* [PATCH] dma: pl330: ensure DMA descriptors are zero-initialised
@ 2013-11-29 11:50 Will Deacon
2013-11-29 12:57 ` Shevchenko, Andriy
2013-11-29 15:18 ` Jassi Brar
0 siblings, 2 replies; 4+ messages in thread
From: Will Deacon @ 2013-11-29 11:50 UTC (permalink / raw)
To: linux-arm-kernel
I see the following splat with 3.13-rc1 when attempting to perform DMA:
[ 253.004516] Alignment trap: not handling instruction e1902f9f at [<c0204b40>]
[ 253.004583] Unhandled fault: alignment exception (0x221) at 0xdfdfdfd7
[ 253.004646] Internal error: : 221 [#1] PREEMPT SMP ARM
[ 253.004691] Modules linked in: dmatest(+) [last unloaded: dmatest]
[ 253.004798] CPU: 0 PID: 671 Comm: kthreadd Not tainted 3.13.0-rc1+ #2
[ 253.004864] task: df9b0900 ti: df03e000 task.ti: df03e000
[ 253.004937] PC is at dmaengine_unmap_put+0x14/0x34
[ 253.005010] LR is at pl330_tasklet+0x3c8/0x550
[ 253.005087] pc : [<c0204b44>] lr : [<c0207478>] psr: a00e0193
[ 253.005087] sp : df03fe48 ip : 00000000 fp : df03bf18
[ 253.005178] r10: bf00e108 r9 : 00000001 r8 : 00000000
[ 253.005245] r7 : df837040 r6 : dfb41800 r5 : df837048 r4 : df837000
[ 253.005316] r3 : dfdfdfcf r2 : dfb41f80 r1 : df837048 r0 : dfdfdfd7
[ 253.005384] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
[ 253.005459] Control: 30c5387d Table: 9fb9ba80 DAC: fffffffd
[ 253.005520] Process kthreadd (pid: 671, stack limit = 0xdf03e248)
This is due to desc->txd.unmap containing garbage (uninitialised memory).
Rather than add another dummy initialisation to _init_desc, instead
ensure that the descriptors are zero-initialised during allocation and
remove the dummy, per-field initialisation.
Cc: Jassi Brar <jaswinder.singh@linaro.org>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
drivers/dma/pl330.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 98641eaca080..79e52a94f054 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2492,14 +2492,8 @@ static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx)
static inline void _init_desc(struct dma_pl330_desc *desc)
{
- desc->pchan = NULL;
desc->req.x = &desc->px;
desc->req.token = desc;
- desc->rqcfg.swap = SWAP_NO;
- desc->rqcfg.privileged = 0;
- desc->rqcfg.insnaccess = 0;
- desc->rqcfg.scctl = SCCTRL0;
- desc->rqcfg.dcctl = DCCTRL0;
desc->req.cfg = &desc->rqcfg;
desc->req.xfer_cb = dma_pl330_rqcb;
desc->txd.tx_submit = pl330_tx_submit;
@@ -2517,7 +2511,7 @@ static int add_desc(struct dma_pl330_dmac *pdmac, gfp_t flg, int count)
if (!pdmac)
return 0;
- desc = kmalloc(count * sizeof(*desc), flg);
+ desc = kzalloc(count * sizeof(*desc), flg);
if (!desc)
return 0;
--
1.8.2.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] dma: pl330: ensure DMA descriptors are zero-initialised
2013-11-29 11:50 [PATCH] dma: pl330: ensure DMA descriptors are zero-initialised Will Deacon
@ 2013-11-29 12:57 ` Shevchenko, Andriy
2013-11-29 14:41 ` Will Deacon
2013-11-29 15:18 ` Jassi Brar
1 sibling, 1 reply; 4+ messages in thread
From: Shevchenko, Andriy @ 2013-11-29 12:57 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, 2013-11-29 at 11:50 +0000, Will Deacon wrote:
> I see the following splat with 3.13-rc1 when attempting to perform DMA:
>
> [ 253.004516] Alignment trap: not handling instruction e1902f9f at [<c0204b40>]
> [ 253.004583] Unhandled fault: alignment exception (0x221) at 0xdfdfdfd7
> [ 253.004646] Internal error: : 221 [#1] PREEMPT SMP ARM
> [ 253.004691] Modules linked in: dmatest(+) [last unloaded: dmatest]
> [ 253.004798] CPU: 0 PID: 671 Comm: kthreadd Not tainted 3.13.0-rc1+ #2
