* RE: [PATCH 2/2] dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler
2020-06-11 12:17 ` [PATCH 2/2] dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler Krzysztof Kozlowski
@ 2020-06-11 13:04 ` Robin Gong
2020-06-11 13:10 ` Krzysztof Kozlowski
2020-06-11 13:21 ` [PATCH] dmaengine: mcf-edma: Fix NULL pointer exception in mcf_edma_tx_handler Krzysztof Kozlowski
2020-06-12 2:22 ` [PATCH 2/2] dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler Robin Gong
2 siblings, 1 reply; 6+ messages in thread
From: Robin Gong @ 2020-06-11 13:04 UTC (permalink / raw)
To: Krzysztof Kozlowski, Vinod Koul, Dan Williams, Peng Ma,
Fabio Estevam, dmaengine@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
On 2020/06/11 20:18 Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> NULL pointer exception happens occasionally on serial output initiated by login
> timeout. This was reproduced only if kernel was built with significant
> debugging options and EDMA driver is used with serial console.
>
> col-vf50 login: root
> Password:
> Login timed out after 60 seconds.
> Unable to handle kernel NULL pointer dereference at virtual address
> 00000044
> Internal error: Oops: 5 [#1] ARM
> CPU: 0 PID: 157 Comm: login Not tainted 5.7.0-next-20200610-dirty #4
> Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
> (fsl_edma_tx_handler) from [<8016eb10>]
> (__handle_irq_event_percpu+0x64/0x304)
> (__handle_irq_event_percpu) from [<8016eddc>]
> (handle_irq_event_percpu+0x2c/0x7c)
> (handle_irq_event_percpu) from [<8016ee64>]
> (handle_irq_event+0x38/0x5c)
> (handle_irq_event) from [<801729e4>]
> (handle_fasteoi_irq+0xa4/0x160)
> (handle_fasteoi_irq) from [<8016ddcc>]
> (generic_handle_irq+0x34/0x44)
> (generic_handle_irq) from [<8016e40c>]
> (__handle_domain_irq+0x54/0xa8)
> (__handle_domain_irq) from [<80508bc8>] (gic_handle_irq+0x4c/0x80)
> (gic_handle_irq) from [<80100af0>] (__irq_svc+0x70/0x98)
> Exception stack(0x8459fe80 to 0x8459fec8)
> fe80: 72286b00 e3359f64 00000001 0000412d a0070013 85c98840
> 85c98840 a0070013
> fea0: 8054e0d4 00000000 00000002 00000000 00000002 8459fed0
> 8081fbe8 8081fbec
> fec0: 60070013 ffffffff
> (__irq_svc) from [<8081fbec>]
> (_raw_spin_unlock_irqrestore+0x30/0x58)
> (_raw_spin_unlock_irqrestore) from [<8056cb48>]
> (uart_flush_buffer+0x88/0xf8)
> (uart_flush_buffer) from [<80554e60>] (tty_ldisc_hangup+0x38/0x1ac)
> (tty_ldisc_hangup) from [<8054c7f4>] (__tty_hangup+0x158/0x2bc)
> (__tty_hangup) from [<80557b90>]
> (disassociate_ctty.part.1+0x30/0x23c)
> (disassociate_ctty.part.1) from [<8011fc18>] (do_exit+0x580/0xba0)
> (do_exit) from [<801214f8>] (do_group_exit+0x3c/0xb4)
> (do_group_exit) from [<80121580>] (__wake_up_parent+0x0/0x14)
>
> Issue looks like race condition between interrupt handler fsl_edma_tx_handler()
> (called as result of fsl_edma_xfer_desc()) and terminating the transfer with
> fsl_edma_terminate_all().
>
> The fsl_edma_tx_handler() handles interrupt for a transfer with already freed
> edesc and idle==true.
