compat_ioctl() does the right thing. Those where it won't serve (see e.g. n_r3964.c) are also easily dealt with - we need to handle the numeric-argument ioctls (calling the native instance) and, if such would exist, the ioctls that need layout conversion, etc. All in-tree ldiscs dealt with. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'drivers/tty/n_r3964.c')
-rw-r--r--drivers/tty/n_r3964.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c
index dbf1ab36758e..749a608c40b0 100644
--- a/drivers/tty/n_r3964.c
+++ b/drivers/tty/n_r3964.c
@@ -134,6 +134,10 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
const unsigned char *buf, size_t nr);
static int r3964_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg);
+#ifdef CONFIG_COMPAT
+static int r3964_compat_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg);
+#endif
static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old);
static __poll_t r3964_poll(struct tty_struct *tty, struct file *file,
struct poll_table_struct *wait);
@@ -149,6 +153,9 @@ static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
.read = r3964_read,
.write = r3964_write,
.ioctl = r3964_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = r3964_compat_ioctl,
+#endif
.set_termios = r3964_set_termios,
.poll = r3964_poll,
.receive_buf = r3964_receive_buf,
@@ -1210,6 +1217,21 @@ static int r3964_ioctl(struct tty_struct *tty, struct file *file,
}
}
+#ifdef CONFIG_COMPAT
+static int r3964_compat_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case R3964_ENABLE_SIGNALS:
+ case R3964_SETPRIORITY:
+ case R3964_USE_BCC:
+ return r3964_ioctl(tty, file, cmd, arg);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+#endif
+
static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
{
TRACE_L("set_termios");