The patch titled
Char: mxser_new, alter locking in isr
has been added to the -mm tree. Its filename is
char-mxser_new-alter-locking-in-isr.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Char: mxser_new, alter locking in isr
From: Jiri Slaby <jirislaby@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Jiri Slaby <jirislaby@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/char/mxser_new.c | 22 +++++++++-------------
1 files changed, 9 insertions(+), 13 deletions(-)
diff -puN drivers/char/mxser_new.c~char-mxser_new-alter-locking-in-isr drivers/char/mxser_new.c
--- a/drivers/char/mxser_new.c~char-mxser_new-alter-locking-in-isr
+++ a/drivers/char/mxser_new.c
@@ -2073,9 +2073,6 @@ static void mxser_receive_chars(struct m
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
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
(!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
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 i
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 i
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 */
_
Patches currently in -mm which might be from jirislaby@xxxxxxxxx are
git-input.patch
char-tty-delete-wake_up_interruptible-after-tty_wakeup.patch
char-isicom-remove-tty_hangwakeup-bottomhalves.patch
mxser-remove-ambiguous-redefinition-of-init_work.patch
make-drivers-char-mxser_newcmxser_hangup-static.patch
char-isicom-fix-locking-in-isr.patch
char-isicom-augment-card_reset.patch
char-isicom-check-card-state-in-isr.patch
char-isicom-support-higher-rates.patch
char-isicom-correct-probing-removing.patch
char-tty_wakeup-cleanup.patch
char-mxser_new-mark-init-functions.patch
char-mxser_new-remove-useless-spinlock.patch
char-serial167-cleanup.patch
char-n_r3964-cleanup.patch
char-mxser_new-remove-unused-stuff.patch
char-mxser-obsolete-old-nonexperimental-new.patch
char-mxser_new-remove-tty_wakeup-bottomhalf.patch
char-mxser_new-clean-request_irq-call.patch
doc-isicom-remove-reserved-ioctl-number.patch
char-mxser_new-alter-locking-in-isr.patch
char-mxser_new-header-file-cleanup.patch
char-mxser_new-less-loops-in-isr.patch
char-mxser_new-fix-twice-resource-releasing.patch
shrink_slab-handle-bad-shrinkers.patch
-
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