From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:44752 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751328AbdGVRD1 (ORCPT ); Sat, 22 Jul 2017 13:03:27 -0400 Subject: Patch "powerpc/mm/radix: Properly clear process table entry" has been added to the 4.12-stable tree To: benh@kernel.crashing.org, aneesh.kumar@linux.vnet.ibm.com, gregkh@linuxfoundation.org, mpe@ellerman.id.au Cc: , From: Date: Sat, 22 Jul 2017 16:16:21 +0200 Message-ID: <150073298115812@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 powerpc/mm/radix: Properly clear process table entry to the 4.12-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: powerpc-mm-radix-properly-clear-process-table-entry.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From c6bb0b8d426a8cf865ca9c8a532cc3a2927cfceb Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Sat, 8 Jul 2017 07:45:32 -0500 Subject: powerpc/mm/radix: Properly clear process table entry From: Benjamin Herrenschmidt commit c6bb0b8d426a8cf865ca9c8a532cc3a2927cfceb upstream. On radix, the process table entry we want to clear when destroying a context is entry 0, not entry 1. This has no *immediate* consequence on Power9, but it can cause other bugs to become worse. Fixes: 7e381c0ff618 ("powerpc/mm/radix: Add mmu context handling callback for radix") Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/mm/mmu_context_book3s64.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/arch/powerpc/mm/mmu_context_book3s64.c +++ b/arch/powerpc/mm/mmu_context_book3s64.c @@ -223,9 +223,15 @@ void destroy_context(struct mm_struct *m mm->context.cop_lockp = NULL; #endif /* CONFIG_PPC_ICSWX */ - if (radix_enabled()) - process_tb[mm->context.id].prtb1 = 0; - else + if (radix_enabled()) { + /* + * Radix doesn't have a valid bit in the process table + * entries. However we know that at least P9 implementation + * will avoid caching an entry with an invalid RTS field, + * and 0 is invalid. So this will do. + */ + process_tb[mm->context.id].prtb0 = 0; + } else subpage_prot_free(mm); destroy_pagetable_page(mm); __destroy_context(mm->context.id); Patches currently in stable-queue which might be from benh@kernel.crashing.org are queue-4.12/powerpc-mm-radix-properly-clear-process-table-entry.patch