diff options
| author |   Denis Kirjanov <kda@linux-powerpc.org> | 2017-03-30 10:06:19 -0400 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-31 11:37:13 +0200 |
| commit | 19fa6e601b251f13400767813372944b3e2f444b (patch) | |
| tree | f196d95a9163a964826db79b5a9d7b79fec06ffc /drivers/tty/hvc | |
| parent | tty: reset termios state on device registration (diff) | |
| download | linux-dev-19fa6e601b251f13400767813372944b3e2f444b.tar.xz linux-dev-19fa6e601b251f13400767813372944b3e2f444b.zip | |
tty/hvc_console: fix console lock ordering with spinlock
hvc_remove() takes a spin lock first then acquires the console
semaphore. This situation can easily lead to a deadlock scenario
where we call scheduler with spin lock held.
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/hvc')
| -rw-r--r-- | drivers/tty/hvc/hvc_console.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index b19ae36a05ec..a8d399188242 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -920,17 +920,17 @@ int hvc_remove(struct hvc_struct *hp) tty = tty_port_tty_get(&hp->port); + console_lock(); spin_lock_irqsave(&hp->lock, flags); if (hp->index < MAX_NR_HVC_CONSOLES) { - console_lock(); vtermnos[hp->index] = -1; cons_ops[hp->index] = NULL; - console_unlock(); } /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ spin_unlock_irqrestore(&hp->lock, flags); + console_unlock(); /* * We 'put' the instance that was grabbed when the kref instance |