From: Josh Triplett <josh@joshtriplett.org>
To: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Sparse Mailing-list <linux-sparse@vger.kernel.org>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
Christopher Li <sparse@chrisli.org>
Subject: Re: [PATCH] Fix _IOC_TYPECHECK sparse error
Date: Tue, 1 Apr 2014 07:28:53 -0700 [thread overview]
Message-ID: <20140401142852.GA22576@leaf> (raw)
In-Reply-To: <533A64EC.2090106@xs4all.nl>
On Tue, Apr 01, 2014 at 09:04:12AM +0200, Hans Verkuil wrote:
> When running sparse over drivers/media/v4l2-core/v4l2-ioctl.c I get these
> errors:
>
> drivers/media/v4l2-core/v4l2-ioctl.c:2043:9: error: bad integer constant expression
> drivers/media/v4l2-core/v4l2-ioctl.c:2044:9: error: bad integer constant expression
> drivers/media/v4l2-core/v4l2-ioctl.c:2045:9: error: bad integer constant expression
> drivers/media/v4l2-core/v4l2-ioctl.c:2046:9: error: bad integer constant expression
>
> etc.
>
> The root cause of that turns out to be in include/asm-generic/ioctl.h:
>
> #include <uapi/asm-generic/ioctl.h>
>
> /* provoke compile error for invalid uses of size argument */
> extern unsigned int __invalid_size_argument_for_IOC;
> #define _IOC_TYPECHECK(t) \
> ((sizeof(t) == sizeof(t[1]) && \
> sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
> sizeof(t) : __invalid_size_argument_for_IOC)
>
> If it is defined as this (as is already done if __KERNEL__ is not defined):
>
> #define _IOC_TYPECHECK(t) (sizeof(t))
>
> then all is well with the world.
>
> This patch allows sparse to work correctly.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
> diff --git a/include/asm-generic/ioctl.h b/include/asm-generic/ioctl.h
> index d17295b..297fb0d 100644
> --- a/include/asm-generic/ioctl.h
> +++ b/include/asm-generic/ioctl.h
> @@ -3,10 +3,15 @@
>
> #include <uapi/asm-generic/ioctl.h>
>
> +#ifdef __CHECKER__
> +#define _IOC_TYPECHECK(t) (sizeof(t))
> +#else
> /* provoke compile error for invalid uses of size argument */
> extern unsigned int __invalid_size_argument_for_IOC;
> #define _IOC_TYPECHECK(t) \
> ((sizeof(t) == sizeof(t[1]) && \
> sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
> sizeof(t) : __invalid_size_argument_for_IOC)
> +#endif
> +
> #endif /* _ASM_GENERIC_IOCTL_H */
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
prev parent reply other threads:[~2014-04-01 14:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-01 7:04 [PATCH] Fix _IOC_TYPECHECK sparse error Hans Verkuil
2014-04-01 14:28 ` Josh Triplett [this message]
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