From: Guenter Roeck <linux@roeck-us.net>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Ryan Kennedy <ryan5544@gmail.com>,
linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] acpi: watchdog: properly initialize resources
Date: Fri, 15 Sep 2017 15:39:09 -0700 [thread overview]
Message-ID: <20170915223909.GA3420@roeck-us.net> (raw)
In-Reply-To: <20170915195526.1541309-1-arnd@arndb.de>
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 <arnd@arndb.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
> ---
> 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
>
next prev parent reply other threads:[~2017-09-15 22:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-15 19:55 [PATCH] acpi: watchdog: properly initialize resources Arnd Bergmann
2017-09-15 22:39 ` Guenter Roeck [this message]
2017-09-16 6:56 ` Mika Westerberg
2017-09-18 23:41 ` Rafael J. Wysocki
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