[PATCH v1 0/2] Misc fixes for ARM page table allocator (long/short descriptor format)

[PATCH v1 0/2] Misc fixes for ARM page table allocator (long/short descriptor format)

[Oleksandr Tyshchenko]

Hi.

There is a small patch series which contains the same fix for both
descriptor formats based on the preceding RFC patches:
https://lists.linuxfoundation.org/pipermail/iommu/2017-February/020411.html
https://lists.linuxfoundation.org/pipermail/iommu/2017-February/020477.html

Oleksandr Tyshchenko (2):
  iommu/io-pgtable-arm: Check for leaf entry before dereferencing it
  iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it

 drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
 drivers/iommu/io-pgtable-arm.c     | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

-- 
2.7.4

[PATCH v1 1/2] iommu/io-pgtable-arm: Check for leaf entry before dereferencing it

[Oleksandr Tyshchenko]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko-uRwfk40T5oI@public.gmane.org>

Do a check for already installed leaf entry at the current level before
dereferencing it in order to avoid walking the page table down with
wrong pointer to the next level.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko-uRwfk40T5oI@public.gmane.org>
CC: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
CC: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---
 drivers/iommu/io-pgtable-arm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index feacc54..f9bc6eb 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -335,8 +335,12 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
 		if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
 			pte |= ARM_LPAE_PTE_NSTABLE;
 		__arm_lpae_set_pte(ptep, pte, cfg);
-	} else {
+	} else if (!iopte_leaf(pte, lvl)) {
 		cptep = iopte_deref(pte, data);
+	} else {
+		/* We require an unmap first */
+		WARN_ON(!selftest_running);
+		return -EEXIST;
 	}
 
 	/* Rinse, repeat */
-- 
2.7.4

[PATCH v1 2/2] iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it

[Oleksandr Tyshchenko]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko-uRwfk40T5oI@public.gmane.org>

Do a check for already installed leaf entry at the current level before
dereferencing it in order to avoid walking the page table down with
wrong pointer to the next level.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko-uRwfk40T5oI@public.gmane.org>
CC: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
CC: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---
 drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 1c049e2..8d6ca28 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -422,8 +422,12 @@ static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova,
 			pte |= ARM_V7S_ATTR_NS_TABLE;
 
 		__arm_v7s_set_pte(ptep, pte, 1, cfg);
-	} else {
+	} else if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) {
 		cptep = iopte_deref(pte, lvl);
+	} else {
+		/* We require an unmap first */
+		WARN_ON(!selftest_running);
+		return -EEXIST;
 	}
 
 	/* Rinse, repeat */
-- 
2.7.4

Re: [PATCH v1 0/2] Misc fixes for ARM page table allocator (long/short descriptor format)

[Oleksandr Tyshchenko]

Hi, all.

Any comments?

On Mon, Feb 27, 2017 at 2:30 PM, Oleksandr Tyshchenko
<olekstysh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> Hi.
>
> There is a small patch series which contains the same fix for both
> descriptor formats based on the preceding RFC patches:
> https://lists.linuxfoundation.org/pipermail/iommu/2017-February/020411.html
> https://lists.linuxfoundation.org/pipermail/iommu/2017-February/020477.html
>
> Oleksandr Tyshchenko (2):
>   iommu/io-pgtable-arm: Check for leaf entry before dereferencing it
>   iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it
>
>  drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
>  drivers/iommu/io-pgtable-arm.c     | 6 +++++-
>  2 files changed, 10 insertions(+), 2 deletions(-)
>
> --
> 2.7.4
>



-- 
Regards,

Oleksandr Tyshchenko

Re: [PATCH v1 0/2] Misc fixes for ARM page table allocator (long/short descriptor format)

[Robin Murphy]

On 16/03/17 09:19, Oleksandr Tyshchenko wrote:
> Hi, all.
> 
> Any comments?

Er, no, but in a good way ;)

Patches look fine to me, and I see Will's already queued them anyway.

Thanks for the respin, and apologies for losing it in my inbox!

Robin.

> 
> On Mon, Feb 27, 2017 at 2:30 PM, Oleksandr Tyshchenko
> <olekstysh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>> Hi.
>>
>> There is a small patch series which contains the same fix for both
>> descriptor formats based on the preceding RFC patches:
>> https://lists.linuxfoundation.org/pipermail/iommu/2017-February/020411.html
>> https://lists.linuxfoundation.org/pipermail/iommu/2017-February/020477.html
>>
>> Oleksandr Tyshchenko (2):
>>   iommu/io-pgtable-arm: Check for leaf entry before dereferencing it
>>   iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it
>>
>>  drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
>>  drivers/iommu/io-pgtable-arm.c     | 6 +++++-
>>  2 files changed, 10 insertions(+), 2 deletions(-)
>>
>> --
>> 2.7.4
>>
> 
> 
> 

Re: [PATCH v1 0/2] Misc fixes for ARM page table allocator (long/short descriptor format)

[Oleksandr Tyshchenko]

On Thu, Mar 16, 2017 at 1:19 PM, Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org> wrote:
> On 16/03/17 09:19, Oleksandr Tyshchenko wrote:
>> Hi, all.
>>
>> Any comments?
>
> Er, no, but in a good way ;)
>
> Patches look fine to me, and I see Will's already queued them anyway.
>
> Thanks for the respin, and apologies for losing it in my inbox!
>
> Robin.

Great, thank you.

>
>>
>> On Mon, Feb 27, 2017 at 2:30 PM, Oleksandr Tyshchenko
>> <olekstysh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>>> Hi.
>>>
>>> There is a small patch series which contains the same fix for both
>>> descriptor formats based on the preceding RFC patches:
>>> https://lists.linuxfoundation.org/pipermail/iommu/2017-February/020411.html
>>> https://lists.linuxfoundation.org/pipermail/iommu/2017-February/020477.html
>>>
>>> Oleksandr Tyshchenko (2):
>>>   iommu/io-pgtable-arm: Check for leaf entry before dereferencing it
>>>   iommu/io-pgtable-arm-v7s: Check for leaf entry before dereferencing it
>>>
>>>  drivers/iommu/io-pgtable-arm-v7s.c | 6 +++++-
>>>  drivers/iommu/io-pgtable-arm.c     | 6 +++++-
>>>  2 files changed, 10 insertions(+), 2 deletions(-)
>>>
>>> --
>>> 2.7.4
>>>
>>
>>
>>
>



-- 
Regards,

Oleksandr Tyshchenko