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authorAlan Cox <alan@linux.intel.com>2009-11-30 13:17:46 +0000
committerGreg Kroah-Hartman <gregkh@suse.de>2009-12-11 15:18:07 -0800
commit2493c0c166565e36831196446af594eb07892daf (patch)
tree0175b121f39076dbd858fd7e475885e9d804a5f4
parent07f86c03fec711692121bf7f5316e0b3426acc05 (diff)
tty: isicom: fix deadlock on shutdown
Alexander Strakh <strakh@ispras.ru> reported KERNEL_VERSION: 2.6.31 DESCRIBE: Driver drivers/char/isicom.c might sleep in atomic context, because it calls tty_port_xmit_buf under spin_lock. ./drivers/char/isicom.c: 1307 static void isicom_hangup(struct tty_struct *tty) 1308 { ... 1315 spin_lock_irqsave(&port->card->card_lock, flags); 1316 isicom_shutdown_port(port); ... Path to might_sleep macro from isicom_hangup: 1. isicom_hangup calls spin_lock_irqsave (drivers/char/isicom.c:1315) and then calls isicom_shutdown_port. 2. isiscom_shutdown_port calls tty_port_free_xmit_buf at drivers/char/isicom.c:906 3. tty_port_free_xmit_buf calls mutex_lock at drivers/char/tty_port:48 Found by Linux Driver Verification Project. Reported-by: Alexander Strakh <strakh@ispras.ru> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/char/isicom.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c
index 1e91c30..300d5bd 100644
--- a/drivers/char/isicom.c
+++ b/drivers/char/isicom.c
@@ -887,7 +887,6 @@ static void isicom_shutdown_port(struct isi_port *port)
{
struct isi_board *card = port->card;
- tty_port_free_xmit_buf(&port->port);
if (--card->count < 0) {
pr_dbg("isicom_shutdown_port: bad board(0x%lx) count %d.\n",
card->base, card->count);
@@ -927,6 +926,7 @@ static void isicom_shutdown(struct tty_port *port)
outw(card->port_status, card->base + 0x02);
isicom_shutdown_port(ip);
spin_unlock_irqrestore(&card->card_lock, flags);
+ tty_port_free_xmit_buf(port);
}
static void isicom_close(struct tty_struct *tty, struct file *filp)