diff options
author | Amit Shah <amit.shah@redhat.com> | 2010-03-12 11:53:15 +0530 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-03-19 07:17:54 -0700 |
commit | e74d098c66543d0731de62eb747ccd5b636a6f4c (patch) | |
tree | 8ed9937f653cf42a82ca7bd319a69dd35fb2325d /drivers/of/of_i2c.c | |
parent | f157b58511e56d418eb582de96fedc4ea03d8061 (diff) |
hvc_console: Fix race between hvc_close and hvc_remove
Alan pointed out a race in the code where hvc_remove is invoked. The
recent virtio_console work is the first user of hvc_remove().
Alan describes it thus:
The hvc_console assumes that a close and remove call can't occur at the
same time.
In addition tty_hangup(tty) is problematic as tty_hangup is asynchronous
itself....
So this can happen
hvc_close hvc_remove
hung up ? - no
lock
tty = hp->tty
unlock
lock
hp->tty = NULL
unlock
notify del
kref_put the hvc struct
close completes
tty is destroyed
tty_hangup dead tty
tty->ops will be NULL
NULL->...
This patch adds some tty krefs and also converts to using tty_vhangup().
Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>
CC: linuxppc-dev@ozlabs.org
CC: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/of/of_i2c.c')
0 files changed, 0 insertions, 0 deletions