• Hans Verkuil's avatar
    include/asm-generic/ioctl.h: fix _IOC_TYPECHECK sparse error · d55875f5
    Hans Verkuil authored
    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: 's avatarHans Verkuil <hans.verkuil@cisco.com>
    Reviewed-by: 's avatarJosh Triplett <josh@joshtriplett.org>
    Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
    d55875f5
ioctl.h 467 Bytes