[RFC 0/3] mm/vma: some new flags and helpers

[RFC 0/3] mm/vma: some new flags and helpers

[Anshuman Khandual]

The motivation here is to consolidate VMA flag combinations commonly used
across platforms and reduce code duplication while making it uncluttered
in general.

This first introduces a default VM_DATA_DEFAULT_FLAGS which platforms can
easily fall back on without requiring to define any similar data flag
combinations as they currently do. This also adds some more common data
flag combinations which are generally used when the platforms decide to
override the default.

The second patch consolidates VM_READ, VM_WRITE, VM_EXEC as VM_ACCESS_FLAGS
extending the existing VMA accessibility concept via vma_is_accessibility().
VM_ACCESS_FLAGS replaces many other instances which used check all three
VMA access flags simultaneously.

While here, this also adds some more special VMA flag based helpers which
wraps around similar checks at various places thus improving readability.
This series intentionally limits these new helpers which are applicable 
only for special purpose VM flags than the more common ones like VM_READ,
VM_WRITE, VM_EXEC, VM_SHARED etc just to limit code churn. But if there is
common agreement that every flag should have it's own wrapper here, we can
do that as well. Otherwise if this patch seems really unnecessary with much
code churn, will be happy to drop it.

Reviews, comments, suggestions and concerns welcome. Thank you.

This series is based on v5.6-r4 after applying these patches.

1. https://patchwork.kernel.org/cover/11399319/
2. https://patchwork.kernel.org/patch/11399379/

This series is build tested across multiple architectures but boot tested
only on arm64 and x86 platforms.

Cc: linux-alpha@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-mm@kvack.org

Anshuman Khandual (3):
  mm/vma: Define a default value for VM_DATA_DEFAULT_FLAGS
  mm/vma: Introduce VM_ACCESS_FLAGS
  mm/vma: Introduce some more VMA flag wrappers

 arch/alpha/include/asm/page.h        |  3 --
 arch/arc/include/asm/page.h          |  2 +-
 arch/arm/include/asm/page.h          |  4 +-
 arch/arm/mm/fault.c                  |  2 +-
 arch/arm64/include/asm/page.h        |  4 +-
 arch/arm64/mm/fault.c                |  2 +-
 arch/c6x/include/asm/page.h          |  5 +--
 arch/c6x/include/asm/processor.h     |  2 +-
 arch/csky/include/asm/page.h         |  3 --
 arch/h8300/include/asm/page.h        |  2 -
 arch/hexagon/include/asm/page.h      |  3 +-
 arch/ia64/include/asm/page.h         |  5 +--
 arch/m68k/include/asm/page.h         |  3 --
 arch/microblaze/include/asm/page.h   |  2 -
 arch/mips/include/asm/page.h         |  5 +--
 arch/nds32/include/asm/page.h        |  3 --
 arch/nds32/mm/fault.c                |  2 +-
 arch/nios2/include/asm/page.h        |  3 +-
 arch/nios2/include/asm/processor.h   |  2 +-
 arch/openrisc/include/asm/page.h     |  5 ---
 arch/parisc/include/asm/page.h       |  3 --
 arch/powerpc/include/asm/page.h      |  9 +----
 arch/powerpc/include/asm/page_64.h   |  7 +---
 arch/powerpc/mm/book3s64/pkeys.c     |  2 +-
 arch/riscv/include/asm/page.h        |  3 +-
 arch/s390/include/asm/page.h         |  3 +-
 arch/s390/mm/fault.c                 |  2 +-
 arch/sh/include/asm/page.h           |  3 --
 arch/sh/include/asm/processor_64.h   |  2 +-
 arch/sparc/include/asm/mman.h        |  2 +-
 arch/sparc/include/asm/page_32.h     |  3 --
 arch/sparc/include/asm/page_64.h     |  3 --
 arch/unicore32/include/asm/page.h    |  3 --
 arch/unicore32/mm/fault.c            |  2 +-
 arch/x86/include/asm/page_types.h    |  4 +-
 arch/x86/mm/pkeys.c                  |  2 +-
 arch/x86/um/asm/vm-flags.h           | 10 +----
 arch/xtensa/include/asm/page.h       |  3 --
 drivers/staging/gasket/gasket_core.c |  2 +-
 fs/binfmt_elf.c                      |  2 +-
 fs/proc/task_mmu.c                   | 14 +++----
 include/linux/huge_mm.h              |  4 +-
 include/linux/mm.h                   | 58 +++++++++++++++++++++++++++-
 kernel/events/core.c                 |  2 +-
 kernel/events/uprobes.c              |  2 +-
 mm/gup.c                             |  2 +-
 mm/huge_memory.c                     |  6 +--
 mm/hugetlb.c                         |  4 +-
 mm/ksm.c                             |  8 ++--
 mm/madvise.c                         |  4 +-
 mm/memory.c                          |  4 +-
 mm/migrate.c                         |  4 +-
 mm/mlock.c                           |  4 +-
 mm/mmap.c                            | 20 +++++-----
 mm/mprotect.c                        |  9 ++---
 mm/mremap.c                          |  4 +-
 mm/msync.c                           |  3 +-
 mm/rmap.c                            |  6 +--
 mm/shmem.c                           |  8 ++--
 59 files changed, 140 insertions(+), 158 deletions(-)

-- 
2.20.1

[RFC 1/3] mm/vma: Define a default value for VM_DATA_DEFAULT_FLAGS

[Anshuman Khandual]

There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS
This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the
existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros
with standard VMA access flag combinations that are used frequently across
many platforms. Apart from simplification, this reduces code duplication
as well.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-alpha@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-mips@vger.kernel.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-mm@kvack.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/alpha/include/asm/page.h      |  3 ---
 arch/arc/include/asm/page.h        |  2 +-
 arch/arm/include/asm/page.h        |  4 +---
 arch/arm64/include/asm/page.h      |  4 +---
 arch/c6x/include/asm/page.h        |  5 +----
 arch/csky/include/asm/page.h       |  3 ---
 arch/h8300/include/asm/page.h      |  2 --
 arch/hexagon/include/asm/page.h    |  3 +--
 arch/ia64/include/asm/page.h       |  5 +----
 arch/m68k/include/asm/page.h       |  3 ---
 arch/microblaze/include/asm/page.h |  2 --
 arch/mips/include/asm/page.h       |  5 +----
 arch/nds32/include/asm/page.h      |  3 ---
 arch/nios2/include/asm/page.h      |  3 +--
 arch/openrisc/include/asm/page.h   |  5 -----
 arch/parisc/include/asm/page.h     |  3 ---
 arch/powerpc/include/asm/page.h    |  9 ++-------
 arch/powerpc/include/asm/page_64.h |  7 ++-----
 arch/riscv/include/asm/page.h      |  3 +--
 arch/s390/include/asm/page.h       |  3 +--
 arch/sh/include/asm/page.h         |  3 ---
 arch/sparc/include/asm/page_32.h   |  3 ---
 arch/sparc/include/asm/page_64.h   |  3 ---
 arch/unicore32/include/asm/page.h  |  3 ---
 arch/x86/include/asm/page_types.h  |  4 +---
 arch/x86/um/asm/vm-flags.h         | 10 ++--------
 arch/xtensa/include/asm/page.h     |  3 ---
 include/linux/mm.h                 | 15 +++++++++++++++
 28 files changed, 32 insertions(+), 89 deletions(-)

diff --git a/arch/alpha/include/asm/page.h b/arch/alpha/include/asm/page.h
index f3fb2848470a..e241bd88880f 100644
--- a/arch/alpha/include/asm/page.h
+++ b/arch/alpha/include/asm/page.h
@@ -90,9 +90,6 @@ typedef struct page *pgtable_t;
 #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 #endif /* CONFIG_DISCONTIGMEM */
 
-#define VM_DATA_DEFAULT_FLAGS		(VM_READ | VM_WRITE | VM_EXEC | \
-					 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h
index 0a32e8cfd074..b0dfed0f12be 100644
--- a/arch/arc/include/asm/page.h
+++ b/arch/arc/include/asm/page.h
@@ -102,7 +102,7 @@ typedef pte_t * pgtable_t;
 #define virt_addr_valid(kaddr)  pfn_valid(virt_to_pfn(kaddr))
 
 /* Default Permissions for stack/heaps pages (Non Executable) */
-#define VM_DATA_DEFAULT_FLAGS   (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
 
 #define WANT_PAGE_VIRTUAL   1
 
diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h
index c2b75cba26df..11b058a72a5b 100644
--- a/arch/arm/include/asm/page.h
+++ b/arch/arm/include/asm/page.h
@@ -161,9 +161,7 @@ extern int pfn_valid(unsigned long);
 
 #endif /* !__ASSEMBLY__ */
 
-#define VM_DATA_DEFAULT_FLAGS \
-	(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
-	 VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
 #include <asm-generic/getorder.h>
 
