Re: [PATCH] TTY: hvc_console, fix port reference count going to zero prematurely
From: Jiri Slaby <hidden>
Date: 2012-11-14 09:45:48
On 11/14/2012 09:15 AM, Paul Mackerras wrote:
Commit bdb498c20040 "TTY: hvc_console, add tty install" took the port refcounting out of hvc_open()/hvc_close(), but failed to remove the kref_put() and tty_kref_put() calls in hvc_hangup() that were there to remove the extra references that hvc_open() had taken. The result was that doing a vhangup() when the current terminal was a hvc_console, then closing the current terminal, would end up calling destroy_hvc_struct() and making the port disappear entirely. This meant that Fedora 17 systems would boot up but then not display the login prompt on the console, and attempts to open /dev/hvc0 would give a "No such device" error. This fixes it by removing the extra kref_put() and tty_kref_put() calls.
Oh yeah. Thanks. Acked-by: Jiri Slaby <redacted>
quoted hunk ↗ jump to hunk
Signed-off-by: Paul Mackerras <redacted> Cc: stable@vger.kernel.org --- drivers/tty/hvc/hvc_console.c | 7 ------- 1 file changed, 7 deletions(-)diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index a5dec1c..13ee53b 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c@@ -424,7 +424,6 @@ static void hvc_hangup(struct tty_struct *tty) { struct hvc_struct *hp = tty->driver_data; unsigned long flags; - int temp_open_count; if (!hp) return;@@ -444,7 +443,6 @@ static void hvc_hangup(struct tty_struct *tty) return; } - temp_open_count = hp->port.count; hp->port.count = 0; spin_unlock_irqrestore(&hp->port.lock, flags); tty_port_tty_set(&hp->port, NULL);@@ -453,11 +451,6 @@ static void hvc_hangup(struct tty_struct *tty) if (hp->ops->notifier_hangup) hp->ops->notifier_hangup(hp, hp->data); - - while(temp_open_count) { - --temp_open_count; - tty_port_put(&hp->port); - } } /*
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