From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750869AbdCNJkL (ORCPT ); Tue, 14 Mar 2017 05:40:11 -0400 Received: from terminus.zytor.com ([65.50.211.136]:46226 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750787AbdCNJkJ (ORCPT ); Tue, 14 Mar 2017 05:40:09 -0400 Date: Tue, 14 Mar 2017 02:39:25 -0700 From: "tip-bot for Kirill A. Shutemov" Message-ID: Cc: tglx@linutronix.de, akpm@linux-foundation.org, arnd@arndb.de, linux-kernel@vger.kernel.org, bp@alien8.de, kirill.shutemov@linux.intel.com, torvalds@linux-foundation.org, luto@kernel.org, hpa@zytor.com, mhocko@suse.com, dvlasenk@redhat.com, mingo@kernel.org, dave.hansen@intel.com, brgerst@gmail.com, peterz@infradead.org, jpoimboe@redhat.com Reply-To: brgerst@gmail.com, peterz@infradead.org, jpoimboe@redhat.com, dave.hansen@intel.com, luto@kernel.org, mingo@kernel.org, hpa@zytor.com, mhocko@suse.com, dvlasenk@redhat.com, arnd@arndb.de, linux-kernel@vger.kernel.org, tglx@linutronix.de, akpm@linux-foundation.org, bp@alien8.de, kirill.shutemov@linux.intel.com, torvalds@linux-foundation.org In-Reply-To: <20170313143309.16020-6-kirill.shutemov@linux.intel.com> References: <20170313143309.16020-6-kirill.shutemov@linux.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86/mm/vmalloc: Add 5-level paging support Git-Commit-ID: b50858ce3e2a25a7f4638464e857853fbfc81823 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: b50858ce3e2a25a7f4638464e857853fbfc81823 Gitweb: http://git.kernel.org/tip/b50858ce3e2a25a7f4638464e857853fbfc81823 Author: Kirill A. Shutemov AuthorDate: Mon, 13 Mar 2017 17:33:08 +0300 Committer: Ingo Molnar CommitDate: Tue, 14 Mar 2017 08:45:08 +0100 x86/mm/vmalloc: Add 5-level paging support Modify vmalloc_fault() to handle additional page table level. With 4-level paging, copying happens on p4d level, as we have pgd_none() always false if p4d_t is folded. Signed-off-by: Kirill A. Shutemov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Michal Hocko Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170313143309.16020-6-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 605fd5e..8ad91a0 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -435,6 +435,7 @@ void vmalloc_sync_all(void) static noinline int vmalloc_fault(unsigned long address) { pgd_t *pgd, *pgd_ref; + p4d_t *p4d, *p4d_ref; pud_t *pud, *pud_ref; pmd_t *pmd, *pmd_ref; pte_t *pte, *pte_ref; @@ -458,17 +459,37 @@ static noinline int vmalloc_fault(unsigned long address) if (pgd_none(*pgd)) { set_pgd(pgd, *pgd_ref); arch_flush_lazy_mmu_mode(); - } else { + } else if (CONFIG_PGTABLE_LEVELS > 4) { + /* + * With folded p4d, pgd_none() is always false, so the pgd may + * point to an empty page table entry and pgd_page_vaddr() + * will return garbage. + * + * We will do the correct sanity check on the p4d level. + */ BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref)); } + /* With 4-level paging, copying happens on the p4d level. */ + p4d = p4d_offset(pgd, address); + p4d_ref = p4d_offset(pgd_ref, address); + if (p4d_none(*p4d_ref)) + return -1; + + if (p4d_none(*p4d)) { + set_p4d(p4d, *p4d_ref); + arch_flush_lazy_mmu_mode(); + } else { + BUG_ON(p4d_pfn(*p4d) != p4d_pfn(*p4d_ref)); + } + /* * Below here mismatches are bugs because these lower tables * are shared: */ - pud = pud_offset(pgd, address); - pud_ref = pud_offset(pgd_ref, address); + pud = pud_offset(p4d, address); + pud_ref = pud_offset(p4d_ref, address); if (pud_none(*pud_ref)) return -1;