From f574874bc861414bbae220b1fe623cbdd098243b Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Sat, 10 Feb 2007 01:45:18 -0800 Subject: [PATCH] [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 Signed-off-by: Jiri Slaby Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/mxser_new.c | 22 +++++++++------------- 1 file 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 */ -- 2.41.0