[PATCH V5 0/7] mm/mmap: Drop arch_vm_get_page_prot() and arch_filter_pgprot()

[PATCH V5 0/7] mm/mmap: Drop arch_vm_get_page_prot() and arch_filter_pgprot()

[Anshuman Khandual]

protection_map[] is an array based construct that translates given vm_flags
combination. This array contains page protection map, which is populated by
the platform via [__S000 .. __S111] and [__P000 .. __P111] exported macros.
Primary usage for protection_map[] is for vm_get_page_prot(), which is used
to determine page protection value for a given vm_flags. vm_get_page_prot()
implementation, could again call platform overrides arch_vm_get_page_prot()
and arch_filter_pgprot(). Some platforms override protection_map[] that was
originally built with __SXXX/__PXXX with different runtime values.

Currently there are multiple layers of abstraction i.e __SXXX/__PXXX macros
, protection_map[], arch_vm_get_page_prot() and arch_filter_pgprot() built
between the platform and generic MM, finally defining vm_get_page_prot().

Hence this series proposes to drop later two abstraction levels and instead
just move the responsibility of defining vm_get_page_prot() to the platform
(still utilizing generic protection_map[] array) itself making it clean and
simple.

This first introduces ARCH_HAS_VM_GET_PAGE_PROT which enables the platforms
to define custom vm_get_page_prot(). This starts converting platforms that
define the overrides arch_filter_pgprot() or arch_vm_get_page_prot() which
enables for those constructs to be dropped off completely.

The series has been inspired from an earlier discuss with Christoph Hellwig

https://lore.kernel.org/all/1632712920-8171-1-git-send-email-anshuman.khandual@arm.com/

This series applies on 5.18-rc2.

This series has been cross built for multiple platforms.

- Anshuman

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: sparclinux@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Changes in V5:

- Collected new tags on various patches in the series
- Coalesced arm64_arch_vm_get_page_prot() into vm_get_page_prot() per Catalin
- Modified powerpc's vm_get_page_prot() implementation per Christophe

Changes in V4:

https://lore.kernel.org/all/20220407103251.1209606-1-anshuman.khandual@arm.com/

- ARCH_HAS_VM_GET_PAGE_PROT now excludes generic protection_map[]
- Changed platform's vm_get_page_prot() to use generic protection_map[]
- Dropped all platform changes not enabling either arch_vm_get_page_prot() or arch_filter_pgprot() 
- Dropped all previous tags as code base has changed

Changes in V3:

https://lore.kernel.org/all/1646045273-9343-1-git-send-email-anshuman.khandual@arm.com/

- Dropped variable 'i' from sme_early_init() on x86 platform
- Moved CONFIG_COLDFIRE vm_get_page_prot() inside arch/m68k/mm/mcfmmu.c
- Moved CONFIG_SUN3 vm_get_page_prot() inside arch/m68k/mm/sun3mmu.c
- Dropped cachebits for vm_get_page_prot() inside arch/m68k/mm/motorola.c
- Dropped PAGE_XXX_C definitions from arch/m68k/include/asm/motorola_pgtable.h
- Used PAGE_XXX instead for vm_get_page_prot() inside arch/m68k/mm/motorola.c
- Dropped all references to protection_map[] in the tree
- Replaced s/extensa/xtensa/ on the patch title
- Moved left over comments from pgtable.h into init.c on nios2 platform

Changes in V2:

https://lore.kernel.org/all/1645425519-9034-1-git-send-email-anshuman.khandual@arm.com/

- Dropped the entire comment block in [PATCH 30/30] per Geert
- Replaced __P010 (although commented) with __PAGE_COPY on arm platform
- Replaced __P101 with PAGE_READONLY on um platform

Changes in V1:

https://lore.kernel.org/all/1644805853-21338-1-git-send-email-anshuman.khandual@arm.com/

- Add white spaces around the | operators 
- Moved powerpc_vm_get_page_prot() near vm_get_page_prot() on powerpc
- Moved arm64_vm_get_page_prot() near vm_get_page_prot() on arm64
- Moved sparc_vm_get_page_prot() near vm_get_page_prot() on sparc
- Compacted vm_get_page_prot() switch cases on all platforms
-  _PAGE_CACHE040 inclusion is dependent on CPU_IS_040_OR_060
- VM_SHARED case should return PAGE_NONE (not PAGE_COPY) on SH platform
- Reorganized VM_SHARED, VM_EXEC, VM_WRITE, VM_READ
- Dropped the last patch [RFC V1 31/31] which added macros for vm_flags combinations
  https://lore.kernel.org/all/1643029028-12710-32-git-send-email-anshuman.khandual@arm.com/

Changes in RFC:

https://lore.kernel.org/all/1643029028-12710-1-git-send-email-anshuman.khandual@arm.com/


