From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:43424 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932426AbeCSJMT (ORCPT ); Mon, 19 Mar 2018 05:12:19 -0400 Subject: Patch "powerpc/mm/hugetlb: Filter out hugepage size not supported by page table layout" has been added to the 4.4-stable tree To: aneesh.kumar@linux.vnet.ibm.com, alexander.levin@microsoft.com, gregkh@linuxfoundation.org, mpe@ellerman.id.au Cc: , From: Date: Mon, 19 Mar 2018 10:09:46 +0100 Message-ID: <152145058619346@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/hugetlb: Filter out hugepage size not supported by page table layout 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: powerpc-mm-hugetlb-filter-out-hugepage-size-not-supported-by-page-table-layout.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 foo@baz Mon Mar 19 09:58:12 CET 2018 From: "Aneesh Kumar K.V" Date: Tue, 21 Mar 2017 22:59:56 +0530 Subject: powerpc/mm/hugetlb: Filter out hugepage size not supported by page table layout From: "Aneesh Kumar K.V" [ Upstream commit a525108cf1cc14651602d678da38fa627a76a724 ] Without this if firmware reports 1MB page size support we will crash trying to use 1MB as hugetlb page size. echo 300 > /sys/kernel/mm/hugepages/hugepages-1024kB/nr_hugepages kernel BUG at ./arch/powerpc/include/asm/hugetlb.h:19! ..... .... [c0000000e2c27b30] c00000000029dae8 .hugetlb_fault+0x638/0xda0 [c0000000e2c27c30] c00000000026fb64 .handle_mm_fault+0x844/0x1d70 [c0000000e2c27d70] c00000000004805c .do_page_fault+0x3dc/0x7c0 [c0000000e2c27e30] c00000000000ac98 handle_page_fault+0x10/0x30 With fix, we don't enable 1MB as hugepage size. bash-4.2# cd /sys/kernel/mm/hugepages/ bash-4.2# ls hugepages-16384kB hugepages-16777216kB Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/mm/hugetlbpage.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -828,6 +828,24 @@ static int __init add_huge_page_size(uns if ((mmu_psize = shift_to_mmu_psize(shift)) < 0) return -EINVAL; +#ifdef CONFIG_PPC_BOOK3S_64 + /* + * We need to make sure that for different page sizes reported by + * firmware we only add hugetlb support for page sizes that can be + * supported by linux page table layout. + * For now we have + * Radix: 2M + * Hash: 16M and 16G + */ + if (radix_enabled()) { + if (mmu_psize != MMU_PAGE_2M) + return -EINVAL; + } else { + if (mmu_psize != MMU_PAGE_16M && mmu_psize != MMU_PAGE_16G) + return -EINVAL; + } +#endif + BUG_ON(mmu_psize_defs[mmu_psize].shift != shift); /* Return if huge page size has already been setup */ Patches currently in stable-queue which might be from aneesh.kumar@linux.vnet.ibm.com are queue-4.4/mm-fix-false-positive-vm_bug_on-in-page_cache_-get-add-_speculative.patch queue-4.4/powerpc-mm-hugetlb-filter-out-hugepage-size-not-supported-by-page-table-layout.patch