From patchwork Thu Sep 29 15:08:23 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mahesh J Salgaonkar X-Patchwork-Id: 116972 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id C2E921012DC for ; Fri, 30 Sep 2011 01:09:19 +1000 (EST) Received: by ozlabs.org (Postfix) id 0A2841007DB; Fri, 30 Sep 2011 01:09:12 +1000 (EST) Delivered-To: linuxppc-dev@ozlabs.org Received: from e23smtp07.au.ibm.com (e23smtp07.au.ibm.com [202.81.31.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp07.au.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 01BB21007D9 for ; Fri, 30 Sep 2011 01:09:11 +1000 (EST) Received: from d23relay05.au.ibm.com (d23relay05.au.ibm.com [202.81.31.247]) by e23smtp07.au.ibm.com (8.14.4/8.13.1) with ESMTP id p8TF9BpF018416 for ; Fri, 30 Sep 2011 01:09:11 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay05.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p8TF74x52167022 for ; Fri, 30 Sep 2011 01:07:04 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p8TF9APe024781 for ; Fri, 30 Sep 2011 01:09:11 +1000 Received: from mars.in.ibm.com ([9.124.218.46]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p8TF9846024031; Fri, 30 Sep 2011 01:09:09 +1000 Subject: [RFC PATCH v2 07/10] fadump: Introduce cleanup routine to invalidate /proc/vmcore. To: linuxppc-dev , Linux Kernel , Benjamin Herrenschmidt From: Mahesh J Salgaonkar Date: Thu, 29 Sep 2011 20:38:23 +0530 Message-ID: <20110929150823.26689.52104.stgit@mars.in.ibm.com> In-Reply-To: <20110929150117.26689.62053.stgit@mars.in.ibm.com> References: <20110929150117.26689.62053.stgit@mars.in.ibm.com> User-Agent: StGit/0.15-1-ged5e-dirty MIME-Version: 1.0 Cc: Anton Blanchard , Milton Miller , "Eric W. Biederman" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.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);