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authorDave Hansen <dave.hansen@linux.intel.com>2016-02-13 00:02:08 +0300
committerIngo Molnar <mingo@kernel.org>2016-02-18 11:31:50 +0300
commit63c17fb8e5a46a16e10e82005748837fd11a2024 (patch)
treeab73d1766b2da48aca26dce24953d608f4a80d85 /mm/Kconfig
parentb3ecd51559ae7a8f40b10443773b9cd0e6a50f5e (diff)
downloadlinux-63c17fb8e5a46a16e10e82005748837fd11a2024.tar.xz
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/Kconfig')
-rw-r--r--mm/Kconfig3
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