Commit b3aca728 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Andrew Morton
Browse files

arm64/mm: enable ARCH_HAS_VM_GET_PAGE_PROT 

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().

Link: https://lkml.kernel.org/r/20220414062125.609297-4-anshuman.khandual@arm.com


Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 634093c5

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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

arch/arm64/include/asm/mman.h

+0 −24
Original line number Diff line number Diff line
@@ -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)

{

arch/arm64/mm/mmap.c

+25 −0
Original line number Diff line number Diff line
@@ -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);