> [ 253.004864] task: df9b0900 ti: df03e000 task.ti: df03e000
> [ 253.004937] PC is at dmaengine_unmap_put+0x14/0x34
> [ 253.005010] LR is at pl330_tasklet+0x3c8/0x550
> [ 253.005087] pc : [<c0204b44>] lr : [<c0207478>] psr: a00e0193
> [ 253.005087] sp : df03fe48 ip : 00000000 fp : df03bf18
> [ 253.005178] r10: bf00e108 r9 : 00000001 r8 : 00000000
> [ 253.005245] r7 : df837040 r6 : dfb41800 r5 : df837048 r4 : df837000
> [ 253.005316] r3 : dfdfdfcf r2 : dfb41f80 r1 : df837048 r0 : dfdfdfd7
> [ 253.005384] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
> [ 253.005459] Control: 30c5387d Table: 9fb9ba80 DAC: fffffffd
> [ 253.005520] Process kthreadd (pid: 671, stack limit = 0xdf03e248)
>
> This is due to desc->txd.unmap containing garbage (uninitialised memory).
>
> Rather than add another dummy initialisation to _init_desc, instead
> ensure that the descriptors are zero-initialised during allocation and
> remove the dummy, per-field initialisation.
>
> Cc: Jassi Brar <jaswinder.singh@linaro.org>
> Cc: Vinod Koul <vinod.koul@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> ---
> drivers/dma/pl330.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 98641eaca080..79e52a94f054 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -2492,14 +2492,8 @@ static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx)
>
> static inline void _init_desc(struct dma_pl330_desc *desc)
> {
> - desc->pchan = NULL;
> desc->req.x = &desc->px;
> desc->req.token = desc;
> - desc->rqcfg.swap = SWAP_NO;
> - desc->rqcfg.privileged = 0;
> - desc->rqcfg.insnaccess = 0;
> - desc->rqcfg.scctl = SCCTRL0;
> - desc->rqcfg.dcctl = DCCTRL0;
> desc->req.cfg = &desc->rqcfg;
> desc->req.xfer_cb = dma_pl330_rqcb;
> desc->txd.tx_submit = pl330_tx_submit;
> @@ -2517,7 +2511,7 @@ static int add_desc(struct dma_pl330_dmac *pdmac, gfp_t flg, int count)
> if (!pdmac)
> return 0;
>
> - desc = kmalloc(count * sizeof(*desc), flg);
> + desc = kzalloc(count * sizeof(*desc), flg);
Maybe kcalloc() ?
> if (!desc)
> return 0;
>
--
Andy Shevchenko <andriy.shevchenko@intel.com>
Intel Finland Oy
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^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] dma: pl330: ensure DMA descriptors are zero-initialised
2013-11-29 12:57 ` Shevchenko, Andriy
@ 2013-11-29 14:41 ` Will Deacon
0 siblings, 0 replies; 4+ messages in thread
From: Will Deacon @ 2013-11-29 14:41 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Nov 29, 2013 at 12:57:50PM +0000, Shevchenko, Andriy wrote:
> On Fri, 2013-11-29 at 11:50 +0000, Will Deacon wrote:
> > diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> > index 98641eaca080..79e52a94f054 100644
> > --- a/drivers/dma/pl330.c
> > +++ b/drivers/dma/pl330.c
> > @@ -2492,14 +2492,8 @@ static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx)
> >
> > static inline void _init_desc(struct dma_pl330_desc *desc)
> > {
> > - desc->pchan = NULL;
> > desc->req.x = &desc->px;
> > desc->req.token = desc;
> > - desc->rqcfg.swap = SWAP_NO;
> > - desc->rqcfg.privileged = 0;
> > - desc->rqcfg.insnaccess = 0;
> > - desc->rqcfg.scctl = SCCTRL0;
> > - desc->rqcfg.dcctl = DCCTRL0;
> > desc->req.cfg = &desc->rqcfg;
> > desc->req.xfer_cb = dma_pl330_rqcb;
> > desc->txd.tx_submit = pl330_tx_submit;
> > @@ -2517,7 +2511,7 @@ static int add_desc(struct dma_pl330_dmac *pdmac, gfp_t flg, int count)
> > if (!pdmac)
> > return 0;
> >
> > - desc = kmalloc(count * sizeof(*desc), flg);
> > + desc = kzalloc(count * sizeof(*desc), flg);
>
> Maybe kcalloc() ?
