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* [PATCH] iommu/io-pgtable-arm-v7s: Don't check PHYS_OFFSET if RAMDOMIZE_BASE is enabled
@ 2018-12-12 13:02 Yong Wu
  2018-12-12 13:39 ` Robin Murphy
  0 siblings, 1 reply; 3+ messages in thread
From: Yong Wu @ 2018-12-12 13:02 UTC (permalink / raw)
  To: Robin Murphy, Will Deacon, Joerg Roedel, Matthias Brugger
  Cc: Tomasz Figa, linux-mediatek, srv_heupstream, linux-kernel,
	linux-arm-kernel, iommu, yong.wu, youlin.pei, Nicolas Boichat,
	CK Hu

If CONFIG_RANDOMIZE_BASE is enabled, the "memstart_addr" will be updated
randomly, then the PHYS_OFFSET may be random.

Fixes: 82db33dc5e49 ("iommu/io-pgtable-arm: Check for v7s-incapable
systems")
Reported-by: CK Hu <ck.hu@mediatek.com>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/io-pgtable-arm-v7s.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 445c3bd..70941e6 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -709,7 +709,7 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
 {
 	struct arm_v7s_io_pgtable *data;
 
-#ifdef PHYS_OFFSET
+#if defined(PHYS_OFFSET) && !defined(CONFIG_RANDOMIZE_BASE)
 	if (upper_32_bits(PHYS_OFFSET))
 		return NULL;
 #endif
-- 
1.9.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] iommu/io-pgtable-arm-v7s: Don't check PHYS_OFFSET if RAMDOMIZE_BASE is enabled
  2018-12-12 13:02 [PATCH] iommu/io-pgtable-arm-v7s: Don't check PHYS_OFFSET if RAMDOMIZE_BASE is enabled Yong Wu
@ 2018-12-12 13:39 ` Robin Murphy
  2018-12-13  2:24   ` Yong Wu
  0 siblings, 1 reply; 3+ messages in thread
From: Robin Murphy @ 2018-12-12 13:39 UTC (permalink / raw)
  To: Yong Wu, Will Deacon, Joerg Roedel, Matthias Brugger
  Cc: Tomasz Figa, linux-mediatek, srv_heupstream, linux-kernel,
	linux-arm-kernel, iommu, youlin.pei, Nicolas Boichat, CK Hu

On 12/12/2018 13:02, Yong Wu wrote:
> If CONFIG_RANDOMIZE_BASE is enabled, the "memstart_addr" will be updated
> randomly, then the PHYS_OFFSET may be random.

Oh, I hadn't ever realised that, good catch. However, since 29859aeb8a6e 
I think we should probably just remove this check altogether.

> Fixes: 82db33dc5e49 ("iommu/io-pgtable-arm: Check for v7s-incapable
> systems")

Note that this alone wouldn't be sufficient for stable prior to 4.18, 
since CONFIG_RANDOMIZE_BASE would then allow the original crash to 
happen again.

Robin.

> Reported-by: CK Hu <ck.hu@mediatek.com>
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
>   drivers/iommu/io-pgtable-arm-v7s.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
> index 445c3bd..70941e6 100644
> --- a/drivers/iommu/io-pgtable-arm-v7s.c
> +++ b/drivers/iommu/io-pgtable-arm-v7s.c
> @@ -709,7 +709,7 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
>   {
>   	struct arm_v7s_io_pgtable *data;
>   
> -#ifdef PHYS_OFFSET
> +#if defined(PHYS_OFFSET) && !defined(CONFIG_RANDOMIZE_BASE)
>   	if (upper_32_bits(PHYS_OFFSET))
>   		return NULL;
>   #endif
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] iommu/io-pgtable-arm-v7s: Don't check PHYS_OFFSET if RAMDOMIZE_BASE is enabled
  2018-12-12 13:39 ` Robin Murphy
@ 2018-12-13  2:24   ` Yong Wu
  0 siblings, 0 replies; 3+ messages in thread
From: Yong Wu @ 2018-12-13  2:24 UTC (permalink / raw)
  To: Robin Murphy
  Cc: Will Deacon, Joerg Roedel, Matthias Brugger, youlin.pei,
	Nicolas Boichat, srv_heupstream, linux-kernel, Tomasz Figa,
	iommu, linux-mediatek, CK Hu, linux-arm-kernel, Stephen Boyd

On Wed, 2018-12-12 at 13:39 +0000, Robin Murphy wrote:
> On 12/12/2018 13:02, Yong Wu wrote:
> > If CONFIG_RANDOMIZE_BASE is enabled, the "memstart_addr" will be updated
> > randomly, then the PHYS_OFFSET may be random.
> 
> Oh, I hadn't ever realised that, good catch. However, since 29859aeb8a6e 
> I think we should probably just remove this check altogether.

Thanks the hint. It looks that I only need revert 82db33dc5e49.

> 
> > Fixes: 82db33dc5e49 ("iommu/io-pgtable-arm: Check for v7s-incapable
> > systems")
> 
> Note that this alone wouldn't be sufficient for stable prior to 4.18, 
> since CONFIG_RANDOMIZE_BASE would then allow the original crash to 
> happen again.

Yes. the problem always exist. Nicolas is fixing this. I will delete the
tag here.

> 
> Robin.
> 
> > Reported-by: CK Hu <ck.hu@mediatek.com>
> > Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> > ---
> >   drivers/iommu/io-pgtable-arm-v7s.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
> > index 445c3bd..70941e6 100644
> > --- a/drivers/iommu/io-pgtable-arm-v7s.c
> > +++ b/drivers/iommu/io-pgtable-arm-v7s.c
> > @@ -709,7 +709,7 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
> >   {
> >   	struct arm_v7s_io_pgtable *data;
> >   
> > -#ifdef PHYS_OFFSET
> > +#if defined(PHYS_OFFSET) && !defined(CONFIG_RANDOMIZE_BASE)
> >   	if (upper_32_bits(PHYS_OFFSET))
> >   		return NULL;
> >   #endif
> > 
> 
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek



^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-12-13  2:24 UTC | newest]

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2018-12-12 13:02 [PATCH] iommu/io-pgtable-arm-v7s: Don't check PHYS_OFFSET if RAMDOMIZE_BASE is enabled Yong Wu
2018-12-12 13:39 ` Robin Murphy
2018-12-13  2:24   ` Yong Wu

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