From 63c17fb8e5a46a16e10e82005748837fd11a2024 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Fri, 12 Feb 2016 13:02:08 -0800 Subject: 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 Reviewed-by: Thomas Gleixner Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dan Williams Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jan Kara Cc: Kirill A. Shutemov Cc: Konstantin Khlebnikov Cc: Linus Torvalds Cc: Mel Gorman Cc: Michal Hocko Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Sasha Levin Cc: Valentin Rothberg Cc: Vladimir Davydov Cc: Vlastimil Babka Cc: Xie XiuQi 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 --- mm/Kconfig | 3 +++ 1 file changed, 3 insertions(+) (limited to 'mm/Kconfig') 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 -- cgit v1.2.3-58-ga151