From mboxrd@z Thu Jan 1 00:00:00 1970 From: gregkh@linuxfoundation.org (gregkh at linuxfoundation.org) Date: Thu, 16 Aug 2018 13:57:18 +0200 Subject: Patch "x86/mm: Disable ioremap free page handling on x86-PAE" has been added to the 4.17-stable tree Message-ID: <1534420638227188@kroah.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This is a note to let you know that I've just added the patch titled x86/mm: Disable ioremap free page handling on x86-PAE to the 4.17-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: x86-mm-disable-ioremap-free-page-handling-on-x86-pae.patch and it can be found in the queue-4.17 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From f967db0b9ed44ec3057a28f3b28efc51df51b835 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Wed, 27 Jun 2018 08:13:46 -0600 Subject: x86/mm: Disable ioremap free page handling on x86-PAE From: Toshi Kani commit f967db0b9ed44ec3057a28f3b28efc51df51b835 upstream. ioremap() supports pmd mappings on x86-PAE. However, kernel's pmd tables are not shared among processes on x86-PAE. Therefore, any update to sync'd pmd entries need re-syncing. Freeing a pte page also leads to a vmalloc fault and hits the BUG_ON in vmalloc_sync_one(). Disable free page handling on x86-PAE. pud_free_pmd_page() and pmd_free_pte_page() simply return 0 if a given pud/pmd entry is present. This assures that ioremap() does not update sync'd pmd entries at the cost of falling back to pte mappings. Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") Reported-by: Joerg Roedel Signed-off-by: Toshi Kani Signed-off-by: Thomas Gleixner Cc: mhocko at suse.com Cc: akpm at linux-foundation.org Cc: hpa at zytor.com Cc: cpandya at codeaurora.org Cc: linux-mm at kvack.org Cc: linux-arm-kernel at lists.infradead.org Cc: stable at vger.kernel.org Cc: Andrew Morton Cc: Michal Hocko Cc: "H. Peter Anvin" Cc: Link: https://lkml.kernel.org/r/20180627141348.21777-2-toshi.kani at hpe.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/pgtable.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -715,6 +715,7 @@ int pmd_clear_huge(pmd_t *pmd) return 0; } +#ifdef CONFIG_X86_64 /** * pud_free_pmd_page - Clear pud entry and free pmd page. * @pud: Pointer to a PUD. @@ -762,4 +763,22 @@ int pmd_free_pte_page(pmd_t *pmd) return 1; } + +#else /* !CONFIG_X86_64 */ + +int pud_free_pmd_page(pud_t *pud) +{ + return pud_none(*pud); +} + +/* + * Disable free page handling on x86-PAE. This assures that ioremap() + * does not update sync'd pmd entries. See vmalloc_sync_one(). + */ +int pmd_free_pte_page(pmd_t *pmd) +{ + return pmd_none(*pmd); +} + +#endif /* CONFIG_X86_64 */ #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ Patches currently in stable-queue which might be from toshi.kani at hpe.com are queue-4.17/x86-mm-disable-ioremap-free-page-handling-on-x86-pae.patch From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 54A196B000A for ; Thu, 16 Aug 2018 07:57:22 -0400 (EDT) Received: by mail-pf1-f197.google.com with SMTP id e15-v6so2007035pfi.5 for ; Thu, 16 Aug 2018 04:57:22 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id t66-v6si27428344pgt.181.2018.08.16.04.57.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Aug 2018 04:57:21 -0700 (PDT) Subject: Patch "x86/mm: Disable ioremap free page handling on x86-PAE" has been added to the 4.17-stable tree From: Date: Thu, 16 Aug 2018 13:57:18 +0200 Message-ID: <1534420638227188@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: 20180627141348.21777-2-toshi.kani@hpe.com, akpm@linux-foundation.org, cpandya@codeaurora.org, gregkh@linuxfoundation.org, hpa@zytor.com, joro@8bytes.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, mhocko@suse.com, tglx@linutronix.detoshi.kani@hpe.com Cc: stable-commits@vger.kernel.org This is a note to let you know that I've just added the patch titled x86/mm: Disable ioremap free page handling on x86-PAE to the 4.17-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: x86-mm-disable-ioremap-free-page-handling-on-x86-pae.patch and it can be found in the queue-4.17 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it.