[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20140904004947.GA17138@vmdeb7>
Date: Wed, 3 Sep 2014 17:49:47 -0700
From: Darren Hart <dvhart@...radead.org>
To: Frans Klaver <fransklaver@...il.com>
Cc: Corentin Chary <corentin.chary@...il.com>,
Matthew Garrett <matthew.garrett@...ula.com>,
acpi4asus-user@...ts.sourceforge.net,
platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: [PATCH] eeepc-laptop: remove possible use of uninitialized value
On Thu, Sep 04, 2014 at 12:53:25AM +0200, Frans Klaver wrote:
> In store_sys_acpi, if count equals zero, or parse_arg()s sscanf call
> fails, 'value' remains possibly uninitialized. In that case 'value'
> shouldn't be used to produce the store_sys_acpi()s return value.
>
> Only test the return value of set_acpi() if we can actually call it.
> Return rv otherwise.
>
> Signed-off-by: Frans Klaver <fransklaver@...il.com>
> ---
> drivers/platform/x86/eeepc-laptop.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/x86/eeepc-laptop.c b/drivers/platform/x86/eeepc-laptop.c
> index bd533c2..41f12ba 100644
> --- a/drivers/platform/x86/eeepc-laptop.c
> +++ b/drivers/platform/x86/eeepc-laptop.c
> @@ -279,10 +279,10 @@ static ssize_t store_sys_acpi(struct device *dev, int cm,
> int rv, value;
>
> rv = parse_arg(buf, count, &value);
> - if (rv > 0)
> - value = set_acpi(eeepc, cm, value);
That was rather horrible wasn't it? :-)
> - if (value < 0)
> - return -EIO;
> + if (rv > 0) {
> + if (set_acpi(eeepc, cm, value) < 0)
> + return -EIO;
Is there a compelling reason not to propogate the return code of set_acpi?
(ENODEV specifically). I see -EIO in Documentation/filesystems/sysfs.txt, but
it's used by default if the show() pointer is NULL (for example), but otherwise
propogates the error.
Specifically it states:
- show() or store() can always return errors. If a bad value comes
through, be sure to return an error.
Greg, does this need to be -EIO? or is returning someting like ENODEV preferable
if it more accurately reflects the error?
--
Darren Hart
Intel Open Source Technology Center
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists