| Message ID | 20100121164801.416170b9@linux.intel.com |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 21 Jan 2010 16:48:01 +0000 Alan Cox <alan@linux.intel.com> wrote: > (Incidentally this doesn't seem to be the only net driver that looks > suspect here) > > e100: Fix the TX workqueue race > > From: Alan Cox <alan@linux.intel.com> > > Nothing stops the workqueue being left to run in parallel with close or a > few other operations. This causes double unmaps and the like. > > See kerneloops.org #1041230 for an example > > Signed-off-by: Alan Cox <alan@linux.intel.com> Most drivers solve this by getting rtnl_lock in the timeout work function.
On 21-01-2010 17:48, Alan Cox wrote: > (Incidentally this doesn't seem to be the only net driver that looks > suspect here) > > e100: Fix the TX workqueue race > > From: Alan Cox <alan@linux.intel.com> > > Nothing stops the workqueue being left to run in parallel with close or a > few other operations. This causes double unmaps and the like. > > See kerneloops.org #1041230 for an example > > Signed-off-by: Alan Cox <alan@linux.intel.com> > --- > > drivers/net/e100.c | 13 +++++++++++-- > 1 files changed, 11 insertions(+), 2 deletions(-) > > > diff --git a/drivers/net/e100.c b/drivers/net/e100.c > index 5c7a155..5e02e4f 100644 > --- a/drivers/net/e100.c > +++ b/drivers/net/e100.c > @@ -2232,7 +2232,7 @@ err_rx_clean_list: > return err; > } > > -static void e100_down(struct nic *nic) > +static void e100_do_down(struct nic *nic) > { > /* wait here for poll to complete */ > napi_disable(&nic->napi); > @@ -2245,6 +2245,15 @@ static void e100_down(struct nic *nic) > e100_rx_clean_list(nic); > } > > +/* For the non TX timeout case we want to kill the tx timeout before > + we do this otherwise a parallel tx timeout will make a nasty mess. */ > + > +static void e100_down(struct nic *nic) > +{ > + cancel_work_sync(&nic->tx_timeout_task); Can't tx_timeout_task be triggered just between these two calls here? Jarek P. > + e100_do_down(nic); > +} > + > static void e100_tx_timeout(struct net_device *netdev) > { > struct nic *nic = netdev_priv(netdev); > @@ -2261,7 +2270,7 @@ static void e100_tx_timeout_task(struct work_struct *work) > > DPRINTK(TX_ERR, DEBUG, "scb.status=0x%02X\n", > ioread8(&nic->csr->scb.status)); > - e100_down(netdev_priv(netdev)); > + e100_do_down(netdev_priv(netdev)); > e100_up(netdev_priv(netdev)); > } > > -- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jan 22, 2010 at 08:42:00AM +0000, Jarek Poplawski wrote: > On 21-01-2010 17:48, Alan Cox wrote: > > (Incidentally this doesn't seem to be the only net driver that looks > > suspect here) > > > > e100: Fix the TX workqueue race > > > > From: Alan Cox <alan@linux.intel.com> > > > > Nothing stops the workqueue being left to run in parallel with close or a > > few other operations. This causes double unmaps and the like. > > > > See kerneloops.org #1041230 for an example > > > > Signed-off-by: Alan Cox <alan@linux.intel.com> > > --- > > > > drivers/net/e100.c | 13 +++++++++++-- > > 1 files changed, 11 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/net/e100.c b/drivers/net/e100.c > > index 5c7a155..5e02e4f 100644 > > --- a/drivers/net/e100.c > > +++ b/drivers/net/e100.c > > @@ -2232,7 +2232,7 @@ err_rx_clean_list: > > return err; > > } > > > > -static void e100_down(struct nic *nic) > > +static void e100_do_down(struct nic *nic) > > { > > /* wait here for poll to complete */ > > napi_disable(&nic->napi); > > @@ -2245,6 +2245,15 @@ static void e100_down(struct nic *nic) > > e100_rx_clean_list(nic); > > } > > > > +/* For the non TX timeout case we want to kill the tx timeout before > > + we do this otherwise a parallel tx timeout will make a nasty mess. */ > > + > > +static void e100_down(struct nic *nic) > > +{ > > + cancel_work_sync(&nic->tx_timeout_task); > > Can't tx_timeout_task be triggered just between these two calls here? More exactly: except when this is called from dev_close(), where it should work OK. (At least until tx_timeout_task doesn't take any lock held here - especially rtnl_lock.) Jarek P. > > > + e100_do_down(nic); > > +} > > + > > static void e100_tx_timeout(struct net_device *netdev) > > { > > struct nic *nic = netdev_priv(netdev); > > @@ -2261,7 +2270,7 @@ static void e100_tx_timeout_task(struct work_struct *work) > > > > DPRINTK(TX_ERR, DEBUG, "scb.status=0x%02X\n", > > ioread8(&nic->csr->scb.status)); > > - e100_down(netdev_priv(netdev)); > > + e100_do_down(netdev_priv(netdev)); > > e100_up(netdev_priv(netdev)); > > } > > > > -- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jan 22, 2010 at 09:07:31AM +0000, Jarek Poplawski wrote: > On Fri, Jan 22, 2010 at 08:42:00AM +0000, Jarek Poplawski wrote: > > On 21-01-2010 17:48, Alan Cox wrote: > > > (Incidentally this doesn't seem to be the only net driver that looks > > > suspect here) > > > > > > e100: Fix the TX workqueue race > > > > > > From: Alan Cox <alan@linux.intel.com> > > > > > > Nothing stops the workqueue being left to run in parallel with close or a > > > few other operations. This causes double unmaps and the like. > > > > > > See kerneloops.org #1041230 for an example > > > > > > Signed-off-by: Alan Cox <alan@linux.intel.com> > > > --- > > > > > > drivers/net/e100.c | 13 +++++++++++-- > > > 1 files changed, 11 insertions(+), 2 deletions(-) > > > > > > > > > diff --git a/drivers/net/e100.c b/drivers/net/e100.c > > > index 5c7a155..5e02e4f 100644 > > > --- a/drivers/net/e100.c > > > +++ b/drivers/net/e100.c > > > @@ -2232,7 +2232,7 @@ err_rx_clean_list: > > > return err; > > > } > > > > > > -static void e100_down(struct nic *nic) > > > +static void e100_do_down(struct nic *nic) > > > { > > > /* wait here for poll to complete */ > > > napi_disable(&nic->napi); > > > @@ -2245,6 +2245,15 @@ static void e100_down(struct nic *nic) > > > e100_rx_clean_list(nic); > > > } > > > > > > +/* For the non TX timeout case we want to kill the tx timeout before > > > + we do this otherwise a parallel tx timeout will make a nasty mess. */ > > > + > > > +static void e100_down(struct nic *nic) > > > +{ > > > + cancel_work_sync(&nic->tx_timeout_task); > > > > Can't tx_timeout_task be triggered just between these two calls here? > > More exactly: except when this is called from dev_close(), where it > should work OK. (At least until tx_timeout_task doesn't take any lock > held here - especially rtnl_lock.) Hmm... Even more exactly, since tx_timeout_task can be triggered not only by dev_watchdog(), dev_close() is suspicious too. Jarek P. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/e100.c b/drivers/net/e100.c index 5c7a155..5e02e4f 100644 --- a/drivers/net/e100.c +++ b/drivers/net/e100.c @@ -2232,7 +2232,7 @@ err_rx_clean_list: return err; } -static void e100_down(struct nic *nic) +static void e100_do_down(struct nic *nic) { /* wait here for poll to complete */ napi_disable(&nic->napi); @@ -2245,6 +2245,15 @@ static void e100_down(struct nic *nic) e100_rx_clean_list(nic); } +/* For the non TX timeout case we want to kill the tx timeout before + we do this otherwise a parallel tx timeout will make a nasty mess. */ + +static void e100_down(struct nic *nic) +{ + cancel_work_sync(&nic->tx_timeout_task); + e100_do_down(nic); +} + static void e100_tx_timeout(struct net_device *netdev) { struct nic *nic = netdev_priv(netdev); @@ -2261,7 +2270,7 @@ static void e100_tx_timeout_task(struct work_struct *work) DPRINTK(TX_ERR, DEBUG, "scb.status=0x%02X\n", ioread8(&nic->csr->scb.status)); - e100_down(netdev_priv(netdev)); + e100_do_down(netdev_priv(netdev)); e100_up(netdev_priv(netdev)); }