>
> Fixes: d6be34fbd39b ("dma: Add Freescale eDMA engine driver support")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> ---
> drivers/dma/fsl-edma.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c index
> eff7ebd8cf35..90bb72af306c 100644
> --- a/drivers/dma/fsl-edma.c
> +++ b/drivers/dma/fsl-edma.c
> @@ -45,6 +45,13 @@ static irqreturn_t fsl_edma_tx_handler(int irq, void
> *dev_id)
> fsl_chan = &fsl_edma->chans[ch];
>
> spin_lock(&fsl_chan->vchan.lock);
> +
> + if (!fsl_chan->edesc) {
Would you like fix the same potential issue in mcf_edma_tx_handler()
of mcf-edma.c?
> + /* terminate_all called before */
> + spin_unlock(&fsl_chan->vchan.lock);
> + continue;
> + }
> +
> if (!fsl_chan->edesc->iscyclic) {
> list_del(&fsl_chan->edesc->vdesc.node);
> vchan_cookie_complete(&fsl_chan->edesc->vdesc);
> --
> 2.7.4
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 2/2] dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler
2020-06-11 13:04 ` Robin Gong
@ 2020-06-11 13:10 ` Krzysztof Kozlowski
0 siblings, 0 replies; 6+ messages in thread
From: Krzysztof Kozlowski @ 2020-06-11 13:10 UTC (permalink / raw)
To: Robin Gong
Cc: Vinod Koul, Dan Williams, Peng Ma, Fabio Estevam,
dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
On Thu, Jun 11, 2020 at 01:04:43PM +0000, Robin Gong wrote:
> On 2020/06/11 20:18 Krzysztof Kozlowski <krzk@kernel.org> wrote:
> >
> > NULL pointer exception happens occasionally on serial output initiated by login
> > timeout. This was reproduced only if kernel was built with significant
> > debugging options and EDMA driver is used with serial console.
> >
> > col-vf50 login: root
> > Password:
> > Login timed out after 60 seconds.
> > Unable to handle kernel NULL pointer dereference at virtual address
> > 00000044
> > Internal error: Oops: 5 [#1] ARM
> > CPU: 0 PID: 157 Comm: login Not tainted 5.7.0-next-20200610-dirty #4
> > Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
> > (fsl_edma_tx_handler) from [<8016eb10>]
> > (__handle_irq_event_percpu+0x64/0x304)
> > (__handle_irq_event_percpu) from [<8016eddc>]
> > (handle_irq_event_percpu+0x2c/0x7c)
> > (handle_irq_event_percpu) from [<8016ee64>]
> > (handle_irq_event+0x38/0x5c)
> > (handle_irq_event) from [<801729e4>]
> > (handle_fasteoi_irq+0xa4/0x160)
> > (handle_fasteoi_irq) from [<8016ddcc>]
> > (generic_handle_irq+0x34/0x44)
> > (generic_handle_irq) from [<8016e40c>]
> > (__handle_domain_irq+0x54/0xa8)
> > (__handle_domain_irq) from [<80508bc8>] (gic_handle_irq+0x4c/0x80)
> > (gic_handle_irq) from [<80100af0>] (__irq_svc+0x70/0x98)
> > Exception stack(0x8459fe80 to 0x8459fec8)
> > fe80: 72286b00 e3359f64 00000001 0000412d a0070013 85c98840
> > 85c98840 a0070013
> > fea0: 8054e0d4 00000000 00000002 00000000 00000002 8459fed0
> > 8081fbe8 8081fbec
> > fec0: 60070013 ffffffff
> > (__irq_svc) from [<8081fbec>]
> > (_raw_spin_unlock_irqrestore+0x30/0x58)
> > (_raw_spin_unlock_irqrestore) from [<8056cb48>]
> > (uart_flush_buffer+0x88/0xf8)
> > (uart_flush_buffer) from [<80554e60>] (tty_ldisc_hangup+0x38/0x1ac)
> > (tty_ldisc_hangup) from [<8054c7f4>] (__tty_hangup+0x158/0x2bc)
> > (__tty_hangup) from [<80557b90>]
> > (disassociate_ctty.part.1+0x30/0x23c)
> > (disassociate_ctty.part.1) from [<8011fc18>] (do_exit+0x580/0xba0)
> > (do_exit) from [<801214f8>] (do_group_exit+0x3c/0xb4)
> > (do_group_exit) from [<80121580>] (__wake_up_parent+0x0/0x14)
> >
> > Issue looks like race condition between interrupt handler fsl_edma_tx_handler()
> > (called as result of fsl_edma_xfer_desc()) and terminating the transfer with
> > fsl_edma_terminate_all().