Yup, that could work. I'll include that in v2 pending any other comments.
Cheers,
Will
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] dma: pl330: ensure DMA descriptors are zero-initialised
2013-11-29 11:50 [PATCH] dma: pl330: ensure DMA descriptors are zero-initialised Will Deacon
2013-11-29 12:57 ` Shevchenko, Andriy
@ 2013-11-29 15:18 ` Jassi Brar
1 sibling, 0 replies; 4+ messages in thread
From: Jassi Brar @ 2013-11-29 15:18 UTC (permalink / raw)
To: linux-arm-kernel
Hi Will,
On Fri, Nov 29, 2013 at 5:20 PM, Will Deacon <will.deacon@arm.com> wrote:
>
> I see the following splat with 3.13-rc1 when attempting to perform DMA:
>
> [ 253.004516] Alignment trap: not handling instruction e1902f9f at [<c0204b40>]
> [ 253.004583] Unhandled fault: alignment exception (0x221) at 0xdfdfdfd7
> [ 253.004646] Internal error: : 221 [#1] PREEMPT SMP ARM
> [ 253.004691] Modules linked in: dmatest(+) [last unloaded: dmatest]
> [ 253.004798] CPU: 0 PID: 671 Comm: kthreadd Not tainted 3.13.0-rc1+ #2
> [ 253.004864] task: df9b0900 ti: df03e000 task.ti: df03e000
> [ 253.004937] PC is at dmaengine_unmap_put+0x14/0x34
> [ 253.005010] LR is at pl330_tasklet+0x3c8/0x550
> [ 253.005087] pc : [<c0204b44>] lr : [<c0207478>] psr: a00e0193
> [ 253.005087] sp : df03fe48 ip : 00000000 fp : df03bf18
> [ 253.005178] r10: bf00e108 r9 : 00000001 r8 : 00000000
> [ 253.005245] r7 : df837040 r6 : dfb41800 r5 : df837048 r4 : df837000
> [ 253.005316] r3 : dfdfdfcf r2 : dfb41f80 r1 : df837048 r0 : dfdfdfd7
> [ 253.005384] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
> [ 253.005459] Control: 30c5387d Table: 9fb9ba80 DAC: fffffffd
> [ 253.005520] Process kthreadd (pid: 671, stack limit = 0xdf03e248)
>
> This is due to desc->txd.unmap containing garbage (uninitialised memory).
>
> Rather than add another dummy initialisation to _init_desc, instead
> ensure that the descriptors are zero-initialised during allocation and
> remove the dummy, per-field initialisation.
>
> Cc: Jassi Brar <jaswinder.singh@linaro.org>
> Cc: Vinod Koul <vinod.koul@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> ---
> drivers/dma/pl330.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 98641eaca080..79e52a94f054 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -2492,14 +2492,8 @@ static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx)
>
> static inline void _init_desc(struct dma_pl330_desc *desc)
> {
> - desc->pchan = NULL;
> desc->req.x = &desc->px;
> desc->req.token = desc;
> - desc->rqcfg.swap = SWAP_NO;
> - desc->rqcfg.privileged = 0;
> - desc->rqcfg.insnaccess = 0;
> - desc->rqcfg.scctl = SCCTRL0;
> - desc->rqcfg.dcctl = DCCTRL0;
>
These happen to evaluate to 0, but for completeness sake they ought to
be initialized somewhere. Otherwise we might as well drop these
members.
However I don't strongly feel about either way. So whatever comes in v2...
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2013-11-29 15:18 ` Jassi Brar
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