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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6BA3C433F5 for ; Fri, 29 Oct 2021 16:31:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF93761177 for ; Fri, 29 Oct 2021 16:31:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229940AbhJ2QeO (ORCPT ); Fri, 29 Oct 2021 12:34:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:24635 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229868AbhJ2QeO (ORCPT ); Fri, 29 Oct 2021 12:34:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635525105; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dbWwVV+hbGE8rMi2XL6X6jxBbZPWjHobzY3RTESINF4=; b=F1zfIjYRuiv6nLNRS/QwcSfLXTco5ttmp8tWfb3na5gbslovdhI/jE79c7Rd6evCw1KIde xjkIiq2DPSZ9wd28gUVsqhmeFDYbE2nte2gZ4H7JmUKXxky+W5LyYsOhAUkFPnowAoqTL4 zdaa+v3FkjB32UGjkNYBqu7q2jRipo0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-529-i6DUpVqoMI-6IH-xfuwpdA-1; Fri, 29 Oct 2021 12:31:40 -0400 X-MC-Unique: i6DUpVqoMI-6IH-xfuwpdA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B7C3618D6A25; Fri, 29 Oct 2021 16:31:39 +0000 (UTC) Received: from rhtmp (unknown [10.39.192.188]) by smtp.corp.redhat.com (Postfix) with ESMTP id 43DC860936; Fri, 29 Oct 2021 16:31:35 +0000 (UTC) Date: Fri, 29 Oct 2021 18:31:32 +0200 From: Philipp Rudo To: Baoquan He Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kexec@lists.infradead.org, dyoung@redhat.com, akpm@linux-foundation.org Subject: Re: [PATCH] s390/kexec: fix memory leak of ipl report buffer Message-ID: <20211029183132.20839ad0@rhtmp> In-Reply-To: <20211029092635.14804-1-bhe@redhat.com> References: <20211029092635.14804-1-bhe@redhat.com> Organization: Red Hat inc. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org Hi Baoquan, On Fri, 29 Oct 2021 17:26:35 +0800 Baoquan He wrote: > A memory leak is reported by kmemleak scanning: > > unreferenced object 0x38000195000 (size 4096): > comm "kexec", pid 8548, jiffies 4294953647 (age 32443.270s) > hex dump (first 32 bytes): > 00 00 00 c8 20 00 00 00 00 00 00 c0 02 80 00 00 .... ........... > 40 40 40 40 40 40 40 40 00 00 00 00 00 00 00 00 @@@@@@@@........ > backtrace: > [<0000000011a2f199>] __vmalloc_node_range+0xc0/0x140 > [<0000000081fa2752>] vzalloc+0x5a/0x70 > [<0000000063a4c92d>] ipl_report_finish+0x2c/0x180 > [<00000000553304da>] kexec_file_add_ipl_report+0xf4/0x150 > [<00000000862d033f>] kexec_file_add_components+0x124/0x160 > [<000000000d2717bb>] arch_kexec_kernel_image_load+0x62/0x90 > [<000000002e0373b6>] kimage_file_alloc_init+0x1aa/0x2e0 > [<0000000060f2d14f>] __do_sys_kexec_file_load+0x17c/0x2c0 > [<000000008c86fe5a>] __s390x_sys_kexec_file_load+0x40/0x50 > [<000000001fdb9dac>] __do_syscall+0x1bc/0x1f0 > [<000000003ee4258d>] system_call+0x78/0xa0 > > The ipl report buffer is allocated via vmalloc, while has no chance to free > if the kexe loading is unloaded. This will cause obvious memory leak > when kexec/kdump kernel is reloaded, manually, or triggered, e.g by > memory hotplug. > > Here, add struct kimage_arch to s390 to pass out the ipl report buffer > address, and introduce arch dependent function > arch_kimage_file_post_load_cleanup() to free it when unloaded. > > Signed-off-by: Baoquan He other than a missing Fixes: 99feaa717e55 ("s390/kexec_file: Create ipl report and pass to next kernel") the patch looks good to me. Reviewed-by: Philipp Rudo > --- > arch/s390/include/asm/kexec.h | 7 +++++++ > arch/s390/kernel/machine_kexec_file.c | 9 +++++++++ > 2 files changed, 16 insertions(+) > > diff --git a/arch/s390/include/asm/kexec.h b/arch/s390/include/asm/kexec.h > index ea398a05f643..9f16e99fb882 100644 > --- a/arch/s390/include/asm/kexec.h > +++ b/arch/s390/include/asm/kexec.h > @@ -74,6 +74,13 @@ void *kexec_file_add_components(struct kimage *image, > int arch_kexec_do_relocs(int r_type, void *loc, unsigned long val, > unsigned long addr); > > +#define ARCH_HAS_KIMAGE_ARCH > + > +struct kimage_arch { > + void *ipl_buf; > +}; > + > + > extern const struct kexec_file_ops s390_kexec_image_ops; > extern const struct kexec_file_ops s390_kexec_elf_ops; > > diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c > index f9e4baa64b67..584c48b631b2 100644 > --- a/arch/s390/kernel/machine_kexec_file.c > +++ b/arch/s390/kernel/machine_kexec_file.c > @@ -202,6 +202,7 @@ static int kexec_file_add_ipl_report(struct kimage *image, > buf.buffer = ipl_report_finish(data->report); > buf.bufsz = data->report->size; > buf.memsz = buf.bufsz; > + image->arch.ipl_buf = buf.buffer; > > data->memsz += buf.memsz; > > @@ -321,3 +322,11 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > > return kexec_image_probe_default(image, buf, buf_len); > } > + > +int arch_kimage_file_post_load_cleanup(struct kimage *image) > +{ > + kvfree(image->arch.ipl_buf); > + image->arch.ipl_buf = NULL; > + > + return kexec_image_post_load_cleanup_default(image); > +}