From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59571 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752323AbcEAVuC (ORCPT ); Sun, 1 May 2016 17:50:02 -0400 Subject: Patch "arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission" has been added to the 4.4-stable tree To: catalin.marinas@arm.com, gkulkarni@cavium.com, gkulkarni@caviumnetworks.com, gregkh@linuxfoundation.org Cc: , From: Date: Sun, 01 May 2016 14:50:00 -0700 Message-ID: <1462139400196180@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-update-pte_rdonly-in-set_pte_at-for-prot_none-permission.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From fdc69e7df3cb24f18a93192641786e5b7ecd1dfe Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 9 Mar 2016 16:31:29 +0000 Subject: arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission From: Catalin Marinas commit fdc69e7df3cb24f18a93192641786e5b7ecd1dfe upstream. The set_pte_at() function must update the hardware PTE_RDONLY bit depending on the state of the PTE_WRITE and PTE_DIRTY bits of the given entry value. However, it currently only performs this for pte_valid() entries, ignoring PTE_PROT_NONE. The side-effect is that PROT_NONE mappings would not have the PTE_RDONLY bit set. Without CONFIG_ARM64_HW_AFDBM, this is not an issue since such PROT_NONE pages are not accessible anyway. With commit 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits"), the ptep_set_wrprotect() function was re-written to cope with automatic hardware updates of the dirty state. As an optimisation, only PTE_RDONLY is checked to assess the "dirty" status. Since set_pte_at() does not set this bit for PROT_NONE mappings, such pages may be considered "dirty" as a result of ptep_set_wrprotect(). This patch updates the pte_valid() check to pte_present() in set_pte_at(). It also adds PTE_PROT_NONE to the swap entry bits comment. Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits") Signed-off-by: Catalin Marinas Reported-by: Ganapatrao Kulkarni Tested-by: Ganapatrao Kulkarni Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/pgtable.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -263,7 +263,7 @@ extern void __sync_icache_dcache(pte_t p static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { - if (pte_valid(pte)) { + if (pte_present(pte)) { if (pte_sw_dirty(pte) && pte_write(pte)) pte_val(pte) &= ~PTE_RDONLY; else @@ -640,6 +640,7 @@ extern pgd_t idmap_pg_dir[PTRS_PER_PGD]; * bits 0-1: present (must be zero) * bits 2-7: swap type * bits 8-57: swap offset + * bit 58: PTE_PROT_NONE (must be zero) */ #define __SWP_TYPE_SHIFT 2 #define __SWP_TYPE_BITS 6 Patches currently in stable-queue which might be from catalin.marinas@arm.com are queue-4.4/arm64-update-pte_rdonly-in-set_pte_at-for-prot_none-permission.patch queue-4.4/arm64-honour-pte_write-in-set_pte_at-for-kernel-mappings.patch