Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1707967 > unrolled thread

[PATCH v7 7/9] mm: Add address parameter to arch_validate_prot()

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH v7 7/9] mm: Add address parameter to arch_validate_prot() Khalid Aziz <khalid.aziz@oracle.com> - 2017-08-09 23:30 +0200
    Re: [PATCH v7 7/9] mm: Add address parameter to arch_validate_prot() Michael Ellerman <mpe@ellerman.id.au> - 2017-08-10 15:30 +0200
      Re: [PATCH v7 7/9] mm: Add address parameter to arch_validate_prot() Khalid Aziz <khalid.aziz@oracle.com> - 2017-08-10 16:50 +0200

#1707967 — [PATCH v7 7/9] mm: Add address parameter to arch_validate_prot()

A protection flag may not be valid across entire address space and
hence arch_validate_prot() might need the address a protection bit is
being set on to ensure it is a valid protection flag. For example, sparc
processors support memory corruption detection (as part of ADI feature)
flag on memory addresses mapped on to physical RAM but not on PFN mapped
pages or addresses mapped on to devices. This patch adds address to the
parameters being passed to arch_validate_prot() so protection bits can
be validated in the relevant context.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
---
v7:
	- new patch

 arch/powerpc/include/asm/mman.h | 2 +-
 arch/powerpc/kernel/syscalls.c  | 2 +-
 include/linux/mman.h            | 2 +-
 mm/mprotect.c                   | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 30922f699341..bc74074304a2 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -40,7 +40,7 @@ static inline bool arch_validate_prot(unsigned long prot)
 		return false;
 	return true;
 }
-#define arch_validate_prot(prot) arch_validate_prot(prot)
+#define arch_validate_prot(prot, addr) arch_validate_prot(prot)
 
 #endif /* CONFIG_PPC64 */
 #endif	/* _ASM_POWERPC_MMAN_H */
diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index a877bf8269fe..6d90ddbd2d11 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -48,7 +48,7 @@ static inline long do_mmap2(unsigned long addr, size_t len,
 {
 	long ret = -EINVAL;
 
-	if (!arch_validate_prot(prot))
+	if (!arch_validate_prot(prot, addr))
 		goto out;
 
 	if (shift) {
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 634c4c51fe3a..1693d95a88ee 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -49,7 +49,7 @@ static inline void vm_unacct_memory(long pages)
  *
  * Returns true if the prot flags are valid
  */
-static inline bool arch_validate_prot(unsigned long prot)
+static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
 {
 	return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
 }
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 8edd0d576254..beac2dfbb5fa 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -396,7 +396,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 	end = start + len;
 	if (end <= start)
 		return -ENOMEM;
-	if (!arch_validate_prot(prot))
+	if (!arch_validate_prot(prot, start))
 		return -EINVAL;
 
 	reqprot = prot;
-- 
2.11.0

[toc] | [next] | [standalone]

#1708631

Khalid Aziz <khalid.aziz@oracle.com> writes:

> A protection flag may not be valid across entire address space and
> hence arch_validate_prot() might need the address a protection bit is
> being set on to ensure it is a valid protection flag. For example, sparc
> processors support memory corruption detection (as part of ADI feature)
> flag on memory addresses mapped on to physical RAM but not on PFN mapped
> pages or addresses mapped on to devices. This patch adds address to the
> parameters being passed to arch_validate_prot() so protection bits can
> be validated in the relevant context.
>
> Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
> Cc: Khalid Aziz <khalid@gonehiking.org>
> ---
> v7:
> 	- new patch
>
>  arch/powerpc/include/asm/mman.h | 2 +-
>  arch/powerpc/kernel/syscalls.c  | 2 +-
>  include/linux/mman.h            | 2 +-
>  mm/mprotect.c                   | 2 +-
>  4 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
> index 30922f699341..bc74074304a2 100644
> --- a/arch/powerpc/include/asm/mman.h
> +++ b/arch/powerpc/include/asm/mman.h
> @@ -40,7 +40,7 @@ static inline bool arch_validate_prot(unsigned long prot)
>  		return false;
>  	return true;
>  }
> -#define arch_validate_prot(prot) arch_validate_prot(prot)
> +#define arch_validate_prot(prot, addr) arch_validate_prot(prot)

This can be simpler, as just:

#define arch_validate_prot arch_validate_prot

cheers

[toc] | [prev] | [next] | [standalone]

#1708689

On 08/10/2017 07:20 AM, Michael Ellerman wrote:
> Khalid Aziz <khalid.aziz@oracle.com> writes:
> 
>> A protection flag may not be valid across entire address space and
>> hence arch_validate_prot() might need the address a protection bit is
>> being set on to ensure it is a valid protection flag. For example, sparc
>> processors support memory corruption detection (as part of ADI feature)
>> flag on memory addresses mapped on to physical RAM but not on PFN mapped
>> pages or addresses mapped on to devices. This patch adds address to the
>> parameters being passed to arch_validate_prot() so protection bits can
>> be validated in the relevant context.
>>
>> Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
>> Cc: Khalid Aziz <khalid@gonehiking.org>
>> ---
>> v7:
>> 	- new patch
>>
>>   arch/powerpc/include/asm/mman.h | 2 +-
>>   arch/powerpc/kernel/syscalls.c  | 2 +-
>>   include/linux/mman.h            | 2 +-
>>   mm/mprotect.c                   | 2 +-
>>   4 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
>> index 30922f699341..bc74074304a2 100644
>> --- a/arch/powerpc/include/asm/mman.h
>> +++ b/arch/powerpc/include/asm/mman.h
>> @@ -40,7 +40,7 @@ static inline bool arch_validate_prot(unsigned long prot)
>>   		return false;
>>   	return true;
>>   }
>> -#define arch_validate_prot(prot) arch_validate_prot(prot)
>> +#define arch_validate_prot(prot, addr) arch_validate_prot(prot)
> 
> This can be simpler, as just:
> 
> #define arch_validate_prot arch_validate_prot
> 

Hi Michael,

Thanks for reviewing!

My patch expands parameter list for arch_validate_prot() from one to two 
parameters. Existing powerpc version of arch_validate_prot() is written 
with one parameter. If I use the above #define, compilation fails with:

mm/mprotect.c: In function ‘do_mprotect_pkey’:
mm/mprotect.c:399: error: too many arguments to function 
‘arch_validate_prot’

Another way to solve it would be to add the new addr parameter to 
powerpc version of arch_validate_prot() but I chose the less disruptive 
solution of tackling it through #define and expanded the existing 
#define to include the new parameter. Make sense?

Thanks,
Khalid

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web