From b3aca728fb276782ab3c851aedaf3d19b33faabe Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 28 Apr 2022 23:16:13 -0700 Subject: 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: Anshuman Khandual Reviewed-by: Catalin Marinas Cc: Catalin Marinas Cc: Will Deacon Cc: Christophe Leroy Cc: Christoph Hellwig Cc: David S. Miller Cc: Ingo Molnar Cc: Khalid Aziz Cc: Michael Ellerman Cc: Paul Mackerras Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- arch/arm64/mm/mmap.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'arch/arm64/mm/mmap.c') 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); -- cgit v1.2.3