From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751602AbdIOWjN (ORCPT ); Fri, 15 Sep 2017 18:39:13 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:34869 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184AbdIOWjL (ORCPT ); Fri, 15 Sep 2017 18:39:11 -0400 X-Google-Smtp-Source: ADKCNb5si1y0/SzyUOZkRGpqMnAqSsIbdJA5inT7+zXZzATfjWnzoMLAH4DZ03C7IUe1xrhw1ACz6A== Date: Fri, 15 Sep 2017 15:39:09 -0700 From: Guenter Roeck To: Arnd Bergmann Cc: "Rafael J. Wysocki" , Len Brown , Mika Westerberg , Ryan Kennedy , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] acpi: watchdog: properly initialize resources Message-ID: <20170915223909.GA3420@roeck-us.net> References: <20170915195526.1541309-1-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170915195526.1541309-1-arnd@arndb.de> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 15, 2017 at 09:55:18PM +0200, Arnd Bergmann wrote: > We copy a local resource structure into a list, but only > initialize some of its members, as pointed out by gcc-4.4: > > drivers/acpi/acpi_watchdog.c: In function 'acpi_watchdog_init': > drivers/acpi/acpi_watchdog.c:105: error: 'res.child' may be used uninitialized in this function > drivers/acpi/acpi_watchdog.c:105: error: 'res.sibling' may be used uninitialized in this function > drivers/acpi/acpi_watchdog.c:105: error: 'res.parent' may be used uninitialized in this function > drivers/acpi/acpi_watchdog.c:105: error: 'res.desc' may be used uninitialized in this function > drivers/acpi/acpi_watchdog.c:105: error: 'res.name' may be used uninitialized in this function > > Newer compilers can presumably optimize the uninitialized access > away entirely and don't warn at all, but rely on the kzalloc() > to zero the structure first. This adds an explicit initialization > to force consistent behavior. > > Fixes: 058dfc767008 ("ACPI / watchdog: Add support for WDAT hardware watchdog") > Signed-off-by: Arnd Bergmann Acked-by: Guenter Roeck > --- > drivers/acpi/acpi_watchdog.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c > index bf22c29d2517..11b113f8e367 100644 > --- a/drivers/acpi/acpi_watchdog.c > +++ b/drivers/acpi/acpi_watchdog.c > @@ -66,7 +66,7 @@ void __init acpi_watchdog_init(void) > for (i = 0; i < wdat->entries; i++) { > const struct acpi_generic_address *gas; > struct resource_entry *rentry; > - struct resource res; > + struct resource res = {}; > bool found; > > gas = &entries[i].register_region; > -- > 2.9.0 >