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| author |   Peter Hurley <peter@hurleysoftware.com> | 2016-01-09 21:45:10 -0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-28 11:58:02 -0800 |
| commit | f557474ca3a23800dffb790846bcb121fa046c71 (patch) | |
| tree | 0a77a92c9d977bc31a35567afab4c2a268eb6436 /drivers/tty/tty_io.c | |
| parent | tty, n_tty: Remove fasync() ldisc notification (diff) | |
| download | linux-dev-f557474ca3a23800dffb790846bcb121fa046c71.tar.xz linux-dev-f557474ca3a23800dffb790846bcb121fa046c71.zip | |
tty: Add fasync() hung up file operation
VFS uses a two-stage check-and-call method for invoking file_operations
methods, without explicitly snapshotting either the file_operations ptr
or the function ptr. Since the tty core is one of the few VFS users that
changes the f_op file_operations ptr of the file descriptor (when the
tty has been hung up), and since the likelihood of the compiler generating
a reload of either f_op or the function ptr is basically nil, just define
a hung up fasync() file operation that returns an error.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_io.c')
| -rw-r--r-- | drivers/tty/tty_io.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 7533ab1abe72..0140c8669ada 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -468,6 +468,11 @@ static long hung_up_tty_compat_ioctl(struct file *file, return cmd == TIOCSPGRP ? -ENOTTY : -EIO; } +static int hung_up_tty_fasync(int fd, struct file *file, int on) +{ + return -ENOTTY; +} + static const struct file_operations tty_fops = { .llseek = no_llseek, .read = tty_read, @@ -500,6 +505,7 @@ static const struct file_operations hung_up_tty_fops = { .unlocked_ioctl = hung_up_tty_ioctl, .compat_ioctl = hung_up_tty_compat_ioctl, .release = tty_release, + .fasync = hung_up_tty_fasync, }; static DEFINE_SPINLOCK(redirect_lock); |