[PATCH v11 3/3] mm, x86: display pkey in smaps only if arch supports pkeys

[Michael Ellerman]

Ram Pai <linuxram at us.ibm.com> writes:

> On Fri, Feb 02, 2018 at 12:27:27PM +0800, kbuild test robot wrote:
>> Hi Ram,
>> 
>> Thank you for the patch! Yet something to improve:
>> 
>> [auto build test ERROR on linus/master]
>> [also build test ERROR on v4.15 next-20180201]
>> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>> 
>> url:    https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_0day-2Dci_linux_commits_Ram-2DPai_mm-2Dx86-2Dpowerpc-2DEnhancements-2Dto-2DMemory-2DProtection-2DKeys_20180202-2D120004&d=DwIBAg&c=jf_iaSHvJObTbx-siA1ZOg&r=m-UrKChQVkZtnPpjbF6YY99NbT8FBByQ-E-ygV8luxw&m=Fv3tEHet1bTUrDjOnzEhXvGM_4tGlkYhJHPBnWNWgVA&s=Z1W6CV2tfPmLYU8lVv1oDRl2cAyQA76KE2P064A2CQY&e=
>> config: x86_64-randconfig-x005-201804 (attached as .config)
>> compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025
>> reproduce:
>>         # save the attached .config to linux build tree
>>         make ARCH=x86_64 
>> 
>> All error/warnings (new ones prefixed by >>):
>> 
>>    In file included from arch/x86/include/asm/mmu_context.h:8:0,
>>                     from arch/x86/events/core.c:36:
>> >> include/linux/pkeys.h:16:23: error: expected identifier or '(' before numeric constant
>>     #define vma_pkey(vma) 0
>>                           ^
>> >> arch/x86/include/asm/mmu_context.h:298:19: note: in expansion of macro 'vma_pkey'
>>     static inline int vma_pkey(struct vm_area_struct *vma)
>>                       ^~~~~~~~
>> 
>> vim +16 include/linux/pkeys.h
>> 
>>      7	
>>      8	#ifdef CONFIG_ARCH_HAS_PKEYS
>>      9	#include <asm/pkeys.h>
>>     10	#else /* ! CONFIG_ARCH_HAS_PKEYS */
>>     11	#define arch_max_pkey() (1)
>>     12	#define execute_only_pkey(mm) (0)
>>     13	#define arch_override_mprotect_pkey(vma, prot, pkey) (0)
>>     14	#define PKEY_DEDICATED_EXECUTE_ONLY 0
>>     15	#define ARCH_VM_PKEY_FLAGS 0
>>   > 16	#define vma_pkey(vma) 0
>
> Oops. Thanks for catching the issue. The following fix will resolve the error.
>
> diff --git a/arch/x86/include/asm/mmu_context.h
> b/arch/x86/include/asm/mmu_context.h
> index 6d16d15..c1aeb19 100644
> --- a/arch/x86/include/asm/mmu_context.h
> +++ b/arch/x86/include/asm/mmu_context.h
> @@ -238,11 +238,6 @@ static inline int vma_pkey(struct vm_area_struct
> 		*vma)
>  
>         return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT;
> }
> -#else
> -static inline int vma_pkey(struct vm_area_struct *vma)
> -{
> -       return 0;
> -}
>  #endif

That's not working for me (i386_defconfig):

  In file included from ../include/linux/pkeys.h:6:0,
                   from ../arch/x86/kernel/fpu/xstate.c:9:
  ../arch/x86/include/asm/mmu_context.h: In function ‘arch_vma_access_permitted’:
  ../arch/x86/include/asm/mmu_context.h:276:28: error: implicit declaration of function ‘vma_pkey’ [-Werror=implicit-function-declaration]
    return __pkru_allows_pkey(vma_pkey(vma), write);
                              ^~~~~~~~
  In file included from ../include/linux/pkeys.h:6:0,
                   from ../fs/proc/task_mmu.c:21:
  ../arch/x86/include/asm/mmu_context.h: In function ‘arch_vma_access_permitted’:
  ../arch/x86/include/asm/mmu_context.h:276:28: error: implicit declaration of function ‘vma_pkey’ [-Werror=implicit-function-declaration]
    return __pkru_allows_pkey(vma_pkey(vma), write);
                              ^~~~~~~~
  In file included from ../include/linux/pkeys.h:6:0,
                   from ../mm/mmap.c:46:
  ../arch/x86/include/asm/mmu_context.h: In function ‘arch_vma_access_permitted’:
  ../arch/x86/include/asm/mmu_context.h:276:28: error: implicit declaration of function ‘vma_pkey’ [-Werror=implicit-function-declaration]
    return __pkru_allows_pkey(vma_pkey(vma), write);
                              ^~~~~~~~
  In file included from ../include/linux/pkeys.h:6:0,
                   from ../mm/mprotect.c:27:
  ../arch/x86/include/asm/mmu_context.h: In function ‘arch_vma_access_permitted’:
  ../arch/x86/include/asm/mmu_context.h:276:28: error: implicit declaration of function ‘vma_pkey’ [-Werror=implicit-function-declaration]
    return __pkru_allows_pkey(vma_pkey(vma), write);
                              ^~~~~~~~
  In file included from ../include/linux/pkeys.h:6:0,
                   from ../arch/x86/kernel/fpu/core.c:15:
  ../arch/x86/include/asm/mmu_context.h: In function ‘arch_vma_access_permitted’:
  ../arch/x86/include/asm/mmu_context.h:276:28: error: implicit declaration of function ‘vma_pkey’ [-Werror=implicit-function-declaration]
    return __pkru_allows_pkey(vma_pkey(vma), write);
                              ^~~~~~~~

cheers