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
index d39ddb258a04..cb4e1e6ca385 100644
--- a/arch/arm64/include/asm/page.h
+++ b/arch/arm64/include/asm/page.h
@@ -32,9 +32,7 @@ extern int pfn_valid(unsigned long);
 
 #endif /* !__ASSEMBLY__ */
 
-#define VM_DATA_DEFAULT_FLAGS \
-	(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
-	 VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
 #include <asm-generic/getorder.h>
 
diff --git a/arch/c6x/include/asm/page.h b/arch/c6x/include/asm/page.h
index 70db1e7632bc..40079899084d 100644
--- a/arch/c6x/include/asm/page.h
+++ b/arch/c6x/include/asm/page.h
@@ -2,10 +2,7 @@
 #ifndef _ASM_C6X_PAGE_H
 #define _ASM_C6X_PAGE_H
 
-#define VM_DATA_DEFAULT_FLAGS \
-	(VM_READ | VM_WRITE | \
-	((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
-		 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
 #include <asm-generic/page.h>
 
diff --git a/arch/csky/include/asm/page.h b/arch/csky/include/asm/page.h
index 9738eacefdc7..9b98bf31d57c 100644
--- a/arch/csky/include/asm/page.h
+++ b/arch/csky/include/asm/page.h
@@ -85,9 +85,6 @@ extern unsigned long va_pa_offset;
 				 PHYS_OFFSET_OFFSET)
 #define virt_to_page(x)	(mem_map + MAP_NR(x))
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #define pfn_to_kaddr(x)	__va(PFN_PHYS(x))
 
 #include <asm-generic/memory_model.h>
diff --git a/arch/h8300/include/asm/page.h b/arch/h8300/include/asm/page.h
index 8da5124ad344..53e037544239 100644
--- a/arch/h8300/include/asm/page.h
+++ b/arch/h8300/include/asm/page.h
@@ -6,8 +6,6 @@
 #include <linux/types.h>
 
 #define MAP_NR(addr) (((uintptr_t)(addr)-PAGE_OFFSET) >> PAGE_SHIFT)
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 
 #ifndef __ASSEMBLY__
 extern unsigned long rom_length;
diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h
index ee31f36f48f3..7cbf719c578e 100644
--- a/arch/hexagon/include/asm/page.h
+++ b/arch/hexagon/include/asm/page.h
@@ -93,8 +93,7 @@ struct page;
 #define virt_to_page(kaddr) pfn_to_page(PFN_DOWN(__pa(kaddr)))
 
 /* Default vm area behavior is non-executable.  */
-#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | \
-				VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
 
 #define pfn_valid(pfn) ((pfn) < max_mapnr)
 #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
diff --git a/arch/ia64/include/asm/page.h b/arch/ia64/include/asm/page.h
index 5798bd2b462c..b69a5499d75b 100644
--- a/arch/ia64/include/asm/page.h
+++ b/arch/ia64/include/asm/page.h
@@ -218,10 +218,7 @@ get_order (unsigned long size)
 
 #define PAGE_OFFSET			RGN_BASE(RGN_KERNEL)
 
-#define VM_DATA_DEFAULT_FLAGS		(VM_READ | VM_WRITE |					\
-					 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC |		\
-					 (((current->personality & READ_IMPLIES_EXEC) != 0)	\
-					  ? VM_EXEC : 0))
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
 #define GATE_ADDR		RGN_BASE(RGN_GATE)
 
diff --git a/arch/m68k/include/asm/page.h b/arch/m68k/include/asm/page.h
index 05e1e1e77a9a..9d2ef0a51720 100644
--- a/arch/m68k/include/asm/page.h
+++ b/arch/m68k/include/asm/page.h
@@ -55,9 +55,6 @@ extern unsigned long _ramend;
 #define __phys_to_pfn(paddr)	((unsigned long)((paddr) >> PAGE_SHIFT))
 #define __pfn_to_phys(pfn)	PFN_PHYS(pfn)
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #include <asm-generic/getorder.h>
 
 #endif /* _M68K_PAGE_H */
diff --git a/arch/microblaze/include/asm/page.h b/arch/microblaze/include/asm/page.h
index f4b44b24b02e..43bd560b7b67 100644
--- a/arch/microblaze/include/asm/page.h
+++ b/arch/microblaze/include/asm/page.h
@@ -197,8 +197,6 @@ extern int page_is_ram(unsigned long pfn);
 
 #ifdef CONFIG_MMU
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 #endif /* CONFIG_MMU */
 
 #endif /* __KERNEL__ */
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h
index 0ba4ce6e2bf3..e2f503fc7a84 100644
--- a/arch/mips/include/asm/page.h
+++ b/arch/mips/include/asm/page.h
@@ -253,10 +253,7 @@ extern bool __virt_addr_valid(const volatile void *kaddr);
 #define virt_addr_valid(kaddr)						\
 	__virt_addr_valid((const volatile void *) (kaddr))
 
-#define VM_DATA_DEFAULT_FLAGS \
-	(VM_READ | VM_WRITE | \
-	 ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
-	 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
diff --git a/arch/nds32/include/asm/page.h b/arch/nds32/include/asm/page.h
index 86b32014c5f9..add33a7f02c8 100644
--- a/arch/nds32/include/asm/page.h
+++ b/arch/nds32/include/asm/page.h
@@ -59,9 +59,6 @@ typedef struct page *pgtable_t;
 
 #endif /* !__ASSEMBLY__ */
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #endif /* __KERNEL__ */
 
 #endif
diff --git a/arch/nios2/include/asm/page.h b/arch/nios2/include/asm/page.h
index 79fcac61f6ef..6a989819a7c1 100644
--- a/arch/nios2/include/asm/page.h
+++ b/arch/nios2/include/asm/page.h
@@ -98,8 +98,7 @@ static inline bool pfn_valid(unsigned long pfn)
 # define virt_to_page(vaddr)	pfn_to_page(PFN_DOWN(virt_to_phys(vaddr)))
 # define virt_addr_valid(vaddr)	pfn_valid(PFN_DOWN(virt_to_phys(vaddr)))
 
-# define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+# define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
 
 #include <asm-generic/memory_model.h>
 
diff --git a/arch/openrisc/include/asm/page.h b/arch/openrisc/include/asm/page.h
index 01069db59454..aab6e64d6db4 100644
--- a/arch/openrisc/include/asm/page.h
+++ b/arch/openrisc/include/asm/page.h
@@ -86,11 +86,6 @@ typedef struct page *pgtable_t;
 
 #endif /* __ASSEMBLY__ */
 
-
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
-
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
diff --git a/arch/parisc/include/asm/page.h b/arch/parisc/include/asm/page.h
index 796ae29e9b9a..6b3f6740a6a6 100644
--- a/arch/parisc/include/asm/page.h
+++ b/arch/parisc/include/asm/page.h
@@ -180,9 +180,6 @@ extern int npmem_ranges;
 #define page_to_phys(page)	(page_to_pfn(page) << PAGE_SHIFT)
 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 #include <asm/pdc.h>
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 080a0bf8e54b..3ee8df0f66e0 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -240,13 +240,8 @@ static inline bool pfn_valid(unsigned long pfn)
  * and needs to be executable.  This means the whole heap ends
  * up being executable.
  */
-#define VM_DATA_DEFAULT_FLAGS32 \
-	(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
-				 VM_READ | VM_WRITE | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
-#define VM_DATA_DEFAULT_FLAGS64	(VM_READ | VM_WRITE | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS32	VM_DATA_FLAGS_TSK_EXEC
+#define VM_DATA_DEFAULT_FLAGS64	VM_DATA_FLAGS_NON_EXEC
 
 #ifdef __powerpc64__
 #include <asm/page_64.h>
diff --git a/arch/powerpc/include/asm/page_64.h b/arch/powerpc/include/asm/page_64.h
index 5962797f784a..79a9b7c6a132 100644
--- a/arch/powerpc/include/asm/page_64.h
+++ b/arch/powerpc/include/asm/page_64.h
@@ -94,11 +94,8 @@ extern u64 ppc64_pft_size;
  * stack by default, so in the absence of a PT_GNU_STACK program header
  * we turn execute permission off.
  */
-#define VM_STACK_DEFAULT_FLAGS32	(VM_READ | VM_WRITE | VM_EXEC | \
-					 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
-#define VM_STACK_DEFAULT_FLAGS64	(VM_READ | VM_WRITE | \
-					 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_STACK_DEFAULT_FLAGS32	VM_DATA_FLAGS_EXEC
+#define VM_STACK_DEFAULT_FLAGS64	VM_DATA_FLAGS_NON_EXEC
 
 #define VM_STACK_DEFAULT_FLAGS \
 	(is_32bit_task() ? \
diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 8ca1930caa44..2d50f76efe48 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -137,8 +137,7 @@ extern phys_addr_t __phys_addr_symbol(unsigned long x);
 
