linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
* [PATCHv2 1/2] arm: Correct virt_addr_valid
@ 2013-12-16 19:01 Laura Abbott
  2013-12-16 19:01 ` [PATCHv2 2/2] arm64: " Laura Abbott
  2013-12-17 12:08 ` [PATCHv2 1/2] arm: " Will Deacon
  0 siblings, 2 replies; 6+ messages in thread
From: Laura Abbott @ 2013-12-16 19:01 UTC (permalink / raw)
  To: linux-arm-kernel

The definition of virt_addr_valid is that virt_addr_valid should
return true if and only if virt_to_page returns a valid pointer.
The current definition of virt_addr_valid only checks against the
virtual address range. There's no guarantee that just because a
virtual address falls bewteen PAGE_OFFSET and high_memory the
associated physical memory has a valid backing struct page. Follow
the example of other architectures and convert to pfn_valid to
verify that the virtual address is actually valid. The check for
an address between PAGE_OFFSET and high_memory is still necessary
as vmalloc/highmem addresses are not valid with virt_to_page.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
---
 arch/arm/include/asm/memory.h |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index 9ecccc8..6211df0 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -350,7 +350,8 @@ static inline __deprecated void *bus_to_virt(unsigned long x)
 #define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
 
 #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
-#define virt_addr_valid(kaddr)	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory)
+#define virt_addr_valid(kaddr)	(pfn_valid(__pa(kaddr) >> PAGE_SHIFT) && \
+	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory))
 
 #endif
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCHv2 2/2] arm64: Correct virt_addr_valid
  2013-12-16 19:01 [PATCHv2 1/2] arm: Correct virt_addr_valid Laura Abbott
@ 2013-12-16 19:01 ` Laura Abbott
  2013-12-17 12:00   ` Catalin Marinas
  2013-12-17 12:08 ` [PATCHv2 1/2] arm: " Will Deacon
  1 sibling, 1 reply; 6+ messages in thread
From: Laura Abbott @ 2013-12-16 19:01 UTC (permalink / raw)
  To: linux-arm-kernel

The definition of virt_addr_valid is that virt_addr_valid should
return true if and only if virt_to_page returns a valid pointer.
The current definition of virt_addr_valid only checks against the
virtual address range. There's no guarantee that just because a
virtual address falls bewteen PAGE_OFFSET and high_memory the
associated physical memory has a valid backing struct page. Follow
the example of other architectures and convert to pfn_valid to
verify that the virtual address is actually valid.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
---
 arch/arm64/include/asm/memory.h |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 3776217..b8ec776 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -146,8 +146,9 @@ static inline void *phys_to_virt(phys_addr_t x)
 #define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
 
 #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
-#define	virt_addr_valid(kaddr)	(((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
-				 ((void *)(kaddr) < (void *)high_memory))
+#define virt_addr_valid(kaddr)	(pfn_valid(__pa(kaddr) >> PAGE_SHIFT) && \
+	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory))
+
 
 #endif
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCHv2 2/2] arm64: Correct virt_addr_valid
  2013-12-16 19:01 ` [PATCHv2 2/2] arm64: " Laura Abbott
@ 2013-12-17 12:00   ` Catalin Marinas
  2013-12-18 18:20     ` Laura Abbott
  0 siblings, 1 reply; 6+ messages in thread
From: Catalin Marinas @ 2013-12-17 12:00 UTC (permalink / raw)
  To: linux-arm-kernel

On Mon, Dec 16, 2013 at 07:01:45PM +0000, Laura Abbott wrote:
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index 3776217..b8ec776 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -146,8 +146,9 @@ static inline void *phys_to_virt(phys_addr_t x)
>  #define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
>  
>  #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
> -#define	virt_addr_valid(kaddr)	(((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
> -				 ((void *)(kaddr) < (void *)high_memory))
> +#define virt_addr_valid(kaddr)	(pfn_valid(__pa(kaddr) >> PAGE_SHIFT) && \
> +	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory))
> +

I still think the original patch was fine for arm64, no need for
additional checks since we don't have highmem and __pa() is always
linear.

