From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D77FC433FE for ; Mon, 24 Jan 2022 12:58:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242717AbiAXM50 (ORCPT ); Mon, 24 Jan 2022 07:57:26 -0500 Received: from foss.arm.com ([217.140.110.172]:32844 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242629AbiAXM5R (ORCPT ); Mon, 24 Jan 2022 07:57:17 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EF7A4D6E; Mon, 24 Jan 2022 04:57:16 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.43.190]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1590B3F774; Mon, 24 Jan 2022 04:57:13 -0800 (PST) From: Anshuman Khandual To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, Anshuman Khandual Subject: [RFC V1 02/31] mm/mmap: Clarify protection_map[] indices Date: Mon, 24 Jan 2022 18:26:39 +0530 Message-Id: <1643029028-12710-3-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1643029028-12710-1-git-send-email-anshuman.khandual@arm.com> References: <1643029028-12710-1-git-send-email-anshuman.khandual@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org protection_map[] maps vm_flags access combinations into page protection value as defined by the platform via __PXXX and __SXXX macros. The array indices in protection_map[], represents vm_flags access combinations but it's not very intuitive to derive. This makes it clear and explicit. Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual --- mm/mmap.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 1e8fdb0b51ed..254d716220df 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -102,8 +102,22 @@ static void unmap_region(struct mm_struct *mm, * x: (yes) yes */ pgprot_t protection_map[16] __ro_after_init = { - __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111, - __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111 + [VM_NONE] = __P000, + [VM_READ] = __P001, + [VM_WRITE] = __P010, + [VM_READ|VM_WRITE] = __P011, + [VM_EXEC] = __P100, + [VM_EXEC|VM_READ] = __P101, + [VM_EXEC|VM_WRITE] = __P110, + [VM_EXEC|VM_READ|VM_WRITE] = __P111, + [VM_SHARED] = __S000, + [VM_SHARED|VM_READ] = __S001, + [VM_SHARED|VM_WRITE] = __S010, + [VM_SHARED|VM_READ|VM_WRITE] = __S011, + [VM_SHARED|VM_EXEC] = __S100, + [VM_SHARED|VM_READ|VM_EXEC] = __S101, + [VM_SHARED|VM_WRITE|VM_EXEC] = __S110, + [VM_SHARED|VM_READ|VM_WRITE|VM_EXEC] = __S111 }; #ifndef CONFIG_ARCH_HAS_FILTER_PGPROT -- 2.25.1