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authorJiri Slaby <jirislaby@gmail.com>2007-02-10 01:45:18 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-11 10:51:29 -0800
commitf574874bc861414bbae220b1fe623cbdd098243b (patch)
treef905e9170338a295e897013c9ab01ca189f08dbe /drivers
parent765d94c1b37d08be02eea6abbff70c0fda0ba984 (diff)
[PATCH] Char: mxser_new, alter locking in isr
Avoid oopsing when stress-testing open/close -- port->tty is NULL sometimes, but is expected to be non-NULL, since dereferencing. Receive/transmit chars iff ASYNC_CLOSING is not set and ASYNC_INITIALIZED is set. Thanks Sergei for pointing this out and testing. Cc: Sergei Organov <osv@javad.com> Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/char/mxser_new.c22
1 files changed, 9 insertions, 13 deletions
diff --git a/drivers/char/mxser_new.c b/drivers/char/mxser_new.c
index 8da883340dd..ec61cf81b7e 100644
--- a/drivers/char/mxser_new.c
+++ b/drivers/char/mxser_new.c
@@ -2073,9 +2073,6 @@ static void mxser_receive_chars(struct mxser_port *port, int *status)
int cnt = 0;
int recv_room;
int max = 256;
- unsigned long flags;
-
- spin_lock_irqsave(&port->slock, flags);
recv_room = tty->receive_room;
if ((recv_room == 0) && (!port->ldisc_stop_rx))
@@ -2159,7 +2156,6 @@ end_intr:
mxvar_log.rxcnt[port->tty->index] += cnt;
port->mon_data.rxcnt += cnt;
port->mon_data.up_rxcnt += cnt;
- spin_unlock_irqrestore(&port->slock, flags);
tty_flip_buffer_push(tty);
}
@@ -2167,9 +2163,6 @@ end_intr:
static void mxser_transmit_chars(struct mxser_port *port)
{
int count, cnt;
- unsigned long flags;
-
- spin_lock_irqsave(&port->slock, flags);
if (port->x_char) {
outb(port->x_char, port->ioaddr + UART_TX);
@@ -2178,11 +2171,11 @@ static void mxser_transmit_chars(struct mxser_port *port)
port->mon_data.txcnt++;
port->mon_data.up_txcnt++;
port->icount.tx++;
- goto unlock;
+ return;
}
if (port->xmit_buf == 0)
- goto unlock;
+ return;
if ((port->xmit_cnt <= 0) || port->tty->stopped ||
(port->tty->hw_stopped &&
@@ -2190,7 +2183,7 @@ static void mxser_transmit_chars(struct mxser_port *port)
(!port->board->chip_flag))) {
port->IER &= ~UART_IER_THRI;
outb(port->IER, port->ioaddr + UART_IER);
- goto unlock;
+ return;
}
cnt = port->xmit_cnt;
@@ -2215,8 +2208,6 @@ static void mxser_transmit_chars(struct mxser_port *port)
port->IER &= ~UART_IER_THRI;
outb(port->IER, port->ioaddr + UART_IER);
}
-unlock:
- spin_unlock_irqrestore(&port->slock, flags);
}
/*
@@ -2257,12 +2248,16 @@ static irqreturn_t mxser_interrupt(int irq, void *dev_id)
port = &brd->ports[i];
int_cnt = 0;
+ spin_lock(&port->slock);
do {
iir = inb(port->ioaddr + UART_IIR);
if (iir & UART_IIR_NO_INT)
break;
iir &= MOXA_MUST_IIR_MASK;
- if (!port->tty) {
+ if (!port->tty ||
+ (port->flags & ASYNC_CLOSING) ||
+ !(port->flags &
+ ASYNC_INITIALIZED)) {
status = inb(port->ioaddr + UART_LSR);
outb(0x27, port->ioaddr + UART_FCR);
inb(port->ioaddr + UART_MSR);
@@ -2308,6 +2303,7 @@ static irqreturn_t mxser_interrupt(int irq, void *dev_id)
mxser_transmit_chars(port);
}
} while (int_cnt++ < MXSER_ISR_PASS_LIMIT);
+ spin_unlock(&port->slock);
}
if (pass_counter++ > MXSER_ISR_PASS_LIMIT)
break; /* Prevent infinite loops */