Re: [PATCH V4 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

2022-04-10 Thread Christophe Leroy 


Le 11/04/2022 à 07:31, Anshuman Khandual a écrit :
> 
> 
> On 4/9/22 17:06, Christophe Leroy wrote:
>>
>>
>> Le 08/04/2022 à 14:53, Christophe Leroy a écrit :
>>>
>>>
>>> Le 07/04/2022 à 12:32, Anshuman Khandual a écrit :
 This defines and exports a platform specific custom vm_get_page_prot() via
 subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
 arch_vm_get_page_prot() as powerpc_vm_get_page_prot() and moves it near
 vm_get_page_prot().

 Cc: Michael Ellerman 
 Cc: Paul Mackerras 
 Cc: linuxppc-dev@lists.ozlabs.org
 Cc: linux-ker...@vger.kernel.org
 Signed-off-by: Anshuman Khandual 
 ---
    arch/powerpc/Kconfig    |  1 +
    arch/powerpc/include/asm/mman.h | 12 
    arch/powerpc/mm/mmap.c  | 26 ++
    3 files changed, 27 insertions(+), 12 deletions(-)

 diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
 index 174edabb74fa..eb9b6ddbf92f 100644
 --- a/arch/powerpc/Kconfig
 +++ b/arch/powerpc/Kconfig
 @@ -140,6 +140,7 @@ config PPC
    select ARCH_HAS_TICK_BROADCAST    if 
 GENERIC_CLOCKEVENTS_BROADCAST
    select ARCH_HAS_UACCESS_FLUSHCACHE
    select ARCH_HAS_UBSAN_SANITIZE_ALL
 +    select ARCH_HAS_VM_GET_PAGE_PROT
    select ARCH_HAVE_NMI_SAFE_CMPXCHG
    select ARCH_KEEP_MEMBLOCK
    select ARCH_MIGHT_HAVE_PC_PARPORT
 diff --git a/arch/powerpc/include/asm/mman.h 
 b/arch/powerpc/include/asm/mman.h
 index 7cb6d18f5cd6..1b024e64c8ec 100644
 --- a/arch/powerpc/include/asm/mman.h
 +++ b/arch/powerpc/include/asm/mman.h
 @@ -24,18 +24,6 @@ static inline unsigned long 
 arch_calc_vm_prot_bits(unsigned long prot,
    }
    #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, 
 pkey)
 -static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
 -{
 -#ifdef CONFIG_PPC_MEM_KEYS
 -    return (vm_flags & VM_SAO) ?
 -    __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
 -    __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
 -#else
 -    return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
 -#endif
 -}
 -#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
 -
    static inline bool arch_validate_prot(unsigned long prot, unsigned long 
 addr)
    {
    if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | 
 PROT_SAO))
 diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
 index c475cf810aa8..cd17bd6fa36b 100644
 --- a/arch/powerpc/mm/mmap.c
 +++ b/arch/powerpc/mm/mmap.c
 @@ -254,3 +254,29 @@ void arch_pick_mmap_layout(struct mm_struct *mm, 
 struct rlimit *rlim_stack)
    mm->get_unmapped_area = arch_get_unmapped_area_topdown;
    }
    }
 +
 +#ifdef CONFIG_PPC64
 +static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
 +{
 +#ifdef CONFIG_PPC_MEM_KEYS
 +    return (vm_flags & VM_SAO) ?
 +    __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
 +    __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
 +#else
 +    return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
 +#endif
 +}
 +#else
 +static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
 +{
 +    return __pgprot(0);
 +}
 +#endif /* CONFIG_PPC64 */
>>>
>>> Can we reduce this forest of #ifdefs and make it more readable ?
>>>
>>> mm/mmap.c is going away with patch 
>>> https://patchwork.ozlabs.org/project/linuxppc-dev/patch/d6d849621f821af253e777a24eda4c648814a76e.1646847562.git.christophe.le...@csgroup.eu/
>>>
>>> So it would be better to add two versions of vm_get_page_prot(), for 
>>> instance one in mm/pgtable_64.c and one in mm/pgtable_32.c
>>
>> Indeed, you don't need anything at all for PPC32. All you need to do is
>>
>>  select ARCH_HAS_VM_GET_PAGE_PROT if PPC64
>>
>> And in fact it could even be PPC_BOOK3S_64 instead of PPC64 because 
>> CONFIG_PPC_MEM_KEYS depends on PPC_BOOK3S_64 and _PAGE_SAO is 0 on nohash/64.
>>
>> So you can then put it into arch/powerpc/mm/book3s64/pgtable.c
> 
> Would something like the following change work ?

