From: Will Deacon <will.deacon@arm.com>
To: dmaengine@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Will Deacon <will.deacon@arm.com>,
Jassi Brar <jaswinder.singh@linaro.org>,
Vinod Koul <vinod.koul@intel.com>,
Dan Williams <dan.j.williams@intel.com>
Subject: [PATCH] dma: pl330: ensure DMA descriptors are zero-initialised
Date: Fri, 29 Nov 2013 11:50:28 +0000 [thread overview]
Message-ID: <1385725828-836-1-git-send-email-will.deacon@arm.com> (raw)
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
WARNING: multiple messages have this Message-ID (diff)
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] dma: pl330: ensure DMA descriptors are zero-initialised
Date: Fri, 29 Nov 2013 11:50:28 +0000 [thread overview]
Message-ID: <1385725828-836-1-git-send-email-will.deacon@arm.com> (raw)
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
next reply other threads:[~2013-11-29 11:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-29 11:50 Will Deacon [this message]
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 12:57 ` Shevchenko, Andriy
2013-11-29 14:41 ` Will Deacon
2013-11-29 14:41 ` Will Deacon
2013-11-29 15:18 ` Jassi Brar
2013-11-29 15:18 ` Jassi Brar
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