 #define virt_addr_valid(vaddr)	(pfn_valid(virt_to_pfn(vaddr)))
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
 
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 1019efd85b9d..089f49230966 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -176,8 +176,7 @@ static inline int devmem_is_allowed(unsigned long pfn)
 
 #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC
 
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
diff --git a/arch/sh/include/asm/page.h b/arch/sh/include/asm/page.h
index 5eef8be3e59f..ea8d68f58e39 100644
--- a/arch/sh/include/asm/page.h
+++ b/arch/sh/include/asm/page.h
@@ -182,9 +182,6 @@ typedef struct page *pgtable_t;
 #endif
 #define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
diff --git a/arch/sparc/include/asm/page_32.h b/arch/sparc/include/asm/page_32.h
index b76d59edec8c..478260002836 100644
--- a/arch/sparc/include/asm/page_32.h
+++ b/arch/sparc/include/asm/page_32.h
@@ -133,9 +133,6 @@ extern unsigned long pfn_base;
 #define pfn_valid(pfn)		(((pfn) >= (pfn_base)) && (((pfn)-(pfn_base)) < max_mapnr))
 #define virt_addr_valid(kaddr)	((((unsigned long)(kaddr)-PAGE_OFFSET)>>PAGE_SHIFT) < max_mapnr)
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #include <asm-generic/memory_model.h>
 #include <asm-generic/getorder.h>
 
diff --git a/arch/sparc/include/asm/page_64.h b/arch/sparc/include/asm/page_64.h
index e80f2d5bf62f..254dffd85fb1 100644
--- a/arch/sparc/include/asm/page_64.h
+++ b/arch/sparc/include/asm/page_64.h
@@ -158,9 +158,6 @@ extern unsigned long PAGE_OFFSET;
 
 #endif /* !(__ASSEMBLY__) */
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #include <asm-generic/getorder.h>
 
 #endif /* _SPARC64_PAGE_H */
diff --git a/arch/unicore32/include/asm/page.h b/arch/unicore32/include/asm/page.h
index 8a89335673f9..96d6bdf180bd 100644
--- a/arch/unicore32/include/asm/page.h
+++ b/arch/unicore32/include/asm/page.h
@@ -69,9 +69,6 @@ extern int pfn_valid(unsigned long);
 
 #endif /* !__ASSEMBLY__ */
 
-#define VM_DATA_DEFAULT_FLAGS \
-	(VM_READ | VM_WRITE | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #include <asm-generic/getorder.h>
 
 #endif
diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
index c85e15010f48..e27aa6be6320 100644
--- a/arch/x86/include/asm/page_types.h
+++ b/arch/x86/include/asm/page_types.h
@@ -35,9 +35,7 @@
 
 #define PAGE_OFFSET		((unsigned long)__PAGE_OFFSET)
 
-#define VM_DATA_DEFAULT_FLAGS \
-	(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
-	 VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
 #define __PHYSICAL_START	ALIGN(CONFIG_PHYSICAL_START, \
 				      CONFIG_PHYSICAL_ALIGN)
diff --git a/arch/x86/um/asm/vm-flags.h b/arch/x86/um/asm/vm-flags.h
index 7c297e9e2413..df7a3896f5dd 100644
--- a/arch/x86/um/asm/vm-flags.h
+++ b/arch/x86/um/asm/vm-flags.h
@@ -9,17 +9,11 @@
 
 #ifdef CONFIG_X86_32
 
-#define VM_DATA_DEFAULT_FLAGS \
-	(VM_READ | VM_WRITE | \
-	((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
-		 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_TSK_EXEC
 
 #else
 
-#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
-	VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-#define VM_STACK_DEFAULT_FLAGS (VM_GROWSDOWN | VM_READ | VM_WRITE | \
-	VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_STACK_DEFAULT_FLAGS (VM_GROWSDOWN | VM_DATA_FLAGS_EXEC)
 
 #endif
 #endif
diff --git a/arch/xtensa/include/asm/page.h b/arch/xtensa/include/asm/page.h
index f4771c29c7e9..37ce25ef92d6 100644
--- a/arch/xtensa/include/asm/page.h
+++ b/arch/xtensa/include/asm/page.h
@@ -203,8 +203,5 @@ static inline unsigned long ___pa(unsigned long va)
 
 #endif /* __ASSEMBLY__ */
 
-#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-
 #include <asm-generic/memory_model.h>
 #endif /* _XTENSA_PAGE_H */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index b0e53ef13ff1..7a764ae6ab68 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -342,6 +342,21 @@ extern unsigned int kobjsize(const void *objp);
 /* Bits set in the VMA until the stack is in its final location */
 #define VM_STACK_INCOMPLETE_SETUP	(VM_RAND_READ | VM_SEQ_READ)
 
+#define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
+
+/* Common data flag combinations */
+#define VM_DATA_FLAGS_TSK_EXEC	(VM_READ | VM_WRITE | TASK_EXEC | \
+				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_FLAGS_NON_EXEC	(VM_READ | VM_WRITE | VM_MAYREAD | \
+				 VM_MAYWRITE | VM_MAYEXEC)
+#define VM_DATA_FLAGS_EXEC	(VM_READ | VM_WRITE | VM_EXEC | \
+				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
+#ifndef VM_DATA_DEFAULT_FLAGS		/* arch can override this */
+#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
+				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#endif
+
 #ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
 #endif
-- 
2.20.1

Re: [RFC 1/3] mm/vma: Define a default value for VM_DATA_DEFAULT_FLAGS

[Geert Uytterhoeven]

On Mon, Mar 2, 2020 at 7:48 AM Anshuman Khandual
<anshuman.khandual@arm.com> wrote:
> There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS
> This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the
> existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros
> with standard VMA access flag combinations that are used frequently across
> many platforms. Apart from simplification, this reduces code duplication
> as well.

> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

>  arch/m68k/include/asm/page.h       |  3 ---

For m68k:
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [RFC 1/3] mm/vma: Define a default value for VM_DATA_DEFAULT_FLAGS

[Vlastimil Babka]

On 3/2/20 7:47 AM, Anshuman Khandual wrote:
> There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS
> This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the
> existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros
> with standard VMA access flag combinations that are used frequently across
> many platforms. Apart from simplification, this reduces code duplication
> as well.
> 
> Cc: Richard Henderson <rth@twiddle.net>
> Cc: Vineet Gupta <vgupta@synopsys.com>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Mark Salter <msalter@redhat.com>
> Cc: Guo Ren <guoren@kernel.org>
> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
> Cc: Brian Cain <bcain@codeaurora.org>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Michal Simek <monstr@monstr.eu>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Nick Hu <nickhu@andestech.com>
> Cc: Ley Foon Tan <ley.foon.tan@intel.com>
> Cc: Jonas Bonn <jonas@southpole.se>
> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Paul Walmsley <paul.walmsley@sifive.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Rich Felker <dalias@libc.org>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Guan Xuetao <gxt@pku.edu.cn>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Jeff Dike <jdike@addtoit.com>
> Cc: Chris Zankel <chris@zankel.net>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-alpha@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-snps-arc@lists.infradead.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-c6x-dev@linux-c6x.org
> Cc: uclinux-h8-devel@lists.sourceforge.jp
> Cc: linux-hexagon@vger.kernel.org
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-m68k@lists.linux-m68k.org
> Cc: linux-mips@vger.kernel.org
> Cc: nios2-dev@lists.rocketboards.org
> Cc: openrisc@lists.librecores.org
> Cc: linux-parisc@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-riscv@lists.infradead.org
> Cc: linux-s390@vger.kernel.org
> Cc: linux-sh@vger.kernel.org
> Cc: sparclinux@vger.kernel.org
> Cc: linux-um@lists.infradead.org
> Cc: linux-xtensa@linux-xtensa.org
> Cc: linux-mm@kvack.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>

Nit:

> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index b0e53ef13ff1..7a764ae6ab68 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -342,6 +342,21 @@ extern unsigned int kobjsize(const void *objp);
>  /* Bits set in the VMA until the stack is in its final location */
>  #define VM_STACK_INCOMPLETE_SETUP	(VM_RAND_READ | VM_SEQ_READ)
>  
> +#define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
> +
> +/* Common data flag combinations */
> +#define VM_DATA_FLAGS_TSK_EXEC	(VM_READ | VM_WRITE | TASK_EXEC | \
> +				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
> +#define VM_DATA_FLAGS_NON_EXEC	(VM_READ | VM_WRITE | VM_MAYREAD | \
> +				 VM_MAYWRITE | VM_MAYEXEC)
> +#define VM_DATA_FLAGS_EXEC	(VM_READ | VM_WRITE | VM_EXEC | \
> +				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
> +
> +#ifndef VM_DATA_DEFAULT_FLAGS		/* arch can override this */
> +#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
> +				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)

Should you use VM_DATA_FLAGS_EXEC here? Yeah one more macro to expand, but it's
right above this.