> >
> > The fsl_edma_tx_handler() handles interrupt for a transfer with already freed
> > edesc and idle==true.
> >
> > Fixes: d6be34fbd39b ("dma: Add Freescale eDMA engine driver support")
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> > ---
> > drivers/dma/fsl-edma.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c index
> > eff7ebd8cf35..90bb72af306c 100644
> > --- a/drivers/dma/fsl-edma.c
> > +++ b/drivers/dma/fsl-edma.c
> > @@ -45,6 +45,13 @@ static irqreturn_t fsl_edma_tx_handler(int irq, void
> > *dev_id)
> > fsl_chan = &fsl_edma->chans[ch];
> >
> > spin_lock(&fsl_chan->vchan.lock);
> > +
> > + if (!fsl_chan->edesc) {
> Would you like fix the same potential issue in mcf_edma_tx_handler()
> of mcf-edma.c?
Sure. I'll make another commit as it should be backported to different
kernel.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] dmaengine: mcf-edma: Fix NULL pointer exception in mcf_edma_tx_handler
2020-06-11 12:17 ` [PATCH 2/2] dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler Krzysztof Kozlowski
2020-06-11 13:04 ` Robin Gong
@ 2020-06-11 13:21 ` Krzysztof Kozlowski
2020-06-12 2:20 ` Robin Gong
2020-06-12 2:22 ` [PATCH 2/2] dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler Robin Gong
2 siblings, 1 reply; 6+ messages in thread
From: Krzysztof Kozlowski @ 2020-06-11 13:21 UTC (permalink / raw)
To: Vinod Koul, Dan Williams, Angelo Dureghello, dmaengine,
linux-kernel
Cc: Robin Gong, Peng Ma, Fabio Estevam, Krzysztof Kozlowski, stable
On Toradex Colibri VF50 (Vybrid VF5xx) with fsl-edma driver NULL pointer
exception happens occasionally on serial output initiated by login
timeout.
This was reproduced only if kernel was built with significant debugging
options and EDMA driver is used with serial console.
Issue looks like a race condition between interrupt handler
fsl_edma_tx_handler() (called as a result of fsl_edma_xfer_desc()) and
terminating the transfer with fsl_edma_terminate_all().
The fsl_edma_tx_handler() handles interrupt for a transfer with already
freed edesc and idle==true.
The mcf-edma driver shares design and lot of code with fsl-edma. It
looks like being affected by same problem. Fix this pattern the same
way as fix for fsl-edma driver.
Fixes: e7a3ff92eaf1 ("dmaengine: fsl-edma: add ColdFire mcf5441x edma support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Not tested on HW.
