From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754128Ab1KGKeH (ORCPT ); Mon, 7 Nov 2011 05:34:07 -0500 Received: from e28smtp06.in.ibm.com ([122.248.162.6]:47943 "EHLO e28smtp06.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754125Ab1KGKeF (ORCPT ); Mon, 7 Nov 2011 05:34:05 -0500 Subject: [RFC PATCH v4 07/10] fadump: Introduce cleanup routine to invalidate /proc/vmcore. To: linuxppc-dev , Linux Kernel , Benjamin Herrenschmidt From: Mahesh J Salgaonkar Cc: Amerigo Wang , Ananth Narayan , Milton Miller , Haren Myneni , Anton Blanchard , "Eric W. Biederman" Date: Mon, 07 Nov 2011 15:26:12 +0530 Message-ID: <20111107095612.1997.27442.stgit@mars.in.ibm.com> In-Reply-To: <20111107095215.1997.14866.stgit@mars.in.ibm.com> References: <20111107095215.1997.14866.stgit@mars.in.ibm.com> User-Agent: StGit/0.15-1-ged5e-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit x-cbid: 11110709-9574-0000-0000-000000133AB3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mahesh Salgaonkar With the firmware-assisted dump support we don't require a reboot when we are in second kernel after crash. The second kernel after crash is a normal kernel boot and has knowledge about entire system RAM with the page tables initialized for entire system RAM. Hence once the dump is saved to disk, we can just release the reserved memory area for general use and continue with second kernel as production kernel. Hence when we release the reserved memory that contains dump data, the '/proc/vmcore' will not be valid anymore. Hence this patch introduces a cleanup routine that invalidates and removes the /proc/vmcore file. This routine will be invoked before we release the reserved dump memory area. Signed-off-by: Mahesh Salgaonkar --- fs/proc/vmcore.c | 23 +++++++++++++++++++++++ 1 files changed, 23 insertions(+), 0 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index cd99bf5..fae5526 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -699,3 +699,26 @@ static int __init vmcore_init(void) return 0; } module_init(vmcore_init) + +/* Cleanup function for vmcore module. */ +void vmcore_cleanup(void) +{ + struct list_head *pos, *next; + + if (proc_vmcore) { + remove_proc_entry(proc_vmcore->name, proc_vmcore->parent); + proc_vmcore = NULL; + } + + /* clear the vmcore list. */ + list_for_each_safe(pos, next, &vmcore_list) { + struct vmcore *m; + + m = list_entry(pos, struct vmcore, list); + list_del(&m->list); + kfree(m); + } + kfree(elfcorebuf); + elfcorebuf = NULL; +} +EXPORT_SYMBOL_GPL(vmcore_cleanup);