From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Verkuil Subject: [PATCH] Fix _IOC_TYPECHECK sparse error Date: Tue, 01 Apr 2014 09:04:12 +0200 Message-ID: <533A64EC.2090106@xs4all.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Linus Torvalds , LKML Cc: Sparse Mailing-list , Linux Media Mailing List , Christopher Li List-Id: linux-sparse@vger.kernel.org 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 /* 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 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 +#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 */