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author | Al Viro <viro@zeniv.linux.org.uk> | 2018-09-13 22:12:15 -0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2018-10-13 00:50:53 -0400 |
commit | f0193d3ea73b966b5dbfa272c8228d743b8856ef (patch) | |
tree | c882a171c8706f274a7e09d8f7297c36ed750e34 /drivers/tty/tty_io.c | |
parent | 7ee329655189f32f0c17e0bad60c23a69b003e9e (diff) | |
download | op-kernel-dev-f0193d3ea73b966b5dbfa272c8228d743b8856ef.zip op-kernel-dev-f0193d3ea73b966b5dbfa272c8228d743b8856ef.tar.gz |
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/tty_io.c')
-rw-r--r-- | drivers/tty/tty_io.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 1a55c3e..cd8df45 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2824,6 +2824,9 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd, return hung_up_tty_compat_ioctl(file, cmd, arg); if (ld->ops->compat_ioctl) retval = ld->ops->compat_ioctl(tty, file, cmd, arg); + if (retval == -ENOIOCTLCMD && ld->ops->ioctl) + retval = ld->ops->ioctl(tty, file, + (unsigned long)compat_ptr(cmd), arg); tty_ldisc_deref(ld); return retval; |