Anshuman Khandual (6):
  mm/mmap: Add new config ARCH_HAS_VM_GET_PAGE_PROT
  powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT
  arm64/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT
  sparc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT
  mm/mmap: Drop arch_filter_pgprot()
  mm/mmap: Drop arch_vm_get_page_pgprot()

Christoph Hellwig (1):
  x86/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

 arch/arm64/Kconfig                 |  1 +
 arch/arm64/include/asm/mman.h      | 24 --------------------
 arch/arm64/mm/mmap.c               | 25 +++++++++++++++++++++
 arch/powerpc/Kconfig               |  1 +
 arch/powerpc/include/asm/mman.h    | 12 ----------
 arch/powerpc/mm/book3s64/pgtable.c | 20 +++++++++++++++++
 arch/sparc/Kconfig                 |  1 +
 arch/sparc/include/asm/mman.h      |  6 -----
 arch/sparc/mm/init_64.c            | 13 +++++++++++
 arch/x86/Kconfig                   |  2 +-
 arch/x86/include/asm/pgtable.h     |  5 -----
 arch/x86/include/uapi/asm/mman.h   | 14 ------------
 arch/x86/mm/Makefile               |  2 +-
 arch/x86/mm/pgprot.c               | 35 ++++++++++++++++++++++++++++++
 include/linux/mman.h               |  4 ----
 mm/Kconfig                         |  2 +-
 mm/mmap.c                          | 14 ++++--------
 17 files changed, 103 insertions(+), 78 deletions(-)
 create mode 100644 arch/x86/mm/pgprot.c

-- 
2.25.1

[PATCH V5 1/7] mm/mmap: Add new config ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

Add a new config ARCH_HAS_VM_GET_PAGE_PROT, which when subscribed enables a
given platform to define its own vm_get_page_prot() but still utilizing the
generic protection_map[] array.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 mm/Kconfig | 3 +++
 mm/mmap.c  | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/mm/Kconfig b/mm/Kconfig
index 034d87953600..b1f7624276f8 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -765,6 +765,9 @@ config ARCH_HAS_CURRENT_STACK_POINTER
 config ARCH_HAS_FILTER_PGPROT
 	bool
 
+config ARCH_HAS_VM_GET_PAGE_PROT
+	bool
+
 config ARCH_HAS_PTE_DEVMAP
 	bool
 
diff --git a/mm/mmap.c b/mm/mmap.c
index 3aa839f81e63..87cb2eaf7e1a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -106,6 +106,7 @@ pgprot_t protection_map[16] __ro_after_init = {
 	__S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
 };
 
+#ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT
 #ifndef CONFIG_ARCH_HAS_FILTER_PGPROT
 static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
 {
@@ -122,6 +123,7 @@ pgprot_t vm_get_page_prot(unsigned long vm_flags)
 	return arch_filter_pgprot(ret);
 }
 EXPORT_SYMBOL(vm_get_page_prot);
+#endif	/* CONFIG_ARCH_HAS_VM_GET_PAGE_PROT */
 
 static pgprot_t vm_pgprot_modify(pgprot_t oldprot, unsigned long vm_flags)
 {
-- 
2.25.1

[PATCH V5 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
arch_vm_get_page_prot() as __vm_get_page_prot() and moves it near
vm_get_page_prot().

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/powerpc/Kconfig               |  1 +
 arch/powerpc/include/asm/mman.h    | 12 ------------
 arch/powerpc/mm/book3s64/pgtable.c | 20 ++++++++++++++++++++
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 174edabb74fa..69e44358a235 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -140,6 +140,7 @@ config PPC
 	select ARCH_HAS_TICK_BROADCAST		if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAS_UACCESS_FLUSHCACHE
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
+	select ARCH_HAS_VM_GET_PAGE_PROT	if PPC_BOOK3S_64
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_KEEP_MEMBLOCK
 	select ARCH_MIGHT_HAVE_PC_PARPORT
diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
index 7cb6d18f5cd6..1b024e64c8ec 100644
--- a/arch/powerpc/include/asm/mman.h
+++ b/arch/powerpc/include/asm/mman.h
@@ -24,18 +24,6 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
 }
 #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
 
-static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
-{
-#ifdef CONFIG_PPC_MEM_KEYS
-	return (vm_flags & VM_SAO) ?
-		__pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
-		__pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
-#else
-	return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
-#endif
-}
-#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
-
 static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
 {
 	if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 052e6590f84f..d0319524e27f 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -7,6 +7,7 @@
 #include <linux/mm_types.h>
 #include <linux/memblock.h>
 #include <linux/memremap.h>
+#include <linux/pkeys.h>
 #include <linux/debugfs.h>
 #include <misc/cxl-base.h>
 
@@ -549,3 +550,22 @@ unsigned long memremap_compat_align(void)
 }
 EXPORT_SYMBOL_GPL(memremap_compat_align);
 #endif
+
+static pgprot_t __vm_get_page_prot(unsigned long vm_flags)
+{
+#ifdef CONFIG_PPC_MEM_KEYS
+	return (vm_flags & VM_SAO) ?
+		__pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
+		__pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
+#else
+	return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
+#endif
+}
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	return __pgprot(pgprot_val(protection_map[vm_flags &
+			(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+			pgprot_val(__vm_get_page_prot(vm_flags)));
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1

[PATCH V5 3/7] arm64/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. It localizes arch_vm_get_page_prot()
and moves it near vm_get_page_prot().

