On Fri, 09 May 2014 09:43:58 +0200 Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > Andrew, can you merge this for 3.15 or 3.16 (you decide)? While it fixes a sparse error > for the media subsystem, it is not really appropriate to go through our media tree. > > Thanks, > > Hans > > > 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. > > --- 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 */ Can't we use BUILD_BUG_ON() here? That's neater, more standard and BUILD_BUG_ON() already has sparse handling. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