Yes that looks good to me.

Thanks
Christophe

> 
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index eb9b6ddbf92f..69e44358a235 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -140,7 +140,7 @@ config PPC
>  select ARCH_HAS_TICK_BROADCAST  if 
> GENERIC_CLOCKEVENTS_BROADCAST
>  select ARCH_HAS_UACCESS_FLUSHCACHE
>  select ARCH_HAS_UBSAN_SANITIZE_ALL
> -   select ARCH_HAS_VM_GET_PAGE_PROT
> +   select ARCH_HAS_VM_GET_PAGE_PROTif PPC_BOOK3S_64
>  select ARCH_HAVE_NMI_SAFE_CMPXCHG
>  select ARCH_KEEP_MEMBLOCK
>  select

Re: [PATCH V4 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

2022-04-10 Thread Anshuman Khandual 



On 4/9/22 17:06, Christophe Leroy wrote:
> 
> 
> Le 08/04/2022 à 14:53, Christophe Leroy a écrit :
>>
>>
>> Le 07/04/2022 à 12:32, Anshuman Khandual a écrit :
>>> This defines and exports a platform specific custom vm_get_page_prot() via
>>> subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
>>> arch_vm_get_page_prot() as powerpc_vm_get_page_prot() and moves it near
>>> vm_get_page_prot().
>>>
>>> Cc: Michael Ellerman 
>>> Cc: Paul Mackerras 
>>> Cc: linuxppc-dev@lists.ozlabs.org
>>> Cc: linux-ker...@vger.kernel.org
>>> Signed-off-by: Anshuman Khandual 
>>> ---
>>>   arch/powerpc/Kconfig    |  1 +
>>>   arch/powerpc/include/asm/mman.h | 12 
>>>   arch/powerpc/mm/mmap.c  | 26 ++
>>>   3 files changed, 27 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>> index 174edabb74fa..eb9b6ddbf92f 100644
>>> --- a/arch/powerpc/Kconfig
>>> +++ b/arch/powerpc/Kconfig
>>> @@ -140,6 +140,7 @@ config PPC
>>>   select ARCH_HAS_TICK_BROADCAST    if GENERIC_CLOCKEVENTS_BROADCAST
>>>   select ARCH_HAS_UACCESS_FLUSHCACHE
>>>   select ARCH_HAS_UBSAN_SANITIZE_ALL
>>> +    select ARCH_HAS_VM_GET_PAGE_PROT
>>>   select ARCH_HAVE_NMI_SAFE_CMPXCHG
>>>   select ARCH_KEEP_MEMBLOCK
>>>   select ARCH_MIGHT_HAVE_PC_PARPORT
>>> diff --git a/arch/powerpc/include/asm/mman.h 
>>> b/arch/powerpc/include/asm/mman.h
>>> index 7cb6d18f5cd6..1b024e64c8ec 100644
>>> --- a/arch/powerpc/include/asm/mman.h
>>> +++ b/arch/powerpc/include/asm/mman.h
>>> @@ -24,18 +24,6 @@ static inline unsigned long 
>>> arch_calc_vm_prot_bits(unsigned long prot,
>>>   }
>>>   #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, 
>>> pkey)
>>> -static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
>>> -{
>>> -#ifdef CONFIG_PPC_MEM_KEYS
>>> -    return (vm_flags & VM_SAO) ?
>>> -    __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
>>> -    __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
>>> -#else
>>> -    return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
>>> -#endif
>>> -}
>>> -#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
>>> -
>>>   static inline bool arch_validate_prot(unsigned long prot, unsigned long 
>>> addr)
>>>   {
>>>   if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | 
>>> PROT_SAO))
>>> diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
>>> index c475cf810aa8..cd17bd6fa36b 100644
>>> --- a/arch/powerpc/mm/mmap.c
>>> +++ b/arch/powerpc/mm/mmap.c
>>> @@ -254,3 +254,29 @@ void arch_pick_mmap_layout(struct mm_struct *mm, 
>>> struct rlimit *rlim_stack)
>>>   mm->get_unmapped_area = arch_get_unmapped_area_topdown;
>>>   }
>>>   }
>>> +
>>> +#ifdef CONFIG_PPC64
>>> +static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
>>> +{
>>> +#ifdef CONFIG_PPC_MEM_KEYS
>>> +    return (vm_flags & VM_SAO) ?
>>> +    __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
>>> +    __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
>>> +#else
>>> +    return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
>>> +#endif
>>> +}
>>> +#else
>>> +static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
>>> +{
>>> +    return __pgprot(0);
>>> +}
>>> +#endif /* CONFIG_PPC64 */
>>
>> Can we reduce this forest of #ifdefs and make it more readable ?
>>
>> mm/mmap.c is going away with patch 
>> https://patchwork.ozlabs.org/project/linuxppc-dev/patch/d6d849621f821af253e777a24eda4c648814a76e.1646847562.git.christophe.le...@csgroup.eu/
>>
>> So it would be better to add two versions of vm_get_page_prot(), for 
>> instance one in mm/pgtable_64.c and one in mm/pgtable_32.c
> 
> Indeed, you don't need anything at all for PPC32. All you need to do is
> 
> select ARCH_HAS_VM_GET_PAGE_PROT if PPC64
> 
> And in fact it could even be PPC_BOOK3S_64 instead of PPC64 because 
> CONFIG_PPC_MEM_KEYS depends on PPC_BOOK3S_64 and _PAGE_SAO is 0 on nohash/64.
> 
> So you can then put it into arch/powerpc/mm/book3s64/pgtable.c