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm64/Kconfig            |  1 +
 arch/arm64/include/asm/mman.h | 24 ------------------------
 arch/arm64/mm/mmap.c          | 25 +++++++++++++++++++++++++
 3 files changed, 26 insertions(+), 24 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 57c4c995965f..dd0b15162bb3 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -45,6 +45,7 @@ config ARM64
 	select ARCH_HAS_SYSCALL_WRAPPER
 	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_HAS_ZONE_DMA_SET if EXPERT
 	select ARCH_HAVE_ELF_PROT
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h
index e3e28f7daf62..5966ee4a6154 100644
--- a/arch/arm64/include/asm/mman.h
+++ b/arch/arm64/include/asm/mman.h
@@ -35,30 +35,6 @@ static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags)
 }
 #define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags)
 
-static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
-{
-	pteval_t prot = 0;
-
-	if (vm_flags & VM_ARM64_BTI)
-		prot |= PTE_GP;
-
-	/*
-	 * There are two conditions required for returning a Normal Tagged
-	 * memory type: (1) the user requested it via PROT_MTE passed to
-	 * mmap() or mprotect() and (2) the corresponding vma supports MTE. We
-	 * register (1) as VM_MTE in the vma->vm_flags and (2) as
-	 * VM_MTE_ALLOWED. Note that the latter can only be set during the
-	 * mmap() call since mprotect() does not accept MAP_* flags.
-	 * Checking for VM_MTE only is sufficient since arch_validate_flags()
-	 * does not permit (VM_MTE & !VM_MTE_ALLOWED).
-	 */
-	if (vm_flags & VM_MTE)
-		prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED);
-
-	return __pgprot(prot);
-}
-#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
-
 static inline bool arch_validate_prot(unsigned long prot,
 	unsigned long addr __always_unused)
 {
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
index 77ada00280d9..78e9490f748d 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -55,3 +55,28 @@ static int __init adjust_protection_map(void)
 	return 0;
 }
 arch_initcall(adjust_protection_map);
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	pteval_t prot = pgprot_val(protection_map[vm_flags &
+				   (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
+
+	if (vm_flags & VM_ARM64_BTI)
+		prot |= PTE_GP;
+
+	/*
+	 * There are two conditions required for returning a Normal Tagged
+	 * memory type: (1) the user requested it via PROT_MTE passed to
+	 * mmap() or mprotect() and (2) the corresponding vma supports MTE. We
+	 * register (1) as VM_MTE in the vma->vm_flags and (2) as
+	 * VM_MTE_ALLOWED. Note that the latter can only be set during the
+	 * mmap() call since mprotect() does not accept MAP_* flags.
+	 * Checking for VM_MTE only is sufficient since arch_validate_flags()
+	 * does not permit (VM_MTE & !VM_MTE_ALLOWED).
+	 */
+	if (vm_flags & VM_MTE)
+		prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED);
+
+	return __pgprot(prot);
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1

[PATCH V5 4/7] sparc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. It localizes arch_vm_get_page_prot()
as sparc_vm_get_page_prot() and moves near vm_get_page_prot().

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: sparclinux@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/sparc/Kconfig            |  1 +
 arch/sparc/include/asm/mman.h |  6 ------
 arch/sparc/mm/init_64.c       | 13 +++++++++++++
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 9200bc04701c..85b573643af6 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -84,6 +84,7 @@ config SPARC64
 	select PERF_USE_VMALLOC
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select HAVE_C_RECORDMCOUNT
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select HAVE_ARCH_AUDITSYSCALL
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h
index 274217e7ed70..af9c10c83dc5 100644
--- a/arch/sparc/include/asm/mman.h
+++ b/arch/sparc/include/asm/mman.h
@@ -46,12 +46,6 @@ static inline unsigned long sparc_calc_vm_prot_bits(unsigned long prot)
 	}
 }
 
-#define arch_vm_get_page_prot(vm_flags) sparc_vm_get_page_prot(vm_flags)
-static inline pgprot_t sparc_vm_get_page_prot(unsigned long vm_flags)
-{
-	return (vm_flags & VM_SPARC_ADI) ? __pgprot(_PAGE_MCD_4V) : __pgprot(0);
-}
-
 #define arch_validate_prot(prot, addr) sparc_validate_prot(prot, addr)
 static inline int sparc_validate_prot(unsigned long prot, unsigned long addr)
 {
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 8b1911591581..dcb17763c1f2 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -3184,3 +3184,16 @@ void copy_highpage(struct page *to, struct page *from)
 	}
 }
 EXPORT_SYMBOL(copy_highpage);
+
+static pgprot_t sparc_vm_get_page_prot(unsigned long vm_flags)
+{
+	return (vm_flags & VM_SPARC_ADI) ? __pgprot(_PAGE_MCD_4V) : __pgprot(0);
+}
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	return __pgprot(pgprot_val(protection_map[vm_flags &
+			(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+			pgprot_val(sparc_vm_get_page_prot(vm_flags)));
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1

[PATCH V5 5/7] x86/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

From: Christoph Hellwig <hch@infradead.org>

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. This also unsubscribes from config
ARCH_HAS_FILTER_PGPROT, after dropping off arch_filter_pgprot() and
arch_vm_get_page_prot().