> +#endif
> +
>  #ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
>  #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
>  #endif
> 

Re: [RFC 1/3] mm/vma: Define a default value for VM_DATA_DEFAULT_FLAGS

[Anshuman Khandual]

On 03/03/2020 10:55 PM, Vlastimil Babka wrote:
> On 3/2/20 7:47 AM, Anshuman Khandual wrote:
>> There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS
>> This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the
>> existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros
>> with standard VMA access flag combinations that are used frequently across
>> many platforms. Apart from simplification, this reduces code duplication
>> as well.
>>
>> Cc: Richard Henderson <rth@twiddle.net>
>> Cc: Vineet Gupta <vgupta@synopsys.com>
>> Cc: Russell King <linux@armlinux.org.uk>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Mark Salter <msalter@redhat.com>
>> Cc: Guo Ren <guoren@kernel.org>
>> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
>> Cc: Brian Cain <bcain@codeaurora.org>
>> Cc: Tony Luck <tony.luck@intel.com>
>> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
>> Cc: Michal Simek <monstr@monstr.eu>
>> Cc: Ralf Baechle <ralf@linux-mips.org>
>> Cc: Paul Burton <paulburton@kernel.org>
>> Cc: Nick Hu <nickhu@andestech.com>
>> Cc: Ley Foon Tan <ley.foon.tan@intel.com>
>> Cc: Jonas Bonn <jonas@southpole.se>
>> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Paul Walmsley <paul.walmsley@sifive.com>
>> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
>> Cc: Rich Felker <dalias@libc.org>
>> Cc: "David S. Miller" <davem@davemloft.net>
>> Cc: Guan Xuetao <gxt@pku.edu.cn>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Jeff Dike <jdike@addtoit.com>
>> Cc: Chris Zankel <chris@zankel.net>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: linux-alpha@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: linux-snps-arc@lists.infradead.org
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: linux-c6x-dev@linux-c6x.org
>> Cc: uclinux-h8-devel@lists.sourceforge.jp
>> Cc: linux-hexagon@vger.kernel.org
>> Cc: linux-ia64@vger.kernel.org
>> Cc: linux-m68k@lists.linux-m68k.org
>> Cc: linux-mips@vger.kernel.org
>> Cc: nios2-dev@lists.rocketboards.org
>> Cc: openrisc@lists.librecores.org
>> Cc: linux-parisc@vger.kernel.org
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Cc: linux-riscv@lists.infradead.org
>> Cc: linux-s390@vger.kernel.org
>> Cc: linux-sh@vger.kernel.org
>> Cc: sparclinux@vger.kernel.org
>> Cc: linux-um@lists.infradead.org
>> Cc: linux-xtensa@linux-xtensa.org
>> Cc: linux-mm@kvack.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
> 
> Nit:
> 
>> diff --git a/include/linux/mm.h b/include/linux/mm.h
>> index b0e53ef13ff1..7a764ae6ab68 100644
>> --- a/include/linux/mm.h
>> +++ b/include/linux/mm.h
>> @@ -342,6 +342,21 @@ extern unsigned int kobjsize(const void *objp);
>>  /* Bits set in the VMA until the stack is in its final location */
>>  #define VM_STACK_INCOMPLETE_SETUP	(VM_RAND_READ | VM_SEQ_READ)
>>  
>> +#define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
>> +
>> +/* Common data flag combinations */
>> +#define VM_DATA_FLAGS_TSK_EXEC	(VM_READ | VM_WRITE | TASK_EXEC | \
>> +				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
>> +#define VM_DATA_FLAGS_NON_EXEC	(VM_READ | VM_WRITE | VM_MAYREAD | \
>> +				 VM_MAYWRITE | VM_MAYEXEC)
>> +#define VM_DATA_FLAGS_EXEC	(VM_READ | VM_WRITE | VM_EXEC | \
>> +				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
>> +
>> +#ifndef VM_DATA_DEFAULT_FLAGS		/* arch can override this */
>> +#define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
>> +				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
> 
> Should you use VM_DATA_FLAGS_EXEC here? Yeah one more macro to expand, but it's
> right above this.

Sure, can do that.

> 
>> +#endif
>> +
>>  #ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
>>  #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
>>  #endif
>>
> 
> 
> 

[RFC 2/3] mm/vma: Introduce VM_ACCESS_FLAGS

[Anshuman Khandual]

There are many places where all basic VMA access flags (read, write, exec)
are initialized or checked against as a group. One such example is during
page fault. Existing vma_is_accessible() wrapper already creates the notion
of VMA accessibility as a group access permissions. Hence lets just create
VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which will not only reduce code
duplication but also extend the VMA accessibility concept in general.

Cc: Russell King <linux@armlinux.org.uk>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Mark Salter <msalter@redhat.com>
Cc: Nick Hu <nickhu@andestech.com>
CC: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Springer <rspringer@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: nios2-dev@lists.rocketboards.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm/mm/fault.c                  | 2 +-
 arch/arm64/mm/fault.c                | 2 +-
 arch/c6x/include/asm/processor.h     | 2 +-
 arch/nds32/mm/fault.c                | 2 +-
 arch/nios2/include/asm/processor.h   | 2 +-
 arch/powerpc/mm/book3s64/pkeys.c     | 2 +-
 arch/s390/mm/fault.c                 | 2 +-
 arch/sh/include/asm/processor_64.h   | 2 +-
 arch/unicore32/mm/fault.c            | 2 +-
 arch/x86/mm/pkeys.c                  | 2 +-
 drivers/staging/gasket/gasket_core.c | 2 +-
 include/linux/mm.h                   | 4 +++-
 mm/mmap.c                            | 4 ++--
 mm/mprotect.c                        | 7 +++----
 14 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index bd0f4821f7e1..2c71028d9d6b 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -189,7 +189,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
  */
 static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
 {
-	unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
+	unsigned int mask = VM_ACCESS_FLAGS;
 
 	if ((fsr & FSR_WRITE) && !(fsr & FSR_CM))
 		mask = VM_WRITE;
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 85566d32958f..63f31206a12e 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -445,7 +445,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
 	const struct fault_info *inf;
 	struct mm_struct *mm = current->mm;
 	vm_fault_t fault, major = 0;
-	unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC;
+	unsigned long vm_flags = VM_ACCESS_FLAGS;
 	unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	if (kprobe_page_fault(regs, esr))
diff --git a/arch/c6x/include/asm/processor.h b/arch/c6x/include/asm/processor.h
index 1456f5e11de3..77372b8c28d7 100644
--- a/arch/c6x/include/asm/processor.h
+++ b/arch/c6x/include/asm/processor.h
@@ -57,7 +57,7 @@ struct thread_struct {
 }
 
 #define INIT_MMAP { \
-	&init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, \
+	&init_mm, 0, 0, NULL, PAGE_SHARED, VM_ACCESS_FLAGS, 1, \
 	NULL, NULL }
 
 #define task_pt_regs(task) \
diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c
index 906dfb25353c..55387a31bf42 100644
--- a/arch/nds32/mm/fault.c
+++ b/arch/nds32/mm/fault.c
@@ -79,7 +79,7 @@ void do_page_fault(unsigned long entry, unsigned long addr,
 	struct vm_area_struct *vma;
 	int si_code;
 	vm_fault_t fault;
-	unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
+	unsigned int mask = VM_ACCESS_FLAGS;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	error_code = error_code & (ITYPE_mskINST | ITYPE_mskETYPE);
diff --git a/arch/nios2/include/asm/processor.h b/arch/nios2/include/asm/processor.h
index 94bcb86f679f..fbfb3ab14cfc 100644
--- a/arch/nios2/include/asm/processor.h
+++ b/arch/nios2/include/asm/processor.h
@@ -51,7 +51,7 @@ struct thread_struct {
 };
 
 #define INIT_MMAP \
-	{ &init_mm, (0), (0), __pgprot(0x0), VM_READ | VM_WRITE | VM_EXEC }
+	{ &init_mm, (0), (0), __pgprot(0x0), VM_ACCESS_FLAGS }
 
 # define INIT_THREAD {			\
 	.kregs	= NULL,			\
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 59e0ebbd8036..11fd52b24f68 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -315,7 +315,7 @@ int __execute_only_pkey(struct mm_struct *mm)
 static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
 {
 	/* Do this check first since the vm_flags should be hot */
-	if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC)
+	if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC)
 		return false;
 
 	return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey);
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 7b0bb475c166..b2cb3c0d0e1a 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -584,7 +584,7 @@ void do_dat_exception(struct pt_regs *regs)
 	int access;
 	vm_fault_t fault;
 
