From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751481AbeEQFMh (ORCPT ); Thu, 17 May 2018 01:12:37 -0400 Received: from ms11p00im-qufv17100601.me.com ([17.58.37.33]:34786 "EHLO ms11p00im-qufv17100601.me.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750727AbeEQFMg (ORCPT ); Thu, 17 May 2018 01:12:36 -0400 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-05-17_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 clxscore=1011 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1805170049 Date: Thu, 17 May 2018 07:12:26 +0200 From: damian To: Baoquan He Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, lcapitulino@redhat.com, keescook@chromium.org, tglx@linutronix.de, x86@kernel.org, hpa@zytor.com, fanc.fnst@cn.fujitsu.com, yasu.isimatu@gmail.com, indou.takao@jp.fujitsu.com, douly.fnst@cn.fujitsu.com Subject: Re: [PATCH 1/2] x86/boot/KASLR: Add two functions for 1GB huge pages handling Message-id: <20180517051225.GA2361@zrhn9910b> Mail-followup-to: Baoquan He , linux-kernel@vger.kernel.org, mingo@kernel.org, lcapitulino@redhat.com, keescook@chromium.org, tglx@linutronix.de, x86@kernel.org, hpa@zytor.com, fanc.fnst@cn.fujitsu.com, yasu.isimatu@gmail.com, indou.takao@jp.fujitsu.com, douly.fnst@cn.fujitsu.com References: <20180516100532.14083-1-bhe@redhat.com> <20180516100532.14083-2-bhe@redhat.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-disposition: inline In-reply-to: <20180516100532.14083-2-bhe@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16. May 18:05, Baoquan He wrote: > Functions parse_gb_huge_pages() and process_gb_huge_page() are introduced to > handle conflict between KASLR and huge pages, will be used in the next patch. > > Function parse_gb_huge_pages() is used to parse kernel command-line to get > how many 1GB huge pages have been specified. A static global variable > 'max_gb_huge_pages' is added to store the number. > > And process_gb_huge_page() is used to skip as many 1GB huge pages as possible > from the passed in memory region according to the specified number. > > Signed-off-by: Baoquan He > --- > arch/x86/boot/compressed/kaslr.c | 71 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 71 insertions(+) > > diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c > index a0a50b91ecef..13bd879cdc5d 100644 > --- a/arch/x86/boot/compressed/kaslr.c > +++ b/arch/x86/boot/compressed/kaslr.c > @@ -215,6 +215,32 @@ static void mem_avoid_memmap(char *str) > memmap_too_large = true; > } > > +/* Store the number of 1GB huge pages which user specified.*/ > +static unsigned long max_gb_huge_pages; > + > +static int parse_gb_huge_pages(char *param, char* val) > +{ > + char *p; > + u64 mem_size; > + static bool gbpage_sz = false; > + > + if (!strcmp(param, "hugepagesz")) { > + p = val; > + mem_size = memparse(p, &p); > + if (mem_size == PUD_SIZE) { > + if (gbpage_sz) > + warn("Repeadly set hugeTLB page size of 1G!\n"); > + gbpage_sz = true; > + } else > + gbpage_sz = false; > + } else if (!strcmp(param, "hugepages") && gbpage_sz) { > + p = val; > + max_gb_huge_pages = simple_strtoull(p, &p, 0); > + debug_putaddr(max_gb_huge_pages); > + } > +} Hello, the return value is missing for the function or not ? regards Damian > + > + > static int handle_mem_memmap(void) > { > char *args = (char *)get_cmd_line_ptr(); > @@ -466,6 +492,51 @@ static void store_slot_info(struct mem_vector *region, unsigned long image_size) > } > } > > +/* Skip as many 1GB huge pages as possible in the passed region. */ > +static void process_gb_huge_page(struct mem_vector *region, unsigned long image_size) > +{ > + int i = 0; > + unsigned long addr, size; > + struct mem_vector tmp; > + > + if (!max_gb_huge_pages) { > + store_slot_info(region, image_size); > + return; > + } > + > + addr = ALIGN(region->start, PUD_SIZE); > + /* If Did we raise the address above the passed in memory entry? */ > + if (addr < region->start + region->size) > + size = region->size - (addr - region->start); > + > + /* Check how many 1GB huge pages can be filtered out*/ > + while (size > PUD_SIZE && max_gb_huge_pages) { > + size -= PUD_SIZE; > + max_gb_huge_pages--; > + i++; > + } > + > + if (!i) { > + store_slot_info(region, image_size); > + return; > + } > + > + /* Process the remaining regions after filtering out. */ > + > + if (addr >= region->start + image_size) { > + tmp.start = region->start; > + tmp.size = addr - region->start; > + store_slot_info(&tmp, image_size); > + } > + > + size = region->size - (addr - region->start) - i * PUD_SIZE; > + if (size >= image_size) { > + tmp.start = addr + i*PUD_SIZE; > + tmp.size = size; > + store_slot_info(&tmp, image_size); > + } > +} > + > static unsigned long slots_fetch_random(void) > { > unsigned long slot; > -- > 2.13.6 >