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/x86/Kconfig                 |  2 +-
 arch/x86/include/asm/pgtable.h   |  5 -----
 arch/x86/include/uapi/asm/mman.h | 14 -------------
 arch/x86/mm/Makefile             |  2 +-
 arch/x86/mm/pgprot.c             | 35 ++++++++++++++++++++++++++++++++
 5 files changed, 37 insertions(+), 21 deletions(-)
 create mode 100644 arch/x86/mm/pgprot.c

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b0142e01002e..c355c420150e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -76,7 +76,6 @@ config X86
 	select ARCH_HAS_EARLY_DEBUG		if KGDB
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FAST_MULTIPLIER
-	select ARCH_HAS_FILTER_PGPROT
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_KCOV			if X86_64
@@ -95,6 +94,7 @@ config X86
 	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
 	select ARCH_HAS_SYSCALL_WRAPPER
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_HAS_DEBUG_WX
 	select ARCH_HAS_ZONE_DMA_SET if EXPERT
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 62ab07e24aef..3563f4645fa1 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -649,11 +649,6 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
 
 #define canon_pgprot(p) __pgprot(massage_pgprot(p))
 
-static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
-{
-	return canon_pgprot(prot);
-}
-
 static inline int is_new_memtype_allowed(u64 paddr, unsigned long size,
 					 enum page_cache_mode pcm,
 					 enum page_cache_mode new_pcm)
diff --git a/arch/x86/include/uapi/asm/mman.h b/arch/x86/include/uapi/asm/mman.h
index d4a8d0424bfb..775dbd3aff73 100644
--- a/arch/x86/include/uapi/asm/mman.h
+++ b/arch/x86/include/uapi/asm/mman.h
@@ -5,20 +5,6 @@
 #define MAP_32BIT	0x40		/* only give out 32bit addresses */
 
 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
-/*
- * Take the 4 protection key bits out of the vma->vm_flags
- * value and turn them in to the bits that we can put in
- * to a pte.
- *
- * Only override these if Protection Keys are available
- * (which is only on 64-bit).
- */
-#define arch_vm_get_page_prot(vm_flags)	__pgprot(	\
-		((vm_flags) & VM_PKEY_BIT0 ? _PAGE_PKEY_BIT0 : 0) |	\
-		((vm_flags) & VM_PKEY_BIT1 ? _PAGE_PKEY_BIT1 : 0) |	\
-		((vm_flags) & VM_PKEY_BIT2 ? _PAGE_PKEY_BIT2 : 0) |	\
-		((vm_flags) & VM_PKEY_BIT3 ? _PAGE_PKEY_BIT3 : 0))
-
 #define arch_calc_vm_prot_bits(prot, key) (		\
 		((key) & 0x1 ? VM_PKEY_BIT0 : 0) |      \
 		((key) & 0x2 ? VM_PKEY_BIT1 : 0) |      \
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index fe3d3061fc11..fb6b41a48ae5 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -20,7 +20,7 @@ CFLAGS_REMOVE_mem_encrypt_identity.o	= -pg
 endif
 
 obj-y				:=  init.o init_$(BITS).o fault.o ioremap.o extable.o mmap.o \
-				    pgtable.o physaddr.o setup_nx.o tlb.o cpu_entry_area.o maccess.o
+				    pgtable.o physaddr.o setup_nx.o tlb.o cpu_entry_area.o maccess.o pgprot.o
 
 obj-y				+= pat/
 
diff --git a/arch/x86/mm/pgprot.c b/arch/x86/mm/pgprot.c
new file mode 100644
index 000000000000..763742782286
--- /dev/null
+++ b/arch/x86/mm/pgprot.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <asm/pgtable.h>
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	unsigned long val = pgprot_val(protection_map[vm_flags &
+				      (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
+
+#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
+	/*
+	 * Take the 4 protection key bits out of the vma->vm_flags value and
+	 * turn them in to the bits that we can put in to a pte.
+	 *
+	 * Only override these if Protection Keys are available (which is only
+	 * on 64-bit).
+	 */
+	if (vm_flags & VM_PKEY_BIT0)
+		val |= _PAGE_PKEY_BIT0;
+	if (vm_flags & VM_PKEY_BIT1)
+		val |= _PAGE_PKEY_BIT1;
+	if (vm_flags & VM_PKEY_BIT2)
+		val |= _PAGE_PKEY_BIT2;
+	if (vm_flags & VM_PKEY_BIT3)
+		val |= _PAGE_PKEY_BIT3;
+#endif
+
+	val = __sme_set(val);
+	if (val & _PAGE_PRESENT)
+		val &= __supported_pte_mask;
+	return __pgprot(val);
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1