-	access = VM_READ | VM_EXEC | VM_WRITE;
+	access = VM_ACCESS_FLAGS;
 	fault = do_exception(regs, access);
 	if (unlikely(fault))
 		do_fault_error(regs, access, fault);
diff --git a/arch/sh/include/asm/processor_64.h b/arch/sh/include/asm/processor_64.h
index 53efc9f51ef1..3b8187284e3f 100644
--- a/arch/sh/include/asm/processor_64.h
+++ b/arch/sh/include/asm/processor_64.h
@@ -121,7 +121,7 @@ struct thread_struct {
 };
 
 #define INIT_MMAP \
-{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
+{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_ACCESS_FLAGS, 1, NULL, NULL }
 
 #define INIT_THREAD  {				\
 	.sp		= sizeof(init_stack) +	\
diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c
index 76342de9cf8c..fc27c274d358 100644
--- a/arch/unicore32/mm/fault.c
+++ b/arch/unicore32/mm/fault.c
@@ -149,7 +149,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
  */
 static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
 {
-	unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
+	unsigned int mask = VM_ACCESS_FLAGS;
 
 	if (!(fsr ^ 0x12))	/* write? */
 		mask = VM_WRITE;
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index c6f84c0b5d7a..8873ed1438a9 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -63,7 +63,7 @@ int __execute_only_pkey(struct mm_struct *mm)
 static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
 {
 	/* Do this check first since the vm_flags should be hot */
-	if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC)
+	if ((vma->vm_flags & VM_ACCESS_FLAGS) != VM_EXEC)
 		return false;
 	if (vma_pkey(vma) != vma->vm_mm->context.execute_only_pkey)
 		return false;
diff --git a/drivers/staging/gasket/gasket_core.c b/drivers/staging/gasket/gasket_core.c
index be6b50f454b4..81bb7d58dc49 100644
--- a/drivers/staging/gasket/gasket_core.c
+++ b/drivers/staging/gasket/gasket_core.c
@@ -689,7 +689,7 @@ static bool gasket_mmap_has_permissions(struct gasket_dev *gasket_dev,
 
 	/* Make sure that no wrong flags are set. */
 	requested_permissions =
-		(vma->vm_flags & (VM_WRITE | VM_READ | VM_EXEC));
+		(vma->vm_flags & VM_ACCESS_FLAGS);
 	if (requested_permissions & ~(bar_permissions)) {
 		dev_dbg(gasket_dev->dev,
 			"Attempting to map a region with requested permissions "
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7a764ae6ab68..525026df1e58 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -368,6 +368,8 @@ extern unsigned int kobjsize(const void *objp);
 #endif
 
 #define VM_STACK_FLAGS	(VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
+#define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC)
+
 
 /*
  * Special vmas that are non-mergable, non-mlock()able.
@@ -558,7 +560,7 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma)
 
 static inline bool vma_is_accessible(struct vm_area_struct *vma)
 {
-	return vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC);
+	return vma->vm_flags & VM_ACCESS_FLAGS;
 }
 
 #ifdef CONFIG_SHMEM
diff --git a/mm/mmap.c b/mm/mmap.c
index 0d295f49b24d..f9a01763857b 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -106,7 +106,7 @@ static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
 pgprot_t vm_get_page_prot(unsigned long vm_flags)
 {
 	pgprot_t ret = __pgprot(pgprot_val(protection_map[vm_flags &
-				(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+				(VM_ACCESS_FLAGS | VM_SHARED)]) |
 			pgprot_val(arch_vm_get_page_prot(vm_flags)));
 
 	return arch_filter_pgprot(ret);
@@ -1221,7 +1221,7 @@ static int anon_vma_compatible(struct vm_area_struct *a, struct vm_area_struct *
 	return a->vm_end == b->vm_start &&
 		mpol_equal(vma_policy(a), vma_policy(b)) &&
 		a->vm_file == b->vm_file &&
-		!((a->vm_flags ^ b->vm_flags) & ~(VM_READ|VM_WRITE|VM_EXEC|VM_SOFTDIRTY)) &&
+		!((a->vm_flags ^ b->vm_flags) & ~(VM_ACCESS_FLAGS | VM_SOFTDIRTY)) &&
 		b->vm_pgoff == a->vm_pgoff + ((b->vm_start - a->vm_start) >> PAGE_SHIFT);
 }
 
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 7a8e84f86831..4921a4211c6b 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -359,7 +359,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
 	 */
 	if (arch_has_pfn_modify_check() &&
 	    (vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) &&
-	    (newflags & (VM_READ|VM_WRITE|VM_EXEC)) == 0) {
+	    (newflags & VM_ACCESS_FLAGS) == 0) {
 		pgprot_t new_pgprot = vm_get_page_prot(newflags);
 
 		error = walk_page_range(current->mm, start, end,
@@ -530,15 +530,14 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 		 * If a permission is not passed to mprotect(), it must be
 		 * cleared from the VMA.
 		 */
-		mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC |
-					VM_FLAGS_CLEAR;
+		mask_off_old_flags = VM_ACCESS_FLAGS | VM_FLAGS_CLEAR;
 
 		new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey);
 		newflags = calc_vm_prot_bits(prot, new_vma_pkey);
 		newflags |= (vma->vm_flags & ~mask_off_old_flags);
 
 		/* newflags >> 4 shift VM_MAY% in place of VM_% */
-		if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) {
+		if ((newflags & ~(newflags >> 4)) & VM_ACCESS_FLAGS) {
 			error = -EACCES;
 			goto out;
 		}
-- 
2.20.1

Re: [RFC 2/3] mm/vma: Introduce VM_ACCESS_FLAGS

[Vlastimil Babka]

On 3/2/20 7:47 AM, Anshuman Khandual wrote:
> There are many places where all basic VMA access flags (read, write, exec)
> are initialized or checked against as a group. One such example is during
> page fault. Existing vma_is_accessible() wrapper already creates the notion
> of VMA accessibility as a group access permissions. Hence lets just create
> VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which will not only reduce code
> duplication but also extend the VMA accessibility concept in general.
> 
> Cc: Russell King <linux@armlinux.org.uk>
> CC: Catalin Marinas <catalin.marinas@arm.com>
> CC: Mark Salter <msalter@redhat.com>
> Cc: Nick Hu <nickhu@andestech.com>
> CC: Ley Foon Tan <ley.foon.tan@intel.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
> Cc: Guan Xuetao <gxt@pku.edu.cn>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Rob Springer <rspringer@google.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-c6x-dev@linux-c6x.org
> Cc: nios2-dev@lists.rocketboards.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-s390@vger.kernel.org
> Cc: linux-sh@vger.kernel.org
> Cc: devel@driverdev.osuosl.org
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

Dunno. Such mask seems ok for testing flags, but it's a bit awkward when
initializing flags, where it covers just one of many combinations that seem
used. But no strong opinions, patch looks correct.

Re: [RFC 2/3] mm/vma: Introduce VM_ACCESS_FLAGS

[Anshuman Khandual]

On 03/03/2020 11:18 PM, Vlastimil Babka wrote:
> On 3/2/20 7:47 AM, Anshuman Khandual wrote:
>> There are many places where all basic VMA access flags (read, write, exec)
>> are initialized or checked against as a group. One such example is during
>> page fault. Existing vma_is_accessible() wrapper already creates the notion
>> of VMA accessibility as a group access permissions. Hence lets just create
>> VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which will not only reduce code
>> duplication but also extend the VMA accessibility concept in general.
>>
>> Cc: Russell King <linux@armlinux.org.uk>
>> CC: Catalin Marinas <catalin.marinas@arm.com>
>> CC: Mark Salter <msalter@redhat.com>
>> Cc: Nick Hu <nickhu@andestech.com>
>> CC: Ley Foon Tan <ley.foon.tan@intel.com>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
>> Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
>> Cc: Guan Xuetao <gxt@pku.edu.cn>
>> Cc: Dave Hansen <dave.hansen@linux.intel.com>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Rob Springer <rspringer@google.com>
>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: linux-c6x-dev@linux-c6x.org
>> Cc: nios2-dev@lists.rocketboards.org
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Cc: linux-s390@vger.kernel.org
>> Cc: linux-sh@vger.kernel.org
>> Cc: devel@driverdev.osuosl.org
>> Cc: linux-mm@kvack.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> 
> Dunno. Such mask seems ok for testing flags, but it's a bit awkward when
> initializing flags, where it covers just one of many combinations that seem
> used. But no strong opinions, patch looks correct.

Fair enough. The fact that it covers only one of the many init combinations
used at various places, is indeed a good point. The page fault handlers does
start with VMA flags mask as VM_ACCESS_FLAGS, hence will keep them and drop
other init cases here.

