lkml.org 
[lkml]   [2015]   [May]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 07/12] mm: Pass the 4-bit protection key in via PROT_ bits to syscalls
On 05/07/2015 12:11 PM, One Thousand Gnomes wrote:
>> diff -puN include/uapi/asm-generic/mman-common.h~pkeys-11-user-abi-bits include/uapi/asm-generic/mman-common.h
>> --- a/include/uapi/asm-generic/mman-common.h~pkeys-11-user-abi-bits 2015-05-07 10:31:43.367276719 -0700
>> +++ b/include/uapi/asm-generic/mman-common.h 2015-05-07 10:31:43.370276855 -0700
>> @@ -10,6 +10,10 @@
>> #define PROT_WRITE 0x2 /* page can be written */
>> #define PROT_EXEC 0x4 /* page can be executed */
>> #define PROT_SEM 0x8 /* page may be used for atomic ops */
>> +#define PROT_PKEY0 0x10 /* protection key value (bit 0) */
>> +#define PROT_PKEY1 0x20 /* protection key value (bit 1) */
>> +#define PROT_PKEY2 0x40 /* protection key value (bit 2) */
>> +#define PROT_PKEY3 0x80 /* protection key value (bit 3) */
>
> Thats leaking deep Intelisms into asm-generic which makes me very
> uncomfortable. Whether we need to reserve some bits for "arch specific"
> is one question, what we do with them ought not to be leaking out.
>
> To start with trying to port code people will want to do
>
> #define PROT_PKEY0 0
> #define PROT_PKEY1 0

Yeah, I feel pretty uncomfortable with it as well. I really don't
expect these to live like this in asm-generic when I submit this.

Powerpc and ia64 have _something_ resembling protection keys, so the
concept isn't entirely x86 or Intel-specific. My hope would be that we
do this in a way that other architectures can use.




\
 
 \ /
  Last update: 2015-05-07 21:41    [W:0.080 / U:0.372 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site