Would something like the following change work ?

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index eb9b6ddbf92f..69e44358a235 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -140,7 +140,7 @@ config PPC
select ARCH_HAS_TICK_BROADCAST  if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
select ARCH_HAS_UBSAN_SANITIZE_ALL
-   select ARCH_HAS_VM_GET_PAGE_PROT
+   select ARCH_HAS_VM_GET_PAGE_PROTif PPC_BOOK3S_64
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
select ARCH_MIGHT_HAVE_PC_PARPORT
diff --git a/arch/powerpc/mm/book3s64/pgtable.c 
b/arch/powerpc/mm/book3s64/pgtable.c
index 052e6590f84f..59d235519b44 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -7,6 +7,7 @@
 #include 
 #include 
 #include

Re: [PATCH V4 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

2022-04-09 Thread Christophe Leroy 




Le 08/04/2022 à 14:53, Christophe Leroy a écrit :



Le 07/04/2022 à 12:32, Anshuman Khandual a écrit :
This defines and exports a platform specific custom vm_get_page_prot() 
via

subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
arch_vm_get_page_prot() as powerpc_vm_get_page_prot() and moves it near
vm_get_page_prot().

Cc: Michael Ellerman 
Cc: Paul Mackerras 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-ker...@vger.kernel.org
Signed-off-by: Anshuman Khandual 
---
  arch/powerpc/Kconfig    |  1 +
  arch/powerpc/include/asm/mman.h | 12 
  arch/powerpc/mm/mmap.c  | 26 ++
  3 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 174edabb74fa..eb9b6ddbf92f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -140,6 +140,7 @@ config PPC
  select ARCH_HAS_TICK_BROADCAST    if 
GENERIC_CLOCKEVENTS_BROADCAST

  select ARCH_HAS_UACCESS_FLUSHCACHE
  select ARCH_HAS_UBSAN_SANITIZE_ALL
+    select ARCH_HAS_VM_GET_PAGE_PROT
  select ARCH_HAVE_NMI_SAFE_CMPXCHG
  select ARCH_KEEP_MEMBLOCK
  select ARCH_MIGHT_HAVE_PC_PARPORT
diff --git a/arch/powerpc/include/asm/mman.h 
b/arch/powerpc/include/asm/mman.h

index 7cb6d18f5cd6..1b024e64c8ec 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -24,18 +24,6 @@ static inline unsigned long 
arch_calc_vm_prot_bits(unsigned long prot,

  }
  #define arch_calc_vm_prot_bits(prot, pkey) 
arch_calc_vm_prot_bits(prot, pkey)

