From patchwork Wed Jul 13 18:08:00 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: 104580 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 1BC3F10CF09 for ; Thu, 14 Jul 2011 04:08:45 +1000 (EST) 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 E91A110C81E for ; Thu, 14 Jul 2011 04:08:03 +1000 (EST) Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.31.245]) by e23smtp07.au.ibm.com (8.14.4/8.13.1) with ESMTP id p6DI83Ko018212 for ; Thu, 14 Jul 2011 04:08:03 +1000 Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p6DI83Uh557072 for ; Thu, 14 Jul 2011 04:08:03 +1000 Received: from d23av02.au.ibm.com (loopback [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p6DI82Jc023126 for ; Thu, 14 Jul 2011 04:08:03 +1000 Received: from mars.in.ibm.com ([9.77.213.63]) by d23av02.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p6DI80vZ023102; Thu, 14 Jul 2011 04:08:01 +1000 Subject: [RFC PATCH 07/10] fadump: Introduce cleanup routine to invalidate /proc/vmcore. To: Benjamin Herrenschmidt , linuxppc-dev , Linux Kernel From: Mahesh J Salgaonkar Date: Wed, 13 Jul 2011 23:38:00 +0530 Message-ID: <20110713180751.6210.64850.stgit@mars.in.ibm.com> In-Reply-To: <20110713180252.6210.34810.stgit@mars.in.ibm.com> References: <20110713180252.6210.34810.stgit@mars.in.ibm.com> User-Agent: StGit/0.15-1-ged5e-dirty MIME-Version: 1.0 Cc: Michael Ellerman , 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 | 20 ++++++++++++++++++++ 1 files changed, 20 insertions(+), 0 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index cd99bf5..1aa3d7b 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -699,3 +699,23 @@ 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); + + /* 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); +} +EXPORT_SYMBOL_GPL(vmcore_cleanup);