diff mbox series

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

Message ID 20220407103251.1209606-3-anshuman.khandual@arm.com
State New
Headers show
Series mm/mmap: Drop arch_vm_get_page_prot() and arch_filter_pgprot() | expand

Commit Message

Anshuman Khandual April 7, 2022, 10:32 a.m. UTC
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 <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/powerpc/Kconfig            |  1 +
 arch/powerpc/include/asm/mman.h | 12 ------------
 arch/powerpc/mm/mmap.c          | 26 ++++++++++++++++++++++++++
 3 files changed, 27 insertions(+), 12 deletions(-)

Comments

Christophe Leroy April 8, 2022, 12:53 p.m. UTC | #1
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 <mpe@ellerman.id.au>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>   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.leroy@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
Christophe Leroy April 9, 2022, 11:36 a.m. UTC | #2
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 <mpe@ellerman.id.au>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>   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.leroy@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
Anshuman Khandual April 11, 2022, 5:31 a.m. UTC | #3
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 <mpe@ellerman.id.au>
>>> Cc: Paul Mackerras <paulus@samba.org>
>>> Cc: linuxppc-dev@lists.ozlabs.org
>>> Cc: linux-kernel@vger.kernel.org
>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>>> ---
>>>   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.leroy@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_PROT        if 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 <linux/mm_types.h>
 #include <linux/memblock.h>
 #include <linux/memremap.h>
+#include <linux/pkeys.h>
 #include <linux/debugfs.h>
 #include <misc/cxl-base.h>
 
@@ -549,3 +550,22 @@ unsigned long memremap_compat_align(void)
 }
 EXPORT_SYMBOL_GPL(memremap_compat_align);
 #endif
+
+static pgprot_t __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
+}
+
+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(__vm_get_page_prot(vm_flags)));
+}
+EXPORT_SYMBOL(vm_get_page_prot);
Christophe Leroy April 11, 2022, 5:44 a.m. UTC | #4
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 <mpe@ellerman.id.au>
>>>> Cc: Paul Mackerras <paulus@samba.org>
>>>> Cc: linuxppc-dev@lists.ozlabs.org
>>>> Cc: linux-kernel@vger.kernel.org
>>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>>>> ---
>>>>    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.leroy@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_PROT        if 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 <linux/mm_types.h>
>   #include <linux/memblock.h>
>   #include <linux/memremap.h>
> +#include <linux/pkeys.h>
>   #include <linux/debugfs.h>
>   #include <misc/cxl-base.h>
>   
> @@ -549,3 +550,22 @@ unsigned long memremap_compat_align(void)
>   }
>   EXPORT_SYMBOL_GPL(memremap_compat_align);
>   #endif
> +
> +static pgprot_t __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
> +}
> +
> +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(__vm_get_page_prot(vm_flags)));
> +}
> +EXPORT_SYMBOL(vm_get_page_prot);
diff mbox series

Patch

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);