-static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
-{
-#ifdef CONFIG_PPC_MEM_KEYS
-    return (vm_flags & VM_SAO) ?
-    __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
-    __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
-#else
-    return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
-#endif
-}
-#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
-
  static inline bool arch_validate_prot(unsigned long prot, unsigned 
long addr)

  {
  if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | 
PROT_SAO))

diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
index c475cf810aa8..cd17bd6fa36b 100644
--- a/arch/powerpc/mm/mmap.c
+++ b/arch/powerpc/mm/mmap.c
@@ -254,3 +254,29 @@ void arch_pick_mmap_layout(struct mm_struct *mm, 
struct rlimit *rlim_stack)

  mm->get_unmapped_area = arch_get_unmapped_area_topdown;
  }
  }
+
+#ifdef CONFIG_PPC64
+static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
+{
+#ifdef CONFIG_PPC_MEM_KEYS
+    return (vm_flags & VM_SAO) ?
+    __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
+    __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
+#else
+    return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
+#endif
+}
+#else
+static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
+{
+    return __pgprot(0);
+}
+#endif /* CONFIG_PPC64 */


Can we reduce this forest of #ifdefs and make it more readable ?

mm/mmap.c is going away with patch 
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/d6d849621f821af253e777a24eda4c648814a76e.1646847562.git.christophe.le...@csgroup.eu/ 



So it would be better to add two versions of vm_get_page_prot(), for 
instance one in mm/pgtable_64.c and one in mm/pgtable_32.c


Indeed, you don't need anything at all for PPC32. All you need to do is

select ARCH_HAS_VM_GET_PAGE_PROT if PPC64

And in fact it could even be PPC_BOOK3S_64 instead of PPC64 because 
CONFIG_PPC_MEM_KEYS depends on PPC_BOOK3S_64 and _PAGE_SAO is 0 on 
nohash/64.


So you can then put it into arch/powerpc/mm/book3s64/pgtable.c






+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+    return __pgprot(pgprot_val(protection_map[vm_flags &
+    (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+   pgprot_val(powerpc_vm_get_page_prot(vm_flags)));
+}
+EXPORT_SYMBOL(vm_get_page_prot);


By the way I'm a bit puzzled with the name powerpc_vm_get_page_prot(), 
the name suggests that it's just a powerpc replacement of 
vm_get_page_prot(). I'd prefer if it was named __vm_get_page_prot(), it 
would be clearer that it is a complement to vm_get_page_prot() and not a 
remplacement.


Christophe

Re: [PATCH V4 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

2022-04-08 Thread Christophe Leroy 


Le 07/04/2022 à 12:32, Anshuman Khandual a écrit :
> This defines and exports a platform specific custom vm_get_page_prot() via
> subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
> arch_vm_get_page_prot() as powerpc_vm_get_page_prot() and moves it near
> vm_get_page_prot().
> 
> Cc: Michael Ellerman 
> Cc: Paul Mackerras 
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-ker...@vger.kernel.org
> Signed-off-by: Anshuman Khandual 
> ---
>   arch/powerpc/Kconfig|  1 +
>   arch/powerpc/include/asm/mman.h | 12 
>   arch/powerpc/mm/mmap.c  | 26 ++
>   3 files changed, 27 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 174edabb74fa..eb9b6ddbf92f 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -140,6 +140,7 @@ config PPC
>   select ARCH_HAS_TICK_BROADCAST  if GENERIC_CLOCKEVENTS_BROADCAST
>   select ARCH_HAS_UACCESS_FLUSHCACHE
>   select ARCH_HAS_UBSAN_SANITIZE_ALL
> + select ARCH_HAS_VM_GET_PAGE_PROT
>   select ARCH_HAVE_NMI_SAFE_CMPXCHG
>   select ARCH_KEEP_MEMBLOCK
>   select ARCH_MIGHT_HAVE_PC_PARPORT
> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
> index 7cb6d18f5cd6..1b024e64c8ec 100644
> --- a/arch/powerpc/include/asm/mman.h
> +++ b/arch/powerpc/include/asm/mman.h
> @@ -24,18 +24,6 @@ static inline unsigned long 
> arch_calc_vm_prot_bits(unsigned long prot,
>   }
>   #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, 
> pkey)
>   
> -static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
> -{
> -#ifdef CONFIG_PPC_MEM_KEYS
> - return (vm_flags & VM_SAO) ?
> - __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
> - __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
> -#else
> - return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
> -#endif
> -}
> -#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
> -
>   static inline bool arch_validate_prot(unsigned long prot, unsigned long 
> addr)
>   {
>   if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
> diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
> index c475cf810aa8..cd17bd6fa36b 100644
> --- a/arch/powerpc/mm/mmap.c
> +++ b/arch/powerpc/mm/mmap.c
> @@ -254,3 +254,29 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct 
> rlimit *rlim_stack)
>   mm->get_unmapped_area = arch_get_unmapped_area_topdown;
>   }
>   }
> +
> +#ifdef CONFIG_PPC64
> +static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
> +{
> +#ifdef CONFIG_PPC_MEM_KEYS
> + return (vm_flags & VM_SAO) ?
> + __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
> + __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
> +#else
> + return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
> +#endif
> +}
> +#else
> +static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
> +{
> + return __pgprot(0);
> +}
> +#endif /* CONFIG_PPC64 */