---
drivers/dma/mcf-edma.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/dma/mcf-edma.c b/drivers/dma/mcf-edma.c
index e15bd15a9ef6..e12b754e6398 100644
--- a/drivers/dma/mcf-edma.c
+++ b/drivers/dma/mcf-edma.c
@@ -35,6 +35,13 @@ static irqreturn_t mcf_edma_tx_handler(int irq, void *dev_id)
mcf_chan = &mcf_edma->chans[ch];
spin_lock(&mcf_chan->vchan.lock);
+
+ if (!mcf_chan->edesc) {
+ /* terminate_all called before */
+ spin_unlock(&mcf_chan->vchan.lock);
+ continue;
+ }
+
if (!mcf_chan->edesc->iscyclic) {
list_del(&mcf_chan->edesc->vdesc.node);
vchan_cookie_complete(&mcf_chan->edesc->vdesc);
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* RE: [PATCH] dmaengine: mcf-edma: Fix NULL pointer exception in mcf_edma_tx_handler
2020-06-11 13:21 ` [PATCH] dmaengine: mcf-edma: Fix NULL pointer exception in mcf_edma_tx_handler Krzysztof Kozlowski
@ 2020-06-12 2:20 ` Robin Gong
0 siblings, 0 replies; 6+ messages in thread
From: Robin Gong @ 2020-06-12 2:20 UTC (permalink / raw)
To: Krzysztof Kozlowski, Vinod Koul, Dan Williams, Angelo Dureghello,
dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Peng Ma, Fabio Estevam, stable@vger.kernel.org
On 2020/06/11 Krzysztof Kozlowski <krzk@kernel.org> wrote:
> On Toradex Colibri VF50 (Vybrid VF5xx) with fsl-edma driver NULL pointer
> exception happens occasionally on serial output initiated by login timeout.
>
> This was reproduced only if kernel was built with significant debugging options
> and EDMA driver is used with serial console.
>
> Issue looks like a race condition between interrupt handler
> fsl_edma_tx_handler() (called as a result of fsl_edma_xfer_desc()) and
> terminating the transfer with fsl_edma_terminate_all().
>
> The fsl_edma_tx_handler() handles interrupt for a transfer with already freed
> edesc and idle==true.
>
> The mcf-edma driver shares design and lot of code with fsl-edma. It looks like
> being affected by same problem. Fix this pattern the same way as fix for
> fsl-edma driver.
>
> Fixes: e7a3ff92eaf1 ("dmaengine: fsl-edma: add ColdFire mcf5441x edma
> support")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Robin Gong <yibin.gong@nxp.com>
>
> ---
>
> Not tested on HW.
> ---
> drivers/dma/mcf-edma.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/dma/mcf-edma.c b/drivers/dma/mcf-edma.c index
> e15bd15a9ef6..e12b754e6398 100644
> --- a/drivers/dma/mcf-edma.c
> +++ b/drivers/dma/mcf-edma.c
> @@ -35,6 +35,13 @@ static irqreturn_t mcf_edma_tx_handler(int irq, void
> *dev_id)
> mcf_chan = &mcf_edma->chans[ch];
>
> spin_lock(&mcf_chan->vchan.lock);
> +
> + if (!mcf_chan->edesc) {
> + /* terminate_all called before */
> + spin_unlock(&mcf_chan->vchan.lock);
> + continue;
> + }
> +
> if (!mcf_chan->edesc->iscyclic) {
> list_del(&mcf_chan->edesc->vdesc.node);
> vchan_cookie_complete(&mcf_chan->edesc->vdesc);
> --
> 2.7.4
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH 2/2] dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler
2020-06-11 12:17 ` [PATCH 2/2] dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler Krzysztof Kozlowski
2020-06-11 13:04 ` Robin Gong
2020-06-11 13:21 ` [PATCH] dmaengine: mcf-edma: Fix NULL pointer exception in mcf_edma_tx_handler Krzysztof Kozlowski
@ 2020-06-12 2:22 ` Robin Gong
2 siblings, 0 replies; 6+ messages in thread
From: Robin Gong @ 2020-06-12 2:22 UTC (permalink / raw)
To: Krzysztof Kozlowski, Vinod Koul, Dan Williams, Peng Ma,
Fabio Estevam, dmaengine@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
On 2020/06/11 20:18 Krzysztof Kozlowski <krzk@kernel.org> wrote:
> NULL pointer exception happens occasionally on serial output initiated by login
> timeout. This was reproduced only if kernel was built with significant
> debugging options and EDMA driver is used with serial console.