[PATCH V5 6/7] mm/mmap: Drop arch_filter_pgprot()

[Anshuman Khandual]

There are no platforms left which subscribe ARCH_HAS_FILTER_PGPROT. Hence
drop generic arch_filter_pgprot() and also config ARCH_HAS_FILTER_PGPROT.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 mm/Kconfig | 3 ---
 mm/mmap.c  | 9 +--------
 2 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/mm/Kconfig b/mm/Kconfig
index b1f7624276f8..3f7b6d7b69df 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -762,9 +762,6 @@ config ARCH_HAS_CURRENT_STACK_POINTER
 	  register alias named "current_stack_pointer", this config can be
 	  selected.
 
-config ARCH_HAS_FILTER_PGPROT
-	bool
-
 config ARCH_HAS_VM_GET_PAGE_PROT
 	bool
 
diff --git a/mm/mmap.c b/mm/mmap.c
index 87cb2eaf7e1a..edf2a5e38f4d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -107,20 +107,13 @@ pgprot_t protection_map[16] __ro_after_init = {
 };
 
 #ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT
-#ifndef CONFIG_ARCH_HAS_FILTER_PGPROT
-static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
-{
-	return prot;
-}
-#endif
-
 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)]) |
 			pgprot_val(arch_vm_get_page_prot(vm_flags)));
 
-	return arch_filter_pgprot(ret);
+	return ret;
 }
 EXPORT_SYMBOL(vm_get_page_prot);
 #endif	/* CONFIG_ARCH_HAS_VM_GET_PAGE_PROT */
-- 
2.25.1

[PATCH V5 7/7] mm/mmap: Drop arch_vm_get_page_pgprot()

[Anshuman Khandual]

There are no platforms left which use arch_vm_get_page_prot(). Just drop
generic arch_vm_get_page_prot().

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 include/linux/mman.h | 4 ----
 mm/mmap.c            | 3 +--
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/include/linux/mman.h b/include/linux/mman.h
index b66e91b8176c..58b3abd457a3 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -93,10 +93,6 @@ static inline void vm_unacct_memory(long pages)
 #define arch_calc_vm_flag_bits(flags) 0
 #endif
 
-#ifndef arch_vm_get_page_prot
-#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
-#endif
-
 #ifndef arch_validate_prot
 /*
  * This is called from mprotect().  PROT_GROWSDOWN and PROT_GROWSUP have
diff --git a/mm/mmap.c b/mm/mmap.c
index edf2a5e38f4d..db7f33154206 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -110,8 +110,7 @@ pgprot_t protection_map[16] __ro_after_init = {
 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)]) |
-			pgprot_val(arch_vm_get_page_prot(vm_flags)));
+				(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]));
 
 	return ret;
 }
-- 
2.25.1

Re: [PATCH V5 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Christophe Leroy]

Le 12/04/2022 à 06:38, Anshuman Khandual a écrit :
> This defines and exports a platform specific custom vm_get_page_prot() via
> subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
> arch_vm_get_page_prot() as __vm_get_page_prot() and moves it near
> vm_get_page_prot().
> 
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>   arch/powerpc/Kconfig               |  1 +
>   arch/powerpc/include/asm/mman.h    | 12 ------------
>   arch/powerpc/mm/book3s64/pgtable.c | 20 ++++++++++++++++++++
>   3 files changed, 21 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 174edabb74fa..69e44358a235 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -140,6 +140,7 @@ config PPC
>   	select ARCH_HAS_TICK_BROADCAST		if GENERIC_CLOCKEVENTS_BROADCAST
>   	select ARCH_HAS_UACCESS_FLUSHCACHE
>   	select ARCH_HAS_UBSAN_SANITIZE_ALL
> +	select ARCH_HAS_VM_GET_PAGE_PROT	if PPC_BOOK3S_64
>   	select ARCH_HAVE_NMI_SAFE_CMPXCHG
>   	select ARCH_KEEP_MEMBLOCK
>   	select ARCH_MIGHT_HAVE_PC_PARPORT
> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
> index 7cb6d18f5cd6..1b024e64c8ec 100644
> --- a/arch/powerpc/include/asm/mman.h
> +++ b/arch/powerpc/include/asm/mman.h
> @@ -24,18 +24,6 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
>   }
>   #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
>   
> -static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
> -{
> -#ifdef CONFIG_PPC_MEM_KEYS
> -	return (vm_flags & VM_SAO) ?
> -		__pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
> -		__pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
> -#else
> -	return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
> -#endif
> -}
> -#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
> -
>   static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
>   {
>   	if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
> diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
> index 052e6590f84f..d0319524e27f 100644
> --- a/arch/powerpc/mm/book3s64/pgtable.c
> +++ b/arch/powerpc/mm/book3s64/pgtable.c
> @@ -7,6 +7,7 @@
>   #include <linux/mm_types.h>
>   #include <linux/memblock.h>
>   #include <linux/memremap.h>
> +#include <linux/pkeys.h>
>   #include <linux/debugfs.h>
>   #include <misc/cxl-base.h>
>   
> @@ -549,3 +550,22 @@ unsigned long memremap_compat_align(void)
>   }
>   EXPORT_SYMBOL_GPL(memremap_compat_align);
>   #endif
> +
> +static pgprot_t __vm_get_page_prot(unsigned long vm_flags)
> +{
> +#ifdef CONFIG_PPC_MEM_KEYS
> +	return (vm_flags & VM_SAO) ?
> +		__pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
> +		__pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
> +#else
> +	return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
> +#endif
> +}
> +
> +pgprot_t vm_get_page_prot(unsigned long vm_flags)
> +{
> +	return __pgprot(pgprot_val(protection_map[vm_flags &
> +			(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
> +			pgprot_val(__vm_get_page_prot(vm_flags)));
> +}
> +EXPORT_SYMBOL(vm_get_page_prot);

