[PATCH v4 1/1] iommu/arm-smmu: Do not access non-existing S2CR registers

[PATCH v4 1/1] iommu/arm-smmu: Do not access non-existing S2CR registers

[Olav Haugan]

The number of S2CR registers is not properly set when stream
matching is not supported. Fix this and add check that we do not try to
access outside of the number of S2CR regisrers.

Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
---
 drivers/iommu/arm-smmu.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 9fd8754d..1d06ca8 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -548,9 +548,18 @@ static int register_smmu_master(struct arm_smmu_device *smmu,
 	master->of_node			= masterspec->np;
 	master->cfg.num_streamids	= masterspec->args_count;
 
-	for (i = 0; i < master->cfg.num_streamids; ++i)
-		master->cfg.streamids[i] = masterspec->args[i];
-
+	for (i = 0; i < master->cfg.num_streamids; ++i) {
+		u16 streamid = masterspec->args[i];
+
+		if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH) &&
+		     (streamid >= smmu->num_mapping_groups)) {
+			dev_err(dev,
+				"stream ID for master device %s greater than maximum allowed (%d)\n",
+				masterspec->np->name, smmu->num_mapping_groups);
+			return -ERANGE;
+		}
+		master->cfg.streamids[i] = streamid;
+	}
 	return insert_smmu_master(smmu, master);
 }
 
@@ -1734,7 +1743,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
 
 	/* Mark all SMRn as invalid and all S2CRn as bypass */
 	for (i = 0; i < smmu->num_mapping_groups; ++i) {
-		writel_relaxed(~SMR_VALID, gr0_base + ARM_SMMU_GR0_SMR(i));
+		writel_relaxed(0, gr0_base + ARM_SMMU_GR0_SMR(i));
 		writel_relaxed(S2CR_TYPE_BYPASS,
 			gr0_base + ARM_SMMU_GR0_S2CR(i));
 	}
@@ -1875,6 +1884,9 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 		dev_notice(smmu->dev,
 			   "\tstream matching with %u register groups, mask 0x%x",
 			   smmu->num_mapping_groups, mask);
+	} else {
+		smmu->num_mapping_groups = (id >> ID0_NUMSIDB_SHIFT) &
+					   ID0_NUMSIDB_MASK;
 	}
 	smmu->idr[0] = id;
 
@@ -2011,6 +2023,10 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 		smmu->irqs[i] = irq;
 	}
 
+	err = arm_smmu_device_cfg_probe(smmu);
+	if (err)
+		return err;
+
 	i = 0;
 	smmu->masters = RB_ROOT;
 	while (!of_parse_phandle_with_args(dev->of_node, "mmu-masters",
@@ -2027,10 +2043,6 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 	}
 	dev_notice(dev, "registered %d master devices\n", i);
 
-	err = arm_smmu_device_cfg_probe(smmu);
-	if (err)
-		goto out_put_masters;
-
 	parse_driver_options(smmu);
 
 	if (smmu->version > 1 &&
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[PATCH v4 1/1] iommu/arm-smmu: Do not access non-existing S2CR registers

[Will Deacon]

Hi Olav,

On Sat, Aug 23, 2014 at 01:12:32AM +0100, Olav Haugan wrote:
> The number of S2CR registers is not properly set when stream
> matching is not supported. Fix this and add check that we do not try to
> access outside of the number of S2CR regisrers.

Sorry for the bother, but could you base this on either iommu/devel or
iommu/staging please? Now that the merge window is well and truly over, I
moved those branches forward, so you needn't worry about iommu/pci anymore
(which, as you pointed out, contains a bunch of WIP patches which should
hold-up useful fixes like this one).

Cheers,

Will

[PATCH v4 1/1] iommu/arm-smmu: Do not access non-existing S2CR registers

[Will Deacon]

On Tue, Aug 26, 2014 at 11:37:30AM +0100, Will Deacon wrote:
> On Sat, Aug 23, 2014 at 01:12:32AM +0100, Olav Haugan wrote:
> > The number of S2CR registers is not properly set when stream
> > matching is not supported. Fix this and add check that we do not try to
> > access outside of the number of S2CR regisrers.
> 
> Sorry for the bother, but could you base this on either iommu/devel or
> iommu/staging please? Now that the merge window is well and truly over, I
> moved those branches forward, so you needn't worry about iommu/pci anymore
> (which, as you pointed out, contains a bunch of WIP patches which should
> hold-up useful fixes like this one).

Actually, it looks like this was eaten by our sorry excuse for an email
service. I've managed to apply a version from the archive, thanks.

Will

[PATCH v4 1/1] iommu/arm-smmu: Do not access non-existing S2CR registers

[Olav Haugan]

On 8/28/2014 3:55 AM, Will Deacon wrote:
> On Tue, Aug 26, 2014 at 11:37:30AM +0100, Will Deacon wrote:
>> On Sat, Aug 23, 2014 at 01:12:32AM +0100, Olav Haugan wrote:
>>> The number of S2CR registers is not properly set when stream
>>> matching is not supported. Fix this and add check that we do not try to
>>> access outside of the number of S2CR regisrers.
>>
>> Sorry for the bother, but could you base this on either iommu/devel or
>> iommu/staging please? Now that the merge window is well and truly over, I
>> moved those branches forward, so you needn't worry about iommu/pci anymore
>> (which, as you pointed out, contains a bunch of WIP patches which should
>> hold-up useful fixes like this one).
> 
> Actually, it looks like this was eaten by our sorry excuse for an email
> service. I've managed to apply a version from the archive, thanks.
> 

Thanks Will. Sorry for the late reply. I have been OoO.

Thanks,

Olav

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