diff mbox series

[V4,3/7] arm64/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

Message ID 20220407103251.1209606-4-anshuman.khandual@arm.com
State New
Headers show
Series mm/mmap: Drop arch_vm_get_page_prot() and arch_filter_pgprot() | expand

Commit Message

Anshuman Khandual April 7, 2022, 10:32 a.m. UTC
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
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          | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 24 deletions(-)

Comments

Catalin Marinas April 8, 2022, 10:28 a.m. UTC | #1
On Thu, Apr 07, 2022 at 04:02:47PM +0530, Anshuman Khandual wrote:
> diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
> index 77ada00280d9..307534fcec00 100644
> --- a/arch/arm64/mm/mmap.c
> +++ b/arch/arm64/mm/mmap.c
> @@ -55,3 +55,36 @@ static int __init adjust_protection_map(void)
>  	return 0;
>  }
>  arch_initcall(adjust_protection_map);
> +
> +static pgprot_t arm64_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);
> +}
> +
> +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(arm64_arch_vm_get_page_prot(vm_flags)));
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(vm_get_page_prot);

Could you write all this in a single function? I think I mentioned it in
a previous series (untested):

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);

With that:

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Anshuman Khandual April 8, 2022, 11:19 a.m. UTC | #2
On 4/8/22 15:58, Catalin Marinas wrote:
> On Thu, Apr 07, 2022 at 04:02:47PM +0530, Anshuman Khandual wrote:
>> diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
>> index 77ada00280d9..307534fcec00 100644
>> --- a/arch/arm64/mm/mmap.c
>> +++ b/arch/arm64/mm/mmap.c
>> @@ -55,3 +55,36 @@ static int __init adjust_protection_map(void)
>>  	return 0;
>>  }
>>  arch_initcall(adjust_protection_map);
>> +
>> +static pgprot_t arm64_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);
>> +}
>> +
>> +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(arm64_arch_vm_get_page_prot(vm_flags)));
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL(vm_get_page_prot);
> 
> Could you write all this in a single function? I think I mentioned it in
> a previous series (untested):

Right, missed that.

> 
> 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);
> 
> With that:

Sure, will change them into a single function.

> 
> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
>
diff mbox series

Patch

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..307534fcec00 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -55,3 +55,36 @@  static int __init adjust_protection_map(void)
 	return 0;
 }
 arch_initcall(adjust_protection_map);
+
+static pgprot_t arm64_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);
+}
+
+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(arm64_arch_vm_get_page_prot(vm_flags)));
+
+	return ret;
+}
+EXPORT_SYMBOL(vm_get_page_prot);