Commit-ID: 63c17fb8e5a46a16e10e82005748837fd11a2024 Gitweb: http://git.kernel.org/tip/63c17fb8e5a46a16e10e82005748837fd11a2024 Author: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> AuthorDate: Fri, 12 Feb 2016 13:02:08 -0800 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Thu, 18 Feb 2016 09:31:50 +0100 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@xxxxxxxxxxxxxxx> Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Brian Gerst <brgerst@xxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Dave Hansen <dave@xxxxxxxx> Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Sasha Levin <sasha.levin@xxxxxxxxxx> Cc: Valentin Rothberg <valentinrothberg@xxxxxxxxx> Cc: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Xie XiuQi <xiexiuqi@xxxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx Link: http://lkml.kernel.org/r/20160212210208.81AF00D5@xxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/Kconfig | 1 + include/linux/mm.h | 11 +++++++++++ mm/Kconfig | 3 +++ 3 files changed, 15 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3632cdd..fb2ebeb 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -155,6 +155,7 @@ config X86 select VIRT_TO_BUS select X86_DEV_DMA_OPS if X86_64 select X86_FEATURE_NAMES if PROC_FS + select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS config INSTRUCTION_DECODER def_bool y diff --git a/include/linux/mm.h b/include/linux/mm.h index 4c73178..54d173b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -170,6 +170,17 @@ extern unsigned int kobjsize(const void *objp); #define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */ #define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */ +#ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS +#define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */ +#define VM_HIGH_ARCH_BIT_1 33 /* bit only usable on 64-bit architectures */ +#define VM_HIGH_ARCH_BIT_2 34 /* bit only usable on 64-bit architectures */ +#define VM_HIGH_ARCH_BIT_3 35 /* bit only usable on 64-bit architectures */ +#define VM_HIGH_ARCH_0 BIT(VM_HIGH_ARCH_BIT_0) +#define VM_HIGH_ARCH_1 BIT(VM_HIGH_ARCH_BIT_1) +#define VM_HIGH_ARCH_2 BIT(VM_HIGH_ARCH_BIT_2) +#define VM_HIGH_ARCH_3 BIT(VM_HIGH_ARCH_BIT_3) +#endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */ + #if defined(CONFIG_X86) # define VM_PAT VM_ARCH_1 /* PAT reserves whole VMA at once (x86) */ #elif defined(CONFIG_PPC) diff --git a/mm/Kconfig b/mm/Kconfig index 03cbfa0..6cf4399 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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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