From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: [PATCH v3 15/23] mm: Allow arm64 mmap(PROT_MTE) on RAM-based files Date: Tue, 21 Apr 2020 15:25:55 +0100 Message-ID: <20200421142603.3894-16-catalin.marinas@arm.com> References: <20200421142603.3894-1-catalin.marinas@arm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Received: from foss.arm.com ([217.140.110.172]:36034 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728645AbgDUO0j (ORCPT ); Tue, 21 Apr 2020 10:26:39 -0400 In-Reply-To: <20200421142603.3894-1-catalin.marinas@arm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arm-kernel@lists.infradead.org Cc: Will Deacon , Vincenzo Frascino , Szabolcs Nagy , Richard Earnshaw , Kevin Brodsky , Andrey Konovalov , Peter Collingbourne , linux-mm@kvack.org, linux-arch@vger.kernel.org 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 Cc: Will Deacon --- mm/shmem.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/shmem.c b/mm/shmem.c index d722eb830317..73754ed7af69 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2221,6 +2221,9 @@ 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) &&