Commit 51b0bff2 authored Nov 29, 2019 by Catalin Marinas

mm: Allow arm64 mmap(PROT_MTE) on RAM-based files



Since arm64 memory (allocation) tags can only be stored in RAM, mapping
files with PROT_MTE is not allowed by default. RAM-based files like
those in a tmpfs mount or memfd_create() can support memory tagging, so
update the vm_flags accordingly in shmem_mmap().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>

parent 00420905

mm/shmem.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2267,6 +2267,9 @@ static int shmem_mmap(struct file file, struct vm_area_struct vma)
		vma->vm_flags &= ~(VM_MAYWRITE);
		}

		/* arm64 - allow memory tagging on RAM-based files */
		vma->vm_flags \|= VM_MTE_ALLOWED;

		file_accessed(file);
		vma->vm_ops = &shmem_vm_ops;
		if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&

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