From: Hans Verkuil <hverkuil@xs4all.nl>
To: Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>
Cc: Sparse Mailing-list <linux-sparse@vger.kernel.org>,
Linux Media Mailing List <linux-media@vger.kernel.org>,
Christopher Li <sparse@chrisli.org>
Subject: [PATCH] Fix _IOC_TYPECHECK sparse error
Date: Tue, 01 Apr 2014 09:04:12 +0200 [thread overview]
Message-ID: <533A64EC.2090106@xs4all.nl> (raw)
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>
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 */
next reply other threads:[~2014-04-01 7:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-01 7:04 Hans Verkuil [this message]
2014-04-01 14:28 ` [PATCH] Fix _IOC_TYPECHECK sparse error Josh Triplett
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