-- 
Catalin

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCHv2 1/2] arm: Correct virt_addr_valid
  2013-12-16 19:01 [PATCHv2 1/2] arm: Correct virt_addr_valid Laura Abbott
  2013-12-16 19:01 ` [PATCHv2 2/2] arm64: " Laura Abbott
@ 2013-12-17 12:08 ` Will Deacon
  1 sibling, 0 replies; 6+ messages in thread
From: Will Deacon @ 2013-12-17 12:08 UTC (permalink / raw)
  To: linux-arm-kernel

On Mon, Dec 16, 2013 at 07:01:44PM +0000, Laura Abbott wrote:
> The definition of virt_addr_valid is that virt_addr_valid should
> return true if and only if virt_to_page returns a valid pointer.
> The current definition of virt_addr_valid only checks against the
> virtual address range. There's no guarantee that just because a
> virtual address falls bewteen PAGE_OFFSET and high_memory the
> associated physical memory has a valid backing struct page. Follow
> the example of other architectures and convert to pfn_valid to
> verify that the virtual address is actually valid. The check for
> an address between PAGE_OFFSET and high_memory is still necessary
> as vmalloc/highmem addresses are not valid with virt_to_page.
> 
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Nicolas Pitre <nico@linaro.org>
> Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
> ---
>  arch/arm/include/asm/memory.h |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
> index 9ecccc8..6211df0 100644
> --- a/arch/arm/include/asm/memory.h
> +++ b/arch/arm/include/asm/memory.h
> @@ -350,7 +350,8 @@ static inline __deprecated void *bus_to_virt(unsigned long x)
>  #define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
>  
>  #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
> -#define virt_addr_valid(kaddr)	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory)
> +#define virt_addr_valid(kaddr)	(pfn_valid(__pa(kaddr) >> PAGE_SHIFT) && \
> +	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory))

Can you change the order of the check please, so that we do the quicker
lowmem range checks before the pfn_valid check? I know I backed down on the
latter being slow, but it's still slower than what we had before and
changing the order of the conjunction is easy to do.

Cheers,

Will

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCHv2 2/2] arm64: Correct virt_addr_valid
  2013-12-17 12:00   ` Catalin Marinas
@ 2013-12-18 18:20     ` Laura Abbott
  2013-12-18 18:30       ` Catalin Marinas
  0 siblings, 1 reply; 6+ messages in thread
From: Laura Abbott @ 2013-12-18 18:20 UTC (permalink / raw)
  To: linux-arm-kernel

On 12/17/2013 4:00 AM, Catalin Marinas wrote:
> On Mon, Dec 16, 2013 at 07:01:45PM +0000, Laura Abbott wrote:
>> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
>> index 3776217..b8ec776 100644
>> --- a/arch/arm64/include/asm/memory.h
>> +++ b/arch/arm64/include/asm/memory.h
>> @@ -146,8 +146,9 @@ static inline void *phys_to_virt(phys_addr_t x)
>>   #define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
>>
>>   #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
>> -#define	virt_addr_valid(kaddr)	(((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
>> -				 ((void *)(kaddr) < (void *)high_memory))
>> +#define virt_addr_valid(kaddr)	(pfn_valid(__pa(kaddr) >> PAGE_SHIFT) && \
>> +	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory))
>> +
>
> I still think the original patch was fine for arm64, no need for
> additional checks since we don't have highmem and __pa() is always
> linear.
>

Okay, do you want to go ahead and just take the previous version then?

Laura

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCHv2 2/2] arm64: Correct virt_addr_valid
  2013-12-18 18:20     ` Laura Abbott
@ 2013-12-18 18:30       ` Catalin Marinas
  0 siblings, 0 replies; 6+ messages in thread
From: Catalin Marinas @ 2013-12-18 18:30 UTC (permalink / raw)
  To: linux-arm-kernel

On Wed, Dec 18, 2013 at 06:20:32PM +0000, Laura Abbott wrote:
> On 12/17/2013 4:00 AM, Catalin Marinas wrote:
> > On Mon, Dec 16, 2013 at 07:01:45PM +0000, Laura Abbott wrote:
> >> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> >> index 3776217..b8ec776 100644
> >> --- a/arch/arm64/include/asm/memory.h
> >> +++ b/arch/arm64/include/asm/memory.h
> >> @@ -146,8 +146,9 @@ static inline void *phys_to_virt(phys_addr_t x)
> >>   #define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
> >>
> >>   #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
> >> -#define	virt_addr_valid(kaddr)	(((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
> >> -				 ((void *)(kaddr) < (void *)high_memory))
> >> +#define virt_addr_valid(kaddr)	(pfn_valid(__pa(kaddr) >> PAGE_SHIFT) && \
> >> +	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory))
> >> +
> >
> > I still think the original patch was fine for arm64, no need for
> > additional checks since we don't have highmem and __pa() is always
> > linear.
> 
> Okay, do you want to go ahead and just take the previous version then?

I already did (while Will is away ;)). Thanks.

-- 
Catalin

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2013-12-18 18:30 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-12-16 19:01 [PATCHv2 1/2] arm: Correct virt_addr_valid Laura Abbott
2013-12-16 19:01 ` [PATCHv2 2/2] arm64: " Laura Abbott
2013-12-17 12:00   ` Catalin Marinas
2013-12-18 18:20     ` Laura Abbott
2013-12-18 18:30       ` Catalin Marinas
2013-12-17 12:08 ` [PATCHv2 1/2] arm: " Will Deacon

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).