* [PATCH kernel] powerpc/powernv/ioda: Fix endianness when reading TCEs
@ 2016-07-20 4:26 Alexey Kardashevskiy
2016-07-20 9:16 ` David Gibson
2016-07-22 5:50 ` [kernel] " Michael Ellerman
0 siblings, 2 replies; 3+ messages in thread
From: Alexey Kardashevskiy @ 2016-07-20 4:26 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Alexey Kardashevskiy, David Gibson, stable, #, 4.2+
The iommu_table_ops::exchange() callback writes new TCE to the table
and returns old value and permission mask. The old TCE value is
correctly converted from BE to CPU endian; however permission mask
was calculated from BE value and therefore always returned DMA_NONE
which could cause memory leak on LE systems using VFIO SPAPR TCE IOMMU v1
driver.
This fixes pnv_tce_xchg() to have @oldtce a CPU endian.
Fixes: 05c6cfb9dce0d13d37e9d007ee6a4af36f1c0a58
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
arch/powerpc/platforms/powernv/pci.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 1d92bd9..7b17f88 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -620,8 +620,8 @@ int pnv_tce_xchg(struct iommu_table *tbl, long index,
if (newtce & TCE_PCI_WRITE)
newtce |= TCE_PCI_READ;
- oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
- *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ | TCE_PCI_WRITE);
+ oldtce = be64_to_cpu(xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce)));
+ *hpa = oldtce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
*direction = iommu_tce_direction(oldtce);
return 0;
--
2.5.0.rc3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH kernel] powerpc/powernv/ioda: Fix endianness when reading TCEs
2016-07-20 4:26 [PATCH kernel] powerpc/powernv/ioda: Fix endianness when reading TCEs Alexey Kardashevskiy
@ 2016-07-20 9:16 ` David Gibson
2016-07-22 5:50 ` [kernel] " Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: David Gibson @ 2016-07-20 9:16 UTC (permalink / raw)
To: Alexey Kardashevskiy; +Cc: linuxppc-dev, stable, #, 4.2+
[-- Attachment #1: Type: text/plain, Size: 1702 bytes --]
On Wed, Jul 20, 2016 at 02:26:51PM +1000, Alexey Kardashevskiy wrote:
> The iommu_table_ops::exchange() callback writes new TCE to the table
> and returns old value and permission mask. The old TCE value is
> correctly converted from BE to CPU endian; however permission mask
> was calculated from BE value and therefore always returned DMA_NONE
> which could cause memory leak on LE systems using VFIO SPAPR TCE IOMMU v1
> driver.
>
> This fixes pnv_tce_xchg() to have @oldtce a CPU endian.
>
> Fixes: 05c6cfb9dce0d13d37e9d007ee6a4af36f1c0a58
> Cc: stable@vger.kernel.org # 4.2+
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> arch/powerpc/platforms/powernv/pci.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
> index 1d92bd9..7b17f88 100644
> --- a/arch/powerpc/platforms/powernv/pci.c
> +++ b/arch/powerpc/platforms/powernv/pci.c
> @@ -620,8 +620,8 @@ int pnv_tce_xchg(struct iommu_table *tbl, long index,
> if (newtce & TCE_PCI_WRITE)
> newtce |= TCE_PCI_READ;
>
> - oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
> - *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ | TCE_PCI_WRITE);
> + oldtce = be64_to_cpu(xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce)));
> + *hpa = oldtce & ~(TCE_PCI_READ | TCE_PCI_WRITE);
> *direction = iommu_tce_direction(oldtce);
>
> return 0;
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [kernel] powerpc/powernv/ioda: Fix endianness when reading TCEs
2016-07-20 4:26 [PATCH kernel] powerpc/powernv/ioda: Fix endianness when reading TCEs Alexey Kardashevskiy
2016-07-20 9:16 ` David Gibson
@ 2016-07-22 5:50 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2016-07-22 5:50 UTC (permalink / raw)
To: Alexey Kardashevskiy, linuxppc-dev
Cc: Alexey Kardashevskiy, #, 4.2+, stable, David Gibson
On Wed, 2016-20-07 at 04:26:51 UTC, Alexey Kardashevskiy wrote:
> The iommu_table_ops::exchange() callback writes new TCE to the table
> and returns old value and permission mask. The old TCE value is
> correctly converted from BE to CPU endian; however permission mask
> was calculated from BE value and therefore always returned DMA_NONE
> which could cause memory leak on LE systems using VFIO SPAPR TCE IOMMU v1
> driver.
>
> This fixes pnv_tce_xchg() to have @oldtce a CPU endian.
>
> Fixes: 05c6cfb9dce0d13d37e9d007ee6a4af36f1c0a58
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/802a345183c0308aa64969cca6
cheers
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-07-20 9:16 ` David Gibson
2016-07-22 5:50 ` [kernel] " Michael Ellerman
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