>
> col-vf50 login: root
> Password:
> Login timed out after 60 seconds.
> Unable to handle kernel NULL pointer dereference at virtual address
> 00000044
> Internal error: Oops: 5 [#1] ARM
> CPU: 0 PID: 157 Comm: login Not tainted 5.7.0-next-20200610-dirty #4
> Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
> (fsl_edma_tx_handler) from [<8016eb10>]
> (__handle_irq_event_percpu+0x64/0x304)
> (__handle_irq_event_percpu) from [<8016eddc>]
> (handle_irq_event_percpu+0x2c/0x7c)
> (handle_irq_event_percpu) from [<8016ee64>]
> (handle_irq_event+0x38/0x5c)
> (handle_irq_event) from [<801729e4>]
> (handle_fasteoi_irq+0xa4/0x160)
> (handle_fasteoi_irq) from [<8016ddcc>]
> (generic_handle_irq+0x34/0x44)
> (generic_handle_irq) from [<8016e40c>]
> (__handle_domain_irq+0x54/0xa8)
> (__handle_domain_irq) from [<80508bc8>] (gic_handle_irq+0x4c/0x80)
> (gic_handle_irq) from [<80100af0>] (__irq_svc+0x70/0x98)
> Exception stack(0x8459fe80 to 0x8459fec8)
> fe80: 72286b00 e3359f64 00000001 0000412d a0070013 85c98840
> 85c98840 a0070013
> fea0: 8054e0d4 00000000 00000002 00000000 00000002 8459fed0
> 8081fbe8 8081fbec
> fec0: 60070013 ffffffff
> (__irq_svc) from [<8081fbec>]
> (_raw_spin_unlock_irqrestore+0x30/0x58)
> (_raw_spin_unlock_irqrestore) from [<8056cb48>]
> (uart_flush_buffer+0x88/0xf8)
> (uart_flush_buffer) from [<80554e60>] (tty_ldisc_hangup+0x38/0x1ac)
> (tty_ldisc_hangup) from [<8054c7f4>] (__tty_hangup+0x158/0x2bc)
> (__tty_hangup) from [<80557b90>]
> (disassociate_ctty.part.1+0x30/0x23c)
> (disassociate_ctty.part.1) from [<8011fc18>] (do_exit+0x580/0xba0)
> (do_exit) from [<801214f8>] (do_group_exit+0x3c/0xb4)
> (do_group_exit) from [<80121580>] (__wake_up_parent+0x0/0x14)
>
> Issue looks like race condition between interrupt handler fsl_edma_tx_handler()
> (called as result of fsl_edma_xfer_desc()) and terminating the transfer with
> fsl_edma_terminate_all().
>
> The fsl_edma_tx_handler() handles interrupt for a transfer with already freed
> edesc and idle==true.
>
> Fixes: d6be34fbd39b ("dma: Add Freescale eDMA engine driver support")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> ---
> drivers/dma/fsl-edma.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c index
> eff7ebd8cf35..90bb72af306c 100644
> --- a/drivers/dma/fsl-edma.c
> +++ b/drivers/dma/fsl-edma.c
> @@ -45,6 +45,13 @@ static irqreturn_t fsl_edma_tx_handler(int irq, void
> *dev_id)
> fsl_chan = &fsl_edma->chans[ch];
>
> spin_lock(&fsl_chan->vchan.lock);
> +
> + if (!fsl_chan->edesc) {
> + /* terminate_all called before */
> + spin_unlock(&fsl_chan->vchan.lock);
> + continue;
> + }
Reviewed-by: Robin Gong <yibin.gong@nxp.com>
> +
> if (!fsl_chan->edesc->iscyclic) {
> list_del(&fsl_chan->edesc->vdesc.node);
> vchan_cookie_complete(&fsl_chan->edesc->vdesc);
> --
> 2.7.4
^ permalink raw reply [flat|nested] 6+ messages in thread