[RFC 3/3] mm/vma: Introduce some more VMA flag wrappers

[Anshuman Khandual]

This adds the following new VMA flag wrappers which will replace current
open encodings across various places. This should not have any functional
implications.

vma_is_dontdump()
vma_is_noreserve()
vma_is_special()
vma_is_locked()
vma_is_mergeable()
vma_is_softdirty()
vma_is_thp()
vma_is_nothp()

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: sparclinux@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/sparc/include/asm/mman.h |  2 +-
 fs/binfmt_elf.c               |  2 +-
 fs/proc/task_mmu.c            | 14 ++++++-------
 include/linux/huge_mm.h       |  4 ++--
 include/linux/mm.h            | 39 +++++++++++++++++++++++++++++++++++
 kernel/events/core.c          |  2 +-
 kernel/events/uprobes.c       |  2 +-
 mm/gup.c                      |  2 +-
 mm/huge_memory.c              |  6 +++---
 mm/hugetlb.c                  |  4 ++--
 mm/ksm.c                      |  8 +++----
 mm/madvise.c                  |  4 ++--
 mm/memory.c                   |  4 ++--
 mm/migrate.c                  |  4 ++--
 mm/mlock.c                    |  4 ++--
 mm/mmap.c                     | 16 +++++++-------
 mm/mprotect.c                 |  2 +-
 mm/mremap.c                   |  4 ++--
 mm/msync.c                    |  3 +--
 mm/rmap.c                     |  6 +++---
 mm/shmem.c                    |  8 +++----
 21 files changed, 89 insertions(+), 51 deletions(-)

diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h
index f94532f25db1..661c56add451 100644
--- a/arch/sparc/include/asm/mman.h
+++ b/arch/sparc/include/asm/mman.h
@@ -80,7 +80,7 @@ static inline int sparc_validate_prot(unsigned long prot, unsigned long addr)
 				 * tags on them. Disallow ADI on mergeable
 				 * pages.
 				 */
-				if (vma->vm_flags & VM_MERGEABLE)
+				if (vma_is_mergeable(vma))
 					return 0;
 			}
 		}
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 1eb63867e266..5d41047a4a77 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1305,7 +1305,7 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
 	if (always_dump_vma(vma))
 		goto whole;
 
-	if (vma->vm_flags & VM_DONTDUMP)
+	if (vma_is_dontdump(vma))
 		return 0;
 
 	/* support for DAX */
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 3ba9ae83bff5..e425a8cc6c15 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -523,7 +523,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 {
 	struct mem_size_stats *mss = walk->private;
 	struct vm_area_struct *vma = walk->vma;
-	bool locked = !!(vma->vm_flags & VM_LOCKED);
+	bool locked = vma_is_locked(vma);
 	struct page *page = NULL;
 
 	if (pte_present(*pte)) {
@@ -575,7 +575,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
 {
 	struct mem_size_stats *mss = walk->private;
 	struct vm_area_struct *vma = walk->vma;
-	bool locked = !!(vma->vm_flags & VM_LOCKED);
+	bool locked = vma_is_locked(vma);
 	struct page *page;
 
 	/* FOLL_DUMP will return -EFAULT on huge zero page */
@@ -1187,7 +1187,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 		tlb_gather_mmu(&tlb, mm, 0, -1);
 		if (type == CLEAR_REFS_SOFT_DIRTY) {
 			for (vma = mm->mmap; vma; vma = vma->vm_next) {
-				if (!(vma->vm_flags & VM_SOFTDIRTY))
+				if (!vma_is_softdirty(vma))
 					continue;
 				up_read(&mm->mmap_sem);
 				if (down_write_killable(&mm->mmap_sem)) {
@@ -1309,7 +1309,7 @@ static int pagemap_pte_hole(unsigned long start, unsigned long end,
 			break;
 
 		/* Addresses in the VMA. */
-		if (vma->vm_flags & VM_SOFTDIRTY)
+		if (vma_is_softdirty(vma))
 			pme = make_pme(0, PM_SOFT_DIRTY);
 		for (; addr < min(end, vma->vm_end); addr += PAGE_SIZE) {
 			err = add_to_pagemap(addr, &pme, pm);
@@ -1354,7 +1354,7 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
 		flags |= PM_FILE;
 	if (page && page_mapcount(page) == 1)
 		flags |= PM_MMAP_EXCLUSIVE;
-	if (vma->vm_flags & VM_SOFTDIRTY)
+	if (vma_is_softdirty(vma))
 		flags |= PM_SOFT_DIRTY;
 
 	return make_pme(frame, flags);
@@ -1376,7 +1376,7 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
 		pmd_t pmd = *pmdp;
 		struct page *page = NULL;
 
-		if (vma->vm_flags & VM_SOFTDIRTY)
+		if (vma_is_softdirty(vma))
 			flags |= PM_SOFT_DIRTY;
 
 		if (pmd_present(pmd)) {
@@ -1464,7 +1464,7 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
 	int err = 0;
 	pte_t pte;
 
-	if (vma->vm_flags & VM_SOFTDIRTY)
+	if (vma_is_softdirty(vma))
 		flags |= PM_SOFT_DIRTY;
 
 	pte = huge_ptep_get(ptep);
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 5aca3d1bdb32..e04bd9eef47e 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -97,7 +97,7 @@ extern unsigned long transparent_hugepage_flags;
  */
 static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 {
-	if (vma->vm_flags & VM_NOHUGEPAGE)
+	if (vma_is_nothp(vma))
 		return false;
 
 	if (is_vma_temporary_stack(vma))
@@ -119,7 +119,7 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 
 	if (transparent_hugepage_flags &
 				(1 << TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
-		return !!(vma->vm_flags & VM_HUGEPAGE);
+		return vma_is_thp(vma);
 
 	return false;
 }
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 525026df1e58..4927e939a51d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -563,6 +563,45 @@ static inline bool vma_is_accessible(struct vm_area_struct *vma)
 	return vma->vm_flags & VM_ACCESS_FLAGS;
 }
 
+static inline bool vma_is_dontdump(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_DONTDUMP;
+}
+
+static inline bool vma_is_noreserve(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_NORESERVE;
+}
+
+static inline bool vma_is_special(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_SPECIAL;
+}
+
+static inline bool vma_is_locked(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_LOCKED;
+}
+
+static inline bool vma_is_thp(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_HUGEPAGE;
+}
+
+static inline bool vma_is_nothp(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_NOHUGEPAGE;
+}
+
+static inline bool vma_is_mergeable(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_MERGEABLE;
+}
+
+static inline bool vma_is_softdirty(struct vm_area_struct *vma)
+{
+	return vma->vm_flags & VM_SOFTDIRTY;
+}
 #ifdef CONFIG_SHMEM
 /*
  * The vma_is_shmem is not inline because it is used only by slow
diff --git a/kernel/events/core.c b/kernel/events/core.c
index ef5be3ed0580..8f7a4b15026a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7692,7 +7692,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
 		flags |= MAP_DENYWRITE;
 	if (vma->vm_flags & VM_MAYEXEC)
 		flags |= MAP_EXECUTABLE;
-	if (vma->vm_flags & VM_LOCKED)
+	if (vma_is_locked(vma))
 		flags |= MAP_LOCKED;
 	if (is_vm_hugetlb_page(vma))
 		flags |= MAP_HUGETLB;
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index ece7e13f6e4a..5527098c1912 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -211,7 +211,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
 		try_to_free_swap(old_page);
 	page_vma_mapped_walk_done(&pvmw);
 
-	if (vma->vm_flags & VM_LOCKED)
+	if (vma_is_locked(vma))
 		munlock_vma_page(old_page);
 	put_page(old_page);
 
diff --git a/mm/gup.c b/mm/gup.c
index 58c8cbfeded6..ca23d23a90f2 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -289,7 +289,7 @@ static struct page *follow_page_pte(struct vm_area_struct *vma,
 		 */
 		mark_page_accessed(page);
 	}
-	if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
+	if ((flags & FOLL_MLOCK) && vma_is_locked(vma)) {
 		/* Do not mlock pte-mapped THP */
 		if (PageTransCompound(page))
 			goto out;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b08b199f9a11..d59ecb872ff2 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -674,7 +674,7 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf,
  */
 static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma)
 {
-	const bool vma_madvised = !!(vma->vm_flags & VM_HUGEPAGE);
+	const bool vma_madvised = vma_is_thp(vma);
 
 	/* Always do synchronous compaction */
 	if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags))
@@ -1499,7 +1499,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
 	VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page);
 	if (flags & FOLL_TOUCH)
 		touch_pmd(vma, addr, pmd, flags);
-	if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) {
+	if ((flags & FOLL_MLOCK) && vma_is_locked(vma)) {
 		/*
 		 * We don't mlock() pte-mapped THPs. This way we can avoid
 		 * leaking mlocked pages into non-VM_LOCKED VMAs.
@@ -3082,7 +3082,7 @@ void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new)
 	else
 		page_add_file_rmap(new, true);
 	set_pmd_at(mm, mmun_start, pvmw->pmd, pmde);
-	if ((vma->vm_flags & VM_LOCKED) && !PageDoubleMap(new))
+	if (vma_is_locked(vma) && !PageDoubleMap(new))
 		mlock_vma_page(new);
 	update_mmu_cache_pmd(vma, address, pvmw->pmd);
 }
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dd8737a94bec..efe40f533224 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -757,7 +757,7 @@ void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
 /* Returns true if the VMA has associated reserve pages */
 static bool vma_has_reserves(struct vm_area_struct *vma, long chg)
 {
-	if (vma->vm_flags & VM_NORESERVE) {
+	if (vma_is_noreserve(vma)) {
 		/*
 		 * This address is already reserved by other process(chg == 0),
 		 * so, we should decrement reserved count. Without decrementing,
@@ -4558,7 +4558,7 @@ int hugetlb_reserve_pages(struct inode *inode,
 	 * attempt will be made for VM_NORESERVE to allocate a page
 	 * without using reserves
 	 */
-	if (vm_flags & VM_NORESERVE)
+	if (vma_is_noreserve(vma))
 		return 0;
 
 	/*
diff --git a/mm/ksm.c b/mm/ksm.c
index d17c7d57d0d8..8bf11a543c27 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -525,7 +525,7 @@ static struct vm_area_struct *find_mergeable_vma(struct mm_struct *mm,
 	vma = find_vma(mm, addr);
 	if (!vma || vma->vm_start > addr)
 		return NULL;
-	if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+	if (!vma_is_mergeable(vma) || !vma->anon_vma)
 		return NULL;
 	return vma;
 }
@@ -980,7 +980,7 @@ static int unmerge_and_remove_all_rmap_items(void)
 		for (vma = mm->mmap; vma; vma = vma->vm_next) {
 			if (ksm_test_exit(mm))
 				break;
-			if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
+			if (!vma_is_mergeable(vma) || !vma->anon_vma)
 				continue;
 			err = unmerge_ksm_pages(vma,
 						vma->vm_start, vma->vm_end);
@@ -1251,7 +1251,7 @@ static int try_to_merge_one_page(struct vm_area_struct *vma,
 			err = replace_page(vma, page, kpage, orig_pte);
 	}
 
-	if ((vma->vm_flags & VM_LOCKED) && kpage && !err) {
+	if (vma_is_locked(vma) && kpage && !err) {
 		munlock_vma_page(page);
 		if (!PageMlocked(kpage)) {
 			unlock_page(page);
@@ -2284,7 +2284,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
 		vma = find_vma(mm, ksm_scan.address);
 
 	for (; vma; vma = vma->vm_next) {
-		if (!(vma->vm_flags & VM_MERGEABLE))
+		if (!vma_is_mergeable(vma))
 			continue;
 		if (ksm_scan.address < vma->vm_start)
 			ksm_scan.address = vma->vm_start;
diff --git a/mm/madvise.c b/mm/madvise.c
index 43b47d3fae02..ffd6a4ff4c99 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -106,7 +106,7 @@ static long madvise_behavior(struct vm_area_struct *vma,
 		new_flags |= VM_DONTDUMP;
 		break;
 	case MADV_DODUMP:
-		if (!is_vm_hugetlb_page(vma) && new_flags & VM_SPECIAL) {
+		if (!is_vm_hugetlb_page(vma) && vma_is_special(vma)) {
 			error = -EINVAL;
 			goto out;
 		}
@@ -821,7 +821,7 @@ static long madvise_remove(struct vm_area_struct *vma,
 
 	*prev = NULL;	/* tell sys_madvise we drop mmap_sem */
 
-	if (vma->vm_flags & VM_LOCKED)
+	if (vma_is_locked(vma))
 		return -EINVAL;
 
 	f = vma->vm_file;
diff --git a/mm/memory.c b/mm/memory.c
index 2f07747612b7..c45386dae91b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2604,7 +2604,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 		 * Don't let another task, with possibly unlocked vma,
 		 * keep the mlocked page.
 		 */
-		if (page_copied && (vma->vm_flags & VM_LOCKED)) {
+		if (page_copied && vma_is_locked(vma)) {
 			lock_page(old_page);	/* LRU manipulation */
 			if (PageMlocked(old_page))
 				munlock_vma_page(old_page);
@@ -3083,7 +3083,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 
 	swap_free(entry);
 	if (mem_cgroup_swap_full(page) ||
-	    (vma->vm_flags & VM_LOCKED) || PageMlocked(page))
+	    vma_is_locked(vma) || PageMlocked(page))
 		try_to_free_swap(page);
 	unlock_page(page);
 	if (page != swapcache && swapcache) {
diff --git a/mm/migrate.c b/mm/migrate.c
index b1092876e537..45ac5b750e77 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -270,7 +270,7 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
 			else
 				page_add_file_rmap(new, false);
 		}
-		if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new))
+		if (vma_is_locked(vma) && !PageTransCompound(new))
 			mlock_vma_page(new);
 
 		if (PageTransHuge(page) && PageMlocked(page))
@@ -2664,7 +2664,7 @@ int migrate_vma_setup(struct migrate_vma *args)
 	args->start &= PAGE_MASK;
 	args->end &= PAGE_MASK;
 	if (!args->vma || is_vm_hugetlb_page(args->vma) ||
-	    (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma))
+	    (vma_is_special(args->vma) || vma_is_dax(args->vma))
 		return -EINVAL;
 	if (nr_pages <= 0)
 		return -EINVAL;
diff --git a/mm/mlock.c b/mm/mlock.c
index a72c1eeded77..3d4f66f2dee9 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -526,7 +526,7 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
 	int lock = !!(newflags & VM_LOCKED);
 	vm_flags_t old_flags = vma->vm_flags;
 
-	if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
+	if (newflags == vma->vm_flags || vma_is_special(vma) ||
 	    is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm) ||
 	    vma_is_dax(vma))
 		/* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */
@@ -654,7 +654,7 @@ static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm,
 			continue;
 		if (start + len <=  vma->vm_start)
 			break;
-		if (vma->vm_flags & VM_LOCKED) {
+		if (vma_is_locked(vma)) {
 			if (start > vma->vm_start)
 				count -= (start - vma->vm_start);
 			if (start + len < vma->vm_end) {
diff --git a/mm/mmap.c b/mm/mmap.c
index f9a01763857b..c93cad8aa9ac 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2279,7 +2279,7 @@ static int acct_stack_growth(struct vm_area_struct *vma,
 		return -ENOMEM;
 
 	/* mlock limit tests */
-	if (vma->vm_flags & VM_LOCKED) {
+	if (vma_is_locked(vma)) {
 		unsigned long locked;
 		unsigned long limit;
 		locked = mm->locked_vm + grow;
@@ -2374,7 +2374,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 				 * against concurrent vma expansions.
 				 */
 				spin_lock(&mm->page_table_lock);
-				if (vma->vm_flags & VM_LOCKED)
+				if (vma_is_locked(vma))
 					mm->locked_vm += grow;
 				vm_stat_account(mm, vma->vm_flags, grow);
 				anon_vma_interval_tree_pre_update_vma(vma);
@@ -2454,7 +2454,7 @@ int expand_downwards(struct vm_area_struct *vma,
 				 * against concurrent vma expansions.
 				 */
 				spin_lock(&mm->page_table_lock);
-				if (vma->vm_flags & VM_LOCKED)
+				if (vma_is_locked(vma))
 					mm->locked_vm += grow;
 				vm_stat_account(mm, vma->vm_flags, grow);
 				anon_vma_interval_tree_pre_update_vma(vma);
@@ -2508,7 +2508,7 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr)
 	/* don't alter vm_end if the coredump is running */
 	if (!prev || !mmget_still_valid(mm) || expand_stack(prev, addr))
 		return NULL;
-	if (prev->vm_flags & VM_LOCKED)
+	if (vma_is_locked(prev))
 		populate_vma_page_range(prev, addr, prev->vm_end, NULL);
 	return prev;
 }
@@ -2538,7 +2538,7 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr)
 	start = vma->vm_start;
 	if (expand_stack(vma, addr))
 		return NULL;
-	if (vma->vm_flags & VM_LOCKED)
+	if (vma_is_locked(vma))
 		populate_vma_page_range(vma, addr, start, NULL);
 	return vma;
 }
@@ -2790,7 +2790,7 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
 	if (mm->locked_vm) {
 		struct vm_area_struct *tmp = vma;
 		while (tmp && tmp->vm_start < end) {
-			if (tmp->vm_flags & VM_LOCKED) {
+			if (vma_is_locked(tmp)) {
 				mm->locked_vm -= vma_pages(tmp);
 				munlock_vma_pages_all(tmp);
 			}
@@ -2925,7 +2925,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 
 	flags &= MAP_NONBLOCK;
 	flags |= MAP_SHARED | MAP_FIXED | MAP_POPULATE;
-	if (vma->vm_flags & VM_LOCKED) {
+	if (vma_is_locked(vma)) {
 		struct vm_area_struct *tmp;
 		flags |= MAP_LOCKED;
 