This looks functionnaly OK, but I think we could go in the same 
direction as ARM and try to integrate __vm_get_page_prot() inside 
vm_get_page_prot() to get something simpler and cleaner:

Something like below (untested):

pgprot_t vm_get_page_prot(unsigned long vm_flags)
{
	unsigned long prot = pgprot_val(protection_map[vm_flags &
				 (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);

	if (vm_flags & VM_SAO)
		prot |= _PAGE_SAO

#ifdef CONFIG_PPC_MEM_KEYS
	prot |= vmflag_to_pte_pkey_bits(vm_flags);
#endif

	return __pgprot(prot);
}

Re: [PATCH V5 6/7] mm/mmap: Drop arch_filter_pgprot()

[Christophe Leroy]

Le 12/04/2022 à 06:38, Anshuman Khandual a écrit :
> There are no platforms left which subscribe ARCH_HAS_FILTER_PGPROT. Hence
> drop generic arch_filter_pgprot() and also config ARCH_HAS_FILTER_PGPROT.
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>   mm/Kconfig | 3 ---
>   mm/mmap.c  | 9 +--------
>   2 files changed, 1 insertion(+), 11 deletions(-)
> 
> diff --git a/mm/Kconfig b/mm/Kconfig
> index b1f7624276f8..3f7b6d7b69df 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -762,9 +762,6 @@ config ARCH_HAS_CURRENT_STACK_POINTER
>   	  register alias named "current_stack_pointer", this config can be
>   	  selected.
>   
> -config ARCH_HAS_FILTER_PGPROT
> -	bool
> -
>   config ARCH_HAS_VM_GET_PAGE_PROT
>   	bool
>   
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 87cb2eaf7e1a..edf2a5e38f4d 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -107,20 +107,13 @@ pgprot_t protection_map[16] __ro_after_init = {
>   };
>   
>   #ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT
> -#ifndef CONFIG_ARCH_HAS_FILTER_PGPROT
> -static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
> -{
> -	return prot;
> -}
> -#endif
> -
>   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)]) |
>   			pgprot_val(arch_vm_get_page_prot(vm_flags)));
>   
> -	return arch_filter_pgprot(ret);
> +	return ret;

You can drop 'ret' and directly do:

	return  __pgprot(pgprot_val(protection_map[vm_flags &
			(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
			pgprot_val(arch_vm_get_page_prot(vm_flags)));


>   }
>   EXPORT_SYMBOL(vm_get_page_prot);
>   #endif	/* CONFIG_ARCH_HAS_VM_GET_PAGE_PROT */

Re: [PATCH V5 7/7] mm/mmap: Drop arch_vm_get_page_pgprot()

[Christophe Leroy]

Le 12/04/2022 à 06:38, Anshuman Khandual a écrit :
> There are no platforms left which use arch_vm_get_page_prot(). Just drop
> generic arch_vm_get_page_prot().
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
>   include/linux/mman.h | 4 ----
>   mm/mmap.c            | 3 +--
>   2 files changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/include/linux/mman.h b/include/linux/mman.h
> index b66e91b8176c..58b3abd457a3 100644
> --- a/include/linux/mman.h
> +++ b/include/linux/mman.h
> @@ -93,10 +93,6 @@ static inline void vm_unacct_memory(long pages)
>   #define arch_calc_vm_flag_bits(flags) 0
>   #endif
>   
> -#ifndef arch_vm_get_page_prot
> -#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
> -#endif
> -
>   #ifndef arch_validate_prot
>   /*
>    * This is called from mprotect().  PROT_GROWSDOWN and PROT_GROWSUP have
> diff --git a/mm/mmap.c b/mm/mmap.c
> index edf2a5e38f4d..db7f33154206 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -110,8 +110,7 @@ pgprot_t protection_map[16] __ro_after_init = {
>   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)]) |
> -			pgprot_val(arch_vm_get_page_prot(vm_flags)));
> +				(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]));
>   
>   	return ret;
>   }