Can we reduce this forest of #ifdefs and make it more readable ?

mm/mmap.c is going away with patch 
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/d6d849621f821af253e777a24eda4c648814a76e.1646847562.git.christophe.le...@csgroup.eu/

So it would be better to add two versions of vm_get_page_prot(), for 
instance one in mm/pgtable_64.c and one in mm/pgtable_32.c


> +
> +pgprot_t vm_get_page_prot(unsigned long vm_flags)
> +{
> + return __pgprot(pgprot_val(protection_map[vm_flags &
> + (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
> +pgprot_val(powerpc_vm_get_page_prot(vm_flags)));
> +}
> +EXPORT_SYMBOL(vm_get_page_prot);

By the way I'm a bit puzzled with the name powerpc_vm_get_page_prot(), 
the name suggests that it's just a powerpc replacement of 
vm_get_page_prot(). I'd prefer if it was named __vm_get_page_prot(), it 
would be clearer that it is a complement to vm_get_page_prot() and not a 
remplacement.

Christophe

[PATCH V4 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

2022-04-07 Thread Anshuman Khandual 
This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
arch_vm_get_page_prot() as powerpc_vm_get_page_prot() and moves it near
vm_get_page_prot().

Cc: Michael Ellerman 
Cc: Paul Mackerras 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-ker...@vger.kernel.org
Signed-off-by: Anshuman Khandual 
---
 arch/powerpc/Kconfig|  1 +
 arch/powerpc/include/asm/mman.h | 12 
 arch/powerpc/mm/mmap.c  | 26 ++
 3 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 174edabb74fa..eb9b6ddbf92f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -140,6 +140,7 @@ config PPC
select ARCH_HAS_TICK_BROADCAST  if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
select ARCH_HAS_UBSAN_SANITIZE_ALL
+   select ARCH_HAS_VM_GET_PAGE_PROT
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_KEEP_MEMBLOCK
select ARCH_MIGHT_HAVE_PC_PARPORT
diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 7cb6d18f5cd6..1b024e64c8ec 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -24,18 +24,6 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned 
long prot,
 }
 #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
 
-static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
-{
-#ifdef CONFIG_PPC_MEM_KEYS
-   return (vm_flags & VM_SAO) ?
-   __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
-   __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
-#else
-   return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
-#endif
-}
-#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
-
 static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
 {
if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c
index c475cf810aa8..cd17bd6fa36b 100644
--- a/arch/powerpc/mm/mmap.c
+++ b/arch/powerpc/mm/mmap.c
@@ -254,3 +254,29 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct 
rlimit *rlim_stack)
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
 }
+
+#ifdef CONFIG_PPC64
+static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
+{
+#ifdef CONFIG_PPC_MEM_KEYS
+   return (vm_flags & VM_SAO) ?
+   __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
+   __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
+#else
+   return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
+#endif
+}
+#else
+static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags)
+{
+   return __pgprot(0);
+}
+#endif /* CONFIG_PPC64 */
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+   return __pgprot(pgprot_val(protection_map[vm_flags &
+   (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+  pgprot_val(powerpc_vm_get_page_prot(vm_flags)));
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1