@@ -3105,7 +3105,7 @@ void exit_mmap(struct mm_struct *mm)
 	if (mm->locked_vm) {
 		vma = mm->mmap;
 		while (vma) {
-			if (vma->vm_flags & VM_LOCKED)
+			if (vma_is_locked(vma))
 				munlock_vma_pages_all(vma);
 			vma = vma->vm_next;
 		}
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 4921a4211c6b..d7d4629979fc 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -117,7 +117,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 			/* Avoid taking write faults for known dirty pages */
 			if (dirty_accountable && pte_dirty(ptent) &&
 					(pte_soft_dirty(ptent) ||
-					 !(vma->vm_flags & VM_SOFTDIRTY))) {
+					 !vma_is_softdirty(vma))) {
 				ptent = pte_mkwrite(ptent);
 			}
 			ptep_modify_prot_commit(vma, addr, pte, oldpte, ptent);
diff --git a/mm/mremap.c b/mm/mremap.c
index af363063ea23..25d5ecbb783f 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -472,7 +472,7 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
 	if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
 		return ERR_PTR(-EFAULT);
 
-	if (vma->vm_flags & VM_LOCKED) {
+	if (vma_is_locked(vma)) {
 		unsigned long locked, lock_limit;
 		locked = mm->locked_vm << PAGE_SHIFT;
 		lock_limit = rlimit(RLIMIT_MEMLOCK);
@@ -681,7 +681,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 			}
 
 			vm_stat_account(mm, vma->vm_flags, pages);
-			if (vma->vm_flags & VM_LOCKED) {
+			if (vma_is_locked(vma)) {
 				mm->locked_vm += pages;
 				locked = true;
 				new_addr = addr;
diff --git a/mm/msync.c b/mm/msync.c
index c3bd3e75f687..e02327f8ccca 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -75,8 +75,7 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
 			unmapped_error = -ENOMEM;
 		}
 		/* Here vma->vm_start <= start < vma->vm_end. */
-		if ((flags & MS_INVALIDATE) &&
-				(vma->vm_flags & VM_LOCKED)) {
+		if ((flags & MS_INVALIDATE) && vma_is_locked(vma)) {
 			error = -EBUSY;
 			goto out_unlock;
 		}
diff --git a/mm/rmap.c b/mm/rmap.c
index b3e381919835..b7941238aea9 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -785,7 +785,7 @@ static bool page_referenced_one(struct page *page, struct vm_area_struct *vma,
 	while (page_vma_mapped_walk(&pvmw)) {
 		address = pvmw.address;
 
-		if (vma->vm_flags & VM_LOCKED) {
+		if (vma_is_locked(vma)) {
 			page_vma_mapped_walk_done(&pvmw);
 			pra->vm_flags |= VM_LOCKED;
 			return false; /* To break the loop */
@@ -1379,7 +1379,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	enum ttu_flags flags = (enum ttu_flags)arg;
 
 	/* munlock has nothing to gain from examining un-locked vmas */
-	if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED))
+	if ((flags & TTU_MUNLOCK) && !vma_is_locked(vma))
 		return true;
 
 	if (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION) &&
@@ -1429,7 +1429,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 		 * skipped over this mm) then we should reactivate it.
 		 */
 		if (!(flags & TTU_IGNORE_MLOCK)) {
-			if (vma->vm_flags & VM_LOCKED) {
+			if (vma_is_locked(vma)) {
 				/* PTE-mapped THP are never mlocked */
 				if (!PageTransCompound(page)) {
 					/*
diff --git a/mm/shmem.c b/mm/shmem.c
index aad3ba74b0e9..23fb58bb1e94 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2058,10 +2058,10 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
 
 	sgp = SGP_CACHE;
 
-	if ((vma->vm_flags & VM_NOHUGEPAGE) ||
+	if (vma_is_nothp(vma) ||
 	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
 		sgp = SGP_NOHUGE;
-	else if (vma->vm_flags & VM_HUGEPAGE)
+	else if (vma_is_thp(vma))
 		sgp = SGP_HUGE;
 
 	err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
@@ -3986,7 +3986,7 @@ bool shmem_huge_enabled(struct vm_area_struct *vma)
 	loff_t i_size;
 	pgoff_t off;
 
-	if ((vma->vm_flags & VM_NOHUGEPAGE) ||
+	if (vma_is_nothp(vma) ||
 	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
 		return false;
 	if (shmem_huge == SHMEM_HUGE_FORCE)
@@ -4007,7 +4007,7 @@ bool shmem_huge_enabled(struct vm_area_struct *vma)
 			/* fall through */
 		case SHMEM_HUGE_ADVISE:
 			/* TODO: implement fadvise() hints */
-			return (vma->vm_flags & VM_HUGEPAGE);
+			return (vma_is_thp(vma));
 		default:
 			VM_BUG_ON(1);
 			return false;
-- 
2.20.1

Re: [RFC 3/3] mm/vma: Introduce some more VMA flag wrappers

[Hugh Dickins]

On Mon, 2 Mar 2020, Anshuman Khandual wrote:

> This adds the following new VMA flag wrappers which will replace current
> open encodings across various places. This should not have any functional
> implications.
> 
> vma_is_dontdump()
> vma_is_noreserve()
> vma_is_special()
> vma_is_locked()
> vma_is_mergeable()
> vma_is_softdirty()
> vma_is_thp()
> vma_is_nothp()

Why?? Please don't. I am not at all keen on your 1/3 and 2/3 (some
of us actually like to see what the VM_ flags are where they're used,
without having to chase through scattered wrappers hiding them),
but this 3/3 particularly upset me.

There is a good reason for the (hideously named) is_vm_hugetlb_page(vma):
to save "#ifdef CONFIG_HUGETLB_PAGE"s all over (though I suspect the
same could have been achieved much more nicely by #define VM_HUGETLB 0);
but hiding all flags in vma_is_whatever()s is counter-productive churn.

Improved readability? Not to my eyes.

Hugh

Re: [RFC 3/3] mm/vma: Introduce some more VMA flag wrappers

[Anshuman Khandual]

On 03/03/2020 12:04 PM, Hugh Dickins wrote:
> On Mon, 2 Mar 2020, Anshuman Khandual wrote:
> 
>> This adds the following new VMA flag wrappers which will replace current
>> open encodings across various places. This should not have any functional
>> implications.
>>
>> vma_is_dontdump()
>> vma_is_noreserve()
>> vma_is_special()
>> vma_is_locked()
>> vma_is_mergeable()
>> vma_is_softdirty()
>> vma_is_thp()
>> vma_is_nothp()
> 
> Why?? Please don't. I am not at all keen on your 1/3 and 2/3 (some
> of us actually like to see what the VM_ flags are where they're used,
> without having to chase through scattered wrappers hiding them),
> but this 3/3 particularly upset me.

Can understand your reservations regarding 3/3. But I had called that out
in the series cover letter that this patch can be dropped if related code
churn is not justified.

But 1/3 does create a default flag combination for VM_DATA_DEFAULT_FLAGS
with a value that is used by multiple platforms at the moment. This is
very similar to the existing VM_STACK_DEFAULT_FLAGS which has a default
value. Then why cannot VM_DATA_DEFAULT_FLAGS have one ? More over this
also saves some code duplication across platforms.

Regarding the patch 2/3, when there are many existing VMA flag overrides
like VM_STACK_FLAGS, VM_STACK_INCOMPLETE_SETUP, VM_INIT_DEF_MASK etc why
cannot a commonly used VMA flag combination with a very specific meaning
(i.e accessibility) get one. Do you have any particular concern here
which I might be missing.

> 
> There is a good reason for the (hideously named) is_vm_hugetlb_page(vma):
> to save "#ifdef CONFIG_HUGETLB_PAGE"s all over (though I suspect the
> same could have been achieved much more nicely by #define VM_HUGETLB 0);
> but hiding all flags in vma_is_whatever()s is counter-productive churn.

Makes sense, I can understand your reservation here.

> 
> Improved readability? Not to my eyes.

As mentioned before, I dont feel strongly about patch 3/3 and will drop.

Re: [RFC 3/3] mm/vma: Introduce some more VMA flag wrappers

[Alexey Dobriyan]

On Tue, Mar 03, 2020 at 02:43:21PM +0530, Anshuman Khandual wrote:
> On 03/03/2020 12:04 PM, Hugh Dickins wrote:
> > On Mon, 2 Mar 2020, Anshuman Khandual wrote:

> >> vma_is_dontdump()
> >> vma_is_noreserve()
> >> vma_is_special()
> >> vma_is_locked()
> >> vma_is_mergeable()
> >> vma_is_softdirty()
> >> vma_is_thp()
> >> vma_is_nothp()

> > Improved readability? Not to my eyes.
> 
> As mentioned before, I dont feel strongly about patch 3/3 and will drop.

Should be "const struct vm_area_struct *" anyway.