__pgprot(pgprot_val(x)) is a no-op.

You can simply do:

	return protection_map[vm_flags &
		(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED);

Re: [PATCH V5 7/7] mm/mmap: Drop arch_vm_get_page_pgprot()

[Anshuman Khandual]

On 4/12/22 18:00, Christophe Leroy wrote:
> 
> 
> Le 12/04/2022 à 06:38, Anshuman Khandual a écrit :
>> There are no platforms left which use arch_vm_get_page_prot(). Just drop
>> generic arch_vm_get_page_prot().
>>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: linux-mm@kvack.org
>> Cc: linux-kernel@vger.kernel.org
>> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>   include/linux/mman.h | 4 ----
>>   mm/mmap.c            | 3 +--
>>   2 files changed, 1 insertion(+), 6 deletions(-)
>>
>> diff --git a/include/linux/mman.h b/include/linux/mman.h
>> index b66e91b8176c..58b3abd457a3 100644
>> --- a/include/linux/mman.h
>> +++ b/include/linux/mman.h
>> @@ -93,10 +93,6 @@ static inline void vm_unacct_memory(long pages)
>>   #define arch_calc_vm_flag_bits(flags) 0
>>   #endif
>>   
>> -#ifndef arch_vm_get_page_prot
>> -#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
>> -#endif
>> -
>>   #ifndef arch_validate_prot
>>   /*
>>    * This is called from mprotect().  PROT_GROWSDOWN and PROT_GROWSUP have
>> diff --git a/mm/mmap.c b/mm/mmap.c
>> index edf2a5e38f4d..db7f33154206 100644
>> --- a/mm/mmap.c
>> +++ b/mm/mmap.c
>> @@ -110,8 +110,7 @@ pgprot_t protection_map[16] __ro_after_init = {
>>   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)]) |
>> -			pgprot_val(arch_vm_get_page_prot(vm_flags)));
>> +				(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]));
>>   
>>   	return ret;
>>   }
> 
> __pgprot(pgprot_val(x)) is a no-op.
> 
> You can simply do:
> 
> 	return protection_map[vm_flags &
> 		(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED);

Sure, will do.

Re: [PATCH V5 6/7] mm/mmap: Drop arch_filter_pgprot()

[Anshuman Khandual]

On 4/12/22 17:59, Christophe Leroy wrote:
> 
> 
> Le 12/04/2022 à 06:38, Anshuman Khandual a écrit :
>> There are no platforms left which subscribe ARCH_HAS_FILTER_PGPROT. Hence
>> drop generic arch_filter_pgprot() and also config ARCH_HAS_FILTER_PGPROT.
>>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: linux-mm@kvack.org
>> Cc: linux-kernel@vger.kernel.org
>> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>   mm/Kconfig | 3 ---
>>   mm/mmap.c  | 9 +--------
>>   2 files changed, 1 insertion(+), 11 deletions(-)
>>
>> diff --git a/mm/Kconfig b/mm/Kconfig
>> index b1f7624276f8..3f7b6d7b69df 100644
>> --- a/mm/Kconfig
>> +++ b/mm/Kconfig
>> @@ -762,9 +762,6 @@ config ARCH_HAS_CURRENT_STACK_POINTER
>>   	  register alias named "current_stack_pointer", this config can be
>>   	  selected.
>>   
>> -config ARCH_HAS_FILTER_PGPROT
>> -	bool
>> -
>>   config ARCH_HAS_VM_GET_PAGE_PROT
>>   	bool
>>   
>> diff --git a/mm/mmap.c b/mm/mmap.c
>> index 87cb2eaf7e1a..edf2a5e38f4d 100644
>> --- a/mm/mmap.c
>> +++ b/mm/mmap.c
>> @@ -107,20 +107,13 @@ pgprot_t protection_map[16] __ro_after_init = {
>>   };
>>   
>>   #ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT
>> -#ifndef CONFIG_ARCH_HAS_FILTER_PGPROT
>> -static inline pgprot_t arch_filter_pgprot(pgprot_t prot)
>> -{
>> -	return prot;
>> -}
>> -#endif
>> -
>>   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)]) |
>>   			pgprot_val(arch_vm_get_page_prot(vm_flags)));
>>   
>> -	return arch_filter_pgprot(ret);
>> +	return ret;
> 
> You can drop 'ret' and directly do:
> 
> 	return  __pgprot(pgprot_val(protection_map[vm_flags &
> 			(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
> 			pgprot_val(arch_vm_get_page_prot(vm_flags)));

Sure, will do.

