From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02659C43387 for ; Tue, 8 Jan 2019 08:47:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE1E52070B for ; Tue, 8 Jan 2019 08:47:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728062AbfAHIrG (ORCPT ); Tue, 8 Jan 2019 03:47:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43470 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727295AbfAHIrG (ORCPT ); Tue, 8 Jan 2019 03:47:06 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 04AAE138210; Tue, 8 Jan 2019 08:47:06 +0000 (UTC) Received: from dhcp-128-65.nay.redhat.com (ovpn-12-56.pek2.redhat.com [10.72.12.56]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7418F5D739; Tue, 8 Jan 2019 08:47:01 +0000 (UTC) Date: Tue, 8 Jan 2019 16:46:57 +0800 From: Dave Young To: Baoquan He Cc: linux-kernel@vger.kernel.org, kexec@lists.infradead.org, AKASHI Takahiro , Andrew Morton , "Eric W. Biederman" , x86@kernel.org, Ingo Molnar , Borislav Petkov , Thomas Gleixner , Vivek Goyal Subject: Re: [PATCH V2] x86/kexec: fix a kexec_file_load failure Message-ID: <20190108084657.GA32321@dhcp-128-65.nay.redhat.com> References: <20181228011247.GA9999@dhcp-128-65.nay.redhat.com> <20190108052440.GA17983@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190108052440.GA17983@MiWiFi-R3L-srv> User-Agent: Mutt/1.9.5 (2018-04-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Tue, 08 Jan 2019 08:47:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/08/19 at 01:24pm, Baoquan He wrote: > On 12/28/18 at 09:12am, Dave Young wrote: > > The code cleanup mentioned in Fixes tag changed the behavior of > > kexec_locate_mem_hole. The kexec_locate_mem_hole will try to > > allocate free memory only when kbuf.mem is initialized as zero. > > > > But in x86 kexec_file_load implementation there are a few places > > the kbuf.mem is reused like below: > > /* kbuf initialized, kbuf.mem = 0 */ > > ... > > kexec_add_buffer() > > ... > > kexec_add_buffer() > > > > The second kexec_add_buffer will reuse previous kbuf but not > > reinitialize the kbuf.mem. > > > > Thus kexec_file_load failed because the sanity check failed. > > > > So explictily reset kbuf.mem to fix the issue. > > > > Fixes: b6664ba42f14 ("s390, kexec_file: drop arch_kexec_mem_walk()") > > Signed-off-by: Dave Young > > Cc: > > --- > > V1 -> V2: use KEXEC_BUF_MEM_UNKNOWN in code. > > arch/x86/kernel/crash.c | 1 + > > arch/x86/kernel/kexec-bzimage64.c | 2 ++ > > 2 files changed, 3 insertions(+) > > > > diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > > index f631a3f15587..6b7890c7889b 100644 > > --- a/arch/x86/kernel/crash.c > > +++ b/arch/x86/kernel/crash.c > > @@ -469,6 +469,7 @@ int crash_load_segments(struct kimage *image) > > > > Wondering why this place doesn't need the initialization assignment. > Isn't it to assign in all places before kexec_add_buffer() calling? C designated initializers will make sure to initialize it as zero. We set KEXEC_BUF_MEM_UNKNOWN as 0 so it just works. > > /* Add backup segment. */ > if (image->arch.backup_src_sz) { > } > > > kbuf.memsz = kbuf.bufsz; > > kbuf.buf_align = ELF_CORE_HEADER_ALIGN; > > + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; > > ret = kexec_add_buffer(&kbuf); > > if (ret) { > > vfree((void *)image->arch.elf_headers); > > diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c > > index 278cd07228dd..0d5efa34f359 100644 > > --- a/arch/x86/kernel/kexec-bzimage64.c > > +++ b/arch/x86/kernel/kexec-bzimage64.c > > @@ -434,6 +434,7 @@ static void *bzImage64_load(struct kimage *image, char *kernel, > > kbuf.memsz = PAGE_ALIGN(header->init_size); > > kbuf.buf_align = header->kernel_alignment; > > kbuf.buf_min = MIN_KERNEL_LOAD_ADDR; > > Same question for bzImage64_load(), there are three kexec_add_buffer() > calling, I only saw two initialization in this patch. > > > + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; > > ret = kexec_add_buffer(&kbuf); > > if (ret) > > goto out_free_params; > > @@ -448,6 +449,7 @@ static void *bzImage64_load(struct kimage *image, char *kernel, > > kbuf.bufsz = kbuf.memsz = initrd_len; > > kbuf.buf_align = PAGE_SIZE; > > kbuf.buf_min = MIN_INITRD_LOAD_ADDR; > > + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; > > ret = kexec_add_buffer(&kbuf); > > if (ret) > > goto out_free_params; > > -- > > 2.17.0 > > Thanks Dave