Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422938AbWJFUf0 (ORCPT ); Fri, 6 Oct 2006 16:35:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422939AbWJFUf0 (ORCPT ); Fri, 6 Oct 2006 16:35:26 -0400 Received: from smtp.osdl.org ([65.172.181.4]:6342 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1422938AbWJFUfY (ORCPT ); Fri, 6 Oct 2006 16:35:24 -0400 Date: Fri, 6 Oct 2006 13:35:16 -0700 From: Andrew Morton To: Amol Lad Cc: linux kernel Subject: Re: [PATCH 1/5] ioremap balanced with iounmap for drivers/char/epca.c Message-Id: <20061006133516.c5cbf43b.akpm@osdl.org> In-Reply-To: <1160110625.19143.83.camel@amol.verismonetworks.com> References: <1160110625.19143.83.camel@amol.verismonetworks.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1875 Lines: 46 On Fri, 06 Oct 2006 10:27:05 +0530 Amol Lad wrote: > ioremap must be balanced by an iounmap and failing to do so can result > in a memory leak. > > Tested (compilation only): > - using allmodconfig > - making sure the files are compiling without any warning/error due to > new changes > > Signed-off-by: Amol Lad > --- > epca.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletion(-) > --- > diff -uprN -X linux-2.6.19-rc1-orig/Documentation/dontdiff linux-2.6.19-rc1-orig/drivers/char/epca.c linux-2.6.19-rc1/drivers/char/epca.c > --- linux-2.6.19-rc1-orig/drivers/char/epca.c 2006-10-05 14:00:42.000000000 +0530 > +++ linux-2.6.19-rc1/drivers/char/epca.c 2006-10-05 14:50:00.000000000 +0530 > @@ -1474,8 +1474,11 @@ static void post_fep_init(unsigned int c > if ((bd->type == PCXEVE || bd->type == PCXE) && (readw(memaddr + XEPORTS) < 3)) > shrinkmem = 1; > if (bd->type < PCIXEM) > - if (!request_region((int)bd->port, 4, board_desc[bd->type])) > + if (!request_region((int)bd->port, 4, board_desc[bd->type])) { > + iounmap(bd->re_map_membase); > + bd->re_map_membase = NULL; > return; > + } > memwinon(bd, 0); > I think this will do the wrong thing if (bd->type >= PCIXEM). Maybe it's OK, but it's not immediately obvious from a quick reading. I'm quite worried about changes in crufty old drivers like these - if we break them, the breakage will take a *long* time to be discovered. Too late for us to fix them. Plus a lot of them are just plain badly coded, so extra care is needed to understand the tricks which they're playing. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/