> 
> 
>>   }
>>   EXPORT_SYMBOL(vm_get_page_prot);
>>   #endif	/* CONFIG_ARCH_HAS_VM_GET_PAGE_PROT */

Re: [PATCH V5 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

On 4/12/22 17:57, Christophe Leroy wrote:
> 
> 
> Le 12/04/2022 à 06:38, Anshuman Khandual a écrit :
>> This defines and exports a platform specific custom vm_get_page_prot() via
>> subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
>> arch_vm_get_page_prot() as __vm_get_page_prot() and moves it near
>> vm_get_page_prot().
>>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>>   arch/powerpc/Kconfig               |  1 +
>>   arch/powerpc/include/asm/mman.h    | 12 ------------
>>   arch/powerpc/mm/book3s64/pgtable.c | 20 ++++++++++++++++++++
>>   3 files changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 174edabb74fa..69e44358a235 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -140,6 +140,7 @@ config PPC
>>   	select ARCH_HAS_TICK_BROADCAST		if GENERIC_CLOCKEVENTS_BROADCAST
>>   	select ARCH_HAS_UACCESS_FLUSHCACHE
>>   	select ARCH_HAS_UBSAN_SANITIZE_ALL
>> +	select ARCH_HAS_VM_GET_PAGE_PROT	if PPC_BOOK3S_64
>>   	select ARCH_HAVE_NMI_SAFE_CMPXCHG
>>   	select ARCH_KEEP_MEMBLOCK
>>   	select ARCH_MIGHT_HAVE_PC_PARPORT
>> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
>> index 7cb6d18f5cd6..1b024e64c8ec 100644
>> --- a/arch/powerpc/include/asm/mman.h
>> +++ b/arch/powerpc/include/asm/mman.h
>> @@ -24,18 +24,6 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
>>   }
>>   #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
>>   
>> -static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
>> -{
>> -#ifdef CONFIG_PPC_MEM_KEYS
>> -	return (vm_flags & VM_SAO) ?
>> -		__pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
>> -		__pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
>> -#else
>> -	return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
>> -#endif
>> -}
>> -#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
>> -
>>   static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
>>   {
>>   	if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
>> diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
>> index 052e6590f84f..d0319524e27f 100644
>> --- a/arch/powerpc/mm/book3s64/pgtable.c
>> +++ b/arch/powerpc/mm/book3s64/pgtable.c
>> @@ -7,6 +7,7 @@
>>   #include <linux/mm_types.h>
>>   #include <linux/memblock.h>
>>   #include <linux/memremap.h>
>> +#include <linux/pkeys.h>
>>   #include <linux/debugfs.h>
>>   #include <misc/cxl-base.h>
>>   
>> @@ -549,3 +550,22 @@ unsigned long memremap_compat_align(void)
>>   }
>>   EXPORT_SYMBOL_GPL(memremap_compat_align);
>>   #endif
>> +
>> +static pgprot_t __vm_get_page_prot(unsigned long vm_flags)
>> +{
>> +#ifdef CONFIG_PPC_MEM_KEYS
>> +	return (vm_flags & VM_SAO) ?
>> +		__pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
>> +		__pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
>> +#else
>> +	return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
>> +#endif
>> +}
>> +
>> +pgprot_t vm_get_page_prot(unsigned long vm_flags)
>> +{
>> +	return __pgprot(pgprot_val(protection_map[vm_flags &
>> +			(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
>> +			pgprot_val(__vm_get_page_prot(vm_flags)));
>> +}
>> +EXPORT_SYMBOL(vm_get_page_prot);
> 
> This looks functionnaly OK, but I think we could go in the same 
> direction as ARM and try to integrate __vm_get_page_prot() inside 
> vm_get_page_prot() to get something simpler and cleaner:
> 
> Something like below (untested):
> 
> pgprot_t vm_get_page_prot(unsigned long vm_flags)
> {
> 	unsigned long prot = pgprot_val(protection_map[vm_flags &
> 				 (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
> 
> 	if (vm_flags & VM_SAO)
> 		prot |= _PAGE_SAO
> 
> #ifdef CONFIG_PPC_MEM_KEYS
> 	prot |= vmflag_to_pte_pkey_bits(vm_flags);
> #endif
> 
> 	return __pgprot(prot);
> }

Okay, will integrate these functions into vm_get_page_prot() as suggested.

Re: [PATCH V5 4/7] sparc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[David Miller]

From: Anshuman Khandual <anshuman.khandual@arm.com>
Date: Tue, 12 Apr 2022 10:08:45 +0530

> This defines and exports a platform specific custom vm_get_page_prot() via
> subscribing ARCH_HAS_VM_GET_PAGE_PROT. It localizes arch_vm_get_page_prot()
> as sparc_vm_get_page_prot() and moves near vm_get_page_prot().
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Khalid Aziz <khalid.aziz@oracle.com>
> Cc: sparclinux@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

Acked-by: David S. Miller <davem@davemloft.net>