diff options
| author | Dave Hansen <dave.hansen@linux.intel.com> | 2016-02-12 13:02:08 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-18 09:31:50 +0100 |
| commit | 63c17fb8e5a46a16e10e82005748837fd11a2024 (patch) | |
| tree | ab73d1766b2da48aca26dce24953d608f4a80d85 /mm | |
| parent | b3ecd51559ae7a8f40b10443773b9cd0e6a50f5e (diff) | |
mm/core, x86/mm/pkeys: Store protection bits in high VMA flags
vma->vm_flags is an 'unsigned long', so has space for 32 flags
on 32-bit architectures. The high 32 bits are unused on 64-bit
platforms. We've steered away from using the unused high VMA
bits for things because we would have difficulty supporting it
on 32-bit.
Protection Keys are not available in 32-bit mode, so there is
no concern about supporting this feature in 32-bit mode or on
32-bit CPUs.
This patch carves out 4 bits from the high half of
vma->vm_flags and allows architectures to set config option
to make them available.
Sparse complains about these constants unless we explicitly
call them "UL".
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Valentin Rothberg <valentinrothberg@gmail.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xie XiuQi <xiexiuqi@huawei.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210208.81AF00D5@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/Kconfig | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/Kconfig b/mm/Kconfig index 03cbfa072f42..6cf439948297 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -669,3 +669,6 @@ config ZONE_DEVICE config FRAME_VECTOR bool + +config ARCH_USES_HIGH_VMA_FLAGS + bool |